Putting more ‘modern’ in modern physics education: a Knowledge Building approach using student questions and ideas about the universe

NASA Astrophysics Data System (ADS)

Wagner, Glenn

2017-03-01

Student-generated questions and ideas about our universe are the start of a rich and highly motivating learning environment. Using their curiosity-driven questions and ideas, students form Knowledge Building groups or ‘communities’ where they plan, set goals, design questions for research, and assess the progress of their work, tasks that were once under the control of the teacher. With the understanding that all knowledge and ideas are treated as improvable, students work collaboratively at their level of competency to share their knowledge, ideas and understandings gained from authoritative sources and laboratory activities. Over time, students work collectively to improve the knowledge and ideas of others that result in advances in understanding that benefit not only the individual but the community as a whole. Learning outcomes reported in this paper demonstrate that a Knowledge Building environment applied to introductory cosmology produced similar gains in knowledge and understanding surrounding foundational concepts compared to teacher-centred learning environments. Aside from new knowledge and understanding, students develop important skills and competencies such as question-asking, idea development, communication, collaboration that are becoming ever more important for 21st century living and working. Finally, the process of planning and initiating a Knowledge Building environment that produced the results reported in this paper is outlined.

X-ray Thomson scattering measurements from hohlraum-driven spheres on the OMEGA laser [X-ray Thomson scattering measurements from hohlraum targets on the OMEGA laser

DOE PAGES

Saunders, A. M.; Jenei, A.; Doppner, T.; ...

2016-08-30

X-ray Thomson scattering (XRTS) is a powerful diagnostic for probing warm and hot dense matter. We present the design and results of the first XRTS experiments with hohlraum-driven CH 2 targets on the OMEGA laser. X-rays seen directly from the XRTS x-ray source overshadow the elastic scattering signal from the target capsule, but can be controlled in future experiments. From the inelastic scattering signal, an average plasma temperature is inferred that is in reasonable agreement with the temperatures predicted by simulations. Here, knowledge gained in this experiment show a promising future for further XRTS measurements on indirectly driven OMEGA targets.

X-ray Thomson scattering measurements from hohlraum-driven spheres on the OMEGA laser [X-ray Thomson scattering measurements from hohlraum targets on the OMEGA laser

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

Saunders, A. M.; Jenei, A.; Doppner, T.

X-ray Thomson scattering (XRTS) is a powerful diagnostic for probing warm and hot dense matter. We present the design and results of the first XRTS experiments with hohlraum-driven CH 2 targets on the OMEGA laser. X-rays seen directly from the XRTS x-ray source overshadow the elastic scattering signal from the target capsule, but can be controlled in future experiments. From the inelastic scattering signal, an average plasma temperature is inferred that is in reasonable agreement with the temperatures predicted by simulations. Here, knowledge gained in this experiment show a promising future for further XRTS measurements on indirectly driven OMEGA targets.

Integrative vs. Traditional Learning from the Student Perspective

PubMed Central

Kadmon, Guni; Schmidt, Jan; De Cono, Nicola; Kadmon, Martina

2011-01-01

Background: The interdisciplinary surgery block of the reformed undergraduate curriculum HeiCuMed includes daily cycles of interactive case-based seminars, problem-based tutorials, case presentation by students, skills and communication training, and bedside teaching. The teaching doctors receive didactic training. In contrast, the previous traditional course was based on lectures with only two weekly hours of bedside teaching. Didactic training was not available. Objective: The present work aims at analysing the importance of active participation of students and the didactic components of the reformed and traditional curricula, which contribute to successful learning as evaluated by the students. Method: Differentiated student evaluations of the undergraduate surgical courses between 1999 and 2008 were examined by correlation and regression analyses. Results: The evaluation scores for organisation, dedication of the teaching staff, their ability to make lessons interesting and complex topics easily understandable, and the subjective gain of knowledge were significantly better in HeiCuMed than in the traditional curriculum. However, the dependence of knowledge gain on the didactic quality was the same in both curricula. The quality of discussions and the ability of the teaching doctors to promote active student participation were important to the subjective gain of knowledge in both seminars and practical courses of the reformed curriculum as well as for the overall evaluation of the practical courses but not the gain of knowledge in the traditional curriculum. Conclusion: The findings confirm psychological-educational perceptions, that competent implementation of integrative didactical methods is more important to successful teaching and the subjective gain of knowledge than knowledge transfer by traditional classroom teaching. PMID:21818238

Visuals, Path Control, and Knowledge Gain: Variables that Affect Students' Approval and Enjoyment of a Multimedia Text as a Learning Tool

ERIC Educational Resources Information Center

George-Palilonis, Jennifer; Filak, Vincent

2010-01-01

As graphically driven, animated, interactive applications offer educators new opportunities for shaping course content, new avenues for research arise as well. Along with these developments comes a need to study the effectiveness of the individual tools at our disposal as well as various methods for integrating those tools in a classroom setting.…

A Guided Tour of Mathematical Methods - 2nd Edition

NASA Astrophysics Data System (ADS)

Snieder, Roel

2004-09-01

Mathematical methods are essential tools for all physical scientists. This second edition provides a comprehensive tour of the mathematical knowledge and techniques that are needed by students in this area. In contrast to more traditional textbooks, all the material is presented in the form of problems. Within these problems the basic mathematical theory and its physical applications are well integrated. The mathematical insights that the student acquires are therefore driven by their physical insight. Topics that are covered include vector calculus, linear algebra, Fourier analysis, scale analysis, complex integration, Green's functions, normal modes, tensor calculus, and perturbation theory. The second edition contains new chapters on dimensional analysis, variational calculus, and the asymptotic evaluation of integrals. This book can be used by undergraduates, and lower-level graduate students in the physical sciences. It can serve as a stand-alone text, or as a source of problems and examples to complement other textbooks. All the material is presented in the form of problems Mathematical insights are gained by getting the reader to develop answers themselves Many applications of the mathematics are given

Deconstructing Interocular Suppression: Attention and Divisive Normalization

PubMed Central

Li, Hsin-Hung; Carrasco, Marisa; Heeger, David J.

2015-01-01

In interocular suppression, a suprathreshold monocular target can be rendered invisible by a salient competitor stimulus presented in the other eye. Despite decades of research on interocular suppression and related phenomena (e.g., binocular rivalry, flash suppression, continuous flash suppression), the neural processing underlying interocular suppression is still unknown. We developed and tested a computational model of interocular suppression. The model included two processes that contributed to the strength of interocular suppression: divisive normalization and attentional modulation. According to the model, the salient competitor induced a stimulus-driven attentional modulation selective for the location and orientation of the competitor, thereby increasing the gain of neural responses to the competitor and reducing the gain of neural responses to the target. Additional suppression was induced by divisive normalization in the model, similar to other forms of visual masking. To test the model, we conducted psychophysics experiments in which both the size and the eye-of-origin of the competitor were manipulated. For small and medium competitors, behavioral performance was consonant with a change in the response gain of neurons that responded to the target. But large competitors induced a contrast-gain change, even when the competitor was split between the two eyes. The model correctly predicted these results and outperformed an alternative model in which the attentional modulation was eye specific. We conclude that both stimulus-driven attention (selective for location and feature) and divisive normalization contribute to interocular suppression. PMID:26517321

Deconstructing Interocular Suppression: Attention and Divisive Normalization.

PubMed

Li, Hsin-Hung; Carrasco, Marisa; Heeger, David J

2015-10-01

In interocular suppression, a suprathreshold monocular target can be rendered invisible by a salient competitor stimulus presented in the other eye. Despite decades of research on interocular suppression and related phenomena (e.g., binocular rivalry, flash suppression, continuous flash suppression), the neural processing underlying interocular suppression is still unknown. We developed and tested a computational model of interocular suppression. The model included two processes that contributed to the strength of interocular suppression: divisive normalization and attentional modulation. According to the model, the salient competitor induced a stimulus-driven attentional modulation selective for the location and orientation of the competitor, thereby increasing the gain of neural responses to the competitor and reducing the gain of neural responses to the target. Additional suppression was induced by divisive normalization in the model, similar to other forms of visual masking. To test the model, we conducted psychophysics experiments in which both the size and the eye-of-origin of the competitor were manipulated. For small and medium competitors, behavioral performance was consonant with a change in the response gain of neurons that responded to the target. But large competitors induced a contrast-gain change, even when the competitor was split between the two eyes. The model correctly predicted these results and outperformed an alternative model in which the attentional modulation was eye specific. We conclude that both stimulus-driven attention (selective for location and feature) and divisive normalization contribute to interocular suppression.

Land use compounds habitat losses under projected climate change in a threatened California ecosystem.

PubMed

Riordan, Erin Coulter; Rundel, Philip W

2014-01-01

Given the rapidly growing human population in mediterranean-climate systems, land use may pose a more immediate threat to biodiversity than climate change this century, yet few studies address the relative future impacts of both drivers. We assess spatial and temporal patterns of projected 21(st) century land use and climate change on California sage scrub (CSS), a plant association of considerable diversity and threatened status in the mediterranean-climate California Floristic Province. Using a species distribution modeling approach combined with spatially-explicit land use projections, we model habitat loss for 20 dominant shrub species under unlimited and no dispersal scenarios at two time intervals (early and late century) in two ecoregions in California (Central Coast and South Coast). Overall, projected climate change impacts were highly variable across CSS species and heavily dependent on dispersal assumptions. Projected anthropogenic land use drove greater relative habitat losses compared to projected climate change in many species. This pattern was only significant under assumptions of unlimited dispersal, however, where considerable climate-driven habitat gains offset some concurrent climate-driven habitat losses. Additionally, some of the habitat gained with projected climate change overlapped with projected land use. Most species showed potential northern habitat expansion and southern habitat contraction due to projected climate change, resulting in sharply contrasting patterns of impact between Central and South Coast Ecoregions. In the Central Coast, dispersal could play an important role moderating losses from both climate change and land use. In contrast, high geographic overlap in habitat losses driven by projected climate change and projected land use in the South Coast underscores the potential for compounding negative impacts of both drivers. Limiting habitat conversion may be a broadly beneficial strategy under climate change. We emphasize the importance of addressing both drivers in conservation and resource management planning.

An analysis of the relationship between teachers' acquisition of physics content knowledge and their level of science teaching efficacy

NASA Astrophysics Data System (ADS)

Marion, Virginia Frances

1998-12-01

The goal of Project Inquiry, a two-year long multiphase study, was to transform the delivery of science instruction from a traditional, textbook driven delivery approach to a hands-on, minds-on, constructivist approach. Teachers from a midwestern urban school district were trained in constructivism while learning physics concepts and content through guided inquiry instruction in collaborative groups. The objectives aimed to increase teachers' content expertise and science teaching efficacy, as well as to have teachers become better facilitators of learning. Phase two of the three phases of Project Inquiry was the focus of this study. Fifty-seven teachers participated in Phase two, which began with an intense two week summer institute in 1995. A longitudinal time-series (OxOO), quasi-experimental research design was used to investigate the relationship between science teaching efficacy scores and gains in physics content knowledge. The data consisted of: (a) six sets of pre and post physics content knowledge test scores (electricity, magnetism, matter and balance); (b) three sets of STEBI-A (inservice), Science Teaching Efficacy Belief Instrument scores, a pre to post, pre to follow-up, and post to follow-up; and (c) demographic variables that were used as covariates, grade taught, years of experience, and postbaccalaureate training. Using the general linear model with an Alpha level of.05, and testing the hypothesized relationships, results indicated that although there were significant positive gains in content knowledge (p =.000) and science teaching efficacy (p =.000), the overall average gains in physics content knowledge were not predictive of gains in either Personal Science Teaching Efficacy or Science Outcome Expectancy. Post hoc analysis used individual content gain scores, in regression models that included the three covariates: grade taught, years of experience, and post baccalaureate training, to test the relationship between knowledge gains and efficacy gains. A series of interactions between significant content areas and the covariates was also run. Science Teaching Outcome Expectancy and Personal Science Teaching Efficacy showed different relationships with the predictor variables. Though gains in specific content areas were related to gains in Science Teaching Outcome Expectancy and Personal Science Teaching Efficacy, gains in Personal Science Teaching Efficacy were further modified by the covariates. These results may reflect not only a more complex relationship between content knowledge gain and Personal Science Teaching Efficacy but also the complex nature of the construct. Evaluation of the physics content knowledge tests revealed that the tests were not valid for evaluating 35 of the 37 identified learning objectives. Although the data did not render valid results, it does give insights into possible relationships that may exist given a more stringent investigation with a valid instrument to measure content knowledge gains. In addition, this study demonstrated the importance of considering the likelihood of interactions among a given set of variables and the covariates. The findings also suggest the possible value of considering the psychological factors associated with the change process when planning professional development programs.

Machine Learning

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

Chikkagoudar, Satish; Chatterjee, Samrat; Thomas, Dennis G.

The absence of a robust and unified theory of cyber dynamics presents challenges and opportunities for using machine learning based data-driven approaches to further the understanding of the behavior of such complex systems. Analysts can also use machine learning approaches to gain operational insights. In order to be operationally beneficial, cybersecurity machine learning based models need to have the ability to: (1) represent a real-world system, (2) infer system properties, and (3) learn and adapt based on expert knowledge and observations. Probabilistic models and Probabilistic graphical models provide these necessary properties and are further explored in this chapter. Bayesian Networksmore » and Hidden Markov Models are introduced as an example of a widely used data driven classification/modeling strategy.« less

Ketamine use among regular tobacco and alcohol users as revealed by respondent driven sampling in Taipei: prevalence, expectancy, and users’ risky decision making

PubMed Central

Chen, Wei J.; Ting, Te-Tien; Chang, Chao-Ming; Liu, Ying-Chun; Chen, Chuan-Yu

2014-01-01

The popularity of ketamine for recreational use among young people began to increase, particularly in Asia, in 2000. To gain more knowledge about the use of ketamine among high risk individuals, a respondent-driven sampling (RDS) was implemented among regular alcohol and tobacco users in the Taipei metropolitan area from 2007 to 2010. The sampling was initiated in three different settings (i.e., two in the community and one in a clinic) to recruit seed individuals. Each participant was asked to refer one to five friends known to be regular tobacco smokers and alcohol drinkers to participate in the present study. Incentives were offered differentially upon the completion of an interview and successful referral. Information pertaining to drug use experience was collected by an audio computer-assisted self-interview instrument. Software built for RDS analyses was used for data analyses. Of the 1,115 subjects recruited, about 11.7% of the RDS respondents reported ever having used ketamine. Positive expectancy of ketamine use was positively associated with ketamine use; in contrast, negative expectancy inversely associated with ketamine use. Decision-making characteristics as measured on the Iowa Gambling Task using reinforcement learning models revealed that ketamine users learned less from the most recent event than both tobacco- and drug-naïve controls and regular tobacco and alcohol users. These findings about ketamine use among young people have implications for its prevention and intervention. PMID:25264412

Stakeholder-Driven Quality Improvement: A Compelling Force for Clinical Practice Guidelines.

PubMed

Rosenfeld, Richard M; Wyer, Peter C

2018-01-01

Clinical practice guideline development should be driven by rigorous methodology, but what is less clear is where quality improvement enters the process: should it be a priority-guiding force, or should it enter only after recommendations are formulated? We argue for a stakeholder-driven approach to guideline development, with an overriding goal of quality improvement based on stakeholder perceptions of needs, uncertainties, and knowledge gaps. In contrast, the widely used topic-driven approach, which often makes recommendations based only on randomized controlled trials, is driven by epidemiologic purity and evidence rigor, with quality improvement a downstream consideration. The advantages of a stakeholder-driven versus a topic-driven approach are highlighted by comparisons of guidelines for otitis media with effusion, thyroid nodules, sepsis, and acute bacterial rhinosinusitis. These comparisons show that stakeholder-driven guidelines are more likely to address the quality improvement needs and pressing concerns of clinicians and patients, including understudied populations and patients with multiple chronic conditions. Conversely, a topic-driven approach often addresses "typical" patients, based on research that may not reflect the needs of high-risk groups excluded from studies because of ethical issues or a desire for purity of research design.

Test Platform for Advanced Digital Control of Brushless DC Motors (MSFC Center Director's Discretionary Fund)

NASA Technical Reports Server (NTRS)

Gwaltney, D. A.

2002-01-01

A FY 2001 Center Director's Discretionary Fund task to develop a test platform for the development, implementation. and evaluation of adaptive and other advanced control techniques for brushless DC (BLDC) motor-driven mechanisms is described. Important applications for BLDC motor-driven mechanisms are the translation of specimens in microgravity experiments and electromechanical actuation of nozzle and fuel valves in propulsion systems. Motor-driven aerocontrol surfaces are also being utilized in developmental X vehicles. The experimental test platform employs a linear translation stage that is mounted vertically and driven by a BLDC motor. Control approaches are implemented on a digital signal processor-based controller for real-time, closed-loop control of the stage carriage position. The goal of the effort is to explore the application of advanced control approaches that can enhance the performance of a motor-driven actuator over the performance obtained using linear control approaches with fixed gains. Adaptive controllers utilizing an exact model knowledge controller and a self-tuning controller are implemented and the control system performance is illustrated through the presentation of experimental results.

Methodological comparison of active- and passive-driven oscillations in blood pressure; implications for the assessment of cerebral pressure-flow relationships.

PubMed

Smirl, Jonathan D; Hoffman, Keegan; Tzeng, Yu-Chieh; Hansen, Alex; Ainslie, Philip N

2015-09-01

We examined the between-day reproducibility of active (squat-stand maneuvers)- and passive [oscillatory lower-body negative pressure (OLBNP) maneuvers]-driven oscillations in blood pressure. These relationships were examined in both younger (n = 10; 25 ± 3 yr) and older (n = 9; 66 ± 4 yr) adults. Each testing protocol incorporated rest (5 min), followed by driven maneuvers at 0.05 (5 min) and 0.10 (5 min) Hz to increase blood-pressure variability and improve assessment of the pressure-flow dynamics using linear transfer function analysis. Beat-to-beat blood pressure, middle cerebral artery velocity, and end-tidal partial pressure of CO2 were monitored. The pressure-flow relationship was quantified in the very low (0.02-0.07 Hz) and low (0.07-0.20 Hz) frequencies (LF; spontaneous data) and at 0.05 and 0.10 Hz (driven maneuvers point estimates). Although there were no between-age differences, very few spontaneous and OLBNP transfer function metrics met the criteria for acceptable reproducibility, as reflected in a between-day, within-subject coefficient of variation (CoV) of <20%. Combined CoV data consist of LF coherence (15.1 ± 12.2%), LF gain (15.1 ± 12.2%), and LF normalized gain (18.5 ± 10.9%); OLBNP data consist of 0.05 (12.1 ± 15.%) and 0.10 (4.7 ± 7.8%) Hz coherence. In contrast, the squat-stand maneuvers revealed that all metrics (coherence: 0.6 ± 0.5 and 0.3 ± 0.5%; gain: 17.4 ± 12.3 and 12.7 ± 11.0%; normalized gain: 16.7 ± 10.9 and 15.7 ± 11.0%; and phase: 11.6 ± 10.2 and 17.3 ± 10.8%) at 0.05 and 0.10 Hz, respectively, were considered biologically acceptable for reproducibility. These findings have important implications for the reliable assessment and interpretation of cerebral pressure-flow dynamics in humans. Copyright © 2015 the American Physiological Society.

Methodological comparison of active- and passive-driven oscillations in blood pressure; implications for the assessment of cerebral pressure-flow relationships

PubMed Central

Hoffman, Keegan; Tzeng, Yu-Chieh; Hansen, Alex; Ainslie, Philip N.

2015-01-01

We examined the between-day reproducibility of active (squat-stand maneuvers)- and passive [oscillatory lower-body negative pressure (OLBNP) maneuvers]-driven oscillations in blood pressure. These relationships were examined in both younger (n = 10; 25 ± 3 yr) and older (n = 9; 66 ± 4 yr) adults. Each testing protocol incorporated rest (5 min), followed by driven maneuvers at 0.05 (5 min) and 0.10 (5 min) Hz to increase blood-pressure variability and improve assessment of the pressure-flow dynamics using linear transfer function analysis. Beat-to-beat blood pressure, middle cerebral artery velocity, and end-tidal partial pressure of CO2 were monitored. The pressure-flow relationship was quantified in the very low (0.02-0.07 Hz) and low (0.07–0.20 Hz) frequencies (LF; spontaneous data) and at 0.05 and 0.10 Hz (driven maneuvers point estimates). Although there were no between-age differences, very few spontaneous and OLBNP transfer function metrics met the criteria for acceptable reproducibility, as reflected in a between-day, within-subject coefficient of variation (CoV) of <20%. Combined CoV data consist of LF coherence (15.1 ± 12.2%), LF gain (15.1 ± 12.2%), and LF normalized gain (18.5 ± 10.9%); OLBNP data consist of 0.05 (12.1 ± 15.%) and 0.10 (4.7 ± 7.8%) Hz coherence. In contrast, the squat-stand maneuvers revealed that all metrics (coherence: 0.6 ± 0.5 and 0.3 ± 0.5%; gain: 17.4 ± 12.3 and 12.7 ± 11.0%; normalized gain: 16.7 ± 10.9 and 15.7 ± 11.0%; and phase: 11.6 ± 10.2 and 17.3 ± 10.8%) at 0.05 and 0.10 Hz, respectively, were considered biologically acceptable for reproducibility. These findings have important implications for the reliable assessment and interpretation of cerebral pressure-flow dynamics in humans. PMID:26183476

Reconceptualizing Early and Late Onset: A Life Course Analysis of Older Heroin Users

ERIC Educational Resources Information Center

Boeri, Miriam Williams; Sterk, Claire E.; Elifson, Kirk W.

2008-01-01

Purpose: Researchers' knowledge regarding older users of illicit drugs is limited despite the increasing numbers of users. In this article, we apply a life course perspective to gain a further understanding of older adult drug use, specifically contrasting early- and late-onset heroin users. Design and Methods: We collected qualitative data from…

The Impact of a Comparison Curriculum in Algebra I: A Randomized Experiment

ERIC Educational Resources Information Center

Star, Jon R.; Rittle-Johnson, Bethany; Durkin, Kelley; Newton, Kristie; Pollack, Courtney; Lynch, Kathleen; Gogolen, Claire

2013-01-01

Comparison is a powerful tool that has been shown to improve learning in a variety of domains. In both laboratory studies and small-scale classroom studies, having learners compare and contrast worked examples has been shown to reliably lead to gains in students' knowledge. Comparison is also integral to "best practices" in mathematics…

Is Online Learning a Viable Training Option for Teaching Sexual Assault Forensic Examiners?

PubMed

Patterson, Debra; Resko, Stella M

2015-01-01

This study assessed knowledge attainment of healthcare professionals who participated in a nationwide sexual assault forensic examiner training program developed by the International Association of Forensic Nursing. A comprehensive curriculum was divided into 12 modules that students accessed through an online learning management system. Using a one-group pretest-posttest design, we assessed students' knowledge attainment for all 12 online modules. The results showed that the mean posttest scores were significantly greater than the mean pretest scores for all 12 online modules. On over 40% of the modules, the students exhibited at least a 25% knowledge gain. This study also examined the predictors of knowledge attainment. Using a multiple linear regression model, we found that knowledge attainment was positively associated with a reliable Internet connection, students who were drawn to the training because it was of no cost to them, and those students with higher levels of motivation. By contrast, lower knowledge gains were significantly related to students who reported more work/personal barriers and those who were drawn to sexual assault forensic examiner practice because they, or someone close to them, have personal experience with sexual assault.

Significantly High Thermal Rectification in an Asymmetric Polymer Molecule Driven by Diffusive versus Ballistic Transport.

PubMed

Ma, Hao; Tian, Zhiting

2018-01-10

Tapered bottlebrush polymers have novel nanoscale polymer architecture. Using nonequilibrium molecular dynamics simulations, we showed that these polymers have the unique ability to generate thermal rectification in a single polymer molecule and offer an exceptional platform for unveiling different heat conduction regimes. In sharp contrast to all other reported asymmetric nanostructures, we observed that the heat current from the wide end to the narrow end (the forward direction) in tapered bottlebrush polymers is smaller than that in the opposite direction (the backward direction). We found that a more disordered to less disordered structural transition within tapered bottlebrush polymers is essential for generating nonlinearity in heat conduction for thermal rectification. Moreover, the thermal rectification ratio increased with device length, reaching as high as ∼70% with a device length of 28.5 nm. This large thermal rectification with strong length dependence uncovered an unprecedented phenomenon-diffusive thermal transport in the forward direction and ballistic thermal transport in the backward direction. This is the first observation of radically different transport mechanisms when heat flow direction changes in the same system. The fundamentally new knowledge gained from this study can guide exciting research into nanoscale organic thermal diodes.

Lipid - Motor Interactions: Soap Opera or Symphony?

PubMed

Pathak, Divya; Mallik, Roop

2017-02-01

Intracellular transport of organelles can be driven by multiple motor proteins that bind to the lipid membrane of the organelle and work as a team. We review present knowledge on how lipids orchestrate the recruitment of motors to a membrane. Looking beyond recruitment, we also discuss how heterogeneity and local mechanical properties of the membrane may influence function of motor-teams. These issues gain importance because phagocytosed pathogens use lipid-centric strategies to manipulate motors and survive in host cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

Prospects for development of an innovative water-cooled nuclear reactor for supercritical parameters of coolant

NASA Astrophysics Data System (ADS)

Kalyakin, S. G.; Kirillov, P. L.; Baranaev, Yu. D.; Glebov, A. P.; Bogoslovskaya, G. P.; Nikitenko, M. P.; Makhin, V. M.; Churkin, A. N.

2014-08-01

The state of nuclear power engineering as of February 1, 2014 and the accomplished elaborations of a supercritical-pressure water-cooled reactor are briefly reviewed, and the prospects of this new project are discussed based on this review. The new project rests on the experience gained from the development and operation of stationary water-cooled reactor plants, including VVERs, PWRs, BWRs, and RBMKs (their combined service life totals more than 15 000 reactor-years), and long-term experience gained around the world with operation of thermal power plants the turbines of which are driven by steam with supercritical and ultrasupercritical parameters. The advantages of such reactor are pointed out together with the scientific-technical problems that need to be solved during further development of such installations. The knowledge gained for the last decade makes it possible to refine the concept and to commence the work on designing an experimental small-capacity reactor.

Assessment of contrast gain signature in inferred magnocellular and parvocellular pathways in patients with glaucoma.

PubMed

Sun, Hao; Swanson, William H; Arvidson, Brian; Dul, Mitchell W

2008-11-01

Contrast gain signatures of inferred magnocellular and parvocellular postreceptoral pathways were assessed for patients with glaucoma using a contrast discrimination paradigm developed by Pokorny and Smith. The potential causes for changes in contrast gain signature were investigated using model simulations of ganglion cell contrast responses. Foveal contrast discrimination thresholds were measured with a pedestal-Delta-pedestal paradigm developed by Pokorny and Smith [Pokorny, J., & Smith, V. C. (1997). Psychophysical signatures associated with magnocellular and parvocellular pathway contrast gain. Journal of the Optical Society of America A, 14(9), 2477-2486]. Stimuli were 27 ms luminance increments superimposed on 227 ms pulsed Delta-pedestals. Contrast thresholds and contrast gain signatures mediated by the inferred magnocellular (MC) and parvocellular (PC) pathways were assessed using linear fits to contrast discrimination thresholds at either lower or higher Delta-pedestal contrasts, respectively. Twenty-seven patients with glaucoma were tested, as well as 16 age-similar control subjects free of eye disease. Contrast sensitivity and contrast gain signature mediated by the inferred MC pathway were lower for the glaucoma group, and reduced contrast gain signature was correlated with reduced contrast sensitivity (r(2)=45%, p<.0005). These two parameters mediated by the inferred PC pathway were little affected for the glaucoma group. Model simulations suggest that the reduced contrast sensitivity and contrast gain signature were consistent with the hypothesis that reduced MC ganglion cell dendritic complexity can lead to reduced effective retinal illuminance, and hence increased semi-saturation contrast of the ganglion cell contrast response functions. The contrast sensitivity and contrast gain signature of the inferred MC pathway were reduced in patients with glaucoma. The results were consistent with a model of ganglion cell dysfunction due to reduced synaptic density.

Output characteristics of SASE-driven short wavelength FEL`s

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

Fawley, W.M.

This paper investigates various properties of the ``microspikes`` associated with self-amplified spontaneous emission (SASE) in a short wavelength free-electron laser (FEL). Using results from the 2-D numerical simulation code GINGER, we confirm theoretical predictions such as the convective group velocity in the exponential gain regime. In the saturated gain regime beyond the initial saturation, we find that the average radiation power continues to grow with an approximately linearly dependence upon undulator length. Moreover, the spectrum significantly broadens and shifts in wavelength to the redward direction, with{ital P(w)} approaching a constant, asymptotic value. This is in marked contrast to the exponentialmore » gain regime where the spectrum steadily narrows, {ital P(w)} grows, and the central wavelength remains constant with {ital z}. Via use of a spectrogram diagnostic {ital S(w,t)}, it appears that the radiation pattern in the saturated gain regime is composed of an ensemble of distinct ``sinews`` whose widths AA remain approximately constant but whose central wavelengths can ``chirp`` by varying a small extent with {ital t}.« less

Land Use Compounds Habitat Losses under Projected Climate Change in a Threatened California Ecosystem

PubMed Central

Riordan, Erin Coulter; Rundel, Philip W.

2014-01-01

Given the rapidly growing human population in mediterranean-climate systems, land use may pose a more immediate threat to biodiversity than climate change this century, yet few studies address the relative future impacts of both drivers. We assess spatial and temporal patterns of projected 21st century land use and climate change on California sage scrub (CSS), a plant association of considerable diversity and threatened status in the mediterranean-climate California Floristic Province. Using a species distribution modeling approach combined with spatially-explicit land use projections, we model habitat loss for 20 dominant shrub species under unlimited and no dispersal scenarios at two time intervals (early and late century) in two ecoregions in California (Central Coast and South Coast). Overall, projected climate change impacts were highly variable across CSS species and heavily dependent on dispersal assumptions. Projected anthropogenic land use drove greater relative habitat losses compared to projected climate change in many species. This pattern was only significant under assumptions of unlimited dispersal, however, where considerable climate-driven habitat gains offset some concurrent climate-driven habitat losses. Additionally, some of the habitat gained with projected climate change overlapped with projected land use. Most species showed potential northern habitat expansion and southern habitat contraction due to projected climate change, resulting in sharply contrasting patterns of impact between Central and South Coast Ecoregions. In the Central Coast, dispersal could play an important role moderating losses from both climate change and land use. In contrast, high geographic overlap in habitat losses driven by projected climate change and projected land use in the South Coast underscores the potential for compounding negative impacts of both drivers. Limiting habitat conversion may be a broadly beneficial strategy under climate change. We emphasize the importance of addressing both drivers in conservation and resource management planning. PMID:24466116

ON THE IMPACT OF THREE DIMENSIONS IN SIMULATIONS OF NEUTRINO-DRIVEN CORE-COLLAPSE SUPERNOVA EXPLOSIONS

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

Couch, Sean M., E-mail: smc@flash.uchicago.edu

2013-09-20

We present one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) hydrodynamical simulations of core-collapse supernovae including a parameterized neutrino heating and cooling scheme in order to investigate the critical core neutrino luminosity (L{sub crit}) required for explosion. In contrast to some previous works, we find that 3D simulations explode later than 2D simulations, and that L{sub crit} at fixed mass accretion rate is somewhat higher in three dimensions than in two dimensions. We find, however, that in two dimensions L{sub crit} increases as the numerical resolution of the simulation increases. In contrast to some previous works, we argue that the averagemore » entropy of the gain region is in fact not a good indicator of explosion but is rather a reflection of the greater mass in the gain region in two dimensions. We compare our simulations to semi-analytic explosion criteria and examine the nature of the convective motions in two dimensions and three dimensions. We discuss the balance between neutrino-driven buoyancy and drag forces. In particular, we show that the drag force will be proportional to a buoyant plume's surface area while the buoyant force is proportional to a plume's volume and, therefore, plumes with greater volume-to-surface-area ratios will rise more quickly. We show that buoyant plumes in two dimensions are inherently larger, with greater volume-to-surface-area ratios, than plumes in three dimensions. In the scenario that the supernova shock expansion is dominated by neutrino-driven buoyancy, this balance between buoyancy and drag forces may explain why 3D simulations explode later than 2D simulations and why L{sub crit} increases with resolution. Finally, we provide a comparison of our results with other calculations in the literature.« less

Elevated arousal levels enhance contrast perception.

PubMed

Kim, Dongho; Lokey, Savannah; Ling, Sam

2017-02-01

Our state of arousal fluctuates from moment to moment-fluctuations that can have profound impacts on behavior. Arousal has been proposed to play a powerful, widespread role in the brain, influencing processes as far ranging as perception, memory, learning, and decision making. Although arousal clearly plays a critical role in modulating behavior, the mechanisms underlying this modulation remain poorly understood. To address this knowledge gap, we examined the modulatory role of arousal on one of the cornerstones of visual perception: contrast perception. Using a reward-driven paradigm to manipulate arousal state, we discovered that elevated arousal state substantially enhances visual sensitivity, incurring a multiplicative modulation of contrast response. Contrast defines vision, determining whether objects appear visible or invisible to us, and these results indicate that one of the consequences of decreased arousal state is an impaired ability to visually process our environment.

From Comparison Between Scientists to Gaining Cultural Scientific Knowledge. Leonardo and Galileo

NASA Astrophysics Data System (ADS)

Galili, Igal

2016-03-01

Physics textbooks often present items of disciplinary knowledge in a sequential order of topics of the theory under instruction. Such presentation is usually univocal, that is, isolated from alternative claims and contributions regarding the subject matter in the pertinent scientific discourse. We argue that comparing and contrasting the contributions of scientists addressing similar or the same subject could not only enrich the picture of scientific enterprise, but also possess a special appealing power promoting genuine understanding of the concept considered. This approach draws on the historical tradition from Plutarch in distant past and Koyré in the recent history and philosophy of science. It gains a new support in the discipline-culture structuring of the physics curriculum, seeking cultural content knowledge (CCK) of the subject matter. Here, we address two prominent individuals of Italian Renaissance, Leonardo and Galileo, in their dealing with issues relevant for introductory science courses. Although both figures addressed similar subjects of scientific content, their products were essentially different. Considering this difference is educationally valuable, illustrating the meaning of what students presently learn in the content knowledge of mechanics, optics and astronomy, as well as the nature of science and scientific knowledge.

Assessment of contrast gain signature in inferred magnocellular and parvocellular pathways in patients with glaucoma

PubMed Central

Sun, Hao; Swanson, William H.; Arvidson, Brian; Dul, Mitchell W.

2010-01-01

PURPOSE Contrast gain signatures of inferred magnocellular and parvocellular postreceptoral pathways were assessed for patients with glaucoma using a contrast discrimination paradigm developed by Pokorny and Smith. The potential causes for changes in contrast gain signature were investigated using model simulations of ganglion cell contrast responses. METHODS Foveal contrast discrimination thresholds were measured with a pedestal-Δ-pedestal paradigm developed by Pokorny and Smith (1997). Stimuli were 27 msec luminance increments superimposed on 227 msec pulsed Δ-pedestals. Contrast thresholds and contrast gain signatures mediated by the inferred magnocellular (MC) and parvocellular (PC) pathways were assessed using linear fits to contrast discrimination thresholds at either lower or higher Δ-pedestal contrasts, respectively. Twenty-seven patients with glaucoma were tested, as well as 16 age-similar control subjects free of eye disease. RESULTS Contrast sensitivity and contrast gain signature mediated by the inferred MC pathway were lower for the glaucoma group, and reduced contrast gain signature was correlated with reduced contrast sensitivity (r2=45%, p<0.0005). These two parameters mediated by the inferred PC pathway were little affected for the glaucoma group. Model simulations suggest that the reduced contrast sensitivity and contrast gain signature were consistent with the hypothesis that reduced MC ganglion cell dendritic complexity can lead to reduced effective retinal illuminance, and hence increased semi-saturation contrast of the ganglion cell contrast response functions. CONCLUSIONS The contrast sensitivity and contrast gain signature of the inferred MC pathway were reduced in patients with glaucoma. The results were consistent with a model of ganglion cell dysfunction due to reduced synaptic density. PMID:18501947

Enhancing the T-shaped learning profile when teaching hydrology using data, modeling, and visualization activities

NASA Astrophysics Data System (ADS)

Sanchez, Christopher A.; Ruddell, Benjamin L.; Schiesser, Roy; Merwade, Venkatesh

2016-03-01

Previous research has suggested that the use of more authentic learning activities can produce more robust and durable knowledge gains. This is consistent with calls within civil engineering education, specifically hydrology, that suggest that curricula should more often include professional perspective and data analysis skills to better develop the "T-shaped" knowledge profile of a professional hydrologist (i.e., professional breadth combined with technical depth). It was expected that the inclusion of a data-driven simulation lab exercise that was contextualized within a real-world situation and more consistent with the job duties of a professional in the field, would provide enhanced learning and appreciation of job duties beyond more conventional paper-and-pencil exercises in a lower-division undergraduate course. Results indicate that while students learned in both conditions, learning was enhanced for the data-driven simulation group in nearly every content area. This pattern of results suggests that the use of data-driven modeling and visualization activities can have a significant positive impact on instruction. This increase in learning likely facilitates the development of student perspective and conceptual mastery, enabling students to make better choices about their studies, while also better preparing them for work as a professional in the field.

Enhancing the T-shaped learning profile when teaching hydrology using data, modeling, and visualization activities

NASA Astrophysics Data System (ADS)

Sanchez, C. A.; Ruddell, B. L.; Schiesser, R.; Merwade, V.

2015-07-01

Previous research has suggested that the use of more authentic learning activities can produce more robust and durable knowledge gains. This is consistent with calls within civil engineering education, specifically hydrology, that suggest that curricula should more often include professional perspective and data analysis skills to better develop the "T-shaped" knowledge profile of a professional hydrologist (i.e., professional breadth combined with technical depth). It was expected that the inclusion of a data driven simulation lab exercise that was contextualized within a real-world situation and more consistent with the job duties of a professional in the field, would provide enhanced learning and appreciation of job duties beyond more conventional paper-and-pencil exercises in a lower division undergraduate course. Results indicate that while students learned in both conditions, learning was enhanced for the data-driven simulation group in nearly every content area. This pattern of results suggests that the use of data-driven modeling and visualization activities can have a significant positive impact on instruction. This increase in learning likely facilitates the development of student perspective and conceptual mastery, enabling students to make better choices about their studies, while also better preparing them for work as a professional in the field.

The role of biotic forces in driving macroevolution: beyond the Red Queen

PubMed Central

Voje, Kjetil L.; Holen, Øistein H.; Liow, Lee Hsiang; Stenseth, Nils Chr.

2015-01-01

A multitude of hypotheses claim that abiotic factors are the main drivers of macroevolutionary change. By contrast, Van Valen's Red Queen hypothesis is often put forward as the sole representative of the view that biotic forcing is the main evolutionary driver. This imbalance of hypotheses does not reflect our current knowledge: theoretical work demonstrates the plausibility of biotically driven long-term evolution, whereas empirical work suggests a central role for biotic forcing in macroevolution. We call for a more pluralistic view of how biotic forces may drive long-term evolution that is compatible with both phenotypic stasis in the fossil record and with non-constant extinction rates. Promising avenues of research include contrasting predictions from relevant theories within ecology and macroevolution, as well as embracing both abiotic and biotic proxies while modelling long-term evolutionary data. By fitting models describing hypotheses of biotically driven macroevolution to data, we could dissect their predictions and transcend beyond pattern description, possibly narrowing the divide between our current understanding of micro- and macroevolution. PMID:25948685

Contrast Gain Control in Auditory Cortex

PubMed Central

Rabinowitz, Neil C.; Willmore, Ben D.B.; Schnupp, Jan W.H.; King, Andrew J.

2011-01-01

Summary The auditory system must represent sounds with a wide range of statistical properties. One important property is the spectrotemporal contrast in the acoustic environment: the variation in sound pressure in each frequency band, relative to the mean pressure. We show that neurons in ferret auditory cortex rescale their gain to partially compensate for the spectrotemporal contrast of recent stimulation. When contrast is low, neurons increase their gain, becoming more sensitive to small changes in the stimulus, although the effectiveness of contrast gain control is reduced at low mean levels. Gain is primarily determined by contrast near each neuron's preferred frequency, but there is also a contribution from contrast in more distant frequency bands. Neural responses are modulated by contrast over timescales of ∼100 ms. By using contrast gain control to expand or compress the representation of its inputs, the auditory system may be seeking an efficient coding of natural sounds. PMID:21689603

Optical gain in 1.3-μm electrically driven dilute nitride VCSOAs

PubMed Central

2014-01-01

We report the observation of room-temperature optical gain at 1.3 μm in electrically driven dilute nitride vertical cavity semiconductor optical amplifiers. The gain is calculated with respect to injected power for samples with and without a confinement aperture. At lower injected powers, a gain of almost 10 dB is observed in both samples. At injection powers over 5 nW, the gain is observed to decrease. For nearly all investigated power levels, the sample with confinement aperture gives slightly higher gain. PMID:24417791

Design, Realization, and First Validation of an Immersive Web-Based Virtual Patient Simulator for Training Clinical Decisions in Surgery.

PubMed

Kleinert, Robert; Heiermann, Nadine; Wahba, Roger; Chang, De-Huan; Hölscher, Arnulf H; Stippel, Dirk L

2015-01-01

Immersive patient simulators (IPS) allow an illusionary immersion into a synthetic world where the user can freely navigate through a 3-dimensional environment similar to computer games. Playful learning with IPS allows internalization of medical workflows without harming real patients. Ideally, IPS show high student acceptance and can have positive effect on knowledge gain. Development of IPS with high technical quality is resource intensive. Therefore most of the "high-fidelity" IPS are commercially driven. Usage of IPS in the daily curriculum is still rare. There is no academic-driven simulator that is freely accessible to every student and combines high immersion grade with a profound amount of medical content. Therefore it was our aim to develop an academic-driven IPS prototype that is free to use and combines a high immersion grade with profound medical content. In addition, a first validation of the prototype was conducted. The conceptual design included definition of the following parameters: amount of curricular content, grade of technical quality, availability, and level of validation. A preliminary validation was done with 25 students. Students' opinion about acceptance was evaluated by a Likert-scale questionnaire. Effect on knowledge gain was determined by testing concordance and predictive validity. A custom-made simulator prototype (Artificial learning interface for clinical education [ALICE]) displays a virtual clinic environment that can be explored from a first-person view similar to a video game. By controlling an avatar, the user navigates through the environment, is able to treat virtual patients, and faces the consequence of different decisions. ALICE showed high students' acceptance. There was positive correlation for concordance validity and predictive validity. Simulator usage had positive effect on reproduction of trained content and declarative knowledge. We successfully developed a university-based, IPS prototype (ALICE) with profound medical content. ALICE is a nonprofit simulator, easy to use, and showed high students' acceptance; thus it potentially provides an additional tool for supporting student teaching in the daily clinical curriculum. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Data-driven approach for assessing utility of medical tests using electronic medical records.

PubMed

Skrøvseth, Stein Olav; Augestad, Knut Magne; Ebadollahi, Shahram

2015-02-01

To precisely define the utility of tests in a clinical pathway through data-driven analysis of the electronic medical record (EMR). The information content was defined in terms of the entropy of the expected value of the test related to a given outcome. A kernel density classifier was used to estimate the necessary distributions. To validate the method, we used data from the EMR of the gastrointestinal department at a university hospital. Blood tests from patients undergoing surgery for gastrointestinal surgery were analyzed with respect to second surgery within 30 days of the index surgery. The information content is clearly reflected in the patient pathway for certain combinations of tests and outcomes. C-reactive protein tests coupled to anastomosis leakage, a severe complication show a clear pattern of information gain through the patient trajectory, where the greatest gain from the test is 3-4 days post index surgery. We have defined the information content in a data-driven and information theoretic way such that the utility of a test can be precisely defined. The results reflect clinical knowledge. In the case we used the tests carry little negative impact. The general approach can be expanded to cases that carry a substantial negative impact, such as in certain radiological techniques. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

A Curriculum Experiment in Climate Change Education Using and Integrated Approach of Content Knowledge Instruction and Student-Driven Research to Promote Civic Engagement

NASA Astrophysics Data System (ADS)

Adams, P. E.; Heinrichs, J. F.

2009-12-01

One of the greatest challenges facing the world is climate change. Coupled with this challenge is an under-informed population that has not received a rigorous education about climate change other than what is available through the media. Fort Hays State University is piloting a course on climate change targeted to students early in their academic careers. The course is modeled after our past work (NSF DUE-0088818) of integrating content knowledge instruction and student-driven research where there was a positive correlation between student research engagement and student knowledge gains. The current course, based on prior findings, utilizes a mix of inquiry-based instruction, problem-based learning, and student-driven research to educate and engage the students in understanding climate change. The course was collaboratively developed by a geoscientist and science educator both of whom are active in citizen science programs. The emphasis on civic engagement by students is reflected in the course structure. The course model is unique in that 50% of the course is dedicated to developing core knowledge and technical skills (e.g. critical analysis, writing, data acquisition, data representation, and research design), and 50% to conducting a research project using available data sets from federal agencies and research groups. A key element of the course is a focus on local and regional data sets to make climate change relevant to the students. The research serves as a means of civic engagement by the students as they are tasked to understand their role in communicating their research findings to the community and coping with the local and regional changes they find through their research.

A Curriculum Experiment in Climate Change Education Using an Integrated Approach of Content Knowledge Instruction and Student-Driven Research, Year 2

NASA Astrophysics Data System (ADS)

Adams, P. E.; Heinrichs, J. F.

2010-12-01

One of the greatest challenges facing the world is climate change. Coupled with this challenge is an under-informed population that has not received a rigorous education about climate change other than what is available through the media. Fort Hays State University is in a second year of piloting a course on climate change targeted to students early in their academic careers. The course is modeled after our past work (NSF DUE-0088818) of integrating content knowledge instruction and student-driven research where there was a positive correlation between student research engagement and student knowledge gains. The second pilot offering utilizes a mix of inquiry-based instruction, problem-based learning, and student-driven research to educate and engage the students in understanding climate change. The course was collaboratively developed by a geoscientist and science educator both of whom are active in citizen science programs. The course model is unique in that 50% of the course is dedicated to developing core knowledge and technical skills (e.g. global climate change, critical analysis, writing, data acquisition, data representation, and research design), and 50% to conducting a research project using available data sets from federal agencies and research groups. A key element of the course is a focus on data sets to make climate change relevant to the students. The research serves as a means of civic engagement by the students as they are tasked to understand their role in communicating their research findings to the community and coping with the local and regional changes they find through their research. The impacts of course changes from the first offering to the second offering of the course will be reported, as well as the structure of the course.

Adjustment of Adaptive Gain with Bounded Linear Stability Analysis to Improve Time-Delay Margin for Metrics-Driven Adaptive Control

NASA Technical Reports Server (NTRS)

Bakhtiari-Nejad, Maryam; Nguyen, Nhan T.; Krishnakumar, Kalmanje Srinvas

2009-01-01

This paper presents the application of Bounded Linear Stability Analysis (BLSA) method for metrics driven adaptive control. The bounded linear stability analysis method is used for analyzing stability of adaptive control models, without linearizing the adaptive laws. Metrics-driven adaptive control introduces a notion that adaptation should be driven by some stability metrics to achieve robustness. By the application of bounded linear stability analysis method the adaptive gain is adjusted during the adaptation in order to meet certain phase margin requirements. Analysis of metrics-driven adaptive control is evaluated for a linear damaged twin-engine generic transport model of aircraft. The analysis shows that the system with the adjusted adaptive gain becomes more robust to unmodeled dynamics or time delay.

Accommodation Responds to Optical Vergence and Not Defocus Blur Alone.

PubMed

Del Águila-Carrasco, Antonio J; Marín-Franch, Iván; Bernal-Molina, Paula; Esteve-Taboada, José J; Kruger, Philip B; Montés-Micó, Robert; López-Gil, Norberto

2017-03-01

To determine whether changes in wavefront spherical curvature (optical vergence) are a directional cue for accommodation. Nine subjects participated in this experiment. The accommodation response to a monochromatic target was measured continuously with a custom-made adaptive optics system while astigmatism and higher-order aberrations were corrected in real time. There were two experimental open-loop conditions: vergence-driven condition, where the deformable mirror provided sinusoidal changes in defocus at the retina between -1 and +1 diopters (D) at 0.2 Hz; and blur-driven condition, in which the level of defocus at the retina was always 0 D, but a sinusoidal defocus blur between -1 and +1 D at 0.2 Hz was simulated in the target. Right before the beginning of each trial, the target was moved to an accommodative demand of 2 D. Eight out of nine subjects showed sinusoidal responses for the vergence-driven condition but not for the blur-driven condition. Their average (±SD) gain for the vergence-driven condition was 0.50 (±0.28). For the blur-driven condition, average gain was much smaller at 0.07 (±0.03). The ninth subject showed little to no response for both conditions, with average gain <0.08. Vergence-driven condition gain was significantly different from blur-driven condition gain (P = 0.004). Accommodation responds to optical vergence, even without feedback, and not to changes in defocus blur alone. These results suggest the presence of a retinal mechanism that provides a directional cue for accommodation from optical vergence.

The thermodynamic balance of the Weddell Gyre

NASA Astrophysics Data System (ADS)

Naveira Garabato, Alberto C.; Zika, Jan D.; Jullion, Loïc.; Brown, Peter J.; Holland, Paul R.; Meredith, Michael P.; Bacon, Sheldon

2016-01-01

The thermodynamic balance of the Weddell Gyre is assessed from an inverse estimate of the circulation across the gyre's rim. The gyre experiences a weak net buoyancy gain that arises from a leading-order cancelation between two opposing contributions, linked to two cells of water mass transformation and diapycnal overturning. The lower cell involves a cooling-driven densification of 8.4 ± 2.0 Sv of Circumpolar Deep Water and Antarctic Bottom Water near the gyre's southern and western margins. The upper cell entails a freshening-driven conversion of 4.9 ± 2.0 Sv of Circumpolar Deep Water into lighter upper ocean waters within the gyre interior. The distinct role of salinity between the two cells stems from opposing salinity changes induced by sea ice production, meteoric sources, and admixture of fresh upper ocean waters in the lower cell, which contrasts with coherent reductions in salinity associated with sea ice melting and meteoric sources in the upper cell.

PDON: Parkinson's disease ontology for representation and modeling of the Parkinson's disease knowledge domain.

PubMed

Younesi, Erfan; Malhotra, Ashutosh; Gündel, Michaela; Scordis, Phil; Kodamullil, Alpha Tom; Page, Matt; Müller, Bernd; Springstubbe, Stephan; Wüllner, Ullrich; Scheller, Dieter; Hofmann-Apitius, Martin

2015-09-22

Despite the unprecedented and increasing amount of data, relatively little progress has been made in molecular characterization of mechanisms underlying Parkinson's disease. In the area of Parkinson's research, there is a pressing need to integrate various pieces of information into a meaningful context of presumed disease mechanism(s). Disease ontologies provide a novel means for organizing, integrating, and standardizing the knowledge domains specific to disease in a compact, formalized and computer-readable form and serve as a reference for knowledge exchange or systems modeling of disease mechanism. The Parkinson's disease ontology was built according to the life cycle of ontology building. Structural, functional, and expert evaluation of the ontology was performed to ensure the quality and usability of the ontology. A novelty metric has been introduced to measure the gain of new knowledge using the ontology. Finally, a cause-and-effect model was built around PINK1 and two gene expression studies from the Gene Expression Omnibus database were re-annotated to demonstrate the usability of the ontology. The Parkinson's disease ontology with a subclass-based taxonomic hierarchy covers the broad spectrum of major biomedical concepts from molecular to clinical features of the disease, and also reflects different views on disease features held by molecular biologists, clinicians and drug developers. The current version of the ontology contains 632 concepts, which are organized under nine views. The structural evaluation showed the balanced dispersion of concept classes throughout the ontology. The functional evaluation demonstrated that the ontology-driven literature search could gain novel knowledge not present in the reference Parkinson's knowledge map. The ontology was able to answer specific questions related to Parkinson's when evaluated by experts. Finally, the added value of the Parkinson's disease ontology is demonstrated by ontology-driven modeling of PINK1 and re-annotation of gene expression datasets relevant to Parkinson's disease. Parkinson's disease ontology delivers the knowledge domain of Parkinson's disease in a compact, computer-readable form, which can be further edited and enriched by the scientific community and also to be used to construct, represent and automatically extend Parkinson's-related computable models. A practical version of the Parkinson's disease ontology for browsing and editing can be publicly accessed at http://bioportal.bioontology.org/ontologies/PDON .

Effects of Embodied Learning and Digital Platform on the Retention of Physics Content: Centripetal Force

PubMed Central

Johnson-Glenberg, Mina C.; Megowan-Romanowicz, Colleen; Birchfield, David A.; Savio-Ramos, Caroline

2016-01-01

Embodiment theory proposes that knowledge is grounded in sensorimotor systems, and that learning can be facilitated to the extent that lessons can be mapped to these systems. This study with 109 college-age participants addresses two overarching questions: (a) how are immediate and delayed learning gains affected by the degree to which a lesson is embodied, and (b) how do the affordances of three different educational platforms affect immediate and delayed learning? Six 50 min-long lessons on centripetal force were created. The first factor was the degree of embodiment with two levels: (1) low and (2) high. The second factor was platform with three levels: (1) a large scale “mixed reality” immersive environment containing both digital and hands-on components called SMALLab, (2) an interactive whiteboard system, and (3) a mouse-driven desktop computer. Pre-tests, post-tests, and 1-week follow-up (retention or delayed learning gains) tests were administered resulting in a 2 × 3 × 3 design. Two knowledge subtests were analyzed, one that relied on more declarative knowledge and one that relied on more generative knowledge, e.g., hand-drawing vectors. Regardless of condition, participants made significant immediate learning gains from pre-test to post-test. There were no significant main effects or interactions due to platform or embodiment on immediate learning. However, from post-test to follow-up the level of embodiment interacted significantly with time, such that participants in the high embodiment conditions performed better on the subtest devoted to generative knowledge questions. We posit that better retention of certain types of knowledge can be seen over time when more embodiment is present during the encoding phase. This sort of retention may not appear on more traditional factual/declarative tests. Educational technology designers should consider using more sensorimotor feedback and gestural congruency when designing and opportunities for instructor professional development need to be provided as well. PMID:27933009

Effects of Embodied Learning and Digital Platform on the Retention of Physics Content: Centripetal Force.

PubMed

Johnson-Glenberg, Mina C; Megowan-Romanowicz, Colleen; Birchfield, David A; Savio-Ramos, Caroline

2016-01-01

Embodiment theory proposes that knowledge is grounded in sensorimotor systems, and that learning can be facilitated to the extent that lessons can be mapped to these systems. This study with 109 college-age participants addresses two overarching questions: (a) how are immediate and delayed learning gains affected by the degree to which a lesson is embodied, and (b) how do the affordances of three different educational platforms affect immediate and delayed learning? Six 50 min-long lessons on centripetal force were created. The first factor was the degree of embodiment with two levels: (1) low and (2) high. The second factor was platform with three levels: (1) a large scale "mixed reality" immersive environment containing both digital and hands-on components called SMALLab , (2) an interactive whiteboard system, and (3) a mouse-driven desktop computer. Pre-tests, post-tests, and 1-week follow-up (retention or delayed learning gains) tests were administered resulting in a 2 × 3 × 3 design. Two knowledge subtests were analyzed, one that relied on more declarative knowledge and one that relied on more generative knowledge, e.g., hand-drawing vectors. Regardless of condition, participants made significant immediate learning gains from pre-test to post-test. There were no significant main effects or interactions due to platform or embodiment on immediate learning. However, from post-test to follow-up the level of embodiment interacted significantly with time, such that participants in the high embodiment conditions performed better on the subtest devoted to generative knowledge questions. We posit that better retention of certain types of knowledge can be seen over time when more embodiment is present during the encoding phase. This sort of retention may not appear on more traditional factual/declarative tests. Educational technology designers should consider using more sensorimotor feedback and gestural congruency when designing and opportunities for instructor professional development need to be provided as well.

Contrast gain control: a bilinear model for chromatic selectivity.

PubMed

Singer, B; D'Zmura, M

1995-04-01

We report the results of psychophysical experiments on color contrast induction. In earlier work [Vision Res. 34, 3111 (1994)], we showed that modulating the spatial contrast of an annulus in time induces an apparent modulation of the contrast of a central disk, at isoluminance. Here we vary the chromatic properties of disk and annulus systematically in a study of the interactions among the luminance and the color-opponent channels. Results show that induced contrast depends linearly on both disk and annulus contrast, at low and moderate contrast levels. This dependence leads us to propose a bilinear model for color contrast gain control. The model predicts the magnitude and the chromatic properties of induced contrast. In agreement with experimental results, the model displays chromatic selectivity in contrast gain control and a negligible effect of contrast modulation at isoluminance on the appearance of achromatic contrast. We show that the bilinear model for chromatic selectivity may be realized as a feed-forward multiplicative gain control. Data collected at high contrast levels are fit by embellishing the model with saturating nonlinearities in the contrast gain control of each color channel.

Optical gain in an optically driven three-level ? system in atomic Rb vapor

NASA Astrophysics Data System (ADS)

Ballmann, C. W.; Yakovlev, V. V.

2018-06-01

In this work, we report experimentally achieved optical gain of a weak probe beam in a three-level ? system in a low density Rubidium vapor cell driven by a single pump beam. The maximum measured gain of the probe beam was about 0.12%. This work could lead to new approaches for enhancing molecular spectroscopy applications.

Rapid binge-like eating and body weight gain driven by zona incerta GABA neuron activation.

PubMed

Zhang, Xiaobing; van den Pol, Anthony N

2017-05-26

The neuronal substrate for binge eating, which can at times lead to obesity, is not clear. We find that optogenetic stimulation of mouse zona incerta (ZI) γ-aminobutyric acid (GABA) neurons or their axonal projections to paraventricular thalamus (PVT) excitatory neurons immediately (in 2 to 3 seconds) evoked binge-like eating. Minimal intermittent stimulation led to body weight gain; ZI GABA neuron ablation reduced weight. ZI stimulation generated 35% of normal 24-hour food intake in just 10 minutes. The ZI cells were excited by food deprivation and the gut hunger signal ghrelin. In contrast, stimulation of excitatory axons from the parasubthalamic nucleus to PVT or direct stimulation of PVT glutamate neurons reduced food intake. These data suggest an unexpected robust orexigenic potential for the ZI GABA neurons. Copyright © 2017, American Association for the Advancement of Science.

Knowledge Management Implementation and the Tools Utilized in Healthcare for Evidence-Based Decision Making: A Systematic Review.

PubMed

Shahmoradi, Leila; Safadari, Reza; Jimma, Worku

2017-09-01

Healthcare is a knowledge driven process and thus knowledge management and the tools to manage knowledge in healthcare sector are gaining attention. The aim of this systematic review is to investigate knowledge management implementation and knowledge management tools used in healthcare for informed decision making. Three databases, two journals websites and Google Scholar were used as sources for the review. The key terms used to search relevant articles include: "Healthcare and Knowledge Management"; "Knowledge Management Tools in Healthcare" and "Community of Practices in healthcare". It was found that utilization of knowledge management in healthcare is encouraging. There exist numbers of opportunities for knowledge management implementation, though there are some barriers as well. Some of the opportunities that can transform healthcare are advances in health information and communication technology, clinical decision support systems, electronic health record systems, communities of practice and advanced care planning. Providing the right knowledge at the right time, i.e., at the point of decision making by implementing knowledge management in healthcare is paramount. To do so, it is very important to use appropriate tools for knowledge management and user-friendly system because it can significantly improve the quality and safety of care provided for patients both at hospital and home settings.

Glass transition memorized by the enthalpy-entropy compensation in the shear thinning of supercooled metallic liquids.

PubMed

Zhang, Meng; Liu, Lin

2018-05-03

To unravel the true nature of glass transition, broader insights into glass forming have been gained by examining the stress-driven glassy systems, where strong shear thinning, i.e., a reduced viscosity under increasing shear rate, is encountered. It is argued that arbitrarily small stress-driven shear rates would "melt" the glass and erase any memory of its thermal history. In this work, we report a glass transition memorized by the enthalpy-entropy compensation in strongly shear-thinned supercooled metallic liquids, which coincides with the thermal glass transition in both the transition temperature and the activation Gibbs free energy. Our findings provide distinctive insights into both glass forming and shear thinning, and enrich current knowledge on the ubiquitous enthalpy-entropy compensation empirical law in condensed matter physics. © 2018 IOP Publishing Ltd.

Glass transition memorized by the enthalpy-entropy compensation in the shear thinning of supercooled metallic liquids

NASA Astrophysics Data System (ADS)

Zhang, Meng; Liu, Lin

2018-06-01

To unravel the true nature of glass transition, broader insights into glass forming have been gained by examining the stress-driven glassy systems, where strong shear thinning, i.e. a reduced viscosity under increasing shear rate, is encountered. It is argued that arbitrarily small stress-driven shear rates would ‘melt’ the glass and erase any memory of its thermal history. In this work, we report a glass transition memorized by the enthalpy-entropy compensation in strongly shear-thinned supercooled metallic liquids, which coincides with the thermal glass transition in both the transition temperature and the activation Gibbs free energy. Our findings provide distinctive insights into both glass forming and shear thinning, and enrich current knowledge on the ubiquitous enthalpy-entropy compensation empirical law in condensed matter physics.

Intelligent Data Granulation on Load: Improving Infobright's Knowledge Grid

NASA Astrophysics Data System (ADS)

Ślęzak, Dominik; Kowalski, Marcin

One of the major aspects of Infobright's relational database technology is automatic decomposition of each of data tables onto Rough Rows, each consisting of 64K of original rows. Rough Rows are automatically annotated by Knowledge Nodes that represent compact information about the rows' values. Query performance depends on the quality of Knowledge Nodes, i.e., their efficiency in minimizing the access to the compressed portions of data stored on disk, according to the specific query optimization procedures. We show how to implement the mechanism of organizing the incoming data into such Rough Rows that maximize the quality of the corresponding Knowledge Nodes. Given clear business-driven requirements, the implemented mechanism needs to be fully integrated with the data load process, causing no decrease in the data load speed. The performance gain resulting from better data organization is illustrated by some tests over our benchmark data. The differences between the proposed mechanism and some well-known procedures of database clustering or partitioning are discussed. The paper is a continuation of our patent application [22].

Input-driven versus turnover-driven controls of simulated changes in soil carbon due to land-use change

NASA Astrophysics Data System (ADS)

Nyawira, Sylvia; Nabel, Julia; Brovkin, Victor; Pongratz, Julia

2017-04-01

Modelling studies estimate a global loss in soil carbon caused by land-use changes (LUCs) over the last century. Although it is known that this loss stems from the changes in quantity of litter inputs from the vegetation to the soil (input-driven) and the changes in turnover of carbon in the soil (turnover-driven) associated with LUC, the individual contribution of these two controls to the total changes have not been assessed. Using the dynamic global vegetation model JSBACH, we apply a factor separation approach to isolate the contribution of the input-driven and turnover-driven changes, as well as their synergies, to the total changes in soil carbon from LUC. To assess how land management through crop and wood harvest influences the controls, we compare our results for simulations with and without land management. Our results reveal that for the afforested regions both the input-driven and turnover-driven changes generally result in soil carbon gain, whereas deforested regions exhibit a loss. However, for regions where croplands have increased at the expense of grasslands and pastures, the input-driven changes result in a loss that is partly offset by a gain via the turnover-driven changes. This gain stems from a decrease in the fire-related carbon losses when grasslands or pastures are replaced with croplands. Omitting land management reduces the carbon losses in regions where natural vegetation has been converted to croplands and enhances the gain in afforested regions. The global simulated losses are substantially reduced from 54.0 Pg C to 22.0 Pg C, with the input-driven losses reducing from 54.7 Pg C to 24.9 Pg C. Our study shows that the dominating control of soil carbon losses is through the input-driven changes, which are more directly influenced by human management than the turnover-driven ones.

Indigenous Ways of Knowing: Implications for Participatory Research and Community

PubMed Central

Cochran, Patricia A. L.; Marshall, Catherine A.; Garcia-Downing, Carmen; Kendall, Elizabeth; Cook, Doris; McCubbin, Laurie; Gover, Reva Mariah S.

2008-01-01

Researchers have a responsibility to cause no harm, but research has been a source of distress for indigenous people because of inappropriate methods and practices. The way researchers acquire knowledge in indigenous communities may be as critical for eliminating health disparities as the actual knowledge that is gained about a particular health problem. Researchers working with indigenous communities must continue to resolve conflict between the values of the academic setting and those of the community. It is important to consider the ways of knowing that exist in indigenous communities when developing research methods. Challenges to research partnerships include how to distribute the benefits of the research findings when academic or external needs contrast with the need to protect indigenous knowledge. PMID:18048800

Towards an Enhanced Understanding of Plant–Microbiome Interactions to Improve Phytoremediation: Engineering the Metaorganism

PubMed Central

Thijs, Sofie; Sillen, Wouter; Rineau, Francois; Weyens, Nele; Vangronsveld, Jaco

2016-01-01

Phytoremediation is a promising technology to clean-up contaminated soils based on the synergistic actions of plants and microorganisms. However, to become a widely accepted, and predictable remediation alternative, a deeper understanding of the plant–microbe interactions is needed. A number of studies link the success of phytoremediation to the plant-associated microbiome functioning, though whether the microbiome can exist in alternative, functional states for soil remediation, is incompletely understood. Moreover, current approaches that target the plant host, and environment separately to improve phytoremediation, potentially overlook microbial functions and properties that are part of the multiscale complexity of the plant-environment wherein biodegradation takes place. In contrast, in situ studies of phytoremediation research at the metaorganism level (host and microbiome together) are lacking. Here, we discuss a competition-driven model, based on recent evidence from the metagenomics level, and hypotheses generated by microbial community ecology, to explain the establishment of a catabolic rhizosphere microbiome in a contaminated soil. There is evidence to ground that if the host provides the right level and mix of resources (exudates) over which the microbes can compete, then a competitive catabolic and plant-growth promoting (PGP) microbiome can be selected for as long as it provides a competitive superiority in the niche. The competition-driven model indicates four strategies to interfere with the microbiome. Specifically, the rhizosphere microbiome community can be shifted using treatments that alter the host, resources, environment, and that take advantage of prioritization in inoculation. Our model and suggestions, considering the metaorganism in its natural context, would allow to gain further knowledge on the plant–microbial functions, and facilitate translation to more effective, and predictable phytotechnologies. PMID:27014254

Hearing in noisy environments: noise invariance and contrast gain control

PubMed Central

Willmore, Ben D B; Cooke, James E; King, Andrew J

2014-01-01

Contrast gain control has recently been identified as a fundamental property of the auditory system. Electrophysiological recordings in ferrets have shown that neurons continuously adjust their gain (their sensitivity to change in sound level) in response to the contrast of sounds that are heard. At the level of the auditory cortex, these gain changes partly compensate for changes in sound contrast. This means that sounds which are structurally similar, but have different contrasts, have similar neuronal representations in the auditory cortex. As a result, the cortical representation is relatively invariant to stimulus contrast and robust to the presence of noise in the stimulus. In the inferior colliculus (an important subcortical auditory structure), gain changes are less reliably compensatory, suggesting that contrast- and noise-invariant representations are constructed gradually as one ascends the auditory pathway. In addition to noise invariance, contrast gain control provides a variety of computational advantages over static neuronal representations; it makes efficient use of neuronal dynamic range, may contribute to redundancy-reducing, sparse codes for sound and allows for simpler decoding of population responses. The circuits underlying auditory contrast gain control are still under investigation. As in the visual system, these circuits may be modulated by factors other than stimulus contrast, forming a potential neural substrate for mediating the effects of attention as well as interactions between the senses. PMID:24907308

Blocking the benefit of group-based HIV-prevention efforts during adolescence: the problem of HIV-related stigma.

PubMed

Barker, David H; Swenson, Rebecca R; Brown, Larry K; Stanton, Bonita F; Vanable, Peter A; Carey, Michael P; Valois, Robert F; Diclemente, Ralph J; Salazar, Laura F; Romer, Daniel

2012-04-01

HIV-related stigma has been shown to impede HIV-antibody testing and safer sexual practices in adults. Less is known about its effects on prevention programs among at-risk youth. This study examined the longitudinal relationships between HIV-stigma and HIV-knowledge following completion of a validated group-based intervention. Data were provided by 1,654 African-American adolescents who participated in a large multi-city prevention trial (Project iMPACCS). Participants were randomly assigned to an empirically-validated skill-based intervention or a general health promotion control group. Both stigma and knowledge were assessed at baseline and post-intervention. Results suggested that adolescents participating in the intervention showed improvements in knowledge and decreases in stigma when compared to controls. Improvements in stigma appeared to be partly driven by improvements in knowledge. Higher baseline stigma was shown to reduce gains in knowledge in both the treatment and control groups. Results suggest that HIV-stigma can interfere with how youth identify with and internalize messages from group-based prevention trials.

Genomics, "Discovery Science," Systems Biology, and Causal Explanation: What Really Works?

PubMed

Davidson, Eric H

2015-01-01

Diverse and non-coherent sets of epistemological principles currently inform research in the general area of functional genomics. Here, from the personal point of view of a scientist with over half a century of immersion in hypothesis driven scientific discovery, I compare and deconstruct the ideological bases of prominent recent alternatives, such as "discovery science," some productions of the ENCODE project, and aspects of large data set systems biology. The outputs of these types of scientific enterprise qualitatively reflect their radical definitions of scientific knowledge, and of its logical requirements. Their properties emerge in high relief when contrasted (as an example) to a recent, system-wide, predictive analysis of a developmental regulatory apparatus that was instead based directly on hypothesis-driven experimental tests of mechanism.

Using Two Different Approaches to Assess Dietary Patterns: Hypothesis-Driven and Data-Driven Analysis.

PubMed

Previdelli, Ágatha Nogueira; de Andrade, Samantha Caesar; Fisberg, Regina Mara; Marchioni, Dirce Maria

2016-09-23

The use of dietary patterns to assess dietary intake has become increasingly common in nutritional epidemiology studies due to the complexity and multidimensionality of the diet. Currently, two main approaches have been widely used to assess dietary patterns: data-driven and hypothesis-driven analysis. Since the methods explore different angles of dietary intake, using both approaches simultaneously might yield complementary and useful information; thus, we aimed to use both approaches to gain knowledge of adolescents' dietary patterns. Food intake from a cross-sectional survey with 295 adolescents was assessed by 24 h dietary recall (24HR). In hypothesis-driven analysis, based on the American National Cancer Institute method, the usual intake of Brazilian Healthy Eating Index Revised components were estimated. In the data-driven approach, the usual intake of foods/food groups was estimated by the Multiple Source Method. In the results, hypothesis-driven analysis showed low scores for Whole grains, Total vegetables, Total fruit and Whole fruits), while, in data-driven analysis, fruits and whole grains were not presented in any pattern. High intakes of sodium, fats and sugars were observed in hypothesis-driven analysis with low total scores for Sodium, Saturated fat and SoFAA (calories from solid fat, alcohol and added sugar) components in agreement, while the data-driven approach showed the intake of several foods/food groups rich in these nutrients, such as butter/margarine, cookies, chocolate powder, whole milk, cheese, processed meat/cold cuts and candies. In this study, using both approaches at the same time provided consistent and complementary information with regard to assessing the overall dietary habits that will be important in order to drive public health programs, and improve their efficiency to monitor and evaluate the dietary patterns of populations.

Helminths and the microbiota: parts of the hygiene hypothesis

PubMed Central

Loke, P’ng; Lim, Yvonne A.L.

2015-01-01

In modern societies, diseases that are driven by dysregulated immune responses are increasing at an alarming pace, such as inflammatory bowel diseases and diabetes. There is an urgent need to understand these epidemiological trends, which are likely to be driven by the changing environment of the last few decades. There are complex interactions between human genetic factors and this changing environment that is leading to the increasing prevalence of metabolic and inflammatory diseases. Alterations to human gut bacterial communities (the microbiota) and lowered prevalence of helminth infections are potential environmental factors contributing to immune dysregulation. Helminths have co-evolved with the gut microbiota and their mammalian hosts. This three-way interaction is beginning to be characterized and the knowledge gained may enable the design of new therapeutic strategies to treat metabolic and inflammatory diseases. However, these complex interactions need to be carefully investigated in the context of host genetic backgrounds in order to identify optimal treatment strategies. The complex nature of these interactions raises the possibility that only with highly personalized treatment, with knowledge of individual genetic and microbiota communities, will therapeutic interventions be successful for a majority of the individuals suffering from these complex diseases of immune dysregulation. PMID:25869420

Helminths and the microbiota: parts of the hygiene hypothesis.

PubMed

Loke, P; Lim, Y A L

2015-06-01

In modern societies, diseases that are driven by dysregulated immune responses are increasing at an alarming pace, such as inflammatory bowel diseases and diabetes. There is an urgent need to understand these epidemiological trends, which are likely to be driven by the changing environment of the last few decades. There are complex interactions between human genetic factors and this changing environment that is leading to the increasing prevalence of metabolic and inflammatory diseases. Alterations to human gut bacterial communities (the microbiota) and lowered prevalence of helminth infections are potential environmental factors contributing to immune dysregulation. Helminths have co-evolved with the gut microbiota and their mammalian hosts. This three-way interaction is beginning to be characterized, and the knowledge gained may enable the design of new therapeutic strategies to treat metabolic and inflammatory diseases. However, these complex interactions need to be carefully investigated in the context of host genetic backgrounds to identify optimal treatment strategies. The complex nature of these interactions raises the possibility that only with highly personalized treatment, with knowledge of individual genetic and microbiota communities, will therapeutic interventions be successful for a majority of the individuals suffering from these complex diseases of immune dysregulation. © 2015 John Wiley & Sons Ltd.

Nonlinear dynamics of cortical responses to color in the human cVEP.

PubMed

Nunez, Valerie; Shapley, Robert M; Gordon, James

2017-09-01

The main finding of this paper is that the human visual cortex responds in a very nonlinear manner to the color contrast of pure color patterns. We examined human cortical responses to color checkerboard patterns at many color contrasts, measuring the chromatic visual evoked potential (cVEP) with a dense electrode array. Cortical topography of the cVEPs showed that they were localized near the posterior electrode at position Oz, indicating that the primary cortex (V1) was the major source of responses. The choice of fine spatial patterns as stimuli caused the cVEP response to be driven by double-opponent neurons in V1. The cVEP waveform revealed nonlinear color signal processing in the V1 cortex. The cVEP time-to-peak decreased and the waveform's shape was markedly narrower with increasing cone contrast. Comparison of the linear dynamics of retinal and lateral geniculate nucleus responses with the nonlinear dynamics of the cortical cVEP indicated that the nonlinear dynamics originated in the V1 cortex. The nature of the nonlinearity is a kind of automatic gain control that adjusts cortical dynamics to be faster when color contrast is greater.

Histology-validated x-ray tomography for imaging human coronary arteries

NASA Astrophysics Data System (ADS)

Buscema, Marzia; Schulz, Georg; Deyhle, Hans; Khimchenko, Anna; Matviykiv, Sofiya; Holme, Margaret N.; Hipp, Alexander; Beckmann, Felix; Saxer, Till; Michaud, Katarzyna; Müller, Bert

2016-10-01

Heart disease is the number one cause of death worldwide. To improve therapy and patient outcome, the knowledge of anatomical changes in terms of lumen morphology and tissue composition of constricted arteries is crucial for designing a localized drug delivery to treat atherosclerosis disease. Traditional tissue characterization by histology is a pivotal tool, although it brings disadvantages such as vessel morphology modification during decalcification and slicing. X-ray tomography in absorption and phase contrast modes yields a deep understanding in blood vessel anatomy in healthy and diseased stages: measurements in absorption mode make visible highly absorbing tissue components including cholesterol plaques, whereas phase contrast tomography gains better contrast of the soft tissue components such as vessel walls. Established synchrotron radiation-based micro-CT techniques ensure high performance in terms of 3D visualization of highly absorbing and soft tissues.

Evolution of cooperation driven by incremental learning

NASA Astrophysics Data System (ADS)

Li, Pei; Duan, Haibin

2015-02-01

It has been shown that the details of microscopic rules in structured populations can have a crucial impact on the ultimate outcome in evolutionary games. So alternative formulations of strategies and their revision processes exploring how strategies are actually adopted and spread within the interaction network need to be studied. In the present work, we formulate the strategy update rule as an incremental learning process, wherein knowledge is refreshed according to one's own experience learned from the past (self-learning) and that gained from social interaction (social-learning). More precisely, we propose a continuous version of strategy update rules, by introducing the willingness to cooperate W, to better capture the flexibility of decision making behavior. Importantly, the newly gained knowledge including self-learning and social learning is weighted by the parameter ω, establishing a strategy update rule involving innovative element. Moreover, we quantify the macroscopic features of the emerging patterns to inspect the underlying mechanisms of the evolutionary process using six cluster characteristics. In order to further support our results, we examine the time evolution course for these characteristics. Our results might provide insights for understanding cooperative behaviors and have several important implications for understanding how individuals adjust their strategies under real-life conditions.

The impact of science education games on prescription drug abuse attitudes among teens: a case study.

PubMed

Klisch, Yvonne; Bowling, Kristi G; Miller, Leslie M; Ramos, Miguel A

2013-01-01

Two online science education games, in which players learn about the risks of prescription drug abuse in the context of investigating crimes, were evaluated to determine shifts of prescription drug abuse attitudes attributable to game exposure. High school students from grades 11 and 12 (n = 179) were assigned to one of the games and participated in a pretest, two game-play sessions, and a delayed posttest. Students in both groups demonstrated more negative attitudes toward prescription drug abuse after playing the game, driven by changes of students' normative beliefs and their ability to make the connection between prescription drug abuse and illicit drugs. A secondary aim was to assess gains in science knowledge; however, due to low internal consistency reliabilities of content measures, students' knowledge acquisition could not be determined.

A Knowledge-based System for Intelligent Support in Pharmacogenomics Evidence Assessment: Ontology-driven Evidence Representation and Retrieval.

PubMed

Lee, Chia-Ju; Devine, Beth; Tarczy-Hornoch, Peter

2017-01-01

Pharmacogenomics holds promise as a critical component of precision medicine. Yet, the use of pharmacogenomics in routine clinical care is minimal, partly due to the lack of efficient and effective use of existing evidence. This paper describes the design, development, implementation and evaluation of a knowledge-based system that fulfills three critical features: a) providing clinically relevant evidence, b) applying an evidence-based approach, and c) using semantically computable formalism, to facilitate efficient evidence assessment to support timely decisions on adoption of pharmacogenomics in clinical care. To illustrate functionality, the system was piloted in the context of clopidogrel and warfarin pharmacogenomics. In contrast to existing pharmacogenomics knowledge bases, the developed system is the first to exploit the expressivity and reasoning power of logic-based representation formalism to enable unambiguous expression and automatic retrieval of pharmacogenomics evidence to support systematic review with meta-analysis.

Materials inspired by mathematics.

PubMed

Kotani, Motoko; Ikeda, Susumu

2016-01-01

Our world is transforming into an interacting system of the physical world and the digital world. What will be the materials science in the new era? With the rising expectations of the rapid development of computers, information science and mathematical science including statistics and probability theory, 'data-driven materials design' has become a common term. There is knowledge and experience gained in the physical world in the form of know-how and recipes for the creation of material. An important key is how we establish vocabulary and grammar to translate them into the language of the digital world. In this article, we outline how materials science develops when it encounters mathematics, showing some emerging directions.

Challenges in teaching modern manufacturing technologies

NASA Astrophysics Data System (ADS)

Ngaile, Gracious; Wang, Jyhwen; Gau, Jenn-Terng

2015-07-01

Teaching of manufacturing courses for undergraduate engineering students has become a challenge due to industrial globalisation coupled with influx of new innovations, technologies, customer-driven products. This paper discusses development of a modern manufacturing course taught concurrently in three institutions where students collaborate in executing various projects. Lectures are developed to contain materials featuring advanced manufacturing technologies, R&D trends in manufacturing. Pre- and post-surveys were conducted by an external evaluator to assess the impact of the course on increase in student's knowledge of manufacturing; increase students' preparedness and confidence in effective communication and; increase students' interest in pursuing additional academic studies and/or a career path in manufacturing and high technology. The surveyed data indicate that the students perceived significant gains in manufacturing knowledge and preparedness in effective communication. The study also shows that implementation of a collaborative course within multiple institutions requires a robust and collective communication platform.

Different Signal Enhancement Pathways of Attention and Consciousness Underlie Perception in Humans.

PubMed

van Boxtel, Jeroen J A

2017-06-14

It is not yet known whether attention and consciousness operate through similar or largely different mechanisms. Visual processing mechanisms are routinely characterized by measuring contrast response functions (CRFs). In this report, behavioral CRFs were obtained in humans (both males and females) by measuring afterimage durations over the entire range of inducer stimulus contrasts to reveal visual mechanisms behind attention and consciousness. Deviations relative to the standard CRF, i.e., gain functions, describe the strength of signal enhancement, which were assessed for both changes due to attentional task and conscious perception. It was found that attention displayed a response-gain function, whereas consciousness displayed a contrast-gain function. Through model comparisons, which only included contrast-gain modulations, both contrast-gain and response-gain effects can be explained with a two-level normalization model, in which consciousness affects only the first level and attention affects only the second level. These results demonstrate that attention and consciousness can effectively show different gain functions because they operate through different signal enhancement mechanisms. SIGNIFICANCE STATEMENT The relationship between attention and consciousness is still debated. Mapping contrast response functions (CRFs) has allowed (neuro)scientists to gain important insights into the mechanistic underpinnings of visual processing. Here, the influence of both attention and consciousness on these functions were measured and they displayed a strong dissociation. First, attention lowered CRFs, whereas consciousness raised them. Second, attention manifests itself as a response-gain function, whereas consciousness manifests itself as a contrast-gain function. Extensive model comparisons show that these results are best explained in a two-level normalization model in which consciousness affects only the first level, whereas attention affects only the second level. These findings show dissociations between both the computational mechanisms behind attention and consciousness and the perceptual consequences that they induce. Copyright © 2017 the authors 0270-6474/17/375912-11$15.00/0.

Fostering Self-Reflection and Meaningful Learning: Earth Science Professional Development for Middle School Science Teachers

NASA Astrophysics Data System (ADS)

Monet, Julie A.; Etkina, Eugenia

2008-10-01

This paper describes the analysis of teachers’ journal reflections during an inquiry-based professional development program. As a part of their learning experience, participants reflected on what they learned and how they learned. Progress of subject matter and pedagogical content knowledge was assessed though surveys and pre- and posttests. We found that teachers have difficulties reflecting on their learning and posing meaningful questions. The teachers who could describe how they reasoned from evidence to understand a concept had the highest learning gains. In contrast those teachers who seldom or never described learning a concept by reasoning from evidence showed the smallest learning gains. This analysis suggests that learning to reflect on one’s learning should be an integral part of teachers’ professional development experiences.

Physiological-based modelling of marine fish early life stages provides process knowledge on climate impacts

NASA Astrophysics Data System (ADS)

Peck, M. A.

2016-02-01

Gaining a cause-and-effect understanding of climate-driven changes in marine fish populations at appropriate spatial scales is important for providing robust advice for ecosystem-based fisheries management. Coupling long-term, retrospective analyses and 3-d biophysical, individual-based models (IBMs) shows great potential to reveal mechanism underlying historical changes and to project future changes in marine fishes. IBMs created for marine fish early life stages integrate organismal-level physiological responses and climate-driven changes in marine habitats (from ocean physics to lower trophic level productivity) to test and reveal processes affecting marine fish recruitment. Case studies are provided for hindcasts and future (A1 and B2 projection) simulations performed on some of the most ecologically- and commercially-important pelagic and demersal fishes in the North Sea including European anchovy, Atlantic herring, European sprat and Atlantic cod. We discuss the utility of coupling biophysical IBMs to size-spectrum models to better project indirect (trophodynamic) pathways of climate influence on the early life stages of these and other fishes. Opportunities and challenges are discussed regarding the ability of these physiological-based tools to capture climate-driven changes in living marine resources and food web dynamics of shelf seas.

Direct fluorescence characterisation of a picosecond seeded optical parametric amplifier

NASA Astrophysics Data System (ADS)

Stuart, N. H.; Bigourd, D.; Hill, R. W.; Robinson, T. S.; Mecseki, K.; Patankar, S.; New, G. H. C.; Smith, R. A.

2015-02-01

The temporal intensity contrast of high-power lasers based on optical parametric amplification (OPA) can be limited by parametric fluorescence from the non-linear gain stages. Here we present a spectroscopic method for direct measurement of unwanted parametric fluorescence widely applicable from unseeded to fully seeded and saturated OPA operation. Our technique employs simultaneous spectroscopy of fluorescence photons slightly outside the seed bandwidth and strongly attenuated light at the seed central wavelength. To demonstrate its applicability we have characterised the performance of a two-stage picosecond OPA pre-amplifier with 2.8×105 gain, delivering 335 μJ pulses at 1054 nm. We show that fluorescence from a strongly seeded OPA is reduced by ~500× from the undepleted to full pump depletion regimes. We also determine the vacuum fluctuation driven noise term seeding this OPA fluorescence to be 0.7±0.4 photons ps-1 nm-1 bandwidth. The resulting shot-to-shot statistics highlights a 1.5% probability of a five-fold and 0.3% probability of a ten-fold increase of fluorescence above the average value. Finally, we show that OPA fluorescence can be limited to a few-ps pedestal with 3×10-9 temporal intensity contrast 1.3 ps ahead of an intense laser pulse, a level highly attractive for large scale chirped-pulse OPA laser systems.

Comparison of the performance of tracer kinetic model-driven registration for dynamic contrast enhanced MRI using different models of contrast enhancement.

PubMed

Buonaccorsi, Giovanni A; Roberts, Caleb; Cheung, Sue; Watson, Yvonne; O'Connor, James P B; Davies, Karen; Jackson, Alan; Jayson, Gordon C; Parker, Geoff J M

2006-09-01

The quantitative analysis of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) data is subject to model fitting errors caused by motion during the time-series data acquisition. However, the time-varying features that occur as a result of contrast enhancement can confound motion correction techniques based on conventional registration similarity measures. We have therefore developed a heuristic, locally controlled tracer kinetic model-driven registration procedure, in which the model accounts for contrast enhancement, and applied it to the registration of abdominal DCE-MRI data at high temporal resolution. Using severely motion-corrupted data sets that had been excluded from analysis in a clinical trial of an antiangiogenic agent, we compared the results obtained when using different models to drive the tracer kinetic model-driven registration with those obtained when using a conventional registration against the time series mean image volume. Using tracer kinetic model-driven registration, it was possible to improve model fitting by reducing the sum of squared errors but the improvement was only realized when using a model that adequately described the features of the time series data. The registration against the time series mean significantly distorted the time series data, as did tracer kinetic model-driven registration using a simpler model of contrast enhancement. When an appropriate model is used, tracer kinetic model-driven registration influences motion-corrupted model fit parameter estimates and provides significant improvements in localization in three-dimensional parameter maps. This has positive implications for the use of quantitative DCE-MRI for example in clinical trials of antiangiogenic or antivascular agents.

Contrast gain control in first- and second-order motion perception.

PubMed

Lu, Z L; Sperling, G

1996-12-01

A novel pedestal-plus-test paradigm is used to determine the nonlinear gain-control properties of the first-order (luminance) and the second-order (texture-contrast) motion systems, that is, how these systems' responses to motion stimuli are reduced by pedestals and other masking stimuli. Motion-direction thresholds were measured for test stimuli consisting of drifting luminance and texture-contrast-modulation stimuli superimposed on pedestals of various amplitudes. (A pedestal is a static sine-wave grating of the same type and same spatial frequency as the moving test grating.) It was found that first-order motion-direction thresholds are unaffected by small pedestals, but at pedestal contrasts above 1-2% (5-10 x pedestal threshold), motion thresholds increase proportionally to pedestal amplitude (a Weber law). For first-order stimuli, pedestal masking is specific to the spatial frequency of the test. On the other hand, motion-direction thresholds for texture-contrast stimuli are independent of pedestal amplitude (no gain control whatever) throughout the accessible pedestal amplitude range (from 0 to 40%). However, when baseline carrier contrast increases (with constant pedestal modulation amplitude), motion thresholds increase, showing that gain control in second-order motion is determined not by the modulator (as in first-order motion) but by the carrier. Note that baseline contrast of the carrier is inherently independent of spatial frequency of the modulator. The drastically different gain-control properties of the two motion systems and prior observations of motion masking and motion saturation are all encompassed in a functional theory. The stimulus inputs to both first- and second-order motion process are normalized by feedforward, shunting gain control. The different properties arise because the modulator is used to control the first-order gain and the carrier is used to control the second-order gain.

Data-Driven Design of Intelligent Wireless Networks: An Overview and Tutorial.

PubMed

Kulin, Merima; Fortuna, Carolina; De Poorter, Eli; Deschrijver, Dirk; Moerman, Ingrid

2016-06-01

Data science or "data-driven research" is a research approach that uses real-life data to gain insight about the behavior of systems. It enables the analysis of small, simple as well as large and more complex systems in order to assess whether they function according to the intended design and as seen in simulation. Data science approaches have been successfully applied to analyze networked interactions in several research areas such as large-scale social networks, advanced business and healthcare processes. Wireless networks can exhibit unpredictable interactions between algorithms from multiple protocol layers, interactions between multiple devices, and hardware specific influences. These interactions can lead to a difference between real-world functioning and design time functioning. Data science methods can help to detect the actual behavior and possibly help to correct it. Data science is increasingly used in wireless research. To support data-driven research in wireless networks, this paper illustrates the step-by-step methodology that has to be applied to extract knowledge from raw data traces. To this end, the paper (i) clarifies when, why and how to use data science in wireless network research; (ii) provides a generic framework for applying data science in wireless networks; (iii) gives an overview of existing research papers that utilized data science approaches in wireless networks; (iv) illustrates the overall knowledge discovery process through an extensive example in which device types are identified based on their traffic patterns; (v) provides the reader the necessary datasets and scripts to go through the tutorial steps themselves.

Data-Driven Design of Intelligent Wireless Networks: An Overview and Tutorial

PubMed Central

Kulin, Merima; Fortuna, Carolina; De Poorter, Eli; Deschrijver, Dirk; Moerman, Ingrid

2016-01-01

Data science or “data-driven research” is a research approach that uses real-life data to gain insight about the behavior of systems. It enables the analysis of small, simple as well as large and more complex systems in order to assess whether they function according to the intended design and as seen in simulation. Data science approaches have been successfully applied to analyze networked interactions in several research areas such as large-scale social networks, advanced business and healthcare processes. Wireless networks can exhibit unpredictable interactions between algorithms from multiple protocol layers, interactions between multiple devices, and hardware specific influences. These interactions can lead to a difference between real-world functioning and design time functioning. Data science methods can help to detect the actual behavior and possibly help to correct it. Data science is increasingly used in wireless research. To support data-driven research in wireless networks, this paper illustrates the step-by-step methodology that has to be applied to extract knowledge from raw data traces. To this end, the paper (i) clarifies when, why and how to use data science in wireless network research; (ii) provides a generic framework for applying data science in wireless networks; (iii) gives an overview of existing research papers that utilized data science approaches in wireless networks; (iv) illustrates the overall knowledge discovery process through an extensive example in which device types are identified based on their traffic patterns; (v) provides the reader the necessary datasets and scripts to go through the tutorial steps themselves. PMID:27258286

Ontology Design Patterns as Interfaces (invited)

NASA Astrophysics Data System (ADS)

Janowicz, K.

2015-12-01

In recent years ontology design patterns (ODP) have gained popularity among knowledge engineers. ODPs are modular but self-contained building blocks that are reusable and extendible. They minimize the amount of ontological commitments and thereby are easier to integrate than large monolithic ontologies. Typically, patterns are not directly used to annotate data or to model certain domain problems but are combined and extended to form data and purpose-driven local ontologies that serve the needs of specific applications or communities. By relying on a common set of patterns these local ontologies can be aligned to improve interoperability and enable federated queries without enforcing a top-down model of the domain. In previous work, we introduced ontological views as layer on top of ontology design patterns to ease the reuse, combination, and integration of patterns. While the literature distinguishes multiple types of patterns, e.g., content patterns or logical patterns, we propose to use them as interfaces here to guide the development of ontology-driven systems.

Solid waste management of small island developing states-the case of the Seychelles: a systemic and collaborative study of Swiss and Seychellois students to support policy.

PubMed

Meylan, Grégoire; Lai, Adelene; Hensley, John; Stauffacher, Michael; Krütli, Pius

2018-05-15

Solid waste management (SWM) is a significant challenge for the Seychelles. Waste generation, fueled by economic development and tourism, increases steadily, while landfilling continues to be the main disposal path, thus exacerbating the island nation's specific weaknesses. Due to the small scale of the Seychelles economy, there is little capital available to stimulate innovations in SWM and generate the knowledge for setting priorities and guiding SWM action. Students from ETH Zurich and UniSey conducted a transdisciplinary case study (tdCS) to fill this knowledge gap and gain insights into the obstacles and opportunities related to sustainable SWM. The tdCS approach allowed students to gain comprehensive and in-depth knowledge about the SWM system required to set priorities for action and next steps. The government should streamline the different financial frameworks according to a clear principle (e.g., polluter pays principle). Specific biogenic waste streams represent a potential source of energy and fertilizers. Expanding the scope and densifying the network of collection points could help raise recycling rates of other waste fractions. Diverting biogenic waste and recycling more glass, metals, paper, and plastics would also significantly reduce landfilling rates. Regardless of future amounts of waste ending up on landfills, the latter must be reengineered before the surrounding environment suffers major adverse impacts. All these actions imply a government-driven approach which integrates the views of stakeholders and consumers alike.

The contribution of online peer-to-peer communication among patients with adrenal disease to patient-centered care.

PubMed

Kauw, Dirkjan; Repping-Wuts, Han; Noordzij, Alida; Stikkelbroeck, Nike; Hermus, Ad; Faber, Marjan

2015-02-25

Addison's disease and Cushing's syndrome are rare. The Dutch Adrenal Society offers an online forum for Dutch adrenal patients to meet and communicate. However, little is known about the added value such a forum has for the delivery of patient-centered care. Our aim was to analyze the purposes of online patient-to-patient forum conversations, within the context of patient-centered care. For this study a consecutive sample of 300 questions ("threads") from the past 3.5 years was selected from the forum. The content of these patient-driven questions was analyzed based on the dimensions of patient-centeredness of the Picker Institute. This analysis was performed using ATLAS.ti. From the 390 questions analyzed, 80.8% (N=315) were intended to gain more information about the disease, the treatment, and to verify if other patients had similar complaints. To a much lesser extent (38/390, 9.7%), questions expressed a call for emotional support. Patients answered primarily by giving practical tips to fellow patients and to share their own experiences. On an online patient forum for Cushing's syndrome and Addison's disease, patients appear to primarily gain knowledge and, to a lesser extent, emotional support from their peers. This experience-based knowledge has become a very important information source. As such, patients can make a substantial contribution to the creation of patient-centered care if this knowledge is integrated into the care provided by health care professionals.

The Fusion Gain Analysis of the Inductively Driven Liner Compression Based Fusion

NASA Astrophysics Data System (ADS)

Shimazu, Akihisa; Slough, John

2016-10-01

An analytical analysis of the fusion gain expected in the inductively driven liner compression (IDLC) based fusion is conducted to identify the fusion gain scaling at various operating conditions. The fusion based on the IDLC is a magneto-inertial fusion concept, where a Field-Reversed Configuration (FRC) plasmoid is compressed via the inductively-driven metal liner to drive the FRC to fusion conditions. In the past, an approximate scaling law for the expected fusion gain for the IDLC based fusion was obtained under the key assumptions of (1) D-T fuel at 5-40 keV, (2) adiabatic scaling laws for the FRC dynamics, (3) FRC energy dominated by the pressure balance with the edge magnetic field at the peak compression, and (4) the liner dwell time being liner final diameter divided by the peak liner velocity. In this study, various assumptions made in the previous derivation is relaxed to study the change in the fusion gain scaling from the previous result of G ml1 / 2 El11 / 8 , where ml is the liner mass and El is the peak liner kinetic energy. The implication from the modified fusion gain scaling on the performance of the IDLC fusion reactor system is also explored.

Fabrication of Indocyanine Green and 2H, 3H-perfluoropentane loaded microbubbles for fluorescence and ultrasound imaging

NASA Astrophysics Data System (ADS)

He, Yutong; Wu, Qiang; Ma, Rong; Chang, Shufang; Shao, Pengfei; Xu, Ronald

2016-03-01

As a near-infrared (NIR) fluorescence dye, Indocyanine Green (ICG) has not gained broader clinical applications, owing to its multiple limitations such as concentration-dependent aggregation, low fluorescence quantum yield, poor physicochemical stability and rapid elimination from the body. In the meanwhile, 2H,3H-perfluoropentane (H-PFP) has been widely studied in ultrasound imaging as a vehicle for targeted delivery of contrast agents and drugs. We synthesized a novel dual-modal fluorescence and ultrasound contrast agent by encapsulating ICG and H-PFP in lipid microbubbles using a liquid-driven coaxial flow focusing (LDCFF) process. Uniform microbubbles with the sizes ranging from 1-10um and great ICG loading efficiency was achieved by this method. Our benchtop experiments showed that ICG/H-PFP microbubbles exhibited less aggregation, increased fluorescence intensity and more stable photostability compared to free ICG aqueous solution. Our phantom experiments demonstrated that ICG/H-PFP microbubbles enhanced the imaging contrasts in fluorescence imaging and ultrasonography. Our animal experiments indicated that ICG/H-PFP microbubbles extended the ICG life time and facilitated dual mode fluorescence and ultrasound imaging in vivo.

Harnessing Big Data for Systems Pharmacology

PubMed Central

Xie, Lei; Draizen, Eli J.; Bourne, Philip E.

2017-01-01

Systems pharmacology aims to holistically understand mechanisms of drug actions to support drug discovery and clinical practice. Systems pharmacology modeling (SPM) is data driven. It integrates an exponentially growing amount of data at multiple scales (genetic, molecular, cellular, organismal, and environmental). The goal of SPM is to develop mechanistic or predictive multiscale models that are interpretable and actionable. The current explosions in genomics and other omics data, as well as the tremendous advances in big data technologies, have already enabled biologists to generate novel hypotheses and gain new knowledge through computational models of genome-wide, heterogeneous, and dynamic data sets. More work is needed to interpret and predict a drug response phenotype, which is dependent on many known and unknown factors. To gain a comprehensive understanding of drug actions, SPM requires close collaborations between domain experts from diverse fields and integration of heterogeneous models from biophysics, mathematics, statistics, machine learning, and semantic webs. This creates challenges in model management, model integration, model translation, and knowledge integration. In this review, we discuss several emergent issues in SPM and potential solutions using big data technology and analytics. The concurrent development of high-throughput techniques, cloud computing, data science, and the semantic web will likely allow SPM to be findable, accessible, interoperable, reusable, reliable, interpretable, and actionable. PMID:27814027

Harnessing Big Data for Systems Pharmacology.

PubMed

Xie, Lei; Draizen, Eli J; Bourne, Philip E

2017-01-06

Systems pharmacology aims to holistically understand mechanisms of drug actions to support drug discovery and clinical practice. Systems pharmacology modeling (SPM) is data driven. It integrates an exponentially growing amount of data at multiple scales (genetic, molecular, cellular, organismal, and environmental). The goal of SPM is to develop mechanistic or predictive multiscale models that are interpretable and actionable. The current explosions in genomics and other omics data, as well as the tremendous advances in big data technologies, have already enabled biologists to generate novel hypotheses and gain new knowledge through computational models of genome-wide, heterogeneous, and dynamic data sets. More work is needed to interpret and predict a drug response phenotype, which is dependent on many known and unknown factors. To gain a comprehensive understanding of drug actions, SPM requires close collaborations between domain experts from diverse fields and integration of heterogeneous models from biophysics, mathematics, statistics, machine learning, and semantic webs. This creates challenges in model management, model integration, model translation, and knowledge integration. In this review, we discuss several emergent issues in SPM and potential solutions using big data technology and analytics. The concurrent development of high-throughput techniques, cloud computing, data science, and the semantic web will likely allow SPM to be findable, accessible, interoperable, reusable, reliable, interpretable, and actionable.

Results of Formal Evaluation of a Data and Modeling Driven Hydrology Learning Module

NASA Astrophysics Data System (ADS)

Ruddell, B. L.; Sanchez, C. A.; Schiesser, R.; Merwade, V.

2014-12-01

New hydrologists should not only develop a well-defined knowledgebase of basic hydrological concepts, but also synthesize this factual learning with more authentic 'real-world' knowledge gained from the interpretation and analysis of data from hydrological models (Merwade and Ruddell, 2012, Wagener et al., 2007). However, hydrological instruction is often implemented using a traditional teacher-centered approach (e.g., lectures) (Wagener, 2007). The emergence of rich and dynamic computer simulation techniques which allow students the opportunity for more authentic application of knowledge (Merwade & Ruddell, 2012). This study evaluates the efficacy of using such data-driven simulations to increase the understanding of the field of hydrology in the lower-division undergraduate geoscience classroom. In this study, 88 students at a local community college who were enrolled in an Introductory Earth Science class were evaluated on their learning performance in a unit on applying the Rational Method to estimate hydrographs and flooding for urban areas. Students were either presented with a data and visualization rich computer module (n=52), or with paper and pencil calculation activities (n=36). All conceptual material presented in lecture was consistent across these two conditions. Students were evaluated for not only changes in their knowledge and application of the concepts within the unit (e.g., effects of urbanization and impervious cover, discharge rates), but also for their broad "T-shaped" profile of professional knowledge and skills. While results showed significant (p<.05) increases from pre to post assessments in all learning areas for both groups, there is a significantly larger benefit for the data module group when it came to (1) understanding the effects of urbanization and impervious cover on flooding, (2) applying consistent vocabulary appropriately within context, and (3) explaining the roles and responsibilities of hydrologists and flood managers.

Input-driven versus turnover-driven controls of simulated changes in soil carbon due to land-use change

NASA Astrophysics Data System (ADS)

Nyawira, S. S.; Nabel, J. E. M. S.; Brovkin, V.; Pongratz, J.

2017-08-01

Historical changes in soil carbon associated with land-use change (LUC) result mainly from the changes in the quantity of litter inputs to the soil and the turnover of carbon in soils. We use a factor separation technique to assess how the input-driven and turnover-driven controls, as well as their synergies, have contributed to historical changes in soil carbon associated with LUC. We apply this approach to equilibrium simulations of present-day and pre-industrial land use performed using the dynamic global vegetation model JSBACH. Our results show that both the input-driven and turnover-driven changes generally contribute to a gain in soil carbon in afforested regions and a loss in deforested regions. However, in regions where grasslands have been converted to croplands, we find an input-driven loss that is partly offset by a turnover-driven gain, which stems from a decrease in the fire-related carbon losses. Omitting land management through crop and wood harvest substantially reduces the global losses through the input-driven changes. Our study thus suggests that the dominating control of soil carbon losses is via the input-driven changes, which are more directly accessible to human management than the turnover-driven ones.

Application of Bounded Linear Stability Analysis Method for Metrics-Driven Adaptive Control

NASA Technical Reports Server (NTRS)

Bakhtiari-Nejad, Maryam; Nguyen, Nhan T.; Krishnakumar, Kalmanje

2009-01-01

This paper presents the application of Bounded Linear Stability Analysis (BLSA) method for metrics-driven adaptive control. The bounded linear stability analysis method is used for analyzing stability of adaptive control models, without linearizing the adaptive laws. Metrics-driven adaptive control introduces a notion that adaptation should be driven by some stability metrics to achieve robustness. By the application of bounded linear stability analysis method the adaptive gain is adjusted during the adaptation in order to meet certain phase margin requirements. Analysis of metrics-driven adaptive control is evaluated for a second order system that represents a pitch attitude control of a generic transport aircraft. The analysis shows that the system with the metrics-conforming variable adaptive gain becomes more robust to unmodeled dynamics or time delay. The effect of analysis time-window for BLSA is also evaluated in order to meet the stability margin criteria.

Materials inspired by mathematics

PubMed Central

Kotani, Motoko; Ikeda, Susumu

2016-01-01

Abstract Our world is transforming into an interacting system of the physical world and the digital world. What will be the materials science in the new era? With the rising expectations of the rapid development of computers, information science and mathematical science including statistics and probability theory, ‘data-driven materials design’ has become a common term. There is knowledge and experience gained in the physical world in the form of know-how and recipes for the creation of material. An important key is how we establish vocabulary and grammar to translate them into the language of the digital world. In this article, we outline how materials science develops when it encounters mathematics, showing some emerging directions. PMID:27877877

An integrative view of microbiome-host interactions in inflammatory bowel diseases

PubMed Central

Wlodarska, Marta; Kostic, Aleksandar D.; Xavier, Ramnik J.

2015-01-01

Summary The intestinal microbiota, which is composed of bacteria, viruses, and micro-eukaryotes, acts as an accessory organ system with distinct functions along the intestinal tract that are critical for health. This review focuses on how the microbiota drives intestinal disease through alterations in microbial community architecture, disruption of the mucosal barrier, modulation of innate and adaptive immunity, and dysfunction of the enteric nervous system. Inflammatory bowel disease is used as a model system to understand these microbial-driven pathologies, but the knowledge gained in this space is extended to less well studied intestinal diseases that may also have an important microbial component, including environmental enteropathy and chronic colitis-associated colorectal cancer. PMID:25974300

Recent advances in research on Crimean-Congo hemorrhagic fever

PubMed Central

Papa, Anna; Mirazimi, Ali; Köksal, Iftihar; Estrada-Pena, Augustin; Feldmann, Heinz

2014-01-01

Crimean-Congo hemorrhagic fever (CCHF) is an expanding tick-borne hemorrhagic disease with increasing human and animal health impact. Immense knowledge was gained over the past 10 years mainly due to advances in molecular biology, but also driven by an increased global interest in CCHFV as an emerging/re-emerging zoonotic pathogen. In the present article we discuss the advances in research with focus on CCHF ecology, epidemiology, pathogenesis, diagnostics, prophylaxis and treatment. Despite tremendous achievements, future activities have to concentrate on the development of vaccines and antivirals/therapeutics to combat CCHF. Vector studies need to continue for better public and animal health preparedness and response. We conclude with a roadmap for future research priorities. PMID:25453328

A Data-Driven Solution for Performance Improvement

NASA Technical Reports Server (NTRS)

2002-01-01

Marketed as the "Software of the Future," Optimal Engineering Systems P.I. EXPERT(TM) technology offers statistical process control and optimization techniques that are critical to businesses looking to restructure or accelerate operations in order to gain a competitive edge. Kennedy Space Center granted Optimal Engineering Systems the funding and aid necessary to develop a prototype of the process monitoring and improvement software. Completion of this prototype demonstrated that it was possible to integrate traditional statistical quality assurance tools with robust optimization techniques in a user- friendly format that is visually compelling. Using an expert system knowledge base, the software allows the user to determine objectives, capture constraints and out-of-control processes, predict results, and compute optimal process settings.

Visual Evoked Cortical Potential (VECP) Elicited by Sinusoidal Gratings Controlled by Pseudo-Random Stimulation

PubMed Central

Araújo, Carolina S.; Souza, Givago S.; Gomes, Bruno D.; Silveira, Luiz Carlos L.

2013-01-01

The contributions of contrast detection mechanisms to the visual cortical evoked potential (VECP) have been investigated studying the contrast-response and spatial frequency-response functions. Previously, the use of m-sequences for stimulus control has been almost restricted to multifocal electrophysiology stimulation and, in some aspects, it substantially differs from conventional VECPs. Single stimulation with spatial contrast temporally controlled by m-sequences has not been extensively tested or compared to multifocal techniques. Our purpose was to evaluate the influence of spatial frequency and contrast of sinusoidal gratings on the VECP elicited by pseudo-random stimulation. Nine normal subjects were stimulated by achromatic sinusoidal gratings driven by pseudo random binary m-sequence at seven spatial frequencies (0.4–10 cpd) and three stimulus sizes (4°, 8°, and 16° of visual angle). At 8° subtence, six contrast levels were used (3.12–99%). The first order kernel (K1) did not provide a consistent measurable signal across spatial frequencies and contrasts that were tested–signal was very small or absent–while the second order kernel first (K2.1) and second (K2.2) slices exhibited reliable responses for the stimulus range. The main differences between results obtained with the K2.1 and K2.2 were in the contrast gain as measured in the amplitude versus contrast and amplitude versus spatial frequency functions. The results indicated that K2.1 was dominated by M-pathway, but for some stimulus condition some P-pathway contribution could be found, while the second slice reflected the P-pathway contribution. The present work extended previous findings of the visual pathways contribution to VECP elicited by pseudorandom stimulation for a wider range of spatial frequencies. PMID:23940546

Dependence of the evolution of carbon dynamics in the northern permafrost region on the trajectory of climate change

PubMed Central

Lawrence, David M.; Koven, Charles; Clein, Joy S.; Burke, Eleanor; Chen, Guangsheng; Jafarov, Elchin; MacDougall, Andrew H.; Marchenko, Sergey; Nicolsky, Dmitry; Peng, Shushi; Rinke, Annette; Ciais, Philippe; Gouttevin, Isabelle; Krinner, Gerhard; Moore, John C.; Romanovsky, Vladimir; Schädel, Christina; Schaefer, Kevin; Zhuang, Qianlai

2018-01-01

We conducted a model-based assessment of changes in permafrost area and carbon storage for simulations driven by RCP4.5 and RCP8.5 projections between 2010 and 2299 for the northern permafrost region. All models simulating carbon represented soil with depth, a critical structural feature needed to represent the permafrost carbon–climate feedback, but that is not a universal feature of all climate models. Between 2010 and 2299, simulations indicated losses of permafrost between 3 and 5 million km2 for the RCP4.5 climate and between 6 and 16 million km2 for the RCP8.5 climate. For the RCP4.5 projection, cumulative change in soil carbon varied between 66-Pg C (1015-g carbon) loss to 70-Pg C gain. For the RCP8.5 projection, losses in soil carbon varied between 74 and 652 Pg C (mean loss, 341 Pg C). For the RCP4.5 projection, gains in vegetation carbon were largely responsible for the overall projected net gains in ecosystem carbon by 2299 (8- to 244-Pg C gains). In contrast, for the RCP8.5 projection, gains in vegetation carbon were not great enough to compensate for the losses of carbon projected by four of the five models; changes in ecosystem carbon ranged from a 641-Pg C loss to a 167-Pg C gain (mean, 208-Pg C loss). The models indicate that substantial net losses of ecosystem carbon would not occur until after 2100. This assessment suggests that effective mitigation efforts during the remainder of this century could attenuate the negative consequences of the permafrost carbon–climate feedback. PMID:29581283

Dependence of the evolution of carbon dynamics in the northern permafrost region on the trajectory of climate change

DOE PAGES

McGuire, A. David; Lawrence, David M.; Koven, Charles; ...

2018-03-26

We conducted a model-based assessment of changes in permafrost area and carbon storage for simulations driven by RCP4.5 and RCP8.5 projections between 2010 and 2299 for the northern permafrost region. All models simulating carbon represented soil with depth, a critical structural feature needed to represent the permafrost carbon–climate feedback, but that is not a universal feature of all climate models. Between 2010 and 2299, simulations indicated losses of permafrost between 3 and 5 million km2 for the RCP4.5 climate and between 6 and 16 million km 2 for the RCP8.5 climate. For the RCP4.5 projection, cumulative change in soil carbonmore » varied between 66-Pg C (10 15-g carbon) loss to 70-Pg C gain. For the RCP8.5 projection, losses in soil carbon varied between 74 and 652 Pg C (mean loss, 341 Pg C). For the RCP4.5 projection, gains in vegetation carbon were largely responsible for the overall projected net gains in ecosystem carbon by 2299 (8- to 244-Pg C gains). In contrast, for the RCP8.5 projection, gains in vegetation carbon were not great enough to compensate for the losses of carbon projected by four of the five models; changes in ecosystem carbon ranged from a 641-Pg C loss to a 167-Pg C gain (mean, 208-Pg C loss). The models indicate that substantial net losses of ecosystem carbon would not occur until after 2100. In conclusion, this assessment suggests that effective mitigation efforts during the remainder of this century could attenuate the negative consequences of the permafrost carbon–climate feedback.« less

Dependence of the evolution of carbon dynamics in the northern permafrost region on the trajectory of climate change

USGS Publications Warehouse

McGuire, A. David; Lawrence, David M.; Koven, Charles; Clein, Joy S.; Burke, Eleanor J.; Chen, Guangsheng; Jafarov, Elchin; MacDougall, Andrew H.; Marchenko, Sergey S.; Nicolsky, Dmitry J.; Peng, Shushi; Rinke, Annette; Ciais, Philippe; Gouttevin, Isabelle; Hayes, Daniel J.; Ji, Duoying; Krinner, Gerhard; Moore, John C.; Romanovsky, Vladimir; Schadel, Christina; Schaefer, Kevin; Schuur, Edward A.G.; Zhuang, Qianlai

2018-01-01

We conducted a model-based assessment of changes in permafrost area and carbon storage for simulations driven by RCP4.5 and RCP8.5 projections between 2010 and 2299 for the northern permafrost region. All models simulating carbon represented soil with depth, a critical structural feature needed to represent the permafrost carbon–climate feedback, but that is not a universal feature of all climate models. Between 2010 and 2299, simulations indicated losses of permafrost between 3 and 5 million km2 for the RCP4.5 climate and between 6 and 16 million km2 for the RCP8.5 climate. For the RCP4.5 projection, cumulative change in soil carbon varied between 66-Pg C (1015-g carbon) loss to 70-Pg C gain. For the RCP8.5 projection, losses in soil carbon varied between 74 and 652 Pg C (mean loss, 341 Pg C). For the RCP4.5 projection, gains in vegetation carbon were largely responsible for the overall projected net gains in ecosystem carbon by 2299 (8- to 244-Pg C gains). In contrast, for the RCP8.5 projection, gains in vegetation carbon were not great enough to compensate for the losses of carbon projected by four of the five models; changes in ecosystem carbon ranged from a 641-Pg C loss to a 167-Pg C gain (mean, 208-Pg C loss). The models indicate that substantial net losses of ecosystem carbon would not occur until after 2100. This assessment suggests that effective mitigation efforts during the remainder of this century could attenuate the negative consequences of the permafrost carbon–climate feedback.

Dependence of the evolution of carbon dynamics in the northern permafrost region on the trajectory of climate change.

PubMed

McGuire, A David; Lawrence, David M; Koven, Charles; Clein, Joy S; Burke, Eleanor; Chen, Guangsheng; Jafarov, Elchin; MacDougall, Andrew H; Marchenko, Sergey; Nicolsky, Dmitry; Peng, Shushi; Rinke, Annette; Ciais, Philippe; Gouttevin, Isabelle; Hayes, Daniel J; Ji, Duoying; Krinner, Gerhard; Moore, John C; Romanovsky, Vladimir; Schädel, Christina; Schaefer, Kevin; Schuur, Edward A G; Zhuang, Qianlai

2018-04-10

We conducted a model-based assessment of changes in permafrost area and carbon storage for simulations driven by RCP4.5 and RCP8.5 projections between 2010 and 2299 for the northern permafrost region. All models simulating carbon represented soil with depth, a critical structural feature needed to represent the permafrost carbon-climate feedback, but that is not a universal feature of all climate models. Between 2010 and 2299, simulations indicated losses of permafrost between 3 and 5 million km 2 for the RCP4.5 climate and between 6 and 16 million km 2 for the RCP8.5 climate. For the RCP4.5 projection, cumulative change in soil carbon varied between 66-Pg C (10 15 -g carbon) loss to 70-Pg C gain. For the RCP8.5 projection, losses in soil carbon varied between 74 and 652 Pg C (mean loss, 341 Pg C). For the RCP4.5 projection, gains in vegetation carbon were largely responsible for the overall projected net gains in ecosystem carbon by 2299 (8- to 244-Pg C gains). In contrast, for the RCP8.5 projection, gains in vegetation carbon were not great enough to compensate for the losses of carbon projected by four of the five models; changes in ecosystem carbon ranged from a 641-Pg C loss to a 167-Pg C gain (mean, 208-Pg C loss). The models indicate that substantial net losses of ecosystem carbon would not occur until after 2100. This assessment suggests that effective mitigation efforts during the remainder of this century could attenuate the negative consequences of the permafrost carbon-climate feedback. Copyright © 2018 the Author(s). Published by PNAS.

Dependence of the evolution of carbon dynamics in the northern permafrost region on the trajectory of climate change

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

McGuire, A. David; Lawrence, David M.; Koven, Charles

We conducted a model-based assessment of changes in permafrost area and carbon storage for simulations driven by RCP4.5 and RCP8.5 projections between 2010 and 2299 for the northern permafrost region. All models simulating carbon represented soil with depth, a critical structural feature needed to represent the permafrost carbon–climate feedback, but that is not a universal feature of all climate models. Between 2010 and 2299, simulations indicated losses of permafrost between 3 and 5 million km2 for the RCP4.5 climate and between 6 and 16 million km 2 for the RCP8.5 climate. For the RCP4.5 projection, cumulative change in soil carbonmore » varied between 66-Pg C (10 15-g carbon) loss to 70-Pg C gain. For the RCP8.5 projection, losses in soil carbon varied between 74 and 652 Pg C (mean loss, 341 Pg C). For the RCP4.5 projection, gains in vegetation carbon were largely responsible for the overall projected net gains in ecosystem carbon by 2299 (8- to 244-Pg C gains). In contrast, for the RCP8.5 projection, gains in vegetation carbon were not great enough to compensate for the losses of carbon projected by four of the five models; changes in ecosystem carbon ranged from a 641-Pg C loss to a 167-Pg C gain (mean, 208-Pg C loss). The models indicate that substantial net losses of ecosystem carbon would not occur until after 2100. In conclusion, this assessment suggests that effective mitigation efforts during the remainder of this century could attenuate the negative consequences of the permafrost carbon–climate feedback.« less

The influence of stimulus format on drawing—a functional imaging study of decision making in portrait drawing

PubMed Central

Miall, R.C.; Nam, Se-Ho; Tchalenko, J.

2014-01-01

To copy a natural visual image as a line drawing, visual identification and extraction of features in the image must be guided by top-down decisions, and is usually influenced by prior knowledge. In parallel with other behavioral studies testing the relationship between eye and hand movements when drawing, we report here a functional brain imaging study in which we compared drawing of faces and abstract objects: the former can be strongly guided by prior knowledge, the latter less so. To manipulate the difficulty in extracting features to be drawn, each original image was presented in four formats including high contrast line drawings and silhouettes, and as high and low contrast photographic images. We confirmed the detailed eye–hand interaction measures reported in our other behavioral studies by using in-scanner eye-tracking and recording of pen movements with a touch screen. We also show that the brain activation pattern reflects the changes in presentation formats. In particular, by identifying the ventral and lateral occipital areas that were more highly activated during drawing of faces than abstract objects, we found a systematic increase in differential activation for the face-drawing condition, as the presentation format made the decisions more challenging. This study therefore supports theoretical models of how prior knowledge may influence perception in untrained participants, and lead to experience-driven perceptual modulation by trained artists. PMID:25128710

Evaluation in the Design of Complex Systems

ERIC Educational Resources Information Center

Ho, Li-An; Schwen, Thomas M.

2006-01-01

We identify literature that argues the process of creating knowledge-based system is often imbalanced. In most knowledge-based systems, development is often technology-driven instead of requirement-driven. Therefore, we argue designers must recognize that evaluation is a critical link in the application of requirement-driven development models…

Temporal dynamics of contrast gain in single cells of the cat striate cortex.

PubMed

Bonds, A B

1991-03-01

The response amplitude of cat striate cortical cells is usually reduced after exposure to high-contrast stimuli. The temporal characteristics and contrast sensitivity of this phenomenon were explored by stimulating cortical cells with drifting gratings in which contrast sequentially incremented and decremented in stepwise fashion over time. All responses showed a clear hysteresis, in which contrast gain dropped on average 0.36 log unit and then returned to baseline values within 60 s. Noticeable gain adjustments were seen in as little as 3 s and with peak contrasts as low as 3%. Contrast adaptation was absent in responses from LGN cells. Adaptation was found to depend on temporal frequency of stimulation, with greater and more rapid adaptation at higher temporal frequencies. Two different tests showed that the mechanism controlling response reduction was influenced primarily by stimulus contrast rather than response amplitude. These results support the existence of a rapid and sensitive cortically based system that normalizes the output of cortical cells as a function of local mean contrast. Control of the adaptation appears to arise at least in part across a population of cells, which is consistent with the idea that the gain control serves to limit the information converging from many cells onto subsequent processing areas.

Ultra-high gain diffusion-driven organic transistor.

PubMed

Torricelli, Fabrizio; Colalongo, Luigi; Raiteri, Daniele; Kovács-Vajna, Zsolt Miklós; Cantatore, Eugenio

2016-02-01

Emerging large-area technologies based on organic transistors are enabling the fabrication of low-cost flexible circuits, smart sensors and biomedical devices. High-gain transistors are essential for the development of large-scale circuit integration, high-sensitivity sensors and signal amplification in sensing systems. Unfortunately, organic field-effect transistors show limited gain, usually of the order of tens, because of the large contact resistance and channel-length modulation. Here we show a new organic field-effect transistor architecture with a gain larger than 700. This is the highest gain ever reported for organic field-effect transistors. In the proposed organic field-effect transistor, the charge injection and extraction at the metal-semiconductor contacts are driven by the charge diffusion. The ideal conditions of ohmic contacts with negligible contact resistance and flat current saturation are demonstrated. The approach is general and can be extended to any thin-film technology opening unprecedented opportunities for the development of high-performance flexible electronics.

Ultra-high gain diffusion-driven organic transistor

NASA Astrophysics Data System (ADS)

Torricelli, Fabrizio; Colalongo, Luigi; Raiteri, Daniele; Kovács-Vajna, Zsolt Miklós; Cantatore, Eugenio

2016-02-01

Emerging large-area technologies based on organic transistors are enabling the fabrication of low-cost flexible circuits, smart sensors and biomedical devices. High-gain transistors are essential for the development of large-scale circuit integration, high-sensitivity sensors and signal amplification in sensing systems. Unfortunately, organic field-effect transistors show limited gain, usually of the order of tens, because of the large contact resistance and channel-length modulation. Here we show a new organic field-effect transistor architecture with a gain larger than 700. This is the highest gain ever reported for organic field-effect transistors. In the proposed organic field-effect transistor, the charge injection and extraction at the metal-semiconductor contacts are driven by the charge diffusion. The ideal conditions of ohmic contacts with negligible contact resistance and flat current saturation are demonstrated. The approach is general and can be extended to any thin-film technology opening unprecedented opportunities for the development of high-performance flexible electronics.

Gigawatt peak power generation in a relativistic klystron amplifier driven by 1 kW seed-power

NASA Astrophysics Data System (ADS)

Wu, Y.; Xie, H. Q.; Li, Z. H.; Zhang, Y. J.; Ma, Q. S.

2013-11-01

An S-band high gain relativistic klystron amplifier driven by kW-level RF power is proposed and studied experimentally. In the device, the RF lossy material is introduced to suppress higher mode excitation. An output power of 1.95 GW with a gain of 62.8 dB is obtained in the simulation. Under conditions of an input RF power of 1.38 kW, a microwave pulse with power of 1.9 GW, frequency of 2.86 GHz, and duration of 105 ns is generated in the experiment, and the corresponding gain is 61.4 dB.

Highly anisotropic mobility in solution processed TIPS-pentacene film studied by independently driven four GaIn probes

NASA Astrophysics Data System (ADS)

Yoshimoto, Shinya; Takahashi, Kohtaro; Suzuki, Mitsuharu; Yamada, Hiroko; Miyahara, Ryosuke; Mukai, Kozo; Yoshinobu, Jun

2017-08-01

We have studied in-plane anisotropy in the field-effect mobility of solution-processed organic semiconductor 6,13-bis(triisopropylsilylethynyl)pentacene by using independently driven four gallium indium (Ga-In) probes. Liquid-metal Ga-In probes are highly effective for reproducible conductivity measurements of organic thin films. We demonstrated that a high mobility anisotropy of 44 was obtained by using a square four-probe method and a feedback circuit to keep the channel potential constant. The present method minimized the influences of the contact resistance and the insensitivity of anisotropy in a linear arrangement in two-dimensional field-effect transistors.

Audiologist-driven versus patient-driven fine tuning of hearing instruments.

PubMed

Boymans, Monique; Dreschler, Wouter A

2012-03-01

Two methods of fine tuning the initial settings of hearing aids were compared: An audiologist-driven approach--using real ear measurements and a patient-driven fine-tuning approach--using feedback from real-life situations. The patient-driven fine tuning was conducted by employing the Amplifit(®) II system using audiovideo clips. The audiologist-driven fine tuning was based on the NAL-NL1 prescription rule. Both settings were compared using the same hearing aids in two 6-week trial periods following a randomized blinded cross-over design. After each trial period, the settings were evaluated by insertion-gain measurements. Performance was evaluated by speech tests in quiet, in noise, and in time-reversed speech, presented at 0° and with spatially separated sound sources. Subjective results were evaluated using extensive questionnaires and audiovisual video clips. A total of 73 participants were included. On average, higher gain values were found for the audiologist-driven settings than for the patient-driven settings, especially at 1000 and 2000 Hz. Better objective performance was obtained for the audiologist-driven settings for speech perception in quiet and in time-reversed speech. This was supported by better scores on a number of subjective judgments and in the subjective ratings of video clips. The perception of loud sounds scored higher than when patient-driven, but the overall preference was in favor of the audiologist-driven settings for 67% of the participants.

Can role-play with interactive simulations enhance climate change knowledge, affect and intent to act?

NASA Astrophysics Data System (ADS)

Rooney-varga, J. N.; Sterman, J.; Fracassi, E. P.; Franck, T.; Kapmeier, F.; Kurker, V.; Jones, A.; Rath, K.

2017-12-01

The strong scientific consensus about the reality and risks of anthropogenic climate change stands in stark contrast to widespread confusion and complacency among the public. Many efforts to close that gap, grounded in the information deficit model of risk communication, provide scientific information on climate change through reports and presentations. However, research shows that showing people research does not work: the gap between scientific and public understanding of climate change remains wide. Tools that are rigorously grounded in the science and motivate action on climate change are urgently needed. Here we assess the impact of one such tool, an interactive, role-play simulation, World Climate. Participants take the roles of delegates to the UN climate negotiations and are challenged to create an agreement limiting warming to no more than 2°C. The C-ROADS climate simulation model then provides participants with immediate feedback about the expected impacts of their decisions. Participants use C-ROADS to explore the climate system and use the results to refine their negotiating positions, learning about climate change while experiencing the social dynamics of negotiations and decision-making. Pre- and post-survey results from 21 sessions in eight nations showed significant gains in participants' climate change knowledge, affective engagement, intent to take action, and desire to learn. Contrary to the deficit model, gains in participants' desire to learn more and intention to act were associated with gains in affective engagement, particularly feelings of urgency and hope, but not climate knowledge. Gains were just as strong among participants who oppose government regulation, suggesting the simulation's potential to reach across political divides. Results indicate that simulations like World Climate offer a climate change communication tool that enables people to learn and feel for themselves, which together have the potential to motivate action informed by science.

Modeling lateral geniculate nucleus response with contrast gain control. Part 2: Analysis

PubMed Central

Cope, Davis; Blakeslee, Barbara; McCourt, Mark E.

2014-01-01

Cope, Blakeslee and McCourt (2013) proposed a class of models for LGN ON-cell behavior consisting of a linear response with divisive normalization by local stimulus contrast. Here we analyze a specific model with the linear response defined by a difference-of-Gaussians filter and a circular Gaussian for the gain pool weighting function. For sinusoidal grating stimuli, the parameter region for band-pass behavior of the linear response is determined, the gain control response is shown to act as a switch (changing from “off” to “on” with increasing spatial frequency), and it is shown that large gain pools stabilize the optimal spatial frequency of the total nonlinear response at a fixed value independent of contrast and stimulus magnitude. Under- and super-saturation as well as contrast saturation occur as typical effects of stimulus magnitude. For circular spot stimuli, it is shown that large gain pools stabilize the spot size that yields the maximum response. PMID:24562034

Deficient Binocular Combination Reveals Mechanisms of Anisometropic Amblyopia: Signal Attenuation and Interocular Inhibition

PubMed Central

Huang, Chang-Bing; Zhou, Jiawei; Lu, Zhong-Lin; Zhou, Yifeng

2012-01-01

Amblyopia is a developmental disorder that results in deficits of monocular and binocular vision. It's presently unclear whether these deficits result from attenuation of signals in the amblyopic eye, inhibition by signals in the fellow eye, or both. In this study, we characterize the mechanisms underlying anisometropic amblyopia using a binocular phase and contrast combination paradigm and a contrast-gain control model. Subjects dichoptically viewed two slightly different images and reported the perceived contrast and phase of the resulting cyclopean percept. We found that the properties of binocular combination were abnormal in many aspects, which is explained by a combination of (1) attenuated monocular signal in the amblyopic eye, (2) stronger interocular contrast-gain control from the fellow eye to the signal in amblyopic eye (direct interocular inhibition), and (3) stronger interocular contrast-gain control from the fellow eye to the contrast gain control signal from the amblyopic eye (indirect interocular inhibition). We conclude that anisometropic amblyopia led to both monocular and interocular deficits. A complete understanding of the mechanisms underlying amblyopia requires studies of both monocular deficits and binocular interactions. PMID:21546609

Combining Knowledge and Data Driven Insights for Identifying Risk Factors using Electronic Health Records

PubMed Central

Sun, Jimeng; Hu, Jianying; Luo, Dijun; Markatou, Marianthi; Wang, Fei; Edabollahi, Shahram; Steinhubl, Steven E.; Daar, Zahra; Stewart, Walter F.

2012-01-01

Background: The ability to identify the risk factors related to an adverse condition, e.g., heart failures (HF) diagnosis, is very important for improving care quality and reducing cost. Existing approaches for risk factor identification are either knowledge driven (from guidelines or literatures) or data driven (from observational data). No existing method provides a model to effectively combine expert knowledge with data driven insight for risk factor identification. Methods: We present a systematic approach to enhance known knowledge-based risk factors with additional potential risk factors derived from data. The core of our approach is a sparse regression model with regularization terms that correspond to both knowledge and data driven risk factors. Results: The approach is validated using a large dataset containing 4,644 heart failure cases and 45,981 controls. The outpatient electronic health records (EHRs) for these patients include diagnosis, medication, lab results from 2003–2010. We demonstrate that the proposed method can identify complementary risk factors that are not in the existing known factors and can better predict the onset of HF. We quantitatively compare different sets of risk factors in the context of predicting onset of HF using the performance metric, the Area Under the ROC Curve (AUC). The combined risk factors between knowledge and data significantly outperform knowledge-based risk factors alone. Furthermore, those additional risk factors are confirmed to be clinically meaningful by a cardiologist. Conclusion: We present a systematic framework for combining knowledge and data driven insights for risk factor identification. We demonstrate the power of this framework in the context of predicting onset of HF, where our approach can successfully identify intuitive and predictive risk factors beyond a set of known HF risk factors. PMID:23304365

Studying biodiversity: is a new paradigm really needed?

USGS Publications Warehouse

Nichols, James D.; Cooch, Evan G.; Nichols, Jonathan M.; Sauer, John R.

2012-01-01

Authors in this journal have recommended a new approach to the conduct of biodiversity science. This data-driven approach requires the organization of large amounts of ecological data, analysis of these data to discover complex patterns, and subsequent development of hypotheses corresponding to detected patterns. This proposed new approach has been contrasted with more-traditional knowledge-based approaches in which investigators deduce consequences of competing hypotheses to be confronted with actual data, providing a basis for discriminating among the hypotheses. We note that one approach is directed at hypothesis generation, whereas the other is also focused on discriminating among competing hypotheses. Here, we argue for the importance of using existing knowledge to the separate issues of (a) hypothesis selection and generation and (b) hypothesis discrimination and testing. In times of limited conservation funding, the relative efficiency of different approaches to learning should be an important consideration in decisions about how to study biodiversity.

Newborn screening policy in the United Kingdom & the United States: two different communities of practice.

PubMed

Patch, Christine

2006-01-01

Newborn screening is a rapidly developing area driven by both technological advances and public pressure. If they are not yet, all nurses working with mothers and children will soon be involved with implementing newborn-screening programs, and it is therefore important that they appreciate both the benefits and potential harms of such programs. In the United Kingdom, policy regarding the implementation of newborn-screening programs is developed at national level, and consideration of the introduction of new tests is subject to a formalized evaluation framework. In the United States, by contrast, each state develops its own screening program. Knowledge of developments in newborn screening in different countries that have diverse types of healthcare systems helps to inform nurses about the totality of healthcare for newborns, and assists them in becoming more knowledgeable about how international standards differ from those in the United States.

A review of developmental and applied language research on African American children: from a deficit to difference perspective on dialect differences.

PubMed

Stockman, Ida J

2010-01-01

The contemporary practices of delivering speech, language, and hearing services in schools reflect palpable gains in professional sensitivity to linguistic and cultural diversity. This article reviews the dominant research themes on the oral language of African American preschoolers who contribute to such diversity in the United States. Specifically, it contrasts the historical and current frameworks that have guided studies of (a) such children's acquisition and use of English and (b) the strategies used to assess and modify their language. Research initiatives that can expand knowledge about this group are proposed.

Volume and Value of Big Healthcare Data.

PubMed

Dinov, Ivo D

Modern scientific inquiries require significant data-driven evidence and trans-disciplinary expertise to extract valuable information and gain actionable knowledge about natural processes. Effective evidence-based decisions require collection, processing and interpretation of vast amounts of complex data. The Moore's and Kryder's laws of exponential increase of computational power and information storage, respectively, dictate the need rapid trans-disciplinary advances, technological innovation and effective mechanisms for managing and interrogating Big Healthcare Data. In this article, we review important aspects of Big Data analytics and discuss important questions like: What are the challenges and opportunities associated with this biomedical, social, and healthcare data avalanche? Are there innovative statistical computing strategies to represent, model, analyze and interpret Big heterogeneous data? We present the foundation of a new compressive big data analytics (CBDA) framework for representation, modeling and inference of large, complex and heterogeneous datasets. Finally, we consider specific directions likely to impact the process of extracting information from Big healthcare data, translating that information to knowledge, and deriving appropriate actions.

Volume and Value of Big Healthcare Data

PubMed Central

Dinov, Ivo D.

2016-01-01

Modern scientific inquiries require significant data-driven evidence and trans-disciplinary expertise to extract valuable information and gain actionable knowledge about natural processes. Effective evidence-based decisions require collection, processing and interpretation of vast amounts of complex data. The Moore's and Kryder's laws of exponential increase of computational power and information storage, respectively, dictate the need rapid trans-disciplinary advances, technological innovation and effective mechanisms for managing and interrogating Big Healthcare Data. In this article, we review important aspects of Big Data analytics and discuss important questions like: What are the challenges and opportunities associated with this biomedical, social, and healthcare data avalanche? Are there innovative statistical computing strategies to represent, model, analyze and interpret Big heterogeneous data? We present the foundation of a new compressive big data analytics (CBDA) framework for representation, modeling and inference of large, complex and heterogeneous datasets. Finally, we consider specific directions likely to impact the process of extracting information from Big healthcare data, translating that information to knowledge, and deriving appropriate actions. PMID:26998309

Temperature drives abundance fluctuations, but spatial dynamics is constrained by landscape configuration: Implications for climate-driven range shift in a butterfly.

PubMed

Fourcade, Yoan; Ranius, Thomas; Öckinger, Erik

2017-10-01

Prediction of species distributions in an altered climate requires knowledge on how global- and local-scale factors interact to limit their current distributions. Such knowledge can be gained through studies of spatial population dynamics at climatic range margins. Here, using a butterfly (Pyrgus armoricanus) as model species, we first predicted based on species distribution modelling that its climatically suitable habitats currently extend north of its realized range. Projecting the model into scenarios of future climate, we showed that the distribution of climatically suitable habitats may shift northward by an additional 400 km in the future. Second, we used a 13-year monitoring dataset including the majority of all habitat patches at the species northern range margin to assess the synergetic impact of temperature fluctuations and spatial distribution of habitat, microclimatic conditions and habitat quality, on abundance and colonization-extinction dynamics. The fluctuation in abundance between years was almost entirely determined by the variation in temperature during the species larval development. In contrast, colonization and extinction dynamics were better explained by patch area, between-patch connectivity and host plant density. This suggests that the response of the species to future climate change may be limited by future land use and how its host plants respond to climate change. It is, thus, probable that dispersal limitation will prevent P. armoricanus from reaching its potential future distribution. We argue that models of range dynamics should consider the factors influencing metapopulation dynamics, especially at the range edges, and not only broad-scale climate. It includes factors acting at the scale of habitat patches such as habitat quality and microclimate and landscape-scale factors such as the spatial configuration of potentially suitable patches. Knowledge of population dynamics under various environmental conditions, and the incorporation of realistic scenarios of future land use, appears essential to provide predictions useful for actions mitigating the negative effects of climate change. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

Recent advances in research on Crimean-Congo hemorrhagic fever.

PubMed

Papa, Anna; Mirazimi, Ali; Köksal, Iftihar; Estrada-Pena, Augustin; Feldmann, Heinz

2015-03-01

Crimean-Congo hemorrhagic fever (CCHF) is an expanding tick-borne hemorrhagic disease with increasing human and animal health impact. Immense knowledge was gained over the past 10 years mainly due to advances in molecular biology, but also driven by an increased global interest in CCHFV as an emerging/re-emerging zoonotic pathogen. In the present article, we discuss the advances in research with focus on CCHF ecology, epidemiology, pathogenesis, diagnostics, prophylaxis and treatment. Despite tremendous achievements, future activities have to concentrate on the development of vaccines and antivirals/therapeutics to combat CCHF. Vector studies need to continue for better public and animal health preparedness and response. We conclude with a roadmap for future research priorities. Copyright © 2014 Elsevier B.V. All rights reserved.

STEM Career Changers' Transformation into Science Teachers

NASA Astrophysics Data System (ADS)

Snyder, Catherine; Oliveira, Alandeom W.; Paska, Lawrence M.

2013-06-01

This study examines the transformation (professional growth) of career-changing women scientists who decided to become teachers. Drawing upon Mezirow's Transformative Learning Theory, we tracked their transformation for 3 years. Our findings revealed multiple identities, disorientation, a perceived sense of meaninglessness, loss and eventual regain in confidence, gain in pedagogical knowledge and skill, and changed perceptions of the social roles of science teachers and scientists. Driven by personal choice or need (financial, intellectual), such transformations were achieved through active pursuit of meaning in one's work, critical assessment of assumptions, planning, and trying on the unfamiliar role of a science teacher. It is argued that such transition entails complex changes in thinking about science teaching and identifying oneself as a science teacher.

Biological versus electronic adaptive coloration: how can one inform the other?

PubMed Central

Kreit, Eric; Mäthger, Lydia M.; Hanlon, Roger T.; Dennis, Patrick B.; Naik, Rajesh R.; Forsythe, Eric; Heikenfeld, Jason

2013-01-01

Adaptive reflective surfaces have been a challenge for both electronic paper (e-paper) and biological organisms. Multiple colours, contrast, polarization, reflectance, diffusivity and texture must all be controlled simultaneously without optical losses in order to fully replicate the appearance of natural surfaces and vividly communicate information. This review merges the frontiers of knowledge for both biological adaptive coloration, with a focus on cephalopods, and synthetic reflective e-paper within a consistent framework of scientific metrics. Currently, the highest performance approach for both nature and technology uses colourant transposition. Three outcomes are envisioned from this review: reflective display engineers may gain new insights from millions of years of natural selection and evolution; biologists will benefit from understanding the types of mechanisms, characterization and metrics used in synthetic reflective e-paper; all scientists will gain a clearer picture of the long-term prospects for capabilities such as adaptive concealment and signalling. PMID:23015522

External radioactive markers for PET data-driven respiratory gating in positron emission tomography.

PubMed

Büther, Florian; Ernst, Iris; Hamill, James; Eich, Hans T; Schober, Otmar; Schäfers, Michael; Schäfers, Klaus P

2013-04-01

Respiratory gating is an established approach to overcoming respiration-induced image artefacts in PET. Of special interest in this respect are raw PET data-driven gating methods which do not require additional hardware to acquire respiratory signals during the scan. However, these methods rely heavily on the quality of the acquired PET data (statistical properties, data contrast, etc.). We therefore combined external radioactive markers with data-driven respiratory gating in PET/CT. The feasibility and accuracy of this approach was studied for [(18)F]FDG PET/CT imaging in patients with malignant liver and lung lesions. PET data from 30 patients with abdominal or thoracic [(18)F]FDG-positive lesions (primary tumours or metastases) were included in this prospective study. The patients underwent a 10-min list-mode PET scan with a single bed position following a standard clinical whole-body [(18)F]FDG PET/CT scan. During this scan, one to three radioactive point sources (either (22)Na or (18)F, 50-100 kBq) in a dedicated holder were attached the patient's abdomen. The list mode data acquired were retrospectively analysed for respiratory signals using established data-driven gating approaches and additionally by tracking the motion of the point sources in sinogram space. Gated reconstructions were examined qualitatively, in terms of the amount of respiratory displacement and in respect of changes in local image intensity in the gated images. The presence of the external markers did not affect whole-body PET/CT image quality. Tracking of the markers led to characteristic respiratory curves in all patients. Applying these curves for gated reconstructions resulted in images in which motion was well resolved. Quantitatively, the performance of the external marker-based approach was similar to that of the best intrinsic data-driven methods. Overall, the gain in measured tumour uptake from the nongated to the gated images indicating successful removal of respiratory motion was correlated with the magnitude of the respiratory displacement of the respective tumour lesion, but not with lesion size. Respiratory information can be assessed from list-mode PET/CT through PET data-derived tracking of external radioactive markers. This information can be successfully applied to respiratory gating to reduce motion-related image blurring. In contrast to other previously described PET data-driven approaches, the external marker approach is independent of tumour uptake and thereby applicable even in patients with poor uptake and small tumours.

When size matters: attention affects performance by contrast or response gain.

PubMed

Herrmann, Katrin; Montaser-Kouhsari, Leila; Carrasco, Marisa; Heeger, David J

2010-12-01

Covert attention, the selective processing of visual information in the absence of eye movements, improves behavioral performance. We found that attention, both exogenous (involuntary) and endogenous (voluntary), can affect performance by contrast or response gain changes, depending on the stimulus size and the relative size of the attention field. These two variables were manipulated in a cueing task while stimulus contrast was varied. We observed a change in behavioral performance consonant with a change in contrast gain for small stimuli paired with spatial uncertainty and a change in response gain for large stimuli presented at one location (no uncertainty) and surrounded by irrelevant flanking distracters. A complementary neuroimaging experiment revealed that observers' attention fields were wider with than without spatial uncertainty. Our results support important predictions of the normalization model of attention and reconcile previous, seemingly contradictory findings on the effects of visual attention.

Enhancement of signal-to-noise ratio in Brillouin optical time domain analyzers by dual-probe detection

NASA Astrophysics Data System (ADS)

Iribas, Haritz; Loayssa, Alayn; Sauser, Florian; Llera, Miguel; Le Floch, Sébastien

2017-04-01

We demonstrate a simple technique to enhance the signal-to-noise ratio (SNR) in Brillouin optical time-domain analysis sensors by the addition of gain and loss processes. The technique is based on the shift of the pump pulse optical frequency in a double-sideband probe system, so that the gain and loss processes take place at different frequencies. In this manner, the loss and the gain do not cancel each other out, and it makes possible to take advantage of both informations at the same time, obtaining an improvement of 3 dB on the SNR. Furthermore, the technique does not need an optical filtering, so that larger improvement on SNR and a simplification of the setup are obtained. The method is experimentally demonstrated in a 101 km fiber spool, obtaining a measurement uncertainty of 2.6 MHz (2σ) at the worst-contrast position for 2 m spatial resolution. This leads, to the best of our knowledge, to the highest figure-of-merit in a BOTDA without using coding or raman amplification.

Frequency-specific hippocampal-prefrontal interactions during associative learning

PubMed Central

Brincat, Scott L.; Miller, Earl K.

2015-01-01

Much of our knowledge of the world depends on learning associations (e.g., face-name), for which the hippocampus (HPC) and prefrontal cortex (PFC) are critical. HPC-PFC interactions have rarely been studied in monkeys, whose cognitive/mnemonic abilities are akin to humans. Here, we show functional differences and frequency-specific interactions between HPC and PFC of monkeys learning object-pair associations, an animal model of human explicit memory. PFC spiking activity reflected learning in parallel with behavioral performance, while HPC neurons reflected feedback about whether trial-and-error guesses were correct or incorrect. Theta-band HPC-PFC synchrony was stronger after errors, was driven primarily by PFC to HPC directional influences, and decreased with learning. In contrast, alpha/beta-band synchrony was stronger after correct trials, was driven more by HPC, and increased with learning. Rapid object associative learning may occur in PFC, while HPC may guide neocortical plasticity by signaling success or failure via oscillatory synchrony in different frequency bands. PMID:25706471

Gain, noise, and contrast sensitivity of linear visual neurons

NASA Technical Reports Server (NTRS)

Watson, Andrew B.

1990-01-01

Contrast sensitivity is a measure of the ability of an observer to detect contrast signals of particular spatial and temporal frequencies. A formal definition of contrast sensitivity that can be applied to individual linear visual neurons is derived. A neuron is modeled by a contrast transfer function and its modulus, contrast gain, and by a noise power spectrum. The distributions of neural responses to signal and blank presentations are derived, and from these, a definition of contrast sensitivity is obtained. This formal definition may be used to relate the sensitivities of various populations of neurons, and to relate the sensitivities of neurons to that of the behaving animal.

Ultra-high gain diffusion-driven organic transistor

PubMed Central

Torricelli, Fabrizio; Colalongo, Luigi; Raiteri, Daniele; Kovács-Vajna, Zsolt Miklós; Cantatore, Eugenio

2016-01-01

Emerging large-area technologies based on organic transistors are enabling the fabrication of low-cost flexible circuits, smart sensors and biomedical devices. High-gain transistors are essential for the development of large-scale circuit integration, high-sensitivity sensors and signal amplification in sensing systems. Unfortunately, organic field-effect transistors show limited gain, usually of the order of tens, because of the large contact resistance and channel-length modulation. Here we show a new organic field-effect transistor architecture with a gain larger than 700. This is the highest gain ever reported for organic field-effect transistors. In the proposed organic field-effect transistor, the charge injection and extraction at the metal–semiconductor contacts are driven by the charge diffusion. The ideal conditions of ohmic contacts with negligible contact resistance and flat current saturation are demonstrated. The approach is general and can be extended to any thin-film technology opening unprecedented opportunities for the development of high-performance flexible electronics. PMID:26829567

Architectural Blueprint for Plate Boundary Observatories based on interoperable Data Management Platforms

NASA Astrophysics Data System (ADS)

Kerschke, D. I.; Häner, R.; Schurr, B.; Oncken, O.; Wächter, J.

2014-12-01

Interoperable data management platforms play an increasing role in the advancement of knowledge and technology in many scientific disciplines. Through high quality services they support the establishment of efficient and innovative research environments. Well-designed research environments can facilitate the sustainable utilization, exchange, and re-use of scientific data and functionality by using standardized community models. Together with innovative 3D/4D visualization, these concepts provide added value in improving scientific knowledge-gain, even across the boundaries of disciplines. A project benefiting from the added value is the Integrated Plate boundary Observatory in Chile (IPOC). IPOC is a European-South American network to study earthquakes and deformation at the Chilean continental margin and to monitor the plate boundary system for capturing an anticipated great earthquake in a seismic gap. In contrast to conventional observatories that monitor individual signals only, IPOC captures a large range of different processes through various observation methods (e.g., seismographs, GPS, magneto-telluric sensors, creep-meter, accelerometer, InSAR). For IPOC a conceptual design has been devised that comprises an architectural blueprint for a data management platform based on common and standardized data models, protocols, and encodings as well as on an exclusive use of Free and Open Source Software (FOSS) including visualization components. Following the principles of event-driven service-oriented architectures, the design enables novel processes by sharing and re-using functionality and information on the basis of innovative data mining and data fusion technologies. This platform can help to improve the understanding of the physical processes underlying plate deformations as well as the natural hazards induced by them. Through the use of standards, this blueprint can not only be facilitated for other plate observing systems (e.g., the European Plate Observing System EPOS), it also supports integrated approaches to include sensor networks that provide complementary processes for dynamic monitoring. Moreover, the integration of such observatories into superordinate research infrastructures (federation of virtual observatories) will be enabled.

Trainees' Perceived Knowledge Gain Unrelated to the Training Domain: The Joint Action of Impression Management and Motives

ERIC Educational Resources Information Center

Chiaburu, Dan S.; Huang, Jason L.; Hutchins, Holly M.; Gardner, Richard G.

2014-01-01

Trainees' knowledge gains represent an important outcome in human resource development. In this research, we tested a model examining the joint influence of social desirability (impression management, self-deception) and motives (need for power, need for approval) on trainees' self-reported knowledge gain. We conducted a study with…

Science Literacy of Undergraduates in the United States

NASA Astrophysics Data System (ADS)

Impey, Chris

2013-01-01

Science literacy is a matter of broad concern among scientists, educators, and many policy-makers. National Science Foundation surveys of the general public for biannual Science Indicators series show that respondents on average score less than 2/3 correct on a series of science knowledge questions, and less than half display an understanding of the process of scientific inquiry. Both measures are essentially unchanged over two decades. At the University of Arizona, we have gathered over 11,000 undergraduate student responses to a survey of knowledge and beliefs that is tethered in the NSF survey. This non-science major population demographically represents ten million students nationwide. There is a less than 10% gain in performance in the science knowledge score between the incoming freshmen and seniors who graduate having completed their requirement of three science classes. Belief levels in pseudoscience and supernatural phenomena are disconcertingly high, mostly resistant to college science instruction, and weakly correlated with performance on the science knowledge questions. The Internet is rapidly becoming the primary information source for anyone interested in science so students may not get most of their information from the classroom. Educators and policy makers need to decide what aspects of science knowledge and process are important for adults to know. College science educators have major challenges in better in preparing graduates for participation in a civic society largely driven by science and technology.

Inquiry-Driven Field-Based (IDFB) Ocean Science Classes: an Important Role in College Students' Development as Scientists, and Student Retention in the Geo-science Pipeline.

NASA Astrophysics Data System (ADS)

Crane, N. L.

2004-12-01

Experiential learning, engaging students in the process of science, can not only teach students important skills and knowledge, it can also help them become connected with the process on a personal level. This study investigates the role that Inquiry-Driven Field-Based (IDFB) experiences (primarily field classes) in ocean science have on undergraduate science students' development as ocean scientists. Both cognitive (knowledge-based) and affective (motivation and attitude) measures most important to students were used as indicators of development. Major themes will be presented to illustrate how IDFB science experiences can enhance the academic and personal development of students of science. Through their active engagement in the process of science, students gain important skills and knowledge as well as increased confidence, motivation, and ability to plan for their future (in particular their career and educational pathways). This growth is an important part of their development as scientists; the IDFB experience provides them a way to build a relationship with the world of science, and to better understand what science is, what scientists do, and their own future role as scientists. IDFB experiences have a particularly important role in affective measures of development: students develop an important personal connection to science. By doing science, students learn to be scientists and to understand science and science concepts in context. Many underrepresented students do not have the opportunity to take IDFB classes, and addressing this access issue could be an important step towards engaging more underrepresented students in the field. The nature of IDFB experiences and their impact on students makes them a potentially important mechanism for retaining students in the geo-science `pipeline'.

The influence of stimulus format on drawing--a functional imaging study of decision making in portrait drawing.

PubMed

Miall, R C; Nam, Se-Ho; Tchalenko, J

2014-11-15

To copy a natural visual image as a line drawing, visual identification and extraction of features in the image must be guided by top-down decisions, and is usually influenced by prior knowledge. In parallel with other behavioral studies testing the relationship between eye and hand movements when drawing, we report here a functional brain imaging study in which we compared drawing of faces and abstract objects: the former can be strongly guided by prior knowledge, the latter less so. To manipulate the difficulty in extracting features to be drawn, each original image was presented in four formats including high contrast line drawings and silhouettes, and as high and low contrast photographic images. We confirmed the detailed eye-hand interaction measures reported in our other behavioral studies by using in-scanner eye-tracking and recording of pen movements with a touch screen. We also show that the brain activation pattern reflects the changes in presentation formats. In particular, by identifying the ventral and lateral occipital areas that were more highly activated during drawing of faces than abstract objects, we found a systematic increase in differential activation for the face-drawing condition, as the presentation format made the decisions more challenging. This study therefore supports theoretical models of how prior knowledge may influence perception in untrained participants, and lead to experience-driven perceptual modulation by trained artists. Copyright © 2014. Published by Elsevier Inc.

Eutrophication and Dreissena invasion as drivers of biodiversity: a century of change in the mollusc community of Oneida Lake.

PubMed

Karatayev, Vadim A; Karatayev, Alexander Y; Burlakova, Lyubov E; Rudstam, Lars G

2014-01-01

Changes in nutrient loading and invasive species are among the strongest human-driven disturbances in freshwater ecosystems, but our knowledge on how they affect the biodiversity of lakes is still limited. We conducted a detailed historical analysis of the mollusc community of Oneida Lake based on our comprehensive lakewide study in 2012 and previous surveys dating back to 1915. In the early 20th century, the lake had a high water clarity, with abundant macrophytes and benthic algae, and hosted the most diverse molluscan community in New York State, including 32 gastropod and 9 unionid species. By the 1960s, lake turbidity increased during a period of anthropogenic eutrophication, resulting in a 38% decline in species richness and a 95% reduction in abundance of native gastropods grazing on benthic algae. Following the invasion of Dreissena spp. in 1991 and subsequent increases in water clarity, native gastropod species richness expanded by 37% and abundance increased 20-fold by 2012. In contrast, filter-feeding unionids were unaffected by increased turbidity during the period of eutrophication but were extirpated by dreissenids. Through contrasting effects on turbidity, eutrophication and Dreissena spp. have likely driven the observed changes in native grazing gastropods by affecting the abundance of light-limited benthic algae. Given the high species richness and ecological importance of benthic grazers, monitoring and managing turbidity is important in preserving molluscan diversity.

The trend in mental health-related mortality rates in Australia 1916-2004: implications for policy

PubMed Central

2010-01-01

Background This study determines the trend in mental health-related mortality (defined here as the aggregation of suicide and deaths coded as "mental/behavioural disorders"), and its relative numerical importance, and to argue that this has importance to policy-makers. Its results will have policy relevance because policy-makers have been predominantly concerned with cost-containment, but a re-appraisal of this issue is occurring, and the trade-off between health expenditures and valuable gains in longevity is being emphasised now. This study examines longevity gains from mental health-related interventions, or their absence, at the population level. The study sums mortality data for suicide and mental/behavioural disorders across the relevant ICD codes through time in Australia for the period 1916-2004. There are two measures applied to the mortality rates: the conventional age-standardised headcount; and the age-standardised Potential Years of Life Lost (PYLL), a measure of premature mortality. Mortality rates formed from these data are analysed via comparisons with mortality rates for All Causes, and with circulatory diseases, cancer and motor vehicle accidents, measured by both methods. Results This study finds the temporal trend in mental health-related mortality rates (which reflects the longevity of people with mental illness) has worsened through time. There are no gains. This trend contrasts with the (known) gains in longevity from All Causes, and the gains from decreases achieved in previously rising mortality rates from circulatory diseases and motor vehicle accidents. Also, PYLL calculation shows mental health-related mortality is a proportionately greater cause of death compared with applying headcount metrics. Conclusions There are several factors that could reverse this trend. First, improved access to interventions or therapies for mental disorders could decrease the mortality analysed here. Second, it is important also that new efficacious therapies for various mental disorders be developed. Furthermore, it is also important that suicide prevention strategies be implemented, particularly for at-risk groups. To bring the mental health sector into parity with many other parts of the health system will require knowledge of the causative factors that underlie mental disorders, which can, in turn, lead to efficacious therapies. As in any case of a knowledge deficit, what is needed are resources to address that knowledge gap. Conceiving the problem in this way, ie as a knowledge gap, indicates the crucial role of research and development activity. This term implies a concern, not simply with basic research, but also with applied research. It is commonplace in other sectors of the economy to emphasise the trichotomy of invention, innovation and diffusion of new products and processes. This three-fold conception is also relevant to addressing the knowledge gap in the mental health sector. PMID:20145728

TU-F-CAMPUS-I-05: Investigation of An EMCCD Detector with Variable Gain in a Micro-CT System

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

Krishnakumar, S Bysani; Ionita, C; Rudin, S

Purpose: To investigate the performance of a newly built Electron Multiplying Charged Coupled Device (EMCCD) based Micro-CT system, with variable detector gain, using a phantom containing contrast agent of different concentrations. Methods: We built a micro- CT system with an EMCCD having 8 microns pixels and on-chip variable gain. We tested the system using a phantom containing five tubes filled with different iodine contrast solutions (30% to 70%). First, we scanned the phantom using various x-ray exposures values at 40 kVp and constant detector gain. Next, for the same tube currents, the detector gain was increased to maintain the airmore » value of the projection image constant. A standard FDK algorithm was used to reconstruct the data. Performance was analyzed by comparing the signal-to-noise ratio (SNR) measurements for increased gain with those for the low constant gain at each exposure. Results: The high detector gain reconstructed data SNR was always greater than the low gain data SNR for all x-ray settings and for all iodine features. The largest increases were observed for low contrast features, 30% iodine concentration, where the SNR improvement approached 2. Conclusion: One of the first implementations of an EMCCD based micro- CT system was presented and used to image a phantom with various iodine solution concentrations. The analysis of the reconstructed volumes showed a significant improvement of the SNR especially for low contrast features. The unique on-chip gain feature is a substantial benefit allowing the use of the system at very low x-ray exposures per frame.Partial support: NIH grant R01EB002873 and Toshiba Medical Systems Corp. Partial support: NIH grant R01EB002873 and Toshiba Medical Systems Corp.« less

Center/surround organization of retinal bipolar cells: High correlation of fundamental responses of center and surround to sinusoidal contrasts

PubMed Central

Burkhardt, Dwight A.; Bartoletti, Theodore M.; Thoreson, Wallace B.

2012-01-01

Receptive field organization of cone-driven bipolar cells was investigated by intracellular recording in the intact light-adapted retina of the tiger salamander (Ambystoma tigrinum). Centered spots and concentric annuli of optimum dimensions were used to selectively stimulate the receptive field center and surround with sinusoidal modulations of contrast at 3 Hz. At low contrasts, responses of both the center and surround of both ON and OFF bipolar cells were linear, showing high gain and thus contrast enhancement relative to cones. The contrast/response curves for the fundamental response, measured by a Fast Fourier Transform, reached half maximum amplitude quickly at 13% contrast followed by saturation at high contrasts. The variation of the normalized amplitude of the center and surround responses was remarkably similar, showing linear regression over the entire response range with very high correlations, r2 = 0.97 for both ON and OFF cells. The contrast/response curves of both center and surround for both ON and OFF cells were well fit (r2 = 0.98) by an equation for single-site binding. In about half the cells studied, the nonlinear waveforms of center and surround could be brought into coincidence by scaling and shifting the surround response in time. This implies that a nonlinearity, common to both center and surround, occurs after polarity inversion at the cone feedback synapse. Evidence from paired whole-cell recordings between single cones and OFF bipolar cells suggests that substantial nonlinearity is not due to transmission at the cone synapse but instead arises from intrinsic bipolar cell and network mechanisms. When sinusoidal contrast modulations were applied to the center and surround simultaneously, clear additivity was observed for small responses in both ON and OFF cells, whereas the interaction was strikingly nonadditive for large responses. The contribution of the surround was then greatly reduced, suggesting attenuation at the cone feedback synapse. PMID:21439110

Bringing Up Girls in Science (BUGS): The Effectiveness of an Afterschool Environmental Science Program for Increasing Female Students' Interest in Science Careers

NASA Astrophysics Data System (ADS)

Tyler-Wood, Tandra; Ellison, Amber; Lim, Okyoung; Periathiruvadi, Sita

2012-02-01

Bringing Up Girls in Science (BUGS) was an afterschool program for 4th and 5th grade girls that provided authentic learning experiences in environmental science as well as valuable female mentoring opportunities in an effort to increase participants' academic achievement in science. BUGS participants demonstrated significantly greater amounts of gain in science knowledge as measured by the Iowa Test of Basic Skills in Science (ITBS-S). The original BUGS participants and contrasts have now completed high school and entered college, allowing researchers to assess the long-term impact of the BUGS program. Fourteen former BUGS participants completed two instruments to assess their perceptions of science and science, technology, engineering, and mathematics (STEM) careers. Their results were compared to four contrast groups composed entirely of females: 12 former BUGS contrasts, 10 college science majors, 10 non-science majors, and 9 current STEM professionals. Results indicate that BUGS participants have higher perceptions of science careers than BUGS contrasts. There were no significant differences between BUGS participants, Science Majors, and STEM professionals in their perceptions of science and STEM careers, whereas the BUGS contrast group was significantly lower than BUGS participants, Science Majors, and STEM Professionals. Additional results and implications are discussed within.

Large system change challenges: addressing complex critical issues in linked physical and social domains

NASA Astrophysics Data System (ADS)

Waddell, Steve; Cornell, Sarah; Hsueh, Joe; Ozer, Ceren; McLachlan, Milla; Birney, Anna

2015-04-01

Most action to address contemporary complex challenges, including the urgent issues of global sustainability, occurs piecemeal and without meaningful guidance from leading complex change knowledge and methods. The potential benefit of using such knowledge is greater efficacy of effort and investment. However, this knowledge and its associated tools and methods are under-utilized because understanding about them is low, fragmented between diverse knowledge traditions, and often requires shifts in mindsets and skills from expert-led to participant-based action. We have been engaged in diverse action-oriented research efforts in Large System Change for sustainability. For us, "large" systems can be characterized as large-scale systems - up to global - with many components, of many kinds (physical, biological, institutional, cultural/conceptual), operating at multiple levels, driven by multiple forces, and presenting major challenges for people involved. We see change of such systems as complex challenges, in contrast with simple or complicated problems, or chaotic situations. In other words, issues and sub-systems have unclear boundaries, interact with each other, and are often contradictory; dynamics are non-linear; issues are not "controllable", and "solutions" are "emergent" and often paradoxical. Since choices are opportunity-, power- and value-driven, these social, institutional and cultural factors need to be made explicit in any actionable theory of change. Our emerging network is sharing and building a knowledge base of experience, heuristics, and theories of change from multiple disciplines and practice domains. We will present our views on focal issues for the development of the field of large system change, which include processes of goal-setting and alignment; leverage of systemic transitions and transformation; and the role of choice in influencing critical change processes, when only some sub-systems or levels of the system behave in purposeful ways, while others are undeniably and unavoidably deterministic.

Design of a Knowledge Driven HIS

PubMed Central

Pryor, T. Allan; Clayton, Paul D.; Haug, Peter J.; Wigertz, Ove

1987-01-01

Design of the software architecture for a knowledge driven HIS is presented. In our design the frame has been used as the basic unit of knowledge representation. The structure of the frame is being designed to be sufficiently universal to contain knowledge required to implement not only expert systems, but almost all traditional HIS functions including ADT, order entry and results review. The design incorporates a two level format for the knowledge. The first level as ASCII records is used to maintain the knowledge base while the second level converted by special knowledge compilers to standard computer languages is used for efficient implementation of the knowledge applications.

Enabling Data-Driven Methodologies Across the Data Lifecycle and Ecosystem

NASA Astrophysics Data System (ADS)

Doyle, R. J.; Crichton, D.

2017-12-01

NASA has unlocked unprecedented scientific knowledge through exploration of the Earth, our solar system, and the larger universe. NASA is generating enormous amounts of data that are challenging traditional approaches to capturing, managing, analyzing and ultimately gaining scientific understanding from science data. New architectures, capabilities and methodologies are needed to span the entire observing system, from spacecraft to archive, while integrating data-driven discovery and analytic capabilities. NASA data have a definable lifecycle, from remote collection point to validated accessibility in multiple archives. Data challenges must be addressed across this lifecycle, to capture opportunities and avoid decisions that may limit or compromise what is achievable once data arrives at the archive. Data triage may be necessary when the collection capacity of the sensor or instrument overwhelms data transport or storage capacity. By migrating computational and analytic capability to the point of data collection, informed decisions can be made about which data to keep; in some cases, to close observational decision loops onboard, to enable attending to unexpected or transient phenomena. Along a different dimension than the data lifecycle, scientists and other end-users must work across an increasingly complex data ecosystem, where the range of relevant data is rarely owned by a single institution. To operate effectively, scalable data architectures and community-owned information models become essential. NASA's Planetary Data System is having success with this approach. Finally, there is the difficult challenge of reproducibility and trust. While data provenance techniques will be part of the solution, future interactive analytics environments must support an ability to provide a basis for a result: relevant data source and algorithms, uncertainty tracking, etc., to assure scientific integrity and to enable confident decision making. Advances in data science offer opportunities to gain new insights from space missions and their vast data collections. We are working to innovate new architectures, exploit emerging technologies, develop new data-driven methodologies, and transfer them across disciplines, while working across the dual dimensions of the data lifecycle and the data ecosystem.

Image contrast enhancement based on a local standard deviation model

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

Chang, Dah-Chung; Wu, Wen-Rong

1996-12-31

The adaptive contrast enhancement (ACE) algorithm is a widely used image enhancement method, which needs a contrast gain to adjust high frequency components of an image. In the literature, the gain is usually inversely proportional to the local standard deviation (LSD) or is a constant. But these cause two problems in practical applications, i.e., noise overenhancement and ringing artifact. In this paper a new gain is developed based on Hunt`s Gaussian image model to prevent the two defects. The new gain is a nonlinear function of LSD and has the desired characteristic emphasizing the LSD regions in which details aremore » concentrated. We have applied the new ACE algorithm to chest x-ray images and the simulations show the effectiveness of the proposed algorithm.« less

Microbe-driven turnover offsets mineral-mediated storage of soil carbon under elevated CO2

NASA Astrophysics Data System (ADS)

Sulman, Benjamin N.; Phillips, Richard P.; Oishi, A. Christopher; Shevliakova, Elena; Pacala, Stephen W.

2014-12-01

The sensitivity of soil organic carbon (SOC) to changing environmental conditions represents a critical uncertainty in coupled carbon cycle-climate models. Much of this uncertainty arises from our limited understanding of the extent to which root-microbe interactions induce SOC losses (through accelerated decomposition or `priming') or indirectly promote SOC gains (via `protection' through interactions with mineral particles). We developed a new SOC model to examine priming and protection responses to rising atmospheric CO2. The model captured disparate SOC responses at two temperate free-air CO2 enrichment (FACE) experiments. We show that stabilization of `new' carbon in protected SOC pools may equal or exceed microbial priming of `old' SOC in ecosystems with readily decomposable litter and high clay content (for example, Oak Ridge). In contrast, carbon losses induced through priming dominate the net SOC response in ecosystems with more resistant litters and lower clay content (for example, Duke). The SOC model was fully integrated into a global terrestrial carbon cycle model to run global simulations of elevated CO2 effects. Although protected carbon provides an important constraint on priming effects, priming nonetheless reduced SOC storage in the majority of terrestrial areas, partially counterbalancing SOC gains from enhanced ecosystem productivity.

Organizational impact of evidence-informed decision making training initiatives: a case study comparison of two approaches.

PubMed

Champagne, François; Lemieux-Charles, Louise; Duranceau, Marie-France; MacKean, Gail; Reay, Trish

2014-05-02

The impact of efforts by healthcare organizations to enhance the use of evidence to improve organizational processes through training programs has seldom been assessed. We therefore endeavored to assess whether and how the training of mid- and senior-level healthcare managers could lead to organizational change. We conducted a theory-driven evaluation of the organizational impact of healthcare leaders' participation in two training programs using a logic model based on Nonaka's theory of knowledge conversion. We analyzed six case studies nested within the two programs using three embedded units of analysis (individual, group and organization). Interviews were conducted during intensive one-week data collection site visits. A total of 84 people were interviewed. We found that the impact of training could primarily be felt in trainees' immediate work environments. The conversion of attitudes was found to be easier to achieve than the conversion of skills. Our results show that, although socialization and externalization were common in all cases, a lack of combination impeded the conversion of skills. We also identified several individual, organizational and program design factors that facilitated and/or impeded the dissemination of the attitudes and skills gained by trainees to other organizational members. Our theory-driven evaluation showed that factors before, during and after training can influence the extent of skills and knowledge transfer. Our evaluation went further than previous research by revealing the influence--both positive and negative--of specific organizational factors on extending the impact of training programs.

Adaptive gamma correction-based expert system for nonuniform illumination face enhancement

NASA Astrophysics Data System (ADS)

Abdelhamid, Iratni; Mustapha, Aouache; Adel, Oulefki

2018-03-01

The image quality of a face recognition system suffers under severe lighting conditions. Thus, this study aims to develop an approach for nonuniform illumination adjustment based on an adaptive gamma correction (AdaptGC) filter that can solve the aforementioned issue. An approach for adaptive gain factor prediction was developed via neural network model-based cross-validation (NN-CV). To achieve this objective, a gamma correction function and its effects on the face image quality with different gain values were examined first. Second, an orientation histogram (OH) algorithm was assessed as a face's feature descriptor. Subsequently, a density histogram module was developed for face label generation. During the NN-CV construction, the model was assessed to recognize the OH descriptor and predict the face label. The performance of the NN-CV model was evaluated by examining the statistical measures of root mean square error and coefficient of efficiency. Third, to evaluate the AdaptGC enhancement approach, an image quality metric was adopted using enhancement by entropy, contrast per pixel, second-derivative-like measure of enhancement, and sharpness, then supported by visual inspection. The experiment results were examined using five face's databases, namely, extended Yale-B, Carnegie Mellon University-Pose, Illumination, and Expression, Mobio, FERET, and Oulu-CASIA-NIR-VIS. The final results prove that AdaptGC filter implementation compared with state-of-the-art methods is the best choice in terms of contrast and nonuniform illumination adjustment. In summary, the benefits attained prove that AdaptGC is driven by a profitable enhancement rate, which provides satisfying features for high rate face recognition systems.

Southern Ocean air-sea heat flux, SST spatial anomalies, and implications for multi-decadal upper ocean heat content trends.

NASA Astrophysics Data System (ADS)

Tamsitt, V. M.; Talley, L. D.; Mazloff, M. R.

2014-12-01

The Southern Ocean displays a zonal dipole (wavenumber one) pattern in sea surface temperature (SST), with a cool zonal anomaly in the Atlantic and Indian sectors and a warm zonal anomaly in the Pacific sector, associated with the large northward excursion of the Malvinas and southeastward flow of the Antarctic Circumpolar Current (ACC). To the north of the cool Indian sector is the warm, narrow Agulhas Return Current (ARC). Air-sea heat flux is largely the inverse of this SST pattern, with ocean heat gain in the Atlantic/Indian, cooling in the southeastward-flowing ARC, and cooling in the Pacific, based on adjusted fluxes from the Southern Ocean State Estimate (SOSE), a ⅙° eddy permitting model constrained to all available in situ data. This heat flux pattern is dominated by turbulent heat loss from the ocean (latent and sensible), proportional to perturbations in the difference between SST and surface air temperature, which are maintained by ocean advection. Locally in the Indian sector, intense heat loss along the ARC is contrasted by ocean heat gain of 0.11 PW south of the ARC. The IPCC AR5 50 year depth-averaged 0-700 m temperature trend shows surprising similarities in its spatial pattern, with upper ocean warming in the ARC contrasted by cooling to the south. Using diagnosed heat budget terms from the most recent (June 2014) 6-year run of the SOSE we find that surface cooling in the ARC is balanced by heating from south-eastward advection by the current whereas heat gain in the ACC is balanced by cooling due to northward Ekman transport driven by strong westerly winds. These results suggest that spatial patterns in multi-decadal upper ocean temperature trends depend on regional variations in upper ocean dynamics.

Visual signal detection in structured backgrounds. II. Effects of contrast gain control, background variations, and white noise

NASA Technical Reports Server (NTRS)

Eckstein, M. P.; Ahumada, A. J. Jr; Watson, A. B.

1997-01-01

Studies of visual detection of a signal superimposed on one of two identical backgrounds show performance degradation when the background has high contrast and is similar in spatial frequency and/or orientation to the signal. To account for this finding, models include a contrast gain control mechanism that pools activity across spatial frequency, orientation and space to inhibit (divisively) the response of the receptor sensitive to the signal. In tasks in which the observer has to detect a known signal added to one of M different backgrounds grounds due to added visual noise, the main sources of degradation are the stochastic noise in the image and the suboptimal visual processing. We investigate how these two sources of degradation (contrast gain control and variations in the background) interact in a task in which the signal is embedded in one of M locations in a complex spatially varying background (structured background). We use backgrounds extracted from patient digital medical images. To isolate effects of the fixed deterministic background (the contrast gain control) from the effects of the background variations, we conduct detection experiments with three different background conditions: (1) uniform background, (2) a repeated sample of structured background, and (3) different samples of structured background. Results show that human visual detection degrades from the uniform background condition to the repeated background condition and degrades even further in the different backgrounds condition. These results suggest that both the contrast gain control mechanism and the background random variations degrade human performance in detection of a signal in a complex, spatially varying background. A filter model and added white noise are used to generate estimates of sampling efficiencies, an equivalent internal noise, an equivalent contrast-gain-control-induced noise, and an equivalent noise due to the variations in the structured background.

Model of visual contrast gain control and pattern masking

NASA Technical Reports Server (NTRS)

Watson, A. B.; Solomon, J. A.

1997-01-01

We have implemented a model of contrast gain and control in human vision that incorporates a number of key features, including a contrast sensitivity function, multiple oriented bandpass channels, accelerating nonlinearities, and a devisive inhibitory gain control pool. The parameters of this model have been optimized through a fit to the recent data that describe masking of a Gabor function by cosine and Gabor masks [J. M. Foley, "Human luminance pattern mechanisms: masking experiments require a new model," J. Opt. Soc. Am. A 11, 1710 (1994)]. The model achieves a good fit to the data. We also demonstrate how the concept of recruitment may accommodate a variant of this model in which excitatory and inhibitory paths have a common accelerating nonlinearity, but which include multiple channels tuned to different levels of contrast.

Space industrialization. [space flight and environment for commercial/utilitarian purposes

NASA Technical Reports Server (NTRS)

Disher, J. H.

1977-01-01

Space industrialization is defined as the use of space flight and the space environment for commercial or utilitarian purposes in contrast to other uses such as gains in basic scientific knowledge, national defense, or exploration. Some unique attributes of space that make it amenable to industrial use include overview of the earth, the 'zero gravity' effect, potential for near perfect vacuum, unlimited reservoir for disposal of waste products, availability of essentially uninterrupted flow of solar energy, and the 'perpetual motion' characteristic of orbital mechanics. The role of human participation in assembling and maintaining the large sophisticated systems that will be required for future space industrialization needs is considered.

Magnetic Resonance of Pelvic and Gastrointestinal Emergencies.

PubMed

Wongwaisayawan, Sirote; Kaewlai, Rathachai; Dattwyler, Matthew; Abujudeh, Hani H; Singh, Ajay K

2016-05-01

Magnetic resonance (MR) imaging is gaining increased acceptance in the emergency setting despite the continued dominance of computed tomography. MR has the advantages of more precise tissue characterization, superior soft tissue contrast, and a lack of ionizing radiation. Traditional barriers to emergent MR are being overcome by streamlined imaging protocols and newer rapid-acquisition sequences. As the utilization of MR imaging in the emergency department increases, a strong working knowledge of the MR appearance of the most commonly encountered abdominopelvic pathologies is essential. In this article, MR imaging protocols and findings of acute pelvic, scrotal, and gastrointestinal pathologies are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Advances in Omics and Bioinformatics Tools for Systems Analyses of Plant Functions

PubMed Central

Mochida, Keiichi; Shinozaki, Kazuo

2011-01-01

Omics and bioinformatics are essential to understanding the molecular systems that underlie various plant functions. Recent game-changing sequencing technologies have revitalized sequencing approaches in genomics and have produced opportunities for various emerging analytical applications. Driven by technological advances, several new omics layers such as the interactome, epigenome and hormonome have emerged. Furthermore, in several plant species, the development of omics resources has progressed to address particular biological properties of individual species. Integration of knowledge from omics-based research is an emerging issue as researchers seek to identify significance, gain biological insights and promote translational research. From these perspectives, we provide this review of the emerging aspects of plant systems research based on omics and bioinformatics analyses together with their associated resources and technological advances. PMID:22156726

Omics strategies for revealing Yersinia pestis virulence

PubMed Central

Yang, Ruifu; Du, Zongmin; Han, Yanping; Zhou, Lei; Song, Yajun; Zhou, Dongsheng; Cui, Yujun

2012-01-01

Omics has remarkably changed the way we investigate and understand life. Omics differs from traditional hypothesis-driven research because it is a discovery-driven approach. Mass datasets produced from omics-based studies require experts from different fields to reveal the salient features behind these data. In this review, we summarize omics-driven studies to reveal the virulence features of Yersinia pestis through genomics, trascriptomics, proteomics, interactomics, etc. These studies serve as foundations for further hypothesis-driven research and help us gain insight into Y. pestis pathogenesis. PMID:23248778

Modeling Root Exudation, Priming and Protection in Soil Carbon Responses to Elevated CO2 from Ecosystem to Global Scales

NASA Astrophysics Data System (ADS)

Sulman, B. N.; Phillips, R.; Shevliakova, E.; Oishi, A. C.; Pacala, S. W.

2014-12-01

The sensitivity of soil organic carbon (SOC) to changing environmental conditions represents a critical uncertainty in coupled carbon cycle-climate models. Much of this uncertainty arises from our limited understanding of the extent to which plants induce SOC losses (through accelerated decomposition or "priming") or promote SOC gains (via stabilization through physico-chemical protection). We developed a new SOC model, "Carbon, Organisms, Rhizosphere and Protection in the Soil Environment" (CORPSE), to examine the net effect of priming and protection in response to rising atmospheric CO2, and conducted simulations of rhizosphere priming effects at both ecosystem and global scales. At the ecosystem scale, the model successfully captured and explained disparate SOC responses at the Duke and Oak Ridge free-air CO2 enrichment (FACE) experiments. We show that stabilization of "new" carbon in protected SOC pools may equal or exceed microbial priming of "old" SOC in ecosystems with readily decomposable litter (e.g. Oak Ridge). In contrast, carbon losses owing to priming dominate the net SOC response in ecosystems with more resistant litters (e.g. Duke). For global simulations, the model was fully integrated into the Geophysical Fluid Dynamics Laboratory (GFDL) land model LM3. Globally, priming effects driven by enhanced root exudation and expansion of the rhizosphere reduced SOC storage in the majority of terrestrial areas, partially counterbalancing SOC gains from the enhanced ecosystem productivity driven by CO2 fertilization. Collectively, our results suggest that SOC stocks globally depend not only on temperature and moisture, but also on vegetation responses to environmental changes, and that protected C may provide an important constraint on priming effects.

Effects of contrast on smooth pursuit eye movements.

PubMed

Spering, Miriam; Kerzel, Dirk; Braun, Doris I; Hawken, Michael J; Gegenfurtner, Karl R

2005-05-20

It is well known that moving stimuli can appear to move more slowly when contrast is reduced (P. Thompson, 1982). Here we address the question whether changes in stimulus contrast also affect smooth pursuit eye movements. Subjects were asked to smoothly track a moving Gabor patch. Targets varied in velocity (1, 8, and 15 deg/s), spatial frequency (0.1, 1, 4, and 8 c/deg), and contrast, ranging from just below individual thresholds to maximum contrast. Results show that smooth pursuit eye velocity gain rose significantly with increasing contrast. Below a contrast level of two to three times threshold, pursuit gain, acceleration, latency, and positional accuracy were severely impaired. Therefore, the smooth pursuit motor response shows the same kind of slowing at low contrast that was demonstrated in previous studies on perception.

Design and Implementation of an Interface Editor for the Amadeus Multi- Relational Database Front-end System

DTIC Science & Technology

1993-03-25

application of Object-Oriented Programming (OOP) and Human-Computer Interface (HCI) design principles. Knowledge gained from each topic has been incorporated...through the ap- plication of Object-Oriented Programming (OOP) and Human-Computer Interface (HCI) design principles. Knowledge gained from each topic has...programming and Human-Computer Interface (HCI) design. Knowledge gained from each is applied to the design of a Form-based interface for database data

The impact of a dedicated Science-Technology-Society (STS) course on student knowledge of STS content

NASA Astrophysics Data System (ADS)

Barron, Paul E.

In the last half century, public awareness of issues such as population growth, environmental pollution and the threat of nuclear war has pressured science education to reform to increase student social responsibility. The emerging Science-Technology-Society (STS) movement addressed these concerns by developing numerous strategies and curricula. Considerable diagnostic research has been conducted on student knowledge of the nature of science, but not on the wider scope of STS content (e.g., the nature of science and technology and their interactions with society). However, researchers have not widely studied the impact of comprehensive STS curricula on students' knowledge of STS content nor the nature of STS teaching practice that influenced this knowledge gain. This study examined student success and teacher performance in a special STS course in Ontario, Canada. Research questions focused on the STS content knowledge gain by students completing this course and the impact of the STS teachers' teaching practices on this knowledge gain. Student data were collected using pre-course and post-course assessments of students' STS content knowledge. Teacher data were obtained using semi-structured interviews, classroom observations and videotapes. Statistical analysis indicated that, after completing the STS course, students significantly increased their STS content knowledge as measured by the Views on Science Technology Society instrument. Gender and academic achievement had no significant impact on this knowledge gain, implying that this course, as taught by these teachers, could appeal to a wide range of students as a general education course. The second part of the study indicated that detailed research is needed on the relationship between STS teaching practice and student STS content knowledge gain. The small sample size prevents generalizations but initial indications show that factors such constructivist teaching practices and strong teacher STS content knowledge may generate greater student knowledge gains than didactic teaching and weak teacher STS content knowledge. In this limited sample, it was found that constructivist teaching practice can overcome weak teacher STS content knowledge in increasing student STS content knowledge. In addition, other factors such as problem-solving and decision-making skills need to be studied as part of an overall framework for STS teaching.

Training Children in Pedestrian Safety: Distinguishing Gains in Knowledge from Gains in Safe Behavior

PubMed Central

McClure, Leslie A.

2014-01-01

Pedestrian injuries contribute greatly to child morbidity and mortality. Recent evidence suggests that training within virtual pedestrian environments may improve children’s street crossing skills, but may not convey knowledge about safety in street environments. We hypothesized that (a) children will gain pedestrian safety knowledge via videos/software/internet websites, but not when trained by virtual pedestrian environment or other strategies; (b) pedestrian safety knowledge will be associated with safe pedestrian behavior both before and after training; and (c) increases in knowledge will be associated with increases in safe behavior among children trained individually at streetside locations, but not those trained by means of other strategies. We analyzed data from a randomized controlled trial evaluating pedestrian safety training. We randomly assigned 240 children ages 7–8 to one of four training conditions: videos/software/internet, virtual reality (VR), individualized streetside instruction, or a no-contact control. Both virtual and field simulations of street crossing at 2-lane bi-directional mid-block locations assessed pedestrian behavior at baseline, post-training, and 6-month follow-up. Pedestrian knowledge was assessed orally on all three occasions. Children trained by videos/software/internet, and those trained individually, showed increased knowledge following training relative to children in the other groups (ps < 0.01). Correlations between pedestrian safety knowledge and pedestrian behavior were mostly non-significant. Correlations between change in knowledge and change in behavior from pre- to post-intervention also were non-significant, both for the full sample and within conditions. Children trained using videos/software/internet gained knowledge but did not change their behavior. Children trained individually gained in both knowledge and safer behavior. Children trained virtually gained in safer behavior but not knowledge. If VR is used for training, tools like videos/internet might effectively supplement training. We discovered few associations between knowledge and behavior, and none between changes in knowledge and behavior. Pedestrian safety knowledge and safe pedestrian behavior may be orthogonal constructs that should be considered independently for research and training purposes. PMID:24573688

Case studies of first-year critical science teachers

NASA Astrophysics Data System (ADS)

Love, Kurt A.

Brent Davis and Dennis Sumara (1997) performed a study of themselves and another professor who took a sabbatical to work in an elementary school for a year. Their intentions, as professors focused on cognition, was to create a change in teaching practices throughout the school that aligned more closely with social cognitive research. However, their experiences did not go as planned. Each found that he could not just simply bring their philosophies into their classrooms independent of the sociocultural context of the school. They found very quickly that none of them could act as fully autonomous agents. They described their experiences as being part of the sociocultural fabric of the school because each of their teaching practices changed in ways that they did not anticipate and in ways that were not philosophically aligned. However, they also found that this was a two-way relationship. They were not describing completely deterministic experiences. Davis and Sumara described observing colleagues changing their practices in ways that did incorporate some of the philosophies that they espoused during their tenure at the elementary school. They explain their experience as one where they were pushed and pulled by the sociocultural context and they also pushed and pulled on the sociocultural context. This dissertation focuses on three first-year science teachers (a 4 th grade teacher and two high school science teachers) who identified as wanting to bring critical, feminist, and ecojustice perspectives into their teaching practices. Each enacts these practices much differently in the context of the sociocultural contexts of their own schools, and often changed their teaching practices in ways that seemed to more closely align with those contexts. Each of the three dealt with external and internal hegemonic pressures that caused them to align more closely with their contexts. The philosophical foundations of their sociocultural contexts were manifested externally through technical controls (i.e. district-wide curriculum, state testing, district-wide common assessments, and state standards) and bureaucratic controls (i.e. mandates from administration that reinforce compliance to the technical controls) (Edwards, 1979; Irwin, 1996), sociocultural cues from administrators, colleagues, and students, and were made seemingly impenetrable via intensification, or high workloads that prevent reflective and critical thinking (Apple, 1988; Irwin, 1996). The internalized hegemonic pressures included their own feelings of internalized domination, surplus powerlessness (driven by feelings of isolation and self-blame) (Irwin, 1996; Lerner, 1986), and internalized dispositional views of their students (driven by feelings that their students were not capable of critical social thinking). Each of their case studies focus on how the philosophical differences between the first-year teachers and the sociocultural contexts contrasted providing constant tension for each of the three teachers in terms of their decision-making and their teaching practices. The technical controls seemed to be at the root of most of the external hegemonic pressures and even their internal hegemonic pressures. This paper will focus on the philosophical underpinnings of the state standards in science, the statewide tests, the district curricula, and district-wide common assessments that drove the teachers' practices. The philosophical foundations of their sociocultural contexts were: (1) knowledge as static and objectified, (2) curricular knowledge as the preferred knowledge, (3) standardized testing as a preferred method of gaining data about students' understandings of content, (4) uniform, decontextualized information as "neutral" facts and preferred knowledge, and (5) the summative view of 1-4 as a schooling process that produces learning that is preferred. The first-year teachers' philosophies together contrasted the philosophies of their sociocultural contexts. The first-year teachers held that: (1) knowledge has a deep connection with power in that knowledge is a construction of those in the dominant groups' views of reality, (2) knowledge is not static, but is a co-creative, continuous process, (3) knowledge is a contested terrain, (4) students should be offered the opportunities to explore the knowledge-power relationships, as well as act in their communities to disrupt social and ecological injustices, and (5) the summative view of 1-4 is their preferred view of the schooling process. This study describes how the three teachers responded to the hegemonic pressures of their sociocultural contexts in the form of technical and bureaucratic controls as well as the amplified messages from their colleagues, administrators, and students. This study also describes their own internalized feelings of fear, isolation, and a sense of not being able to make change in their schools. This study focuses on the complex experience of each of the three teachers as they struggle to exert their agency in a context where the ideology is clearly opposed to their own. (Abstract shortened by UMI.)

Bringing Grand Canyon to the College Campus: Assessment of Student Learning in the Geosciences Through Virtual Field Trip Games for Mobile Smart-Devices

NASA Astrophysics Data System (ADS)

Bursztyn, N.; Walker, A.; Shelton, B.; Pederson, J. L.

2015-12-01

Geoscience educators have long considered field trips to be the most effective way of attracting students into the discipline. A solution for bringing student-driven, engaging, kinesthetic field experiences to a broader audience lies in ongoing advances in mobile-communication technology. This NSF-TUES funded project developed three virtual field trip experiences for smartphones and tablets (on geologic time, geologic structures, and hydrologic processes), and then tested their performance in terms of student interest in geoscience as well as gains in learning. The virtual field trips utilize the GPS capabilities of smartphones and tablets, requiring the students to navigate outdoors in the real world while following a map on their smart device. This research, involving 873 students at five different college campuses, used analysis of covariance (ANCOVA) and multiple regression for statistical methods. Gains in learning across all participants are minor, and not statistically different between intervention and control groups. Predictors of gains in content comprehension for all three modules are the students' initial interest in the subject and their base level knowledge. For the Geologic Time and Structures modules, being a STEM major is an important predictor of student success. Most pertinent for this research, for Geologic Time and Hydrologic Processes, gains in student learning can be predicted by having completed those particular virtual field trips. Gender and race had no statistical impact, indicating that the virtual field trip modules have broad reach across student demographics. In related research, these modules have been shown to increase student interest in the geosciences more definitively than the learning gains here. Thus, future work should focus on improving the educational impact of mobile-device field trips, as their eventual incorporation into curricula is inevitable.

Binocular combination of phase and contrast explained by a gain-control and gain-enhancement model

PubMed Central

Ding, Jian; Klein, Stanley A.; Levi, Dennis M.

2013-01-01

We investigated suprathreshold binocular combination, measuring both the perceived phase and perceived contrast of a cyclopean sine wave. We used a paradigm adapted from Ding and Sperling (2006, 2007) to measure the perceived phase by indicating the apparent location (phase) of the dark trough in the horizontal cyclopean sine wave relative to a black horizontal reference line, and we used the same stimuli to measure perceived contrast by matching the binocular combined contrast to a standard contrast presented to one eye. We found that under normal viewing conditions (high contrast and long stimulus duration), perceived contrast is constant, independent of the interocular contrast ratio and the interocular phase difference, while the perceived phase shifts smoothly from one eye to the other eye depending on the contrast ratios. However, at low contrasts and short stimulus durations, binocular combination is more linear and contrast summation is phase-dependent. To account for phase-dependent contrast summation, we incorporated a fusion remapping mechanism into our model, using disparity energy to shift the monocular phases towards the cyclopean phase in order to align the two eyes' images through motor/sensory fusion. The Ding-Sperling model with motor/sensory fusion mechanism gives a reasonable account of the phase dependence of binocular contrast combination and can account for either the perceived phase or the perceived contrast of a cyclopean sine wave separately; however it requires different model parameters for the two. However, when fit to both phase and contrast data simultaneously, the Ding-Sperling model fails. Incorporating interocular gain enhancement into the model results in a significant improvement in fitting both phase and contrast data simultaneously, successfully accounting for both linear summation at low contrast energy and strong nonlinearity at high contrast energy. PMID:23397038

Tunable ring laser with internal injection seeding and an optically-driven photonic crystal reflector.

PubMed

Zheng, Jie; Ge, Chun; Wagner, Clark J; Lu, Meng; Cunningham, Brian T; Hewitt, J Darby; Eden, J Gary

2012-06-18

Continuous tuning over a 1.6 THz region in the near-infrared (842.5-848.6 nm) has been achieved with a hybrid ring/external cavity laser having a single, optically-driven grating reflector and gain provided by an injection-seeded semiconductor amplifier. Driven at 532 nm and incorporating a photonic crystal with an azobenzene overlayer, the reflector has a peak reflectivity of ~80% and tunes at the rate of 0.024 nm per mW of incident green power. In a departure from conventional ring or external cavity lasers, the frequency selectivity for this system is provided by the passband of the tunable photonic crystal reflector and line narrowing in a high gain amplifier. Sub - 0.1 nm linewidths and amplifier extraction efficiencies above 97% are observed with the reflector tuned to 842.5 nm.

9 GeV energy gain in a beam-driven plasma wakefield accelerator

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

Litos, M.; Adli, E.; Allen, J. M.

2016-02-15

An electron beam has gained a maximum energy of 9 GeV per particle in a 1.3 m-long electron beam-driven plasma wakefield accelerator. The amount of charge accelerated in the spectral peak was 28.3 pC, and the root-mean-square energy spread was 5.0%. The mean accelerated charge and energy gain per particle of the 215 shot data set was 115 pC and 5.3 GeV, respectively, corresponding to an acceleration gradient of 4.0 GeV m -1 at the spectral peak. Moreover, the mean energy spread of the data set was 5.1%. Our results are consistent with the extrapolation of the previously reported energymore » gain results using a shorter, 36 cm-long plasma source to within 10%, evincing a non-evolving wake structure that can propagate distances of over a meter in length. Wake-loading effects were evident in the data through strong dependencies observed between various spectral properties and the amount of accelerated charge.« less

The motivation to control and the origin of mind: exploring the life-mind joint point in the Tree of Knowledge System.

PubMed

Geary, David C

2005-01-01

The evolved function of brain, cognitive, affective, conscious-psychological, and behavioral systems is to enable animals to attempt to gain control of the social (e.g., mates), biological (e.g., prey), and physical (e.g., nesting spots) resources that have tended to covary with survival and reproductive outcomes during the species' evolutionary history. These resources generate information patterns that range from invariant to variant. Invariant information is consistent across generations and within lifetimes (e.g., the prototypical shape of a human face) and is associated with modular brain and cognitive systems that coalesce around the domains of folk psychology, folk biology, and folk physics. The processing of information in these domains is implicit and results in automatic bottom-up behavioral responses. Variant information varies across generations and within lifetimes (e.g., as in social dynamics) and is associated with plastic brain and cognitive systems and explicit, consciously driven top-down behavioral responses. The fundamentals of this motivation-to-control model are outlined and links are made to Henriques' (2004) Tree of Knowledge System and Behavioral Investment Theory.

Empirically derived guidance for social scientists to influence environmental policy

PubMed Central

Brown, Katrina; Crissman, Charles; De Young, Cassandra; Gooch, Margaret; James, Craig; Jessen, Sabine; Johnson, Dave; Marshall, Paul; Wachenfeld, Dave; Wrigley, Damian

2017-01-01

Failure to stem trends of ecological disruption and associated loss of ecosystem services worldwide is partly due to the inadequate integration of the human dimension into environmental decision-making. Decision-makers need knowledge of the human dimension of resource systems and of the social consequences of decision-making if environmental management is to be effective and adaptive. Social scientists have a central role to play, but little guidance exists to help them influence decision-making processes. We distil 348 years of cumulative experience shared by 31 environmental experts across three continents into advice for social scientists seeking to increase their influence in the environmental policy arena. Results focus on the importance of process, engagement, empathy and acumen and reveal the importance of understanding and actively participating in policy processes through co-producing knowledge and building trust. The insights gained during this research might empower a science-driven cultural change in science-policy relations for the routine integration of the human dimension in environmental decision making; ultimately for an improved outlook for earth’s ecosystems and the billions of people that depend on them. PMID:28278238

A review of biomaterials in bone defect healing, remaining shortcomings and future opportunities for bone tissue engineering

PubMed Central

Winkler, T.; Sass, F. A.; Schmidt-Bleek, K.

2018-01-01

Despite its intrinsic ability to regenerate form and function after injury, bone tissue can be challenged by a multitude of pathological conditions. While innovative approaches have helped to unravel the cascades of bone healing, this knowledge has so far not improved the clinical outcomes of bone defect treatment. Recent findings have allowed us to gain in-depth knowledge about the physiological conditions and biological principles of bone regeneration. Now it is time to transfer the lessons learned from bone healing to the challenging scenarios in defects and employ innovative technologies to enable biomaterial-based strategies for bone defect healing. This review aims to provide an overview on endogenous cascades of bone material formation and how these are transferred to new perspectives in biomaterial-driven approaches in bone regeneration. Cite this article: T. Winkler, F. A. Sass, G. N. Duda, K. Schmidt-Bleek. A review of biomaterials in bone defect healing, remaining shortcomings and future opportunities for bone tissue engineering: The unsolved challenge. Bone Joint Res 2018;7:232–243. DOI: 10.1302/2046-3758.73.BJR-2017-0270.R1.

Innovation and design of a web-based pain education interprofessional resource.

PubMed

Lax, Leila; Watt-Watson, Judy; Lui, Michelle; Dubrowski, Adam; McGillion, Michael; Hunter, Judith; Maclennan, Cameron; Knickle, Kerry; Robb, Anja; Lapeyre, Jaime

2011-01-01

The present article describes educational innovation processes and design of a web-based pain interprofessional resource for prelicensure health science students in universities across Canada. Operationalization of educational theory in design coupled with formative evaluation of design are discussed, along with strategies that support collaborative innovation. Educational design was driven by content, theory and evaluation. Pain misbeliefs and teaching points along the continuum from acute to persistent pain were identified. Knowledge-building theory, situated learning, reflection and novel designs for cognitive scaffolding were then employed. Design research principles were incorporated to inform iterative and ongoing design. An authentic patient case was constructed, situated in interprofessional complex care to highlight learning objectives related to pre-operative, postoperative and treatment up to one year, for a surgical cancer patient. Pain mechanisms, assessment and management framed content creation. Knowledge building scaffolds were used, which included video simulations, embedded resources, concurrent feedback, practice-based reflective exercises and commentaries. Scaffolds were refined to specifically support knowledge translation. Illustrative commentaries were designed to explicate pain misbeliefs and best practices. Architecture of the resource was mapped; a multimedia, interactive prototype was created. This pain education resource was developed primarily for individual use, with extensions for interprofessional collective discourse. Translation of curricular content scripts into representation maps supported the collaborative design process by establishing a common visual language. The web-based prototype will be formatively and summatively evaluated to assess pedagogic design, knowledge-translation scaffolds, pain knowledge gains, relevance, feasibility and fidelity of this educational innovation.

Trends in European liver death rates: implications for alcohol policy.

PubMed

Jewell, Jo; Sheron, Nick

2010-06-01

Changing alcohol consumption has led to a three- to fivefold increase in liver deaths in the UK and Finland, and a three- to fivefold decrease in France and Italy. Increasing consumption from a low baseline has been driven by fiscal, marketing and commercial factors--some of which have occurred as a result of countries joining the EU. In contrast consumption has fallen from previously very high levels as a result of shifting social and cultural factors; a move from rural to urban lifestyles and increased health consciousness. The marketing drive in these countries has had to shift from a model based on quantity to one based on quality, which means that health gains have occurred alongside a steady improvement in the overall value of the wine industry. Fiscal incentives--minimum pricing, restricting cross border trade and more volumetric taxation could aid this shift. A healthier population and a healthy drinks industry are not incompatible.

Impact of New Camera Technologies on Discoveries in Cell Biology.

PubMed

Stuurman, Nico; Vale, Ronald D

2016-08-01

New technologies can make previously invisible phenomena visible. Nowhere is this more obvious than in the field of light microscopy. Beginning with the observation of "animalcules" by Antonie van Leeuwenhoek, when he figured out how to achieve high magnification by shaping lenses, microscopy has advanced to this day by a continued march of discoveries driven by technical innovations. Recent advances in single-molecule-based technologies have achieved unprecedented resolution, and were the basis of the Nobel prize in Chemistry in 2014. In this article, we focus on developments in camera technologies and associated image processing that have been a major driver of technical innovations in light microscopy. We describe five types of developments in camera technology: video-based analog contrast enhancement, charge-coupled devices (CCDs), intensified sensors, electron multiplying gain, and scientific complementary metal-oxide-semiconductor cameras, which, together, have had major impacts in light microscopy. © 2016 Marine Biological Laboratory.

Flexible Contrast Gain Control in the Right Hemisphere

ERIC Educational Resources Information Center

Okubo, Matia; Nicholls, Michael E. R.

2005-01-01

This study investigates whether the right hemisphere has more flexible contrast gain control settings for the identification of spatial frequency. Right-handed participants identified 1 and 9 cycles per degree sinusoidal gratings presented either to the left visual field-right hemisphere (LVF-RH) or the right visual field-left hemisphere (RVF-LH).…

Metabolic Stress and Compromised Identity of Pancreatic Beta Cells

PubMed Central

Swisa, Avital; Glaser, Benjamin; Dor, Yuval

2017-01-01

Beta cell failure is a central feature of type 2 diabetes (T2D), but the molecular underpinnings of the process remain only partly understood. It has been suggested that beta cell failure in T2D involves massive cell death. Other studies ascribe beta cell failure to cell exhaustion, due to chronic oxidative or endoplasmic reticulum stress leading to cellular dysfunction. More recently it was proposed that beta cells in T2D may lose their differentiated identity, possibly even gaining features of other islet cell types. The loss of beta cell identity appears to be driven by glucotoxicity inhibiting the activity of key beta cell transcription factors including Pdx1, Nkx6.1, MafA and Pax6, thereby silencing beta cell genes and derepressing alternative islet cell genes. The loss of beta cell identity is at least partly reversible upon normalization of glycemia, with implications for the reversibility of T2D, although it is not known if beta cell failure reaches eventually a point of no return. In this review we discuss current evidence for metabolism-driven compromised beta cell identity, key knowledge gaps and opportunities for utility in the treatment of T2D. PMID:28270834

Metabolic Stress and Compromised Identity of Pancreatic Beta Cells.

PubMed

Swisa, Avital; Glaser, Benjamin; Dor, Yuval

2017-01-01

Beta cell failure is a central feature of type 2 diabetes (T2D), but the molecular underpinnings of the process remain only partly understood. It has been suggested that beta cell failure in T2D involves massive cell death. Other studies ascribe beta cell failure to cell exhaustion, due to chronic oxidative or endoplasmic reticulum stress leading to cellular dysfunction. More recently it was proposed that beta cells in T2D may lose their differentiated identity, possibly even gaining features of other islet cell types. The loss of beta cell identity appears to be driven by glucotoxicity inhibiting the activity of key beta cell transcription factors including Pdx1, Nkx6.1, MafA and Pax6, thereby silencing beta cell genes and derepressing alternative islet cell genes. The loss of beta cell identity is at least partly reversible upon normalization of glycemia, with implications for the reversibility of T2D, although it is not known if beta cell failure reaches eventually a point of no return. In this review we discuss current evidence for metabolism-driven compromised beta cell identity, key knowledge gaps and opportunities for utility in the treatment of T2D.

Study of gain-coupled distributed feedback laser based on high order surface gain-coupled gratings

NASA Astrophysics Data System (ADS)

Gao, Feng; Qin, Li; Chen, Yongyi; Jia, Peng; Chen, Chao; Cheng, LiWen; Chen, Hong; Liang, Lei; Zeng, Yugang; Zhang, Xing; Wu, Hao; Ning, Yongqiang; Wang, Lijun

2018-03-01

Single-longitudinal-mode, gain-coupled distributed feedback (DFB) lasers based on high order surface gain-coupled gratings are achieved. Periodic surface metal p-contacts with insulated grooves realize gain-coupled mechanism. To enhance gain contrast in the quantum wells without the introduction of effective index-coupled effect, groove length and depth were well designed. Our devices provided a single longitudinal mode with the maximum CW output power up to 48.8 mW/facet at 971.31 nm at 250 mA without facet coating, 3dB linewidth (<3.2 pm) and SMSR (>39 dB). Optical bistable characteristic was observed with a threshold current difference. Experimentally, devices with different cavity lengths were contrasted on power-current and spectrum characteristics. Due to easy fabrication technique and stable performance, it provides a method of fabricating practical gain-coupled distributed feedback lasers for commercial applications.

Differences in intersaccadic adaptation transfer between inward and outward adaptation.

PubMed

Schnier, Fabian; Lappe, Markus

2011-09-01

Saccadic adaptation is a mechanism to increase or decrease the amplitude gain of subsequent saccades, if a saccade is not on target. Recent research has shown that the mechanism of gain increasing, or outward adaptation, and the mechanism of gain decreasing, or inward adaptation, rely on partly different processes. We investigate how outward and inward adaptation of reactive saccades transfer to other types of saccades, namely scanning, overlap, memory-guided, and gap saccades. Previous research has shown that inward adaptation of reactive saccades transfers only partially to these other saccade types, suggesting differences in the control mechanisms between these saccade categories. We show that outward adaptation transfers stronger to scanning and overlap saccades than inward adaptation, and that the strength of transfer depends on the duration for which the saccade target is visible before saccade onset. Furthermore, we show that this transfer is mainly driven by an increase in saccade duration, which is apparent for all saccade categories. Inward adaptation, in contrast, is accompanied by a decrease in duration and in peak velocity, but only the peak velocity decrease transfers from reactive saccades to other saccade categories, i.e., saccadic duration remains constant or even increases for test saccades of the other categories. Our results, therefore, show that duration and peak velocity are independent parameters of saccadic adaptation and that they are differently involved in the transfer of adaptation between saccade categories. Furthermore, our results add evidence that inward and outward adaptation are different processes.

Mass Gains of the Antarctic Ice Sheet Exceed Losses

NASA Technical Reports Server (NTRS)

Zwally, H. Jay; Li, Jun; Robbins, John; Saba, Jack L.; Yi, Donghui; Brenner, Anita; Bromwich, David

2012-01-01

During 2003 to 2008, the mass gain of the Antarctic ice sheet from snow accumulation exceeded the mass loss from ice discharge by 49 Gt/yr (2.5% of input), as derived from ICESat laser measurements of elevation change. The net gain (86 Gt/yr) over the West Antarctic (WA) and East Antarctic ice sheets (WA and EA) is essentially unchanged from revised results for 1992 to 2001 from ERS radar altimetry. Imbalances in individual drainage systems (DS) are large (-68% to +103% of input), as are temporal changes (-39% to +44%). The recent 90 Gt/yr loss from three DS (Pine Island, Thwaites-Smith, and Marie-Bryd Coast) of WA exceeds the earlier 61 Gt/yr loss, consistent with reports of accelerating ice flow and dynamic thinning. Similarly, the recent 24 Gt/yr loss from three DS in the Antarctic Peninsula (AP) is consistent with glacier accelerations following breakup of the Larsen B and other ice shelves. In contrast, net increases in the five other DS of WA and AP and three of the 16 DS in East Antarctica (EA) exceed the increased losses. Alternate interpretations of the mass changes driven by accumulation variations are given using results from atmospheric-model re-analysis and a parameterization based on 5% change in accumulation per degree of observed surface temperature change. A slow increase in snowfall with climate waRMing, consistent with model predictions, may be offsetting increased dynamic losses.

Eutrophication and Dreissena Invasion as Drivers of Biodiversity: A Century of Change in the Mollusc Community of Oneida Lake

PubMed Central

Karatayev, Vadim A.; Karatayev, Alexander Y.; Burlakova, Lyubov E.; Rudstam, Lars G.

2014-01-01

Changes in nutrient loading and invasive species are among the strongest human-driven disturbances in freshwater ecosystems, but our knowledge on how they affect the biodiversity of lakes is still limited. We conducted a detailed historical analysis of the mollusc community of Oneida Lake based on our comprehensive lakewide study in 2012 and previous surveys dating back to 1915. In the early 20th century, the lake had a high water clarity, with abundant macrophytes and benthic algae, and hosted the most diverse molluscan community in New York State, including 32 gastropod and 9 unionid species. By the 1960s, lake turbidity increased during a period of anthropogenic eutrophication, resulting in a 38% decline in species richness and a 95% reduction in abundance of native gastropods grazing on benthic algae. Following the invasion of Dreissena spp. in 1991 and subsequent increases in water clarity, native gastropod species richness expanded by 37% and abundance increased 20-fold by 2012. In contrast, filter-feeding unionids were unaffected by increased turbidity during the period of eutrophication but were extirpated by dreissenids. Through contrasting effects on turbidity, eutrophication and Dreissena spp. have likely driven the observed changes in native grazing gastropods by affecting the abundance of light-limited benthic algae. Given the high species richness and ecological importance of benthic grazers, monitoring and managing turbidity is important in preserving molluscan diversity. PMID:25010705

Participation in HIV Behavioral Research: Unanticipated Benefits and Burdens.

PubMed

Tross, Susan; Pinho, Veronica; Lima, Jennifer E; Ghiroli, Megan; Elkington, Katherine S; Strauss, David H; Wainberg, Milton L

2018-04-30

HIV behavioral research has provided an invaluable knowledge base for effective approaches to behavioral challenges along the HIV care cascade. Little attention has been paid to tracking unanticipated effects of research participation, whether negative or positive. We used qualitative methods to elicit impressions of unanticipated effects of participation in behavioral research. An instrument was developed and piloted to assess positive (emotional gains, practical gains, HIV prevention knowledge and skills gains) and negative (emotional stress, discomfort with research) unanticipated effects. Participants (N = 25) from five projects, including men who have sex with men, adults who use substances, and youth, reported multiple positive unanticipated effects (sexual and drug risk reduction, goal setting, improvements in self-esteem and mood, relationship gains, health care behavior gains, knowledge and introspection gains) and rare unanticipated negative effects. Developing a systematic tool of unanticipated positive and negative effects of participation in behavioral research is a crucial next step.

Study of Impact on Undergraduates' Entrepreneurial Failure Based on the Model of Psychological Resilience-Knowledge Acquisition

ERIC Educational Resources Information Center

Jing, Tang; Dancheng, Luo; Ye, Zhao

2016-01-01

Purpose: The entrepreneurship is a course of gaining knowledge from the failure and stimulating positive energy constantly. The entrepreneur's psychological resilience is the key to gain knowledge (positive energy) from failure (negative energy). The education of undergraduate entrepreneurship is one of the priorities these days. Educators shall…

Radiation reaction effect on laser driven auto-resonant particle acceleration

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

Sagar, Vikram; Sengupta, Sudip; Kaw, P. K.

2015-12-15

The effects of radiation reaction force on laser driven auto-resonant particle acceleration scheme are studied using Landau-Lifshitz equation of motion. These studies are carried out for both linear and circularly polarized laser fields in the presence of static axial magnetic field. From the parametric study, a radiation reaction dominated region has been identified in which the particle dynamics is greatly effected by this force. In the radiation reaction dominated region, the two significant effects on particle dynamics are seen, viz., (1) saturation in energy gain by the initially resonant particle and (2) net energy gain by an initially non-resonant particlemore » which is caused due to resonance broadening. It has been further shown that with the relaxation of resonance condition and with optimum choice of parameters, this scheme may become competitive with the other present-day laser driven particle acceleration schemes. The quantum corrections to the Landau-Lifshitz equation of motion have also been taken into account. The difference in the energy gain estimates of the particle by the quantum corrected and classical Landau-Lifshitz equation is found to be insignificant for the present day as well as upcoming laser facilities.« less

Changing the Spatial Scope of Attention Alters Patterns of Neural Gain in Human Cortex

PubMed Central

Garcia, Javier O.; Rungratsameetaweemana, Nuttida; Sprague, Thomas C.

2014-01-01

Over the last several decades, spatial attention has been shown to influence the activity of neurons in visual cortex in various ways. These conflicting observations have inspired competing models to account for the influence of attention on perception and behavior. Here, we used electroencephalography (EEG) to assess steady-state visual evoked potentials (SSVEP) in human subjects and showed that highly focused spatial attention primarily enhanced neural responses to high-contrast stimuli (response gain), whereas distributed attention primarily enhanced responses to medium-contrast stimuli (contrast gain). Together, these data suggest that different patterns of neural modulation do not reflect fundamentally different neural mechanisms, but instead reflect changes in the spatial extent of attention. PMID:24381272

Can knowledge exchange support the implementation of a health-promoting schools approach? Perceived outcomes of knowledge exchange in the COMPASS study.

PubMed

Brown, Kristin M; Elliott, Susan J; Robertson-Wilson, Jennifer; Vine, Michelle M; Leatherdale, Scott T

2018-03-13

Despite the potential population-level impact of a health-promoting schools approach, schools face challenges in implementation, indicating a gap between school health research and practice. Knowledge exchange provides an opportunity to reduce this gap; however, there has been limited evaluation of these initiatives. This research explored researchers' and knowledge users' perceptions of outcomes associated with a knowledge exchange initiative within COMPASS, a longitudinal study of Canadian secondary students and schools. Schools received annual tailored summaries of their students' health behaviours and suggestions for action and were linked with knowledge brokers to support them in taking action to improve student health. Qualitative semi-structured interviews were conducted with COMPASS researchers (n = 13), school staff (n = 13), and public health stakeholders (n = 4) to explore their experiences with COMPASS knowledge exchange. Key issues included how knowledge users used school-specific findings, perceived outcomes of knowledge exchange, and suggestions for change. Outcomes for both knowledge users and researchers were identified; interestingly, knowledge users attributed more outcomes to using school-specific findings than knowledge brokering. School and public health participants indicated school-specific findings informed their programming and planning. Importantly, knowledge exchange provided a platform for partnerships between researchers, schools, and public health units. Knowledge brokering allowed researchers to gain feedback from knowledge users to enhance the study and a better understanding of the school environment. Interestingly, COMPASS knowledge exchange outcomes aligned with Samdal and Rowling's eight theory-driven implementation components for health-promoting schools. Hence, knowledge exchange may provide a mechanism to help schools implement a health-promoting schools approach. This research contributes to the limited literature regarding outcomes of knowledge brokering in public health and knowledge exchange in school health research. However, since not all schools engaged in knowledge brokering, and not all schools that engaged discussed these outcomes, further research is needed to determine the amount of engagement required for change and examine the process of COMPASS knowledge brokering to consider how to increase school engagement.

Oral CCR5 inhibitors: will they make it through?

PubMed

Biswas, Priscilla; Nozza, Silvia; Scarlatti, Gabriella; Lazzarin, Adriano; Tambussi, Giuseppe

2006-05-01

The therapeutic armamentarium against HIV has recently gained a drug belonging to a novel class of antiretrovirals, the entry inhibitors. The last decade has driven an in-depth knowledge of the HIV entry process, unravelling the multiple engagements of the HIV envelope proteins with the cellular receptorial complex that is composed of a primary receptor (CD4) and a co-receptor (CCR5 or CXCR4). The vast majority of HIV-infected subjects exhibit biological viral variants that use CCR5 as a co-receptor. Individuals with a mutated CCR5 gene, both homo- and heterozygotes, appear to be healthy. For these and other reasons, CCR5 represents an appealing target for treatment intervention, although certain challenges can not be ignored. Promising small-molecule, orally bioavailable CCR5 antagonists are under development for the treatment of HIV-1 infection.

Organizational impact of evidence-informed decision making training initiatives: a case study comparison of two approaches

PubMed Central

2014-01-01

Background The impact of efforts by healthcare organizations to enhance the use of evidence to improve organizational processes through training programs has seldom been assessed. We therefore endeavored to assess whether and how the training of mid- and senior-level healthcare managers could lead to organizational change. Methods We conducted a theory-driven evaluation of the organizational impact of healthcare leaders’ participation in two training programs using a logic model based on Nonaka’s theory of knowledge conversion. We analyzed six case studies nested within the two programs using three embedded units of analysis (individual, group and organization). Interviews were conducted during intensive one-week data collection site visits. A total of 84 people were interviewed. Results We found that the impact of training could primarily be felt in trainees’ immediate work environments. The conversion of attitudes was found to be easier to achieve than the conversion of skills. Our results show that, although socialization and externalization were common in all cases, a lack of combination impeded the conversion of skills. We also identified several individual, organizational and program design factors that facilitated and/or impeded the dissemination of the attitudes and skills gained by trainees to other organizational members. Conclusions Our theory-driven evaluation showed that factors before, during and after training can influence the extent of skills and knowledge transfer. Our evaluation went further than previous research by revealing the influence—both positive and negative—of specific organizational factors on extending the impact of training programs. PMID:24885800

Making Data-Driven Decisions: Silent Reading

ERIC Educational Resources Information Center

Trudel, Heidi

2007-01-01

Due in part to conflicting opinions and research results, the practice of sustained silent reading (SSR) in schools has been questioned. After a frustrating experience with SSR, the author of this article began a data-driven decision-making process to gain new insights on how to structure silent reading in a classroom, including a comparison…

Rayleigh-Taylor mixing with time-dependent acceleration

NASA Astrophysics Data System (ADS)

Abarzhi, Snezhana

2016-10-01

We extend the momentum model to describe Rayleigh-Taylor (RT) mixing driven by a time-dependent acceleration. The acceleration is a power-law function of time, similarly to astrophysical and plasma fusion applications. In RT flow the dynamics of a fluid parcel is driven by a balance per unit mass of the rates of momentum gain and loss. We find analytical solutions in the cases of balanced and imbalanced gains and losses, and identify their dependence on the acceleration exponent. The existence is shown of two typical regimes of self-similar RT mixing-acceleration-driven Rayleigh-Taylor-type and dissipation-driven Richtymer-Meshkov-type with the latter being in general non-universal. Possible scenarios are proposed for transitions from the balanced dynamics to the imbalanced self-similar dynamics. Scaling and correlations properties of RT mixing are studied on the basis of dimensional analysis. Departures are outlined of RT dynamics with time-dependent acceleration from canonical cases of homogeneous turbulence as well as blast waves with first and second kind self-similarity. The work is supported by the US National Science Foundation.

Rayleigh-Taylor mixing with space-dependent acceleration

NASA Astrophysics Data System (ADS)

Abarzhi, Snezhana

2016-11-01

We extend the momentum model to describe Rayleigh-Taylor (RT) mixing driven by a space-dependent acceleration. The acceleration is a power-law function of space coordinate, similarly to astrophysical and plasma fusion applications. In RT flow the dynamics of a fluid parcel is driven by a balance per unit mass of the rates of momentum gain and loss. We find analytical solutions in the cases of balanced and imbalanced gains and losses, and identify their dependence on the acceleration exponent. The existence is shown of two typical sub-regimes of self-similar RT mixing - the acceleration-driven Rayleigh-Taylor-type mixing and dissipation-driven Richtymer-Meshkov-type mixing with the latter being in general non-universal. Possible scenarios are proposed for transitions from the balanced dynamics to the imbalanced self-similar dynamics. Scaling and correlations properties of RT mixing are studied on the basis of dimensional analysis. Departures are outlined of RT dynamics with space-dependent acceleration from canonical cases of homogeneous turbulence as well as blast waves with first and second kind self-similarity. The work is supported by the US National Science Foundation.

A Study of the Competency of Third Year Medical Students to Interpret Biochemically Based Clinical Scenarios Using Knowledge and Skills Gained in Year 1 and 2

ERIC Educational Resources Information Center

Gowda, Veena Bhaskar S.; Nagaiah, Bhaskar Hebbani; Sengodan, Bharathi

2016-01-01

Medical students build clinical knowledge on the grounds of previously obtained basic knowledge. The study aimed to evaluate the competency of third year medical students to interpret biochemically based clinical scenarios using knowledge and skills gained during year 1 and 2 of undergraduate medical training. Study was conducted on year 3 MBBS…

D and D Knowledge Management Information Tool - 2012 - 12106

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

Upadhyay, H.; Lagos, L.; Quintero, W.

2012-07-01

Deactivation and decommissioning (D and D) work is a high priority activity across the Department of Energy (DOE) complex. Subject matter specialists (SMS) associated with the different ALARA (As-Low-As-Reasonably-Achievable) Centers, DOE sites, Energy Facility Contractors Group (EFCOG) and the D and D community have gained extensive knowledge and experience over the years in the cleanup of the legacy waste from the Manhattan Project. To prevent the D and D knowledge and expertise from being lost over time from the evolving and aging workforce, DOE and the Applied Research Center (ARC) at Florida International University (FIU) proposed to capture and maintainmore » this valuable information in a universally available and easily usable system. D and D KM-IT provides single point access to all D and D related activities through its knowledge base. It is a community driven system. D and D KM-IT makes D and D knowledge available to the people who need it at the time they need it and in a readily usable format. It uses the World Wide Web as the primary source for content in addition to information collected from subject matter specialists and the D and D community. It brings information in real time through web based custom search processes and its dynamic knowledge repository. Future developments include developing a document library, providing D and D information access on mobile devices for the Technology module and Hotline, and coordinating multiple subject matter specialists to support the Hotline. The goal is to deploy a high-end sophisticated and secured system to serve as a single large knowledge base for all the D and D activities. The system consolidates a large amount of information available on the web and presents it to users in the simplest way possible. (authors)« less

Knowledge Creation in Nursing Education

PubMed Central

Hassanian, Zahra Marzieh; Ahanchian, Mohammad Reza; Ahmadi, Suleiman; Gholizadeh, Rezvan Hossein; Karimi-Moonaghi, Hossein

2015-01-01

In today’s society, knowledge is recognized as a valuable social asset and the educational system is in search of a new strategy that allows them to construct their knowledge and experience. The purpose of this study was to explore the process of knowledge creation in nursing education. In the present study, the grounded theory approach was used. This method provides a comprehensive approach to collecting, organizing, and analyzing data. Data were obtained through 17 semi-structured interviews with nursing faculties and nursing students. Purposeful and theoretical sampling was conducted. Based on the method of Strauss and Corbin, the data were analyzed using fragmented, deep, and constant-comparative methods. The main categories included striving for growth and reduction of ambiguity, use of knowledge resources, dynamism of mind and social factors, converting knowledge, and creating knowledge. Knowledge was converted through mind processes, individual and group reflection, praxis and research, and resulted in the creation of nursing knowledge. Discrete nursing knowledge is gained through disconformity research in order to gain more individual advantages. The consequence of this analysis was gaining new knowledge. Knowledge management must be included in the mission and strategic planning of nursing education, and it should be planned through operational planning in order to create applicable knowledge. PMID:25716383

Thrombin promotes diet-induced obesity through fibrin-driven inflammation.

PubMed

Kopec, Anna K; Abrahams, Sara R; Thornton, Sherry; Palumbo, Joseph S; Mullins, Eric S; Divanovic, Senad; Weiler, Hartmut; Owens, A Phillip; Mackman, Nigel; Goss, Ashley; van Ryn, Joanne; Luyendyk, James P; Flick, Matthew J

2017-08-01

Obesity promotes a chronic inflammatory and hypercoagulable state that drives cardiovascular disease, type 2 diabetes, fatty liver disease, and several cancers. Elevated thrombin activity underlies obesity-linked thromboembolic events, but the mechanistic links between the thrombin/fibrin(ogen) axis and obesity-associated pathologies are incompletely understood. In this work, immunohistochemical studies identified extravascular fibrin deposits within white adipose tissue and liver as distinct features of mice fed a high-fat diet (HFD) as well as obese patients. Fibγ390-396A mice carrying a mutant form of fibrinogen incapable of binding leukocyte αMβ2-integrin were protected from HFD-induced weight gain and elevated adiposity. Fibγ390-396A mice had markedly diminished systemic, adipose, and hepatic inflammation with reduced macrophage counts within white adipose tissue, as well as near-complete protection from development of fatty liver disease and glucose dysmetabolism. Homozygous thrombomodulin-mutant ThbdPro mice, which have elevated thrombin procoagulant function, gained more weight and developed exacerbated fatty liver disease when fed a HFD compared with WT mice. In contrast, treatment with dabigatran, a direct thrombin inhibitor, limited HFD-induced obesity development and suppressed progression of sequelae in mice with established obesity. Collectively, these data provide proof of concept that targeting thrombin or fibrin(ogen) may limit pathologies in obese patients.

Is it all about the self? The effect of self-control depletion on ultimatum game proposers

PubMed Central

Halali, Eliran; Bereby-Meyer, Yoella; Ockenfels, Axel

2013-01-01

In the ultimatum-game, as in many real-life social exchange situations, the selfish motive to maximize own gains conflicts with fairness preferences. In the present study we manipulated the availability of cognitive-control resources for ultimatum-game proposers to test whether preference for fairness is a deliberative cognitive-controlled act or an automatic act. In two experiments we found that a shortage of cognitive control (ego depletion) led proposers in the ultimatum game (UG) to propose significantly more equal split offers than non-depleted proposers. These results can be interpreted as resulting from an automatic concern for fairness, or from a greater fear of rejection, which would be in line with a purely self-interested response. To separate these competing explanations, in Experiment 2 we conducted a dictator-game in which the responder cannot reject the offer. In contrast to the increased fairness behavior demonstrated by depleted ultimatum-game proposers, we found that depleted dictator-game allocators chose the equal split significantly less often than non-depleted allocators. These results indicate that fairness preferences are automatically driven among UG proposers. The automatic fair behavior, however, at least partially reflects concern about self-interest gain. We discuss different explanations for these results. PMID:23781182

Thrombin promotes diet-induced obesity through fibrin-driven inflammation

PubMed Central

Kopec, Anna K.; Abrahams, Sara R.; Thornton, Sherry; Palumbo, Joseph S.; Mullins, Eric S.; Weiler, Hartmut; Mackman, Nigel; Goss, Ashley; van Ryn, Joanne; Luyendyk, James P.; Flick, Matthew J.

2017-01-01

Obesity promotes a chronic inflammatory and hypercoagulable state that drives cardiovascular disease, type 2 diabetes, fatty liver disease, and several cancers. Elevated thrombin activity underlies obesity-linked thromboembolic events, but the mechanistic links between the thrombin/fibrin(ogen) axis and obesity-associated pathologies are incompletely understood. In this work, immunohistochemical studies identified extravascular fibrin deposits within white adipose tissue and liver as distinct features of mice fed a high-fat diet (HFD) as well as obese patients. Fibγ390–396A mice carrying a mutant form of fibrinogen incapable of binding leukocyte αMβ2-integrin were protected from HFD-induced weight gain and elevated adiposity. Fibγ390–396A mice had markedly diminished systemic, adipose, and hepatic inflammation with reduced macrophage counts within white adipose tissue, as well as near-complete protection from development of fatty liver disease and glucose dysmetabolism. Homozygous thrombomodulin-mutant ThbdPro mice, which have elevated thrombin procoagulant function, gained more weight and developed exacerbated fatty liver disease when fed a HFD compared with WT mice. In contrast, treatment with dabigatran, a direct thrombin inhibitor, limited HFD-induced obesity development and suppressed progression of sequelae in mice with established obesity. Collectively, these data provide proof of concept that targeting thrombin or fibrin(ogen) may limit pathologies in obese patients. PMID:28737512

Is it all about the self? The effect of self-control depletion on ultimatum game proposers.

PubMed

Halali, Eliran; Bereby-Meyer, Yoella; Ockenfels, Axel

2013-01-01

In the ultimatum-game, as in many real-life social exchange situations, the selfish motive to maximize own gains conflicts with fairness preferences. In the present study we manipulated the availability of cognitive-control resources for ultimatum-game proposers to test whether preference for fairness is a deliberative cognitive-controlled act or an automatic act. In two experiments we found that a shortage of cognitive control (ego depletion) led proposers in the ultimatum game (UG) to propose significantly more equal split offers than non-depleted proposers. These results can be interpreted as resulting from an automatic concern for fairness, or from a greater fear of rejection, which would be in line with a purely self-interested response. To separate these competing explanations, in Experiment 2 we conducted a dictator-game in which the responder cannot reject the offer. In contrast to the increased fairness behavior demonstrated by depleted ultimatum-game proposers, we found that depleted dictator-game allocators chose the equal split significantly less often than non-depleted allocators. These results indicate that fairness preferences are automatically driven among UG proposers. The automatic fair behavior, however, at least partially reflects concern about self-interest gain. We discuss different explanations for these results.

Tumor driven by gain-of-function HER2 H878Y mutant is highly sensitive to HER2 inhibitor

PubMed Central

Hu, Zexi; Hu, Yong; Liu, Xicheng; Xi, Rongwen; Zhang, Aiqun; Liu, Deruo; Xie, Qiang; Chen, Liang

2015-01-01

HER2, a well established oncogenic member of EGFR family, is among the most intensely investigated kinase drug targets. In contrast to hotspot mutations of EGFR, few mutations of HER2 locate in activation loop within kinase domain. We previously reported the molecular mechanism underlying hyper kinase activity of HER2H878Y, a mutation located in activation loop. However, its tumorigenicity in vivo and relevant therapeutics remain to be determined. Here, we report for the first time that HER2H878Y was tumorigenic in vivo in lung adenocarcinoma transgenic mouse model. Induced expression of HER2H878Y in lung epithelial compartments resulted in formation of poorly differentiated lung adenocarcinoma with bronchioloalveolar carcinoma (BAC) features. Strikingly, we found that these tumors depended on continuous expression of HER2H878Y for maintenance. Typical HER2 downstream signaling mediators, including PLCγ1, STAT5 and AKT, were hyperactivated in HER2H878Y driven lung tumors. More importantly, administration of HKI-272, a tyrosine kinase inhibitor (TKI), efficiently shrank HER2H878Y driven tumors in transgenic mouse model. Moreover, we found that combinational treatment with HKI272 and mTOR inhibitor, Rapamycin, showed a superior cytotoxicity to H878Y mutant transformed cells and enhanced activity to elicit apoptosis and inhibit growth in situ in tumorous area. Our work therefore showed that HER2H878Y mutant was a reasonable drug target. Hence, our work supported the assessment of HKI-272/rapamycin treatment in clinical trials. PMID:26375550

Multi-Level Assessment of Scientific Content Knowledge Gains Associated with Socioscientific Issues-Based Instruction

ERIC Educational Resources Information Center

Klosterman, Michelle L.; Sadler, Troy D.

2010-01-01

This study explored the impact of using a socioscientific issue (SSI) based curriculum on developing science content knowledge. Using a multi-level assessment design, student content knowledge gains were measured before and after implementation of a three-week unit on global warming (a prominent SSI) that explored both the relevant science content…

Parental Strategies for Knowledge of Adolescents’ Friends: Distinct from Monitoring?

PubMed Central

Miller, Brenda A.; Duke, Michael R.; Ames, Genevieve M.

2012-01-01

Parental monitoring is defined as a set of behaviors used to gain knowledge about an adolescent’s whereabouts, friends and associates, and activities. However, can knowledge of adolescents’ whereabouts/activities, and friends all be attained through the same strategies? Or do they require their own strategies? This study used qualitative interviews with 173 parents of older adolescents from 100 families. Emergent themes described strategies by which parents gain information about their adolescents’ friends and the substance use of those friends. The strategies included direct interaction with the friend, gaining information from the teen, using second-hand sources, and making assumptions. Some of these strategies were consistent with previous research, while others raise new questions and provide interesting new directions to pursue. Primarily, additional consideration needs to be given to assessments of parental monitoring that include strategies for gaining knowledge of adolescents’ friends and their substance use. PMID:23209361

Designing Cognitively Diagnostic Assessment for Algebraic Content Knowledge and Thinking Skills

ERIC Educational Resources Information Center

Zhang, Zhidong

2018-01-01

This study explored a diagnostic assessment method that emphasized the cognitive process of algebra learning. The study utilized a design and a theory-driven model to examine the content knowledge. Using the theory driven model, the thinking skills of algebra learning was also examined. A Bayesian network model was applied to represent the theory…

Outcomes With a Self-Fitting Hearing Aid.

PubMed

Keidser, Gitte; Convery, Elizabeth

2018-01-01

Self-fitting hearing aids (SFHAs)-devices that enable self-directed threshold measurements leading to a prescribed hearing aid (HA) setting, and fine-tuning, without the need for professional support-are now commercially available. This study examined outcomes obtained with one commercial SFHA, the Companion (SoundWorld Solutions), when support was available from a clinical assistant during self-fitting. Participants consisted of 27 experienced and 25 new HA users who completed the self-fitting process, resulting in 38 user-driven and 14 clinician-driven fittings. Following 12 weeks' experience with the SFHAs in the field, outcomes measured included the following: coupler gain and output, HA handling and management skills, speech recognition in noise, and self-reported benefit and satisfaction. In addition, the conventionally fitted HAs of 22 of the experienced participants who had user-driven fittings were evaluated. Irrespective of HA experience, the type of fitting (user- or clinician-driven) had no significant effect on coupler gain, speech recognition scores, or self-reported benefit and satisfaction. Users selected significantly higher low-frequency gain in the SFHAs when compared with the conventionally fitted HAs. The conventionally fitted HAs were rated significantly higher for benefit and satisfaction on some subscales due to negative issues with the physical design and implementation of the SFHAs, rather than who drove the fitting process. Poorer cognitive function was associated with poorer handling and management of the SFHAs. Findings suggest that with the right design and support, SFHAs may be a viable option to improve the accessibility of hearing health care.

Input-Driven Differences in Toddlers' Perception of a Disappearing Phonological Contrast

ERIC Educational Resources Information Center

van der Feest, Suzanne V. H.; Johnson, Elizabeth K.

2016-01-01

How does phonological development differ in children exposed to one versus two variants of a single language? If children receive mixed evidence for a phonological contrast (i.e., one language variant in the environment maintains a contrast while another neutralizes it), will they treat this contrast as noncontrastive (i.e., as allophonic)? Or…

Data collection and analysis strategies for phMRI.

PubMed

Mandeville, Joseph B; Liu, Christina H; Vanduffel, Wim; Marota, John J A; Jenkins, Bruce G

2014-09-01

Although functional MRI traditionally has been applied mainly to study changes in task-induced brain function, evolving acquisition methodologies and improved knowledge of signal mechanisms have increased the utility of this method for studying responses to pharmacological stimuli, a technique often dubbed "phMRI". The proliferation of higher magnetic field strengths and the use of exogenous contrast agent have boosted detection power, a critical factor for successful phMRI due to the restricted ability to average multiple stimuli within subjects. Receptor-based models of neurovascular coupling, including explicit pharmacological models incorporating receptor densities and affinities and data-driven models that incorporate weak biophysical constraints, have demonstrated compelling descriptions of phMRI signal induced by dopaminergic stimuli. This report describes phMRI acquisition and analysis methodologies, with an emphasis on data-driven analyses. As an example application, statistically efficient data-driven regressors were used to describe the biphasic response to the mu-opioid agonist remifentanil, and antagonism using dopaminergic and GABAergic ligands revealed modulation of the mesolimbic pathway. Results illustrate the power of phMRI as well as our incomplete understanding of mechanisms underlying the signal. Future directions are discussed for phMRI acquisitions in human studies, for evolving analysis methodologies, and for interpretative studies using the new generation of simultaneous PET/MRI scanners. This article is part of the Special Issue Section entitled 'Neuroimaging in Neuropharmacology'. Copyright © 2014 Elsevier Ltd. All rights reserved.

2 Gbit/s 0.5 μm complementary metal-oxide semiconductor optical transceiver with event-driven dynamic power-on capability

NASA Astrophysics Data System (ADS)

Wang, Xingle; Kiamilev, Fouad; Gui, Ping; Wang, Xiaoqing; Ekman, Jeremy; Zuo, Yongrong; Blankenberg, Jason; Haney, Michael

2006-06-01

A 2 Gb/s0.5 μm complementary metal-oxide semiconductor optical transceiver designed for board- or backplane level power-efficient interconnections is presented. The transceiver supports optical wake-on-link (OWL), an event-driven dynamic power-on technique. Depending on external events, the transceiver resides in either the active mode or the sleep mode and switches accordingly. The active-to-sleep transition shuts off the normal, gigabit link and turns on dedicated circuits to establish a low-power (~1.8 mW), low data rate (less than 100 Mbits/s) link. In contrast the normal, gigabit link consumes over 100 mW. Similarly the sleep-to-active transition shuts off the low-power link and turns on the normal, gigabit link. The low-power link, sharing the same optical channel with the normal, gigabit link, is used to achieve transmitter/receiver pair power-on synchronization and greatly reduces the power consumption of the transceiver. A free-space optical platform was built to evaluate the transceiver performance. The experiment successfully demonstrated the event-driven dynamic power-on operation. To our knowledge, this is the first time a dynamic power-on scheme has been implemented for optical interconnects. The areas of the circuits that implement the low-power link are approximately one-tenth of the areas of the gigabit link circuits.

Tracking neural correlates of successful learning over repeated sequence observations

PubMed Central

Steinemann, Natalie A.; Moisello, Clara; Ghilardi, M. Felice; Kelly, Simon P.

2016-01-01

The neural correlates of memory formation in humans have long been investigated by exposing subjects to diverse material and comparing responses to items later remembered to those forgotten. Tasks requiring memorization of sensory sequences afford unique possibilities for linking neural memorization processes to behavior, because, rather than comparing across different items of varying content, each individual item can be examined across the successive learning states of being initially unknown, newly learned, and eventually, fully known. Sequence learning paradigms have not yet been exploited in this way, however. Here, we analyze the event-related potentials of subjects attempting to memorize sequences of visual locations over several blocks of repeated observation, with respect to pre- and post-block recall tests. Over centro-parietal regions, we observed a rapid P300 component superimposed on a broader positivity, which exhibited distinct modulations across learning states that were replicated in two separate experiments. Consistent with its well-known encoding of surprise, the P300 deflection monotonically decreased over blocks as locations became better learned and hence more expected. In contrast, the broader positivity was especially elevated at the point when a given item was newly learned, i.e., started being successfully recalled. These results implicate the Broad Positivity in endogenously-driven, intentional memory formation, whereas the P300, in processing the current stimulus to the degree that it was previously uncertain, indexes the cumulative knowledge thereby gained. The decreasing surprise/P300 effect significantly predicted learning success both across blocks and across subjects. This presents a new, neural-based means to evaluate learning capabilities independent of verbal reports, which could have considerable value in distinguishing genuine learning disabilities from difficulties to communicate the outcomes of learning, or perceptual impairments, in a range of clinical brain disorders. PMID:27155129

Novel particle and radiation sources and advanced materials

NASA Astrophysics Data System (ADS)

Mako, Frederick

2016-03-01

The influence Norman Rostoker had on the lives of those who had the pleasure of knowing him is profound. The skills and knowledge I gained as a graduate student researching collective ion acceleration has fueled a career that has evolved from particle beam physics to include particle and radiation source development and advanced materials research, among many other exciting projects. The graduate research performed on collective ion acceleration was extended by others to form the backbone for laser driven plasma ion acceleration. Several years after graduate school I formed FM Technologies, Inc., (FMT), and later Electron Technologies, Inc. (ETI). Currently, as the founder and president of both FMT and ETI, the Rostoker influence can still be felt. One technology that we developed is a self-bunching RF fed electron gun, called the Micro-Pulse Gun (MPG). The MPG has important applications for RF accelerators and microwave tube technology, specifically clinically improved medical linacs and "green" klystrons. In addition to electron beam and RF source research, knowledge of materials and material interactions gained indirectly in graduate school has blossomed into breakthroughs in materials joining technologies. Most recently, silicon carbide joining technology has been developed that gives robust helium leak tight, high temperature and high strength joints between ceramic-to-ceramic and ceramic-to-metal. This joining technology has the potential to revolutionize the ethylene production, nuclear fuel and solar receiver industries by finally allowing for the practical use of silicon carbide as furnace coils, fuel rods and solar receptors, respectively, which are applications that have been needed for decades.

Novel particle and radiation sources and advanced materials

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

Mako, Frederick

The influence Norman Rostoker had on the lives of those who had the pleasure of knowing him is profound. The skills and knowledge I gained as a graduate student researching collective ion acceleration has fueled a career that has evolved from particle beam physics to include particle and radiation source development and advanced materials research, among many other exciting projects. The graduate research performed on collective ion acceleration was extended by others to form the backbone for laser driven plasma ion acceleration. Several years after graduate school I formed FM Technologies, Inc., (FMT), and later Electron Technologies, Inc. (ETI). Currently,more » as the founder and president of both FMT and ETI, the Rostoker influence can still be felt. One technology that we developed is a self-bunching RF fed electron gun, called the Micro-Pulse Gun (MPG). The MPG has important applications for RF accelerators and microwave tube technology, specifically clinically improved medical linacs and “green” klystrons. In addition to electron beam and RF source research, knowledge of materials and material interactions gained indirectly in graduate school has blossomed into breakthroughs in materials joining technologies. Most recently, silicon carbide joining technology has been developed that gives robust helium leak tight, high temperature and high strength joints between ceramic-to-ceramic and ceramic-to-metal. This joining technology has the potential to revolutionize the ethylene production, nuclear fuel and solar receiver industries by finally allowing for the practical use of silicon carbide as furnace coils, fuel rods and solar receptors, respectively, which are applications that have been needed for decades.« less

Keldysh meets Lindblad: Correlated Gain and Loss in Higher Order Perturbation Theory

NASA Astrophysics Data System (ADS)

Stace, Tom; Mueller, Clemens

Motivated by correlated decay processes driving gain, loss and lasing in driven artificial quantum systems, we develop a theoretical technique using Keldysh diagrammatic perturbation theory to derive a Lindblad master equation that goes beyond the usual second order perturbation theory. We demonstrate the method on the driven dissipative Rabi model, including terms up to fourth order in the interaction between the qubit and both the resonator and environment. This results in a large class of Lindblad dissipators and associated rates which go beyond the terms that have previously been proposed to describe similar systems. All of the additional terms contribute to the system behaviour at the same order of perturbation theory. We then apply these results to analyse the phonon-assisted steady-state gain of a microwave field driving a double quantum-dot in a resonator. We show that resonator gain and loss are substantially affected by dephasing- assisted dissipative processes in the quantum-dot system. These additional processes, which go beyond recently proposed polaronic theories, are in good quantitative agreement with experimental observations.

Knowledge-driven genomic interactions: an application in ovarian cancer.

PubMed

Kim, Dokyoon; Li, Ruowang; Dudek, Scott M; Frase, Alex T; Pendergrass, Sarah A; Ritchie, Marylyn D

2014-01-01

Effective cancer clinical outcome prediction for understanding of the mechanism of various types of cancer has been pursued using molecular-based data such as gene expression profiles, an approach that has promise for providing better diagnostics and supporting further therapies. However, clinical outcome prediction based on gene expression profiles varies between independent data sets. Further, single-gene expression outcome prediction is limited for cancer evaluation since genes do not act in isolation, but rather interact with other genes in complex signaling or regulatory networks. In addition, since pathways are more likely to co-operate together, it would be desirable to incorporate expert knowledge to combine pathways in a useful and informative manner. Thus, we propose a novel approach for identifying knowledge-driven genomic interactions and applying it to discover models associated with cancer clinical phenotypes using grammatical evolution neural networks (GENN). In order to demonstrate the utility of the proposed approach, an ovarian cancer data from the Cancer Genome Atlas (TCGA) was used for predicting clinical stage as a pilot project. We identified knowledge-driven genomic interactions associated with cancer stage from single knowledge bases such as sources of pathway-pathway interaction, but also knowledge-driven genomic interactions across different sets of knowledge bases such as pathway-protein family interactions by integrating different types of information. Notably, an integration model from different sources of biological knowledge achieved 78.82% balanced accuracy and outperformed the top models with gene expression or single knowledge-based data types alone. Furthermore, the results from the models are more interpretable because they are framed in the context of specific biological pathways or other expert knowledge. The success of the pilot study we have presented herein will allow us to pursue further identification of models predictive of clinical cancer survival and recurrence. Understanding the underlying tumorigenesis and progression in ovarian cancer through the global view of interactions within/between different biological knowledge sources has the potential for providing more effective screening strategies and therapeutic targets for many types of cancer.

User-driven sampling strategies in image exploitation

NASA Astrophysics Data System (ADS)

Harvey, Neal; Porter, Reid

2013-12-01

Visual analytics and interactive machine learning both try to leverage the complementary strengths of humans and machines to solve complex data exploitation tasks. These fields overlap most significantly when training is involved: the visualization or machine learning tool improves over time by exploiting observations of the human-computer interaction. This paper focuses on one aspect of the human-computer interaction that we call user-driven sampling strategies. Unlike relevance feedback and active learning sampling strategies, where the computer selects which data to label at each iteration, we investigate situations where the user selects which data is to be labeled at each iteration. User-driven sampling strategies can emerge in many visual analytics applications but they have not been fully developed in machine learning. User-driven sampling strategies suggest new theoretical and practical research questions for both visualization science and machine learning. In this paper we identify and quantify the potential benefits of these strategies in a practical image analysis application. We find user-driven sampling strategies can sometimes provide significant performance gains by steering tools towards local minima that have lower error than tools trained with all of the data. In preliminary experiments we find these performance gains are particularly pronounced when the user is experienced with the tool and application domain.

Transverse Myelitis

MedlinePlus

... cord injury to study strategies for replacement or regeneration of spinal cord nerve cells. The knowledge gained from such research should lead ... cord injury to study strategies for replacement or regeneration of spinal cord nerve cells. The knowledge gained from such research should lead ...

A Normalization Framework for Emotional Attention

PubMed Central

Zhang, Xilin; Japee, Shruti; Safiullah, Zaid; Ungerleider, Leslie G.

2016-01-01

The normalization model of attention proposes that attention can affect performance by response- or contrast-gain changes, depending on the size of the stimulus and attention field. Here, we manipulated the attention field by emotional valence, negative faces versus positive faces, while holding stimulus size constant in a spatial cueing task. We observed changes in the cueing effect consonant with changes in response gain for negative faces and contrast gain for positive faces. Neuroimaging experiments confirmed that subjects’ attention fields were narrowed for negative faces and broadened for positive faces. Importantly, across subjects, the self-reported emotional strength of negative faces and positive faces correlated, respectively, both with response- and contrast-gain changes and with primary visual cortex (V1) narrowed and broadened attention fields. Effective connectivity analysis showed that the emotional valence-dependent attention field was closely associated with feedback from the dorsolateral prefrontal cortex (DLPFC) to V1. These findings indicate a crucial involvement of DLPFC in the normalization processes of emotional attention. PMID:27870851

A Normalization Framework for Emotional Attention.

PubMed

Zhang, Xilin; Japee, Shruti; Safiullah, Zaid; Mlynaryk, Nicole; Ungerleider, Leslie G

2016-11-01

The normalization model of attention proposes that attention can affect performance by response- or contrast-gain changes, depending on the size of the stimulus and attention field. Here, we manipulated the attention field by emotional valence, negative faces versus positive faces, while holding stimulus size constant in a spatial cueing task. We observed changes in the cueing effect consonant with changes in response gain for negative faces and contrast gain for positive faces. Neuroimaging experiments confirmed that subjects' attention fields were narrowed for negative faces and broadened for positive faces. Importantly, across subjects, the self-reported emotional strength of negative faces and positive faces correlated, respectively, both with response- and contrast-gain changes and with primary visual cortex (V1) narrowed and broadened attention fields. Effective connectivity analysis showed that the emotional valence-dependent attention field was closely associated with feedback from the dorsolateral prefrontal cortex (DLPFC) to V1. These findings indicate a crucial involvement of DLPFC in the normalization processes of emotional attention.

Christian Learner: Wisdom and Gaining Knowledge Equals Joy

ERIC Educational Resources Information Center

Nagle, Bonne

2012-01-01

When a Christian learner gains insight that learning is needed and takes the appropriate action to learn the knowledge and apply it, there will be joy and satisfaction with learning. The premise for this paper is in the Bible verse Ecclesiastes 2:26: (NASB) "For to a person who is good in His sight He has given wisdom and knowledge and joy..."…

Contrast Adaptation Implies Two Spatiotemporal Channels but Three Adapting Processes

ERIC Educational Resources Information Center

Langley, Keith; Bex, Peter J.

2007-01-01

The contrast gain control model of adaptation predicts that the effects of contrast adaptation correlate with contrast sensitivity. This article reports that the effects of high contrast spatiotemporal adaptors are maximum when adapting around 19 Hz, which is a factor of two or more greater than the peak in contrast sensitivity. To explain the…

HMM-based lexicon-driven and lexicon-free word recognition for online handwritten Indic scripts.

PubMed

Bharath, A; Madhvanath, Sriganesh

2012-04-01

Research for recognizing online handwritten words in Indic scripts is at its early stages when compared to Latin and Oriental scripts. In this paper, we address this problem specifically for two major Indic scripts--Devanagari and Tamil. In contrast to previous approaches, the techniques we propose are largely data driven and script independent. We propose two different techniques for word recognition based on Hidden Markov Models (HMM): lexicon driven and lexicon free. The lexicon-driven technique models each word in the lexicon as a sequence of symbol HMMs according to a standard symbol writing order derived from the phonetic representation. The lexicon-free technique uses a novel Bag-of-Symbols representation of the handwritten word that is independent of symbol order and allows rapid pruning of the lexicon. On handwritten Devanagari word samples featuring both standard and nonstandard symbol writing orders, a combination of lexicon-driven and lexicon-free recognizers significantly outperforms either of them used in isolation. In contrast, most Tamil word samples feature the standard symbol order, and the lexicon-driven recognizer outperforms the lexicon free one as well as their combination. The best recognition accuracies obtained for 20,000 word lexicons are 87.13 percent for Devanagari when the two recognizers are combined, and 91.8 percent for Tamil using the lexicon-driven technique.

Dichoptic training in adults with amblyopia: Additional stereoacuity gains over monocular training.

PubMed

Liu, Xiang-Yun; Zhang, Jun-Yun

2017-08-04

Dichoptic training is a recent focus of research on perceptual learning in adults with amblyopia, but whether and how dichoptic training is superior to traditional monocular training is unclear. Here we investigated whether dichoptic training could further boost visual acuity and stereoacuity in monocularly well-trained adult amblyopic participants. During dichoptic training the participants used the amblyopic eye to practice a contrast discrimination task, while a band-filtered noise masker was simultaneously presented in the non-amblyopic fellow eye. Dichoptic learning was indexed by the increase of maximal tolerable noise contrast for successful contrast discrimination in the amblyopic eye. The results showed that practice tripled maximal tolerable noise contrast in 13 monocularly well-trained amblyopic participants. Moreover, the training further improved stereoacuity by 27% beyond the 55% gain from previous monocular training, but unchanged visual acuity of the amblyopic eyes. Therefore our dichoptic training method may produce extra gains of stereoacuity, but not visual acuity, in adults with amblyopia after monocular training. Copyright © 2017 Elsevier Ltd. All rights reserved.

Is a Little Knowledge a Good Thing? College Students Gain Knowledge, but Knowledge Increase Does Not Equal Attitude Change regarding Same-Sex Sexual Orientation and Gender Reassignment Surgery in Sexuality Courses

ERIC Educational Resources Information Center

Noland, Ramona M.; Bass, Martha A.; Keathley, Rosanne S.; Miller, Rowland

2009-01-01

The gains in knowledge and changes of attitudes of students in undergraduate sexuality courses in two different academic disciplines were compared to those of their peers without college sexuality education in a variety of other psychology courses. All students had similar scores on tests of sexual anatomy, behavior, and health at the start of the…

Innovation and design of a web-based pain education interprofessional resource

PubMed Central

Lax, Leila; Watt-Watson, Judy; Lui, Michelle; Dubrowski, Adam; McGillion, Michael; Hunter, Judith; MacLennan, Cameron; Knickle, Kerry; Robb, Anja; Lapeyre, Jaime

2011-01-01

INTRODUCTION: The present article describes educational innovation processes and design of a web-based pain interprofessional resource for prelicensure health science students in universities across Canada. Operationalization of educational theory in design coupled with formative evaluation of design are discussed, along with strategies that support collaborative innovation. METHODS: Educational design was driven by content, theory and evaluation. Pain misbeliefs and teaching points along the continuum from acute to persistent pain were identified. Knowledge-building theory, situated learning, reflection and novel designs for cognitive scaffolding were then employed. Design research principles were incorporated to inform iterative and ongoing design. RESULTS: An authentic patient case was constructed, situated in inter-professional complex care to highlight learning objectives related to pre-operative, postoperative and treatment up to one year, for a surgical cancer patient. Pain mechanisms, assessment and management framed content creation. Knowledge building scaffolds were used, which included video simulations, embedded resources, concurrent feedback, practice-based reflective exercises and commentaries. Scaffolds were refined to specifically support knowledge translation. Illustrative commentaries were designed to explicate pain misbeliefs and best practices. Architecture of the resource was mapped; a multimedia, interactive prototype was created. This pain education resource was developed primarily for individual use, with extensions for interprofessional collective discourse. DISCUSSION: Translation of curricular content scripts into representation maps supported the collaborative design process by establishing a common visual language. The web-based prototype will be formatively and summatively evaluated to assess pedagogic design, knowledge-translation scaffolds, pain knowledge gains, relevance, feasibility and fidelity of this educational innovation. PMID:22184552

Interprofessional education increases knowledge, promotes team building, and changes practice in the care of Parkinson's disease.

PubMed

Cohen, Elaine V; Hagestuen, Ruth; González-Ramos, Gladys; Cohen, Hillel W; Bassich, Celia; Book, Elaine; Bradley, Kathy P; Carter, Julie H; Di Minno, Mariann; Gardner, Joan; Giroux, Monique; González, Manny J; Holten, Sandra; Joseph, Ricky; Kornegay, Denise D; Simpson, Patricia A; Tomaino, Concetta M; Vandendolder, Richard P; Walde-Douglas, Maria; Wichmann, Rosemary; Morgan, John C

2016-01-01

Examine outcomes for the National Parkinson Foundation (NPF) Allied Team Training for Parkinson (ATTP), an interprofessional education (IPE) program in Parkinson's disease (PD) and team-based care for medicine, nursing, occupational, physical and music therapies, physician assistant, social work and speech-language pathology disciplines. Healthcare professionals need education in evidence-based PD practices and working effectively in teams. Few evidence-based models of IPE in PD exist. Knowledge about PD, team-based care, the role of other disciplines and attitudes towards healthcare teams were measured before and after a protocol-driven training program. Knowledge, attitudes and practice changes were again measured at 6-month post-training. Trainee results were compared to results of controls. Twenty-six NPF-ATTP trainings were held across the U.S. (2003-2013). Compared to control participants (n = 100), trainees (n = 1468) showed statistically significant posttest improvement in all major outcomes, including self-perceived (p < 0.001) and objective knowledge (p < 0.001), Understanding Role of Other Disciplines (p < 0.001), Attitudes Toward Health Care Teams Scale (p < 0.001), and the Attitudes Toward Value of Teams (p < 0.001) subscale. Despite some decline, significant improvements were largely sustained at six-month post-training. Qualitative analyses confirmed post-training practice changes. The NPF-ATTP model IPE program showed sustained positive gains in knowledge of PD, team strategies and role of other disciplines, team attitudes, and important practice improvements. Further research should examine longer-term outcomes, objectively measure practice changes and mediators, and determine impact on patient outcomes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Adaptive Robust Output Feedback Control for a Marine Dynamic Positioning System Based on a High-Gain Observer.

PubMed

Du, Jialu; Hu, Xin; Liu, Hongbo; Chen, C L Philip

2015-11-01

This paper develops an adaptive robust output feedback control scheme for dynamically positioned ships with unavailable velocities and unknown dynamic parameters in an unknown time-variant disturbance environment. The controller is designed by incorporating the high-gain observer and radial basis function (RBF) neural networks in vectorial backstepping method. The high-gain observer provides the estimations of the ship position and heading as well as velocities. The RBF neural networks are employed to compensate for the uncertainties of ship dynamics. The adaptive laws incorporating a leakage term are designed to estimate the weights of RBF neural networks and the bounds of unknown time-variant environmental disturbances. In contrast to the existing results of dynamic positioning (DP) controllers, the proposed control scheme relies only on the ship position and heading measurements and does not require a priori knowledge of the ship dynamics and external disturbances. By means of Lyapunov functions, it is theoretically proved that our output feedback controller can control a ship's position and heading to the arbitrarily small neighborhood of the desired target values while guaranteeing that all signals in the closed-loop DP control system are uniformly ultimately bounded. Finally, simulations involving two ships are carried out, and simulation results demonstrate the effectiveness of the proposed control scheme.

Understanding MRI: basic MR physics for physicians.

PubMed

Currie, Stuart; Hoggard, Nigel; Craven, Ian J; Hadjivassiliou, Marios; Wilkinson, Iain D

2013-04-01

More frequently hospital clinicians are reviewing images from MR studies of their patients before seeking formal radiological opinion. This practice is driven by a multitude of factors, including an increased demand placed on hospital services, the wide availability of the picture archiving and communication system, time pressures for patient treatment (eg, in the management of acute stroke) and an inherent desire for the clinician to learn. Knowledge of the basic physical principles behind MRI is essential for correct image interpretation. This article, written for the general hospital physician, describes the basic physics of MRI taking into account the machinery, contrast weighting, spin- and gradient-echo techniques and pertinent safety issues. Examples provided are primarily referenced to neuroradiology reflecting the subspecialty for which MR currently has the greatest clinical application.

How invasive is TMJ double-contrast arthrography in combination with cinematography? Patient discomfort versus known diagnostic gain.

PubMed

Engelke, W; Mommaerts, M

1990-04-01

There is no doubt that double-contrast TMJ fluoroscopic tomography enables a differential diagnosis and treatment in internal derangement pathosis. Its indication is, apart from the expected diagnostic gain, also determined by the degree of its invasiveness, and other alternative diagnostics being available (nuclear magnetic resonance). Data on patient discomfort and complications were gathered in 63 arthrotomographies; pain sensations and mandibular mobility, during and after the procedure in particular, were studied. We consider, along with Westesson, the procedure to be less invasive than commonly considered, once the surgeon-radiologist has gained enough experience.

Joint representation of translational and rotational components of optic flow in parietal cortex

PubMed Central

Sunkara, Adhira; DeAngelis, Gregory C.; Angelaki, Dora E.

2016-01-01

Terrestrial navigation naturally involves translations within the horizontal plane and eye rotations about a vertical (yaw) axis to track and fixate targets of interest. Neurons in the macaque ventral intraparietal (VIP) area are known to represent heading (the direction of self-translation) from optic flow in a manner that is tolerant to rotational visual cues generated during pursuit eye movements. Previous studies have also reported that eye rotations modulate the response gain of heading tuning curves in VIP neurons. We tested the hypothesis that VIP neurons simultaneously represent both heading and horizontal (yaw) eye rotation velocity by measuring heading tuning curves for a range of rotational velocities of either real or simulated eye movements. Three findings support the hypothesis of a joint representation. First, we show that rotation velocity selectivity based on gain modulations of visual heading tuning is similar to that measured during pure rotations. Second, gain modulations of heading tuning are similar for self-generated eye rotations and visually simulated rotations, indicating that the representation of rotation velocity in VIP is multimodal, driven by both visual and extraretinal signals. Third, we show that roughly one-half of VIP neurons jointly represent heading and rotation velocity in a multiplicatively separable manner. These results provide the first evidence, to our knowledge, for a joint representation of translation direction and rotation velocity in parietal cortex and show that rotation velocity can be represented based on visual cues, even in the absence of efference copy signals. PMID:27095846

Assessment of High-school Students Engaged in the EarthLabs Climate Modules using the Climate Concept Inventory

NASA Astrophysics Data System (ADS)

McNeal, K.; Libarkin, J. C.; Ledley, T. S.; Gold, A. U.; Lynds, S. E.; Haddad, N.; Ellins, K.; Dunlap, C.; Bardar, E. W.; Youngman, E.

2015-12-01

Instructors must have on hand appropriate assessments that align with their teaching and learning goals in order to provide evidence of student learning. We have worked with curriculum developers and scientists to develop the Climate Concept Inventory (CCI), which meets goals of the EarthLabs Climate on-line curriculum. The developed concept inventory includes 19 content-driven multiple choice questions, six affective-based multiple choice questions, one confidence question, three open-ended questions, and eight demographic questions. Our analysis of the instrument applies item response theory and uses item characteristic curves. We have assessed over 500 students in nearly twenty high school classrooms in Mississippi and Texas that have engaged in the implementation of the EarthLabs curriculum and completed the CCI. Results indicate that students had pre-post gains on 9 out of 10 of the content-based multiple choice questions with positive gains in answer choice selection ranging from 1.72% to 42%. Students significantly reported increased confidence with 15% more students reporting that they were either very or fairly confident with their answers. Of the six affective questions posed, 5 out of 6 showed significant shifts towards gains in knowledge, awareness, and information about Earth's climate system. The research has resulted in a robust and validated climate concept inventory for use with advanced high school students, where we have been able to apply its use within the EarthLabs project.

Keystone characteristics that support cultural resilience in Karen refugee parents

NASA Astrophysics Data System (ADS)

Harper, Susan G.

2016-12-01

This participatory action research study used the conceptual framework of social-ecological resilience to explore how Karen (pronounced Ka·rén) refugee parents re-construct cultural resilience in resettlement. The funds of knowledge approach helped to define essential knowledge used by Karen parents within their own community. Framing this study around the concept of resilience situated it within an emancipatory paradigm: refugee parents were actors choosing their own cultural identity and making decisions about what cultural knowledge was important for the science education of their children. Sustainability science with its capacity to absorb indigenous knowledge as legitimate scientific knowledge offered a critical platform for reconciling Karen knowledge with scientific knowledge for science education. Photovoice, participant observation, and semi-structured interviews were used to create visual and written narrative portraits of Karen parents. Narrative analysis revealed that Karen parents had constructed a counter-narrative in Burma and Thailand that enabled them to resist assimilation into the dominant ethnic culture; by contrast, their narrative of life in resettlement in the U.S. focused on the potential for self-determination. Keystone characteristics that contributed to cultural resilience were identified to be the community garden and education as a gateway to a transformed future. Anchored in a cultural tradition of farming, these Karen parents gained perspective and comfort in continuity and the potential of self-determination rooted in the land. Therefore, a cross-cultural learning community for Karen elementary school students that incorporates the Karen language and Karen self-sustaining knowledge of horticulture would be an appropriate venue for building a climate of reciprocity for science learning.

Attention reorganizes connectivity across networks in a frequency specific manner.

PubMed

Kwon, Soyoung; Watanabe, Masataka; Fischer, Elvira; Bartels, Andreas

2017-01-01

Attention allows our brain to focus its limited resources on a given task. It does so by selective modulation of neural activity and of functional connectivity (FC) across brain-wide networks. While there is extensive literature on activity changes, surprisingly few studies examined brain-wide FC modulations that can be cleanly attributed to attention compared to matched visual processing. In contrast to prior approaches, we used an ultra-long trial design that avoided transients from trial onsets, included slow fluctuations (<0.1Hz) that carry important information on FC, and allowed for frequency-segregated analyses. We found that FC derived from long blocks had a nearly two-fold higher gain compared to FC derived from traditional (short) block designs. Second, attention enhanced intrinsic (negative or positive) correlations across networks, such as between the default-mode network (DMN), the dorsal attention network (DAN), and the visual system (VIS). In contrast attention de-correlated the intrinsically correlated visual regions. Third, the de-correlation within VIS was driven primarily by high frequencies, whereas the increase in DAN-VIS predominantly by low frequencies. These results pinpoint two fundamentally distinct effects of attention on connectivity. Information flow increases between distinct large-scale networks, and de-correlation within sensory cortex indicates decreased redundancy. Copyright © 2016 Elsevier Inc. All rights reserved.

Giant lipid vesicles under electric field pulses assessed by non invasive imaging.

PubMed

Mauroy, Chloé; Portet, Thomas; Winterhalder, Martin; Bellard, Elisabeth; Blache, Marie-Claire; Teissié, Justin; Zumbusch, Andreas; Rols, Marie-Pierre

2012-10-01

We present experimental results regarding the effects of electric pulses on giant unilamellar vesicles (GUVs). We have used phase contrast and coherent anti-Stokes Raman scattering (CARS) microscopy as relevant optical approaches to gain insight into membrane changes under electropermeabilization. No addition of exogenous molecules (lipid analogue, fluorescent dye) was needed. Therefore, experiments were performed on pure lipid systems avoiding possible artefacts linked to their use. Structural membrane changes were assessed by loss of contrast inside the GUVs due to sucrose and glucose mixing. Our observations, performed at the single vesicle level, indicate these changes are under the control of the number of pulses and field intensity. Larger number of pulses enhances membrane alterations. A threshold value of the field intensity must be applied to allow exchange of molecules between GUVs and the external medium. This threshold depends on the size of the vesicles, the larger GUVs being affected at lower electric field strengths than the smaller ones. Our experimental data are well described by a simple model in which molecule entry is driven by direct exchange. The CARS microscopic study of the effect of pulse duration confirms that pulses, in the ms time range, induce loss of lipids and membrane deformations facing the electrodes. Copyright © 2012 Elsevier B.V. All rights reserved.

Cognitive algorithms: dynamic logic, working of the mind, evolution of consciousness and cultures

NASA Astrophysics Data System (ADS)

Perlovsky, Leonid I.

2007-04-01

The paper discusses evolution of consciousness driven by the knowledge instinct, a fundamental mechanism of the mind which determines its higher cognitive functions. Dynamic logic mathematically describes the knowledge instinct. It overcomes past mathematical difficulties encountered in modeling intelligence and relates it to mechanisms of concepts, emotions, instincts, consciousness and unconscious. The two main aspects of the knowledge instinct are differentiation and synthesis. Differentiation is driven by dynamic logic and proceeds from vague and unconscious states to more crisp and conscious states, from less knowledge to more knowledge at each hierarchical level of the mind. Synthesis is driven by dynamic logic operating in a hierarchical organization of the mind; it strives to achieve unity and meaning of knowledge: every concept finds its deeper and more general meaning at a higher level. These mechanisms are in complex relationship of symbiosis and opposition, which leads to complex dynamics of evolution of consciousness and cultures. Modeling this dynamics in a population leads to predictions for the evolution of consciousness, and cultures. Cultural predictive models can be compared to experimental data and used for improvement of human conditions. We discuss existing evidence and future research directions.

Contrast statistics for foveated visual systems: fixation selection by minimizing contrast entropy

NASA Astrophysics Data System (ADS)

Raj, Raghu; Geisler, Wilson S.; Frazor, Robert A.; Bovik, Alan C.

2005-10-01

The human visual system combines a wide field of view with a high-resolution fovea and uses eye, head, and body movements to direct the fovea to potentially relevant locations in the visual scene. This strategy is sensible for a visual system with limited neural resources. However, for this strategy to be effective, the visual system needs sophisticated central mechanisms that efficiently exploit the varying spatial resolution of the retina. To gain insight into some of the design requirements of these central mechanisms, we have analyzed the effects of variable spatial resolution on local contrast in 300 calibrated natural images. Specifically, for each retinal eccentricity (which produces a certain effective level of blur), and for each value of local contrast observed at that eccentricity, we measured the probability distribution of the local contrast in the unblurred image. These conditional probability distributions can be regarded as posterior probability distributions for the ``true'' unblurred contrast, given an observed contrast at a given eccentricity. We find that these conditional probability distributions are adequately described by a few simple formulas. To explore how these statistics might be exploited by central perceptual mechanisms, we consider the task of selecting successive fixation points, where the goal on each fixation is to maximize total contrast information gained about the image (i.e., minimize total contrast uncertainty). We derive an entropy minimization algorithm and find that it performs optimally at reducing total contrast uncertainty and that it also works well at reducing the mean squared error between the original image and the image reconstructed from the multiple fixations. Our results show that measurements of local contrast alone could efficiently drive the scan paths of the eye when the goal is to gain as much information about the spatial structure of a scene as possible.

Knowledge-guided golf course detection using a convolutional neural network fine-tuned on temporally augmented data

NASA Astrophysics Data System (ADS)

Chen, Jingbo; Wang, Chengyi; Yue, Anzhi; Chen, Jiansheng; He, Dongxu; Zhang, Xiuyan

2017-10-01

The tremendous success of deep learning models such as convolutional neural networks (CNNs) in computer vision provides a method for similar problems in the field of remote sensing. Although research on repurposing pretrained CNN to remote sensing tasks is emerging, the scarcity of labeled samples and the complexity of remote sensing imagery still pose challenges. We developed a knowledge-guided golf course detection approach using a CNN fine-tuned on temporally augmented data. The proposed approach is a combination of knowledge-driven region proposal, data-driven detection based on CNN, and knowledge-driven postprocessing. To confront data complexity, knowledge-derived cooccurrence, composition, and area-based rules are applied sequentially to propose candidate golf regions. To confront sample scarcity, we employed data augmentation in the temporal domain, which extracts samples from multitemporal images. The augmented samples were then used to fine-tune a pretrained CNN for golf detection. Finally, commission error was further suppressed by postprocessing. Experiments conducted on GF-1 imagery prove the effectiveness of the proposed approach.

Are There Cognitive Consequences of Binge Drinking during College?

ERIC Educational Resources Information Center

Trolian, Teniell L.; An, Brian P.; Pascarella, Ernest T.

2016-01-01

For this study we considered the influence of binge drinking behavior in college on students' critical thinking gains. Findings suggest that binge drinking has a negative influence on students' critical thinking gains over 4 years of college and that this effect was driven by students with the lowest levels of precollege critical thinking. In both…

Flexible cue combination in the guidance of attention in visual search

PubMed Central

Brand, John; Oriet, Chris; Johnson, Aaron P.; Wolfe, Jeremy M.

2014-01-01

Hodsoll and Humphreys (2001) have assessed the relative contributions of stimulus-driven and user-driven knowledge on linearly- and nonlinearly separable search. However, the target feature used to determine linear separability in their task (i.e., target size) was required to locate the target. In the present work, we investigated the contributions of stimulus-driven and user-driven knowledge when a linearly- or nonlinearly-separable feature is available but not required for target identification. We asked observers to complete a series of standard color X orientation conjunction searches in which target size was either linearly- or nonlinearly separable from the size of the distractors. When guidance by color X orientation and by size information are both available, observers rely on whichever information results in the best search efficiency. This is the case irrespective of whether we provide target foreknowledge by blocking stimulus conditions, suggesting that feature information is used in both a stimulus-driven and user-driven fashion. PMID:25463553

Pregnant women lack accurate knowledge of their BMI and recommended gestational weight gain.

PubMed

Jeffs, Emma; Haszard, Jillian J; Sharp, Benjamin; Gullam, Joanna; Paterson, Helen

2016-08-05

To investigate pregnant women's knowledge of their body mass index (BMI) and their knowledge of gestational weight gain guidelines. Participants were recruited when attending their nuchal translucency scan at between 11 and 13 weeks, 6-days gestation in Dunedin or Christchurch, New Zealand. Recruitment staff measured participants' weight and height. By way of a self-administered, paper-based survey, participants were asked to identify their body size (including: underweight (BMI <18.5 kg/m2); normal weight (18.5-24.9); overweight (25-29.9); and obese (≥30)), and recommended gestational weight gain (including the 2009 Institute of Medicine guidelines for healthy weight gain in pregnancy, along with the options: "I should not gain any weight in my pregnancy", plus "It does not matter how much weight I gain"). Participant-measured BMI was compared to responses for perceived BMI and recommended gestational weight gain to assess accuracy. Demographic predictors of accuracy were also investigated. In total, 644 women were included. Sixty-six percent of these correctly identified their BMI category, however only 31% identified their correct gestational weight gain recommendation. Overweight and obese women were much more likely to underestimate their BMI than normal weight women (p<0.001 for both). Overweight and obese women were also more likely to overestimate their weight gain recommendation (OR=4, p<0.001; OR=18, p<0.001, respectively) while normal weight women were more likely to underestimate their weight gain recommendation (p<0.001). Independent of BMI, women of New Zealand European ethnicity were less likely to underestimate their recommended gestational weight gain compared to other women of non-Māori/non-Pacific Island ethnicity (p=0.001), whereas younger women (p=0.012) were more likely to underestimate recommended gestational weight gain. The present study indicates that New Zealand women, particularly those who are overweight and obese, lack accurate knowledge of their own body size, and this may lead to an under- or over-estimation of appropriate gestational weight gain, which may in turn lead to increased risk of poor health outcomes in pregnancy. Education strategies related to healthy weight gain in pregnancy are urgently required.

Contrast Gain Control Model Fits Masking Data

NASA Technical Reports Server (NTRS)

Watson, Andrew B.; Solomon, Joshua A.; Null, Cynthia H. (Technical Monitor)

1994-01-01

We studied the fit of a contrast gain control model to data of Foley (JOSA 1994), consisting of thresholds for a Gabor patch masked by gratings of various orientations, or by compounds of two orientations. Our general model includes models of Foley and Teo & Heeger (IEEE 1994). Our specific model used a bank of Gabor filters with octave bandwidths at 8 orientations. Excitatory and inhibitory nonlinearities were power functions with exponents of 2.4 and 2. Inhibitory pooling was broad in orientation, but narrow in spatial frequency and space. Minkowski pooling used an exponent of 4. All of the data for observer KMF were well fit by the model. We have developed a contrast gain control model that fits masking data. Unlike Foley's, our model accepts images as inputs. Unlike Teo & Heeger's, our model did not require multiple channels for different dynamic ranges.

Evaluating Otto the Auto: Does Engagement in an Interactive Website Improve Young Children's Transportation Safety?

PubMed

Schwebel, David C; Johnston, Anna; Shen, Jiabin; Li, Peng

2017-07-19

Transportation-related injuries are a leading cause of pediatric death, and effective interventions are limited. Otto the Auto is a website offering engaging, interactive activities. We evaluated Otto among a sample of sixty-nine 4- and 5-year-old children, who participated in a randomized parallel group design study. Following baseline evaluation, children engaged with either Otto or a control website for 2 weeks and then were re-evaluated. Children who used Otto failed to show increases in transportation safety knowledge or behavior compared to the control group, although there was a dosage effect whereby children who engaged in the website more with parents gained safer behavior patterns. We conclude Otto may have some efficacy when engaged by children with their parents, but continued efforts to develop and refine engaging, effective, theory-driven strategies to teach children transportation safety, including via internet, should be pursued.

Integrated Approaches to Drug Discovery for Oxidative Stress-Related Retinal Diseases.

PubMed

Nishimura, Yuhei; Hara, Hideaki

2016-01-01

Excessive oxidative stress induces dysregulation of functional networks in the retina, resulting in retinal diseases such as glaucoma, age-related macular degeneration, and diabetic retinopathy. Although various therapies have been developed to reduce oxidative stress in retinal diseases, most have failed to show efficacy in clinical trials. This may be due to oversimplification of target selection for such a complex network as oxidative stress. Recent advances in high-throughput technologies have facilitated the collection of multilevel omics data, which has driven growth in public databases and in the development of bioinformatics tools. Integration of the knowledge gained from omics databases can be used to generate disease-related biological networks and to identify potential therapeutic targets within the networks. Here, we provide an overview of integrative approaches in the drug discovery process and provide simple examples of how the approaches can be exploited to identify oxidative stress-related targets for retinal diseases.

Integrated Approaches to Drug Discovery for Oxidative Stress-Related Retinal Diseases

PubMed Central

Hara, Hideaki

2016-01-01

Excessive oxidative stress induces dysregulation of functional networks in the retina, resulting in retinal diseases such as glaucoma, age-related macular degeneration, and diabetic retinopathy. Although various therapies have been developed to reduce oxidative stress in retinal diseases, most have failed to show efficacy in clinical trials. This may be due to oversimplification of target selection for such a complex network as oxidative stress. Recent advances in high-throughput technologies have facilitated the collection of multilevel omics data, which has driven growth in public databases and in the development of bioinformatics tools. Integration of the knowledge gained from omics databases can be used to generate disease-related biological networks and to identify potential therapeutic targets within the networks. Here, we provide an overview of integrative approaches in the drug discovery process and provide simple examples of how the approaches can be exploited to identify oxidative stress-related targets for retinal diseases. PMID:28053689

Food Science for the Public Good

NASA Astrophysics Data System (ADS)

Miller, Cassandra

If you are interested in food science, looking for a meaningful career path, and are motivated by the desire to make a difference, you may find that a career working for the public good can be very rewarding. Often, such opportunities address issues of social responsibility, sustainability, public health, and/or economic development. Food scientists who choose this path typically have an interest in social and public health issues, and are usually driven by the achievement of some sort of social, health, or societal gain. As food science in itself is a very broad discipline, applying this knowledge for the public good can also take a variety of paths. Whether you're interested in manufacturing, food safety, nutrition, food policy, product development, quality control, marketing and sales, or any other discipline that makes up the diverse field of food science, various opportunities exist to make a difference to society.

Host genetics of HIV acquisition and viral control.

PubMed

Shea, Patrick R; Shianna, Kevin V; Carrington, Mary; Goldstein, David B

2013-01-01

Since the discovery of HIV as the cause of AIDS, numerous insights have been gained from studies of its natural history and epidemiology. It has become clear that there are substantial interindividual differences in the risk of HIV acquisition and course of disease. Meanwhile, the field of human genetics has undergone a series of rapid transitions that have fundamentally altered the approach to studying HIV host genetics. We aim to describe the field as it has transitioned from the era of candidate-gene studies and the era of genome-wide association studies (GWAS) to its current state in the infancy of comprehensive sequencing. In some ways the field has come full circle, having evolved from being driven almost exclusively by our knowledge of immunology, to a bias-free GWAS approach, to a point where our ability to catalogue human variation far outstrips our ability to biologically interpret it.

Evaluating Otto the Auto: Does Engagement in an Interactive Website Improve Young Children’s Transportation Safety?

PubMed Central

Johnston, Anna; Shen, Jiabin; Li, Peng

2017-01-01

Transportation-related injuries are a leading cause of pediatric death, and effective interventions are limited. Otto the Auto is a website offering engaging, interactive activities. We evaluated Otto among a sample of sixty-nine 4- and 5-year-old children, who participated in a randomized parallel group design study. Following baseline evaluation, children engaged with either Otto or a control website for 2 weeks and then were re-evaluated. Children who used Otto failed to show increases in transportation safety knowledge or behavior compared to the control group, although there was a dosage effect whereby children who engaged in the website more with parents gained safer behavior patterns. We conclude Otto may have some efficacy when engaged by children with their parents, but continued efforts to develop and refine engaging, effective, theory-driven strategies to teach children transportation safety, including via internet, should be pursued. PMID:28753920

Increasing Ethnic Minority Participation in Substance Abuse Clinical Trials: Lessons Learned in the National Institute on Drug Abuse’s Clinical Trials Network

PubMed Central

Burlew, Kathleen; Larios, Sandra; Suarez-Morales, Lourdes; Holmes, Beverly; Venner, Kamilla; Chavez, Roberta

2012-01-01

Underrepresentation in clinical trials limits the extent to which ethnic minorities benefit from advances in substance abuse treatment. The objective of this article is to share the knowledge gained within the Clinical Trials Network (CTN) of the National Institute on Drug Abuse and other research on recruiting and retaining ethnic minorities into substance abuse clinical trials. The article includes a discussion of two broad areas for improving inclusion— community involvement and cultural adaptation. CTN case studies are included to illustrate three promising strategies for improving ethnic minority inclusion: respondent-driven sampling, community-based participatory research, and the cultural adaptation of the recruitment and retention procedures. The article concludes with two sections describing a number of methodological concerns in the current research base and our proposed research agenda for improving ethnic minority inclusion that builds on the CTN experience. PMID:21988575

Increasing ethnic minority participation in substance abuse clinical trials: lessons learned in the National Institute on Drug Abuse's Clinical Trials Network.

PubMed

Burlew, Kathleen; Larios, Sandra; Suarez-Morales, Lourdes; Holmes, Beverly; Venner, Kamilla; Chavez, Roberta

2011-10-01

Underrepresentation in clinical trials limits the extent to which ethnic minorities benefit from advances in substance abuse treatment. The objective of this article is to share the knowledge gained within the Clinical Trials Network (CTN) of the National Institute on Drug Abuse and other research on recruiting and retaining ethnic minorities into substance abuse clinical trials. The article includes a discussion of two broad areas for improving inclusion-community involvement and cultural adaptation. CTN case studies are included to illustrate three promising strategies for improving ethnic minority inclusion: respondent-driven sampling, community-based participatory research, and the cultural adaptation of the recruitment and retention procedures. The article concludes with two sections describing a number of methodological concerns in the current research base and our proposed research agenda for improving ethnic minority inclusion that builds on the CTN experience.

Dynamics of normalization underlying masking in human visual cortex.

PubMed

Tsai, Jeffrey J; Wade, Alex R; Norcia, Anthony M

2012-02-22

Stimulus visibility can be reduced by other stimuli that overlap the same region of visual space, a process known as masking. Here we studied the neural mechanisms of masking in humans using source-imaged steady state visual evoked potentials and frequency-domain analysis over a wide range of relative stimulus strengths of test and mask stimuli. Test and mask stimuli were tagged with distinct temporal frequencies and we quantified spectral response components associated with the individual stimuli (self terms) and responses due to interaction between stimuli (intermodulation terms). In early visual cortex, masking alters the self terms in a manner consistent with a reduction of input contrast. We also identify a novel signature of masking: a robust intermodulation term that peaks when the test and mask stimuli have equal contrast and disappears when they are widely different. We fit all of our data simultaneously with family of a divisive gain control models that differed only in their dynamics. Models with either very short or very long temporal integration constants for the gain pool performed worse than a model with an integration time of ∼30 ms. Finally, the absolute magnitudes of the response were controlled by the ratio of the stimulus contrasts, not their absolute values. This contrast-contrast invariance suggests that many neurons in early visual cortex code relative rather than absolute contrast. Together, these results provide a more complete description of masking within the normalization framework of contrast gain control and suggest that contrast normalization accomplishes multiple functional goals.

Knowledge, attitudes, and beliefs regarding weight gain during pregnancy among Hispanic women.

PubMed

Tovar, Alison; Chasan-Taber, Lisa; Bermudez, Odilia I; Hyatt, Raymond R; Must, Aviva

2010-11-01

Pregnancy weight gain may be a risk factor for the development of obesity highlighting the importance of identifying psychosocial risk factors for pregnancy weight gain. The goal of this qualitative pilot study was to evaluate knowledge, attitudes and beliefs regarding weight gain during pregnancy among predominantly Puerto Rican women, a group with higher rates of obesity as compared to non-Hispanic white women. We conducted four focus groups stratified by level of acculturation and BMI. Women reported receiving advice about pregnancy weight gain predominantly from nutritionists and family members rather than from their physicians. The majority of overweight/obese women reported that they had not received any recommendations for weight gain during pregnancy from physicians. Pregnancy weight gain advice was not consistent with the 1990 Institute of Medicine Guidelines. Overall, attitudes towards weight gain recommendations differed by weight status, whereas feelings and dietary beliefs about weight gain differed according to level of acculturation. Our findings inform behavior change strategies for meeting pregnancy weight gain recommendations.

Knowledge, Attitudes, and Beliefs Regarding Weight Gain During Pregnancy Among Hispanic Women

PubMed Central

Chasan-Taber, Lisa; Bermudez, Odilia I.; Hyatt, Raymond R.; Must, Aviva

2012-01-01

Pregnancy weight gain may be a risk factor for the development of obesity highlighting the importance of identifying psychosocial risk factors for pregnancy weight gain. The goal of this qualitative pilot study was to evaluate knowledge, attitudes and beliefs regarding weight gain during pregnancy among predominantly Puerto Rican women, a group with higher rates of obesity as compared to non-Hispanic white women. We conducted four focus groups stratified by level of acculturation and BMI. Women reported receiving advice about pregnancy weight gain predominantly from nutritionists and family members rather than from their physicians. The majority of overweight/obese women reported that they had not received any recommendations for weight gain during pregnancy from physicians. Pregnancy weight gain advice was not consistent with the 1990 Institute of Medicine Guidelines. Overall, attitudes towards weight gain recommendations differed by weight status, whereas feelings and dietary beliefs about weight gain differed according to level of acculturation. Our findings inform behavior change strategies for meeting pregnancy weight gain recommendations. PMID:19760160

Innate Immune Recognition of HIV-1

PubMed Central

Iwasaki, Akiko

2012-01-01

In contrast to the extraordinary body of knowledge gained over the past three decades on the virology, pathogenesis, and immunology of HIV-1 infection, innate sensors that detect HIV-1 had remained elusive until recently. By virtue of integration, retroviridae makes up a substantial portion of our genome. Thus, immune strategies that deal with endogenous retroviruses are, by necessity, those of self-preservation and not of virus elimination. Some of the principles of such strategies may also apply for defense against exogenous retroviruses including HIV-1. Here, I highlight several sensors that have recently been revealed to be capable of recognizing distinct features of HIV-1 infection, while taking into account the host-retrovirus relationship that converges on avoiding pathogenic inflammatory consequences. PMID:22999945

[Art-chance and art-experience in classical Greece].

PubMed

Ban, Deokjin

2011-06-30

In Classical Greece, works defining the nature of art appeared in the various disciplines like medicine, rhetoric, dietetics, architecture and painting. Hippocratic authors tried to show that an art of medicine existed indeed. They contrasted the concept of art with that of chance, not experience that Plato and Aristotle distinguished from art. In fact there are similarities and discrepancies between Hippocratic epistemology and Platoic epistemology. Hippocratic authors maintained that the products of chance were not captured by art. They distinguished the domain of art charactered by explanatory knowledge and prediction from the domain of chance ruled by the unexplained and the unforeseeable. They minimized the role of luck and believed the role of art. Hippocratic authors thought that professional ability contained both knowledge and experience. In Hippocratic corpus, experience is a synonym of competence and usually has a positive meaning. But Plato gave empirical knowledge the disdainful sense and decided a ranking between two types of knowledge. Both Hippocratic authors and Plato held that a genuine art had connection with explanatory knowledge of the nature of its subject matter. A common theme that goes through arguments about art-chance and art-chance is the connection between art and nature. Hippocratic authors and Plato regarded art as a highly systematic process. Art provides us with general and explanatory knowledge of human nature. Art and nature is a mutual relationship. The systematic understanding of nature helps us gain the exactness of art and an exact art helps us understand nature well.

Knowledge enabled plan of care and documentation prototype.

PubMed

DaDamio, Rebecca; Gugerty, Brian; Kennedy, Rosemary

2006-01-01

There exist significant challenges in integrating the plan of care into documentation and point of care operational processes. A plan of care is often a static artifact that meets regulatory standards with limited influence on supporting goal-directed care delivery processes. Although this prototype is applicable to many clinical disciplines, we will highlight nursing processes in demonstrating a knowledge-driven computerized solution that fully integrates the plan of care within documentation. The knowledge-driven solution reflects evidenced-based practice; is an effective tool for managing problems, orders/interventions, and the patient's progress towards expected outcomes; meets regulatory standards; and drives quality and process improvement. The knowledge infrastructure consists of fully represented terminology, structured clinical expressions utilizing the controlled terminology and clinical knowledge representing evidence-based practice.

Tropical nighttime warming as a dominant driver of variability in the terrestrial carbon sink

Treesearch

William R. L. Anderegg; Ashley P. Ballantyne; W. Kolby Smith; Joseph Majkut; Sam Rabin; Claudie Beaulieu; Richard Birdsey; John P. Dunne; Richard A. Houghton; Ranga B. Myneni; Yude Pan; Jorge L. Sarmiento; Nathan Serota; Elena Shevliakova; Pieter Tans; Stephen W. Pacala

2015-01-01

The terrestrial biosphere is currently a strong carbon (C) sink but may switch to a source in the 21st century as climate-driven losses exceed CO2-driven C gains, thereby accelerating global warming. Although it has long been recognized that tropical climate plays a critical role in regulating interannual climate variability, the causal link...

EOS Operations Systems: EDOS Implemented Changes to Reduce Operations Costs

NASA Technical Reports Server (NTRS)

Cordier, Guy R.; Gomez-Rosa, Carlos; McLemore, Bruce D.

2007-01-01

The authors describe in this paper the progress achieved to-date with the reengineering of the Earth Observing System (EOS) Data and Operations System (EDOS), the experience gained in the process and the ensuing reduction of ground systems operations costs. The reengineering effort included a major methodology change, applying to an existing schedule driven system, a data-driven system approach.

High-contrast germanium-doped silica-on-silicon waveguides

NASA Astrophysics Data System (ADS)

Dumais, Patrick; Callender, Claire; Blanchetière, Chantal; Ledderhof, Chris

2012-10-01

Silica-on-silicon planar lightwave circuits have a number of advantages including stability and low insertion loss to optical fiber networks. Standard GeO2 doping levels in the waveguide cores lead to a refractive index contrast, n/n, of 0.75%-2%. This range of index contrast requires relatively large bend radii in order to minimize bend losses. This limits the density scaling of these circuits. By using high dopant levels for a Δn/n of 4%, the bend radius can be decreased to less than 1 mm, from which significant gains in optical circuit density can be obtained. In addition, low-loss ring resonators with free spectral ranges of a few tens of gigahertz can be realized, enabling some additional optical signal processing and filtering on that scale. Optical devices with such high dopant levels have been reported by Bellman et al. in 2004 [1] but to the authors' knowledge, no other experimental work on high-delta GeO2-doped waveguides has been reported since. In this paper, we present experimental measurements on high-delta devices including directional couplers, MMI couplers, Mach-Zehnder interferometers, and ring resonators. Device performance, including propagation loss, bend loss, interferometer contrast ratio and birefringence will be presented. We demonstrate that ring resonators with 40 GHz free spectral range can be fabricated for optical signal processing.

Emittance Effects on Gain in $W$ -Band TWTs

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

Carlsten, Bruce Eric; Nichols, Kimberley E.; Shchegolkov, Dmitry Yu.

We consider the main effects of beam emittance on W-band traveling-wave tube (TWT) performance and gain. Specifically, we consider a representative dielectric TWT structure with ~5 dB/cm of gain driven by a 5-A, 20-keV, sheet electron beam that is focused by a wiggler magnetic field. The normalized beam transverse emittance must be about 1 μm or lower to ensure that both the transport is stable and the gain is not degraded by the effective energy spread arising from the emittance. This emittance limit scales roughly inversely with frequency.

Emittance Effects on Gain in $W$ -Band TWTs

DOE PAGES

Carlsten, Bruce Eric; Nichols, Kimberley E.; Shchegolkov, Dmitry Yu.; ...

2016-10-20

We consider the main effects of beam emittance on W-band traveling-wave tube (TWT) performance and gain. Specifically, we consider a representative dielectric TWT structure with ~5 dB/cm of gain driven by a 5-A, 20-keV, sheet electron beam that is focused by a wiggler magnetic field. The normalized beam transverse emittance must be about 1 μm or lower to ensure that both the transport is stable and the gain is not degraded by the effective energy spread arising from the emittance. This emittance limit scales roughly inversely with frequency.

Engaging One Health for Non-Communicable Diseases in Africa: Perspective for Mycotoxins

PubMed Central

Ladeira, Carina; Frazzoli, Chiara; Orisakwe, Orish Ebere

2017-01-01

The role of mycotoxins—e.g., aflatoxins, ochratoxins, trichothecenes, zearalenone, fumonisins, tremorgenic toxins, and ergot alkaloids—has been recognized in the etiology of a number of diseases. In many African countries, the public health impact of chronic (indoor) and/or repeated (dietary) mycotoxin exposure is largely ignored hitherto, with impact on human health, food security, and export of African agricultural food products. Notwithstanding, African scientific research reached milestones that, when linked to findings gained by the international scientific community, make the design and implementation of science-driven governance schemes feasible. Starting from Nigeria as leading African Country, this article (i) overviews available data on mycotoxins exposure in Africa; (ii) discusses new food safety issues, such as the environment–feed–food chain and toxic exposures of food producing animals in risk assessment and management; (iii) identifies milestones for mycotoxins risk management already reached in West Africa; and (iv) points out preliminary operationalization aspects for shielding communities from direct (on health) and indirect (on trade, economies, and livelihoods) effects of mycotoxins. An African science-driven engaging of scientific knowledge by development actors is expected therefore. In particular, One health/One prevention is suggested, as it proved to be a strategic and sustainable development framework. PMID:29085817

Glycerol metabolism and transport in yeast and fungi: established knowledge and ambiguities.

PubMed

Klein, Mathias; Swinnen, Steve; Thevelein, Johan M; Nevoigt, Elke

2017-03-01

There is huge variability among yeasts with regard to their efficiency in utilizing glycerol as the sole source of carbon and energy. Certain species show growth rates with glycerol comparable to those reached with glucose as carbon source; others are virtually unable to utilize glycerol, especially in synthetic medium. Most of our current knowledge regarding glycerol uptake and catabolic pathways has been gained from studying laboratory strains of the model yeast Saccharomyces cerevisiae. The growth of these strains on glycerol is dependent on the presence of medium supplements such as amino acids and nucleobases. In contrast, there is only fragmentary knowledge about S. cerevisiae isolates able to grow in synthetic glycerol medium without such supplements as well as about growth of non-Saccharomyces yeast species on glycerol. Thus, more research is required to understand why certain strains and species show superior growth performance on glycerol compared with common S. cerevisiae laboratory strains. This mini-review summarizes what is known so far about the gene products and pathways involved in glycerol metabolism and transport in yeast and fungi as well as the regulation of these processes. © 2016 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Specific noncovalent interactions at protein-ligand interface: implications for rational drug design.

PubMed

Zhou, P; Huang, J; Tian, F

2012-01-01

Specific noncovalent interactions that are indicative of attractive, directional intermolecular forces have always been of key interest to medicinal chemists in their search for the "glue" that holds drugs and their targets together. With the rapid increase in the number of solved biomolecular structures as well as the performance enhancement of computer hardware and software in recent years, it is now possible to give more comprehensive insight into the geometrical characteristics and energetic landscape of certain sophisticated noncovalent interactions present at the binding interface of protein receptors and small ligands based on accumulated knowledge gaining from the combination of two quite disparate but complementary approaches: crystallographic data analysis and quantum-mechanical ab initio calculation. In this perspective, we survey massive body of published works relating to structural characterization and theoretical investigation of three kinds of strong, specific, direct, enthalpy-driven intermolecular forces, including hydrogen bond, halogen bond and salt bridge, involved in the formation of protein-ligand complex architecture in order to characterize their biological functions in conferring affinity and specificity for ligand recognition by host protein. In particular, the biomedical implications of raised knowledge are discussed with respect to potential applications in rational drug design.

Evolving from academic to academic entrepreneur: overcoming barriers to scientific progress and finance.

PubMed

Miller, Andrew D

2016-07-01

The overall goal of my career as an academic chemist has always been the design and creation of advanced therapeutics and diagnostics that address unmet medical need in the management of chronic diseases. Realising this goal has been an immensely difficult process involving multidisciplinary problem-driven research at the chemistry-biology-medicine interfaces. With success in the laboratory, I started seriously to question the value of remaining an academic whose career is spent in the pursuit of knowledge and understanding alone without making any significant effort to translate knowledge and understanding gained into products of genuine utility for public benefit. Therefore, I elected by choice to become an academic entrepreneur, seeking opportunities wherever possible for the translation of the best of my personal and collaborative academic research work into potentially valuable and useful products. This choice has brought with it many unexpected difficulties and challenges. Nevertheless, progress bas been made and sufficient learnt to suggest that this would be an appropriate moment to take stock and provide some personal reflections on what it takes to design and create advanced therapeutics and diagnostics in the laboratory then seek to develop, innovate and translate the best towards market.

Preschool Interpersonal Relationships Predict Kindergarten Achievement: Mediated by Gains in Emotion Knowledge

PubMed Central

Torres, Marcela M.; Domitrovich, Celene E.; Bierman, Karen L.

2016-01-01

Using longitudinal data, this study tested a model in which preschool interpersonal relationships promoted kindergarten achievement in a pathway mediated by growth in emotion knowledge. The sample included 164 children attending Head Start (14% Hispanic-American, 30% African-American, 56% Caucasian; 56% girls). Preschool interpersonal relationships were indexed by student-teacher relationship closeness and positive peer interactions. Two measures of emotion knowledge (identifying emotions in photographs, recognizing emotions in stories) were assessed at the start and end of the preschool year. Structural equation models revealed that positive interpersonal relationships (with teachers and peers) predicted gains in emotion knowledge (identification, recognition) during the preschool year. Positive interpersonal relationships in preschool also predicted kindergarten achievement (controlling for initial preschool achievement); however, this association was mediated by gains in emotion knowledge during the preschool year. Implications are discussed for school readiness programs serving economically-disadvantaged children. PMID:27630379

A knowledge-driven probabilistic framework for the prediction of protein-protein interaction networks.

PubMed

Browne, Fiona; Wang, Haiying; Zheng, Huiru; Azuaje, Francisco

2010-03-01

This study applied a knowledge-driven data integration framework for the inference of protein-protein interactions (PPI). Evidence from diverse genomic features is integrated using a knowledge-driven Bayesian network (KD-BN). Receiver operating characteristic (ROC) curves may not be the optimal assessment method to evaluate a classifier's performance in PPI prediction as the majority of the area under the curve (AUC) may not represent biologically meaningful results. It may be of benefit to interpret the AUC of a partial ROC curve whereby biologically interesting results are represented. Therefore, the novel application of the assessment method referred to as the partial ROC has been employed in this study to assess predictive performance of PPI predictions along with calculating the True positive/false positive rate and true positive/positive rate. By incorporating domain knowledge into the construction of the KD-BN, we demonstrate improvement in predictive performance compared with previous studies based upon the Naive Bayesian approach. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Are All Clinical Studies Sponsored by Industry Not Valid?

PubMed Central

Heinemann, Lutz

2008-01-01

Industry-sponsored studies have such a bad reputation that some journals require an additional statistical analysis by an independent statistician. This commentary discusses some of the reasons why academic people tend to believe that “academic” science is better than industry-driven science. Most likely, when it comes to publications, the risk of fraud exists in both worlds as the pressure to publish “significant” data is prevalent in both worlds. In contrast to the academic world, the level of control by regulatory bodies for industry-sponsored studies is much higher. Therefore, the quality of industry-driven studies is high, at least when it comes to the quality of data. One of the main reasons why academic people are so skeptical about the pharmaceutical industry is a lack of knowledge about the work done in industry. It is as demanding and scientific as in other industries. In turn, many physicians working in the pharmaceutical industry have low self-esteem. Also, the pharmaceutical industry should improve its self-presentation adequately to get rid of its bad image. There is a clear need for more communication between both worlds in order to better understand the mutual difficulties and needs. PMID:19885307

High-performance workplace practices in nursing homes: an economic perspective.

PubMed

Bishop, Christine E

2014-02-01

To develop implications for research, practice and policy, selected economics and human resources management research literature was reviewed to compare and contrast nursing home culture change work practices with high-performance human resource management systems in other industries. The organization of nursing home work under culture change has much in common with high-performance work systems, which are characterized by increased autonomy for front-line workers, self-managed teams, flattened supervisory hierarchy, and the aspiration that workers use specific knowledge gained on the job to enhance quality and customization. However, successful high-performance work systems also entail intensive recruitment, screening, and on-going training of workers, and compensation that supports selective hiring and worker commitment; these features are not usual in the nursing home sector. Thus despite many parallels with high-performance work systems, culture change work systems are missing essential elements: those that require higher compensation. If purchasers, including public payers, were willing to pay for customized, resident-centered care, productivity gains could be shared with workers, and the nursing home sector could move from a low-road to a high-road employment system.

Velocity-dependent emission factors of benzene, toluene and C 2-benzenes of a passenger car equipped with and without a regulated 3-way catalyst

NASA Astrophysics Data System (ADS)

Heeb, Norbert V.; Forss, Anna-Maria; Bach, Christian; Mattrel, Peter

Time-resolved chemical ionization mass spectrometry (CI-MS) has been used to investigate the velocity-dependent emission factors for benzene, toluene, the C 2-benzenes (xylenes and ethyl benzene) and nitrogen monoxide of a gasoline-driven passenger car (1.4 l, model year 1995) driven with or without catalytic exhaust gas treatment. A set of seven different driving cycles - including the European Driving Cycle (EDC), the US Urban (FTP 75) and the Highway driving cycles - with a total driving time of 12,000 s have been studied. From the obtained emission data, two sets of 15,300 and 17,200 data points which represent transient driving in the velocity range of 0-150 km h -1 and in an acceleration window of -2-3 m s -2 were explored to gain velocity-dependent emission factors. The passenger car, equipped with a regulated rhodium-platinum based three-way catalyst, showed optimal conversion efficiency (>95%) for benzene in the velocity range of 60-120 km h -1. The conversion of benzene was reduced (<80%) when driving below 50 km h -1 and the BTXE emissions significantly increased when driven at higher speed and engine load (>130 km h -1). Whereas the conversion efficiency for the class of C 2-benzenes was reduced to 10%, no net conversion could be found for toluene and benzene when driven above 130 km h -1. In contrast, the benzene and toluene emissions exceeded those of the untreated exhaust gas in the velocity range of 130-150 km h -1 by 50-92% and by 10-34%, respectively. Thus, benzene and toluene were formed across the examined three-way catalyst if the engine is operated for an extended time in a fuel-rich mode (lambda<1).

Collaborative research in medical education: a discussion of theory and practice.

PubMed

O'Sullivan, Patricia S; Stoddard, Hugh A; Kalishman, Summers

2010-12-01

Medical education researchers are inherently collaborators. This paper presents a discussion of theoretical frameworks, issues and challenges around collaborative research to prepare medical education researchers to enter into successful collaborations. It gives emphasis to the conceptual issues associated with collaborative research and applies these to medical education research. Although not a systematic literature review, the paper provides a rich discussion of issues which medical education researchers might consider when undertaking collaborative studies. Building on the work of others, we have classified collaborative research in three dimensions according to: the number of administrative units represented; the number of academic fields present, and the manner in which knowledge is created. Although some literature on collaboration focuses on the more traditional positivist perspective and emphasises outcomes, other literature comes from the constructivist framework, in which research is not driven by hypotheses and the approaches emphasised, but by the interaction between investigator and subject. Collaborations are more effective when participants overtly clarify their motivations, values, definitions of appropriate data and accepted methodologies. These should be agreed upon prior to commencing a study. The way we currently educate researchers should be restructured if we want them to be able to undertake interdisciplinary research. Despite calls for researchers to be educated differently, most training programmes for developing researchers have demonstrated a limited, if not contrary, response to these calls. Collaborative research in medical education should be driven by the problem being investigated, by the new knowledge gained and by the interpersonal interactions that may be achieved. Success rests on recognising that many of the research problems we, as medical educators, address are fundamentally interdisciplinary in nature. This represents a transition to bridge the dichotomy often presented in medical education between theory building and addressing practical needs. © Blackwell Publishing Ltd 2010.

Morpho-dynamics of the Brahmaputra-Jamuna River, Bangladesh

NASA Astrophysics Data System (ADS)

Sarker, Maminul H.; Thorne, Colin R.; Aktar, M. Nazneen; Ferdous, Md. Ruknul

2014-06-01

The Jamuna River is the downstream continuation of the Brahmaputra in Bangladesh. It is one of the largest sand-bed braided rivers in the world and every year it erodes thousand hectares of mainland floodplain, rendering tens of thousands of people landless and/or homeless. Understanding the morpho-dynamics of this river and its responses to the various drivers of morphological change that act on it is essential to improving the livelihoods of millions of floodplain dwellers in Bangladesh, especially given the threats posed by climate change. Reliable data, information and knowledge of river process are sparse and so progress in linking the impacts of multiple drivers (including neo-tectonics, earthquakes, large-scale avulsions and engineering interventions) to complex morphological responses depends on making best use of historical maps, time-series satellite images, hydro-morphological data, expert judgment and local knowledge. This paper draws on all these sources to chronicle the morphological evolution of the Jamuna River since the avulsion that created it about 200 years ago, and to establish temporal trends and spatial patterns in the changes that have characterized process-response mechanisms in this fluvial system since then. The understanding gained from these investigations then supports deeper analyses to: explain how historical migration of the river westward has produced significant contrasts between left and right (west) bank material properties; elucidate the relationships between discharge, fluvial processes, anabranch instability and floodplain erosion rates, and; identify causal links between drivers and morphological responses at a variety of time and space scales. Finally, the new knowledge generated by the analyses developed herein are combined with existing, conceptual and empirical process-response models for the Jamuna to predict possible future morphological adjustments in ways helpful in identifying appropriate strategies for climate change adaptation in Bangladesh. The enhanced knowledge gained from these historical and contemporary investigations may also be useful in assessing the impacts of natural and anthropogenic drivers on other large, braided rivers.

Visualization and simulation of density driven convection in porous media using magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Montague, James A.; Pinder, George F.; Gonyea, Jay V.; Hipko, Scott; Watts, Richard

2018-05-01

Magnetic resonance imaging is used to observe solute transport in a 40 cm long, 26 cm diameter sand column that contained a central core of low permeability silica surrounded by higher permeability well-sorted sand. Low concentrations (2.9 g/L) of Magnevist, a gadolinium based contrast agent, produce density driven convection within the column when it starts in an unstable state. The unstable state, for this experiment, exists when higher density contrast agent is present above the lower density water. We implement a numerical model in OpenFOAM to reproduce the observed fluid flow and transport from a density difference of 0.3%. The experimental results demonstrate the usefulness of magnetic resonance imaging in observing three-dimensional gravity-driven convective-dispersive transport behaviors in medium scale experiments.

Do 2nd and 3rd Grade Teachers' Linguistic Knowledge and Instructional Practices Predict Spelling Gains in Weaker Spellers?

ERIC Educational Resources Information Center

Puliatte, Alison; Ehri, Linnea C.

2018-01-01

The relationship between 2nd and 3rd grade teachers' linguistic knowledge and spelling instructional practices and their students' spelling gains from fall to spring was examined. Second grade (N = 16) and 3rd grade (N = 16) teachers were administered an instructional practices survey and a linguistic knowledge test. Total scores on the two…

76 FR 12749 - Agency Information Collection Activities: Proposed Collection; Comment Request, 1660-0044...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-08

... concerning knowledge and skills gained through emergency management related courses. DATES: Comments must be... the Emergency Management Institute to self-assess the knowledge and skills gained through emergency... DEPARTMENT OF HOMELAND SECURITY Federal Emergency Management Agency [Docket ID: FEMA-2011-0008...

One-day workshop-based training improves physical activity prescription knowledge in Latin American physicians: a pre-test post-test study.

PubMed

Arciniegas Calle, Maria C; Lobelo, Felipe; Jiménez, Mario A; Páez, Diana C; Cortés, Sebastian; de Lima, Andrés; Duperly, John

2016-12-05

The physical inactivity pandemic and related non-communicable diseases have made it imperative for medical doctors (MDs) to effectively provide lifestyle counseling as part of prevention and treatment plans for patients. A one-day certification workshop was designed to improve MDs PA prescription knowledge, as part of the Exercise is Medicine® (EIM®) global health initiative. The objective was to determine knowledge gain of MDs participating in a standardized, one-day PA prescription workshop performed throughout Latin America (LA). A 20-question multiple-choice test on PA topics, based on international guidelines, was completed before and after the workshop. Pre and post-test analyses, without a control group, were performed on 1044 MDs after the 8-h workshop that was delivered 41 times across 12 LA countries, from January 2014 to January 2015. Knowledge improvement was determined using the class-average normalized gain and individual relative gain. T-tests with 95% confidence interval levels were conducted to analyze differences between MD specialties. Test scores improved on average from 67 to 82% after the workshop (p <0.001). The average total individual relative gain was 29% [CI: 26 to 32%]. Relative gain by country ranged from 9.3% [CI: 2 to 16%; Nicaragua] to 73% [CI: 47 to 98%; Dominican Republic]. The mean of the 41 workshops' class-average normalized gain was 46% [CI: 42 to 51%]. The largest groups of participants were general practitioners (GPs) (33%; n = 348), internal medicine (19%; n = 194), and family medicine (9%n = 92) specialists. Relative gain for GPs was not different than for all grouped primary care specialties (30% vs. 27%, p =0.48). The knowledge gain was higher for the workshop modules on screening/risk stratification and prescription (43% [CI: 39-48%] and 38% [CI: 34-42%], than for the module on PA benefits and risks (26% [CI: 23-28%]). This one-day workshop had a positive impact on the knowledge gain of MD's on the topic of PA prescription. Although all groups of specialties increased knowledge, GPs and family medicine MDs benefited the most. This short course is an effective continuing education strategy for teaching PA assessment, counseling and prescription to MDs in Latin America, a topic rarely included in the training of MD's in the region and the world. Further follow-up is needed to ascertain impact on PA counseling practices.

Bio-amplifier with Driven Shield Inputs to Reduce Electrical Noise and its Application to Laboratory Teaching of Electrophysiology

PubMed Central

Matsuzaka, Yoshiya; Ichihara, Toshiaki; Abe, Toshihiko; Mushiake, Hajime

2012-01-01

We describe a custom-designed bio-amplifier and its use in teaching neurophysiology to undergraduate students. The amplifier has the following features: 1) differential amplification with driven shield inputs, which makes it workable even in electrically unshielded environments, 2) high input impedance to allow recordings of small signals through high signal source impedance, 3) dual fixed frequency bandpass filters (1–340Hz for surface EMG, EEG, local field potential etc and 320Hz – 3.4kHz for neuronal action potential recording) and independent gain controllers (up to x107,000) to allow the recording of different signals from the same source (e.g., local field potential and spiking activity of neurons), and 4) printed circuit board technology for easy replication with consistent quality. We compared its performance with a commercial amplifier in an electrically noisy environment. Even without any electrostatic shield, it recorded clear electromyographic activity with little interference from other electric appliances. In contrast, the commercial amplifier’s performance severely deteriorated under the same condition. We used this amplifier to build a computer-controlled stimulation and measurement system for electroencephalographic recordings by undergraduate students. The students successfully recorded various sensory evoked potentials with clarity that otherwise would have required costly instruments. This amplifier is a low-cost yet reliable instrument for electro-physiological recording both in education and research. PMID:23504543

Photoluminescence and gain/absorption spectra of a driven-dissipative electron-hole-photon condensate

NASA Astrophysics Data System (ADS)

Hanai, Ryo; Littlewood, Peter B.; Ohashi, Yoji

2018-06-01

We investigate theoretically nonequilibrium effects on photoluminescence and gain/absorption spectra of a driven-dissipative exciton-polariton condensate, by employing the combined Hartree-Fock-Bogoliubov theory with the generalized random phase approximation extended to the Keldysh formalism. Our calculated photoluminescence spectra is in semiquantitative agreement with experiments, where features such as a blue shift of the emission from the condensate, the appearance of the dispersionless feature of a diffusive Goldstone mode, and the suppression of the dispersive profile of the mode are obtained. We show that the nonequilibrium nature of the exciton-polariton condensate strongly suppresses the visibility of the Bogoliubov dispersion in the negative energy branch (ghost branch) in photoluminescence spectra. We also show that the trace of this branch can be captured as a hole burning effect in gain/absorption spectra. Our results indicate that the nonequilibrium nature of the exciton-polariton condensate strongly reduces quantum depletion, while a scattering channel to the ghost branch is still present.

Climate change will seriously impact bird species dwelling above the treeline: A prospective study for the Italian Alps.

PubMed

Ferrarini, Alessandro; Alatalo, Juha M; Gustin, Marco

2017-07-15

High mountain systems are predicted to be especially vulnerable to the impact of climate change, with the climatically-constrained tree limit rapidly shifted upslope. In turn, the impact of upward treeline migration on mountain-dwelling bird species is expected to significantly reduce habitat suitability. We developed the first projection of the expected climate-driven rise of the whole treeline (19,256km) of the Italian Alps. The study area extends over 20,700km 2 , ranging over 550km in longitude and 320km in latitude. We then investigated how much the expected treeline rise will induce a) shrinking and shifting of the elevation range and b) loss in suitable habitat for the flagship species rock ptarmigan, an alpine bird species dwelling above the treeline and, similarly to many other alpine species, highly vulnerable to treeline rise. We also investigated the potential gain in suitable habitat for rock ptarmigan due to the climate-driven upshift in the uppermost thermal limit. At lower altitudes (1500-1600m a.s.l.), the average expected upshift in the current treeline resulted in 195, 274 and 354m over the short (2010-2039), medium (2040-2069) and long term (2070-2099) respectively. Above 2400m a.s.l., it was less than 30m even in the long term. Overall, during the three climate periods the extent of suitable habitat for rock ptarmigan above the current treeline is projected to decrease by 28.12%, 38.43% and 49.11% respectively. In contrast, the expected gain in suitable habitat due to the shift in the uppermost thermal limit will be severely restrained by the limited surface extension in the top portion of the Italian Alps. The presented approach can promote similar studies elsewhere in the globe, providing a regional perspective to the projection of climate change impact on bird species dwelling above the treeline. Copyright © 2017 Elsevier B.V. All rights reserved.

Knowledge management in healthcare: towards 'knowledge-driven' decision-support services.

PubMed

Abidi, S S

2001-09-01

In this paper, we highlight the involvement of Knowledge Management in a healthcare enterprise. We argue that the 'knowledge quotient' of a healthcare enterprise can be enhanced by procuring diverse facets of knowledge from the seemingly placid healthcare data repositories, and subsequently operationalising the procured knowledge to derive a suite of Strategic Healthcare Decision-Support Services that can impact strategic decision-making, planning and management of the healthcare enterprise. In this paper, we firstly present a reference Knowledge Management environment-a Healthcare Enterprise Memory-with the functionality to acquire, share and operationalise the various modalities of healthcare knowledge. Next, we present the functional and architectural specification of a Strategic Healthcare Decision-Support Services Info-structure, which effectuates a synergy between knowledge procurement (vis-à-vis Data Mining) and knowledge operationalisation (vis-à-vis Knowledge Management) techniques to generate a suite of strategic knowledge-driven decision-support services. In conclusion, we argue that the proposed Healthcare Enterprise Memory is an attempt to rethink the possible sources of leverage to improve healthcare delivery, hereby providing a valuable strategic planning and management resource to healthcare policy makers.

The Effect of Positive and Negative Feedback on Risk-Taking across Different Contexts.

PubMed

Losecaat Vermeer, Annabel B; Sanfey, Alan G

2015-01-01

Preferences for risky choices have often been shown to be unstable and context-dependent. Though people generally avoid gambles with mixed outcomes, a phenomenon often attributed to loss aversion, contextual factors can impact this dramatically. For example, people typically prefer risky options after a financial loss, while generally choosing safer options after a monetary gain. However, it is unclear what exactly contributes to these preference shifts as a function of prior outcomes, as these gain/loss outcomes are usually confounded with participant performance, and therefore it is unclear whether these effects are driven purely by the monetary gains or losses, or rather by success or failure at the actual task. Here, we experimentally separated the effects of monetary gains/losses from performance success/failure prior to a standard risky choice. Participants performed a task in which they experienced contextual effects: 1) monetary gain or loss based directly on performance, 2) monetary gain or loss that was randomly awarded and was, crucially, independent from performance, and 3) success or failure feedback based on performance, but without any monetary incentive. Immediately following these positive/negative contexts, participants were presented with a gain-loss gamble that they had to decide to either play or pass. We found that risk preferences for identical sets of gambles were biased by positive and negative contexts containing monetary gains and losses, but not by contexts containing performance feedback. This data suggests that the observed framing effects are driven by aversion for monetary losses and not simply by the positive or negative valence of the context, or by potential moods resulting from positive or negative contexts. These results highlight the specific context dependence of risk preferences.

Knowledge Sharing at Work: An Examination of Organizational Antecedents

ERIC Educational Resources Information Center

Behnke, Tricia M.

2010-01-01

With the rapid pace of today's knowledge-driven industries, organizations are turning to successful knowledge management initiatives to obtain sustainable competitive advantage. As a result, one facet of knowledge management, knowledge sharing at work, has received increased researcher and practitioner attention in the last decade. However, in the…

Gaining Insights into Children's Geometric Knowledge

ERIC Educational Resources Information Center

Mack, Nancy K.

2007-01-01

This article describes how research on children's geometric thinking was used in conjunction with the picture book "The Greedy Triangle" to gain valuable insights into children's prior geometric knowledge of polygons. Exercises focused on the names, visual appearance, and properties of polygons, as well as real-world connections for each, are…

Steps toward Gaining Knowledge of World Music Pedagogy

ERIC Educational Resources Information Center

Carlisle, Katie

2013-01-01

This article presents steps toward gaining knowledge of world music pedagogy for K-12 general music educators. The majority of the article details steps that invite engagement within everyday contexts with accessible resources within local and online communities. The steps demonstrate ways general music teachers can diversify and self-direct their…

Health Literacy Predicts Cardiac Knowledge Gains in Cardiac Rehabilitation Participants

ERIC Educational Resources Information Center

Mattson, Colleen C.; Rawson, Katherine; Hughes, Joel W.; Waechter, Donna; Rosneck, James

2015-01-01

Objective: Health literacy is increasingly recognised as a potentially important patient characteristic related to patient education efforts. We evaluated whether health literacy would predict gains in knowledge after completion of patient education in cardiac rehabilitation. Method: This was a re-post observational analysis study design based on…

Managing the data deluge: data-driven GO category assignment improves while complexity of functional annotation increases.

PubMed

Gobeill, Julien; Pasche, Emilie; Vishnyakova, Dina; Ruch, Patrick

2013-01-01

The available curated data lag behind current biological knowledge contained in the literature. Text mining can assist biologists and curators to locate and access this knowledge, for instance by characterizing the functional profile of publications. Gene Ontology (GO) category assignment in free text already supports various applications, such as powering ontology-based search engines, finding curation-relevant articles (triage) or helping the curator to identify and encode functions. Popular text mining tools for GO classification are based on so called thesaurus-based--or dictionary-based--approaches, which exploit similarities between the input text and GO terms themselves. But their effectiveness remains limited owing to the complex nature of GO terms, which rarely occur in text. In contrast, machine learning approaches exploit similarities between the input text and already curated instances contained in a knowledge base to infer a functional profile. GO Annotations (GOA) and MEDLINE make possible to exploit a growing amount of curated abstracts (97 000 in November 2012) for populating this knowledge base. Our study compares a state-of-the-art thesaurus-based system with a machine learning system (based on a k-Nearest Neighbours algorithm) for the task of proposing a functional profile for unseen MEDLINE abstracts, and shows how resources and performances have evolved. Systems are evaluated on their ability to propose for a given abstract the GO terms (2.8 on average) used for curation in GOA. We show that since 2006, although a massive effort was put into adding synonyms in GO (+300%), our thesaurus-based system effectiveness is rather constant, reaching from 0.28 to 0.31 for Recall at 20 (R20). In contrast, thanks to its knowledge base growth, our machine learning system has steadily improved, reaching from 0.38 in 2006 to 0.56 for R20 in 2012. Integrated in semi-automatic workflows or in fully automatic pipelines, such systems are more and more efficient to provide assistance to biologists. DATABASE URL: http://eagl.unige.ch/GOCat/

Levels of reconstruction as complementarity in mixed methods research: a social theory-based conceptual framework for integrating qualitative and quantitative research.

PubMed

Carroll, Linda J; Rothe, J Peter

2010-09-01

Like other areas of health research, there has been increasing use of qualitative methods to study public health problems such as injuries and injury prevention. Likewise, the integration of qualitative and quantitative research (mixed-methods) is beginning to assume a more prominent role in public health studies. Likewise, using mixed-methods has great potential for gaining a broad and comprehensive understanding of injuries and their prevention. However, qualitative and quantitative research methods are based on two inherently different paradigms, and their integration requires a conceptual framework that permits the unity of these two methods. We present a theory-driven framework for viewing qualitative and quantitative research, which enables us to integrate them in a conceptually sound and useful manner. This framework has its foundation within the philosophical concept of complementarity, as espoused in the physical and social sciences, and draws on Bergson's metaphysical work on the 'ways of knowing'. Through understanding how data are constructed and reconstructed, and the different levels of meaning that can be ascribed to qualitative and quantitative findings, we can use a mixed-methods approach to gain a conceptually sound, holistic knowledge about injury phenomena that will enhance our development of relevant and successful interventions.

Demand Driven Acquisition of E-Books in a Small Online Academic Library: Growing Pains and Assessing Gains

ERIC Educational Resources Information Center

Longley, Dana H.

2016-01-01

How does a smaller, fully online academic library offer a wide and deep collection of academic level e-books to its distance learners in a sustainable and affordable way? The State University of New York (SUNY) Empire State College Online Library, with a staff of four, has used demand-driven e-book acquisitions since September 2013. Despite…

Determining knowledge and behaviour change after nutrition screening among older adults.

PubMed

Southgate, Katherine M; Keller, Heather H; Reimer, Holly D

2010-01-01

Two education interventions involving personalized messages after nutrition screening in older adults were compared to determine changes in nutrition knowledge and risk behaviour. Of 150 older adults randomly selected from a local seniors' centre, 61 completed baseline screening and a demographic and nutrition knowledge questionnaire and were randomized to one of two groups. Group A received personalized letters plus an educational booklet, and Group B received personalized letters only. All materials were sent through the mail. Forty-four participants completed post-test questionnaires to determine change in knowledge and risk behaviour. Both groups had reduced nutrition risk scores and increased knowledge scores at post-test. After the intervention, a significant difference was observed in knowledge change by treatment group. Group A participants experienced greater gains in knowledge, with a mean gain of 5.43 points, than did those in Group B, who had a mean gain of 1.36 points (p=0.018). Screening and education with print materials have the potential to change risk behaviour and nutrition knowledge in older adults. A specially designed booklet on older adults' nutrition risk factors plus a personalized letter provide an effective education strategy for older adults after screening.

Effect of DM Actuator Errors on the WFIRST/AFTA Coronagraph Contrast Performance

NASA Technical Reports Server (NTRS)

Sidick, Erkin; Shi, Fang

2015-01-01

The WFIRST/AFTA 2.4 m space telescope currently under study includes a stellar coronagraph for the imaging and the spectral characterization of extrasolar planets. The coronagraph employs two sequential deformable mirrors (DMs) to compensate for phase and amplitude errors in creating dark holes. DMs are critical elements in high contrast coronagraphs, requiring precision and stability measured in picometers to enable detection of Earth-like exoplanets. Working with a low-order wavefront-sensor the DM that is conjugate to a pupil can also be used to correct low-order wavefront drift during a scientific observation. However, not all actuators in a DM have the same gain. When using such a DM in low-order wavefront sensing and control subsystem, the actuator gain errors introduce high-spatial frequency errors to the DM surface and thus worsen the contrast performance of the coronagraph. We have investigated the effects of actuator gain errors and the actuator command digitization errors on the contrast performance of the coronagraph through modeling and simulations, and will present our results in this paper.

Understanding the nature of information seeking behavior in critical care: implications for the design of health information technology.

PubMed

Kannampallil, Thomas G; Franklin, Amy; Mishra, Rashmi; Almoosa, Khalid F; Cohen, Trevor; Patel, Vimla L

2013-01-01

Information in critical care environments is distributed across multiple sources, such as paper charts, electronic records, and support personnel. For decision-making tasks, physicians have to seek, gather, filter and organize information from various sources in a timely manner. The objective of this research is to characterize the nature of physicians' information seeking process, and the content and structure of clinical information retrieved during this process. Eight medical intensive care unit physicians provided a verbal think-aloud as they performed a clinical diagnosis task. Verbal descriptions of physicians' activities, sources of information they used, time spent on each information source, and interactions with other clinicians were captured for analysis. The data were analyzed using qualitative and quantitative approaches. We found that the information seeking process was exploratory and iterative and driven by the contextual organization of information. While there was no significant differences between the overall time spent paper or electronic records, there was marginally greater relative information gain (i.e., more unique information retrieved per unit time) from electronic records (t(6)=1.89, p=0.1). Additionally, information retrieved from electronic records was at a higher level (i.e., observations and findings) in the knowledge structure than paper records, reflecting differences in the nature of knowledge utilization across resources. A process of local optimization drove the information seeking process: physicians utilized information that maximized their information gain even though it required significantly more cognitive effort. Implications for the design of health information technology solutions that seamlessly integrate information seeking activities within the workflow, such as enriching the clinical information space and supporting efficient clinical reasoning and decision-making, are discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

Velocity, safety, or both? How do balance and strength of goal conflicts affect drivers' behaviour, feelings and physiological responses?

PubMed

Schmidt-Daffy, Martin; Brandenburg, Stefan; Beliavski, Alina

2013-06-01

Motivational models of driving behaviour agree that choice of speed is modulated by drivers' goals. Whilst it is accepted that some goals favour fast driving and others favour safe driving, little is known about the interplay of these conflicting goals. In the present study, two aspects of this interplay are investigated: the balance of conflict and the strength of conflict. Thirty-two participants completed several simulated driving runs in which fast driving was rewarded with a monetary gain if the end of the track was reached. However, unpredictably, some runs ended with the appearance of a deer. In these runs, fast driving was punished with a monetary loss. The ratio between the magnitudes of gains and losses varied in order to manipulate the balance of conflict. The absolute magnitudes of both gains and losses altered the strength of conflict. Participants drove slower, reported an increase in anxiety-related feelings, and showed indications of physiological arousal if there was more money at stake. In contrast, only marginal effects of varying the ratio between gains and losses were observed. Results confirm that the strength of a safety-velocity conflict is an important determinant of drivers' behaviour, feelings, and physiological responses. The lack of evidence for the balance of conflict playing a role suggests that in each condition, participants subjectively weighted the loss higher than the gain (loss aversion). It is concluded that the interplay of the subjective values that drivers attribute to objective incentives for fast and safe driving is a promising field for future research. Incorporating this knowledge into motivational theories of driving behaviour might improve their contribution to the design of adequate road safety measures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Using a filtering task to measure the spatial extent of selective attention

PubMed Central

Palmer, John; Moore, Cathleen M.

2009-01-01

The spatial extent of attention was investigated by measuring sensitivity to stimuli at to-be-ignored locations. Observers detected a stimulus at a cued location (target), while ignoring otherwise identical stimuli at nearby locations (foils). Only an attentional cue distinguished target from foil. Several experiments varied the contrast and separation of targets and foils. Two theories of selection were compared: contrast gain and a version of attention switching called an all-or-none mixture model. Results included large effects of separation, rejection of the contrast gain model, and the measurement of the size and profile of the spatial extent of attention. PMID:18405935

Binocular combination of luminance profiles

PubMed Central

Ding, Jian; Levi, Dennis M.

2017-01-01

We develop and test a new two-dimensional model for binocular combination of the two eyes' luminance profiles. For first-order stimuli, the model assumes that one eye's luminance profile first goes through a luminance compressor, receives gain-control and gain-enhancement from the other eye, and then linearly combines the other eye's output profile. For second-order stimuli, rectification is added in the signal path of the model before the binocular combination site. Both the total contrast and luminance energies, weighted sums over both the space and spatial-frequency domains, were used in the interocular gain-control, while only the total contrast energy was used in the interocular gain-enhancement. To challenge the model, we performed a binocular brightness matching experiment over a large range of background and target luminances. The target stimulus was a dichoptic disc with a sharp edge that has an increment or decrement luminance from its background. The disk's interocular luminance ratio varied from trial to trial. To refine the model we tested three luminance compressors, five nested binocular combination models (including the Ding–Sperling and the DSKL models), and examined the presence or absence of total luminance energy in the model. We found that (1) installing a luminance compressor, either a logarithmic luminance function or luminance gain-control, (2) including both contrast and luminance energies, and (3) adding interocular gain-enhancement (the DSKL model) to a combined model significantly improved its performance. The combined model provides a systematic account of binocular luminance summation over a large range of luminance input levels. It gives a unified explanation of Fechner's paradox observed on a dark background, and a winner-take-all phenomenon observed on a light background. To further test the model, we conducted two additional experiments: luminance summation of discs with asymmetric contour information (Experiment 2), similar to Levelt (1965) and binocular combination of second-order contrast-modulated gratings (Experiment 3). We used the model obtained in Experiment 1 to predict the results of Experiments 2 and 3 and the results of our previous studies. Model simulations further refined the contrast space weight and contrast sensitivity functions that are installed in the model, and provide a reasonable account for rebalancing of imbalanced binocular vision by reducing the mean luminance in the dominant eye. PMID:29098293

The wavelength of supercritical surface tension driven Benard convection

NASA Technical Reports Server (NTRS)

Koschmieder, E. L.

1991-01-01

The size or the wavelength of moderately supercritical surface tension driven Benard convection has been investigated experimentally in a thin fluid layer of large aspect ratio. It has been found that the number of the hexagonal convection cells increases with increased temperature differences, up to 1.3 times the critical temperature difference. That means that the wavelength of surface tension driven convection decreases after onset of the instability for moderately nonlinear conditions. This result is in striking contrast to the well-known increase of the wavelength of buoyancy driven Rayleigh-Benard convection.

Using Program Theory-Driven Evaluation Science to Crack the Da Vinci Code

ERIC Educational Resources Information Center

Donaldson, Stewart I.

2005-01-01

Program theory-driven evaluation science uses substantive knowledge, as opposed to method proclivities, to guide program evaluations. It aspires to update, clarify, simplify, and make more accessible the evolving theory of evaluation practice commonly referred to as theory-driven or theory-based evaluation. The evaluator in this chapter provides a…

Laser speckle imaging based on photothermally driven convection.

PubMed

Regan, Caitlin; Choi, Bernard

2016-02-01

Laser speckle imaging (LSI) is an interferometric technique that provides information about the relative speed of moving scatterers in a sample. Photothermal LSI overcomes limitations in depth resolution faced by conventional LSI by incorporating an excitation pulse to target absorption by hemoglobin within the vascular network. Here we present results from experiments designed to determine the mechanism by which photothermal LSI decreases speckle contrast. We measured the impact of mechanical properties on speckle contrast, as well as the spatiotemporal temperature dynamics and bulk convective motion occurring during photothermal LSI. Our collective data strongly support the hypothesis that photothermal LSI achieves a transient reduction in speckle contrast due to bulk motion associated with thermally driven convection. The ability of photothermal LSI to image structures below a scattering medium may have important preclinical and clinical applications.

Unsteady specific work and isentropic efficiency of a radial turbine driven by pulsed detonations

NASA Astrophysics Data System (ADS)

Rouser, Kurt P.

There has been longstanding government and industry interest in pressure-gain combustion for use in Brayton cycle based engines. Theoretically, pressure-gain combustion allows heat addition with reduced entropy loss. The pulsed detonation combustor (PDC) is a device that can provide such pressure-gain combustion and possibly replace typical steady deflagration combustors. The PDC is inherently unsteady, however, and comparisons with conventional steady deflagration combustors must be based upon time-integrated performance variables. In this study, the radial turbine of a Garrett automotive turbocharger was coupled directly to and driven, full admission, by a PDC in experiments fueled by hydrogen or ethylene. Data included pulsed cycle time histories of turbine inlet and exit temperature, pressure, velocity, mass flow, and enthalpy. The unsteady inlet flowfield showed momentary reverse flow, and thus unsteady accumulation and expulsion of mass and enthalpy within the device. The coupled turbine-driven compressor provided a time-resolved measure of turbine power. Peak power increased with PDC fill fraction, and duty cycle increased with PDC frequency. Cycle-averaged unsteady specific work increased with fill fraction and frequency. An unsteady turbine efficiency formulation is proposed, including heat transfer effects, enthalpy flux-weighted total pressure ratio, and ensemble averaging over multiple cycles. Turbine efficiency increased with frequency but was lower than the manufacturer reported conventional steady turbine efficiency.

Is NeII a Tracer for X-Rays in Disks around Tauri Stars?

NASA Astrophysics Data System (ADS)

Guedel, Manuel

2007-10-01

Although dust grains dominate the appearance of protoplanetary disks because of their high opacity, the key processes for disk evolution and planetesimal formation are driven through the dynamical state of the gas. In contrast to the dust component, we do not have a similar knowledge of the gas component. One of the Spitzer breakthroughs was the detection of the [Ne II] 12.8um line. Glassgold et al. (2007) proposed that this line provides diagnostics for a warm disk surface layer that is heated and ionized by stellar X-rays. A correlation of the [Ne II] luminosity with the X-ray luminosity is expected. The statistical sample so far available is insufficient to test this hypothesis. We aim at significantly enlarging the sample, with the goal of confirming or refuting this model.

Fast Mechanically Driven Daughter Cell Separation Is Widespread in Actinobacteria.

PubMed

Zhou, Xiaoxue; Halladin, David K; Theriot, Julie A

2016-08-30

Dividing cells of the coccoid Gram-positive bacterium Staphylococcus aureus undergo extremely rapid (millisecond) daughter cell separation (DCS) driven by mechanical crack propagation, a strategy that is very distinct from the gradual, enzymatically driven cell wall remodeling process that has been well described in several rod-shaped model bacteria. To determine if other bacteria, especially those in the same phylum (Firmicutes) or with similar coccoid shapes as S. aureus, might use a similar mechanically driven strategy for DCS, we used high-resolution video microscopy to examine cytokinesis in a phylogenetically wide range of species with various cell shapes and sizes. We found that fast mechanically driven DCS is rather rare in the Firmicutes (low G+C Gram positives), observed only in Staphylococcus and its closest coccoid relatives in the Macrococcus genus, and we did not observe this division strategy among the Gram-negative Proteobacteria In contrast, several members of the high-G+C Gram-positive phylum Actinobacteria (Micrococcus luteus, Brachybacterium faecium, Corynebacterium glutamicum, and Mycobacterium smegmatis) with diverse shapes ranging from coccoid to rod all undergo fast mechanical DCS during cell division. Most intriguingly, similar fast mechanical DCS was also observed during the sporulation of the actinobacterium Streptomyces venezuelae Much of our knowledge on bacterial cytokinesis comes from studying rod-shaped model organisms such as Escherichia coli and Bacillus subtilis Less is known about variations in this process among different bacterial species. While cell division in many bacteria has been characterized to some extent genetically or biochemically, few species have been examined using video microscopy to uncover the kinetics of cytokinesis and daughter cell separation (DCS). In this work, we found that fast (millisecond) DCS is exhibited by species in two independent clades of Gram-positive bacteria and is particularly prevalent among the Actinobacteria, a diverse group that includes significant pathogens as well as bacteria that generate medically important antibiotics. Copyright © 2016 Zhou et al.

Knowledge, attitudes, and perceptions of autism spectrum disorder in a stratified sampling of preschool teachers in China.

PubMed

Liu, Yingna; Li, Jialing; Zheng, Qiaolan; Zaroff, Charles M; Hall, Brian J; Li, Xiuhong; Hao, Yuantao

2016-05-13

In China, children with Autism Spectrum Disorder (ASD) can potentially benefit from universal education policies and recent initiatives designed to address the needs of children with developmental disorders. However, adequate schooling is often unavailable for children with ASD, in part because teachers lack the knowledge and skills needed to work with this population. To better understand the current state of knowledge of ASD in China, we surveyed knowledge and attitudes regarding the disorder in preschool teachers. A total of 471 preschool teachers in the cities of Guangzhou and Foshan, China completed questionnaires assessing participant demographics, knowledge of typical child development and knowledge of ASD, attitudes towards ASD, practices and self-perceptions of efficacy in the education of children with ASD, and awareness of organizations and intervention approaches devoted to the care of individuals with ASD. The correlation between individual- and school-level variables with current knowledge of typical child development and ASD was examined using univariate and multivariate analyses. The majority (84%) of participants answered correctly more than half of the questionnaire items assessing understanding of typical child development. In contrast, 83% provided inaccurate responses to more than half of the questionnaire items assessing knowledge of ASD. Knowledge of typical child development and knowledge of ASD were both associated with geographic region (teachers in Guangzhou had greater knowledge than those in Foshan, p < 0.0001). Knowledge of ASD was also associated with a higher education level (p < 0.05) and school type (p = 0.023). In general, participants believed fairly strongly in the need for greater service provision for children with ASD, and were receptive towards receiving additional specialized training. Most participants were unaware of ASD-specific organizations and empirically validated intervention approaches. Knowledge of ASD is lacking in preschool teachers in China, and greater teacher training and instruction is needed. Nonetheless, teachers report a willingness and motivation to gain the skills needed to maximize the educational experiences of children with ASD.

Visualization and simulation of density driven convection in porous media using magnetic resonance imaging.

PubMed

Montague, James A; Pinder, George F; Gonyea, Jay V; Hipko, Scott; Watts, Richard

2018-05-01

Magnetic resonance imaging is used to observe solute transport in a 40cm long, 26cm diameter sand column that contained a central core of low permeability silica surrounded by higher permeability well-sorted sand. Low concentrations (2.9g/L) of Magnevist, a gadolinium based contrast agent, produce density driven convection within the column when it starts in an unstable state. The unstable state, for this experiment, exists when higher density contrast agent is present above the lower density water. We implement a numerical model in OpenFOAM to reproduce the observed fluid flow and transport from a density difference of 0.3%. The experimental results demonstrate the usefulness of magnetic resonance imaging in observing three-dimensional gravity-driven convective-dispersive transport behaviors in medium scale experiments. Copyright © 2017 Elsevier B.V. All rights reserved.

Binocular contrast-gain control for natural scenes: Image structure and phase alignment.

PubMed

Huang, Pi-Chun; Dai, Yu-Ming

2018-05-01

In the context of natural scenes, we applied the pattern-masking paradigm to investigate how image structure and phase alignment affect contrast-gain control in binocular vision. We measured the discrimination thresholds of bandpass-filtered natural-scene images (targets) under various types of pedestals. Our first experiment had four pedestal types: bandpass-filtered pedestals, unfiltered pedestals, notch-filtered pedestals (which enabled removal of the spatial frequency), and misaligned pedestals (which involved rotation of unfiltered pedestals). Our second experiment featured six types of pedestals: bandpass-filtered, unfiltered, and notch-filtered pedestals, and the corresponding phase-scrambled pedestals. The thresholds were compared for monocular, binocular, and dichoptic viewing configurations. The bandpass-filtered pedestal and unfiltered pedestals showed classic dipper shapes; the dipper shapes of the notch-filtered, misaligned, and phase-scrambled pedestals were weak. We adopted a two-stage binocular contrast-gain control model to describe our results. We deduced that the phase-alignment information influenced the contrast-gain control mechanism before the binocular summation stage and that the phase-alignment information and structural misalignment information caused relatively strong divisive inhibition in the monocular and interocular suppression stages. When the pedestals were phase-scrambled, the elimination of the interocular suppression processing was the most convincing explanation of the results. Thus, our results indicated that both phase-alignment information and similar image structures cause strong interocular suppression. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effectiveness of Addiction Science Presentations to Treatment Professionals, Using a Modified Solomon Study Design.

ERIC Educational Resources Information Center

Erickson, Carlton K.; Wilcox, Richard E.; Miller, Gary W.; Littlefield, John H.; Lawson, Kenneth A.

2003-01-01

Assesses the instructional effectiveness of three-hour addiction science workshops presented to health-care professionals. The workshop participants showed significant knowledge gain and belief changes. After six months, knowledge gains decreased, but were still higher than pre-test scores. Concludes that motivated health-care professionals can…

Elementary Students' Retention of Environmental Science Knowledge: Connected Science Instruction versus Direct Instruction

ERIC Educational Resources Information Center

Upadhyay, Bhaskar; DeFranco, Cristina

2008-01-01

This study compares 3rd-grade elementary students' gain and retention of science vocabulary over time in two different classes--"connected science instruction" versus "direct instruction." Data analysis yielded that students who received connected science instruction showed less gain in science knowledge in the short term compared to students who…

Are College Rankings an Indicator of Quality Education?

ERIC Educational Resources Information Center

Schmidt, William; Burroughs, Nathan; Cogan, Lee; Houang, Richard

2011-01-01

Educators need a way of determining how much additional knowledge has been gained by students in a given educational program in comparison with other programs. From the U.S. Teacher Education Study in Mathematics (TEDS), they now have such information. The TEDS yields empirical data on the educational experiences and content knowledge gains of a…

Proximate Effects of a Child Sexual Abuse Prevention Program in Elementary School Children.

ERIC Educational Resources Information Center

Hebert, Martine; Lavoie, Francine; Piche, Christiane; Poitras, Michele

2001-01-01

The effects of the sexual child abuse prevention program ESPACE were evaluated with 133 Canadian children (grades 1-3). Children participating in the prevention program showed greater preventive knowledge and skills relative to children not participating. Follow-up data showed knowledge gains were maintained while the preventive skill gains may…

Knowledge Management Systems: Linking Contribution, Refinement and Use

ERIC Educational Resources Information Center

Chung, Ting-ting

2009-01-01

Electronic knowledge repositories represent one of the fundamental tools for knowledge management (KM) initiatives. Existing research, however, has largely focused on supply-side driven research questions, such as employee motivation to contribute knowledge to a repository. This research turns attention to the dynamic relationship between the…

Preexposure to Objects That Contrast in Familiarity Improves Young Children's Lexical Knowledge Judgment

ERIC Educational Resources Information Center

Hartin, Travis L.; Stevenson, Colleen M.; Merriman, William E.

2016-01-01

The ability to judge the limits of one's own knowledge may play an important role in knowledge acquisition. The current study tested the prediction that preschoolers would judge the limits of their lexical knowledge more accurately if they were first exposed to a few objects of contrasting familiarity. Such preexposure was hypothesized to increase…

A large-scale study of the ultrawideband microwave dielectric properties of normal, benign and malignant breast tissues obtained from cancer surgeries

NASA Astrophysics Data System (ADS)

Lazebnik, Mariya; Popovic, Dijana; McCartney, Leah; Watkins, Cynthia B.; Lindstrom, Mary J.; Harter, Josephine; Sewall, Sarah; Ogilvie, Travis; Magliocco, Anthony; Breslin, Tara M.; Temple, Walley; Mew, Daphne; Booske, John H.; Okoniewski, Michal; Hagness, Susan C.

2007-10-01

The development of microwave breast cancer detection and treatment techniques has been driven by reports of substantial contrast in the dielectric properties of malignant and normal breast tissues. However, definitive knowledge of the dielectric properties of normal and diseased breast tissues at microwave frequencies has been limited by gaps and discrepancies across previously published studies. To address these issues, we conducted a large-scale study to experimentally determine the ultrawideband microwave dielectric properties of a variety of normal, malignant and benign breast tissues, measured from 0.5 to 20 GHz using a precision open-ended coaxial probe. Previously, we reported the dielectric properties of normal breast tissue samples obtained from reduction surgeries. Here, we report the dielectric properties of normal (adipose, glandular and fibroconnective), malignant (invasive and non-invasive ductal and lobular carcinomas) and benign (fibroadenomas and cysts) breast tissue samples obtained from cancer surgeries. We fit a one-pole Cole-Cole model to the complex permittivity data set of each characterized sample. Our analyses show that the contrast in the microwave-frequency dielectric properties between malignant and normal adipose-dominated tissues in the breast is considerable, as large as 10:1, while the contrast in the microwave-frequency dielectric properties between malignant and normal glandular/fibroconnective tissues in the breast is no more than about 10%.

User-Driven Sampling Strategies in Image Exploitation

DOE PAGES

Harvey, Neal R.; Porter, Reid B.

2013-12-23

Visual analytics and interactive machine learning both try to leverage the complementary strengths of humans and machines to solve complex data exploitation tasks. These fields overlap most significantly when training is involved: the visualization or machine learning tool improves over time by exploiting observations of the human-computer interaction. This paper focuses on one aspect of the human-computer interaction that we call user-driven sampling strategies. Unlike relevance feedback and active learning sampling strategies, where the computer selects which data to label at each iteration, we investigate situations where the user selects which data is to be labeled at each iteration. User-drivenmore » sampling strategies can emerge in many visual analytics applications but they have not been fully developed in machine learning. We discovered that in user-driven sampling strategies suggest new theoretical and practical research questions for both visualization science and machine learning. In this paper we identify and quantify the potential benefits of these strategies in a practical image analysis application. We find user-driven sampling strategies can sometimes provide significant performance gains by steering tools towards local minima that have lower error than tools trained with all of the data. Furthermore, in preliminary experiments we find these performance gains are particularly pronounced when the user is experienced with the tool and application domain.« less

Quantum entanglement and a metaphysics of relations

NASA Astrophysics Data System (ADS)

Esfeld, Michael

This paper argues for a metaphysics of relations based on a characterization of quantum entanglement in terms of non-separability, thereby regarding entanglement as a sort of holism. By contrast to a radical metaphysics of relations, the position set out in this paper recognizes things that stand in the relations, but claims that, as far as the relations are concerned, there is no need for these things to have qualitative intrinsic properties underlying the relations. This position thus opposes a metaphysics of individual things that are characterized by intrinsic properties. A principal problem of the latter position is that it seems that we cannot gain any knowledge of these properties insofar as they are intrinsic. Against this background, the rationale behind a metaphysics of relations is to avoid a gap between epistemology and metaphysics.

Contrasting losses and gains increases the predictability of behavior by frontal EEG asymmetry

PubMed Central

Telpaz, Ariel; Yechiam, Eldad

2014-01-01

Frontal asymmetry measured at rest using EEG is considered a stable marker of approach-avoidance behaviors and risk taking. We examined whether without salient cues of attention in the form of losses, predictability is reduced. Fifty-seven participants performed an experiential decision task in a gain-only, loss-only, and mixed (gains and losses) condition. Increased risk taking on the part of individuals with relatively high left frontal activation, as denoted by the Alpha band, was only observed in the task involving both gains and losses. Event-related potential analysis sheds light on the processes leading to this pattern. Left-frontal dominant individuals had increased fronto-central P300 activation following risky compared to safe outcomes, while right-frontal dominant individuals did not show a P300 difference following safe and risky outcomes. This interaction also only emerged when losses were contrasted with gains. The findings highlight the sensitivity of behavioral predictability to cues of valence. PMID:24817845

Making Knowledge Services Work in Higher Education

ERIC Educational Resources Information Center

Norris, Donald M.; Lefrere, Paul; Mason, Jon

2006-01-01

Over the past three years, knowledge-based practices in higher education have advanced, driving the development of low/no-cost, mass-market tools for knowledge sharing and reducing some barriers to change. New investors in higher education are developing strategies to exploit the knowledge-driven value propositions. Existing institutions, anxious…

Adult Age Differences in Knowledge-Driven Reading

ERIC Educational Resources Information Center

Miller, Lisa M. Soederberg; Stine-Morrow, Elizabeth A. L.; Kirkorian, Heather L.; Conroy, Michelle L.

2004-01-01

The authors investigated the effects of domain knowledge on online reading among younger and older adults. Individuals were randomly assigned to either a domain-relevant (i.e., high-knowledge) or domain-irrelevant (i.e., low-knowledge) training condition. Two days later, participants read target passages on a computer that drew on information…

Analysing the Role of Business Intelligence, Knowledge Sharing and Organisational Innovation on Gaining Competitive Advantage

ERIC Educational Resources Information Center

Eidizadeh, Rosa; Salehzadeh, Reza; Chitsaz Esfahani, Ali

2017-01-01

Purpose: This paper aims to study the role of business intelligence, knowledge sharing and organisational innovation on gaining competitive advantage. Design/Methodology/Approach: The statistical population of the study was the managers and the specialists of some export companies of which 213 persons participated in this research. Path analysis…

Doctors Online: Learning Using an Internet Based Content Management System

ERIC Educational Resources Information Center

Pullen, Darren

2013-01-01

The past century has seen spectacular gains in the breadth and depth of medical knowledge, but the potential of these gains has been hampered by a slow system of disseminating knowledge. Over the course of medical education numerous technologies and methods have been used to deliver continuing medical education (CME) to health care professionals…

Verbal Final Exam in Introductory Biology Yields Gains in Student Content Knowledge and Longitudinal Performance

ERIC Educational Resources Information Center

Luckie, Douglas B.; Rivkin, Aaron M.; Aubry, Jacob R.; Marengo, Benjamin J.; Creech, Leah R.; Sweeder, Ryan D.

2013-01-01

We studied gains in student learning over eight semesters in which an introductory biology course curriculum was changed to include optional verbal final exams (VFs). Students could opt to demonstrate their mastery of course material via structured oral exams with the professor. In a quantitative assessment of cell biology content knowledge,…

Evaluating data distribution and drift vulnerabilities of machine learning algorithms in secure and adversarial environments

NASA Astrophysics Data System (ADS)

Nelson, Kevin; Corbin, George; Blowers, Misty

2014-05-01

Machine learning is continuing to gain popularity due to its ability to solve problems that are difficult to model using conventional computer programming logic. Much of the current and past work has focused on algorithm development, data processing, and optimization. Lately, a subset of research has emerged which explores issues related to security. This research is gaining traction as systems employing these methods are being applied to both secure and adversarial environments. One of machine learning's biggest benefits, its data-driven versus logic-driven approach, is also a weakness if the data on which the models rely are corrupted. Adversaries could maliciously influence systems which address drift and data distribution changes using re-training and online learning. Our work is focused on exploring the resilience of various machine learning algorithms to these data-driven attacks. In this paper, we present our initial findings using Monte Carlo simulations, and statistical analysis, to explore the maximal achievable shift to a classification model, as well as the required amount of control over the data.

Process consistency in models: The importance of system signatures, expert knowledge, and process complexity

NASA Astrophysics Data System (ADS)

Hrachowitz, M.; Fovet, O.; Ruiz, L.; Euser, T.; Gharari, S.; Nijzink, R.; Freer, J.; Savenije, H. H. G.; Gascuel-Odoux, C.

2014-09-01

Hydrological models frequently suffer from limited predictive power despite adequate calibration performances. This can indicate insufficient representations of the underlying processes. Thus, ways are sought to increase model consistency while satisfying the contrasting priorities of increased model complexity and limited equifinality. In this study, the value of a systematic use of hydrological signatures and expert knowledge for increasing model consistency was tested. It was found that a simple conceptual model, constrained by four calibration objective functions, was able to adequately reproduce the hydrograph in the calibration period. The model, however, could not reproduce a suite of hydrological signatures, indicating a lack of model consistency. Subsequently, testing 11 models, model complexity was increased in a stepwise way and counter-balanced by "prior constraints," inferred from expert knowledge to ensure a model which behaves well with respect to the modeler's perception of the system. We showed that, in spite of unchanged calibration performance, the most complex model setup exhibited increased performance in the independent test period and skill to better reproduce all tested signatures, indicating a better system representation. The results suggest that a model may be inadequate despite good performance with respect to multiple calibration objectives and that increasing model complexity, if counter-balanced by prior constraints, can significantly increase predictive performance of a model and its skill to reproduce hydrological signatures. The results strongly illustrate the need to balance automated model calibration with a more expert-knowledge-driven strategy of constraining models.

Integrating complex business processes for knowledge-driven clinical decision support systems.

PubMed

Kamaleswaran, Rishikesan; McGregor, Carolyn

2012-01-01

This paper presents in detail the component of the Complex Business Process for Stream Processing framework that is responsible for integrating complex business processes to enable knowledge-driven Clinical Decision Support System (CDSS) recommendations. CDSSs aid the clinician in supporting the care of patients by providing accurate data analysis and evidence-based recommendations. However, the incorporation of a dynamic knowledge-management system that supports the definition and enactment of complex business processes and real-time data streams has not been researched. In this paper we discuss the process web service as an innovative method of providing contextual information to a real-time data stream processing CDSS.

Improving education for the management of contrast reactions: an online didactic model.

PubMed

Niell, Bethany L; Vartanians, Vartan M; Halpern, Elkan P

2014-02-01

Radiologists could improve their knowledge of contrast reaction management. The aim of this study was to evaluate to what degree the implementation of a didactic module resulted in improved technologist, nurse, and physician knowledge and comfort levels regarding the appropriate management of adverse reactions to contrast media. After institutional review board approval was obtained, nurses, technologists, and physicians involved in contrast administration were required to complete the educational module. Premodule and postmodule assessments were designed online. Each assessment included knowledge-based questions regarding the appropriate management of different types of contrast reactions, as well as questions regarding each respondent's comfort level with the treatment of various types of adverse contrast reactions. Comfort level was measured using a 6-point, Likert-type scale. Premodule and postmodule assessment scores were compared using McNemar's test. After module completion, physicians demonstrated a statistically significant improvement in knowledge regarding the proper administration route, concentration, and dose of intramuscular epinephrine. Physicians demonstrated significantly increased comfort with the administration of intramuscular epinephrine to adult and pediatric patients after module completion (P < .05). Module completion resulted in statistically significant improvements in respondents' comfort levels with the treatment of an adverse reaction to contrast media, although 19% of personnel still reported feeling uncomfortable after completing the module. Didactic instruction in contrast reaction management results in improved knowledge and comfort levels for physicians, nurses, and technologists. However, a significant percentage of personnel still reported feeling uncomfortable treating an adverse contrast reaction after module completion, suggesting that didactic instruction alone may be inadequate. Copyright © 2014 American College of Radiology. Published by Elsevier Inc. All rights reserved.

An investigation of the practice activities and coaching behaviors of professional top-level youth soccer coaches.

PubMed

Partington, M; Cushion, C

2013-06-01

The aim of this study was to investigate the coaching behaviors of elite English youth soccer coaches in different practice settings and gain insight into the coaches' cognitive processes underpinning these behaviors. The practice setting was split into two types of activities, "training form" and "playing form," and behavioral data were collected using a modified version of the Coach Analysis and Intervention System. Interpretive interview data were triangulated with the behavioral data to ensure that both the "what" and the "why" of the coaches' behavior and practice were considered. The results showed the coaches using more "training form" activities than "playing form," and using high levels of prescriptive instruction, regardless of practice type, in contrast to a stated desire to "developing the whole player," creating "decision makers," and being a "facilitator of knowledge creation." The interviews revealed that the coaches had a low self-awareness about their behavior, with an epistemological gap identified between understanding and practice, with statements of intent not being matched by knowledge and action. © 2011 John Wiley & Sons A/S.

Laser speckle imaging based on photothermally driven convection

PubMed Central

Regan, Caitlin; Choi, Bernard

2016-01-01

Abstract. Laser speckle imaging (LSI) is an interferometric technique that provides information about the relative speed of moving scatterers in a sample. Photothermal LSI overcomes limitations in depth resolution faced by conventional LSI by incorporating an excitation pulse to target absorption by hemoglobin within the vascular network. Here we present results from experiments designed to determine the mechanism by which photothermal LSI decreases speckle contrast. We measured the impact of mechanical properties on speckle contrast, as well as the spatiotemporal temperature dynamics and bulk convective motion occurring during photothermal LSI. Our collective data strongly support the hypothesis that photothermal LSI achieves a transient reduction in speckle contrast due to bulk motion associated with thermally driven convection. The ability of photothermal LSI to image structures below a scattering medium may have important preclinical and clinical applications. PMID:26927221

Knowledge diffusion of dynamical network in terms of interaction frequency.

PubMed

Liu, Jian-Guo; Zhou, Qing; Guo, Qiang; Yang, Zhen-Hua; Xie, Fei; Han, Jing-Ti

2017-09-07

In this paper, we present a knowledge diffusion (SKD) model for dynamic networks by taking into account the interaction frequency which always used to measure the social closeness. A set of agents, which are initially interconnected to form a random network, either exchange knowledge with their neighbors or move toward a new location through an edge-rewiring procedure. The activity of knowledge exchange between agents is determined by a knowledge transfer rule that the target node would preferentially select one neighbor node to transfer knowledge with probability p according to their interaction frequency instead of the knowledge distance, otherwise, the target node would build a new link with its second-order neighbor preferentially or select one node in the system randomly with probability 1 - p. The simulation results show that, comparing with the Null model defined by the random selection mechanism and the traditional knowledge diffusion (TKD) model driven by knowledge distance, the knowledge would spread more fast based on SKD driven by interaction frequency. In particular, the network structure of SKD would evolve as an assortative one, which is a fundamental feature of social networks. This work would be helpful for deeply understanding the coevolution of the knowledge diffusion and network structure.

Are lemmings prey or predators?

NASA Astrophysics Data System (ADS)

Turchin, P.; Oksanen, L.; Ekerholm, P.; Oksanen, T.; Henttonen, H.

2000-06-01

Large oscillations in the populations of Norwegian lemmings have mystified both professional ecologists and lay public. Ecologists suspect that these oscillations are driven by a trophic mechanism: either an interaction between lemmings and their food supply, or an interaction between lemmings and their predators. If lemming cycles are indeed driven by a trophic interaction, can we tell whether lemmings act as the resource (`prey') or the consumer (`predator')? In trophic interaction models, peaks of resource density generally have a blunt, rounded shape, whereas peaks of consumer density are sharp and angular. Here we have applied several statistical tests to three lemming datasets and contrasted them with comparable data for cyclic voles. We find that vole peaks are blunt, consistent with their cycles being driven by the interaction with predators. In contrast, the shape of lemming peaks is consistent with the hypothesis that lemmings are functional predators, that is, their cycles are driven by their interaction with food plants. Our findings suggest that a single mechanism, such as interaction between rodents and predators, is unlikely to provide the `universal' explanation of all cyclic rodent dynamics.

Differential Classical Conditioning Selectively Heightens Response Gain of Neural Population Activity in Human Visual Cortex

PubMed Central

Song, Inkyung; Keil, Andreas

2015-01-01

Neutral cues, after being reliably paired with noxious events, prompt defensive engagement and amplified sensory responses. To examine the neurophysiology underlying these adaptive changes, we quantified the contrast-response function of visual cortical population activity during differential aversive conditioning. Steady-state visual evoked potentials (ssVEPs) were recorded while participants discriminated the orientation of rapidly flickering grating stimuli. During each trial, luminance contrast of the gratings was slowly increased and then decreased. Right-tilted gratings (CS+) were paired with loud white noise but left-tilted gratings (CS−) were not. The contrast-following waveform envelope of ssVEPs showed selective amplification of the CS+ only during the high-contrast stage of the viewing epoch. Findings support the notion that motivational relevance, learned in a time frame of minutes, affects vision through a response gain mechanism. PMID:24981277

Deriving Lindblad master equations with Keldysh diagrams: Correlated gain and loss in higher order perturbation theory

NASA Astrophysics Data System (ADS)

Müller, Clemens; Stace, Thomas M.

2017-01-01

Motivated by correlated decay processes producing gain, loss, and lasing in driven semiconductor quantum dots [Phys. Rev. Lett. 113, 036801 (2014), 10.1103/PhysRevLett.113.036801; Science 347, 285 (2015), 10.1126/science.aaa2501; Phys. Rev. Lett. 114, 196802 (2015), 10.1103/PhysRevLett.114.196802], we develop a theoretical technique by using Keldysh diagrammatic perturbation theory to derive a Lindblad master equation that goes beyond the usual second-order perturbation theory. We demonstrate the method on the driven dissipative Rabi model, including terms up to fourth order in the interaction between the qubit and both the resonator and environment. This results in a large class of Lindblad dissipators and associated rates which go beyond the terms that have previously been proposed to describe similar systems. All of the additional terms contribute to the system behavior at the same order of perturbation theory. We then apply these results to analyze the phonon-assisted steady-state gain of a microwave field driving a double quantum dot in a resonator. We show that resonator gain and loss are substantially affected by dephasing-assisted dissipative processes in the quantum-dot system. These additional processes, which go beyond recently proposed polaronic theories, are in good quantitative agreement with experimental observations.

Student Identity Considerations and Implications Associated with Socioscientific Issues Instruction

NASA Astrophysics Data System (ADS)

Ruzek, Mitchel James

The purpose of this investigation was to explore how aspects of identity, perceived levels of controversy, and the strength of a student's attachment to their controversial identity relate to conceptual understanding and knowledge acquisition during socioscientific issues (SSI) based instruction in a biology classroom. The knowledge gained from this study will have the capacity to enhance our understanding of the role that attachment to identity plays during SSI negotiation. Additionally, insight was gained into the role played by aspects of identity in conceptual understanding of scientifically controversial topics during SSI based instruction. This study contributed to the existing knowledge base in science education by illuminating processes involved in socioscientific issue navigation among students of differing perceptions of controversy as well as students who held aspects of controversial identity that may or may not interact with the specific issues chosen. Students demonstrated evidence of variations of reasoning, justification, perception of controversy, and aspects of knowledge gain as they negotiated the issues of marijuana safety and fast food legality. Additionally, evidence was provided that showed general knowledge gain throughout the group during socioscientific issues instruction. It has been said that one of the appeals of the SSI instructional model is that is serves not only as a context for the delivery of content, but acts as a catalyst for various forms of epistemological beliefs and research into the development of conceptual and psychological knowledge structures (Zeidler, 2013). This investigation supports the deeper understanding of the contribution of controversy perception to epistemology as well as conceptual and psychological knowledge structures during SSI navigation.

Conceptual change strategies in teaching genetics

NASA Astrophysics Data System (ADS)

Batzli, Laura Elizabeth

The purpose of this study was to evaluate the effectiveness of utilizing conceptual change strategies when teaching high school genetics. The study examined the effects of structuring instruction to provide students with cognitive situations which promote conceptual change, specifically instruction was structured to elicit students' prior knowledge. The goal of the study was that the students would not only be able to solve genetics problems and define basic terminology but they would also have constructed more scientific schemas of the actual processes involved in inheritance. This study is based on the constructivist theory of learning and conceptual change research which suggest that students are actively involved in the process of relating new information to prior knowledge as they construct new knowledge. Two sections of biology II classes received inquiry based instruction and participated in structured cooperative learning groups. However, the unique difference in the treatment group's instruction was the use of structured thought time and the resulting social interaction between the students. The treatment group students' instructional design allowed students to socially construct their cognitive knowledge after elicitation of their prior knowledge. In contrast, the instructional design for the control group students allowed them to socially construct their cognitive knowledge of genetics without the individually structured thought time. The results indicated that the conceptual change strategies with individually structured thought time improved the students' scientific mastery of genetics concepts and they maintained fewer post instructional alternative conceptions. Although all students gained the ability to correctly solve genetics problems, the treatment group students were able to explain the processes involved in terms of meiosis. The treatment group students were also able to better apply their knowledge to novel genetic situations. The implications for genetics instruction from these results were discussed.

Superluminal propagation in a poly-chromatically driven gain assisted four-level N-type atomic system

NASA Astrophysics Data System (ADS)

Amin Bacha, Bakht; Ahmad, Iftikhar; Ullah, Arif; Ali, Hazrat

2013-10-01

We investigate the behavior of light propagation in an N-type four-level gain assisted model (Agarwal and Dasgupta 2004 Phys. Rev. A 70 023802) under poly-chromatic pump fields. The system exhibits interesting results of multiple controllable pairs of the gain doublet profile with changes in the intensity of the control field. We observe multiple anomalous dispersive regions for superluminal propagation in the medium. A negative group velocity of -37.50 m s-1 with a negative time delay of -8 ms is observed between each gain doublet in anomalous dispersive regions. This generalized model and its predictions can be tested with existing experimental setups.

Hybrid-drive implosion system for ICF targets

DOEpatents

Mark, James W.

1988-08-02

Hybrid-drive implosion systems (20,40) for ICF targets (10,22,42) are described which permit a significant increase in target gain at fixed total driver energy. The ICF target is compressed in two phases, an initial compression phase and a final peak power phase, with each phase driven by a separate, optimized driver. The targets comprise a hollow spherical ablator (12) surroundingly disposed around fusion fuel (14). The ablator is first compressed to higher density by a laser system (24), or by an ion beam system (44), that in each case is optimized for this initial phase of compression of the target. Then, following compression of the ablator, energy is directly delivered into the compressed ablator by an ion beam driver system (30,48) that is optimized for this second phase of operation of the target. The fusion fuel (14) is driven, at high gain, to conditions wherein fusion reactions occur. This phase separation allows hydrodynamic efficiency and energy deposition uniformity to be individually optimized, thereby securing significant advantages in energy gain. In additional embodiments, the same or separate drivers supply energy for ICF target implosion.

Hybrid-drive implosion system for ICF targets

DOEpatents

Mark, James W.

1988-01-01

Hybrid-drive implosion systems (20,40) for ICF targets (10,22,42) are described which permit a significant increase in target gain at fixed total driver energy. The ICF target is compressed in two phases, an initial compression phase and a final peak power phase, with each phase driven by a separate, optimized driver. The targets comprise a hollow spherical ablator (12) surroundingly disposed around fusion fuel (14). The ablator is first compressed to higher density by a laser system (24), or by an ion beam system (44), that in each case is optimized for this initial phase of compression of the target. Then, following compression of the ablator, energy is directly delivered into the compressed ablator by an ion beam driver system (30,48) that is optimized for this second phase of operation of the target. The fusion fuel (14) is driven, at high gain, to conditions wherein fusion reactions occur. This phase separation allows hydrodynamic efficiency and energy deposition uniformity to be individually optimized, thereby securing significant advantages in energy gain. In additional embodiments, the same or separate drivers supply energy for ICF target implosion.

Hybrid-drive implosion system for ICF targets

DOEpatents

Mark, J.W.K.

1987-10-14

Hybrid-drive implosion systems for ICF targets are described which permit a significant increase in target gain at fixed total driver energy. The ICF target is compressed in two phases, an initial compression phase and a final peak power phase, with each phase driven by a separate, optimized driver. The targets comprise a hollow spherical ablator surroundingly disposed around fusion fuel. The ablator is first compressed to higher density by a laser system, or by an ion beam system, that in each case is optimized for this initial phase of compression of the target. Then, following compression of the ablator, energy is directly delivered into the compressed ablator by an ion beam driver system that is optimized for this second phase of operation of the target. The fusion fuel is driven, at high gain, to conditions wherein fusion reactions occur. This phase separation allows hydrodynamic efficiency and energy deposition uniformity to be individually optimized, thereby securing significant advantages in energy gain. In additional embodiments, the same or separate drivers supply energy for ICF target implosion. 3 figs.

Unsteady Specific Work and Isentropic Efficiency of a Radial Turbine Driven by Pulsed Detonations

DTIC Science & Technology

2012-06-14

iv AFIT/DS/ENY/12-25 Abstract There has been longstanding government and industry interest in pressure-gain combustion for use in Brayton cycle...10 III.A. Unsteady Flow in Conventional Brayton Cycle Turbines ........................10 III.B. Unsteady Flow in Pulsed Detonation Driven...Szpynda and Nalim 2007) 114 Figure 69. Heiser and Pratt comparison of ideal PDE, Humphrey, and Brayton cycles on a temperature-entropy diagram (Heiser

Electrically Driven Photonic Crystal Nanocavity Devices

DTIC Science & Technology

2012-01-01

material, here gallium arsenide and indium arsenide self- assembled quantum dots (QDs). QDs are preferred for the gain medium because they can have...blue points ) and 150 K (green points ). The black lines are linear fits to the above threshold output power of the lasers, which are used to find the...SHAMBAT et al.: ELECTRICALLY DRIVEN PHOTONIC CRYSTAL NANOCAVITY DEVICES 1707 Fig. 13. (a) Tilted SEM picture of a fabricated triple cavity device. The in

A Projection Quality-Driven Tube Current Modulation Method in Cone-Beam CT for IGRT: Proof of Concept.

PubMed

Men, Kuo; Dai, Jianrong

2017-12-01

To develop a projection quality-driven tube current modulation method in cone-beam computed tomography for image-guided radiotherapy based on the prior attenuation information obtained by the planning computed tomography and then evaluate its effect on a reduction in the imaging dose. The QCKV-1 phantom with different thicknesses (0-400 mm) of solid water upon it was used to simulate different attenuation (μ). Projections were acquired with a series of tube current-exposure time product (mAs) settings, and a 2-dimensional contrast to noise ratio was analyzed for each projection to create a lookup table of mAs versus 2-dimensional contrast to noise ratio, μ. Before a patient underwent computed tomography, the maximum attenuation [Formula: see text] within the 95% range of each projection angle (θ) was estimated according to the planning computed tomography images. Then, a desired 2-dimensional contrast to noise ratio value was selected, and the mAs setting at θ was calculated with the lookup table of mAs versus 2-dimensional contrast to noise ratio,[Formula: see text]. Three-dimensional cone-beam computed tomography images were reconstructed using the projections acquired with the selected mAs. The imaging dose was evaluated with a polymethyl methacrylate dosimetry phantom in terms of volume computed tomography dose index. Image quality was analyzed using a Catphan 503 phantom with an oval body annulus and a pelvis phantom. For the Catphan 503 phantom, the cone-beam computed tomography image obtained by the projection quality-driven tube current modulation method had a similar quality to that of conventional cone-beam computed tomography . However, the proposed method could reduce the imaging dose by 16% to 33% to achieve an equivalent contrast to noise ratio value. For the pelvis phantom, the structural similarity index was 0.992 with a dose reduction of 39.7% for the projection quality-driven tube current modulation method. The proposed method could reduce the additional dose to the patient while not degrading the image quality for cone-beam computed tomography. The projection quality-driven tube current modulation method could be especially beneficial to patients who undergo cone-beam computed tomography frequently during a treatment course.

Driven by a passion for people and their pets (and dancing).

PubMed

Bailey, Paula

2016-04-30

Paula Bailey thought she might enter academia after gaining clinical experience. However, a period of travelling and locum work confirmed her enjoyment of practice life. British Veterinary Association.

Local Knowledge Brokerage for Data-Driven Policy and Practice in Education

ERIC Educational Resources Information Center

Vanhoof, Jan; Mahieu, Paul

2013-01-01

The concept of "knowledge brokerage" focuses on promoting the integration of the best available evidence into policy and practice-related decisions. In this study, emphasis is put on the knowledge brokerage role of cities. The study aims at finding similarities and differences in existing educational knowledge brokerage initiatives, at…

Undisciplining Knowledge Production: Development Driven Higher Education in South Africa

ERIC Educational Resources Information Center

Winberg, Christine

2006-01-01

South African higher education institutions are increasingly under scrutiny to produce knowledge that is more relevant to South Africa's social and economic needs, more representative of the diversity of its knowledge producers, and more inclusive of the variety of the sites where knowledge is produced. Only a small percentage of South Africans…

The Relationship between the Use of Spaced Repetition Software with a TOEIC Word List and TOEIC Score Gains

ERIC Educational Resources Information Center

Bower, Jack Victor; Rutson-Griffiths, Arthur

2016-01-01

A strong relationship between L2 vocabulary knowledge and L2 reading and listening comprehension is well established. However, less research has been conducted to explore correlations between pedagogic interventions to increase vocabulary knowledge and score gains on standardized L2 proficiency tests. This study addresses this gap in the research…

Women's Reflections on Formal Sex Education and the Advantage of Gaining Informal Sexual Knowledge through a Feminist Lens

ERIC Educational Resources Information Center

Edwards, Nichole

2016-01-01

By recognising the limitations of formal sex education, young people are able to seek out alternative material, gaining informal sexual knowledge through their own means and through a wide variety of sources. This paper derives from part of a larger study centred on feminism and heterosexuality in practice which features 17 feminist-identified…

Examining Information Problem-Solving, Knowledge, and Application Gains within Two Instructional Methods: Problem-Based and Computer-Mediated Participatory Simulation

ERIC Educational Resources Information Center

Newell, Terrance S.

2008-01-01

This study compared the effectiveness of two instructional methods--problem-based instruction within a face-to-face context and computer-mediated participatory simulation--in increasing students' content knowledge and application gains in the area of information problem-solving. The instructional methods were implemented over a four-week period. A…

State transitions and feedback mechanisms control hydrology in the constructed catchment ´Chicken Creeḱ

NASA Astrophysics Data System (ADS)

Schaaf, Wolfgang; Gerwin, Werner; Hinz, Christoph; Zaplata, Markus

2016-04-01

Landscapes and ecosystems are complex systems with many feedback mechanisms acting between the various abiotic and biotic components. The knowledge about these interacting processes is mainly derived from mature ecosystems. The initial development of ecosystem complexity may involve state transitions following catastrophic shifts, disturbances or transgression of thresholds. The Chicken Creek catchment was constructed in 2005 in the mining area of Lusatia/Germany to study processes and feedback mechanisms during ecosystem evolution. The hillslope-shaped 6 ha site has defined boundary conditions and well-documented inner structures. The dominating substrate above the underlying clay layer is Pleistocene sandy material representing mainly the lower C horizon of the former landscape. Since 2005, the unrestricted, unmanaged development of the catchment was intensively monitored. During the ten years since then, we observed characteristic state transitions in catchment functioning driven by feedbacks between original substrate properties, surface structures, soil development and vegetation succession. Whereas surface runoff induced by surface crusting and infiltration dominated catchment hydrology in the first years, the impact of vegetation on hydrological pathways and groundwater levels became more and more evident during the last years. Discharge from the catchment changed from episodic events driven by precipitation and surface runoff to groundwater driven. This general picture is overlain by spatial patterns and single episodic events of external drivers. The scientific value of the Chicken Creek site with known boundary conditions and structure information could help in disentangling general feedback mechanisms between hydrologic, pedogenic, biological and geomorphological processes as well as a in gaining a more integrative view of succession and its drivers during the transition from initial, less complex systems to more mature ecosystems. Long-term time series of data are a key for a better understanding of these processes and the effects on ecosystem resilience and self-organization.

TH-D-204-00: The Pursuit of Radiation Oncology Performance Excellence

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

NONE

The Malcolm Baldrige National Quality Improvement Act was signed into law in 1987 to advance U.S. business competitiveness and economic growth. Administered by the National Institute of Standards and Technology NIST, the Act created the Baldrige National Quality Program, now renamed the Baldrige Performance Excellence Program. The comprehensive analytical approaches referred to as the Baldrige Healthcare Criteria, are very well suited for the evaluation and sustainable improvement of radiation oncology management and operations. A multidisciplinary self-assessment approach is used for radiotherapy program evaluation and development in order to generate a fact based knowledge driven system for improving quality of care,more » increasing patient satisfaction, building employee engagement, and boosting organizational innovation. The methodology also provides a valuable framework for benchmarking an individual radiation oncology practice against guidelines defined by accreditation and professional organizations and regulatory agencies. Learning Objectives: To gain knowledge of the Baldrige Performance Excellence Program as it relates to Radiation Oncology. To appreciate the value of a multidisciplinary self-assessment approach in the pursuit of Radiation Oncology quality care, patient satisfaction, and workforce commitment. To acquire a set of useful measurement tools with which an individual Radiation Oncology practice can benchmark its performance against guidelines defined by accreditation and professional organizations and regulatory agencies.« less

TH-D-204-01: The Pursuit of Radiation Oncology Performance Excellence

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

Sternick, E.

The Malcolm Baldrige National Quality Improvement Act was signed into law in 1987 to advance U.S. business competitiveness and economic growth. Administered by the National Institute of Standards and Technology NIST, the Act created the Baldrige National Quality Program, now renamed the Baldrige Performance Excellence Program. The comprehensive analytical approaches referred to as the Baldrige Healthcare Criteria, are very well suited for the evaluation and sustainable improvement of radiation oncology management and operations. A multidisciplinary self-assessment approach is used for radiotherapy program evaluation and development in order to generate a fact based knowledge driven system for improving quality of care,more » increasing patient satisfaction, building employee engagement, and boosting organizational innovation. The methodology also provides a valuable framework for benchmarking an individual radiation oncology practice against guidelines defined by accreditation and professional organizations and regulatory agencies. Learning Objectives: To gain knowledge of the Baldrige Performance Excellence Program as it relates to Radiation Oncology. To appreciate the value of a multidisciplinary self-assessment approach in the pursuit of Radiation Oncology quality care, patient satisfaction, and workforce commitment. To acquire a set of useful measurement tools with which an individual Radiation Oncology practice can benchmark its performance against guidelines defined by accreditation and professional organizations and regulatory agencies.« less

Assessing progression of clinical reasoning through virtual patients: An exploratory study.

PubMed

Forsberg, Elenita; Ziegert, Kristina; Hult, Håkan; Fors, Uno

2016-01-01

To avoid test-driven learning, there have been discussions regarding the use of more formative assessments in health care education to promote students' deep learning. Feedback is important in formative assessment, but many students ignore it; therefore, interventions should be introduced which stimulate them to reflect on the new knowledge. The aim for this study was to explore if Virtual Patient (VP)-based formative assessments, in connection with self-evaluations, had an impact on postgraduate pediatric nursing students' development of clinical reasoning abilities. Students' self-evaluations served as the basis for measuring progress. Data was analysed using deductive content analysis. The findings showed a clear progression of the clinical reasoning ability of the students. After the first assessment, the students described feelings of uncertainty and that their knowledge gaps were exposed. At the mid-course assessment the awareness of improved clinical reasoning was obvious and the students were more certain of knowing how to solve the VP cases. In the final assessment, self-efficacy was expressed. VP-based assessments, in connection with self-evaluations, early in the education resulted in a gain of students' own identification of the concept of clinical reasoning, awareness of what to focus on during clinical practice and visualised expected clinical competence. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biological inquiry: a new course and assessment plan in response to the call to transform undergraduate biology.

PubMed

Goldey, Ellen S; Abercrombie, Clarence L; Ivy, Tracie M; Kusher, Dave I; Moeller, John F; Rayner, Doug A; Smith, Charles F; Spivey, Natalie W

2012-01-01

We transformed our first-year curriculum in biology with a new course, Biological Inquiry, in which >50% of all incoming, first-year students enroll. The course replaced a traditional, content-driven course that relied on outdated approaches to teaching and learning. We diversified pedagogical practices by adopting guided inquiry in class and in labs, which are devoted to building authentic research skills through open-ended experiments. Students develop core biological knowledge, from the ecosystem to molecular level, and core skills through regular practice in hypothesis testing, reading primary literature, analyzing data, interpreting results, writing in disciplinary style, and working in teams. Assignments and exams require higher-order cognitive processes, and students build new knowledge and skills through investigation of real-world problems (e.g., malaria), which engages students' interest. Evidence from direct and indirect assessment has guided continuous course revision and has revealed that compared with the course it replaced, Biological Inquiry produces significant learning gains in all targeted areas. It also retains 94% of students (both BA and BS track) compared with 79% in the majors-only course it replaced. The project has had broad impact across the entire college and reflects the input of numerous constituencies and close collaboration among biology professors and students.

A critical evaluation of ecological indices for the comparative analysis of microbial communities based on molecular datasets.

PubMed

Lucas, Rico; Groeneveld, Jürgen; Harms, Hauke; Johst, Karin; Frank, Karin; Kleinsteuber, Sabine

2017-01-01

In times of global change and intensified resource exploitation, advanced knowledge of ecophysiological processes in natural and engineered systems driven by complex microbial communities is crucial for both safeguarding environmental processes and optimising rational control of biotechnological processes. To gain such knowledge, high-throughput molecular techniques are routinely employed to investigate microbial community composition and dynamics within a wide range of natural or engineered environments. However, for molecular dataset analyses no consensus about a generally applicable alpha diversity concept and no appropriate benchmarking of corresponding statistical indices exist yet. To overcome this, we listed criteria for the appropriateness of an index for such analyses and systematically scrutinised commonly employed ecological indices describing diversity, evenness and richness based on artificial and real molecular datasets. We identified appropriate indices warranting interstudy comparability and intuitive interpretability. The unified diversity concept based on 'effective numbers of types' provides the mathematical framework for describing community composition. Additionally, the Bray-Curtis dissimilarity as a beta-diversity index was found to reflect compositional changes. The employed statistical procedure is presented comprising commented R-scripts and example datasets for user-friendly trial application. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Biological Inquiry: A New Course and Assessment Plan in Response to the Call to Transform Undergraduate Biology

PubMed Central

Goldey, Ellen S.; Abercrombie, Clarence L.; Ivy, Tracie M.; Kusher, Dave I.; Moeller, John F.; Rayner, Doug A.; Smith, Charles F.; Spivey, Natalie W.

2012-01-01

We transformed our first-year curriculum in biology with a new course, Biological Inquiry, in which >50% of all incoming, first-year students enroll. The course replaced a traditional, content-driven course that relied on outdated approaches to teaching and learning. We diversified pedagogical practices by adopting guided inquiry in class and in labs, which are devoted to building authentic research skills through open-ended experiments. Students develop core biological knowledge, from the ecosystem to molecular level, and core skills through regular practice in hypothesis testing, reading primary literature, analyzing data, interpreting results, writing in disciplinary style, and working in teams. Assignments and exams require higher-order cognitive processes, and students build new knowledge and skills through investigation of real-world problems (e.g., malaria), which engages students’ interest. Evidence from direct and indirect assessment has guided continuous course revision and has revealed that compared with the course it replaced, Biological Inquiry produces significant learning gains in all targeted areas. It also retains 94% of students (both BA and BS track) compared with 79% in the majors-only course it replaced. The project has had broad impact across the entire college and reflects the input of numerous constituencies and close collaboration among biology professors and students. PMID:23222831

NEUTRINO-DRIVEN CONVECTION IN CORE-COLLAPSE SUPERNOVAE: HIGH-RESOLUTION SIMULATIONS

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

Radice, David; Ott, Christian D.; Abdikamalov, Ernazar

2016-03-20

We present results from high-resolution semiglobal simulations of neutrino-driven convection in core-collapse supernovae. We employ an idealized setup with parameterized neutrino heating/cooling and nuclear dissociation at the shock front. We study the internal dynamics of neutrino-driven convection and its role in redistributing energy and momentum through the gain region. We find that even if buoyant plumes are able to locally transfer heat up to the shock, convection is not able to create a net positive energy flux and overcome the downward transport of energy from the accretion flow. Turbulent convection does, however, provide a significant effective pressure support to the accretionmore » flow as it favors the accumulation of energy, mass, and momentum in the gain region. We derive an approximate equation that is able to explain and predict the shock evolution in terms of integrals of quantities such as the turbulent pressure in the gain region or the effects of nonradial motion of the fluid. We use this relation as a way to quantify the role of turbulence in the dynamics of the accretion shock. Finally, we investigate the effects of grid resolution, which we change by a factor of 20 between the lowest and highest resolution. Our results show that the shallow slopes of the turbulent kinetic energy spectra reported in previous studies are a numerical artifact. Kolmogorov scaling is progressively recovered as the resolution is increased.« less

Design of fuzzy system by NNs and realization of adaptability

NASA Technical Reports Server (NTRS)

Takagi, Hideyuki

1993-01-01

The issue of designing and tuning fuzzy membership functions by neural networks (NN's) was started by NN-driven Fuzzy Reasoning in 1988. NN-driven fuzzy reasoning involves a NN embedded in the fuzzy system which generates membership values. In conventional fuzzy system design, the membership functions are hand-crafted by trial and error for each input variable. In contrast, NN-driven fuzzy reasoning considers several variables simultaneously and can design a multidimensional, nonlinear membership function for the entire subspace.

Knowledge Searching and Sharing on Virtual Networks.

ERIC Educational Resources Information Center

Helokunnas, Tuija; Herrala, Juha

2001-01-01

Describes searching and sharing of knowledge on virtual networks, based on experiences gained when hosting virtual knowledge networks at Tampere University of Technology in Finland. Discusses information and knowledge management studies; role of information technology in knowledge searching and sharing; implementation and experiences of the…

Effect of additional optical pumping injection into the ground-state ensemble on the gain and the phase recovery acceleration of quantum-dot semiconductor optical amplifiers

NASA Astrophysics Data System (ADS)

Kim, Jungho

2014-02-01

The effect of additional optical pumping injection into the ground-state ensemble on the ultrafast gain and the phase recovery dynamics of electrically-driven quantum-dot semiconductor optical amplifiers is numerically investigated by solving 1088 coupled rate equations. The ultrafast gain and the phase recovery responses are calculated with respect to the additional optical pumping power. Increasing the additional optical pumping power can significantly accelerate the ultrafast phase recovery, which cannot be done by increasing the injection current density.

Walking like dinosaurs: chickens with artificial tails provide clues about non-avian theropod locomotion.

PubMed

Grossi, Bruno; Iriarte-Díaz, José; Larach, Omar; Canals, Mauricio; Vásquez, Rodrigo A

2014-01-01

Birds still share many traits with their dinosaur ancestors, making them the best living group to reconstruct certain aspects of non-avian theropod biology. Bipedal, digitigrade locomotion and parasagittal hindlimb movement are some of those inherited traits. Living birds, however, maintain an unusually crouched hindlimb posture and locomotion powered by knee flexion, in contrast to the inferred primitive condition of non-avian theropods: more upright posture and limb movement powered by femur retraction. Such functional differences, which are associated with a gradual, anterior shift of the centre of mass in theropods along the bird line, make the use of extant birds to study non-avian theropod locomotion problematic. Here we show that, by experimentally manipulating the location of the centre of mass in living birds, it is possible to recreate limb posture and kinematics inferred for extinct bipedal dinosaurs. Chickens raised wearing artificial tails, and consequently with more posteriorly located centre of mass, showed a more vertical orientation of the femur during standing and increased femoral displacement during locomotion. Our results support the hypothesis that gradual changes in the location of the centre of mass resulted in more crouched hindlimb postures and a shift from hip-driven to knee-driven limb movements through theropod evolution. This study suggests that, through careful experimental manipulations during the growth phase of ontogeny, extant birds can potentially be used to gain important insights into previously unexplored aspects of bipedal non-avian theropod locomotion.

Walking Like Dinosaurs: Chickens with Artificial Tails Provide Clues about Non-Avian Theropod Locomotion

PubMed Central

Grossi, Bruno; Iriarte-Díaz, José; Larach, Omar; Canals, Mauricio; Vásquez, Rodrigo A.

2014-01-01

Birds still share many traits with their dinosaur ancestors, making them the best living group to reconstruct certain aspects of non-avian theropod biology. Bipedal, digitigrade locomotion and parasagittal hindlimb movement are some of those inherited traits. Living birds, however, maintain an unusually crouched hindlimb posture and locomotion powered by knee flexion, in contrast to the inferred primitive condition of non-avian theropods: more upright posture and limb movement powered by femur retraction. Such functional differences, which are associated with a gradual, anterior shift of the centre of mass in theropods along the bird line, make the use of extant birds to study non-avian theropod locomotion problematic. Here we show that, by experimentally manipulating the location of the centre of mass in living birds, it is possible to recreate limb posture and kinematics inferred for extinct bipedal dinosaurs. Chickens raised wearing artificial tails, and consequently with more posteriorly located centre of mass, showed a more vertical orientation of the femur during standing and increased femoral displacement during locomotion. Our results support the hypothesis that gradual changes in the location of the centre of mass resulted in more crouched hindlimb postures and a shift from hip-driven to knee-driven limb movements through theropod evolution. This study suggests that, through careful experimental manipulations during the growth phase of ontogeny, extant birds can potentially be used to gain important insights into previously unexplored aspects of bipedal non-avian theropod locomotion. PMID:24505491

Contrasting Effects of Vocabulary Knowledge on Temporal and Parietal Brain Structure across Lifespan

ERIC Educational Resources Information Center

Richardson, Fiona M.; Thomas, Michael S. C.; Filippi, Roberto; Harth, Helen; Price, Cathy J.

2010-01-01

Using behavioral, structural, and functional imaging techniques, we demonstrate contrasting effects of vocabulary knowledge on temporal and parietal brain structure in 47 healthy volunteers who ranged in age from 7 to 73 years. In the left posterior supramarginal gyrus, vocabulary knowledge was positively correlated with gray matter density in…

An interactive Bayesian geostatistical inverse protocol for hydraulic tomography

USGS Publications Warehouse

Fienen, Michael N.; Clemo, Tom; Kitanidis, Peter K.

2008-01-01

Hydraulic tomography is a powerful technique for characterizing heterogeneous hydrogeologic parameters. An explicit trade-off between characterization based on measurement misfit and subjective characterization using prior information is presented. We apply a Bayesian geostatistical inverse approach that is well suited to accommodate a flexible model with the level of complexity driven by the data and explicitly considering uncertainty. Prior information is incorporated through the selection of a parameter covariance model characterizing continuity and providing stability. Often, discontinuities in the parameter field, typically caused by geologic contacts between contrasting lithologic units, necessitate subdivision into zones across which there is no correlation among hydraulic parameters. We propose an interactive protocol in which zonation candidates are implied from the data and are evaluated using cross validation and expert knowledge. Uncertainty introduced by limited knowledge of dynamic regional conditions is mitigated by using drawdown rather than native head values. An adjoint state formulation of MODFLOW-2000 is used to calculate sensitivities which are used both for the solution to the inverse problem and to guide protocol decisions. The protocol is tested using synthetic two-dimensional steady state examples in which the wells are located at the edge of the region of interest.

The organized melee: Emergence of collective behavior in concentrated suspensions of swimming bacteria and associated phenomena

NASA Astrophysics Data System (ADS)

Cisneros Salerno, Luis

Suspensions of the aerobic bacteria Bacilus subtilis develop patterns and flows from the interplay of motility, chemotaxis and buoyancy. In sessile drops, such bioconvectively driven flows carry plumes down the slanted meniscus and concentrate cells at the drop edge, while in pendant drops such self-concentration occurs at the bottom. These dynamics are explained quantitatively by a mathematical model consisting of oxygen diffusion and consumption, chemotaxis, and viscous fluid dynamics. Concentrated regions in both geometries comprise nearly close-packed populations, forming the collective "Zooming BioNematic" (ZBN) phase. This state exhibits large-scale orientational coherence, analogous to the molecular alignment of nematic liquid crystals, coupled with remarkable spatial and temporal correlations of velocity and vorticity, as measured by both novel and standard applications of particle imaging velocimetry. To probe mechanisms leading to this phase, response of individual cells to steric stress was explored, finding that they can reverse swimming direction at spatial constrictions without turning the cell body. The consequences of this propensity to flip the flagella are quantified, showing that "forwards" and "backwards" motion are dynamically and morphologically indistinguishable. Finally, experiments and mathematical modeling show that complex flows driven by previously unknown bipolar flagellar arrangements are induced when B. subtilis are confined in a thin layer of fluid, between asymmetric boundaries. The resulting driven flow circulates around the cell body ranging over several cell diameters, in contrast to the more localized flows surrounding free swimmers. This discovery extends our knowledge of the dynamic geometry of bacteria and their flagella, and reveals new mechanisms for motility-associated molecular transport and intercellular communication.

Bounded Linear Stability Margin Analysis of Nonlinear Hybrid Adaptive Control

NASA Technical Reports Server (NTRS)

Nguyen, Nhan T.; Boskovic, Jovan D.

2008-01-01

This paper presents a bounded linear stability analysis for a hybrid adaptive control that blends both direct and indirect adaptive control. Stability and convergence of nonlinear adaptive control are analyzed using an approximate linear equivalent system. A stability margin analysis shows that a large adaptive gain can lead to a reduced phase margin. This method can enable metrics-driven adaptive control whereby the adaptive gain is adjusted to meet stability margin requirements.

The Knowledge-Based Software Assistant: Beyond CASE

NASA Technical Reports Server (NTRS)

Carozzoni, Joseph A.

1993-01-01

This paper will outline the similarities and differences between two paradigms of software development. Both support the whole software life cycle and provide automation for most of the software development process, but have different approaches. The CASE approach is based on a set of tools linked by a central data repository. This tool-based approach is data driven and views software development as a series of sequential steps, each resulting in a product. The Knowledge-Based Software Assistant (KBSA) approach, a radical departure from existing software development practices, is knowledge driven and centers around a formalized software development process. KBSA views software development as an incremental, iterative, and evolutionary process with development occurring at the specification level.

Adaptive integral robust control and application to electromechanical servo systems.

PubMed

Deng, Wenxiang; Yao, Jianyong

2017-03-01

This paper proposes a continuous adaptive integral robust control with robust integral of the sign of the error (RISE) feedback for a class of uncertain nonlinear systems, in which the RISE feedback gain is adapted online to ensure the robustness against disturbances without the prior bound knowledge of the additive disturbances. In addition, an adaptive compensation integrated with the proposed adaptive RISE feedback term is also constructed to further reduce design conservatism when the system also exists parametric uncertainties. Lyapunov analysis reveals the proposed controllers could guarantee the tracking errors are asymptotically converging to zero with continuous control efforts. To illustrate the high performance nature of the developed controllers, numerical simulations are provided. At the end, an application case of an actual electromechanical servo system driven by motor is also studied, with some specific design consideration, and comparative experimental results are obtained to verify the effectiveness of the proposed controllers. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Necroptosis: Modules and molecular switches with therapeutic implications.

PubMed

Arora, Deepika; Sharma, Pradeep Kumar; Siddiqui, Mohammed Haris; Shukla, Yogeshwer

2017-06-01

Among the various programmed cell death (PCD) pathways, "Necroptosis" has gained much importance as a novel paradigm of cell death. This pathway has emerged as a backup mechanism when physiologically conserved PCD (apoptosis) is non-functional either genetically or pathogenically. The expanding spectrum of necroptosis from physiological development to diverse patho-physiological disorders, including xenobiotics-mediated toxicity has now grabbed the attention worldwide. The efficient role of necroptosis regulators in disease development and management are under constant examination. In fact, few regulators (e.g. MLKL) have already paved their way towards clinical trials and others are in queue. In this review, emphasis has been paid to the various contributing factors and molecular switches that can regulate necroptosis. Here we linked the overview of current knowledge of this enigmatic signaling with magnitude of therapeutics that may underpin the opportunities for novel therapeutic approaches to suppress the pathogenesis of necroptosis-driven disorders. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Gas Foil Bearings for Space Propulsion Nuclear Electric Power Generation

NASA Technical Reports Server (NTRS)

Howard, Samuel A.; DellaCorte, Christopher

2006-01-01

The choice of power conversion technology is critical in directing the design of a space vehicle for the future NASA mission to Mars. One candidate design consists of a foil bearing supported turbo alternator driven by a helium-xenon gas mixture heated by a nuclear reactor. The system is a closed-loop, meaning there is a constant volume of process fluid that is sealed from the environment. Therefore, foil bearings are proposed due to their ability to use the process gas as a lubricant. As such, the rotor dynamics of a foil bearing supported rotor is an important factor in the eventual design. The current work describes a rotor dynamic analysis to assess the viability of such a system. A brief technology background, assumptions, analyses, and conclusions are discussed in this report. The results indicate that a foil bearing supported turbo alternator is possible, although more work will be needed to gain knowledge about foil bearing behavior in helium-xenon gas.

Local Learning Strategies for Wake Identification

NASA Astrophysics Data System (ADS)

Colvert, Brendan; Alsalman, Mohamad; Kanso, Eva

2017-11-01

Swimming agents, biological and engineered alike, must navigate the underwater environment to survive. Tasks such as autonomous navigation, foraging, mating, and predation require the ability to extract critical cues from the hydrodynamic environment. A substantial body of evidence supports the hypothesis that biological systems leverage local sensing modalities, including flow sensing, to gain knowledge of their global surroundings. The nonlinear nature and high degree of complexity of fluid dynamics makes the development of algorithms for implementing localized sensing in bioinspired engineering systems essentially intractable for many systems of practical interest. In this work, we use techniques from machine learning for training a bioinspired swimmer to learn from its environment. We demonstrate the efficacy of this strategy by learning how to sense global characteristics of the wakes of other swimmers measured only from local sensory information. We conclude by commenting on the advantages and limitations of this data-driven, machine learning approach and its potential impact on broader applications in underwater sensing and navigation.

How to build a course in mathematical-biological modeling: content and processes for knowledge and skill.

PubMed

Hoskinson, Anne-Marie

2010-01-01

Biological problems in the twenty-first century are complex and require mathematical insight, often resulting in mathematical models of biological systems. Building mathematical-biological models requires cooperation among biologists and mathematicians, and mastery of building models. A new course in mathematical modeling presented the opportunity to build both content and process learning of mathematical models, the modeling process, and the cooperative process. There was little guidance from the literature on how to build such a course. Here, I describe the iterative process of developing such a course, beginning with objectives and choosing content and process competencies to fulfill the objectives. I include some inductive heuristics for instructors seeking guidance in planning and developing their own courses, and I illustrate with a description of one instructional model cycle. Students completing this class reported gains in learning of modeling content, the modeling process, and cooperative skills. Student content and process mastery increased, as assessed on several objective-driven metrics in many types of assessments.

Assessing Behavioural Manifestations Prior to Clinical Diagnosis of Huntington Disease: "Anger and Irritability" and "Obsessions and Compulsions"

PubMed Central

Vaccarino, Anthony L; Anonymous; Anderson, Karen E.; Borowsky, Beth; Coccaro, Emil; Craufurd, David; Endicott, Jean; Giuliano, Joseph; Groves, Mark; Guttman, Mark; Ho, Aileen K; Kupchak, Peter; Paulsen, Jane S.; Stanford, Matthew S.; van Kammen, Daniel P; Watson, David; Wu, Kevin D; Evans, Ken

2011-01-01

The Functional Rating Scale Taskforce for pre-Huntington Disease (FuRST-pHD) is a multinational, multidisciplinary initiative with the goal of developing a data-driven, comprehensive, psychometrically sound, rating scale for assessing symptoms and functional ability in prodromal and early Huntington disease (HD) gene expansion carriers. The process involves input from numerous sources to identify relevant symptom domains, including HD individuals, caregivers, and experts from a variety of fields, as well as knowledge gained from the analysis of data from ongoing large-scale studies in HD using existing clinical scales. This is an iterative process in which an ongoing series of field tests in prodromal (prHD) and early HD individuals provides the team with data on which to make decisions regarding which questions should undergo further development or testing and which should be excluded. We report here the development and assessment of the first iteration of interview questions aimed to assess "Anger and Irritability" and "Obsessions and Compulsions" in prHD individuals. PMID:21826116

Obstructive sleep apnea: current perspectives

PubMed Central

Osman, Amal M; Carter, Sophie G; Carberry, Jayne C; Eckert, Danny J

2018-01-01

The prevalence of obstructive sleep apnea (OSA) continues to rise. So too do the health, safety, and economic consequences. On an individual level, the causes and consequences of OSA can vary substantially between patients. In recent years, four key contributors to OSA pathogenesis or “phenotypes” have been characterized. These include a narrow, crowded, or collapsible upper airway “anatomical compromise” and “non-anatomical” contributors such as ineffective pharyngeal dilator muscle function during sleep, a low threshold for arousal to airway narrowing during sleep, and unstable control of breathing (high loop gain). Each of these phenotypes is a target for therapy. This review summarizes the latest knowledge on the different contributors to OSA with a focus on measurement techniques including emerging clinical tools designed to facilitate translation of new cause-driven targeted approaches to treat OSA. The potential for some of the specific pathophysiological causes of OSA to drive some of the key symptoms and consequences of OSA is also highlighted. PMID:29416383

How to Build a Course in Mathematical–Biological Modeling: Content and Processes for Knowledge and Skill

PubMed Central

2010-01-01

Biological problems in the twenty-first century are complex and require mathematical insight, often resulting in mathematical models of biological systems. Building mathematical–biological models requires cooperation among biologists and mathematicians, and mastery of building models. A new course in mathematical modeling presented the opportunity to build both content and process learning of mathematical models, the modeling process, and the cooperative process. There was little guidance from the literature on how to build such a course. Here, I describe the iterative process of developing such a course, beginning with objectives and choosing content and process competencies to fulfill the objectives. I include some inductive heuristics for instructors seeking guidance in planning and developing their own courses, and I illustrate with a description of one instructional model cycle. Students completing this class reported gains in learning of modeling content, the modeling process, and cooperative skills. Student content and process mastery increased, as assessed on several objective-driven metrics in many types of assessments. PMID:20810966

Automated segmentation of middle hepatic vein in non-contrast x-ray CT images based on an atlas-driven approach

NASA Astrophysics Data System (ADS)

Kitagawa, Teruhiko; Zhou, Xiangrong; Hara, Takeshi; Fujita, Hiroshi; Yokoyama, Ryujiro; Kondo, Hiroshi; Kanematsu, Masayuki; Hoshi, Hiroaki

2008-03-01

In order to support the diagnosis of hepatic diseases, understanding the anatomical structures of hepatic lobes and hepatic vessels is necessary. Although viewing and understanding the hepatic vessels in contrast media-enhanced CT images is easy, the observation of the hepatic vessels in non-contrast X-ray CT images that are widely used for the screening purpose is difficult. We are developing a computer-aided diagnosis (CAD) system to support the liver diagnosis based on non-contrast X-ray CT images. This paper proposes a new approach to segment the middle hepatic vein (MHV), a key structure (landmark) for separating the liver region into left and right lobes. Extraction and classification of hepatic vessels are difficult in non-contrast X-ray CT images because the contrast between hepatic vessels and other liver tissues is low. Our approach uses an atlas-driven method by the following three stages. (1) Construction of liver atlases of left and right hepatic lobes using a learning datasets. (2) Fully-automated enhancement and extraction of hepatic vessels in liver regions. (3) Extraction of MHV based on the results of (1) and (2). The proposed approach was applied to 22 normal liver cases of non-contrast X-ray CT images. The preliminary results show that the proposed approach achieves the success in 14 cases for MHV extraction.

Positive contrast of SPIO-labeled cells by off-resonant reconstruction of 3D radial half-echo bSSFP.

PubMed

Diwoky, Clemens; Liebmann, Daniel; Neumayer, Bernhard; Reinisch, Andreas; Knoll, Florian; Strunk, Dirk; Stollberger, Rudolf

2015-01-01

This article describes a new acquisition and reconstruction concept for positive contrast imaging of cells labeled with superparamagnetic iron oxides (SPIOs). Overcoming the limitations of a negative contrast representation as gained with gradient echo and fully balanced steady state (bSSFP), the proposed method delivers a spatially localized contrast with high cellular sensitivity not accomplished by other positive contrast methods. Employing a 3D radial bSSFP pulse sequence with half-echo sampling, positive cellular contrast is gained by adding artificial global frequency offsets to each half-echo before image reconstruction. The new contrast regime is highlighted with numerical intravoxel simulations including the point-spread function for 3D half-echo acquisitions. Furthermore, the new method is validated on the basis of in vitro cell phantom measurements on a clinical MRI platform, where the measured contrast-to-noise ratio (CNR) of the new approach exceeds even the negative contrast of bSSFP. Finally, an in vivo proof of principle study based on a mouse model with a clear depiction of labeled cells within a subcutaneous cell islet containing a cell density as low as 7 cells/mm(3) is presented. The resultant isotropic images show robustness to motion and a high CNR, in addition to an enhanced specificity due to the positive contrast of SPIO-labeled cells. Copyright © 2014 John Wiley & Sons, Ltd.

Child Characteristics by Science Instruction Interactions in Second and Third Grade and Their Relation to Students' Content-Area Knowledge, Vocabulary, and Reading Skill Gains

ERIC Educational Resources Information Center

Connor, Carol McDonald; Rice, Diana C.; Canto, Angela I.; Southerland, Sherry A.; Underwood, Phyllis; Kaya, Sibel; Fishman, Barry; Morrison, Frederick J.

2012-01-01

The associations among second- and third-grade students' content-area knowledge, vocabulary, and reading gains and the science instruction they received were examined in this exploratory longitudinal study. We also asked whether there were child characteristics x instruction interaction effects on students' content-area literacy. Second graders (n…

Stacking up against alternative conceptions: using Uno cards to introduce discourse and argumentation

NASA Astrophysics Data System (ADS)

Dunac, Patricia S.; Demir, Kadir

2013-11-01

We engaged secondary science students in a teacher and student constructed Uno card game (UCG) to change their conceptual understanding of the various energy transformations. The paper outlines how we incorporated Toulmin’s argumentation pattern (Toulmin 1958 The Uses of Argument (Cambridge: Cambridge University Press)) in the UCG, using discourse (Erduran et al 2004 Sci. Educ. 88 915-33) and through a 5E learning cycle (Bybee 1997 Achieving Scientific Literacy: From Purposes to Practices (Portsmouth, NH: Heinemann Educational Books)). The activity helped students develop a deeper understanding of the energy transformation among and between different sources. Students experienced a conceptual gain in their ways of thinking, in contrast to traditional teaching and learning practices. The collaboration and interaction between teacher-student(s) and between students fostered an environment where they became co-constructors of knowledge.

A knowledge-driven approach to cluster validity assessment.

PubMed

Bolshakova, Nadia; Azuaje, Francisco; Cunningham, Pádraig

2005-05-15

This paper presents an approach to assessing cluster validity based on similarity knowledge extracted from the Gene Ontology. The program is freely available for non-profit use on request from the authors.

Gain in stochastic resonance: Precise numerics versus linear response theory beyond the two-mode approximation

NASA Astrophysics Data System (ADS)

Casado-Pascual, Jesús; Denk, Claus; Gómez-Ordóñez, José; Morillo, Manuel; Hänggi, Peter

2003-03-01

In the context of the phenomenon of stochastic resonance (SR), we study the correlation function, the signal-to-noise ratio (SNR), and the ratio of output over input SNR, i.e., the gain, which is associated to the nonlinear response of a bistable system driven by time-periodic forces and white Gaussian noise. These quantifiers for SR are evaluated using the techniques of linear response theory (LRT) beyond the usually employed two-mode approximation scheme. We analytically demonstrate within such an extended LRT description that the gain can indeed not exceed unity. We implement an efficient algorithm, based on work by Greenside and Helfand (detailed in the Appendix), to integrate the driven Langevin equation over a wide range of parameter values. The predictions of LRT are carefully tested against the results obtained from numerical solutions of the corresponding Langevin equation over a wide range of parameter values. We further present an accurate procedure to evaluate the distinct contributions of the coherent and incoherent parts of the correlation function to the SNR and the gain. As a main result we show for subthreshold driving that both the correlation function and the SNR can deviate substantially from the predictions of LRT and yet the gain can be either larger or smaller than unity. In particular, we find that the gain can exceed unity in the strongly nonlinear regime which is characterized by weak noise and very slow multifrequency subthreshold input signals with a small duty cycle. This latter result is in agreement with recent analog simulation results by Gingl et al. [ICNF 2001, edited by G. Bosman (World Scientific, Singapore, 2002), pp. 545 548; Fluct. Noise Lett. 1, L181 (2001)].

Developing "My Asthma Diary": a process exemplar of a patient-driven arts-based knowledge translation tool.

PubMed

Archibald, Mandy M; Hartling, Lisa; Ali, Samina; Caine, Vera; Scott, Shannon D

2018-06-05

Although it is well established that family-centered education is critical to managing childhood asthma, the information needs of parents of children with asthma are not being met through current educational approaches. Patient-driven educational materials that leverage the power of the storytelling and the arts show promise in communicating health information and assisting in illness self-management. However, such arts-based knowledge translation approaches are in their infancy, and little is known about how to develop such tools for parents. This paper reports on the development of "My Asthma Diary" - an innovative knowledge translation tool based on rigorous research evidence and tailored to parents' asthma-related information needs. We used a multi-stage process to develop four eBook prototypes of "My Asthma Diary." We conducted formative research on parents' information needs and identified high quality research evidence on childhood asthma, and used these data to inform the development of the asthma eBooks. We established interdisciplinary consulting teams with health researchers, practitioners, and artists to help iteratively create the knowledge translation tools. We describe the iterative, transdisciplinary process of developing asthma eBooks which incorporates: (I) parents' preferences and information needs on childhood asthma, (II) quality evidence on childhood asthma and its management, and (III) the engaging and informative powers of storytelling and visual art as methods to communicate complex health information to parents. We identified four dominant methodological and procedural challenges encountered during this process: (I) working within an inter-disciplinary team, (II) quantity and ordering of information, (III) creating a composite narrative, and (IV) balancing actual and ideal management scenarios. We describe a replicable and rigorous multi-staged approach to developing a patient-driven, creative knowledge translation tool, which can be adapted for use with different populations and contexts. We identified specific procedural and methodological challenges that others conducting comparable work should consider, particularly as creative, patient-driven knowledge translation strategies continue to emerge across health disciplines.

Mirror-assisted coherent backscattering from the Mollow sidebands

NASA Astrophysics Data System (ADS)

Piovella, N.; Teixeira, R. Celistrino; Kaiser, R.; Courteille, Ph. W.; Bachelard, R.

2017-11-01

In front of a mirror, the radiation of weakly driven large disordered clouds presents an interference fringe in the backward direction, on top of an incoherent background. Although strongly driven atoms usually present little coherent scattering, we show here that the mirror-assisted version can produce high contrast fringes, for arbitrarily high saturation parameters. The contrast of the fringes oscillates with the Rabi frequency of the atomic transition and the distance between the mirror and the atoms, due to the coherent interference between the carrier and the Mollow sidebands of the saturated resonant fluorescence spectrum emitted by the atoms. The setup thus represents a powerful platform to study the spectral properties of ensembles of correlated scatterers.

E-learning courses in epilepsy--concept, evaluation, and experience with the e-learning course "genetics of epilepsies".

PubMed

Wehrs, Verena Hézser-V; Pfäfflin, Margarete; May, Theodor W

2007-05-01

To evaluate the efficacy of the e-learning course "Genetics of Epilepsies" and to assess the experiences of the participants and e-moderators with this new approach. Prospective, controlled study with waiting group (control group, n = 18) and e-learning group (n = 20). The control group got the same reference literature list as the e-learning group. Both groups were assessed twice: The e-learning group before and after the course; the control group was assessed at the same times. increase in knowledge about genetics of epilepsies using questionnaires based on items formulated by experts (internal consistency, Cronbach's alpha = 0.86). Main hypothesis: greater increase of knowledge in the e-learning group compared to control group. assessment of the educational course and learning environment by participants and by tutors/e-moderators. Significant time x group interaction and group effect (ANOVA, each p < 0.01) with regard to knowledge. At baseline, the groups did not differ with respect to knowledge about genetics of epilepsy. In contrast to the control group, the increase of knowledge in the e-learning group was highly significant (p < 0.001). The majority of the participants of the e-learning course was content with their personal learning process (75% agree, 15% strongly agree). Most of them reported a gain in competence in the treatment and counseling of people with epilepsy (38.9% agree, 50% strongly agree). All participants would recommend this course to others and all but one participant are interested in other e-learning courses. The study indicates e-learning courses are an appropriate tool to improve knowledge of physicians in genetics of epilepsy.

Learning to prescribe - pharmacists' experiences of supplementary prescribing training in England.

PubMed

Cooper, Richard J; Lymn, Joanne; Anderson, Claire; Avery, Anthony; Bissell, Paul; Guillaume, Louise; Hutchinson, Allen; Murphy, Elizabeth; Ratcliffe, Julie; Ward, Paul

2008-12-05

The introduction of non-medical prescribing for professions such as pharmacy and nursing in recent years offers additional responsibilities and opportunities but attendant training issues. In the UK and in contrast to some international models, becoming a non-medical prescriber involves the completion of an accredited training course offered by many higher education institutions, where the skills and knowledge necessary for prescribing are learnt. to explore pharmacists' perceptions and experiences of learning to prescribe on supplementary prescribing (SP) courses, particularly in relation to inter-professional learning, course content and subsequent use of prescribing in practice. A postal questionnaire survey was sent to all 808 SP registered pharmacists in England in April 2007, exploring demographic, training, prescribing, safety culture and general perceptions of SP. After one follow-up, 411 (51%) of pharmacists responded. 82% agreed SP training was useful, 58% agreed courses provided appropriate knowledge and 62% agreed that the necessary prescribing skills were gained. Clinical examination, consultation skills training and practical experience with doctors were valued highly; pharmacology training and some aspects of course delivery were criticised. Mixed views on inter-professional learning were reported - insights into other professions being valued but knowledge and skills differences considered problematic. 67% believed SP and recent independent prescribing (IP) should be taught together, with more diagnostic training wanted; few pharmacists trained in IP, but many were training or intending to train. There was no association between pharmacists' attitudes towards prescribing training and when they undertook training between 2004 and 2007 but earlier cohorts were more likely to be using supplementary prescribing in practice. Pharmacists appeared to value their SP training and suggested improvements that could inform future courses. The benefits of inter-professional learning, however, may conflict with providing profession-specific training. SP training may be perceived to be an instrumental 'stepping stone' in pharmacists' professional project of gaining full IP status.

Interdisciplinary action supporting sexual assault prevention efforts in rural elementary schools.

PubMed

Hayward, K S; Pehrsson, D E

2000-01-01

The purpose of this study was to evaluate if knowledge is gained by rural, elementary school-aged children of sexual assault prevention concepts following implementation of an interdisciplinary prevention program. Rural children (N = 294 pretest and N = 301 posttest) were tested before and after delivery of a theater program developed for teaching sexual assault prevention concepts. The program was delivered to children enrolled in the 3rd and 4th grades of 3 rural elementary schools. Analysis of variance results indicate an increase in knowledge gained in all age groups. Significant difference in knowledge gained occurred in concept areas related to touch by authority figures, secrets, uncomfortable touch by individuals known to them, strangers, and boys' risk of abuse. Results support the need for ongoing interdisciplinary efforts to teach children sexual assault prevention concepts.

A synopsis of test results and knowledge gained from the Phase-0 CSI evolutionary model

NASA Technical Reports Server (NTRS)

Belvin, W. Keith; Elliott, Kenny B.; Horta, Lucas G.

1993-01-01

The Phase-0 CSI Evolutionary Model (CEM) is a testbed for the study of space platform global line-of-sight (LOS) pointing. Now that the tests have been completed, a summary of hardware and closed-loop test experiences is necessary to insure a timely dissemination of the knowledge gained. The testbed is described and modeling experiences are presented followed by a summary of the research performed by various investigators. Some early lessons on implementing the closed-loop controllers are described with particular emphasis on real-time computing requirements. A summary of closed-loop studies and a synopsis of test results are presented. Plans for evolving the CEM from phase 0 to phases 1 and 2 are also described. Subsequently, a summary of knowledge gained from the design and testing of the Phase-0 CEM is made.

The impact of cervical cancer education for deaf women using a video educational tool employing American sign language, open captioning, and graphics.

PubMed

Choe, Sun; Lim, Rod Seung-Hwan; Clark, Karen; Wang, Regina; Branz, Patricia; Sadler, Georgia Robins

2009-01-01

Deaf women encounter barriers to accessing cancer information. In this study, we evaluated whether deaf women's knowledge could be increased by viewing a graphically enriched, American Sign Language (ASL) cervical cancer education video. A blind, randomized trial evaluated knowledge gain and retention. Deaf women (n = 130) completed questionnaires before, after, and 2 months after viewing the video. With only a single viewing of the in-depth video, the experimental group gained and retained significantly more cancer knowledge than the control group. Giving deaf women access to the ASL cervical cancer education video (http://cancer.ucsd.edu/deafinfo) significantly increased their knowledge of cervical cancer.

Evaluation of an Intelligent Tutoring System in Pathology: Effects of External Representation on Performance Gains, Metacognition, and Acceptance

PubMed Central

Crowley, Rebecca S.; Legowski, Elizabeth; Medvedeva, Olga; Tseytlin, Eugene; Roh, Ellen; Jukic, Drazen

2007-01-01

Objective Determine effects of computer-based tutoring on diagnostic performance gains, meta-cognition, and acceptance using two different problem representations. Describe impact of tutoring on spectrum of diagnostic skills required for task performance. Identify key features of student-tutor interaction contributing to learning gains. Design Prospective, between-subjects study, controlled for participant level of training. Resident physicians in two academic pathology programs spent four hours using one of two interfaces which differed mainly in external problem representation. The case-focused representation provided an open-learning environment in which students were free to explore evidence-hypothesis relationships within a case, but could not visualize the entire diagnostic space. The knowledge-focused representation provided an interactive representation of the entire diagnostic space, which more tightly constrained student actions. Measurements Metrics included results of pretest, post-test and retention-test for multiple choice and case diagnosis tests, ratios of performance to student reported certainty, results of participant survey, learning curves, and interaction behaviors during tutoring. Results Students had highly significant learning gains after one tutoring session. Learning was retained at one week. There were no differences between the two interfaces in learning gains on post-test or retention test. Only students in the knowledge-focused interface exhibited significant metacognitive gains from pretest to post-test and pretest to retention test. Students rated the knowledge-focused interface significantly higher than the case-focused interface. Conclusions Cognitive tutoring is associated with improved diagnostic performance in a complex medical domain. The effect is retained at one-week post-training. Knowledge-focused external problem representation shows an advantage over case-focused representation for metacognitive effects and user acceptance. PMID:17213494

Evaluation of an intelligent tutoring system in pathology: effects of external representation on performance gains, metacognition, and acceptance.

PubMed

Crowley, Rebecca S; Legowski, Elizabeth; Medvedeva, Olga; Tseytlin, Eugene; Roh, Ellen; Jukic, Drazen

2007-01-01

Determine effects of computer-based tutoring on diagnostic performance gains, meta-cognition, and acceptance using two different problem representations. Describe impact of tutoring on spectrum of diagnostic skills required for task performance. Identify key features of student-tutor interaction contributing to learning gains. Prospective, between-subjects study, controlled for participant level of training. Resident physicians in two academic pathology programs spent four hours using one of two interfaces which differed mainly in external problem representation. The case-focused representation provided an open-learning environment in which students were free to explore evidence-hypothesis relationships within a case, but could not visualize the entire diagnostic space. The knowledge-focused representation provided an interactive representation of the entire diagnostic space, which more tightly constrained student actions. Metrics included results of pretest, post-test and retention-test for multiple choice and case diagnosis tests, ratios of performance to student reported certainty, results of participant survey, learning curves, and interaction behaviors during tutoring. Students had highly significant learning gains after one tutoring session. Learning was retained at one week. There were no differences between the two interfaces in learning gains on post-test or retention test. Only students in the knowledge-focused interface exhibited significant metacognitive gains from pretest to post-test and pretest to retention test. Students rated the knowledge-focused interface significantly higher than the case-focused interface. Cognitive tutoring is associated with improved diagnostic performance in a complex medical domain. The effect is retained at one-week post-training. Knowledge-focused external problem representation shows an advantage over case-focused representation for metacognitive effects and user acceptance.

Cost-effectiveness of iso- versus low-osmolality contrast media in outpatients with high risk of contrast medium-induced nephropathy.

PubMed

Chicaíza-Becerra, Liliana Alejandra; García-Molina, Mario; Gamboa, Óscar

2012-06-01

Contrast media can cause acute renal failure by direct toxic effects on the tubular cells and kidney ischemia. Diabetics and hospitalized patients have a greater risk of developing contrast-induced nephropathy than the general population. The cost effectiveness of iso and low-osmolality contrast media was assessed in high risk outpatients. The analysis was based on a systematic literature review comparing the nephrotoxic effects of iso- to low-osmolality contrast media. Only direct costs were considered; these were obtained from the official tariff manual. Incremental cost-effectiveness ratios, efficiency curves and acceptability curves were calculated. Univariate sensitivity analyses were performed for costs and effects, as well as probabilistic analyses. Zero and 3% discounts were applied to results. The cost-effectiveness threshold was equal to the per capita GDP per life-year gained. Alternatives with Iopamidol and Iodixanol are preferable to the others, because both reduce risk of contrast-induced nephropathy and are less costly. The incremental cost-effectiveness of the Iodixanol alternative compared to the Iopamidol alternative is US$ 14,660 per additional life year gained; this is more than twice the threshold. The low-osmolality contrast medium, Iopamidol, appears to be cost-effective when compared with Iohexol or other low-osmolality contrast media (Iopromide, Iobitridol, Iomeprol, Iopentol and Ioxilan) in contrast-induced nephropathy, high-risk outpatients. The choice of the iso-osmolality contrast medium, Iodixanol, depends on its cost per vial and on the willingness to pay.

Documentation and knowledge acquisition

NASA Technical Reports Server (NTRS)

Rochowiak, Daniel; Moseley, Warren

1990-01-01

Traditional approaches to knowledge acquisition have focused on interviews. An alternative focuses on the documentation associated with a domain. Adopting a documentation approach provides some advantages during familiarization. A knowledge management tool was constructed to gain these advantages.

The critical success factors and impact of prior knowledge to nursing students when transferring nursing knowledge during nursing clinical practise.

PubMed

Tsai, Ming-Tien; Tsai, Ling-Long

2005-11-01

Nursing practise plays an important role in transferring nursing knowledge to nursing students. From the related literature review, prior knowledge will affect how learners gain new knowledge. There has been no direct examination of the prior knowledge interaction effect on students' performance and its influence on nursing students when evaluating the knowledge transfer success factors. This study explores (1) the critical success factors in transferring nursing knowledge, (2) the impact of prior knowledge when evaluating the success factors for transferring nursing knowledge. This research utilizes in-depth interviews to probe the initial success factor phase. A total of 422 valid questionnaires were conducted by the authors. The data were analysed by comparing the mean score and t-test between two groups. Seventeen critical success factors were identified by the two groups of students. Twelve items were selected to examine the diversity in the two groups. Students with prior knowledge were more independent than the other group. They also preferred self-directed learning over students without prior knowledge. Students who did not have prior knowledge were eager to take every opportunity to gain experience and more readily adopted new knowledge.

Impact of GODAE Products on Nested HYCOM Simulations of the West Florida Shelf

DTIC Science & Technology

2009-01-20

circulation and the Atlantic Meridional Overturning Circulation . For temperature, the non-assimilative outer model had a cold...associated with the basin-scale wind-driven gyres and with the Atlantic Meridional Overturning Circulation is incor- rectly represented. In contrast...not contain realistic LC transport variability associated with the wind-driven gyre circulation and the Atlantic Meridio- nal Overturning Circulation

A molecular dynamics approach to barrodiffusion

NASA Astrophysics Data System (ADS)

Cooley, James; Marciante, Mathieu; Murillo, Michael

2016-10-01

Unexpected phenomena in the reaction rates for Inertial Confinement Fusion (ICF) capsules have led to a renewed interest in the thermo-dynamically driven diffusion process for the past 10 years, often described collectively as barodiffusion. In the current context, barodiffusion would manifest as a process that separates ions of differing mass and charge ratios due to pressure and temperature gradients set-up through shock structures in the capsule core. Barrodiffusion includes additional mass transfer terms that account for the irreversible transport of species due to gradients in the system, both thermodynamic and electric e.g, i = - ρD [ ∇c +kp ∇ln(pi) +kT(i) ∇ln(Ti) +kt(e) ∇ln(Te) +eke/Ti ∇ϕ ] . Several groups have attacked this phenomena using continuum scale models and supplemented with kinetic theory to derive coefficients for the different diffusion terms based on assumptions about the collisional processes. In contrast, we have applied a molecular dynamics (MD) simulation to this system to gain a first-principle understanding of the rate kinetics and to assess the accuracy of the differin

Sophisticated epistemologies of physics versus high-stakes tests: How do elite high school students respond to competing influences about how to learn physics?

NASA Astrophysics Data System (ADS)

Yerdelen-Damar, Sevda; Elby, Andrew

2016-06-01

This study investigates how elite Turkish high school physics students claim to approach learning physics when they are simultaneously (i) engaged in a curriculum that led to significant gains in their epistemological sophistication and (ii) subject to a high-stakes college entrance exam. Students reported taking surface (rote) approaches to learning physics, largely driven by college entrance exam preparation and therefore focused on algorithmic problem solving at the expense of exploring concepts and real-life examples more deeply. By contrast, in recommending study strategies to "Arzu," a hypothetical student who doesn't need to take a college entrance exam and just wants to understand physics deeply, the students focused more on linking concepts and real-life examples and on making sense of the formulas and concepts—deep approaches to learning that reflect somewhat sophisticated epistemologies. These results illustrate how students can epistemically compartmentalize, consciously taking different epistemic stances—different views of what counts as knowing and learning—in different contexts even within the same discipline.

The role of the 5f valence orbitals of early actinides in chemical bonding

PubMed Central

Vitova, T.; Pidchenko, I.; Fellhauer, D.; Bagus, P. S.; Joly, Y.; Pruessmann, T.; Bahl, S.; Gonzalez-Robles, E.; Rothe, J.; Altmaier, M.; Denecke, M. A.; Geckeis, H.

2017-01-01

One of the long standing debates in actinide chemistry is the level of localization and participation of the actinide 5f valence orbitals in covalent bonds across the actinide series. Here we illuminate the role of the 5f valence orbitals of uranium, neptunium and plutonium in chemical bonding using advanced spectroscopies: actinide M4,5 HR-XANES and 3d4f RIXS. Results reveal that the 5f orbitals are active in the chemical bonding for uranium and neptunium, shown by significant variations in the level of their localization evidenced in the spectra. In contrast, the 5f orbitals of plutonium appear localized and surprisingly insensitive to different bonding environments. We envisage that this report of using relative energy differences between the 5fδ/ϕ and 5fπ*/5fσ* orbitals as a qualitative measure of overlap-driven actinyl bond covalency will spark activity, and extend to numerous applications of RIXS and HR-XANES to gain new insights into the electronic structures of the actinide elements. PMID:28681848

The role of the 5f valence orbitals of early actinides in chemical bonding

NASA Astrophysics Data System (ADS)

Vitova, T.; Pidchenko, I.; Fellhauer, D.; Bagus, P. S.; Joly, Y.; Pruessmann, T.; Bahl, S.; Gonzalez-Robles, E.; Rothe, J.; Altmaier, M.; Denecke, M. A.; Geckeis, H.

2017-07-01

One of the long standing debates in actinide chemistry is the level of localization and participation of the actinide 5f valence orbitals in covalent bonds across the actinide series. Here we illuminate the role of the 5f valence orbitals of uranium, neptunium and plutonium in chemical bonding using advanced spectroscopies: actinide M4,5 HR-XANES and 3d4f RIXS. Results reveal that the 5f orbitals are active in the chemical bonding for uranium and neptunium, shown by significant variations in the level of their localization evidenced in the spectra. In contrast, the 5f orbitals of plutonium appear localized and surprisingly insensitive to different bonding environments. We envisage that this report of using relative energy differences between the 5fδ/φ and 5fπ*/5fσ* orbitals as a qualitative measure of overlap-driven actinyl bond covalency will spark activity, and extend to numerous applications of RIXS and HR-XANES to gain new insights into the electronic structures of the actinide elements.

Evaporation-Driven Charge Redistribution and Current Generation for Energy Harvesting Applications

DTIC Science & Technology

2008-12-01

has occurred and the system has a net positive energy gain, ∆Ecycle, as given by equation (5). 2 2 1 outstorecycle VCE =∆ (5) 5.5 Voltage...then the energy gained using the constant charge model can be represented by equation ( 2 ). minmaxminmax )( 2 1 VVCCE −=∆ ( 2 ) 3. DEVICE...evaporation. Evaporation can be the caused by changes in multiple environmental conditions such as: ( 1 ) percent relative humidity, ( 2 ) temperature, (3

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.

Compensating effect of the coherent synchrotron radiation in bunch compressors

NASA Astrophysics Data System (ADS)

Jing, Yichao; Hao, Yue; Litvinenko, Vladimir N.

2013-06-01

Typical bunch compression for a high-gain free-electron laser (FEL) requires a large compression ratio. Frequently, this compression is distributed in multiple stages along the beam transport line. However, for a high-gain FEL driven by an energy recovery linac (ERL), compression must be accomplished in a single strong compressor located at the beam line’s end; otherwise the electron beam would be affected severely by coherent synchrotron radiation (CSR) in the ERL’s arcs. In such a scheme, the CSR originating from the strong compressors could greatly degrade the quality of the electron beam. In this paper, we present our design for a bunch compressor that will limit the effect of CSR on the e-beam’s quality. We discuss our findings from a study of such a compressor, and detail its potential for an FEL driven by a multipass ERL developed for the electron-Relativistic Heavy Ion Collider.

Parametric Study of Pulse-Combustor-Driven Ejectors at High-Pressure

NASA Technical Reports Server (NTRS)

Yungster, Shaye; Paxson, Daniel E.; Perkins, Hugh D.

2015-01-01

Pulse-combustor configurations developed in recent studies have demonstrated performance levels at high-pressure operating conditions comparable to those observed at atmospheric conditions. However, problems related to the way fuel was being distributed within the pulse combustor were still limiting performance. In the first part of this study, new configurations are investigated computationally aimed at improving the fuel distribution and performance of the pulse-combustor. Subsequent sections investigate the performance of various pulse-combustor driven ejector configurations operating at highpressure conditions, focusing on the effects of fuel equivalence ratio and ejector throat area. The goal is to design pulse-combustor-ejector configurations that maximize pressure gain while achieving a thermal environment acceptable to a turbine, and at the same time maintain acceptable levels of NOx emissions and flow non-uniformities. The computations presented here have demonstrated pressure gains of up to 2.8%.

Parametric Study of Pulse-Combustor-Driven Ejectors at High-Pressure

NASA Technical Reports Server (NTRS)

Yungster, Shaye; Paxson, Daniel E.; Perkins, Hugh D.

2015-01-01

Pulse-combustor configurations developed in recent studies have demonstrated performance levels at high-pressure operating conditions comparable to those observed at atmospheric conditions. However, problems related to the way fuel was being distributed within the pulse combustor were still limiting performance. In the first part of this study, new configurations are investigated computationally aimed at improving the fuel distribution and performance of the pulse-combustor. Subsequent sections investigate the performance of various pulse-combustor driven ejector configurations operating at high pressure conditions, focusing on the effects of fuel equivalence ratio and ejector throat area. The goal is to design pulse-combustor-ejector configurations that maximize pressure gain while achieving a thermal environment acceptable to a turbine, and at the same time maintain acceptable levels of NO(x) emissions and flow non-uniformities. The computations presented here have demonstrated pressure gains of up to 2.8.

Semi-analytic model of plasma-jet-driven magneto-inertial fusion

DOE PAGES

Langendorf, Samuel J.; Hsu, Scott C.

2017-03-01

A semi-analytic model for plasma-jet-driven magneto-inertial fusion is presented here. Compressions of a magnetized plasma target by a spherically imploding plasma liner are calculated in one dimension (1D), accounting for compressible hydrodynamics and ionization of the liner material, energy losses due to conduction and radiation, fusion burn and alpha deposition, separate ion and electron temperatures in the target, magnetic pressure, and fuel burn-up. Results show 1D gains of 3–30 at spherical convergence ratio <15 and 20–40 MJ of liner energy, for cases in which the liner thickness is 1 cm and the initial radius of a preheated magnetized target ismore » 4 cm. Some exploration of parameter space and physics settings is presented. The yields observed suggest that there is a possibility of igniting additional dense fuel layers to reach high gain.« less

Mission Driven and Data Informed Leadership

ERIC Educational Resources Information Center

Holter, Anthony C.; Frabutt, James M.

2012-01-01

The contemporary challenges facing Catholic schools and Catholic school leaders are widely known. Effective and systemic solutions to these mounting challenges are less widely known or discussed. This article highlights the skills, knowledge, and dispositions associated with mission driven and data informed leadership--an orientation to school…

Who Owns the Data? Open Data for Healthcare

PubMed Central

Kostkova, Patty; Brewer, Helen; de Lusignan, Simon; Fottrell, Edward; Goldacre, Ben; Hart, Graham; Koczan, Phil; Knight, Peter; Marsolier, Corinne; McKendry, Rachel A.; Ross, Emma; Sasse, Angela; Sullivan, Ralph; Chaytor, Sarah; Stevenson, Olivia; Velho, Raquel; Tooke, John

2016-01-01

Research on large shared medical datasets and data-driven research are gaining fast momentum and provide major opportunities for improving health systems as well as individual care. Such open data can shed light on the causes of disease and effects of treatment, including adverse reactions side-effects of treatments, while also facilitating analyses tailored to an individual’s characteristics, known as personalized or “stratified medicine.” Developments, such as crowdsourcing, participatory surveillance, and individuals pledging to become “data donors” and the “quantified self” movement (where citizens share data through mobile device-connected technologies), have great potential to contribute to our knowledge of disease, improving diagnostics, and delivery of ­healthcare and treatment. There is not only a great potential but also major concerns over privacy, confidentiality, and control of data about individuals once it is shared. Issues, such as user trust, data privacy, transparency over the control of data ownership, and the implications of data analytics for personal privacy with potentially intrusive inferences, are becoming increasingly scrutinized at national and international levels. This can be seen in the recent backlash over the proposed implementation of care.data, which enables individuals’ NHS data to be linked, retained, and shared for other uses, such as research and, more controversially, with businesses for commercial exploitation. By way of contrast, through increasing popularity of social media, GPS-enabled mobile apps and tracking/wearable devices, the IT industry and MedTech giants are pursuing new projects without clear public and policy discussion about ownership and responsibility for user-generated data. In the absence of transparent regulation, this paper addresses the opportunities of Big Data in healthcare together with issues of responsibility and accountability. It also aims to pave the way for public policy to support a balanced agenda that safeguards personal information while enabling the use of data to improve public health. PMID:26925395

Who Owns the Data? Open Data for Healthcare.

PubMed

Kostkova, Patty; Brewer, Helen; de Lusignan, Simon; Fottrell, Edward; Goldacre, Ben; Hart, Graham; Koczan, Phil; Knight, Peter; Marsolier, Corinne; McKendry, Rachel A; Ross, Emma; Sasse, Angela; Sullivan, Ralph; Chaytor, Sarah; Stevenson, Olivia; Velho, Raquel; Tooke, John

2016-01-01

Research on large shared medical datasets and data-driven research are gaining fast momentum and provide major opportunities for improving health systems as well as individual care. Such open data can shed light on the causes of disease and effects of treatment, including adverse reactions side-effects of treatments, while also facilitating analyses tailored to an individual's characteristics, known as personalized or "stratified medicine." Developments, such as crowdsourcing, participatory surveillance, and individuals pledging to become "data donors" and the "quantified self" movement (where citizens share data through mobile device-connected technologies), have great potential to contribute to our knowledge of disease, improving diagnostics, and delivery of -healthcare and treatment. There is not only a great potential but also major concerns over privacy, confidentiality, and control of data about individuals once it is shared. Issues, such as user trust, data privacy, transparency over the control of data ownership, and the implications of data analytics for personal privacy with potentially intrusive inferences, are becoming increasingly scrutinized at national and international levels. This can be seen in the recent backlash over the proposed implementation of care.data, which enables individuals' NHS data to be linked, retained, and shared for other uses, such as research and, more controversially, with businesses for commercial exploitation. By way of contrast, through increasing popularity of social media, GPS-enabled mobile apps and tracking/wearable devices, the IT industry and MedTech giants are pursuing new projects without clear public and policy discussion about ownership and responsibility for user-generated data. In the absence of transparent regulation, this paper addresses the opportunities of Big Data in healthcare together with issues of responsibility and accountability. It also aims to pave the way for public policy to support a balanced agenda that safeguards personal information while enabling the use of data to improve public health.

Weight Self-Regulation Process in Adolescence: The Relationship between Control Weight Attitudes, Behaviors, and Body Weight Status

PubMed Central

Pich, Jordi; Bibiloni, Maria del Mar; Pons, Antoni; Tur, Josep A.

2015-01-01

Adolescents’ self-control weight behaviors were assessed (N = 1961; 12–17 years old; 2007–2008) in the Balearic Islands, Spain. The study analyzed the relationships between body weight status, body image, and self-weight concern, and actual attempts to lose weight by restrained eating and/or increased exercising. In terms of regulatory focus theory (RFT), we considered that efforts to lose or to maintain weight (successful or failed) would be motivated either by a “promotion focus” (to show an attractive body), or a “prevention focus” (to avoid social rejection of fatness), or both. Results showed that 41% of overweight boys and 25% of obese boys stated that they had never made any attempt to lose weight, and 13 and 4% in females. Around half of overweight boys and around a quarter of obese boys stated that they were “Not at all” concerned about weight gain, and girls’ percentages decreased to 13 and 11%, respectively. By contrast, 57% of normal weight girls monitored their weight and stated that they had tried to become slim at least once. Weight self-regulation in females attempted to combine diet and exercise, while boys relied almost exclusively on exercise. Apparent lack of consciousness of body weight status among overweight boys, and more important, subsequent absence of behaviors to reduce their weight clearly challenges efforts to prevent obesity. We argue that several causes may be involved in this outcome, including unconscious, emotional (self-defense), and cognitive (dissonance) mechanisms driven by perceived social stigmatization of obesity. The active participation of social values of male and female body image (strong vs. pretty), and the existence of social habituation to overweight are suggested. A better knowledge of psychosocial mechanisms underlying adolescent weight self-control may improve obesity epidemics. PMID:26284248

Is Sustainability Knowledge Half the Battle? An Examination of Sustainability Knowledge, Attitudes, Norms, and Efficacy to Understand Sustainable Behaviours

ERIC Educational Resources Information Center

Heeren, Alexander John; Singh, Ajay S.; Zwickle, Adam; Koontz, Tomas M.; Slagle, Kristina M.; McCreery, Anna C.

2016-01-01

Purpose: The purpose of this study is to examine the relationship of sustainability knowledge to pro-environmental behaviour. A common misperception is that unsustainable behaviours are largely driven by a lack of knowledge of the underlying societal costs and the contributing factors leading to environmental degradation. Such a perception assumes…

Developmental Foundations of Children's Fraction Magnitude Knowledge.

PubMed

Mou, Yi; Li, Yaoran; Hoard, Mary K; Nugent, Lara D; Chu, Felicia W; Rouder, Jeffrey N; Geary, David C

2016-01-01

The conceptual insight that fractions represent magnitudes is a critical yet daunting step in children's mathematical development, and the knowledge of fraction magnitudes influences children's later mathematics learning including algebra. In this study, longitudinal data were analyzed to identify the mathematical knowledge and domain-general competencies that predicted 8 th and 9 th graders' (n=122) knowledge of fraction magnitudes and its cross-grade gains. Performance on the fraction magnitude measures predicted 9 th grade algebra achievement. Understanding and fluently identifying the numerator-denominator relation in 7 th grade emerged as the key predictor of later fraction magnitudes knowledge in both 8 th and 9 th grades. Competence at using fraction procedures, knowledge of whole number magnitudes, and the central executive contributed to 9 th but not 8 th graders' fraction magnitude knowledge, and knowledge of whole number magnitude contributed to cross-grade gains. The key results suggest fluent processing of numerator-denominator relations presages students' understanding of fractions as magnitudes and that the integration of whole number and fraction magnitudes occurs gradually.

Constructing cardiovascular fitness knowledge in physical education

PubMed Central

Zhang, Tan; Chen, Ang; Chen, Senlin; Hong, Deockki; Loflin, Jerry; Ennis, Catherine

2015-01-01

In physical education, it has become necessary for children to learn kinesiological knowledge for understanding the benefits of physical activity and developing a physically active lifestyle. This study was conducted to determine the extent to which cognitive assignments about healthful living and fitness contributed to knowledge growth on cardiorespiratory fitness and health. Fourth grade students (N = 616) from 15 randomly sampled urban elementary schools completed 34 cognitive assignments related to the cardiorespiratory physical activities they were engaged in across 10 lessons. Performance on the assignments were analyzed in relation to their knowledge gain measured using a standardized knowledge test. A multivariate discriminant analysis revealed that the cognitive assignments contributed to knowledge gain but the contribution varied assignment by assignment. A multiple regression analysis indicated that students’ assignment performance by lesson contributed positively to their knowledge growth scores. A content analysis based on the constructivist learning framework showed that observing–reasoning assignments contributed the most to knowledge growth. Analytical and analytical–application assignments contributed less than the constructivist theories would predict. PMID:25995702

Value of Flat-detector Computed Tomography Angiography with Intravenous Contrast Media Injection in the Evaluation and Treatment of Acutely Ruptured Aneurysms of the AcomA complex: A Single Center Experience in 15 Cases.

PubMed

Rösch, Julie; Lang, Stefan; Gölitz, Philipp; Kallmünzer, Bernd; Rössler, Karl; Doerfler, Arnd; Struffert, Tobias

2017-05-05

To illustrate the added value of flat-detector computed tomography angiography with intravenous contrast media injection (intravenous FDCTA) in the evaluation of complex A1/A2/AcomA aneurysms. We retrospectively reviewed 15 patients with ruptured aneurysms. In each patient, an intravenous FDCTA was performed and its diagnostic value investigated. In all patients, FDCTA contributed relevant additional information concerning the anatomy of the A1/A2/AcomA complex and the relationship of the aneurysm neck to these vascular structures, which could not be gained by 2D- and 3D-DSA, and changed the management in 33% of the patients (5 out of 15). In an additional 5 cases, knowledge of the detailed anatomy was helpful to plan the exact stent position. In case of complex A1/A2/AcomA aneurysms, intravenous FDCTA is an effective option to visualize the exact location of the aneurysm neck and the relationship between the aneurysm and the adjacent vessels. Thus, it is of significant added value in the precise planning of a therapeutic strategy.

Light Responsive Polymer Membranes: A Review

PubMed Central

Nicoletta, Fiore Pasquale; Cupelli, Daniela; Formoso, Patrizia; De Filpo, Giovanni; Colella, Valentina; Gugliuzza, Annarosa

2012-01-01

In recent years, stimuli responsive materials have gained significant attention in membrane separation processes due to their ability to change specific properties in response to small external stimuli, such as light, pH, temperature, ionic strength, pressure, magnetic field, antigen, chemical composition, and so on. In this review, we briefly report recent progresses in light-driven materials and membranes. Photo-switching mechanisms, valved-membrane fabrication and light-driven properties are examined. Advances and perspectives of light responsive polymer membranes in biotechnology, chemistry and biology areas are discussed. PMID:24957966

Efficacy of Blended Preservice Training for Resource Parents

PubMed Central

White, Lee; Delaney, Richard; Pacifici, Caesar; Nelson, Carol; Whitkin, Josh; Lovejoy, Maureen; Smalley, Betsy Keefer

2017-01-01

To evaluate a new way of meeting the growing demand for training prospective resource parents, our study compared the efficacy of a blended online and in-person approach with a traditional classroom-only approach. Findings based on a sample of 111 resource parent prospects showed significantly greater gains in knowledge from pre- to posttest for the blended approach over the classroom-only approach. The blended approach also produced dramatically lower dropout rates during preservice training. Both groups made significant gains in parenting awareness from pre to post, but those gains were greater for the classroom-only approach. Post hoc analyses examined this finding more closely. Satisfaction with training was comparably high for both groups. Gains in knowledge and awareness were sustained at a 3-month follow-up assessment. PMID:28626240

Developing a habitat-driven approach to CWWT design

USGS Publications Warehouse

Sartoris, James J.; Thullen, Joan S.

1998-01-01

A habitat-driven approach to CWWT design is defined as designing the constructed wetland to maximize habitat values for a given site within the constraints of meeting specified treatment criteria. This is in contrast to the more typical approach of designing the CWWT to maximize treatment efficiency, and then, perhaps, adding wildlife habitat features. The habitat-driven approach is advocated for two reasons: (1) because good wetland habitat is critically lacking, and (2) because it is hypothesized that well-designed habitat will result in good, sustainable wastewater treatment.

Sensory gain control (amplification) as a mechanism of selective attention: electrophysiological and neuroimaging evidence.

PubMed Central

Hillyard, S A; Vogel, E K; Luck, S J

1998-01-01

Both physiological and behavioral studies have suggested that stimulus-driven neural activity in the sensory pathways can be modulated in amplitude during selective attention. Recordings of event-related brain potentials indicate that such sensory gain control or amplification processes play an important role in visual-spatial attention. Combined event-related brain potential and neuroimaging experiments provide strong evidence that attentional gain control operates at an early stage of visual processing in extrastriate cortical areas. These data support early selection theories of attention and provide a basis for distinguishing between separate mechanisms of attentional suppression (of unattended inputs) and attentional facilitation (of attended inputs). PMID:9770220

Hidden Expert Knowledge: The Knowledge That Counts for the Small School-District Superintendent

ERIC Educational Resources Information Center

Hyle, Adrienne E.; Ivory, Gary; McClellan, Rhonda L.

2010-01-01

Using Bereiter and Scardamalia's (1993) hidden expert knowledge, we explored what knowledge counts from the perspectives of working small school-district superintendents and the ways in which they gain that knowledge. This qualitative study used focus groups as its primary data collection method. Participants were 37 superintendents of districts…

Knowledge Management Formal and Informal Mentoring: An Empirical Investigation in Lebanese Banks

ERIC Educational Resources Information Center

Karkoulian, Silva; Halawi, Leila A.; McCarthy, Richard V.

2008-01-01

Purpose: As businesses continue to forge ahead in the twenty-first century, knowledge management (KM) has materialized as a significant differentiator. The process of creating new knowledge, sharing, and preserving such knowledge, is crucial for achieving competitive advantage. To gain maximum benefit from new knowledge, it must be efficiently…

Development and testing of a CD-ROM program for improving adolescent knowledge of inflammatory bowel disease.

PubMed

Boamah, Lynelle M; Bohren, Janet R; Pentiuk, Scott; Baker, Raymond; Yi, Michael; Moyer, M Susan

2010-05-01

The aim of this study was to design a theory-based educational program for adolescents with inflammatory bowel disease (IBD) using an interactive multimedia CD-ROM and to test its effectiveness in improving knowledge in IBD. Curriculum-based instruction using educational theory and principles was designed for adolescents on an interactive multimedia CD-ROM. Twenty subjects completed summative evaluation of the CD-ROM measuring gain in knowledge about IBD immediately and 9 months after instruction. Subjects found the CD-ROM to be informative, appealing, and easy to use. The mean baseline score of the adolescents on the Crohn's and Colitis Knowledge questionnaire was 12.2 (standard deviation 5.14, range 3-24). After an average of 30 minutes of self-directed learning, adolescent subjects increased their posttest score to a mean of 19.8, a gain of 7.6 points over baseline (95% confidence interval 5.2-10.1, P < 0.0001). Knowledge of medications, disease complications, and gastrointestinal structure and function was gained and retained upon retesting at 9 months with a mean Crohn's and Colitis Knowledge questionnaire score of 17.5 (standard deviation 3.9, range 12-26), which was still an improvement over the mean pretest knowledge score of 12.2 (P < 0.001). Adolescents with IBD have low baseline knowledge about their disease. A rigorously developed interactive educational tool is now available for instructing adolescent patients about their IBD.

Electrically driven hybrid Si/III-V Fabry-Pérot lasers based on adiabatic mode transformers.

PubMed

Ben Bakir, B; Descos, A; Olivier, N; Bordel, D; Grosse, P; Augendre, E; Fulbert, L; Fedeli, J M

2011-05-23

We report the first demonstration of an electrically driven hybrid silicon/III-V laser based on adiabatic mode transformers. The hybrid structure is formed by two vertically superimposed waveguides separated by a 100-nm-thick SiO2 layer. The top waveguide, fabricated in an InP/InGaAsP-based heterostructure, serves to provide optical gain. The bottom Si-waveguides system, which supports all optical functions, is constituted by two tapered rib-waveguides (mode transformers), two distributed Bragg reflectors (DBRs) and a surface-grating coupler. The supermodes of this hybrid structure are controlled by an appropriate design of the tapers located at the edges of the gain region. In the middle part of the device almost all the field resides in the III-V waveguide so that the optical mode experiences maximal gain, while in regions near the III-V facets, mode transformers ensure an efficient transfer of the power flow towards Si-waveguides. The investigated device operates under quasi-continuous wave regime. The room temperature threshold current is 100 mA, the side-mode suppression ratio is as high as 20 dB, and the fiber-coupled output power is ~7 mW.

Contextualizing Nature of Science Instruction in Socioscientific Issues

NASA Astrophysics Data System (ADS)

Eastwood, Jennifer Lynne; Sadler, Troy D.; Zeidler, Dana L.; Lewis, Anna; Amiri, Leila; Applebaum, Scott

2012-10-01

The purpose of this study was to investigate the effects of two learning contexts for explicit-reflective nature of science (NOS) instruction, socioscientific issues (SSI) driven and content driven, on student NOS conceptions. Four classes of 11th and 12th grade anatomy and physiology students participated. Two classes experienced a curricular sequence organized around SSI (the SSI group), and two classes experienced a content-based sequence (the Content group). An open-ended NOS questionnaire was administered to both groups at the beginning and end of the school year and analyzed to generate student profiles. Quantitative analyses were performed to compare pre-instruction NOS conceptions between groups as well as pre to post changes within groups and between groups. Both SSI and Content groups showed significant gains in most NOS themes, but between-group gains were not significantly different. Qualitative analysis of post-instruction responses, however, revealed that students in the SSI group tended to use examples to describe their views of the social/cultural NOS. The findings support SSI contexts as effective for promoting gains in students' NOS understanding and suggest that these contexts facilitate nuanced conceptions that should be further explored.

Pesticide risk perceptions and the differences between farmers and extensionists: Towards a knowledge-in-context model

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

Ríos-González, Adriana, E-mail: adrianariosg@hotmail.com; The Africa and Latin America Research Groups Network; Jansen, Kees, E-mail: Kees.Jansen@wur.nl

A growing body of literature analyzes farmer perceptions of pesticide risk, but much less attention has been given to differences in risk perception between farmers and technical experts. Furthermore, inconsistencies in knowledge have too easily been explained in terms of lack of knowledge rather than exploring the underlying reasons for particular forms of thinking about pesticide risks. By doing this, the division between expert and lay knowledge has been deepened rather than transcended. Objective: This study aims to understand differences and similarities among the perceptions of pesticide risks of farmers, farm workers, and technical experts such as extensionists, by applyingmore » a social science approach towards knowledge and risk attitudes. Methods: Semi-structured interviews and field observations were conducted to smallholders, farm workers, extensionists, health professionals and scientists involved in the use and handling of pesticides. Subsequently, a survey was carried out to quantify the farmers and extensionists' acceptance or rejection of typical assertions expressed previously in the semi-structured interviews. Results: Smallholders showed to gain knowledge from their own experiences and to adapt pesticides practices, which is a potential basis for transforming notions of pesticide safety and risk reduction strategies. Though extensionists have received formal education, they sometimes develop ideas deviating from the technical perspective. The risk perception of the studied actors appeared to vary according to their role in the agricultural labor process; they varied much less than expected according to their schooling level. Conclusions: Commitment to the technical perspective is not dramatically different for extensionists on the one hand and farmers as well as farm workers on the other hand. Ideas about a supposed lack of knowledge by farmers and the need of formal training are too much driven by a deficit model of knowledge. Further research on risk perceptions of pesticides and training of rural people will benefit from the development of a knowledge-in-context model. -- Highlights: • Researching perceptions of farmers' extensionists and other professionals. • Experts as well as farmers deviate from the technical perspective. • Blaming who is responsible for pesticide problems creates expert-lay division. • Qualitative and quantitative methods, not as complementary but integrated. • Knowledge-in-context model as an alternative to the knowledge-deficit model.« less

Precipitation-driven carbon balance controls survivorship of desert biocrust mosses.

PubMed

Coe, Kirsten K; Belnap, Jayne; Sparks, Jed P

2012-07-01

Precipitation patterns including the magnitude, timing, and seasonality of rainfall are predicted to undergo substantial alterations in arid regions in the future, and desert organisms may be more responsive to such changes than to shifts in only mean annual rainfall. Soil biocrust communities (consisting of cyanobacteria, lichen, and mosses) are ubiquitous to desert ecosystems, play an array of ecological roles, and display a strong sensitivity to environmental changes. Crust mosses are particularly responsive to changes in precipitation and exhibit rapid declines in biomass and mortality following the addition of small rainfall events. Further, loss of the moss component in biocrusts leads to declines in crust structure and function. In this study, we sought to understand the physiological responses of the widespread and often dominant biocrust moss Syntrichia caninervis to alterations in rainfall. Moss samples were collected during all four seasons and exposed to two rainfall event sizes and three desiccation period (DP) lengths. A carbon balance approach based on single precipitation events was used to define the carbon gain or loss during a particular hydration period. Rainfall event size was the strongest predictor of carbon balance, and the largest carbon gains were associated with the largest precipitation events. In contrast, small precipitation events resulted in carbon deficits for S. caninervis. Increasing the length of the DP prior to an event resulted in reductions in carbon balance, probably because of the increased energetic cost of hydration following more intense bouts of desiccation. The season of collection (i.e., physiological status of the moss) modulated these responses, and the effects of DP and rainfall on carbon balance were different in magnitude (and often in sign) for different seasons. In particular, S. caninervis displayed higher carbon balances in the winter than in the summer, even for events of identical size. Overall, our results suggest that annual carbon balance and survivorship in biocrust mosses are largely driven by precipitation, and because of the role mosses play in biocrusts, changes in intra-annual precipitation patterns can have implications for hydrology, soil stability, and nutrient cycling in dryland systems.

Effects of climate change on the delivery of soil-mediated ecosystem services within the primary sector in temperate ecosystems: a review and New Zealand case study.

PubMed

Orwin, Kate H; Stevenson, Bryan A; Smaill, Simeon J; Kirschbaum, Miko U F; Dickie, Ian A; Clothier, Brent E; Garrett, Loretta G; van der Weerden, Tony J; Beare, Michael H; Curtin, Denis; de Klein, Cecile A M; Dodd, Michael B; Gentile, Roberta; Hedley, Carolyn; Mullan, Brett; Shepherd, Mark; Wakelin, Steven A; Bell, Nigel; Bowatte, Saman; Davis, Murray R; Dominati, Estelle; O'Callaghan, Maureen; Parfitt, Roger L; Thomas, Steve M

2015-08-01

Future human well-being under climate change depends on the ongoing delivery of food, fibre and wood from the land-based primary sector. The ability to deliver these provisioning services depends on soil-based ecosystem services (e.g. carbon, nutrient and water cycling and storage), yet we lack an in-depth understanding of the likely response of soil-based ecosystem services to climate change. We review the current knowledge on this topic for temperate ecosystems, focusing on mechanisms that are likely to underpin differences in climate change responses between four primary sector systems: cropping, intensive grazing, extensive grazing and plantation forestry. We then illustrate how our findings can be applied to assess service delivery under climate change in a specific region, using New Zealand as an example system. Differences in the climate change responses of carbon and nutrient-related services between systems will largely be driven by whether they are reliant on externally added or internally cycled nutrients, the extent to which plant communities could influence responses, and variation in vulnerability to erosion. The ability of soils to regulate water under climate change will mostly be driven by changes in rainfall, but can be influenced by different primary sector systems' vulnerability to soil water repellency and differences in evapotranspiration rates. These changes in regulating services resulted in different potentials for increased biomass production across systems, with intensively managed systems being the most likely to benefit from climate change. Quantitative prediction of net effects of climate change on soil ecosystem services remains a challenge, in part due to knowledge gaps, but also due to the complex interactions between different aspects of climate change. Despite this challenge, it is critical to gain the information required to make such predictions as robust as possible given the fundamental role of soils in supporting human well-being. © 2015 John Wiley & Sons Ltd.

Rod- versus cone-driven ERGs at different stimulus sizes in normal subjects and retinitis pigmentosa patients.

PubMed

Aher, Avinash J; McKeefry, Declan J; Parry, Neil R A; Maguire, John; Murray, I J; Tsai, Tina I; Huchzermeyer, Cord; Kremers, Jan

2018-02-01

To study how rod- and cone-driven responses depend on stimulus size in normal subjects and patients with retinitis pigmentosa (RP), and to show that comparisons between responses to full-field (FF) and smaller stimuli can be useful in diagnosing and monitoring disorders of the peripheral retina without the need for lengthy dark adaptation periods. The triple silent substitution technique was used to isolate L-cone-, M-cone- and rod-driven ERGs with 19, 18 and 33% photoreceptor contrasts, respectively, under identical mean luminance conditions. Experiments were conducted on five normal subjects and three RP patients. ERGs on control subjects were recorded at nine different temporal frequencies (between 2 and 60 Hz) for five different stimulus sizes: FF, 70°, 60°, 50° and 40° diameter circular stimuli. Experiments on RP patients involved rod- and L-cone-driven ERG measurements with FF and 40° stimuli at 8 and 48 Hz. Response amplitudes were defined as those of the first harmonic component after Fourier analysis. In normal subjects, rod-driven responses displayed a fundamentally different behavior than cone-driven responses, particularly at low temporal frequencies. At low and intermediate temporal frequencies (≤ 12 Hz), rod-driven signals increased by a factor of about four when measured with smaller stimuli. In contrast, L- and M-cone-driven responses in this frequency region did not change substantially with stimulus size. At high temporal frequencies (≥ 24 Hz), both rod- and cone-driven response amplitudes decreased with decreasing stimulus size. Signals obtained from rod-isolating stimuli under these conditions are likely artefactual. Interestingly, in RP patients, both rod-driven and L-cone-driven ERGs were similar using 40° and FF stimuli. The increased responses with smaller stimuli in normal subjects to rod-isolating stimuli indicate that a fundamentally different mechanism drives the ERGs in comparison with the cone-driven responses. We propose that the increased responses are caused by stray light stimulating the peripheral retina, thereby allowing peripheral rod-driven function to be studied using the triple silent substitution technique at photopic luminances. The method is effective in studying impaired peripheral rod- and cone- function in RP patients.

Materials Knowledge Systems in Python - A Data Science Framework for Accelerated Development of Hierarchical Materials.

PubMed

Brough, David B; Wheeler, Daniel; Kalidindi, Surya R

2017-03-01

There is a critical need for customized analytics that take into account the stochastic nature of the internal structure of materials at multiple length scales in order to extract relevant and transferable knowledge. Data driven Process-Structure-Property (PSP) linkages provide systemic, modular and hierarchical framework for community driven curation of materials knowledge, and its transference to design and manufacturing experts. The Materials Knowledge Systems in Python project (PyMKS) is the first open source materials data science framework that can be used to create high value PSP linkages for hierarchical materials that can be leveraged by experts in materials science and engineering, manufacturing, machine learning and data science communities. This paper describes the main functions available from this repository, along with illustrations of how these can be accessed, utilized, and potentially further refined by the broader community of researchers.

Materials Knowledge Systems in Python - A Data Science Framework for Accelerated Development of Hierarchical Materials

PubMed Central

Brough, David B; Wheeler, Daniel; Kalidindi, Surya R.

2017-01-01

There is a critical need for customized analytics that take into account the stochastic nature of the internal structure of materials at multiple length scales in order to extract relevant and transferable knowledge. Data driven Process-Structure-Property (PSP) linkages provide systemic, modular and hierarchical framework for community driven curation of materials knowledge, and its transference to design and manufacturing experts. The Materials Knowledge Systems in Python project (PyMKS) is the first open source materials data science framework that can be used to create high value PSP linkages for hierarchical materials that can be leveraged by experts in materials science and engineering, manufacturing, machine learning and data science communities. This paper describes the main functions available from this repository, along with illustrations of how these can be accessed, utilized, and potentially further refined by the broader community of researchers. PMID:28690971

English and the Knowledge Economy: A Critical Analysis

ERIC Educational Resources Information Center

Collin, Ross

2014-01-01

This article focuses on knowledge economy discourse and considers the appeal of this discourse to English educators. Knowledge economy discourse is defined as a mode of thought and expression that assumes a broad-based economy driven by innovation will soon emerge in the USA. This discourse, it is argued, offers English teachers solutions to some…

Developing Knowledge Creating Technical Education Institutions through the Voice of Teachers: Content Analysis Approach

ERIC Educational Resources Information Center

Song, Ji Hoon; Kim, Hye Kyoung; Park, Sunyoung; Bae, Sang Hoon

2014-01-01

The purpose of this study was to develop an empirical data-driven model for a knowledge creation school system in career technical education (CTE) by identifying supportive and hindering factors influencing knowledge creation practices in CTE schools. Nonaka and colleagues' (Nonaka & Konno, 1998; Nonaka & Takeuchi, 1995) knowledge…

A Finnish Concept for Academic Entrepreneurship: The Case of Satakunta University of Applied Sciences

ERIC Educational Resources Information Center

Lain, Kari

2008-01-01

In a knowledge-driven economy there is a growing need for deeper and more productive interaction between higher education and industry. The full exploitation of knowledge requires strategies, incentives, appropriate systems and strong interaction between the transfer processes and the main processes in higher education. In a knowledge-based…

Knowledge Valorisation: A Route of Knowledge That Ends In Surplus Value (An Example of The Netherlands)

ERIC Educational Resources Information Center

Hladchenko, Myroslava

2016-01-01

Purpose: The purpose of this paper is to explore the reasons of the success of the Netherlands in knowledge valorisation: what are the actors that participate in knowledge valorisation process and what are their functions; what is the route of knowledge in valorisation; what "surplus value" does knowledge gain in the valorisation…

Low-level contrast statistics are diagnostic of invariance of natural textures

PubMed Central

Groen, Iris I. A.; Ghebreab, Sennay; Lamme, Victor A. F.; Scholte, H. Steven

2012-01-01

Texture may provide important clues for real world object and scene perception. To be reliable, these clues should ideally be invariant to common viewing variations such as changes in illumination and orientation. In a large image database of natural materials, we found textures with low-level contrast statistics that varied substantially under viewing variations, as well as textures that remained relatively constant. This led us to ask whether textures with constant contrast statistics give rise to more invariant representations compared to other textures. To test this, we selected natural texture images with either high (HV) or low (LV) variance in contrast statistics and presented these to human observers. In two distinct behavioral categorization paradigms, participants more often judged HV textures as “different” compared to LV textures, showing that textures with constant contrast statistics are perceived as being more invariant. In a separate electroencephalogram (EEG) experiment, evoked responses to single texture images (single-image ERPs) were collected. The results show that differences in contrast statistics correlated with both early and late differences in occipital ERP amplitude between individual images. Importantly, ERP differences between images of HV textures were mainly driven by illumination angle, which was not the case for LV images: there, differences were completely driven by texture membership. These converging neural and behavioral results imply that some natural textures are surprisingly invariant to illumination changes and that low-level contrast statistics are diagnostic of the extent of this invariance. PMID:22701419

Changes in ocean circulation and carbon storage are decoupled from air-sea CO2 fluxes

NASA Astrophysics Data System (ADS)

Marinov, I.; Gnanadesikan, A.

2011-02-01

The spatial distribution of the air-sea flux of carbon dioxide is a poor indicator of the underlying ocean circulation and of ocean carbon storage. The weak dependence on circulation arises because mixing-driven changes in solubility-driven and biologically-driven air-sea fluxes largely cancel out. This cancellation occurs because mixing driven increases in the poleward residual mean circulation result in more transport of both remineralized nutrients and heat from low to high latitudes. By contrast, increasing vertical mixing decreases the storage associated with both the biological and solubility pumps, as it decreases remineralized carbon storage in the deep ocean and warms the ocean as a whole.

Changes in ocean circulation and carbon storage are decoupled from air-sea CO2 fluxes

NASA Astrophysics Data System (ADS)

Marinov, I.; Gnanadesikan, A.

2010-11-01

The spatial distribution of the air-sea flux of carbon dioxide is a poor indicator of the underlying ocean circulation and of ocean carbon storage. The weak dependence on circulation arises because mixing-driven changes in solubility-driven and biologically-driven air-sea fluxes largely cancel out. This cancellation occurs because mixing driven increases in the poleward residual mean circulation results in more transport of both remineralized nutrients and heat from low to high latitudes. By contrast, increasing vertical mixing decreases the storage associated with both the biological and solubility pumps, as it decreases remineralized carbon storage in the deep ocean and warms the ocean as a whole.

Memory plasticity in older adults: Cognitive predictors of training response and maintenance following learning of number-consonant mnemonic.

PubMed

Sandberg, Petra; Rönnlund, Michael; Derwinger-Hallberg, Anna; Stigsdotter Neely, Anna

2016-10-01

The study investigated the relationship between cognitive factors and gains in number recall following training in a number-consonant mnemonic in a sample of 112 older adults (M = 70.9 years). The cognitive factors examined included baseline episodic memory, working memory, processing speed, and verbal knowledge. In addition, predictors of maintenance of gains to a follow-up assessment, eight months later, were examined. Whereas working memory was a prominent predictor of baseline recall, the magnitude of gains in recall from pre- to post-test assessments were predicted by baseline episodic memory, processing speed, and verbal knowledge. Verbal knowledge was the only significant predictor of maintenance. Collectively, the results indicate the need to consider multiple factors to account for individual differences in memory plasticity. The potential contribution of additional factors to individual differences in memory plasticity is discussed.

Schema-driven facilitation of new hierarchy learning in the transitive inference paradigm

PubMed Central

Kumaran, Dharshan

2013-01-01

Prior knowledge, in the form of a mental schema or framework, is viewed to facilitate the learning of new information in a range of experimental and everyday scenarios. Despite rising interest in the cognitive and neural mechanisms underlying schema-driven facilitation of new learning, few paradigms have been developed to examine this issue in humans. Here we develop a multiphase experimental scenario aimed at characterizing schema-based effects in the context of a paradigm that has been very widely used across species, the transitive inference task. We show that an associative schema, comprised of prior knowledge of the rank positions of familiar items in the hierarchy, has a marked effect on transitivity performance and the development of relational knowledge of the hierarchy that cannot be accounted for by more general changes in task strategy. Further, we show that participants are capable of deploying prior knowledge to successful effect under surprising conditions (i.e., when corrective feedback is totally absent), but only when the associative schema is robust. Finally, our results provide insights into the cognitive mechanisms underlying such schema-driven effects, and suggest that new hierarchy learning in the transitive inference task can occur through a contextual transfer mechanism that exploits the structure of associative experiences. PMID:23782509

Schema-driven facilitation of new hierarchy learning in the transitive inference paradigm.

PubMed

Kumaran, Dharshan

2013-06-19

Prior knowledge, in the form of a mental schema or framework, is viewed to facilitate the learning of new information in a range of experimental and everyday scenarios. Despite rising interest in the cognitive and neural mechanisms underlying schema-driven facilitation of new learning, few paradigms have been developed to examine this issue in humans. Here we develop a multiphase experimental scenario aimed at characterizing schema-based effects in the context of a paradigm that has been very widely used across species, the transitive inference task. We show that an associative schema, comprised of prior knowledge of the rank positions of familiar items in the hierarchy, has a marked effect on transitivity performance and the development of relational knowledge of the hierarchy that cannot be accounted for by more general changes in task strategy. Further, we show that participants are capable of deploying prior knowledge to successful effect under surprising conditions (i.e., when corrective feedback is totally absent), but only when the associative schema is robust. Finally, our results provide insights into the cognitive mechanisms underlying such schema-driven effects, and suggest that new hierarchy learning in the transitive inference task can occur through a contextual transfer mechanism that exploits the structure of associative experiences.

Parafoveal Target Detectability Reversal Predicted by Local Luminance and Contrast Gain Control

NASA Technical Reports Server (NTRS)

Ahumada, Albert J., Jr.; Beard, Bettina L.; Null, Cynthia H. (Technical Monitor)

1996-01-01

This project is part of a program to develop image discrimination models for the prediction of the detectability of objects in a range of backgrounds. We wanted to see if the models could predict parafoveal object detection as well as they predict detection in foveal vision. We also wanted to make our simplified models more general by local computation of luminance and contrast gain control. A signal image (0.78 x 0.17 deg) was made by subtracting a simulated airport runway scene background image (2.7 deg square) from the same scene containing an obstructing aircraft. Signal visibility contrast thresholds were measured in a fully crossed factorial design with three factors: eccentricity (0 deg or 4 deg), background (uniform or runway scene background), and fixed-pattern white noise contrast (0%, 5%, or 10%). Three experienced observers responded to three repetitions of 60 2IFC trials in each condition and thresholds were estimated by maximum likelihood probit analysis. In the fovea the average detection contrast threshold was 4 dB lower for the runway background than for the uniform background, but in the parafovea, the average threshold was 6 dB higher for the runway background than for the uniform background. This interaction was similar across the different noise levels and for all three observers. A likely reason for the runway background giving a lower threshold in the fovea is the low luminance near the signal in that scene. In our model, the local luminance computation is controlled by a spatial spread parameter. When this parameter and a corresponding parameter for the spatial spread of contrast gain were increased for the parafoveal predictions, the model predicts the interaction of background with eccentricity.

Knowledge Transfer between SMEs and Higher Education Institutions: Differences between Universities and Colleges of Higher Education in the Netherlands

ERIC Educational Resources Information Center

Delfmann, Heike; Koster, Sierdjan

2012-01-01

Knowledge transfer (KT) between higher education institutions (HEIs) and businesses is seen as a key element of innovation in knowledge-driven economies: HEIs generate knowledge that can be adopted in the regional economy. This process of valorization has been studied extensively, mainly with a focus on universities. In the Netherlands, there is a…

Knowledge Management and Global Information Dissemination

ERIC Educational Resources Information Center

Umunadi, Ejiwoke Kennedy

2014-01-01

The paper looked at knowledge management and global information dissemination. Knowledge is a very powerful tool for survival, growth and development. It can be seen as the information, understanding and skills that you gain through education or experience. The paper was addressed under the following sub-headings: Knowledge management knowledge…

Knowledge Management: A System Dynamics Perspective

ERIC Educational Resources Information Center

Saurabh, Kumar

2005-01-01

In the present day market scenario of intense competition, organizations need to know what they know and be able to leverage on its knowledge base to gain competitive advantage. In this knowledge era, organisations can create and sustain competitive advantage through initiation of appropriate knowledge management processes. The organisations that…

Valuing Local Knowledge: Indigenous People and Intellectual Property Rights.

ERIC Educational Resources Information Center

Brush, Stephen B., Ed.; Stabinsky, Doreen, Ed.

Intellectual property enables individuals to gain financially from sharing unique and useful knowledge. Compensating indigenous people for sharing their knowledge and resources might both validate and be an equitable reward for indigenous knowledge of biological resources, and might promote the conservation of those resources. This book contains…

The Impact of Cervical Cancer Education for Deaf Women Using a Video Educational Tool Employing American Sign Language, Open Captioning, and Graphics

PubMed Central

Choe, Sun; Lim, Rod Seung-Hwan; Clark, Karen; Wang, Regina; Branz, Patricia; Sadler, Georgia Robins

2013-01-01

Background Deaf women encounter barriers to accessing cancer information. In this study, we evaluated whether deaf women's knowledge could be increased by viewing a graphically enriched, American Sign Language (ASL) cervical cancer education video. Methods A blind, randomized trial evaluated knowledge gain and retention. Deaf women (n = 130) completed questionnaires before, after, and 2 months after viewing the video. Results With only a single viewing of the in-depth video, the experimental group gained and retained significantly more cancer knowledge than the control group. Conclusions Giving deaf women access to the ASL cervical cancer education video (http://cancer.ucsd.edu/deafinfo) significantly increased their knowledge of cervical cancer. PMID:19259859

Entropy of Stationary Nonequilibrium Measures of Boundary Driven Symmetric Simple Exclusion Processes

NASA Astrophysics Data System (ADS)

Bernardin, Cédric; Landim, Claudio

2010-12-01

We examine the entropy of stationary nonequilibrium measures of boundary driven symmetric simple exclusion processes. In contrast with the Gibbs-Shannon entropy (Bahadoran in J. Stat. Phys. 126(4-5):1069-1082, 2007; Derrida et al. in J. Stat. Phys. 126(4-5):1083-1108, 2007), the entropy of nonequilibrium stationary states differs from the entropy of local equilibrium states.

CrossTalk, The Journal of Defense Software Engineering. Volume 28 Number 1. Jan/Feb 2015

DTIC Science & Technology

2015-02-01

5.63 1.03 Positive Gain 1.19 42% 1.10 27% 1.20 31% 0.44 12% Table 7. Group 1 & 2 Pretest and Posttest Means and Gain Scores. The one ...linked to team performance [6][7][8] and is considered one of the most important small group variables [9] with cohesion-performance being driven by...increased team cohesion. Measuring Cohesion In order to measure team cohesion, one must first understand the correlated cohesion constructs. The Group

The response of a linear monostable system and its application in parameters estimation for PSK signals

NASA Astrophysics Data System (ADS)

Duan, Chaowei; Zhan, Yafeng

2016-03-01

The output characteristics of a linear monostable system driven with a periodic signal and an additive white Gaussian noise are studied in this paper. Theoretical analysis shows that the output signal-to-noise ratio (SNR) decreases monotonously with the increasing noise intensity but the output SNR-gain is stable. Inspired by this high SNR-gain phenomenon, this paper applies the linear monostable system in the parameters estimation algorithm for phase shift keying (PSK) signals and improves the estimation performance.

Exploring Preschool Children’s Science Content Knowledge

PubMed Central

Guo, Ying; Piasta, Shayne B.; Bowles, Ryan P.

2014-01-01

Research Findings The purpose of this study was to describe children’s science content knowledge and examine the early predictors of science content knowledge in a sample of 194 typically developing preschool children. Children’s science content knowledge was assessed in the fall (Time 1) and spring (Time 2) of the preschool year. Results showed that children exhibited significant gains in science content knowledge over the course of the preschool year. Hierarchical linear modeling results indicated that the level of maternal education (i.e., holding at least a bachelor’s degree) significantly predicted children’s Time 1 science content knowledge. Children’s cognitive, math, and language skills at Time 1 were all significant concurrent predictors of Time 1 science content knowledge. However, only Time 1 math skills significantly predicted residualized gains in science content knowledge (i.e., Time 2 scores with Time 1 scores as covariates). Practice or Policy Factors related to individual differences in young children’s science content knowledge may be important for early childhood educators to consider in their efforts to provide more support to children who may need help with science learning. PMID:25541574

Knowledge Management Framework for Emerging Infectious Diseases Preparedness and Response: Design and Development of Public Health Document Ontology

PubMed Central

Zhang, Zhizun; Gonzalez, Mila C; Morse, Stephen S

2017-01-01

Background There are increasing concerns about our preparedness and timely coordinated response across the globe to cope with emerging infectious diseases (EIDs). This poses practical challenges that require exploiting novel knowledge management approaches effectively. Objective This work aims to develop an ontology-driven knowledge management framework that addresses the existing challenges in sharing and reusing public health knowledge. Methods We propose a systems engineering-inspired ontology-driven knowledge management approach. It decomposes public health knowledge into concepts and relations and organizes the elements of knowledge based on the teleological functions. Both knowledge and semantic rules are stored in an ontology and retrieved to answer queries regarding EID preparedness and response. Results A hybrid concept extraction was implemented in this work. The quality of the ontology was evaluated using the formal evaluation method Ontology Quality Evaluation Framework. Conclusions Our approach is a potentially effective methodology for managing public health knowledge. Accuracy and comprehensiveness of the ontology can be improved as more knowledge is stored. In the future, a survey will be conducted to collect queries from public health practitioners. The reasoning capacity of the ontology will be evaluated using the queries and hypothetical outbreaks. We suggest the importance of developing a knowledge sharing standard like the Gene Ontology for the public health domain. PMID:29021130

Uncovering a Dynamic Feature of the Transcriptional Regulatory Network for Anterior-Posterior Patterning in the Drosophila Embryo

PubMed Central

Liu, Junbo; Ma, Jun

2013-01-01

Anterior-posterior (AP) patterning in the Drosophila embryo is dependent on the Bicoid (Bcd) morphogen gradient. However, most target genes of Bcd also require additional inputs to establish their expression domains, reflective of the operation of a cross-regulatory network and contributions of other maternal signals. This is in contrast to hunchback (hb), which has an anterior expression domain driven by an enhancer that appears to respond primarily to the Bcd input. To gain a better understanding of the regulatory logic of the AP patterning network, we perform quantitative studies that specifically investigate the dynamics of hb transcription during development. We show that Bcd-dependent hb transcription, monitored by the intron-containing nascent transcripts near the P2 promoter, is turned off quickly–on the order of a few minutes–upon entering the interphase of nuclear cycle 14A. This shutdown contrasts with earlier cycles during which active hb transcription can persist until the moment when the nucleus enters mitosis. The shutdown takes place at a time when the nuclear Bcd gradient profile in the embryo remains largely intact, suggesting that this is a process likely subject to control of a currently unknown regulatory mechanism. We suggest that this dynamic feature offers a window of opportunity for hb to faithfully interpret, and directly benefit from, Bcd gradient properties, including its scaling properties, to help craft a robust AP patterning outcome. PMID:23646132

Predicting pan-tropical climate change induced forest stock gains and losses—implications for REDD

NASA Astrophysics Data System (ADS)

Gumpenberger, Marlies; Vohland, Katrin; Heyder, Ursula; Poulter, Benjamin; Macey, Kirsten; Rammig, Anja; Popp, Alexander; Cramer, Wolfgang

2010-01-01

Deforestation is a major threat to tropical forests worldwide, contributing up to one-fifth of global carbon emissions into the atmosphere. Despite protection efforts, deforestation of tropical forests has continued in recent years. Providing incentives to reducing deforestation has been proposed in the United Nations Framework Convention on Climate Change (UNFCCC) Bali negotiations in 2007 to decelerate emissions from deforestation (REDD—reduced emissions from deforestation and forest degradation). A number of methodological issues such as ensuring permanence, establishing reference emissions levels that do not reward business-as-usual and having a measuring, reporting and verification system in place are essential elements in implementing successful REDD schemes. To assess the combined impacts of climate and land-use change on tropical forest carbon stocks in the 21st century, we use a dynamic global vegetation model (LPJ DGVM) driven by five different climate change projections under a given greenhouse gas emission scenario (SRES A2) and two contrasting land-use change scenarios. We find that even under a complete stop of deforestation after the period of the Kyoto Protocol (post-2012) some countries may continue to lose carbon stocks due to climate change. Especially at risk is tropical Latin America, although the presence and magnitude of the risk depends on the climate change scenario. By contrast, strong protection of forests could increase carbon uptake in many tropical countries, due to CO2 fertilization effects, even under altered climate regimes.

A Model-Driven Approach to e-Course Management

ERIC Educational Resources Information Center

Savic, Goran; Segedinac, Milan; Milenkovic, Dušica; Hrin, Tamara; Segedinac, Mirjana

2018-01-01

This paper presents research on using a model-driven approach to the development and management of electronic courses. We propose a course management system which stores a course model represented as distinct machine-readable components containing domain knowledge of different course aspects. Based on this formally defined platform-independent…

Enhancing Extensive Reading with Data-Driven Learning

ERIC Educational Resources Information Center

Hadley, Gregory; Charles, Maggie

2017-01-01

This paper investigates using data-driven learning (DDL) as a means of stimulating greater lexicogrammatical knowledge and reading speed among lower proficiency learners in an extensive reading program. For 16 weekly 90-minute sessions, an experimental group (12 students) used DDL materials created from a corpus developed from the Oxford Bookworms…

A Decision Fusion Framework for Treatment Recommendation Systems.

PubMed

Mei, Jing; Liu, Haifeng; Li, Xiang; Xie, Guotong; Yu, Yiqin

2015-01-01

Treatment recommendation is a nontrivial task--it requires not only domain knowledge from evidence-based medicine, but also data insights from descriptive, predictive and prescriptive analysis. A single treatment recommendation system is usually trained or modeled with a limited (size or quality) source. This paper proposes a decision fusion framework, combining both knowledge-driven and data-driven decision engines for treatment recommendation. End users (e.g. using the clinician workstation or mobile apps) could have a comprehensive view of various engines' opinions, as well as the final decision after fusion. For implementation, we leverage several well-known fusion algorithms, such as decision templates and meta classifiers (of logistic and SVM, etc.). Using an outcome-driven evaluation metric, we compare the fusion engine with base engines, and our experimental results show that decision fusion is a promising way towards a more valuable treatment recommendation.

Stakeholder surveys of Canadian healthcare performance: what are they telling us? Who should be listening? Who should be acting, and how?

PubMed

Nemis-White, Joanna; Torr, Emily; Gogovor, Amede; Marshall, Lucas; Ahmed, Sara; Aylen, John; Montague, Terrence

2014-01-01

Eleven Health Care in Canada (HCIC) surveys, spanning 1998-2014, offer a comprehensive overview of the changing perceptions of physician, nurse, pharmacist, administrator and public stakeholders of the nation's health status, its burden of illness and its quality and cost of care. Overall, there persists a universal sense of quality in our health system--despite evidence that national health status is declining, chronic illnesses are increasing, patients' timely access to care and ability to afford care are diminishing and all these indicators are predicted to worsen over time. Among the public and health professionals, key priorities for improving future patient care are increasing professional schools' output and team-based care, along with enhanced use of national supply systems to reduce costs of care. Among HCIC survey partners, the overarching goal has been, and remains, the utilization of knowledge gained from the surveys to facilitate evidence-driven health policy and improved patient care and outcomes. Practical foci are the development of knowledge translation (KT) activities and assessment of their impact. This paper outlines current initiatives to track reach of member and non-member audiences for HCIC information; to ascertain how they perceive and value the various KT messages, vehicles and metrics; and to potentially identify a hierarchy of efficacy for impact factors. The primary objective is to inform future HCIC survey design and reporting, especially identification of KT vehicles and venues that are most effective in terms of reach and impact in facilitating understanding of, and subsequent action around, the knowledge generated.

Multifamily psychoeducation groups (MFPG) for families of children with bipolar disorder.

PubMed

Fristad, Mary A; Goldberg-Arnold, Jill S; Gavazzi, Stephen M

2002-08-01

Multi-family psychoeducation groups (MFPG) have been developed and tested for adults, but not for children with bipolar disorder (BPD). We present data from a pilot study of our manual-driven MFPG treatment for families of children with mood disorders and address two questions: Do families of children with BPD and families of children with major depressive disorder/dysthymic disorder (MDD/DD): 1) differ at treatment entry?; 2) benefit equally from intervention? A total of 35 children (n=16, BPD; n=19, MDD/DD) aged 8-11 years and their parents were randomized into immediate MFPG plus treatment as usual (TAU) or wait-list + TAU and assessed periodically. At baseline, there was a trend toward parents in BPD families being more knowledgeable about mood symptoms than parents in MDD/DD families (p < 0.04). Additionally at baseline, children with BPD evidenced greater mood severity historically and a trend toward more hospitalizations, day treatment, outpatient treatment, medication trials, and placement in special education classrooms than children with MDD/DD. Immediately following and 4 months post-treatment, both BPD and MDD/DD families described having gained knowledge, skills, support, and positive attitudes during treatment. MDD/DD families increased their knowledge of symptoms to the same level as BPD families. While BPD families enter treatment with more impaired children and more extensive treatment histories, both BPD and MDD/DD families benefit from intervention. The clinical issues concerning combining families of children with bipolar and depressive spectrum illnesses in groups are discussed. Clinical impressions suggest that such combinations are clinically feasible and potentially beneficial.

Quality risk management in pharmaceutical development.

PubMed

Charoo, Naseem Ahmad; Ali, Areeg Anwer

2013-07-01

The objective of ICH Q8, Q9 and Q10 documents is application of systemic and science based approach to formulation development for building quality into product. There is always some uncertainty in new product development. Good risk management practice is essential for success of new product development in decreasing this uncertainty. In quality by design paradigm, the product performance properties relevant to the patient are predefined in target product profile (TPP). Together with prior knowledge and experience, TPP helps in identification of critical quality attributes (CQA's). Initial risk assessment which identifies risks to these CQA's provides impetus for product development. Product and process are designed to gain knowledge about these risks, devise strategies to eliminate or mitigate these risks and meet objectives set in TPP. By laying more emphasis on high risk events the protection level of patient is increased. The process being scientifically driven improves the transparency and reliability of the manufacturer. The focus on risk to the patient together with flexible development approach saves invaluable resources, increases confidence on quality and reduces compliance risk. The knowledge acquired in analysing risks to CQA's permits construction of meaningful design space. Within the boundaries of the design space, variation in critical material characteristics and process parameters must be managed in order to yield a product having the desired characteristics. Specifications based on product and process understanding are established such that product will meet the specifications if tested. In this way, the product is amenable to real time release, since specifications only confirm quality but they do not serve as a means of effective process control.

Feasibility and effectiveness of a brief, intensive phylogenetics workshop in a middle-income country.

PubMed

Pollett, S; Leguia, M; Nelson, M I; Maljkovic Berry, I; Rutherford, G; Bausch, D G; Kasper, M; Jarman, R; Melendrez, M

2016-01-01

There is an increasing role for bioinformatic and phylogenetic analysis in tropical medicine research. However, scientists working in low- and middle-income regions may lack access to training opportunities in these methods. To help address this gap, a 5-day intensive bioinformatics workshop was offered in Lima, Peru. The syllabus is presented here for others who want to develop similar programs. To assess knowledge gained, a 20-point knowledge questionnaire was administered to participants (21 participants) before and after the workshop, covering topics on sequence quality control, alignment/formatting, database retrieval, models of evolution, sequence statistics, tree building, and results interpretation. Evolution/tree-building methods represented the lowest scoring domain at baseline and after the workshop. There was a considerable median gain in total knowledge scores (increase of 30%, p<0.001) with gains as high as 55%. A 5-day workshop model was effective in improving the pathogen-applied bioinformatics knowledge of scientists working in a middle-income country setting. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Computational Properties of the Hippocampus Increase the Efficiency of Goal-Directed Foraging through Hierarchical Reinforcement Learning

PubMed Central

Chalmers, Eric; Luczak, Artur; Gruber, Aaron J.

2016-01-01

The mammalian brain is thought to use a version of Model-based Reinforcement Learning (MBRL) to guide “goal-directed” behavior, wherein animals consider goals and make plans to acquire desired outcomes. However, conventional MBRL algorithms do not fully explain animals' ability to rapidly adapt to environmental changes, or learn multiple complex tasks. They also require extensive computation, suggesting that goal-directed behavior is cognitively expensive. We propose here that key features of processing in the hippocampus support a flexible MBRL mechanism for spatial navigation that is computationally efficient and can adapt quickly to change. We investigate this idea by implementing a computational MBRL framework that incorporates features inspired by computational properties of the hippocampus: a hierarchical representation of space, “forward sweeps” through future spatial trajectories, and context-driven remapping of place cells. We find that a hierarchical abstraction of space greatly reduces the computational load (mental effort) required for adaptation to changing environmental conditions, and allows efficient scaling to large problems. It also allows abstract knowledge gained at high levels to guide adaptation to new obstacles. Moreover, a context-driven remapping mechanism allows learning and memory of multiple tasks. Simulating dorsal or ventral hippocampal lesions in our computational framework qualitatively reproduces behavioral deficits observed in rodents with analogous lesions. The framework may thus embody key features of how the brain organizes model-based RL to efficiently solve navigation and other difficult tasks. PMID:28018203

Terahertz-driven linear electron acceleration

PubMed Central

Nanni, Emilio A.; Huang, Wenqian R.; Hong, Kyung-Han; Ravi, Koustuban; Fallahi, Arya; Moriena, Gustavo; Dwayne Miller, R. J.; Kärtner, Franz X.

2015-01-01

The cost, size and availability of electron accelerators are dominated by the achievable accelerating gradient. Conventional high-brightness radio-frequency accelerating structures operate with 30–50 MeV m−1 gradients. Electron accelerators driven with optical or infrared sources have demonstrated accelerating gradients orders of magnitude above that achievable with conventional radio-frequency structures. However, laser-driven wakefield accelerators require intense femtosecond sources and direct laser-driven accelerators suffer from low bunch charge, sub-micron tolerances and sub-femtosecond timing requirements due to the short wavelength of operation. Here we demonstrate linear acceleration of electrons with keV energy gain using optically generated terahertz pulses. Terahertz-driven accelerating structures enable high-gradient electron/proton accelerators with simple accelerating structures, high repetition rates and significant charge per bunch. These ultra-compact terahertz accelerators with extremely short electron bunches hold great potential to have a transformative impact for free electron lasers, linear colliders, ultrafast electron diffraction, X-ray science and medical therapy with X-rays and electron beams. PMID:26439410

Terahertz-driven linear electron acceleration

DOE PAGES

Nanni, Emilio A.; Huang, Wenqian R.; Hong, Kyung-Han; ...

2015-10-06

The cost, size and availability of electron accelerators are dominated by the achievable accelerating gradient. Conventional high-brightness radio-frequency accelerating structures operate with 30–50 MeVm -1 gradients. Electron accelerators driven with optical or infrared sources have demonstrated accelerating gradients orders of magnitude above that achievable with conventional radio-frequency structures. However, laser-driven wakefield accelerators require intense femtosecond sources and direct laser-driven accelerators suffer from low bunch charge, sub-micron tolerances and sub-femtosecond timing requirements due to the short wavelength of operation. Here we demonstrate linear acceleration of electrons with keV energy gain using optically generated terahertz pulses. Terahertz-driven accelerating structures enable high-gradient electron/protonmore » accelerators with simple accelerating structures, high repetition rates and significant charge per bunch. As a result, these ultra-compact terahertz accelerators with extremely short electron bunches hold great potential to have a transformative impact for free electron lasers, linear colliders, ultrafast electron diffraction, X-ray science and medical therapy with X-rays and electron beams.« less

Age-differences in cognitive flexibility when overcoming a preexisting bias through feedback.

PubMed

Wilson, Cristina G; Nusbaum, Amy T; Whitney, Paul; Hinson, John M

2018-08-01

Older adults are often worse than younger adults at adapting to changing situational demands, and this difference is commonly attributed to an age-related decline in acquiring and updating information. Previous research on aging and cognitive flexibility has used measures that require adapting to novel associations learned during a laboratory task (e.g., choice X led to positive outcomes but now leads to negative outcomes). However, in everyday life people must frequently overcome associations based on preexisting beliefs and biases (e.g., you like to eat cake, but your doctor said to limit your sugar intake). The goal of the present study was to examine possible age-differences in overcoming a preexisting bias and determine whether age-related changes in the acquisition and updating of information influence this form of flexibility. Older (n = 20) and younger (n = 20) adults completed a novel task in which repeated choices were made between a sure option (gain or loss) and one of two risky options that were initially ambiguous. Optimal performance required overcoming a framing bias toward being risk seeking to avoid a sure loss and risk averse when offered a sure gain. Probe questions assessed knowledge of choice outcomes, while skin conductance assessed physiological reactions to choices and choice outcomes. Both older and younger adults demonstrated flexibility by reducing the impact of bias over trials, but younger adults had better performance overall. Age-differences were associated with distinct aspects of processing. Young adults had more precise knowledge of choice outcomes and developed skin conductance responses in anticipation of bad choices that were not apparent in older adults. Older adults showed significant improvement over trials in their ability to decrease bias-driven choices, but younger showed greater flexibility. Age-differences in task performance were based on differences in learning and corresponding representations of task-relevant information.

Object detection in natural backgrounds predicted by discrimination performance and models

NASA Technical Reports Server (NTRS)

Rohaly, A. M.; Ahumada, A. J. Jr; Watson, A. B.

1997-01-01

Many models of visual performance predict image discriminability, the visibility of the difference between a pair of images. We compared the ability of three image discrimination models to predict the detectability of objects embedded in natural backgrounds. The three models were: a multiple channel Cortex transform model with within-channel masking; a single channel contrast sensitivity filter model; and a digital image difference metric. Each model used a Minkowski distance metric (generalized vector magnitude) to summate absolute differences between the background and object plus background images. For each model, this summation was implemented with three different exponents: 2, 4 and infinity. In addition, each combination of model and summation exponent was implemented with and without a simple contrast gain factor. The model outputs were compared to measures of object detectability obtained from 19 observers. Among the models without the contrast gain factor, the multiple channel model with a summation exponent of 4 performed best, predicting the pattern of observer d's with an RMS error of 2.3 dB. The contrast gain factor improved the predictions of all three models for all three exponents. With the factor, the best exponent was 4 for all three models, and their prediction errors were near 1 dB. These results demonstrate that image discrimination models can predict the relative detectability of objects in natural scenes.

Application of Artificial Intelligence (AI) programming techniques to tactical guidance for fighter aircraft

NASA Technical Reports Server (NTRS)

Mcmanus, John W.; Goodrich, Kenneth H.

1989-01-01

A research program investigating the use of Artificial Intelligence (AI) programming techniques to aid in the development of a Tactical Decision Generator (TDG) for Within-Visual-Range (WVR) air combat engagements is discussed. The application of AI methods for development and implementation of the TDG is presented. The history of the Adaptive Maneuvering Logic (AML) program is traced and current versions of the (AML) program is traced and current versions of the AML program are compared and contrasted with the TDG system. The Knowledge-Based Systems (KBS) used by the TDG to aid in the decision-making process are outlined and example rules are presented. The results of tests to evaluate the performance of the TDG against a version of AML and against human pilots in the Langley Differential Maneuvering Simulator (DMS) are presented. To date, these results have shown significant performance gains in one-versus-one air combat engagements.

Reform in teaching preclinical pathophysiology.

PubMed

Li, Yong-Yu; Li, Kun; Yao, Hong; Xu, Xiao-Juan; Cai, Qiao-Lin

2015-12-01

Pathophysiology is a scientific discipline that studies the onset and progression of pathological conditions and diseases, and pathophysiology is one of the core courses in most preclinical medical curricula. In China, most medical schools house a Department of Pathophysiology, in contrast to medical schools in many developed countries. The staff in Chinese Departments of Pathophysiology generally consists of full-time instructors or lecturers who teach medical students. These lecturers are sometimes lacking in clinic knowledge and experiences. To overcome this, in recent years, we have been trying to bring new trends in teaching pathophysiology into our curriculum. Our purpose in writing this article was to share our experiences with our colleagues and peers worldwide in the hope that the insights we have gained in pathophysiology teaching will be of some value to educators who advocate teaching reform in medical schools. Copyright © 2015 The American Physiological Society.

Genome-wide analysis captures the determinants of the antibiotic cross-resistance interaction network

PubMed Central

Lázár, Viktória; Nagy, István; Spohn, Réka; Csörgő, Bálint; Györkei, Ádám; Nyerges, Ákos; Horváth, Balázs; Vörös, Andrea; Busa-Fekete, Róbert; Hrtyan, Mónika; Bogos, Balázs; Méhi, Orsolya; Fekete, Gergely; Szappanos, Balázs; Kégl, Balázs; Papp, Balázs; Pál, Csaba

2014-01-01

Understanding how evolution of antimicrobial resistance increases resistance to other drugs is a challenge of profound importance. By combining experimental evolution and genome sequencing of 63 laboratory-evolved lines, we charted a map of cross-resistance interactions between antibiotics in Escherichia coli, and explored the driving evolutionary principles. Here, we show that (1) convergent molecular evolution is prevalent across antibiotic treatments, (2) resistance conferring mutations simultaneously enhance sensitivity to many other drugs and (3) 27% of the accumulated mutations generate proteins with compromised activities, suggesting that antibiotic adaptation can partly be achieved without gain of novel function. By using knowledge on antibiotic properties, we examined the determinants of cross-resistance and identified chemogenomic profile similarity between antibiotics as the strongest predictor. In contrast, cross-resistance between two antibiotics is independent of whether they show synergistic effects in combination. These results have important implications on the development of novel antimicrobial strategies. PMID:25000950

Evaluation of an interpretive videotape program using electronic feedback to measure audience perceptions and knowledge gained

NASA Astrophysics Data System (ADS)

Boyette, Cheryl Tate

Audience preferences and perceptions influence the effectiveness of interpretive programs. The purpose of this study was to determine the preferences of students (grades 3 & 4) and adults for presenter style and delivery, and video production techniques. Other study objectives were the exploration of relationships between knowledge gained and perceived enjoyment of the video. Similarities and differences between the groups of the study; students, pre-service teachers, members of community improvement organizations, and professional interpreters were examined. This study combined recall evaluation techniques with real-time, moment-to-moment data to evaluate the preferences and perceptions of adult and child audiences All data including moment-to-moment perceptions of enjoyment of the interpretive video "Buckeye the Tree Guy" were collected using an electronic feedback system the Perception Analyzer. The videotape developed with a grant from Texas Forest Service presented information on how, when, where, and why to plant and maintain trees in an urban environment. Knowledge gained was measures using a Solomon 4-group design. Student knowledge gained was increased for the treatment group. Adults and students agreed on presenter delivery but significance was found between the groups on presenter style. Significance for perceived enjoyment was found between the student and adult groups. Overall impression of the presenter was a strong influence on overall enjoyment of the video.

High Performance Visualization using Query-Driven Visualizationand Analytics

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

Bethel, E. Wes; Campbell, Scott; Dart, Eli

2006-06-15

Query-driven visualization and analytics is a unique approach for high-performance visualization that offers new capabilities for knowledge discovery and hypothesis testing. The new capabilities akin to finding needles in haystacks are the result of combining technologies from the fields of scientific visualization and scientific data management. This approach is crucial for rapid data analysis and visualization in the petascale regime. This article describes how query-driven visualization is applied to a hero-sized network traffic analysis problem.

Climate-driven thresholds for chemical weathering in postglacial soils of New Zealand

NASA Astrophysics Data System (ADS)

Dixon, Jean L.; Chadwick, Oliver A.; Vitousek, Peter M.

2016-09-01

Chemical weathering in soils dissolves and alters minerals, mobilizes metals, liberates nutrients to terrestrial and aquatic ecosystems, and may modulate Earth's climate over geologic time scales. Climate-weathering relationships are often considered fundamental controls on the evolution of Earth's surface and biogeochemical cycles. However, surprisingly little consensus has emerged on if and how climate controls chemical weathering, and models and data from published literature often give contrasting correlations and predictions for how weathering rates and climate variables such as temperature or moisture are related. Here we combine insights gained from the different approaches, methods, and theory of the soil science, biogeochemistry, and geomorphology communities to tackle the fundamental question of how rainfall influences soil chemical properties. We explore climate-driven variations in weathering and soil development in young, postglacial soils of New Zealand, measuring soil elemental geochemistry along a large precipitation gradient (400-4700 mm/yr) across the Waitaki basin on Te Waipounamu, the South Island. Our data show a strong climate imprint on chemical weathering in these young soils. This climate control is evidenced by rapid nonlinear changes along the gradient in total and exchangeable cations in soils and in the increased movement and redistribution of metals with rainfall. The nonlinear behavior provides insight into why climate-weathering relationships may be elusive in some landscapes. These weathering thresholds also have significant implications for how climate may influence landscape evolution and the release of rock-derived nutrients to ecosystems, as landscapes that transition to wetter climates across this threshold may weather and deplete rapidly.

Handbook of Research on Innovative Technology Integration in Higher Education

ERIC Educational Resources Information Center

Nafukho, Fredrick Muyia, Ed.; Irby, Beverly J., Ed.

2015-01-01

Our increasingly globalized world is driven by shared knowledge, and nowhere is that knowledge more important than in education. Now more than ever, there is a demand for technology that will assist in the spread of knowledge through customized, self-paced, and on-demand learning. The Handbook of Research on Innovative Technology Integration in…

Single-source dual-energy spectral multidetector CT of pancreatic adenocarcinoma: optimization of energy level viewing significantly increases lesion contrast.

PubMed

Patel, B N; Thomas, J V; Lockhart, M E; Berland, L L; Morgan, D E

2013-02-01

To evaluate lesion contrast in pancreatic adenocarcinoma patients using spectral multidetector computed tomography (MDCT) analysis. The present institutional review board-approved, Health Insurance Portability and Accountability Act of 1996 (HIPAA)-compliant retrospective study evaluated 64 consecutive adults with pancreatic adenocarcinoma examined using a standardized, multiphasic protocol on a single-source, dual-energy MDCT system. Pancreatic phase images (35 s) were acquired in dual-energy mode; unenhanced and portal venous phases used standard MDCT. Lesion contrast was evaluated on an independent workstation using dual-energy analysis software, comparing tumour to non-tumoural pancreas attenuation (HU) differences and tumour diameter at three energy levels: 70 keV; individual subject-optimized viewing energy level (based on the maximum contrast-to-noise ratio, CNR); and 45 keV. The image noise was measured for the same three energies. Differences in lesion contrast, diameter, and noise between the different energy levels were analysed using analysis of variance (ANOVA). Quantitative differences in contrast gain between 70 keV and CNR-optimized viewing energies, and between CNR-optimized and 45 keV were compared using the paired t-test. Thirty-four women and 30 men (mean age 68 years) had a mean tumour diameter of 3.6 cm. The median optimized energy level was 50 keV (range 40-77). The mean ± SD lesion contrast values (non-tumoural pancreas - tumour attenuation) were: 57 ± 29, 115 ± 70, and 146 ± 74 HU (p = 0.0005); the lengths of the tumours were: 3.6, 3.3, and 3.1 cm, respectively (p = 0.026); and the contrast to noise ratios were: 24 ± 7, 39 ± 12, and 59 ± 17 (p = 0.0005) for 70 keV, the optimized energy level, and 45 keV, respectively. For individuals, the mean ± SD contrast gain from 70 keV to the optimized energy level was 59 ± 45 HU; and the mean ± SD contrast gain from the optimized energy level to 45 keV was 31 ± 25 HU (p = 0.007). Significantly increased pancreatic lesion contrast was noted at lower viewing energies using spectral MDCT. Individual patient CNR-optimized energy level images have the potential to improve lesion conspicuity. Copyright © 2012 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Why Bother to Calibrate? Model Consistency and the Value of Prior Information

NASA Astrophysics Data System (ADS)

Hrachowitz, Markus; Fovet, Ophelie; Ruiz, Laurent; Euser, Tanja; Gharari, Shervan; Nijzink, Remko; Savenije, Hubert; Gascuel-Odoux, Chantal

2015-04-01

Hydrological models frequently suffer from limited predictive power despite adequate calibration performances. This can indicate insufficient representations of the underlying processes. Thus ways are sought to increase model consistency while satisfying the contrasting priorities of increased model complexity and limited equifinality. In this study the value of a systematic use of hydrological signatures and expert knowledge for increasing model consistency was tested. It was found that a simple conceptual model, constrained by 4 calibration objective functions, was able to adequately reproduce the hydrograph in the calibration period. The model, however, could not reproduce 20 hydrological signatures, indicating a lack of model consistency. Subsequently, testing 11 models, model complexity was increased in a stepwise way and counter-balanced by using prior information about the system to impose "prior constraints", inferred from expert knowledge and to ensure a model which behaves well with respect to the modeller's perception of the system. We showed that, in spite of unchanged calibration performance, the most complex model set-up exhibited increased performance in the independent test period and skill to reproduce all 20 signatures, indicating a better system representation. The results suggest that a model may be inadequate despite good performance with respect to multiple calibration objectives and that increasing model complexity, if efficiently counter-balanced by available prior constraints, can increase predictive performance of a model and its skill to reproduce hydrological signatures. The results strongly illustrate the need to balance automated model calibration with a more expert-knowledge driven strategy of constraining models.

Why Bother and Calibrate? Model Consistency and the Value of Prior Information.

NASA Astrophysics Data System (ADS)

Hrachowitz, M.; Fovet, O.; Ruiz, L.; Euser, T.; Gharari, S.; Nijzink, R.; Freer, J. E.; Savenije, H.; Gascuel-Odoux, C.

2014-12-01

Hydrological models frequently suffer from limited predictive power despite adequate calibration performances. This can indicate insufficient representations of the underlying processes. Thus ways are sought to increase model consistency while satisfying the contrasting priorities of increased model complexity and limited equifinality. In this study the value of a systematic use of hydrological signatures and expert knowledge for increasing model consistency was tested. It was found that a simple conceptual model, constrained by 4 calibration objective functions, was able to adequately reproduce the hydrograph in the calibration period. The model, however, could not reproduce 20 hydrological signatures, indicating a lack of model consistency. Subsequently, testing 11 models, model complexity was increased in a stepwise way and counter-balanced by using prior information about the system to impose "prior constraints", inferred from expert knowledge and to ensure a model which behaves well with respect to the modeller's perception of the system. We showed that, in spite of unchanged calibration performance, the most complex model set-up exhibited increased performance in the independent test period and skill to reproduce all 20 signatures, indicating a better system representation. The results suggest that a model may be inadequate despite good performance with respect to multiple calibration objectives and that increasing model complexity, if efficiently counter-balanced by available prior constraints, can increase predictive performance of a model and its skill to reproduce hydrological signatures. The results strongly illustrate the need to balance automated model calibration with a more expert-knowledge driven strategy of constraining models.

Set-relevance determines the impact of distractors on episodic memory retrieval.

PubMed

Kwok, Sze Chai; Shallice, Tim; Macaluso, Emiliano

2014-09-01

We investigated the interplay between stimulus-driven attention and memory retrieval with a novel interference paradigm that engaged both systems concurrently on each trial. Participants encoded a 45-min movie on Day 1 and, on Day 2, performed a temporal order judgment task during fMRI. Each retrieval trial comprised three images presented sequentially, and the task required participants to judge the temporal order of the first and the last images ("memory probes") while ignoring the second image, which was task irrelevant ("attention distractor"). We manipulated the content relatedness and the temporal proximity between the distractor and the memory probes, as well as the temporal distance between two probes. Behaviorally, short temporal distances between the probes led to reduced retrieval performance. Distractors that at encoding were temporally close to the first probe image reduced these costs, specifically when the distractor was content unrelated to the memory probes. The imaging results associated the distractor probe temporal proximity with activation of the right ventral attention network. By contrast, the precuneus was activated for high-content relatedness between distractors and probes and in trials including a short distance between the two memory probes. The engagement of the right ventral attention network by specific types of distractors suggests a link between stimulus-driven attention control and episodic memory retrieval, whereas the activation pattern of the precuneus implicates this region in memory search within knowledge/content-based hierarchies.

The nature of declarative and nondeclarative knowledge for implicit and explicit learning.

PubMed

Kirkhart, M W

2001-10-01

Using traditional implicit and explicit artificial-grammar learning tasks, the author investigated the similarities and differences between the acquisition of declarative knowledge under implicit and explicit learning conditions and the functions of the declarative knowledge during testing. Results suggested that declarative knowledge was not predictive of or required for implicit learning but was related to consistency in implicit learning performance. In contrast, declarative knowledge was predictive of and required for explicit learning and was related to consistency in performance. For explicit learning, the declarative knowledge functioned as a guide for other behavior. In contrast, for implicit learning, the declarative knowledge did not serve as a guide for behavior but was instead a post hoc description of the most commonly seen stimuli.

Learning style impact on knowledge gains in human patient simulation.

PubMed

Shinnick, Mary Ann; Woo, Mary A

2015-01-01

Human patient simulation (HPS) is a widely used method of teaching in nursing education. While it is believed that a student's learning style impacts knowledge gains in HPS, there is little evidence to support this. This study sought to determine the impact of learning style on knowledge gains after a heart failure (HF) simulation experience in pre-licensure nursing students. A convenience sample of four cohorts of prelicensure nursing students (n=161) were recruited from three Baccalaureate Schools of Nursing at the same point in their curriculum (age 25.7±6.6 years; gender=85.5% female) and participated in HPS using a HF simulation on a high-fidelity manikin. Learning style was assessed by the Kolb Learning Style Inventory (LSI) and pre- and post-HPS knowledge measured by parallel, validated, knowledge tests. The LSI identifies 4 learning styles, (Assimilating Diverging, Accommodating, and Converging). In some cases, learners present a balanced learning profile-an emphasis of all four equally. Statistical analysis consisted of t-tests and ANOVA. HF knowledge scores post-HPS compared to pre-HPS scores revealed a mean improvement of 7 points (p<0.001) showing evidence of learning. Within group score increases between the pre-test and post-test were seen for the Assimilating (66.68±20.87 to 83.35±12.59; p=0.07), Diverging (61.95±11.08 to 69.86±12.33; p<0.01) and balanced profiles (64.4±12.45 to 71.8±10.14; p<0.01), but not for Converging or Accommodating profiles (73% of sample). Post-hoc paired t-tests revealed a large effect size for the Assimilators (0.91) and moderate effect sizes for both the Divergers and balanced profiles (0.67 and 0.65, respectively). These findings confirm that knowledge gains occur with HPS and provide evidence that HPS is an effective teaching methodology for nursing students identifying with most types of learning styles. Copyright © 2014 Elsevier Ltd. All rights reserved.

Time scales of circulation and mixing processes of San Francisco Bay waters

USGS Publications Warehouse

Walters, R.A.; Cheng, R.T.; Conomos, T.J.

1985-01-01

Conceptual models for tidal period and low-frequency variations in sea level, currents, and mixing processes in the northern and southern reaches of San Francisco Bay describe the contrasting characteristics and dissimilar processes and rates in these embayments: The northern reach is a partially mixed estuary whereas the southern reach (South Bay) is a tidally oscillating lagoon with density-driven exchanges with the northern reach. The mixed semidiurnal tides are mixtures of progressive and standing waves. The relatively simple oscillations in South Bay are nearly standing waves, with energy propagating down the channels and dispersing into the broad shoal areas. The tides of the northern reach have the general properties of a progressive wave but are altered at the constriction of the embayments and gradually change in an upstream direction to a mixture of progressive and standing waves. The spring and neap variations of the tides are pronounced and cause fortnightly varying tidal currents that affect mixing and salinity stratification in the water column. Wind stress on the water surface, freshwater inflow, and tidal currents interacting with the complex bay configuration are the major local forcing mechanisms creating low-frequency variations in sea level and currents. These local forcing mechanisms drive the residual flows which, with tidal diffusion, control the water-replacement rates in the estuary. In the northern reach, the longitudinal density gradient drives an estuarine circulation in the channels, and the spatial variation in tidal amplitude creates a tidally-driven residual circulation. In contrast, South Bay exhibits a balance between wind-driven circulation and tidally-driven residual circulation for most of the year. During winter, however, there can be sufficient density variations to drive multilayer (2 to 3) flows in the channel of South Bay. Mixing models (that include both diffusive and dispersive processes) are based on time scales associated with salt variations at the boundaries and those associated with the local forcing mechanisms, while the spatial scales of variations are dependent upon the configuration of the embayments. In the northern reach, where the estuarine circulation is strong, the salt flux is carried by the mean advection of the mean salt field. Where large salinity gradients are present, the tidal correlation part of the salt flux is of the same order as the advective part. Our knowledge of mixing and exchange rates in South Bay is poor. As this embayment is nearly isohaline, the salt flux is dominated entirely by the mean advection of the mean salt field. During and after peaks in river discharge, water mixing becomes more dynamic, with a strong density-driven current creating a net exchange of both water mass and salt. These exchanges are stronger during neap tides. Residence times of the water masses vary seasonally and differ between reaches. In the northern reach, residence times are on the order of days for high winter river discharge and of months for summer periods. The residence times for South Bay are fairly long (on the order of several months) during summer, and typically shorter (less than a month) during winter when density-driven exchanges occur. ?? 1985 Dr W. Junk Publishers.

Collaborative Learning Using a Project across Multiple Business Courses: A Cognitive Load and Knowledge Convergence Approach

ERIC Educational Resources Information Center

Bhowmick, Sandeep; Chandra, Aruna; Harper, Jeffrey S.; Sweetin, Vernon

2015-01-01

Four business professors at a state university in the Midwestern United States launched a collaborative learning project grounded in cognitive learning theory and knowledge convergence theory with the objective of assessing student learning gains in cross-functional knowledge (CFK), course-related knowledge (CRK), and overall satisfaction with…

Achieving and Sustaining New Knowledge Development in High-Expectation Start-Ups

ERIC Educational Resources Information Center

Matricano, Diego

2010-01-01

In markets characterized by strong competition, new knowledge and new knowledge development are generally recognized as the key means for an enterprise to gain competitive advantage. This knowledge-based competitive advantage is critical for all commercial ventures, but is especially so for high-expectation start-ups (technology-based ventures…

Developmental Foundations of Children’s Fraction Magnitude Knowledge

PubMed Central

Mou, Yi; Li, Yaoran; Hoard, Mary K.; Nugent, Lara D.; Chu, Felicia W.; Rouder, Jeffrey N.; Geary, David C.

2016-01-01

The conceptual insight that fractions represent magnitudes is a critical yet daunting step in children’s mathematical development, and the knowledge of fraction magnitudes influences children’s later mathematics learning including algebra. In this study, longitudinal data were analyzed to identify the mathematical knowledge and domain-general competencies that predicted 8th and 9th graders’ (n=122) knowledge of fraction magnitudes and its cross-grade gains. Performance on the fraction magnitude measures predicted 9th grade algebra achievement. Understanding and fluently identifying the numerator-denominator relation in 7th grade emerged as the key predictor of later fraction magnitudes knowledge in both 8th and 9th grades. Competence at using fraction procedures, knowledge of whole number magnitudes, and the central executive contributed to 9th but not 8th graders’ fraction magnitude knowledge, and knowledge of whole number magnitude contributed to cross-grade gains. The key results suggest fluent processing of numerator-denominator relations presages students’ understanding of fractions as magnitudes and that the integration of whole number and fraction magnitudes occurs gradually. PMID:27773965

Adherence to prescribed exercise and diet regimens two months post-cardiac rehabilitation.

PubMed

Scotto, Carrie J; Waechter, Donna J; Rosneck, James

2011-01-01

Adherence to diet and exercise regimens significantly limits morbidity and mortality for cardiac patients. Research at six and 12 months post CR program indicates that healthy behaviours learned in CR are not sustained. However, little is known about the extent of adherence in the immediate program completion period. To determine CR participants' knowledge of their diet and exercise prescription and the degree of adherence two months after completing CR, and to examine demographic and clinical variables to identify relationships to adherence behaviours. Participants (n = 174) were recruited from Phase II CR over a one-year period. The Diet Habit Survey (DHS) and Duke Activity Status Index (DASI) scores were administered at admission, discharge, and two months post discharge. Structured telephone interviews were conducted to evaluate adherence behaviours. Spearman correlation was used to determine relationships between demographic and clinical variables and adherence behaviours. Repeated measures ANOVA showed DHS and DASI scores were significantly higher at discharge (p < 0.001) without significant drift at two months post program (p < 0.09). These scores were in contrast with low self-report of knowledge of dietary and exercise recommendations and adherence to dietary and exercise instructions. Lower knowledge about diet and exercise were correlated with employment (diet, p < 0.001; exercise, p < 0.025). Decreased dietary adherence was correlated with BMI (p < 0.005). Exercise adherence was correlated with gender (p < 0.021) and marital status (p < 0.042). Although CR participants gain and retain knowledge about necessary dietary changes and improve their exercise activity tolerance during CR, most fail to translate the information into health promoting behaviour changes beginning in the immediate discharge period. Research to identify methods that transform knowledge into lasting behaviour change post CR is needed.

Improving diet and exercise in pregnancy with Video Doctor counseling: a randomized trial.

PubMed

Jackson, Rebecca A; Stotland, Naomi E; Caughey, Aaron B; Gerbert, Barbara

2011-05-01

To determine if an interactive, computerized Video Doctor counseling tool improves self-reported diet and exercise in pregnant women. A randomized trial comparing a Video Doctor intervention to usual care in ethnically diverse, low-income, English-speaking pregnant women was conducted. Brief messages about diet, exercise, and weight gain were delivered by an actor-portrayed Video Doctor twice during pregnancy. In the Video Doctor group (n=158), there were statistically significant increases from baseline in exercise (+28 min), intake of fruits and vegetables, whole grains, fish, avocado and nuts, and significant decreases in intake of sugary foods, refined grains, high fat meats, fried foods, solid fats, and fast food. In contrast, there were no changes from baseline for any of these outcomes in the usual care group (n=163). Nutrition knowledge improved significantly over time in both groups but more so in the Video Doctor group. Clinician-patient discussions about these topics occurred significantly more frequently in the Video Doctor group. There was no difference in weight gain between groups. A brief Video Doctor intervention can improve exercise and dietary behaviors in pregnant women. The Video Doctor can be integrated into prenatal care to assist clinicians with effective diet and exercise counseling. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Theoretical study of the design and performance of a high-gain, high-extraction-efficiency FEL oscillator

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

Goldstein, J.; Nguyen, D.C.; Sheffield, R.L.

1996-10-01

We present the results of theoretical and simulation studies of the design and performance of a new F type of FEL oscillator. This device, known by the acronym RAFEL for Regenerative Amplifier Free-Electron Laser, will be constructed in the space presently occupied by the AFEL (Advanced FEL) at Los Alamos, and will be driven by an upgraded (to higher average power) version of the present AFEL linac. In order to achieve a long-time-averaged optical output power of {approximately} 1 kW using an electron beam with an average power of {approximately} 20 kW, a rather high extraction efficiency {eta} {approximately} 5%more » is required. We have designed a 2-m-long undulator to attain this goal: the first meter is untapered and provides high gain while the second meter is linearly-tapered in magnetic field amplitude to provide high extraction efficiency in the standard K-M-R manner. Two-plane focusing and linear polarization of the undulator are assumed. Electron-beam properties from PARMEIA simulations of the AFEL accelerator were used in the design. A large saturated gain, {approximately} 500, requires a very small optical feedback to keep the device operating at steady-state. However, the large gain leads to distorted optical modes which require two- and three-dimensional simulations to adequately treat diffraction effects. This FEL will be driven by 17 MeV electrons and will operate in the 16 {mu}m spectral region.« less

Effect of microbubble contrast on intracranial blood flow velocity assessed by transcranial Doppler.

PubMed

Logallo, Nicola; Fromm, Annette; Waje-Andreassen, Ulrike; Thomassen, Lars; Matre, Knut

2014-03-01

Ultrasound contrast agents (UCA) salvage a considerable number of transcranial Doppler (TCD) exams which would have failed because of poor bone window. UCA bolus injection causes an undesirable increase in measured blood flow velocity (BFV). The effect of UCA continuous infusion on measured BFV has not been investigated, and some in vitro experiments suggest that gain reduction during UCA administration may also influence measured BFV. This study aimed to investigate the effect of UCA continuous infusion on BFV measured by TCD and the influence of gain reduction on these measurements in a clinical setting. The right middle cerebral artery of ten patients with optimal bone window was insonated using a 2 MHz probe. UCA were administered using an infusion pump. BFV was measured (1) at baseline, (2) during UCA infusion, (3) during UCA infusion with gain reduction, and (4) after UCA wash-out phase. Gain reduction was based on the agreement between two neurosonographers on the degree of gain reduction necessary to restore baseline Doppler signal intensity (DSI). Actual DSI was estimated offline by analysis of raw data. BFV measured during UCA infusion with no gain adjustment was significantly higher than baseline BFV [peak systolic velocity (PSV): 85.1 ± 19.7 vs. 74.4 ± 19.7 cm/s, p < 0.0001; Mean velocity (MV): 56.5 ± 11.8 vs. 50.2 ± 12.3 cm/s, p < 0.0001]. BFV measured during UCA infusion with gain reduction was not significantly higher than baseline BFV (PSV: 74.3 ± 18.9 vs. 74.4 ± 19.4 cm/s, p = 0.8; MV: 49.4 ± 11.0 vs. 50.2 ± 12.3 cm/s, p = 0.8). Actual DSI during UCA infusion with gain reduction was not significantly higher than baseline DSI (13 ± 1 vs. 13 ± 1 dB). This study shows that UCA continuous infusion leads to an increase in measured BFV which may be counteracted by reducing Doppler gain thus restoring pre-contrast DSI.

Reconstructions of parameters of radiophysical chaotic generator with delayed feedback from short time series

NASA Astrophysics Data System (ADS)

Ishbulatov, Yu. M.; Karavaev, A. S.; Kiselev, A. R.; Semyachkina-Glushkovskaya, O. V.; Postnov, D. E.; Bezruchko, B. P.

2018-04-01

A method for the reconstruction of time-delayed feedback system is investigated, which is based on the detection of synchronous response of a slave time-delay system with respect to the driving from the master system under study. The structure of the driven system is similar to the structure of the studied time-delay system, but the feedback circuit is broken in the driven system. The method efficiency is tested using short and noisy data gained from an electronic chaotic oscillator with time-delayed feedback.

An Investigation of Neutrino-driven Convection and the Core Collapse Supernova Mechanism Using Multigroup Neutrino Transport

NASA Astrophysics Data System (ADS)

Mezzacappa, A.; Calder, A. C.; Bruenn, S. W.; Blondin, J. M.; Guidry, M. W.; Strayer, M. R.; Umar, A. S.

1998-03-01

We investigate neutrino-driven convection in core collapse supernovae and its ramifications for the explosion mechanism. We begin with a postbounce model that is optimistic in two important respects: (1) we begin with a 15 M⊙ precollapse model, which is representative of the class of stars with compact iron cores; (2) we implement Newtonian gravity. Our precollapse model is evolved through core collapse and bounce in one dimension using multigroup (neutrino energy-dependent) flux-limited diffusion (MGFLD) neutrino transport and Newtonian Lagrangian hydrodynamics, providing realistic initial conditions for the postbounce convection and evolution. Our two-dimensional simulation begins at 12 ms after bounce and proceeds for 500 ms. We couple two-dimensional piecewise parabolic method (PPM) hydrodynamics to precalculated one-dimensional MGFLD neutrino transport. (The neutrino distributions used for matter heating and deleptonization in our two-dimensional run are obtained from an accompanying one-dimensional simulation. The accuracy of this approximation is assessed.) For the moment, we sacrifice dimensionality for realism in other aspects of our neutrino transport. MGFLD is an implementation of neutrino transport that simultaneously (1) is multigroup and (2) simulates with sufficient realism the transport of neutrinos in opaque, semitransparent, and transparent regions. Both are crucial to the accurate determination of postshock neutrino heating, which sensitively depends on the luminosities, spectra, and flux factors of the electron neutrinos and antineutrinos emerging from their respective neutrinospheres. By 137 ms after bounce, we see neutrino-driven convection rapidly developing beneath the shock. By 212 ms after bounce, this convection becomes large scale, characterized by higher entropy, expanding upflows and lower entropy, denser, finger-like downflows. The upflows reach the shock and distort it from sphericity. The radial convection velocities at this time become supersonic just below the shock, reaching magnitudes in excess of 109 cm s-1. Eventually, however, the shock recedes to smaller radii, and at ~500 ms after bounce there is no evidence in our simulation of an explosion or of a developing explosion. Our angle-averaged density, entropy, electron fraction, and radial velocity profiles in our two-dimensional model agree well with their counterparts in our accompanying one-dimensional MGFLD run above and below the neutrino-driven convection region. In the convection region, the one-dimensional and angle-averaged profiles differ somewhat because (1) convection tends to flatten the density, entropy, and electron fraction profiles, and (2) the shock radius is boosted somewhat by convection. However, the differences are not significant, indicating that, while vigorous, neutrino-driven convection in our model does not have a significant impact on the overall shock dynamics. The differences between our results and those of other groups are considered. These most likely result from differences in (1) numerical hydrodynamics methods; (2) initial postbounce models, and, most important; (3) neutrino transport approximations. We have compared our neutrino luminosities, rms energies, and inverse flux factors with those from the exploding models of other groups. Above all, we find that the neutrino rms energies computed by our multigroup (MGFLD) transport are significantly lower than the values obtained by Burrows and coworkers, who specified their neutrino spectra by tying the neutrino temperature to the matter temperature at the neutrinosphere and by choosing the neutrino degeneracy parameter arbitrarily, and by Herant and coworkers in their transport scheme, which (1) is gray and (2) patches together optically thick and thin regions. The most dramatic difference between our results and those of Janka and Müller is exhibited by the difference in the net cooling rate below the gain radii: Our rate is 2-3 times greater during the critical 50-100 ms after bounce. We have computed the mass and internal energy in the gain region as a function of time. Up to ~150 ms after bounce, we find that both increase as a result of the increasing gain region volume, as the gain and shock radii diverge. However, at all subsequent times, we find that the mass and internal energy in the gain region decrease with time in accordance with the density falloff in the preshock region and with the flow of matter into the gain region at the shock and out of the gain region at the gain radius. Therefore, we see no evidence in the simulations presented here that neutrino-driven convection leads to mass and energy accumulation in the gain region. We have compared our one- and two-dimensional densities, temperatures, and electron fractions in the region below the electron neutrino and antineutrino gain radii, above which the neutrino luminosities are essentially constant (i.e., the neutrino sources are entirely enclosed), in an effort to assess how spherically symmetric our neutrino sources remain during our two-dimensional evolution, and therefore, in an effort to assess our use of precalculated one-dimensional MGFLD neutrino distributions in calculating the matter heating and deleptonization. We find no difference below the neutrinosphere radii. Between the neutrinosphere and gain radii we find no differences with obvious ramifications for the supernova outcome. We note that the interplay between neutrino transport and convection below the neutrinospheres is a delicate matter and is discussed at greater length in another paper (Mezzacappa and coworkers). However, the results presented therein do support our use of precalculated one-dimensional MGFLD in the present context. Failure in our ``optimistic'' 15 M⊙ Newtonian model leads us to conclude that it is unlikely, at least in our approximation, that neutrino-driven convection will lead to explosions for more massive stars with fatter iron cores or in cases in which general relativity is included.

Integrating Learner-Driven and Organization-Driven Agendas: A Workplace Study.

ERIC Educational Resources Information Center

Lessard, Richard

For the past 4 years, Alpena Community College (ACC) in Michigan has been involved in the Workplace Partnership Project (WPP), a federally funded program which brings basic skills classes into the worksite to help upgrade employees' math, reading, writing, problem-solving, and science knowledge. The college works with partner companies to help…

Visualising community: using participant-driven photo-elicitation for research and application

Treesearch

Paul M. Van Auken; Svein J. Frisvoll; Susan I. Stewart

2010-01-01

Despite a contemporary socio-culture revolving around cultural consumption of imagery, metaphors, representations and "gaze", photo-elicitation is a rarely used method for social scientists and planners to acquire knowledge. In this paper, we discuss participant-driven photo-elicitation, a process in which participant photos are paired with in-depth...

Comparison of Live Versus Online Instruction of a Novel Soft Skills Course in Mongolia

PubMed Central

Strehlow, Matthew C; Dorjsuren, Khandregzen; Newberry, Jennifer A

2017-01-01

Background Soft skills are essential for employee success in the global marketplace; however, many developing countries lack content experts to provide the requisite instruction to an emerging workforce. One possible solution is to use an online, open-access curriculum. To date, no studies on soft skills curricula using an online learning platform have been undertaken in Mongolia. Objective To evaluate the efficacy of an online versus classroom platform to deliver a novel soft skills course in Mongolia. Methods A series of eight lectures along with corresponding surveys and multiple choice question tests were developed and translated into the Mongolian language. Two different delivery modalities, online and traditional classroom lectures, were then compared for knowledge gain, comfort level, and satisfaction. Knowledge gain and comfort level were assessed pre- and post-course, while satisfaction was assessed only post-course. Results Enrollment in the online and classroom courses was 89 students and 291 students, respectively. Sixty-two online students (68% female) and 114 classroom students (77% female) completed the entire course and took the post-test. The online cohort had higher pre-test scores than the classroom cohort (46.4% and 37.3%, respectively, p < 0.01). The online cohort’s overall knowledge gain was not significant (0.4%, p=0.87), but the classroom cohort’s knowledge gain was significant (13.9%, p < 0.01). Both the online and classroom cohorts demonstrated significant improvement in overall comfort level for all soft skills topics (p < 0.01). Both cohorts were also highly satisfied with the course, as assessed on a Likert scale (4.59 for online, 4.40 for classroom). Conclusion The study compared two cohorts of Mongolian college students who took either an online or classroom-based soft skills course, and it was found that knowledge gain was significantly higher for the classroom group, while comfort and satisfaction with individual course topics was comparable. PMID:29399428

Comparison of Live Versus Online Instruction of a Novel Soft Skills Course in Mongolia.

PubMed

Mahadevan, Aditya; Strehlow, Matthew C; Dorjsuren, Khandregzen; Newberry, Jennifer A

2017-11-30

Background Soft skills are essential for employee success in the global marketplace; however, many developing countries lack content experts to provide the requisite instruction to an emerging workforce. One possible solution is to use an online, open-access curriculum. To date, no studies on soft skills curricula using an online learning platform have been undertaken in Mongolia. Objective To evaluate the efficacy of an online versus classroom platform to deliver a novel soft skills course in Mongolia. Methods A series of eight lectures along with corresponding surveys and multiple choice question tests were developed and translated into the Mongolian language. Two different delivery modalities, online and traditional classroom lectures, were then compared for knowledge gain, comfort level, and satisfaction. Knowledge gain and comfort level were assessed pre- and post-course, while satisfaction was assessed only post-course. Results Enrollment in the online and classroom courses was 89 students and 291 students, respectively. Sixty-two online students (68% female) and 114 classroom students (77% female) completed the entire course and took the post-test. The online cohort had higher pre-test scores than the classroom cohort (46.4% and 37.3%, respectively, p < 0.01). The online cohort's overall knowledge gain was not significant (0.4%, p=0.87), but the classroom cohort's knowledge gain was significant (13.9%, p < 0.01). Both the online and classroom cohorts demonstrated significant improvement in overall comfort level for all soft skills topics (p < 0.01). Both cohorts were also highly satisfied with the course, as assessed on a Likert scale (4.59 for online, 4.40 for classroom). Conclusion The study compared two cohorts of Mongolian college students who took either an online or classroom-based soft skills course, and it was found that knowledge gain was significantly higher for the classroom group, while comfort and satisfaction with individual course topics was comparable.

The views of migrant health workers living in Austria and Belgium on return migration to sub-Saharan Africa.

PubMed

Poppe, Annelien; Wojczewski, Silvia; Taylor, Katherine; Kutalek, Ruth; Peersman, Wim

2016-06-30

The negative consequences of the brain drain of sub-Saharan African health workers for source countries are well documented and include understaffed facilities, decreased standards of care and higher workloads. However, studies suggest that, if migrated health workers eventually return to their home countries, this may lead to beneficial effects following the transfer of their acquired skills and knowledge (brain gain). The present study aims to explore the factors influencing the intentions for return migration of sub-Saharan African health workers who emigrated to Austria and Belgium, and gain further insight into the potential of circular migration. Semi-structured interviews with 27 sub-Saharan African health workers in Belgium and Austria were conducted. As mentioned by the respondents, the main barriers for returning were family, structural crises in the source country, and insecurity. These barriers overrule the perceived drivers, which were nearly all pull factors and emotion driven. Despite the fact that only a minority plans to return permanently, many wish to return regularly to work in the healthcare sector or to contribute to the development of their source country. As long as safety and structural stability cannot be guaranteed in source countries, the number of return migrants is likely to remain low. National governments and regional organizations could play a role in facilitating the engagement of migrant health workers in the development of the healthcare system in source countries.

Investigating the state of physiologically based kinetic modelling practices and challenges associated with gaining regulatory acceptance of model applications.

PubMed

Paini, Alicia; Leonard, Jeremy A; Kliment, Tomas; Tan, Yu-Mei; Worth, Andrew

2017-11-01

Physiologically based kinetic (PBK) models are used widely throughout a number of working sectors, including academia and industry, to provide insight into the dosimetry related to observed adverse health effects in humans and other species. Use of these models has increased over the last several decades, especially in conjunction with emerging alternative methods to animal testing, such as in vitro studies and data-driven in silico quantitative-structure-activity-relationship (QSAR) predictions. Experimental information derived from these new approach methods can be used as input for model parameters and allows for increased confidence in models for chemicals that did not have in vivo data for model calibration. Despite significant advancements in good modelling practice (GMP) for model development and evaluation, there remains some reluctance among regulatory agencies to use such models during the risk assessment process. Here, the results of a survey disseminated to the modelling community are presented in order to inform the frequency of use and applications of PBK models in science and regulatory submission. Additionally, the survey was designed to identify a network of investigators involved in PBK modelling and knowledgeable of GMP so that they might be contacted in the future for peer review of PBK models, especially in regards to vetting the models to such a degree as to gain a greater acceptance for regulatory purposes. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Bright Sparks of Our Future!

NASA Astrophysics Data System (ADS)

Riordan, Naoimh

2016-04-01

My name is Naoimh Riordan and I am the Vice Principal of Rockboro Primary School in Cork City, South of Ireland. I am a full time class primary teacher and I teach 4th class, my students are aged between 9-10 years. My passion for education has developed over the years and grown towards STEM (Science, Technology, Engineering and Mathematics) subjects. I believe these subjects are the way forward for our future. My passion and beliefs are driven by the unique after school programme that I have developed. It is titled "Sparks" coming from the term Bright Sparks. "Sparks" is an after school programme with a difference where the STEM subjects are concentrated on through lessons such as Science, Veterinary Science Computer Animation /Coding, Eco engineering, Robotics, Magical Maths, Chess and Creative Writing. All these subjects are taught through activity based learning and are one-hour long each week for a ten-week term. "Sparks" is fully inclusive and non-selective which gives all students of any level of ability an opportunity to engage into these subjects. "Sparks" is open to all primary students in County Cork. The "Sparks" after school programme is taught by tutors from the different Universities and Colleges in Cork City. It works very well because the tutor brings their knowledge, skills and specialised equipment from their respective universities and in turn the tutor gains invaluable teaching practise, can trial a pilot programme in a chosen STEM subject and gain an insight into what works in the physical classroom.

A Feasibility Trial of Mental Health First Aid First Nations: Acceptability, Cultural Adaptation, and Preliminary Outcomes.

PubMed

Crooks, Claire V; Lapp, Andrea; Auger, Monique; van der Woerd, Kim; Snowshoe, Angela; Rogers, Billie Jo; Tsuruda, Samantha; Caron, Cassidy

2018-03-25

The Mental Health First Aid First Nations course was adapted from Mental Health First Aid Basic to create a community-based, culturally safe and relevant approach to promoting mental health literacy in First Nations contexts. Over 2.5 days, the course aims to build community capacity by teaching individuals to recognize and respond to mental health crises. This feasibility trial utilized mixed methods to evaluate the acceptability, cultural adaptation, and preliminary effectiveness of MHFAFN. Our approach was grounded in community-based participatory research principles, emphasizing relationship-driven procedures to collecting data and choice for how participants shared their voices. Data included participant interviews (n = 89), and surveys (n = 91) from 10 groups in four provinces. Surveys contained open-ended questions, retrospective pre-post ratings, and a scenario. We utilized data from nine facilitator interviews and 24 facilitator implementation surveys. The different lines of evidence converged to highlight strong acceptability, mixed reactions to the cultural adaptation, and gains in participants' knowledge, mental health first aid skill application, awareness, and self-efficacy, and reductions in stigma beliefs. Beyond promoting individual gains, the course served as a community-wide prevention approach by situating mental health in a colonial context and highlighting local resources and cultural strengths for promoting mental well-being. © 2018 The Authors American Journal of Community Psychology published by Wiley Periodicals, Inc. on behalf of Society for Community Research and Action.

Visual Contrast Sensitivity Improvement by Right Frontal High-Beta Activity Is Mediated by Contrast Gain Mechanisms and Influenced by Fronto-Parietal White Matter Microstructure

PubMed Central

Quentin, Romain; Elkin Frankston, Seth; Vernet, Marine; Toba, Monica N.; Bartolomeo, Paolo; Chanes, Lorena; Valero-Cabré, Antoni

2016-01-01

Behavioral and electrophysiological studies in humans and non-human primates have correlated frontal high-beta activity with the orienting of endogenous attention and shown the ability of the latter function to modulate visual performance. We here combined rhythmic transcranial magnetic stimulation (TMS) and diffusion imaging to study the relation between frontal oscillatory activity and visual performance, and we associated these phenomena to a specific set of white matter pathways that in humans subtend attentional processes. High-beta rhythmic activity on the right frontal eye field (FEF) was induced with TMS and its causal effects on a contrast sensitivity function were recorded to explore its ability to improve visual detection performance across different stimulus contrast levels. Our results show that frequency-specific activity patterns engaged in the right FEF have the ability to induce a leftward shift of the psychometric function. This increase in visual performance across different levels of stimulus contrast is likely mediated by a contrast gain mechanism. Interestingly, microstructural measures of white matter connectivity suggest a strong implication of right fronto-parietal connectivity linking the FEF and the intraparietal sulcus in propagating high-beta rhythmic signals across brain networks and subtending top-down frontal influences on visual performance. PMID:25899709

Generation of 103 fs mode-locked pulses by a gain linewidth-variable Nd,Y:CaF2 disordered crystal.

PubMed

Qin, Z P; Xie, G Q; Ma, J; Ge, W Y; Yuan, P; Qian, L J; Su, L B; Jiang, D P; Ma, F K; Zhang, Q; Cao, Y X; Xu, J

2014-04-01

We have demonstrated a diode-pumped passively mode-locked femtosecond Nd,Y:CaF2 disordered crystal laser for the first time to our knowledge. By choosing appropriate Y-doping concentration, a broad fluorescence linewidth of 31 nm has been obtained from the gain linewidth-variable Nd,Y:CaF2 crystal. With the Nd,Y:CaF2 disordered crystal as gain medium, the mode-locked laser generated pulses with pulse duration as short as 103 fs, average output power of 89 mW, and repetition rate of 100 MHz. To our best knowledge, this is the shortest pulse generated from Nd-doped crystal lasers so far. The research results show that the Nd,Y:CaF2 disordered crystal will be a potential alternative as gain medium of repetitive chirped pulse amplification for high-peak-power lasers.

Blood Basics

MedlinePlus

... CME) and recertification Educational Programs Programs to enhance knowledge, research, and expertise Advocacy In This Section Action ... Pacific Latin America Meeting on Hematologic Malignancies Gain knowledge, through “How I Treat” presentations, that can help ...

Differential effects of exogenous and endogenous attention on second-order texture contrast sensitivity

PubMed Central

Barbot, Antoine; Landy, Michael S.; Carrasco, Marisa

2012-01-01

The visual system can use a rich variety of contours to segment visual scenes into distinct perceptually coherent regions. However, successfully segmenting an image is a computationally expensive process. Previously we have shown that exogenous attention—the more automatic, stimulus-driven component of spatial attention—helps extract contours by enhancing contrast sensitivity for second-order, texture-defined patterns at the attended location, while reducing sensitivity at unattended locations, relative to a neutral condition. Interestingly, the effects of exogenous attention depended on the second-order spatial frequency of the stimulus. At parafoveal locations, attention enhanced second-order contrast sensitivity to relatively high, but not to low second-order spatial frequencies. In the present study we investigated whether endogenous attention—the more voluntary, conceptually-driven component of spatial attention—affects second-order contrast sensitivity, and if so, whether its effects are similar to those of exogenous attention. To that end, we compared the effects of exogenous and endogenous attention on the sensitivity to second-order, orientation-defined, texture patterns of either high or low second-order spatial frequencies. The results show that, like exogenous attention, endogenous attention enhances second-order contrast sensitivity at the attended location and reduces it at unattended locations. However, whereas the effects of exogenous attention are a function of the second-order spatial frequency content, endogenous attention affected second-order contrast sensitivity independent of the second-order spatial frequency content. This finding supports the notion that both exogenous and endogenous attention can affect second-order contrast sensitivity, but that endogenous attention is more flexible, benefitting performance under different conditions. PMID:22895879

On uncertainty in information and ignorance in knowledge

NASA Astrophysics Data System (ADS)

Ayyub, Bilal M.

2010-05-01

This paper provides an overview of working definitions of knowledge, ignorance, information and uncertainty and summarises formalised philosophical and mathematical framework for their analyses. It provides a comparative examination of the generalised information theory and the generalised theory of uncertainty. It summarises foundational bases for assessing the reliability of knowledge constructed as a collective set of justified true beliefs. It discusses system complexity for ancestor simulation potentials. It offers value-driven communication means of knowledge and contrarian knowledge using memes and memetics.

Compositional clustering in task structure learning

PubMed Central

Frank, Michael J.

2018-01-01

Humans are remarkably adept at generalizing knowledge between experiences in a way that can be difficult for computers. Often, this entails generalizing constituent pieces of experiences that do not fully overlap, but nonetheless share useful similarities with, previously acquired knowledge. However, it is often unclear how knowledge gained in one context should generalize to another. Previous computational models and data suggest that rather than learning about each individual context, humans build latent abstract structures and learn to link these structures to arbitrary contexts, facilitating generalization. In these models, task structures that are more popular across contexts are more likely to be revisited in new contexts. However, these models can only re-use policies as a whole and are unable to transfer knowledge about the transition structure of the environment even if only the goal has changed (or vice-versa). This contrasts with ecological settings, where some aspects of task structure, such as the transition function, will be shared between context separately from other aspects, such as the reward function. Here, we develop a novel non-parametric Bayesian agent that forms independent latent clusters for transition and reward functions, affording separable transfer of their constituent parts across contexts. We show that the relative performance of this agent compared to an agent that jointly clusters reward and transition functions depends environmental task statistics: the mutual information between transition and reward functions and the stochasticity of the observations. We formalize our analysis through an information theoretic account of the priors, and propose a meta learning agent that dynamically arbitrates between strategies across task domains to optimize a statistical tradeoff. PMID:29672581

Impact of gestational weight gain on fetal growth in obese normoglycemic mothers: a comparative study.

PubMed

Elhddad, Agzail S; Fairlie, Fiona; Lashen, Hany

2014-08-01

To assess the pattern of gestational weight gain (GWG) and its effect on fetal growth among normogylycemic obese and lean mothers. Prospective longitudinal study. Teaching hospitals, Sheffield, UK. Forty-six euglycemic obese and 30 lean mothers and their offspring. The contrast slope of GWG was calculated and its impact on fetal growth trajectory and birth anthropometry examined in both groups. The GWG contrast slope trended significantly upward in both groups but it was steeper among lean mothers (p = 0.003), particularly in second trimester. Lean mothers had a biphasic GWG pattern with a higher early weight gain (p = 0.02), whereas obese mothers had a monophasic GWG. Both groups had similar third trimester GWG. The GWG contrast slope was influenced by early pregnancy maternal anthropometry in the obese group only. Nonetheless, the obese mothers' glucose and insulin indices had no significant relationship to GWG. GWG had a significant positive relationship with intrauterine femur length (r = 0.32, p = 0.04) and abdominal circumference (r = 0.42, p = 0.006) growth trajectories, as well as birthweight standard deviation scores (r = 0.32, p = 0.036) and the ponderal index (r = 0.45, p = 0.003) in the obese mothers. Gestational weight gain among lean mothers is biphasic and significantly higher than their obese counterparts, but without effect on fetal growth. The obese mothers' monophasic weight gain was influenced by their anthropometry, but not by their insulin or glucose indices, and impacted on the growth of their babies. © 2014 Nordic Federation of Societies of Obstetrics and Gynecology.

Knowledge Management Framework for Emerging Infectious Diseases Preparedness and Response: Design and Development of Public Health Document Ontology.

PubMed

Zhang, Zhizun; Gonzalez, Mila C; Morse, Stephen S; Venkatasubramanian, Venkat

2017-10-11

There are increasing concerns about our preparedness and timely coordinated response across the globe to cope with emerging infectious diseases (EIDs). This poses practical challenges that require exploiting novel knowledge management approaches effectively. This work aims to develop an ontology-driven knowledge management framework that addresses the existing challenges in sharing and reusing public health knowledge. We propose a systems engineering-inspired ontology-driven knowledge management approach. It decomposes public health knowledge into concepts and relations and organizes the elements of knowledge based on the teleological functions. Both knowledge and semantic rules are stored in an ontology and retrieved to answer queries regarding EID preparedness and response. A hybrid concept extraction was implemented in this work. The quality of the ontology was evaluated using the formal evaluation method Ontology Quality Evaluation Framework. Our approach is a potentially effective methodology for managing public health knowledge. Accuracy and comprehensiveness of the ontology can be improved as more knowledge is stored. In the future, a survey will be conducted to collect queries from public health practitioners. The reasoning capacity of the ontology will be evaluated using the queries and hypothetical outbreaks. We suggest the importance of developing a knowledge sharing standard like the Gene Ontology for the public health domain. ©Zhizun Zhang, Mila C Gonzalez, Stephen S Morse, Venkat Venkatasubramanian. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 11.10.2017.

Professional development for primary science teaching in Thailand: Knowledge, orientations, and practices of professional developers and professional development participants

NASA Astrophysics Data System (ADS)

Musikul, Kusalin

The purpose of this study was to examine an entire PD project as a case to understand the dynamic nature of science PD in a holistic manner. I used a pedagogical content knowledge model by Magnusson, Krajcik, and Borko (1999) as my theoretical framework in examining the professional developers' and teacher participants' knowledge, orientation, and practice for professional development and elementary science teaching. The case study is my research tradition; I used grounded theory for data analysis. The primary data sources were interview, card sort activity, and observation field notes collected during the PD and subsequently in teacher participants' classrooms. Secondary data sources were documents and artifacts that I collected from the professional developers and teachers. An analysis of the data led me to interpret the following findings: (a) the professional developers displayed multiple orientations. These orientations included activity-driven, didactic, discovery, and pedagogy-driven orientations. The orientations that were found among the professional developers deviated from the reformed Thai Science Education Standards; (b) the professional developers had limited PCK for PD, which were knowledge of teachers' learning, knowledge of PD strategies, knowledge of PD curriculum, and knowledge of assessment.; (c) the professional developers' knowledge and orientations influenced their decisions in selecting PD activities and teaching approaches; (d) their orientations and PCK as well as the time factor influenced the design and implementation of the professional development; (e) the elementary teachers displayed didactic, activity-driven, and academic rigor orientations. The orientations that the teachers displayed deviated from the reformed Thai Science Education Standards; and (f) the elementary teachers exhibited limited PCK. It is evident that the limitation of one type of knowledge resulted in an ineffective use of other components of PCK. This study demonstrates the nature of PD in the context of Thailand in a holistic view to understand knowledge, orientation, and implementation of professional developers and professional development participants. Furthermore, the findings have implications for professional development and professional developers in Thailand and include worldwide with respect to promoting sustain and intensive professional development and developing professional developers.

Information Professional or IT Professional?: The Knowledge and Skills Required by Academic Librarians in the Digital Library Environment

ERIC Educational Resources Information Center

Raju, Jaya

2017-01-01

As library and information science (LIS) becomes an increasingly technology-driven profession, particularly in the academic library environment, questions arise as to the extent of information technology (IT) knowledge and skills that LIS professionals require. The purpose of this paper is to ascertain what IT knowledge and skills are needed by…