Using Biomedically Relevant Multimedia Content in an Introductory Physics Course for Life Science and Pre-health Students

NASA Astrophysics Data System (ADS)

Mylott, Elliot; Kutschera, Ellynne; Dunlap, Justin C.; Christensen, Warren; Widenhorn, Ralf

2016-04-01

We will describe a one-quarter pilot algebra-based introductory physics course for pre-health and life science majors. The course features videos with biomedical experts and cogent biomedically inspired physics content. The materials were used in a flipped classroom as well as an all-online environment where students interacted with multimedia materials online and prior to engaging in classroom activities. Pre-lecture questions on both the medical content covered in the video media and the physics concepts in the written material were designed to engage students and probe their understanding of physics. The course featured group discussion and peer-lead instruction. Following in-class instruction, students engaged with homework assignments which explore the connections of physics and the medical field in a quantitative manner. Course surveys showed a positive response by the vast majority of students. Students largely indicated that the course helped them to make a connection between physics and the biomedical field. The biomedical focus and different course format were seen as an improvement to previous traditional physics instruction.

Brains--Computers--Machines: Neural Engineering in Science Classrooms

ERIC Educational Resources Information Center

Chudler, Eric H.; Bergsman, Kristen Clapper

2016-01-01

Neural engineering is an emerging field of high relevance to students, teachers, and the general public. This feature presents online resources that educators and scientists can use to introduce students to neural engineering and to integrate core ideas from the life sciences, physical sciences, social sciences, computer science, and engineering…

Features of MCNP6 Relevant to Medical Radiation Physics

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

Hughes, H. Grady III; Goorley, John T.

2012-08-29

MCNP (Monte Carlo N-Particle) is a general-purpose Monte Carlo code for simulating the transport of neutrons, photons, electrons, positrons, and more recently other fundamental particles and heavy ions. Over many years MCNP has found a wide range of applications in many different fields, including medical radiation physics. In this presentation we will describe and illustrate a number of significant recently-developed features in the current version of the code, MCNP6, having particular utility for medical physics. Among these are major extensions of the ability to simulate large, complex geometries, improvement in memory requirements and speed for large lattices, introduction of mesh-basedmore » isotopic reaction tallies, advances in radiography simulation, expanded variance-reduction capabilities, especially for pulse-height tallies, and a large number of enhancements in photon/electron transport.« less

Application of musical timbre discrimination features to active sonar classification

NASA Astrophysics Data System (ADS)

Young, Victor W.; Hines, Paul C.; Pecknold, Sean

2005-04-01

In musical acoustics significant effort has been devoted to uncovering the physical basis of timbre perception. Most investigations into timbre rely on multidimensional scaling (MDS), in which different musical sounds are arranged as points in multidimensional space. The Euclidean distance between points corresponds to the perceptual distance between sounds and the multidimensional axes are linked to measurable properties of the sounds. MDS has identified numerous temporal and spectral features believed to be important to timbre perception. There is reason to believe that some of these features may have wider application in the disparate field of underwater acoustics, since anecdotal evidence suggests active sonar returns from metallic objects sound different than natural clutter returns when auralized by human operators. This is particularly encouraging since attempts to develop robust automatic classifiers capable of target-clutter discrimination over a wide range of operational conditions have met with limited success. Spectral features relevant to target-clutter discrimination are believed to include click-pitch and envelope irregularity; relevant temporal features are believed to include duration, sub-band attack/decay time, and time separation pitch. Preliminary results from an investigation into the role of these timbre features in target-clutter discrimination will be presented. [Work supported by NSERC and GDC.

Assessing environmental features related to mental health: a reliability study of visual streetscape images.

PubMed

Wu, Yu-Tzu; Nash, Paul; Barnes, Linda E; Minett, Thais; Matthews, Fiona E; Jones, Andy; Brayne, Carol

2014-10-22

An association between depressive symptoms and features of built environment has been reported in the literature. A remaining research challenge is the development of methods to efficiently capture pertinent environmental features in relevant study settings. Visual streetscape images have been used to replace traditional physical audits and directly observe the built environment of communities. The aim of this work is to examine the inter-method reliability of the two audit methods for assessing community environments with a specific focus on physical features related to mental health. Forty-eight postcodes in urban and rural areas of Cambridgeshire, England were randomly selected from an alphabetical list of streets hosted on a UK property website. The assessment was conducted in July and August 2012 by both physical and visual image audits based on the items in Residential Environment Assessment Tool (REAT), an observational instrument targeting the micro-scale environmental features related to mental health in UK postcodes. The assessor used the images of Google Street View and virtually "walked through" the streets to conduct the property and street level assessments. Gwet's AC1 coefficients and Bland-Altman plots were used to compare the concordance of two audits. The results of conducting the REAT by visual image audits generally correspond to direct observations. More variations were found in property level items regarding physical incivilities, with broad limits of agreement which importantly lead to most of the variation in the overall REAT score. Postcodes in urban areas had lower consistency between the two methods than rural areas. Google Street View has the potential to assess environmental features related to mental health with fair reliability and provide a less resource intense method of assessing community environments than physical audits.

Magnetic nanoparticles: preparation, physical properties, and applications in biomedicine

PubMed Central

2012-01-01

Finally, we have addressed some relevant findings on the importance of having well-defined synthetic strategies developed for the generation of MNPs, with a focus on particle formation mechanism and recent modifications made on the preparation of monodisperse samples of relatively large quantities not only with similar physical features, but also with similar crystallochemical characteristics. Then, different methodologies for the functionalization of the prepared MNPs together with the characterization techniques are explained. Theorical views on the magnetism of nanoparticles are considered. PMID:22348683

Algorithms for Spectral Decomposition with Applications to Optical Plume Anomaly Detection

NASA Technical Reports Server (NTRS)

Srivastava, Askok N.; Matthews, Bryan; Das, Santanu

2008-01-01

The analysis of spectral signals for features that represent physical phenomenon is ubiquitous in the science and engineering communities. There are two main approaches that can be taken to extract relevant features from these high-dimensional data streams. The first set of approaches relies on extracting features using a physics-based paradigm where the underlying physical mechanism that generates the spectra is used to infer the most important features in the data stream. We focus on a complementary methodology that uses a data-driven technique that is informed by the underlying physics but also has the ability to adapt to unmodeled system attributes and dynamics. We discuss the following four algorithms: Spectral Decomposition Algorithm (SDA), Non-Negative Matrix Factorization (NMF), Independent Component Analysis (ICA) and Principal Components Analysis (PCA) and compare their performance on a spectral emulator which we use to generate artificial data with known statistical properties. This spectral emulator mimics the real-world phenomena arising from the plume of the space shuttle main engine and can be used to validate the results that arise from various spectral decomposition algorithms and is very useful for situations where real-world systems have very low probabilities of fault or failure. Our results indicate that methods like SDA and NMF provide a straightforward way of incorporating prior physical knowledge while NMF with a tuning mechanism can give superior performance on some tests. We demonstrate these algorithms to detect potential system-health issues on data from a spectral emulator with tunable health parameters.

Vortices at Microwave Frequencies

NASA Astrophysics Data System (ADS)

Silva, Enrico; Pompeo, Nicola; Dobrovolskiy, Oleksandr V.

2017-11-01

The behavior of vortices at microwave frequencies is an extremely useful source of information on the microscopic parameters that enter the description of the vortex dynamics. This feature has acquired particular relevance since the discovery of unusual superconductors, such as cuprates. Microwave investigation then extended its field of application to many families of superconductors, including the artificially nanostructured materials. It is then important to understand the basics of the physics of vortices moving at high frequency, as well as to understand what information the experiments can yield (and what they can not). The aim of this brief review is to introduce the readers to some basic aspects of the physics of vortices under a microwave electromagnetic field, and to guide them to an understanding of the experiment, also by means of the illustration of some relevant results.

Isothermal Circumstellar Dust Shell Model for Teaching

ERIC Educational Resources Information Center

Robinson, G.; Towers, I. N.; Jovanoski, Z.

2009-01-01

We introduce a model of radiative transfer in circumstellar dust shells. By assuming that the shell is both isothermal and its thickness is small compared to its radius, the model is simple enough for students to grasp and yet still provides a quantitative description of the relevant physical features. The isothermal model can be used in a…

The derivation of scenic utility functions and surfaces and their role in landscape management

Treesearch

John W. Hamilton; Gregory J. Buhyoff; J. Douglas Wellman

1979-01-01

This paper outlines a methodological approach for determining relevant physical landscape features which people use in formulating judgments about scenic utility. This information, coupled with either empirically derived or rationally stipulated regression techniques, may be used to produce scenic utility functions and surfaces. These functions can provide a means for...

Near-Infrared Band Strengths of Molecules Diluted in N2 and H2O Ice Mixtures Relevant to Interstellar and Planetary Ices

NASA Technical Reports Server (NTRS)

Richey, Christina Rae; Gerakines, P.A.

2012-01-01

The relative abundances of ices in astrophysical environments rely on accurate laboratory measurements of physical parameters, such as band strengths (or absorption intensities), determined for the molecules of interest in relevant mixtures. In an extension of our previous study on pure-ice samples, here we focus on the near-infrared absorption features of molecules in mixtures with the dominant components of interstellar and planetary ices, H2O and N2. We present experimentally measured near-infrared spectral information (peak positions, widths, and band strengths) for both H2O- and N2-dominated mixtures of CO (carbon monoxide), CO2 (carbon dioxide), CH4 (methane), and NH3 (ammonia). Band strengths were determined during sample deposition by correlating the growth of near-infrared features (10,000-4000 per centimeter, 1-2.5 micrometers) with better-known mid-infrared features (4000-400 per centimeter, 2.5-25 micrometers) at longer wavelengths.

Amplitude, frequency, and timbre with the French horn

NASA Astrophysics Data System (ADS)

Konz, Nicholas; Ruiz, Michael J.

2018-07-01

The French horn is used to introduce the three basic properties of periodic waves: amplitude, frequency, and waveform. These features relate to the perceptual characteristics of loudness, pitch, and timbre encountered in everyday language. Visualizations are provided in the form of oscilloscope screenshots, spectrograms, and Fourier spectra to illustrate the physics. Introductory students will find the musical relevance interesting as they experience a real-world application of physics. Demonstrations playing the French horn are provided in an accompanying video (Ruiz 2018 Video: Amplitude, frequency, and timbre with the French horn http://mjtruiz.com/ped/horn/).

An appraisal of the literature on teaching physical examination skills.

PubMed

Easton, Graham; Stratford-Martin, James; Atherton, Helen

2012-07-01

To discover which models for teaching physical examination skills have been proposed, and to appraise the evidence for each. We conducted a narrative review of relevant literature from 1990-2010. We searched the databases MEDLINE, PsycINFO, and ERIC (The Education Resource Information Centre) for the terms: 'physical examination' AND 'teaching' as both MESH terms and keyword searches. We excluded web-based or video teaching, non-physical examination skills (e.g. communication skills), and articles about simulated patients or models. We identified five relevant articles. These five studies outlined several approaches to teaching physical examination skills, including Peyton's 4-step model, an adaptation of his model to a 6-step model; the silent run through; and collaborative discovery. There was little evidence to support one method over others. One controlled trial suggested that silent run-through could improve performance of complex motor tasks, and another suggested that collaborative discovery improves students' ability to recognise key findings in cardiac examinations. There are several models for teaching physical examinations, but few are designed specifically for that purpose and there is little evidence to back any one model over another. We propose an approach which adopts several key features of these models. Future research could usefully evaluate the effectiveness of the proposed models, or develop innovative practical models for teaching examination skills.

The semantic richness of abstract concepts

PubMed Central

Recchia, Gabriel; Jones, Michael N.

2012-01-01

We contrasted the predictive power of three measures of semantic richness—number of features (NFs), contextual dispersion (CD), and a novel measure of number of semantic neighbors (NSN)—for a large set of concrete and abstract concepts on lexical decision and naming tasks. NSN (but not NF) facilitated processing for abstract concepts, while NF (but not NSN) facilitated processing for the most concrete concepts, consistent with claims that linguistic information is more relevant for abstract concepts in early processing. Additionally, converging evidence from two datasets suggests that when NSN and CD are controlled for, the features that most facilitate processing are those associated with a concept's physical characteristics and real-world contexts. These results suggest that rich linguistic contexts (many semantic neighbors) facilitate early activation of abstract concepts, whereas concrete concepts benefit more from rich physical contexts (many associated objects and locations). PMID:23205008

Nonlocal approach to nonequilibrium thermodynamics and nonlocal heat diffusion processes

NASA Astrophysics Data System (ADS)

El-Nabulsi, Rami Ahmad

2018-04-01

We study some aspects of nonequilibrium thermodynamics and heat diffusion processes based on Suykens's nonlocal-in-time kinetic energy approach recently introduced in the literature. A number of properties and insights are obtained in particular the emergence of oscillating entropy and nonlocal diffusion equations which are relevant to a number of physical and engineering problems. Several features are obtained and discussed in details.

Bayesian feature selection for high-dimensional linear regression via the Ising approximation with applications to genomics.

PubMed

Fisher, Charles K; Mehta, Pankaj

2015-06-01

Feature selection, identifying a subset of variables that are relevant for predicting a response, is an important and challenging component of many methods in statistics and machine learning. Feature selection is especially difficult and computationally intensive when the number of variables approaches or exceeds the number of samples, as is often the case for many genomic datasets. Here, we introduce a new approach--the Bayesian Ising Approximation (BIA)-to rapidly calculate posterior probabilities for feature relevance in L2 penalized linear regression. In the regime where the regression problem is strongly regularized by the prior, we show that computing the marginal posterior probabilities for features is equivalent to computing the magnetizations of an Ising model with weak couplings. Using a mean field approximation, we show it is possible to rapidly compute the feature selection path described by the posterior probabilities as a function of the L2 penalty. We present simulations and analytical results illustrating the accuracy of the BIA on some simple regression problems. Finally, we demonstrate the applicability of the BIA to high-dimensional regression by analyzing a gene expression dataset with nearly 30 000 features. These results also highlight the impact of correlations between features on Bayesian feature selection. An implementation of the BIA in C++, along with data for reproducing our gene expression analyses, are freely available at http://physics.bu.edu/∼pankajm/BIACode. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Critical Pedagogy and APA: A Resonant (and Timely) Interdisciplinary Blend.

PubMed

Connolly, Maureen; Harvey, William J

2018-04-12

Critical pedagogy owes much of its emergence, development, and ongoing relevance to the work of Paulo Freire whose legacy remains relevant for a next generation of scholars who seek to explore issues of inclusion, oppression, social justice, and authentic expression. An interdisciplinary dialogue between critical pedagogy and adapted physical activity is timely, appropriate, and should focus on complex profiles of neurodiversity, mental illness, and mental health, with emphasis on pedagogic practices of practitioners in service delivery and teacher educators who prepare them for professional practice. A case-based scenario approach is used to present practitioner and teacher educator practices. Concrete examples are provided for analyzing and understanding deeper issues and challenges related to neurodiversity in a variety of embodied dimensions in educational and activity contexts. We work with Szostak's approach to interdisciplinary research and model an analysis strategy that integrates and applies the methodological features of interdisciplinarity, adapted physical activity, and critical pedagogy.

Numerical simulations of Z-Pinch experiments to create supersonic differentially-rotating plasma flows

NASA Astrophysics Data System (ADS)

Bochi, Matteo; Ummels, Sebastiaan; Chittenden, Jeremy; Lebedev, Sergey

2011-10-01

Recently, it was proposed that a small number of plasma jets produced by lasers could be used to generate a plasma configuration relevant to some features of astrophysical accretion disc physics. We propose complementary experimental configurations which employ converging flows generated in a cylindrical wire array Z-pinch modified to produce a rotating plasma. In this paper we present 3D MHD simulations using the code GORGON which show how this approach can be implemented at the MAGPIE facility at Imperial College, London. We will present the general scenario and the results of a parametric study relating the parameters of the array with the features of the resulting plasma. In particular, we will show how a rotating plasma cylinder or ring, with typical rotation velocity 30 Km/s and Mach number 8 is formed, and how, after about 1-2 revolutions, the material of the plasma ring is ejected in a pair of thermally driven, conical outflows propagating along the rotation axis. We will discuss to what aspects of the physics of accretion discs, the results of such experiments could be relevant. We will also consider the effects of different magnetic configurations, which further expand the possibility to relate the experiments with the astrophysical discs. Experimental implementation of some of these setups is currently in progress on MAGPIE.

Individual and social learning processes involved in the acquisition and generalization of tool use in macaques

PubMed Central

Macellini, S.; Maranesi, M.; Bonini, L.; Simone, L.; Rozzi, S.; Ferrari, P. F.; Fogassi, L.

2012-01-01

Macaques can efficiently use several tools, but their capacity to discriminate the relevant physical features of a tool and the social factors contributing to their acquisition are still poorly explored. In a series of studies, we investigated macaques' ability to generalize the use of a stick as a tool to new objects having different physical features (study 1), or to new contexts, requiring them to adapt the previously learned motor strategy (study 2). We then assessed whether the observation of a skilled model might facilitate tool-use learning by naive observer monkeys (study 3). Results of study 1 and study 2 showed that monkeys trained to use a tool generalize this ability to tools of different shape and length, and learn to adapt their motor strategy to a new task. Study 3 demonstrated that observing a skilled model increases the observers' manipulations of a stick, thus facilitating the individual discovery of the relevant properties of this object as a tool. These findings support the view that in macaques, the motor system can be modified through tool use and that it has a limited capacity to adjust the learnt motor skills to a new context. Social factors, although important to facilitate the interaction with tools, are not crucial for tool-use learning. PMID:22106424

Local equilibrium solutions in simple anisotropic cosmological models, as described by relativistic fluid dynamics

NASA Astrophysics Data System (ADS)

Shogin, Dmitry; Amund Amundsen, Per

2016-10-01

We test the physical relevance of the full and the truncated versions of the Israel-Stewart (IS) theory of irreversible thermodynamics in a cosmological setting. Using a dynamical systems method, we determine the asymptotic future of plane symmetric Bianchi type I spacetimes with a viscous mathematical fluid, keeping track of the magnitude of the relative dissipative fluxes, which determines the applicability of the IS theory. We consider the situations where the dissipative mechanisms of shear and bulk viscosity are involved separately and simultaneously. It is demonstrated that the only case in the given model when the fluid asymptotically approaches local thermal equilibrium, and the underlying assumptions of the IS theory are therefore not violated, is that of a dissipative fluid with vanishing bulk viscosity. The truncated IS equations for shear viscosity are found to produce solutions which manifest pathological dynamical features and, in addition, to be strongly sensitive to the choice of initial conditions. Since these features are observed already in the case of an oversimplified mathematical fluid model, we have no reason to assume that the truncation of the IS transport equations will produce relevant results for physically more realistic fluids. The possible role of bulk and shear viscosity in cosmological evolution is also discussed.

Force Density Function Relationships in 2-D Granular Media

NASA Technical Reports Server (NTRS)

Youngquist, Robert C.; Metzger, Philip T.; Kilts, Kelly N.

2004-01-01

An integral transform relationship is developed to convert between two important probability density functions (distributions) used in the study of contact forces in granular physics. Developing this transform has now made it possible to compare and relate various theoretical approaches with one another and with the experimental data despite the fact that one may predict the Cartesian probability density and another the force magnitude probability density. Also, the transforms identify which functional forms are relevant to describe the probability density observed in nature, and so the modified Bessel function of the second kind has been identified as the relevant form for the Cartesian probability density corresponding to exponential forms in the force magnitude distribution. Furthermore, it is shown that this transform pair supplies a sufficient mathematical framework to describe the evolution of the force magnitude distribution under shearing. Apart from the choice of several coefficients, whose evolution of values must be explained in the physics, this framework successfully reproduces the features of the distribution that are taken to be an indicator of jamming and unjamming in a granular packing. Key words. Granular Physics, Probability Density Functions, Fourier Transforms

Borderline Personality Features, Anger, and Intimate Partner Violence: An Experimental Manipulation of Rejection.

PubMed

Armenti, Nicholas A; Babcock, Julia C

2018-04-01

Individuals with borderline personality features may be susceptible to react to situational stressors with negative and interpersonally maladaptive emotionality (e.g., anger) and aggression. The current study attempted to test two moderated mediation models to investigate dispositional risk factors associated with borderline personality features and intimate partner violence (IPV). Results from an experimental rejection induction paradigm were examined using moderated regression to observe contextual reactions to imagined romantic rejection from a current romantic partner among individuals with borderline personality features. An ethnically diverse sample of 218 undergraduates at a large public university in the southwestern United States was recruited. Participants responded to demographic questions and self-report measures, and engaged in an experimental rejection induction paradigm. Borderline personality features was positively associated with rejection sensitivity, physical assault, and psychological aggression. Contrary to initial hypotheses, rejection sensitivity did not serve as a mediator of the relations between borderline personality features and physical assault and psychological aggression. However, trait anger mediated the relation between borderline personality features and psychological aggression. As such, trait anger may be an important explanatory variable in the relation between borderline personality features and psychological aggression specifically. Results of the rejection induction paradigm indicated that, for individuals who were asked to imagine an ambiguous rejection, the relation between borderline personality features and state anger post-rejection was strengthened. For individuals who imagined a critical rejection, there was no significant relation between borderline personality features and state anger post-rejection. Findings suggest that trait anger may be an important dispositional factor in the link between borderline personality features and IPV. In addition, contextual factors, such as ambiguous rejection by an intimate partner, may be especially relevant in activating anger or aggression in individuals with borderline personality features.

What History Tells Us about the Distinct Nature of Chemistry.

PubMed

Chang, Hasok

2017-11-01

Attention to the history of chemistry can help us recognise the characteristics of chemistry that have helped to maintain it as a separate scientific discipline with a unique identity. Three such features are highlighted in this paper. First, chemistry has maintained a distinct type of theoretical thinking, independent from that of physics even in the era of quantum chemistry. Second, chemical research has always been shaped by its ineliminable practical relevance and usefulness. Third, the lived experience of chemistry, spanning the laboratory, the classroom and everyday life, is distinctive in its multidimensional sensuousness. Furthermore, I argue that the combination of these three features makes chemistry an exemplary science.

Learning relevant features of data with multi-scale tensor networks

NASA Astrophysics Data System (ADS)

Miles Stoudenmire, E.

2018-07-01

Inspired by coarse-graining approaches used in physics, we show how similar algorithms can be adapted for data. The resulting algorithms are based on layered tree tensor networks and scale linearly with both the dimension of the input and the training set size. Computing most of the layers with an unsupervised algorithm, then optimizing just the top layer for supervised classification of the MNIST and fashion MNIST data sets gives very good results. We also discuss mixing a prior guess for supervised weights together with an unsupervised representation of the data, yielding a smaller number of features nevertheless able to give good performance.

Features: Real-Time Adaptive Feature and Document Learning for Web Search.

ERIC Educational Resources Information Center

Chen, Zhixiang; Meng, Xiannong; Fowler, Richard H.; Zhu, Binhai

2001-01-01

Describes Features, an intelligent Web search engine that is able to perform real-time adaptive feature (i.e., keyword) and document learning. Explains how Features learns from users' document relevance feedback and automatically extracts and suggests indexing keywords relevant to a search query, and learns from users' keyword relevance feedback…

Persuasive Technology in Mobile Applications Promoting Physical Activity: a Systematic Review.

PubMed

Matthews, John; Win, Khin Than; Oinas-Kukkonen, Harri; Freeman, Mark

2016-03-01

Persuasive technology in mobile applications can be used to influence the behaviour of users. A framework known as the Persuasive Systems Design model has been developed for designing and evaluating systems that influence the attitudes or behaviours of users. This paper reviews the current state of mobile applications for health behavioural change with an emphasis on applications that promote physical activity. The inbuilt persuasive features of mobile applications were evaluated using the Persuasive Systems Design model. A database search was conducted to identify relevant articles. Articles were then reviewed using the Persuasive Systems Design model as a framework for analysis. Primary task support, dialogue support, and social support were found to be moderately represented in the selected articles. However, system credibility support was found to have only low levels of representation as a persuasive systems design feature in mobile applications for supporting physical activity. To ensure that available mobile technology resources are best used to improve the wellbeing of people, it is important that the design principles that influence the effectiveness of persuasive technology be understood.

Learning physical descriptors for materials science by compressed sensing

NASA Astrophysics Data System (ADS)

Ghiringhelli, Luca M.; Vybiral, Jan; Ahmetcik, Emre; Ouyang, Runhai; Levchenko, Sergey V.; Draxl, Claudia; Scheffler, Matthias

2017-02-01

The availability of big data in materials science offers new routes for analyzing materials properties and functions and achieving scientific understanding. Finding structure in these data that is not directly visible by standard tools and exploitation of the scientific information requires new and dedicated methodology based on approaches from statistical learning, compressed sensing, and other recent methods from applied mathematics, computer science, statistics, signal processing, and information science. In this paper, we explain and demonstrate a compressed-sensing based methodology for feature selection, specifically for discovering physical descriptors, i.e., physical parameters that describe the material and its properties of interest, and associated equations that explicitly and quantitatively describe those relevant properties. As showcase application and proof of concept, we describe how to build a physical model for the quantitative prediction of the crystal structure of binary compound semiconductors.

Online social networks that connect users to physical activity partners: a review and descriptive analysis.

PubMed

Nakhasi, Atul; Shen, Album Xiaotian; Passarella, Ralph Joseph; Appel, Lawrence J; Anderson, Cheryl Am

2014-06-16

The US Centers for Disease Control and Prevention have identified a lack of encouragement, support, or companionship from family and friends as a major barrier to physical activity. To overcome this barrier, online social networks are now actively leveraging principles of companion social support in novel ways. The aim was to evaluate the functionality, features, and usability of existing online social networks which seek to increase physical activity and fitness among users by connecting them to physical activity partners, not just online, but also face-to-face. In September 2012, we used 3 major databases to identify the website addresses for relevant online social networks. We conducted a Google search using 8 unique keyword combinations: the common keyword "find" coupled with 1 of 4 prefix terms "health," "fitness," "workout," or "physical" coupled with 1 of 2 stem terms "activity partners" or "activity buddies." We also searched 2 prominent technology start-up news sites, TechCrunch and Y Combinator, using 2 unique keyword combinations: the common keyword "find" coupled with 1 of 2 stem terms "activity partners" and "activity buddies." Sites were defined as online social health activity networks if they had the ability to (1) actively find physical activity partners or activities for the user, (2) offer dynamic, real-time tracking or sharing of social activities, and (3) provide virtual profiles to users. We excluded from our analysis sites that were not Web-based, publicly available, in English, or free. Of the 360 initial search results, we identified 13 websites that met our complete criteria of an online social health activity network. Features such as physical activity creation (13/13, 100%) and private messaging (12/13, 92%) appeared almost universally among these websites. However, integration with Web 2.0 technologies such as Facebook and Twitter (9/13, 69%) and the option of direct event joining (8/13, 62%) were not as universally present. Largely absent were more sophisticated features that would enable greater usability, such as interactive engagement prompts (3/13, 23%) and system-created best fit activities (3/13, 23%). Several major online social networks that connect users to physical activity partners currently exist and use standardized features to achieve their goals. Future research is needed to better understand how users utilize these features and how helpful they truly are.

Women in Physics: A Caribbean Perspective

NASA Astrophysics Data System (ADS)

Tanner, Kandice

2009-03-01

This paper is concerned with aspects of post-secondary education of women in physics in the Caribbean, focusing more specifically on the main university campuses in Trinidad and Tobago, Jamaica, and Barbados. Within this framework, there are three institutions of tertiary education that provide for undergraduate and post-graduate studies in physics. On average, the bachelor-level graduating class is roughly 40% female. A great majority of these students go on to seek master's degrees in engineering. Among those enrolled in graduate programs featuring research in astronomy, materials science, environmental physics, medical physics, and quantum physics, 58% are female. Significant numbers of women from the selected countries and from the Caribbean region are engaged in bachelor and doctoral programs in physics abroad, but no formal survey is available to provide the relevant quantitative information. However, an attempt will be made to quantify this component. Based in part on personal experience, a comparison will be made between domestic and foreign educational pathways, in terms of access to resources, level of research training, and occupational opportunities following graduation.

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

Kelly, J.R.; Duke, T.W.; Harwell, M.A.

Potential effects of oil drilling-fluid discharges upon Thalassia seagrass ecosystems were examined to provide general insights and raise ecotoxicological issues relevant to problems of addressing a priori, ecolgical effects of anthropogenic actions. Microcosm experiments have demonstrated effects upon both autotrophic and heterotrophic species, as well as the processes of primary productivity and decomposition. Significant ecological changes may result from disturbance effects related to the physical presence of higher particle loads, in addition to effects resulting from toxic features of drilling fluids.

Walkability of local communities: using geographic information systems to objectively assess relevant environmental attributes.

PubMed

Leslie, Eva; Coffee, Neil; Frank, Lawrence; Owen, Neville; Bauman, Adrian; Hugo, Graeme

2007-03-01

Geographic Information Systems (GIS) can be used to objectively measure features of the built environment that may influence adults' physical activity, which is an important determinant of chronic disease. We describe how a previously developed index of walkability was operationalised in an Australian context, using available spatial data. The index was used to generate a stratified sampling frame for the selection of households from 32 communities for the PLACE (Physical Activity in Localities and Community Environments) study. GIS data have the potential to be used to construct measures of environmental attributes and to develop indices of walkability for cities, regions or local communities.

Gender and appearance accuracy: Women's advantage over men is restricted to dress items.

PubMed

Horgan, Terrence Glenn; McGrath, Marianne Patricia; Bastien, Carl; Wegman, Patrick

2017-01-01

Which aspects of people's appearance do women remember better than men? Women were predicted to remember the dress-related items but not the physical characteristics of targets more accurately than men, given that the former might be a more female-relevant domain of interest among perceivers. Participants watched a videotaped target and then completed a surprise test of their memory for her/his appearance. Men were as accurate as women at remembering the target's physical features but less accurate than woman at recalling what the target was wearing. Discussion focuses on the implications of these findings for eyewitness accuracy.

Graphene oxide based contacts as probes of biomedical signals

NASA Astrophysics Data System (ADS)

Hallfors, N. G.; Devarajan, A.; Farhat, I. A. H.; Abdurahman, A.; Liao, K.; Gater, D. L.; Elnaggar, M. I.; Isakovic, A. F.

We have developed a series of graphene oxide (GOx) on polymer contacts and have demonstrated these to be useful for collection of standard biomedically relevant signals, such as electrocardiogram (ECG). The process is wet solution-based and allows for control and tuning of the basic physical parameters of GOx, such as electrical and optical properties, simply by choosing the number of GOx layers. Our GOx characterization measurements show spectral (FTIR, XPS, IR absorbance) features most relevant to such performance, and point towards the likely explanations about the mechanisms for controlling the physical properties relevant for the contact performance. Structural (X-ray topography) and surface characterization (AFM, SEM) indicates to what degree these contacts can be considered homogeneous and therefore provide information on yield and repeatability. We compare the ECG signals recorded by standard commercial probes (Ag/AgCl) and GOx probes, displaying minor differences the solution to which may lead to a whole new way we perform ECG data collection, including wearable electronics and IoT friendly ECG monitoring. We acknowledge support from Mubadala-SRC AC4ES and from SRC 2011-KJ-2190. We thank J. B. Warren and G. L. Carr (BNL) for assistance.

A systematic review of universal campaigns targeting child physical abuse prevention

PubMed Central

Poole, Mary Kathryn; Seal, David W.; Taylor, Catherine A.

2014-01-01

The purpose of this review was to better understand the impact of universal campaign interventions with a media component aimed at preventing child physical abuse (CPA). The review included 17 studies featuring 15 campaigns conducted from 1989 to 2011 in five countries. Seven studies used experimental designs, but most were quasi-experimental. CPA incidence was assessed in only three studies and decreased significantly in two. Studies also found significant reductions in relevant outcomes such as dysfunctional parenting, child problem behaviors and parental anger as well as increases in parental self-efficacy and knowledge of concepts and actions relevant to preventing child abuse. The following risk factors were most frequently targeted in campaigns: lack of knowledge regarding positive parenting techniques, parental impulsivity, the stigma of asking for help, inadequate social support and inappropriate expectations for a child’s developmental stage. The evidence base for universal campaigns designed to prevent CPA remains inconclusive due to the limited availability of rigorous evaluations; however, Triple-P is a notable exception. Given the potential for such interventions to shift population norms relevant to CPA and reduce rates of CPA, there is a need to further develop and rigorously evaluate such campaigns. PMID:24711483

The role of audience participation and task relevance on change detection during a card trick.

PubMed

Smith, Tim J

2015-01-01

Magicians utilize many techniques for misdirecting audience attention away from the secret sleight of a trick. One technique is to ask an audience member to participate in a trick either physically by asking them to choose a card or cognitively by having them keep track of a card. While such audience participation is an established part of most magic the cognitive mechanisms by which it operates are unknown. Failure to detect changes to objects while passively viewing magic tricks has been shown to be conditional on the changing feature being irrelevant to the current task. How change blindness operates during interactive tasks is unclear but preliminary evidence suggests that relevance of the changing feature may also play a role (Triesch et al., 2003). The present study created a simple on-line card trick inspired by Triesch et al.'s (2003) that allowed playing cards to be instantaneously replaced without distraction or occlusion as participants were either actively sorting the cards (Doing condition) or watching another person perform the task (Watching conditions). Participants were given one of three sets of instructions. The relevance of the card color to the task increased across the three instructions. During half of the trials a card changed color (but retained its number) as it was moving to the stack. Participants were instructed to immediately report such changes. Analysis of the probability of reporting a change revealed that actively performing the sorting task led to more missed changes than passively watching the same task but only when the changing feature was irrelevant to the sorting task. If the feature was relevant during either the pick-up or put-down action change detection was as good as during the watching block. These results confirm the ability of audience participation to create subtle dynamics of attention and perception during a magic trick and hide otherwise striking changes at the center of attention.

The role of audience participation and task relevance on change detection during a card trick

PubMed Central

Smith, Tim J.

2015-01-01

Magicians utilize many techniques for misdirecting audience attention away from the secret sleight of a trick. One technique is to ask an audience member to participate in a trick either physically by asking them to choose a card or cognitively by having them keep track of a card. While such audience participation is an established part of most magic the cognitive mechanisms by which it operates are unknown. Failure to detect changes to objects while passively viewing magic tricks has been shown to be conditional on the changing feature being irrelevant to the current task. How change blindness operates during interactive tasks is unclear but preliminary evidence suggests that relevance of the changing feature may also play a role (Triesch et al., 2003). The present study created a simple on-line card trick inspired by Triesch et al.’s (2003) that allowed playing cards to be instantaneously replaced without distraction or occlusion as participants were either actively sorting the cards (Doing condition) or watching another person perform the task (Watching conditions). Participants were given one of three sets of instructions. The relevance of the card color to the task increased across the three instructions. During half of the trials a card changed color (but retained its number) as it was moving to the stack. Participants were instructed to immediately report such changes. Analysis of the probability of reporting a change revealed that actively performing the sorting task led to more missed changes than passively watching the same task but only when the changing feature was irrelevant to the sorting task. If the feature was relevant during either the pick-up or put-down action change detection was as good as during the watching block. These results confirm the ability of audience participation to create subtle dynamics of attention and perception during a magic trick and hide otherwise striking changes at the center of attention. PMID:25698986

The hormesis database: the occurrence of hormetic dose responses in the toxicological literature.

PubMed

Calabrese, Edward J; Blain, Robyn B

2011-10-01

In 2005 we published an assessment of dose responses that satisfied a priori evaluative criteria for inclusion within the relational retrieval hormesis database (Calabrese and Blain, 2005). The database included information on study characteristics (e.g., biological model, gender, age and other relevant aspects, number of doses, dose distribution/range, quantitative features of the dose response, temporal features/repeat measures, and physical/chemical properties of the agents). The 2005 article covered information for about 5000 dose responses; the present article has been expanded to cover approximately 9000 dose responses. This assessment extends and strengthens the conclusion of the 2005 paper that the hormesis concept is broadly generalizable, being independent of biological model, endpoint measured and chemical class/physical agent. It also confirmed the definable quantitative features of hormetic dose responses in which the strong majority of dose responses display maximum stimulation less than twice that of the control group and a stimulatory width that is within approximately 10-20-fold of the estimated toxicological or pharmacological threshold. The remarkable consistency of the quantitative features of the hormetic dose response suggests that hormesis may provide an estimate of biological plasticity that is broadly generalized across plant, microbial and animal (invertebrate and vertebrate) models. Copyright © 2011 Elsevier Inc. All rights reserved.

A Dimensionally Aligned Signal Projection for Classification of Unintended Radiated Emissions

DOE PAGES

Vann, Jason Michael; Karnowski, Thomas P.; Kerekes, Ryan; ...

2017-04-24

Characterization of unintended radiated emissions (URE) from electronic devices plays an important role in many research areas from electromagnetic interference to nonintrusive load monitoring to information system security. URE can provide insights for applications ranging from load disaggregation and energy efficiency to condition-based maintenance of equipment-based upon detected fault conditions. URE characterization often requires subject matter expertise to tailor transforms and feature extractors for the specific electrical devices of interest. We present a novel approach, named dimensionally aligned signal projection (DASP), for projecting aligned signal characteristics that are inherent to the physical implementation of many commercial electronic devices. These projectionsmore » minimize the need for an intimate understanding of the underlying physical circuitry and significantly reduce the number of features required for signal classification. We present three possible DASP algorithms that leverage frequency harmonics, modulation alignments, and frequency peak spacings, along with a two-dimensional image manipulation method for statistical feature extraction. To demonstrate the ability of DASP to generate relevant features from URE, we measured the conducted URE from 14 residential electronic devices using a 2 MS/s collection system. Furthermore, a linear discriminant analysis classifier was trained using DASP generated features and was blind tested resulting in a greater than 90% classification accuracy for each of the DASP algorithms and an accuracy of 99.1% when DASP features are used in combination. Furthermore, we show that a rank reduced feature set of the combined DASP algorithms provides a 98.9% classification accuracy with only three features and outperforms a set of spectral features in terms of general classification as well as applicability across a broad number of devices.« less

A Dimensionally Aligned Signal Projection for Classification of Unintended Radiated Emissions

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

Vann, Jason Michael; Karnowski, Thomas P.; Kerekes, Ryan

Characterization of unintended radiated emissions (URE) from electronic devices plays an important role in many research areas from electromagnetic interference to nonintrusive load monitoring to information system security. URE can provide insights for applications ranging from load disaggregation and energy efficiency to condition-based maintenance of equipment-based upon detected fault conditions. URE characterization often requires subject matter expertise to tailor transforms and feature extractors for the specific electrical devices of interest. We present a novel approach, named dimensionally aligned signal projection (DASP), for projecting aligned signal characteristics that are inherent to the physical implementation of many commercial electronic devices. These projectionsmore » minimize the need for an intimate understanding of the underlying physical circuitry and significantly reduce the number of features required for signal classification. We present three possible DASP algorithms that leverage frequency harmonics, modulation alignments, and frequency peak spacings, along with a two-dimensional image manipulation method for statistical feature extraction. To demonstrate the ability of DASP to generate relevant features from URE, we measured the conducted URE from 14 residential electronic devices using a 2 MS/s collection system. Furthermore, a linear discriminant analysis classifier was trained using DASP generated features and was blind tested resulting in a greater than 90% classification accuracy for each of the DASP algorithms and an accuracy of 99.1% when DASP features are used in combination. Furthermore, we show that a rank reduced feature set of the combined DASP algorithms provides a 98.9% classification accuracy with only three features and outperforms a set of spectral features in terms of general classification as well as applicability across a broad number of devices.« less

Content-based cell pathology image retrieval by combining different features

NASA Astrophysics Data System (ADS)

Zhou, Guangquan; Jiang, Lu; Luo, Limin; Bao, Xudong; Shu, Huazhong

2004-04-01

Content Based Color Cell Pathology Image Retrieval is one of the newest computer image processing applications in medicine. Recently, some algorithms have been developed to achieve this goal. Because of the particularity of cell pathology images, the result of the image retrieval based on single characteristic is not satisfactory. A new method for pathology image retrieval by combining color, texture and morphologic features to search cell images is proposed. Firstly, nucleus regions of leukocytes in images are automatically segmented by K-mean clustering method. Then single leukocyte region is detected by utilizing thresholding algorithm segmentation and mathematics morphology. The features that include color, texture and morphologic features are extracted from single leukocyte to represent main attribute in the search query. The features are then normalized because the numerical value range and physical meaning of extracted features are different. Finally, the relevance feedback system is introduced. So that the system can automatically adjust the weights of different features and improve the results of retrieval system according to the feedback information. Retrieval results using the proposed method fit closely with human perception and are better than those obtained with the methods based on single feature.

Practical Radiobiology for Proton Therapy Planning

NASA Astrophysics Data System (ADS)

Jones, Bleddyn

2017-12-01

Practical Radiobiology for Proton Therapy Planning covers the principles, advantages and potential pitfalls that occur in proton therapy, especially its radiobiological modelling applications. This book is intended to educate, inform and to stimulate further research questions. Additionally, it will help proton therapy centres when designing new treatments or when unintended errors or delays occur. The clear descriptions of useful equations for high LET particle beam applications, worked examples of many important clinical situations, and discussion of how proton therapy may be optimized are all important features of the text. This important book blends the relevant physics, biology and medical aspects of this multidisciplinary subject. Part of Series in Physics and Engineering in Medicine and Biology.

Biophysical model of prokaryotic diversity in geothermal hot springs.

PubMed

Klales, Anna; Duncan, James; Nett, Elizabeth Janus; Kane, Suzanne Amador

2012-02-01

Recent studies of photosynthetic bacteria living in geothermal hot spring environments have revealed surprisingly complex ecosystems with an unexpected level of genetic diversity. One case of particular interest involves the distribution along hot spring thermal gradients of genetically distinct bacterial strains that differ in their preferred temperatures for reproduction and photosynthesis. In such systems, a single variable, temperature, defines the relevant environmental variation. In spite of this, each region along the thermal gradient exhibits multiple strains of photosynthetic bacteria adapted to several distinct thermal optima, rather than a single thermal strain adapted to the local environmental temperature. Here we analyze microbiology data from several ecological studies to show that the thermal distribution data exhibit several universal features independent of location and specific bacterial strain. These include the distribution of optimal temperatures of different thermal strains and the functional dependence of the net population density on temperature. We present a simple population dynamics model of these systems that is highly constrained by biophysical data and by physical features of the environment. This model can explain in detail the observed thermal population distributions, as well as certain features of population dynamics observed in laboratory studies of the same organisms. © 2012 American Physical Society

Perceptual learning: toward a comprehensive theory.

PubMed

Watanabe, Takeo; Sasaki, Yuka

2015-01-03

Visual perceptual learning (VPL) is long-term performance increase resulting from visual perceptual experience. Task-relevant VPL of a feature results from training of a task on the feature relevant to the task. Task-irrelevant VPL arises as a result of exposure to the feature irrelevant to the trained task. At least two serious problems exist. First, there is the controversy over which stage of information processing is changed in association with task-relevant VPL. Second, no model has ever explained both task-relevant and task-irrelevant VPL. Here we propose a dual plasticity model in which feature-based plasticity is a change in a representation of the learned feature, and task-based plasticity is a change in processing of the trained task. Although the two types of plasticity underlie task-relevant VPL, only feature-based plasticity underlies task-irrelevant VPL. This model provides a new comprehensive framework in which apparently contradictory results could be explained.

Application of all relevant feature selection for failure analysis of parameter-induced simulation crashes in climate models

NASA Astrophysics Data System (ADS)

Paja, W.; Wrzesień, M.; Niemiec, R.; Rudnicki, W. R.

2015-07-01

The climate models are extremely complex pieces of software. They reflect best knowledge on physical components of the climate, nevertheless, they contain several parameters, which are too weakly constrained by observations, and can potentially lead to a crash of simulation. Recently a study by Lucas et al. (2013) has shown that machine learning methods can be used for predicting which combinations of parameters can lead to crash of simulation, and hence which processes described by these parameters need refined analyses. In the current study we reanalyse the dataset used in this research using different methodology. We confirm the main conclusion of the original study concerning suitability of machine learning for prediction of crashes. We show, that only three of the eight parameters indicated in the original study as relevant for prediction of the crash are indeed strongly relevant, three other are relevant but redundant, and two are not relevant at all. We also show that the variance due to split of data between training and validation sets has large influence both on accuracy of predictions and relative importance of variables, hence only cross-validated approach can deliver robust prediction of performance and relevance of variables.

[Methodologic inconsistency in anamnesis education at medical schools].

PubMed

Zago, M A

1989-01-01

Some relevant points of the process of obtaining the medical anamnesis and physical examination, and the formulation of diagnostic hypotheses are analyzed. The main methodological features include: preponderance of qualitative data, absence of preselected hypotheses, direct involvement of the observer (physician) with the data source (patient), and selection of hypotheses and changes of the patient during the process. Thus, diagnostic investigation does not follow the paradigm of quantitative scientific method, rooted on the logic positivism, which dominates medical research and education.

Oculomotor selection underlies feature retention in visual working memory.

PubMed

Hanning, Nina M; Jonikaitis, Donatas; Deubel, Heiner; Szinte, Martin

2016-02-01

Oculomotor selection, spatial task relevance, and visual working memory (WM) are described as three processes highly intertwined and sustained by similar cortical structures. However, because task-relevant locations always constitute potential saccade targets, no study so far has been able to distinguish between oculomotor selection and spatial task relevance. We designed an experiment that allowed us to dissociate in humans the contribution of task relevance, oculomotor selection, and oculomotor execution to the retention of feature representations in WM. We report that task relevance and oculomotor selection lead to dissociable effects on feature WM maintenance. In a first task, in which an object's location was encoded as a saccade target, its feature representations were successfully maintained in WM, whereas they declined at nonsaccade target locations. Likewise, we observed a similar WM benefit at the target of saccades that were prepared but never executed. In a second task, when an object's location was marked as task relevant but constituted a nonsaccade target (a location to avoid), feature representations maintained at that location did not benefit. Combined, our results demonstrate that oculomotor selection is consistently associated with WM, whereas task relevance is not. This provides evidence for an overlapping circuitry serving saccade target selection and feature-based WM that can be dissociated from processes encoding task-relevant locations. Copyright © 2016 the American Physiological Society.

Reward and attentional control in visual search.

PubMed

Yantis, Steven; Anderson, Brian A; Wampler, Emma K; Laurent, Patryk A

2012-01-01

It has long been known that the control of attention in visual search depends both on voluntary, top-down deployment according to context-specific goals, and on involuntary, stimulus-driven capture based on the physical conspicuity of perceptual objects. Recent evidence suggests that pairing target stimuli with reward can modulate the voluntary deployment of attention, but there is little evidence that reward modulates the involuntary deployment of attention to task-irrelevant distractors. We report several experiments that investigate the role of reward learning on attentional control. Each experiment involved a training phase and a test phase. In the training phase, different colors were associated with different amounts of monetary reward. In the test phase, color was not task-relevant and participants searched for a shape singleton; in most experiments no reward was delivered in the test phase. We first show that attentional capture by physically salient distractors is magnified by a previous association with reward. In subsequent experiments we demonstrate that physically inconspicuous stimuli previously associated with reward capture attention persistently during extinction--even several days after training. Furthermore, vulnerability to attentional capture by high-value stimuli is negatively correlated across individuals with working memory capacity and positively correlated with trait impulsivity. An analysis of intertrial effects reveals that value-driven attentional capture is spatially specific. Finally, when reward is delivered at test contingent on the task-relevant shape feature, recent reward history modulates value-driven attentional capture by the irrelevant color feature. The influence of learned value on attention may provide a useful model of clinical syndromes characterized by similar failures of cognitive control, including addiction, attention-deficit/hyperactivity disorder, and obesity.

Reward and Attentional Control in Visual Search

PubMed Central

Anderson, Brian A.; Wampler, Emma K.; Laurent, Patryk A.

2015-01-01

It has long been known that the control of attention in visual search depends both on voluntary, top-down deployment according to context-specific goals, and on involuntary, stimulus-driven capture based on the physical conspicuity of perceptual objects. Recent evidence suggests that pairing target stimuli with reward can modulate the voluntary deployment of attention, but there is little evidence that reward modulates the involuntary deployment of attention to task-irrelevant distractors. We report several experiments that investigate the role of reward learning on attentional control. Each experiment involved a training phase and a test phase. In the training phase, different colors were associated with different amounts of monetary reward. In the test phase, color was not task-relevant and participants searched for a shape singleton; in most experiments no reward was delivered in the test phase. We first show that attentional capture by physically salient distractors is magnified by a previous association with reward. In subsequent experiments we demonstrate that physically inconspicuous stimuli previously associated with reward capture attention persistently during extinction—even several days after training. Furthermore, vulnerability to attentional capture by high-value stimuli is negatively correlated across individuals with working memory capacity and positively correlated with trait impulsivity. An analysis of intertrial effects reveals that value-driven attentional capture is spatially specific. Finally, when reward is delivered at test contingent on the task-relevant shape feature, recent reward history modulates value-driven attentional capture by the irrelevant color feature. The influence of learned value on attention may provide a useful model of clinical syndromes characterized by similar failures of cognitive control, including addiction, attention-deficit/hyperactivity disorder, and obesity. PMID:23437631

Task-relevant perceptual features can define categories in visual memory too.

PubMed

Antonelli, Karla B; Williams, Carrick C

2017-11-01

Although Konkle, Brady, Alvarez, and Oliva (2010, Journal of Experimental Psychology: General, 139(3), 558) claim that visual long-term memory (VLTM) is organized on underlying conceptual, not perceptual, information, visual memory results from visual search tasks are not well explained by this theory. We hypothesized that when viewing an object, any task-relevant visual information is critical to the organizational structure of VLTM. In two experiments, we examined the organization of VLTM by measuring the amount of retroactive interference created by objects possessing different combinations of task-relevant features. Based on task instructions, only the conceptual category was task relevant or both the conceptual category and a perceptual object feature were task relevant. Findings indicated that when made task relevant, perceptual object feature information, along with conceptual category information, could affect memory organization for objects in VLTM. However, when perceptual object feature information was task irrelevant, it did not contribute to memory organization; instead, memory defaulted to being organized around conceptual category information. These findings support the theory that a task-defined organizational structure is created in VLTM based on the relevance of particular object features and information.

Network analysis of named entity co-occurrences in written texts

NASA Astrophysics Data System (ADS)

Amancio, Diego Raphael

2016-06-01

The use of methods borrowed from statistics and physics to analyze written texts has allowed the discovery of unprecedent patterns of human behavior and cognition by establishing links between models features and language structure. While current models have been useful to unveil patterns via analysis of syntactical and semantical networks, only a few works have probed the relevance of investigating the structure arising from the relationship between relevant entities such as characters, locations and organizations. In this study, we represent entities appearing in the same context as a co-occurrence network, where links are established according to a null model based on random, shuffled texts. Computational simulations performed in novels revealed that the proposed model displays interesting topological features, such as the small world feature, characterized by high values of clustering coefficient. The effectiveness of our model was verified in a practical pattern recognition task in real networks. When compared with traditional word adjacency networks, our model displayed optimized results in identifying unknown references in texts. Because the proposed representation plays a complementary role in characterizing unstructured documents via topological analysis of named entities, we believe that it could be useful to improve the characterization of written texts (and related systems), specially if combined with traditional approaches based on statistical and deeper paradigms.

Quantum physics in neuroscience and psychology: A neurophysicalmodel of the mind/brain interaction

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

Schwartz, Jeffrey M.; Stapp, Henry P.; Beauregard, Mario

Neuropsychological research on the neural basis of behavior generally posits that brain mechanisms will ultimately suffice to explain all psychologically described phenomena. This assumption stems from the idea that the brain is made up entirely of material particles and fields, and that all causal mechanisms relevant to neuroscience can therefore be formulated solely in terms of properties of these elements. Thus terms having intrinsic mentalistic and/or experiential content (e.g., ''feeling,'' ''knowing,'' and ''effort'') are not included as primary causal factors. This theoretical restriction is motivated primarily by ideas about the natural world that have been known to be fundamentally incorrectmore » for more than three quarters of a century. Contemporary basic physical theory differs profoundly from classical physics on the important matter of how the consciousness of human agents enters into the structure of empirical phenomena. The new principles contradict the older idea that local mechanical processes alone can account for the structure of all observed empirical data. Contemporary physical theory brings directly and irreducibly into the overall causal structure certain psychologically described choices made by human agents about how they will act. This key development in basic physical theory is applicable to neuroscience, and it provides neuroscientists and psychologists with an alternative conceptual framework for describing neural processes. Indeed, due to certain structural features of ion channels critical to synaptic function, contemporary physical theory must in principle be used when analyzing human brain dynamics. The new framework, unlike its classical-physics-based predecessor is erected directly upon, and is compatible with, the prevailing principles of physics, and is able to represent more adequately than classical concepts the neuroplastic mechanisms relevant to the growing number of empirical studies of the capacity of directed attention and mental effort to systematically alter brain function.« less

Quantum physics in neuroscience and psychology: a neurophysical model of mind–brain interaction

PubMed Central

Schwartz, Jeffrey M; Stapp, Henry P; Beauregard, Mario

2005-01-01

Neuropsychological research on the neural basis of behaviour generally posits that brain mechanisms will ultimately suffice to explain all psychologically described phenomena. This assumption stems from the idea that the brain is made up entirely of material particles and fields, and that all causal mechanisms relevant to neuroscience can therefore be formulated solely in terms of properties of these elements. Thus, terms having intrinsic mentalistic and/or experiential content (e.g. ‘feeling’, ‘knowing’ and ‘effort’) are not included as primary causal factors. This theoretical restriction is motivated primarily by ideas about the natural world that have been known to be fundamentally incorrect for more than three-quarters of a century. Contemporary basic physical theory differs profoundly from classic physics on the important matter of how the consciousness of human agents enters into the structure of empirical phenomena. The new principles contradict the older idea that local mechanical processes alone can account for the structure of all observed empirical data. Contemporary physical theory brings directly and irreducibly into the overall causal structure certain psychologically described choices made by human agents about how they will act. This key development in basic physical theory is applicable to neuroscience, and it provides neuroscientists and psychologists with an alternative conceptual framework for describing neural processes. Indeed, owing to certain structural features of ion channels critical to synaptic function, contemporary physical theory must in principle be used when analysing human brain dynamics. The new framework, unlike its classic-physics-based predecessor, is erected directly upon, and is compatible with, the prevailing principles of physics. It is able to represent more adequately than classic concepts the neuroplastic mechanisms relevant to the growing number of empirical studies of the capacity of directed attention and mental effort to systematically alter brain function. PMID:16147524

Permafrost on Mars: distribution, formation, and geological role

NASA Technical Reports Server (NTRS)

Nummedal, D.

1984-01-01

The morphology of channels, valleys, chaotic and fretted terrains and many smaller features on Mars is consistent with the hypothesis that localized deterioration of thick layers of ice-rich permafrost was a dominant geologic process on the Martian surface. Such ground ice deterioration gave rise to large-scale mass movement, including sliding, slumping and sediment gravity flowage, perhaps also catastropic floods. In contrast to Earth, such mass movement processes on Mars lack effective competition from erosion by surface runoff. Therefore, Martian features due to mass movement grew to reach immense size without being greatly modified by secondary erosional processes. The Viking Mission to Mars in 1976 provided adequate measurements of the relevant physical parameters to constrain models for Martian permafrost.

Selection of features within and without objects: effects of gestalt appearance and object-based instruction on behavior and event-related brain potentials.

PubMed

Verleger, Rolf; Groen, Margriet; Heide, Wolfgang; Sobieralska, Kinga; Jaśkowski, Piotr

2008-05-01

We studied how physical and instructed embedding of features in gestalts affects perceptual selection. Four ovals on the horizontal midline were either unconnected or pairwise connected by circles, forming ears of left and right heads (gestalts). Relevant to responding was the position of one colored oval, either within its pair or relative to fixation ("object-based" or "fixation-based" instruction). Responses were faster under fixation- than object-based instruction, less so with gestalts. Previously reported increases of N1 when evoked by features within objects were replicated for fixation-based instruction only. There was no effect of instruction on N2pc. However P1 increased under the adequate instruction, object-based for gestalts, fixation-based for unconnected items, which presumably indicated how foci of attention were set by expecting specific stimuli under instructions that specified how to bind these stimuli to objects.

Visualization of the Invisible: The Qubit as Key to Quantum Physics

NASA Astrophysics Data System (ADS)

Dür, Wolfgang; Heusler, Stefan

2014-11-01

Quantum mechanics is one of the pillars of modern physics, however rather difficult to teach at the introductory level due to the conceptual difficulties and the required advanced mathematics. Nevertheless, attempts to identify relevant features of quantum mechanics and to put forward concepts of how to teach it have been proposed.1-8 Here we present an approach to quantum physics based on the simplest quantum mechanical system—the quantum bit (qubit).1 Like its classical counterpart—the bit—a qubit corresponds to a two-level system, i.e., some system with a physical property that can admit two possible values. While typically a physical system has more than just one property or the property can admit more than just two values, in many situations most degrees of freedom can be considered to be fixed or frozen. Hence a variety of systems can be effectively described as a qubit. For instance, one may consider the spin of an electron or atom, with spin up and spin down as two possible values, and where other properties of the particle such as its mass or its position are fixed. Further examples include the polarization degree of freedom of a photon (horizontal and vertical polarization), two electronic degrees of freedom (i.e., two energy levels) of an atom, or the position of an atom in a double well potential (atom in left or right well). In all cases, only two states are relevant to describe the system.

A systematic review of universal campaigns targeting child physical abuse prevention.

PubMed

Poole, Mary Kathryn; Seal, David W; Taylor, Catherine A

2014-06-01

The purpose of this review was to better understand the impact of universal campaign interventions with a media component aimed at preventing child physical abuse (CPA). The review included 17 studies featuring 15 campaigns conducted from 1989 to 2011 in five countries. Seven studies used experimental designs, but most were quasi-experimental. CPA incidence was assessed in only three studies and decreased significantly in two. Studies also found significant reductions in relevant outcomes such as dysfunctional parenting, child problem behaviors and parental anger as well as increases in parental self-efficacy and knowledge of concepts and actions relevant to preventing child abuse. The following risk factors were most frequently targeted in campaigns: lack of knowledge regarding positive parenting techniques, parental impulsivity, the stigma of asking for help, inadequate social support and inappropriate expectations for a child's developmental stage. The evidence base for universal campaigns designed to prevent CPA remains inconclusive due to the limited availability of rigorous evaluations; however, Triple-P is a notable exception. Given the potential for such interventions to shift population norms relevant to CPA and reduce rates of CPA, there is a need to further develop and rigorously evaluate such campaigns. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Dorsal hippocampus is necessary for visual categorization in rats.

PubMed

Kim, Jangjin; Castro, Leyre; Wasserman, Edward A; Freeman, John H

2018-02-23

The hippocampus may play a role in categorization because of the need to differentiate stimulus categories (pattern separation) and to recognize category membership of stimuli from partial information (pattern completion). We hypothesized that the hippocampus would be more crucial for categorization of low-density (few relevant features) stimuli-due to the higher demand on pattern separation and pattern completion-than for categorization of high-density (many relevant features) stimuli. Using a touchscreen apparatus, rats were trained to categorize multiple abstract stimuli into two different categories. Each stimulus was a pentagonal configuration of five visual features; some of the visual features were relevant for defining the category whereas others were irrelevant. Two groups of rats were trained with either a high (dense, n = 8) or low (sparse, n = 8) number of category-relevant features. Upon reaching criterion discrimination (≥75% correct, on 2 consecutive days), bilateral cannulas were implanted in the dorsal hippocampus. The rats were then given either vehicle or muscimol infusions into the hippocampus just prior to various testing sessions. They were tested with: the previously trained stimuli (trained), novel stimuli involving new irrelevant features (novel), stimuli involving relocated features (relocation), and a single relevant feature (singleton). In training, the dense group reached criterion faster than the sparse group, indicating that the sparse task was more difficult than the dense task. In testing, accuracy of both groups was equally high for trained and novel stimuli. However, both groups showed impaired accuracy in the relocation and singleton conditions, with a greater deficit in the sparse group. The testing data indicate that rats encode both the relevant features and the spatial locations of the features. Hippocampal inactivation impaired visual categorization regardless of the density of the category-relevant features for the trained, novel, relocation, and singleton stimuli. Hippocampus-mediated pattern completion and pattern separation mechanisms may be necessary for visual categorization involving overlapping irrelevant features. © 2018 Wiley Periodicals, Inc.

Attentional Selection Can Be Predicted by Reinforcement Learning of Task-relevant Stimulus Features Weighted by Value-independent Stickiness.

PubMed

Balcarras, Matthew; Ardid, Salva; Kaping, Daniel; Everling, Stefan; Womelsdorf, Thilo

2016-02-01

Attention includes processes that evaluate stimuli relevance, select the most relevant stimulus against less relevant stimuli, and bias choice behavior toward the selected information. It is not clear how these processes interact. Here, we captured these processes in a reinforcement learning framework applied to a feature-based attention task that required macaques to learn and update the value of stimulus features while ignoring nonrelevant sensory features, locations, and action plans. We found that value-based reinforcement learning mechanisms could account for feature-based attentional selection and choice behavior but required a value-independent stickiness selection process to explain selection errors while at asymptotic behavior. By comparing different reinforcement learning schemes, we found that trial-by-trial selections were best predicted by a model that only represents expected values for the task-relevant feature dimension, with nonrelevant stimulus features and action plans having only a marginal influence on covert selections. These findings show that attentional control subprocesses can be described by (1) the reinforcement learning of feature values within a restricted feature space that excludes irrelevant feature dimensions, (2) a stochastic selection process on feature-specific value representations, and (3) value-independent stickiness toward previous feature selections akin to perseveration in the motor domain. We speculate that these three mechanisms are implemented by distinct but interacting brain circuits and that the proposed formal account of feature-based stimulus selection will be important to understand how attentional subprocesses are implemented in primate brain networks.

Exploring the Relationship of Task Performance and Physical and Cognitive Fatigue During a Daylong Light Precision Task.

PubMed

Yung, Marcus; Manji, Rahim; Wells, Richard P

2017-11-01

Our aim was to explore the relationship between fatigue and operation system performance during a simulated light precision task over an 8-hr period using a battery of physical (central and peripheral) and cognitive measures. Fatigue may play an important role in the relationship between poor ergonomics and deficits in quality and productivity. However, well-controlled laboratory studies in this area have several limitations, including the lack of work relevance of fatigue exposures and lack of both physical and cognitive measures. There remains a need to understand the relationship between physical and cognitive fatigue and task performance at exposure levels relevant to realistic production or light precision work. Errors and fatigue measures were tracked over the course of a micropipetting task. Fatigue responses from 10 measures and errors in pipetting technique, precision, and targeting were submitted to principal component analysis to descriptively analyze features and patterns. Fatigue responses and error rates contributed to three principal components (PCs), accounting for 50.9% of total variance. Fatigue responses grouped within the three PCs reflected central and peripheral upper extremity fatigue, postural sway, and changes in oculomotor behavior. In an 8-hr light precision task, error rates shared similar patterns to both physical and cognitive fatigue responses, and/or increases in arousal level. The findings provide insight toward the relationship between fatigue and operation system performance (e.g., errors). This study contributes to a body of literature documenting task errors and fatigue, reflecting physical (both central and peripheral) and cognitive processes.

The Effects of Goal Relevance and Perceptual Features on Emotional Items and Associative Memory

PubMed Central

Mao, Wei B.; An, Shu; Yang, Xiao F.

2017-01-01

Showing an emotional item in a neutral background scene often leads to enhanced memory for the emotional item and impaired associative memory for background details. Meanwhile, both top–down goal relevance and bottom–up perceptual features played important roles in memory binding. We conducted two experiments and aimed to further examine the effects of goal relevance and perceptual features on emotional items and associative memory. By manipulating goal relevance (asking participants to categorize only each item image as living or non-living or to categorize each whole composite picture consisted of item image and background scene as natural scene or manufactured scene) and perceptual features (controlling visual contrast and visual familiarity) in two experiments, we found that both high goal relevance and salient perceptual features (high salience of items vs. high familiarity of items) could promote emotional item memory, but they had different effects on associative memory for emotional items and neutral backgrounds. Specifically, high goal relevance and high perceptual-salience of items could jointly impair the associative memory for emotional items and neutral backgrounds, while the effect of item familiarity on associative memory for emotional items would be modulated by goal relevance. High familiarity of items could increase associative memory for negative items and neutral backgrounds only in the low goal relevance condition. These findings suggest the effect of emotion on associative memory is not only related to attentional capture elicited by emotion, but also can be affected by goal relevance and perceptual features of stimulus. PMID:28790943

The Effects of Goal Relevance and Perceptual Features on Emotional Items and Associative Memory.

PubMed

Mao, Wei B; An, Shu; Yang, Xiao F

2017-01-01

Showing an emotional item in a neutral background scene often leads to enhanced memory for the emotional item and impaired associative memory for background details. Meanwhile, both top-down goal relevance and bottom-up perceptual features played important roles in memory binding. We conducted two experiments and aimed to further examine the effects of goal relevance and perceptual features on emotional items and associative memory. By manipulating goal relevance (asking participants to categorize only each item image as living or non-living or to categorize each whole composite picture consisted of item image and background scene as natural scene or manufactured scene) and perceptual features (controlling visual contrast and visual familiarity) in two experiments, we found that both high goal relevance and salient perceptual features (high salience of items vs. high familiarity of items) could promote emotional item memory, but they had different effects on associative memory for emotional items and neutral backgrounds. Specifically, high goal relevance and high perceptual-salience of items could jointly impair the associative memory for emotional items and neutral backgrounds, while the effect of item familiarity on associative memory for emotional items would be modulated by goal relevance. High familiarity of items could increase associative memory for negative items and neutral backgrounds only in the low goal relevance condition. These findings suggest the effect of emotion on associative memory is not only related to attentional capture elicited by emotion, but also can be affected by goal relevance and perceptual features of stimulus.

Nicholas Metropolis Award for Outstanding Doctoral Thesis Work in Computational Physics Talk: Equation of State of the Dilute Fermi Gases

NASA Astrophysics Data System (ADS)

Chang, Soon Yong

2008-04-01

In the recent years, dilute Fermi gases have played the center stage role in the many-body physics. The gas of neutral alkali atoms such as Lithium-6 and Potassium-40 can be trapped at temperatures below the Fermi degeneracy. The most relevant feature of these gases is that the interaction is tunable and strongly interacting superfluid can be artificially created. I will discuss the recent progress in understanding the ground state properties of the dilute Fermi gases at different interaction regimes. First, I will present the case of the spin symmetric systems where the Fermi gas can smoothly crossover from the BCS regime to the BEC regime. Then, I will discuss the case of the spin polarized systems, where different quantum phases can occur as a function of the polarization. In the laboratory, the trapped Fermi gas shows spatial dependence of the different quantum phases. This can be understood in the context of the local variation of the chemical potential. I will present the most accurate quantum ab initio results and the relevant experiments.

Intentional attention switching in dichotic listening: exploring the efficiency of nonspatial and spatial selection.

PubMed

Lawo, Vera; Fels, Janina; Oberem, Josefa; Koch, Iring

2014-10-01

Using an auditory variant of task switching, we examined the ability to intentionally switch attention in a dichotic-listening task. In our study, participants responded selectively to one of two simultaneously presented auditory number words (spoken by a female and a male, one for each ear) by categorizing its numerical magnitude. The mapping of gender (female vs. male) and ear (left vs. right) was unpredictable. The to-be-attended feature for gender or ear, respectively, was indicated by a visual selection cue prior to auditory stimulus onset. In Experiment 1, explicitly cued switches of the relevant feature dimension (e.g., from gender to ear) and switches of the relevant feature within a dimension (e.g., from male to female) occurred in an unpredictable manner. We found large performance costs when the relevant feature switched, but switches of the relevant feature dimension incurred only small additional costs. The feature-switch costs were larger in ear-relevant than in gender-relevant trials. In Experiment 2, we replicated these findings using a simplified design (i.e., only within-dimension switches with blocked dimensions). In Experiment 3, we examined preparation effects by manipulating the cueing interval and found a preparation benefit only when ear was cued. Together, our data suggest that the large part of attentional switch costs arises from reconfiguration at the level of relevant auditory features (e.g., left vs. right) rather than feature dimensions (ear vs. gender). Additionally, our findings suggest that ear-based target selection benefits more from preparation time (i.e., time to direct attention to one ear) than gender-based target selection.

Initial development of a computer-aided diagnosis tool for solitary pulmonary nodules

NASA Astrophysics Data System (ADS)

Catarious, David M., Jr.; Baydush, Alan H.; Floyd, Carey E., Jr.

2001-07-01

This paper describes the development of a computer-aided diagnosis (CAD) tool for solitary pulmonary nodules. This CAD tool is built upon physically meaningful features that were selected because of their relevance to shape and texture. These features included a modified version of the Hotelling statistic (HS), a channelized HS, three measures of fractal properties, two measures of spicularity, and three manually measured shape features. These features were measured from a difficult database consisting of 237 regions of interest (ROIs) extracted from digitized chest radiographs. The center of each 256x256 pixel ROI contained a suspicious lesion which was sent to follow-up by a radiologist and whose nature was later clinically determined. Linear discriminant analysis (LDA) was used to search the feature space via sequential forward search using percentage correct as the performance metric. An optimized feature subset, selected for the highest accuracy, was then fed into a three layer artificial neural network (ANN). The ANN's performance was assessed by receiver operating characteristic (ROC) analysis. A leave-one-out testing/training methodology was employed for the ROC analysis. The performance of this system is competitive with that of three radiologists on the same database.

Quantum and Multidimensional Explanations in a Neurobiological Context of Mind.

PubMed

Korf, Jakob

2015-08-01

This article examines the possible relevance of physical-mathematical multidimensional or quantum concepts aiming at understanding the (human) mind in a neurobiological context. Some typical features of the quantum and multidimensional concepts are briefly introduced, including entanglement, superposition, holonomic, and quantum field theories. Next, we consider neurobiological principles, such as the brain and its emerging (physical) mind, evolutionary and ontological origins, entropy, syntropy/neg-entropy, causation, and brain energy metabolism. In many biological processes, including biochemical conversions, protein folding, and sensory perception, the ubiquitous involvement of quantum mechanisms is well recognized. Quantum and multidimensional approaches might be expected to help describe and model both brain and mental processes, but an understanding of their direct involvement in mental activity, that is, without mediation by molecular processes, remains elusive. More work has to be done to bridge the gap between current neurobiological and physical-mathematical concepts with their associated quantum-mind theories. © The Author(s) 2014.

Magnetic Braking: A Video Analysis

NASA Astrophysics Data System (ADS)

Molina-Bolívar, J. A.; Abella-Palacios, A. J.

2012-10-01

This paper presents a laboratory exercise that introduces students to the use of video analysis software and the Lenz's law demonstration. Digital techniques have proved to be very useful for the understanding of physical concepts. In particular, the availability of affordable digital video offers students the opportunity to actively engage in kinematics in introductory-level physics.1,2 By using digital videos frame advance features and "marking" the position of a moving object in each frame, students are able to more precisely determine the position of an object at much smaller time increments than would be possible with common time devices. Once the student collects data consisting of positions and times, these values may be manipulated to determine velocity and acceleration. There are a variety of commercial and free applications that can be used for video analysis. Because the relevant technology has become inexpensive, video analysis has become a prevalent tool in introductory physics courses.

Culturally adapting a physical activity intervention for Somali women: the need for theory and innovation to promote equity.

PubMed

Murray, Kate E; Ermias, Azieb; Lung, Amber; Mohamed, Amina Sheik; Ellis, B Heidi; Linke, Sarah; Kerr, Jacqueline; Bowen, Deborah J; Marcus, Bess H

2017-03-01

There is pressing need for innovation in clinical research to more effectively recruit, engage, retain, and promote health among diverse populations overburdened by health disparities. The purpose of this study is to provide a detailed illustration of the cultural adaptation of an evidence-based intervention to bolster translational research with currently underserved communities. The cultural adaptation heuristic framework described by Barrera and colleagues is applied to the adaptation of a physical activity evidence-based intervention with adult Somali women. Widespread changes were required to ensure program feasibility and acceptability, including the reduction of assessment protocols and changes discordant with current trends in physical activity research. The cultural adaptation of evidence-based interventions offers an important mechanism for reducing health disparities. Improved reporting standards, assessment of features relevant to underserved communities, and greater funding requirements to ensure better representation are needed to promote more widespread access for all people.

Role of theory in space science

NASA Technical Reports Server (NTRS)

1983-01-01

The goal of theory is to understand how the fundamental laws of physics laws of physics and chemistry give rise to the features of the universe. It is recommended that NASA establish independent theoretical research programs in planetary sciences and in astrophysics similar to the solar-system plasma-physics theory program, which is characterized by stable, long-term support for theorists in university departments, NASA centers, and other organizations engaged in research in topics relevant to present and future space-derived data. It is recommended that NASA keep these programs under review to full benefit from the resulting research and to assure opportunities for inflow of new ideas and investigators. Also, provisions should be made by NASA for the computing needs of the theorists in the programs. Finally, it is recommended that NASA involve knowledgeable theorists in mission planning activities at all levels, from the formulation of long-term scientific strategies through the planning and operation of specific missions.

From a Vital Sign to Vitality: Selling Exercise So Patients Want to Buy It.

PubMed

Segar, Michelle L; Guérin, Eva; Phillips, Edward; Fortier, Michelle

2016-01-01

Exercise is Medicine (EIM) and physical activity as a vital sign are based on health-focused research and reflect ideal frames and messages for clinicians. However, they are nonoptimal for patients because they do not address what drives patients' decision-making and motivation. With the growing national emphasis on patient-centered and value-based care, it is the perfect time for EIM to evolve and advance a second-level consumer-oriented exercise prescription and communication strategy. Through research on decision-making, motivation, consumer behavior, and meaningful goal pursuit, this article features six evidence-based issues to help clinicians make physical activity more relevant and compelling for patients to sustain in ways that concurrently support patient-centered care. Physical activity prescriptions and counseling can evolve to reflect affective and behavioral science and sell exercise so patients want to buy it.

Life is physics and chemistry and communication.

PubMed

Witzany, Guenther

2015-04-01

Manfred Eigen extended Erwin Schroedinger's concept of "life is physics and chemistry" through the introduction of information theory and cybernetic systems theory into "life is physics and chemistry and information." Based on this assumption, Eigen developed the concepts of quasispecies and hypercycles, which have been dominant in molecular biology and virology ever since. He insisted that the genetic code is not just used metaphorically: it represents a real natural language. However, the basics of scientific knowledge changed dramatically within the second half of the 20th century. Unfortunately, Eigen ignored the results of the philosophy of science discourse on essential features of natural languages and codes: a natural language or code emerges from populations of living agents that communicate. This contribution will look at some of the highlights of this historical development and the results relevant for biological theories about life. © 2014 New York Academy of Sciences.

Natural tuning: towards a proof of concept

NASA Astrophysics Data System (ADS)

Dubovsky, Sergei; Gorbenko, Victor; Mirbabayi, Mehrdad

2013-09-01

The cosmological constant problem and the absence of new natural physics at the electroweak scale, if confirmed by the LHC, may either indicate that the nature is fine-tuned or that a refined notion of naturalness is required. We construct a family of toy UV complete quantum theories providing a proof of concept for the second possibility. Low energy physics is described by a tuned effective field theory, which exhibits relevant interactions not protected by any symmetries and separated by an arbitrary large mass gap from the new "gravitational" physics, represented by a set of irrelevant operators. Nevertheless, the only available language to describe dynamics at all energy scales does not require any fine-tuning. The interesting novel feature of this construction is that UV physics is not described by a fixed point, but rather exhibits asymptotic fragility. Observation of additional unprotected scalars at the LHC would be a smoking gun for this scenario. Natural tuning also favors TeV scale unification.

Evaluation of food-relevant chemicals in the ToxCast high ...

EPA Pesticide Factsheets

There are thousands of chemicals that are directly added to or come in contact with food, many of which have undergone little to no toxicological evaluation. The ToxCast high-throughput screening (HTS) program has evaluated over 1,800 chemicals in concentration-response across ~820 assay endpoints and continues to grow; with all data completely available to the public, this resource serves as a unique opportunity to evaluate the bioactivity of chemicals in vitro. This study investigated the chemical landscape of the food-relevant chemical universe using cheminformatics analyses, and subsequently evaluated the bioactivity of food-relevant chemicals included in the ToxCast HTS program. Initially, a list of 9,437 food-relevant chemicals was compiled by comprehensively mining publicly available sources for direct food additives, food contact substances, indirect food additives, and pesticides. Of these food-relevant chemicals, 4,638 were associated with curated structure definition files amenable to defining physical/chemical features used to generate chemical fingerprints. Clustering was conducted based on the chemical fingerprints using a self-organizing map approach. This revealed that pesticides, food contact substances, and direct food additives generally clustered apart from one another, supporting that these categories reflect not only different uses but also distinct chemistries. Subsequently, 967 of the 9,437 food-relevant chemicals were identified in the T

Application of all-relevant feature selection for the failure analysis of parameter-induced simulation crashes in climate models

NASA Astrophysics Data System (ADS)

Paja, Wiesław; Wrzesien, Mariusz; Niemiec, Rafał; Rudnicki, Witold R.

2016-03-01

Climate models are extremely complex pieces of software. They reflect the best knowledge on the physical components of the climate; nevertheless, they contain several parameters, which are too weakly constrained by observations, and can potentially lead to a simulation crashing. Recently a study by Lucas et al. (2013) has shown that machine learning methods can be used for predicting which combinations of parameters can lead to the simulation crashing and hence which processes described by these parameters need refined analyses. In the current study we reanalyse the data set used in this research using different methodology. We confirm the main conclusion of the original study concerning the suitability of machine learning for the prediction of crashes. We show that only three of the eight parameters indicated in the original study as relevant for prediction of the crash are indeed strongly relevant, three others are relevant but redundant and two are not relevant at all. We also show that the variance due to the split of data between training and validation sets has a large influence both on the accuracy of predictions and on the relative importance of variables; hence only a cross-validated approach can deliver a robust prediction of performance and relevance of variables.

Keyword extraction by nonextensivity measure.

PubMed

Mehri, Ali; Darooneh, Amir H

2011-05-01

The presence of a long-range correlation in the spatial distribution of a relevant word type, in spite of random occurrences of an irrelevant word type, is an important feature of human-written texts. We classify the correlation between the occurrences of words by nonextensive statistical mechanics for the word-ranking process. In particular, we look at the nonextensivity parameter as an alternative metric to measure the spatial correlation in the text, from which the words may be ranked in terms of this measure. Finally, we compare different methods for keyword extraction. © 2011 American Physical Society

Nanopatterned polymer brushes: conformation, fabrication and applications.

PubMed

Yu, Qian; Ista, Linnea K; Gu, Renpeng; Zauscher, Stefan; López, Gabriel P

2016-01-14

Surfaces with end-grafted, nanopatterned polymer brushes that exhibit well-defined feature dimensions and controlled chemical and physical properties provide versatile platforms not only for investigation of nanoscale phenomena at biointerfaces, but also for the development of advanced devices relevant to biotechnology and electronics applications. In this review, we first give a brief introduction of scaling behavior of nanopatterned polymer brushes and then summarize recent progress in fabrication and application of nanopatterned polymer brushes. Specifically, we highlight applications of nanopatterned stimuli-responsive polymer brushes in the areas of biomedicine and biotechnology.

Nanopatterned polymer brushes: conformation, fabrication and applications

NASA Astrophysics Data System (ADS)

Yu, Qian; Ista, Linnea K.; Gu, Renpeng; Zauscher, Stefan; López, Gabriel P.

2015-12-01

Surfaces with end-grafted, nanopatterned polymer brushes that exhibit well-defined feature dimensions and controlled chemical and physical properties provide versatile platforms not only for investigation of nanoscale phenomena at biointerfaces, but also for the development of advanced devices relevant to biotechnology and electronics applications. In this review, we first give a brief introduction of scaling behavior of nanopatterned polymer brushes and then summarize recent progress in fabrication and application of nanopatterned polymer brushes. Specifically, we highlight applications of nanopatterned stimuli-responsive polymer brushes in the areas of biomedicine and biotechnology.

Kernel-Based Relevance Analysis with Enhanced Interpretability for Detection of Brain Activity Patterns

PubMed Central

Alvarez-Meza, Andres M.; Orozco-Gutierrez, Alvaro; Castellanos-Dominguez, German

2017-01-01

We introduce Enhanced Kernel-based Relevance Analysis (EKRA) that aims to support the automatic identification of brain activity patterns using electroencephalographic recordings. EKRA is a data-driven strategy that incorporates two kernel functions to take advantage of the available joint information, associating neural responses to a given stimulus condition. Regarding this, a Centered Kernel Alignment functional is adjusted to learning the linear projection that best discriminates the input feature set, optimizing the required free parameters automatically. Our approach is carried out in two scenarios: (i) feature selection by computing a relevance vector from extracted neural features to facilitating the physiological interpretation of a given brain activity task, and (ii) enhanced feature selection to perform an additional transformation of relevant features aiming to improve the overall identification accuracy. Accordingly, we provide an alternative feature relevance analysis strategy that allows improving the system performance while favoring the data interpretability. For the validation purpose, EKRA is tested in two well-known tasks of brain activity: motor imagery discrimination and epileptic seizure detection. The obtained results show that the EKRA approach estimates a relevant representation space extracted from the provided supervised information, emphasizing the salient input features. As a result, our proposal outperforms the state-of-the-art methods regarding brain activity discrimination accuracy with the benefit of enhanced physiological interpretation about the task at hand. PMID:29056897

Is social engagement linked to body image and depression among aging women?

PubMed

Sabik, Natalie J

2017-01-01

Maintaining an active and engaged social life is a critical component of aging well, and women are generally more socially active than men. However, as women age their self-perceptions of their bodies may reduce social behaviors and consequently, increase depressive symptoms. Because little is known about how body image is associated with social engagement and depressive symptoms among aging women, four aspects of body image: satisfaction with cosmetic features, body function, physical appearance, and weight were assessed among women aged 65 and older (n = 123). Regression analyses indicated that cosmetic appearance, body function, and physical appearance were associated with depressive symptoms, whereas satisfaction with weight was unrelated. Further, both greater satisfaction with cosmetic features and body function were associated with higher levels of social engagement, and social engagement mediated the association between these aspects of body satisfaction and depressive symptoms. The findings indicate that specific age-relevant aspects of body satisfaction are linked to social behavior and depression among aging women, and reduced body satisfaction may lead to lower social engagement, and consequently aging women's health and well-being may be diminished.

Tunnelling in asymmetric double-well potentials: varying initial states

NASA Astrophysics Data System (ADS)

Cordes, J. G.; Das, A. K.

2001-02-01

Tunnelling in a double-well potential has features which are not derivable through a mere extension of the concepts used in the context of a single potential barrier with no confining walls on either side. Furthermore, an asymmetric double-well potential, relevant in many contemporary areas of physics and chemistry, possesses certain distinctive aspects in contrast to the relatively simple case of a symmetric double-well potential. In this paper a self-contained numerical and analytical study of these features is reported, and a theoretical model is presented with special attention being given to a unified treatment of both the symmetric and asymmetric cases. The popularly used pair-state model is critically examined, and the important role of the initial state (which is rarely discussed in the literature) is highlighted with specific examples.

Irrelevant Features of a Stimulus Can Either Facilitate or Disrupt Performance in a Working Memory Task: The Role of Fluid Intelligence

PubMed Central

Perfetti, Bernardo; Tesse, Marcello; Varanese, Sara; Saggino, Aristide; Onofrj, Marco

2011-01-01

It has been shown that fluid intelligence (gf) is fundamental to overcome interference due to information of a previously encoded item along a task-relevant domain. However, the biasing effect of task-irrelevant dimensions is still unclear as well as its relation with gf. The present study aimed at clarifying these issues. Gf was assessed in 60 healthy subjects. In a different session, the same subjects performed two versions (letter-detection and spatial) of a three-back working memory task with a set of physically identical stimuli (letters) presented at different locations on the screen. In the letter-detection task, volunteers were asked to match stimuli on the basis of their identity whereas, in the spatial task, they were required to match items on their locations. Cross-domain bias was manipulated by pseudorandomly inserting a match between the current and the three back items on the irrelevant domain. Our findings showed that a task-irrelevant feature of a salient stimulus can actually bias the ongoing performance. We revealed that, at trials in which the current and the three-back items matched on the irrelevant domain, group accuracy was lower (interference). On the other hand, at trials in which the two items matched on both the relevant and irrelevant domains, the group showed an enhancement of the performance (facilitation). Furthermore, we demonstrated that individual differences in fluid intelligence covaries with the ability to override cross-domain interference in that higher gf subjects showed better performance at interference trials than low gf subjects. Altogether, our findings suggest that stimulus features irrelevant to the task can affect cognitive performance along the relevant domain and that gf plays an important role in protecting relevant memory contents from the hampering effect of such a bias. PMID:22022580

Simulating Extraterrestrial Ices in the Laboratory

NASA Astrophysics Data System (ADS)

Berisford, D. F.; Carey, E. M.; Hand, K. P.; Choukroun, M.

2017-12-01

Several ongoing experiments at JPL attempt to simulate the ice environment for various regimes associated with icy moons. The Europa Penitent Ice Experiment (EPIX) simulates the surface environment of an icy moon, to investigate the physics of ice surface morphology growth. This experiment features half-meter-scale cryogenic ice samples, cryogenic radiative sink environment, vacuum conditions, and diurnal cycling solar simulation. The experiment also includes several smaller fixed-geometry vacuum chambers for ice simulation at Earth-like and intermediate temperature and vacuum conditions for development of surface morphology growth scaling relations. Additionally, an ice cutting facility built on a similar platform provides qualitative data on the mechanical behavior of cryogenic ice with impurities under vacuum, and allows testing of ice cutting/sampling tools relevant for landing spacecraft. A larger cutting facility is under construction at JPL, which will provide more quantitative data and allow full-scale sampling tool tests. Another facility, the JPL Ice Physics Laboratory, features icy analog simulant preparation abilities that range icy solar system objects such as Mars, Ceres and the icy satellites of Saturn and Jupiter. In addition, the Ice Physics Lab has unique facilities for Icy Analog Tidal Simulation and Rheological Studies of Cryogenic Icy Slurries, as well as equipment to perform thermal and mechanical properties testing on icy analog materials and their response to sinusoidal tidal stresses.

Reconstructing the spectrotemporal modulations of real-life sounds from fMRI response patterns

PubMed Central

Santoro, Roberta; Moerel, Michelle; De Martino, Federico; Valente, Giancarlo; Ugurbil, Kamil; Yacoub, Essa; Formisano, Elia

2017-01-01

Ethological views of brain functioning suggest that sound representations and computations in the auditory neural system are optimized finely to process and discriminate behaviorally relevant acoustic features and sounds (e.g., spectrotemporal modulations in the songs of zebra finches). Here, we show that modeling of neural sound representations in terms of frequency-specific spectrotemporal modulations enables accurate and specific reconstruction of real-life sounds from high-resolution functional magnetic resonance imaging (fMRI) response patterns in the human auditory cortex. Region-based analyses indicated that response patterns in separate portions of the auditory cortex are informative of distinctive sets of spectrotemporal modulations. Most relevantly, results revealed that in early auditory regions, and progressively more in surrounding regions, temporal modulations in a range relevant for speech analysis (∼2–4 Hz) were reconstructed more faithfully than other temporal modulations. In early auditory regions, this effect was frequency-dependent and only present for lower frequencies (<∼2 kHz), whereas for higher frequencies, reconstruction accuracy was higher for faster temporal modulations. Further analyses suggested that auditory cortical processing optimized for the fine-grained discrimination of speech and vocal sounds underlies this enhanced reconstruction accuracy. In sum, the present study introduces an approach to embed models of neural sound representations in the analysis of fMRI response patterns. Furthermore, it reveals that, in the human brain, even general purpose and fundamental neural processing mechanisms are shaped by the physical features of real-world stimuli that are most relevant for behavior (i.e., speech, voice). PMID:28420788

Making data matter: Voxel printing for the digital fabrication of data across scales and domains.

PubMed

Bader, Christoph; Kolb, Dominik; Weaver, James C; Sharma, Sunanda; Hosny, Ahmed; Costa, João; Oxman, Neri

2018-05-01

We present a multimaterial voxel-printing method that enables the physical visualization of data sets commonly associated with scientific imaging. Leveraging voxel-based control of multimaterial three-dimensional (3D) printing, our method enables additive manufacturing of discontinuous data types such as point cloud data, curve and graph data, image-based data, and volumetric data. By converting data sets into dithered material deposition descriptions, through modifications to rasterization processes, we demonstrate that data sets frequently visualized on screen can be converted into physical, materially heterogeneous objects. Our approach alleviates the need to postprocess data sets to boundary representations, preventing alteration of data and loss of information in the produced physicalizations. Therefore, it bridges the gap between digital information representation and physical material composition. We evaluate the visual characteristics and features of our method, assess its relevance and applicability in the production of physical visualizations, and detail the conversion of data sets for multimaterial 3D printing. We conclude with exemplary 3D-printed data sets produced by our method pointing toward potential applications across scales, disciplines, and problem domains.

The LAILAPS search engine: a feature model for relevance ranking in life science databases.

PubMed

Lange, Matthias; Spies, Karl; Colmsee, Christian; Flemming, Steffen; Klapperstück, Matthias; Scholz, Uwe

2010-03-25

Efficient and effective information retrieval in life sciences is one of the most pressing challenge in bioinformatics. The incredible growth of life science databases to a vast network of interconnected information systems is to the same extent a big challenge and a great chance for life science research. The knowledge found in the Web, in particular in life-science databases, are a valuable major resource. In order to bring it to the scientist desktop, it is essential to have well performing search engines. Thereby, not the response time nor the number of results is important. The most crucial factor for millions of query results is the relevance ranking. In this paper, we present a feature model for relevance ranking in life science databases and its implementation in the LAILAPS search engine. Motivated by the observation of user behavior during their inspection of search engine result, we condensed a set of 9 relevance discriminating features. These features are intuitively used by scientists, who briefly screen database entries for potential relevance. The features are both sufficient to estimate the potential relevance, and efficiently quantifiable. The derivation of a relevance prediction function that computes the relevance from this features constitutes a regression problem. To solve this problem, we used artificial neural networks that have been trained with a reference set of relevant database entries for 19 protein queries. Supporting a flexible text index and a simple data import format, this concepts are implemented in the LAILAPS search engine. It can easily be used both as search engine for comprehensive integrated life science databases and for small in-house project databases. LAILAPS is publicly available for SWISSPROT data at http://lailaps.ipk-gatersleben.de.

Demands on attention and the role of response priming in visual discrimination of feature conjunctions.

PubMed

Fournier, Lisa R; Herbert, Rhonda J; Farris, Carrie

2004-10-01

This study examined how response mapping of features within single- and multiple-feature targets affects decision-based processing and attentional capacity demands. Observers judged the presence or absence of 1 or 2 target features within an object either presented alone or with distractors. Judging the presence of 2 features relative to the less discriminable of these features alone was faster (conjunction benefits) when the task-relevant features differed in discriminability and were consistently mapped to responses. Conjunction benefits were attributed to asynchronous decision priming across attended, task-relevant dimensions. A failure to find conjunction benefits for disjunctive conjunctions was attributed to increased memory demands and variable feature-response mapping for 2- versus single-feature targets. Further, attentional demands were similar between single- and 2-feature targets when response mapping, memory demands, and discriminability of the task-relevant features were equated between targets. Implications of the findings for recent attention models are discussed. (c) 2004 APA, all rights reserved

Which Features Make Illustrations in Multimedia Learning Interesting?

ERIC Educational Resources Information Center

Magner, Ulrike Irmgard Elisabeth; Glogger, Inga; Renkl, Alexander

2016-01-01

How can illustrations motivate learners in multimedia learning? Which features make illustrations interesting? Beside the theoretical relevance of addressing these questions, these issues are practically relevant when instructional designers are to decide which features of illustrations can trigger situational interest irrespective of individual…

MODELING GALACTIC EXTINCTION WITH DUST AND 'REAL' POLYCYCLIC AROMATIC HYDROCARBONS

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

Mulas, Giacomo; Casu, Silvia; Cecchi-Pestellini, Cesare

We investigate the remarkable apparent variety of galactic extinction curves by modeling extinction profiles with core-mantle grains and a collection of single polycyclic aromatic hydrocarbons. Our aim is to translate a synthetic description of dust into physically well-grounded building blocks through the analysis of a statistically relevant sample of different extinction curves. All different flavors of observed extinction curves, ranging from the average galactic extinction curve to virtually 'bumpless' profiles, can be described by the present model. We prove that a mixture of a relatively small number (54 species in 4 charge states each) of polycyclic aromatic hydrocarbons can reproducemore » the features of the extinction curve in the ultraviolet, dismissing an old objection to the contribution of polycyclic aromatic hydrocarbons to the interstellar extinction curve. Despite the large number of free parameters (at most the 54 Multiplication-Sign 4 column densities of each species in each ionization state included in the molecular ensemble plus the 9 parameters defining the physical properties of classical particles), we can strongly constrain some physically relevant properties such as the total number of C atoms in all species and the mean charge of the mixture. Such properties are found to be largely independent of the adopted dust model whose variation provides effects that are orthogonal to those brought about by the molecular component. Finally, the fitting procedure, together with some physical sense, suggests (but does not require) the presence of an additional component of chemically different very small carbonaceous grains.« less

Cell-like features imprinted in the physical nano- and micro-topography of the environment modify the responses to anti-cancer drugs of endometrial cancer cells.

PubMed

Tan, Li Hui; Sykes, Peter H; Alkaisi, Maan M; Evans, John J

2017-02-14

Topographical features of cells at nanometre resolution were fabricated in polystyrene. The study investigated the effect of physical topography on the response of cancer cells to the common anticancer drugs, paclitaxel and doxorubicin. Human endometrial cancer cells (Ishikawa) were incubated on substrates containing cell-like features that had been fabricated using our bioimprint methodology to create moulds of cells with positive (convex) and negative (concave) topography. Control cultures were performed on flat substrates. Effects of the drugs on caspase-3 expression, proliferating nuclear antigen (PCNA) expression, cell number and vascular endothelial growth factor (VEGF) secretion were determined. Results revealed that the topography influenced the cell responses in a drug-dependent manner i.e. paclitaxel effects were sensitive to topography differently to those of doxorubicin. In addition, function signalling pathways were sensitive to the detailed topography i.e. positive imprint and negative imprint induced distinct response patterns. The results in this study show for the first time that a culture surface with cell-like topography, that has both nano- and micro-resolution, influences endometrial cancer cell responses to chemotherapy drugs. The effects are dependent on the topography and also on the chemotherapy drug. In particular, the platforms described have potential to provide substrates with high physical relevancy on which to undertake preclinical testing of new drugs. The method also allows for use of different cell types to provide cell-specific topography. The results imply that physical architecture of the cancer cell environment may be a suitable prospective target to enhance clinical activity of traditional drugs. Additionally or alternatively we provide compelling support for the notion that understanding the physical component of the nano- and micro-environment may encourage a redirection of drug development. Further, our observation that the cells distinguish between the different cell-like topographies (positive and negative bioimprints) indicates that a realistic topography is advantageous as growth platforms in experiment design.

Hyperspectral Image Enhancement and Mixture Deep-Learning Classification of Corneal Epithelium Injuries.

PubMed

Noor, Siti Salwa Md; Michael, Kaleena; Marshall, Stephen; Ren, Jinchang

2017-11-16

In our preliminary study, the reflectance signatures obtained from hyperspectral imaging (HSI) of normal and abnormal corneal epithelium tissues of porcine show similar morphology with subtle differences. Here we present image enhancement algorithms that can be used to improve the interpretability of data into clinically relevant information to facilitate diagnostics. A total of 25 corneal epithelium images without the application of eye staining were used. Three image feature extraction approaches were applied for image classification: (i) image feature classification from histogram using a support vector machine with a Gaussian radial basis function (SVM-GRBF); (ii) physical image feature classification using deep-learning Convolutional Neural Networks (CNNs) only; and (iii) the combined classification of CNNs and SVM-Linear. The performance results indicate that our chosen image features from the histogram and length-scale parameter were able to classify with up to 100% accuracy; particularly, at CNNs and CNNs-SVM, by employing 80% of the data sample for training and 20% for testing. Thus, in the assessment of corneal epithelium injuries, HSI has high potential as a method that could surpass current technologies regarding speed, objectivity, and reliability.

Transition probabilities for non self-adjoint Hamiltonians in infinite dimensional Hilbert spaces

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

Bagarello, F., E-mail: fabio.bagarello@unipa.it

In a recent paper we have introduced several possible inequivalent descriptions of the dynamics and of the transition probabilities of a quantum system when its Hamiltonian is not self-adjoint. Our analysis was carried out in finite dimensional Hilbert spaces. This is useful, but quite restrictive since many physically relevant quantum systems live in infinite dimensional Hilbert spaces. In this paper we consider this situation, and we discuss some applications to well known models, introduced in the literature in recent years: the extended harmonic oscillator, the Swanson model and a generalized version of the Landau levels Hamiltonian. Not surprisingly we willmore » find new interesting features not previously found in finite dimensional Hilbert spaces, useful for a deeper comprehension of this kind of physical systems.« less

Thermalization and prethermalization in isolated quantum systems: a theoretical overview

NASA Astrophysics Data System (ADS)

Mori, Takashi; Ikeda, Tatsuhiko N.; Kaminishi, Eriko; Ueda, Masahito

2018-06-01

The approach to thermal equilibrium, or thermalization, in isolated quantum systems is among the most fundamental problems in statistical physics. Recent theoretical studies have revealed that thermalization in isolated quantum systems has several remarkable features, which emerge from quantum entanglement and are quite distinct from those in classical systems. Experimentally, well isolated and highly controllable ultracold quantum gases offer an ideal testbed to study the nonequilibrium dynamics in isolated quantum systems, promoting intensive recent theoretical endeavors on this fundamental subject. Besides thermalization, many isolated quantum systems show intriguing behavior in relaxation processes, especially prethermalization. Prethermalization occurs when there is a clear separation of relevant time scales and has several different physical origins depending on individual systems. In this review, we overview theoretical approaches to the problems of thermalization and prethermalization.

Contingent attentional capture across multiple feature dimensions in a temporal search task.

PubMed

Ito, Motohiro; Kawahara, Jun I

2016-01-01

The present study examined whether attention can be flexibly controlled to monitor two different feature dimensions (shape and color) in a temporal search task. Specifically, we investigated the occurrence of contingent attentional capture (i.e., interference from task-relevant distractors) and resulting set reconfiguration (i.e., enhancement of single task-relevant set). If observers can restrict searches to a specific value for each relevant feature dimension independently, the capture and reconfiguration effect should only occur when the single relevant distractor in each dimension appears. Participants identified a target letter surrounded by a non-green square or a non-square green frame. The results revealed contingent attentional capture, as target identification accuracy was lower when the distractor contained a target-defining feature than when it contained a nontarget feature. Resulting set reconfiguration was also obtained in that accuracy was superior when the current target's feature (e.g., shape) corresponded to the defining feature of the present distractor (shape) than when the current target's feature did not match the distractor's feature (color). This enhancement was not due to perceptual priming. The present study demonstrated that the principles of contingent attentional capture and resulting set reconfiguration held even when multiple target feature dimensions were monitored. Copyright © 2015 Elsevier B.V. All rights reserved.

Identifying the relevant features of the National Digital Cadastral Database (NDCDB) for spatial analysis by using the Delphi Technique

NASA Astrophysics Data System (ADS)

Halim, N. Z. A.; Sulaiman, S. A.; Talib, K.; Ng, E. G.

2018-02-01

This paper explains the process carried out in identifying the relevant features of the National Digital Cadastral Database (NDCDB) for spatial analysis. The research was initially a part of a larger research exercise to identify the significance of NDCDB from the legal, technical, role and land-based analysis perspectives. The research methodology of applying the Delphi technique is substantially discussed in this paper. A heterogeneous panel of 14 experts was created to determine the importance of NDCDB from the technical relevance standpoint. Three statements describing the relevant features of NDCDB for spatial analysis were established after three rounds of consensus building. It highlighted the NDCDB’s characteristics such as its spatial accuracy, functions, and criteria as a facilitating tool for spatial analysis. By recognising the relevant features of NDCDB for spatial analysis in this study, practical application of NDCDB for various analysis and purpose can be widely implemented.

Effects of chronic mild stress on the development of drug dependence in rats.

PubMed

Papp, Mariusz; Gruca, Piotr; Lason-Tyburkiewicz, Magdalena; Litwa, Ewa; Willner, Paul

2014-09-01

There is high comorbidity between depression and addiction. Features of addiction relevant to depression have been studied extensively, but less is known about features of depression relevant to addiction. Here, we have studied the effects of chronic mild stress (CMS), a valid animal model of depression, on measures of physical and psychological dependence resulting from subchronic treatment of rats with three drugs of abuse that act through disparate neurobiological mechanisms: morphine, nicotine and diazepam. In animals not treated subchronically with drugs of abuse, CMS increased the withdrawal-like effects of the opiate antagonist naloxone, but not those of the nicotinic antagonist mecamylamine or the benzodiazepine antagonist flumazenil. In animals treated subchronically with drugs of abuse, CMS exacerbated, precipitated and conditioned withdrawal effects associated with all three antagonists. CMS also potentiated withdrawal-induced and cue-induced place aversions associated with all three antagonists. All of the effects of CMS were reversed by chronic treatment with the specific serotonin reuptake inhibitor citalopram. These results suggest that treatment of comorbid depression, although not a primary treatment for addiction, may facilitate other treatments for addiction, by decreasing the severity of withdrawal symptoms and the likelihood of relapse.

Features of hypochondriasis and illness worry in the general population in Germany.

PubMed

Martin, Alexandra; Jacobi, Frank

2006-01-01

Although hypochondriasis is considered to be of high relevance in the healthcare sector, its prevalence in the general population has been investigated in few studies. The aims of this study were to estimate prevalence rates of hypochondriasis and of subthreshold conditions and to describe their associated features such as quality of life and healthcare utilization in a representative community sample. Analyses of the present study are based on the German Health Interview and Examination Survey-Mental Health Supplement (N = 4181, representative for the German population from 18-65 years). The assessment included interviews for somatic conditions and mental disorders and self-report ratings on health-related quality of life, healthcare utilization, disability days, and physical activity. Only three cases (0.05%) were identified as meeting full criteria of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) hypochondriasis. The prevalence rate of the less restrictively defined form of hypochondriasis, ("subthreshold hypochondriasis") was 0.58% and an additional 2.12% reported having had illness worries for at least 6 months but did not meet further hypochondriasis criteria. The two subthreshold diagnostic groups provided strong evidence of difference from the nonhypochondriac controls: comorbidity with psychiatric and medical disorders and healthcare utilization were higher, and quality of life was markedly reduced. The results provide additional support to not only consider "full" DSM-IV hypochondriasis, which is a very rare disorder in the general population, but also to include less restrictive hypochondriac conditions--associated with a clinically relevant degree of psychological and physical impairment--into clinical and scientific considerations.

Dynamic Integration of Task-Relevant Visual Features in Posterior Parietal Cortex

PubMed Central

Freedman, David J.

2014-01-01

Summary The primate visual system consists of multiple hierarchically organized cortical areas, each specialized for processing distinct aspects of the visual scene. For example, color and form are encoded in ventral pathway areas such as V4 and inferior temporal cortex, while motion is preferentially processed in dorsal pathway areas such as the middle temporal area. Such representations often need to be integrated perceptually to solve tasks which depend on multiple features. We tested the hypothesis that the lateral intraparietal area (LIP) integrates disparate task-relevant visual features by recording from LIP neurons in monkeys trained to identify target stimuli composed of conjunctions of color and motion features. We show that LIP neurons exhibit integrative representations of both color and motion features when they are task relevant, and task-dependent shifts of both direction and color tuning. This suggests that LIP plays a role in flexibly integrating task-relevant sensory signals. PMID:25199703

Associations of dietary habits, physical activity and cognitive views with gestational diabetes mellitus among Chinese women.

PubMed

Li, Qing; Xiong, Ribo; Wang, Liang; Cui, Junying; Shi, Linna; Liu, Yungang; Luo, Bingde

2014-08-01

To evaluate the relationship between dietary habits, physical activity and cognitive views and the risk of gestational diabetes mellitus (GDM) in Chinese women. A cross-sectional study to explore the potential risk factors of GMD through the International Physical Activity Questionnaire, an FFQ and a self-designed structured questionnaire, respectively. Guangzhou, Guangdong Province, China. Chinese pregnant women (n 571) who underwent a 75-g oral glucose tolerance test at their 24th to 28th gestational week. Thirteen per cent of the investigated women were identified as having GDM, and an increased intake of local featured foods and lower physical activity were observed in the GDM-positive group v. the GDM-negative group. Women who regarded early-pregnancy morning sickness as relevant to fetal abnormalities and those with unlimited dietary intake after the ending of morning sickness both had an increased risk for GDM (P = 0·018 and P = 0·038, respectively). After multiple logistic regression analysis, cognitive views for unlimited food intake subsequent to morning sickness, increased consumption of energy-dense snack foods and high-glycaemic-index fruits were strongly associated with the risk of GDM (OR = 1·911, P = 0·032; OR = 1·050, P = 0·001; and OR = 1·002, P = 0·017, respectively). Local featured foods and incorrect cognitive views on pregnancy-related health were closely related to the risk of GDM in Chinese women. Intensive health education about pregnancy physiology and reasonable dietary and physical exercise behaviours should be strengthened for the control of GDM.

Biomechanical factors and physical examination findings in osteoarthritis of the knee: associations with tissue abnormalities assessed by conventional radiography and high-resolution 3.0 Tesla magnetic resonance imaging.

PubMed

Knoop, Jesper; Dekker, Joost; Klein, Jan-Paul; van der Leeden, Marike; van der Esch, Martin; Reiding, Dick; Voorneman, Ramon E; Gerritsen, Martijn; Roorda, Leo D; Steultjens, Martijn P M; Lems, Willem F

2012-10-05

We aimed to explore the associations between knee osteoarthritis (OA)-related tissue abnormalities assessed by conventional radiography (CR) and by high-resolution 3.0 Tesla magnetic resonance imaging (MRI), as well as biomechanical factors and findings from physical examination in patients with knee OA. This was an explorative cross-sectional study of 105 patients with knee OA. Index knees were imaged using CR and MRI. Multiple features from CR and MRI (cartilage, osteophytes, bone marrow lesions, effusion and synovitis) were related to biomechanical factors (quadriceps and hamstrings muscle strength, proprioceptive accuracy and varus-valgus laxity) and physical examination findings (bony tenderness, crepitus, bony enlargement and palpable warmth), using multivariable regression analyses. Quadriceps weakness was associated with cartilage integrity, effusion, synovitis (all detected by MRI) and CR-detected joint space narrowing. Knee joint laxity was associated with MRI-detected cartilage integrity, CR-detected joint space narrowing and osteophyte formation. Multiple tissue abnormalities including cartilage integrity, osteophytes and effusion, but only those detected by MRI, were found to be associated with physical examination findings such as crepitus. We observed clinically relevant findings, including a significant association between quadriceps weakness and both effusion and synovitis, detected by MRI. Inflammation was detected in over one-third of the participants, emphasizing the inflammatory component of OA and a possible important role for anti-inflammatory therapies in knee OA. In general, OA-related tissue abnormalities of the knee, even those detected by MRI, were found to be discordant with biomechanical and physical examination features.

Identifying Bottom-Up and Top-Down Components of Attentional Weight by Experimental Analysis and Computational Modeling

ERIC Educational Resources Information Center

Nordfang, Maria; Dyrholm, Mads; Bundesen, Claus

2013-01-01

The attentional weight of a visual object depends on the contrast of the features of the object to its local surroundings (feature contrast) and the relevance of the features to one's goals (feature relevance). We investigated the dependency in partial report experiments with briefly presented stimuli but unspeeded responses. The task was to…

Nanoscale Pore Features and Associated Fluid Behavior in Shale

NASA Astrophysics Data System (ADS)

Cole, D. R.; Striolo, A.

2017-12-01

Unconventional hydrocarbons occurring in economic abundance require greater than industry-standard levels of technology or investment to exploit. Geological formations that host unconventional oil and gas are extraordinarily heterogeneous and exhibit a wide range of physical and chemical features that can vary over many orders of magnitude in length scale. The size, distribution and connectivity of these confined geometries, the chemistry of the solid, the chemistry of the fluids and their physical properties collectively dictate how fluids migrate into and through these micro- and nano-environments, wet and ultimately react with the solid surfaces. Our current understanding of the rates and mechanisms of fluid and mass transport and interaction within these multiporosity systems at the molecular scale is far less robust than we would like. This presentation will take a two-fold approach to this topic area. First, a brief overview is provided that highlights the use of advanced electron microscopy and neutrons scattering methods to quantify the nature of the nanopore system that hosts hydrocarbons in representative gas shale formations such as the Utica, Marcellus and Eagle Ford. Second, results will be presented that leverage the application of state-of-the-art experimental, analytical and computational tools to assess key features of the fluid-matrix interaction relevant to shale settings. The multidisciplinary approaches highlighted will include neutron scattering and NMR experiments, thermodynamic measurements and molecular-level simulations to quantitatively assess molecular properties of C-O-H fluids confined to well-characterized porous media, subjected to temperatures and pressures relevant to subsurface energy systems. These studies conducted in concert are beginning to provide a fundamental understanding at the molecular level of how intrinsically different hydrocarbon-bearing fluids behave in confined geometries compared to bulk systems, and shed light on key geochemical processes such as fluid wetting, competitive sorption and the onset of mineral dissolution and precipitation.

High-performance coupled poro-hydro-mechanical models to resolve fluid escape pipes

NASA Astrophysics Data System (ADS)

Räss, Ludovic; Makhnenko, Roman; Podladchikov, Yury

2017-04-01

Field observations and laboratory experiments exhibit inelastic deformation features arising in many coupled settings relevant to geo-applications. These irreversible deformations and their specific patterns suggest a rather ductile or brittle mechanism, such as viscous creep or micro cracks, taking place on both geological (long) and human (short) timescales. In order to understand the underlying mechanisms responsible for these deformation features, there is a current need to accurately resolve the non-linearities inherent to strongly coupled physical processes. Among the large variety of modelling tools and softwares available nowadays in the community, very few are capable to efficiently solve coupled systems with high accuracy in both space and time and run efficiently on modern hardware. Here, we propose a robust framework to solve coupled multi-physics hydro-mechanical processes on very high spatial and temporal resolution in both two and three dimensions. Our software relies on the Finite-Difference Method and a pseudo-transient scheme is used to converge to the implicit solution of the system of poro-visco-elasto-plastic equations at each physical time step. The rheology including viscosity estimates for major reservoir rock types is inferred from novel lab experiments and confirms the ease of flow of sedimentary rocks. Our results propose a physical mechanism responsible for the generation of high permeability pathways in fluid saturated porous media and predict their propagation in rates observable on operational timescales. Finally, our software scales linearly on more than 5000 GPUs.

Feature-selective Attention in Frontoparietal Cortex: Multivoxel Codes Adjust to Prioritize Task-relevant Information.

PubMed

Jackson, Jade; Rich, Anina N; Williams, Mark A; Woolgar, Alexandra

2017-02-01

Human cognition is characterized by astounding flexibility, enabling us to select appropriate information according to the objectives of our current task. A circuit of frontal and parietal brain regions, often referred to as the frontoparietal attention network or multiple-demand (MD) regions, are believed to play a fundamental role in this flexibility. There is evidence that these regions dynamically adjust their responses to selectively process information that is currently relevant for behavior, as proposed by the "adaptive coding hypothesis" [Duncan, J. An adaptive coding model of neural function in prefrontal cortex. Nature Reviews Neuroscience, 2, 820-829, 2001]. Could this provide a neural mechanism for feature-selective attention, the process by which we preferentially process one feature of a stimulus over another? We used multivariate pattern analysis of fMRI data during a perceptually challenging categorization task to investigate whether the representation of visual object features in the MD regions flexibly adjusts according to task relevance. Participants were trained to categorize visually similar novel objects along two orthogonal stimulus dimensions (length/orientation) and performed short alternating blocks in which only one of these dimensions was relevant. We found that multivoxel patterns of activation in the MD regions encoded the task-relevant distinctions more strongly than the task-irrelevant distinctions: The MD regions discriminated between stimuli of different lengths when length was relevant and between the same objects according to orientation when orientation was relevant. The data suggest a flexible neural system that adjusts its representation of visual objects to preferentially encode stimulus features that are currently relevant for behavior, providing a neural mechanism for feature-selective attention.

Temporal self-regulation theory: a neurobiologically informed model for physical activity behavior

PubMed Central

Hall, Peter A.; Fong, Geoffrey T.

2015-01-01

Dominant explanatory models for physical activity behavior are limited by the exclusion of several important components, including temporal dynamics, ecological forces, and neurobiological factors. The latter may be a critical omission, given the relevance of several aspects of cognitive function for the self-regulatory processes that are likely required for consistent implementation of physical activity behavior in everyday life. This narrative review introduces temporal self-regulation theory (TST; Hall and Fong, 2007, 2013) as a new explanatory model for physical activity behavior. Important features of the model include consideration of the default status of the physical activity behavior, as well as the disproportionate influence of temporally proximal behavioral contingencies. Most importantly, the TST model proposes positive feedback loops linking executive function (EF) and the performance of physical activity behavior. Specifically, those with relatively stronger executive control (and optimized brain structures supporting it, such as the dorsolateral prefrontal cortex (PFC)) are able to implement physical activity with more consistency than others, which in turn serves to strengthen the executive control network itself. The TST model has the potential to explain everyday variants of incidental physical activity, sport-related excellence via capacity for deliberate practice, and variability in the propensity to schedule and implement exercise routines. PMID:25859196

Neutron cross section measurements at n-TOF for ADS related studies

NASA Astrophysics Data System (ADS)

Mastinu, P. F.; Abbondanno, U.; Aerts, G.; Álvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Bustreo, N.; aumann, P.; vá, F. Be; Berthoumieux, E.; Calviño, F.; Cano-Ott, D.; Capote, R.; Carrillo de Albornoz, A.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillmann, I.; Dolfini, R.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; itzpatrick, L.; Frais-Kölbl, H.; Fujii, K.; Furman, W.; Guerrero, C.; Goncalves, I.; Gallino, R.; Gonzalez-Romero, E.; Goverdovski, A.; Gramegna, F.; Griesmayer, E.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Isaev, S.; Jericha, E.; Kadi, Y.; Käppeler, F.; Karamanis, D.; Karadimos, D.; Kerveno, M.; Ketlerov, V.; Koehler, P.; Konovalov, V.; Kossionides, E.; Krti ka, M.; Lamboudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marques, L.; Marrone, S.; Massimi, C.; Mengoni, A.; Milazzo, P. M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O'Brien, S.; Oshima, M.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rosetti, M.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wendler, H.; Wiescherand, M.; Wisshak, K.

2006-05-01

A neutron Time-of-Flight facility (n_TOF) is available at CERN since 2001. The innovative features of the neutron beam, in particular the high instantaneous flux, the wide energy range, the high resolution and the low background, make this facility unique for measurements of neutron induced reactions relevant to the field of Emerging Nuclear Technologies, as well as to Nuclear Astrophysics and Fundamental Nuclear Physics. The scientific motivations that have led to the construction of this new facility are here presented. The main characteristics of the n_TOF neutron beam are described, together with the features of the experimental apparata used for cross-section measurements. The main results of the first measurement campaigns are presented. Preliminary results of capture cross-section measurements of minor actinides, important to ADS project for nuclear waste transmutation, are finally discussed.

Protein sectors: evolutionary units of three-dimensional structure

PubMed Central

Halabi, Najeeb; Rivoire, Olivier; Leibler, Stanislas; Ranganathan, Rama

2011-01-01

Proteins display a hierarchy of structural features at primary, secondary, tertiary, and higher-order levels, an organization that guides our current understanding of their biological properties and evolutionary origins. Here, we reveal a structural organization distinct from this traditional hierarchy by statistical analysis of correlated evolution between amino acids. Applied to the S1A serine proteases, the analysis indicates a decomposition of the protein into three quasi-independent groups of correlated amino acids that we term “protein sectors”. Each sector is physically connected in the tertiary structure, has a distinct functional role, and constitutes an independent mode of sequence divergence in the protein family. Functionally relevant sectors are evident in other protein families as well, suggesting that they may be general features of proteins. We propose that sectors represent a structural organization of proteins that reflects their evolutionary histories. PMID:19703402

Varying irrelevant phonetic features hinders learning of the feature being trained.

PubMed

Antoniou, Mark; Wong, Patrick C M

2016-01-01

Learning to distinguish nonnative words that differ in a critical phonetic feature can be difficult. Speech training studies typically employ methods that explicitly direct the learner's attention to the relevant nonnative feature to be learned. However, studies on vision have demonstrated that perceptual learning may occur implicitly, by exposing learners to stimulus features, even if they are irrelevant to the task, and it has recently been suggested that this task-irrelevant perceptual learning framework also applies to speech. In this study, subjects took part in a seven-day training regimen to learn to distinguish one of two nonnative features, namely, voice onset time or lexical tone, using explicit training methods consistent with most speech training studies. Critically, half of the subjects were exposed to stimuli that varied not only in the relevant feature, but in the irrelevant feature as well. The results showed that subjects who were trained with stimuli that varied in the relevant feature and held the irrelevant feature constant achieved the best learning outcomes. Varying both features hindered learning and generalization to new stimuli.

Flowable Resin Composites: A Systematic Review and Clinical Considerations

PubMed Central

Rodrigues, Jean C.

2015-01-01

Background Little is known about flowable composite materials. Most literature mentions conventional composite materials at large, giving minimal emphasis to flowables in particular. This paper briefly gives an in depth insight to the multiple facets of this versatile material. Aim To exclusively review the most salient features of flowable composite materials in comparison to conventional composites and to give clinicians a detailed understanding of the advantages, drawbacks, indications and contraindications based on composition and physical/mechanical properties. Methodology Data Sources: A thorough literature search from the year 1996 up to January 2015 was done on PubMed Central, The Cochrane Library, Science Direct, Wiley Online Library, and Google Scholar. Grey literature (pending patents, technical reports etc.) was also screened. The search terms used were “dental flowable resin composites”. Search Strategy After omitting the duplicates/repetitions, a total of 491 full text articles were assessed. As including all articles were out of the scope of this paper. Only relevant articles that fulfilled the reviewer’s objectives {mentioning indications, contraindications, applications, assessment of physical/mechanical/biological properties (in vitro/ in vivo /ex vivo)} were considered. A total of 92 full text articles were selected. Conclusion Flowable composites exhibit a variable composition and consequently variable mechanical/ physical properties. Clinicians must be aware of this aspect to make a proper material selection based on specific properties and indications of each material relevant to a particular clinical situation. PMID:26266238

Advanced alerting features: displaying new relevant data and retracting alerts.

PubMed Central

Kuperman, G. J.; Hiltz, F. L.; Teich, J. M.

1997-01-01

We added two advanced features to our automated alerting system. The first feature identifies and displays, at the time an alert is reviewed, relevant data filed between the login time of a specimen leading to an alerting result and the time the alert is reviewed. Relevant data is defined as data of the same kind as generated the alert. The other feature retracts alerts when the alerting value is edited and no longer satisfies the alerting criteria. We evaluated the two features for a 14-week period (new relevant data) and a 6-week period (retraction). Of a total of 1104 alerts in the 14-week evaluation, 286 (25.9%) had new relevant data displayed at alert review time. Of the 286, 75.2% were due to additions of comments to the original piece of alerting data; 24.1% were due to new or pending laboratory results of the same type that generated the alert. Two alerts (out of 490) were retracted in a 6 week period. We conclude that in our system, new clinically relevant data is often added between the time of specimen login and the time that an alerting result from that specimen is reviewed. Retractions occur rarely but are important to detect and communicate. PMID:9357625

Integrating the glioblastoma microenvironment into engineered experimental models

PubMed Central

Xiao, Weikun; Sohrabi, Alireza; Seidlits, Stephanie K

2017-01-01

Glioblastoma (GBM) is the most lethal cancer originating in the brain. Its high mortality rate has been attributed to therapeutic resistance and rapid, diffuse invasion – both of which are strongly influenced by the unique microenvironment. Thus, there is a need to develop new models that mimic individual microenvironmental features and are able to provide clinically relevant data. Current understanding of the effects of the microenvironment on GBM progression, established experimental models of GBM and recent developments using bioengineered microenvironments as ex vivo experimental platforms that mimic the biochemical and physical properties of GBM tumors are discussed. PMID:28883992

Apollo 14 rock samples

NASA Technical Reports Server (NTRS)

Carlson, I. C.

1978-01-01

Petrographic descriptions of all Apollo 14 samples larger than 1 cm in any dimension are presented. The sample description format consists of: (1) an introductory section which includes information on lunar sample location, orientation, and return containers, (2) a section on physical characteristics, which contains the sample mass, dimensions, and a brief description; (3) surface features, including zap pits, cavities, and fractures as seen in binocular view; (4) petrographic description, consisting of a binocular description and, if possible, a thin section description; and (5) a discussion of literature relevant to sample petrology is included for samples which have previously been examined by the scientific community.

Fundamentals and advances in magnetic hyperthermia

NASA Astrophysics Data System (ADS)

Périgo, E. A.; Hemery, G.; Sandre, O.; Ortega, D.; Garaio, E.; Plazaola, F.; Teran, F. J.

2015-12-01

Nowadays, magnetic hyperthermia constitutes a complementary approach to cancer treatment. The use of magnetic particles as heating mediators, proposed in the 1950s, provides a novel strategy for improving tumor treatment and, consequently, patient's quality of life. This review reports a broad overview about several aspects of magnetic hyperthermia addressing new perspectives and the progress on relevant features such as the ad hoc preparation of magnetic nanoparticles, physical modeling of magnetic heating, methods to determine the heat dissipation power of magnetic colloids including the development of experimental apparatus and the influence of biological matrices on the heating efficiency.

Selection-for-action in visual search.

PubMed

Hannus, Aave; Cornelissen, Frans W; Lindemann, Oliver; Bekkering, Harold

2005-01-01

Grasping an object rather than pointing to it enhances processing of its orientation but not its color. Apparently, visual discrimination is selectively enhanced for a behaviorally relevant feature. In two experiments we investigated the limitations and targets of this bias. Specifically, in Experiment 1 we were interested to find out whether the effect is capacity demanding, therefore we manipulated the set-size of the display. The results indicated a clear cognitive processing capacity requirement, i.e. the magnitude of the effect decreased for a larger set size. Consequently, in Experiment 2, we investigated if the enhancement effect occurs only at the level of behaviorally relevant feature or at a level common to different features. Therefore we manipulated the discriminability of the behaviorally neutral feature (color). Again, results showed that this manipulation influenced the action enhancement of the behaviorally relevant feature. Particularly, the effect of the color manipulation on the action enhancement suggests that the action effect is more likely to bias the competition between different visual features rather than to enhance the processing of the relevant feature. We offer a theoretical account that integrates the action-intention effect within the biased competition model of visual selective attention.

Feature relevance assessment for the semantic interpretation of 3D point cloud data

NASA Astrophysics Data System (ADS)

Weinmann, M.; Jutzi, B.; Mallet, C.

2013-10-01

The automatic analysis of large 3D point clouds represents a crucial task in photogrammetry, remote sensing and computer vision. In this paper, we propose a new methodology for the semantic interpretation of such point clouds which involves feature relevance assessment in order to reduce both processing time and memory consumption. Given a standard benchmark dataset with 1.3 million 3D points, we first extract a set of 21 geometric 3D and 2D features. Subsequently, we apply a classifier-independent ranking procedure which involves a general relevance metric in order to derive compact and robust subsets of versatile features which are generally applicable for a large variety of subsequent tasks. This metric is based on 7 different feature selection strategies and thus addresses different intrinsic properties of the given data. For the example of semantically interpreting 3D point cloud data, we demonstrate the great potential of smaller subsets consisting of only the most relevant features with 4 different state-of-the-art classifiers. The results reveal that, instead of including as many features as possible in order to compensate for lack of knowledge, a crucial task such as scene interpretation can be carried out with only few versatile features and even improved accuracy.

Does the choice of display system influence perception and visibility of clinically relevant features in digital pathology images?

NASA Astrophysics Data System (ADS)

Kimpe, Tom; Rostang, Johan; Avanaki, Ali; Espig, Kathryn; Xthona, Albert; Cocuranu, Ioan; Parwani, Anil V.; Pantanowitz, Liron

2014-03-01

Digital pathology systems typically consist of a slide scanner, processing software, visualization software, and finally a workstation with display for visualization of the digital slide images. This paper studies whether digital pathology images can look different when presenting them on different display systems, and whether these visual differences can result in different perceived contrast of clinically relevant features. By analyzing a set of four digital pathology images of different subspecialties on three different display systems, it was concluded that pathology images look different when visualized on different display systems. The importance of these visual differences is elucidated when they are located in areas of the digital slide that contain clinically relevant features. Based on a calculation of dE2000 differences between background and clinically relevant features, it was clear that perceived contrast of clinically relevant features is influenced by the choice of display system. Furthermore, it seems that the specific calibration target chosen for the display system has an important effect on the perceived contrast of clinically relevant features. Preliminary results suggest that calibrating to DICOM GSDF calibration performed slightly worse than sRGB, while a new experimental calibration target CSDF performed better than both DICOM GSDF and sRGB. This result is promising as it suggests that further research work could lead to better definition of an optimized calibration target for digital pathology images resulting in a positive effect on clinical performance.

[The most common vital events in women 45-64 years of age. Repercussions as psychophysical stressors].

PubMed

Marín Torrens, R M; Sánchez Cánovas, J; Donat Colomer, F; Dupuy Layo, M J; Salas Trejo, M D

1996-05-15

To find what vital events middle-aged women in our society most often experience and their influence as stress factors on physical health and subjective psychological well-being. A multivariant transversal study. 5 primary care centres in Valencia and Alicante. 306 women chosen at random among those seen at these health centres. Frequency analysis of vital events. Correlation analysis with questionnaires on physical symptoms and diseases, psychological well-being, work situation, emotional behaviour, sexuality and relationships with their partner. ANOVA: dividing the sample into 2 groups based on mean adaptive effort. The most common events numbered 23. The ANOVA showed a significant association between greater adaptive effort and negative emotional behaviour, personal control, material well-being, relationship with the partner, and physical and psychological symptoms. The relevance of daily events as generators of stress was confirmed, as was the impact of these and major events on these women's physical and psychological health. The importance of attending women at this stage of their lives from an integrated and interdisciplinary perspective, which tackles the physiological, psychological and cultural features together, was shown.

Framework for Evaluating Water Quality of the New England Crystalline Rock Aquifers

USGS Publications Warehouse

Harte, Philip T.; Robinson, Gilpin R.; Ayotte, Joseph D.; Flanagan, Sarah M.

2008-01-01

Little information exists on regional ground-water-quality patterns for the New England crystalline rock aquifers (NECRA). A systematic approach to facilitate regional evaluation is needed for several reasons. First, the NECRA are vulnerable to anthropogenic and natural contaminants such as methyl tert-butyl ether (MTBE), arsenic, and radon gas. Second, the physical characteristics of the aquifers, termed 'intrinsic susceptibility', can lead to variable and degraded water quality. A framework approach for characterizing the aquifer region into areas of similar hydrogeology is described in this report and is based on hypothesized relevant physical features and chemical conditions (collectively termed 'variables') that affect regional patterns of ground-water quality. A framework for comparison of water quality across the NECRA consists of a group of spatial variables related to aquifer properties, hydrologic conditions, and contaminant sources. These spatial variables are grouped under four general categories (features) that can be mapped across the aquifers: (1) geologic, (2) hydrophysiographic, (3) land-use land-cover, and (4) geochemical. On a regional scale, these variables represent indicators of natural and anthropogenic sources of contaminants, as well as generalized physical and chemical characteristics of the aquifer system that influence ground-water chemistry and flow. These variables can be used in varying combinations (depending on the contaminant) to categorize the aquifer into areas of similar hydrogeologic characteristics to evaluate variation in regional water quality through statistical testing.

Predicting remaining life by fusing the physics of failure modeling with diagnostics

NASA Astrophysics Data System (ADS)

Kacprzynski, G. J.; Sarlashkar, A.; Roemer, M. J.; Hess, A.; Hardman, B.

2004-03-01

Technology that enables failure prediction of critical machine components (prognostics) has the potential to significantly reduce maintenance costs and increase availability and safety. This article summarizes a research effort funded through the U.S. Defense Advanced Research Projects Agency and Naval Air System Command aimed at enhancing prognostic accuracy through more advanced physics-of-failure modeling and intelligent utilization of relevant diagnostic information. H-60 helicopter gear is used as a case study to introduce both stochastic sub-zone crack initiation and three-dimensional fracture mechanics lifing models along with adaptive model updating techniques for tuning key failure mode variables at a local material/damage site based on fused vibration features. The overall prognostic scheme is aimed at minimizing inherent modeling and operational uncertainties via sensed system measurements that evolve as damage progresses.

[Structural plasticity associated with drugs addiction].

PubMed

Zhu, Jie; Cao, Guo-fen; Dang, Yong-hui; Chen, Teng

2011-12-01

An essential feature of drug addiction is that an individual continues to use drug despite the threat of severely adverse physical or psychosocial consequences. Persistent changes in behavior and psychological function that occur as a function of drugs of abuse are thought to be due to the reorganization of synaptic connections (structural plasticity) in relevant brain circuits (especially the brains reward circuits). In this paper we summarized evidence that, indeed, exposure to amphetamine, cocaine, nicotine or morphine produced persistent changes in the structure of dendrites and dendritic spines on cells in relevant brain regions. We also approached the potential molecular mechanisms of these changes. It is suggested that structural plasticity associated with exposure to drugs of abuse reflects a reorganization of patterns of synaptic connectivity in these neural systems, a reorganization that alters their operation, thus contributing to some of the persistent sequela associated with drug use-including addiction.

Synchrotron x-ray diffraction studies of the structural properties of electrode materials in operating battery cells

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

Thurston, T.R.; Jisrawi, N.M.; Mukerjee, S.

Hard x rays from a synchrotron source were utilized in diffraction experiments which probed the bulk of electrode materials while they were operating {ital in} {ital situ} in battery cells. Two technologically relevant electrode materials were examined; an {ital AB}{sub 2}-type anode in a nickel{endash}metal{endash}hydride cell and a LiMn{sub 2}O{sub 4} cathode in a Li-ion {open_quote}{open_quote}rocking chair{close_quote}{close_quote} cell. Structural features such as lattice expansions and contractions, phase transitions, and the formation of multiple phases were easily observed as either hydrogen or lithium was electrochemically intercalated in and out of the electrode materials. The relevance of this technique for future studiesmore » of battery electrode materials is discussed. {copyright} {ital 1996 American Institute of Physics.}« less

A unified framework for image retrieval using keyword and visual features.

PubMed

Jing, Feng; Li, Mingling; Zhang, Hong-Jiang; Zhang, Bo

2005-07-01

In this paper, a unified image retrieval framework based on both keyword annotations and visual features is proposed. In this framework, a set of statistical models are built based on visual features of a small set of manually labeled images to represent semantic concepts and used to propagate keywords to other unlabeled images. These models are updated periodically when more images implicitly labeled by users become available through relevance feedback. In this sense, the keyword models serve the function of accumulation and memorization of knowledge learned from user-provided relevance feedback. Furthermore, two sets of effective and efficient similarity measures and relevance feedback schemes are proposed for query by keyword scenario and query by image example scenario, respectively. Keyword models are combined with visual features in these schemes. In particular, a new, entropy-based active learning strategy is introduced to improve the efficiency of relevance feedback for query by keyword. Furthermore, a new algorithm is proposed to estimate the keyword features of the search concept for query by image example. It is shown to be more appropriate than two existing relevance feedback algorithms. Experimental results demonstrate the effectiveness of the proposed framework.

Oxide films state analysis by IR spectroscopy based on the simple oscillator approximation

NASA Astrophysics Data System (ADS)

Volkov, N. V.; Yakutkina, T. V.; Karpova, V. V.

2017-05-01

Stabilization of structure-phase state in a wide temperature range is one of the most important problems of improving properties of oxide compounds. As such, the search of new effective methods for obtaining metal oxides with desired physic-chemical, electro-physical and thermal properties and their control is important and relevant. The aim of this work is identification features state of the oxide films of some metals Be, Al, Fe, Cu, Zr on the metal surface of the polycrystalline samples by infrared spectroscopy. To identify the resonance emission bands the algorithm of IR-spectra processing was developed and realized on the basis of table processor EXCEL-2010, which allow revealing characteristic resonance bands successfully and identification of inorganic chemical compounds. In the frame of simple oscillator model, resonance frequencies of normal vibrations of water and some inorganic compounds: metal oxides - Be, Al, Fe, Cu, Zr were calculated and characteristic frequencies for different states (aggregate, deformation, phase) were specified. By means of IR-spectroscopy fundamental possibility of revealing oxides films on metal substrate features state is shown, that allow development and optimization of the technology for production of the oxide films with desired properties.

Herschel and the Molecular Universe

NASA Technical Reports Server (NTRS)

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

2006-01-01

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

Dream features in the early stages of Parkinson's disease.

PubMed

Bugalho, Paulo; Paiva, Teresa

2011-11-01

Few studies have investigated the relation between dream features and cognition in Parkinson's disease (PD), although vivid dreams, hallucinations and cognitive decline have been proposed as successive steps of a pathological continuum. Our objectives were therefore to characterize the dreams of early stage PD and to study the relation between dream characteristics, cognitive function, motor status, depression, dopaminergic treatment, and the presence of REM sleep behaviour disorder (RBD) and hallucinations. Dreams of 19 male PD patients and 21 matched control subjects were classified according to Hall and van de Castle system. h statistics was used to compare the dream content between patients and controls. We tested the relation between patients' dreams characteristics and cognitive function (Frontal assessment battery (FAB) and Mini-Mental State Examination tests) depression (Beck depression inventory), motor function (UPDRS), dopaminergic treatment, the presence of RBD (according to clinical criteria) and hallucinations, using general linear model statistics. Patients and controls differed only on FAB scores. Relevant differences in the Hall and van de Castle scale were found between patient's dreams and those of the control group, regarding animals, aggression/friendliness, physical aggression, befriender (higher in the patient group) and aggressor and bodily misfortunes (lower in the patient group) features. Cognitive and particularly frontal dysfunction had a significant influence on the frequency of physical aggression and animal related features, while dopaminergic doses, depressive symptoms, hallucinations and RBD did not. We found a pattern of dream alteration characterized by heightened aggressiveness and the presence of animals. These were related to more severe frontal dysfunction, which could be the origin of such changes.

Active living for rural youth: addressing physical inactivity in rural communities.

PubMed

Yousefian, Anush; Ziller, Erika; Swartz, Jon; Hartley, David

2009-01-01

Rural youth are at greater risk than urban youth for obesity and physical inactivity. Active living research incorporates an ecological approach to promoting physical activity (PA) by recognizing that individual behavior, social environments, physical environments, and policies contribute to behavior change. Active living research and interventions have been limited primarily to urban settings. Because rural communities have unique environmental features and sociocultural characteristics, this project combines insights from current active living models with more focused consideration of the physical and social realities of rural areas. In this study, we report on our efforts to develop, test, and refine a conceptual model describing the interaction between the individual and the environment as it enhances or thwarts active living in rural communities. Our findings revealed a host of relevant "predisposing" and "enabling" factors, including sociodemographic, environmental, policy, and programmatic elements, that extend across the four domains of active living--transportation, recreation, occupation, and household. A one-size approach to PA promotion will not fit the needs of rural youth. Given the unique challenges that rural communities face, efforts to combat childhood obesity must consider rural residents a priority population. More research, interventions, and evaluations on ways to promote rural PA are needed.

A Comprehensive Comparison of Relativistic Particle Integrators

NASA Astrophysics Data System (ADS)

Ripperda, B.; Bacchini, F.; Teunissen, J.; Xia, C.; Porth, O.; Sironi, L.; Lapenta, G.; Keppens, R.

2018-03-01

We compare relativistic particle integrators commonly used in plasma physics, showing several test cases relevant for astrophysics. Three explicit particle pushers are considered, namely, the Boris, Vay, and Higuera–Cary schemes. We also present a new relativistic fully implicit particle integrator that is energy conserving. Furthermore, a method based on the relativistic guiding center approximation is included. The algorithms are described such that they can be readily implemented in magnetohydrodynamics codes or Particle-in-Cell codes. Our comparison focuses on the strengths and key features of the particle integrators. We test the conservation of invariants of motion and the accuracy of particle drift dynamics in highly relativistic, mildly relativistic, and non-relativistic settings. The methods are compared in idealized test cases, i.e., without considering feedback onto the electrodynamic fields, collisions, pair creation, or radiation. The test cases include uniform electric and magnetic fields, {\\boldsymbol{E}}× {\\boldsymbol{B}} fields, force-free fields, and setups relevant for high-energy astrophysics, e.g., a magnetic mirror, a magnetic dipole, and a magnetic null. These tests have direct relevance for particle acceleration in shocks and in magnetic reconnection.

Attention to Distinct Goal-relevant Features Differentially Guides Semantic Knowledge Retrieval.

PubMed

Hanson, Gavin K; Chrysikou, Evangelia G

2017-07-01

A critical aspect of conceptual knowledge is the selective activation of goal-relevant aspects of meaning. Although the contributions of ventrolateral prefrontal and posterior temporal areas to semantic cognition are well established, the precise role of posterior parietal cortex in semantic control remains unknown. Here, we examined whether this region modulates attention to goal-relevant features within semantic memory according to the same principles that determine the salience of task-relevant object properties during visual attention. Using multivoxel pattern analysis, we decoded attentional referents during a semantic judgment task, in which participants matched an object cue to a target according to concrete (i.e., color, shape) or abstract (i.e., function, thematic context) semantic features. The goal-relevant semantic feature participants attended to (e.g., color or shape, function or theme) could be decoded from task-associated cortical activity with above-chance accuracy, a pattern that held for both concrete and abstract semantic features. A Bayesian confusion matrix analysis further identified differential contributions to representing attentional demands toward specific object properties across lateral prefrontal, posterior temporal, and inferior parietal regions, with the dorsolateral pFC supporting distinctions between higher-order properties and the left intraparietal sulcus being the only region supporting distinctions across all semantic features. These results are the first to demonstrate that patterns of neural activity in the parietal cortex are sensitive to which features of a concept are attended to, thus supporting the contributions of posterior parietal cortex to semantic control.

Identifying marker genes in transcription profiling data using a mixture of feature relevance experts.

PubMed

Chow, M L; Moler, E J; Mian, I S

2001-03-08

Transcription profiling experiments permit the expression levels of many genes to be measured simultaneously. Given profiling data from two types of samples, genes that most distinguish the samples (marker genes) are good candidates for subsequent in-depth experimental studies and developing decision support systems for diagnosis, prognosis, and monitoring. This work proposes a mixture of feature relevance experts as a method for identifying marker genes and illustrates the idea using published data from samples labeled as acute lymphoblastic and myeloid leukemia (ALL, AML). A feature relevance expert implements an algorithm that calculates how well a gene distinguishes samples, reorders genes according to this relevance measure, and uses a supervised learning method [here, support vector machines (SVMs)] to determine the generalization performances of different nested gene subsets. The mixture of three feature relevance experts examined implement two existing and one novel feature relevance measures. For each expert, a gene subset consisting of the top 50 genes distinguished ALL from AML samples as completely as all 7,070 genes. The 125 genes at the union of the top 50s are plausible markers for a prototype decision support system. Chromosomal aberration and other data support the prediction that the three genes at the intersection of the top 50s, cystatin C, azurocidin, and adipsin, are good targets for investigating the basic biology of ALL/AML. The same data were employed to identify markers that distinguish samples based on their labels of T cell/B cell, peripheral blood/bone marrow, and male/female. Selenoprotein W may discriminate T cells from B cells. Results from analysis of transcription profiling data from tumor/nontumor colon adenocarcinoma samples support the general utility of the aforementioned approach. Theoretical issues such as choosing SVM kernels and their parameters, training and evaluating feature relevance experts, and the impact of potentially mislabeled samples on marker identification (feature selection) are discussed.

Joint Concept Correlation and Feature-Concept Relevance Learning for Multilabel Classification.

PubMed

Zhao, Xiaowei; Ma, Zhigang; Li, Zhi; Li, Zhihui

2018-02-01

In recent years, multilabel classification has attracted significant attention in multimedia annotation. However, most of the multilabel classification methods focus only on the inherent correlations existing among multiple labels and concepts and ignore the relevance between features and the target concepts. To obtain more robust multilabel classification results, we propose a new multilabel classification method aiming to capture the correlations among multiple concepts by leveraging hypergraph that is proved to be beneficial for relational learning. Moreover, we consider mining feature-concept relevance, which is often overlooked by many multilabel learning algorithms. To better show the feature-concept relevance, we impose a sparsity constraint on the proposed method. We compare the proposed method with several other multilabel classification methods and evaluate the classification performance by mean average precision on several data sets. The experimental results show that the proposed method outperforms the state-of-the-art methods.

Hyperspectral Image Enhancement and Mixture Deep-Learning Classification of Corneal Epithelium Injuries

PubMed Central

Md Noor, Siti Salwa; Michael, Kaleena; Marshall, Stephen; Ren, Jinchang

2017-01-01

In our preliminary study, the reflectance signatures obtained from hyperspectral imaging (HSI) of normal and abnormal corneal epithelium tissues of porcine show similar morphology with subtle differences. Here we present image enhancement algorithms that can be used to improve the interpretability of data into clinically relevant information to facilitate diagnostics. A total of 25 corneal epithelium images without the application of eye staining were used. Three image feature extraction approaches were applied for image classification: (i) image feature classification from histogram using a support vector machine with a Gaussian radial basis function (SVM-GRBF); (ii) physical image feature classification using deep-learning Convolutional Neural Networks (CNNs) only; and (iii) the combined classification of CNNs and SVM-Linear. The performance results indicate that our chosen image features from the histogram and length-scale parameter were able to classify with up to 100% accuracy; particularly, at CNNs and CNNs-SVM, by employing 80% of the data sample for training and 20% for testing. Thus, in the assessment of corneal epithelium injuries, HSI has high potential as a method that could surpass current technologies regarding speed, objectivity, and reliability. PMID:29144388

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

Knott, C.N.; Waddington, C.J.; Albergo, S.

The interactions of {sup 36}Ar projectile nuclei with energies of 361, 546, and 765 MeV/nucleon and {sup 40}Ar nuclei with 352 MeV/nucleon, have been studied in a liquid-hydrogen target as part of a program to study interactions of relevance to the problem of cosmic-ray propagation in the interstellar medium. We have measured the cross sections for the production of isotopic fragments of the projectile nuclei in these interactions. The variations of these cross sections with mass, charge, and energy, are examined for insights into any systematic features of this type of fragmentation reaction that might aid predictions of other, unmeasuredmore » cross sections. These cross sections are also compared with the values derived from the most commonly used prediction techniques. It is suggested that these techniques could be improved by taking account of the systematic features identified here. {copyright} {ital 1997} {ital The American Physical Society}« less

Quality Perception of the 2012 World Indoor Athletics Championships

PubMed Central

2016-01-01

Abstract The objective of this study was to compare the views of spectators concerning the quality perception of the World Indoor Athletics Championships. The study group consisted of 568 spectators who watched the events. A measurement scale of event quality in spectator sports (SEQSS) developed by Ko et al. (2011) was used as a data collection tool in the study. In order to determine the views of the spectators concerning the quality of the Indoor Athletics Championships, the dimensions constituting the scale were compared according to the demographic features of the sample group. As a consequence, important differences in most of the dimensions of the scale were revealed with respect to the demographic data of the subjects. The most relevant finding of the study is that the dimension of “physical environment quality”, which is one of the dimensions constituting the event quality, differed significantly in all comparisons that were made according to demographic features. PMID:28031769

Supramolecular assembly/reassembly processes: molecular motors and dynamers operating at surfaces.

PubMed

Ciesielski, Artur; Samorì, Paolo

2011-04-01

Among the many significant advances within the field of supramolecular chemistry over the past decades, the development of the so-called "dynamers" features a direct relevance to materials science. Defined as "combinatorial dynamic polymers", dynamers are constitutional dynamic systems and materials resulting from the application of the principles of supramolecular chemistry to polymer science. Like supramolecular materials in general, dynamers are reversible dynamic multifunctional architectures, capable of modifying their constitution by exchanging, recombining, incorporating components. They may exhibit a variety of novel properties and behave as adaptive materials. In this review we focus on the design of responsive switchable monolayers, i.e. monolayers capable to undergo significant changes in their physical or chemical properties as a result of external stimuli. Scanning tunneling microscopy studies provide direct evidence with a sub-nanometre resolution, on the formation and dynamic response of these self-assembled systems featuring controlled geometries and properties.

Ghost features in Doppler-broadened spectra of rovibrational transitions in trapped HD+ ions

NASA Astrophysics Data System (ADS)

Patra, Sayan; Koelemeij, J. C. J.

2017-02-01

Doppler broadening plays an important role in laser rovibrational spectroscopy of trapped deuterated molecular hydrogen ions (HD+), even at the millikelvin temperatures achieved through sympathetic cooling by laser-cooled beryllium ions. Recently, Biesheuvel et al. (2016) presented a theoretical lineshape model for such transitions which not only considers linestrengths and Doppler broadening, but also the finite sample size and population redistribution by blackbody radiation, which are important in view of the long storage and probe times achievable in ion traps. Here, we employ the rate equation model developed by Biesheuvel et al. to theoretically study the Doppler-broadened hyperfine structure of the (v, L) : (0, 3) → (4, 2) rovibrational transition in HD+ at 1442 nm. We observe prominent yet hitherto unrecognized ghost features in the simulated spectrum, whose positions depend on the Doppler width, transition rates, and saturation levels of the hyperfine components addressed by the laser. We explain the origin and behavior of such features, and we provide a simple quantitative guideline to assess whether ghost features may appear. As such ghost features may be common to saturated Doppler-broadened spectra of rotational and vibrational transitions in trapped ions composed of partly overlapping lines, our work illustrates the necessity to use lineshape models that take into account all the relevant physics.

Modeling the Evolution of Beliefs Using an Attentional Focus Mechanism

PubMed Central

Marković, Dimitrije; Gläscher, Jan; Bossaerts, Peter; O’Doherty, John; Kiebel, Stefan J.

2015-01-01

For making decisions in everyday life we often have first to infer the set of environmental features that are relevant for the current task. Here we investigated the computational mechanisms underlying the evolution of beliefs about the relevance of environmental features in a dynamical and noisy environment. For this purpose we designed a probabilistic Wisconsin card sorting task (WCST) with belief solicitation, in which subjects were presented with stimuli composed of multiple visual features. At each moment in time a particular feature was relevant for obtaining reward, and participants had to infer which feature was relevant and report their beliefs accordingly. To test the hypothesis that attentional focus modulates the belief update process, we derived and fitted several probabilistic and non-probabilistic behavioral models, which either incorporate a dynamical model of attentional focus, in the form of a hierarchical winner-take-all neuronal network, or a diffusive model, without attention-like features. We used Bayesian model selection to identify the most likely generative model of subjects’ behavior and found that attention-like features in the behavioral model are essential for explaining subjects’ responses. Furthermore, we demonstrate a method for integrating both connectionist and Bayesian models of decision making within a single framework that allowed us to infer hidden belief processes of human subjects. PMID:26495984

A bootstrap based Neyman-Pearson test for identifying variable importance.

PubMed

Ditzler, Gregory; Polikar, Robi; Rosen, Gail

2015-04-01

Selection of most informative features that leads to a small loss on future data are arguably one of the most important steps in classification, data analysis and model selection. Several feature selection (FS) algorithms are available; however, due to noise present in any data set, FS algorithms are typically accompanied by an appropriate cross-validation scheme. In this brief, we propose a statistical hypothesis test derived from the Neyman-Pearson lemma for determining if a feature is statistically relevant. The proposed approach can be applied as a wrapper to any FS algorithm, regardless of the FS criteria used by that algorithm, to determine whether a feature belongs in the relevant set. Perhaps more importantly, this procedure efficiently determines the number of relevant features given an initial starting point. We provide freely available software implementations of the proposed methodology.

Illuminating the conceptual structure of the space of moral violations with searchlight representational similarity analysis.

PubMed

Wasserman, E A; Chakroff, A; Saxe, R; Young, L

2017-10-01

Characterizing how representations of moral violations are organized, cognitively and neurally, is central to understanding how people conceive and judge them. Past work has identified brain regions that represent morally relevant features and distinguish moral domains, but has not yet advanced a broader account of where and on what basis neural representations of moral violations are organized. With searchlight representational similarity analysis, we investigate where category membership drives similarity in neural patterns during moral judgment of violations from two key moral domains: Harm and Purity. Representations converge across domains in a network of regions resembling the mentalizing network. However, Harm and Purity violation representations respectively converge in different regions: precuneus (PC) and left inferior frontal gyrus (LIFG). Examining substructure within moral domains, Harm violations converge in PC regardless of subdomain (physical harms, psychological harms), while Purity subdomains (pathogen-related violations, sex-related violations) converge in distinct sets of regions - mirroring a dissociation observed in principal-component analysis of behavioral data. Further, we find initial evidence for representation of morally relevant features within these two domain-encoding regions. The present analyses offer a case study for understanding how organization within the complex conceptual space of moral violations is reflected in the organization of neural patterns across the cortex. Copyright © 2017 Elsevier Inc. All rights reserved.

Mammogram classification scheme using 2D-discrete wavelet and local binary pattern for detection of breast cancer

NASA Astrophysics Data System (ADS)

Adi Putra, Januar

2018-04-01

In this paper, we propose a new mammogram classification scheme to classify the breast tissues as normal or abnormal. Feature matrix is generated using Local Binary Pattern to all the detailed coefficients from 2D-DWT of the region of interest (ROI) of a mammogram. Feature selection is done by selecting the relevant features that affect the classification. Feature selection is used to reduce the dimensionality of data and features that are not relevant, in this paper the F-test and Ttest will be performed to the results of the feature extraction dataset to reduce and select the relevant feature. The best features are used in a Neural Network classifier for classification. In this research we use MIAS and DDSM database. In addition to the suggested scheme, the competent schemes are also simulated for comparative analysis. It is observed that the proposed scheme has a better say with respect to accuracy, specificity and sensitivity. Based on experiments, the performance of the proposed scheme can produce high accuracy that is 92.71%, while the lowest accuracy obtained is 77.08%.

Welding arc plasma physics

NASA Technical Reports Server (NTRS)

Cain, Bruce L.

1990-01-01

The problems of weld quality control and weld process dependability continue to be relevant issues in modern metal welding technology. These become especially important for NASA missions which may require the assembly or repair of larger orbiting platforms using automatic welding techniques. To extend present welding technologies for such applications, NASA/MSFC's Materials and Processes Lab is developing physical models of the arc welding process with the goal of providing both a basis for improved design of weld control systems, and a better understanding of how arc welding variables influence final weld properties. The physics of the plasma arc discharge is reasonably well established in terms of transport processes occurring in the arc column itself, although recourse to sophisticated numerical treatments is normally required to obtain quantitative results. Unfortunately the rigor of these numerical computations often obscures the physics of the underlying model due to its inherent complexity. In contrast, this work has focused on a relatively simple physical model of the arc discharge to describe the gross features observed in welding arcs. Emphasis was placed of deriving analytic expressions for the voltage along the arc axis as a function of known or measurable arc parameters. The model retains the essential physics for a straight polarity, diffusion dominated free burning arc in argon, with major simplifications of collisionless sheaths and simple energy balances at the electrodes.

Selecting relevant 3D image features of margin sharpness and texture for lung nodule retrieval.

PubMed

Ferreira, José Raniery; de Azevedo-Marques, Paulo Mazzoncini; Oliveira, Marcelo Costa

2017-03-01

Lung cancer is the leading cause of cancer-related deaths in the world. Its diagnosis is a challenge task to specialists due to several aspects on the classification of lung nodules. Therefore, it is important to integrate content-based image retrieval methods on the lung nodule classification process, since they are capable of retrieving similar cases from databases that were previously diagnosed. However, this mechanism depends on extracting relevant image features in order to obtain high efficiency. The goal of this paper is to perform the selection of 3D image features of margin sharpness and texture that can be relevant on the retrieval of similar cancerous and benign lung nodules. A total of 48 3D image attributes were extracted from the nodule volume. Border sharpness features were extracted from perpendicular lines drawn over the lesion boundary. Second-order texture features were extracted from a cooccurrence matrix. Relevant features were selected by a correlation-based method and a statistical significance analysis. Retrieval performance was assessed according to the nodule's potential malignancy on the 10 most similar cases and by the parameters of precision and recall. Statistical significant features reduced retrieval performance. Correlation-based method selected 2 margin sharpness attributes and 6 texture attributes and obtained higher precision compared to all 48 extracted features on similar nodule retrieval. Feature space dimensionality reduction of 83 % obtained higher retrieval performance and presented to be a computationaly low cost method of retrieving similar nodules for the diagnosis of lung cancer.

Attention improves encoding of task-relevant features in the human visual cortex

PubMed Central

Jehee, Janneke F.M.; Brady, Devin K.; Tong, Frank

2011-01-01

When spatial attention is directed towards a particular stimulus, increased activity is commonly observed in corresponding locations of the visual cortex. Does this attentional increase in activity indicate improved processing of all features contained within the attended stimulus, or might spatial attention selectively enhance the features relevant to the observer’s task? We used fMRI decoding methods to measure the strength of orientation-selective activity patterns in the human visual cortex while subjects performed either an orientation or contrast discrimination task, involving one of two laterally presented gratings. Greater overall BOLD activation with spatial attention was observed in areas V1-V4 for both tasks. However, multivariate pattern analysis revealed that orientation-selective responses were enhanced by attention only when orientation was the task-relevant feature, and not when the grating’s contrast had to be attended. In a second experiment, observers discriminated the orientation or color of a specific lateral grating. Here, orientation-selective responses were enhanced in both tasks but color-selective responses were enhanced only when color was task-relevant. In both experiments, task-specific enhancement of feature-selective activity was not confined to the attended stimulus location, but instead spread to other locations in the visual field, suggesting the concurrent involvement of a global feature-based attentional mechanism. These results suggest that attention can be remarkably selective in its ability to enhance particular task-relevant features, and further reveal that increases in overall BOLD amplitude are not necessarily accompanied by improved processing of stimulus information. PMID:21632942

Attention improves encoding of task-relevant features in the human visual cortex.

PubMed

Jehee, Janneke F M; Brady, Devin K; Tong, Frank

2011-06-01

When spatial attention is directed toward a particular stimulus, increased activity is commonly observed in corresponding locations of the visual cortex. Does this attentional increase in activity indicate improved processing of all features contained within the attended stimulus, or might spatial attention selectively enhance the features relevant to the observer's task? We used fMRI decoding methods to measure the strength of orientation-selective activity patterns in the human visual cortex while subjects performed either an orientation or contrast discrimination task, involving one of two laterally presented gratings. Greater overall BOLD activation with spatial attention was observed in visual cortical areas V1-V4 for both tasks. However, multivariate pattern analysis revealed that orientation-selective responses were enhanced by attention only when orientation was the task-relevant feature and not when the contrast of the grating had to be attended. In a second experiment, observers discriminated the orientation or color of a specific lateral grating. Here, orientation-selective responses were enhanced in both tasks, but color-selective responses were enhanced only when color was task relevant. In both experiments, task-specific enhancement of feature-selective activity was not confined to the attended stimulus location but instead spread to other locations in the visual field, suggesting the concurrent involvement of a global feature-based attentional mechanism. These results suggest that attention can be remarkably selective in its ability to enhance particular task-relevant features and further reveal that increases in overall BOLD amplitude are not necessarily accompanied by improved processing of stimulus information.

Resolving the Origin of Pseudo-Single Domain Magnetic Behavior

NASA Astrophysics Data System (ADS)

Roberts, Andrew P.; Almeida, Trevor P.; Church, Nathan S.; Harrison, Richard J.; Heslop, David; Li, Yiliang; Li, Jinhua; Muxworthy, Adrian R.; Williams, Wyn; Zhao, Xiang

2017-12-01

The term "pseudo-single domain" (PSD) has been used to describe the transitional state in rock magnetism that spans the particle size range between the single domain (SD) and multidomain (MD) states. The particle size range for the stable SD state in the most commonly occurring terrestrial magnetic mineral, magnetite, is so narrow ( 20-75 nm) that it is widely considered that much of the paleomagnetic record of interest is carried by PSD rather than stable SD particles. The PSD concept has, thus, become the dominant explanation for the magnetization associated with a major fraction of particles that record paleomagnetic signals throughout geological time. In this paper, we argue that in contrast to the SD and MD states, the term PSD does not describe the relevant physical processes, which have been documented extensively using three-dimensional micromagnetic modeling and by parallel research in material science and solid-state physics. We also argue that features attributed to PSD behavior can be explained by nucleation of a single magnetic vortex immediately above the maximum stable SD transition size. With increasing particle size, multiple vortices, antivortices, and domain walls can nucleate, which produce variable cancellation of magnetic moments and a gradual transition into the MD state. Thus, while the term PSD describes a well-known transitional state, it fails to describe adequately the physics of the relevant processes. We recommend that use of this term should be discontinued in favor of "vortex state," which spans a range of behaviors associated with magnetic vortices.

International variation in neighborhood walkability, transit, and recreation environments using geographic information systems: the IPEN adult study.

PubMed

Adams, Marc A; Frank, Lawrence D; Schipperijn, Jasper; Smith, Graham; Chapman, James; Christiansen, Lars B; Coffee, Neil; Salvo, Deborah; du Toit, Lorinne; Dygrýn, Jan; Hino, Adriano Akira Ferreira; Lai, Poh-chin; Mavoa, Suzanne; Pinzón, José David; Van de Weghe, Nico; Cerin, Ester; Davey, Rachel; Macfarlane, Duncan; Owen, Neville; Sallis, James F

2014-10-25

The World Health Organization recommends strategies to improve urban design, public transportation, and recreation facilities to facilitate physical activity for non-communicable disease prevention for an increasingly urbanized global population. Most evidence supporting environmental associations with physical activity comes from single countries or regions with limited variation in urban form. This paper documents variation in comparable built environment features across countries from diverse regions. The International Physical Activity and the Environment Network (IPEN) study of adults aimed to measure the full range of variation in the built environment using geographic information systems (GIS) across 12 countries on 5 continents. Investigators in Australia, Belgium, Brazil, Colombia, the Czech Republic, Denmark, China, Mexico, New Zealand, Spain, the United Kingdom, and the United States followed a common research protocol to develop internationally comparable measures. Using detailed instructions, GIS-based measures included features such as walkability (i.e., residential density, street connectivity, mix of land uses), and access to public transit, parks, and private recreation facilities around each participant's residential address using 1-km and 500-m street network buffers. Eleven of 12 countries and 15 cities had objective GIS data on built environment features. We observed a 38-fold difference in median residential densities, a 5-fold difference in median intersection densities and an 18-fold difference in median park densities. Hong Kong had the highest and North Shore, New Zealand had the lowest median walkability index values, representing a difference of 9 standard deviations in GIS-measured walkability. Results show that comparable measures can be created across a range of cultural settings revealing profound global differences in urban form relevant to physical activity. These measures allow cities to be ranked more precisely than previously possible. The highly variable measures of urban form will be used to explain individuals' physical activity, sedentary behaviors, body mass index, and other health outcomes on an international basis. Present measures provide the ability to estimate dose-response relationships from projected changes to the built environment that would otherwise be impossible.

Data driven analysis of rain events: feature extraction, clustering, microphysical /macro physical relationship

NASA Astrophysics Data System (ADS)

Djallel Dilmi, Mohamed; Mallet, Cécile; Barthes, Laurent; Chazottes, Aymeric

2017-04-01

The study of rain time series records is mainly carried out using rainfall rate or rain accumulation parameters estimated on a fixed integration time (typically 1 min, 1 hour or 1 day). In this study we used the concept of rain event. In fact, the discrete and intermittent natures of rain processes make the definition of some features inadequate when defined on a fixed duration. Long integration times (hour, day) lead to mix rainy and clear air periods in the same sample. Small integration time (seconds, minutes) will lead to noisy data with a great sensibility to detector characteristics. The analysis on the whole rain event instead of individual short duration samples of a fixed duration allows to clarify relationships between features, in particular between macro physical and microphysical ones. This approach allows suppressing the intra-event variability partly due to measurement uncertainties and allows focusing on physical processes. An algorithm based on Genetic Algorithm (GA) and Self Organising Maps (SOM) is developed to obtain a parsimonious characterisation of rain events using a minimal set of variables. The use of self-organizing map (SOM) is justified by the fact that it allows to map a high dimensional data space in a two-dimensional space while preserving as much as possible the initial space topology in an unsupervised way. The obtained SOM allows providing the dependencies between variables and consequently removing redundant variables leading to a minimal subset of only five features (the event duration, the rain rate peak, the rain event depth, the event rain rate standard deviation and the absolute rain rate variation of order 0.5). To confirm relevance of the five selected features the corresponding SOM is analyzed. This analysis shows clearly the existence of relationships between features. It also shows the independence of the inter-event time (IETp) feature or the weak dependence of the Dry percentage in event (Dd%e) feature. This confirms that a rain time series can be considered by an alternation of independent rain event and no rain period. The five selected feature are used to perform a hierarchical clustering of the events. The well-known division between stratiform and convective events appears clearly. This classification into two classes is then refined in 5 fairly homogeneous subclasses. The data driven analysis performed on whole rain events instead of fixed length samples allows identifying strong relationships between macrophysics (based on rain rate) and microphysics (based on raindrops) features. We show that among the 5 identified subclasses some of them have specific microphysics characteristics. Obtaining information on microphysical characteristics of rainfall events from rain gauges measurement suggests many implications in development of the quantitative precipitation estimation (QPE), for the improvement of rain rate retrieval algorithm in remote sensing context.

Adaptive resolution simulation of oligonucleotides

NASA Astrophysics Data System (ADS)

Netz, Paulo A.; Potestio, Raffaello; Kremer, Kurt

2016-12-01

Nucleic acids are characterized by a complex hierarchical structure and a variety of interaction mechanisms with other molecules. These features suggest the need of multiscale simulation methods in order to grasp the relevant physical properties of deoxyribonucleic acid (DNA) and RNA using in silico experiments. Here we report an implementation of a dual-resolution modeling of a DNA oligonucleotide in physiological conditions; in the presented setup only the nucleotide molecule and the solvent and ions in its proximity are described at the atomistic level; in contrast, the water molecules and ions far from the DNA are represented as computationally less expensive coarse-grained particles. Through the analysis of several structural and dynamical parameters, we show that this setup reliably reproduces the physical properties of the DNA molecule as observed in reference atomistic simulations. These results represent a first step towards a realistic multiscale modeling of nucleic acids and provide a quantitatively solid ground for their simulation using dual-resolution methods.

Heat transfer from nanoparticles: a corresponding state analysis.

PubMed

Merabia, Samy; Shenogin, Sergei; Joly, Laurent; Keblinski, Pawel; Barrat, Jean-Louis

2009-09-08

In this contribution, we study situations in which nanoparticles in a fluid are strongly heated, generating high heat fluxes. This situation is relevant to experiments in which a fluid is locally heated by using selective absorption of radiation by solid particles. We first study this situation for different types of molecular interactions, using models for gold particles suspended in octane and in water. As already reported in experiments, very high heat fluxes and temperature elevations (leading eventually to particle destruction) can be observed in such situations. We show that a very simple modeling based on Lennard-Jones (LJ) interactions captures the essential features of such experiments and that the results for various liquids can be mapped onto the LJ case, provided a physically justified (corresponding state) choice of parameters is made. Physically, the possibility of sustaining very high heat fluxes is related to the strong curvature of the interface that inhibits the formation of an insulating vapor film.

Progress in high-energy cosmic ray physics

NASA Astrophysics Data System (ADS)

Mollerach, S.; Roulet, E.

2018-01-01

We review some of the recent progress in our knowledge about high-energy cosmic rays, with an emphasis on the interpretation of the different observational results. We discuss the effects that are relevant to shape the cosmic ray spectrum and the explanations proposed to account for its features and for the observed changes in composition. The physics of air-showers is summarized and we also present the results obtained on the proton-air cross section and on the muon content of the showers. We discuss the cosmic ray propagation through magnetic fields, the effects of diffusion and of magnetic lensing, the cosmic ray interactions with background radiation fields and the production of secondary neutrinos and photons. We also consider the cosmic ray anisotropies, both at large and small angular scales, presenting the results obtained from the TeV up to the highest energies and discuss the models proposed to explain their origin.

Physical Regulation of the Self-Assembly of Tobacco Mosaic Virus Coat Protein

PubMed Central

Kegel, Willem K.; van der Schoot, Paul

2006-01-01

We present a statistical mechanical model based on the principle of mass action that explains the main features of the in vitro aggregation behavior of the coat protein of tobacco mosaic virus (TMV). By comparing our model to experimentally obtained stability diagrams, titration experiments, and calorimetric data, we pin down three competing factors that regulate the transitions between the different kinds of aggregated state of the coat protein. These are hydrophobic interactions, electrostatic interactions, and the formation of so-called “Caspar” carboxylate pairs. We suggest that these factors could be universal and relevant to a large class of virus coat proteins. PMID:16731551

Influence of surface heterogeneity in electroosmotic flows—Implications in chromatography, fluid mixing, and chemical reactions in microdevices

NASA Astrophysics Data System (ADS)

Adrover, Alessandra; Giona, Massimiliano; Pagnanelli, Francesca; Toro, Luigi

2007-04-01

We analyze the influence of surface heterogeneity, inducing a random ζ-potential at the walls in electroosmotic incompressible flows. Specifically, we focus on how surface heterogeneity modifies the physico-chemical processes (transport, chemical reaction, mixing) occurring in microchannel and microreactors. While the macroscopic short-time features associated with solute transport (e.g. chromatographic patterns) do not depend significantly on ζ-potential heterogeneity, spatial randomness in the surface ζ-potential modifies the spectral properties of the advection-diffusion operator, determining different long-term properties of transport/reaction phenomena compared to the homogeneous case. Examples of physical relevance (chromatography, infinitely fast reactions) are addressed.

Clinical anatomy of the elbow and shoulder.

PubMed

Villaseñor-Ovies, Pablo; Vargas, Angélica; Chiapas-Gasca, Karla; Canoso, Juan J; Hernández-Díaz, Cristina; Saavedra, Miguel Ángel; Navarro-Zarza, José Eduardo; Kalish, Robert A

The elbow patients herein discussed feature common soft tissue conditions such as tennis elbow, golfers' elbow and olecranon bursitis. Relevant anatomical structures for these conditions can easily be identified and demonstrated by cross examination by instructors and participants. Patients usually present rotator cuff tendinopathy, frozen shoulder, axillary neuropathy and suprascapular neuropathy. The structures involved in tendinopathy and frozen shoulder can be easily identified and demonstrated under normal conditions. The axillary and the suprascapular nerves have surface landmarks but cannot be palpated. In neuropathy however, physical findings in both neuropathies are pathognomonic and will be discussed. Copyright © 2012 Elsevier España, S.L. All rights reserved.

Flame propagation in two-dimensional solids: Particle-resolved studies with complex plasmas

NASA Astrophysics Data System (ADS)

Yurchenko, S. O.; Yakovlev, E. V.; Couëdel, L.; Kryuchkov, N. P.; Lipaev, A. M.; Naumkin, V. N.; Kislov, A. Yu.; Ovcharov, P. V.; Zaytsev, K. I.; Vorob'ev, E. V.; Morfill, G. E.; Ivlev, A. V.

2017-10-01

Using two-dimensional (2D) complex plasmas as an experimental model system, particle-resolved studies of flame propagation in classical 2D solids are carried out. Combining experiments, theory, and molecular dynamics simulations, we demonstrate that the mode-coupling instability operating in 2D complex plasmas reveals all essential features of combustion, such as an activated heat release, two-zone structure of the self-similar temperature profile ("flame front"), as well as thermal expansion of the medium and temperature saturation behind the front. The presented results are of relevance for various fields ranging from combustion and thermochemistry, to chemical physics and synthesis of materials.

On the dynamical basis of the classification of normal galaxies

PubMed Central

Haass, J.; Bertin, G.; Lin, C. C.

1982-01-01

Some realistic galaxy models have been found to support discrete unstable spiral modes. Here, through the study of the relevant physical mechanisms and an extensive numerical investigation of the properties of the dominant modes in a wide class of galactic equilibria, we show how spiral structures are excited with different morphological features, depending on the properties of the equilibrium model. We identify the basic dynamical parameters and mechanisms and compare the resulting morphology of spiral modes with the actual classification of galaxies. The present study suggests a dynamical basis for the transition among various types and subclasses of normal and barred spiral galaxies. Images PMID:16593200

Giant surfactants provide a versatile platform for sub-10-nm nanostructure engineering

PubMed Central

Yu, Xinfei; Yue, Kan; Hsieh, I-Fan; Li, Yiwen; Dong, Xue-Hui; Liu, Chang; Xin, Yu; Wang, Hsiao-Fang; Shi, An-Chang; Newkome, George R.; Chen, Er-Qiang; Zhang, Wen-Bin; Cheng, Stephen Z. D.

2013-01-01

The engineering of structures across different length scales is central to the design of novel materials with controlled macroscopic properties. Herein, we introduce a unique class of self-assembling materials, which are built upon shape- and volume-persistent molecular nanoparticles and other structural motifs, such as polymers, and can be viewed as a size-amplified version of the corresponding small-molecule counterparts. Among them, “giant surfactants” with precise molecular structures have been synthesized by “clicking” compact and polar molecular nanoparticles to flexible polymer tails of various composition and architecture at specific sites. Capturing the structural features of small-molecule surfactants but possessing much larger sizes, giant surfactants bridge the gap between small-molecule surfactants and block copolymers and demonstrate a duality of both materials in terms of their self-assembly behaviors. The controlled structural variations of these giant surfactants through precision synthesis further reveal that their self-assemblies are remarkably sensitive to primary chemical structures, leading to highly diverse, thermodynamically stable nanostructures with feature sizes around 10 nm or smaller in the bulk, thin-film, and solution states, as dictated by the collective physical interactions and geometric constraints. The results suggest that this class of materials provides a versatile platform for engineering nanostructures with sub-10-nm feature sizes. These findings are not only scientifically intriguing in understanding the chemical and physical principles of the self-assembly, but also technologically relevant, such as in nanopatterning technology and microelectronics. PMID:23716680

Is filtering difficulty the basis of attentional deficits in schizophrenia?

PubMed

Ravizza, Susan M; Robertson, Lynn C; Carter, Cameron S; Nordahl, Thomas E; Salo, Ruth E

2007-06-30

The distractibility that schizophrenia patients display may be the result of a deficiency in filtering out irrelevant information. The aim of the current study was to assess whether patients with schizophrenia exhibit greater difficulty when task-irrelevant features change compared to healthy participants. Thirteen medicated outpatients with a diagnosis of schizophrenia and thirteen age- and parental education-matched controls performed a target selection task in which the task-relevant letter or the task-irrelevant features of color, and/or location repeated or switched. Participants were required to respond by pressing the appropriate key associated with the target letter. These patients with schizophrenia were slower when the task-relevant target letter switched than when it repeated. In contrast, schizophrenia patients performed similarly to controls when task-irrelevant information changed. Thus, we found no evidence that patients with schizophrenia were impaired in inhibiting irrelevant perceptual features. In contrast, changes in task-relevant features were problematic for patients relative to control participants. These results suggest that medicated outpatients who are mild to moderately symptomatic do not exhibit global impairments of feature processing. Instead, impairments are restricted to situations when task-relevant features vary. The current findings also suggest that when a course of action is not implied by an irrelevant feature, outpatients' behavior is not modulated by extraneous visual information any more than in healthy controls.

Structure and Function in Homodimeric Enzymes: Simulations of Cooperative and Independent Functional Motions.

PubMed

Wells, Stephen A; van der Kamp, Marc W; McGeagh, John D; Mulholland, Adrian J

2015-01-01

Large-scale conformational change is a common feature in the catalytic cycles of enzymes. Many enzymes function as homodimers with active sites that contain elements from both chains. Symmetric and anti-symmetric cooperative motions in homodimers can potentially lead to correlated active site opening and/or closure, likely to be important for ligand binding and release. Here, we examine such motions in two different domain-swapped homodimeric enzymes: the DcpS scavenger decapping enzyme and citrate synthase. We use and compare two types of all-atom simulations: conventional molecular dynamics simulations to identify physically meaningful conformational ensembles, and rapid geometric simulations of flexible motion, biased along normal mode directions, to identify relevant motions encoded in the protein structure. The results indicate that the opening/closure motions are intrinsic features of both unliganded enzymes. In DcpS, conformational change is dominated by an anti-symmetric cooperative motion, causing one active site to close as the other opens; however a symmetric motion is also significant. In CS, we identify that both symmetric (suggested by crystallography) and asymmetric motions are features of the protein structure, and as a result the behaviour in solution is largely non-cooperative. The agreement between two modelling approaches using very different levels of theory indicates that the behaviours are indeed intrinsic to the protein structures. Geometric simulations correctly identify and explore large amplitudes of motion, while molecular dynamics simulations indicate the ranges of motion that are energetically feasible. Together, the simulation approaches are able to reveal unexpected functionally relevant motions, and highlight differences between enzymes.

Structure and Function in Homodimeric Enzymes: Simulations of Cooperative and Independent Functional Motions

PubMed Central

McGeagh, John D.; Mulholland, Adrian J.

2015-01-01

Large-scale conformational change is a common feature in the catalytic cycles of enzymes. Many enzymes function as homodimers with active sites that contain elements from both chains. Symmetric and anti-symmetric cooperative motions in homodimers can potentially lead to correlated active site opening and/or closure, likely to be important for ligand binding and release. Here, we examine such motions in two different domain-swapped homodimeric enzymes: the DcpS scavenger decapping enzyme and citrate synthase. We use and compare two types of all-atom simulations: conventional molecular dynamics simulations to identify physically meaningful conformational ensembles, and rapid geometric simulations of flexible motion, biased along normal mode directions, to identify relevant motions encoded in the protein structure. The results indicate that the opening/closure motions are intrinsic features of both unliganded enzymes. In DcpS, conformational change is dominated by an anti-symmetric cooperative motion, causing one active site to close as the other opens; however a symmetric motion is also significant. In CS, we identify that both symmetric (suggested by crystallography) and asymmetric motions are features of the protein structure, and as a result the behaviour in solution is largely non-cooperative. The agreement between two modelling approaches using very different levels of theory indicates that the behaviours are indeed intrinsic to the protein structures. Geometric simulations correctly identify and explore large amplitudes of motion, while molecular dynamics simulations indicate the ranges of motion that are energetically feasible. Together, the simulation approaches are able to reveal unexpected functionally relevant motions, and highlight differences between enzymes. PMID:26241964

Neglected features of lifestyle: Their relevance in non-alcoholic fatty liver disease

PubMed Central

Trovato, Francesca M; Martines, Giuseppe Fabio; Brischetto, Daniela; Trovato, Guglielmo; Catalano, Daniela

2016-01-01

AIM To investigated in non-alcoholic-fatty-liver-disease (NAFLD), with ultrasound (US)-detected fatty liver, and in a group of non-alcoholic and otherwise healthy subjects, relationship of neglected features of lifestyle with NAFLD and obesity. METHODS Five hundred and thirty-two NAFLD and 667 non-NAFLD healthy subjects, age 21-60 years were studied. Severity of liver steatosis was assessed by US bright liver score. The adherence to mediterranean diet score (AMDS) was assessed on the basis of a 1-wk recall computerized questionnaire which included a detailed physical activity reports (Baecke questionnaire). The western dietary profile score, as a simplified paradigm of unhealthy diet, a questionnaire quantifying sun exposure score and a sleep habits questionnaires provided a further comprehensive lifestyle assessment. RESULTS Body mass index (BMI), insulin resistance (HOMA), and triglycerides, poorer adherence to a mediterranean diet profile, sedentary habits, minor sun exposure and use of “western diet” foods are greater in NAFLD. Multiple linear regression analysis, weighted by years of age, displays BMI, HOMA and AMDS as the most powerful independent predictors of fatty liver severity; however, also the physical activity score, the western diet habit and the sun exposure score are acting inside the model with significant independent effects. CONCLUSION Articulated clinical intervention, according to our results, are justified in NAFLD and can be pursued addressing by focused intervention nutritional profile, physical exercise mainly in open-air subsets for enhancing sun exposure and healthier sleep duration and rhythm. PMID:27957244

The CEOP Inter-Monsoon Studies (CIMS)

NASA Technical Reports Server (NTRS)

Lau, William K. M.

2003-01-01

Prediction of climate relies on models, and better model prediction depends on good model physics. Improving model physics requires the maximal utilization of climate data of the past, present and future. CEOP provides the first example of a comprehensive, integrated global and regional data set, consisting of globally gridded data, reference site in-situ observations, model location time series (MOLTS), and integrated satellite data for a two-year period covering two complete annual cycles of 2003-2004. The monsoon regions are the most important socio-economically in terms of devastation by floods and droughts, and potential impacts from climate change md fluctuatinns nf the hydrologic cyc!e. Scientifically, it is most challenging, because of complex interactions of atmosphere, land and oceans, local vs. remote forcings in contributing to climate variability and change in the region. Given that many common features, and physical teleconnection exist among different monsoon regions, an international research focus on monsoon must be coordinated and sustained. Current models of the monsoon are grossly inadequate for regional predictions. For improvement, models must be confronted with relevant observations, and model physic developers must be made to be aware of the wealth of information from existing climate data, field measurements, and satellite data that can be used to improve models. Model transferability studles must be conducted. CIMS is a major initiative under CEOP to engage the modeling and the observational communities to join in a coordinated effort to study the monsoons. The objectives of CIMS are (a) To provide a better understanding of fundamental physical processes (diurnal cycle, annual cycle, and intraseasonal oscillations) in monsoon regions around the world and (b) To demonstrate the synergy and utility of CEOP data in providing a pathway for model physics evaluation and improvement. In this talk, I will present the basic concepts of CIMS and the key scientific problems facing monsoon climates and provide examples of common monsoon features, and possible monsoon induced teleconnections linking different parts of the world.

About the composition of self-relevance: Conjunctions not features are bound to the self.

PubMed

Schäfer, Sarah; Frings, Christian; Wentura, Dirk

2016-06-01

Sui and colleagues (Journal of Experimental Psychology: Human Perception and Performance, 38, 1105-1117, 2012) introduced a matching paradigm to investigate prioritized processing of instructed self-relevance. They arbitrarily assigned simple geometric shapes to the participant and two other persons. Subsequently, the task was to judge whether label-shape pairings matched or not. The authors found a remarkable self-prioritization effect, that is, for matching self-related trials verification was very fast and accurate in comparison to the non-matching conditions. We analyzed whether single features or feature conjunctions are tagged to the self. In particular, we assigned colored shapes to the labels and included partial-matching trials (i.e., trials in which only one feature matched the label, whereas the other feature did not match the label). If single features are tagged to the self, partial matches would result in interference, whereas they should elicit the same data pattern as non-matching trials if only feature conjunctions are tagged to the self. Our data suggest the latter; only feature conjunctions are tagged to the self and are processed in a prioritized manner. This result emphasizes the functionality of self-relevance as a selection mechanism.

Average vs item response theory scores: an illustration using neighbourhood measures in relation to physical activity in adults with arthritis.

PubMed

Mielenz, T J; Callahan, L F; Edwards, M C

2017-01-01

Our study had two main objectives: 1) to determine whether perceived neighbourhood physical features are associated with physical activity levels in adults with arthritis; and 2) to determine whether the conclusions are more precise when item response theory (IRT) scores are used instead of average scores for the perceived neighbourhood physical features scales. Information on health outcomes, neighbourhood characteristics, and physical activity levels were collected using a telephone survey of 937 participants with self-reported arthritis. Neighbourhood walkability and aesthetic features and physical activity levels were measured by self-report. Adjusted proportional odds models were constructed separately for each neighbourhood physical features scale. We found that among adults with arthritis, poorer perceived neighbourhood physical features (both walkability and aesthetics) are associated with decreased physical activity level compared to better perceived neighbourhood features. This association was only observed in our adjusted models when IRT scoring was employed with the neighbourhood physical feature scales (walkability scale: odds ratio [OR] 1.20, 95% confidence interval [CI] 1.02, 1.41; aesthetics scale: OR 1.32, 95% CI 1.09, 1.62), not when average scoring was used (walkability scale: OR 1.14, 95% CI 1.00, 1.30; aesthetics scale: OR 1.16, 95% CI 1.00, 1.36). In adults with arthritis, those reporting poorer walking and aesthetics features were found to have decreased physical activity levels compared to those reporting better features when IRT scores were used, but not when using average scores. This study may inform public health physical environmental interventions implemented to increase physical activity, especially since arthritis prevalence is expected to be close to 20% of the population in 2020. Based on NIH initiatives, future health research will utilize IRT scores. The differences found in this study may be a precursor for research on how past and future treatment effects may vary between these two types of measurement scores. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Therapeutic considerations of sarcopenia in heart failure patients.

PubMed

Saitoh, Masakazu; Ebner, Nicole; von Haehling, Stephan; Anker, Stefan D; Springer, Jochen

2018-02-01

Sarcopenia is a common feature, and affects 20-47% of patients with heart failure (HF). Sarcopenia is also an independent predictor of impaired functional capacity, even after adjusting for clinical relevant variables, which is associated with adverse outcome in patients with HF. Areas covered: Several different pathophysiological pathways are involved in sarcopenic processes including altered nutrient intake and absorption, hormonal factor, inflammatory processes, oxidative stress, cellular proteolysis, and unhealthy lifestyle. Nutritional therapy, physical activity and/or exercise training have been associated with improved muscle mass or physical performance in HF. Few studies reported beneficial effects for muscle mass and physical performance, in those who received angiotensin-converting enzyme (ACE) inhibitors, or/and beta-blocker. In addition, testosterone, selective androgen receptor modulators, ghrelin agonist and myostatin inhibitors are currently under study as possible future therapeutic options. Expert commentary: Regular and adequate level of physical activity and/or exercise training, and sufficient nutritional intake or special nutritional supplementation may represent the best strategy for prevention or delay of sarcopenia and worsening physical performance in patients with HF. Maximal tolerated dosages of standard therapies for HF such as ACE-inhibitors or beta-blockers are first-line strategy, however it is difficult to recommend other pharmacological agents as part of routine treatment of sarcopenia.

2D and 3D virtual interactive laboratories of physics on Unity platform

NASA Astrophysics Data System (ADS)

González, J. D.; Escobar, J. H.; Sánchez, H.; De la Hoz, J.; Beltrán, J. R.

2017-12-01

Using the cross-platform game engine Unity, we develop virtual laboratories for PC, consoles, mobile devices and website as an innovative tool to study physics. There is extensive uptake of ICT in the teaching of science and its impact on the learning, and considering the limited availability of laboratories for physics teaching and the difficulties this causes in the learning of school students, we design the virtual laboratories to enhance studentâĂŹs knowledge of concepts in physics. To achieve this goal, we use Unity due to provide support bump mapping, reflection mapping, parallax mapping, dynamics shadows using shadows maps, full-screen post-processing effects and render-to-texture. Unity can use the best variant for the current video hardware and, if none are compatible, to use an alternative shader that may sacrifice features for performance. The control over delivery to mobile devices, web browsers, consoles and desktops is the main reason Unity is the best option among the same kind cross-platform. Supported platforms include Android, Apple TV, Linux, iOS, Nintendo 3DS line, macOS, PlayStation 4, Windows Phone 8, Wii but also an asset server and Nvidia’s PhysX physics engine which is the most relevant tool on Unity for our PhysLab.

Associations between park features and adolescent park use for physical activity.

PubMed

Edwards, Nicole; Hooper, Paula; Knuiman, Matthew; Foster, Sarah; Giles-Corti, Billie

2015-02-18

Eighty per cent of adolescents globally do insufficient physical activity. Parks are a popular place for adolescents to be active. However, little is known about which park features are associated with higher levels of park use by adolescents. This study aimed to examine which environmental park features, and combination of features, were correlated with higher levels of park use for physical activity among adolescents. By examining park features in parks used by adolescents for physical activity, this study also aimed to create a park 'attractiveness' score predictive of adolescent park use, and to identify factors that might predict use of their closest park. Adolescents (n = 1304) living in Geraldton, a large rural centre of Western Australia, completed a survey that measured physical activity behaviour, perceptions of park availability and the main park used for physical activity. All parks in the study area (n = 58) were digitized using a Geographic Information System (GIS) and features audited using the Public Open Space Desktop Auditing Tool (POSDAT). Only 27% of participants reported using their closest park for physical activity. Park use was associated with seven features: presence of a skate park, walking paths, barbeques, picnic table, public access toilets, lighting around courts and equipment and number of trees >25. When combined to create an overall attractiveness score, every additional 'attractive' feature present, resulted in a park being nearly three times more likely to be in the high use category. To increase park use for physical activity, urban planners and designers should incorporate park features attractive to adolescents.

A 'learning-by-doing' treatment planning tutorial for medical physicists.

PubMed

Meyer, J; Hartmann, B; Kalet, I

2009-06-01

A framework for a tutorial for treatment planning in radiation oncology physics was developed, based on the University of Washington treatment planning system Prism. The tutorial is aimed at students in Medical Physics to accompany the lectures on treatment planning to enhance their theoretical knowledge. A web-based layout was chosen to allow independent work of the students. The tutorial guides the students through three different learning modules, designed mainly to enhance their understanding of the processes involved in treatment planning but also to learn the specific features of a modern treatment planning system. Each of the modules contains four units, with the aim to introduce the relevant Prism features, practice skills in different tasks and finally check the learning outcomes with a challenge and a self-scoring quiz. A survey for students' feedback completes the tutorial. Various tools and learning methods help to create an interactive, appealing learning environment, in which the emphasis is shifted from teacher-centred to student-centred learning paradigms. In summary, Prism lends itself well for educational purposes. The tutorial covers all main aspects of treatment planning. In its current form the tutorial is self-contained but still adjustable and expandable. The tutorial can be made available upon request to the authors.

Visualizing spatial correlation: structural and electronic orders in iron-based superconductors on atomic scale

NASA Astrophysics Data System (ADS)

Maksov, Artem; Ziatdinov, Maxim; Li, Li; Sefat, Athena; Maksymovych, Petro; Kalinin, Sergei

Crystalline matter on the nanoscale level often exhibits strongly inhomogeneous structural and electronic orders, which have a profound effect on macroscopic properties. This may be caused by subtle interplay between chemical disorder, strain, magnetic, and structural order parameters. We present a novel approach based on combination of high resolution scanning tunneling microscopy/spectroscopy (STM/S) and deep data style analysis for automatic separation, extraction, and correlation of structural and electronic behavior which might lead us to uncovering the underlying sources of inhomogeneity in in iron-based family of superconductors (FeSe, BaFe2As2) . We identify STS spectral features using physically robust Bayesian linear unmixing, and show their direct relevance to the fundamental physical properties of the system, including electronic states associated with individual defects and impurities. We collect structural data from individual unit cells on the crystalline lattice, and calculate both global and local indicators of spatial correlation with electronic features, demonstrating, for the first time, a direct quantifiable connection between observed structural order parameters extracted from the STM data and electronic order parameters identified within the STS data. This research was sponsored by the Division of Materials Sciences and Engineering, Office of Science, Basic Energy Sciences, US DOE.

Enlarging the `knowledge toolbox': helping students prepare for an innovation-driven world

NASA Astrophysics Data System (ADS)

Nilsen, Elizabeth

2015-03-01

Physics students graduate from their course of studies to enter the ``world of work.'' While for many years that transition meant joining a large corporation for a life-long career, this is no longer the case. Today's graduates will find their career with a series of organizations - often start-ups and small to mid-sized organizations - whose future depends on the ability to rapidly leverage technical knowledge into useful products and services. This session will discuss the value of preparing physics students to be innovators and entrepreneurs, both as a strategy to prepare them for future careers, as well as an opportunity to fully engage students in seeing the relevance of physics to ``real world'' challenges. The session will feature three case studies: 1) embedding core knowledge and skills within a technical content course; 2) building learning experiences around a team-based start-up exploration; 3) engaging an entire department in considering how to comprehensively include innovation & entrepreneurship themes in the curriculum. The session will conclude with information about how faculty members and institutions can access resources for adopting this approach to their course offerings.

Zhang-Rice physics and anomalous copper states in A-site ordered perovskites

PubMed Central

Meyers, D.; Mukherjee, Swarnakamal; Cheng, J.-G.; Middey, S.; Zhou, J.-S.; Goodenough, J. B.; Gray, B. A.; Freeland, J. W.; Saha-Dasgupta, T.; Chakhalian, J.

2013-01-01

In low dimensional cuprates several interesting phenomena, including high Tc superconductivity, are deeply connected to electron correlations on Cu and the presence of the Zhang-Rice (ZR) singlet state. Here, we report on direct spectroscopic observation of the ZR state responsible for the low-energy physical properties in two isostructural A-site ordered cuprate perovskites, CaCu3Co4O12 and CaCu3Cr4O12 as revealed by resonant soft x-ray absorption spectroscopy on the Cu L3,2- and O K-edges. These measurements reveal the signature of Cu in the high-energy 3+ (3d8), the typical 2+ (3d9), as well as features of the ZR singlet state (i.e., 3d9L, L denotes an oxygen hole). First principles GGA + U calculations affirm that the B-site cation controls the degree of Cu-O hybridization and, thus, the Cu valency. These findings introduce another avenue for the study and manipulation of cuprates, bypassing the complexities inherent to conventional chemical doping (i.e. disorder) that hinder the relevant physics. PMID:23666066

Sputtering of ices in the outer solar system

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

Johnson, R.E.

1996-01-01

Exploration of the outer solar system has led to studies in a new area of physics: electronically induced sputtering of low-temperature, condensed-gas solids (ices). Many of the icy bodies in the outer solar system were found to be bombarded by relatively intense fluxes of ions and electrons, causing both changes in their optical reflectance and ejection (sputtering) of molecules from their surfaces. The small cohesive energies of the condensed-gas solids afford relatively large sputtering rates from the electronic excitations produced in the solid by fast ions and electrons. Such sputtering produces an ambient gas about an icy body, often themore » source of the local plasma. This colloquium outlines the physics of the sputtering of ices and its relevance to several outer-solar-system phenomena: the sputter-produced plasma trapped in Saturn{close_quote}s magnetosphere; the O{sub 2} atmosphere on Europa; and optical absorption features such as SO{sub 2} in the surface of Europa and O{sub 2} and, possibly, O{sub 3} in the surface of Ganymede. {copyright} {ital 1996 The American Physical Society.}« less

Physics To Go: an Outreach Digital Library

NASA Astrophysics Data System (ADS)

Lee, Edward V.

2006-12-01

Physics to Go, part of the NSF-funded ComPADRE digital library, is a collection of websites for informal physics learning. This talk will present Physics To Go’s homepage features, show how these features are created, how resources are identified, and how Physics To Go complements other physics outreach websites.

Phenomenological study of decoherence in solid-state spin qubits due to nuclear spin diffusion

NASA Astrophysics Data System (ADS)

Biercuk, Michael J.; Bluhm, Hendrik

2011-06-01

We present a study of the prospects for coherence preservation in solid-state spin qubits using dynamical decoupling protocols. Recent experiments have provided the first demonstrations of multipulse dynamical decoupling sequences in this qubit system, but quantitative analyses of potential coherence improvements have been hampered by a lack of concrete knowledge of the relevant noise processes. We present calculations of qubit coherence under the application of arbitrary dynamical decoupling pulse sequences based on an experimentally validated semiclassical model. This phenomenological approach bundles the details of underlying noise processes into a single experimentally relevant noise power spectral density. Our results show that the dominant features of experimental measurements in a two-electron singlet-triplet spin qubit can be replicated using a 1/ω2 noise power spectrum associated with nuclear spin flips in the host material. Beginning with this validation, we address the effects of nuclear programming, high-frequency nuclear spin dynamics, and other high-frequency classical noise sources, with conjectures supported by physical arguments and microscopic calculations where relevant. Our results provide expected performance bounds and identify diagnostic metrics that can be measured experimentally in order to better elucidate the underlying nuclear spin dynamics.

Addressing trend-related changes within cumulative effects studies in water resources planning

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

Canter, L.W., E-mail: envimptr@aol.com; Chawla, M.K.; Swor, C.T.

2014-01-15

Summarized herein are 28 case studies wherein trend-related causative physical, social, or institutional changes were connected to consequential changes in runoff, water quality, and riparian and aquatic ecological features. The reviewed cases were systematically evaluated relative to their identified environmental effects; usage of analytical frameworks, and appropriate models, methods, and technologies; and the attention given to mitigation and/or management of the resultant causative and consequential changes. These changes also represent important considerations in project design and operation, and in cumulative effects studies associated therewith. The cases were grouped into five categories: institutional changes associated with legislation and policies (seven cases);more » physical changes from land use changes in urbanizing watersheds (eight cases); physical changes from land use changes and development projects in watersheds (four cases); physical, institutional, and social changes from land use and related policy changes in river basins (three cases); and multiple changes within a comprehensive study of land use and policy changes in the Willamette River Basin in Oregon (six cases). A tabulation of 110 models, methods and technologies used in the studies is also presented. General observations from this review were that the features were unique for each case; the consequential changes were logically based on the causative changes; the analytical frameworks provided relevant structures for the studies, and the identified methods and technologies were pertinent for addressing both the causative and consequential changes. One key lesson was that the cases provide useful, “real-world” illustrations of the importance of addressing trend-related changes in cumulative effects studies within water resources planning. Accordingly, they could be used as an “initial tool kit” for addressing trend-related changes.« less

Paving the COWpath: data-driven design of pediatric order sets

PubMed Central

Zhang, Yiye; Padman, Rema; Levin, James E

2014-01-01

Objective Evidence indicates that users incur significant physical and cognitive costs in the use of order sets, a core feature of computerized provider order entry systems. This paper develops data-driven approaches for automating the construction of order sets that match closely with user preferences and workflow while minimizing physical and cognitive workload. Materials and methods We developed and tested optimization-based models embedded with clustering techniques using physical and cognitive click cost criteria. By judiciously learning from users’ actual actions, our methods identify items for constituting order sets that are relevant according to historical ordering data and grouped on the basis of order similarity and ordering time. We evaluated performance of the methods using 47 099 orders from the year 2011 for asthma, appendectomy and pneumonia management in a pediatric inpatient setting. Results In comparison with existing order sets, those developed using the new approach significantly reduce the physical and cognitive workload associated with usage by 14–52%. This approach is also capable of accommodating variations in clinical conditions that affect order set usage and development. Discussion There is a critical need to investigate the cognitive complexity imposed on users by complex clinical information systems, and to design their features according to ‘human factors’ best practices. Optimizing order set generation using cognitive cost criteria introduces a new approach that can potentially improve ordering efficiency, reduce unintended variations in order placement, and enhance patient safety. Conclusions We demonstrate that data-driven methods offer a promising approach for designing order sets that are generalizable, data-driven, condition-based, and up to date with current best practices. PMID:24674844

Developing an Automated Method for Detection of Operationally Relevant Ocean Fronts and Eddies

NASA Astrophysics Data System (ADS)

Rogers-Cotrone, J. D.; Cadden, D. D. H.; Rivera, P.; Wynn, L. L.

2016-02-01

Since the early 90's, the U.S. Navy has utilized an observation-based process for identification of frontal systems and eddies. These Ocean Feature Assessments (OFA) rely on trained analysts to identify and position ocean features using satellite-observed sea surface temperatures. Meanwhile, as enhancements and expansion of the navy's Hybrid Coastal Ocean Model (HYCOM) and Regional Navy Coastal Ocean Model (RNCOM) domains have proceeded, the Naval Oceanographic Office (NAVO) has provided Tactical Oceanographic Feature Assessments (TOFA) that are based on data-validated model output but also rely on analyst identification of significant features. A recently completed project has migrated OFA production to the ArcGIS-based Acoustic Reach-back Cell Ocean Analysis Suite (ARCOAS), enabling use of additional observational datasets and significantly decreasing production time; however, it has highlighted inconsistencies inherent to this analyst-based identification process. Current efforts are focused on development of an automated method for detecting operationally significant fronts and eddies that integrates model output and observational data on a global scale. Previous attempts to employ techniques from the scientific community have been unable to meet the production tempo at NAVO. Thus, a system that incorporates existing techniques (Marr-Hildreth, Okubo-Weiss, etc.) with internally-developed feature identification methods (from model-derived physical and acoustic properties) is required. Ongoing expansions to the ARCOAS toolset have shown promising early results.

Feature saliency and feedback information interactively impact visual category learning

PubMed Central

Hammer, Rubi; Sloutsky, Vladimir; Grill-Spector, Kalanit

2015-01-01

Visual category learning (VCL) involves detecting which features are most relevant for categorization. VCL relies on attentional learning, which enables effectively redirecting attention to object’s features most relevant for categorization, while ‘filtering out’ irrelevant features. When features relevant for categorization are not salient, VCL relies also on perceptual learning, which enables becoming more sensitive to subtle yet important differences between objects. Little is known about how attentional learning and perceptual learning interact when VCL relies on both processes at the same time. Here we tested this interaction. Participants performed VCL tasks in which they learned to categorize novel stimuli by detecting the feature dimension relevant for categorization. Tasks varied both in feature saliency (low-saliency tasks that required perceptual learning vs. high-saliency tasks), and in feedback information (tasks with mid-information, moderately ambiguous feedback that increased attentional load, vs. tasks with high-information non-ambiguous feedback). We found that mid-information and high-information feedback were similarly effective for VCL in high-saliency tasks. This suggests that an increased attentional load, associated with the processing of moderately ambiguous feedback, has little effect on VCL when features are salient. In low-saliency tasks, VCL relied on slower perceptual learning; but when the feedback was highly informative participants were able to ultimately attain the same performance as during the high-saliency VCL tasks. However, VCL was significantly compromised in the low-saliency mid-information feedback task. We suggest that such low-saliency mid-information learning scenarios are characterized by a ‘cognitive loop paradox’ where two interdependent learning processes have to take place simultaneously. PMID:25745404

A new method for constructing networks from binary data

NASA Astrophysics Data System (ADS)

van Borkulo, Claudia D.; Borsboom, Denny; Epskamp, Sacha; Blanken, Tessa F.; Boschloo, Lynn; Schoevers, Robert A.; Waldorp, Lourens J.

2014-08-01

Network analysis is entering fields where network structures are unknown, such as psychology and the educational sciences. A crucial step in the application of network models lies in the assessment of network structure. Current methods either have serious drawbacks or are only suitable for Gaussian data. In the present paper, we present a method for assessing network structures from binary data. Although models for binary data are infamous for their computational intractability, we present a computationally efficient model for estimating network structures. The approach, which is based on Ising models as used in physics, combines logistic regression with model selection based on a Goodness-of-Fit measure to identify relevant relationships between variables that define connections in a network. A validation study shows that this method succeeds in revealing the most relevant features of a network for realistic sample sizes. We apply our proposed method to estimate the network of depression and anxiety symptoms from symptom scores of 1108 subjects. Possible extensions of the model are discussed.

3D facial expression recognition using maximum relevance minimum redundancy geometrical features

NASA Astrophysics Data System (ADS)

Rabiu, Habibu; Saripan, M. Iqbal; Mashohor, Syamsiah; Marhaban, Mohd Hamiruce

2012-12-01

In recent years, facial expression recognition (FER) has become an attractive research area, which besides the fundamental challenges, it poses, finds application in areas, such as human-computer interaction, clinical psychology, lie detection, pain assessment, and neurology. Generally the approaches to FER consist of three main steps: face detection, feature extraction and expression recognition. The recognition accuracy of FER hinges immensely on the relevance of the selected features in representing the target expressions. In this article, we present a person and gender independent 3D facial expression recognition method, using maximum relevance minimum redundancy geometrical features. The aim is to detect a compact set of features that sufficiently represents the most discriminative features between the target classes. Multi-class one-against-one SVM classifier was employed to recognize the seven facial expressions; neutral, happy, sad, angry, fear, disgust, and surprise. The average recognition accuracy of 92.2% was recorded. Furthermore, inter database homogeneity was investigated between two independent databases the BU-3DFE and UPM-3DFE the results showed a strong homogeneity between the two databases.

United States Army physical readiness training: rationale and evaluation of the physical training doctrine.

PubMed

Knapik, Joseph J; Rieger, William; Palkoska, Frank; Van Camp, Steven; Darakjy, Salima

2009-07-01

This paper reviews the rationale and evaluations of Physical Readiness Training (PRT), the new U.S. Army physical training doctrine designed to improve soldiers' physical capability for military operations. The purposes of PRT are to improve physical fitness, prevent injuries, progressively train soldiers, and develop soldiers' self-confidence and discipline. The PRT follows the principles of progressive overload, regularity, specificity, precision, variety, and balance. Specificity was achieved by examining the standard list of military (warrior) tasks and determining 1) the physical requirements, 2) the fitness components involved, and 3) the training activities that most likely could improve the military tasks. Injury-prevention features include reduced running mileage, exercise variety (cross-training), and gradual, progressive training. In 3 military field studies, the overall adjusted risk of injury was 1.5-1.8 times higher in groups of soldiers performing traditional military physical training programs when compared with groups using a PRT program. Scores on the Army Physical Fitness Test were similar or higher in groups using PRT programs. In an 8-week laboratory study comparing PRT with a weightlifting/running program, both programs resulted in major improvements in militarily relevant tasks (e.g., 3.2-km walk/run with 32-kg load, 400-m run with 18-kg load, 5- to 30-second rushes to and from prone position, 80-kg casualty drag, obstacle course). When compared with traditional military physical training programs, PRT consistently resulted in fewer injuries and in equal or greater improvements in fitness and military task performance.

Better physical activity classification using smartphone acceleration sensor.

PubMed

Arif, Muhammad; Bilal, Mohsin; Kattan, Ahmed; Ahamed, S Iqbal

2014-09-01

Obesity is becoming one of the serious problems for the health of worldwide population. Social interactions on mobile phones and computers via internet through social e-networks are one of the major causes of lack of physical activities. For the health specialist, it is important to track the record of physical activities of the obese or overweight patients to supervise weight loss control. In this study, acceleration sensor present in the smartphone is used to monitor the physical activity of the user. Physical activities including Walking, Jogging, Sitting, Standing, Walking upstairs and Walking downstairs are classified. Time domain features are extracted from the acceleration data recorded by smartphone during different physical activities. Time and space complexity of the whole framework is done by optimal feature subset selection and pruning of instances. Classification results of six physical activities are reported in this paper. Using simple time domain features, 99 % classification accuracy is achieved. Furthermore, attributes subset selection is used to remove the redundant features and to minimize the time complexity of the algorithm. A subset of 30 features produced more than 98 % classification accuracy for the six physical activities.

Comparative evaluation of features and techniques for identifying activity type and estimating energy cost from accelerometer data

PubMed Central

Kate, Rohit J.; Swartz, Ann M.; Welch, Whitney A.; Strath, Scott J.

2016-01-01

Wearable accelerometers can be used to objectively assess physical activity. However, the accuracy of this assessment depends on the underlying method used to process the time series data obtained from accelerometers. Several methods have been proposed that use this data to identify the type of physical activity and estimate its energy cost. Most of the newer methods employ some machine learning technique along with suitable features to represent the time series data. This paper experimentally compares several of these techniques and features on a large dataset of 146 subjects doing eight different physical activities wearing an accelerometer on the hip. Besides features based on statistics, distance based features and simple discrete features straight from the time series were also evaluated. On the physical activity type identification task, the results show that using more features significantly improve results. Choice of machine learning technique was also found to be important. However, on the energy cost estimation task, choice of features and machine learning technique were found to be less influential. On that task, separate energy cost estimation models trained specifically for each type of physical activity were found to be more accurate than a single model trained for all types of physical activities. PMID:26862679

A curricular frame for physics education: Development, comparison with students' interests, and impact on students' achievement and self-concept

NASA Astrophysics Data System (ADS)

Häussler, Peter; Hoffmann, Lore

2000-11-01

This article presents three interlinked studies aimed at: (1) developing a curricular frame for physics education; (2) assessing the students' interest in the contents, contexts, and activities that are suggested by that curricular frame; and (3) developing a curriculum that is in line with that frame and measuring its cognitive and emotional effects on students. The curricular frame was developed by adopting the Delphi technique and drawing on the expertise of 73 persons selected according to specified selection criteria. Interest data of some 8000 students and information of the presently taught physics curriculum were sampled longitudinally as well as cross-sectionally in various German Länder (states) by questionnaire. The third study comprised 23 experimental and 7 control classes. As a result of the comparison between the features of the curricular frame, the interest structure of students, and the current physics curriculum, there is a remarkable congruency between students' interest in physics and the kind of physics education identified in the Delphi study as being relevant. However, there is a considerable discrepancy between students' interest and the kind of physics instruction practiced in the physics classroom. Regression analysis revealed that students' interest in physics as a school subject is hardly related to their interest in physics, but mainly to the students' self-esteem of being good achievers. The data strongly suggest physics be taught so that students have a chance to develop a positive physics-related self-concept and to link physics with situations they encounter outside the classroom. A curriculum based on these principles proved superior compared to a traditional curriculum.

Prediction of lysine glutarylation sites by maximum relevance minimum redundancy feature selection.

PubMed

Ju, Zhe; He, Jian-Jun

2018-06-01

Lysine glutarylation is new type of protein acylation modification in both prokaryotes and eukaryotes. To better understand the molecular mechanism of glutarylation, it is important to identify glutarylated substrates and their corresponding glutarylation sites accurately. In this study, a novel bioinformatics tool named GlutPred is developed to predict glutarylation sites by using multiple feature extraction and maximum relevance minimum redundancy feature selection. On the one hand, amino acid factors, binary encoding, and the composition of k-spaced amino acid pairs features are incorporated to encode glutarylation sites. And the maximum relevance minimum redundancy method and the incremental feature selection algorithm are adopted to remove the redundant features. On the other hand, a biased support vector machine algorithm is used to handle the imbalanced problem in glutarylation sites training dataset. As illustrated by 10-fold cross-validation, the performance of GlutPred achieves a satisfactory performance with a Sensitivity of 64.80%, a Specificity of 76.60%, an Accuracy of 74.90% and a Matthew's correlation coefficient of 0.3194. Feature analysis shows that some k-spaced amino acid pair features play the most important roles in the prediction of glutarylation sites. The conclusions derived from this study might provide some clues for understanding the molecular mechanisms of glutarylation. Copyright © 2018 Elsevier Inc. All rights reserved.

Burnout during residency training: a literature review.

PubMed

Ishak, Waguih William; Lederer, Sara; Mandili, Carla; Nikravesh, Rose; Seligman, Laurie; Vasa, Monisha; Ogunyemi, Dotun; Bernstein, Carol A

2009-12-01

Burnout is a state of mental and physical exhaustion related to work or care giving activities. Burnout during residency training has gained significant attention secondary to concerns regarding job performance and patient care. This article reviews the relevant literature on burnout in order to provide information to educators about its prevalence, features, impact, and potential interventions. Studies were identified through a Medline and PsychInfo search from 1974 to 2009. Fifty-one studies were identified. Definition and description of burnout and measurement methods are presented followed by a thorough review of the studies. An examination of the burnout literature reveals that it is prevalent in medical students (28%-45%), residents (27%-75%, depending on specialty), as well as practicing physicians. Psychological distress and physical symptoms can impact work performance and patient safety. Distress during medical school can lead to burnout, which in turn can result in negative consequences as a working physician. Burnout also poses significant challenges during early training years in residency. Time demands, lack of control, work planning, work organization, inherently difficult job situations, and interpersonal relationships, are considered factors contributing to residents' burnout. Potential interventions include workplace-driven and individual-driven measures. Workplace interventions include education about burnout, workload modifications, increasing the diversity of work duties, stress management training, mentoring, emotional intelligence training, and wellness workshops. Individual-driven behavioral, social, and physical activities include promoting interpersonal professional relations, meditation, counseling, and exercise. Educators need to develop an active awareness of burnout and ought to consider incorporating relevant instruction and interventions during the process of training resident physicians.

[Pulmonary veno-occlusive disease/pulmonary capillary hemangiomatosis: A case report and literature review].

PubMed

Xiong, Xianliang; Zhu, Tengteng; Li, Jiang

2018-05-28

Pulmonary veno-occlusive disease (PVOD)/pulmonary capillary hemangiomatosis (PCH) is a rare form of pulmonary vascular disease that causes pulmonary arterial hypertension. The diagnosis of PVOD/PCH can be established by the combination of clinical features, physical examination, radiological findings, lung function, bronchoscopy and other resources. There is no established medical therapy for PVOD/PCH, and the only curative therapy for PVOD/PCH is lung transplantation. A girl with PVOD/PCH was diagnosed in the Second Xiangya Hospital. Combining the characteristics for this case with the relevant literature, we summarized the epidemiology, etiology, diagnosis and treatment for the disease to raise doctors' awareness for this rare disease.

Radiative Processes in Jets

NASA Astrophysics Data System (ADS)

Vila, Gabriela S.

Relativistic jets and collimated outflows are ubiquitous phenomena in astrophysical settings, from young stellar objects up to Active Galactic Nuclei. The observed emission from some of these jets can cover the whole electromagnetic spectrum, from radio to gamma-rays. The relevant features of the spectral energy distributions depend on the nature of the source and on the characteristics of the surrounding environment. Here the author reviews the main physical processes that command the interactions between populations of relativistic particles locally accelerated in the jets, with matter, radiation and magnetic fields. Special attention is given to the conditions that lead to the dominance of the different radiative mechanisms. Examples from various types of sources are used to illustrate these effects.

Galactic civilizations: Population dynamics and interstellar diffusion

NASA Technical Reports Server (NTRS)

Newman, W. I.; Sagan, C.

1978-01-01

The interstellar diffusion of galactic civilizations is reexamined by potential theory; both numerical and analytical solutions are derived for the nonlinear partial differential equations which specify a range of relevant models, drawn from blast wave physics, soil science, and, especially, population biology. An essential feature of these models is that, for all civilizations, population growth must be limited by the carrying capacity of the environment. Dispersal is fundamentally a diffusion process; a density-dependent diffusivity describes interstellar emigration. Two models are considered: the first describing zero population growth (ZPG), and the second which also includes local growth and saturation of a planetary population, and for which an asymptotic traveling wave solution is found.

6 CFR 37.15 - Physical security features for the driver's license or identification card.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 6 Domestic Security 1 2010-01-01 2010-01-01 false Physical security features for the driver's license or identification card. 37.15 Section 37.15 Domestic Security DEPARTMENT OF HOMELAND SECURITY..., Verification, and Card Issuance Requirements § 37.15 Physical security features for the driver's license or...

Multiple mechanisms in the perception of face gender: Effect of sex-irrelevant features.

PubMed

Komori, Masashi; Kawamura, Satoru; Ishihara, Shigekazu

2011-06-01

Effects of sex-relevant and sex-irrelevant facial features on the evaluation of facial gender were investigated. Participants rated masculinity of 48 male facial photographs and femininity of 48 female facial photographs. Eighty feature points were measured on each of the facial photographs. Using a generalized Procrustes analysis, facial shapes were converted into multidimensional vectors, with the average face as a starting point. Each vector was decomposed into a sex-relevant subvector and a sex-irrelevant subvector which were, respectively, parallel and orthogonal to the main male-female axis. Principal components analysis (PCA) was performed on the sex-irrelevant subvectors. One principal component was negatively correlated with both perceived masculinity and femininity, and another was correlated only with femininity, though both components were orthogonal to the male-female dimension (and thus by definition sex-irrelevant). These results indicate that evaluation of facial gender depends on sex-irrelevant as well as sex-relevant facial features.

An Optimization-Based Method for Feature Ranking in Nonlinear Regression Problems.

PubMed

Bravi, Luca; Piccialli, Veronica; Sciandrone, Marco

2017-04-01

In this paper, we consider the feature ranking problem, where, given a set of training instances, the task is to associate a score with the features in order to assess their relevance. Feature ranking is a very important tool for decision support systems, and may be used as an auxiliary step of feature selection to reduce the high dimensionality of real-world data. We focus on regression problems by assuming that the process underlying the generated data can be approximated by a continuous function (for instance, a feedforward neural network). We formally state the notion of relevance of a feature by introducing a minimum zero-norm inversion problem of a neural network, which is a nonsmooth, constrained optimization problem. We employ a concave approximation of the zero-norm function, and we define a smooth, global optimization problem to be solved in order to assess the relevance of the features. We present the new feature ranking method based on the solution of instances of the global optimization problem depending on the available training data. Computational experiments on both artificial and real data sets are performed, and point out that the proposed feature ranking method is a valid alternative to existing methods in terms of effectiveness. The obtained results also show that the method is costly in terms of CPU time, and this may be a limitation in the solution of large-dimensional problems.

MHD Instability and Turbulence in the Tachocline

NASA Technical Reports Server (NTRS)

Werne, Joe; Wagner, William J. (Technical Monitor)

2003-01-01

The focus of this project was to study the physical processes that govern tachocline dynamics and structure. Specific features explored included stratification, shear, waves, and toroidal and poloidal background fields. In order to address recent theoretical work on anisotropic mixing and dynamics in the tachocline, we were particularly interested in such anisotropic mixing for the specific tachocline processes studied. Transition to turbulence often shapes the largest-scale features that appear spontaneously in a flow during the development of turbulence. The resulting large-scale straining field can control the subsequent dynamics; therefore, anticipation of the large-scale straining field that results for individual realizations of the transition to turbulence can be important for subsequent dynamics, flow morphology, and transport characteristics. As a result, we paid particular attention to the development of turbulence in the stratified and sheared environment of the tachocline. This is complicated by the fact that the linearly stability of sheared MHD flows is non-self-adjoint, implying that normal asymptotic linear stability theory may not be relevant.

Vocal Identity Recognition in Autism Spectrum Disorder

PubMed Central

Lin, I-Fan; Yamada, Takashi; Komine, Yoko; Kato, Nobumasa; Kato, Masaharu; Kashino, Makio

2015-01-01

Voices can convey information about a speaker. When forming an abstract representation of a speaker, it is important to extract relevant features from acoustic signals that are invariant to the modulation of these signals. This study investigated the way in which individuals with autism spectrum disorder (ASD) recognize and memorize vocal identity. The ASD group and control group performed similarly in a task when asked to choose the name of the newly-learned speaker based on his or her voice, and the ASD group outperformed the control group in a subsequent familiarity test when asked to discriminate the previously trained voices and untrained voices. These findings suggest that individuals with ASD recognized and memorized voices as well as the neurotypical individuals did, but they categorized voices in a different way: individuals with ASD categorized voices quantitatively based on the exact acoustic features, while neurotypical individuals categorized voices qualitatively based on the acoustic patterns correlated to the speakers' physical and mental properties. PMID:26070199

Vocal Identity Recognition in Autism Spectrum Disorder.

PubMed

Lin, I-Fan; Yamada, Takashi; Komine, Yoko; Kato, Nobumasa; Kato, Masaharu; Kashino, Makio

2015-01-01

Voices can convey information about a speaker. When forming an abstract representation of a speaker, it is important to extract relevant features from acoustic signals that are invariant to the modulation of these signals. This study investigated the way in which individuals with autism spectrum disorder (ASD) recognize and memorize vocal identity. The ASD group and control group performed similarly in a task when asked to choose the name of the newly-learned speaker based on his or her voice, and the ASD group outperformed the control group in a subsequent familiarity test when asked to discriminate the previously trained voices and untrained voices. These findings suggest that individuals with ASD recognized and memorized voices as well as the neurotypical individuals did, but they categorized voices in a different way: individuals with ASD categorized voices quantitatively based on the exact acoustic features, while neurotypical individuals categorized voices qualitatively based on the acoustic patterns correlated to the speakers' physical and mental properties.

Coexistence of type-II Dirac point and weak topological phase in Pt 3 Sn

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

Kim, Minsung; Wang, Cai -Zhuang; Ho, Kai -Ming

Intriguing topological phases may appear in both insulating and semimetallic states. Topological insulators exhibit topologically nontrivial band inversion, while topological Dirac/Weyl semimetals show “relativistic” linear band crossings. Here, we report an unusual topological state of Pt 3Sn, where the two topological features appear simultaneously. Based on first-principles calculations, we show that Pt 3Sn is a three-dimensional weak topological semimetal with topologically nontrivial band inversion between the valence and conduction bands, where the band structure also possesses type-II Dirac points at the boundary of two electron pockets. The formation of the Dirac points can be understood in terms of the representationsmore » of relevant symmetry groups and the compatibility relations. The topological surface states appear in accordance with the nontrivial bulk band topology. As a result, the unique coexistence of the two distinct topological features in Pt 3Sn enlarges the material scope in topological physics, and is potentially useful for spintronics.« less

Coexistence of type-II Dirac point and weak topological phase in Pt 3 Sn

DOE PAGES

Kim, Minsung; Wang, Cai -Zhuang; Ho, Kai -Ming

2017-11-06

Intriguing topological phases may appear in both insulating and semimetallic states. Topological insulators exhibit topologically nontrivial band inversion, while topological Dirac/Weyl semimetals show “relativistic” linear band crossings. Here, we report an unusual topological state of Pt 3Sn, where the two topological features appear simultaneously. Based on first-principles calculations, we show that Pt 3Sn is a three-dimensional weak topological semimetal with topologically nontrivial band inversion between the valence and conduction bands, where the band structure also possesses type-II Dirac points at the boundary of two electron pockets. The formation of the Dirac points can be understood in terms of the representationsmore » of relevant symmetry groups and the compatibility relations. The topological surface states appear in accordance with the nontrivial bulk band topology. As a result, the unique coexistence of the two distinct topological features in Pt 3Sn enlarges the material scope in topological physics, and is potentially useful for spintronics.« less

Evolution of Biological Image Stabilization.

PubMed

Hardcastle, Ben J; Krapp, Holger G

2016-10-24

The use of vision to coordinate behavior requires an efficient control design that stabilizes the world on the retina or directs the gaze towards salient features in the surroundings. With a level gaze, visual processing tasks are simplified and behaviorally relevant features from the visual environment can be extracted. No matter how simple or sophisticated the eye design, mechanisms have evolved across phyla to stabilize gaze. In this review, we describe functional similarities in eyes and gaze stabilization reflexes, emphasizing their fundamental role in transforming sensory information into motor commands that support postural and locomotor control. We then focus on gaze stabilization design in flying insects and detail some of the underlying principles. Systems analysis reveals that gaze stabilization often involves several sensory modalities, including vision itself, and makes use of feedback as well as feedforward signals. Independent of phylogenetic distance, the physical interaction between an animal and its natural environment - its available senses and how it moves - appears to shape the adaptation of all aspects of gaze stabilization. Copyright © 2016 Elsevier Ltd. All rights reserved.

Investigating the multi-causal and complex nature of the accident causal influence of construction project features.

PubMed

Manu, Patrick A; Ankrah, Nii A; Proverbs, David G; Suresh, Subashini

2012-09-01

Construction project features (CPFs) are organisational, physical and operational attributes that characterise construction projects. Although previous studies have examined the accident causal influence of CPFs, the multi-causal attribute of this causal phenomenon still remain elusive and thus requires further investigation. Aiming to shed light on this facet of the accident causal phenomenon of CPFs, this study examines relevant literature and crystallises the attained insight of the multi-causal attribute by a graphical model which is subsequently operationalised by a derived mathematical risk expression that offers a systematic approach for evaluating the potential of CPFs to cause harm and consequently their health and safety (H&S) risk implications. The graphical model and the risk expression put forth by the study thus advance current understanding of the accident causal phenomenon of CPFs and they present an opportunity for project participants to manage the H&S risk associated with CPFs from the early stages of project procurement. Copyright © 2011 Elsevier Ltd. All rights reserved.

Measurement of food-related approach-avoidance biases: Larger biases when food stimuli are task relevant.

PubMed

Lender, Anja; Meule, Adrian; Rinck, Mike; Brockmeyer, Timo; Blechert, Jens

2018-06-01

Strong implicit responses to food have evolved to avoid energy depletion but contribute to overeating in today's affluent environments. The Approach-Avoidance Task (AAT) supposedly assesses implicit biases in response to food stimuli: Participants push pictures on a monitor "away" or pull them "near" with a joystick that controls a corresponding image zoom. One version of the task couples movement direction with image content-independent features, for example, pulling blue-framed images and pushing green-framed images regardless of content ('irrelevant feature version'). However, participants might selectively attend to this feature and ignore image content and, thus, such a task setup might underestimate existing biases. The present study tested this attention account by comparing two irrelevant feature versions of the task with either a more peripheral (image frame color: green vs. blue) or central (small circle vs. cross overlaid over the image content) image feature as response instruction to a 'relevant feature version', in which participants responded to the image content, thus making it impossible to ignore that content. Images of chocolate-containing foods and of objects were used, and several trait and state measures were acquired to validate the obtained biases. Results revealed a robust approach bias towards food only in the relevant feature condition. Interestingly, a positive correlation with state chocolate craving during the task was found when all three conditions were combined, indicative of criterion validity of all three versions. However, no correlations were found with trait chocolate craving. Results provide a strong case for the relevant feature version of the AAT for bias measurement. They also point to several methodological avenues for future research around selective attention in the irrelevant versions and task validity regarding trait vs. state variables. Copyright © 2018 Elsevier Ltd. All rights reserved.

Planning to avoid trouble in the operating room: experts' formulation of the preoperative plan.

PubMed

Zilbert, Nathan R; St-Martin, Laurent; Regehr, Glenn; Gallinger, Steven; Moulton, Carol-Anne

2015-01-01

The purpose of this study was to capture the preoperative plans of expert hepato-pancreato-biliary (HPB) surgeons with the goal of finding consistent aspects of the preoperative planning process. HPB surgeons were asked to think aloud when reviewing 4 preoperative computed tomography scans of patients with distal pancreatic tumors. The imaging features they identified and the planned actions they proposed were tabulated. Surgeons viewed the tabulated list of imaging features for each case and rated the relevance of each feature for their subsequent preoperative plan. Average rater intraclass correlation coefficients were calculated for each type of data collected (imaging features detected, planned actions reported, and relevance of each feature) to establish whether the surgeons were consistent with one another in their responses. Average rater intraclass correlation coefficient values greater than 0.7 were considered indicative of consistency. Division of General Surgery, University of Toronto. HPB surgeons affiliated with the University of Toronto. A total of 11 HPB surgeons thought aloud when reviewing 4 computed tomography scans. Surgeons were consistent in the imaging features they detected but inconsistent in the planned actions they reported. Of the HPB surgeons, 8 completed the assessment of feature relevance. For 3 of the 4 cases, the surgeons were consistent in rating the relevance of specific imaging features on their preoperative plans. These results suggest that HPB surgeons are consistent in some aspects of the preoperative planning process but not others. The findings further our understanding of the preoperative planning process and will guide future research on the best ways to incorporate the teaching and evaluation of preoperative planning into surgical training. Copyright © 2014 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Application of Physics Based Distributed Hydrologic Models to Assess Anthropologic Land Disturbance in Watersheds

NASA Astrophysics Data System (ADS)

Downer, C. W.; Ogden, F. L.; Byrd, A. R.

2008-12-01

The Department of Defense (DoD) manages approximately 200,000 km2 of land within the United States on military installations and flood control and river improvement projects. The Watershed Systems Group (WSG) within the Coastal and Hydraulics Laboratory of the Engineer Research and Development Center (ERDC) supports the US Army and the US Army Corps of Engineers in both military and civil operations through the development, modification and application of surface and sub-surface hydrologic models. The US Army has a long history of land management and the development of analytical tools to assist with the management of US Army lands. The US Army has invested heavily in the distributed hydrologic model GSSHA and its predecessor CASC2D. These tools have been applied at numerous military and civil sites to analyze the effects of landscape alteration on hydrologic response and related consequences, changes in erosion and sediment transport, along with associated contaminants. Examples include: impacts of military training and land management activities, impact of changing land use (urbanization or environmental restoration), as well as impacts of management practices employed to abate problems, i.e. Best Management Practices (BMPs). Traditional models such as HSPF and SWAT, are largely conceptual in nature. GSSHA attempts to simulate the physical processes actually occurring in the watershed allowing the user to explicitly simulate changing parameter values in response to changes in land use, land cover, elevation, etc. Issues of scale raise questions: How do we best include fine-scale land use or management features in models of large watersheds? Do these features have to be represented explicitly through physical processes in the watershed domain? Can a point model, physical or empirical, suffice? Can these features be lumped into coarsely resolved numerical grids or sub-watersheds? In this presentation we will discuss the US Army's distributed hydrologic models in terms of how they simulate the relevant processes and present multiple applications of the models used for analyzing land management and land use change. Using these applications as a basis we will discuss issues related to the analysis of anthropogenic alterations in the landscape.

Self-relevant beauty evaluation: Evidence from an event-related potentials study.

PubMed

Kong, Fanchang; Zhang, Yan; Tian, Yuan; Fan, Cuiying; Zhou, Zongkui

2015-03-01

This study examines the electrophysiological correlates of beauty evaluation when participants performed the self-reference task. About 13 (7 men, 6 women) undergraduates participated in the experiment using event-related potentials. Results showed that the response to self-relevant information was faster compared to other-relevant information and no significant differences for self-relevant relative to mother-relevant information were observed. Both physical and interior beauty words for self-relevant information showed an enhanced late positive component as compared to other-relevant information. Physical beauty for self-relevant information yielded a larger late positive component in contrast to mother-relevant information but not for interior beauty. This study indicates that beauty is specific to the person who judges it though an individual and one's mother may hold similar views of interior beauty.

Real time gesture based control: A prototype development

NASA Astrophysics Data System (ADS)

Bhargava, Deepshikha; Solanki, L.; Rai, Satish Kumar

2016-03-01

The computer industry is getting advanced. In a short span of years, industry is growing high with advanced techniques. Robots have been replacing humans, increasing the efficiency, accessibility and accuracy of the system and creating man-machine interaction. Robotic industry is developing many new trends. However, they still need to be controlled by humans itself. This paper presents an approach to control a motor like a robot with hand gestures not by old ways like buttons or physical devices. Controlling robots with hand gestures is very popular now-a-days. Currently, at this level, gesture features are applied for detecting and tracking the hand in real time. A principal component analysis algorithm is being used for identification of a hand gesture by using open CV image processing library. Contours, convex-hull, and convexity defects are the gesture features. PCA is a statistical approach used for reducing the number of variables in hand recognition. While extracting the most relevant information (feature) contained in the images (hand). After detecting and recognizing hand a servo motor is being controlled, which uses hand gesture as an input device (like mouse and keyboard), and reduces human efforts.

Learning from physics-based earthquake simulators: a minimal approach

NASA Astrophysics Data System (ADS)

Artale Harris, Pietro; Marzocchi, Warner; Melini, Daniele

2017-04-01

Physics-based earthquake simulators are aimed to generate synthetic seismic catalogs of arbitrary length, accounting for fault interaction, elastic rebound, realistic fault networks, and some simple earthquake nucleation process like rate and state friction. Through comparison of synthetic and real catalogs seismologists can get insights on the earthquake occurrence process. Moreover earthquake simulators can be used to to infer some aspects of the statistical behavior of earthquakes within the simulated region, by analyzing timescales not accessible through observations. The develoment of earthquake simulators is commonly led by the approach "the more physics, the better", pushing seismologists to go towards simulators more earth-like. However, despite the immediate attractiveness, we argue that this kind of approach makes more and more difficult to understand which physical parameters are really relevant to describe the features of the seismic catalog at which we are interested. For this reason, here we take an opposite minimal approach and analyze the behavior of a purposely simple earthquake simulator applied to a set of California faults. The idea is that a simple model may be more informative than a complex one for some specific scientific objectives, because it is more understandable. The model has three main components: the first one is a realistic tectonic setting, i.e., a fault dataset of California; the other two components are quantitative laws for earthquake generation on each single fault, and the Coulomb Failure Function for modeling fault interaction. The final goal of this work is twofold. On one hand, we aim to identify the minimum set of physical ingredients that can satisfactorily reproduce the features of the real seismic catalog, such as short-term seismic cluster, and to investigate on the hypothetical long-term behavior, and faults synchronization. On the other hand, we want to investigate the limits of predictability of the model itself.

A combined Fisher and Laplacian score for feature selection in QSAR based drug design using compounds with known and unknown activities.

PubMed

Valizade Hasanloei, Mohammad Amin; Sheikhpour, Razieh; Sarram, Mehdi Agha; Sheikhpour, Elnaz; Sharifi, Hamdollah

2018-02-01

Quantitative structure-activity relationship (QSAR) is an effective computational technique for drug design that relates the chemical structures of compounds to their biological activities. Feature selection is an important step in QSAR based drug design to select the most relevant descriptors. One of the most popular feature selection methods for classification problems is Fisher score which aim is to minimize the within-class distance and maximize the between-class distance. In this study, the properties of Fisher criterion were extended for QSAR models to define the new distance metrics based on the continuous activity values of compounds with known activities. Then, a semi-supervised feature selection method was proposed based on the combination of Fisher and Laplacian criteria which exploits both compounds with known and unknown activities to select the relevant descriptors. To demonstrate the efficiency of the proposed semi-supervised feature selection method in selecting the relevant descriptors, we applied the method and other feature selection methods on three QSAR data sets such as serine/threonine-protein kinase PLK3 inhibitors, ROCK inhibitors and phenol compounds. The results demonstrated that the QSAR models built on the selected descriptors by the proposed semi-supervised method have better performance than other models. This indicates the efficiency of the proposed method in selecting the relevant descriptors using the compounds with known and unknown activities. The results of this study showed that the compounds with known and unknown activities can be helpful to improve the performance of the combined Fisher and Laplacian based feature selection methods.

A combined Fisher and Laplacian score for feature selection in QSAR based drug design using compounds with known and unknown activities

NASA Astrophysics Data System (ADS)

Valizade Hasanloei, Mohammad Amin; Sheikhpour, Razieh; Sarram, Mehdi Agha; Sheikhpour, Elnaz; Sharifi, Hamdollah

2018-02-01

Quantitative structure-activity relationship (QSAR) is an effective computational technique for drug design that relates the chemical structures of compounds to their biological activities. Feature selection is an important step in QSAR based drug design to select the most relevant descriptors. One of the most popular feature selection methods for classification problems is Fisher score which aim is to minimize the within-class distance and maximize the between-class distance. In this study, the properties of Fisher criterion were extended for QSAR models to define the new distance metrics based on the continuous activity values of compounds with known activities. Then, a semi-supervised feature selection method was proposed based on the combination of Fisher and Laplacian criteria which exploits both compounds with known and unknown activities to select the relevant descriptors. To demonstrate the efficiency of the proposed semi-supervised feature selection method in selecting the relevant descriptors, we applied the method and other feature selection methods on three QSAR data sets such as serine/threonine-protein kinase PLK3 inhibitors, ROCK inhibitors and phenol compounds. The results demonstrated that the QSAR models built on the selected descriptors by the proposed semi-supervised method have better performance than other models. This indicates the efficiency of the proposed method in selecting the relevant descriptors using the compounds with known and unknown activities. The results of this study showed that the compounds with known and unknown activities can be helpful to improve the performance of the combined Fisher and Laplacian based feature selection methods.

Introductory Physics Laboratories for Life Scientists - Hands on Physics of Complex Systems

NASA Astrophysics Data System (ADS)

Losert, Wolfgang; Moore, Kim

2015-03-01

We have developed a set of laboratories and hands on activities to accompany a new two-semester interdisciplinary physics course that has been successfully implemented as the required physics course for premeds at the University of Maryland. The laboratories include significant content on physics relevant to cellular scales, from chemical interactions to random motion and charge screening in fluids. We also introduce the students to research-grade equipment and modern physics analysis tools in contexts relevant to biology, while maintaining the pedagogically valuable open-ended laboratory structure of reformed laboratories.

Free-living monitoring of Parkinson's disease: Lessons from the field.

PubMed

Del Din, Silvia; Godfrey, Alan; Mazzà, Claudia; Lord, Sue; Rochester, Lynn

2016-09-01

Wearable technology comprises miniaturized sensors (eg, accelerometers) worn on the body and/or paired with mobile devices (eg, smart phones) allowing continuous patient monitoring in unsupervised, habitual environments (termed free-living). Wearable technologies are revolutionizing approaches to health care as a result of their utility, accessibility, and affordability. They are positioned to transform Parkinson's disease (PD) management through the provision of individualized, comprehensive, and representative data. This is particularly relevant in PD where symptoms are often triggered by task and free-living environmental challenges that cannot be replicated with sufficient veracity elsewhere. This review concerns use of wearable technology in free-living environments for people with PD. It outlines the potential advantages of wearable technologies and evidence for these to accurately detect and measure clinically relevant features including motor symptoms, falls risk, freezing of gait, gait, functional mobility, and physical activity. Technological limitations and challenges are highlighted, and advances concerning broader aspects are discussed. Recommendations to overcome key challenges are made. To date there is no fully validated system to monitor clinical features or activities in free-living environments. Robust accuracy and validity metrics for some features have been reported, and wearable technology may be used in these cases with a degree of confidence. Utility and acceptability appears reasonable, although testing has largely been informal. Key recommendations include adopting a multidisciplinary approach for standardizing definitions, protocols, and outcomes. Robust validation of developed algorithms and sensor-based metrics is required along with testing of utility. These advances are required before widespread clinical adoption of wearable technology can be realized. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

Remembering Complex Objects in Visual Working Memory: Do Capacity Limits Restrict Objects or Features?

PubMed Central

Hardman, Kyle; Cowan, Nelson

2014-01-01

Visual working memory stores stimuli from our environment as representations that can be accessed by high-level control processes. This study addresses a longstanding debate in the literature about whether storage limits in visual working memory include a limit to the complexity of discrete items. We examined the issue with a number of change-detection experiments that used complex stimuli which possessed multiple features per stimulus item. We manipulated the number of relevant features of the stimulus objects in order to vary feature load. In all of our experiments, we found that increased feature load led to a reduction in change-detection accuracy. However, we found that feature load alone could not account for the results, but that a consideration of the number of relevant objects was also required. This study supports capacity limits for both feature and object storage in visual working memory. PMID:25089739

Feature-based attentional modulations in the absence of direct visual stimulation.

PubMed

Serences, John T; Boynton, Geoffrey M

2007-07-19

When faced with a crowded visual scene, observers must selectively attend to behaviorally relevant objects to avoid sensory overload. Often this selection process is guided by prior knowledge of a target-defining feature (e.g., the color red when looking for an apple), which enhances the firing rate of visual neurons that are selective for the attended feature. Here, we used functional magnetic resonance imaging and a pattern classification algorithm to predict the attentional state of human observers as they monitored a visual feature (one of two directions of motion). We find that feature-specific attention effects spread across the visual field-even to regions of the scene that do not contain a stimulus. This spread of feature-based attention to empty regions of space may facilitate the perception of behaviorally relevant stimuli by increasing sensitivity to attended features at all locations in the visual field.

ME(SSY)**2: Monte Carlo Code for Star Cluster Simulations

NASA Astrophysics Data System (ADS)

Freitag, Marc Dewi

2013-02-01

ME(SSY)**2 stands for “Monte-carlo Experiments with Spherically SYmmetric Stellar SYstems." This code simulates the long term evolution of spherical clusters of stars; it was devised specifically to treat dense galactic nuclei. It is based on the pioneering Monte Carlo scheme proposed by Hénon in the 70's and includes all relevant physical ingredients (2-body relaxation, stellar mass spectrum, collisions, tidal disruption, ldots). It is basically a Monte Carlo resolution of the Fokker-Planck equation. It can cope with any stellar mass spectrum or velocity distribution. Being a particle-based method, it also allows one to take stellar collisions into account in a very realistic way. This unique code, featuring most important physical processes, allows million particle simulations, spanning a Hubble time, in a few CPU days on standard personal computers and provides a wealth of data only rivalized by N-body simulations. The current version of the software requires the use of routines from the "Numerical Recipes in Fortran 77" (http://www.nrbook.com/a/bookfpdf.php).

Plasma Processes for Semiconductor Fabrication

NASA Astrophysics Data System (ADS)

Hitchon, W. N. G.

1999-01-01

Plasma processing is a central technique in the fabrication of semiconductor devices. This self-contained book provides an up-to-date description of plasma etching and deposition in semiconductor fabrication. It presents the basic physics and chemistry of these processes, and shows how they can be accurately modeled. The author begins with an overview of plasma reactors and discusses the various models for understanding plasma processes. He then covers plasma chemistry, addressing the effects of different chemicals on the features being etched. Having presented the relevant background material, he then describes in detail the modeling of complex plasma systems, with reference to experimental results. The book closes with a useful glossary of technical terms. No prior knowledge of plasma physics is assumed in the book. It contains many homework exercises and serves as an ideal introduction to plasma processing and technology for graduate students of electrical engineering and materials science. It will also be a useful reference for practicing engineers in the semiconductor industry.

Heat transfer from nanoparticles: A corresponding state analysis

PubMed Central

Merabia, Samy; Shenogin, Sergei; Joly, Laurent; Keblinski, Pawel; Barrat, Jean-Louis

2009-01-01

In this contribution, we study situations in which nanoparticles in a fluid are strongly heated, generating high heat fluxes. This situation is relevant to experiments in which a fluid is locally heated by using selective absorption of radiation by solid particles. We first study this situation for different types of molecular interactions, using models for gold particles suspended in octane and in water. As already reported in experiments, very high heat fluxes and temperature elevations (leading eventually to particle destruction) can be observed in such situations. We show that a very simple modeling based on Lennard–Jones (LJ) interactions captures the essential features of such experiments and that the results for various liquids can be mapped onto the LJ case, provided a physically justified (corresponding state) choice of parameters is made. Physically, the possibility of sustaining very high heat fluxes is related to the strong curvature of the interface that inhibits the formation of an insulating vapor film. PMID:19571000

Hydrodynamics on Supercomputers: Interacting Binary Stars

NASA Astrophysics Data System (ADS)

Blondin, J. M.

1997-05-01

The interaction of close binary stars accounts for a wide variety of peculiar objects scattered throughout our Galaxy. The unique features of Algols, Symbiotics, X-ray binaries, cataclysmic variables and many others are linked to the dynamics of the circumstellar gas which can take forms from tidal streams and accretion disks to colliding stellar winds. As in many other areas of astrophysics, large scale computing has provided a powerful new tool in the study of interacting binaries. In the research to be described, hydrodynamic simulations are used to create a "laboratory", within which one can "experiment": change the system and observe (and predict) the effects of those changes. This type of numerical experimentation, when buttressed by analytic studies, provides a means of interpreting observations, identifying and understanding the relevant physics, and visualizing the physical system. The results of such experiments will be shown, including the structure of tidal streams in Roche lobe overflow systems, mass accretion in X-ray binaries, and the formation of accretion disks.

Correlations in star networks: from Bell inequalities to network inequalities

NASA Astrophysics Data System (ADS)

Tavakoli, Armin; Olivier Renou, Marc; Gisin, Nicolas; Brunner, Nicolas

2017-07-01

The problem of characterizing classical and quantum correlations in networks is considered. Contrary to the usual Bell scenario, where distant observers share a physical system emitted by one common source, a network features several independent sources, each distributing a physical system to a subset of observers. In the quantum setting, the observers can perform joint measurements on initially independent systems, which may lead to strong correlations across the whole network. In this work, we introduce a technique to systematically map a Bell inequality to a family of Bell-type inequalities bounding classical correlations on networks in a star-configuration. Also, we show that whenever a given Bell inequality can be violated by some entangled state ρ, then all the corresponding network inequalities can be violated by considering many copies of ρ distributed in the star network. The relevance of these ideas is illustrated by applying our method to a specific multi-setting Bell inequality. We derive the corresponding network inequalities, and study their quantum violations.

Electroencephalogram Signal Classification for Automated Epileptic Seizure Detection Using Genetic Algorithm

PubMed Central

Nanthini, B. Suguna; Santhi, B.

2017-01-01

Background: Epilepsy causes when the repeated seizure occurs in the brain. Electroencephalogram (EEG) test provides valuable information about the brain functions and can be useful to detect brain disorder, especially for epilepsy. In this study, application for an automated seizure detection model has been introduced successfully. Materials and Methods: The EEG signals are decomposed into sub-bands by discrete wavelet transform using db2 (daubechies) wavelet. The eight statistical features, the four gray level co-occurrence matrix and Renyi entropy estimation with four different degrees of order, are extracted from the raw EEG and its sub-bands. Genetic algorithm (GA) is used to select eight relevant features from the 16 dimension features. The model has been trained and tested using support vector machine (SVM) classifier successfully for EEG signals. The performance of the SVM classifier is evaluated for two different databases. Results: The study has been experimented through two different analyses and achieved satisfactory performance for automated seizure detection using relevant features as the input to the SVM classifier. Conclusion: Relevant features using GA give better accuracy performance for seizure detection. PMID:28781480

Using isomorphic problems to learn introductory physics

NASA Astrophysics Data System (ADS)

Lin, Shih-Yin; Singh, Chandralekha

2011-12-01

In this study, we examine introductory physics students’ ability to perform analogical reasoning between two isomorphic problems which employ the same underlying physics principles but have different surface features. Three hundred sixty-two students from a calculus-based and an algebra-based introductory physics course were given a quiz in the recitation in which they had to first learn from a solved problem provided and take advantage of what they learned from it to solve another problem (which we call the quiz problem) which was isomorphic. Previous research suggests that the multiple-concept quiz problem is challenging for introductory students. Students in different recitation classes received different interventions in order to help them discern and exploit the underlying similarities of the isomorphic solved and quiz problems. We also conducted think-aloud interviews with four introductory students in order to understand in depth the difficulties they had and explore strategies to provide better scaffolding. We found that most students were able to learn from the solved problem to some extent with the scaffolding provided and invoke the relevant principles in the quiz problem. However, they were not necessarily able to apply the principles correctly. Research suggests that more scaffolding is needed to help students in applying these principles appropriately. We outline a few possible strategies for future investigation.

Exploring ν signals in dark matter detectors

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

Harnik, Roni; Kopp, Joachim; Machado, Pedro A.N., E-mail: roni@fnal.gov, E-mail: jkopp@fnal.gov, E-mail: accioly@fma.if.usp.br

2012-07-01

We investigate standard and non-standard solar neutrino signals in direct dark matter detection experiments. It is well known that even without new physics, scattering of solar neutrinos on nuclei or electrons is an irreducible background for direct dark matter searches, once these experiments reach the ton scale. Here, we entertain the possibility that neutrino interactions are enhanced by new physics, such as new light force carriers (for instance a ''dark photon'') or neutrino magnetic moments. We consider models with only the three standard neutrino flavors, as well as scenarios with extra sterile neutrinos. We find that low-energy neutrino-electron and neutrino-nucleusmore » scattering rates can be enhanced by several orders of magnitude, potentially enough to explain the event excesses observed in CoGeNT and CRESST. We also investigate temporal modulation in these neutrino signals, which can arise from geometric effects, oscillation physics, non-standard neutrino energy loss, and direction-dependent detection efficiencies. We emphasize that, in addition to providing potential explanations for existing signals, models featuring new physics in the neutrino sector can also be very relevant to future dark matter searches, where, on the one hand, they can be probed and constrained, but on the other hand, their signatures could also be confused with dark matter signals.« less

Exploring nu Signals in Dark Matter Detectors

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

Harnik, Roni; Kopp, Joachim; Machado, Pedro A.N.

2012-02-01

We investigate standard and non-standard solar neutrino signals in direct dark matter detection experiments. It is well known that even without new physics, scattering of solar neutrinos on nuclei or electrons is an irreducible background for direct dark matter searches, once these experiments each the ton scale. Here, we entertain the possibility that neutrino interactions are enhanced by new physics, such as new light force carriers (for instance a "dark photon") or neutrino magnetic moments. We consider models with only the three standard neutrino flavors, as well as scenarios with extra sterile neutrinos. We find that low-energy neutrino--electron and neutrino--nucleusmore » scattering rates can be enhanced by several orders of magnitude, potentially enough to explain the event excesses observed in CoGeNT and CRESST. We also investigate temporal modulation in these neutrino signals, which can arise from geometric effects, oscillation physics, non-standard neutrino energy loss, and direction-dependent detection efficiencies. We emphasize that, in addition to providing potential explanations for existing signals, models featuring new physics in the neutrino sector can also be very relevant to future dark matter searches, where, on the one hand, they can be probed and constrained, but on the other hand, their signatures could also be confused with dark matter signals.« less

Methodology to model the energy and greenhouse gas emissions of electronic software distributions.

PubMed

Williams, Daniel R; Tang, Yinshan

2012-01-17

A new electronic software distribution (ESD) life cycle analysis (LCA) methodology and model structure were constructed to calculate energy consumption and greenhouse gas (GHG) emissions. In order to counteract the use of high level, top-down modeling efforts, and to increase result accuracy, a focus upon device details and data routes was taken. In order to compare ESD to a relevant physical distribution alternative, physical model boundaries and variables were described. The methodology was compiled from the analysis and operational data of a major online store which provides ESD and physical distribution options. The ESD method included the calculation of power consumption of data center server and networking devices. An in-depth method to calculate server efficiency and utilization was also included to account for virtualization and server efficiency features. Internet transfer power consumption was analyzed taking into account the number of data hops and networking devices used. The power consumed by online browsing and downloading was also factored into the model. The embedded CO(2)e of server and networking devices was proportioned to each ESD process. Three U.K.-based ESD scenarios were analyzed using the model which revealed potential CO(2)e savings of 83% when ESD was used over physical distribution. Results also highlighted the importance of server efficiency and utilization methods.

Interaction of Physical Exposures and Occupational Factors on Sickness Absence in Automotive Industry Workers.

PubMed

Valirad, Fateme; Ghaffari, Mostafa; Abdi, Alireza; Attarchi, Mirsaeed; Mircheraghi, Seyed Farzin; Mohammadi, Saber

2015-04-23

Increased sickness absence in recent years has been a trouble making issue in industrial society. Identify the causes of sickness absence and its influencing factors, is an important step to control and reduce its associated complications and costs. The aim of this study was to evaluate main factors associated with the incidence of sickness absence. In 2012, a cross-sectional study on 758 employees of a car accessories producing company was applied and relevant information about the number of days and episodes of sickness absence, Disease resulting in absence from work, personal features, occupational factors and physical exposures were collected. To determine risk factors associated with sickness absence, Logistic regression analysis was used. The most common diseases leading to sickness absence in order of frequency were Respiratory diseases, musculoskeletal disorders, gastrointestinal diseases and injuries at work. Musculoskeletal disorders increased the danger of long term absence by 4/33 times. Blue collar and shift works were the most important occupational factors associated with the incidence of sickness absence. The main physical factors that affect incidence of sickness absence were frequent bending-twisting and heavy lifting. Identifying controllable factors of sickness absence and trying to prevent and modify them such as compliance of ergonomic principals to decrease physical can be effective in reducing sickness absence.

Rogue waves: a unique approach to multidisciplinary physics

NASA Astrophysics Data System (ADS)

Residori, S.; Onorato, M.; Bortolozzo, U.; Arecchi, F. T.

2017-01-01

Rogue waves are giant waves appearing erratically and unexpectedly on the ocean surfaces. Their existence, considered as mythical in the ancient times, has recently been recognised by the scientific community and, since then, rogue waves have become the object of numerous theoretical and experimental studies. Their relevance is not restricted to oceanography, but it extends in a wide spectrum of physical contexts. General models and mathematical tools have been developed on a interdisciplinary ground and many experiments have been specifically conceived for the observation of rogue waves in a variety of different physical systems. Rogue wave phenomena are, nowadays, studied, for instance, in hydrodynamics, optics, plasmas, complex media, Bose-Einstein condensation and acoustics. We can, therefore, consider rogue waves as a paradigmatic description, able to account for the manifestation of extreme events in multidisciplinary physics. In this review, we present the main physical concepts and mathematical tools for the description of rogue waves. We will refer mostly to examples from water waves and optics, the two domains having in common the non-linear Schrödinger equation from which prototype rogue wave solutions can be derived. We will highlight the most common features of the rogue wave phenomena, as the large deviations from the Gaussian statistics of the amplitude, the existence of many uncorrelated 'grains' of activity and their clustering in inhomogeneous spatial domains via large-scale symmetry breaking.

The cost of selective attention in category learning: Developmental differences between adults and infants

PubMed Central

Best, Catherine A.; Yim, Hyungwook; Sloutsky, Vladimir M.

2013-01-01

Selective attention plays an important role in category learning. However, immaturities of top-down attentional control during infancy coupled with successful category learning suggest that early category learning is achieved without attending selectively. Research presented here examines this possibility by focusing on category learning in infants (6–8 months old) and adults. Participants were trained on a novel visual category. Halfway through the experiment, unbeknownst to participants, the to-be-learned category switched to another category, where previously relevant features became irrelevant and previously irrelevant features became relevant. If participants attend selectively to the relevant features of the first category, they should incur a cost of selective attention immediately after the unknown category switch. Results revealed that adults demonstrated a cost, as evidenced by a decrease in accuracy and response time on test trials as well as a decrease in visual attention to newly relevant features. In contrast, infants did not demonstrate a similar cost of selective attention as adults despite evidence of learning both to-be-learned categories. Findings are discussed as supporting multiple systems of category learning and as suggesting that learning mechanisms engaged by adults may be different from those engaged by infants. PMID:23773914

Advancing representation of hydrologic processes in the Soil and Water Assessment Tool (SWAT) through integration of the TOPographic MODEL (TOPMODEL) features

USGS Publications Warehouse

Chen, J.; Wu, Y.

2012-01-01

This paper presents a study of the integration of the Soil and Water Assessment Tool (SWAT) model and the TOPographic MODEL (TOPMODEL) features for enhancing the physical representation of hydrologic processes. In SWAT, four hydrologic processes, which are surface runoff, baseflow, groundwater re-evaporation and deep aquifer percolation, are modeled by using a group of empirical equations. The empirical equations usually constrain the simulation capability of relevant processes. To replace these equations and to model the influences of topography and water table variation on streamflow generation, the TOPMODEL features are integrated into SWAT, and a new model, the so-called SWAT-TOP, is developed. In the new model, the process of deep aquifer percolation is removed, the concept of groundwater re-evaporation is refined, and the processes of surface runoff and baseflow are remodeled. Consequently, three parameters in SWAT are discarded, and two new parameters to reflect the TOPMODEL features are introduced. SWAT-TOP and SWAT are applied to the East River basin in South China, and the results reveal that, compared with SWAT, the new model can provide a more reasonable simulation of the hydrologic processes of surface runoff, groundwater re-evaporation, and baseflow. This study evidences that an established hydrologic model can be further improved by integrating the features of another model, which is a possible way to enhance our understanding of the workings of catchments.

Exploring the Relevance of the Personal and Social Responsibility Model in Adapted Physical Activity: A Collective Case Study

ERIC Educational Resources Information Center

Wright, Paul M.; White, Katherine; Gaebler-Spira, Deborah

2004-01-01

The purpose of this study was to examine the application of the Personal and Social Responsibility Model (PSRM) in an adapted physical activity program. Although the PSRM was developed for use with underserved youth, scholars in the field of adapted physical activity have noted its potential relevance for children with disabilities. Using a…

Relevance of physics to the pharmacy major.

PubMed

McCall, Richard P

2007-08-15

To offer a physics course that is relevant to pharmacy students, yet still contains many of the fundamental principles of physics. The course was modified over a period of several years to include activities and examples that were related to other courses in the curriculum. Course evaluations were given to assess student attitudes about the importance of physics in the pharmacy curriculum. Students' attitudes have changed over time to appreciate the role that physics plays in their studies. Students gained confidence in their ability to learn in other courses.

A Qualitative Study of Environmental Factors Important for Physical Activity in Rural Adults.

PubMed

Cleland, Verity; Hughes, Clarissa; Thornton, Lukar; Venn, Alison; Squibb, Kathryn; Ball, Kylie

2015-01-01

Despite increasing evidence that the physical environment impacts on physical activity among urban-dwellers, little attention has been devoted to understanding this relationship in rural populations. Work in this area is further hindered by a lack of environmental measures specifically designed for rural settings. This qualitative study aimed to explore the salience of urban physical activity environment constructs among rural adults. In 2011, 49 rural men and women from three distinct areas (coastal, animal-based farming, forestry/plant-based farming) of rural Tasmania, Australia, were purposively recruited to participate in semi-structured interviews. Interviews explored features of the built and social environment commonly examined in studies of urban adults, including functional characteristics (eg, lighting, footpaths, roads/verges), road and personal safety, availability and accessibility of places to be active, destinations, and aesthetics. Interviews were recorded, transcribed verbatim and analysed using a content-thematic approach using QSR NVivo software. While some urban environmental constructs were salient to these rural adults, such as availability of and accessibility to places to be active, some constructs were operationalised differently, such as road safety (where large trucks and winding roads rather than traffic density was of concern), or were not considered relevant (eg, personal safety related to crime, availability of walkable destinations, aesthetics). The measurement of the physical environment in rural populations may require reconsideration and/or modification to ensure salience and appropriate quantification of associations with physical activity in future studies.

A Qualitative Study of Environmental Factors Important for Physical Activity in Rural Adults

PubMed Central

Cleland, Verity; Hughes, Clarissa; Thornton, Lukar; Venn, Alison; Squibb, Kathryn; Ball, Kylie

2015-01-01

Purpose Despite increasing evidence that the physical environment impacts on physical activity among urban-dwellers, little attention has been devoted to understanding this relationship in rural populations. Work in this area is further hindered by a lack of environmental measures specifically designed for rural settings. This qualitative study aimed to explore the salience of urban physical activity environment constructs among rural adults. Methods In 2011, 49 rural men and women from three distinct areas (coastal, animal-based farming, forestry/plant-based farming) of rural Tasmania, Australia, were purposively recruited to participate in semi-structured interviews. Interviews explored features of the built and social environment commonly examined in studies of urban adults, including functional characteristics (eg, lighting, footpaths, roads/verges), road and personal safety, availability and accessibility of places to be active, destinations, and aesthetics. Interviews were recorded, transcribed verbatim and analysed using a content-thematic approach using QSR NVivo software. Findings While some urban environmental constructs were salient to these rural adults, such as availability of and accessibility to places to be active, some constructs were operationalised differently, such as road safety (where large trucks and winding roads rather than traffic density was of concern), or were not considered relevant (eg, personal safety related to crime, availability of walkable destinations, aesthetics). Conclusions The measurement of the physical environment in rural populations may require reconsideration and/or modification to ensure salience and appropriate quantification of associations with physical activity in future studies. PMID:26554376

Embedding an Identity-Matching Task within a Prompting Hierarchy to Facilitate Acquisition of Conditional Discriminations in Children with Autism

PubMed Central

Fisher, Wayne W; Kodak, Tiffany; Moore, James W

2007-01-01

Least-to-most prompting hierarchies (e.g., progressing from verbal to modeled to physical prompts until the target response occurs) may be ineffective when the prompts do not cue the individual to attend to the relevant stimulus dimensions. In such cases, emission of the target response persistently requires one or more of the higher level prompts, a condition called prompt dependence (Clark & Green, 2004). Reinforcement of differential observing responses (DORs) has sometimes been used to ensure that participants attend to the relevant stimulus dimensions in matching-to-sample (MTS) tasks (e.g., Dube & McIlvane, 1999). For 2 participants with autism, we embedded an identity-matching task within a prompting hierarchy as a DOR to increase the likelihood that the participants attended to and discriminated the relevant features of the comparison stimuli in an MTS task. This procedure was compared with a traditional least-to-most prompting hierarchy and a no-reinforcement control condition in a multielement design. Results for both participants indicated that mastery-level acquisition of spoken-word-to-picture relations occurred only under the identity-matching condition. Findings are discussed relative to the use of DORs to facilitate acquisition of conditional discriminations in persons with autism or other conditions who do not attend to the comparison stimuli. PMID:17970262

Embedding an identity-matching task within a prompting hierarchy to facilitate acquisition of conditional discriminations in children with autism.

PubMed

Fisher, Wayne W; Kodak, Tiffany; Moore, James W

2007-01-01

Least-to-most prompting hierarchies (e.g., progressing from verbal to modeled to physical prompts until the target response occurs) may be ineffective when the prompts do not cue the individual to attend to the relevant stimulus dimensions. In such cases, emission of the target response persistently requires one or more of the higher level prompts, a condition called prompt dependence (Clark & Green, 2004). Reinforcement of differential observing responses (DORs) has sometimes been used to ensure that participants attend to the relevant stimulus dimensions in matching-to-sample (MTS) tasks (e.g., Dube & McIlvane, 1999). For 2 participants with autism, we embedded an identity-matching task within a prompting hierarchy as a DOR to increase the likelihood that the participants attended to and discriminated the relevant features of the comparison stimuli in an MTS task. This procedure was compared with a traditional least-to-most prompting hierarchy and a no-reinforcement control condition in a multielement design. Results for both participants indicated that mastery-level acquisition of spoken-word-to-picture relations occurred only under the identity-matching condition. Findings are discussed relative to the use of DORs to facilitate acquisition of conditional discriminations in persons with autism or other conditions who do not attend to the comparison stimuli.

Smoke Ring Physics

ERIC Educational Resources Information Center

Huggins, Elisha

2011-01-01

The behavior of smoke rings, tornados, and quantized vortex rings in superfluid helium has many features in common. These features can be described by the same mathematics we use when introducing Ampere's law in an introductory physics course. We discuss these common features. (Contains 7 figures.)

The unbuilt environment: culture moderates the built environment for physical activity.

PubMed

Perrin, Andrew J; Caren, Neal; Skinner, Asheley C; Odulana, Adebowale; Perrin, Eliana M

2016-12-05

While research has demonstrated a link between the built environment and obesity, much variation remains unexplained. Physical features are necessary, but not sufficient, for physical activity: residents must choose to use these features in health-promoting ways. This article reveals a role for local culture in tempering the effect of the physical environment on physical activity behaviors. We developed Systematic Cultural Observation (SCO) to observe place-based, health-related culture in Lenoir County, NC (population ~60,000). Photographs (N = 6450) were taken systematically from 150 most-used road segments and geocoded. Coders assessed physical activity (PA) opportunities (e.g., public or private activity spaces, pedestrian-friendly features) and presence of people in each photograph. 28.7% of photographs contained some PA feature. Most were private or pedestrian; 3.1% contained public PA space. Only 1.5% of photographs with any PA features (2% of those with public PA space, 0.7% of those with private) depicted people despite appropriate weather and daylight conditions. Even when PA opportunities existed in this rural county, they were rarely used. This may be the result of culture ("unbuilt environment") that disfavors physical activity even in the presence of features that allow it. Policies promoting built environments designed for healthy lifestyles should consider local culture (shared styles, skills, habits, and beliefs) to maximize positive outcomes.

Reward- and attention-related biasing of sensory selection in visual cortex.

PubMed

Buschschulte, Antje; Boehler, Carsten N; Strumpf, Hendrik; Stoppel, Christian; Heinze, Hans-Jochen; Schoenfeld, Mircea A; Hopf, Jens-Max

2014-05-01

Attention to task-relevant features leads to a biasing of sensory selection in extrastriate cortex. Features signaling reward seem to produce a similar bias, but how modulatory effects due to reward and attention relate to each other is largely unexplored. To address this issue, it is critical to separate top-down settings defining reward relevance from those defining attention. To this end, we used a visual search paradigm in which the target's definition (attention to color) was dissociated from reward relevance by delivering monetary reward on search frames where a certain task-irrelevant color was combined with the target-defining color to form the target object. We assessed the state of neural biasing for the attended and reward-relevant color by analyzing the neuromagnetic brain response to asynchronously presented irrelevant distractor probes drawn in the target-defining color, the reward-relevant color, and a completely irrelevant color as a reference. We observed that for the prospect of moderate rewards, the target-defining color but not the reward-relevant color produced a selective enhancement of the neuromagnetic response between 180 and 280 msec in ventral extrastriate visual cortex. Increasing reward prospect caused a delayed attenuation (220-250 msec) of the response to reward probes, which followed a prior (160-180 msec) response enhancement in dorsal ACC. Notably, shorter latency responses in dorsal ACC were associated with stronger attenuation in extrastriate visual cortex. Finally, an analysis of the brain response to the search frames revealed that the presence of the reward-relevant color in search distractors elicited an enhanced response that was abolished after increasing reward size. The present data together indicate that when top-down definitions of reward relevance and attention are separated, the behavioral significance of reward-associated features is still rapidly coded in higher-level cortex areas, thereby commanding effective top-down inhibitory control to counter a selection bias for those features in extrastriate visual cortex.

Nanoparticle–Cell Interactions: Relevance for Public Health

PubMed Central

2017-01-01

Nanoparticles, especially metal oxide nanoparticles, are used in a wide range of commercial and industrial applications that result in direct human contact, such as titanium dioxide nanoparticles in paints, food colorings, and cosmetics, or indirectly through release of nanoparticle-containing materials into the environment. Workers who process nanoparticles for downstream applications are exposed to especially high concentrations of nanoparticles. For physical chemists, nanoparticles present an interesting area of study as the small size of nanoparticles changes the properties from that of the bulk material, leading to novel properties and reactivity. For the public health community, this reduction in particle size means that exposure limits and outcomes that were determined from bulk material properties are not necessarily valid. Informed determination of exposure limits requires a fundamental understanding of how nanoparticles interact with cells. This Feature Article highlights the areas of intersection between physical chemistry and public health in understanding nanoparticle–cell interactions, with a focus on titanium dioxide nanoparticles. It provides an overview of recent research examining the interaction of titanium dioxide nanoparticles with cells in the absence of UV light and provides recommendations for additional nanoparticle–cell research in which physical chemistry expertise could help to inform the public health community. PMID:29111728

Nanoparticle-Cell Interactions: Relevance for Public Health.

PubMed

Runa, Sabiha; Hussey, Michael; Payne, Christine K

2018-01-25

Nanoparticles, especially metal oxide nanoparticles, are used in a wide range of commercial and industrial applications that result in direct human contact, such as titanium dioxide nanoparticles in paints, food colorings, and cosmetics, or indirectly through release of nanoparticle-containing materials into the environment. Workers who process nanoparticles for downstream applications are exposed to especially high concentrations of nanoparticles. For physical chemists, nanoparticles present an interesting area of study as the small size of nanoparticles changes the properties from that of the bulk material, leading to novel properties and reactivity. For the public health community, this reduction in particle size means that exposure limits and outcomes that were determined from bulk material properties are not necessarily valid. Informed determination of exposure limits requires a fundamental understanding of how nanoparticles interact with cells. This Feature Article highlights the areas of intersection between physical chemistry and public health in understanding nanoparticle-cell interactions, with a focus on titanium dioxide nanoparticles. It provides an overview of recent research examining the interaction of titanium dioxide nanoparticles with cells in the absence of UV light and provides recommendations for additional nanoparticle-cell research in which physical chemistry expertise could help to inform the public health community.

Teachers' Source Evaluation Self-Efficacy Predicts Their Use of Relevant Source Features When Evaluating the Trustworthiness of Web Sources on Special Education

ERIC Educational Resources Information Center

Andreassen, Rune; Bråten, Ivar

2013-01-01

Building on prior research and theory concerning source evaluation and the role of self-efficacy in the context of online learning, this study investigated the relationship between teachers' beliefs about their capability to evaluate the trustworthiness of sources and their reliance on relevant source features when judging the trustworthiness…

Can the History of Science Contribute to Modelling in Physics Teaching?

NASA Astrophysics Data System (ADS)

Machado, Juliana; Braga, Marco Antônio Barbosa

2016-10-01

A characterization of the modelling process in science is proposed for science education, based on Mario Bunge's ideas about the construction of models in science. Galileo's Dialogues are analysed as a potentially fruitful starting point to implement strategies aimed at modelling in the classroom in the light of that proposal. It is argued that a modelling process for science education can be conceived as the evolution from phenomenological approaches towards more representational ones, emphasizing the role of abstraction and idealization in model construction. The shift of reference of theories—from sensible objects to conceptual objects—and the black-box models construction process, which are both explicitly presented features in Galileo's Dialogues, are indicated as highly relevant aspects for modelling in science education.

Mouse social stress induces increased fear conditioning, helplessness and fatigue to physical challenge together with markers of altered immune and dopamine function.

PubMed

Azzinnari, Damiano; Sigrist, Hannes; Staehli, Simon; Palme, Rupert; Hildebrandt, Tobias; Leparc, German; Hengerer, Bastian; Seifritz, Erich; Pryce, Christopher R

2014-10-01

In neuropsychiatry, animal studies demonstrating causal effects of environmental manipulations relevant to human aetiology on behaviours relevant to human psychopathologies are valuable. Such valid models can improve understanding of aetio-pathophysiology and preclinical discovery and development of new treatments. In depression, specific uncontrollable stressful life events are major aetiological factors, and subsequent generalized increases in fearfulness, helplessness and fatigue are core symptoms or features. Here we exposed adult male C57BL/6 mice to 15-day psychosocial stress with loss of social control but minimal physical wounding. One cohort was assessed in a 3-day test paradigm of motor activity, fear conditioning and 2-way avoid-escape behaviour on days 16-18, and a second cohort was assessed in a treadmill fatigue paradigm on days 19 and 29, followed by the 3-day paradigm on days 30-32. All tests used a physical aversive stimulus, namely mild, brief electroshocks. Socially stressed mice displayed decreased motor activity, increased fear acquisition, decreased 2-way avoid-escape responding (increased helplessness) and increased fatigue. They also displayed increased plasma TNF and spleen hypertrophy, and adrenal hypertrophy without hyper-corticoidism. In a third cohort, psychosocial stress effects on brain gene expression were assessed using next generation sequencing. Gene expression was altered in pathways of inflammation and G-protein coupled receptors in prefrontal cortex and amygdala; in the latter, expression of genes important in dopamine function were de-regulated including down-regulated Drd2, Adora2a and Darpp-32. This model can be applied to identify targets for treating psychopathologies such as helplessness or fatigue, and to screen compounds/biologics developed to act at these targets. Copyright © 2014 Elsevier Ltd. All rights reserved.

Feature-Selective Attention Adaptively Shifts Noise Correlations in Primary Auditory Cortex.

PubMed

Downer, Joshua D; Rapone, Brittany; Verhein, Jessica; O'Connor, Kevin N; Sutter, Mitchell L

2017-05-24

Sensory environments often contain an overwhelming amount of information, with both relevant and irrelevant information competing for neural resources. Feature attention mediates this competition by selecting the sensory features needed to form a coherent percept. How attention affects the activity of populations of neurons to support this process is poorly understood because population coding is typically studied through simulations in which one sensory feature is encoded without competition. Therefore, to study the effects of feature attention on population-based neural coding, investigations must be extended to include stimuli with both relevant and irrelevant features. We measured noise correlations ( r noise ) within small neural populations in primary auditory cortex while rhesus macaques performed a novel feature-selective attention task. We found that the effect of feature-selective attention on r noise depended not only on the population tuning to the attended feature, but also on the tuning to the distractor feature. To attempt to explain how these observed effects might support enhanced perceptual performance, we propose an extension of a simple and influential model in which shifts in r noise can simultaneously enhance the representation of the attended feature while suppressing the distractor. These findings present a novel mechanism by which attention modulates neural populations to support sensory processing in cluttered environments. SIGNIFICANCE STATEMENT Although feature-selective attention constitutes one of the building blocks of listening in natural environments, its neural bases remain obscure. To address this, we developed a novel auditory feature-selective attention task and measured noise correlations ( r noise ) in rhesus macaque A1 during task performance. Unlike previous studies showing that the effect of attention on r noise depends on population tuning to the attended feature, we show that the effect of attention depends on the tuning to the distractor feature as well. We suggest that these effects represent an efficient process by which sensory cortex simultaneously enhances relevant information and suppresses irrelevant information. Copyright © 2017 the authors 0270-6474/17/375378-15$15.00/0.

Feature-Selective Attention Adaptively Shifts Noise Correlations in Primary Auditory Cortex

PubMed Central

2017-01-01

Sensory environments often contain an overwhelming amount of information, with both relevant and irrelevant information competing for neural resources. Feature attention mediates this competition by selecting the sensory features needed to form a coherent percept. How attention affects the activity of populations of neurons to support this process is poorly understood because population coding is typically studied through simulations in which one sensory feature is encoded without competition. Therefore, to study the effects of feature attention on population-based neural coding, investigations must be extended to include stimuli with both relevant and irrelevant features. We measured noise correlations (rnoise) within small neural populations in primary auditory cortex while rhesus macaques performed a novel feature-selective attention task. We found that the effect of feature-selective attention on rnoise depended not only on the population tuning to the attended feature, but also on the tuning to the distractor feature. To attempt to explain how these observed effects might support enhanced perceptual performance, we propose an extension of a simple and influential model in which shifts in rnoise can simultaneously enhance the representation of the attended feature while suppressing the distractor. These findings present a novel mechanism by which attention modulates neural populations to support sensory processing in cluttered environments. SIGNIFICANCE STATEMENT Although feature-selective attention constitutes one of the building blocks of listening in natural environments, its neural bases remain obscure. To address this, we developed a novel auditory feature-selective attention task and measured noise correlations (rnoise) in rhesus macaque A1 during task performance. Unlike previous studies showing that the effect of attention on rnoise depends on population tuning to the attended feature, we show that the effect of attention depends on the tuning to the distractor feature as well. We suggest that these effects represent an efficient process by which sensory cortex simultaneously enhances relevant information and suppresses irrelevant information. PMID:28432139

42 CFR 423.578 - Exceptions process.

Code of Federal Regulations, 2011 CFR

2011-10-01

... and medical and scientific evidence and the known relevant physical or mental characteristics of the... evidence and medical and scientific evidence and the known relevant physical or mental characteristics of... reasonable and complete exceptions procedures subject to CMS' approval for this type of coverage...

42 CFR 423.578 - Exceptions process.

Code of Federal Regulations, 2013 CFR

2013-10-01

... and medical and scientific evidence and the known relevant physical or mental characteristics of the... evidence and medical and scientific evidence and the known relevant physical or mental characteristics of... maintain reasonable and complete exceptions procedures subject to CMS' approval for this type of coverage...

Estimation of Symptom Severity During Chemotherapy From Passively Sensed Data: Exploratory Study

PubMed Central

Dey, Anind K; Ferreira, Denzil; Kamarck, Thomas; Sun, Weijing; Bae, Sangwon; Doryab, Afsaneh

2017-01-01

Background Physical and psychological symptoms are common during chemotherapy in cancer patients, and real-time monitoring of these symptoms can improve patient outcomes. Sensors embedded in mobile phones and wearable activity trackers could be potentially useful in monitoring symptoms passively, with minimal patient burden. Objective The aim of this study was to explore whether passively sensed mobile phone and Fitbit data could be used to estimate daily symptom burden during chemotherapy. Methods A total of 14 patients undergoing chemotherapy for gastrointestinal cancer participated in the 4-week study. Participants carried an Android phone and wore a Fitbit device for the duration of the study and also completed daily severity ratings of 12 common symptoms. Symptom severity ratings were summed to create a total symptom burden score for each day, and ratings were centered on individual patient means and categorized into low, average, and high symptom burden days. Day-level features were extracted from raw mobile phone sensor and Fitbit data and included features reflecting mobility and activity, sleep, phone usage (eg, duration of interaction with phone and apps), and communication (eg, number of incoming and outgoing calls and messages). We used a rotation random forests classifier with cross-validation and resampling with replacement to evaluate population and individual model performance and correlation-based feature subset selection to select nonredundant features with the best predictive ability. Results Across 295 days of data with both symptom and sensor data, a number of mobile phone and Fitbit features were correlated with patient-reported symptom burden scores. We achieved an accuracy of 88.1% for our population model. The subset of features with the best accuracy included sedentary behavior as the most frequent activity, fewer minutes in light physical activity, less variable and average acceleration of the phone, and longer screen-on time and interactions with apps on the phone. Mobile phone features had better predictive ability than Fitbit features. Accuracy of individual models ranged from 78.1% to 100% (mean 88.4%), and subsets of relevant features varied across participants. Conclusions Passive sensor data, including mobile phone accelerometer and usage and Fitbit-assessed activity and sleep, were related to daily symptom burden during chemotherapy. These findings highlight opportunities for long-term monitoring of cancer patients during chemotherapy with minimal patient burden as well as real-time adaptive interventions aimed at early management of worsening or severe symptoms. PMID:29258977

Estimation of Symptom Severity During Chemotherapy From Passively Sensed Data: Exploratory Study.

PubMed

Low, Carissa A; Dey, Anind K; Ferreira, Denzil; Kamarck, Thomas; Sun, Weijing; Bae, Sangwon; Doryab, Afsaneh

2017-12-19

Physical and psychological symptoms are common during chemotherapy in cancer patients, and real-time monitoring of these symptoms can improve patient outcomes. Sensors embedded in mobile phones and wearable activity trackers could be potentially useful in monitoring symptoms passively, with minimal patient burden. The aim of this study was to explore whether passively sensed mobile phone and Fitbit data could be used to estimate daily symptom burden during chemotherapy. A total of 14 patients undergoing chemotherapy for gastrointestinal cancer participated in the 4-week study. Participants carried an Android phone and wore a Fitbit device for the duration of the study and also completed daily severity ratings of 12 common symptoms. Symptom severity ratings were summed to create a total symptom burden score for each day, and ratings were centered on individual patient means and categorized into low, average, and high symptom burden days. Day-level features were extracted from raw mobile phone sensor and Fitbit data and included features reflecting mobility and activity, sleep, phone usage (eg, duration of interaction with phone and apps), and communication (eg, number of incoming and outgoing calls and messages). We used a rotation random forests classifier with cross-validation and resampling with replacement to evaluate population and individual model performance and correlation-based feature subset selection to select nonredundant features with the best predictive ability. Across 295 days of data with both symptom and sensor data, a number of mobile phone and Fitbit features were correlated with patient-reported symptom burden scores. We achieved an accuracy of 88.1% for our population model. The subset of features with the best accuracy included sedentary behavior as the most frequent activity, fewer minutes in light physical activity, less variable and average acceleration of the phone, and longer screen-on time and interactions with apps on the phone. Mobile phone features had better predictive ability than Fitbit features. Accuracy of individual models ranged from 78.1% to 100% (mean 88.4%), and subsets of relevant features varied across participants. Passive sensor data, including mobile phone accelerometer and usage and Fitbit-assessed activity and sleep, were related to daily symptom burden during chemotherapy. These findings highlight opportunities for long-term monitoring of cancer patients during chemotherapy with minimal patient burden as well as real-time adaptive interventions aimed at early management of worsening or severe symptoms. ©Carissa A Low, Anind K Dey, Denzil Ferreira, Thomas Kamarck, Weijing Sun, Sangwon Bae, Afsaneh Doryab. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 19.12.2017.

Identification of symptom and functional domains that fibromyalgia patients would like to see improved: a cluster analysis.

PubMed

Bennett, Robert M; Russell, Jon; Cappelleri, Joseph C; Bushmakin, Andrew G; Zlateva, Gergana; Sadosky, Alesia

2010-06-28

The purpose of this study was to determine whether some of the clinical features of fibromyalgia (FM) that patients would like to see improved aggregate into definable clusters. Seven hundred and eighty-eight patients with clinically confirmed FM and baseline pain > or =40 mm on a 100 mm visual analogue scale ranked 5 FM clinical features that the subjects would most like to see improved after treatment (one for each priority quintile) from a list of 20 developed during focus groups. For each subject, clinical features were transformed into vectors with rankings assigned values 1-5 (lowest to highest ranking). Logistic analysis was used to create a distance matrix and hierarchical cluster analysis was applied to identify cluster structure. The frequency of cluster selection was determined, and cluster importance was ranked using cluster scores derived from rankings of the clinical features. Multidimensional scaling was used to visualize and conceptualize cluster relationships. Six clinical features clusters were identified and named based on their key characteristics. In order of selection frequency, the clusters were Pain (90%; 4 clinical features), Fatigue (89%; 4 clinical features), Domestic (42%; 4 clinical features), Impairment (29%; 3 functions), Affective (21%; 3 clinical features), and Social (9%; 2 functional). The "Pain Cluster" was ranked of greatest importance by 54% of subjects, followed by Fatigue, which was given the highest ranking by 28% of subjects. Multidimensional scaling mapped these clusters to two dimensions: Status (bounded by Physical and Emotional domains), and Setting (bounded by Individual and Group interactions). Common clinical features of FM could be grouped into 6 clusters (Pain, Fatigue, Domestic, Impairment, Affective, and Social) based on patient perception of relevance to treatment. Furthermore, these 6 clusters could be charted in the 2 dimensions of Status and Setting, thus providing a unique perspective for interpretation of FM symptomatology.

Exploring the Association Between Emotional Abuse and Childhood Borderline Personality Features: The Moderating Role of Personality Traits

PubMed Central

Gratz, Kim L.; Latzman, Robert D.; Tull, Matthew T.; Reynolds, Elizabeth K.; Lejuez, C. W.

2012-01-01

Most of the extant literature on borderline personality disorder has focused on the course, consequences, and correlates of this disorder among adults. However, little is known about childhood borderline personality (BP) features, or the factors associated with the emergence of BP pathology in childhood. A greater understanding of childhood BP features and associated risk factors has important implications for the development of primary and secondary prevention programs. The goal of the present study was to examine the interrelationships among two BP-relevant traits (affective dysfunction and impulsivity), a BP-relevant environmental stressor (emotional abuse), and BP features in a sample of 225 children aged 11 to 14 years. Results provide support for the role of both trait vulnerabilities and environmental stressors in childhood BP features. Further, findings highlight the moderating role of affective dysfunction in the relationship between emotional abuse and childhood BP features. PMID:21658531

Comparison of Different EHG Feature Selection Methods for the Detection of Preterm Labor

PubMed Central

Alamedine, D.; Khalil, M.; Marque, C.

2013-01-01

Numerous types of linear and nonlinear features have been extracted from the electrohysterogram (EHG) in order to classify labor and pregnancy contractions. As a result, the number of available features is now very large. The goal of this study is to reduce the number of features by selecting only the relevant ones which are useful for solving the classification problem. This paper presents three methods for feature subset selection that can be applied to choose the best subsets for classifying labor and pregnancy contractions: an algorithm using the Jeffrey divergence (JD) distance, a sequential forward selection (SFS) algorithm, and a binary particle swarm optimization (BPSO) algorithm. The two last methods are based on a classifier and were tested with three types of classifiers. These methods have allowed us to identify common features which are relevant for contraction classification. PMID:24454536

Childcare Service Centers’ Preferences and Intentions to Use a Web-Based Program to Implement Healthy Eating and Physical Activity Policies and Practices: A Cross-Sectional Study

PubMed Central

Williams, Christopher Michael; Finch, Meghan; Wyse, Rebecca; Jones, Jannah; Freund, Megan; Wiggers, John Henry; Nathan, Nicole; Dodds, Pennie; Wolfenden, Luke

2015-01-01

Background Overweight and obesity is a significant public health problem that impacts a large number of children globally. Supporting childcare centers to deliver healthy eating and physical activity-promoting policies and practices is a recommended strategy for obesity prevention, given that such services provide access to a substantial proportion of children during a key developmental period. Electronic Web-based interventions represent a novel way to support childcare service providers to implement such policies and practices. Objective This study aimed to assess: (1) childcare centers’ current use of technology, (2) factors associated with intention to use electronic Web-based interventions, and (3) Web-based features that managers rated as useful to support staff with implementing healthy eating and physical activity-promoting policies and practices. Methods A computer-assisted telephone interview (CATI) was conducted with service managers from long day care centers and preschools. The CATI assessed the following: (1) childcare center characteristics, (2) childcare centers’ use of electronic devices, (3) intention to use a hypothetical electronic Web-based program—assessed using the Technology Acceptance Model (TAM) with ratings between 1 (strongly disagree) and 7 (strongly agree), and (4) features rated as useful to include in a Web-based program. Results Overall, 214 service centers out of 277 (77.3%) consented to participate. All service centers except 2 reported using computers (212/214, 99.1%), whereas 40.2% (86/214) used portable tablets. A total of 71.9% (151/210) of childcare service managers reported a score of 6 or more for intention to use a hypothetical electronic Web-based program. In a multivariable logistic regression analysis, intention to use the program was significantly associated with perceived ease of use (P=.002, odds ratio [OR] 3.9, 95% CI 1.6-9.2) and perceived usefulness (P<.001, OR 28,95% CI 8.0-95.2). Features reported by service managers as useful or very useful for a Web-based program included decision-support tools to support staff with menu planning (117/129, 90.7%), links to relevant resources (212/212, 100%), updated information on guidelines (208/212, 98.1%), and feedback regarding childcare center performance in relation to other childcare centers (212/212, 100%). Conclusions Childcare service managers reported high intention to use a Web-based program and identified several useful features to support staff to implement healthy eating and physical activity policies and practices. Further descriptive and intervention research examining the development and use of such a program to support childcare centers with the implementation of healthy eating and physical activity-promoting policies and practices is warranted. PMID:25931430

Childcare service centers' preferences and intentions to use a web-based program to implement healthy eating and physical activity policies and practices: a cross-sectional study.

PubMed

Yoong, Sze Lin; Williams, Christopher Michael; Finch, Meghan; Wyse, Rebecca; Jones, Jannah; Freund, Megan; Wiggers, John Henry; Nathan, Nicole; Dodds, Pennie; Wolfenden, Luke

2015-04-30

Overweight and obesity is a significant public health problem that impacts a large number of children globally. Supporting childcare centers to deliver healthy eating and physical activity-promoting policies and practices is a recommended strategy for obesity prevention, given that such services provide access to a substantial proportion of children during a key developmental period. Electronic Web-based interventions represent a novel way to support childcare service providers to implement such policies and practices. This study aimed to assess: (1) childcare centers' current use of technology, (2) factors associated with intention to use electronic Web-based interventions, and (3) Web-based features that managers rated as useful to support staff with implementing healthy eating and physical activity-promoting policies and practices. A computer-assisted telephone interview (CATI) was conducted with service managers from long day care centers and preschools. The CATI assessed the following: (1) childcare center characteristics, (2) childcare centers' use of electronic devices, (3) intention to use a hypothetical electronic Web-based program-assessed using the Technology Acceptance Model (TAM) with ratings between 1 (strongly disagree) and 7 (strongly agree), and (4) features rated as useful to include in a Web-based program. Overall, 214 service centers out of 277 (77.3%) consented to participate. All service centers except 2 reported using computers (212/214, 99.1%), whereas 40.2% (86/214) used portable tablets. A total of 71.9% (151/210) of childcare service managers reported a score of 6 or more for intention to use a hypothetical electronic Web-based program. In a multivariable logistic regression analysis, intention to use the program was significantly associated with perceived ease of use (P=.002, odds ratio [OR] 3.9, 95% CI 1.6-9.2) and perceived usefulness (P<.001, OR 28,95% CI 8.0-95.2). Features reported by service managers as useful or very useful for a Web-based program included decision-support tools to support staff with menu planning (117/129, 90.7%), links to relevant resources (212/212, 100%), updated information on guidelines (208/212, 98.1%), and feedback regarding childcare center performance in relation to other childcare centers (212/212, 100%). Childcare service managers reported high intention to use a Web-based program and identified several useful features to support staff to implement healthy eating and physical activity policies and practices. Further descriptive and intervention research examining the development and use of such a program to support childcare centers with the implementation of healthy eating and physical activity-promoting policies and practices is warranted.

Short time-scale wind forced variability in the Río de la Plata Estuary and its role on ichthyoplankton retention

NASA Astrophysics Data System (ADS)

Simionato, C. G.; Berasategui, A.; Meccia, V. L.; Acha, M.; Mianzan, H.

2008-01-01

The Río de la Plata Estuary presents a strong bottom salinity front located over a submerged shoal. Apparently favored by retention processes, it is a spawning ground for several coastal fishes. This estuary is very shallow and essentially wind driven and, moreover, in time scales relevant to biota, estuarine circulation is wind dominated and highly variable. Two intriguing questions are, therefore, how this system can favor retention and what the involved mechanisms are. This paper qualitatively explores mechanisms involved in the estuary where retention is favored applying numerical simulations in which neutral particles - simulating fish eggs and early larvae - are released along the bottom frontal zone and tracked for different wind conditions. Results suggest that retentive features can be a consequence of estuarine response to natural wind variability acting over bathymetric features. For winds from most directions, particles either remain trapped near their launching position or move northeastward to southwestward along the shoal. As alternation of winds that favor along-shoal motion is the dominant feature of wind variability in the region, a retentive scenario results from prevailing wind variability. Additionally, winds that tend to export particles with a poor chance of being restored to the front are neither frequent nor persistent. Results show, therefore, that physical forcing alone might generate a retentive scenario at the inner part of this estuary. The physical retention mechanism is more effective for bottom than for surface launched particles. Wind statistics indicate that the proposed mechanism has different implications for retention along the seasons. Spring is the most favorable season, followed by summer, when particles would have a larger propensity to reach the southern area of the estuary (Samborombón Bay). Fall and winter are increasingly less favorable. All these features are consistent with patterns observed in the region in organisms having different life history traits.

Physical and biophysical assessment of highly fluorescent, magnetic quantum dots of a wurtzite-phase manganese selenide system

NASA Astrophysics Data System (ADS)

Sarma, Runjun; Das, Queen; Hussain, Anowar; Ramteke, Anand; Choudhury, Amarjyoti; Mohanta, Dambarudhar

2014-07-01

Combining fluorescence and magnetic features in a non-iron based, select type of quantum dots (QDs) can have immense value in cellular imaging, tagging and other nano-bio interface applications, including targeted drug delivery. Herein, we report on the colloidal synthesis and physical and biophysical assessment of wurtzite-type manganese selenide (MnSe) QDs in cell culture media. Aiming to provide a suitable colloidal system of biological relevance, different concentrations of reactants and ligands (e.g., thioglycolic acid, TGA) have been considered. The average size of the QDs is ˜7 nm, which exhibited a quantum yield of ˜75% as compared to rhodamine 6 G dye®. As revealed from time-resolved photoluminescence (TR-PL) response, the near band edge emission followed a bi-exponential decay feature with characteristic times of ˜0.64 ns and 3.04 ns. At room temperature, the QDs were found to exhibit paramagnetic features with coercivity and remanence impelled by TGA concentrations. With BSA as a dispersing agent, the QDs showed an improved optical stability in Dulbecco’s Modified Eagle Media® (DMEM) and Minimum Essential Media® (MEM), as compared to the Roswell Park Memorial Institute® (RPMI-1640) media. Finally, the cell viability of lymphocytes was found to be strongly influenced by the concentration of MnSe QDs, and had a safe limit upto 0.5 μM. With BSA inclusion in cell media, the cellular uptake of MnSe QDs was observed to be more prominent, as revealed from fluorescence imaging. The fabrication of water soluble, nontoxic MnSe QDs would open up an alternative strategy in nanobiotechnology, while preserving their luminescent and magnetic properties intact.

Individual differences in attention strategies during detection, fine discrimination, and coarse discrimination

PubMed Central

Hecker, Elizabeth A.; Serences, John T.; Srinivasan, Ramesh

2013-01-01

Interacting with the environment requires the ability to flexibly direct attention to relevant features. We examined the degree to which individuals attend to visual features within and across Detection, Fine Discrimination, and Coarse Discrimination tasks. Electroencephalographic (EEG) responses were measured to an unattended peripheral flickering (4 or 6 Hz) grating while individuals (n = 33) attended to orientations that were offset by 0°, 10°, 20°, 30°, 40°, and 90° from the orientation of the unattended flicker. These unattended responses may be sensitive to attentional gain at the attended spatial location, since attention to features enhances early visual responses throughout the visual field. We found no significant differences in tuning curves across the three tasks in part due to individual differences in strategies. We sought to characterize individual attention strategies using hierarchical Bayesian modeling, which grouped individuals into families of curves that reflect attention to the physical target orientation (“on-channel”) or away from the target orientation (“off-channel”) or a uniform distribution of attention. The different curves were related to behavioral performance; individuals with “on-channel” curves had lower thresholds than individuals with uniform curves. Individuals with “off-channel” curves during Fine Discrimination additionally had lower thresholds than those assigned to uniform curves, highlighting the perceptual benefits of attending away from the physical target orientation during fine discriminations. Finally, we showed that a subset of individuals with optimal curves (“on-channel”) during Detection also demonstrated optimal curves (“off-channel”) during Fine Discrimination, indicating that a subset of individuals can modulate tuning optimally for detection and discrimination. PMID:23678013

Assessment of Mental, Emotional and Physical Stress through Analysis of Physiological Signals Using Smartphones.

PubMed

Mohino-Herranz, Inma; Gil-Pita, Roberto; Ferreira, Javier; Rosa-Zurera, Manuel; Seoane, Fernando

2015-10-08

Determining the stress level of a subject in real time could be of special interest in certain professional activities to allow the monitoring of soldiers, pilots, emergency personnel and other professionals responsible for human lives. Assessment of current mental fitness for executing a task at hand might avoid unnecessary risks. To obtain this knowledge, two physiological measurements were recorded in this work using customized non-invasive wearable instrumentation that measures electrocardiogram (ECG) and thoracic electrical bioimpedance (TEB) signals. The relevant information from each measurement is extracted via evaluation of a reduced set of selected features. These features are primarily obtained from filtered and processed versions of the raw time measurements with calculations of certain statistical and descriptive parameters. Selection of the reduced set of features was performed using genetic algorithms, thus constraining the computational cost of the real-time implementation. Different classification approaches have been studied, but neural networks were chosen for this investigation because they represent a good tradeoff between the intelligence of the solution and computational complexity. Three different application scenarios were considered. In the first scenario, the proposed system is capable of distinguishing among different types of activity with a 21.2% probability error, for activities coded as neutral, emotional, mental and physical. In the second scenario, the proposed solution distinguishes among the three different emotional states of neutral, sadness and disgust, with a probability error of 4.8%. In the third scenario, the system is able to distinguish between low mental load and mental overload with a probability error of 32.3%. The computational cost was calculated, and the solution was implemented in commercially available Android-based smartphones. The results indicate that execution of such a monitoring solution is negligible compared to the nominal computational load of current smartphones.

Diagnostic and prognostic value of history-taking and physical examination in undifferentiated peripheral inflammatory arthritis: a systematic review.

PubMed

Kuriya, Bindee; Villeneuve, Edith; Bombardier, Claire

2011-03-01

To review the diagnostic and prognostic value of history/physical examination among patients with undifferentiated peripheral inflammatory arthritis (UPIA). We conducted a systematic review evaluating the association between history/physical examination features and a diagnostic or prognostic outcome. Nineteen publications were included. Advanced age, female sex, and morning stiffness were predictive of a diagnosis of rheumatoid arthritis (RA) from UPIA. A higher number of tender and swollen joints, small/large joint involvement in the upper/lower extremities, and symmetrical involvement were associated with progression to RA. Similar features were associated with persistent disease and erosions, while disability at baseline and extraarticular features were predictive of future disability. History/physical examination features are heterogeneously reported. Several features predict progression from UPIA to RA or a poor prognosis. Continued measurements in the UPIA population are needed to determine if these features are valid and reliable predictors of outcomes, especially as new definitions for RA and disease states emerge.

A report on older-age bipolar disorder from the International Society for Bipolar Disorders Task Force

PubMed Central

Sajatovic, Martha; Strejilevich, Sergio A; Gildengers, Ariel G; Dols, Annemiek; Al Jurdi, Rayan K; Forester, Brent P; Kessing, Lars Vedel; Beyer, John; Manes, Facundo; Rej, Soham; Rosa, Adriane R; Schouws, Sigfried NTM; Tsai, Shang-Ying; Young, Robert C; Shulman, Kenneth I

2015-01-01

Objectives In the coming generation, older adults with bipolar disorder (BD) will increase in absolute numbers as well as proportion of the general population. This is the first report of the International Society for Bipolar Disorder (ISBD) Task Force on Older-Age Bipolar Disorder (OABD). Methods This task force report addresses the unique aspects of OABD including epidemiology and clinical features, neuropathology and biomarkers, physical health, cognition, and care approaches. Results The report describes an expert consensus summary on OABD that is intended to advance the care of patients, and shed light on issues of relevance to BD research across the lifespan. Although there is still a dearth of research and health efforts focused on older adults with BD, emerging data has brought some answers, innovative questions, and novel perspectives related to the notion of late onset, medical comorbidity, and the vexing issue of cognitive impairment and decline. Conclusions Improving our understanding of the biological, clinical, and social underpinnings relevant to OABD is an indispensable step in building a complete map of BD across the lifespan. PMID:26384588

Clustering document fragments using background color and texture information

NASA Astrophysics Data System (ADS)

Chanda, Sukalpa; Franke, Katrin; Pal, Umapada

2012-01-01

Forensic analysis of questioned documents sometimes can be extensively data intensive. A forensic expert might need to analyze a heap of document fragments and in such cases to ensure reliability he/she should focus only on relevant evidences hidden in those document fragments. Relevant document retrieval needs finding of similar document fragments. One notion of obtaining such similar documents could be by using document fragment's physical characteristics like color, texture, etc. In this article we propose an automatic scheme to retrieve similar document fragments based on visual appearance of document paper and texture. Multispectral color characteristics using biologically inspired color differentiation techniques are implemented here. This is done by projecting document color characteristics to Lab color space. Gabor filter-based texture analysis is used to identify document texture. It is desired that document fragments from same source will have similar color and texture. For clustering similar document fragments of our test dataset we use a Self Organizing Map (SOM) of dimension 5×5, where the document color and texture information are used as features. We obtained an encouraging accuracy of 97.17% from 1063 test images.

Nutrition and Supplementation in Soccer.

PubMed

Oliveira, César Chaves; Ferreira, Diogo; Caetano, Carlos; Granja, Diana; Pinto, Ricardo; Mendes, Bruno; Sousa, Mónica

2017-05-12

Contemporary elite soccer features increased physical demands during match-play, as well as a larger number of matches per season. Now more than ever, aspects related to performance optimization are highly regarded by both players and soccer coaches. Here, nutrition takes a special role as most elite teams try to provide an adequate diet to guarantee maximum performance while ensuring a faster recovery from matches and training exertions. It is currently known that manipulation and periodization of macronutrients, as well as sound hydration practices, have the potential to interfere with training adaptation and recovery. A careful monitoring of micronutrient status is also relevant to prevent undue fatigue and immune impairment secondary to a deficiency status. Furthermore, the sensible use of evidence-based dietary supplements may also play a role in soccer performance optimization. In this sense, several nutritional recommendations have been issued. This detailed and comprehensive review addresses the most relevant and up-to-date nutritional recommendations for elite soccer players, covering from macro and micronutrients to hydration and selected supplements in different contexts (daily requirements, pre, peri and post training/match and competition).

Nutrition and Supplementation in Soccer

PubMed Central

Oliveira, César Chaves; Ferreira, Diogo; Caetano, Carlos; Granja, Diana; Pinto, Ricardo; Mendes, Bruno; Sousa, Mónica

2017-01-01

Contemporary elite soccer features increased physical demands during match-play, as well as a larger number of matches per season. Now more than ever, aspects related to performance optimization are highly regarded by both players and soccer coaches. Here, nutrition takes a special role as most elite teams try to provide an adequate diet to guarantee maximum performance while ensuring a faster recovery from matches and training exertions. It is currently known that manipulation and periodization of macronutrients, as well as sound hydration practices, have the potential to interfere with training adaptation and recovery. A careful monitoring of micronutrient status is also relevant to prevent undue fatigue and immune impairment secondary to a deficiency status. Furthermore, the sensible use of evidence-based dietary supplements may also play a role in soccer performance optimization. In this sense, several nutritional recommendations have been issued. This detailed and comprehensive review addresses the most relevant and up-to-date nutritional recommendations for elite soccer players, covering from macro and micronutrients to hydration and selected supplements in different contexts (daily requirements, pre, peri and post training/match and competition). PMID:29910389

Visualizing Gyrokinetic Turbulence in a Tokamak

NASA Astrophysics Data System (ADS)

Stantchev, George

2005-10-01

Multi-dimensional data output from gyrokinetic microturbulence codes are often difficult to visualize, in part due to the non-trivial geometry of the underlying grids, in part due to high irregularity of the relevant scalar field structures in turbulent regions. For instance, traditional isosurface extraction methods are likely to fail for the electrostatic potential field whose level sets may exhibit various geometric pathologies. To address these issues we develop an advanced interactive 3D gyrokinetic turbulence visualization framework which we apply in the study of microtearing instabilities calculated with GS2 in the MAST and NSTX geometries. In these simulations GS2 uses field-line-following coordinates such that the computational domain maps in physical space to a long, twisting flux tube with strong cross-sectional shear. Using statistical wavelet analysis we create a sparse multiple-scale volumetric representation of the relevant scalar fields, which we visualize via a variation of the so called splatting technique. To handle the problem of highly anisotropic flux tube configurations we adapt a geometry-driven surface illumination algorithm that places local light sources for effective feature-enhanced visualization.

Post-conflict slowing after incongruent stimuli: from general to conflict-specific.

PubMed

Rey-Mermet, Alodie; Meier, Beat

2017-05-01

Encountering a cognitive conflict not only slows current performance, but it can also affect subsequent performance, in particular when the conflict is induced with bivalent stimuli (i.e., stimuli with relevant features for two different tasks) or with incongruent trials (i.e., stimuli with relevant features for two response alternatives). The post-conflict slowing following bivalent stimuli, called "bivalency effect", affects all subsequent stimuli, irrespective of whether the subsequent stimuli share relevant features with the conflict stimuli. To date, it is unknown whether the conflict induced by incongruent stimuli results in a similar post-conflict slowing. To investigate this, we performed six experiments in which participants switched between two tasks. In one task, incongruent stimuli appeared occasionally; in the other task, stimuli shared no feature with the incongruent trials. The results showed an initial performance slowing that affected all tasks after incongruent trials. On further trials, however, the slowing only affected the task sharing features with the conflict stimuli. Therefore, the post-conflict slowing following incongruent stimuli is first general and then becomes conflict-specific across trials. These findings are discussed within current task switching and cognitive control accounts.

The cost of selective attention in category learning: developmental differences between adults and infants.

PubMed

Best, Catherine A; Yim, Hyungwook; Sloutsky, Vladimir M

2013-10-01

Selective attention plays an important role in category learning. However, immaturities of top-down attentional control during infancy coupled with successful category learning suggest that early category learning is achieved without attending selectively. Research presented here examines this possibility by focusing on category learning in infants (6-8months old) and adults. Participants were trained on a novel visual category. Halfway through the experiment, unbeknownst to participants, the to-be-learned category switched to another category, where previously relevant features became irrelevant and previously irrelevant features became relevant. If participants attend selectively to the relevant features of the first category, they should incur a cost of selective attention immediately after the unknown category switch. Results revealed that adults demonstrated a cost, as evidenced by a decrease in accuracy and response time on test trials as well as a decrease in visual attention to newly relevant features. In contrast, infants did not demonstrate a similar cost of selective attention as adults despite evidence of learning both to-be-learned categories. Findings are discussed as supporting multiple systems of category learning and as suggesting that learning mechanisms engaged by adults may be different from those engaged by infants. Copyright © 2013 Elsevier Inc. All rights reserved.

DISCOVER-AQ

Atmospheric Science Data Center

2017-01-31

... Relevant Documents:  DISCOVER-AQ - Airborne Science Data for Atmospheric Composition DISCOVER-AQ - NASA Earth ... DISCOVER-AQ - Mission Highlight Featured Articles : Articles featuring DISCOVER-AQ data products SCAR-B ...

Remembering complex objects in visual working memory: do capacity limits restrict objects or features?

PubMed

Hardman, Kyle O; Cowan, Nelson

2015-03-01

Visual working memory stores stimuli from our environment as representations that can be accessed by high-level control processes. This study addresses a longstanding debate in the literature about whether storage limits in visual working memory include a limit to the complexity of discrete items. We examined the issue with a number of change-detection experiments that used complex stimuli that possessed multiple features per stimulus item. We manipulated the number of relevant features of the stimulus objects in order to vary feature load. In all of our experiments, we found that increased feature load led to a reduction in change-detection accuracy. However, we found that feature load alone could not account for the results but that a consideration of the number of relevant objects was also required. This study supports capacity limits for both feature and object storage in visual working memory. PsycINFO Database Record (c) 2015 APA, all rights reserved.

Joint Feature Extraction and Classifier Design for ECG-Based Biometric Recognition.

PubMed

Gutta, Sandeep; Cheng, Qi

2016-03-01

Traditional biometric recognition systems often utilize physiological traits such as fingerprint, face, iris, etc. Recent years have seen a growing interest in electrocardiogram (ECG)-based biometric recognition techniques, especially in the field of clinical medicine. In existing ECG-based biometric recognition methods, feature extraction and classifier design are usually performed separately. In this paper, a multitask learning approach is proposed, in which feature extraction and classifier design are carried out simultaneously. Weights are assigned to the features within the kernel of each task. We decompose the matrix consisting of all the feature weights into sparse and low-rank components. The sparse component determines the features that are relevant to identify each individual, and the low-rank component determines the common feature subspace that is relevant to identify all the subjects. A fast optimization algorithm is developed, which requires only the first-order information. The performance of the proposed approach is demonstrated through experiments using the MIT-BIH Normal Sinus Rhythm database.

MememxGATE: Unearthing Latent Content Features for Improved Search and Relevancy Ranking Across Scientific Literature

NASA Astrophysics Data System (ADS)

Wilson, B. D.; McGibbney, L. J.; Mattmann, C. A.; Ramirez, P.; Joyce, M.; Whitehall, K. D.

2015-12-01

Quantifying scientific relevancy is of increasing importance to NASA and the research community. Scientific relevancy may be defined by mapping the impacts of a particular NASA mission, instrument, and/or retrieved variables to disciplines such as climate predictions, natural hazards detection and mitigation processes, education, and scientific discoveries. Related to relevancy, is the ability to expose data with similar attributes. This in turn depends upon the ability for us to extract latent, implicit document features from scientific data and resources and make them explicit, accessible and useable for search activities amongst others. This paper presents MemexGATE; a server side application, command line interface and computing environment for running large scale metadata extraction, general architecture text engineering, document classification and indexing tasks over document resources such as social media streams, scientific literature archives, legal documentation, etc. This work builds on existing experiences using MemexGATE (funded, developed and validated through the DARPA Memex Progrjam PI Mattmann) for extracting and leveraging latent content features from document resources within the Materials Research domain. We extend the software functionality capability to the domain of scientific literature with emphasis on the expansion of gazetteer lists, named entity rules, natural language construct labeling (e.g. synonym, antonym, hyponym, etc.) efforts to enable extraction of latent content features from data hosted by wide variety of scientific literature vendors (AGU Meeting Abstract Database, Springer, Wiley Online, Elsevier, etc.) hosting earth science literature. Such literature makes both implicit and explicit references to NASA datasets and relationships between such concepts stored across EOSDIS DAAC's hence we envisage that a significant part of this effort will also include development and understanding of relevancy signals which can ultimately be utilized for improved search and relevancy ranking across scientific literature.

Statistical interpretation of machine learning-based feature importance scores for biomarker discovery.

PubMed

Huynh-Thu, Vân Anh; Saeys, Yvan; Wehenkel, Louis; Geurts, Pierre

2012-07-01

Univariate statistical tests are widely used for biomarker discovery in bioinformatics. These procedures are simple, fast and their output is easily interpretable by biologists but they can only identify variables that provide a significant amount of information in isolation from the other variables. As biological processes are expected to involve complex interactions between variables, univariate methods thus potentially miss some informative biomarkers. Variable relevance scores provided by machine learning techniques, however, are potentially able to highlight multivariate interacting effects, but unlike the p-values returned by univariate tests, these relevance scores are usually not statistically interpretable. This lack of interpretability hampers the determination of a relevance threshold for extracting a feature subset from the rankings and also prevents the wide adoption of these methods by practicians. We evaluated several, existing and novel, procedures that extract relevant features from rankings derived from machine learning approaches. These procedures replace the relevance scores with measures that can be interpreted in a statistical way, such as p-values, false discovery rates, or family wise error rates, for which it is easier to determine a significance level. Experiments were performed on several artificial problems as well as on real microarray datasets. Although the methods differ in terms of computing times and the tradeoff, they achieve in terms of false positives and false negatives, some of them greatly help in the extraction of truly relevant biomarkers and should thus be of great practical interest for biologists and physicians. As a side conclusion, our experiments also clearly highlight that using model performance as a criterion for feature selection is often counter-productive. Python source codes of all tested methods, as well as the MATLAB scripts used for data simulation, can be found in the Supplementary Material.

The DC8 as an Exemplar of Relevant Physics

ERIC Educational Resources Information Center

Lockett, T. K.

1974-01-01

Presents data on aircraft take off and landing, including measurements of turning speeds, triangle of velocities method, fuel consumption, air pressure differences, air turbulence, maintenance inspection, and airborne radar. Indicates the materials can serve as relevant physics examples in teaching sixth and seventh form pupils. (CC)

Topics in Non-Equilibrium Dynamics and the Emergence of Spacetime

NASA Astrophysics Data System (ADS)

Engelhardt, Dalit

The Anti-de Sitter / Conformal Field Theory (AdS/CFT) correspondence that arises in string theory has had implications for the study of phenomena across a range of subfields in physics, from spacetime geometry to the behavior of condensed matter systems. Two major themes that have featured prominently in these investigations have been the behavior of systems out of equilibrium, and the emergence of spacetime. In this thesis, aspects of these themes are considered and analyzed. The question of equilibration and thermalization in 2D conformal field theories is addressed and refined via a number of observations about local versus global thermalization in such systems, the validity of particular diagnostics of thermalization, the dependence of the equilibration behavior of a conformal field theory on its operator spectrum, and the holographic dual of the generalized Gibbs ensemble that is of interest in studies of equilibration in systems with a large number of conserved quantities. A formalism for analyzing the non-equilibrium dynamics of 1+1-dimensional conformal field theories is discussed, and its physical relevance is motivated with an example connecting such a system to an experimental system that exhibited unusual equilibration behavior. Qualitative agreement is demonstrated between the CFT picture and the experimental observations. The emergence of spacetime geometry from quantum entanglement, while largely a byproduct of considerations from holographic dualities, has also been proposed to have a direct, non-holographic manifestation. Here a particular realization of such a direct emergence is presented through a demonstration that, in the presence of quantum entanglement alone, certain observations of electric fields in the entangled system appear qualitatively the same as the corresponding observations in a physically-connected geometric spacetime, so that the entanglement effectively mimics particular features associated with geometric connectivity.

A Review of Quantum Confinement

NASA Astrophysics Data System (ADS)

Connerade, Jean-Patrick

2009-12-01

A succinct history of the Confined Atom problem is presented. The hydrogen atom confined to the centre of an impenetrable sphere counts amongst the exactly soluble problems of physics, alongside much more noted exact solutions such as Black Body Radiation and the free Hydrogen atom in absence of any radiation field. It shares with them the disadvantage of being an idealisation, while at the same time encapsulating in a simple way particular aspects of physical reality. The problem was first formulated by Sommerfeld and Welker [1]—henceforth cited as SW—in connection with the behaviour of atoms at very high pressures, and the solution was published on the occasion of Pauli's 60th birthday celebration. At the time, it seemed that there was not much other connection with physical reality beyond a few simple aspects connected to the properties of atoms in solids, for which more appropriate models were soon developed. Thus, confined atoms attracted little attention until the advent of the metallofullerene, which provided the first example of a confined atom with properties quite closely related to those originally considered by SW. Since then, the problem has received much more attention, and many more new features of quantum confinement, quantum compression, the quantum Faraday cage, electronic reorganisation, cavity resonances, etc have been described, which are relevant to real systems. Also, a number of other situations have been uncovered experimentally to which quantum confinement is relevant. Thus, studies of the confined atom are now more numerous, and have been extended both in terms of the models used and the systems to which they can be applied. Connections to thermodynamics are explored through the properties of a confined two-level atom adapted from Einstein's celebrated model, and issues of dynamical screening of electromagnetic radiation by the confining shell are discussed in connection with the Faraday cage produced by a confining conducting shell. The conclusions are shown to be relevant to a proposed `quantum computer'. The description of the actual geometry of C60, as opposed to a purely spherical approximation, leads to some qualification of the computed results.

Stimulus-response correspondence effect as a function of temporal overlap between relevant and irrelevant information processing.

PubMed

Wang, Dong-Yuan Debbie; Richard, F Dan; Ray, Brittany

2016-01-01

The stimulus-response correspondence (SRC) effect refers to advantages in performance when stimulus and response correspond in dimensions or features, even if the common features are irrelevant to the task. Previous research indicated that the SRC effect depends on the temporal course of stimulus information processing. The current study investigated how the temporal overlap between relevant and irrelevant stimulus processing influences the SRC effect. In this experiment, the irrelevant stimulus (a previously associated tone) preceded the relevant stimulus (a coloured rectangle). The irrelevant and relevant stimuli onset asynchrony was varied to manipulate the temporal overlap between the irrelevant and relevant stimuli processing. Results indicated that the SRC effect size varied as a quadratic function of the temporal overlap between the relevant stimulus and irrelevant stimulus. This finding extends previous experimental observations that the SRC effect size varies in an increasing or decreasing function with reaction time. The current study demonstrated a quadratic function between effect size and the temporal overlap.

A Genetic Algorithm Based Support Vector Machine Model for Blood-Brain Barrier Penetration Prediction

PubMed Central

Zhang, Daqing; Xiao, Jianfeng; Zhou, Nannan; Luo, Xiaomin; Jiang, Hualiang; Chen, Kaixian

2015-01-01

Blood-brain barrier (BBB) is a highly complex physical barrier determining what substances are allowed to enter the brain. Support vector machine (SVM) is a kernel-based machine learning method that is widely used in QSAR study. For a successful SVM model, the kernel parameters for SVM and feature subset selection are the most important factors affecting prediction accuracy. In most studies, they are treated as two independent problems, but it has been proven that they could affect each other. We designed and implemented genetic algorithm (GA) to optimize kernel parameters and feature subset selection for SVM regression and applied it to the BBB penetration prediction. The results show that our GA/SVM model is more accurate than other currently available log BB models. Therefore, to optimize both SVM parameters and feature subset simultaneously with genetic algorithm is a better approach than other methods that treat the two problems separately. Analysis of our log BB model suggests that carboxylic acid group, polar surface area (PSA)/hydrogen-bonding ability, lipophilicity, and molecular charge play important role in BBB penetration. Among those properties relevant to BBB penetration, lipophilicity could enhance the BBB penetration while all the others are negatively correlated with BBB penetration. PMID:26504797

A reassessment of the role of tidal dispersion in estuaries and bays

USGS Publications Warehouse

Geyer, W. Rockwell; Signell, Richard P.

1992-01-01

The role of tidal dispersion is reassessed, based on a consideration of the relevant physical mechanisms, particularly those elucidated by numerical simulations of tide-induced dispersion. It appears that the principal influence of tidal currents on dispersion occurs at length scales of the tidal excursion and smaller; thus the effectiveness of tidal dispersion depends on the relative scale of the tidal excursion to the spacing between major bathymetric and shoreline features. In estuaries where the typical spacing of topographic features is less than the tidal excursion, tidal dispersion may contribute significantly to the overall flushing. In estuaries and embayments in which the typical spacing between major features is larger than the tidal excursion, the influence of tidal dispersion will be localized, and it will not markedly contribute to overall flushing. Tidal dispersion is most pronounced in regions of abrupt topographic changes such as headlands and inlets, where flow separation occurs. The strong strain rate in the region of flow separation tends to stretch patches of fluid into long filaments, which are subsequently rolled up and distorted by the transient eddy field. The dispersion process accomplished by the tides varies strongly as a function of position and tidal phase and thus does not lend itself to parameterization by an eddy diffusion coefficient.

Manufactured solutions for the three-dimensional Euler equations with relevance to Inertial Confinement Fusion

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

Waltz, J., E-mail: jwaltz@lanl.gov; Canfield, T.R.; Morgan, N.R.

2014-06-15

We present a set of manufactured solutions for the three-dimensional (3D) Euler equations. The purpose of these solutions is to allow for code verification against true 3D flows with physical relevance, as opposed to 3D simulations of lower-dimensional problems or manufactured solutions that lack physical relevance. Of particular interest are solutions with relevance to Inertial Confinement Fusion (ICF) capsules. While ICF capsules are designed for spherical symmetry, they are hypothesized to become highly 3D at late time due to phenomena such as Rayleigh–Taylor instability, drive asymmetry, and vortex decay. ICF capsules also involve highly nonlinear coupling between the fluid dynamicsmore » and other physics, such as radiation transport and thermonuclear fusion. The manufactured solutions we present are specifically designed to test the terms and couplings in the Euler equations that are relevant to these phenomena. Example numerical results generated with a 3D Finite Element hydrodynamics code are presented, including mesh convergence studies.« less

Bio-physical modeling of time-resolved forward scattering by Listeria colonies

NASA Astrophysics Data System (ADS)

Bae, Euiwon; Banada, Padmapriya P.; Bhunia, Arun K.; Hirleman, E. Daniel

2006-10-01

We have developed a detection system and associated protocol based on optical forward scattering where the bacterial colonies of various species and strains growing on solid nutrient surfaces produced unique scatter signatures. The aim of the present investigation was to develop a bio-physical model for the relevant phenomena. In particular, we considered time-varying macroscopic morphological properties of the growing colonies and modeled the scattering using scalar diffraction theory. For the present work we performed detailed studies with three species of Listeria; L. innocua, L. monocytogenes, and L. ivanovii. The baseline experiments involved cultures grown on brain heart infusion (BHI) agar and the scatter images were captured every six hours for an incubation period of 42 hours. The morphologies of the colonies were studied by phase contrast microscopy, including measurement of the diameter of the colony. Growth curves, represented by colony diameter as a function of time, were compared with the time-evolution of scattering signatures. Similar studies were carried out with L. monocytogenes grown on different substrates. Non-dimensionalizing incubation time in terms of the time to reach stationary phase was effective in reducing the dimensionality of the model. Bio-physical properties of the colony such as diameter, bacteria density variation, surface curvature/profile, and transmission coefficient are important parameters in predicting the features of the forward scattering signatures. These parameters are included in a baseline model that treats the colony as a concentric structure with radial variations in phase modulation. In some cases azimuthal variations and random phase inclusions were included as well. The end result is a protocol (growth media, incubation time and conditions) that produces reproducible and distinguishable scatter patterns for a variety of harmful food borne pathogens in a short period of time. Further, the bio-physical model we developed is very effective in predicting the dominant features of the scattering signatures required by the identification process and will be effective for informing further improvements in the instrumentation.

Prediction of active sites of enzymes by maximum relevance minimum redundancy (mRMR) feature selection.

PubMed

Gao, Yu-Fei; Li, Bi-Qing; Cai, Yu-Dong; Feng, Kai-Yan; Li, Zhan-Dong; Jiang, Yang

2013-01-27

Identification of catalytic residues plays a key role in understanding how enzymes work. Although numerous computational methods have been developed to predict catalytic residues and active sites, the prediction accuracy remains relatively low with high false positives. In this work, we developed a novel predictor based on the Random Forest algorithm (RF) aided by the maximum relevance minimum redundancy (mRMR) method and incremental feature selection (IFS). We incorporated features of physicochemical/biochemical properties, sequence conservation, residual disorder, secondary structure and solvent accessibility to predict active sites of enzymes and achieved an overall accuracy of 0.885687 and MCC of 0.689226 on an independent test dataset. Feature analysis showed that every category of the features except disorder contributed to the identification of active sites. It was also shown via the site-specific feature analysis that the features derived from the active site itself contributed most to the active site determination. Our prediction method may become a useful tool for identifying the active sites and the key features identified by the paper may provide valuable insights into the mechanism of catalysis.

Comprehensive and critical review of the predictive properties of the various mass models

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

Haustein, P.E.

1984-01-01

Since the publication of the 1975 Mass Predictions approximately 300 new atomic masses have been reported. These data come from a variety of experimental studies using diverse techniques and they span a mass range from the lightest isotopes to the very heaviest. It is instructive to compare these data with the 1975 predictions and several others (Moeller and Nix, Monahan, Serduke, Uno and Yamada which appeared latter. Extensive numerical and graphical analyses have been performed to examine the quality of the mass predictions from the various models and to identify features in these models that require correction. In general, theremore » is only rough correlation between the ability of a particular model to reproduce the measured mass surface which had been used to refine its adjustable parameters and that model's ability to predict correctly the new masses. For some models distinct systematic features appear when the new mass data are plotted as functions of relevant physical variables. Global intercomparisons of all the models are made first, followed by several examples of types of analysis performed with individual mass models.« less

Optical Fiber-Based MR-Compatible Sensors for Medical Applications: An Overview

PubMed Central

Taffoni, Fabrizio; Formica, Domenico; Saccomandi, Paola; Di Pino, Giovanni; Schena, Emiliano

2013-01-01

During last decades, Magnetic Resonance (MR)—compatible sensors based on different techniques have been developed due to growing demand for application in medicine. There are several technological solutions to design MR-compatible sensors, among them, the one based on optical fibers presents several attractive features. The high elasticity and small size allow designing miniaturized fiber optic sensors (FOS) with metrological characteristics (e.g., accuracy, sensitivity, zero drift, and frequency response) adequate for most common medical applications; the immunity from electromagnetic interference and the absence of electrical connection to the patient make FOS suitable to be used in high electromagnetic field and intrinsically safer than conventional technologies. These two features further heightened the potential role of FOS in medicine making them especially attractive for application in MRI. This paper provides an overview of MR-compatible FOS, focusing on the sensors employed for measuring physical parameters in medicine (i.e., temperature, force, torque, strain, and position). The working principles of the most promising FOS are reviewed in terms of their relevant advantages and disadvantages, together with their applications in medicine. PMID:24145918

Technology adoption and prediction tools for everyday technologies aimed at people with dementia.

PubMed

Chaurasia, Priyanka; McClean, Sally I; Nugent, Chris D; Cleland, Ian; Shuai Zhang; Donnelly, Mark P; Scotney, Bryan W; Sanders, Chelsea; Smith, Ken; Norton, Maria C; Tschanz, JoAnn

2016-08-01

A wide range of assistive technologies have been developed to support the elderly population with the goal of promoting independent living. The adoption of these technology based solutions is, however, critical to their overarching success. In our previous research we addressed the significance of modelling user adoption to reminding technologies based on a range of physical, environmental and social factors. In our current work we build upon our initial modeling through considering a wider range of computational approaches and identify a reduced set of relevant features that can aid the medical professionals to make an informed choice of whether to recommend the technology or not. The adoption models produced were evaluated on a multi-criterion basis: in terms of prediction performance, robustness and bias in relation to two types of errors. The effects of data imbalance on prediction performance was also considered. With handling the imbalance in the dataset, a 16 feature-subset was evaluated consisting of 173 instances, resulting in the ability to differentiate between adopters and non-adopters with an overall accuracy of 99.42 %.

Spin dynamics and exchange interactions in CuO measured by neutron scattering

NASA Astrophysics Data System (ADS)

Jacobsen, H.; Gaw, S. M.; Princep, A. J.; Hamilton, E.; Tóth, S.; Ewings, R. A.; Enderle, M.; Wheeler, E. M. Hétroy; Prabhakaran, D.; Boothroyd, A. T.

2018-04-01

The magnetic properties of CuO encompass several contemporary themes in condensed-matter physics, including quantum magnetism, magnetic frustration, magnetically-induced ferroelectricity, and orbital currents. Here we report polarized and unpolarized neutron inelastic scattering measurements which provide a comprehensive map of the cooperative spin dynamics in the low-temperature antiferromagnetic (AFM) phase of CuO throughout much of the Brillouin zone. At high energies (E ≳100 meV ), the spectrum displays continuum features consistent with the des Cloizeax-Pearson dispersion for an ideal S =1/2 Heisenberg AFM chain. At lower energies, the spectrum becomes more three dimensional, and we find that a linear spin-wave model for a Heisenberg AFM provides a very good description of the data, allowing for an accurate determination of the relevant exchange constants in an effective spin Hamiltonian for CuO. In the high-temperature helicoidal phase, there are features in the measured low-energy spectrum that we could not reproduce with a spin-only model. We discuss how these might be associated with the magnetically-induced multiferroic behavior observed in this phase.

Modeling perceived stress via HRV and accelerometer sensor streams.

PubMed

Wu, Min; Cao, Hong; Nguyen, Hai-Long; Surmacz, Karl; Hargrove, Caroline

2015-08-01

Discovering and modeling of stress patterns of human beings is a key step towards achieving automatic stress monitoring, stress management and healthy lifestyle. As various wearable sensors become popular, it becomes possible for individuals to acquire their own relevant sensory data and to automatically assess their stress level on the go. Previous studies for stress analysis were conducted in the controlled laboratory and clinic settings. These studies are not suitable for stress monitoring in one's daily life as various physical activities may affect the physiological signals. In this paper, we address such issue by integrating two modalities of sensors, i.e., HRV sensors and accelerometers, to monitor the perceived stress levels in daily life. We gathered both the heart and the motion data from 8 participants continuously for about 2 weeks. We then extracted features from both sensory data and compared the existing machine learning methods for learning personalized models to interpret the perceived stress levels. Experimental results showed that Bagging classifier with feature selection is able to achieve a prediction accuracy 85.7%, indicating our stress monitoring on daily basis is fairly practical.

Thermal-to-visible face recognition using partial least squares.

PubMed

Hu, Shuowen; Choi, Jonghyun; Chan, Alex L; Schwartz, William Robson

2015-03-01

Although visible face recognition has been an active area of research for several decades, cross-modal face recognition has only been explored by the biometrics community relatively recently. Thermal-to-visible face recognition is one of the most difficult cross-modal face recognition challenges, because of the difference in phenomenology between the thermal and visible imaging modalities. We address the cross-modal recognition problem using a partial least squares (PLS) regression-based approach consisting of preprocessing, feature extraction, and PLS model building. The preprocessing and feature extraction stages are designed to reduce the modality gap between the thermal and visible facial signatures, and facilitate the subsequent one-vs-all PLS-based model building. We incorporate multi-modal information into the PLS model building stage to enhance cross-modal recognition. The performance of the proposed recognition algorithm is evaluated on three challenging datasets containing visible and thermal imagery acquired under different experimental scenarios: time-lapse, physical tasks, mental tasks, and subject-to-camera range. These scenarios represent difficult challenges relevant to real-world applications. We demonstrate that the proposed method performs robustly for the examined scenarios.

The Teaching Effectiveness of a Relevant Physics Course

NASA Astrophysics Data System (ADS)

Hobson, Art

1998-04-01

If America is to achieve the science literacy that is ssential to industrialized democracy, all students must study such topics as scientific methodology, pseudoscience, critical thinking, ozone depletion, technological risk, and global warming. My large-enrollment liberal-arts physics course covers the great principles of physics along with several such philosophical and societal topics. Students find these topics relevant and fascinating, leading to strong course evaluations and large enrollments by non-scientists even in courses labeled physics. I will describe this course and present some evidence indicating that the course is effective in communicating physics and its interdisciplinary connections. A textbook, Physics: Concepts and Connections (Prentice Hall, 1995, 2nd edition to appear in June 1998), is available.

Feature-based memory-driven attentional capture: visual working memory content affects visual attention.

PubMed

Olivers, Christian N L; Meijer, Frank; Theeuwes, Jan

2006-10-01

In 7 experiments, the authors explored whether visual attention (the ability to select relevant visual information) and visual working memory (the ability to retain relevant visual information) share the same content representations. The presence of singleton distractors interfered more strongly with a visual search task when it was accompanied by an additional memory task. Singleton distractors interfered even more when they were identical or related to the object held in memory, but only when it was difficult to verbalize the memory content. Furthermore, this content-specific interaction occurred for features that were relevant to the memory task but not for irrelevant features of the same object or for once-remembered objects that could be forgotten. Finally, memory-related distractors attracted more eye movements but did not result in longer fixations. The results demonstrate memory-driven attentional capture on the basis of content-specific representations. Copyright 2006 APA.

Eyes Matched to the Prize: The State of Matched Filters in Insect Visual Circuits.

PubMed

Kohn, Jessica R; Heath, Sarah L; Behnia, Rudy

2018-01-01

Confronted with an ever-changing visual landscape, animals must be able to detect relevant stimuli and translate this information into behavioral output. A visual scene contains an abundance of information: to interpret the entirety of it would be uneconomical. To optimally perform this task, neural mechanisms exist to enhance the detection of important features of the sensory environment while simultaneously filtering out irrelevant information. This can be accomplished by using a circuit design that implements specific "matched filters" that are tuned to relevant stimuli. Following this rule, the well-characterized visual systems of insects have evolved to streamline feature extraction on both a structural and functional level. Here, we review examples of specialized visual microcircuits for vital behaviors across insect species, including feature detection, escape, and estimation of self-motion. Additionally, we discuss how these microcircuits are modulated to weigh relevant input with respect to different internal and behavioral states.

Attentional Selection of Feature Conjunctions Is Accomplished by Parallel and Independent Selection of Single Features.

PubMed

Andersen, Søren K; Müller, Matthias M; Hillyard, Steven A

2015-07-08

Experiments that study feature-based attention have often examined situations in which selection is based on a single feature (e.g., the color red). However, in more complex situations relevant stimuli may not be set apart from other stimuli by a single defining property but by a specific combination of features. Here, we examined sustained attentional selection of stimuli defined by conjunctions of color and orientation. Human observers attended to one out of four concurrently presented superimposed fields of randomly moving horizontal or vertical bars of red or blue color to detect brief intervals of coherent motion. Selective stimulus processing in early visual cortex was assessed by recordings of steady-state visual evoked potentials (SSVEPs) elicited by each of the flickering fields of stimuli. We directly contrasted attentional selection of single features and feature conjunctions and found that SSVEP amplitudes on conditions in which selection was based on a single feature only (color or orientation) exactly predicted the magnitude of attentional enhancement of SSVEPs when attending to a conjunction of both features. Furthermore, enhanced SSVEP amplitudes elicited by attended stimuli were accompanied by equivalent reductions of SSVEP amplitudes elicited by unattended stimuli in all cases. We conclude that attentional selection of a feature-conjunction stimulus is accomplished by the parallel and independent facilitation of its constituent feature dimensions in early visual cortex. The ability to perceive the world is limited by the brain's processing capacity. Attention affords adaptive behavior by selectively prioritizing processing of relevant stimuli based on their features (location, color, orientation, etc.). We found that attentional mechanisms for selection of different features belonging to the same object operate independently and in parallel: concurrent attentional selection of two stimulus features is simply the sum of attending to each of those features separately. This result is key to understanding attentional selection in complex (natural) scenes, where relevant stimuli are likely to be defined by a combination of stimulus features. Copyright © 2015 the authors 0270-6474/15/359912-08$15.00/0.

A machine learning approach to galaxy-LSS classification - I. Imprints on halo merger trees

NASA Astrophysics Data System (ADS)

Hui, Jianan; Aragon, Miguel; Cui, Xinping; Flegal, James M.

2018-04-01

The cosmic web plays a major role in the formation and evolution of galaxies and defines, to a large extent, their properties. However, the relation between galaxies and environment is still not well understood. Here, we present a machine learning approach to study imprints of environmental effects on the mass assembly of haloes. We present a galaxy-LSS machine learning classifier based on galaxy properties sensitive to the environment. We then use the classifier to assess the relevance of each property. Correlations between galaxy properties and their cosmic environment can be used to predict galaxy membership to void/wall or filament/cluster with an accuracy of 93 per cent. Our study unveils environmental information encoded in properties of haloes not normally considered directly dependent on the cosmic environment such as merger history and complexity. Understanding the physical mechanism by which the cosmic web is imprinted in a halo can lead to significant improvements in galaxy formation models. This is accomplished by extracting features from galaxy properties and merger trees, computing feature scores for each feature and then applying support vector machine (SVM) to different feature sets. To this end, we have discovered that the shape and depth of the merger tree, formation time, and density of the galaxy are strongly associated with the cosmic environment. We describe a significant improvement in the original classification algorithm by performing LU decomposition of the distance matrix computed by the feature vectors and then using the output of the decomposition as input vectors for SVM.

Measuring the Interestingness of Articles in a Limited User Environment

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

Pon, Raymond K.

Search engines, such as Google, assign scores to news articles based on their relevancy to a query. However, not all relevant articles for the query may be interesting to a user. For example, if the article is old or yields little new information, the article would be uninteresting. Relevancy scores do not take into account what makes an article interesting, which varies from user to user. Although methods such as collaborative filtering have been shown to be effective in recommendation systems, in a limited user environment, there are not enough users that would make collaborative filtering effective. A general framework,more » called iScore, is presented for defining and measuring the 'interestingness' of articles, incorporating user-feedback. iScore addresses various aspects of what makes an article interesting, such as topic relevancy, uniqueness, freshness, source reputation, and writing style. It employs various methods to measure these features and uses a classifier operating on these features to recommend articles. The basic iScore configuration is shown to improve recommendation results by as much as 20%. In addition to the basic iScore features, additional features are presented to address the deficiencies of existing feature extractors, such as one that tracks multiple topics, called MTT, and a version of the Rocchio algorithm that learns its parameters online as it processes documents, called eRocchio. The inclusion of both MTT and eRocchio into iScore is shown to improve iScore recommendation results by as much as 3.1% and 5.6%, respectively. Additionally, in TREC11 Adaptive Filter Task, eRocchio is shown to be 10% better than the best filter in the last run of the task. In addition to these two major topic relevancy measures, other features are also introduced that employ language models, phrases, clustering, and changes in topics to improve recommendation results. These additional features are shown to improve recommendation results by iScore by up to 14%. Due to varying reasons that users hold regarding why an article is interesting, an online feature selection method in naive Bayes is also introduced. Online feature selection can improve recommendation results in iScore by up to 18.9%. In summary, iScore in its best configuration can outperform traditional IR techniques by as much as 50.7%. iScore and its components are evaluated in the news recommendation task using three datasets from Yahoo! News, actual users, and Digg. iScore and its components are also evaluated in the TREC Adaptive Filter task using the Reuters RCV1 corpus.« less

Efficient robust conditional random fields.

PubMed

Song, Dongjin; Liu, Wei; Zhou, Tianyi; Tao, Dacheng; Meyer, David A

2015-10-01

Conditional random fields (CRFs) are a flexible yet powerful probabilistic approach and have shown advantages for popular applications in various areas, including text analysis, bioinformatics, and computer vision. Traditional CRF models, however, are incapable of selecting relevant features as well as suppressing noise from noisy original features. Moreover, conventional optimization methods often converge slowly in solving the training procedure of CRFs, and will degrade significantly for tasks with a large number of samples and features. In this paper, we propose robust CRFs (RCRFs) to simultaneously select relevant features. An optimal gradient method (OGM) is further designed to train RCRFs efficiently. Specifically, the proposed RCRFs employ the l1 norm of the model parameters to regularize the objective used by traditional CRFs, therefore enabling discovery of the relevant unary features and pairwise features of CRFs. In each iteration of OGM, the gradient direction is determined jointly by the current gradient together with the historical gradients, and the Lipschitz constant is leveraged to specify the proper step size. We show that an OGM can tackle the RCRF model training very efficiently, achieving the optimal convergence rate [Formula: see text] (where k is the number of iterations). This convergence rate is theoretically superior to the convergence rate O(1/k) of previous first-order optimization methods. Extensive experiments performed on three practical image segmentation tasks demonstrate the efficacy of OGM in training our proposed RCRFs.

78 FR 16828 - Endangered and Threatened Wildlife and Plants; Status Review of the West Coast Distinct...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-19

...; biology and ecology; and habitat selection. (2) Information on the effects of potential threat factors... particular physical or biological features that are essential to the conservation of the species and where such physical or biological features are found; (c) Whether any of these features may require special...

Accelerating research into bio-based FDCA-polyesters by using small scale parallel film reactors.

PubMed

Gruter, Gert-Jan M; Sipos, Laszlo; Adrianus Dam, Matheus

2012-02-01

High Throughput experimentation has been well established as a tool in early stage catalyst development and catalyst and process scale-up today. One of the more challenging areas of catalytic research is polymer catalysis. The main difference with most non-polymer catalytic conversions is the fact that the product is not a well defined molecule and the catalytic performance cannot be easily expressed only in terms of catalyst activity and selectivity. In polymerization reactions, polymer chains are formed that can have various lengths (resulting in a molecular weight distribution rather than a defined molecular weight), that can have different compositions (when random or block co-polymers are produced), that can have cross-linking (often significantly affecting physical properties), that can have different endgroups (often affecting subsequent processing steps) and several other variations. In addition, for polyolefins, mass and heat transfer, oxygen and moisture sensitivity, stereoregularity and many other intrinsic features make relevant high throughput screening in this field an incredible challenge. For polycondensation reactions performed in the melt often the viscosity becomes already high at modest molecular weights, which greatly influences mass transfer of the condensation product (often water or methanol). When reactions become mass transfer limited, catalyst performance comparison is often no longer relevant. This however does not mean that relevant experiments for these application areas cannot be performed on small scale. Relevant catalyst screening experiments for polycondensation reactions can be performed in very efficient small scale parallel equipment. Both transesterification and polycondensation as well as post condensation through solid-stating in parallel equipment have been developed. Next to polymer synthesis, polymer characterization also needs to be accelerated without making concessions to quality in order to draw relevant conclusions.

Contextualized Instruction: Teaching Relevant Behaviors in Relevant Contexts.

ERIC Educational Resources Information Center

Reboy, Lisa M.; Semb, George B.

In contextualized instruction, the critical features of a context are considered important for the acquisition and transfer of a skill. Examples of contextualized instruction programs are Functional Context Education (FCE) and Anchored Instruction (AI). FCE involves the teaching of reading and mathematics skills in contexts that are relevant to…

Association between leg strength and muscle cross-sectional area of the quadriceps femoris with the physical activity level in octogenarians.

PubMed

Latorre-Román, Pedro Á; Arévalo-Arévalo, Juan Manuel; García-Pinillos, Felipe

2016-06-03

Aging is a complex physiological process whose main feature is the progressive loss of functionality, which may be delayed or attenuated by improving physical fitness.  To determine the association between leg strength and the muscle cross-sectional area of the quadriceps femoris in relation to physical activity level in the elderly.  Thirty-two functionally autonomous people over 80 years (men: 82.80±2.09 years; women: 83.77±4.09 years) participated in this study. The Barthel Index, the Yale Physical Activity Survey and the Chair Stand Test were the instruments used.  There were significant differences between sexes in muscle area (p<0.001) in the Chair Stand Test (p=0.028) and the walk index (p=0.029), with higher values in men. The muscle area and the Chair Stand Test correlated significantly with the walk index (r=0.445, p<0.005, and r=0.522, p<0.001, respectively) and the total weekly activity index (r=0.430, p<0.005, and r=0.519, p<0.001, respectively). In the multiple linear regression models for the total weekly activity index, muscle area and the Chair Stand Test, only the latter behaved as a predictor variable.  Muscle strength and muscle mass of quadriceps showed a significant association with the physical activity level in older people. Leg muscle strength was useful to reveal muscle mass and physical activity level in older people, which is relevant as a clinical practice indicator.

T-ray relevant frequencies for osteosarcoma classification

NASA Astrophysics Data System (ADS)

Withayachumnankul, W.; Ferguson, B.; Rainsford, T.; Findlay, D.; Mickan, S. P.; Abbott, D.

2006-01-01

We investigate the classification of the T-ray response of normal human bone cells and human osteosarcoma cells, grown in culture. Given the magnitude and phase responses within a reliable spectral range as features for input vectors, a trained support vector machine can correctly classify the two cell types to some extent. Performance of the support vector machine is deteriorated by the curse of dimensionality, resulting from the comparatively large number of features in the input vectors. Feature subset selection methods are used to select only an optimal number of relevant features for inputs. As a result, an improvement in generalization performance is attainable, and the selected frequencies can be used for further describing different mechanisms of the cells, responding to T-rays. We demonstrate a consistent classification accuracy of 89.6%, while the only one fifth of the original features are retained in the data set.

Interaction Between Spatial and Feature Attention in Posterior Parietal Cortex

PubMed Central

Ibos, Guilhem; Freedman, David J.

2016-01-01

Summary Lateral intraparietal (LIP) neurons encode a vast array of sensory and cognitive variables. Recently, we proposed that the flexibility of feature representations in LIP reflect the bottom-up integration of sensory signals, modulated by feature-based attention (FBA), from upstream feature-selective cortical neurons. Moreover, LIP activity is also strongly modulated by the position of space-based attention (SBA). However, the mechanisms by which SBA and FBA interact to facilitate the representation of task-relevant spatial and non-spatial features in LIP remain unclear. We recorded from LIP neurons during performance of a task which required monkeys to detect specific conjunctions of color, motion-direction, and stimulus position. Here we show that FBA and SBA potentiate each other’s effect in a manner consistent with attention gating the flow of visual information along the cortical visual pathway. Our results suggest that linear bottom-up integrative mechanisms allow LIP neurons to emphasize task-relevant spatial and non-spatial features. PMID:27499082

Sequence-Based Prediction of RNA-Binding Proteins Using Random Forest with Minimum Redundancy Maximum Relevance Feature Selection.

PubMed

Ma, Xin; Guo, Jing; Sun, Xiao

2015-01-01

The prediction of RNA-binding proteins is one of the most challenging problems in computation biology. Although some studies have investigated this problem, the accuracy of prediction is still not sufficient. In this study, a highly accurate method was developed to predict RNA-binding proteins from amino acid sequences using random forests with the minimum redundancy maximum relevance (mRMR) method, followed by incremental feature selection (IFS). We incorporated features of conjoint triad features and three novel features: binding propensity (BP), nonbinding propensity (NBP), and evolutionary information combined with physicochemical properties (EIPP). The results showed that these novel features have important roles in improving the performance of the predictor. Using the mRMR-IFS method, our predictor achieved the best performance (86.62% accuracy and 0.737 Matthews correlation coefficient). High prediction accuracy and successful prediction performance suggested that our method can be a useful approach to identify RNA-binding proteins from sequence information.

Interaction between Spatial and Feature Attention in Posterior Parietal Cortex.

PubMed

Ibos, Guilhem; Freedman, David J

2016-08-17

Lateral intraparietal (LIP) neurons encode a vast array of sensory and cognitive variables. Recently, we proposed that the flexibility of feature representations in LIP reflect the bottom-up integration of sensory signals, modulated by feature-based attention (FBA), from upstream feature-selective cortical neurons. Moreover, LIP activity is also strongly modulated by the position of space-based attention (SBA). However, the mechanisms by which SBA and FBA interact to facilitate the representation of task-relevant spatial and non-spatial features in LIP remain unclear. We recorded from LIP neurons during performance of a task that required monkeys to detect specific conjunctions of color, motion direction, and stimulus position. Here we show that FBA and SBA potentiate each other's effect in a manner consistent with attention gating the flow of visual information along the cortical visual pathway. Our results suggest that linear bottom-up integrative mechanisms allow LIP neurons to emphasize task-relevant spatial and non-spatial features. Copyright © 2016 Elsevier Inc. All rights reserved.

[Combining speech sample and feature bilateral selection algorithm for classification of Parkinson's disease].

PubMed

Zhang, Xiaoheng; Wang, Lirui; Cao, Yao; Wang, Pin; Zhang, Cheng; Yang, Liuyang; Li, Yongming; Zhang, Yanling; Cheng, Oumei

2018-02-01

Diagnosis of Parkinson's disease (PD) based on speech data has been proved to be an effective way in recent years. However, current researches just care about the feature extraction and classifier design, and do not consider the instance selection. Former research by authors showed that the instance selection can lead to improvement on classification accuracy. However, no attention is paid on the relationship between speech sample and feature until now. Therefore, a new diagnosis algorithm of PD is proposed in this paper by simultaneously selecting speech sample and feature based on relevant feature weighting algorithm and multiple kernel method, so as to find their synergy effects, thereby improving classification accuracy. Experimental results showed that this proposed algorithm obtained apparent improvement on classification accuracy. It can obtain mean classification accuracy of 82.5%, which was 30.5% higher than the relevant algorithm. Besides, the proposed algorithm detected the synergy effects of speech sample and feature, which is valuable for speech marker extraction.

Robotics handbook. Version 1: For the interested party and professional

NASA Astrophysics Data System (ADS)

1993-12-01

This publication covers several categories of information about robotics. The first section provides a brief overview of the field of Robotics. The next section provides a reasonably detailed look at the NASA Robotics program. The third section features a listing of companies and organization engaging in robotics or robotic-related activities; followed by a listing of associations involved in the field; followed by a listing of publications and periodicals which cover elements of robotics or related fields. The final section is an abbreviated abstract of referred journal material and other reference material relevant to the technology and science of robotics, including such allied fields as vision perception; three-space axis orientation and measurement systems and associated inertial reference technology and algorithms; and physical and mechanical science and technology related to robotics.

Creating and Using a Consumer Chemical Molecular Graphics Database: The "Molecule of the Day" - A Great Way To Begin Your Lecture

NASA Astrophysics Data System (ADS)

Scharberg, Maureen A.; Cox, Oran E.; Barelli, Carl A.

1997-07-01

"The Molecule of the Day" consumer chemical database has been created to allow introductory chemistry students to explore molecular structures of chemicals in household products, and to provide opportunities in molecular modeling for undergraduate chemistry students. Before class begins, an overhead transparency is displayed which shows a three-dimensional molecular structure of a household chemical, and lists relevant features and uses of this chemical. Within answers to questionnaires, students have commented that this molecular graphics database has helped them to visually connect the microscopic structure of a molecule with its physical and chemical properties, as well as its uses in consumer products. It is anticipated that this database will be incorporated into a navigational software package such as Netscape.

a Dosimetry Assessment for the Core Restraint of AN Advanced Gas Cooled Reactor

NASA Astrophysics Data System (ADS)

Thornton, D. A.; Allen, D. A.; Tyrrell, R. J.; Meese, T. C.; Huggon, A. P.; Whiley, G. S.; Mossop, J. R.

2009-08-01

This paper describes calculations of neutron damage rates within the core restraint structures of Advanced Gas Cooled Reactors (AGRs). Using advanced features of the Monte Carlo radiation transport code MCBEND, and neutron source data from core follow calculations performed with the reactor physics code PANTHER, a detailed model of the reactor cores of two of British Energy's AGR power plants has been developed for this purpose. Because there are no relevant neutron fluence measurements directly supporting this assessment, results of benchmark comparisons and successful validation of MCBEND for Magnox reactors have been used to estimate systematic and random uncertainties on the predictions. In particular, it has been necessary to address the known under-prediction of lower energy fast neutron responses associated with the penetration of large thicknesses of graphite.

Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory

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

Aab, A.; Abreu, P.; Andringa, S.

2017-04-01

We present a combined fit of a simple astrophysical model of UHECR sources to both the energy spectrum and mass composition data measured by the Pierre Auger Observatory. The fit has been performed for energies above 5 ⋅ 10{sup 18} eV, i.e. the region of the all-particle spectrum above the so-called 'ankle' feature. The astrophysical model we adopted consists of identical sources uniformly distributed in a comoving volume, where nuclei are accelerated through a rigidity-dependent mechanism. The fit results suggest sources characterized by relatively low maximum injection energies, hard spectra and heavy chemical composition. We also show that uncertainties aboutmore » physical quantities relevant to UHECR propagation and shower development have a non-negligible impact on the fit results.« less

A hybrid quantum eraser scheme for characterization of free-space and fiber communication channels

NASA Astrophysics Data System (ADS)

Nape, Isaac; Kyeremah, Charlotte; Vallés, Adam; Rosales-Guzmán, Carmelo; Buah-Bassuah, Paul K.; Forbes, Andrew

2018-02-01

We demonstrate a simple projective measurement based on the quantum eraser concept that can be used to characterize the disturbances of any communication channel. Quantum erasers are commonly implemented as spatially separated path interferometric schemes. Here we exploit the advantages of redefining the which-path information in terms of spatial modes, replacing physical paths with abstract paths of orbital angular momentum (OAM). Remarkably, vector modes (natural modes of free-space and fiber) have a non-separable feature of spin-orbit coupled states, equivalent to the description of two independently marked paths. We explore the effects of fiber perturbations by probing a step-index optical fiber channel with a vector mode, relevant to high-order spatial mode encoding of information for ultra-fast fiber communications.

Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory

NASA Astrophysics Data System (ADS)

Aab, A.; Abreu, P.; Aglietta, M.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Anastasi, G. A.; Anchordoqui, L.; Andrada, B.; Andringa, S.; Aramo, C.; Arqueros, F.; Arsene, N.; Asorey, H.; Assis, P.; Aublin, J.; Avila, G.; Badescu, A. M.; Balaceanu, A.; Barreira Luz, R. J.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Biteau, J.; Blaess, S. G.; Blanco, A.; Blazek, J.; Bleve, C.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Borodai, N.; Botti, A. M.; Brack, J.; Brancus, I.; Bretz, T.; Bridgeman, A.; Briechle, F. L.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, L.; Cancio, A.; Canfora, F.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Chavez, A. G.; Chinellato, J. A.; Chudoba, J.; Clay, R. W.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Cronin, J.; D'Amico, S.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Jong, S. J.; De Mauro, G.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; Debatin, J.; Deligny, O.; Di Giulio, C.; di Matteo, A.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; D'Olivo, J. C.; Dorosti, Q.; dos Anjos, R. C.; Dova, M. T.; Dundovic, A.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Fick, B.; Figueira, J. M.; Filipčič, A.; Fratu, O.; Freire, M. M.; Fujii, T.; Fuster, A.; Gaior, R.; García, B.; Garcia-Pinto, D.; Gaté, F.; Gemmeke, H.; Gherghel-Lascu, A.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Głas, D.; Glaser, C.; Golup, G.; Gómez Berisso, M.; Gómez Vitale, P. F.; González, N.; Gorgi, A.; Gorham, P.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huege, T.; Hulsman, J.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Johnsen, J. A.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Katkov, I.; Keilhauer, B.; Kemp, E.; Kemp, J.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kuempel, D.; Kukec Mezek, G.; Kunka, N.; Kuotb Awad, A.; LaHurd, D.; Lauscher, M.; Legumina, R.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopes, L.; López, R.; López Casado, A.; Luce, Q.; Lucero, A.; Malacari, M.; Mallamaci, M.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Mariş, I. C.; Marsella, G.; Martello, D.; Martinez, H.; Martínez Bravo, O.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melo, D.; Menshikov, A.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Mockler, D.; Mollerach, S.; Montanet, F.; Morello, C.; Mostafá, M.; Müller, A. L.; Müller, G.; Muller, M. A.; Müller, S.; Mussa, R.; Naranjo, I.; Nellen, L.; Nguyen, P. H.; Niculescu-Oglinzanu, M.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, H.; Núñez, L. A.; Ochilo, L.; Oikonomou, F.; Olinto, A.; Palatka, M.; Pallotta, J.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pedreira, F.; Pȩkala, J.; Pelayo, R.; Peña-Rodriguez, J.; Pereira, L. A. S.; Perlín, M.; Perrone, L.; Peters, C.; Petrera, S.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Ramos-Pollan, R.; Rautenberg, J.; Ravignani, D.; Revenu, B.; Ridky, J.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rogozin, D.; Roncoroni, M. J.; Roth, M.; Roulet, E.; Rovero, A. C.; Ruehl, P.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santos, E. M.; Santos, E.; Sarazin, F.; Sarmento, R.; Sarmiento, C. A.; Sato, R.; Schauer, M.; Scherini, V.; Schieler, H.; Schimp, M.; Schmidt, D.; Scholten, O.; Schovánek, P.; Schröoder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sigl, G.; Silli, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sonntag, S.; Sorokin, J.; Squartini, R.; Stanca, D.; Stanič, S.; Stasielak, J.; Stassi, P.; Strafella, F.; Suarez, F.; Suarez Durán, M.; Sudholz, T.; Suomijärvi, T.; Supanitsky, A. D.; Swain, J.; Szadkowski, Z.; Taboada, A.; Taborda, O. A.; Tapia, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Tomankova, L.; Tomé, B.; Torralba Elipe, G.; Travnicek, P.; Trini, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Vergara Quispe, I. D.; Verzi, V.; Vicha, J.; Villaseñor, L.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weindl, A.; Wiencke, L.; Wilczyński, H.; Winchen, T.; Wirtz, M.; Wittkowski, D.; Wundheiler, B.; Yang, L.; Yelos, D.; Yushkov, A.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zepeda, A.; Zimmermann, B.; Ziolkowski, M.; Zong, Z.; Zong, Z.

2017-04-01

We present a combined fit of a simple astrophysical model of UHECR sources to both the energy spectrum and mass composition data measured by the Pierre Auger Observatory. The fit has been performed for energies above 5 ṡ 1018 eV, i.e. the region of the all-particle spectrum above the so-called "ankle" feature. The astrophysical model we adopted consists of identical sources uniformly distributed in a comoving volume, where nuclei are accelerated through a rigidity-dependent mechanism. The fit results suggest sources characterized by relatively low maximum injection energies, hard spectra and heavy chemical composition. We also show that uncertainties about physical quantities relevant to UHECR propagation and shower development have a non-negligible impact on the fit results.

Energy exchange analysis in droplet dynamics via the Navier-Stokes-Cahn-Hilliard model

NASA Astrophysics Data System (ADS)

Espath, L. F. R.; Sarmiento, A. F.; Vignal, P.; Varga, B. O. N.; Cortes, A. M. A.; Dalcin, L.; Calo, V. M.

2016-06-01

We develop the energy budget equation of the coupled Navier-Stokes-Cahn-Hilliard (NSCH) system. We use the NSCH equations to model the dynamics of liquid droplets in a liquid continuum. Buoyancy effects are accounted for through the Boussinesq assumption. We physically interpret each quantity involved in the energy exchange to further insight into the model. Highly resolved simulations involving density-driven flows and merging of droplets allow us to analyze these energy budgets. In particular, we focus on the energy exchanges when droplets merge, and describe flow features relevant to this phenomenon. By comparing our numerical simulations to analytical predictions and experimental results available in the literature, we conclude that modeling droplet dynamics within the framework of NSCH equations is a sensible approach worth further research.

Making Time for Spacetime: The Story of a National Science Cafe Effort

NASA Astrophysics Data System (ADS)

Redmond, Kendra; Chakrabarti, Anish

2012-03-01

Science Cafes are live and lively events that take place in casual settings such as coffeehouses or bars, are open to everyone, and feature an engaging conversation with a scientist about a compelling scientific topic. The Science Cafe movement in the United States is a grassroots effort to really engage the public in discussions about science and its relevance to society, inspired by the United Kingdom Cafe Scientifique organization. With support from NOVA and the related website sciencecafes.org, a number of Society of Physics Students chapters hosted local Cosmic Cafes (cosmic themed science cafes) in late 2011 and early 2012. This presentation will discuss the goals and models of the Science Cafe movement, the Cosmic Cafe effort, lessons learned, and how you can get involved.

Robotics handbook. Version 1: For the interested party and professional

NASA Technical Reports Server (NTRS)

1993-01-01

This publication covers several categories of information about robotics. The first section provides a brief overview of the field of Robotics. The next section provides a reasonably detailed look at the NASA Robotics program. The third section features a listing of companies and organization engaging in robotics or robotic-related activities; followed by a listing of associations involved in the field; followed by a listing of publications and periodicals which cover elements of robotics or related fields. The final section is an abbreviated abstract of referred journal material and other reference material relevant to the technology and science of robotics, including such allied fields as vision perception; three-space axis orientation and measurement systems and associated inertial reference technology and algorithms; and physical and mechanical science and technology related to robotics.

Features of the use of time-frequency distributions for controlling the mixture-producing aggregate

NASA Astrophysics Data System (ADS)

Fedosenkov, D. B.; Simikova, A. A.; Fedosenkov, B. A.

2018-05-01

The paper submits and argues the information on filtering properties of the mixing unit as a part of the mixture-producing aggregate. Relevant theoretical data concerning a channel transfer function of the mixing unit and multidimensional material flow signals are adduced here. Note that ordinary one-dimensional material flow signals are defined in terms of time-frequency distributions of Cohen’s class representations operating with Gabor wavelet functions. Two time-frequencies signal representations are written about in the paper to show how one can solve controlling problems as applied to mixture-producing systems: they are the so-called Rihaczek and Wigner-Ville distributions. In particular, the latter illustrates low-pass filtering properties that are practically available in any of low-pass elements of a physical system.

Effects of preprocessing Landsat MSS data on derived features

NASA Technical Reports Server (NTRS)

Parris, T. M.; Cicone, R. C.

1983-01-01

Important to the use of multitemporal Landsat MSS data for earth resources monitoring, such as agricultural inventories, is the ability to minimize the effects of varying atmospheric and satellite viewing conditions, while extracting physically meaningful features from the data. In general, the approaches to the preprocessing problem have been derived from either physical or statistical models. This paper compares three proposed algorithms; XSTAR haze correction, Color Normalization, and Multiple Acquisition Mean Level Adjustment. These techniques represent physical, statistical, and hybrid physical-statistical models, respectively. The comparisons are made in the context of three feature extraction techniques; the Tasseled Cap, the Cate Color Cube. and Normalized Difference.

Prediction of Protein Modification Sites of Pyrrolidone Carboxylic Acid Using mRMR Feature Selection and Analysis

PubMed Central

Zheng, Lu-Lu; Niu, Shen; Hao, Pei; Feng, KaiYan; Cai, Yu-Dong; Li, Yixue

2011-01-01

Pyrrolidone carboxylic acid (PCA) is formed during a common post-translational modification (PTM) of extracellular and multi-pass membrane proteins. In this study, we developed a new predictor to predict the modification sites of PCA based on maximum relevance minimum redundancy (mRMR) and incremental feature selection (IFS). We incorporated 727 features that belonged to 7 kinds of protein properties to predict the modification sites, including sequence conservation, residual disorder, amino acid factor, secondary structure and solvent accessibility, gain/loss of amino acid during evolution, propensity of amino acid to be conserved at protein-protein interface and protein surface, and deviation of side chain carbon atom number. Among these 727 features, 244 features were selected by mRMR and IFS as the optimized features for the prediction, with which the prediction model achieved a maximum of MCC of 0.7812. Feature analysis showed that all feature types contributed to the modification process. Further site-specific feature analysis showed that the features derived from PCA's surrounding sites contributed more to the determination of PCA sites than other sites. The detailed feature analysis in this paper might provide important clues for understanding the mechanism of the PCA formation and guide relevant experimental validations. PMID:22174779

Arrows as anchors: An analysis of the material features of electric field vector arrows

NASA Astrophysics Data System (ADS)

Gire, Elizabeth; Price, Edward

2014-12-01

Representations in physics possess both physical and conceptual aspects that are fundamentally intertwined and can interact to support or hinder sense making and computation. We use distributed cognition and the theory of conceptual blending with material anchors to interpret the roles of conceptual and material features of representations in students' use of representations for computation. We focus on the vector-arrows representation of electric fields and describe this representation as a conceptual blend of electric field concepts, physical space, and the material features of the representation (i.e., the physical writing and the surface upon which it is drawn). In this representation, spatial extent (e.g., distance on paper) is used to represent both distances in coordinate space and magnitudes of electric field vectors. In conceptual blending theory, this conflation is described as a clash between the input spaces in the blend. We explore the benefits and drawbacks of this clash, as well as other features of this representation. This analysis is illustrated with examples from clinical problem-solving interviews with upper-division physics majors. We see that while these intermediate physics students make a variety of errors using this representation, they also use the geometric features of the representation to add electric field contributions and to organize the problem situation productively.

Photopolymerized materials and patterning for improved performance of neural prosthetics

NASA Astrophysics Data System (ADS)

Tuft, Bradley William

Neural prosthetics are used to replace or substantially augment remaining motor and sensory functions of neural pathways that were lost or damaged due to physical trauma, disease, or genetics. However, due to poor spatial signal resolution, neural prostheses fail to recapitulate the intimate, precise interactions inherent to neural networks. Designing materials and interfaces that direct de novo nerve growth to spatially specific stimulating elements is, therefore, a promising method to enhance signal specificity and performance of prostheses such as the successful cochlear implant (CI) and the developing retinal implant. In this work, the spatial and temporal reaction control inherent to photopolymerization was used to develop methods to generate micro and nanopatterned materials that direct neurite growth from prosthesis relevant neurons. In particular, neurite growth and directionality has been investigated in response to physical, mechanical, and chemical cues on photopolymerized surfaces. Spiral ganglion neurons (SGNs) serve as the primary neuronal model as they are the principal target for CI stimulation. The objective of the research is to rationally design materials that spatially direct neurite growth and to translate fundamental understanding of nerve cell-material interactions into methods of nerve regeneration that improve neural prosthetic performance. A rapid, single-step photopolymerization method was developed to fabricate micro and nanopatterned physical cues on methacrylate surfaces by selectively blocking light with photomasks. Feature height is readily tuned by modulating parameters of the photopolymerizaiton including initiator concentration and species, light intensity, separation distance from the photomask, and radiation exposure time. Alignment of neural elements increases significantly with increasing feature amplitude and constant periodicity, as well as with decreasing periodicity and constant amplitude. SGN neurite alignment strongly correlates with the maximum feature slope. Neurite alignment is compared on unpatterned, unidirectional, and multidirectional photopolymerized micropatterns. The effect of substrate rigidity on neurite alignment to physical cues was determined by maintaining equivalent pattern microfeatures, afforded by the reaction control of photopolymerization, while concomitantly altering the composition of several copolymer platforms to tune matrix stiffness. For each platform, neurite alignment to unidirectional patterns increases with increasing substrate rigidity. Interestingly, SGN neurites respond to material stiffness cues that are orders of magnitude higher (GPa) than what is typically ascribed to neural environments (kPa). Finally, neurite behavior at bioactive borders of various adhesion modulating molecules was evaluated on micropatterned materials to determine which cues took precedence in establishing neurite directionality. At low microfeatures aspect ratios, neurites align to the pattern direction but are then caused to turn and repel from or turn and align to bioactive borders. Conversely, physical cues dominate neurite path-finding as pattern feature slope increases, i.e. aspect ratio of sloping photopolymerized features increases, causing neurites to readily cross bioactive borders. The photopolymerization method developed in this work to generate micro and nanopatterned materials serves as an additional surface engineering tool that enables investigation of cell-material interactions including directed de novo neurite growth. The results of this interdisciplinary effort contribute substantially to polymer neural regeneration technology and will lead to development of advanced biomaterials that improve neural prosthetic tissue integration and performance by spatially directing nerve growth.

UNDERSTANDING HOW PLANETS BECOME MASSIVE. I. DESCRIPTION AND VALIDATION OF A NEW TOY MODEL

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

Ormel, C. W.; Kobayashi, H., E-mail: ormel@astro.berkeley.edu, E-mail: hkobayas@nagoya-u.ac.jp

2012-03-10

The formation of giant planets requires the accumulation of {approx}10 Earth masses in solids; but how do protoplanets acquire their mass? There are many, often competing, processes that regulate the accretion rate of protoplanets. To assess their effects we present a new, publicly available toy model. The rationale behind the toy model is that it encompasses as many physically relevant processes as possible, but at the same time does not compromise its simplicity, speed, and physical insight. The toy model follows a modular structure, where key features-e.g., planetesimal fragmentation, radial orbital decay, nebula turbulence-can be switched on or off. Ourmore » model assumes three discrete components (fragments, planetesimals, and embryos) and is zero dimensional in space. We have tested the outcomes of the toy model against literature results and generally find satisfactory agreement. We include, for the first time, model features that capture the three-way interactions among small particles, gas, and protoplanets. Collisions among planetesimals will result in fragmentation, transferring a substantial amount of the solid mass to small particles, which couple strongly to the gas. Our results indicate that the efficiency of the accretion process then becomes very sensitive to the gas properties-especially to the turbulent state and the magnitude of the disk headwind (the decrease of the orbital velocity of the gas with respect to Keplerian)-as well as to the characteristic fragment size.« less

Before the N400: effects of lexical-semantic violations in visual cortex.

PubMed

Dikker, Suzanne; Pylkkanen, Liina

2011-07-01

There exists an increasing body of research demonstrating that language processing is aided by context-based predictions. Recent findings suggest that the brain generates estimates about the likely physical appearance of upcoming words based on syntactic predictions: words that do not physically look like the expected syntactic category show increased amplitudes in the visual M100 component, the first salient MEG response to visual stimulation. This research asks whether violations of predictions based on lexical-semantic information might similarly generate early visual effects. In a picture-noun matching task, we found early visual effects for words that did not accurately describe the preceding pictures. These results demonstrate that, just like syntactic predictions, lexical-semantic predictions can affect early visual processing around ∼100ms, suggesting that the M100 response is not exclusively tuned to recognizing visual features relevant to syntactic category analysis. Rather, the brain might generate predictions about upcoming visual input whenever it can. However, visual effects of lexical-semantic violations only occurred when a single lexical item could be predicted. We argue that this may be due to the fact that in natural language processing, there is typically no straightforward mapping between lexical-semantic fields (e.g., flowers) and visual or auditory forms (e.g., tulip, rose, magnolia). For syntactic categories, in contrast, certain form features do reliably correlate with category membership. This difference may, in part, explain why certain syntactic effects typically occur much earlier than lexical-semantic effects. Copyright © 2011 Elsevier Inc. All rights reserved.

Effects of azimuth-symmetric acceptance cutoffs on the measured asymmetry in unpolarized Drell-Yan fixed-target experiments

NASA Astrophysics Data System (ADS)

Bianconi, A.; Bussa, M. P.; Destefanis, M.; Ferrero, L.; Greco, M.; Maggiora, M.; Spataro, S.

2013-04-01

Fixed-target unpolarized Drell-Yan experiments often feature an acceptance depending on the polar angle of the lepton tracks in the laboratory frame. Typically leptons are detected in a defined angular range, with a dead zone in the forward region. If the cutoffs imposed by the angular acceptance are independent of the azimuth, at first sight they do not appear dangerous for a measurement of the cos(2 φ) asymmetry, which is relevant because of its association with the violation of the Lam-Tung rule and with the Boer-Mulders function. On the contrary, direct simulations show that up to 10 percent asymmetries are produced by these cutoffs. These artificial asymmetries present qualitative features that allow them to mimic the physical ones. They introduce some model dependence in the measurements of the cos(2 φ) asymmetry, since a precise reconstruction of the acceptance in the Collins-Soper frame requires a Monte Carlo simulation, that in turn requires some detailed physical input to generate event distributions. Although experiments in the eighties seem to have been aware of this problem, the possibility of using the Boer-Mulders function as an input parameter in the extraction of transversity has much increased the requirements of precision on this measurement. Our simulations show that the safest approach to these measurements is a strong cutoff on the Collins-Soper polar angle. This reduces statistics, but does not necessarily decrease the precision in a measurement of the Boer-Mulders function.

Comprehensive analysis of line-edge and line-width roughness for EUV lithography

NASA Astrophysics Data System (ADS)

Bonam, Ravi; Liu, Chi-Chun; Breton, Mary; Sieg, Stuart; Seshadri, Indira; Saulnier, Nicole; Shearer, Jeffrey; Muthinti, Raja; Patlolla, Raghuveer; Huang, Huai

2017-03-01

Pattern transfer fidelity is always a major challenge for any lithography process and needs continuous improvement. Lithographic processes in semiconductor industry are primarily driven by optical imaging on photosensitive polymeric material (resists). Quality of pattern transfer can be assessed by quantifying multiple parameters such as, feature size uniformity (CD), placement, roughness, sidewall angles etc. Roughness in features primarily corresponds to variation of line edge or line width and has gained considerable significance, particularly due to shrinking feature sizes and variations of features in the same order. This has caused downstream processes (Etch (RIE), Chemical Mechanical Polish (CMP) etc.) to reconsider respective tolerance levels. A very important aspect of this work is relevance of roughness metrology from pattern formation at resist to subsequent processes, particularly electrical validity. A major drawback of current LER/LWR metric (sigma) is its lack of relevance across multiple downstream processes which effects material selection at various unit processes. In this work we present a comprehensive assessment of Line Edge and Line Width Roughness at multiple lithographic transfer processes. To simulate effect of roughness a pattern was designed with periodic jogs on the edges of lines with varying amplitudes and frequencies. There are numerous methodologies proposed to analyze roughness and in this work we apply them to programmed roughness structures to assess each technique's sensitivity. This work also aims to identify a relevant methodology to quantify roughness with relevance across downstream processes.

Application of Multilabel Learning Using the Relevant Feature for Each Label in Chronic Gastritis Syndrome Diagnosis

PubMed Central

Liu, Guo-Ping; Yan, Jian-Jun; Wang, Yi-Qin; Fu, Jing-Jing; Xu, Zhao-Xia; Guo, Rui; Qian, Peng

2012-01-01

Background. In Traditional Chinese Medicine (TCM), most of the algorithms are used to solve problems of syndrome diagnosis that only focus on one syndrome, that is, single label learning. However, in clinical practice, patients may simultaneously have more than one syndrome, which has its own symptoms (signs). Methods. We employed a multilabel learning using the relevant feature for each label (REAL) algorithm to construct a syndrome diagnostic model for chronic gastritis (CG) in TCM. REAL combines feature selection methods to select the significant symptoms (signs) of CG. The method was tested on 919 patients using the standard scale. Results. The highest prediction accuracy was achieved when 20 features were selected. The features selected with the information gain were more consistent with the TCM theory. The lowest average accuracy was 54% using multi-label neural networks (BP-MLL), whereas the highest was 82% using REAL for constructing the diagnostic model. For coverage, hamming loss, and ranking loss, the values obtained using the REAL algorithm were the lowest at 0.160, 0.142, and 0.177, respectively. Conclusion. REAL extracts the relevant symptoms (signs) for each syndrome and improves its recognition accuracy. Moreover, the studies will provide a reference for constructing syndrome diagnostic models and guide clinical practice. PMID:22719781

On the possibility of real time air quality and toxicology assessment using multi-wavelength photoacoustic spectroscopy

NASA Astrophysics Data System (ADS)

Ajtai, Tibor; Pinter, Mate; Utry, Noemi; Kiss-Albert, Gergely; Palagyi, Andrea; Manczinger, Laszlo; Vagvölgyi, Csaba; Szabo, Gabor; Bozoki, Zoltan

2016-04-01

In this study we present results of field measurement campaigns focusing on the in-situ characterization of absorption spectra and the health relevance of light absorbing carbonaceous (LAC) in the ambient. The absorption spectra is measured @ 266, 355, 532 and 1064 nm by our state-of-the-art four-wavelength photoacoustic instrument, while for health relevance the eco- cito and genotoxicity parameters were measured using standardized methodologies. We experimentally demonstrated a correlation between the toxicities and the measured absorption spectra quantified by its wavelength dependency. Based on this correlation, we present novel possibilities on real-time air quality monitoring. LAC is extensively studied not only because of its considerable climate effects but as a serious air pollutant too. Gradually increasing number of studies demonstrated experimentally that the health effect of LAC is more serious than it is expected based on its share in total atmospheric aerosol mass. Furthermore during many local pollution events LAC not only has dominancy but it is close to exclusivity. Altogether due to its climate and health effects many studies and proposed regulations focus on the physical, chemical and toxicological properties of LAC as well as on its source apportionment. Despites of its importance, there is not yet a widely accepted standard methodology for the real-time and selective identification of LAC. There are many different reasons of that: starting from its complex inherent physicochemical features including many unknown constituents, via masking effect of ambient on the inherent physicochemical properties taking place even in case of a short residence, ending with the lack of reliable instrumentation for its health or source relevant parameters. Therefore, the methodology and instrument development for selective and reliable identification of LAC is timely and important issues in climate and air quality researches. Recently, many studies demonstrated correlation between the chemical compositions and the absorption features of LAC which open up novel possibilities in real time source apportionment and in air quality monitoring.

Selecting relevant and feasible measurement instruments for the revised Dutch clinical practice guideline for physical therapy in patients after stroke.

PubMed

Otterman, Nicoline; Veerbeek, Janne; Schiemanck, Sven; van der Wees, Philip; Nollet, Frans; Kwakkel, Gert

2017-07-01

To select relevant and feasible instruments for the revision of the Dutch clinical practice guideline for physical therapy in patients with stroke. In this implementation study a comprehensive proposal for ICF categories and matching instruments was developed, based on reliability and validity. Relevant instruments were then selected in a consensus round by 11 knowledge brokers who were responsible for the implementation of the selected instruments. The feasibility of the selected instruments was tested by 36 physical therapists at different work settings within stroke services. Finally, instruments that were deemed relevant and feasible were included in the revised guideline. A total of 28 instruments were recommended for inclusion in the revised guideline. Nineteen instruments were retained from the previous guideline. Ten new instruments were tested in clinical practice, seven of which were found feasible. Two more instruments were added after critical appraisal of the set of the measurement instruments. The revised guideline contains 28 relevant and feasible instrument selected and tested in clinical practice by physical therapists. Further education and implementation is needed to integrate instruments in clinical practice. Further research is proposed for developing and implementing a core set of measurement instruments to be used at fixed time points to establish data registries that allow for continuous improvement of rehabilitation for stroke patients. Implications for Rehabilitation The revised Dutch Stroke Physical Therapy Guideline recommends a total of 28 instruments, that are relevant and feasible for clinical practice of physical therapist in the different settings of stroke rehabilitation. The selection of instrument in daily practice should be part of the clinical reasoning process of PTs and be tailored to individual patients' needs and the degree of priority of the affected ICF category. Suggested education strategies for further integration of instruments in of the daily practice of PTs in Stroke Rehabilitation are: 'Training on the job' and 'peer assessment in clinical situations'.

Time domain simulations of preliminary breakdown pulses in natural lightning.

PubMed

Carlson, B E; Liang, C; Bitzer, P; Christian, H

2015-06-16

Lightning discharge is a complicated process with relevant physical scales spanning many orders of magnitude. In an effort to understand the electrodynamics of lightning and connect physical properties of the channel to observed behavior, we construct a simulation of charge and current flow on a narrow conducting channel embedded in three-dimensional space with the time domain electric field integral equation, the method of moments, and the thin-wire approximation. The method includes approximate treatment of resistance evolution due to lightning channel heating and the corona sheath of charge surrounding the lightning channel. Focusing our attention on preliminary breakdown in natural lightning by simulating stepwise channel extension with a simplified geometry, our simulation reproduces the broad features observed in data collected with the Huntsville Alabama Marx Meter Array. Some deviations in pulse shape details are evident, suggesting future work focusing on the detailed properties of the stepping mechanism. Preliminary breakdown pulses can be reproduced by simulated channel extension Channel heating and corona sheath formation are crucial to proper pulse shape Extension processes and channel orientation significantly affect observations.

Requirements for Large Eddy Simulation Computations of Variable-Speed Power Turbine Flows

NASA Technical Reports Server (NTRS)

Ameri, Ali A.

2016-01-01

Variable-speed power turbines (VSPTs) operate at low Reynolds numbers and with a wide range of incidence angles. Transition, separation, and the relevant physics leading to them are important to VSPT flow. Higher fidelity tools such as large eddy simulation (LES) may be needed to resolve the flow features necessary for accurate predictive capability and design of such turbines. A survey conducted for this report explores the requirements for such computations. The survey is limited to the simulation of two-dimensional flow cases and endwalls are not included. It suggests that a grid resolution necessary for this type of simulation to accurately represent the physics may be of the order of Delta(x)+=45, Delta(x)+ =2 and Delta(z)+=17. Various subgrid-scale (SGS) models have been used and except for the Smagorinsky model, all seem to perform well and in some instances the simulations worked well without SGS modeling. A method of specifying the inlet conditions such as synthetic eddy modeling (SEM) is necessary to correctly represent the inlet conditions.

Time domain simulations of preliminary breakdown pulses in natural lightning

PubMed Central

Carlson, B E; Liang, C; Bitzer, P; Christian, H

2015-01-01

Lightning discharge is a complicated process with relevant physical scales spanning many orders of magnitude. In an effort to understand the electrodynamics of lightning and connect physical properties of the channel to observed behavior, we construct a simulation of charge and current flow on a narrow conducting channel embedded in three-dimensional space with the time domain electric field integral equation, the method of moments, and the thin-wire approximation. The method includes approximate treatment of resistance evolution due to lightning channel heating and the corona sheath of charge surrounding the lightning channel. Focusing our attention on preliminary breakdown in natural lightning by simulating stepwise channel extension with a simplified geometry, our simulation reproduces the broad features observed in data collected with the Huntsville Alabama Marx Meter Array. Some deviations in pulse shape details are evident, suggesting future work focusing on the detailed properties of the stepping mechanism. Key Points Preliminary breakdown pulses can be reproduced by simulated channel extension Channel heating and corona sheath formation are crucial to proper pulse shape Extension processes and channel orientation significantly affect observations PMID:26664815

Connectivity for Healthcare and Well-Being Management: Examples from Six European Projects

PubMed Central

Kamel Boulos, Maged N.; Lou, Ricardo Castellot; Anastasiou, Athanasios; Nugent, Chris D.; Alexandersson, Jan; Zimmermann, Gottfried; Cortes, Ulises; Casas, Roberto

2009-01-01

Technological advances and societal changes in recent years have contributed to a shift in traditional care models and in the relationship between patients and their doctors/carers, with (in general) an increase in the patient-carer physical distance and corresponding changes in the modes of access to relevant care information by all groups. The objective of this paper is to showcase the research efforts of six projects (that the authors are currently, or have recently been, involved in), CAALYX, eCAALYX, COGKNOW, EasyLine+, I2HOME, and SHARE-it, all funded by the European Commission towards a future where citizens can take an active role into managing their own healthcare. Most importantly, sensitive groups of citizens, such as the elderly, chronically ill and those suffering from various physical and cognitive disabilities, will be able to maintain vital and feature-rich connections with their families, friends and healthcare providers, who can then respond to, and prevent, the development of adverse health conditions in those they care for in a timely manner, wherever the carers and the people cared for happen to be. PMID:19742164

Vibrational algorithms for quantitative crystallographic analyses of hydroxyapatite-based biomaterials: II, application to decayed human teeth.

PubMed

Adachi, Tetsuya; Pezzotti, Giuseppe; Yamamoto, Toshiro; Ichioka, Hiroaki; Boffelli, Marco; Zhu, Wenliang; Kanamura, Narisato

2015-05-01

A systematic investigation, based on highly spectrally resolved Raman spectroscopy, was undertaken to research the efficacy of vibrational assessments in locating chemical and crystallographic fingerprints for the characterization of dental caries and the early detection of non-cavitated carious lesions. Raman results published by other authors have indicated possible approaches for this method. However, they conspicuously lacked physical insight at the molecular scale and, thus, the rigor necessary to prove the efficacy of this spectroscopy method. After solving basic physical challenges in a companion paper, we apply them here in the form of newly developed Raman algorithms for practical dental research. Relevant differences in mineral crystallite (average) orientation and texture distribution were revealed for diseased enamel at different stages compared with healthy mineralized enamel. Clear spectroscopy features could be directly translated in terms of a rigorous and quantitative classification of crystallography and chemical characteristics of diseased enamel structures. The Raman procedure enabled us to trace back otherwise invisible characteristics in early caries, in the translucent zone (i.e., the advancing front of the disease) and in the body of lesion of cavitated caries.

Permissible Home Range Estimation (PHRE) in restricted habitats: A new algorithm and an evaluation for sea otters

USGS Publications Warehouse

Tarjan, Lily M; Tinker, M. Tim

2016-01-01

Parametric and nonparametric kernel methods dominate studies of animal home ranges and space use. Most existing methods are unable to incorporate information about the underlying physical environment, leading to poor performance in excluding areas that are not used. Using radio-telemetry data from sea otters, we developed and evaluated a new algorithm for estimating home ranges (hereafter Permissible Home Range Estimation, or “PHRE”) that reflects habitat suitability. We began by transforming sighting locations into relevant landscape features (for sea otters, coastal position and distance from shore). Then, we generated a bivariate kernel probability density function in landscape space and back-transformed this to geographic space in order to define a permissible home range. Compared to two commonly used home range estimation methods, kernel densities and local convex hulls, PHRE better excluded unused areas and required a smaller sample size. Our PHRE method is applicable to species whose ranges are restricted by complex physical boundaries or environmental gradients and will improve understanding of habitat-use requirements and, ultimately, aid in conservation efforts.

Feature Vector Construction Method for IRIS Recognition

NASA Astrophysics Data System (ADS)

Odinokikh, G.; Fartukov, A.; Korobkin, M.; Yoo, J.

2017-05-01

One of the basic stages of iris recognition pipeline is iris feature vector construction procedure. The procedure represents the extraction of iris texture information relevant to its subsequent comparison. Thorough investigation of feature vectors obtained from iris showed that not all the vector elements are equally relevant. There are two characteristics which determine the vector element utility: fragility and discriminability. Conventional iris feature extraction methods consider the concept of fragility as the feature vector instability without respect to the nature of such instability appearance. This work separates sources of the instability into natural and encodinginduced which helps deeply investigate each source of instability independently. According to the separation concept, a novel approach of iris feature vector construction is proposed. The approach consists of two steps: iris feature extraction using Gabor filtering with optimal parameters and quantization with separated preliminary optimized fragility thresholds. The proposed method has been tested on two different datasets of iris images captured under changing environmental conditions. The testing results show that the proposed method surpasses all the methods considered as a prior art by recognition accuracy on both datasets.

Vision and change in introductory physics for the life sciences

NASA Astrophysics Data System (ADS)

Mochrie, S. G. J.

2016-07-01

Since 2010, our physics department has offered a re-imagined calculus-based introductory physics sequence for the life sciences. These courses include a selection of biologically and medically relevant topics that we believe are more meaningful to undergraduate premedical and biological science students than those found in a traditional course. In this paper, we highlight new aspects of the first-semester course, and present a comparison of student evaluations of this course versus a more traditional one. We also present the effect on student perception of the relevance of physics to biology and medicine after having taken this course.

Clinically Relevant Physical Benefits of Exercise Interventions in Breast Cancer Survivors.

PubMed

Kirkham, Amy A; Bland, Kelcey A; Sayyari, Sarah; Campbell, Kristin L; Davis, Margot K

2016-02-01

Evidence is currently limited for the effect of exercise on breast cancer clinical outcomes. However, several of the reported physical benefits of exercise, including peak oxygen consumption, functional capacity, muscle strength and lean mass, cardiovascular risk factors, and bone health, have established associations with disability, cardiovascular disease risk, morbidity, and mortality. This review will summarize the clinically relevant physical benefits of exercise interventions in breast cancer survivors and discuss recommendations for achieving these benefits. It will also describe potential differences in intervention delivery that may impact outcomes and, lastly, describe current physical activity guidelines for cancer survivors.

The role of park conditions and features on park visitation and physical activity.

PubMed

Rung, Ariane L; Mowen, Andrew J; Broyles, Stephanie T; Gustat, Jeanette

2011-09-01

Neighborhood parks play an important role in promoting physical activity. We examined the effect of activity area, condition, and presence of supporting features on number of park users and park-based physical activity levels. 37 parks and 154 activity areas within parks were assessed during summer 2008 for their features and park-based physical activity. Outcomes included any park use, number of park users, mean and total energy expenditure. Independent variables included type and condition of activity area, supporting features, size of activity area, gender, and day of week. Multilevel models controlled for clustering of observations at activity area and park levels. Type of activity area was associated with number of park users, mean and total energy expenditure, with basketball courts having the highest number of users and total energy expenditure, and playgrounds having the highest mean energy expenditure. Condition of activity areas was positively associated with number of basketball court users and inversely associated with number of green space users and total green space energy expenditure. Various supporting features were both positively and negatively associated with each outcome. This study provides evidence regarding characteristics of parks that can contribute to achieving physical activity goals within recreational spaces.

An Experimental Introduction to Acoustics

NASA Astrophysics Data System (ADS)

Black, Andy Nicholas; Magruder, Robert H.

2017-11-01

Learning and understanding physics requires more than studying physics texts. It requires doing physics. Doing research is a key opportunity for students to connect physical principles with their everyday experience. A powerful way to introduce students to research and technique is through subjects in which they might find interest. Presented is an experiment that serves to introduce an advanced undergraduate or high school student to conducting research in acoustics via an experiment involving a standard dreadnought acoustic guitar, recording industry-related equipment, and relevant industrial analysis software. This experimental process is applicable to a wide range of acoustical topics including both acoustic and electric instruments. Also, the student has a hands-on experience with relevant audio engineering technology to study physical principles.

Reliable classification of facial phenotypic variation in craniofacial microsomia: a comparison of physical exam and photographs.

PubMed

Birgfeld, Craig B; Heike, Carrie L; Saltzman, Babette S; Leroux, Brian G; Evans, Kelly N; Luquetti, Daniela V

2016-03-31

Craniofacial microsomia is a common congenital condition for which children receive longitudinal, multidisciplinary team care. However, little is known about the etiology of craniofacial microsomia and few outcome studies have been published. In order to facilitate large, multicenter studies in craniofacial microsomia, we assessed the reliability of phenotypic classification based on photographs by comparison with direct physical examination. Thirty-nine children with craniofacial microsomia underwent a physical examination and photographs according to a standardized protocol. Three clinicians completed ratings during the physical examination and, at least a month later, using respective photographs for each participant. We used descriptive statistics for participant characteristics and intraclass correlation coefficients (ICCs) to assess reliability. The agreement between ratings on photographs and physical exam was greater than 80 % for all 15 categories included in the analysis. The ICC estimates were higher than 0.6 for most features. Features with the highest ICC included: presence of epibulbar dermoids, ear abnormalities, and colobomas (ICC 0.85, 0.81, and 0.80, respectively). Orbital size, presence of pits, tongue abnormalities, and strabismus had the lowest ICC, values (0.17 or less). There was not a strong tendency for either type of rating, physical exam or photograph, to be more likely to designate a feature as abnormal. The agreement between photographs and physical exam regarding the presence of a prior surgery was greater than 90 % for most features. Our results suggest that categorization of facial phenotype in children with CFM based on photographs is reliable relative to physical examination for most facial features.

Biomedically relevant chemical and physical properties of coal combustion products.

PubMed Central

Fisher, G L

1983-01-01

The evaluation of the potential public and occupational health hazards of developing and existing combustion processes requires a detailed understanding of the physical and chemical properties of effluents available for human and environmental exposures. These processes produce complex mixtures of gases and aerosols which may interact synergistically or antagonistically with biological systems. Because of the physicochemical complexity of the effluents, the biomedically relevant properties of these materials must be carefully assessed. Subsequent to release from combustion sources, environmental interactions further complicate assessment of the toxicity of combustion products. This report provides an overview of the biomedically relevant physical and chemical properties of coal fly ash. Coal fly ash is presented as a model complex mixture for health and safety evaluation of combustion processes. PMID:6337824

CLINICAL APPROACH TO THE DIAGNOSTIC EVALUATION OF HERDITARY AND ACQUIRED NEUROMUSCULAR DISEASES

PubMed Central

McDonald, Craig M.

2012-01-01

SYNOPSIS In the context of a neuromuscular disease diagnostic evaluation, the clinician still must be able to obtain a relevant patient and family history and perform focused general, musculoskeletal, neurologic and functional physical examinations to direct further diagnostic evaluations. Laboratory studies for hereditary neuromuscular diseases include relevant molecular genetic studies. The EMG and nerve conduction studies remain an extension of the physical examination and help to guide further diagnostic studies such as molecular genetic studies, and muscle and nerve biopsies. All diagnostic information needs to be interpreted not in isolation, but within the context of relevant historical information, family history, physical examination findings, and laboratory data, electrophysiologic findings, pathologic findings, and molecular genetic findings if obtained. PMID:22938875

The Power of Materials Science Tools for Gaining Insights into Organic Semiconductors

NASA Astrophysics Data System (ADS)

Treat, Neil D.; Westacott, Paul; Stingelin, Natalie

2015-07-01

The structure of organic semiconductors can be complex because features from the molecular level (such as molecular conformation) to the micrometer scale (such as the volume fraction and composition of phases, phase distribution, and domain size) contribute to the definition of the optoelectronic landscape of the final architectures and, hence, to device performance. As a consequence, a detailed understanding of how to manipulate molecular ordering, e.g., through knowledge of relevant phase transitions, of the solidification process, of relevant solidification mechanisms, and of kinetic factors, is required to induce the desired optoelectronic response. In this review, we discuss relevant structural features of single-component and multicomponent systems; provide a case study of the multifaceted structure that polymer:fullerene systems can adopt; and highlight relevant solidification mechanisms such as nucleation and growth, liquid-liquid phase separation, and spinodal decomposition. In addition, cocrystal formation, solid solutions, and eutectic systems are treated and their relevance within the optoelectronic area emphasized.

Dysmorphic features and developmental outcome of 2-year-old children.

PubMed

Seggers, Jorien; Haadsma, Maaike L; Bos, Arend F; Heineman, Maas Jan; Middelburg, Karin J; van den Heuvel, Edwin R; Hadders-Algra, Mijna

2014-11-01

The aim of this study was to assess the associations between dysmorphic features and neurological, mental, psychomotor, and behavioural development in order to improve our understanding of aetiological pathways leading to minor developmental problems. In our cross-sectional study, 272 generally healthy 2-year-olds (143 males, 129 females; median gestational age 39 weeks, [range 30-43wks]), born after a parental history of subfertility either with or without fertility treatment, were examined. Dysmorphic features were classified as abnormalities (clinically relevant or not), minor anomalies, or common variants according to Merks' classification system. Hempel's neurological assessment resulted in a neurological optimality score (NOS) and fluency score. Mental and psychomotor development were assessed with the Dutch version of the Bayley Scales of Infant Development and behavioural development with the Achenbach Child Behaviour Checklist. Of the different types of dysmorphic feature, clinically relevant abnormalities were most strongly associated with a lower NOS (difference -2.53, 95% confidence interval [CI] -4.23 to -0.83) and fluency score (difference -0.62, 95% CI -1.1 to -0.15). The presence of one or more abnormalities (clinically relevant or not) or one or more common variants was significantly associated with a lower NOS, and the presence of three or more minor anomalies was associated with lower fluency scores. Dysmorphic features were not associated with mental, psychomotor, or behavioural development. As dysmorphic features originate during the first trimester of pregnancy, the association between dysmorphic features and minor alterations in neurodevelopment may suggest an early ontogenetic origin of subtle neurological deviations. © 2014 Mac Keith Press.

Gene features selection for three-class disease classification via multiple orthogonal partial least square discriminant analysis and S-plot using microarray data.

PubMed

Yang, Mingxing; Li, Xiumin; Li, Zhibin; Ou, Zhimin; Liu, Ming; Liu, Suhuan; Li, Xuejun; Yang, Shuyu

2013-01-01

DNA microarray analysis is characterized by obtaining a large number of gene variables from a small number of observations. Cluster analysis is widely used to analyze DNA microarray data to make classification and diagnosis of disease. Because there are so many irrelevant and insignificant genes in a dataset, a feature selection approach must be employed in data analysis. The performance of cluster analysis of this high-throughput data depends on whether the feature selection approach chooses the most relevant genes associated with disease classes. Here we proposed a new method using multiple Orthogonal Partial Least Squares-Discriminant Analysis (mOPLS-DA) models and S-plots to select the most relevant genes to conduct three-class disease classification and prediction. We tested our method using Golub's leukemia microarray data. For three classes with subtypes, we proposed hierarchical orthogonal partial least squares-discriminant analysis (OPLS-DA) models and S-plots to select features for two main classes and their subtypes. For three classes in parallel, we employed three OPLS-DA models and S-plots to choose marker genes for each class. The power of feature selection to classify and predict three-class disease was evaluated using cluster analysis. Further, the general performance of our method was tested using four public datasets and compared with those of four other feature selection methods. The results revealed that our method effectively selected the most relevant features for disease classification and prediction, and its performance was better than that of the other methods.

The Lake-Catchment (LakeCat) Dataset for characterizing hydrologically-relevant landscape features for lakes across the conterminous US

EPA Science Inventory

Lake conditions, including their biota, respond to both natural and human-related landscape features. Characterizing these features within the contributing areas (i.e., delineated watersheds) of lakes could improve the analysis and the sustainable use and management of these impo...

Many local pattern texture features: which is better for image-based multilabel human protein subcellular localization classification?

PubMed

Yang, Fan; Xu, Ying-Ying; Shen, Hong-Bin

2014-01-01

Human protein subcellular location prediction can provide critical knowledge for understanding a protein's function. Since significant progress has been made on digital microscopy, automated image-based protein subcellular location classification is urgently needed. In this paper, we aim to investigate more representative image features that can be effectively used for dealing with the multilabel subcellular image samples. We prepared a large multilabel immunohistochemistry (IHC) image benchmark from the Human Protein Atlas database and tested the performance of different local texture features, including completed local binary pattern, local tetra pattern, and the standard local binary pattern feature. According to our experimental results from binary relevance multilabel machine learning models, the completed local binary pattern, and local tetra pattern are more discriminative for describing IHC images when compared to the traditional local binary pattern descriptor. The combination of these two novel local pattern features and the conventional global texture features is also studied. The enhanced performance of final binary relevance classification model trained on the combined feature space demonstrates that different features are complementary to each other and thus capable of improving the accuracy of classification.

Combining local and global limitations of visual search.

PubMed

Põder, Endel

2017-04-01

There are different opinions about the roles of local interactions and central processing capacity in visual search. This study attempts to clarify the problem using a new version of relevant set cueing. A central precue indicates two symmetrical segments (that may contain a target object) within a circular array of objects presented briefly around the fixation point. The number of objects in the relevant segments, and density of objects in the array were varied independently. Three types of search experiments were run: (a) search for a simple visual feature (color, size, and orientation); (b) conjunctions of simple features; and (c) spatial configuration of simple features (rotated Ts). For spatial configuration stimuli, the results were consistent with a fixed global processing capacity and standard crowding zones. For simple features and their conjunctions, the results were different, dependent on the features involved. While color search exhibits virtually no capacity limits or crowding, search for an orientation target was limited by both. Results for conjunctions of features can be partly explained by the results from the respective features. This study shows that visual search is limited by both local interference and global capacity, and the limitations are different for different visual features.

Parallel perceptual enhancement and hierarchic relevance evaluation in an audio-visual conjunction task.

PubMed

Potts, Geoffrey F; Wood, Susan M; Kothmann, Delia; Martin, Laura E

2008-10-21

Attention directs limited-capacity information processing resources to a subset of available perceptual representations. The mechanisms by which attention selects task-relevant representations for preferential processing are not fully known. Triesman and Gelade's [Triesman, A., Gelade, G., 1980. A feature integration theory of attention. Cognit. Psychol. 12, 97-136.] influential attention model posits that simple features are processed preattentively, in parallel, but that attention is required to serially conjoin multiple features into an object representation. Event-related potentials have provided evidence for this model showing parallel processing of perceptual features in the posterior Selection Negativity (SN) and serial, hierarchic processing of feature conjunctions in the Frontal Selection Positivity (FSP). Most prior studies have been done on conjunctions within one sensory modality while many real-world objects have multimodal features. It is not known if the same neural systems of posterior parallel processing of simple features and frontal serial processing of feature conjunctions seen within a sensory modality also operate on conjunctions between modalities. The current study used ERPs and simultaneously presented auditory and visual stimuli in three task conditions: Attend Auditory (auditory feature determines the target, visual features are irrelevant), Attend Visual (visual features relevant, auditory irrelevant), and Attend Conjunction (target defined by the co-occurrence of an auditory and a visual feature). In the Attend Conjunction condition when the auditory but not the visual feature was a target there was an SN over auditory cortex, when the visual but not auditory stimulus was a target there was an SN over visual cortex, and when both auditory and visual stimuli were targets (i.e. conjunction target) there were SNs over both auditory and visual cortex, indicating parallel processing of the simple features within each modality. In contrast, an FSP was present when either the visual only or both auditory and visual features were targets, but not when only the auditory stimulus was a target, indicating that the conjunction target determination was evaluated serially and hierarchically with visual information taking precedence. This indicates that the detection of a target defined by audio-visual conjunction is achieved via the same mechanism as within a single perceptual modality, through separate, parallel processing of the auditory and visual features and serial processing of the feature conjunction elements, rather than by evaluation of a fused multimodal percept.

Utility of stages of change construct in the planning of physical activity interventions among playgroup mothers.

PubMed

Jones, Carlie; Jancey, Jonine; Howat, Peter; Dhaliwal, Satvinder; Burns, Sharyn; McManus, Alexandra; Hills, Andrew P; Anderson, Annie S

2013-07-29

The objective of this research was to assess the physical activity levels among a unique cohort of Western Australian (WA) mothers with young children who attend a WA Playgroup. Associated factors were also investigated, including self-efficacy for physical activity, social support for exercise, relevant socio-demographic correlates, as well as the stages of change construct within the Transtheoretical Model (TTM). 421 women completed a questionnaire assessing physical activity behaviours. Of these, 368 participants completed the relevant physical activity evaluation items. 82.5% and 17.5% of the sample were classified as active and inactive, respectively. Associations between physical activity status and exercise stage of change were found. Additional associations were established for partner support and self-efficacy for physical activity. The majority of the sample was classified as active. Despite the high percentage of active participants, this study confirms the usefulness of the stages of change measure in that it can be utilised by health promotion practitioners to report physical activity behaviour and develop appropriate intervention strategies among a time poor and hard to reach population. Specifically the results are relevant to mothers in over 16,000 WA families who are involved with Playgroup WA programs. Interventions aimed at improving physical activity levels in mothers with young children should also consider the need to improve self-efficacy and social support.

Examining Physical and Sexual Abuse Histories as Correlates of Suicide Risk Among Firefighters.

PubMed

Hom, Melanie A; Matheny, Natalie L; Stanley, Ian H; Rogers, Megan L; Cougle, Jesse R; Joiner, Thomas E

2017-12-01

Research indicates that physical and sexual abuse are associated with increased suicide risk; however, these associations have not been investigated among firefighters-an occupational group that has been shown to be at elevated suicide risk. This study examined whether physical and sexual abuse histories are associated with (a) career suicide ideation, plans, and attempts; and (b) current suicide risk (controlling for theoretically relevant symptoms) in this occupational group. A sample of 929 U.S. firefighters completed self-report surveys that assessed lifetime history of physical and sexual abuse; career suicide ideation, plans, and attempts; current suicide risk; and theoretically relevant symptoms. Logistic regression analyses revealed that individuals who reported a history of physical abuse were significantly more likely to report career suicide ideation, adjusted odds ratio [AOR] = 6.12, plans, AOR = 13.05, and attempts, AOR = 23.81, than those who did not. A similar pattern of findings emerged for individuals who reported a sexual abuse history, AORs = 7.83, 18.35, and 29.58 respectively. Linear regression analyses revealed that physical and sexual abuse histories each significantly predicted current suicide risk, even after controlling for theoretically relevant symptoms and demographics, pr 2 = .07 and .06, respectively. Firefighters with a history of physical and/or sexual abuse may be at increased risk for suicidal thoughts and behaviors. A history of physical and sexual abuse were each significantly correlated with current suicide risk in this population, even after accounting for the effects of theoretically relevant symptoms. Thus, when conceptualizing suicide risk among firefighters, factors not necessarily related to one's firefighter career should be considered. Copyright © 2017 International Society for Traumatic Stress Studies.

Testing the idea of privileged awareness of self-relevant information.

PubMed

Stein, Timo; Siebold, Alisha; van Zoest, Wieske

2016-03-01

Self-relevant information is prioritized in processing. Some have suggested the mechanism driving this advantage is akin to the automatic prioritization of physically salient stimuli in information processing (Humphreys & Sui, 2015). Here we investigate whether self-relevant information is prioritized for awareness under continuous flash suppression (CFS), as has been found for physical salience. Gabor patches with different orientations were first associated with the labels You or Other. Participants were more accurate in matching the self-relevant association, replicating previous findings of self-prioritization. However, breakthrough into awareness from CFS did not differ between self- and other-associated Gabors. These findings demonstrate that self-relevant information has no privileged access to awareness. Rather than modulating the initial visual processes that precede and lead to awareness, the advantage of self-relevant information may better be characterized as prioritization at later processing stages. (c) 2016 APA, all rights reserved).

Analysis of respiratory events in obstructive sleep apnea syndrome: Inter-relations and association to simple nocturnal features.

PubMed

Ghandeharioun, H; Rezaeitalab, F; Lotfi, R

2016-01-01

This study carefully evaluates the association of different respiration-related events to each other and to simple nocturnal features in obstructive sleep apnea-hypopnea syndrome (OSAS). The events include apneas, hypopneas, respiratory event-related arousals and snores. We conducted a statistical study on 158 adults who underwent polysomnography between July 2012 and May 2014. To monitor relevance, along with linear statistical strategies like analysis of variance and bootstrapping a correlation coefficient standard error, the non-linear method of mutual information is also applied to illuminate vague results of linear techniques. Based on normalized mutual information weights (NMIW), indices of apnea are 1.3 times more relevant to AHI values than those of hypopnea. NMIW for the number of blood oxygen desaturation below 95% is considerable (0.531). The next relevant feature is "respiratory arousals index" with NMIW of 0.501. Snore indices (0.314), and BMI (0.203) take the next place. Based on NMIW values, snoring events are nearly one-third (29.9%) more dependent to hypopneas than RERAs. 1. The more sever the OSAS is, the more frequently the apneic events happen. 2. The association of snore with hypopnea/RERA revealed which is routinely ignored in regression-based OSAS modeling. 3. The statistical dependencies of oximetry features potentially can lead to home-based screening of OSAS. 4. Poor ESS-AHI relevance in the database under study indicates its disability for the OSA diagnosis compared to oximetry. 5. Based on poor RERA-snore/ESS relevance, detailed history of the symptoms plus polysomnography is suggested for accurate diagnosis of RERAs. Copyright © 2015 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.

The "Finding Physics" Project: Recognizing and Exploring Physics outside the Classroom

ERIC Educational Resources Information Center

Beck, Judith; Perkins, James

2016-01-01

Students in introductory physics classes often have difficulty recognizing the relevance of physics concepts outside the confines of the physics classroom, lab, and textbook. Even though textbooks and instructors often provide examples of physics applications from a wide array of areas, students have difficulty relating physics to their own lives.…

Independent and additive repetition priming of motion direction and color in visual search.

PubMed

Kristjánsson, Arni

2009-03-01

Priming of visual search for Gabor patch stimuli, varying in color and local drift direction, was investigated. The task relevance of each feature varied between the different experimental conditions compared. When the target defining dimension was color, a large effect of color repetition was seen as well as a smaller effect of the repetition of motion direction. The opposite priming pattern was seen when motion direction defined the target--the effect of motion direction repetition was this time larger than for color repetition. Finally, when neither was task relevant, and the target defining dimension was the spatial frequency of the Gabor patch, priming was seen for repetition of both color and motion direction, but the effects were smaller than in the previous two conditions. These results show that features do not necessarily have to be task relevant for priming to occur. There is little interaction between priming following repetition of color and motion, these two features show independent and additive priming effects, most likely reflecting that the two features are processed at separate processing sites in the nervous system, consistent with previous findings from neuropsychology & neurophysiology. The implications of the findings for theoretical accounts of priming in visual search are discussed.

Learning to rank-based gene summary extraction.

PubMed

Shang, Yue; Hao, Huihui; Wu, Jiajin; Lin, Hongfei

2014-01-01

In recent years, the biomedical literature has been growing rapidly. These articles provide a large amount of information about proteins, genes and their interactions. Reading such a huge amount of literature is a tedious task for researchers to gain knowledge about a gene. As a result, it is significant for biomedical researchers to have a quick understanding of the query concept by integrating its relevant resources. In the task of gene summary generation, we regard automatic summary as a ranking problem and apply the method of learning to rank to automatically solve this problem. This paper uses three features as a basis for sentence selection: gene ontology relevance, topic relevance and TextRank. From there, we obtain the feature weight vector using the learning to rank algorithm and predict the scores of candidate summary sentences and obtain top sentences to generate the summary. ROUGE (a toolkit for summarization of automatic evaluation) was used to evaluate the summarization result and the experimental results showed that our method outperforms the baseline techniques. According to the experimental result, the combination of three features can improve the performance of summary. The application of learning to rank can facilitate the further expansion of features for measuring the significance of sentences.

Prolonged grief symptoms related to loss of physical functioning: examining unique associations with medical service utilization.

PubMed

Holland, Jason M; Graves, Stacy; Klingspon, Kara L; Rozalski, Vincent

2016-01-01

Prolonged grief, a severe and chronic form of grieving most commonly studied in the context of bereavement, may have relevance to losses associated with chronic illness (e.g. grief related to loss of functioning or loss of a planned future). The purpose of the present study is to examine the unique associations between prolonged grief symptoms and service utilization patterns. An online self-report assessment battery was administered among a sample of 275 older adults with at least one chronic illness that caused significant physical impairment. Even after statistically controlling for relevant physical health (e.g. severity of physical limitations, somatic symptoms, number of chronic illnesses) and psychosocial variables (e.g. social support, depression/anxiety), more severe prolonged grief symptoms were associated with a greater number of emergency room visits, overnight stays in the hospital and total nights in the hospital. These findings highlight the importance of screening for prolonged grief symptomatology with older individuals with a debilitating chronic illness. Recent evidence suggests that prolonged grief may have relevance for losses associated with physical illness. The present study shows that prolonged grief reactions related to physical illness (e.g. grieving the loss of functioning) are uniquely associated with increased hospital-based service utilization. Given the relevance of prolonged grief reactions in this population, practitioners may wish to assess for these symptoms. Future clinical research should focus on developing interventions to target prolonged grief symptoms associated with these losses.

The construction of meaning.

PubMed

Kintsch, Walter; Mangalath, Praful

2011-04-01

We argue that word meanings are not stored in a mental lexicon but are generated in the context of working memory from long-term memory traces that record our experience with words. Current statistical models of semantics, such as latent semantic analysis and the Topic model, describe what is stored in long-term memory. The CI-2 model describes how this information is used to construct sentence meanings. This model is a dual-memory model, in that it distinguishes between a gist level and an explicit level. It also incorporates syntactic information about how words are used, derived from dependency grammar. The construction of meaning is conceptualized as feature sampling from the explicit memory traces, with the constraint that the sampling must be contextually relevant both semantically and syntactically. Semantic relevance is achieved by sampling topically relevant features; local syntactic constraints as expressed by dependency relations ensure syntactic relevance. Copyright © 2010 Cognitive Science Society, Inc.

Feature Selection for Speech Emotion Recognition in Spanish and Basque: On the Use of Machine Learning to Improve Human-Computer Interaction

PubMed Central

Arruti, Andoni; Cearreta, Idoia; Álvarez, Aitor; Lazkano, Elena; Sierra, Basilio

2014-01-01

Study of emotions in human–computer interaction is a growing research area. This paper shows an attempt to select the most significant features for emotion recognition in spoken Basque and Spanish Languages using different methods for feature selection. RekEmozio database was used as the experimental data set. Several Machine Learning paradigms were used for the emotion classification task. Experiments were executed in three phases, using different sets of features as classification variables in each phase. Moreover, feature subset selection was applied at each phase in order to seek for the most relevant feature subset. The three phases approach was selected to check the validity of the proposed approach. Achieved results show that an instance-based learning algorithm using feature subset selection techniques based on evolutionary algorithms is the best Machine Learning paradigm in automatic emotion recognition, with all different feature sets, obtaining a mean of 80,05% emotion recognition rate in Basque and a 74,82% in Spanish. In order to check the goodness of the proposed process, a greedy searching approach (FSS-Forward) has been applied and a comparison between them is provided. Based on achieved results, a set of most relevant non-speaker dependent features is proposed for both languages and new perspectives are suggested. PMID:25279686

Exploring Possible Selves in a First-Year Physics Foundation Class: Engaging Students by Establishing Relevance

ERIC Educational Resources Information Center

Bennett, Dawn; Roberts, Lynne; Creagh, Christine

2016-01-01

Students often complain that they cannot see the relevance of what they are being taught in foundation physics classes. While revising and adjusting the curriculum and teaching are important, this study suggests it might also be useful to help students view their learning in relation to their future career aspirations. This paper reports on a…

Modeling Exoplanetary Haze and Cloud Effects for Transmission Spectroscopy in the TRAPPIST-1 System

NASA Astrophysics Data System (ADS)

Moran, Sarah E.; Horst, Sarah M.; Lewis, Nikole K.; Batalha, Natasha E.; de Wit, Julien

2018-01-01

We present theoretical transmission spectra of the planets TRAPPIST-1d, e, f, and g using a version of the CaltecH Inverse ModEling and Retrieval Algorithms (CHIMERA) atmospheric modeling code. We use particle size, aerosol production rates, and aerosol composition inputs from recent laboratory experiments relevant for the TRAPPIST-1 system to constrain cloud and haze behavior and their effects on transmission spectra. We explore these cloud and haze cases for a variety of theoretical atmospheric compositions including hydrogen-, nitrogen-, and carbon dioxide-dominated atmospheres. Then, we demonstrate the feasibility of physically-motivated, laboratory-supported clouds and hazes to obscure spectral features at wavelengths and resolutions relevant to instruments on the Hubble Space Telescope and the upcoming James Webb Space Telescope. Lastly, with laboratory based constraints of haze production rates for terrestrial exoplanets, we constrain possible bulk atmospheric compositions of the TRAPPIST-1 planets based on current observations. We show that continued collection of optical data, beyond the supported wavelength range of the James Webb Telescope, is necessary to explore the full effect of hazes for transmission spectra of exoplanetary atmospheres like the TRAPPIST-1 system.

'Fish matters': the relevance of fish skin biology to investigative dermatology.

PubMed

Rakers, Sebastian; Gebert, Marina; Uppalapati, Sai; Meyer, Wilfried; Maderson, Paul; Sell, Anne F; Kruse, Charli; Paus, Ralf

2010-04-01

Fish skin is a multi-purpose tissue that serves numerous vital functions including chemical and physical protection, sensory activity, behavioural purposes or hormone metabolism. Further, it is an important first-line defense system against pathogens, as fish are continuously exposed to multiple microbial challenges in their aquatic habitat. Fish skin excels in highly developed antimicrobial features, many of which have been preserved throughout evolution, and infection defense principles employed by piscine skin are still operative in human skin. This review argues that it is both rewarding and important for investigative dermatologists to revive their interest in fish skin biology, as it provides insights into numerous fundamental issues that are of major relevance to mammalian skin. The basic molecular insights provided by zebrafish in vivo-genomics for genetic, regeneration and melanoma research, the complex antimicrobial defense systems of fish skin and the molecular controls of melanocyte stem cells are just some of the fascinating examples that illustrate the multiple potential uses of fish skin models in investigative dermatology. We synthesize the essentials of fish skin biology and highlight selected aspects that are of particular comparative interest to basic and clinically applied human skin research.

A report on older-age bipolar disorder from the International Society for Bipolar Disorders Task Force.

PubMed

Sajatovic, Martha; Strejilevich, Sergio A; Gildengers, Ariel G; Dols, Annemiek; Al Jurdi, Rayan K; Forester, Brent P; Kessing, Lars Vedel; Beyer, John; Manes, Facundo; Rej, Soham; Rosa, Adriane R; Schouws, Sigfried Ntm; Tsai, Shang-Ying; Young, Robert C; Shulman, Kenneth I

2015-11-01

In the coming generation, older adults with bipolar disorder (BD) will increase in absolute numbers as well as proportion of the general population. This is the first report of the International Society for Bipolar Disorder (ISBD) Task Force on Older-Age Bipolar Disorder (OABD). This task force report addresses the unique aspects of OABD including epidemiology and clinical features, neuropathology and biomarkers, physical health, cognition, and care approaches. The report describes an expert consensus summary on OABD that is intended to advance the care of patients, and shed light on issues of relevance to BD research across the lifespan. Although there is still a dearth of research and health efforts focused on older adults with BD, emerging data have brought some answers, innovative questions, and novel perspectives related to the notion of late onset, medical comorbidity, and the vexing issue of cognitive impairment and decline. Improving our understanding of the biological, clinical, and social underpinnings relevant to OABD is an indispensable step in building a complete map of BD across the lifespan. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Automatic Modulation Classification of Common Communication and Pulse Compression Radar Waveforms using Cyclic Features

DTIC Science & Technology

2013-03-01

intermediate frequency LFM linear frequency modulation MAP maximum a posteriori MATLAB® matrix laboratory ML maximun likelihood OFDM orthogonal frequency...spectrum, frequency hopping, and orthogonal frequency division multiplexing ( OFDM ) modulations. Feature analysis would be a good research thrust to...determine feature relevance and decide if removing any features improves performance. Also, extending the system for simulations using a MIMO receiver or

20 CFR 404.1560 - When we will consider your vocational background.

Code of Federal Regulations, 2010 CFR

2010-04-01

... section. (b) Past relevant work. We will first compare our assessment of your residual functional capacity with the physical and mental demands of your past relevant work. (1) Definition of past relevant work. Past relevant work is work that you have done within the past 15 years, that was substantial gainful...

Neural mechanisms of selective attention in the somatosensory system.

PubMed

Gomez-Ramirez, Manuel; Hysaj, Kristjana; Niebur, Ernst

2016-09-01

Selective attention allows organisms to extract behaviorally relevant information while ignoring distracting stimuli that compete for the limited resources of their central nervous systems. Attention is highly flexible, and it can be harnessed to select information based on sensory modality, within-modality feature(s), spatial location, object identity, and/or temporal properties. In this review, we discuss the body of work devoted to understanding mechanisms of selective attention in the somatosensory system. In particular, we describe the effects of attention on tactile behavior and corresponding neural activity in somatosensory cortex. Our focus is on neural mechanisms that select tactile stimuli based on their location on the body (somatotopic-based attention) or their sensory feature (feature-based attention). We highlight parallels between selection mechanisms in touch and other sensory systems and discuss several putative neural coding schemes employed by cortical populations to signal the behavioral relevance of sensory inputs. Specifically, we contrast the advantages and disadvantages of using a gain vs. spike-spike correlation code for representing attended sensory stimuli. We favor a neural network model of tactile attention that is composed of frontal, parietal, and subcortical areas that controls somatosensory cells encoding the relevant stimulus features to enable preferential processing throughout the somatosensory hierarchy. Our review is based on data from noninvasive electrophysiological and imaging data in humans as well as single-unit recordings in nonhuman primates. Copyright © 2016 the American Physiological Society.

Neural mechanisms of selective attention in the somatosensory system

PubMed Central

Hysaj, Kristjana; Niebur, Ernst

2016-01-01

Selective attention allows organisms to extract behaviorally relevant information while ignoring distracting stimuli that compete for the limited resources of their central nervous systems. Attention is highly flexible, and it can be harnessed to select information based on sensory modality, within-modality feature(s), spatial location, object identity, and/or temporal properties. In this review, we discuss the body of work devoted to understanding mechanisms of selective attention in the somatosensory system. In particular, we describe the effects of attention on tactile behavior and corresponding neural activity in somatosensory cortex. Our focus is on neural mechanisms that select tactile stimuli based on their location on the body (somatotopic-based attention) or their sensory feature (feature-based attention). We highlight parallels between selection mechanisms in touch and other sensory systems and discuss several putative neural coding schemes employed by cortical populations to signal the behavioral relevance of sensory inputs. Specifically, we contrast the advantages and disadvantages of using a gain vs. spike-spike correlation code for representing attended sensory stimuli. We favor a neural network model of tactile attention that is composed of frontal, parietal, and subcortical areas that controls somatosensory cells encoding the relevant stimulus features to enable preferential processing throughout the somatosensory hierarchy. Our review is based on data from noninvasive electrophysiological and imaging data in humans as well as single-unit recordings in nonhuman primates. PMID:27334956

Memory for a single object has differently variable precisions for relevant and irrelevant features.

PubMed

Swan, Garrett; Collins, John; Wyble, Brad

2016-01-01

Working memory is a limited resource. To further characterize its limitations, it is vital to understand exactly what is encoded about a visual object beyond the "relevant" features probed in a particular task. We measured the memory quality of a task-irrelevant feature of an attended object by coupling a delayed estimation task with a surprise test. Participants were presented with a single colored arrow and were asked to retrieve just its color for the first half of the experiment before unexpectedly being asked to report its direction. Mixture modeling of the data revealed that participants had highly variable precision on the surprise test, indicating a coarse-grained memory for the irrelevant feature. Following the surprise test, all participants could precisely recall the arrow's direction; however, this improvement in direction memory came at a cost in precision for color memory even though only a single object was being remembered. We attribute these findings to varying levels of attention to different features during memory encoding.

Evaluation of the Relevance of a Web-Based "Ask an Expert" Feature: StratSoy and Soy and Human Health Queries.

ERIC Educational Resources Information Center

Wool, D. L.; Kanfer, A. G.; Michaels, J.; Thompson, S.; Morris, S. A.; Hasler, C. M.

2000-01-01

A study of the "Ask an Expert" feature of StratSoy, a Web-based information system, surveyed 50 users and 48 using it for the first time. Topic areas of interest and web site features desired by respondents were identified. (JOW)

Multiple Mechanisms in the Perception of Face Gender: Effect of Sex-Irrelevant Features

ERIC Educational Resources Information Center

Komori, Masashi; Kawamura, Satoru; Ishihara, Shigekazu

2011-01-01

Effects of sex-relevant and sex-irrelevant facial features on the evaluation of facial gender were investigated. Participants rated masculinity of 48 male facial photographs and femininity of 48 female facial photographs. Eighty feature points were measured on each of the facial photographs. Using a generalized Procrustes analysis, facial shapes…

The Features of Female Managers' Personality Traits in Organization

ERIC Educational Resources Information Center

Gabdreeva, Guzel Sh.; Khalfieva, Alisa R.

2016-01-01

The relevance of the "female" management features study is driven by the active penetration of women to management in various fields and the emergence of a new social category "Business-women". The article contains the results of a study aimed to identify the features of personal properties and structure of low-level,…

Unsupervised Feature Learning With Winner-Takes-All Based STDP

PubMed Central

Ferré, Paul; Mamalet, Franck; Thorpe, Simon J.

2018-01-01

We present a novel strategy for unsupervised feature learning in image applications inspired by the Spike-Timing-Dependent-Plasticity (STDP) biological learning rule. We show equivalence between rank order coding Leaky-Integrate-and-Fire neurons and ReLU artificial neurons when applied to non-temporal data. We apply this to images using rank-order coding, which allows us to perform a full network simulation with a single feed-forward pass using GPU hardware. Next we introduce a binary STDP learning rule compatible with training on batches of images. Two mechanisms to stabilize the training are also presented : a Winner-Takes-All (WTA) framework which selects the most relevant patches to learn from along the spatial dimensions, and a simple feature-wise normalization as homeostatic process. This learning process allows us to train multi-layer architectures of convolutional sparse features. We apply our method to extract features from the MNIST, ETH80, CIFAR-10, and STL-10 datasets and show that these features are relevant for classification. We finally compare these results with several other state of the art unsupervised learning methods. PMID:29674961

Task representation in individual and joint settings

PubMed Central

Prinz, Wolfgang

2015-01-01

This paper outlines a framework for task representation and discusses applications to interference tasks in individual and joint settings. The framework is derived from the Theory of Event Coding (TEC). This theory regards task sets as transient assemblies of event codes in which stimulus and response codes interact and shape each other in particular ways. On the one hand, stimulus and response codes compete with each other within their respective subsets (horizontal interactions). On the other hand, stimulus and response code cooperate with each other (vertical interactions). Code interactions instantiating competition and cooperation apply to two time scales: on-line performance (i.e., doing the task) and off-line implementation (i.e., setting the task). Interference arises when stimulus and response codes overlap in features that are irrelevant for stimulus identification, but relevant for response selection. To resolve this dilemma, the feature profiles of event codes may become restructured in various ways. The framework is applied to three kinds of interference paradigms. Special emphasis is given to joint settings where tasks are shared between two participants. Major conclusions derived from these applications include: (1) Response competition is the chief driver of interference. Likewise, different modes of response competition give rise to different patterns of interference; (2) The type of features in which stimulus and response codes overlap is also a crucial factor. Different types of such features give likewise rise to different patterns of interference; and (3) Task sets for joint settings conflate intraindividual conflicts between responses (what), with interindividual conflicts between responding agents (whom). Features of response codes may, therefore, not only address responses, but also responding agents (both physically and socially). PMID:26029085

Object properties and cognitive load in the formation of associative memory during precision lifting.

PubMed

Li, Yong; Randerath, Jennifer; Bauer, Hans; Marquardt, Christian; Goldenberg, Georg; Hermsdörfer, Joachim

2009-01-03

When we manipulate familiar objects in our daily life, our grip force anticipates the physical demands right from the moment of contact with the object, indicating the existence of a memory for relevant object properties. This study explores the formation and consolidation of the memory processes that associate either familiar (size) or arbitrary object features (color) with object weight. In the general task, participants repetitively lifted two differently weighted objects (580 and 280 g) in a pseudo-random order. Forty young healthy adults participated in this study and were randomly distributed into four groups: Color Cue Single task (CCS, blue and red, 9.8(3)cm(3)), Color Cue Dual task (CCD), No Cue (NC) and Size Cue (SC, 9.8(3) and 6(3)cm(3)) group. All groups performed a repetitive precision grasp-lift task and were retested with the same protocol after a 5-min pause. The CCD group was also required to simultaneously perform a memory task during each lift of differently weighted objects coded by color. The results show that groups lifting objects with arbitrary or familiar features successfully formed the association between object weight and manipulated object features and incorporated this into grip force programming, as observed in the different scaling of grip force and grip force rate for different object weights. An arbitrary feature, i.e., color, can be sufficiently associated with object weight, however with less strength than the familiar feature of size. The simultaneous memory task impaired anticipatory force scaling during repetitive object lifting but did not jeopardize the learning process and the consolidation of the associative memory.

Joint trajectories for social and physical aggression as predictors of adolescent maladjustment: internalizing symptoms, rule-breaking behaviors, and borderline and narcissistic personality features.

PubMed

Underwood, Marion K; Beron, Kurt J; Rosen, Lisa H

2011-05-01

This investigation examined the relation between developmental trajectories jointly estimated for social and physical aggression and adjustment problems at age 14. Teachers provided ratings of children's social and physical aggression in Grades 3, 4, 5, 6, and 7 for a sample of 255 children (131 girls, 21% African American, 52% European American, 21% Mexican American). Participants, parents, and teachers completed measures of the adolescent's adjustment to assess internalizing symptoms, rule-breaking behaviors, and borderline and narcissistic personality features. Results showed that membership in a high and rising trajectory group predicted rule-breaking behaviors and borderline personality features. Membership in a high desister group predicted internalizing symptoms, rule-breaking behaviors, and borderline and narcissistic personality features. The findings suggest that although low levels of social and physical aggression may not bode poorly for adjustment, individuals engaging in high levels of social and physical aggression in middle childhood may be at greatest risk for adolescent psychopathology, whether they increase or desist in their aggression through early adolescence.

Joint trajectories for social and physical aggression as predictors of adolescent maladjustment: Internalizing symptoms, rule-breaking behaviors, and borderline and narcissistic personality features

PubMed Central

UNDERWOOD, MARION K.; BERON, KURT J.; ROSEN, LISA H.

2011-01-01

This investigation examined the relation between developmental trajectories jointly estimated for social and physical aggression and adjustment problems at age 14. Teachers provided ratings of children's social and physical aggression in Grades 3, 4, 5, 6, and 7 for a sample of 255 children (131 girls, 21% African American, 52% European American, 21% Mexican American). Participants, parents, and teachers completed measures of the adolescent's adjustment to assess internalizing symptoms, rule-breaking behaviors, and borderline and narcissistic personality features. Results showed that membership in a high and rising trajectory group predicted rule-breaking behaviors and borderline personality features. Membership in a high desister group predicted internalizing symptoms, rule-breaking behaviors, and borderline and narcissistic personality features. The findings suggest that although low levels of social and physical aggression may not bode poorly for adjustment, individuals engaging in high levels of social and physical aggression in middle childhood may be at greatest risk for adolescent psychopathology, whether they increase or desist in their aggression through early adolescence. PMID:21532919

Classification of Automated Search Traffic

NASA Astrophysics Data System (ADS)

Buehrer, Greg; Stokes, Jack W.; Chellapilla, Kumar; Platt, John C.

As web search providers seek to improve both relevance and response times, they are challenged by the ever-increasing tax of automated search query traffic. Third party systems interact with search engines for a variety of reasons, such as monitoring a web site’s rank, augmenting online games, or possibly to maliciously alter click-through rates. In this paper, we investigate automated traffic (sometimes referred to as bot traffic) in the query stream of a large search engine provider. We define automated traffic as any search query not generated by a human in real time. We first provide examples of different categories of query logs generated by automated means. We then develop many different features that distinguish between queries generated by people searching for information, and those generated by automated processes. We categorize these features into two classes, either an interpretation of the physical model of human interactions, or as behavioral patterns of automated interactions. Using the these detection features, we next classify the query stream using multiple binary classifiers. In addition, a multiclass classifier is then developed to identify subclasses of both normal and automated traffic. An active learning algorithm is used to suggest which user sessions to label to improve the accuracy of the multiclass classifier, while also seeking to discover new classes of automated traffic. Performance analysis are then provided. Finally, the multiclass classifier is used to predict the subclass distribution for the search query stream.

The FAMULATUR PLUS as an innovative approach for teaching physical examination skills.

PubMed

Jerg, Achim; Öchsner, Wolfgang; Wander, Henriette; Traue, Harald C; Jerg-Bretzke, Lucia

2016-01-01

The FAMULATUR PLUS is an innovative approach to teaching physical examination skills. The concept is aimed at medical students during the clinical part of their studies and includes a clinical traineeship (English for "Famulatur") extended to include various courses ("PLUS"). The courses are divided into clinical examination courses and problembased-learning (PBL) seminars. The concept's special feature is the full integration of these courses into a 30-day hospital traineeship. The aim is to facilitate the transfer of knowledge from the courses into daily practice. Each week of the FAMULATUR PLUS is structured in line with the courses and focuses on a particular part of the body (e.g., abdomen). A physical examination course under the supervision of a physician is offered at the beginning of the week. Here, medical students learn the relevant examination techniques by practicing on each other (partner exercises). Subsequently, the techniques taught are applied independently during everyday work on the ward, corrected by the supervisor, if necessary, and thereby reinforced. The final POL seminar takes place towards the end of the week. Possible differential diagnoses are developed based on a clinical case study. The goal is to check these by taking a fictitious medical history and performing a physical examination, as well as to make a preliminary diagnosis. Finally, during the PBL seminar, medical students will be shown how physical examination techniques can be efficiently applied in the diagnosis of common cardinal symptoms (e.g., abdominal pain). The initial implementation of the FAMULATUR PLUS proved the practical feasibility of the concept. In addition, the accompanying evaluation showed that the participants of the pilot project improved with regard to their practical physical examination skills.

The FAMULATUR PLUS as an innovative approach for teaching physical examination skills

PubMed Central

Jerg, Achim; Öchsner, Wolfgang; Wander, Henriette; Traue, Harald C.; Jerg-Bretzke, Lucia

2016-01-01

The FAMULATUR PLUS is an innovative approach to teaching physical examination skills. The concept is aimed at medical students during the clinical part of their studies and includes a clinical traineeship (English for “Famulatur”) extended to include various courses (“PLUS”). The courses are divided into clinical examination courses and problembased-learning (PBL) seminars. The concept’s special feature is the full integration of these courses into a 30-day hospital traineeship. The aim is to facilitate the transfer of knowledge from the courses into daily practice. Each week of the FAMULATUR PLUS is structured in line with the courses and focuses on a particular part of the body (e.g., abdomen). A physical examination course under the supervision of a physician is offered at the beginning of the week. Here, medical students learn the relevant examination techniques by practicing on each other (partner exercises). Subsequently, the techniques taught are applied independently during everyday work on the ward, corrected by the supervisor, if necessary, and thereby reinforced. The final POL seminar takes place towards the end of the week. Possible differential diagnoses are developed based on a clinical case study. The goal is to check these by taking a fictitious medical history and performing a physical examination, as well as to make a preliminary diagnosis. Finally, during the PBL seminar, medical students will be shown how physical examination techniques can be efficiently applied in the diagnosis of common cardinal symptoms (e.g., abdominal pain). The initial implementation of the FAMULATUR PLUS proved the practical feasibility of the concept. In addition, the accompanying evaluation showed that the participants of the pilot project improved with regard to their practical physical examination skills. PMID:26958652

WE-E-218-01: Writing and Reviewing Papers in Medical Physics.

PubMed

Hendee, W; Slattery, P; Rogers, D; Karellas, A

2012-06-01

There is an art to writing a scientific paper so that it communicates accurately, succinctly, and comprehensively. Developing this art comes with experience, and sharing that experience with younger physicists is an obligation of senior scientists, especially those with editorial responsibilities for the journal. In this workshop, the preparation of a scientific manuscript will be dissected so participants can appreciate how each part is developed and then assembled into a complete paper. Then the review process for the paper will be discussed, including how to examine a paper and write an insightful and constructive review. Finally, we will consider the challenge of accommodating the concerns and recommendations of a reviewer in preparing a revision of the paper. A second feature of the workshop will be a discussion of the process of electronic submission of a paper for consideration by Medical Physics. The web-based PeerX-Press engine for manuscript submission and management will be examined, with attention to special features such as epaps and line-referencing. Finally, new features of Medical Physics will be explained, such as Vision 20/20 manuscripts, Physics Letters and the standardized formatting of book reviews. 1. Improve the participants' abilities to write a scientific manuscript. 2. Understand the review process for Medical Physics manuscripts and how to participate in and benefit from it. 3. Appreciate the many features of the PeerX-Press electronic management process for Medical Physics manuscripts. 4. Develop a knowledge of new features of Medical Physics. © 2012 American Association of Physicists in Medicine.

No-reference image quality assessment based on natural scene statistics and gradient magnitude similarity

NASA Astrophysics Data System (ADS)

Jia, Huizhen; Sun, Quansen; Ji, Zexuan; Wang, Tonghan; Chen, Qiang

2014-11-01

The goal of no-reference/blind image quality assessment (NR-IQA) is to devise a perceptual model that can accurately predict the quality of a distorted image as human opinions, in which feature extraction is an important issue. However, the features used in the state-of-the-art "general purpose" NR-IQA algorithms are usually natural scene statistics (NSS) based or are perceptually relevant; therefore, the performance of these models is limited. To further improve the performance of NR-IQA, we propose a general purpose NR-IQA algorithm which combines NSS-based features with perceptually relevant features. The new method extracts features in both the spatial and gradient domains. In the spatial domain, we extract the point-wise statistics for single pixel values which are characterized by a generalized Gaussian distribution model to form the underlying features. In the gradient domain, statistical features based on neighboring gradient magnitude similarity are extracted. Then a mapping is learned to predict quality scores using a support vector regression. The experimental results on the benchmark image databases demonstrate that the proposed algorithm correlates highly with human judgments of quality and leads to significant performance improvements over state-of-the-art methods.

Deep learning based classification of breast tumors with shear-wave elastography.

PubMed

Zhang, Qi; Xiao, Yang; Dai, Wei; Suo, Jingfeng; Wang, Congzhi; Shi, Jun; Zheng, Hairong

2016-12-01

This study aims to build a deep learning (DL) architecture for automated extraction of learned-from-data image features from the shear-wave elastography (SWE), and to evaluate the DL architecture in differentiation between benign and malignant breast tumors. We construct a two-layer DL architecture for SWE feature extraction, comprised of the point-wise gated Boltzmann machine (PGBM) and the restricted Boltzmann machine (RBM). The PGBM contains task-relevant and task-irrelevant hidden units, and the task-relevant units are connected to the RBM. Experimental evaluation was performed with five-fold cross validation on a set of 227 SWE images, 135 of benign tumors and 92 of malignant tumors, from 121 patients. The features learned with our DL architecture were compared with the statistical features quantifying image intensity and texture. Results showed that the DL features achieved better classification performance with an accuracy of 93.4%, a sensitivity of 88.6%, a specificity of 97.1%, and an area under the receiver operating characteristic curve of 0.947. The DL-based method integrates feature learning with feature selection on SWE. It may be potentially used in clinical computer-aided diagnosis of breast cancer. Copyright © 2016 Elsevier B.V. All rights reserved.

Semantic point cloud interpretation based on optimal neighborhoods, relevant features and efficient classifiers

NASA Astrophysics Data System (ADS)

Weinmann, Martin; Jutzi, Boris; Hinz, Stefan; Mallet, Clément

2015-07-01

3D scene analysis in terms of automatically assigning 3D points a respective semantic label has become a topic of great importance in photogrammetry, remote sensing, computer vision and robotics. In this paper, we address the issue of how to increase the distinctiveness of geometric features and select the most relevant ones among these for 3D scene analysis. We present a new, fully automated and versatile framework composed of four components: (i) neighborhood selection, (ii) feature extraction, (iii) feature selection and (iv) classification. For each component, we consider a variety of approaches which allow applicability in terms of simplicity, efficiency and reproducibility, so that end-users can easily apply the different components and do not require expert knowledge in the respective domains. In a detailed evaluation involving 7 neighborhood definitions, 21 geometric features, 7 approaches for feature selection, 10 classifiers and 2 benchmark datasets, we demonstrate that the selection of optimal neighborhoods for individual 3D points significantly improves the results of 3D scene analysis. Additionally, we show that the selection of adequate feature subsets may even further increase the quality of the derived results while significantly reducing both processing time and memory consumption.

Anxiety or agitation in mood disorder with mixed features: A review with a focus on validity as a dimensional criterion.

PubMed

Shim, In Hee; Bae, Dong Sik; Bahk, Won-Myong

2016-08-01

The diagnostic validity of mixed features, excluding anxiety or psychomotor agitation in mood disorders, has not yet been fully examined. PubMed and relevant English-language literature (regardless of year) were searched. Keywords were mixed or mixed state or mixed features or mixed episode and anxious or anxiety or agitation and bipolar disorder or depressive disorder or mood disorder or affective disorder. Most studies on anxiety or psychomotor agitation have included a significant correlation relevant to the "with mixed features" specifier, although it is common in both poles of mood episodes regardless of the predominant polarity. There is some confusion between the characteristic of classical mixed states and the definition of the mixed features specifier with the newly added anxious distress specifier in DSM-5, specifically, whether to include anxiety and agitation as significant characteristics. This change is of concern because a large proportion of patients with mixed features are now unspecified, and this may influence treatment planning and prognosis. The findings of our review suggest that anxiety and psychomotor agitation can be core symptoms in mood episodes with mixed features and important clinical clues for prediction of treatment effects and disease course.

Tractable Experiment Design via Mathematical Surrogates

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

Williams, Brian J.

This presentation summarizes the development and implementation of quantitative design criteria motivated by targeted inference objectives for identifying new, potentially expensive computational or physical experiments. The first application is concerned with estimating features of quantities of interest arising from complex computational models, such as quantiles or failure probabilities. A sequential strategy is proposed for iterative refinement of the importance distributions used to efficiently sample the uncertain inputs to the computational model. In the second application, effective use of mathematical surrogates is investigated to help alleviate the analytical and numerical intractability often associated with Bayesian experiment design. This approach allows formore » the incorporation of prior information into the design process without the need for gross simplification of the design criterion. Illustrative examples of both design problems will be presented as an argument for the relevance of these research problems.« less

Hooke's figurations: a figural drawing attributed to Robert Hooke.

PubMed

Hunter, Matthew C

2010-09-20

The experimental philosopher Robert Hooke (1635-1703) is known to have apprenticed to the leading painter Peter Lely on his first arrival in London in the late 1640s. Yet the relevance of Hooke's artistic training to his mature draughtsmanship and identity has remained unclear. Shedding light on that larger interpretive problem, this article argues for the attribution to Hooke of a figural drawing now in Tate Britain (T10678). This attributed drawing is especially interesting because it depicts human subjects and bears Hooke's name functioning as an artistic signature, both highly unusual features for his draughtsmanship. From evidence of how this drawing was collected and physically placed alongside images by leading artists in the early eighteenth century, I suggest how it can offer new insight into the reception of Hooke and his graphic work in the early Enlightenment.

A hierarchy for modeling high speed propulsion systems

NASA Technical Reports Server (NTRS)

Hartley, Tom T.; Deabreu, Alex

1991-01-01

General research efforts on reduced order propulsion models for control systems design are overviewed. Methods for modeling high speed propulsion systems are discussed including internal flow propulsion systems that do not contain rotating machinery such as inlets, ramjets, and scramjets. The discussion is separated into four sections: (1) computational fluid dynamics model for the entire nonlinear system or high order nonlinear models; (2) high order linearized model derived from fundamental physics; (3) low order linear models obtained from other high order models; and (4) low order nonlinear models. Included are special considerations on any relevant control system designs. The methods discussed are for the quasi-one dimensional Euler equations of gasdynamic flow. The essential nonlinear features represented are large amplitude nonlinear waves, moving normal shocks, hammershocks, subsonic combustion via heat addition, temperature dependent gases, detonation, and thermal choking.

Overview of somatization: diagnosis, epidemiology, and management.

PubMed

Escobar, J I

1996-01-01

This article outlines critical issues in the psychiatric assessment of patients presenting with medically unexplained physical symptoms that form the core of the somatoform disorders in current nosologies. The prevalence of these disorders in communities and clinical settings emphasizes that a majority of these patients are primary care service users rather than mental health clients. A brief review of previous studies on the pharmacological management of these syndromes with antidepressants highlights unique features of these disorders that are relevant to the design of double-blind studies. The promising results emerging from some of these studies bring new excitement to the field that may help counter the prevailing therapeutic nihilism, thus attracting new investigators to this area. Finally, several caveats are provided on issues of research design and interpretation for the benefit of those entering this field of research.

Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory

DOE PAGES

Aab, A.; Abreu, P.; Aglietta, M.; ...

2017-04-20

In this paper, we present a combined fit of a simple astrophysical model of UHECR sources to both the energy spectrum and mass composition data measured by the Pierre Auger Observatory. The fit has been performed for energies above 5 • 10 18 eV, i.e. the region of the all-particle spectrum above the so-called 'ankle' feature. The astrophysical model we adopted consists of identical sources uniformly distributed in a comoving volume, where nuclei are accelerated through a rigidity-dependent mechanism. The fit results suggest sources characterized by relatively low maximum injection energies, hard spectra and heavy chemical composition. We also show thatmore » uncertainties about physical quantities relevant to UHECR propagation and shower development have a non-negligible impact on the fit results.« less

Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory

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

Aab, A.; Abreu, P.; Aglietta, M.

In this paper, we present a combined fit of a simple astrophysical model of UHECR sources to both the energy spectrum and mass composition data measured by the Pierre Auger Observatory. The fit has been performed for energies above 5 • 10 18 eV, i.e. the region of the all-particle spectrum above the so-called 'ankle' feature. The astrophysical model we adopted consists of identical sources uniformly distributed in a comoving volume, where nuclei are accelerated through a rigidity-dependent mechanism. The fit results suggest sources characterized by relatively low maximum injection energies, hard spectra and heavy chemical composition. We also show thatmore » uncertainties about physical quantities relevant to UHECR propagation and shower development have a non-negligible impact on the fit results.« less

Cosmic sculpture: a new way to visualise the cosmic microwave background

NASA Astrophysics Data System (ADS)

Clements, D. L.; Sato, S.; Portela Fonseca, A.

2017-01-01

3D printing presents an attractive alternative to visual representation of physical datasets such as astronomical images that can be used for research, outreach or teaching purposes, and is especially relevant to people with a visual disability. We here report the use of 3D printing technology to produce a representation of the all-sky cosmic microwave background (CMB) intensity anisotropy maps produced by the Planck mission. The success of this work in representing key features of the CMB is discussed as is the potential of this approach for representing other astrophysical data sets. 3D printing such datasets represents a highly complementary approach to the usual 2D projections used in teaching and outreach work, and can also form the basis of undergraduate projects. The CAD files used to produce the models discussed in this paper are made available.

Identification of Chinese medicine syndromes in persistent insomnia associated with major depressive disorder: a latent tree analysis.

PubMed

Yeung, Wing-Fai; Chung, Ka-Fai; Zhang, Nevin Lian-Wen; Zhang, Shi Ping; Yung, Kam-Ping; Chen, Pei-Xian; Ho, Yan-Yee

2016-01-01

Chinese medicine (CM) syndrome (zheng) differentiation is based on the co-occurrence of CM manifestation profiles, such as signs and symptoms, and pulse and tongue features. Insomnia is a symptom that frequently occurs in major depressive disorder despite adequate antidepressant treatment. This study aims to identify co-occurrence patterns in participants with persistent insomnia and major depressive disorder from clinical feature data using latent tree analysis, and to compare the latent variables with relevant CM syndromes. One hundred and forty-two participants with persistent insomnia and a history of major depressive disorder completed a standardized checklist (the Chinese Medicine Insomnia Symptom Checklist) specially developed for CM syndrome classification of insomnia. The checklist covers symptoms and signs, including tongue and pulse features. The clinical features assessed by the checklist were analyzed using Lantern software. CM practitioners with relevant experience compared the clinical feature variables under each latent variable with reference to relevant CM syndromes, based on a previous review of CM syndromes. The symptom data were analyzed to build the latent tree model and the model with the highest Bayes information criterion score was regarded as the best model. This model contained 18 latent variables, each of which divided participants into two clusters. Six clusters represented more than 50 % of the sample. The clinical feature co-occurrence patterns of these six clusters were interpreted as the CM syndromes Liver qi stagnation transforming into fire, Liver fire flaming upward, Stomach disharmony, Hyperactivity of fire due to yin deficiency, Heart-kidney noninteraction, and Qi deficiency of the heart and gallbladder. The clinical feature variables that contributed significant cumulative information coverage (at least 95 %) were identified. Latent tree model analysis on a sample of depressed participants with insomnia revealed 13 clinical feature co-occurrence patterns, four mutual-exclusion patterns, and one pattern with a single clinical feature variable.

The Relationships between Ball Throwing Velocity and Physical-Psychomotor Features for Talent Identification in Physical Education

ERIC Educational Resources Information Center

Karadenizli, Zeynep Inci

2016-01-01

The aim of this study is to investigate the relationships between ball throwing velocity (BTV), and physical features and anaerobic power (AP) for talent identification in team handball players. Players (n: 54) at 21,91 ± 4,94 age, training experience 11,19 ± 4,46 years participated voluntarily to study. These players consist of 54 Turkish…

The relationship between visual working memory and attention: retention of precise colour information in the absence of effects on perceptual selection.

PubMed

Hollingworth, Andrew; Hwang, Seongmin

2013-10-19

We examined the conditions under which a feature value in visual working memory (VWM) recruits visual attention to matching stimuli. Previous work has suggested that VWM supports two qualitatively different states of representation: an active state that interacts with perceptual selection and a passive (or accessory) state that does not. An alternative hypothesis is that VWM supports a single form of representation, with the precision of feature memory controlling whether or not the representation interacts with perceptual selection. The results of three experiments supported the dual-state hypothesis. We established conditions under which participants retained a relatively precise representation of a parcticular colour. If the colour was immediately task relevant, it reliably recruited attention to matching stimuli. However, if the colour was not immediately task relevant, it failed to interact with perceptual selection. Feature maintenance in VWM is not necessarily equivalent with feature-based attentional selection.

Learning feature representations with a cost-relevant sparse autoencoder.

PubMed

Längkvist, Martin; Loutfi, Amy

2015-02-01

There is an increasing interest in the machine learning community to automatically learn feature representations directly from the (unlabeled) data instead of using hand-designed features. The autoencoder is one method that can be used for this purpose. However, for data sets with a high degree of noise, a large amount of the representational capacity in the autoencoder is used to minimize the reconstruction error for these noisy inputs. This paper proposes a method that improves the feature learning process by focusing on the task relevant information in the data. This selective attention is achieved by weighting the reconstruction error and reducing the influence of noisy inputs during the learning process. The proposed model is trained on a number of publicly available image data sets and the test error rate is compared to a standard sparse autoencoder and other methods, such as the denoising autoencoder and contractive autoencoder.

Weighted Distance Functions Improve Analysis of High-Dimensional Data: Application to Molecular Dynamics Simulations.

PubMed

Blöchliger, Nicolas; Caflisch, Amedeo; Vitalis, Andreas

2015-11-10

Data mining techniques depend strongly on how the data are represented and how distance between samples is measured. High-dimensional data often contain a large number of irrelevant dimensions (features) for a given query. These features act as noise and obfuscate relevant information. Unsupervised approaches to mine such data require distance measures that can account for feature relevance. Molecular dynamics simulations produce high-dimensional data sets describing molecules observed in time. Here, we propose to globally or locally weight simulation features based on effective rates. This emphasizes, in a data-driven manner, slow degrees of freedom that often report on the metastable states sampled by the molecular system. We couple this idea to several unsupervised learning protocols. Our approach unmasks slow side chain dynamics within the native state of a miniprotein and reveals additional metastable conformations of a protein. The approach can be combined with most algorithms for clustering or dimensionality reduction.

Physical human-robot interaction of an active pelvis orthosis: toward ergonomic assessment of wearable robots.

PubMed

d'Elia, Nicolò; Vanetti, Federica; Cempini, Marco; Pasquini, Guido; Parri, Andrea; Rabuffetti, Marco; Ferrarin, Maurizio; Molino Lova, Raffaele; Vitiello, Nicola

2017-04-14

In human-centered robotics, exoskeletons are becoming relevant for addressing needs in the healthcare and industrial domains. Owing to their close interaction with the user, the safety and ergonomics of these systems are critical design features that require systematic evaluation methodologies. Proper transfer of mechanical power requires optimal tuning of the kinematic coupling between the robotic and anatomical joint rotation axes. We present the methods and results of an experimental evaluation of the physical interaction with an active pelvis orthosis (APO). This device was designed to effectively assist in hip flexion-extension during locomotion with a minimum impact on the physiological human kinematics, owing to a set of passive degrees of freedom for self-alignment of the human and robotic hip flexion-extension axes. Five healthy volunteers walked on a treadmill at different speeds without and with the APO under different levels of assistance. The user-APO physical interaction was evaluated in terms of: (i) the deviation of human lower-limb joint kinematics when wearing the APO with respect to the physiological behavior (i.e., without the APO); (ii) relative displacements between the APO orthotic shells and the corresponding body segments; and (iii) the discrepancy between the kinematics of the APO and the wearer's hip joints. The results show: (i) negligible interference of the APO in human kinematics under all the experimented conditions; (ii) small (i.e., < 1 cm) relative displacements between the APO cuffs and the corresponding body segments (called stability); and (iii) significant increment in the human-robot kinematics discrepancy at the hip flexion-extension joint associated with speed and assistance level increase. APO mechanics and actuation have negligible interference in human locomotion. Human kinematics was not affected by the APO under all tested conditions. In addition, under all tested conditions, there was no relevant relative displacement between the orthotic cuffs and the corresponding anatomical segments. Hence, the physical human-robot coupling is reliable. These facts prove that the adopted mechanical design of passive degrees of freedom allows an effective human-robot kinematic coupling. We believe that this analysis may be useful for the definition of evaluation metrics for the ergonomics assessment of wearable robots.

Memory Scanning, Introversion-Extraversion, and Levels of Processing.

ERIC Educational Resources Information Center

Eysenck, Michael W.; Eysenck, M. Christine

1979-01-01

Investigated was the hypothesis that high arousal increases processing of physical characteristics and reduces processing of semantic characteristics. While introverts and extroverts had equivalent scanning rates for physical features, introverts were significantly slower in searching for semantic features of category membership, indicating…

Creative Learning Identities

ERIC Educational Resources Information Center

Jeffrey, Bob

2008-01-01

Making learning relevant involves many aspects of teaching such as attention to levels of maturity, individual inclinations, emotional, physical, aesthetic and cognitive activity and group dynamics. However, making learning relevant is not only a teacher led activity, for learners make activities relevant by the identification of connections with…

Uncommon and/or bizarre features of dementia: Part III.

PubMed

Cipriani, Gabriele; Nuti, Angelo; Danti, Sabrina; Picchi, Lucia; Di Fiorino, Mario

2018-06-01

Clinical neurologists have long recognized that dementia can present as atypical or variant syndromes/symptoms. This study aimed at describing uncommon or bizarre symptoms/syndromes observed in patients suffering from dementia. Medline and Google scholar searches were conducted for relevant articles, chapters, and books published before 2018. Search terms used included compulsion, dementia, extracampine hallucination, disordered gambling, humour, and obsession. Publications found through this indexed search were reviewed for further relevant references. The uncommon/bizarre feature of dementia was described as case reports and there were no systematic investigations.

Policy-Making Theory as an Analytical Framework in Policy Analysis: Implications for Research Design and Professional Advocacy.

PubMed

Sheldon, Michael R

2016-01-01

Policy studies are a recent addition to the American Physical Therapy Association's Research Agenda and are critical to our understanding of various federal, state, local, and organizational policies on the provision of physical therapist services across the continuum of care. Policy analyses that help to advance the profession's various policy agendas will require relevant theoretical frameworks to be credible. The purpose of this perspective article is to: (1) demonstrate the use of a policy-making theory as an analytical framework in a policy analysis and (2) discuss how sound policy analysis can assist physical therapists in becoming more effective change agents, policy advocates, and partners with other relevant stakeholder groups. An exploratory study of state agency policy responses to address work-related musculoskeletal disorders is provided as a contemporary example to illustrate key points and to demonstrate the importance of selecting a relevant analytical framework based on the context of the policy issue under investigation. © 2016 American Physical Therapy Association.

Quantum Interactive Dualism: An Alternative to Materialism

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

Stapp, Henry P

2005-06-01

Materialism rest implicitly upon the general conception of nature promoted by Galileo and Newton during the seventeenth century. It features the causal closure of the physical: The course of physically described events for all time is fixed by laws that refer exclusively to the physically describeable features of nature, and initial conditions on these feature. No reference to subjective thoughts or feeling of human beings enter. That simple conception of nature was found during the first quarter of the twentieth century to be apparently incompatible with the empirical facts. The founders of quantum theory created a new fundamental physical theory,more » quantum theory, which introduced crucially into the causal structure certain conscious choices made by human agents about how they will act. These conscious human choices are ''free'' in the sense that they are not fixed by the known laws. But they can influence the course of physically described events. Thus the principle of the causal closure of the physical fails. Applications in psycho-neuro-dynamics are described.« less

Multitasking: Effects of processing multiple auditory feature patterns

PubMed Central

Miller, Tova; Chen, Sufen; Lee, Wei Wei; Sussman, Elyse S.

2016-01-01

ERPs and behavioral responses were measured to assess how task-irrelevant sounds interact with task processing demands and affect the ability to monitor and track multiple sound events. Participants listened to four-tone sequential frequency patterns, and responded to frequency pattern deviants (reversals of the pattern). Irrelevant tone feature patterns (duration and intensity) and respective pattern deviants were presented together with frequency patterns and frequency pattern deviants in separate conditions. Responses to task-relevant and task-irrelevant feature pattern deviants were used to test processing demands for irrelevant sound input. Behavioral performance was significantly better when there were no distracting feature patterns. Errors primarily occurred in response to the to-be-ignored feature pattern deviants. Task-irrelevant elicitation of ERP components was consistent with the error analysis, indicating a level of processing for the irrelevant features. Task-relevant elicitation of ERP components was consistent with behavioral performance, demonstrating a “cost” of performance when there were two feature patterns presented simultaneously. These results provide evidence that the brain tracked the irrelevant duration and intensity feature patterns, affecting behavioral performance. Overall, our results demonstrate that irrelevant informational streams are processed at a cost, which may be considered a type of multitasking that is an ongoing, automatic processing of taskirrelevant sensory events. PMID:25939456

Relation between childhood maltreatment and severe intrafamilial male-perpetrated physical violence in Chinese community: the mediating role of borderline and antisocial personality disorder features.

PubMed

Liu, Na; Zhang, Yalin; Brady, Heward John; Cao, Yuping; He, Ying; Zhang, Yingli

2012-01-01

This study investigates the role of borderline personality disorder (BPD) and antisocial personality disorder (ASPD) features as mediators of the effects of childhood maltreatment on severe intrafamilial physical violence amongst Chinese male perpetrators. A cross-sectional survey and face-to-face interview were conducted to examine childhood maltreatment, personality disorder features, impulsivity, aggression, and severe intrafamilial physical violence in a community sample of 206 abusive men in China. The results suggest that ASPD or BPD features mediate between childhood maltreatment and intimate partner violence perpetration in Chinese abusive men. These findings may yield clinical and forensic implications for assessing the psychopathology of abusive men, and may steer the intervention of intimate partner violence. © 2011 Wiley Periodicals, Inc.

Longitudinal MRI assessment: the identification of relevant features in the development of Posterior Fossa Syndrome in children

NASA Astrophysics Data System (ADS)

Spiteri, M.; Lewis, E.; Windridge, D.; Avula, S.

2015-03-01

Up to 25% of children who undergo brain tumour resection surgery in the posterior fossa develop posterior fossa syndrome (PFS). This syndrome is characterised by mutism and disturbance in speech. Our hypothesis is that there is a correlation between PFS and the occurrence of hypertrophic olivary degeneration (HOD) in lobes within the posterior fossa, known as the inferior olivary nuclei (ION). HOD is exhibited as an increase in size and intensity of the ION on an MR image. Intra-operative MRI (IoMRI) is used during surgical procedures at the Alder Hey Children's Hospital, Liver- pool, England, in the treatment of Posterior Fossa tumours and allows visualisation of the brain during surgery. The final MR scan on the IoMRI allows early assessment of the ION immediately after the surgical procedure. The longitudinal MRI data of 28 patients was analysed in a collaborative study with Alder Hey Children's Hospital, in order to identify the most relevant imaging features that relate to the development of PFS, specifically related to HOD. A semi-automated segmentation process was carried out to delineate the ION on each MRI. Feature selection techniques were used to identify the most relevant features amongst the MRI data, demographics and clinical data provided by the hospital. A support vector machine (SVM) was used to analyse the discriminative ability of the selected features. The results indicate the presence of HOD as the most efficient feature that correlates with the development of PFS, followed by the change in intensity and size of the ION and whether HOD occurred bilaterally or unilaterally.

Celluloid angels: a research study of nurses in feature films 1900-2007.

PubMed

Stanley, David J

2008-10-01

This paper is a report of a study examining the influence on how nursing and nurses are portrayed in feature films made between 1900 and 2007, with a nurse as their main or a principle character and a story-line related specifically to nursing. Nurses and the nursing profession are frequently portrayed negatively or stereotypically in the media, with nurses often being portrayed as feminine and caring but not as leaders or professionals capable of autonomous practice. A mixed method approach was used to examine feature films made in the Western world. Over 36,000 feature film synopses were reviewed (via CINAHL, ProQuest and relevant movie-specific literature) for the keywords 'nurse'/'nursing'. Identified films were analysed quantitatively to determine their country of production, genre, plot(s) and other relevant data, and qualitatively to identify the emergence of themes related to the image of nurses/nursing in films. For the period from 1900 to 2007, 280 relevant feature films were identified. Most films were made in the United States of America or United Kingdom, although in recent years films have been increasingly produced in other countries. Early films portrayed nurses as self-sacrificial heroines, sex objects and romantics. More recent films increasingly portray them as strong and self-confident, professionals. Nurse-related films offer a unique insight into the image of nurses and how they have been portrayed. Nurses need to be aware of the impact the film industry has on how nurses and nursing are perceived and represented in feature films.

Objective assessment of MPEG-2 video quality

NASA Astrophysics Data System (ADS)

Gastaldo, Paolo; Zunino, Rodolfo; Rovetta, Stefano

2002-07-01

The increasing use of video compression standards in broadcasting television systems has required, in recent years, the development of video quality measurements that take into account artifacts specifically caused by digital compression techniques. In this paper we present a methodology for the objective quality assessment of MPEG video streams by using circular back-propagation feedforward neural networks. Mapping neural networks can render nonlinear relationships between objective features and subjective judgments, thus avoiding any simplifying assumption on the complexity of the model. The neural network processes an instantaneous set of input values, and yields an associated estimate of perceived quality. Therefore, the neural-network approach turns objective quality assessment into adaptive modeling of subjective perception. The objective features used for the estimate are chosen according to the assessed relevance to perceived quality and are continuously extracted in real time from compressed video streams. The overall system mimics perception but does not require any analytical model of the underlying physical phenomenon. The capability to process compressed video streams represents an important advantage over existing approaches, like avoiding the stream-decoding process greatly enhances real-time performance. Experimental results confirm that the system provides satisfactory, continuous-time approximations for actual scoring curves concerning real test videos.

Flow regimes in a trapped vortex cell

NASA Astrophysics Data System (ADS)

Lasagna, D.; Iuso, G.

2016-03-01

This paper presents results of an experimental investigation on the flow in a trapped vortex cell, embedded into a flat plate, and interacting with a zero-pressure-gradient boundary layer. The objective of the work is to describe the flow features and elucidate some of the governing physical mechanisms, in the light of recent investigations on flow separation control using vortex cells. Hot-wire velocity measurements of the shear layer bounding the cell and of the boundary layers upstream and downstream are reported, together with spectral and correlation analyses of wall-pressure fluctuation measurements. Smoke flow visualisations provide qualitative insight into some relevant features of the internal flow, namely a large-scale flow unsteadiness and possible mechanisms driving the rotation of the vortex core. Results are presented for two very different regimes: a low-Reynolds-number case where the incoming boundary layer is laminar and its momentum thickness is small compared to the cell opening, and a moderately high-Reynolds-number case, where the incoming boundary layer is turbulent and the ratio between the momentum thickness and the opening length is significantly larger than in the first case. Implications of the present findings to flow control applications of trapped vortex cells are also discussed.

Social firms: sustainable employment for people with mental illness.

PubMed

Williams, Anne; Fossey, Ellie; Harvey, Carol

2012-01-01

Social firms or enterprises aim to offer sustainable employment in supportive workplaces for people who are disadvantaged in the labour market. Therefore, this study sought to explore employees' views in one social firm about the features of their workplace that they found supportive. Seven employees were recruited, all of whom experienced persistent mental illness, and had worked in this social firm for between eleven months and six years. A semi-structured interview, the Work Environment Impact Scale (version 2.0), was used to explore participants' views of their workplace and to rate how its physical and social characteristics impacted them. Participants also rated their job satisfaction with a modified Indiana Job Satisfaction Scale. Features of the social firm workplace identified by these employees as contributing to their sustained employment and satisfaction were the rewards, task demands, work schedule, and workplace interactions with supervisors and other co-workers. From their views, guiding principles for the development of supportive workplaces and evaluation of their capacity to afford sustainable employment were derived. This study adds to current knowledge about workplace supports from an employee perspective, and is of relevance for informing future social firm development, workplace design and evaluation.

PREDICTING CORONAL MASS EJECTIONS USING MACHINE LEARNING METHODS

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

Bobra, M. G.; Ilonidis, S.

Of all the activity observed on the Sun, two of the most energetic events are flares and coronal mass ejections (CMEs). Usually, solar active regions that produce large flares will also produce a CME, but this is not always true. Despite advances in numerical modeling, it is still unclear which circumstances will produce a CME. Therefore, it is worthwhile to empirically determine which features distinguish flares associated with CMEs from flares that are not. At this time, no extensive study has used physically meaningful features of active regions to distinguish between these two populations. As such, we attempt to domore » so by using features derived from (1) photospheric vector magnetic field data taken by the Solar Dynamics Observatory ’s Helioseismic and Magnetic Imager instrument and (2) X-ray flux data from the Geostationary Operational Environmental Satellite’s X-ray Flux instrument. We build a catalog of active regions that either produced both a flare and a CME (the positive class) or simply a flare (the negative class). We then use machine-learning algorithms to (1) determine which features distinguish these two populations, and (2) forecast whether an active region that produces an M- or X-class flare will also produce a CME. We compute the True Skill Statistic, a forecast verification metric, and find that it is a relatively high value of ∼0.8 ± 0.2. We conclude that a combination of six parameters, which are all intensive in nature, will capture most of the relevant information contained in the photospheric magnetic field.« less

Clinical and histologic features of acute-onset erythroderma in dogs with gastrointestinal disease: 18 cases (2005-2015).

PubMed

Cain, Christine L; Bradley, Charles W; Mauldin, Elizabeth A

2017-12-15

OBJECTIVE To describe the clinical and histologic features of acute erythroderma in dogs with gastrointestinal disease. DESIGN Retrospective case series. ANIMALS 18 dogs with erythroderma and gastrointestinal disease. PROCEDURES Medical records and biopsy specimens were reviewed. Information collected from medical records included signalment, clinical signs, physical examination and diagnostic test results, treatment, and outcome. The Naranjo algorithm was used to estimate the probability of an adverse drug reaction for each dog. RESULTS All dogs had an acute onset of erythematous macules or generalized erythroderma. Histologic features of skin biopsy specimens had 3 patterns representing a progressive spectrum of inflammation. Most dogs had vomiting (n = 17) and hematochezia (10). Signs of gastrointestinal disease became evident before, after, or concurrent with the onset of skin lesions in 10, 3, and 5 dogs, respectively. Inflammatory bowel disease, pancreatitis, and adverse food reaction were diagnosed in 5, 3, and 3 dogs, respectively. The cause of the gastrointestinal signs was not identified for 8 dogs. Eight dogs had a Naranjo score consistent with a possible adverse drug reaction. Treatment of skin lesions included drug withdrawal (n = 15), antihistamines (16), and corticosteroids (14). Signs of gastrointestinal disease and skin lesions resolved at a mean of 4.6 days and 20.8 days, respectively, after onset. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated acute erythroderma may be associated with > 1 gastrointestinal disease or an adverse drug reaction in some dogs. Recognition of the clinical and histologic features of this syndrome is essential for accurate diagnosis.

Characteristics of Chinese m-Health Applications for Diabetes Self-Management.

PubMed

Nie, Lisa; Xie, Bo; Yang, Yan; Shan, Yan Min

2016-07-01

To examine the features and types of health information provided in Chinese diabetes mobile applications (apps) for patients' self-management. Through multiple rounds of screening, we identified a total of 95 relevant iOS (Apple, Cupertino, CA) and Android™ (Google, Mountain View, CA) apps and examined each app's features and health information types based on each app's description in the app stores. We used a 15-feature algorithm to evaluate the apps' abilities for supporting diabetic patients' self-management, based on U.S. national standards for diabetes self-management. We also adapted the health information wants framework to analyze the types of information that the apps provided for diabetic patients. Diabetes education was the most common feature, provided by 75% of the apps. Blood glucose checking was enabled by 65% of the apps. Diet management, insulin checking, and physical activity monitoring were enabled by 53%, 49%, and 44% of the apps, respectively. Only a small percentage of the apps enabled psychosocial support (29%) or tracking of blood pressure (14%), cholesterol (14%), or body mass index (11%). None of the apps provided all seven types of information posited by the health information wants framework. Only a small percentage of the apps provided information about psychosocial support (29%), healthcare providers (24%), or healthcare facilities (24%). Information about complementary and alternative medicine was the least likely type of information provided in the apps, with only 7% of the apps providing this type of information. Our findings have important implications for improving the quality of Chinese diabetes mobile apps to facilitate patients' self-management.

Response of algal metrics to nutrients and physical factors and identification of nutrient thresholds in agricultural streams

USGS Publications Warehouse

Black, R.W.; Moran, P.W.; Frankforter, J.D.

2011-01-01

Many streams within the United States are impaired due to nutrient enrichment, particularly in agricultural settings. The present study examines the response of benthic algal communities in agricultural and minimally disturbed sites from across the western United States to a suite of environmental factors, including nutrients, collected at multiple scales. The first objective was to identify the relative importance of nutrients, habitat and watershed features, and macroinvertebrate trophic structure to explain algal metrics derived from deposition and erosion habitats. The second objective was to determine if thresholds in total nitrogen (TN) and total phosphorus (TP) related to algal metrics could be identified and how these thresholds varied across metrics and habitats. Nutrient concentrations within the agricultural areas were elevated and greater than published threshold values. All algal metrics examined responded to nutrients as hypothesized. Although nutrients typically were the most important variables in explaining the variation in each of the algal metrics, environmental factors operating at multiple scales also were important. Calculated thresholds for TN or TP based on the algal metrics generated from samples collected from erosion and deposition habitats were not significantly different. Little variability in threshold values for each metric for TN and TP was observed. The consistency of the threshold values measured across multiple metrics and habitats suggest that the thresholds identified in this study are ecologically relevant. Additional work to characterize the relationship between algal metrics, physical and chemical features, and nuisance algal growth would be of benefit to the development of nutrient thresholds and criteria. ?? 2010 The Author(s).

Response of algal metrics to nutrients and physical factors and identification of nutrient thresholds in agricultural streams.

PubMed

Black, Robert W; Moran, Patrick W; Frankforter, Jill D

2011-04-01

Many streams within the United States are impaired due to nutrient enrichment, particularly in agricultural settings. The present study examines the response of benthic algal communities in agricultural and minimally disturbed sites from across the western United States to a suite of environmental factors, including nutrients, collected at multiple scales. The first objective was to identify the relative importance of nutrients, habitat and watershed features, and macroinvertebrate trophic structure to explain algal metrics derived from deposition and erosion habitats. The second objective was to determine if thresholds in total nitrogen (TN) and total phosphorus (TP) related to algal metrics could be identified and how these thresholds varied across metrics and habitats. Nutrient concentrations within the agricultural areas were elevated and greater than published threshold values. All algal metrics examined responded to nutrients as hypothesized. Although nutrients typically were the most important variables in explaining the variation in each of the algal metrics, environmental factors operating at multiple scales also were important. Calculated thresholds for TN or TP based on the algal metrics generated from samples collected from erosion and deposition habitats were not significantly different. Little variability in threshold values for each metric for TN and TP was observed. The consistency of the threshold values measured across multiple metrics and habitats suggest that the thresholds identified in this study are ecologically relevant. Additional work to characterize the relationship between algal metrics, physical and chemical features, and nuisance algal growth would be of benefit to the development of nutrient thresholds and criteria.

A Static Color Discontinuity Can Capture Spatial Attention when the Target Is an Abrupt-Onset Singleton

ERIC Educational Resources Information Center

Burnham, Bryan R.; Neely, James H.

2008-01-01

C. L. Folk, R. W. Remington, and J. C. Johnston's (1992) contingent involuntary orienting hypothesis states that a salient visual feature will involuntarily capture attention only when the observer's attentional set includes similar features. In four experiments, when the target's relevant feature was its being an abruptly onset singleton,…

Organizational-Pedagogical Conditions to Form the Foreign Competence in Students with the Features of Linguistic Giftedness

ERIC Educational Resources Information Center

Panfilova, Valentina Michailovna; Panfilov, Alexey Nikolaevich; Merzon, Elena Efimovna

2015-01-01

The study of foreign competence at the present stage of the higher education development becomes more relevant. The article emphasizes the organizational-pedagogical conditions, providing the formation of foreign competence in students with the features of linguistic giftedness. The way to reveal the students, who have the features of linguistic…

Recall of Television Content as a Function of Content Type and Level of Production Feature Use.

ERIC Educational Resources Information Center

Calvert, Sandra; Watkins, Bruce

This study investigated developmental changes in children's recall of televised central and incidental content. Central content was plot-relevant; incidental content was peripheral to the plot. Both content types were classified at two levels of production features, high salience and low salience. High salience features were high action, loud…

Report of the COSPAR mars special regions colloquium

USGS Publications Warehouse

Kminek, G.; Rummel, J.D.; Cockell, C.S.; Atlas, R.; Barlow, N.; Beaty, D.; Boynton, W.; Carr, M.; Clifford, S.; Conley, C.A.; Davila, A.F.; Debus, A.; Doran, P.; Hecht, M.; Heldmann, J.; Helbert, J.; Hipkin, V.; Horneck, G.; Kieft, Thomas L.; Klingelhoefer, G.; Meyer, M.; Newsom, H.; Ori, G.G.; Parnell, J.; Prieur, D.; Raulin, F.; Schulze-Makuch, D.; Spry, J.A.; Stabekis, P.E.; Stackebrandt, E.; Vago, J.; Viso, M.; Voytek, M.; Wells, L.; Westall, F.

2010-01-01

In this paper we present the findings of a COSPAR Mars Special Regions Colloquium held in Rome in 2007. We review and discuss the definition of Mars Special Regions, the physical parameters used to define Mars Special Regions, and physical features on Mars that can be interpreted as Mars Special Regions. We conclude that any region experiencing temperatures > -25 ??C for a few hours a year and a water activity > 0.5 can potentially allow the replication of terrestrial microorganisms. Physical features on Mars that can be interpreted as meeting these conditions constitute a Mars Special Region. Based on current knowledge of the martian environment and the conservative nature of planetary protection, the following features constitute Mars Special regions: Gullies and bright streaks associated with them, pasted-on terrain, deep subsurface, dark streaks only on a case-by-case basis, others to be determined. The parameter definition and the associated list of physical features should be re-evaluated on a regular basis. ?? 2010 COSPAR. Published by Elsevier Ltd. All rights reserved.

PREFACE: Special section featuring selected papers from the 3rd International Workshop on Numerical Modelling of High Temperature Superconductors Special section featuring selected papers from the 3rd International Workshop on Numerical Modelling of High Temperature Superconductors

NASA Astrophysics Data System (ADS)

Granados, Xavier; Sánchez, Àlvar; López-López, Josep

2012-10-01

The development of superconducting applications and superconducting engineering requires the support of consistent tools which can provide models for obtaining a good understanding of the behaviour of the systems and predict novel features. These models aim to compute the behaviour of the superconducting systems, design superconducting devices and systems, and understand and test the behavior of the superconducting parts. 50 years ago, in 1962, Charles Bean provided the superconducting community with a model efficient enough to allow the computation of the response of a superconductor to external magnetic fields and currents flowing through in an understandable way: the so called critical-state model. Since then, in addition to the pioneering critical-state approach, other tools have been devised for designing operative superconducting systems, allowing integration of the superconducting design in nearly standard electromagnetic computer-aided design systems by modelling the superconducting parts with consideration of time-dependent processes. In April 2012, Barcelona hosted the 3rd International Workshop on Numerical Modelling of High Temperature Superconductors (HTS), the third in a series of workshops started in Lausanne in 2010 and followed by Cambridge in 2011. The workshop reflected the state-of-the-art and the new initiatives of HTS modelling, considering mathematical, physical and technological aspects within a wide and interdisciplinary scope. Superconductor Science and Technology is now publishing a selection of papers from the workshop which have been selected for their high quality. The selection comprises seven papers covering mathematical, physical and technological topics which contribute to an improvement in the development of procedures, understanding of phenomena and development of applications. We hope that they provide a perspective on the relevance and growth that the modelling of HTS superconductors has achieved in the past 25 years.

Design and physical features of inductive coaxial copper vapor lasers

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

Batenin, V. M.; Kazaryan, M. A.; Karpukhin, V. T.

A physical model of a copper vapor laser pumped by a pulse-periodic inductive (electrodeless) discharge is considered. The feasibility of efficient laser pumping by an inductive discharge and reaching high output parameters comparable to those of conventional copper vapor lasers pumped by a longitudinal electrode discharge is demonstrated. The design and physical features of an inductive copper vapor laser with an annular working volume are discussed.

Lexical Studies of Filipino Person Descriptors: Adding Personality-Relevant Social and Physical Attributes

PubMed Central

Imperio, Shellah Myra; Church, A. Timothy; Katigbak, Marcia S.; Reyes, Jose Alberto S.

2009-01-01

Lexical studies have focused on traits. In the Filipino language, we investigated whether additional dimensions can be identified when personality-relevant terms for social roles, statuses, and effects, plus physical attributes, are included. Filipino students (N = 496) rated themselves on 268 such terms, plus 253 markers of trait and evaluative dimensions. We identified 10 dimensions of social and physical attributes—Prominence, Uselessness, Attractiveness, Respectability, Uniqueness, Destructiveness, Presentableness, Strength, Dangerousness, and Charisma. Most of these dimensions did not correspond in a one-to-one manner to Filipino or alternative trait models (Big Five, HEXACO, ML7). However, considerable redundancy was observed between the social and physical attribute dimensions and trait and evaluative dimensions. Thus, social and physical attributes communicate information about personality traits, and vice-versa. PMID:19779603

Associations between positive and negative affect and 12-month physical disorders in a national sample.

PubMed

Weiser, Eric B

2012-06-01

Associations between positive and negative affect and a range of 12-month physical disorders were investigated in the Midlife Development in the United States Survey, a nationally representative sample of 3,032 adults ages 25-74. These associations were examined, controlling for relevant sociodemographic and psychiatric covariates. High positive affect was associated with decreased risk of physical disorders, whereas high negative affect was associated with increased risk. However, associations between positive affect and physical disorders were partially attenuated following adjustment for concurrent negative affect. Additionally, high affect balance was associated with decreased risk of physical disorders before and after adjustments. These findings underscore the relevance of affective disposition in health status, suggesting that both positive and negative affect may serve as viable health risk parameters.

Jet-images — deep learning edition

DOE PAGES

de Oliveira, Luke; Kagan, Michael; Mackey, Lester; ...

2016-07-13

Building on the notion of a particle physics detector as a camera and the collimated streams of high energy particles, or jets, it measures as an image, we investigate the potential of machine learning techniques based on deep learning architectures to identify highly boosted W bosons. Modern deep learning algorithms trained on jet images can out-perform standard physically-motivated feature driven approaches to jet tagging. We develop techniques for visualizing how these features are learned by the network and what additional information is used to improve performance. Finally, this interplay between physically-motivated feature driven tools and supervised learning algorithms is generalmore » and can be used to significantly increase the sensitivity to discover new particles and new forces, and gain a deeper understanding of the physics within jets.« less

Jet-images — deep learning edition

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

de Oliveira, Luke; Kagan, Michael; Mackey, Lester

Building on the notion of a particle physics detector as a camera and the collimated streams of high energy particles, or jets, it measures as an image, we investigate the potential of machine learning techniques based on deep learning architectures to identify highly boosted W bosons. Modern deep learning algorithms trained on jet images can out-perform standard physically-motivated feature driven approaches to jet tagging. We develop techniques for visualizing how these features are learned by the network and what additional information is used to improve performance. Finally, this interplay between physically-motivated feature driven tools and supervised learning algorithms is generalmore » and can be used to significantly increase the sensitivity to discover new particles and new forces, and gain a deeper understanding of the physics within jets.« less

Sports physical

MedlinePlus

... this page: //medlineplus.gov/ency/patientinstructions/000673.htm Sports physical To use the sharing features on this ... or routine checkups. Why do you Need a Sports Physical? The sports physical is done to: Find ...

A Study of Flame Physics and Solid Propellant Rocket Physics

DTIC Science & Technology

2007-10-01

and ellipsoids, and the packing of pellets relevant to igniter modeling. Other topics are the instabilities of smolder waves, premixed flame...instabilities in narrow tubes, and flames supported by a spinning porous plug burner . Much of this work has been reported in the high-quality archival...perchlorate in fuel binder, the combustion of model propellant packs of ellipses and ellipsoids, and the packing of pellets relevant to igniter modeling

Nanostructure symmetry: Relevance for physics and computing

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

Dupertuis, Marc-André; Oberli, D. Y.; Karlsson, K. F.

2014-03-31

We review the research done in recent years in our group on the effects of nanostructure symmetry, and outline its relevance both for nanostructure physics and for computations of their electronic and optical properties. The exemples of C3v and C2v quantum dots are used. A number of surprises and non-trivial aspects are outlined, and a few symmetry-based tools for computing and analysis are shortly presented.

Differential prioritization between relevance and redundancy in correlation-based feature selection techniques for multiclass gene expression data.

PubMed

Ooi, Chia Huey; Chetty, Madhu; Teng, Shyh Wei

2006-06-23

Due to the large number of genes in a typical microarray dataset, feature selection looks set to play an important role in reducing noise and computational cost in gene expression-based tissue classification while improving accuracy at the same time. Surprisingly, this does not appear to be the case for all multiclass microarray datasets. The reason is that many feature selection techniques applied on microarray datasets are either rank-based and hence do not take into account correlations between genes, or are wrapper-based, which require high computational cost, and often yield difficult-to-reproduce results. In studies where correlations between genes are considered, attempts to establish the merit of the proposed techniques are hampered by evaluation procedures which are less than meticulous, resulting in overly optimistic estimates of accuracy. We present two realistically evaluated correlation-based feature selection techniques which incorporate, in addition to the two existing criteria involved in forming a predictor set (relevance and redundancy), a third criterion called the degree of differential prioritization (DDP). DDP functions as a parameter to strike the balance between relevance and redundancy, providing our techniques with the novel ability to differentially prioritize the optimization of relevance against redundancy (and vice versa). This ability proves useful in producing optimal classification accuracy while using reasonably small predictor set sizes for nine well-known multiclass microarray datasets. For multiclass microarray datasets, especially the GCM and NCI60 datasets, DDP enables our filter-based techniques to produce accuracies better than those reported in previous studies which employed similarly realistic evaluation procedures.

What Can We Learn from a Simple Physics-Based Earthquake Simulator?

NASA Astrophysics Data System (ADS)

Artale Harris, Pietro; Marzocchi, Warner; Melini, Daniele

2018-03-01

Physics-based earthquake simulators are becoming a popular tool to investigate on the earthquake occurrence process. So far, the development of earthquake simulators is commonly led by the approach "the more physics, the better". However, this approach may hamper the comprehension of the outcomes of the simulator; in fact, within complex models, it may be difficult to understand which physical parameters are the most relevant to the features of the seismic catalog at which we are interested. For this reason, here, we take an opposite approach and analyze the behavior of a purposely simple earthquake simulator applied to a set of California faults. The idea is that a simple simulator may be more informative than a complex one for some specific scientific objectives, because it is more understandable. Our earthquake simulator has three main components: the first one is a realistic tectonic setting, i.e., a fault data set of California; the second is the application of quantitative laws for earthquake generation on each single fault, and the last is the fault interaction modeling through the Coulomb Failure Function. The analysis of this simple simulator shows that: (1) the short-term clustering can be reproduced by a set of faults with an almost periodic behavior, which interact according to a Coulomb failure function model; (2) a long-term behavior showing supercycles of the seismic activity exists only in a markedly deterministic framework, and quickly disappears introducing a small degree of stochasticity on the recurrence of earthquakes on a fault; (3) faults that are strongly coupled in terms of Coulomb failure function model are synchronized in time only in a marked deterministic framework, and as before, such a synchronization disappears introducing a small degree of stochasticity on the recurrence of earthquakes on a fault. Overall, the results show that even in a simple and perfectly known earthquake occurrence world, introducing a small degree of stochasticity may blur most of the deterministic time features, such as long-term trend and synchronization among nearby coupled faults.

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

Jeffrey A Appel

BTeV is a new Fermilab beauty and charm experiment designed to operate in the CZero region of the Tevatron collider. Critical to the success of BTeV is its pixel detector. The unique features of this pixel detector include its proximity to the beam, its operation with a beam crossing time of 132 ns, and the need for the detector information to be read out quickly enough to be used for the lowest level trigger. This talk presents an overview of the pixel detector design, giving the motivations for the technical choices made. The status of the current R&D on detectormore » components is also reviewed. Additional Pixel 2002 talks on the BTeV pixel detector are given by Dave Christian[1], Mayling Wong[2], and Sergio Zimmermann[3]. Table 1 gives a selection of pixel detector parameters for the ALICE, ATLAS, BTeV, and CMS experiments. Comparing the progression of this table, which I have been updating for the last several years, has shown a convergence of specifications. Nevertheless, significant differences endure. The BTeV data-driven readout, horizontal and vertical position resolution better than 9 {micro}m with the {+-} 300 mr forward acceptance, and positioning in vacuum and as close as 6 mm from the circulating beams remain unique. These features are driven by the physics goals of the BTeV experiment. Table 2 demonstrates that the vertex trigger performance made possible by these features is requisite for a very large fraction of the B meson decay physics which is so central to the motivation for BTeV. For most of the physics quantities of interest listed in the table, the vertex trigger is essential. The performance of the BTeV pixel detector may be summarized by looking at particular physics examples; e.g., the B{sub s} meson decay B{sub s} {yields} D{sub s}{sup -} K{sup +}. For that decay, studies using GEANT3 simulations provide quantitative measures of performance. For example, the separation between the B{sub s} decay point and the primary proton-antiproton interaction can be measured with an rms uncertainty of 138 {micro}m. This, with the uncertainty in the decay vertex position, leads to an uncertainty of the B{sub s} proper decay time of 46 fs. Even if the parameter x{sub s} equals 25 (where the current lower limit on x{sub s} is about 15), the corresponding relevant proper time is 400 fs. So, the detector resolution is more than adequate to make an excellent measurement of this parameter.« less

The Sunnel: Engaging Visitors in Solar Research via a Tunnel Through the Sun

NASA Astrophysics Data System (ADS)

DeMuth, Nora H.; Walker, C. E.

2006-12-01

The publicly accessible hallway space inside the McMath-Pierce Solar Telescope building on Kitt Peak has great untapped potential to house a display that would be relevant and understandable to KPNO visitors without the need for mediation or further explanation. An effective display would unite background content on solar physics and astronomy, and information on current solar research techniques and results in an accessible way that would excite and engage visitors. Considering these requirements, we created a concept currently dubbed the Sunnel (for “Sun-tunnel”). The Sunnel consists of two 95by 13-foot murals of the layers of the Sun stretching down the visitor hallway in the McMath-Pierce Solar Telescope. Temperatures of the layers are represented by the colors of the peak in the corresponding black-body curves, and solar features such as sunspots and pressure waves are represented by abstract designs flowing along the walls. A photon path will be laid on the floor using tiles, and several posters highlighting current solar research and background science content relevant to solar research will be displayed on one wall. An audio tour featuring interviews with solar researchers guides visitors along the Sunnel, engaging them and supporting deeper appreciation of the solar research. Installation of the murals is scheduled for early 2007, just in time to celebrate the International Heliophysical Year. DeMuth's research was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation through Scientific Program Order No. 3 (AST-0243875) of the Cooperative Agreement No. AST-0132798 between the Association of Universities for Research in Astronomy (AURA) and the NSF.

Considerations for Observational Research Using Large Data Sets in Radiation Oncology

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

Jagsi, Reshma, E-mail: rjagsi@med.umich.edu; Bekelman, Justin E.; Chen, Aileen

The radiation oncology community has witnessed growing interest in observational research conducted using large-scale data sources such as registries and claims-based data sets. With the growing emphasis on observational analyses in health care, the radiation oncology community must possess a sophisticated understanding of the methodological considerations of such studies in order to evaluate evidence appropriately to guide practice and policy. Because observational research has unique features that distinguish it from clinical trials and other forms of traditional radiation oncology research, the International Journal of Radiation Oncology, Biology, Physics assembled a panel of experts in health services research to provide a concisemore » and well-referenced review, intended to be informative for the lay reader, as well as for scholars who wish to embark on such research without prior experience. This review begins by discussing the types of research questions relevant to radiation oncology that large-scale databases may help illuminate. It then describes major potential data sources for such endeavors, including information regarding access and insights regarding the strengths and limitations of each. Finally, it provides guidance regarding the analytical challenges that observational studies must confront, along with discussion of the techniques that have been developed to help minimize the impact of certain common analytical issues in observational analysis. Features characterizing a well-designed observational study include clearly defined research questions, careful selection of an appropriate data source, consultation with investigators with relevant methodological expertise, inclusion of sensitivity analyses, caution not to overinterpret small but significant differences, and recognition of limitations when trying to evaluate causality. This review concludes that carefully designed and executed studies using observational data that possess these qualities hold substantial promise for advancing our understanding of many unanswered questions of importance to the field of radiation oncology.« less

Considerations for observational research using large data sets in radiation oncology.

PubMed

Jagsi, Reshma; Bekelman, Justin E; Chen, Aileen; Chen, Ronald C; Hoffman, Karen; Shih, Ya-Chen Tina; Smith, Benjamin D; Yu, James B

2014-09-01

The radiation oncology community has witnessed growing interest in observational research conducted using large-scale data sources such as registries and claims-based data sets. With the growing emphasis on observational analyses in health care, the radiation oncology community must possess a sophisticated understanding of the methodological considerations of such studies in order to evaluate evidence appropriately to guide practice and policy. Because observational research has unique features that distinguish it from clinical trials and other forms of traditional radiation oncology research, the International Journal of Radiation Oncology, Biology, Physics assembled a panel of experts in health services research to provide a concise and well-referenced review, intended to be informative for the lay reader, as well as for scholars who wish to embark on such research without prior experience. This review begins by discussing the types of research questions relevant to radiation oncology that large-scale databases may help illuminate. It then describes major potential data sources for such endeavors, including information regarding access and insights regarding the strengths and limitations of each. Finally, it provides guidance regarding the analytical challenges that observational studies must confront, along with discussion of the techniques that have been developed to help minimize the impact of certain common analytical issues in observational analysis. Features characterizing a well-designed observational study include clearly defined research questions, careful selection of an appropriate data source, consultation with investigators with relevant methodological expertise, inclusion of sensitivity analyses, caution not to overinterpret small but significant differences, and recognition of limitations when trying to evaluate causality. This review concludes that carefully designed and executed studies using observational data that possess these qualities hold substantial promise for advancing our understanding of many unanswered questions of importance to the field of radiation oncology. Copyright © 2014 Elsevier Inc. All rights reserved.

49 CFR 845.25 - Examination of witnesses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... witnesses. (b) Materiality, relevancy, and competency of witness testimony, exhibits, or physical evidence... inquiry, opportunity shall be given to show materiality, relevancy, or competency of the testimony or...

LANGUAGE EXPERIENCE SHAPES PROCESSING OF PITCH RELEVANT INFORMATION IN THE HUMAN BRAINSTEM AND AUDITORY CORTEX: ELECTROPHYSIOLOGICAL EVIDENCE.

PubMed

Krishnan, Ananthanarayan; Gandour, Jackson T

2014-12-01

Pitch is a robust perceptual attribute that plays an important role in speech, language, and music. As such, it provides an analytic window to evaluate how neural activity relevant to pitch undergo transformation from early sensory to later cognitive stages of processing in a well coordinated hierarchical network that is subject to experience-dependent plasticity. We review recent evidence of language experience-dependent effects in pitch processing based on comparisons of native vs. nonnative speakers of a tonal language from electrophysiological recordings in the auditory brainstem and auditory cortex. We present evidence that shows enhanced representation of linguistically-relevant pitch dimensions or features at both the brainstem and cortical levels with a stimulus-dependent preferential activation of the right hemisphere in native speakers of a tone language. We argue that neural representation of pitch-relevant information in the brainstem and early sensory level processing in the auditory cortex is shaped by the perceptual salience of domain-specific features. While both stages of processing are shaped by language experience, neural representations are transformed and fundamentally different at each biological level of abstraction. The representation of pitch relevant information in the brainstem is more fine-grained spectrotemporally as it reflects sustained neural phase-locking to pitch relevant periodicities contained in the stimulus. In contrast, the cortical pitch relevant neural activity reflects primarily a series of transient temporal neural events synchronized to certain temporal attributes of the pitch contour. We argue that experience-dependent enhancement of pitch representation for Chinese listeners most likely reflects an interaction between higher-level cognitive processes and early sensory-level processing to improve representations of behaviorally-relevant features that contribute optimally to perception. It is our view that long-term experience shapes this adaptive process wherein the top-down connections provide selective gating of inputs to both cortical and subcortical structures to enhance neural responses to specific behaviorally-relevant attributes of the stimulus. A theoretical framework for a neural network is proposed involving coordination between local, feedforward, and feedback components that can account for experience-dependent enhancement of pitch representations at multiple levels of the auditory pathway. The ability to record brainstem and cortical pitch relevant responses concurrently may provide a new window to evaluate the online interplay between feedback, feedforward, and local intrinsic components in the hierarchical processing of pitch relevant information.

LANGUAGE EXPERIENCE SHAPES PROCESSING OF PITCH RELEVANT INFORMATION IN THE HUMAN BRAINSTEM AND AUDITORY CORTEX: ELECTROPHYSIOLOGICAL EVIDENCE

PubMed Central

Krishnan, Ananthanarayan; Gandour, Jackson T.

2015-01-01

Pitch is a robust perceptual attribute that plays an important role in speech, language, and music. As such, it provides an analytic window to evaluate how neural activity relevant to pitch undergo transformation from early sensory to later cognitive stages of processing in a well coordinated hierarchical network that is subject to experience-dependent plasticity. We review recent evidence of language experience-dependent effects in pitch processing based on comparisons of native vs. nonnative speakers of a tonal language from electrophysiological recordings in the auditory brainstem and auditory cortex. We present evidence that shows enhanced representation of linguistically-relevant pitch dimensions or features at both the brainstem and cortical levels with a stimulus-dependent preferential activation of the right hemisphere in native speakers of a tone language. We argue that neural representation of pitch-relevant information in the brainstem and early sensory level processing in the auditory cortex is shaped by the perceptual salience of domain-specific features. While both stages of processing are shaped by language experience, neural representations are transformed and fundamentally different at each biological level of abstraction. The representation of pitch relevant information in the brainstem is more fine-grained spectrotemporally as it reflects sustained neural phase-locking to pitch relevant periodicities contained in the stimulus. In contrast, the cortical pitch relevant neural activity reflects primarily a series of transient temporal neural events synchronized to certain temporal attributes of the pitch contour. We argue that experience-dependent enhancement of pitch representation for Chinese listeners most likely reflects an interaction between higher-level cognitive processes and early sensory-level processing to improve representations of behaviorally-relevant features that contribute optimally to perception. It is our view that long-term experience shapes this adaptive process wherein the top-down connections provide selective gating of inputs to both cortical and subcortical structures to enhance neural responses to specific behaviorally-relevant attributes of the stimulus. A theoretical framework for a neural network is proposed involving coordination between local, feedforward, and feedback components that can account for experience-dependent enhancement of pitch representations at multiple levels of the auditory pathway. The ability to record brainstem and cortical pitch relevant responses concurrently may provide a new window to evaluate the online interplay between feedback, feedforward, and local intrinsic components in the hierarchical processing of pitch relevant information. PMID:25838636

Optical high-performance computing: introduction to the JOSA A and Applied Optics feature.

PubMed

Caulfield, H John; Dolev, Shlomi; Green, William M J

2009-08-01

The feature issues in both Applied Optics and the Journal of the Optical Society of America A focus on topics of immediate relevance to the community working in the area of optical high-performance computing.

Research Update: Sport and Physical Activity for People with Physical Disabilities.

ERIC Educational Resources Information Center

Smith, Ralph W.

1993-01-01

Examines research on sport and physical activity for individuals with physical disabilities, focusing on psychosocial characteristics of participants, physiological impacts of participation, and performance enhancement. With the advent of the Americans with Disabilities Act (1990), such research has relevance for all recreation professionals. (SM)

Borderline personality features as a predictor of forms and functions of aggression during middle childhood: examining the roles of gender and physiological reactivity.

PubMed

Banny, Adrienne M; Tseng, Wan-Ling; Murray-Close, Dianna; Pitula, Clio E; Crick, Nicki R

2014-08-01

The present longitudinal investigation examined borderline personality features as a predictor of aggression 1 year later. Moderation by physiological reactivity and gender was also explored. One hundred ninety-six children (M = 10.11 years, SD = 0.64) participated in a laboratory stress protocol in which their systolic blood pressure, diastolic blood pressure, and skin conductance reactivity to recounting a relational stressor (e.g., threats to relationships or exclusion) were assessed. Teachers provided reports on subtypes of aggressive behavior (i.e., reactive relational, proactive relational, reactive physical, and proactive physical), and children completed a self-report measure of borderline personality features. Path analyses indicated that borderline personality features predicted increases in reactive relational aggression and proactive relational aggression among girls who evinced heightened physiological reactivity to interpersonal stress. In contrast, borderline personality features predicted decreases in proactive physical aggression in girls. Findings suggest that borderline personality features promote engagement in relationally aggressive behaviors among girls, particularly in the context of emotional dysregulation.

Assessing physical functioning on pain management programmes: the unique contribution of directly assessed physical performance measures and their relationship to self-reports

PubMed Central

Guildford, Beth J; Jacobs, Clair M; Daly-Eichenhardt, Aisling; Scott, Whitney; McCracken, Lance M

2016-01-01

Physical functioning is a recommended outcome domain for pain management programmes. It can be assessed by self-report and by direct assessment of performance. Although physical performance measures may provide unique and useful information about patient functioning over and above self-report measures, it is not entirely clear which of the many possible performances to assess. This study investigated a battery of three directly assessed physical performance measures and their relationship to three currently used self-report measures of general health and functioning. The three performance measures were sensitive to treatment; patients performed significantly better on all three measures following completion of the pain management programme. The three performance measures were shown to represent a single underlying dimension, and there was a significant degree of overlap between them. The performance measures were shown to be relevant in explaining variation in the self-report measures, as well as to offer a clinically relevant different dimension of assessment to self-report. Future research could focus on developing performance-based measures that capture quality of movement and that are sensitive to relevant processes of therapeutic change. PMID:28386404

Dynamical Vertex Approximation for the Hubbard Model

NASA Astrophysics Data System (ADS)

Toschi, Alessandro

A full understanding of correlated electron systems in the physically relevant situations of three and two dimensions represents a challenge for the contemporary condensed matter theory. However, in the last years considerable progress has been achieved by means of increasingly more powerful quantum many-body algorithms, applied to the basic model for correlated electrons, the Hubbard Hamiltonian. Here, I will review the physics emerging from studies performed with the dynamical vertex approximation, which includes diagrammatic corrections to the local description of the dynamical mean field theory (DMFT). In particular, I will first discuss the phase diagram in three dimensions with a special focus on the commensurate and incommensurate magnetic phases, their (quantum) critical properties, and the impact of fluctuations on electronic lifetimes and spectral functions. In two dimensions, the effects of non-local fluctuations beyond DMFT grow enormously, determining the appearance of a low-temperature insulating behavior for all values of the interaction in the unfrustrated model: Here the prototypical features of the Mott-Hubbard metal-insulator transition, as well as the existence of magnetically ordered phases, are completely overwhelmed by antiferromagnetic fluctuations of exponentially large extension, in accordance with the Mermin-Wagner theorem. Eventually, by a fluctuation diagnostics analysis of cluster DMFT self-energies, the same magnetic fluctuations are identified as responsible for the pseudogap regime in the holed-doped frustrated case, with important implications for the theoretical modeling of the cuprate physics.

A study of amplitude information-frequency characteristics for underwater active electrolocation system.

PubMed

Peng, Jiegang

2015-11-04

Weakly electric fish sense their surroundings in complete darkness by their active electrolocation system. For biologists, the active electrolocation system has been investigated for near 60 years. And for engineers, bio-inspired active electrolocation sensor has been investigated for about 20 years. But how the amplitude information response will be affected by frequencies of detecting electric fields in the active electrolocation system was rarely investigated. In this paper, an electrolocation experiment system has been built. The amplitude information-frequency characteristics (AIFC) of the electrolocation system for sinusoidal electric fields of varying frequencies have been investigated. We find that AIFC of the electrolocation system have relevance to the material properties and geometric features of the probed object and conductivity of surrounding water. Detect frequency dead zone (DFDZ) and frequency inflection point (FIP) of AIFC for the electrolocation system were found. The analysis model of the electrolocation system has been investigated for many years, but DFDZ and FIP of AIFC can be difficult to explain by those models. In order to explain those AIFC phenomena for the electrolocation system, a simple relaxation model based on Cole-Cole model which is not only a mathematical explanation but it is a physical one for the electrolocation system was advanced. We also advance a hypothesis for physical mechanism of weakly electrical fish electrolocation system. It may have reference value for physical mechanism of weakly electrical fish active electrolocation system.

Exercise and environment: New qualitative work to link popular practice and public health.

PubMed

Hitchings, Russell; Latham, Alan

2017-07-01

The health benefits of physical activity are many and well known. Those hoping to promote public health are therefore understandably keen on encouraging physical exercise. This commentary considers the role of qualitative research in this undertaking, given a context in which medical researchers have more commonly taken a quantitative approach to the motivations that are thought to underpin exercise. Our core argument is that studies concerned with how particular environments are inhabited by particular groups of exercisers could play a more central part in public health promotion. In making this case, and by way of an introduction to this Health and Place special issue, we present a series of statements that we think could usefully guide the further development of this work. Specifically, we argue for further attention to: the ways in which different material settings play into the exercise experience; how many of the exercise practices that we may hope to understand sit rather uneasily with the idea of sport; the subtleties of how sociality features in contemporary exercise practices; the physical pleasures that come from exercise; and how exercise practices are both acquired by individuals and evolve as a whole. In so doing, the aim is to encourage relevant researchers to engage more directly in conversation with health promoters instead of either being indifferent to, or critical of, them. Copyright © 2017. Published by Elsevier Ltd.

Development and evaluation of a physics-based windblown ...

EPA Pesticide Factsheets

A new windblown dust emission treatment was incorporated in the Community Multiscale Air Quality (CMAQ) modeling system. This new model treatment has been built upon previously developed physics-based parameterization schemes from the literature. A distinct and novel feature of this scheme, however, is the incorporation of a newly developed dynamic relation for the surface roughness length relevant to small-scale dust generation processes. Through this implementation, the effect of nonerodible elements on the local flow acceleration, drag partitioning, and surface coverage protection is modeled in a physically based and consistent manner. Careful attention is paid in integrating the new windblown dust treatment in the CMAQ model to ensure that the required input parameters are correctly configured. To test the performance of the new dust module in CMAQ, the entire year 2011 is simulated for the continental United States, with particular emphasis on the southwestern United States (SWUS) where windblown dust concentrations are relatively large. Overall, the model shows good performance with the daily mean bias of soil concentrations fluctuating in the range of ±1 µg m−3 for the entire year. Springtime soil concentrations are in quite good agreement (normalized mean bias of 8.3%) with observations, while moderate to high underestimation of soil concentration is seen in the summertime. The latter is attributed to the issue of representing the convective dust sto

Teacher Explanation of Physics Concepts: A Video Study

ERIC Educational Resources Information Center

Geelan, David

2013-01-01

Video recordings of Year 11 physics lessons were analyzed to identify key features of teacher explanations. Important features of the explanations used included teachers' ability to move between qualitative and quantitative modes of discussion, attention to what students require to succeed in high stakes examinations, thoughtful use of…

Feature diagnosticity and task context shape activity in human scene-selective cortex.

PubMed

Lowe, Matthew X; Gallivan, Jason P; Ferber, Susanne; Cant, Jonathan S

2016-01-15

Scenes are constructed from multiple visual features, yet previous research investigating scene processing has often focused on the contributions of single features in isolation. In the real world, features rarely exist independently of one another and likely converge to inform scene identity in unique ways. Here, we utilize fMRI and pattern classification techniques to examine the interactions between task context (i.e., attend to diagnostic global scene features; texture or layout) and high-level scene attributes (content and spatial boundary) to test the novel hypothesis that scene-selective cortex represents multiple visual features, the importance of which varies according to their diagnostic relevance across scene categories and task demands. Our results show for the first time that scene representations are driven by interactions between multiple visual features and high-level scene attributes. Specifically, univariate analysis of scene-selective cortex revealed that task context and feature diagnosticity shape activity differentially across scene categories. Examination using multivariate decoding methods revealed results consistent with univariate findings, but also evidence for an interaction between high-level scene attributes and diagnostic visual features within scene categories. Critically, these findings suggest visual feature representations are not distributed uniformly across scene categories but are shaped by task context and feature diagnosticity. Thus, we propose that scene-selective cortex constructs a flexible representation of the environment by integrating multiple diagnostically relevant visual features, the nature of which varies according to the particular scene being perceived and the goals of the observer. Copyright © 2015 Elsevier Inc. All rights reserved.

Community development corporations could potentially improve research on causal associations between environmental features and physical activity.

PubMed

Suminski, Richard; Wasserman, Jason A; Mayfield, Carlene A; Kubic, Micah; Porter, Julie

2014-09-01

Community development corporations (CDC) are worldwide entities that create environments facilitating physical activity. At the same time, researchers face challenges conducting cost-effective, longitudinal studies on how environmental changes affect physical activity. To provide evidence suggesting that CDC initiatives could potentially be integrated into a research framework for examining the influence of environmental improvements on physical activity. Quality of Life Plans (QLP) developed by a CDC and stakeholders from 6 lower-income neighborhoods were systematically reviewed to obtain data about environmental features targeted for change and the strategies used to bring about those changes. Strategies were deemed pro-physical activity if previous studies suggested they have the potential to affect physical activity. A total of 348 strategies were proposed of which 164 were pro-physical activity. Six environmental features were targeted including crime (57 strategies), aesthetics (39), facilities (30), walkability (17), destinations (14), and programs (5). Strategies involved implementing (90 strategies), planning (33), assessing (26), and securing funding (13). Progress reports indicated that 37.4% of the pro-physical activity strategies were implemented 1 year following the development of the QLPs. These results suggest that activities of CDCs could potentially be systematically integrated into the scientific study of environmental influences on physical activity.

The Personality Assessment Inventory as a Proxy for the Psychopathy Checklist-Revised: Testing the Incremental Validity and Cross-Sample Robustness of the Antisocial Features Scale

ERIC Educational Resources Information Center

Douglas, Kevin S.; Guy, Laura S.; Edens, John F.; Boer, Douglas P.; Hamilton, Jennine

2007-01-01

The Personality Assessment Inventory's (PAI's) ability to predict psychopathic personality features, as assessed by the Psychopathy Checklist-Revised (PCL-R), was examined. To investigate whether the PAI Antisocial Features (ANT) Scale and subscales possessed incremental validity beyond other theoretically relevant PAI scales, optimized regression…

Familiarity effects in the construction of facial-composite images using modern software systems.

PubMed

Frowd, Charlie D; Skelton, Faye C; Butt, Neelam; Hassan, Amal; Fields, Stephen; Hancock, Peter J B

2011-12-01

We investigate the effect of target familiarity on the construction of facial composites, as used by law enforcement to locate criminal suspects. Two popular software construction methods were investigated. Participants were shown a target face that was either familiar or unfamiliar to them and constructed a composite of it from memory using a typical 'feature' system, involving selection of individual facial features, or one of the newer 'holistic' types, involving repeated selection and breeding from arrays of whole faces. This study found that composites constructed of a familiar face were named more successfully than composites of an unfamiliar face; also, naming of composites of internal and external features was equivalent for construction of unfamiliar targets, but internal features were better named than the external features for familiar targets. These findings applied to both systems, although benefit emerged for the holistic type due to more accurate construction of internal features and evidence for a whole-face advantage. STATEMENT OF RELEVANCE: This work is of relevance to practitioners who construct facial composites with witnesses to and victims of crime, as well as for software designers to help them improve the effectiveness of their composite systems.

Vocal Features of Song and Speech: Insights from Schoenberg's Pierrot Lunaire.

PubMed

Merrill, Julia; Larrouy-Maestri, Pauline

2017-01-01

Similarities and differences between speech and song are often examined. However, the perceptual definition of these two types of vocalization is challenging. Indeed, the prototypical characteristics of speech or song support top-down processes, which influence listeners' perception of acoustic information. In order to examine vocal features associated with speaking and singing, we propose an innovative approach designed to facilitate bottom-up mechanisms in perceiving vocalizations by using material situated between speech and song: Speechsong. 25 participants were asked to evaluate 20 performances of a speechsong composition by Arnold Schoenberg, "Pierrot lunaire" op. 21 from 1912, evaluating 20 features of vocal-articulatory expression. Raters provided reliable judgments concerning the vocal features used by the performers and did not show strong appeal or specific expectations in reference to Schoenberg's piece. By examining the relationship between the vocal features and the impression of song or speech, the results confirm the importance of pitch (height, contour, range), but also point to the relevance of register, timbre, tension and faucal distance. Besides highlighting vocal features associated with speech and song, this study supports the relevance of the present approach of focusing on a theoretical middle category in order to better understand vocal expression in song and speech.

The Role of Competitive Inhibition and Top-Down Feedback in Binding during Object Recognition

PubMed Central

Wyatte, Dean; Herd, Seth; Mingus, Brian; O’Reilly, Randall

2012-01-01

How does the brain bind together visual features that are processed concurrently by different neurons into a unified percept suitable for processes such as object recognition? Here, we describe how simple, commonly accepted principles of neural processing can interact over time to solve the brain’s binding problem. We focus on mechanisms of neural inhibition and top-down feedback. Specifically, we describe how inhibition creates competition among neural populations that code different features, effectively suppressing irrelevant information, and thus minimizing illusory conjunctions. Top-down feedback contributes to binding in a similar manner, but by reinforcing relevant features. Together, inhibition and top-down feedback contribute to a competitive environment that ensures only the most appropriate features are bound together. We demonstrate this overall proposal using a biologically realistic neural model of vision that processes features across a hierarchy of interconnected brain areas. Finally, we argue that temporal synchrony plays only a limited role in binding – it does not simultaneously bind multiple objects, but does aid in creating additional contrast between relevant and irrelevant features. Thus, our overall theory constitutes a solution to the binding problem that relies only on simple neural principles without any binding-specific processes. PMID:22719733

Dynamic updating of hippocampal object representations reflects new conceptual knowledge

PubMed Central

Mack, Michael L.; Love, Bradley C.; Preston, Alison R.

2016-01-01

Concepts organize the relationship among individual stimuli or events by highlighting shared features. Often, new goals require updating conceptual knowledge to reflect relationships based on different goal-relevant features. Here, our aim is to determine how hippocampal (HPC) object representations are organized and updated to reflect changing conceptual knowledge. Participants learned two classification tasks in which successful learning required attention to different stimulus features, thus providing a means to index how representations of individual stimuli are reorganized according to changing task goals. We used a computational learning model to capture how people attended to goal-relevant features and organized object representations based on those features during learning. Using representational similarity analyses of functional magnetic resonance imaging data, we demonstrate that neural representations in left anterior HPC correspond with model predictions of concept organization. Moreover, we show that during early learning, when concept updating is most consequential, HPC is functionally coupled with prefrontal regions. Based on these findings, we propose that when task goals change, object representations in HPC can be organized in new ways, resulting in updated concepts that highlight the features most critical to the new goal. PMID:27803320

Accounting for Sitting and Moving: An Analysis of Sedentary Behavior in Mass Media Campaigns.

PubMed

Knox, Emily; Biddle, Stuart; Esliger, Dale W; Piggin, Joe; Sherar, Lauren

2015-09-01

Mass media campaigns are an important tool for promoting health-related physical activity. The relevance of sedentary behavior to public health has propelled it to feature prominently in health campaigns across the world. This study explored the use of messages regarding sedentary behavior in health campaigns within the context of current debates surrounding the association between sedentary behavior and health, and messaging strategies to promote moderate-to-vigorous physical activity (MVPA). A web-based search of major campaigns in the United Kingdom, United States, Canada, and Australia was performed to identify the main campaign from each country. A directed content analysis was then conducted to analyze the inclusion of messages regarding sedentary behavior in health campaigns and to elucidate key themes. Important areas for future research were illustrated. Four key themes from the campaigns emerged: clinging to sedentary behavior guidelines, advocating reducing sedentary behavior as a first step on the activity continuum and the importance of light activity, confusing the promotion of MVPA, and the demonization of sedentary behavior. Strategies for managing sedentary behavior as an additional complicating factor in health promotion are urgently required. Lessons learned from previous health communication campaigns should stimulate research to inform future messaging strategies.

QCD next-to-leading-order predictions matched to parton showers for vector-like quark models.

PubMed

Fuks, Benjamin; Shao, Hua-Sheng

2017-01-01

Vector-like quarks are featured by a wealth of beyond the Standard Model theories and are consequently an important goal of many LHC searches for new physics. Those searches, as well as most related phenomenological studies, however, rely on predictions evaluated at the leading-order accuracy in QCD and consider well-defined simplified benchmark scenarios. Adopting an effective bottom-up approach, we compute next-to-leading-order predictions for vector-like-quark pair production and single production in association with jets, with a weak or with a Higgs boson in a general new physics setup. We additionally compute vector-like-quark contributions to the production of a pair of Standard Model bosons at the same level of accuracy. For all processes under consideration, we focus both on total cross sections and on differential distributions, most these calculations being performed for the first time in our field. As a result, our work paves the way to precise extraction of experimental limits on vector-like quarks thanks to an accurate control of the shapes of the relevant observables and emphasise the extra handles that could be provided by novel vector-like-quark probes never envisaged so far.

Lab experiments investigating astrophysical jet physics

NASA Astrophysics Data System (ADS)

Bellan, Paul

2014-10-01

Dynamics relevant to astrophysical plasmas is being investigated in lab experiments having similar physics and topology, but much smaller time and space scales. High speed movies and numerical simulations both show that highly collimated MHD-driven plasma flows are a critical feature; these collimated flows can be considered to be a lab version of an astrophysical jet. Having both axial and azimuthal magnetic fields, the jet is effectively an axially lengthening plasma-confining flux tube with embedded helical magnetic field (flux rope). The jet velocity is in good agreement with an MHD acceleration model. Axial stagnation of the jet compresses embedded azimuthal magnetic flux and so results in jet self-collimation. Jets kink when they breach the Kruskal-Shafranov stability limit. The lateral acceleration of a sufficiently strong kink can provide an effective gravity which provides the environment for a spontaneously-developing, fine-scale, extremely fast Rayleigh-Taylor instability that erodes the current channel to be smaller than the ion skin depth. This cascade from the ideal MHD scale of the kink to the non-MHD ion skin depth scale can result in a fast magnetic reconnection whereby the jet breaks off from its source electrode. Supported by USDOE and NSF.

High Fidelity Modeling of Turbulent Mixing and Chemical Kinetics Interactions in a Post-Detonation Flow Field

NASA Astrophysics Data System (ADS)

Sinha, Neeraj; Zambon, Andrea; Ott, James; Demagistris, Michael

2015-06-01

Driven by the continuing rapid advances in high-performance computing, multi-dimensional high-fidelity modeling is an increasingly reliable predictive tool capable of providing valuable physical insight into complex post-detonation reacting flow fields. Utilizing a series of test cases featuring blast waves interacting with combustible dispersed clouds in a small-scale test setup under well-controlled conditions, the predictive capabilities of a state-of-the-art code are demonstrated and validated. Leveraging physics-based, first principle models and solving large system of equations on highly-resolved grids, the combined effects of finite-rate/multi-phase chemical processes (including thermal ignition), turbulent mixing and shock interactions are captured across the spectrum of relevant time-scales and length scales. Since many scales of motion are generated in a post-detonation environment, even if the initial ambient conditions are quiescent, turbulent mixing plays a major role in the fireball afterburning as well as in dispersion, mixing, ignition and burn-out of combustible clouds in its vicinity. Validating these capabilities at the small scale is critical to establish a reliable predictive tool applicable to more complex and large-scale geometries of practical interest.

Unsupervised Learning and Pattern Recognition of Biological Data Structures with Density Functional Theory and Machine Learning.

PubMed

Chen, Chien-Chang; Juan, Hung-Hui; Tsai, Meng-Yuan; Lu, Henry Horng-Shing

2018-01-11

By introducing the methods of machine learning into the density functional theory, we made a detour for the construction of the most probable density function, which can be estimated by learning relevant features from the system of interest. Using the properties of universal functional, the vital core of density functional theory, the most probable cluster numbers and the corresponding cluster boundaries in a studying system can be simultaneously and automatically determined and the plausibility is erected on the Hohenberg-Kohn theorems. For the method validation and pragmatic applications, interdisciplinary problems from physical to biological systems were enumerated. The amalgamation of uncharged atomic clusters validated the unsupervised searching process of the cluster numbers and the corresponding cluster boundaries were exhibited likewise. High accurate clustering results of the Fisher's iris dataset showed the feasibility and the flexibility of the proposed scheme. Brain tumor detections from low-dimensional magnetic resonance imaging datasets and segmentations of high-dimensional neural network imageries in the Brainbow system were also used to inspect the method practicality. The experimental results exhibit the successful connection between the physical theory and the machine learning methods and will benefit the clinical diagnoses.

Design and evaluation of a software prototype for participatory planning of environmental adaptations.

PubMed

Eriksson, J; Ek, A; Johansson, G

2000-03-01

A software prototype to support the planning process for adapting home and work environments for people with physical disabilities was designed and later evaluated. The prototype exploits low-cost three-dimensional (3-D) graphics products in the home computer market. The essential features of the prototype are: interactive rendering with optional hardware acceleration, interactive walk-throughs, direct manipulation tools for moving objects and measuring distances, and import of 3-D-objects from a library. A usability study was conducted, consisting of two test sessions (three weeks apart) and a final interview. The prototype was then tested and evaluated by representatives of future users: five occupational therapist students, and four persons with physical disability, with no previous experience of the prototype. Emphasis in the usability study was placed on the prototype's efficiency and learnability. We found that it is possible to realise a planning tool for environmental adaptations, both regarding usability and technical efficiency. The usability evaluation confirms our findings from previous case studies, regarding the relevance and positive attitude towards this kind of planning tool. Although the prototype was found to be satisfactorily efficient for the basic tasks, the paper presents several suggestions for improvement of future prototype versions.

Functional connectivity supporting the selective maintenance of feature-location binding in visual working memory

PubMed Central

Takahama, Sachiko; Saiki, Jun

2014-01-01

Information on an object's features bound to its location is very important for maintaining object representations in visual working memory. Interactions with dynamic multi-dimensional objects in an external environment require complex cognitive control, including the selective maintenance of feature-location binding. Here, we used event-related functional magnetic resonance imaging to investigate brain activity and functional connectivity related to the maintenance of complex feature-location binding. Participants were required to detect task-relevant changes in feature-location binding between objects defined by color, orientation, and location. We compared a complex binding task requiring complex feature-location binding (color-orientation-location) with a simple binding task in which simple feature-location binding, such as color-location, was task-relevant and the other feature was task-irrelevant. Univariate analyses showed that the dorsolateral prefrontal cortex (DLPFC), hippocampus, and frontoparietal network were activated during the maintenance of complex feature-location binding. Functional connectivity analyses indicated cooperation between the inferior precentral sulcus (infPreCS), DLPFC, and hippocampus during the maintenance of complex feature-location binding. In contrast, the connectivity for the spatial updating of simple feature-location binding determined by reanalyzing the data from Takahama et al. (2010) demonstrated that the superior parietal lobule (SPL) cooperated with the DLPFC and hippocampus. These results suggest that the connectivity for complex feature-location binding does not simply reflect general memory load and that the DLPFC and hippocampus flexibly modulate the dorsal frontoparietal network, depending on the task requirements, with the infPreCS involved in the maintenance of complex feature-location binding and the SPL involved in the spatial updating of simple feature-location binding. PMID:24917833

Functional connectivity supporting the selective maintenance of feature-location binding in visual working memory.

PubMed

Takahama, Sachiko; Saiki, Jun

2014-01-01

Information on an object's features bound to its location is very important for maintaining object representations in visual working memory. Interactions with dynamic multi-dimensional objects in an external environment require complex cognitive control, including the selective maintenance of feature-location binding. Here, we used event-related functional magnetic resonance imaging to investigate brain activity and functional connectivity related to the maintenance of complex feature-location binding. Participants were required to detect task-relevant changes in feature-location binding between objects defined by color, orientation, and location. We compared a complex binding task requiring complex feature-location binding (color-orientation-location) with a simple binding task in which simple feature-location binding, such as color-location, was task-relevant and the other feature was task-irrelevant. Univariate analyses showed that the dorsolateral prefrontal cortex (DLPFC), hippocampus, and frontoparietal network were activated during the maintenance of complex feature-location binding. Functional connectivity analyses indicated cooperation between the inferior precentral sulcus (infPreCS), DLPFC, and hippocampus during the maintenance of complex feature-location binding. In contrast, the connectivity for the spatial updating of simple feature-location binding determined by reanalyzing the data from Takahama et al. (2010) demonstrated that the superior parietal lobule (SPL) cooperated with the DLPFC and hippocampus. These results suggest that the connectivity for complex feature-location binding does not simply reflect general memory load and that the DLPFC and hippocampus flexibly modulate the dorsal frontoparietal network, depending on the task requirements, with the infPreCS involved in the maintenance of complex feature-location binding and the SPL involved in the spatial updating of simple feature-location binding.

Unsupervised feature relevance analysis applied to improve ECG heartbeat clustering.

PubMed

Rodríguez-Sotelo, J L; Peluffo-Ordoñez, D; Cuesta-Frau, D; Castellanos-Domínguez, G

2012-10-01

The computer-assisted analysis of biomedical records has become an essential tool in clinical settings. However, current devices provide a growing amount of data that often exceeds the processing capacity of normal computers. As this amount of information rises, new demands for more efficient data extracting methods appear. This paper addresses the task of data mining in physiological records using a feature selection scheme. An unsupervised method based on relevance analysis is described. This scheme uses a least-squares optimization of the input feature matrix in a single iteration. The output of the algorithm is a feature weighting vector. The performance of the method was assessed using a heartbeat clustering test on real ECG records. The quantitative cluster validity measures yielded a correctly classified heartbeat rate of 98.69% (specificity), 85.88% (sensitivity) and 95.04% (general clustering performance), which is even higher than the performance achieved by other similar ECG clustering studies. The number of features was reduced on average from 100 to 18, and the temporal cost was a 43% lower than in previous ECG clustering schemes. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

What's color got to do with it? The influence of color on visual attention in different categories.

PubMed

Frey, Hans-Peter; Honey, Christian; König, Peter

2008-10-23

Certain locations attract human gaze in natural visual scenes. Are there measurable features, which distinguish these locations from others? While there has been extensive research on luminance-defined features, only few studies have examined the influence of color on overt attention. In this study, we addressed this question by presenting color-calibrated stimuli and analyzing color features that are known to be relevant for the responses of LGN neurons. We recorded eye movements of 15 human subjects freely viewing colored and grayscale images of seven different categories. All images were also analyzed by the saliency map model (L. Itti, C. Koch, & E. Niebur, 1998). We find that human fixation locations differ between colored and grayscale versions of the same image much more than predicted by the saliency map. Examining the influence of various color features on overt attention, we find two extreme categories: while in rainforest images all color features are salient, none is salient in fractals. In all other categories, color features are selectively salient. This shows that the influence of color on overt attention depends on the type of image. Also, it is crucial to analyze neurophysiologically relevant color features for quantifying the influence of color on attention.

Physics in the Great Depression

ERIC Educational Resources Information Center

Weiner, Charles

1970-01-01

Describes the criticism of science during the early 1930's, when questions about the internal dynamics of the physics community- reduced research funds, slackening employment opportunities and lower public esteem for physics and its relationship with society were raised. States that the problem of social relevance of physics is still very real…

Physics in Literature

ERIC Educational Resources Information Center

Manos, Harry

2014-01-01

Physics offers a cross-discipline perspective to understanding other subjects. The purpose of this paper is to provide examples of physics in literature that physics and astronomy teachers can use to give students an indication of the relevance of science as depicted in the humanities. It is not possible to cite the thousands of examples…

Physical examination of upper extremity compressive neuropathies.

PubMed

Popinchalk, Samuel P; Schaffer, Alyssa A

2012-10-01

A thorough history and physical examination are vital to the assessment of upper extremity compressive neuropathies. This article summarizes relevant anatomy and physical examination findings associated with upper extremity compressive neuropathies. Copyright © 2012 Elsevier Inc. All rights reserved.

Efficacy of bowel cancer appeals for promoting physical activity.

PubMed

Jalleh, Geoffrey; Donovan, Robert J; Slevin, Terry; Dixon, Helen

2005-08-01

To investigate the potential efficacy of bowel cancer prevention messages in increasing intentions to be more physically active. A convenience sample of 281 physically inactive persons aged 30-60 years was recruited in the Perth city centre and randomly assigned to a bowel cancer and physical activity message or a heart disease and physical activity message. After reading a booklet containing information about physical activity and its link either to bowel cancer (n = 141) or cardiovascular disease (n = 140), respondents filled in a self-completion questionnaire. The main response measures were impact on intentions to be more physically active, and perceived believability and relevance of the message. Perceived believability of the message was high in both conditions. Perceived personal relevance of the message was substantially lower in the bowel cancer than the cardiovascular disease condition. Overall, the cardiovascular disease condition achieved somewhat higher behavioural intentions than the bowel cancer condition. The finding that two in three respondents in the bowel cancer condition had increased intention to increase their level of physical activity provides support for the potential efficacy of promoting physical activity in reducing the risk of bowel cancer.

Fishermen Follow Fine-scaled Physical Ocean Features For Finance

NASA Astrophysics Data System (ADS)

Fuller, E.; Watson, J. R.; Samhouri, J.; Castruccio, F. S.

2016-12-01

The seascapes on which many millions of people make their living and secure food have complex and dynamic spatial features - the figurative hills and valleys - that control where and how people work at sea. Here, we quantify the physical mosaic of the surface ocean by identifying Lagrangian Coherent Structures for a whole seascape - the California Current - and assess their impact on the spatial distribution of fishing. We show that there is a mixed response: some fisheries track these physical features, and others avoid them. This spatial behavior maps to economic impacts: we find that tuna fishermen can expect to make three times more revenue per trip if fishing occurs on strong coherent structures. These results highlight a connection between the physical state of the oceans, the spatial patterns of human activity and ultimately the economic prosperity of coastal communities.

Bridging Physics and Biology Using Resistance and Axons

ERIC Educational Resources Information Center

Dyer, Joshua M.

2014-01-01

When teaching physics, it is often difficult to get biology-oriented students to see the relevance of physics. A complaint often heard is that biology students are required to take physics for the Medical College Admission Test (MCAT) as part of a "weeding out" process, but that they don't feel like they need physics for biology. Despite…

2017 Topical Workshop on Electronics for Particle Physics

NASA Astrophysics Data System (ADS)

2017-09-01

The workshop will cover all aspects of electronics for particle physics experiments, and accelerator instrumentation of general interest to users. LHC experiments (and their operational experience) will remain a focus of the meeting but a strong emphasis on R&D for future experimentation will be maintained, such as SLHC, CLIC, ILC, neutrino facilities as well as other particle and astroparticle physics experiments. The purpose of the workshop is: To present results and original concepts for electronic research and development relevant to experiments as well as accelerator and beam instrumentation at future facilities; To review the status of electronics for the LHC experiments; To identify and encourage common efforts for the development of electronics; To promote information exchange and collaboration in the relevant engineering and physics communities.

What Is Physics Problem-Solving Competency? The Views of Arnold Sommerfeld and Enrico Fermi

NASA Astrophysics Data System (ADS)

Niss, Martin

2018-05-01

A central goal of physics education is to teach problem-solving competency, but the description of the nature of this competency is somehwat fragmentary and implicit in the literature. The present article uses recent historical scholarship on Arnold Sommerfeld and Enrico Fermi to identify and characterize two positions on the nature of physics problem-solving competency. The first, Sommerfeld's, is a "theory first, phenomenon second" approach. Here, the relevant problems originate in one of the theories of physics and the goal of the problem-solver is to make a mathematical analysis of the relevant equation(s) and then give a qualitative analysis of the phenomenon that arise from these mathematical results. Fermi's position is a "phenomenon first, theory second" approach, where the starting point is a physical phenomenon that is analyzed and then brought into the realm of a physics theory. The two positions are illustrated with solutions to two problems and it is shown that the two positions are reflected in problem collections of university educations in physics.

Introduction to the special issue Hermann Weyl and the philosophy of the 'New Physics'

NASA Astrophysics Data System (ADS)

De Bianchi, Silvia; Catren, Gabriel

2018-02-01

This Special Issue Hermann Weyl and the Philosophy of the 'New Physics' has two main objectives: first, to shed fresh light on the relevance of Weyl's work for modern physics and, second, to evaluate the importance of Weyl's work and ideas for contemporary philosophy of physics. Regarding the first objective, this Special Issue emphasizes aspects of Weyl's work (e.g. his work on spinors in n dimensions) whose importance has recently been emerging in research fields across both mathematical and experimental physics, as well as in the history and philosophy of physics. Regarding the second objective, this Special Issue addresses the relevance of Weyl's ideas regarding important open problems in the philosophy of physics, such as the problem of characterizing scientific objectivity and the problem of providing a satisfactory interpretation of fundamental symmetries in gauge theories and quantum mechanics. In this Introduction, we sketch the state of the art in Weyl studies and we summarize the content of the contributions to the present volume.

The importance of psychological and social factors in influencing the uptake and maintenance of physical activity after stroke: a structured review of the empirical literature.

PubMed

Morris, Jacqui; Oliver, Tracey; Kroll, Thilo; Macgillivray, Steve

2012-01-01

Background. People with stroke are not maintaining adequate engagement in physical activity (PA) for health and functional benefit. This paper sought to describe any psychological and social factors that may influence physical activity engagement after stroke. Methods. A structured literature review of studies indexed in MEDLINE, CinAHL, P&BSC, and PsycINFO using search terms relevant to stroke, physical disabilities, and PA. Publications reporting empirical findings (quantitative or qualitative) regarding psychological and/or social factors were included. Results. Twenty studies from 19 publications (9 surveys, 1 RCT, and 10 qualitative studies) were included. Seventeen studies reported findings pertinent to psychological factors and fourteen findings pertinent to social factors. Conclusion. Self-efficacy, physical activity beliefs, and social support appear particularly relevant to physical activity behaviour after stroke and should be included in theoretically based physical interventions. The Transtheoretical Model and the Theory of Planned Behaviour are candidate behavioural models that may support intervention development.

Evaluating Questionnaires Used to Assess Self-Reported Physical Activity and Psychosocial Outcomes Among Survivors of Adolescent and Young Adult Cancer: A Cognitive Interview Study.

PubMed

Wurz, Amanda; Brunet, Jennifer

2017-09-01

Physical activity is increasingly being studied as a way to improve psychosocial outcomes (e.g., quality of life, self-efficacy, physical self-perceptions, self-esteem, body image, posttraumatic growth) among survivors of adolescent and young adult (AYA) cancer. Assessing levels of and associations between self-reported physical activity and psychosocial outcomes requires clear, appropriate, and relevant questionnaires. To explore how survivors of AYA cancer interpreted and responded to the following eight published questionnaires: Leisure Time Exercise Questionnaire, Exercise Self-Efficacy Scale, Physical Self-Description Questionnaire, Rosenberg Global Self-Esteem Scale, Multidimensional Body-Self Relations Questionnaire, Posttraumatic Growth Inventory, Functional Assessment of Cancer Therapy-General (FACT-G), RAND 36-Item Health Survey 1.0 (RAND-36), cognitive interviews were conducted with three men and four women age 18-36 years who were diagnosed with cancer at age 16-35 years. Initially, the first seven questionnaires listed above were assessed. Summaries of the interviews were prepared and compared across participants. Potential concerns were identified with the FACT-G; thus, a second interview was conducted with participants to explore the clarity, appropriateness, and relevance of the RAND-36. Concerns identified for the FACT-G related mostly to the lack of relevance of items pertaining to cancer-specific aspects of quality of life given that participants were posttreatment. No or few concerns related to comprehension and/or structure/logic were identified for the other questionnaires. In general, the questionnaires assessed were clear, appropriate, and relevant. Participants' feedback suggested they could be used to assess self-reported physical activity and varied psychosocial outcomes in studies with survivors of AYA cancer, either with or without slight modifications.

Evaluation of linear classifiers on articles containing pharmacokinetic evidence of drug-drug interactions.

PubMed

Kolchinsky, A; Lourenço, A; Li, L; Rocha, L M

2013-01-01

Drug-drug interaction (DDI) is a major cause of morbidity and mortality. DDI research includes the study of different aspects of drug interactions, from in vitro pharmacology, which deals with drug interaction mechanisms, to pharmaco-epidemiology, which investigates the effects of DDI on drug efficacy and adverse drug reactions. Biomedical literature mining can aid both kinds of approaches by extracting relevant DDI signals from either the published literature or large clinical databases. However, though drug interaction is an ideal area for translational research, the inclusion of literature mining methodologies in DDI workflows is still very preliminary. One area that can benefit from literature mining is the automatic identification of a large number of potential DDIs, whose pharmacological mechanisms and clinical significance can then be studied via in vitro pharmacology and in populo pharmaco-epidemiology. We implemented a set of classifiers for identifying published articles relevant to experimental pharmacokinetic DDI evidence. These documents are important for identifying causal mechanisms behind putative drug-drug interactions, an important step in the extraction of large numbers of potential DDIs. We evaluate performance of several linear classifiers on PubMed abstracts, under different feature transformation and dimensionality reduction methods. In addition, we investigate the performance benefits of including various publicly-available named entity recognition features, as well as a set of internally-developed pharmacokinetic dictionaries. We found that several classifiers performed well in distinguishing relevant and irrelevant abstracts. We found that the combination of unigram and bigram textual features gave better performance than unigram features alone, and also that normalization transforms that adjusted for feature frequency and document length improved classification. For some classifiers, such as linear discriminant analysis (LDA), proper dimensionality reduction had a large impact on performance. Finally, the inclusion of NER features and dictionaries was found not to help classification.

Dealing with Disengagement through Diversity: An Electronic Curriculum for Cultural Relevance.

ERIC Educational Resources Information Center

Gabbard, David A.; L'Esperance, Mark; Perez, Theresa; Atkinson, Terry

2002-01-01

Examines specific features of the online Blackboard distance learning platform that enhance the advantages of alternative teacher certification programs, especially with regard to helping teachers develop a culturally relevant pedagogy. Focuses on North Carolina's NCTeach program, which provides an accelerated certification process for people…

Standard Model of Particle Physics--a health physics perspective.

PubMed

Bevelacqua, J J

2010-11-01

The Standard Model of Particle Physics is reviewed with an emphasis on its relationship to the physics supporting the health physics profession. Concepts important to health physics are emphasized and specific applications are presented. The capability of the Standard Model to provide health physics relevant information is illustrated with application of conservation laws to neutron and muon decay and in the calculation of the neutron mean lifetime.

Equipment Management for Sensor Networks: Linking Physical Infrastructure and Actions to Observational Data

NASA Astrophysics Data System (ADS)

Jones, A. S.; Horsburgh, J. S.; Matos, M.; Caraballo, J.

2015-12-01

Networks conducting long term monitoring using in situ sensors need the functionality to track physical equipment as well as deployments, calibrations, and other actions related to site and equipment maintenance. The observational data being generated by sensors are enhanced if direct linkages to equipment details and actions can be made. This type of information is typically recorded in field notebooks or in static files, which are rarely linked to observations in a way that could be used to interpret results. However, the record of field activities is often relevant to analysis or post-processing of the observational data. We have developed an underlying database schema and deployed a web interface for recording and retrieving information on physical infrastructure and related actions for observational networks. The database schema for equipment was designed as an extension to the Observations Data Model 2 (ODM2), a community-developed information model for spatially discrete, feature based earth observations. The core entities of ODM2 describe location, observed variable, and timing of observations, and the equipment extension contains entities to provide additional metadata specific to the inventory of physical infrastructure and associated actions. The schema is implemented in a relational database system for storage and management with an associated web interface. We designed the web-based tools for technicians to enter and query information on the physical equipment and actions such as site visits, equipment deployments, maintenance, and calibrations. These tools were implemented for the iUTAH (innovative Urban Transitions and Aridregion Hydrosustainability) ecohydrologic observatory, and we anticipate that they will be useful for similar large-scale monitoring networks desiring to link observing infrastructure to observational data to increase the quality of sensor-based data products.

Constraining the Enceladus Plume and Understanding Its Physics via Numerical Simulation from Underground Source to Infinity

NASA Astrophysics Data System (ADS)

Yeoh, S. K.; Li, Z.; Goldstein, D. B.; Varghese, P. L.; Trafton, L. M.; Levin, D. A.

2014-12-01

The Enceladus ice/vapor plume not only accounts for the various features observed in the Saturnian system, such as the E-ring, the narrow neutral H2O torus, and Enceladus' own bright albedo, but also raises exciting new possibilities, including the existence of liquid water on Enceladus. Therefore, understanding the plume and its physics is important. Here we assume that the plume arises from flow expansion within multiple narrow subsurface cracks connected to reservoirs of liquid water underground, and simulate this expanding flow from the underground reservoir out to several Enceladus radii where Cassini data are available for comparison. The direct simulation Monte Carlo (DSMC) method is used to simulate the subsurface and near-field collisional regions and a free-molecular model is used to propagate the plume out into the far-field. We include the following physical processes in our simulations: the flow interaction with the crack walls, grain condensation from the vapor phase, non-equilibrium effects (e.g. freezing of molecular internal energy modes), the interaction between the vapor and the ice grains, the gravitational fields of Enceladus and Saturn, and Coriolis and centrifugal forces (due to motion in non-inertial reference frame). The end result is a plume model that includes the relevant physics of the flow from the underground source out to where Cassini measurements are taken. We have made certain assumptions about the channel geometry and reservoir conditions. The model is constrained using various available Cassini data (particularly those of INMS, CDA and UVIS) to understand the plume physics as well as estimate the vapor and grain production rates and its temporal variability.

[Prevention and treatment of the complications of polycystic ovarian syndrome--the significance of evidence-based, interdisciplinary management].

PubMed

Gődény, Sándor; Csenteri, Orsolya Karola

2015-12-13

Polycystic ovary syndrome is the most common hormonal and metabolic disorder likely to affect women. The syndrome is often associated with obesity, hyperinsulinemia and adversely affects endocrine, metabolic, and cardiovascular health. The complex feature of the syndrome requires an interdisciplinary approach to treatment, where cooperation of paediatrician, internist, gynaecologist, endocrinologist, dermatologist, psychologist and oncologist is essential. The prevention and the treatment should be based on the best available evidence. This should include physical examination, laboratory tests for hormones, serum insulin, glucose, lipids, in addition patient's preferences should be considered, too. To maximise health gain of polycystic ovarian syndrome, adequate, effective, efficient and safe treatment is necessary. This article summarises the highest available evidence provided by meta-analyses and systematic reviews of the prevention of metabolic and cardiovascular complications of the syndrome, and discusses the relevant evidence published in the literature.

Deep data mining in a real space: Separation of intertwined electronic responses in a lightly doped BaFe 2As 2

DOE PAGES

Ziatdinov, Maxim; Maksov, Artem; Li, Li; ...

2016-10-25

Electronic interactions present in material compositions close to the superconducting dome play a key role in the manifestation of high-T c superconductivity. In many correlated electron systems, however, the parent or underdoped states exhibit strongly inhomogeneous electronic landscape at the nanoscale that may be associated with competing, coexisting, or intertwined chemical disorder, strain, magnetic, and structural order parameters. Here we demonstrate an approach based on a combination of scanning tunneling microscopy/spectroscopy and advanced statistical learning for an automatic separation and extraction of statistically significant electronic behaviors in the spin density wave regime of a lightly (~1%) gold-doped BaFe 2As 2.more » Lastly, we show that the decomposed STS spectral features have a direct relevance to fundamental physical properties of the system, such as SDW-induced gap, pseudogap-like state, and impurity resonance states.« less

Deep data mining in a real space: Separation of intertwined electronic responses in a lightly doped BaFe 2As 2

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

Ziatdinov, Maxim; Maksov, Artem; Li, Li

Electronic interactions present in material compositions close to the superconducting dome play a key role in the manifestation of high-T c superconductivity. In many correlated electron systems, however, the parent or underdoped states exhibit strongly inhomogeneous electronic landscape at the nanoscale that may be associated with competing, coexisting, or intertwined chemical disorder, strain, magnetic, and structural order parameters. Here we demonstrate an approach based on a combination of scanning tunneling microscopy/spectroscopy and advanced statistical learning for an automatic separation and extraction of statistically significant electronic behaviors in the spin density wave regime of a lightly (~1%) gold-doped BaFe 2As 2.more » Lastly, we show that the decomposed STS spectral features have a direct relevance to fundamental physical properties of the system, such as SDW-induced gap, pseudogap-like state, and impurity resonance states.« less

Bayesian parameter estimation for chiral effective field theory

NASA Astrophysics Data System (ADS)

Wesolowski, Sarah; Furnstahl, Richard; Phillips, Daniel; Klco, Natalie

2016-09-01

The low-energy constants (LECs) of a chiral effective field theory (EFT) interaction in the two-body sector are fit to observable data using a Bayesian parameter estimation framework. By using Bayesian prior probability distributions (pdfs), we quantify relevant physical expectations such as LEC naturalness and include them in the parameter estimation procedure. The final result is a posterior pdf for the LECs, which can be used to propagate uncertainty resulting from the fit to data to the final observable predictions. The posterior pdf also allows an empirical test of operator redundancy and other features of the potential. We compare results of our framework with other fitting procedures, interpreting the underlying assumptions in Bayesian probabilistic language. We also compare results from fitting all partial waves of the interaction simultaneously to cross section data compared to fitting to extracted phase shifts, appropriately accounting for correlations in the data. Supported in part by the NSF and DOE.

Molecular Growth Inside of Polycyclic Aromatic Hydrocarbon Clusters Induced by Ion Collisions.

PubMed

Delaunay, Rudy; Gatchell, Michael; Rousseau, Patrick; Domaracka, Alicja; Maclot, Sylvain; Wang, Yang; Stockett, Mark H; Chen, Tao; Adoui, Lamri; Alcamí, Manuel; Martín, Fernando; Zettergren, Henning; Cederquist, Henrik; Huber, Bernd A

2015-05-07

The present work combines experimental and theoretical studies of the collision between keV ion projectiles and clusters of pyrene, one of the simplest polycyclic aromatic hydrocarbons (PAHs). Intracluster growth processes induced by ion collisions lead to the formation of a wide range of new molecules with masses larger than that of the pyrene molecule. The efficiency of these processes is found to strongly depend on the mass and velocity of the incoming projectile. Classical molecular dynamics simulations of the entire collision process-from the ion impact (nuclear scattering) to the formation of new molecular species-reproduce the essential features of the measured molecular growth process and also yield estimates of the related absolute cross sections. More elaborate density functional tight binding calculations yield the same growth products as the classical simulations. The present results could be relevant to understand the physical chemistry of the PAH-rich upper atmosphere of Saturn's moon Titan.

Infrasonic Effect of Solar Eclipses

NASA Astrophysics Data System (ADS)

Pushin, V. F.; Chernogor, L. F.

2013-06-01

The relevance of this study is due to the need to understand, physical effects associated with rare phenomenon, solar eclipse. Until recently, the features of internal gravity wave generation, have been studied in the 10 -100 min period range, while in this, study an attempt is made to confirm the fact of generation, and estimate the general parameters of infrasound oscillations, associated with solar eclipses in the 1-10 min period range. The observations were made with the HF Doppler radar at vertical, incidence. The data were subjected to spectral analysis and, band-pass filtering. The solar eclipses that had occurred over, Kharkiv city (Ukraine) within 1999-2011 are determined to be, associated with Doppler shift of frequency oscillations in the, infrasound frequency band ( 5-8 min period range) and with, amplitude of 20 -100 mHz. The corresponding amplitude, of electron density oscillations was approximately equal to, 0.1- 0.5 %.

Experimental Replication of an Aeroengine Combustion Instability

NASA Technical Reports Server (NTRS)

Cohen, J. M.; Hibshman, J. R.; Proscia, W.; Rosfjord, T. J.; Wake, B. E.; McVey, J. B.; Lovett, J.; Ondas, M.; DeLaat, J.; Breisacher, K.

2000-01-01

Combustion instabilities in gas turbine engines are most frequently encountered during the late phases of engine development, at which point they are difficult and expensive to fix. The ability to replicate an engine-traceable combustion instability in a laboratory-scale experiment offers the opportunity to economically diagnose the problem (to determine the root cause), and to investigate solutions to the problem, such as active control. The development and validation of active combustion instability control requires that the causal dynamic processes be reproduced in experimental test facilities which can be used as a test bed for control system evaluation. This paper discusses the process through which a laboratory-scale experiment was designed to replicate an instability observed in a developmental engine. The scaling process used physically-based analyses to preserve the relevant geometric, acoustic and thermo-fluid features. The process increases the probability that results achieved in the single-nozzle experiment will be scalable to the engine.

A practical nonlocal model for heat transport in magnetized laser plasmas

NASA Astrophysics Data System (ADS)

Nicolaï, Ph. D.; Feugeas, J.-L. A.; Schurtz, G. P.

2006-03-01

A model of nonlocal transport for multidimensional radiation magnetohydrodynamics codes is presented. In laser produced plasmas, it is now believed that the heat transport can be strongly modified by the nonlocal nature of the electron conduction. Other mechanisms, such as self-generated magnetic fields, may also affect the heat transport. The model described in this work, based on simplified Fokker-Planck equations aims at extending the model of G. Schurtz, Ph. Nicolaï, and M. Busquet [Phys. Plasmas 7, 4238 (2000)] to magnetized plasmas. A complete system of nonlocal equations is derived from kinetic equations with self-consistent electric and magnetic fields. These equations are analyzed and simplified in order to be implemented into large laser fusion codes and coupled to other relevant physics. The model is applied to two laser configurations that demonstrate the main features of the model and point out the nonlocal Righi-Leduc effect in a multidimensional case.

An overview of remote sensing and geodesy for epidemiology and public health application.

PubMed

Hay, S I

2000-01-01

The techniques of remote sensing (RS) and geodesy have the potential to revolutionize the discipline of epidemiology and its application in human health. As a new departure from conventional epidemiological methods, these techniques require some detailed explanation. This review provides the theoretical background to RS including (i) its physical basis, (ii) an explanation of the orbital characteristics and specifications of common satellite sensor systems, (iii) details of image acquisition and procedures adopted to overcome inherent sources of data degradation, and (iv) a background to geophysical data preparation. This information allows RS applications in epidemiology to be readily interpreted. Some of the techniques used in geodesy, to locate features precisely on Earth so that they can be registered to satellite sensor-derived images, are also included. While the basic principles relevant to public health are presented here, inevitably many of the details must be left to specialist texts.

Light self-focusing in the atmosphere: Thin window model

DOE PAGES

Vaseva, Irina A.; Fedoruk, Mikhail P.; Rubenchik, Alexander M.; ...

2016-08-02

Ultra-high power (exceeding the self-focusing threshold by more than three orders of magnitude) light beams from ground-based laser systems may find applications in space-debris cleaning. The propagation of such powerful laser beams through the atmosphere reveals many novel interesting features compared to traditional light self-focusing. It is demonstrated here that for the relevant laser parameters, when the thickness of the atmosphere is much shorter than the focusing length (that is, of the orbit scale), the beam transit through the atmosphere in lowest order produces phase distortion only. This means that by using adaptive optics it may be possible to eliminatemore » the impact of self-focusing in the atmosphere on the laser beam. Furthermore, the area of applicability of the proposed “thin window” model is broader than the specific physical problem considered here. For instance, it might find applications in femtosecond laser material processing.« less

Internal friction between fluid particles of MHD tangent hyperbolic fluid with heat generation: Using coefficients improved by Cash and Karp

NASA Astrophysics Data System (ADS)

Salahuddin, T.; Khan, Imad; Malik, M. Y.; Khan, Mair; Hussain, Arif; Awais, Muhammad

2017-05-01

The present work examines the internal resistance between fluid particles of tangent hyperbolic fluid flow due to a non-linear stretching sheet with heat generation. Using similarity transformations, the governing system of partial differential equations is transformed into a coupled non-linear ordinary differential system with variable coefficients. Unlike the current analytical works on the flow problems in the literature, the main concern here is to numerically work out and find the solution by using Runge-Kutta-Fehlberg coefficients improved by Cash and Karp (Naseer et al., Alexandria Eng. J. 53, 747 (2014)). To determine the relevant physical features of numerous mechanisms acting on the deliberated problem, it is sufficient to have the velocity profile and temperature field and also the drag force and heat transfer rate all as given in the current paper.

van der Waals Layered Materials: Opportunities and Challenges.

PubMed

Duong, Dinh Loc; Yun, Seok Joon; Lee, Young Hee

2017-12-26

Since graphene became available by a scotch tape technique, a vast class of two-dimensional (2D) van der Waals (vdW) layered materials has been researched intensively. What is more intriguing is that the well-known physics and chemistry of three-dimensional (3D) bulk materials are often irrelevant, revealing exotic phenomena in 2D vdW materials. By further constructing heterostructures of these materials in the planar and vertical directions, which can be easily achieved via simple exfoliation techniques, numerous quantum mechanical devices have been demonstrated for fundamental research and technological applications. It is, therefore, necessary to review the special features in 2D vdW materials and to discuss the remaining issues and challenges. Here, we review the vdW materials library, technology relevance, and specialties of vdW materials covering the vdW interaction, strong Coulomb interaction, layer dependence, dielectric screening engineering, work function modulation, phase engineering, heterostructures, stability, growth issues, and the remaining challenges.

Improving activity recognition using temporal coherence.

PubMed

Ataya, Abbas; Jallon, Pierre; Bianchi, Pascal; Doron, Maeva

2013-01-01

Assessment of daily physical activity using data from wearable sensors has recently become a prominent research area in the biomedical engineering field and a substantial application for pattern recognition. In this paper, we present an accelerometer-based activity recognition scheme on the basis of a hierarchical structured classifier. A first step consists of distinguishing static activities from dynamic ones in order to extract relevant features for each activity type. Next, a separate classifier is applied to detect more specific activities of the same type. On top of our activity recognition system, we introduce a novel approach to take into account the temporal coherence of activities. Inter-activity transition information is modeled by a directed graph Markov chain. Confidence measures in activity classes are then evaluated from conventional classifier's outputs and coupled with the graph to reinforce activity estimation. Accurate results and significant improvement of activity detection are obtained when applying our system for the recognition of 9 activities for 48 subjects.

A characteristic length scale causes anomalous size effects and boundary programmability in mechanical metamaterials

NASA Astrophysics Data System (ADS)

Coulais, Corentin; Kettenis, Chris; van Hecke, Martin

2018-01-01

The architecture of mechanical metamaterials is designed to harness geometry, nonlinearity and topology to obtain advanced functionalities such as shape morphing, programmability and one-way propagation. Although a purely geometric framework successfully captures the physics of small systems under idealized conditions, large systems or heterogeneous driving conditions remain essentially unexplored. Here we uncover strong anomalies in the mechanics of a broad class of metamaterials, such as auxetics, shape changers or topological insulators; a non-monotonic variation of their stiffness with system size, and the ability of textured boundaries to completely alter their properties. These striking features stem from the competition between rotation-based deformations--relevant for small systems--and ordinary elasticity, and are controlled by a characteristic length scale which is entirely tunable by the architectural details. Our study provides new vistas for designing, controlling and programming the mechanics of metamaterials.

Methane hydrate studies: Delineating properties of host sediments to establish reproducible decomposition kinetics: Chapter 16

USGS Publications Warehouse

Mahajan, Devinder; Servio, Phillip; Jones, Keith W.; Feng, Huan; Winters, William J.; Taylor, C.E.; Kwwan, J.T.

2004-01-01

We have presented a summary of measurements on the physical properties of sediments relevant to methane hydrate recovery. The data includes not only geotechnical determinations, but also the CMT data that gives porosity values and pathways through the sediment material. The results show that CMT techniques can be used to study sediment properties on a micrometer-size scale. Since the technique is non-destructive, changes in the sediment microstructures as a function of pressure and temperature can be measured. It is also feasible to look at formation of methane hydrates in the sediment structure as has already been demonstrated [7–9]. A longer term challenge is to start from the microscale data and calculate the macroscopic quantities shown in Table 2. We also note that the CMT measurements help in identification of different minerals found in the sediments. This feature of CMT was not exploited in this survey.