Science as Structured Imagination

ERIC Educational Resources Information Center

De Cruz, Helen; De Smedt, Johan

2010-01-01

This paper offers an analysis of scientific creativity based on theoretical models and experimental results of the cognitive sciences. Its core idea is that scientific creativity--like other forms of creativity--is structured and constrained by prior ontological expectations. Analogies provide scientists with a powerful epistemic tool to overcome…

The Convergence of Institutional Logics on the Community College Sector and the Normalization of Emotional Labor: A New Theoretical Approach for Considering the Community College Faculty Labor Expectations

ERIC Educational Resources Information Center

Gonzales, Leslie D.; Ayers, David F.

2018-01-01

Little empirical research has systematically focused on, or interrogated, the labor expectations set forth for community college faculty. Thus, in this paper, we present a theoretical argument, which we formed by (re) reading several community college focused studies through various theoretical lenses. Ultimately, we merged two…

Content Specificity of Expectancy Beliefs and Task Values in Elementary Physical Education

PubMed Central

Chen, Ang; Martin, Robert; Ennis, Catherine D.; Sun, Haichun

2015-01-01

The curriculum may superimpose a content-specific context that mediates motivation (Bong, 2001). This study examined content specificity of the expectancy-value motivation in elementary school physical education. Students’ expectancy beliefs and perceived task values from a cardiorespiratory fitness unit, a muscular fitness unit, and a traditional skill/game unit were analyzed using constant comparison coding procedures, multivariate analysis of variance, χ2, and correlation analyses. There was no difference in the intrinsic interest value among the three content conditions. Expectancy belief, attainment, and utility values were significantly higher for the cardiorespiratory fitness curriculum. Correlations differentiated among the expectancy-value components of the content conditions, providing further evidence of content specificity in the expectancy-value motivation process. The findings suggest that expectancy beliefs and task values should be incorporated in the theoretical platform for curriculum development based on the learning outcomes that can be specified with enhanced motivation effect. PMID:18664044

Options for Location in the Organizational Structure.

ERIC Educational Resources Information Center

Taylor, Alton L.

1990-01-01

The location of the institutional research unit within the organizational structure influences the role it plays in supporting effective decision making. A theoretical framework of organizational structure based on division of labor can be applied to higher education institutions, with implications for staffing and expectations for performance.…

Generational Differences in Technology Adoption in Community Colleges

ERIC Educational Resources Information Center

Rosario, Victoria C.

2012-01-01

This research study investigated the technological perceptions and expectations of community college students, faculty, administrators, and Information Technology (IT) staff. The theoretical framework is based upon two assumptions on the process of technological innovation: it can be explained by diffusion of adoption theory, and by studying the…

Internship Quality Predicts Career Exploration of High School Students

ERIC Educational Resources Information Center

Gamboa, Vitor; Paixao, Maria Paula; Neves de Jesus, Saul

2013-01-01

The provision of workplace-based experiences (internship/placement) is an important component of the training program of students attending vocational education courses. Regarding the impact of such experiences on vocational development, research results are not conclusive enough, mainly, if we consider the theoretical expectation that work…

Developing and testing a theoretical model linking work-family conflict to employee safety.

PubMed

Cullen, Jennifer C; Hammer, Leslie B

2007-07-01

Despite work-family conflict being recognized as a source of stress, no published research to our knowledge has considered how it negatively affects workplace safety. A theoretical model linking strain-based work-family conflict and employee safety was tested with 243 health care workers. Within this model, work-family conflict is conceptualized as a workplace hazard. As expected, strong work performance norms and high work overload were associated with higher work-family conflict; increased family-to-work conflict was associated with decreased compliance with safety rules and less willingness to participate in discretionary safety meetings. Work-to-family conflict, however, was not associated with safety. These findings underscore the importance of work redesign strategies that consider work performance norms and work-family conflict for expecting a return on investment in terms of a safer workplace. Copyright 2007 APA

The detectability of brown dwarfs - Predictions and uncertainties

NASA Technical Reports Server (NTRS)

Nelson, L. A.; Rappaport, S.; Joss, P. C.

1993-01-01

In order to determine the likelihood for the detection of isolated brown dwarfs in ground-based observations as well as in future spaced-based astronomy missions, and in order to evaluate the significance of any detections that might be made, we must first know the expected surface density of brown dwarfs on the celestial sphere as a function of limiting magnitude, wavelength band, and Galactic latitude. It is the purpose of this paper to provide theoretical estimates of this surface density, as well as the range of uncertainty in these estimates resulting from various theoretical uncertainties. We first present theoretical cooling curves for low-mass stars that we have computed with the latest version of our stellar evolution code. We use our evolutionary results to compute theoretical brown-dwarf luminosity functions for a wide range of assumed initial mass functions and stellar birth rate functions. The luminosity functions, in turn, are utilized to compute theoretical surface density functions for brown dwarfs on the celestial sphere. We find, in particular, that for reasonable theoretical assumptions, the currently available upper bounds on the brown-dwarf surface density are consistent with the possibility that brown dwarfs contribute a substantial fraction of the mass of the Galactic disk.

Theoretical Accuracy of Along-Track Displacement Measurements from Multiple-Aperture Interferometry (MAI)

PubMed Central

Jung, Hyung-Sup; Lee, Won-Jin; Zhang, Lei

2014-01-01

The measurement of precise along-track displacements has been made with the multiple-aperture interferometry (MAI). The empirical accuracies of the MAI measurements are about 6.3 and 3.57 cm for ERS and ALOS data, respectively. However, the estimated empirical accuracies cannot be generalized to any interferometric pair because they largely depend on the processing parameters and coherence of the used SAR data. A theoretical formula is given to calculate an expected MAI measurement accuracy according to the system and processing parameters and interferometric coherence. In this paper, we have investigated the expected MAI measurement accuracy on the basis of the theoretical formula for the existing X-, C- and L-band satellite SAR systems. The similarity between the expected and empirical MAI measurement accuracies has been tested as well. The expected accuracies of about 2–3 cm and 3–4 cm (γ = 0.8) are calculated for the X- and L-band SAR systems, respectively. For the C-band systems, the expected accuracy of Radarsat-2 ultra-fine is about 3–4 cm and that of Sentinel-1 IW is about 27 cm (γ = 0.8). The results indicate that the expected MAI measurement accuracy of a given interferometric pair can be easily calculated by using the theoretical formula. PMID:25251408

Testing a pollen-parent fecundity distribution model on seed-parent fecundity distributions in bee-pollinated forage legume polycrosses

USDA-ARS?s Scientific Manuscript database

Random mating (i.e., panmixis) is a fundamental assumption in quantitative genetics. In outcrossing bee-pollinated perennial forage legume polycrosses, mating is assumed by default to follow theoretical random mating. This assumption informs breeders of expected inbreeding estimates based on polycro...

Supporting Academic Persistence in Low-Skilled Adult Learners

ERIC Educational Resources Information Center

O'Neill, Susan; Thomson, Margareta Maria

2013-01-01

The current literature review explores the factors that contribute to academic persistence for adult learners. The aim of the study is to identify current research-based strategies aimed at supporting learner persistence, particularly for low-skilled adults. Elements of three theoretical frameworks, namely, expectancy-value theory (EVT), goal…

Making Connections: Replicating and Extending the Utility Value Intervention in the Classroom

ERIC Educational Resources Information Center

Hulleman, Chris S.; Kosovich, Jeff J.; Barron, Kenneth E.; Daniel, David B.

2017-01-01

We replicated and extended prior research investigating a theoretically guided intervention based on expectancy-value theory designed to enhance student learning outcomes (e.g., Hulleman & Harackiewicz, 2009). First, we replicated prior work by demonstrating that the utility value intervention, which manipulated whether students made…

Essential Elements for Recruitment and Retention: Generation Y

ERIC Educational Resources Information Center

Luscombe, Jenna; Lewis, Ioni; Biggs, Herbert C.

2013-01-01

Purpose: Generation Y (Gen Y) is the newest and largest generation entering the workforce. Gen Y may differ from previous generations in work-related characteristics which may have recruitment and retention repercussions. Currently, limited theoretically-based research exists regarding Gen Y's work expectations and goals in relation to…

Development of a Survey to Examine the Factors That Motivate Secondary Education Teachers' Use of Problem-Based Learning (PBL)

ERIC Educational Resources Information Center

Lao, Huei-Chen

2016-01-01

In this quantitative study, a survey was developed and administered to middle and high school teachers to examine what factors motivated them to implement problem-based learning (PBL). Using Expectancy-Value Theory by Eccles et al. (1983) and Self-Determination Theory by Ryan and Deci (2000b) as the theoretical framework, this instrument measured…

Electron Capture in Slow Collision of He^2++H : Revisited

NASA Astrophysics Data System (ADS)

Krstic, Ps

2003-05-01

Very early experimental data (Fite et al. al., Proc. R. Soc. A 268, 527 (1962)) for He^2++H, recent ORNL measurements for Ne^2+ + H and our theoretical estimates suggest that the electron capture cross sections for these strongly exoergic collision systems drop slower toward low collision energies than expected from previous theories. We perform a theoretical study to establish and understand the true nature of this controversy. The calculations are based on the Hidden Crossings MOCC method, augmented with rotational and turning point effects.

Incorporating coping into an expectancy framework for explaining drinking behaviour.

PubMed

Hasking, Penelope A; Oei, Tian P S

2008-01-01

Expectancy Theory has offered much in the way of understanding alcohol use and abuse, and has contributed greatly to prevention and treatment initiatives. However although many cognitive-behavioural treatment approaches are based on expectancy constructs, such as outcome expectancies and self-efficacy, high relapse rates imply that expectancy theory may be too narrow in scope, and that additional variables need to be examined if a comprehensive understanding of drinking behaviour, and better treatment outcomes, are to be achieved. We suggest that the coping strategies an individual employs present one such set of variables that have largely been neglected from an expectancy framework. Although coping skills training is routinely used in prevention and treatment of alcohol problems, coping research has suffered from a poor theoretical framework. In this paper we review the existing research relating expectancies, self-efficacy and coping to drinking behaviour and propose a model which explains both social and dependent drinking, by incorporating coping into an expectancy theory framework. We also outline research and clinical implications of the proposed model.

Fitting observed and theoretical choices - women's choices about prenatal diagnosis of Down syndrome.

PubMed

Seror, Valerie

2008-05-01

Choices regarding prenatal diagnosis of Down syndrome - the most frequent chromosomal defect - are particularly relevant to decision analysis, since women's decisions are based on the assessment of their risk of carrying a child with Down syndrome, and involve tradeoffs (giving birth to an affected child vs procedure-related miscarriage). The aim of this study, based on face-to-face interviews with 78 women aged 25-35 with prior experience of pregnancy, was to compare the women' expressed choices towards prenatal diagnosis with those derived from theoretical models of choice (expected utility theory, rank-dependent theory, and cumulative prospect theory). The main finding obtained in this study was that the cumulative prospect model fitted the observed choices best: both subjective transformation of probabilities and loss aversion, which are basic features of the cumulative prospect model, have to be taken into account to make the observed choices consistent with the theoretical ones.

Lifetime Measurement of the 229Th nuclear isomer

NASA Astrophysics Data System (ADS)

Seiferle, Benedict; von der Wense, Lars; Thirolf, Peter G.

2017-01-01

The first excited isomeric state of 229Th possesses the lowest energy among all known excited nuclear states. The expected energy is accessible with today's laser technology and in principle allows for a direct optical laser excitation of the nucleus. The isomer decays via three channels to its ground state (internal conversion, γ decay, and bound internal conversion), whose strengths depend on the charge state of Thm229 . We report on the measurement of the internal-conversion decay half-life of neutral Thm229 . A half-life of 7 ±1 μ s has been measured, which is in the range of theoretical predictions and, based on the theoretically expected lifetime of ≈1 04 s of the photonic decay channel, gives further support for an internal conversion coefficient of ≈1 09, thus constraining the strength of a radiative branch in the presence of internal conversion.

Positron-alkali atom scattering

NASA Technical Reports Server (NTRS)

Mceachran, R. P.; Horbatsch, M.; Stauffer, A. D.; Ward, S. J.

1990-01-01

Positron-alkali atom scattering was recently investigated both theoretically and experimentally in the energy range from a few eV up to 100 eV. On the theoretical side calculations of the integrated elastic and excitation cross sections as well as total cross sections for Li, Na and K were based upon either the close-coupling method or the modified Glauber approximation. These theoretical results are in good agreement with experimental measurements of the total cross section for both Na and K. Resonance structures were also found in the L = 0, 1 and 2 partial waves for positron scattering from the alkalis. The structure of these resonances appears to be quite complex and, as expected, they occur in conjunction with the atomic excitation thresholds. Currently both theoretical and experimental work is in progress on positron-Rb scattering in the same energy range.

Forestry returns evaluated for uneven-aged management in two Appalachian woodlots

Treesearch

Orris D. McCauley; George R., Jr. Trimble; George R. Trimble

1972-01-01

The forestry profession holds many theoretical concepts about the economics of forest stand culture and development. However, the literature contains only a limited number of reports showing expected monetary outcomes over time that are based on actual measurements made of applied forest practices in natural hardwood stands. This is such a report.

Expectation and Variation with a Virtual Die

ERIC Educational Resources Information Center

Watson, Jane; English, Lyn

2015-01-01

By the time students reach the middle years they have experienced many chance activities based on dice. Common among these are rolling one die to explore the relationship of frequency and theoretical probability, and rolling two dice and summing the outcomes to consider their probabilities. Although dice may be considered overused by some, the…

An Appreciative Inquiry into an Urban Drug Court: Cultural Transformation

ERIC Educational Resources Information Center

Calabrese, Raymond; Cohen, Erik

2013-01-01

The purpose of this study was to use an appreciative inquiry (AI) theoretical research perspective and change methodology to transform the working relationships and cultural expectations of members through the discovery of their positive core leading to an optimistic and confidence-based future for an urban drug court. This study describes how…

Top-down modulation in the infant brain: Learning-induced expectations rapidly affect the sensory cortex at 6 months.

PubMed

Emberson, Lauren L; Richards, John E; Aslin, Richard N

2015-08-04

Recent theoretical work emphasizes the role of expectation in neural processing, shifting the focus from feed-forward cortical hierarchies to models that include extensive feedback (e.g., predictive coding). Empirical support for expectation-related feedback is compelling but restricted to adult humans and nonhuman animals. Given the considerable differences in neural organization, connectivity, and efficiency between infant and adult brains, it is a crucial yet open question whether expectation-related feedback is an inherent property of the cortex (i.e., operational early in development) or whether expectation-related feedback develops with extensive experience and neural maturation. To determine whether infants' expectations about future sensory input modulate their sensory cortices without the confounds of stimulus novelty or repetition suppression, we used a cross-modal (audiovisual) omission paradigm and used functional near-infrared spectroscopy (fNIRS) to record hemodynamic responses in the infant cortex. We show that the occipital cortex of 6-month-old infants exhibits the signature of expectation-based feedback. Crucially, we found that this region does not respond to auditory stimuli if they are not predictive of a visual event. Overall, these findings suggest that the young infant's brain is already capable of some rudimentary form of expectation-based feedback.

Should we expect population thresholds for wildlife disease?

USGS Publications Warehouse

Lloyd-Smith, James O.; Cross, P.C.; Briggs, C.J.; Daugherty, M.; Getz, W.M.; Latto, J.; Sanchez, M.; Smith, A.; Swei, A.

2005-01-01

Host population thresholds for invasion or persistence of infectious disease are core concepts of disease ecology, and underlie on-going and controversial disease control policies based on culling and vaccination. Empirical evidence for these thresholds in wildlife populations has been sparse, however, though recent studies have narrowed this gap. Here we review the theoretical bases for population thresholds for disease, revealing why they are difficult to measure and sometimes are not even expected, and identifying important facets of wildlife ecology left out of current theories. We discuss strengths and weaknesses of selected empirical studies that have reported disease thresholds for wildlife, identify recurring obstacles, and discuss implications of our imperfect understanding of wildlife thresholds for disease control policy.

[Development of technologies of population health management in Kazakhstan based on an integrated assessment of the combined exposure to environmental factors].

PubMed

Sraubaev, E N; Serik, B

2013-01-01

At present there is overdue necessity of an integral approach to the assessment of health status and the impact of environmental factors on it, in the development of science-based management decisions and programs on improvement of the health status of the population of Kazakhstan and in the increase in life expectancy from the birth and healthy life expectancy. The purpose of the proposed program--improving health and increasing life expectancy from the birth and healthy life expectancy of the population of Kazakhstan. Based on a meta-analysis to justify the target age group in which an implementation of complex of preventive measures will increase both the life expectancy from the birth and healthy life expectancy, to perform a comprehensive health screening for the basic classes of diseases and behavioral characteristics of the target group in the course of a multicentre studies to give a comprehensive hygienic characteristics of the ecological status of the studied regions and to develop the Health Passport of the region, to develop a model of the combined effects of environmental factors on health; to create a theoretical model for the calculation of life expectancy from the birth and healthy life expectancy, taking into account the limits of modifiability of factors that affect them, and justify a comprehensive program of management decisions on modification of factors, to carry out pilot studies on the development and validation technological (managemental) solutions to control modifiable factors that affect life expectancy from the birth and healthy life expectancy.

Wavelength routing beyond the standard graph coloring approach

NASA Astrophysics Data System (ADS)

Blankenhorn, Thomas

2004-04-01

When lightpaths are routed in the planning stage of transparent optical networks, the textbook approach is to use algorithms that try to minimize the overall number of wavelengths used in the . We demonstrate that this method cannot be expected to minimize actual costs when the marginal cost of instlling more wavelengths is a declining function of the number of wavelengths already installed, as is frequently the case. We further demonstrate how cost optimization can theoretically be improved with algorithms based on Prim"s algorithm. Finally, we test this theory with simulaion on a series of actual network topologies, which confirm the theoretical analysis.

An Information Theoretic Approach for Measuring Data Discovery and Utilization During Analytical and Decision Making Processes

DTIC Science & Technology

2015-07-31

and make the expected decision outcomes. The scenario is based around a scripted storyboard where an organized crime network is operating in a city to...interdicted by law enforcement to disrupt the network. The scenario storyboard was used to develop a probabilistic vehicle traffic model in order to

Investigating the Construct Measured by Banked Gap-Fill Items: Evidence from Eye-Tracking

ERIC Educational Resources Information Center

McCray, Gareth; Brunfaut, Tineke

2018-01-01

This study investigates test-takers' processing while completing banked gap-fill tasks, designed to test reading proficiency, in order to test theoretically based expectations about the variation in cognitive processes of test-takers across levels of performance. Twenty-eight test-takers' eye traces on 24 banked gap-fill items (on six tasks) were…

Analysis of the Cape Cod tracer data

USGS Publications Warehouse

Ezzedine, Souheil; Rubin, Yoram

1997-01-01

An analysis of the Cape Cod test was performed using several first- and higher-order theoretical models. We compare conditional and unconditional solutions of the transport equation and employ them for analysis of the experimental data. We consider spatial moments, mass breakthrough curves, and the distribution of the solute mass in space. The concentration measurements were also analyzed using theoretical models for the expected value and variance of concentration. The theoretical models we employed are based on the spatial correlation structure of the conductivity field, without any fitting of parameters to the tracer data, and hence we can test the predictive power of the theories tested. The effects of recharge on macrodispersion are investigated, and it is shown that recharge provides a reasonable explanation for the enhanced lateral spread of the Cape Cod plume. The compendium of the experimental results presented here is useful for testing of theoretical and numerical models.

VAXELN Experimentation: Programming a Real-Time Periodic Task Dispatcher Using VAXELN Ada 1.1

DTIC Science & Technology

1987-11-01

synchronization to the SQM and VAXELN semaphores. Based on real-time scheduling theory, the optimal rate-monotonic scheduling algorithm [Lui 73...schedulability test based on the rate-monotonic algorithm , namely task-lumping [Sha 871, was necessary to cal- culate the theoretically expected schedulability...8217 Guide Digital Equipment Corporation, Maynard, MA, 1986. [Lui 73] Liu, C.L., Layland, J.W. Scheduling Algorithms for Multi-programming in a Hard-Real-Time

Working together versus working autonomously: a new power-dependence perspective on the individual-level of analysis.

PubMed

de Jong, Simon B

2014-01-01

Recent studies have indicated that it is important to investigate the interaction between task interdependence and task autonomy because this interaction can affect team effectiveness. However, only a limited number of studies have been conducted and those studies focused solely on the team level of analysis. Moreover, there has also been a dearth of theoretical development. Therefore, this study develops and tests an alternative theoretical perspective in an attempt to understand if, and if so why, this interaction is important at the individual level of analysis. Based on interdependence theory and power-dependence theory, we expected that highly task-interdependent individuals who reported high task autonomy would be more powerful and better performers. In contrast, we expected that similarly high task-interdependent individuals who reported less task autonomy would be less powerful and would be weaker performers. These expectations were supported by multi-level and bootstrapping analyses performed on a multi-source dataset (self-, peer-, manager-ratings) comprised of 182 employees drawn from 37 teams. More specifically, the interaction between task interdependence and task autonomy was γ =.128, p <.05 for power and γ =.166, p <.05 for individual performance. The 95% bootstrap interval ranged from .0038 to .0686.

Water in dense molecular clouds

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

Wannier, P.G.; Kuiper, T.B.H.; Frerking, M.A.

1991-08-01

The G.P. Kuiper Airborne Observatory (KAO) was used to make initial observations of the half-millimeter ground-state transition of water in seven giant molecular clouds and in two late-type stars. No significant detections were made, and the resulting upper limits are significantly below those expected from other, indirect observations and from several theoretical models. The implied interstellar H2O/CO abundance is less than 0.003 in the cores of three giant molecular clouds. This value is less than expected from cloud chemistry models and also than estimates based on HDO and H3O(+) observations. 78 refs.

Heterozygote Advantage in a Finite Population: Black Color in Wolves.

PubMed

Hedrick, Philip W; Stahler, Daniel R; Dekker, Dick

2014-01-01

There is a striking color polymorphism for wolves in the Yellowstone National Park where approximately half the wolves are black. The genetic basis for this polymorphism is known, and fitnesses of the genotypes are estimated. These estimates suggest that there is strong heterozygote advantage but substantial asymmetry in the fitness differences of the 2 homozygotes. Theoretically, such fitnesses in a finite population are thought to reduce genetic variation at least as fast as if there were no selection at all. Because the color polymorphism has remained at about the same frequency for 17 years, about 4 generations, we investigated whether this was consistent with the theoretical predictions. Counter to this general expectation of loss, given the initial frequency of black wolves, the theoretical expectation in this case was found to be that the frequency would only decline slowly over time. For example, if the effective population size is 20, then the expected black allele frequency after 4 generations would be 0.191, somewhat less than the observed value of 0.237. However, nearly 30% of the time the expected frequency is 0.25 or greater, consistent with the contemporary observed frequency. In other words and in contrast to general theoretical predictions, because of the short period of time in evolutionary terms and the relatively weak selection at low frequencies, the observed variation and the predicted theoretical variation are not inconsistent. © The American Genetic Association 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Conceptualisation of patient satisfaction: a systematic narrative literature review.

PubMed

Batbaatar, Enkhjargal; Dorjdagva, Javkhlanbayar; Luvsannyam, Ariunbat; Amenta, Pietro

2015-09-01

Patient satisfaction concept is widely measured due to its appropriateness to health service; however, evidence suggests that it is a poorly developed concept. This article is a first part of a two-part series of research with a goal to review a current conceptual framework of patient satisfaction and to bring the concept for further operationalisation procedures. The current article aimed to review a theoretical framework that helps the next article to review determinants of patient satisfaction for designing a measurement system. The study used a systematic review method, meta-narrative review, based on the RAMESES guideline with the phases of screening evidence, appraisal evidence, data extraction and synthesis. Patient satisfaction theoretical articles were searched on the two databases MEDLINE and CINAHL. Inclusion criteria were articles published between 1980 and 2014, and English language papers only. There were 36 articles selected for the synthesis. Results showed that most of the patient satisfaction theories and formulations are based on marketing theories and defined as how well health service fulfils patient expectations. However, review demonstrated that a relationship between expectation and satisfaction is unclear and the concept expectation itself is not distinctly theorised as well. Researchers brought satisfaction theories from other fields to the current healthcare literature without much adaptation. Thus, there is a need to attempt to define the patient satisfaction concept from other perspectives or to learn how patients evaluate the care rather than struggling to describe it by consumerist theories. © Royal Society for Public Health 2015.

A Quantum Electronics Approach to Optical Negative Index Metamaterials (NIMs): Homogeneous NIMs in the Solid State

DTIC Science & Technology

2012-03-12

index effect at ~ 27.8 µm. This effect was theoretically predicted earlier, and it is based on coexistence of the spin wave ( magnon ) mode with the...refractive index at ~ 150 GHz, based on analogous plasmon- magnon excitation mechanism. 2.1 Fabrication of Cr doped IO material system...film, that the non-magnetic film possesses no maximum in region 27-28 µm. Such behavior is expected, since the spin waves ( magnons ) which are

Observation and analysis of self-amplified spontaneous emission at the APS low-energy undulator test line

NASA Astrophysics Data System (ADS)

Arnold, N. D.; Attig, J.; Banks, G.; Bechtold, R.; Beczek, K.; Benson, C.; Berg, S.; Berg, W.; Biedron, S. G.; Biggs, J. A.; Borland, M.; Boerste, K.; Bosek, M.; Brzowski, W. R.; Budz, J.; Carwardine, J. A.; Castro, P.; Chae, Y.-C.; Christensen, S.; Clark, C.; Conde, M.; Crosbie, E. A.; Decker, G. A.; Dejus, R. J.; DeLeon, H.; Den Hartog, P. K.; Deriy, B. N.; Dohan, D.; Dombrowski, P.; Donkers, D.; Doose, C. L.; Dortwegt, R. J.; Edwards, G. A.; Eidelman, Y.; Erdmann, M. J.; Error, J.; Ferry, R.; Flood, R.; Forrestal, J.; Freund, H.; Friedsam, H.; Gagliano, J.; Gai, W.; Galayda, J. N.; Gerig, R.; Gilmore, R. L.; Gluskin, E.; Goeppner, G. A.; Goetzen, J.; Gold, C.; Gorski, A. J.; Grelick, A. E.; Hahne, M. W.; Hanuska, S.; Harkay, K. C.; Harris, G.; Hillman, A. L.; Hogrefe, R.; Hoyt, J.; Huang, Z.; Jagger, J. M.; Jansma, W. G.; Jaski, M.; Jones, S. J.; Keane, R. T.; Kelly, A. L.; Keyser, C.; Kim, K.-J.; Kim, S. H.; Kirshenbaum, M.; Klick, J. H.; Knoerzer, K.; Koldenhoven, R. J.; Knott, M.; Labuda, S.; Laird, R.; Lang, J.; Lenkszus, F.; Lessner, E. S.; Lewellen, J. W.; Li, Y.; Lill, R. M.; Lumpkin, A. H.; Makarov, O. A.; Markovich, G. M.; McDowell, M.; McDowell, W. P.; McNamara, P. E.; Meier, T.; Meyer, D.; Michalek, W.; Milton, S. V.; Moe, H.; Moog, E. R.; Morrison, L.; Nassiri, A.; Noonan, J. R.; Otto, R.; Pace, J.; Pasky, S. J.; Penicka, J. M.; Pietryla, A. F.; Pile, G.; Pitts, C.; Power, J.; Powers, T.; Putnam, C. C.; Puttkammer, A. J.; Reigle, D.; Reigle, L.; Ronzhin, D.; Rotela, E. R.; Russell, E. F.; Sajaev, V.; Sarkar, S.; Scapino, J. C.; Schroeder, K.; Seglem, R. A.; Sereno, N. S.; Sharma, S. K.; Sidarous, J. F.; Singh, O.; Smith, T. L.; Soliday, R.; Sprau, G. A.; Stein, S. J.; Stejskal, B.; Svirtun, V.; Teng, L. C.; Theres, E.; Thompson, K.; Tieman, B. J.; Torres, J. A.; Trakhtenberg, E. M.; Travish, G.; Trento, G. F.; Vacca, J.; Vasserman, I. B.; Vinokurov, N. A.; Walters, D. R.; Wang, J.; Wang, X. J.; Warren, J.; Wesling, S.; Weyer, D. L.; Wiemerslage, G.; Wilhelmi, K.; Wright, R.; Wyncott, D.; Xu, S.; Yang, B.-X.; Yoder, W.; Zabel, R. B.

2001-12-01

Exponential growth of self-amplified spontaneous emission at 530 nm was first experimentally observed at the Advanced Photon Source low-energy undulator test line in December 1999. Since then, further detailed measurements and analysis of the results have been made. Here, we present the measurements and compare these with calculations based on measured electron beam properties and theoretical expectations.

A Laser Based Fusion Test Facility

DTIC Science & Technology

2008-10-01

Nike laser have explored the intensities employed by these Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the...and best beam smoothing with KrF makes it the most resistant to such instability. As discussed above, recent experiments using the Nike facility...support this expectation. There is ongoing experimental and theoretical work on Nike , Omega, and eventually NIF to determine these intensity limits

Elasticity reconstruction: Beyond the assumption of local homogeneity

NASA Astrophysics Data System (ADS)

Sinkus, Ralph; Daire, Jean-Luc; Van Beers, Bernard E.; Vilgrain, Valerie

2010-07-01

Elasticity imaging is a novel domain which is currently gaining significant interest in the medical field. Most inversion techniques are based on the homogeneity assumption, i.e. the local spatial derivatives of the complex-shear modulus are ignored. This analysis presents an analytic approach in order to overcome this limitation, i.e. first order spatial derivatives of the real-part of the complex-shear modulus are taken into account. Resulting distributions in a gauged breast lesion phantom agree very well with the theoretical expectations. An in-vivo example of a cholangiocarcinoma demonstrates that the new approach provides maps of the viscoelastic properties which agree much better with expectations from anatomy.

Constraints on spin-dependent parton distributions at large x from global QCD analysis

DOE PAGES

Jimenez-Delgado, P.; Avakian, H.; Melnitchouk, W.

2014-09-28

This study investigate the behavior of spin-dependent parton distribution functions (PDFs) at large parton momentum fractions x in the context of global QCD analysis. We explore the constraints from existing deep-inelastic scattering data, and from theoretical expectations for the leading x → 1 behavior based on hard gluon exchange in perturbative QCD. Systematic uncertainties from the dependence of the PDFs on the choice of parametrization are studied by considering functional forms motivated by orbital angular momentum arguments. Finally, we quantify the reduction in the PDF uncertainties that may be expected from future high-x data from Jefferson Lab at 12 GeV.

DEVS representation of dynamical systems - Event-based intelligent control. [Discrete Event System Specification

NASA Technical Reports Server (NTRS)

Zeigler, Bernard P.

1989-01-01

It is shown how systems can be advantageously represented as discrete-event models by using DEVS (discrete-event system specification), a set-theoretic formalism. Such DEVS models provide a basis for the design of event-based logic control. In this control paradigm, the controller expects to receive confirming sensor responses to its control commands within definite time windows determined by its DEVS model of the system under control. The event-based contral paradigm is applied in advanced robotic and intelligent automation, showing how classical process control can be readily interfaced with rule-based symbolic reasoning systems.

Theoretical analysis of microring resonator-based biosensor with high resolution and free of temperature influence

NASA Astrophysics Data System (ADS)

Jian, Aoqun; Zou, Lu; Tang, Haiquan; Duan, Qianqian; Ji, Jianlong; Zhang, Qianwu; Zhang, Xuming; Sang, Shengbo

2017-06-01

The issue of thermal effects is inevitable for the ultrahigh refractive index (RI) measurement. A biosensor with parallel-coupled dual-microring resonator configuration is proposed to achieve high resolution and free thermal effects measurement. Based on the coupled-resonator-induced transparency effect, the design and principle of the biosensor are introduced in detail, and the performance of the sensor is deduced by simulations. Compared to the biosensor based on a single-ring configuration, the designed biosensor has a 10-fold increased Q value according to the simulation results, thus the sensor is expected to achieve a particularly high resolution. In addition, the output signal of the mathematical model of the proposed sensor can eliminate the thermal influence by adopting an algorithm. This work is expected to have great application potentials in the areas of high-resolution RI measurement, such as biomedical discoveries, virus screening, and drinking water safety.

Using Expectancy Value Theory as a Framework to Reduce Student Resistance to Active Learning: A Proof of Concept.

PubMed

Cooper, Katelyn M; Ashley, Michael; Brownell, Sara E

2017-01-01

There has been a national movement to transition college science courses from passive lectures to active learning environments. Active learning has been shown to be a more effective way for students to learn, yet there is concern that some students are resistant to active learning approaches. Although there is much discussion about student resistance to active learning, few studies have explored this topic. Furthermore, a limited number of studies have applied theoretical frameworks to student engagement in active learning. We propose using a theoretical lens of expectancy value theory to understand student resistance to active learning. In this study, we examined student perceptions of active learning after participating in 40 hours of active learning. We used the principal components of expectancy value theory to probe student experience in active learning: student perceived self-efficacy in active learning, value of active learning, and potential cost of participating in active learning. We found that students showed positive changes in the components of expectancy value theory and reported high levels of engagement in active learning, which provide proof of concept that expectancy value theory can be used to boost student perceptions of active learning and their engagement in active learning classrooms. From these findings, we have built a theoretical framework of expectancy value theory applied to active learning.

Using Expectancy Value Theory as a Framework to Reduce Student Resistance to Active Learning: A Proof of Concept

PubMed Central

Cooper, Katelyn M.; Ashley, Michael; Brownell, Sara E.

2017-01-01

There has been a national movement to transition college science courses from passive lectures to active learning environments. Active learning has been shown to be a more effective way for students to learn, yet there is concern that some students are resistant to active learning approaches. Although there is much discussion about student resistance to active learning, few studies have explored this topic. Furthermore, a limited number of studies have applied theoretical frameworks to student engagement in active learning. We propose using a theoretical lens of expectancy value theory to understand student resistance to active learning. In this study, we examined student perceptions of active learning after participating in 40 hours of active learning. We used the principal components of expectancy value theory to probe student experience in active learning: student perceived self-efficacy in active learning, value of active learning, and potential cost of participating in active learning. We found that students showed positive changes in the components of expectancy value theory and reported high levels of engagement in active learning, which provide proof of concept that expectancy value theory can be used to boost student perceptions of active learning and their engagement in active learning classrooms. From these findings, we have built a theoretical framework of expectancy value theory applied to active learning. PMID:28861130

Filtered maximum likelihood expectation maximization based global reconstruction for bioluminescence tomography.

PubMed

Yang, Defu; Wang, Lin; Chen, Dongmei; Yan, Chenggang; He, Xiaowei; Liang, Jimin; Chen, Xueli

2018-05-17

The reconstruction of bioluminescence tomography (BLT) is severely ill-posed due to the insufficient measurements and diffuses nature of the light propagation. Predefined permissible source region (PSR) combined with regularization terms is one common strategy to reduce such ill-posedness. However, the region of PSR is usually hard to determine and can be easily affected by subjective consciousness. Hence, we theoretically developed a filtered maximum likelihood expectation maximization (fMLEM) method for BLT. Our method can avoid predefining the PSR and provide a robust and accurate result for global reconstruction. In the method, the simplified spherical harmonics approximation (SP N ) was applied to characterize diffuse light propagation in medium, and the statistical estimation-based MLEM algorithm combined with a filter function was used to solve the inverse problem. We systematically demonstrated the performance of our method by the regular geometry- and digital mouse-based simulations and a liver cancer-based in vivo experiment. Graphical abstract The filtered MLEM-based global reconstruction method for BLT.

Patient expectations of dental services. Image affects expectations, and expectations affect perceived service quality.

PubMed

Clow, K E; Fischer, A K; O'Bryan, D

1995-01-01

The authors construct a theoretical model of the antecedents of expectations for dental services by analyzing survey responses from 240 dental patients. The patients' image of the dentist, tangible cues, situational factors, and patient satisfaction with prior service encounters have the greatest influence on expectations of service, whereas marketing variables, such as price and advertising, appear to have no effect.

Empirical modeling of an alcohol expectancy memory network using multidimensional scaling.

PubMed

Rather, B C; Goldman, M S; Roehrich, L; Brannick, M

1992-02-01

Risk-related antecedent variables can be linked to later alcohol consumption by memory processes, and alcohol expectancies may be one relevant memory content. To advance research in this area, it would be useful to apply current memory models such as semantic network theory to explain drinking decision processes. We used multidimensional scaling (MDS) to empirically model a preliminary alcohol expectancy semantic network, from which a theoretical account of drinking decision making was generated. Subanalyses (PREFMAP) showed how individuals with differing alcohol consumption histories may have had different association pathways within the expectancy network. These pathways may have, in turn influenced future drinking levels and behaviors while the person was under the influence of alcohol. All individuals associated positive/prosocial effects with drinking, but heavier drinkers indicated arousing effects as their highest probability associates, whereas light drinkers expected sedation. An important early step in this MDS modeling process is the determination of iso-meaning expectancy adjective groups, which correspond to theoretical network nodes.

Theoretical Near-IR Spectra for Surface Abundance Studies of Massive Stars

NASA Technical Reports Server (NTRS)

Sonneborn, George; Bouret, J.

2011-01-01

We present initial results of a study of abundance and mass loss properties of O-type stars based on theoretical near-IR spectra computed with state-of-the-art stellar atmosphere models. The James Webb Space Telescope (JWST) will be a powerful tool to obtain high signal-to-noise ratio near-IR (1-5 micron) spectra of massive stars in different environments of local galaxies. Our goal is to analyze model near-IR spectra corresponding to those expected from NIRspec on JWST in order to map the wind properties and surface composition across the parameter range of 0 stars and to determine projected rotational velocities. As a massive star evolves, internal coupling, related mixing, and mass loss impact its intrinsic rotation rate. These three parameters form an intricate loop, where enhanced rotation leads to more mixing which in turn changes the mass loss rate, the latter thus affecting the rotation rate. Since the effects of rotation are expected to be much more pronounced at low metallicity, we pay special attention to models for massive stars in the the Small Magellanic Cloud. This galaxy provides a unique opportunity to probe stellar evolution, and the feedback of massive stars on galactic evol.ution in conditions similar to the epoch of maximal star formation. Plain-Language Abstract: We present initial results of a study of abundance and mass loss properties of massive stars based on theoretical near-infrared (1-5 micron) spectra computed with state-of-the-art stellar atmosphere models. This study is to prepare for observations by the James Webb Space Telescope.

Linear Transforms for Fourier Data on the Sphere: Application to High Angular Resolution Diffusion MRI of the Brain

PubMed Central

Haldar, Justin P.; Leahy, Richard M.

2013-01-01

This paper presents a novel family of linear transforms that can be applied to data collected from the surface of a 2-sphere in three-dimensional Fourier space. This family of transforms generalizes the previously-proposed Funk-Radon Transform (FRT), which was originally developed for estimating the orientations of white matter fibers in the central nervous system from diffusion magnetic resonance imaging data. The new family of transforms is characterized theoretically, and efficient numerical implementations of the transforms are presented for the case when the measured data is represented in a basis of spherical harmonics. After these general discussions, attention is focused on a particular new transform from this family that we name the Funk-Radon and Cosine Transform (FRACT). Based on theoretical arguments, it is expected that FRACT-based analysis should yield significantly better orientation information (e.g., improved accuracy and higher angular resolution) than FRT-based analysis, while maintaining the strong characterizability and computational efficiency of the FRT. Simulations are used to confirm these theoretical characteristics, and the practical significance of the proposed approach is illustrated with real diffusion weighted MRI brain data. These experiments demonstrate that, in addition to having strong theoretical characteristics, the proposed approach can outperform existing state-of-the-art orientation estimation methods with respect to measures such as angular resolution and robustness to noise and modeling errors. PMID:23353603

Establishing values-based leadership and value systems in healthcare organizations.

PubMed

Graber, David R; Kilpatrick, Anne Osborne

2008-01-01

The importance of values in organizations is often discussed in management literature. Possessing strong or inspiring values is increasingly considered to be a key quality of successful leaders. Another common theme is that organizational values contribute to the culture and ultimate success of organizations. These conceptions or expectations are clearly applicable to healthcare organizations in the United States. However, healthcare organizations have unique structures and are subject to societal expectations that must be accommodated within an organizational values system. This article describes theoretical literature on organizational values. Cultural and religious influences on Americans and how they may influence expectations from healthcare providers are discussed. Organizational cultures and the training and socialization of the numerous professional groups in healthcare also add to the considerable heterogeneity of value systems within healthcare organizations. These contribute to another challenge confronting healthcare managers--competing or conflicting values within a unit or the entire organization. Organizations often fail to reward members who uphold or enact the organization's values, which can lead to lack of motivation and commitment to the organization. Four key elements of values-based leadership are presented for healthcare managers who seek to develop as values-based leaders. 1) Recognize your personal and professional values, 2) Determine what you expect from the larger organization and what you can implement within your sphere of influence, 3) Understand and incorporate the values of internal stakeholders, and 4) Commit to values-based leadership.

Finnish Primary and Secondary School Students' Interest in Music and Mathematics Relating to Enjoyment of the Subject and Perception of the Importance and Usefulness of the Subject

ERIC Educational Resources Information Center

Tossavainen, Timo; Juvonen, Antti

2015-01-01

Based on an expectancy-value theoretical framework and data (n = 1654) collected in 29 Finnish municipalities using a structured questionnaire, this study examines primary (grades 5-6), lower secondary (grades 7-9) and upper secondary (grades 10-12) students' motivation in music and mathematics. It explores in detail the students' interest in…

Junior Army Officer Retention Intentions: A Path Analytic Model

DTIC Science & Technology

1991-07-01

theoretically useful only if they explain behavior that cannot be predicted within traditional expectancy and equity based motivational models. Scholl (1981), in...argue that long-tenured employees need to justify their behavioral commitment to the organization. They do this by developing more positive attitudes...good" to "very poor" scale to rate opportunities for intrinsic work satisfaction (learn/ develop skills, do interesting work, exercise initiative) in

Chlorine hazard evaluation for the zinc-chlorine electric vehicle battery. Final technical report

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

Zalosh, R.G.; Bajpai, S.N.; Short, T.P.

1980-04-01

An evaluation of the hazards associated with conceivable accidental chlorine releases from zinc-chlorine electric vehicle batteries is presented. Since commercial batteries are not yet available, this hazard assessment is based both on theoretical chlorine dispersion models and small-scale and large-scale spill tests with chlorine hydrate. Six spill tests involving chlorine hydrate indicate that the danger zone in which chlorine vapor concentrations intermittently exceed 100 ppM extends at least 23 m directly downwind of a spill onto a warm road surface. Chlorine concentration data from the hydrate spill tests compare favorably with calculations based on a quasi-steady area source dispersion modelmore » and empirical estimates of the hydrate decomposition rate. The theoretical dispersion model has been combined with assumed hydrate spill probabilities and current motor vehicle accident statistics in order to project expected chlorine-induced fatality rates. These calculations indicate that expected chlorine fatality rates are several times higher in a city with a warm and calm climate than in a colder and windier city. Calculated chlorine-induced fatality rate projections for various climates are presented as a function of hydrate spill probability in order to illustrate the degree of vehicle/battery crashworthiness required to maintain chlorine-induced fatality rates below current vehicle fatility rates due to fires and asphyxiations.« less

Adaptively resizing populations: Algorithm, analysis, and first results

NASA Technical Reports Server (NTRS)

Smith, Robert E.; Smuda, Ellen

1993-01-01

Deciding on an appropriate population size for a given Genetic Algorithm (GA) application can often be critical to the algorithm's success. Too small, and the GA can fall victim to sampling error, affecting the efficacy of its search. Too large, and the GA wastes computational resources. Although advice exists for sizing GA populations, much of this advice involves theoretical aspects that are not accessible to the novice user. An algorithm for adaptively resizing GA populations is suggested. This algorithm is based on recent theoretical developments that relate population size to schema fitness variance. The suggested algorithm is developed theoretically, and simulated with expected value equations. The algorithm is then tested on a problem where population sizing can mislead the GA. The work presented suggests that the population sizing algorithm may be a viable way to eliminate the population sizing decision from the application of GA's.

Behavior determinants among cardiac rehabilitation patients receiving educational interventions: an application of the health action process approach.

PubMed

Ghisi, Gabriela Lima de Melo; Grace, Sherry L; Thomas, Scott; Oh, Paul

2015-05-01

To (1) test the effect of a health action process approach (HAPA) theory-based education program in cardiac rehabilitation (CR) compared to traditional education on patient knowledge and HAPA constructs; and, (2) investigate the theoretical correlates of exercise behavior among CR patients receiving theory-based education. CR patients were exposed to an existing or HAPA-based 6 month education curriculum in this quasi-experimental study. Participants completed a survey assessing exercise behavior, HAPA constructs, and knowledge pre and post-program. 306 patients consented to participate, of which 146 (47.7%) were exposed to the theory-based educational curriculum. There was a significant improvement in patients' overall knowledge pre- to post-CR, as well as in some HAPA constructs and exercise behavior, regardless of curriculum (p < 0.05). Path analysis revealed that knowledge was significantly related to intention formation, and intentions to engage in exercise were not directly related to behavior, which required action planning. The theoretically-informed education curriculum was not associated with greater knowledge or exercise behavior as expected. Education in CR improves knowledge, and theoretical constructs related to exercise behavior. Educational curricula should be designed to not only increase patients' knowledge, but also enhance intentions, self-efficacy, and action planning. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Formation of Monolayer Films by the Spontaneous Assembly of Organic Thiols from Solution onto Gold

DTIC Science & Technology

1988-09-01

estimated a theoretical slope of 1.27 A per CH2 unit and an intercept of 4 A. The dashed line represents the thickness expected for a monolayer tilted 30...angstroms--well below the length scale expected theoretically to give rise to hysteresis.3 1 , 7 8 Figure 4 plots contact angles on a monolayer of...obtained from high resolution spectra and have been rounded to the nearest percent. Atomic compositions were derived from peak areas using photoionization

Formation of Monolayer Films by the Spontaneous Assembly of Organic Thiols from Solution onto Gold

DTIC Science & Technology

1988-09-01

we estimated a theoretical slope of 1.27 A per CH2 unit and an intercept of 4 A. The dashed line represents the thickness expected for a monolayer...a scale of only a few hundred angstroms--well below the length scale expected theoretically to give rise to hysteresis.31 ,78 Figure 4 plots contact... photoionization cross-sections calculated by Scofield117 , corrected for the dependence of the escape depth on the kinetic energy of the electrons (assumed to have

The Electronic Spectra of Phthalocyanine Radical Anions and Cations.

DTIC Science & Technology

1985-03-01

415. (10) McHugh , A.J., Gouterman, M., Weiss, J., Theoret. Chim. Acta, 1972, 24, 346. (11) Henriksson, A. and Sundbom, M., Theoret. Chim. Acta, 1972, 27...oxidisable. The spectra for the nickel (II) Pc species exactly parallel the main group data since no change in oxidation state of the nickel ion is expect- ed18...and no charge transfer is expected in the region under study. 6 In summary, the main group complexes, nickel and cobalt species all have parallel

[Evaluation of the effect of varicella outbreak control measures through a discrete time delay SEIR model].

PubMed

Pan, Jin-ren; Huang, Zheng-qiang; Chen, Kun

2012-04-01

forecast the epidemic trend and to evaluate the effect of outbreak control measures by investigation of a varicella outbreak event with a discrete time delay SEIR model. A discrete time delay model was formulated by discretization method based on a continuous SEIR model with the consideration of the time delay effect on latent period and communicable period. The epidemic trend forecast was carried out based on the number of expected cases. The theoretical effect evaluation was assessed by comparing the results from different emergency control measures. Without any control measures, the theoretical attack rate was 30.16% (504/1671). The course of the epidemic lasted for 4 months and the peak epidemic time was 78 days after the onset of the first case. 'Generation' phenomenon had been observed in the course of the epidemic with the interval of two weeks. The actual number of cases was decreased by 89.48% (451/504) compared with the number of expected cases under no control measure scenario. With the rigorous quarantine measure for all cases on their onset day, when the measure was conducted on 0, 14, 28, 42 days after the onset of the first case, the total numbers of expected cases were 22, 59, 127 and 220 respectively. With the quarantine measure conducted on 14 days after the onset of the first case, when the proportion of quarantine was 30%, 50%, 70%, 90%, the total number of expected cases were 485, 457, 386 and 169, respectively. With the emergent vaccination for all persons, when the measure was conducted on 0, 14, 28, 42 days after the onset of the first case, the total numbers of expected cases were 7, 26, 81 and 202 respectively. With the emergent vaccination conducted on 14 days after the onset of the first case, when the immunization coverage rate was 30%, 50%, 70%, 90%, the total numbers of expected cases were 354, 246, 127 and 40, respectively. The number of expected cases can be regarded as the reference to evaluate the effect of control measures. The simulation results suggest that it will get more benefits to conduct control measures earlier in varicella outbreak events, and the effect of emergent vaccination is better than that of quarantine measure under the same conditions.

Range-based volatility, expected stock returns, and the low volatility anomaly

PubMed Central

2017-01-01

One of the foundations of financial economics is the idea that rational investors will discount stocks with more risk (volatility), which will result in a positive relation between risk and future returns. However, the empirical evidence is mixed when determining how volatility is related to future returns. In this paper, we examine this relation using a range-based measure of volatility, which is shown to be theoretically, numerically, and empirically superior to other measures of volatility. In a variety of tests, we find that range-based volatility is negatively associated with expected stock returns. These results are robust to time-series multifactor models as well as cross-sectional tests. Our findings contribute to the debate about the direction of the relationship between risk and return and confirm the presence of the low volatility anomaly, or the anomalous finding that low volatility stocks outperform high volatility stocks. In other tests, we find that the lower returns associated with range-based volatility are driven by stocks with lottery-like characteristics. PMID:29190652

Range-based volatility, expected stock returns, and the low volatility anomaly.

PubMed

Blau, Benjamin M; Whitby, Ryan J

2017-01-01

One of the foundations of financial economics is the idea that rational investors will discount stocks with more risk (volatility), which will result in a positive relation between risk and future returns. However, the empirical evidence is mixed when determining how volatility is related to future returns. In this paper, we examine this relation using a range-based measure of volatility, which is shown to be theoretically, numerically, and empirically superior to other measures of volatility. In a variety of tests, we find that range-based volatility is negatively associated with expected stock returns. These results are robust to time-series multifactor models as well as cross-sectional tests. Our findings contribute to the debate about the direction of the relationship between risk and return and confirm the presence of the low volatility anomaly, or the anomalous finding that low volatility stocks outperform high volatility stocks. In other tests, we find that the lower returns associated with range-based volatility are driven by stocks with lottery-like characteristics.

Do Others' Views of Us Transfer to New Groups and Tasks?: An Expectation States Approach

ERIC Educational Resources Information Center

Kalkhoff, Will; Younts, C. Wesley; Troyer, Lisa

2011-01-01

The dual nature of the self has been a core concern of social psychology since its inception. We contribute to this longstanding tradition of inquiry by focusing on two lines of research within the expectation states theoretical research program: (1) the study of second-order expectations and (2) research on the durability of expectations. We…

Understanding Students' Motivation in Sport and Physical Education: From the Expectancy-Value Model and Self-Efficacy Theory Perspectives

ERIC Educational Resources Information Center

Gao, Zan; Lee, Amelia M.; Harrison, Louis, Jr.

2008-01-01

In this article, the roles of individuals' expectancy beliefs and incentives (i.e., task value, outcome expectancy) in sport and physical education are examined from expectancy-value model and self-efficacy theory perspectives. Overviews of the two theoretical frameworks and the conceptual and measurement issues are provided, followed by a review…

A passive microwave technique for estimating rainfall and vertical structure information from space. Part 1: Algorithm description

NASA Technical Reports Server (NTRS)

Kummerow, Christian; Giglio, Louis

1994-01-01

This paper describes a multichannel physical approach for retrieving rainfall and vertical structure information from satellite-based passive microwave observations. The algorithm makes use of statistical inversion techniques based upon theoretically calculated relations between rainfall rates and brightness temperatures. Potential errors introduced into the theoretical calculations by the unknown vertical distribution of hydrometeors are overcome by explicity accounting for diverse hydrometeor profiles. This is accomplished by allowing for a number of different vertical distributions in the theoretical brightness temperature calculations and requiring consistency between the observed and calculated brightness temperatures. This paper will focus primarily on the theoretical aspects of the retrieval algorithm, which includes a procedure used to account for inhomogeneities of the rainfall within the satellite field of view as well as a detailed description of the algorithm as it is applied over both ocean and land surfaces. The residual error between observed and calculated brightness temperatures is found to be an important quantity in assessing the uniqueness of the solution. It is further found that the residual error is a meaningful quantity that can be used to derive expected accuracies from this retrieval technique. Examples comparing the retrieved results as well as the detailed analysis of the algorithm performance under various circumstances are the subject of a companion paper.

Consumerism and consumer complexity: implications for university teaching and teaching evaluation.

PubMed

Hall, Wendy A

2013-07-01

A contemporary issue is the effects of a corporate production metaphor and consumerism on university education. Efforts by universities to attract students and teaching strategies aimed at 'adult learners' tend to treat student consumers as a homogeneous group with similar expectations. In this paper, I argue that consumer groups are not uniform. I use Dagevos' theoretical approach to categorize consumers as calculating, traditional, unique, and responsible. Based on the characteristics of consumers occupying these categories, I describe the implications of the varying consumer expectations for teaching. I also consider the implications for evaluation of teaching and call for research taking consumer types into account when evaluating teaching. Copyright © 2013 Elsevier Ltd. All rights reserved.

Outcome regimes of binary raindrop collisions

NASA Astrophysics Data System (ADS)

Testik, Firat Y.

2009-11-01

This study delineates the physical conditions that are responsible for the occurrence of main outcome regimes (i.e., bounce, coalescence, and breakup) for binary drop collisions with a precipitation microphysics perspective. Physical considerations based on the collision kinetic energy and the surface energies of the colliding drops lead to the development of a theoretical regime diagram for the drop/raindrop collision outcomes in the We- p plane ( We — Weber number, p — raindrop diameter ratio). This theoretical regime diagram is supported by laboratory experimental observations of drop collisions using high-speed imaging. Results of this fundamental study bring in new insights into the quantitative understanding of drop dynamics, applications of which extend beyond precipitation microphysics. In particular, results of this drop collision study are expected to give impetus to the physics-based dynamic modeling of the drop size distributions that is essential for various typical modern engineering applications, including numerical modeling of evolution of raindrop size distribution in rain shaft.

Sound radiation from randomly vibrating beams of finite circular cross section

NASA Technical Reports Server (NTRS)

Sutterlin, M. W.; Pierce, A. D.

1976-01-01

The radiation of sound from vibrating cylindrical beams is analyzed based on the frequency of the beam vibrations and the physical characteristics of the beam and its surroundings. A statistical analysis of random beam vibrations allows this result to be independent of the boundary conditions at the ends of the beam. The acoustic power radiated by the beam can be determined from a knowledge of the frequency band vibration data without a knowledge of the individual modal vibration amplitudes. A practical example of the usefulness of this technique is provided by the application of the theoretical calculations to the prediction of the octave band acoustic power output of the picking sticks of an automatic textile loom. Calculations are made of the expected octave band sound pressure levels based on measured acceleration data. These theoretical levels are subsequently compared with actual sound pressure level measurements of loom noise.

The Feedback-Related Negativity and the P300 Brain Potential Are Sensitive to Price Expectation Violations in a Virtual Shopping Task.

PubMed

Schaefer, Alexandre; Buratto, Luciano G; Goto, Nobuhiko; Brotherhood, Emilie V

A large body of evidence shows that buying behaviour is strongly determined by consumers' price expectations and the extent to which real prices violate these expectations. Despite the importance of this phenomenon, little is known regarding its neural mechanisms. Here we show that two patterns of electrical brain activity known to index prediction errors-the Feedback-Related Negativity (FRN) and the feedback-related P300 -were sensitive to price offers that were cheaper than participants' expectations. In addition, we also found that FRN amplitude time-locked to price offers predicted whether a product would be subsequently purchased or not, and further analyses suggest that this result was driven by the sensitivity of the FRN to positive price expectation violations. This finding strongly suggests that ensembles of neurons coding positive prediction errors play a critical role in real-life consumer behaviour. Further, these findings indicate that theoretical models based on the notion of prediction error, such as the Reinforcement Learning Theory, can provide a neurobiologically grounded account of consumer behavior.

The Feedback-Related Negativity and the P300 Brain Potential Are Sensitive to Price Expectation Violations in a Virtual Shopping Task

PubMed Central

Schaefer, Alexandre; Buratto, Luciano G.; Goto, Nobuhiko; Brotherhood, Emilie V.

2016-01-01

A large body of evidence shows that buying behaviour is strongly determined by consumers’ price expectations and the extent to which real prices violate these expectations. Despite the importance of this phenomenon, little is known regarding its neural mechanisms. Here we show that two patterns of electrical brain activity known to index prediction errors–the Feedback-Related Negativity (FRN) and the feedback-related P300 –were sensitive to price offers that were cheaper than participants’ expectations. In addition, we also found that FRN amplitude time-locked to price offers predicted whether a product would be subsequently purchased or not, and further analyses suggest that this result was driven by the sensitivity of the FRN to positive price expectation violations. This finding strongly suggests that ensembles of neurons coding positive prediction errors play a critical role in real-life consumer behaviour. Further, these findings indicate that theoretical models based on the notion of prediction error, such as the Reinforcement Learning Theory, can provide a neurobiologically grounded account of consumer behavior. PMID:27658301

Distribution of eigenfrequencies for oscillations of the ground state in the Thomas-Fermi limit

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

Kevrekidis, P. G.; Pelinovsky, D. E.

In this work, we present a systematic derivation of the distribution of eigenfrequencies for oscillations of the ground state of a repulsive Bose-Einstein condensate in the semi-classical (Thomas-Fermi) limit. Our calculations are performed in one, two, and three-dimensional settings. Connections with the earlier work of Stringari, with numerical computations, and with theoretical expectations for invariant frequencies based on symmetry principles are also given.

Expectancy-Value and Cognitive Process Outcomes in Mathematics Learning: A Structural Equation Analysis

ERIC Educational Resources Information Center

Phan, Huy P.

2014-01-01

Existing research has yielded evidence to indicate that the expectancy-value theoretical model predicts students' learning in various achievement contexts. Achievement values and self-efficacy expectations, for example, have been found to exert positive effects on cognitive process and academic achievement outcomes. We tested a conceptual model…

Locating Sensors for Detecting Source-to-Target Patterns of Special Nuclear Material Smuggling: A Spatial Information Theoretic Approach

PubMed Central

Przybyla, Jay; Taylor, Jeffrey; Zhou, Xuesong

2010-01-01

In this paper, a spatial information-theoretic model is proposed to locate sensors for detecting source-to-target patterns of special nuclear material (SNM) smuggling. In order to ship the nuclear materials from a source location with SNM production to a target city, the smugglers must employ global and domestic logistics systems. This paper focuses on locating a limited set of fixed and mobile radiation sensors in a transportation network, with the intent to maximize the expected information gain and minimize the estimation error for the subsequent nuclear material detection stage. A Kalman filtering-based framework is adapted to assist the decision-maker in quantifying the network-wide information gain and SNM flow estimation accuracy. PMID:22163641

Towards a theory of tiered testing.

PubMed

Hansson, Sven Ove; Rudén, Christina

2007-06-01

Tiered testing is an essential part of any resource-efficient strategy for the toxicity testing of a large number of chemicals, which is required for instance in the risk management of general (industrial) chemicals, In spite of this, no general theory seems to be available for the combination of single tests into efficient tiered testing systems. A first outline of such a theory is developed. It is argued that chemical, toxicological, and decision-theoretical knowledge should be combined in the construction of such a theory. A decision-theoretical approach for the optimization of test systems is introduced. It is based on expected utility maximization with simplified assumptions covering factual and value-related information that is usually missing in the development of test systems.

Locating sensors for detecting source-to-target patterns of special nuclear material smuggling: a spatial information theoretic approach.

PubMed

Przybyla, Jay; Taylor, Jeffrey; Zhou, Xuesong

2010-01-01

In this paper, a spatial information-theoretic model is proposed to locate sensors for detecting source-to-target patterns of special nuclear material (SNM) smuggling. In order to ship the nuclear materials from a source location with SNM production to a target city, the smugglers must employ global and domestic logistics systems. This paper focuses on locating a limited set of fixed and mobile radiation sensors in a transportation network, with the intent to maximize the expected information gain and minimize the estimation error for the subsequent nuclear material detection stage. A Kalman filtering-based framework is adapted to assist the decision-maker in quantifying the network-wide information gain and SNM flow estimation accuracy.

A review of the outcome expectancy construct in physical activity research.

PubMed

Williams, David M; Anderson, Eileen S; Winett, Richard A

2005-02-01

Outcome expectancy is a central construct in social cognitive models of health behavior widely used as frameworks for physical activity research. This article provides a review of the outcome expectancy construct and its application to research on physical activity. Theoretical articles describing definitions and placement of outcome expectancy within social cognitive models, as well as empirical research on outcome expectancy and physical activity, were reviewed. Self-efficacy theory, the transtheoretical model, the theory of planned behavior, and protection motivation theory differ in their labeling and conceptualization of outcome expectancy but unanimously include expected outcomes of behavior. Preliminary empirical investigation of the role of outcome expectancy in understanding physical activity has yielded mixed results. Positive outcome expectancy appears to be more predictive of physical activity in older adults than in young to middle-aged adults, and personal barriers appear to be the most predictive subtype of negative outcome expectancy. In addition, a small number of studies indicate relations between outcome expectancy and other theoretical variables, including behavioral intention, stage of change, and self-efficacy. Further research on the role of outcome expectancy is necessary to design effective physical activity interventions. New directions in outcome expectancy research could involve (a) expanding the conceptualization of outcome expectancy to include expected outcomes of sedentary behavior and affective responses to physical activity, (b) further examination of potential moderators of the relation between outcome expectancy and physical activity (such as outcome value and outcome proximity), (c) distinguishing between the role of outcome expectancy in behavior onset versus behavior maintenance, (d) examining outcome expectancy as a mechanism of change in environmental intervention approaches, and (e) further analysis of interrelations between outcome expectancy and other social cognitive variables.

The Role of Theory in Increasing Adherence to Prescribed Practice

PubMed Central

Richardson, Julie; Wishart, Laurie; Hanna, Steven

2009-01-01

ABSTRACT Purpose: The purpose of this article is to apply theoretical frameworks to adherence behaviour and to guide the development of an intervention to increase adherence to prescribed home programmes. Summary of Key Points: Delivering an effective intervention requires establishing one that is evidence based and of adequate dosage. Two-thirds of patients who receive home exercise prescriptions do not adhere to their home programme, which may contribute to their physiotherapy's being ineffective. The mediating concepts of self-efficacy (SE) and outcome expectations (OE) are common to the five relevant theories used to explain adherence to exercise: the health belief model, protection motivation theory, theory of reasoned action, theory of planned behaviour, and social cognitive theory. Conclusion/Recommendations: Few intervention studies with any theoretical underpinning have examined adherence to exercise. Even fewer have been designed to affect and measure change in the theoretical mediators of SE and OE in patient populations. Physiotherapists must consider increasing adherence as a component of effective physiotherapy. Ongoing research is needed to increase our understanding of adherence to prescribed home programmes and to design interventions to affect theoretical mediators for increasing adherence. PMID:20190989

Status, emotional displays, and the relationally-based evaluation of criminals and their behavior.

PubMed

Dilks, Lisa M; McGrimmon, Tucker S; Thye, Shane R

2015-03-01

This research uses status characteristics theory to expand our knowledge of the effects of status variables (e.g., race, education) and emotional displays on the antecedents of sentencing - evaluations of offender dangerousness and offense seriousness. We present a theoretical formulation that combines three areas of status characteristics research - reward expectations, individual evaluative settings and valued personal characteristics. The result is a quantitative measure that aggregates relative differences in demographic and emotional characteristics between offenders and their victims. The significance of this expectation advantage measure (e) in predicting evaluations of offender dangerousness and offense severity is tested using data from a vignette study. We find empirical support that expectation advantage significantly predicts these sentencing antecedents but not sentencing outcomes directly. We conclude by discussing the implications of our findings for future status and criminological research. Copyright © 2014 Elsevier Inc. All rights reserved.

Measured and calculated K-fluorescence effects on the MTF of an amorphous-selenium based CCD x-ray detector.

PubMed

Hunter, David M; Belev, George; Kasap, Safa; Yaffe, Martin J

2012-02-01

Theoretical reasoning suggests that direct conversion digital x-ray detectors based upon photoconductive amorphous-selenium (a-Se) could attain very high values of the MTF (modulation transfer function) at spatial frequencies well beyond 20 cycles mm(-1). One of the fundamental factors affecting resolution loss, particularly at x-ray energies just above the K-edge of selenium (12.66 keV), is the K-fluorescence reabsorption mechanism, wherein energy can be deposited in the detector at locations laterally displaced from the initial x-ray interaction site. This paper compares measured MTF changes above and below the Se K-edge of a CCD based a-Se x-ray detector with theoretical expectations. A prototype 25 μm sampling pitch (Nyquist frequency = 20 cycles mm(-1), 200 μm thick a-Se layer based x-ray detector, utilizing a specialized CCD readout device (200 × 400 area array), was used to make edge images with monochromatic x-rays above and below the K-edge of Se. A vacuum double crystal monochromator, exposed to polychromatic x-rays from a synchrotron, formed the monochromatic x-ray source. The monochromaticity of the x-rays was 99% or better. The presampling MTF was determined using the slanted edge method. The theory modeling the MTF performance of the detector includes the basic x-ray interaction physics in the a-Se layer as well as effects related to the operation of the CCD and charge trapping at a blocking layer present at the CCD/a-Se interface. The MTF performance of the prototype a-Se CCD was reduced from the theoretical value prescribed by the basic Se x-ray interaction physics, principally by the presence of a blocking layer. Nevertheless, the K-fluorescence reduction in the MTF was observed, approximately as predicted by theory. For the CCD prototype detector, at five cycles mm(-1), there was a 14% reduction of the MTF, from a value of 0.7 below the K-edge of Se, to 0.6 just above the K-edge. The MTF of an a-Se x-ray detector has been measured using monochromatic x-rays above and below the K-edge of selenium. The MTF is poorer above the K-edge by an amount consistent with theoretical expectations.

Linear transforms for Fourier data on the sphere: application to high angular resolution diffusion MRI of the brain.

PubMed

Haldar, Justin P; Leahy, Richard M

2013-05-01

This paper presents a novel family of linear transforms that can be applied to data collected from the surface of a 2-sphere in three-dimensional Fourier space. This family of transforms generalizes the previously-proposed Funk-Radon Transform (FRT), which was originally developed for estimating the orientations of white matter fibers in the central nervous system from diffusion magnetic resonance imaging data. The new family of transforms is characterized theoretically, and efficient numerical implementations of the transforms are presented for the case when the measured data is represented in a basis of spherical harmonics. After these general discussions, attention is focused on a particular new transform from this family that we name the Funk-Radon and Cosine Transform (FRACT). Based on theoretical arguments, it is expected that FRACT-based analysis should yield significantly better orientation information (e.g., improved accuracy and higher angular resolution) than FRT-based analysis, while maintaining the strong characterizability and computational efficiency of the FRT. Simulations are used to confirm these theoretical characteristics, and the practical significance of the proposed approach is illustrated with real diffusion weighted MRI brain data. These experiments demonstrate that, in addition to having strong theoretical characteristics, the proposed approach can outperform existing state-of-the-art orientation estimation methods with respect to measures such as angular resolution and robustness to noise and modeling errors. Copyright © 2013 Elsevier Inc. All rights reserved.

Solar neutrinos and the MSW effect for three-neutrino mixing

NASA Technical Reports Server (NTRS)

Shi, X.; Schramm, David N.

1991-01-01

Researchers considered three-neutrino Mikheyev-Smirnov-Wolfenstein (MSW) mixing, assuming m sub 3 is much greater than m sub 2 is greater than m sub 1 as expected from theoretical consideration if neutrinos have mass. They calculated the corresponding mixing parameter space allowed by the Cl-37 and Kamiokande 2 experiments. They also calculated the expected depletion for the Ga-71 experiment. They explored a range of theoretical uncertainty due to possible astrophysical effects by varying the B-8 neutrino flux and redoing the MSW mixing calculation.

Impact of a parent-child sexual communication campaign: results from a controlled efficacy trial of parents.

PubMed

Davis, Kevin C; Blitstein, Jonathan L; Evans, W Douglas; Kamyab, Kian

2010-07-21

Prior research supports the notion that parents have the ability to influence their children's decisions regarding sexual behavior. Yet parent-based approaches to curbing teen pregnancy and STDs have been relatively unexplored. The Parents Speak Up National Campaign (PSUNC) is a multimedia campaign that attempts to fill this void by targeting parents of teens to encourage parent-child communication about waiting to have sex. The campaign follows a theoretical framework that identifies cognitions that are targeted in campaign messages and theorized to influence parent-child communication. While a previous experimental study showed PSUNC messages to be effective in increasing parent-child communication, it did not address how these effects manifest through the PSUNC theoretical framework. The current study examines the PSUNC theoretical framework by 1) estimating the impact of PSUNC on specific cognitions identified in the theoretical framework and 2) examining whether those cognitions are indeed associated with parent-child communication Our study consists of a randomized efficacy trial of PSUNC messages under controlled conditions. A sample of 1,969 parents was randomly assigned to treatment (PSUNC exposure) and control (no exposure) conditions. Parents were surveyed at baseline, 4 weeks, 6 months, 12 months, and 18 months post-baseline. Linear regression procedures were used in our analyses. Outcome variables included self-efficacy to communicate with child, long-term outcome expectations that communication would be successful, and norms on appropriate age for sexual initiation. We first estimated multivariable models to test whether these cognitive variables predict parent-child communication longitudinally. Longitudinal change in each cognitive variable was then estimated as a function of treatment condition, controlling for baseline individual characteristics. Norms related to appropriate age for sexual initiation and outcome expectations that communication would be successful were predictive of parent-child communication among both mothers and fathers. Treatment condition mothers exhibited larger changes than control mothers in both of these cognitive variables. Fathers exhibited no exposure effects. Results suggest that within a controlled setting, the "wait until older norm" and long-term outcome expectations were appropriate cognitions to target and the PSUNC media materials were successful in impacting them, particularly among mothers. This study highlights the importance of theoretical frameworks for parent-focused campaigns that identify appropriate behavioral precursors that are both predictive of a campaign's distal behavioral outcome and sensitive to campaign messages.

Temperature-strain discrimination in distributed optical fiber sensing using phase-sensitive optical time-domain reflectometry.

PubMed

Lu, Xin; Soto, Marcelo A; Thévenaz, Luc

2017-07-10

A method based on coherent Rayleigh scattering distinctly evaluating temperature and strain is proposed and experimentally demonstrated for distributed optical fiber sensing. Combining conventional phase-sensitive optical time-domain domain reflectometry (ϕOTDR) and ϕOTDR-based birefringence measurements, independent distributed temperature and strain profiles are obtained along a polarization-maintaining fiber. A theoretical analysis, supported by experimental data, indicates that the proposed system for temperature-strain discrimination is intrinsically better conditioned than an equivalent existing approach that combines classical Brillouin sensing with Brillouin dynamic gratings. This is due to the higher sensitivity of coherent Rayleigh scatting compared to Brillouin scattering, thus offering better performance and lower temperature-strain uncertainties in the discrimination. Compared to the Brillouin-based approach, the ϕOTDR-based system here proposed requires access to only one fiber-end, and a much simpler experimental layout. Experimental results validate the full discrimination of temperature and strain along a 100 m-long elliptical-core polarization-maintaining fiber with measurement uncertainties of ~40 mK and ~0.5 με, respectively. These values agree very well with the theoretically expected measurand resolutions.

MADM-based smart parking guidance algorithm

PubMed Central

Li, Bo; Pei, Yijian; Wu, Hao; Huang, Dijiang

2017-01-01

In smart parking environments, how to choose suitable parking facilities with various attributes to satisfy certain criteria is an important decision issue. Based on the multiple attributes decision making (MADM) theory, this study proposed a smart parking guidance algorithm by considering three representative decision factors (i.e., walk duration, parking fee, and the number of vacant parking spaces) and various preferences of drivers. In this paper, the expected number of vacant parking spaces is regarded as an important attribute to reflect the difficulty degree of finding available parking spaces, and a queueing theory-based theoretical method was proposed to estimate this expected number for candidate parking facilities with different capacities, arrival rates, and service rates. The effectiveness of the MADM-based parking guidance algorithm was investigated and compared with a blind search-based approach in comprehensive scenarios with various distributions of parking facilities, traffic intensities, and user preferences. Experimental results show that the proposed MADM-based algorithm is effective to choose suitable parking resources to satisfy users’ preferences. Furthermore, it has also been observed that this newly proposed Markov Chain-based availability attribute is more effective to represent the availability of parking spaces than the arrival rate-based availability attribute proposed in existing research. PMID:29236698

Experimental limits on weak annihilation contributions to decays.

PubMed

Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Phillips, E A; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stoeck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; Thaler, J J; White, E J; Wiss, J; Shepherd, M R; Asner, D M; Edwards, K W; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Ernst, J; Arms, K; Severini, H; Dytman, S A; Love, W; Mehrabyan, S; Mueller, J A; Savinov, V; Li, Z; Lopez, A; Mendez, H; Ramirez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Napolitano, J; He, Q; Muramatsu, H; Park, C S; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Stroynowski, R; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Li, J; Menaa, N; Mountain, R; Nisar, S; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Weinstein, A J; Briere, R A; Chen, G P; Chen, J; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E

2006-03-31

We present the first experimental limits on high-q2 contributions to charmless semileptonic decays of the form expected from the weak annihilation (WA) decay mechanism. Such contributions could bias determinations of /Vub/ from inclusive measurements of B-->Xulupsilon. Using a wide range of models based on available theoretical input we set a limit of GammaWA/Gammab-->u<7.4% (90% confidence level) on the WA fraction, and assess the impact on previous inclusive determinations of /Vub/.

Energetic particle instabilities in fusion plasmas

NASA Astrophysics Data System (ADS)

Sharapov, S. E.; Alper, B.; Berk, H. L.; Borba, D. N.; Breizman, B. N.; Challis, C. D.; Classen, I. G. J.; Edlund, E. M.; Eriksson, J.; Fasoli, A.; Fredrickson, E. D.; Fu, G. Y.; Garcia-Munoz, M.; Gassner, T.; Ghantous, K.; Goloborodko, V.; Gorelenkov, N. N.; Gryaznevich, M. P.; Hacquin, S.; Heidbrink, W. W.; Hellesen, C.; Kiptily, V. G.; Kramer, G. J.; Lauber, P.; Lilley, M. K.; Lisak, M.; Nabais, F.; Nazikian, R.; Nyqvist, R.; Osakabe, M.; Perez von Thun, C.; Pinches, S. D.; Podesta, M.; Porkolab, M.; Shinohara, K.; Schoepf, K.; Todo, Y.; Toi, K.; Van Zeeland, M. A.; Voitsekhovich, I.; White, R. B.; Yavorskij, V.; TG, ITPA EP; Contributors, JET-EFDA

2013-10-01

Remarkable progress has been made in diagnosing energetic particle instabilities on present-day machines and in establishing a theoretical framework for describing them. This overview describes the much improved diagnostics of Alfvén instabilities and modelling tools developed world-wide, and discusses progress in interpreting the observed phenomena. A multi-machine comparison is presented giving information on the performance of both diagnostics and modelling tools for different plasma conditions outlining expectations for ITER based on our present knowledge.

A Game Theoretic Framework for Power Control in Wireless Sensor Networks (POSTPRINT)

DTIC Science & Technology

2010-02-01

which the sensor nodes compute based on past observations. Correspondingly, Pe can only be estimated; for example, with a noncoherent FSK modula...bit error probability for the link (i ! j) is given by some inverse function of j. For example, with noncoherent FSK modulation scheme, Pe ¼ 0:5e j...show the results for two different modulation schemes: DPSK and noncoherent PSK. As expected, with improvement in channel condition, i.e., with increase

Rethinking Theoretical Approaches to Stigma

PubMed Central

Martin, Jack K; Lang, Annie; Olafsdottir, Sigrun

2008-01-01

A resurgence of research and policy efforts on stigma both facilitates and forces a reconsideration of the levels and types of factors that shape reactions to persons with conditions that engender prejudice and discrimination. Focusing on the case of mental illness but drawing from theories and studies of stigma across the social sciences, we propose a framework that brings together theoretical insights from micro, meso and macro level research: Framework Integrating Normative Influences on Stigma (FINIS) starts with Goffman’s notion that understanding stigma requires a language of social relationships, but acknowledges that individuals do not come to social interaction devoid of affect and motivation. Further, all social interactions take place in a context in which organizations, media and larger cultures structure normative expectations which create the possibility of marking “difference”. Labelling theory, social network theory, the limited capacity model of media influence, the social psychology of prejudice and discrimination, and theories of the welfare state all contribute to an understanding of the complex web of expectations shaping stigma. FINIS offers the potential to build a broad-based scientific foundation based on understanding the effects of stigma on the lives of persons with mental illness, the resources devoted to the organizations and families who care for them, and policies and programs designed to combat stigma. We end by discussing the clear implications this framework holds for stigma reduction, even in the face of conflicting results. PMID:18436358

Rethinking theoretical approaches to stigma: a Framework Integrating Normative Influences on Stigma (FINIS).

PubMed

Pescosolido, Bernice A; Martin, Jack K; Lang, Annie; Olafsdottir, Sigrun

2008-08-01

A resurgence of research and policy efforts on stigma both facilitates and forces a reconsideration of the levels and types of factors that shape reactions to persons with conditions that engender prejudice and discrimination. Focusing on the case of mental illness but drawing from theories and studies of stigma across the social sciences, we propose a framework that brings together theoretical insights from micro, meso and macro level research: Framework Integrating Normative Influences on Stigma (FINIS) starts with Goffman's notion that understanding stigma requires a language of social relationships, but acknowledges that individuals do not come to social interaction devoid of affect and motivation. Further, all social interactions take place in a context in which organizations, media and larger cultures structure normative expectations which create the possibility of marking "difference". Labelling theory, social network theory, the limited capacity model of media influence, the social psychology of prejudice and discrimination, and theories of the welfare state all contribute to an understanding of the complex web of expectations shaping stigma. FINIS offers the potential to build a broad-based scientific foundation based on understanding the effects of stigma on the lives of persons with mental illness, the resources devoted to the organizations and families who care for them, and policies and programs designed to combat stigma. We end by discussing the clear implications this framework holds for stigma reduction, even in the face of conflicting results.

Decision-theoretic approach to data acquisition for transit operations planning

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

Ritchie, S.G.

The most costly element of transportation planning and modeling activities in the past has usually been that of data acquisition. This is even truer today when the unit costs of data collection are increasing rapidly and at the same time budgets are severely limited by continuing policies of fiscal austerity in the public sector. The overall objectives of this research were to improve the decisions and decision-making capabilities of transit operators or planners in short-range transit planning, and to improve the quality and cost-effectiveness of associated route or corridor-level data collection and service monitoring activities. A new approach was presentedmore » for sequentially updating the parameters of both simple and multiple linear regression models with stochastic regressors, and for determining the expected value of sample information and expected net gain of sampling for associated sample designs. A new approach was also presented for estimating and updating (both spatially and temporally) the parameters of multinomial logit discrete choice models, and for determining associated optimal sample designs for attribute-based and choice-based sampling methods. The approach provides an effective framework for addressing the issue of optimal sampling method and sample size, which to date have been largely unresolved. The application of these methodologies and the feasibility of the decision-theoretic approach was illustrated with a hypothetical case study example.« less

InChIKey collision resistance: an experimental testing

PubMed Central

2012-01-01

InChIKey is a 27-character compacted (hashed) version of InChI which is intended for Internet and database searching/indexing and is based on an SHA-256 hash of the InChI character string. The first block of InChIKey encodes molecular skeleton while the second block represents various kinds of isomerism (stereo, tautomeric, etc.). InChIKey is designed to be a nearly unique substitute for the parent InChI. However, a single InChIKey may occasionally map to two or more InChI strings (collision). The appearance of collision itself does not compromise the signature as collision-free hashing is impossible; the only viable approach is to set and keep a reasonable level of collision resistance which is sufficient for typical applications. We tested, in computational experiments, how well the real-life InChIKey collision resistance corresponds to the theoretical estimates expected by design. For this purpose, we analyzed the statistical characteristics of InChIKey for datasets of variable size in comparison to the theoretical statistical frequencies. For the relatively short second block, an exhaustive direct testing was performed. We computed and compared to theory the numbers of collisions for the stereoisomers of Spongistatin I (using the whole set of 67,108,864 isomers and its subsets). For the longer first block, we generated, using custom-made software, InChIKeys for more than 3 × 1010 chemical structures. The statistical behavior of this block was tested by comparison of experimental and theoretical frequencies for the various four-letter sequences which may appear in the first block body. From the results of our computational experiments we conclude that the observed characteristics of InChIKey collision resistance are in good agreement with theoretical expectations. PMID:23256896

InChIKey collision resistance: an experimental testing.

PubMed

Pletnev, Igor; Erin, Andrey; McNaught, Alan; Blinov, Kirill; Tchekhovskoi, Dmitrii; Heller, Steve

2012-12-20

InChIKey is a 27-character compacted (hashed) version of InChI which is intended for Internet and database searching/indexing and is based on an SHA-256 hash of the InChI character string. The first block of InChIKey encodes molecular skeleton while the second block represents various kinds of isomerism (stereo, tautomeric, etc.). InChIKey is designed to be a nearly unique substitute for the parent InChI. However, a single InChIKey may occasionally map to two or more InChI strings (collision). The appearance of collision itself does not compromise the signature as collision-free hashing is impossible; the only viable approach is to set and keep a reasonable level of collision resistance which is sufficient for typical applications.We tested, in computational experiments, how well the real-life InChIKey collision resistance corresponds to the theoretical estimates expected by design. For this purpose, we analyzed the statistical characteristics of InChIKey for datasets of variable size in comparison to the theoretical statistical frequencies. For the relatively short second block, an exhaustive direct testing was performed. We computed and compared to theory the numbers of collisions for the stereoisomers of Spongistatin I (using the whole set of 67,108,864 isomers and its subsets). For the longer first block, we generated, using custom-made software, InChIKeys for more than 3 × 1010 chemical structures. The statistical behavior of this block was tested by comparison of experimental and theoretical frequencies for the various four-letter sequences which may appear in the first block body.From the results of our computational experiments we conclude that the observed characteristics of InChIKey collision resistance are in good agreement with theoretical expectations.

Met or matched expectations: what accounts for a successful back pain consultation in primary care?

PubMed Central

Georgy, Ehab E.; Carr, Eloise C.J.; Breen, Alan C.

2011-01-01

Abstract Background  Patients’ as well as doctors’ expectations might be key elements for improving the quality of health care; however, previous conceptual and theoretical frameworks related to expectations often overlook such complex and complementary relationship between patients’ and doctors’ expectations. The concept of ‘matched patient–doctor expectations’ is not properly investigated, and there is lack of literature exploring such aspect of the consultation. Aim  The paper presents a preliminary conceptual model for the relationship between patients’ and doctors’ expectations with specific reference to back pain management in primary care. Methods  The methods employed in this study are integrative literature review, examination of previous theoretical frameworks, identification of conceptual issues in existing literature, and synthesis and development of a preliminary pragmatic conceptual framework. Outcome  A simple preliminary model explaining the formation of expectations in relation to specific antecedents and consequences was developed; the model incorporates several stages and filters (influencing factors, underlying reactions, judgement, formed reactions, outcome and significance) to explain the development and anticipated influence of expectations on the consultation outcome. Conclusion  The newly developed model takes into account several important dynamics that might be key elements for more successful back pain consultation in primary care, mainly the importance of matching patients’ and doctors’ expectations as well as the importance of addressing unmet expectations. PMID:21679288

A Theoretical and Empirical Integrated Method to Select the Optimal Combined Signals for Geometry-Free and Geometry-Based Three-Carrier Ambiguity Resolution.

PubMed

Zhao, Dongsheng; Roberts, Gethin Wyn; Lau, Lawrence; Hancock, Craig M; Bai, Ruibin

2016-11-16

Twelve GPS Block IIF satellites, out of the current constellation, can transmit on three-frequency signals (L1, L2, L5). Taking advantages of these signals, Three-Carrier Ambiguity Resolution (TCAR) is expected to bring much benefit for ambiguity resolution. One of the research areas is to find the optimal combined signals for a better ambiguity resolution in geometry-free (GF) and geometry-based (GB) mode. However, the existing researches select the signals through either pure theoretical analysis or testing with simulated data, which might be biased as the real observation condition could be different from theoretical prediction or simulation. In this paper, we propose a theoretical and empirical integrated method, which first selects the possible optimal combined signals in theory and then refines these signals with real triple-frequency GPS data, observed at eleven baselines of different lengths. An interpolation technique is also adopted in order to show changes of the AR performance with the increase in baseline length. The results show that the AR success rate can be improved by 3% in GF mode and 8% in GB mode at certain intervals of the baseline length. Therefore, the TCAR can perform better by adopting the combined signals proposed in this paper when the baseline meets the length condition.

A Theoretical and Empirical Integrated Method to Select the Optimal Combined Signals for Geometry-Free and Geometry-Based Three-Carrier Ambiguity Resolution

PubMed Central

Zhao, Dongsheng; Roberts, Gethin Wyn; Lau, Lawrence; Hancock, Craig M.; Bai, Ruibin

2016-01-01

Twelve GPS Block IIF satellites, out of the current constellation, can transmit on three-frequency signals (L1, L2, L5). Taking advantages of these signals, Three-Carrier Ambiguity Resolution (TCAR) is expected to bring much benefit for ambiguity resolution. One of the research areas is to find the optimal combined signals for a better ambiguity resolution in geometry-free (GF) and geometry-based (GB) mode. However, the existing researches select the signals through either pure theoretical analysis or testing with simulated data, which might be biased as the real observation condition could be different from theoretical prediction or simulation. In this paper, we propose a theoretical and empirical integrated method, which first selects the possible optimal combined signals in theory and then refines these signals with real triple-frequency GPS data, observed at eleven baselines of different lengths. An interpolation technique is also adopted in order to show changes of the AR performance with the increase in baseline length. The results show that the AR success rate can be improved by 3% in GF mode and 8% in GB mode at certain intervals of the baseline length. Therefore, the TCAR can perform better by adopting the combined signals proposed in this paper when the baseline meets the length condition. PMID:27854324

Which Benefits Are Mentioned Most Often in Drug Development Publications?

PubMed

Strüver, Vanessa

2017-01-01

The aim was to identify theoretically expected as well as actually reported benefits from drug development and the importance of individual patient benefits compared to the collective benefits to society in general. Ethical guidelines require that clinical research involving humans offer the potential for benefit. A number of characteristics can be applied to define research benefit. Often benefit is categorized as being either direct or indirect. Indirect benefits can involve collective benefits for society rather than any benefits to the trial patient or subject. The purpose of this review was to examine which potential individual and societal benefits were mentioned as being expected in publications from government experts and which were mentioned in publications describing completed drug development trial results. Literature on research benefit was first identified by searching the PubMed database using several combinations of the key words benefit and clinical research . The search was limited to articles published in English. A Google search with the same combinations of key words but without any language limitation was then performed. Additionally, the reference lists of promising articles were screened for further thematically related articles. Finally, a narrative review was performed of relevant English- and German-language articles published between 1996 and 2016 to identify which of several potential benefits were either theoretically expected or which were mentioned in publications on clinical drug development trial results. The principal benefits from drug development discussed included 2 main types of benefit, namely individual benefits for the patients and collective benefits for society. Twenty-one of an overall total of 26 articles discussing theoretically expected benefits focused on individual patient benefits, whereas 17 out of 26 articles mentioned collective benefits to society. In these publications, the most commonly mentioned theoretically expected individual patient benefit was the chance to receive up-to-date care (38.1%). A general increase in knowledge about health care, treatments, or drugs (70.6%) was the most commonly mentioned theoretically expected benefit for society. In contrast, all 13 publications reporting actual benefits of clinical drug development trials focused on personal benefits and only 1 of these publications also mentioned a societal benefit. The most commonly mentioned individual benefit was an increased quality of life (53.9%), whereas the only mentioned collective benefit to society was a general gain of knowledge (100.0%). Both theoretically expected and actually reported benefits in the majority of the included publications emphasized the importance of individual patient benefits from drug development rather than the collective benefits to society in general. The authors of these publications emphasized the right of each individual patient or subject to look for and expect some personal benefit from participating in a clinical trial rather than considering societal benefit as a top priority. From an ethical point of view, the benefits each individual patient receives from his or her participation in a clinical trial might also be seen as a societal benefit, especially when the drug or device tested, if approved for marketing, would eventually be made available for other similar patients from the country in which the clinical trial was conducted.

School transitions, peer influence, and educational expectation formation: Girls and boys.

PubMed

Andrew, Megan; Flashman, Jennifer

2017-01-01

School transitions are a regular feature of the educational career. While they are of general interest as instances of academic change, they also represent instances of peer environment and influence change. Previous theoretical and empirical work suggests peer influence is important for students' academic and educational outcomes, especially for the complex decision-making processes leading up to those outcomes. In this manuscript, we study the impact of peers on educational expectation formation at the 8th-to-9th-grade school transition. In doing so, we test a theoretical model that links institutional settings, social influence, and individual decision-making. We find the 9th grade transition likely represents a negative shock for students' college attendance expectations. Independent of this transition, however, stable peer environments further depress expectations. A more equal mixture of new and old peers in the 9th grade likely increases students' educational expectations in contrast. These effects of peer perturbations and the re-organization of social ties they imply mainly apply to female students. But, both male and female students revise their educational expectations in light of changing peer intelligence comparisons, albeit in countervailing ways. Copyright © 2016. Published by Elsevier Inc.

Consumer Expectations of Online Services in the Insurance Industry: An Exploratory Study of Drivers and Outcomes.

PubMed

Méndez-Aparicio, M Dolores; Izquierdo-Yusta, Alicia; Jiménez-Zarco, Ana I

2017-01-01

Today, the customer-brand relationship is fundamental to a company's bottom line, especially in the service sector and with services offered via online channels. In order to maximize its effects, organizations need (1) to know which factors influence the formation of an individual's service expectations in an online environment; and (2) to establish the influence of these expectations on customers' likelihood of recommending a service before they have even used it. In accordance with the TAM model (Davis, 1989; Davis et al., 1992), the TRA model (Fishbein and Ajzen, 1975), the extended UTAUT model (Venkatesh et al., 2012), and the approach described by Alloza (2011), this work proposes a theoretical model of the antecedents and consequences of consumer expectations of online services. In order to validate the proposed theoretical model, a sample of individual insurance company customers was analyzed. The results showed, first, the importance of customers' expectations with regard to the intention to recommend the "private area" of the company's website to other customers prior to using it themselves. They also revealed the importance to expectations of the antecedents perceived usefulness, ease of use, frequency of use, reputation, and subjective norm.

Consumer Expectations of Online Services in the Insurance Industry: An Exploratory Study of Drivers and Outcomes

PubMed Central

Méndez-Aparicio, M. Dolores; Izquierdo-Yusta, Alicia; Jiménez-Zarco, Ana I.

2017-01-01

Today, the customer-brand relationship is fundamental to a company’s bottom line, especially in the service sector and with services offered via online channels. In order to maximize its effects, organizations need (1) to know which factors influence the formation of an individual’s service expectations in an online environment; and (2) to establish the influence of these expectations on customers’ likelihood of recommending a service before they have even used it. In accordance with the TAM model (Davis, 1989; Davis et al., 1992), the TRA model (Fishbein and Ajzen, 1975), the extended UTAUT model (Venkatesh et al., 2012), and the approach described by Alloza (2011), this work proposes a theoretical model of the antecedents and consequences of consumer expectations of online services. In order to validate the proposed theoretical model, a sample of individual insurance company customers was analyzed. The results showed, first, the importance of customers’ expectations with regard to the intention to recommend the “private area” of the company’s website to other customers prior to using it themselves. They also revealed the importance to expectations of the antecedents perceived usefulness, ease of use, frequency of use, reputation, and subjective norm. PMID:28798705

Measuring housing quality in the absence of a monetized real estate market.

PubMed

Rindfuss, Ronald R; Piotrowski, Martin; Thongthai, Varachai; Prasartkul, Pramote

2007-03-01

Measuring housing quality or value or both has been a weak component of demographic and development research in less developed countries that lack an active real estate (housing) market. We describe a new method based on a standardized subjective rating process. It is designed to be used in settings that do not have an active, monetized housing market. The method is applied in an ongoing longitudinal study in north-east Thailand and could be straightforwardly used in many other settings. We develop a conceptual model of the process whereby households come to reside in high-quality or low-quality housing units. We use this theoretical model in conjunction with longitudinal data to show that the new method of measuring housing quality behaves as theoretically expected, thus providing evidence of face validity.

A Theory of False Cognitive Expectancies in Airline Pilots

NASA Astrophysics Data System (ADS)

Cortes, Antonio I.

The Theory of False Cognitive Expectancies was developed by studying high reliability flight operations. Airline pilots depend extensively on cognitive expectancies to perceive, understand, and predict actions and events. Out of 1,363 incident reports submitted by airline pilots to the National Aeronautics and Space Administration Aviation Safety Reporting System over a year's time, 110 reports were found to contain evidence of 127 false cognitive expectancies in pilots. A comprehensive taxonomy was developed with six categories of interest. The dataset of 127 false expectancies was used to initially code tentative taxon values for each category. Intermediate coding through constant comparative analysis completed the taxonomy. The taxonomy was used for the advanced coding of chronological context-dependent visualizations of expectancy factors, known as strands, which depict the major factors in the creation and propagation of each expectancy. Strands were mapped into common networks to detect highly represented expectancy processes. Theoretical integration established 11 sources of false expectancies, the most common expectancy errors, and those conspicuous factors worthy of future study. The most prevalent source of false cognitive expectancies within the dataset was determined to be unconscious individual modeling based on past events. Integrative analyses also revealed relationships between expectancies and flight deck automation, unresolved discrepancies, and levels of situation awareness. Particularly noteworthy were the findings that false expectancies can combine in three possible permutations to diminish situation awareness and examples of how false expectancies can be unwittingly transmitted from one person to another. The theory resulting from this research can enhance the error coding process used during aircraft line oriented safety audits, lays the foundation for developing expectancy management training programs, and will allow researchers to proffer hypotheses for human testing using flight simulators.

What would optimal vegetation do when confronted with steadily increasing atmospheric CO2

NASA Astrophysics Data System (ADS)

Roderick, M. L.; Donohue, R. J.; Yang, Y.; McVicar, T.; Farquhar, G. D.

2015-12-01

The ongoing increase in atmospheric CO2 presents an interesting opportunity for primary producers. An increase in the substrate availability would, with all else equal, stimulate fixation of carbon from the atmosphere. But all else is not necessarily equal and this is only the beginning of a cascade of changes that can ultimately be traced back to the stomatal regulation of water-carbon exchanges. We first discuss theoretical expectations and then deduce how vegetation might respond to changing CO2 in water- and energy-limited environments. We then use satellite observations to test the theoretical expectations.

Theoretical Chemistry Comes Alive: Full Partner with Experiment.

ERIC Educational Resources Information Center

Goddard, William A., III

1985-01-01

The expected thrust for theoretical chemistry in the next decade will be to combine knowledge of fundamental chemical steps/interactions with advances in chemical dynamics, irreversible statistical mechanics, and computer technology to produce simulations of chemical systems with reaction site competition. A sample simulation (using the enzyme…

Development of Probabilistic Understanding in Fourth Grade

ERIC Educational Resources Information Center

English, Lyn D.; Watson, Jane M.

2016-01-01

The authors analyzed the development of 4th-grade students' understanding of the transition from experimental relative frequencies of outcomes to theoretical probabilities with a focus on the foundational statistical concepts of variation and expectation. After observing the decreasing variation from the theoretical probability as the sample size…

High C/O Chemistry and Weak Thermal Inversion in the Extremely Irradiated Atmosphere of Exoplanet WASP-12b

NASA Technical Reports Server (NTRS)

Madhusudhan, Nikku; Harrington, Joseph; Nymeyer, Sarah; Campo, Christopher J.; Wheatley, Peter J.; Deming, Drake; Blecie, Jasmina; Hardy, Ryan A.; Lust, Nate B.; Anderson, David R.;

Theoretical foundations for a quantitative approach to paleogenetics. I, II.

NASA Technical Reports Server (NTRS)

Holmquist, R.

1972-01-01

It is shown that by neglecting the phenomena of multiple hits, back mutation, and chance coincidence errors larger than 100% can be introduced in the calculated value of the average number of nucleotide base differences to be expected between two homologous polynucleotides. Mathematical formulas are derived to correct quantitatively for these effects. It is pointed out that the effects change materially the quantitative aspects of phylogenics, such as the length of the legs of the trees. A number of problems are solved without approximation.-

Decentralized adaptive control

NASA Technical Reports Server (NTRS)

Oh, B. J.; Jamshidi, M.; Seraji, H.

1988-01-01

A decentralized adaptive control is proposed to stabilize and track the nonlinear, interconnected subsystems with unknown parameters. The adaptation of the controller gain is derived by using model reference adaptive control theory based on Lyapunov's direct method. The adaptive gains consist of sigma, proportional, and integral combination of the measured and reference values of the corresponding subsystem. The proposed control is applied to the joint control of a two-link robot manipulator, and the performance in computer simulation corresponds with what is expected in theoretical development.

Statistical studies of animal response data from USF toxicity screening test method

NASA Technical Reports Server (NTRS)

Hilado, C. J.; Machado, A. M.

1978-01-01

Statistical examination of animal response data obtained using Procedure B of the USF toxicity screening test method indicates that the data deviate only slightly from a normal or Gaussian distribution. This slight departure from normality is not expected to invalidate conclusions based on theoretical statistics. Comparison of times to staggering, convulsions, collapse, and death as endpoints shows that time to death appears to be the most reliable endpoint because it offers the lowest probability of missed observations and premature judgements.

Ground motions recorded in Rome during the April 2009 L’Aquila seismic sequence: site response and comparison with ground‐motion predictions based on a global dataset

USGS Publications Warehouse

Caserta, Arrigo; Boore, David; Rovelli, Antonio; Govoni, Aladino; Marra, Fabrizio; Monica, Gieseppe Della; Boschi, Enzo

2013-01-01

The mainshock and moderate‐magnitude aftershocks of the 6 April 2009 M 6.3 L’Aquila seismic sequence, about 90 km northeast of Rome, provided the first earthquake ground‐motion recordings in the urban area of Rome. Before those recordings were obtained, the assessments of the seismic hazard in Rome were based on intensity observations and theoretical considerations. The L’Aquila recordings offer an unprecedented opportunity to calibrate the city response to central Apennine earthquakes—earthquakes that have been responsible for the largest damage to Rome in historical times. Using the data recorded in Rome in April 2009, we show that (1) published theoretical predictions of a 1 s resonance in the Tiber valley are confirmed by observations showing a significant amplitude increase in response spectra at that period, (2) the empirical soil‐transfer functions inferred from spectral ratios are satisfactorily fit through 1D models using the available geological, geophysical, and laboratory data, but local variability can be large for individual events, (3) response spectra for the motions recorded in Rome from the L’Aquila earthquakes are significantly amplified in the radial component at periods near 1 s, even at a firm site on volcanic rocks, and (4) short‐period response spectra are smaller than expected when compared to ground‐motion predictions from equations based on a global dataset, whereas the observed response spectra are higher than expected for periods near 1 s.

Using expectancy-value theory to explore aspects of motivation and engagement in inquiry-based learning in primary mathematics

NASA Astrophysics Data System (ADS)

Fielding-Wells, Jill; O'Brien, Mia; Makar, Katie

2017-03-01

Inquiry-based learning (IBL) is a pedagogical approach in which students address complex, ill-structured problems set in authentic contexts. While IBL is gaining ground in Australia as an instructional practice, there has been little research that considers implications for student motivation and engagement. Expectancy-value theory (Eccles and Wigfield 2002) provides a framework through which children's beliefs about their mathematical competency and their expectation of success are able to be examined and interpreted, alongside students' perceptions of task value. In this paper, Eccles and Wigfield's expectancy-value model has been adopted as a lens to examine a complete unit of mathematical inquiry as undertaken with a class of 9-10-year-old students. Data were sourced from a unit (˜10 lessons) based on geometry and geometrical reasoning. The units were videotaped in full, transcribed, and along with field notes and student work samples, subjected to theoretical coding using the dimensions of Eccles and Wigfield's model. The findings provide insight into aspects of IBL that may impact student motivation and engagement. The study is limited to a single unit; however, the results provide a depth of insight into IBL in practice while identifying features of IBL that may be instrumental in bringing about increased motivation and engagement of students in mathematics. Identifying potentially motivating aspects of IBL enable these to be integrated and more closely studied in IBL practises.

Wave transmission approach based on modal analysis for embedded mechanical systems

NASA Astrophysics Data System (ADS)

Cretu, Nicolae; Nita, Gelu; Ioan Pop, Mihail

2013-09-01

An experimental method for determining the phase velocity in small solid samples is proposed. The method is based on measuring the resonant frequencies of a binary or ternary solid elastic system comprising the small sample of interest and a gauge material of manageable size. The wave transmission matrix of the combined system is derived and the theoretical values of its eigenvalues are used to determine the expected eigenfrequencies that, equated with the measured values, allow for the numerical estimation of the phase velocities in both materials. The known phase velocity of the gauge material is then used to asses the accuracy of the method. Using computer simulation and the experimental values for phase velocities, the theoretical values for the eigenfrequencies of the eigenmodes of the embedded elastic system are obtained, to validate the method. We conclude that the proposed experimental method may be reliably used to determine the elastic properties of small solid samples whose geometries do not allow a direct measurement of their resonant frequencies.

Theoretical estimates of exposure timescales of protein binding sites on DNA regulated by nucleosome kinetics.

PubMed

Parmar, Jyotsana J; Das, Dibyendu; Padinhateeri, Ranjith

2016-02-29

It is being increasingly realized that nucleosome organization on DNA crucially regulates DNA-protein interactions and the resulting gene expression. While the spatial character of the nucleosome positioning on DNA has been experimentally and theoretically studied extensively, the temporal character is poorly understood. Accounting for ATPase activity and DNA-sequence effects on nucleosome kinetics, we develop a theoretical method to estimate the time of continuous exposure of binding sites of non-histone proteins (e.g. transcription factors and TATA binding proteins) along any genome. Applying the method to Saccharomyces cerevisiae, we show that the exposure timescales are determined by cooperative dynamics of multiple nucleosomes, and their behavior is often different from expectations based on static nucleosome occupancy. Examining exposure times in the promoters of GAL1 and PHO5, we show that our theoretical predictions are consistent with known experiments. We apply our method genome-wide and discover huge gene-to-gene variability of mean exposure times of TATA boxes and patches adjacent to TSS (+1 nucleosome region); the resulting timescale distributions have non-exponential tails. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Engagement With a Trauma Recovery Internet Intervention Explained With the Health Action Process Approach (HAPA): Longitudinal Study

PubMed Central

Shoji, Kotaro; Luszczynska, Aleksandra; Benight, Charles C

2018-01-01

Background There has been a growing trend in the delivery of mental health treatment via technology (ie, electronic health, eHealth). However, engagement with eHealth interventions is a concern, and theoretically based research in this area is sparse. Factors that influence engagement are poorly understood, especially in trauma survivors with symptoms of posttraumatic stress. Objective The aim of this study was to examine engagement with a trauma recovery eHealth intervention using the Health Action Process Approach theoretical model. Outcome expectancy, perceived need, pretreatment self-efficacy, and trauma symptoms influence the formation of intentions (motivational phase), followed by planning, which mediates the translation of intentions into engagement (volitional phase). We hypothesized the mediational effect of planning would be moderated by level of treatment self-efficacy. Methods Trauma survivors from around the United States used the eHealth intervention for 2 weeks. We collected baseline demographic, social cognitive predictors, and distress symptoms and measured engagement subjectively and objectively throughout the intervention. Results The motivational phase model explained 48% of the variance, and outcome expectations (beta=.36), perceived need (beta=.32), pretreatment self-efficacy (beta=.13), and trauma symptoms (beta=.21) were significant predictors of intention (N=440). In the volitional phase, results of the moderated mediation model indicated for low levels of treatment self-efficacy, planning mediated the effects of intention on levels of engagement (B=0.89, 95% CI 0.143-2.605; N=115). Conclusions Though many factors can affect engagement, these results offer a theoretical framework for understanding engagement with an eHealth intervention. This study highlighted the importance of perceived need, outcome expectations, self-efficacy, and baseline distress symptoms in the formation of intentions to use the intervention. For those low in treatment self-efficacy, planning may play an important role in the translation of intentions into engagement. Results of this study may help bring some clarification to the question of what makes eHealth interventions work. PMID:29636323

Utilization of waste heat in trucks for increased fuel economy

NASA Technical Reports Server (NTRS)

Leising, C. J.; Purohit, G. P.; Degrey, S. P.; Finegold, J. G.

1978-01-01

The waste heat utilization concepts include preheating, regeneration, turbocharging, turbocompounding, and Rankine engine compounding. Predictions are based on fuel-air cycle analyses, computer simulation, and engine test data. All options are evaluated in terms of maximum theoretical improvements, but the Diesel and adiabatic Diesel are also compared on the basis of maximum expected improvement and expected improvement over a driving cycle. The study indicates that Diesels should be turbocharged and aftercooled to the maximum possible level. The results reveal that Diesel driving cycle performance can be increased by 20% through increased turbocharging, turbocompounding, and Rankine engine compounding. The Rankine engine compounding provides about three times as much improvement as turbocompounding but also costs about three times as much. Performance for either can be approximately doubled if applied to an adiabatic Diesel.

Optimal Decision Stimuli for Risky Choice Experiments: An Adaptive Approach.

PubMed

Cavagnaro, Daniel R; Gonzalez, Richard; Myung, Jay I; Pitt, Mark A

2013-02-01

Collecting data to discriminate between models of risky choice requires careful selection of decision stimuli. Models of decision making aim to predict decisions across a wide range of possible stimuli, but practical limitations force experimenters to select only a handful of them for actual testing. Some stimuli are more diagnostic between models than others, so the choice of stimuli is critical. This paper provides the theoretical background and a methodological framework for adaptive selection of optimal stimuli for discriminating among models of risky choice. The approach, called Adaptive Design Optimization (ADO), adapts the stimulus in each experimental trial based on the results of the preceding trials. We demonstrate the validity of the approach with simulation studies aiming to discriminate Expected Utility, Weighted Expected Utility, Original Prospect Theory, and Cumulative Prospect Theory models.

Observers Exploit Stochastic Models of Sensory Change to Help Judge the Passage of Time

PubMed Central

Ahrens, Misha B.; Sahani, Maneesh

2011-01-01

Summary Sensory stimulation can systematically bias the perceived passage of time [1–5], but why and how this happens is mysterious. In this report, we provide evidence that such biases may ultimately derive from an innate and adaptive use of stochastically evolving dynamic stimuli to help refine estimates derived from internal timekeeping mechanisms [6–15]. A simplified statistical model based on probabilistic expectations of stimulus change derived from the second-order temporal statistics of the natural environment [16, 17] makes three predictions. First, random noise-like stimuli whose statistics violate natural expectations should induce timing bias. Second, a previously unexplored obverse of this effect is that similar noise stimuli with natural statistics should reduce the variability of timing estimates. Finally, this reduction in variability should scale with the interval being timed, so as to preserve the overall Weber law of interval timing. All three predictions are borne out experimentally. Thus, in the context of our novel theoretical framework, these results suggest that observers routinely rely on sensory input to augment their sense of the passage of time, through a process of Bayesian inference based on expectations of change in the natural environment. PMID:21256018

Functional requirements for reward-modulated spike-timing-dependent plasticity.

PubMed

Frémaux, Nicolas; Sprekeler, Henning; Gerstner, Wulfram

2010-10-06

Recent experiments have shown that spike-timing-dependent plasticity is influenced by neuromodulation. We derive theoretical conditions for successful learning of reward-related behavior for a large class of learning rules where Hebbian synaptic plasticity is conditioned on a global modulatory factor signaling reward. We show that all learning rules in this class can be separated into a term that captures the covariance of neuronal firing and reward and a second term that presents the influence of unsupervised learning. The unsupervised term, which is, in general, detrimental for reward-based learning, can be suppressed if the neuromodulatory signal encodes the difference between the reward and the expected reward-but only if the expected reward is calculated for each task and stimulus separately. If several tasks are to be learned simultaneously, the nervous system needs an internal critic that is able to predict the expected reward for arbitrary stimuli. We show that, with a critic, reward-modulated spike-timing-dependent plasticity is capable of learning motor trajectories with a temporal resolution of tens of milliseconds. The relation to temporal difference learning, the relevance of block-based learning paradigms, and the limitations of learning with a critic are discussed.

Spectral-spatial classification of hyperspectral imagery with cooperative game

NASA Astrophysics Data System (ADS)

Zhao, Ji; Zhong, Yanfei; Jia, Tianyi; Wang, Xinyu; Xu, Yao; Shu, Hong; Zhang, Liangpei

2018-01-01

Spectral-spatial classification is known to be an effective way to improve classification performance by integrating spectral information and spatial cues for hyperspectral imagery. In this paper, a game-theoretic spectral-spatial classification algorithm (GTA) using a conditional random field (CRF) model is presented, in which CRF is used to model the image considering the spatial contextual information, and a cooperative game is designed to obtain the labels. The algorithm establishes a one-to-one correspondence between image classification and game theory. The pixels of the image are considered as the players, and the labels are considered as the strategies in a game. Similar to the idea of soft classification, the uncertainty is considered to build the expected energy model in the first step. The local expected energy can be quickly calculated, based on a mixed strategy for the pixels, to establish the foundation for a cooperative game. Coalitions can then be formed by the designed merge rule based on the local expected energy, so that a majority game can be performed to make a coalition decision to obtain the label of each pixel. The experimental results on three hyperspectral data sets demonstrate the effectiveness of the proposed classification algorithm.

An Attributional Theory of Achievement Motivation and Emotion.

ERIC Educational Resources Information Center

Weiner, Bernard

1985-01-01

This article advances an attributional theory of motivation and emotion, with achievement strivings as the theoretical focus. Causes of success and failure share three common properties: locus, stability, and controllability. Stability of causes influences changes in expectancy of success. Expectancy and affect guide motivated behavior.…

Information Dynamics and Aspects of Musical Perception

NASA Astrophysics Data System (ADS)

Dubnov, Shlomo

Musical experience has been often suggested to be related to forming of expectations, their fulfillment or denial. In terms of information theory, expectancies and predictions serve to reduce uncertainty about the future and might be used to efficiently represent and "compress" data. In this chapter we present an information theoretic model of musical listening based on the idea that expectations that arise from past musical material are framing our appraisal of what comes next, and that this process eventually results in creation of emotions or feelings. Using a notion of "information rate" we can measure the amount of information between past and present in the musical signal on different time scales using statistics of sound spectral features. Several musical pieces are analyzed in terms of short and long term information rate dynamics and are compared to analysis of musical form and its structural functions. The findings suggest that a relation exists between information dynamics and musical structure that eventually leads to creation of human listening experience and feelings such as "wow" and "aha".

Positive outcome expectancy mediates the relationship between social influence and Internet addiction among senior high-school students.

PubMed

Lin, Min-Pei; Wu, Jo Yung-Wei; Chen, Chao-Jui; You, Jianing

2018-06-28

Background and aims Based on the foundations of Bandura's social cognitive theory and theory of triadic influence (TTI) theoretical framework, this study was designed to examine the mediating role of positive outcome expectancy of Internet use in the relationship between social influence and Internet addiction (IA) in a large representative sample of senior high-school students in Taiwan. Methods Using a cross-sectional design, 1,922 participants were recruited from senior high schools throughout Taiwan using both stratified and cluster sampling, and a comprehensive survey was administered. Results Structural equation modeling and bootstrap analyses results showed that IA severity was significantly and positively predicted by social influence, and fully mediated through positive outcome expectancy of Internet use. Discussion and conclusions The results not only support Bandura's social cognitive theory and TTI framework, but can also serve as a reference to help educational agencies and mental health organizations design programs and create policies that will help in the prevention of IA among adolescents.

Axisymmetric Eigenmodes of Spheroidal Pure Electron Plasmas

NASA Astrophysics Data System (ADS)

Kawai, Yosuke; Saitoh, Haruhiko; Yoshida, Zensho; Kiwamoto, Yasuhito

2010-11-01

The axisymmetric electrostatic eigenmodes of spheroidal pure electron plasmas have been studied experimentally. It is confirmed that the observed spheroidal plasma attains a theoretically expected equilibrium density distribution, with the exception of a low-density halo distribution surrounding the plasma. When the eigenmode frequency observed for the plasma is compared with the frequency predicted by the dispersion relation derived under ideal conditions wherein the temperature is zero and the boundary is located at an infinite distance from the plasma, it is observed that the absolute value of the observed frequency is systematically higher than the theoretical prediction. Experimental examinations and numerical calculations indicate that the upward shift of the eigenmode frequency cannot be accounted for solely by the finite temperature effect, but is significantly affected by image charges induced on the conducting boundary and the resulting distortion of the density profile from the theoretical expectation.

Speckle phase near random surfaces

NASA Astrophysics Data System (ADS)

Chen, Xiaoyi; Cheng, Chuanfu; An, Guoqiang; Han, Yujing; Rong, Zhenyu; Zhang, Li; Zhang, Meina

2018-03-01

Based on Kirchhoff approximation theory, the speckle phase near random surfaces with different roughness is numerically simulated. As expected, the properties of the speckle phase near the random surfaces are different from that in far field. In addition, as scattering distances and roughness increase, the average fluctuations of the speckle phase become larger. Unusually, the speckle phase is somewhat similar to the corresponding surface topography. We have performed experiments to verify the theoretical simulation results. Studies in this paper contribute to understanding the evolution of speckle phase near a random surface and provide a possible way to identify a random surface structure based on its speckle phase.

Space-based sensor management and geostationary satellites tracking

NASA Astrophysics Data System (ADS)

El-Fallah, A.; Zatezalo, A.; Mahler, R.; Mehra, R. K.; Donatelli, D.

2007-04-01

Sensor management for space situational awareness presents a daunting theoretical and practical challenge as it requires the use of multiple types of sensors on a variety of platforms to ensure that the space environment is continuously monitored. We demonstrate a new approach utilizing the Posterior Expected Number of Targets (PENT) as the sensor management objective function, an observation model for a space-based EO/IR sensor platform, and a Probability Hypothesis Density Particle Filter (PHD-PF) tracker. Simulation and results using actual Geostationary Satellites are presented. We also demonstrate enhanced performance by applying the ProgressiveWeighting Correction (PWC) method for regularization in the implementation of the PHD-PF tracker.

Attention-Seeking during Caregiver Unavailability and Collaboration at Age 2

ERIC Educational Resources Information Center

Gosselin, Marie-Pierre M.; Forman, David R.

2012-01-01

Several theoretical approaches have discussed the role of children's expectations of their parent's responsiveness in explaining motivation to collaborate in acquiring skills. This study attempted to measure these expectations in 102 toddlers (M age = 26.4 months) through observations of attention-seeking (A-S) behaviors during caregiver's…

Fourth Graders' Motivation in an Elementary Physical Education Running Program

ERIC Educational Resources Information Center

Xiang, Ping; McBride, Ron E.; Bruene, April

2004-01-01

In this study we examined students' motivation in an elementary physical education running program using achievement goal theory and an expectancy-value model of achievement choice as theoretical frameworks. Fourth graders (N = 119) completed questionnaires assessing their achievement goals, expectancy-related beliefs, subjective task values, and…

Diversity in Literary Response: Revisiting Gender Expectations

ERIC Educational Resources Information Center

Brendler, Beth M.

2014-01-01

Drawing on and reexamining theories on gender and literacy, derived from research performed between 1974 and 2002, this qualitative study explored the gender assumptions and expectations of Language Arts teachers in a graduate level adolescent literature course at a university in the Midwestern United States. The theoretical framework was…

Predicting Document Retrieval System Performance: An Expected Precision Measure.

ERIC Educational Resources Information Center

Losee, Robert M., Jr.

1987-01-01

Describes an expected precision (EP) measure designed to predict document retrieval performance. Highlights include decision theoretic models; precision and recall as measures of system performance; EP graphs; relevance feedback; and computing the retrieval status value of a document for two models, the Binary Independent Model and the Two Poisson…

Evidence of solar wind energy deposition into the ionosphere of Mars

NASA Technical Reports Server (NTRS)

Mantas, G. P.; Hanson, W. B.

1985-01-01

Suprathermal electron fluxes measured in the ionosphere of Mars by the retarding potential analyzer (RPA) on Viking lander 1 are presented and compared with the photoelectron flux that is produced by the absorption of the solar EUV. The calculation of the equilibrium photoelectron population on Mars is based on the multistream electron transport theory and a model neutral atmosphere and ionosphere that was actually observed by Viking lander 1. From the theoretical equilibrium photoelectron population, the expected RPA volt-ampere characteristic curves are computed and compared with those recorded by the instrument. The theoretical and the observed RPA currents below about 170 km are in agreement, confirming that the solar EUV is the main source of suprathermal electrons at these altitudes. Above about 170 km an additional source of suprathermal electrons is required to explain the observations.

Cognitive engineering models in space systems

NASA Technical Reports Server (NTRS)

Mitchell, Christine M.

1992-01-01

NASA space systems, including mission operations on the ground and in space, are complex, dynamic, predominantly automated systems in which the human operator is a supervisory controller. The human operator monitors and fine-tunes computer-based control systems and is responsible for ensuring safe and efficient system operation. In such systems, the potential consequences of human mistakes and errors may be very large, and low probability of such events is likely. Thus, models of cognitive functions in complex systems are needed to describe human performance and form the theoretical basis of operator workstation design, including displays, controls, and decision support aids. The operator function model represents normative operator behavior-expected operator activities given current system state. The extension of the theoretical structure of the operator function model and its application to NASA Johnson mission operations and space station applications is discussed.

Waveguide-type optical circuits for recognition of optical 8QAM-coded label

NASA Astrophysics Data System (ADS)

Surenkhorol, Tumendemberel; Kishikawa, Hiroki; Goto, Nobuo; Gonchigsumlaa, Khishigjargal

2017-10-01

Optical signal processing is expected to be applied in network nodes. In photonic routers, label recognition is one of the important functions. We have studied different kinds of label recognition methods so far for on-off keying, binary phase-shift keying, quadrature phase-shift keying, and 16 quadrature amplitude modulation-coded labels. We propose a method based on waveguide circuits to recognize an optical eight quadrature amplitude modulation (8QAM)-coded label by simple passive optical signal processing. The recognition of the proposed method is theoretically analyzed and numerically simulated by the finite difference beam propagation method. The noise tolerance is discussed, and bit-error rate against optical signal-to-noise ratio is evaluated. The scalability of the proposed method is also discussed theoretically for two-symbol length 8QAM-coded labels.

A Literature Review of Gaming in Education. Research Report

ERIC Educational Resources Information Center

McClarty, Katie Larsen; Orr, Aline; Frey, Peter M.; Dolan, Robert P.; Vassileva, Victoria; McVay, Aaron

2012-01-01

The use of simulations and digital games in learning and assessment is expected to increase over the next several years. Although there is much theoretical support for the benefits of digital games in learning and education, there is mixed empirical support. This research report provides an overview of the theoretical and empirical evidence behind…

Cross-cultural differences in relationship- and group-based trust.

PubMed

Yuki, Masaki; Maddux, William W; Brewer, Marilynn B; Takemura, Kosuke

2005-01-01

Two experiments explored differences in depersonalized trust (trust toward a relatively unknown target person) across cultures. Based on a recent theoretical framework that postulates predominantly different bases for group behaviors in Western cultures versus Eastern cultures, it was predicted that Americans would tend to trust people primarily based on whether they shared category memberships; however, trust for Japanese was expected to be based on the likelihood of sharing direct or indirect interpersonal links. Results supported these predictions. In both Study 1 (questionnaire study) and Study 2 (online money allocation game), Americans trusted ingroup members more than outgroup members; however, the existence of a potential indirect relationship link increased trust for outgroup members more for Japanese than for Americans. Implications for understanding group processes across cultures are discussed.

Analysis of a spatial tracking subsystem for optical communications

NASA Technical Reports Server (NTRS)

Win, Moe Z.; Chen, CHIEN-C.

1992-01-01

Spatial tracking plays a very critical role in designing optical communication systems because of the small angular beamwidth associated with the optical signal. One possible solution for spatial tracking is to use a nutating mirror which dithers the incoming beam at a rate much higher than the mechanical disturbances. A power detector then senses the change in detected power as the signal is reflected off the nutating mirror. This signal is then correlated with the nutator driver signals to obtain estimates of the azimuth and elevation tracking signals to control the fast scanning mirrors. A theoretical analysis is performed for a spatial tracking system using a nutator disturbed by shot noise and mechanical vibrations. Contributions of shot noise and mechanical vibrations to the total tracking error variance are derived. Given the vibration spectrum and the expected signal power, there exists an optimal amplitude for the nutation which optimizes the receiver performance. The expected performance of a nutator based system is estimated based on the choice of nutation amplitude.

Sources of Social Capital for Malawi People Living With HIV

PubMed Central

Rankin, Sally H.; Jong, SoSon; Matovu, Schola; Youmans, Sharon; Lindgren, Teri

2016-01-01

With one of the highest rates of poverty and HIV in the world, Malawi faith-based organizations (FBOs), non-governmental organizations (NGOs), and community-based organizations (CBOs) are expected to provide tangible and emotional support to people living with HIV (PLWH). Using Lin’s social capital theoretical approach, we examine the perspective of PLWH regarding the adequacy of support responses. Forty-six rural Malawi HIV+ adults provided interviews that were recorded digitally, translated, and transcribed by Malawi research assistants. Atlas.ti was used to organize the data and to aid in the analytic process. Participants expressed disappointment in the lack of resources that could be accessed through the FBOs although their expectations may have been unrealistic. Outcomes from accessing and mobilizing the FBO network were negative in terms of stigmatization by FBO leaders and members, whereas outcomes related to CBOs and NGOs were generally positive in terms of empowerment through HIV information and attendance at support groups. PMID:28462349

More similarities than differences in contemporary theories of social development?: a plea for theory bridging.

PubMed

Leaper, Campbell

2011-01-01

Many contemporary theories of social development are similar and/or share complementary constructs. Yet, there have been relatively few efforts toward theoretical integration. The present chapter represents a call for increased theory bridging. The problem of theoretical fragmentation in psychology is reviewed. Seven highlighted reasons for this predicament include differences between behavioral sciences and other sciences, theoretical paradigms as social identities, the uniqueness assumption, information overload, field fixation, linguistic fragmentation, and few incentives for theoretical integration. Afterward, the feasibility of theoretical synthesis is considered. Finally, some possible directions are proposed for theoretical integration among five contemporary theories of social and gender development: social cognitive theory, expectancy-value theory, cognitive-developmental theory, gender schema theory, and self-categorization theory.

Coherent manipulation of a Si/SiGe-based singlet-triplet qubit

NASA Astrophysics Data System (ADS)

Gyure, Mark

2012-02-01

Electrically defined silicon-based qubits are expected to show improved quantum memory characteristics in comparison to GaAs-based devices due to reduced hyperfine interactions with nuclear spins. Silicon-based qubit devices have proved more challenging to build than their GaAs-based counterparts, but recently several groups have reported substantial progress in single-qubit initialization, measurement, and coherent operation. We report [1] coherent control of electron spins in two coupled quantum dots in an undoped Si/SiGe heterostructure, forming two levels of a singlet-triplet qubit. We measure a nuclei-induced T2^* of 360 ns, an increase over similar measurements in GaAs-based quantum dots by nearly two orders of magnitude. We also describe the results from detailed modeling of our materials and devices that show this value for T2^* is consistent with theoretical expectations for our estimated dot sizes and a natural abundance of ^29Si. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressly or implied, of the United States Department of Defense or the U.S. Government. Approved for public release, distribution unlimited.[4pt] [1] B. M. Maune et al., ``Coherent Singlet-Triplet Oscillations in a Silicon-based Double Quantum Dot,'' accepted by Nature.

Conjunction Assessment Late-Notice High-Interest Event Investigation: Space Weather Aspects

NASA Technical Reports Server (NTRS)

Pachura, D.; Hejduk, M. D.

2016-01-01

Late-notice events usually driven by large changes in primary (protected) object or secondary object state. Main parameter to represent size of state change is component position difference divided by associated standard deviation (epsilon divided by sigma) from covariance. Investigation determined actual frequency of large state changes, in both individual and combined states. Compared them to theoretically expected frequencies. Found that large changes ( (epsilon divided by sigma) is greater than 3) in individual object states occur much more frequently than theory dictates. Effect is less pronounced in radial components and in events with probability of collision (Pc) greater than 1 (sup -5) (1e-5). Found combined state matched much closer to theoretical expectation, especially for radial and cross-track. In-track is expected to be the most vulnerable to modeling errors, so not surprising that non-compliance largest in this component.

Introducing a model of cardiovascular prevention in Nairobi's slums by integrating a public health and private-sector approach: the SCALE-UP study.

PubMed

van de Vijver, Steven; Oti, Samuel; Tervaert, Thijs Cohen; Hankins, Catherine; Kyobutungi, Catherine; Gomez, Gabriela B; Brewster, Lizzy; Agyemang, Charles; Lange, Joep

2013-10-21

Cardiovascular disease (CVD) is a leading cause of death in sub-Saharan Africa (SSA), with annual deaths expected to increase to 2 million by 2030. Currently, most national health systems in SSA are not adequately prepared for this epidemic. This is especially so in slum settlements where access to formal healthcare and resources is limited. To develop and introduce a model of cardiovascular prevention in the slums of Nairobi by integrating public health and private sector approaches. Two non-profit organizations that conduct public health research, Amsterdam Institute for Global Health and Development (AIGHD) and African Population and Health Research Center (APHRC), collaborated with private-sector Boston Consulting Group (BCG) to develop a service delivery package for CVD prevention in slum settings. A theoretic model was designed based on the integration of public and private sector approaches with the focus on costs and feasibility. The final model includes components that aim to improve community awareness, a home-based screening service, patient and provider incentives to seek and deliver treatment specifically for hypertension, and adherence support. The expected outcomes projected by this model could prove potentially cost effective and affordable (1 USD/person/year). The model is currently being implemented in a Nairobi slum and is closely followed by key stakeholders in Kenya including the Ministry of Health, the World Health Organization (WHO), and leading non-governmental organizations (NGOs). Through the collaboration of public health and private sectors, a theoretically cost-effective model was developed for the prevention of CVD and is currently being implemented in the slums of Nairobi. If results are in line with the theoretical projections and first impressions on the ground, scale-up of the service delivery package could be planned in other poor urban areas in Kenya by relevant policymakers and NGOs.

Electrical flicker-noise generated by filling and emptying of impurity states in injectors of quantum-cascade lasers

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

Yamanishi, Masamichi, E-mail: masamiya@crl.hpk.co.jp; Hirohata, Tooru; Hayashi, Syohei

2014-11-14

Free running line-widths (>100 kHz), much broader than intrinsic line-widths ∼100 Hz, of existing quantum-cascade lasers are governed by strong flicker frequency-noise originating from electrical flicker noise. Understanding of microscopic origins of the electrical flicker noises in quantum-cascade lasers is crucially important for the reduction of strength of flicker frequency-noise without assistances of any type of feedback schemes. In this article, an ad hoc model that is based on fluctuating charge-dipoles induced by electron trappings and de-trappings at indispensable impurity states in injector super-lattices of a quantum-cascade laser is proposed, developing theoretical framework based on the model. The validity of the presentmore » model is evaluated by comparing theoretical voltage-noise power spectral densities based on the model with experimental ones obtained by using mid-infrared quantum-cascade lasers with designed impurity-positioning. The obtained experimental results on flicker noises, in comparison with the theoretical ones, shed light on physical mechanisms, such as the inherent one due to impurity states in their injectors and extrinsic ones due to surface states on the ridge-walls and due to residual deep traps, for electrical flicker-noise generation in existing mid-infrared quantum-cascade lasers. It is shown theoretically that quasi-delta doping of impurities in their injectors leads to strong suppression of electrical flicker noise by minimization of the dipole length at a certain temperature, for instance ∼300 K and, in turn, is expected to result in substantial narrowing of the free running line-width down below 10 kHz.« less

Risk of symptomatic dengue for foreign visitors to the 2014 FIFA World Cup in Brazil

PubMed Central

Massad, Eduardo; Wilder-Smith, Annelies; Ximenes, Raphael; Amaku, Marcos; Lopez, Luis Fernandez; Coutinho, Francisco Antonio Bezerra; Coelho, Giovanini Evelim; da Silva, Jarbas Barbosa; Struchiner, Claudio José; Burattini, Marcelo Nascimento

2014-01-01

Brazil will host the FIFA World Cup™, the biggest single-event competition in the world, from June 12-July 13 2014 in 12 cities. This event will draw an estimated 600,000 international visitors. Brazil is endemic for dengue. Hence, attendees of the 2014 event are theoretically at risk for dengue. We calculated the risk of dengue acquisition to non-immune international travellers to Brazil, depending on the football match schedules, considering locations and dates of such matches for June and July 2014. We estimated the average per-capita risk and expected number of dengue cases for each host-city and each game schedule chosen based on reported dengue cases to the Brazilian Ministry of Health for the period between 2010-2013. On the average, the expected number of cases among the 600,000 foreigner tourists during the World Cup is 33, varying from 3-59. Such risk estimates will not only benefit individual travellers for adequate pre-travel preparations, but also provide valuable information for public health professionals and policy makers worldwide. Furthermore, estimates of dengue cases in international travellers during the World Cup can help to anticipate the theoretical risk for exportation of dengue into currently non-infected areas. PMID:24863976

Risk of symptomatic dengue for foreign visitors to the 2014 FIFA World Cup in Brazil.

PubMed

Massad, Eduardo; Wilder-Smith, Annelies; Ximenes, Raphael; Amaku, Marcos; Lopez, Luis Fernandez; Coutinho, Francisco Antonio Bezerra; Coelho, Giovanini Evelim; Silva, Jarbas Barbosa da; Struchiner, Claudio José; Burattini, Marcelo Nascimento

2014-06-01

Brazil will host the FIFA World Cup™, the biggest single-event competition in the world, from June 12-July 13 2014 in 12 cities. This event will draw an estimated 600,000 international visitors. Brazil is endemic for dengue. Hence, attendees of the 2014 event are theoretically at risk for dengue. We calculated the risk of dengue acquisition to non-immune international travellers to Brazil, depending on the football match schedules, considering locations and dates of such matches for June and July 2014. We estimated the average per-capita risk and expected number of dengue cases for each host-city and each game schedule chosen based on reported dengue cases to the Brazilian Ministry of Health for the period between 2010-2013. On the average, the expected number of cases among the 600,000 foreigner tourists during the World Cup is 33, varying from 3-59. Such risk estimates will not only benefit individual travellers for adequate pre-travel preparations, but also provide valuable information for public health professionals and policy makers worldwide. Furthermore, estimates of dengue cases in international travellers during the World Cup can help to anticipate the theoretical risk for exportation of dengue into currently non-infected areas.

Remote sensing of subsurface water temperature by Raman scattering.

PubMed

Leonard, D A; Caputo, B; Hoge, F E

1979-06-01

The application of Raman scattering to remote sensing of subsurface water temperature and salinity is considered, and both theoretical and experimental aspects of the technique are discussed. Recent experimental field measurements obtained in coastal waters and on a trans-Atlantic/Mediterranean research cruise are correlated with theoretical expectations. It is concluded that the Raman technique for remote sensing of subsurface water temperature has been brought from theoretical and laboratory stages to the point where practical utilization can now be developed.

What Students Want: Elements of Job Satisfaction Expectations among Multicultural Cohorts

ERIC Educational Resources Information Center

Brown, Dannie L.

2015-01-01

The purpose of this research was to assess students' expectations of future job satisfaction. Data were collected from 484 students enrolled in the BBA programme at Cape Breton University, Nova Scotia, Canada. Locke's job satisfaction theory and Hackman and Oldham's job characteristics model provided the theoretical foundation for the study.…

Sobering up: A Quantitative Review of Temporal Declines in Expectations

ERIC Educational Resources Information Center

Sweeny, Kate; Krizan, Zlatan

2013-01-01

Although people's outlook on the future tends to be characterized by hope and optimism, over time this outlook often becomes more dire. We review multiple theoretical accounts of this tendency to "sober up" as feedback about outcomes draws near, and we explicate factors critical to promoting these temporal declines in expectations. We then…

Analysis of the trade-off between high crop yield and low yield instability at the global scale

NASA Astrophysics Data System (ADS)

Ben-Ari, Tamara; Makowski, David

2016-10-01

Yield dynamics of major crops species vary remarkably among continents. Worldwide distribution of cropland influences both the expected levels and the interannual variability of global yields. An expansion of cultivated land in the most productive areas could theoretically increase global production, but also increase global yield instability if the most productive regions are characterized by high interannual yield variability. In this letter, we use portfolio analysis to quantify the tradeoff between the expected values and the interannual variance of global yield. We compute optimal frontiers for four crop species i.e., maize, rice, soybean and wheat and show how the distribution of cropland among large world regions can be optimized to either increase expected global crop production or decrease its interannual variability. We also show that a preferential allocation of cropland in the most productive regions can increase global expected yield at the expense of yield stability. Theoretically, optimizing the distribution of a small fraction of total cultivated areas can help find a good compromise between low instability and high crop yields at the global scale.

Let's Peel the Onion Together: An Application of Schein's Model of Organizational Culture

ERIC Educational Resources Information Center

Yilmaz, Gamze

2014-01-01

One of the challenges for undergraduate students is to comprehend abstract and theoretical concepts in communication classes. Given today's college students' expectations for in-class interaction (Rocca, 2010), it is important that instructors integrate hands-on activities in their lesson plans while teaching theoretical concepts.…

The Use of Learning Map Systems to Support the Formative Assessment in Mathematics

ERIC Educational Resources Information Center

Kingston, Neal M.; Broaddus, Angela

2017-01-01

Despite much theoretical support, meta-analysis of the efficacy of formative assessment does not provide empirical evidence commensurate with expectations. This theoretical study suggests that teachers need a better organizing structure to allow a formative assessment process to live up to its promise. We propose that the use of learning map…

A Tunable Laser Source for the Validation of Homogeneous Negative Refractive Index Materials in the Optical Regime

DTIC Science & Technology

2012-03-01

theoretically predicted earlier, and it is based on coexistence of the spin wave ( magnon ) mode with the plasmonic mode, with simultaneous negative...region 27-28 µm. Such behavior is expected, since the spin waves ( magnons ) which are responsible for the maximum are not presented in this specific...the magnon -plasmon resonance in magnetic semiconductors. 22 24 26 28 0.65 0.70 0.75 0.80 0.85 R 22 24 26 28 0.65 0.70 0.75 0.80 0.85 R

TeV radiation from the Crab nebula and other matters

NASA Technical Reports Server (NTRS)

Lamb, R. C.

1990-01-01

The detection of the Crab Nebula via the Cherenkov imaging technique places TeV astronomy on a secure observational footing. The motivation for TeV observations, a discussion of the atmospheric Cherenkov technique, the experimental details of the Crab Nebula detection, and its scientific implications are presented. The present dilemma of VHE/UHE astronomy is that the Crab appears to be the only source whose showers match theoretical expectations. The situation will be clarified as improved ground-based detectors come on-line with sensitivities matching those of the GRO (Gamma Ray Observatory) instruments.

The impact of balance-focused attitudes on job stress: Gender differences evidenced in American and Chinese samples.

PubMed

Li, Chenwei; Wu, Keke 'Coco'; Johnson, Diane E

2018-02-01

Based on gender role expectations model, we examined how balance-focused attitudes would affect job stress by influencing individuals' perceptions of family interference with work (FIW), and investigated whether a gender difference would exist in the relationships among balance-focused attitudes, FIW and job stress. Using two independent samples from the United States and China, we found support for the indirect influence of balance-focused attitudes on job stress, through FIW. Participants with balance-focused attitudes experienced lower levels of job stress as they perceived less interference from family to work. As expected, such indirect effect was more pronounce among male participants, meaning that the male participants benefited more from having balance-focused attitudes. Discussion, theoretical and practical implications are provided. © 2016 International Union of Psychological Science.

Optimal Decision Stimuli for Risky Choice Experiments: An Adaptive Approach

PubMed Central

Cavagnaro, Daniel R.; Gonzalez, Richard; Myung, Jay I.; Pitt, Mark A.

2014-01-01

Collecting data to discriminate between models of risky choice requires careful selection of decision stimuli. Models of decision making aim to predict decisions across a wide range of possible stimuli, but practical limitations force experimenters to select only a handful of them for actual testing. Some stimuli are more diagnostic between models than others, so the choice of stimuli is critical. This paper provides the theoretical background and a methodological framework for adaptive selection of optimal stimuli for discriminating among models of risky choice. The approach, called Adaptive Design Optimization (ADO), adapts the stimulus in each experimental trial based on the results of the preceding trials. We demonstrate the validity of the approach with simulation studies aiming to discriminate Expected Utility, Weighted Expected Utility, Original Prospect Theory, and Cumulative Prospect Theory models. PMID:24532856

Universal patterns or the tale of two systems? Mathematics achievement and educational expectations in post-socialist Europe

PubMed Central

Bodovski, Katerina; Kotok, Stephen; Henck, Adrienne

2014-01-01

Although communist ideology claimed to destroy former class stratification based on labor market capitalist relationships, de facto during socialism one social class hierarchy was substituted for another that was equally unequal. The economic transition during the 1990s increased stratification by wealth, which affected educational inequality. This study examines the relationships among parental education, gender, educational expectations, and mathematics achievement of youths in five post-socialist Eastern European countries, comparing them with three Western countries. We employed the 8th-grade data from the Trends in International Mathematics and Science Study (TIMSS) 1995 and 2007. The findings point to the universal associations between parental education and student outcomes, whereas gender comparisons present interesting East-West differences. The theoretical and policy implications of these findings are discussed. PMID:25346564

Experimental study of refrigeration performance based on linear Fresnel solar thermal photovoltaic system

NASA Astrophysics Data System (ADS)

Song, Jinghui; Yuan, Hui; Xia, Yunfeng; Kan, Weimin; Deng, Xiaowen; Liu, Shi; Liang, Wanlong; Deng, Jianhua

2018-03-01

This paper introduces the working principle and system constitution of the linear Fresnel solar lithium bromide absorption refrigeration cycle, and elaborates several typical structures of absorption refrigeration cycle, including single-effect, two-stage cycle and double-effect lithium bromide absorption refrigeration cycle A 1.n effect absorption chiller system based on the best parameters was introduced and applied to a linear Fresnel solar absorption chiller system. Through the field refrigerator performance test, the results show: Based on this heat cycle design and processing 1.n lithium bromide absorption refrigeration power up to 35.2KW, It can meet the theoretical expectations and has good flexibility and reliability, provides guidance for the use of solar thermal energy.

The Temporal Prediction of Stress in Speech and Its Relation to Musical Beat Perception.

PubMed

Beier, Eleonora J; Ferreira, Fernanda

2018-01-01

While rhythmic expectancies are thought to be at the base of beat perception in music, the extent to which stress patterns in speech are similarly represented and predicted during on-line language comprehension is debated. The temporal prediction of stress may be advantageous to speech processing, as stress patterns aid segmentation and mark new information in utterances. However, while linguistic stress patterns may be organized into hierarchical metrical structures similarly to musical meter, they do not typically present the same degree of periodicity. We review the theoretical background for the idea that stress patterns are predicted and address the following questions: First, what is the evidence that listeners can predict the temporal location of stress based on preceding rhythm? If they can, is it thanks to neural entrainment mechanisms similar to those utilized for musical beat perception? And lastly, what linguistic factors other than rhythm may account for the prediction of stress in natural speech? We conclude that while expectancies based on the periodic presentation of stresses are at play in some of the current literature, other processes are likely to affect the prediction of stress in more naturalistic, less isochronous speech. Specifically, aspects of prosody other than amplitude changes (e.g., intonation) as well as lexical, syntactic and information structural constraints on the realization of stress may all contribute to the probabilistic expectation of stress in speech.

Analysis of the origins and implications of the O-18 content of stratospheric water vapor

NASA Technical Reports Server (NTRS)

Kaye, Jack A.

1990-01-01

Factors influencing the O-18 content of stratospheric H2O are reviewed in order to provide a theoretical framework for the interpretation of measurements of this quantity, which are now becoming available. Depletions in O-18 of 5-10 percent in stratospheric H2O are expected based on the known correlation between that of D and O-18 in tropospheric H2O and observed measurements of large (typically 50 percent) depletions of D in stratosphere H2O. H2O formed in the stratosphere as a result of oxidation of CH4 can be expected to reflect primarily the O-18 content of stratospheric O2, which is the same as that of tropospheric O2 (slightly enhanced with respect to standard mean ocean water). Thus, a reduction in the O-18 depletion is expected with increasing altitude, but not a large enhancement in O-18 in upper stratospheric H2O as found in recent far infrared measurements. The observed large enhancement of O-18 in stratospheric O3 is not expected to be reflected in stratospheric H2O. Necessary laboratory data for the improved quantification of these effects are reviewed.

Preliminary investigation of a water-based method for fast integrating mobility spectrometry

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

Spielman, Steven R.; Hering, Susanne V.; Kuang, Chongai

A water-based condensational growth channel was developed for imaging mobility-separated particles within a parallel plate separation channel of the Fast Integrated Mobility Spectrometer (FIMS). Reported are initial tests of that system, in which the alcohol condenser of the FIMS was replaced by a water-based condensational growth channel. Tests with monodispersed sodium chloride aerosol verify that the water-condensational growth maintained the laminar flow, while providing sufficient growth for particle imaging. Particle positions mapped onto particle mobility, in accordance with theoretical expectations. Particles ranging in size from 12 nm to 100 nm were counted with the same efficiency as with a butanol-based ultrafine particlemore » counter, once inlet and line losses were taken into account.« less

Preliminary investigation of a water-based method for fast integrating mobility spectrometry

DOE PAGES

Spielman, Steven R.; Hering, Susanne V.; Kuang, Chongai; ...

2017-06-06

A water-based condensational growth channel was developed for imaging mobility-separated particles within a parallel plate separation channel of the Fast Integrated Mobility Spectrometer (FIMS). Reported are initial tests of that system, in which the alcohol condenser of the FIMS was replaced by a water-based condensational growth channel. Tests with monodispersed sodium chloride aerosol verify that the water-condensational growth maintained the laminar flow, while providing sufficient growth for particle imaging. Particle positions mapped onto particle mobility, in accordance with theoretical expectations. Particles ranging in size from 12 nm to 100 nm were counted with the same efficiency as with a butanol-based ultrafine particlemore » counter, once inlet and line losses were taken into account.« less

Depressive symptoms, depression proneness, and outcome expectancies for cigarette smoking.

PubMed

Friedman-Wheeler, Dara G; Ahrens, Anthony H; Haaga, David A F; McIntosh, Elizabeth; Thorndike, Frances P

2007-08-01

The high rates of cigarette smoking among depressed persons may be partially explained by increased positive expectancies for cigarette smoking among this population. In view of theoretical and empirical work on depressed people's negative views of the future, though, it would be expected that depressed smokers would hold particularly negative expectancies about the effects of cigarette smoking. The two current studies examined the relations between depression and smoking outcome expectancies in (a) a general population of adult regular smokers and (b) adult smokers seeking to quit smoking. Depressive symptoms and depression proneness both showed significant positive correlations with positive expectancies for cigarette smoking. Several positive correlations with negative expectancies also emerged. Thus, experiencing depressive symptoms may serve to amplify both favorable and unfavorable expectancies about the effects of smoking.

Exploring the Dominant Discourse of Baccalaureate Nursing Education in Iran

PubMed Central

Yazdannik, Ahmadreza; Yousefy, Alireza; Mohammadi, Sepideh

2017-01-01

Introduction: Understanding how academic dominant discourse is implicated in the shaping of nursing identity, professional aspirations and socialization of nursing students is useful as it can lead to strategies that promote nursing profession. Materials and Methods: This is a qualitative research conducted through discourse analysis approach. Semi-structured interviews, focus group, and direct observation of undergraduate theoretical and clinical courses were used to collect the data. Participants were 71 nursing students, 20 nursing educators, and 5 nursing board staffs from five universities in Iran. Results: Data analysis resulted in the development of four main themes that represent essential discourses of nursing education. The discourses explored are theoretical and scientific nursing, domination of biomedical paradigm, caring as an empty signifier, and more than expected role of research in nursing education discourse. Conclusions: The results indicated that academics attempt to define itself based on “scientific knowledge” and faculties seek to socialize students by emphasizing the scientific/theoretical basis of nursing and research, with the dominance of biomedical discourse. It fails to conceptually grasp the reality of nursing practice, and the result is an untested and impoverished theoretical discourse. The analysis highlights the need for the formation of a strong and new discourse, which contains articulation of signifiers extracted from the nature of the profession. PMID:28382053

Update on Linear Mode Photon Counting with the HgCdTe Linear Mode Avalanche Photodiode

NASA Technical Reports Server (NTRS)

Beck, Jeffrey D.; Kinch, Mike; Sun, Xiaoli

2014-01-01

The behavior of the gain-voltage characteristic of the mid-wavelength infrared cutoff HgCdTe linear mode avalanche photodiode (e-APD) is discussed both experimentally and theoretically as a function of the width of the multiplication region. Data are shown that demonstrate a strong dependence of the gain at a given bias voltage on the width of the n- gain region. Geometrical and fundamental theoretical models are examined to explain this behavior. The geometrical model takes into account the gain-dependent optical fill factor of the cylindrical APD. The theoretical model is based on the ballistic ionization model being developed for the HgCdTe APD. It is concluded that the fundamental theoretical explanation is the dominant effect. A model is developed that combines both the geometrical and fundamental effects. The model also takes into account the effect of the varying multiplication width in the low bias region of the gain-voltage curve. It is concluded that the lower than expected gain seen in the first 2 × 8 HgCdTe linear mode photon counting APD arrays, and higher excess noise factor, was very likely due to the larger than typical multiplication region length in the photon counting APD pixel design. The implications of these effects on device photon counting performance are discussed.

[Expectations of hospital administrators about administrative functions of nurses].

PubMed

Melo, M R; Fávero, N; Trevizan, M A; Hayashida, M

1996-01-01

The objective of the present study was to investigate hospital administrator's expectations about the administrative role played by nurses, utilizing functions proposed by the Neoclassical Theory of Administration: planning, organization, direction, and control as theoretical references. An instrument established in TREVIZAN (1989) was applied to 11 hospital administrators. The results showed they expect the four functions to be done by nurses. Therefore, the interaction between nurses and hospital administrators is critical to improve the patient's assistance.

A cognitive framework for analyzing and describing introductory students' use and understanding of mathematics in physics

NASA Astrophysics Data System (ADS)

Tuminaro, Jonathan

Many introductory, algebra-based physics students perform poorly on mathematical problem solving tasks in physics. There are at least two possible, distinct reasons for this poor performance: (1) students simply lack the mathematical skills needed to solve problems in physics, or (2) students do not know how to apply the mathematical skills they have to particular problem situations in physics. While many students do lack the requisite mathematical skills, a major finding from this work is that the majority of students possess the requisite mathematical skills, yet fail to use or interpret them in the context of physics. In this thesis I propose a theoretical framework to analyze and describe students' mathematical thinking in physics. In particular, I attempt to answer two questions. What are the cognitive tools involved in formal mathematical thinking in physics? And, why do students make the kinds of mistakes they do when using mathematics in physics? According to the proposed theoretical framework there are three major theoretical constructs: mathematical resources, which are the knowledge elements that are activated in mathematical thinking and problem solving; epistemic games, which are patterns of activities that use particular kinds of knowledge to create new knowledge or solve a problem; and frames, which are structures of expectations that determine how individuals interpret situations or events. The empirical basis for this study comes from videotaped sessions of college students solving homework problems. The students are enrolled in an algebra-based introductory physics course. The videotapes were transcribed and analyzed using the aforementioned theoretical framework. Two important results from this work are: (1) the construction of a theoretical framework that offers researchers a vocabulary (ontological classification of cognitive structures) and grammar (relationship between the cognitive structures) for understanding the nature and origin of mathematical use in the context physics, and (2) a detailed understanding, in terms of the proposed theoretical framework, of the errors that students make when using mathematics in the context of physics.

Advances in cognitive theory and therapy: the generic cognitive model.

PubMed

Beck, Aaron T; Haigh, Emily A P

2014-01-01

For over 50 years, Beck's cognitive model has provided an evidence-based way to conceptualize and treat psychological disorders. The generic cognitive model represents a set of common principles that can be applied across the spectrum of psychological disorders. The updated theoretical model provides a framework for addressing significant questions regarding the phenomenology of disorders not explained in previous iterations of the original model. New additions to the theory include continuity of adaptive and maladaptive function, dual information processing, energizing of schemas, and attentional focus. The model includes a theory of modes, an organization of schemas relevant to expectancies, self-evaluations, rules, and memories. A description of the new theoretical model is followed by a presentation of the corresponding applied model, which provides a template for conceptualizing a specific disorder and formulating a case. The focus on beliefs differentiates disorders and provides a target for treatment. A variety of interventions are described.

[Developing the Japanese version of the Adult Attachment Style Scale (ECR)].

PubMed

Nakao, Tatsuma; Kato, Kazuo

2004-06-01

This study attempted to adapt into Japanese the Adult Attachment Style Scale (ECR: Experiences in Close Relationships inventory) that was constructed by Brennan, Clark, and Shaver (1998), based on 14 existing scales. Of 387 respondents, 231 who reported having been or are currently involved in romantic relationships were employed for final analysis. We examined validities of the Japanese version of ECR in the two ways: (1) Examining the correlations between "Anxiety" and Self-esteem scale by Rosenberg (1965) which were theoretically related to Self-view, and the correlations between "Avoidance" and Other-view scale by Kato (1999b) which were theoretically related to Other-view; (2) whether or not ECR represents the features of four attachment styles as classified by Relationship Questionnaire (RQ; Bartholomew & Horowitz, 1991). The results supported our expectations. This Japanese version of ECR was demonstrated to have adequate psychometric properties in validity and reliability.

Possibility of designing catalysts beyond the traditional volcano curve: a theoretical framework for multi-phase surfaces.

PubMed

Wang, Ziyun; Wang, Hai-Feng; Hu, P

2015-10-01

The current theory of catalyst activity in heterogeneous catalysis is mainly obtained from the study of catalysts with mono-phases, while most catalysts in real systems consist of multi-phases, the understanding of which is far short of chemists' expectation. Density functional theory (DFT) and micro-kinetics simulations are used to investigate the activities of six mono-phase and nine bi-phase catalysts, using CO hydrogenation that is arguably the most typical reaction in heterogeneous catalysis. Excellent activities that are beyond the activity peak of traditional mono-phase volcano curves are found on some bi-phase surfaces. By analyzing these results, a new framework to understand the unexpected activities of bi-phase surfaces is proposed. Based on the framework, several principles for the design of multi-phase catalysts are suggested. The theoretical framework extends the traditional catalysis theory to understand more complex systems.

From bedside to classroom: the nurse educator transition model.

PubMed

Schoening, Anne M

2013-01-01

The purpose of this qualitative study was to generate a theoretical model that describes the social process that occurs during the role transition from nurse to nurse educator. Recruitment and retention of qualified nurse educators is essential in order to remedy the current staff nurse and faculty shortage in the United States, yet nursing schools face many challenges in this area. This grounded theory study utilized purposive, theoretical sampling to identify 20 nurse educators teaching in baccalaureate nursing programs in the Midwest. The Nurse Educator Transition (NET) model was created from these data.This model identifies four phases in the role transition from nurse to nurse educator: a) the Anticipatory/Expectation Phase, b) the Disorientation Phase, c) the Information-Seeking Phase, and d) the Identity Formation Phase. Recommendations include integrating formal pedagogical education into nursing graduate programs and creating evidence-based orientation and mentoring programs for novice nurse faculty.

Quantum photonic network and physical layer security

NASA Astrophysics Data System (ADS)

Sasaki, Masahide; Endo, Hiroyuki; Fujiwara, Mikio; Kitamura, Mitsuo; Ito, Toshiyuki; Shimizu, Ryosuke; Toyoshima, Morio

2017-06-01

Quantum communication and quantum cryptography are expected to enhance the transmission rate and the security (confidentiality of data transmission), respectively. We study a new scheme which can potentially bridge an intermediate region covered by these two schemes, which is referred to as quantum photonic network. The basic framework is information theoretically secure communications in a free space optical (FSO) wiretap channel, in which an eavesdropper has physically limited access to the main channel between the legitimate sender and receiver. We first review a theoretical framework to quantify the optimal balance of the transmission efficiency and the security level under power constraint and at finite code length. We then present experimental results on channel characterization based on 10 MHz on-off keying transmission in a 7.8 km terrestrial FSO wiretap channel. This article is part of the themed issue 'Quantum technology for the 21st century'.

Quantum photonic network and physical layer security.

PubMed

Sasaki, Masahide; Endo, Hiroyuki; Fujiwara, Mikio; Kitamura, Mitsuo; Ito, Toshiyuki; Shimizu, Ryosuke; Toyoshima, Morio

2017-08-06

Quantum communication and quantum cryptography are expected to enhance the transmission rate and the security (confidentiality of data transmission), respectively. We study a new scheme which can potentially bridge an intermediate region covered by these two schemes, which is referred to as quantum photonic network. The basic framework is information theoretically secure communications in a free space optical (FSO) wiretap channel, in which an eavesdropper has physically limited access to the main channel between the legitimate sender and receiver. We first review a theoretical framework to quantify the optimal balance of the transmission efficiency and the security level under power constraint and at finite code length. We then present experimental results on channel characterization based on 10 MHz on-off keying transmission in a 7.8 km terrestrial FSO wiretap channel.This article is part of the themed issue 'Quantum technology for the 21st century'. © 2017 The Author(s).

Exploring super-Gaussianity toward robust information-theoretical time delay estimation.

PubMed

Petsatodis, Theodoros; Talantzis, Fotios; Boukis, Christos; Tan, Zheng-Hua; Prasad, Ramjee

2013-03-01

Time delay estimation (TDE) is a fundamental component of speaker localization and tracking algorithms. Most of the existing systems are based on the generalized cross-correlation method assuming gaussianity of the source. It has been shown that the distribution of speech, captured with far-field microphones, is highly varying, depending on the noise and reverberation conditions. Thus the performance of TDE is expected to fluctuate depending on the underlying assumption for the speech distribution, being also subject to multi-path reflections and competitive background noise. This paper investigates the effect upon TDE when modeling the source signal with different speech-based distributions. An information theoretical TDE method indirectly encapsulating higher order statistics (HOS) formed the basis of this work. The underlying assumption of Gaussian distributed source has been replaced by that of generalized Gaussian distribution that allows evaluating the problem under a larger set of speech-shaped distributions, ranging from Gaussian to Laplacian and Gamma. Closed forms of the univariate and multivariate entropy expressions of the generalized Gaussian distribution are derived to evaluate the TDE. The results indicate that TDE based on the specific criterion is independent of the underlying assumption for the distribution of the source, for the same covariance matrix.

Trait-based Affective Processes in Alcohol-Involved Risk Behaviors

PubMed Central

Wray, Tyler B.; Simons, Jeffrey S.; Dvorak, Robert D.; Gaher, Raluca M.

2012-01-01

This study tested a theoretical model of alcohol use, markers of extreme intoxication, and risk behavior as a function of trait affect, distress tolerance, and affect-based behavior dysregulation. Positive affective pathways to risk behavior were primarily expected to be indirect via high levels of alcohol use, while negative affect paths were expected to be more directly associated with engagement in risk behavior. In addition, we expected trait affectivity and distress tolerance would primarily exhibit relationships with alcohol use and problems through behavioral dysregulation occurring during extreme affective states. To evaluate these hypotheses, we tested a SEM with three alcohol–related outcomes: “Typical” alcohol use, “blackout” drinking,” and risk behavior. Results were complex, but generally supported the hypotheses. High trait negative affect and low tolerance for affective distress contribute to difficulty controlling behavior when negatively aroused and this is directly associated with increased risk behavior when drinking. In contrast, associations between positive urgency and risk behaviors are indirect via increased alcohol consumption. Positive affectivity exhibited both inverse and positive effects in the model, with the net effect on alcohol outcomes being insignificant. These findings contribute important information about the distinct pathways between affect, alcohol use, and alcohol-involved risk behavior among college students. PMID:22770825

Theoretical Explanations of Environmental Motivations and Expectations of Clients on Green Building Demand and Investment

NASA Astrophysics Data System (ADS)

Iheanyichukwu Joachim, Onuoha; Kamarudin, Norhaya; Uche Aliagha, Godwin; Ufere, Kalu Joseph

2015-01-01

In building industry, green demand and investment creates a positive footprint on the environment. However, these environmental opportunities have not been adequately harnessed and explored by Clients of green building apparently because of poor understanding of the motivating drivers and benefits accruing from green building demand and investment. The decision to demand for or invest in green building is influenced by certain environmental motivating drivers and expectations which have not been fully examined by researchers and not well understood by stakeholders. Based on the Theory of Planned Behaviour (TPB) and Theory of Value Belief Norm (VBN) explanations, this study focused on the Clients, purchasers and users' motivations and intentions to go for green building. Based on the reviewed theories, we hypothesized that environmental motivations and expectations for green building demand and investment are embedded in the environmental quest for protection of eco-system and bio-diversity, improvement of water and air quality, reduction of solid waste, conservation of natural resources, reduction of societal costs of landfill creation and maintenance, minimization of site impact and reduction emission to air and enhanced energy efficiency. However, the predictive validity of these propositions depends on the client's beliefs, values, social pressure, and perceived behavioural control.

Preliminary Findings from the First Two Waves of a Panel Study of Developing Career Expectations.

ERIC Educational Resources Information Center

Hotchkiss, Lawrence; Chiteji, Lisa

This report is an exploratory application of a dynamic mathematical model to express a theory of changes in youth's career expectations over time. Main content is divided into two focuses: (1) theoretical interpretations of the differential equations which embody the mathematical model and (2) reporting and discussion of the results of preliminary…

Connecting High School Physics Experiences, Outcome Expectations, Physics Identity, and Physics Career Choice: A Gender Study

ERIC Educational Resources Information Center

Hazari, Zahra; Sonnert, Gerhard; Sadler, Philip M.; Shanahan, Marie-Claire

2010-01-01

This study explores how students' physics identities are shaped by their experiences in high school physics classes and by their career outcome expectations. The theoretical framework focuses on physics identity and includes the dimensions of student performance, competence, recognition by others, and interest. Drawing data from the Persistence…

Being Caring and Disciplinary--Male Primary School Teachers on Expectations from Others

ERIC Educational Resources Information Center

Hjalmarsson, Maria; Löfdahl, Annica

2014-01-01

The article explores how male primary school teachers view and relate to other people's expectations of them as teachers. The empirical data consists of interviews with seven teachers working in compulsory school grades three to five in a large-sized town in Sweden. The theoretical work on relations among masculinities developed by Connell and the…

Perceived Social Support and Locus of Control as the Predictors of Vocational Outcome Expectations

ERIC Educational Resources Information Center

Isik, Erkan

2013-01-01

The purpose of this study was to examine the relationships of vocational outcome expectation to social support which is an environmental factor and locus of control which is a personal factor. With this purpose, using Social Cognitive Career Theory as the theoretical framework, 263 undergraduate students completed Vocational Outcome Expectations…

Low Noise Mid-Wavelength IR Photodetectors

DTIC Science & Technology

2014-02-19

Theoretical Framework and Calculated Results We will first review the theoretical limit for single-stage photovoltaic (PV) detectors and then proceed...efficient the device utilizes the incident photons. We see that Eq. 12 reduces to the standard expression for a single-absorber photovoltaic detector...mid-IR spectrum, one can expect growing demands and applications for high-speed detectors that operate at thermoelectric cooler temperatures with

Fostering a Commitment to Social Action: How Talking, Thinking, and Feeling Make a Difference in Intergroup Dialogue

ERIC Educational Resources Information Center

Gurin-Sands, Chloe; Gurin, Patricia; Nagda, Biren A.; Osuna, Shardae

2012-01-01

Intergroup dialogue is designed to foster commitment to action. This article analyzes papers written by students in 52 intergroup dialogue courses (N = 739) to test a theoretical model of how intergroup dialogue is expected to encourage frequency of acting to educate others and to collaborate with others. The theoretical model posits that dialogue…

Theoretical framework of the causes of construction time and cost overruns

NASA Astrophysics Data System (ADS)

Ullah, K.; Abdullah, A. H.; Nagapan, S.; Suhoo, S.; Khan, M. S.

2017-11-01

Any construction practitioner fundamental goal is to complete the projects within estimated duration and budgets, and expected quality targets. However, time and cost overruns are regular and universal phenomenon in construction projects and the construction projects in Malaysia has no exemption from the problems of time overrun and cost overrun. In order to accomplish the successful completion of construction projects on specified time and within planned cost, there are various factors that should be given serious attention so that issues such as time and cost overrun can be addressed. This paper aims to construct a framework for the causes of time overrun and cost overrun in construction projects of Malaysia. Based on the relevant literature review, causative factors of time overrun and cost overrun in Malaysian construction projects are summarized and the theoretical frameworks of the causes of construction time overrun and cost overrun is constructed. The developed frameworks for construction time and cost overruns based on the existing literature will assist the construction practitioners to plan the efficient approaches for achieving successful completion of the projects.

A Rationally Designed, General Strategy for Membrane Orientation of Photoinduced Electron Transfer-Based Voltage-Sensitive Dyes.

PubMed

Kulkarni, Rishikesh U; Yin, Hang; Pourmandi, Narges; James, Feroz; Adil, Maroof M; Schaffer, David V; Wang, Yi; Miller, Evan W

2017-02-17

Voltage imaging with fluorescent dyes offers promise for interrogating the complex roles of membrane potential in coordinating the activity of neurons in the brain. Yet, low sensitivity often limits the broad applicability of optical voltage indicators. In this paper, we use molecular dynamics (MD) simulations to guide the design of new, ultrasensitive fluorescent voltage indicators that use photoinduced electron transfer (PeT) as a voltage-sensing switch. MD simulations predict an approximately 16% increase in voltage sensitivity resulting purely from improved alignment of dye with the membrane. We confirm this theoretical finding by synthesizing 9 new voltage-sensitive (VoltageFluor, or VF) dyes and establishing that all of them display the expected improvement of approximately 19%. This synergistic outworking of theory and experiment enabled computational and theoretical estimation of VF dye orientation in lipid bilayers and has yielded the most sensitive PeT-based VF dye to date. We use this new voltage indicator to monitor voltage spikes in neurons from rat hippocampus and human pluripotent-stem-cell-derived dopaminergic neurons.

Measuring neuronal avalanches in disordered systems with absorbing states

NASA Astrophysics Data System (ADS)

Girardi-Schappo, M.; Tragtenberg, M. H. R.

2018-04-01

Power-law-shaped avalanche-size distributions are widely used to probe for critical behavior in many different systems, particularly in neural networks. The definition of avalanche is ambiguous. Usually, theoretical avalanches are defined as the activity between a stimulus and the relaxation to an inactive absorbing state. On the other hand, experimental neuronal avalanches are defined by the activity between consecutive silent states. We claim that the latter definition may be extended to some theoretical models to characterize their power-law avalanches and critical behavior. We study a system in which the separation of driving and relaxation time scales emerges from its structure. We apply both definitions of avalanche to our model. Both yield power-law-distributed avalanches that scale with system size in the critical point as expected. Nevertheless, we find restricted power-law-distributed avalanches outside of the critical region within the experimental procedure, which is not expected by the standard theoretical definition. We remark that these results are dependent on the model details.

Uncertainty and stress: Why it causes diseases and how it is mastered by the brain.

PubMed

Peters, Achim; McEwen, Bruce S; Friston, Karl

2017-09-01

The term 'stress' - coined in 1936 - has many definitions, but until now has lacked a theoretical foundation. Here we present an information-theoretic approach - based on the 'free energy principle' - defining the essence of stress; namely, uncertainty. We address three questions: What is uncertainty? What does it do to us? What are our resources to master it? Mathematically speaking, uncertainty is entropy or 'expected surprise'. The 'free energy principle' rests upon the fact that self-organizing biological agents resist a tendency to disorder and must therefore minimize the entropy of their sensory states. Applied to our everyday life, this means that we feel uncertain, when we anticipate that outcomes will turn out to be something other than expected - and that we are unable to avoid surprise. As all cognitive systems strive to reduce their uncertainty about future outcomes, they face a critical constraint: Reducing uncertainty requires cerebral energy. The characteristic of the vertebrate brain to prioritize its own high energy is captured by the notion of the 'selfish brain'. Accordingly, in times of uncertainty, the selfish brain demands extra energy from the body. If, despite all this, the brain cannot reduce uncertainty, a persistent cerebral energy crisis may develop, burdening the individual by 'allostatic load' that contributes to systemic and brain malfunction (impaired memory, atherogenesis, diabetes and subsequent cardio- and cerebrovascular events). Based on the basic tenet that stress originates from uncertainty, we discuss the strategies our brain uses to avoid surprise and thereby resolve uncertainty. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Consumer trust in the Australian food system - The everyday erosive impact of food labelling.

PubMed

Tonkin, Emma; Webb, Trevor; Coveney, John; Meyer, Samantha B; Wilson, Annabelle M

2016-08-01

Consumer trust in food system actors is foundational for ensuring consumer confidence in food safety. As food labelling is a direct communication between consumers and food system actors, it may influence consumer perceptions of actor trustworthiness. This study explores the judgements formed about the trustworthiness of the food system and its actors through labelling, and the expectations these judgements are based on. In-depth, semi-structured interviews with 24 Australian consumers were conducted. Theoretical sampling focussed on shopping location, dietary requirements, rurality, gender, age and educational background. The methodological approach used (adaptive theory) enabled emerging data to be examined through the lens of a set of guiding theoretical concepts, and theory reconsidered in light of emerging data. Food labelling acted as a surrogate for personal interaction with industry and government for participants. Judgements about the trustworthiness of these actors and the broader food system were formed through interaction with food labelling and were based on expectations of both competence and goodwill. Interaction with labelling primarily reduced trust in actors within the food system, undermining trust in the system as a whole. Labelling has a role as an access point to the food system. Access points are points of vulnerability for systems, where trust can be developed, reinforced or broken down. For the participants in this study, in general labelling demonstrates food system actors lack goodwill and violate their fiduciary responsibility. This paper provides crucial insights for industry and policy actors to use this access point to build, rather than undermine, trust in food systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Differences between genomic-based and pedigree-based relationships in a chicken population, as a function of quality control and pedigree links among individuals.

PubMed

Wang, H; Misztal, I; Legarra, A

2014-12-01

This work studied differences between expected (calculated from pedigree) and realized (genomic, from markers) relationships in a real population, the influence of quality control on these differences, and their fit to current theory. Data included 4940 pure line chickens across five generations genotyped for 57,636 SNP. Pedigrees (5762 animals) were available for the five generations, pedigree starting on the first one. Three levels of quality control were used. With no quality control, mean difference between realized and expected relationships for different type of relationships was ≤ 0.04 with standard deviation ≤ 0.10. With strong quality control (call rate ≥ 0.9, parent-progeny conflicts, minor allele frequency and use of only autosomal chromosomes), these numbers reduced to ≤ 0.02 and ≤ 0.04, respectively. While the maximum difference was 1.02 with the complete data, it was only 0.18 with the latest three generations of genotypes (but including all pedigrees). Variation of expected minus realized relationships agreed with theoretical developments and suggests an effective number of loci of 70 for this population. When the pedigree is complete and as deep as the genotypes, the standard deviation of difference between the expected and realized relationships is around 0.04, all categories confounded. Standard deviation of differences larger than 0.10 suggests bad quality control, mistakes in pedigree recording or genotype labelling, or insufficient depth of pedigree. © 2014 Blackwell Verlag GmbH.

Paternal/maternal attachment, peer support, social expectations of peer interaction, and depressive symptoms.

PubMed

Liu, Yih-Lan

2006-01-01

The aim of this study was to investigate how paternal and maternal attachment might relate to adolescents' peer support, social expectations of peer interaction, and depressive symptoms; 1,144 8th graders in Taiwan participated in the study. The relationships were examined through a structural equating modeling. Consistent with theoretical formulations, adolescents with secure attachments to parents reported higher peer support, fewer negative expectations, and fewer depressive symptoms. Paternal and maternal attachment contribute almost equally to adolescents' social expectations of peer interaction and depressive symptoms. Attachment to the same-sex parent was related to adolescents' perceived peer support.

Satellite angular velocity estimation based on star images and optical flow techniques.

PubMed

Fasano, Giancarmine; Rufino, Giancarlo; Accardo, Domenico; Grassi, Michele

2013-09-25

An optical flow-based technique is proposed to estimate spacecraft angular velocity based on sequences of star-field images. It does not require star identification and can be thus used to also deliver angular rate information when attitude determination is not possible, as during platform de tumbling or slewing. Region-based optical flow calculation is carried out on successive star images preprocessed to remove background. Sensor calibration parameters, Poisson equation, and a least-squares method are then used to estimate the angular velocity vector components in the sensor rotating frame. A theoretical error budget is developed to estimate the expected angular rate accuracy as a function of camera parameters and star distribution in the field of view. The effectiveness of the proposed technique is tested by using star field scenes generated by a hardware-in-the-loop testing facility and acquired by a commercial-off-the shelf camera sensor. Simulated cases comprise rotations at different rates. Experimental results are presented which are consistent with theoretical estimates. In particular, very accurate angular velocity estimates are generated at lower slew rates, while in all cases the achievable accuracy in the estimation of the angular velocity component along boresight is about one order of magnitude worse than the other two components.

Satellite Angular Velocity Estimation Based on Star Images and Optical Flow Techniques

PubMed Central

Fasano, Giancarmine; Rufino, Giancarlo; Accardo, Domenico; Grassi, Michele

2013-01-01

An optical flow-based technique is proposed to estimate spacecraft angular velocity based on sequences of star-field images. It does not require star identification and can be thus used to also deliver angular rate information when attitude determination is not possible, as during platform de tumbling or slewing. Region-based optical flow calculation is carried out on successive star images preprocessed to remove background. Sensor calibration parameters, Poisson equation, and a least-squares method are then used to estimate the angular velocity vector components in the sensor rotating frame. A theoretical error budget is developed to estimate the expected angular rate accuracy as a function of camera parameters and star distribution in the field of view. The effectiveness of the proposed technique is tested by using star field scenes generated by a hardware-in-the-loop testing facility and acquired by a commercial-off-the shelf camera sensor. Simulated cases comprise rotations at different rates. Experimental results are presented which are consistent with theoretical estimates. In particular, very accurate angular velocity estimates are generated at lower slew rates, while in all cases the achievable accuracy in the estimation of the angular velocity component along boresight is about one order of magnitude worse than the other two components. PMID:24072023

Using an interdisciplinary approach to identify factors that affect clinicians' compliance with evidence-based guidelines.

PubMed

Gurses, Ayse P; Marsteller, Jill A; Ozok, A Ant; Xiao, Yan; Owens, Sharon; Pronovost, Peter J

2010-08-01

Our objective was to identify factors that affect clinicians' compliance with the evidence-based guidelines using an interdisciplinary approach and develop a conceptual framework that can provide a comprehensive and practical guide for designing effective interventions. A literature review and a brainstorming session with 11 researchers from a variety of scientific disciplines were used to identify theoretical and conceptual models describing clinicians' guideline compliance. MEDLINE, EMBASE, CINAHL, and the bibliographies of the papers identified were used as data sources for identifying the relevant theoretical and conceptual models. Thirteen different models that originated from various disciplines including medicine, rural sociology, psychology, human factors and systems engineering, organizational management, marketing, and health education were identified. Four main categories of factors that affect compliance emerged from our analysis: clinician characteristics, guideline characteristics, system characteristics, and implementation characteristics. Based on these findings, we developed an interdisciplinary conceptual framework that specifies the expected interrelationships among these four categories of factors and their impact on clinicians' compliance. An interdisciplinary approach is needed to improve clinicians' compliance with evidence-based guidelines. The conceptual framework from this research can provide a comprehensive and systematic guide to identify barriers to guideline compliance and design effective interventions to improve patient safety.

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

Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, J.

The authors present the first observation and cross section measurement of exclusive dijet production in {bar p}p interactions, {bar p}p {yields} {bar p} + dijet + p. Using a data sample of 310 pb{sup -1} collected by the Run II Collider Detector at Fermilab at {radical}s = 1.96 TeV, exclusive cross sections for events with two jets of transverse energy E{sub T}{sup jet} {ge} 10 GeV have been measured as a function of minimum E{sub T}{sup jet}. The exclusive signal is extracted from fits to data distributions based on Monte Carlo simulations of expected dijet signal and background shapes. Themore » simulated background distribution shapes are checked in a study of a largely independent data sample of 200 pb{sup -1} of b-tagged jet events, where exclusive dijet production is expected to be suppressed by the J{sub z} = 0 total angular momentum selection rule. Results obtained are compared with theoretical expectations, and implications for exclusive Higgs boson production at the pp Large Hadron Collider at {radical}s = 14 TeV are discussed.« less

A promising new thermoelectric material - Ruthenium silicide

NASA Technical Reports Server (NTRS)

Vining, Cronin B.; Mccormack, Joseph A.; Zoltan, Andrew; Zoltan, Leslie D.

1991-01-01

Experimental and theoretical efforts directed toward increasing thermoelectric figure of merit values by a factor of 2 or 3 have been encouraging in several respects. An accurate and detailed theoretical model developed for n-type silicon-germanium (SiGe) indicates that ZT values several times higher than currently available are expected under certain conditions. These new, high ZT materials are expected to be significantly different from SiGe, but not unreasonably so. Several promising candidate materials have been identified which may meet the conditions required by theory. One such candidate, ruthenium silicide, currently under development at JPL, has been estimated to have the potential to exhibit figure of merit values 4 times higher than conventional SiGe materials. Recent results are summarized.

Theoretical models for stellar X-ray polarization in compact objects

NASA Technical Reports Server (NTRS)

Meszaros, P.

1991-01-01

Degenerate stellar objects are expected to be strong sources of polarized X-ray emission. This is particularly true for strongly magnetized neutron stars, e.g. accretion or rotation powered pulsars, and gamma ray bursters. In these, linear polarization degrees well in excess of 30 percent are expected. Weaker magnetic field stellar sources, such as old neutron stars in low mass binary systems, white dwarfs and black holes are expected to have polarization degrees in the range 1-3 percent. A great interest attaches to the detection of polarization in these objects, since this would provide invaluable information concerning the geometry, radiation mechanism and magnetic field strength, necessary for testing and proving models of the structure and evolution of stars in their late stages. In this paper we review the theoretical models of the production of polarized radiation in compact stellar X-ray sources, and discuss the possibility of detecting these properties using currently planned detectors to be flown in space.

Statistical Modeling of Robotic Random Walks on Different Terrain

NASA Astrophysics Data System (ADS)

Naylor, Austin; Kinnaman, Laura

Issues of public safety, especially with crowd dynamics and pedestrian movement, have been modeled by physicists using methods from statistical mechanics over the last few years. Complex decision making of humans moving on different terrains can be modeled using random walks (RW) and correlated random walks (CRW). The effect of different terrains, such as a constant increasing slope, on RW and CRW was explored. LEGO robots were programmed to make RW and CRW with uniform step sizes. Level ground tests demonstrated that the robots had the expected step size distribution and correlation angles (for CRW). The mean square displacement was calculated for each RW and CRW on different terrains and matched expected trends. The step size distribution was determined to change based on the terrain; theoretical predictions for the step size distribution were made for various simple terrains. It's Dr. Laura Kinnaman, not sure where to put the Prefix.

Aerodynamics of a highly irregular body at transonic speeds-Analysis of STRATOS flight data.

PubMed

Guerster, Markus; Walter, Ulrich

2017-01-01

In this paper, we analyze the trajectory and body attitude data of Felix Baumgartner's supersonic free fall through the atmosphere on October 14, 2012. As one of us (UW) was scientific advisor to the Red Bull Stratos team, the analysis is based on true body data (body mass, wetted pressure suit surface area) and actual atmospheric data from weather balloon measurements. We also present a fully developed theoretical analysis and solution of atmospheric free fall. By matching the flight data against this solution, we are able to derive and track the drag coefficient CD from the subsonic to the transonic and supersonic regime, and back again. Although the subsonic drag coefficient is the expected CD = 0.60 ± 0.05, surprisingly the transonic compressibility drag coefficient is only 19% of the expected value. We provide a plausible explanation for this unexpected result.

Aerodynamics of a highly irregular body at transonic speeds—Analysis of STRATOS flight data

PubMed Central

Guerster, Markus; Walter, Ulrich

2017-01-01

In this paper, we analyze the trajectory and body attitude data of Felix Baumgartner’s supersonic free fall through the atmosphere on October 14, 2012. As one of us (UW) was scientific advisor to the Red Bull Stratos team, the analysis is based on true body data (body mass, wetted pressure suit surface area) and actual atmospheric data from weather balloon measurements. We also present a fully developed theoretical analysis and solution of atmospheric free fall. By matching the flight data against this solution, we are able to derive and track the drag coefficient CD from the subsonic to the transonic and supersonic regime, and back again. Although the subsonic drag coefficient is the expected CD = 0.60 ± 0.05, surprisingly the transonic compressibility drag coefficient is only 19% of the expected value. We provide a plausible explanation for this unexpected result. PMID:29216204

WFIRST: Exoplanet Target Selection and Scheduling with Greedy Optimization

NASA Astrophysics Data System (ADS)

Keithly, Dean; Garrett, Daniel; Delacroix, Christian; Savransky, Dmitry

2018-01-01

We present target selection and scheduling algorithms for missions with direct imaging of exoplanets, and the Wide Field Infrared Survey Telescope (WFIRST) in particular, which will be equipped with a coronagraphic instrument (CGI). Optimal scheduling of CGI targets can maximize the expected value of directly imaged exoplanets (completeness). Using target completeness as a reward metric and integration time plus overhead time as a cost metric, we can maximize the sum completeness for a mission with a fixed duration. We optimize over these metrics to create a list of target stars using a greedy optimization algorithm based off altruistic yield optimization (AYO) under ideal conditions. We simulate full missions using EXOSIMS by observing targets in this list for their predetermined integration times. In this poster, we report the theoretical maximum sum completeness, mean number of detected exoplanets from Monte Carlo simulations, and the ideal expected value of the simulated missions.

Ideology and gender: observers' system justification and targets' gender as interactive predictors of citizenship expectations.

PubMed

Chiaburu, Dan S; Harris, T Brad; Smith, Troy A

2014-01-01

We integrate system justification and social role theory to explain how observers' system justification and target employees' gender interact to predict observers' expectations of targets' sportsmanship citizenship behaviors. In contrast with social role theory predictions, observers did not expect greater levels of sportsmanship from women compared to men. Yet observers expected more sportsmanship from women (a) when observers were ideologically motivated by gender-specific beliefs (gender-specific system justification; Study 1) and (b) when system justification was cued experimentally (Study 2). A heretofore-unexamined aspect, observers' ideology, modifies their expectations of sportsmanship citizenship across target genders. This has implications for system justification, social role, and organizational citizenship theoretical perspectives.

Contribution of Personality to Self-Efficacy and Outcome Expectations in Selecting a High School Major among Adolescents with Learning Disabilities

ERIC Educational Resources Information Center

Brown, Dikla; Cinamon, Rachel Gali

2016-01-01

The current study focuses on the contribution of five personality traits to the development of self-efficacy and outcome expectations regarding selecting a high school major among adolescents with learning disabilities (LD). Social cognitive career theory and the Big Five personality traits model served as the theoretical framework. Participants…

The Role of Jahoda's Latent and Financial Benefits for Work Involvement: A Longitudinal Study

ERIC Educational Resources Information Center

Stiglbauer, Barbara; Batinic, Bernad

2012-01-01

This study examined the role of the latent and financial benefits of work as defined by Marie Jahoda (1982) in explaining a person's work involvement. Drawing upon theoretical frameworks on work commitment and work motivation, the latent benefits were expected to have a positive, whereas the financial benefits were expected to have a negative…

Exercise in middle-aged adults: self-efficacy and self-presentational outcomes.

PubMed

McAuley, E; Bane, S M; Mihalko, S L

1995-07-01

Whereas self-efficacy expectations have been identified as important determinants of exercise participation patterns, little empirical work that examines efficacy expectations as outcomes of exercise participation or their theoretical relationship to other psychological outcomes associated with exercise has been conducted. In the context of middle-aged males and females, the present study attempted to integrate social cognitive and impression management perspectives with respect to anxiety associated with exercise. Formerly sedentary subjects participated in a 5-month exercise program with assessments of physique anxiety, efficacy, outcome expectations, and anthropometric variables prior to and following the program. Both acute bouts and long-term participation in exercise resulted in significant increases in self-efficacy. In turn, these changes in efficacy and initial positive outcome expectations were significant predictors of reductions in physique anxiety, even when controlling for the influence of gender and reductions in body fat, weight, and circumferences. The findings are discussed in terms of the implications for structure and content of exercise environments and the utility of the proposed theoretical integration. Strategies for enhancing beliefs regarding health and fitness outcomes associated with exercise rather than appearance outcomes may be required to maximize reductions in negative body image.

GeneLab

NASA Technical Reports Server (NTRS)

Berrios, Daniel C.; Thompson, Terri G.

2015-01-01

NASA GeneLab is expected to capture and distribute omics data and experimental and process conditions most relevant to research community in their statistical and theoretical analysis of NASAs omics data.

Expectation Violation in Political Decision Making: A Psychological Case Study.

PubMed

Öllinger, Michael; Meissner, Karin; von Müller, Albrecht; Collado Seidel, Carlos

2017-01-01

Since the early Gestaltists there has been a strong interest in the question of how problem solvers get stuck in a mental impasse. A key idea is that the repeated activation of a successful strategy from the past results in a mental set ('Einstellung') which determines and constrains the option space to solve a problem. We propose that this phenomenon, which mostly was tested by fairly restricted experiments in the lab, could also be applied to more complex problem constellations and naturalistic decision making. We aim at scrutinizing and reconstructing how a mental set determines the misinterpretation of facts in the field of political decision making and leads in consequence to wrong expectations and an ill-defined problem representation. We will exemplify this psychological mechanism considering a historical example, namely the unexpected stabilization of the Franco regime at the end of World War II and its survival thereafter. A specific focus will be drawn to the significant observation that erroneous expectations were taken as the basis for decisions. This is congruent with the notion that in case of discrepancy between preconceived notions and new information, the former prevails over the new findings. Based on these findings, we suggest a theoretical model for expectation violation in political decision making and develop novel approaches for cognitive empirical research on the mechanisms of expectation violation and its maintenance in political decision making processes.

Expectation Violation in Political Decision Making: A Psychological Case Study

PubMed Central

Öllinger, Michael; Meissner, Karin; von Müller, Albrecht; Collado Seidel, Carlos

2017-01-01

Since the early Gestaltists there has been a strong interest in the question of how problem solvers get stuck in a mental impasse. A key idea is that the repeated activation of a successful strategy from the past results in a mental set (‘Einstellung’) which determines and constrains the option space to solve a problem. We propose that this phenomenon, which mostly was tested by fairly restricted experiments in the lab, could also be applied to more complex problem constellations and naturalistic decision making. We aim at scrutinizing and reconstructing how a mental set determines the misinterpretation of facts in the field of political decision making and leads in consequence to wrong expectations and an ill-defined problem representation. We will exemplify this psychological mechanism considering a historical example, namely the unexpected stabilization of the Franco regime at the end of World War II and its survival thereafter. A specific focus will be drawn to the significant observation that erroneous expectations were taken as the basis for decisions. This is congruent with the notion that in case of discrepancy between preconceived notions and new information, the former prevails over the new findings. Based on these findings, we suggest a theoretical model for expectation violation in political decision making and develop novel approaches for cognitive empirical research on the mechanisms of expectation violation and its maintenance in political decision making processes. PMID:29085316

The role of positive/negative outcome expectancy and refusal self-efficacy of Internet use on Internet addiction among college students in Taiwan.

PubMed

Lin, Min-Pei; Ko, Huei-Chen; Wu, Jo Yung-Wei

2008-08-01

Based on Bandura's social cognitive theory, this study was designed to examine positive and negative outcome expectancy and refusal self-efficacy of Internet use and their contribution to Internet addiction among college students by using hierarchical multiple regression analyses in a cross-sectional study design. Schools were first stratified into technical or nontechnical colleges and then into seven majors. A cluster random sampling by department was further applied to randomly choose participants from each major. A representative sample of 4,456 college students participated in this study. The Outcome Expectancy and Refusal Self-Efficacy of Internet Use Questionnaire and the Chen Internet Addiction Scale were used to assess the cognitive factors and the levels of Internet addiction. Results showed that both positive outcome expectancy and negative outcome expectancy were significantly and positively correlated with Internet addiction, and refusal self-efficacy of Internet use was significantly and negatively related to Internet addiction. Further analyses revealed that refusal self-efficacy of Internet use directly and negatively predicted Internet addiction. Moreover, we discovered that positive outcome expectancy positively predicted Internet addiction via refusal self-efficacy of Internet use; however, surprisingly, negative outcome expectancy had both a direct and indirect positive relationship in predicting Internet addiction via the refusal self-efficacy of Internet use. These results give empirical evidence to verify the theoretical effectiveness of the three cognitive factors to Internet addiction and should be incorporated when designing prevention programs and strategies for Internet addicted college students.

A pheromone-rate-based analysis on the convergence time of ACO algorithm.

PubMed

Huang, Han; Wu, Chun-Guo; Hao, Zhi-Feng

2009-08-01

Ant colony optimization (ACO) has widely been applied to solve combinatorial optimization problems in recent years. There are few studies, however, on its convergence time, which reflects how many iteration times ACO algorithms spend in converging to the optimal solution. Based on the absorbing Markov chain model, we analyze the ACO convergence time in this paper. First, we present a general result for the estimation of convergence time to reveal the relationship between convergence time and pheromone rate. This general result is then extended to a two-step analysis of the convergence time, which includes the following: 1) the iteration time that the pheromone rate spends on reaching the objective value and 2) the convergence time that is calculated with the objective pheromone rate in expectation. Furthermore, four brief ACO algorithms are investigated by using the proposed theoretical results as case studies. Finally, the conclusions of the case studies that the pheromone rate and its deviation determine the expected convergence time are numerically verified with the experiment results of four one-ant ACO algorithms and four ten-ant ACO algorithms.

The role of predictive uncertainty in the operational management of reservoirs

NASA Astrophysics Data System (ADS)

Todini, E.

2014-09-01

The present work deals with the operational management of multi-purpose reservoirs, whose optimisation-based rules are derived, in the planning phase, via deterministic (linear and nonlinear programming, dynamic programming, etc.) or via stochastic (generally stochastic dynamic programming) approaches. In operation, the resulting deterministic or stochastic optimised operating rules are then triggered based on inflow predictions. In order to fully benefit from predictions, one must avoid using them as direct inputs to the reservoirs, but rather assess the "predictive knowledge" in terms of a predictive probability density to be operationally used in the decision making process for the estimation of expected benefits and/or expected losses. Using a theoretical and extremely simplified case, it will be shown why directly using model forecasts instead of the full predictive density leads to less robust reservoir management decisions. Moreover, the effectiveness and the tangible benefits for using the entire predictive probability density instead of the model predicted values will be demonstrated on the basis of the Lake Como management system, operational since 1997, as well as on the basis of a case study on the lake of Aswan.

An Integrative Behavioral Model of Information Security Policy Compliance

PubMed Central

Kim, Sang Hoon; Yang, Kyung Hoon; Park, Sunyoung

2014-01-01

The authors found the behavioral factors that influence the organization members' compliance with the information security policy in organizations on the basis of neutralization theory, Theory of planned behavior, and protection motivation theory. Depending on the theory of planned behavior, members' attitudes towards compliance, as well as normative belief and self-efficacy, were believed to determine the intention to comply with the information security policy. Neutralization theory, a prominent theory in criminology, could be expected to provide the explanation for information system security policy violations. Based on the protection motivation theory, it was inferred that the expected efficacy could have an impact on intentions of compliance. By the above logical reasoning, the integrative behavioral model and eight hypotheses could be derived. Data were collected by conducting a survey; 194 out of 207 questionnaires were available. The test of the causal model was conducted by PLS. The reliability, validity, and model fit were found to be statistically significant. The results of the hypotheses tests showed that seven of the eight hypotheses were acceptable. The theoretical implications of this study are as follows: (1) the study is expected to play a role of the baseline for future research about organization members' compliance with the information security policy, (2) the study attempted an interdisciplinary approach by combining psychology and information system security research, and (3) the study suggested concrete operational definitions of influencing factors for information security policy compliance through a comprehensive theoretical review. Also, the study has some practical implications. First, it can provide the guideline to support the successful execution of the strategic establishment for the implement of information system security policies in organizations. Second, it proves that the need of education and training programs suppressing members' neutralization intention to violate information security policy should be emphasized. PMID:24971373

An integrative behavioral model of information security policy compliance.

PubMed

Kim, Sang Hoon; Yang, Kyung Hoon; Park, Sunyoung

2014-01-01

The authors found the behavioral factors that influence the organization members' compliance with the information security policy in organizations on the basis of neutralization theory, Theory of planned behavior, and protection motivation theory. Depending on the theory of planned behavior, members' attitudes towards compliance, as well as normative belief and self-efficacy, were believed to determine the intention to comply with the information security policy. Neutralization theory, a prominent theory in criminology, could be expected to provide the explanation for information system security policy violations. Based on the protection motivation theory, it was inferred that the expected efficacy could have an impact on intentions of compliance. By the above logical reasoning, the integrative behavioral model and eight hypotheses could be derived. Data were collected by conducting a survey; 194 out of 207 questionnaires were available. The test of the causal model was conducted by PLS. The reliability, validity, and model fit were found to be statistically significant. The results of the hypotheses tests showed that seven of the eight hypotheses were acceptable. The theoretical implications of this study are as follows: (1) the study is expected to play a role of the baseline for future research about organization members' compliance with the information security policy, (2) the study attempted an interdisciplinary approach by combining psychology and information system security research, and (3) the study suggested concrete operational definitions of influencing factors for information security policy compliance through a comprehensive theoretical review. Also, the study has some practical implications. First, it can provide the guideline to support the successful execution of the strategic establishment for the implement of information system security policies in organizations. Second, it proves that the need of education and training programs suppressing members' neutralization intention to violate information security policy should be emphasized.

Computation of transmitted and received B1 fields in magnetic resonance imaging.

PubMed

Milles, Julien; Zhu, Yue Min; Chen, Nan-Kuei; Panych, Lawrence P; Gimenez, Gérard; Guttmann, Charles R G

2006-05-01

Computation of B1 fields is a key issue for determination and correction of intensity nonuniformity in magnetic resonance images. This paper presents a new method for computing transmitted and received B1 fields. Our method combines a modified MRI acquisition protocol and an estimation technique based on the Levenberg-Marquardt algorithm and spatial filtering. It enables accurate estimation of transmitted and received B1 fields for both homogeneous and heterogeneous objects. The method is validated using numerical simulations and experimental data from phantom and human scans. The experimental results are in agreement with theoretical expectations.

An Information-Theoretic-based Evolutionary Approach for the Dynamic Search Path Planning Problem

DTIC Science & Technology

2014-05-01

0 12 ,min TT TT EEE EE (18) where 0E and iTE are the initial system entropy and the expected entropy...xlsp 10,| (8) c z f z zc z f z z p p p p 1 1; 0,0, zz EE (10) Posterior zone z target occupancy belief for an s-success l...heuristics (1 and 2) shown at the end of time horizon T is defined as follows: 21 0 2 0 1 0 21 21 ,min,max TT TT TT TT EEE EEEE gg gg TRIG 21

The psychometric properties of the WHOQOL-BREF in Japanese couples

PubMed Central

Sun, Yi; Sugawara, Masumi; Matsumoto, Satoko; Sakai, Atsushi; Takaoka, Junko; Goto, Noriko

2015-01-01

This study investigated the psychometric properties of the Japanese version of the WHOQOL-BREF among 10,693 community-based married Japanese men and women (4376 couples) who were either expecting or raising a child. Analyses of item-response distributions, internal consistency, criterion validity, and discriminant validity indicated that the scale had acceptable reliability and performed well in preliminary tests of validity. Furthermore, dyadic confirmatory factor analysis revealed that the theoretical factor structure was valid and similar across partners, suggesting that men and women define and value quality of life in a similar way. PMID:28070365

Semantically induced memories of love and helping behavior.

PubMed

Lamy, Lubomir; Fischer-Lokou, Jacques; Guéguen, Nicolas

2008-04-01

This study tested the effect of semantically induced thoughts of love on helping behavior. In a natural setting, 253 participants were interviewed and asked to retrieve the memory of a love episode or, in the control condition, a piece of music they loved. They then met another confederate who asked for money. Analysis showed that inducing the idea of love had a significant positive effect on compliance to a request by a male passerby who was asked for help by a female confederate, but not by a female passerby. Theoretical explanations are presented, based on a gender-role expectation hypothesis.

Magnetocrystalline anisotropy in UMn 2 Ge 2 and related Mn-based actinide ferromagnets

DOE PAGES

Parker, David S.; Ghimire, Nirmal; Singleton, John; ...

2015-05-04

We presenmore » t magnetization isotherms in pulsed magnetic fields up to 62 Tesla, supported by first principles calculations, demonstrating a huge uniaxial magnetocrystalline anisotropy energy - approximately 20 MJ/m 3 - in UMn 2 Ge 2 . This large anisotropy results from the extremely strong spin-orbit coupling affecting the uranium 5 f electrons, which in the calculations exhibit a substantial orbital moment exceeding 2 μ B. Finally, we also find from theoretical calculations that a number of isostructural Mn-actinide compounds are expected to have similarly large anisotropy.« less

LMC O Supergiant Mass Loss Rates Determined from P V, S V and IR Excesses

NASA Astrophysics Data System (ADS)

Massa, Derck; Prinja, R.; Fullerton, A.; Lennon, D.

2012-05-01

We use HST/STIS and FUSE spectra and Spitzer/IRAC photometry to obtain independent mass loss rates for 7 LMC O supergiants. The mass loss rates are derived from the P Cygni profiles of the P V 1118, 1128 resonance doublet, the S V 1502 and N IV 1718 excited state lines, and the IR excesses of a combination of ground based and Spitzer photometry. The different mass loss rates are compared to each other and to theoretical expectations. We discuss the causes for the differences between the various determinations.

Exploring the nonlinear regime of light-matter interaction using electronic spins in diamond

NASA Astrophysics Data System (ADS)

Alfasi, Nir; Masis, Sergei; Winik, Roni; Farfurnik, Demitry; Shtempluck, Oleg; Bar-Gill, Nir; Buks, Eyal

2018-06-01

The coupling between defects in diamond and a superconducting microwave resonator is studied in the nonlinear regime. Both negatively charged nitrogen-vacancy and P1 defects are explored. The measured cavity mode response exhibits strong nonlinearity near a spin resonance. Data is compared with theoretical predictions and a good agreement is obtained in a wide range of externally controlled parameters. The nonlinear effect under study in the current paper is expected to play a role in any cavity-based magnetic resonance imaging technique and to impose a fundamental limit upon its sensitivity.

Polarization-based compensation of astigmatism.

PubMed

Chowdhury, Dola Roy; Bhattacharya, Kallol; Chakraborty, Ajay K; Ghosh, Raja

2004-02-01

One approach to aberration compensation of an imaging system is to introduce a suitable phase mask at the aperture plane of an imaging system. We utilize this principle for the compensation of astigmatism. A suitable polarization mask used on the aperture plane together with a polarizer-retarder combination at the input of the imaging system provides the compensating polarization-induced phase steps at different quadrants of the apertures masked by different polarizers. The aberrant phase can be considerably compensated by the proper choice of a polarization mask and suitable selection of the polarization parameters involved. The results presented here bear out our theoretical expectation.

Development INTERDATA 8/32 computer system

NASA Technical Reports Server (NTRS)

Sonett, C. P.

1983-01-01

The capabilities of the Interdata 8/32 minicomputer were examined regarding data and word processing, editing, retrieval, and budgeting as well as data management demands of the user groups in the network. Based on four projected needs: (1) a hands on (open shop) computer for data analysis with large core and disc capability; (2) the expected requirements of the NASA data networks; (3) the need for intermittent large core capacity for theoretical modeling; (4) the ability to access data rapidly either directly from tape or from core onto hard copy, the system proved useful and adequate for the planned requirements.

New size-expanded RNA nucleobase analogs: a detailed theoretical study.

PubMed

Zhang, Laibin; Zhang, Zhenwei; Ren, Tingqi; Tian, Jianxiang; Wang, Mei

2015-04-05

Fluorescent nucleobase analogs have attracted much attention in recent years due to their potential applications in nucleic acids research. In this work, four new size-expanded RNA base analogs were computationally designed and their structural, electronic, and optical properties are investigated by means of DFT calculations. The results indicate that these analogs can form stable Watson-Crick base pairs with natural counterparts and they have smaller ionization potentials and HOMO-LUMO gaps than natural ones. Particularly, the electronic absorption spectra and fluorescent emission spectra are calculated. The calculated excitation maxima are greatly red-shifted compared with their parental and natural bases, allowing them to be selectively excited. In gas phase, the fluorescence from them would be expected to occur around 526, 489, 510, and 462 nm, respectively. The influences of water solution and base pairing on the relevant absorption spectra of these base analogs are also examined. Copyright © 2015 Elsevier B.V. All rights reserved.

Outcome expectancy and self-efficacy: theoretical implications of an unresolved contradiction.

PubMed

Williams, David M

2010-11-01

According to self-efficacy theory, self-efficacy--defined as perceived capability to perform a behavior--causally influences expected outcomes of behavior, but not vice versa. However, research has shown that expected outcomes causally influence self-efficacy judgments, and some authors have argued that this relationship invalidates self-efficacy theory. Bandura has rebutted those arguments saying that self-efficacy judgments are not invalidated when influenced by expected outcomes. This article focuses on a contradiction in Bandura's rebuttal. Specifically, Bandura has argued (a) expected outcomes cannot causally influence self-efficacy, but (b) self-efficacy judgments remain valid when causally influenced by expected outcomes. While the debate regarding outcome expectancies and self-efficacy has subsided in recent years, the inattention to this contradiction has led to a disproportionate focus on self-efficacy as a causal determinant of behavior at the expense of expected outcomes.

Property Values as a Measure of Neighborhoods: An Application of Hedonic Price Theory.

PubMed

Leonard, Tammy; Powell-Wiley, Tiffany M; Ayers, Colby; Murdoch, James C; Yin, Wenyuan; Pruitt, Sandi L

2016-07-01

Researchers measuring relationships between neighborhoods and health have begun using property appraisal data as a source of information about neighborhoods. Economists have developed a rich tool kit to understand how neighborhood characteristics are quantified in appraisal values. This tool kit principally relies on hedonic (implicit) price models and has much to offer regarding the interpretation and operationalization of property appraisal data-derived neighborhood measures, which goes beyond the use of appraisal data as a measure of neighborhood socioeconomic status. We develop a theoretically informed hedonic-based neighborhood measure using residuals of a hedonic price regression applied to appraisal data in a single metropolitan area. We describe its characteristics, reliability in different types of neighborhoods, and correlation with other neighborhood measures (i.e., raw neighborhood appraisal values, census block group poverty, and observed property characteristics). We examine the association between all neighborhood measures and body mass index. The hedonic-based neighborhood measure was correlated in the expected direction with block group poverty rate and observed property characteristics. The neighborhood measure and average raw neighborhood appraisal value, but not census block group poverty, were associated with individual body mass index. We draw theoretically consistent methodology from the economics literature on hedonic price models to demonstrate how to leverage the implicit valuation of neighborhoods contained in publicly available appraisal data. Consistent measurement and application of the hedonic-based neighborhood measures in epidemiology will improve understanding of the relationships between neighborhoods and health. Researchers should proceed with a careful use of appraisal values utilizing theoretically informed methods such as this one.

Determination of the matrix element V(ub) from inclusive B meson decays

NASA Astrophysics Data System (ADS)

Low, Ian

For years the extraction of |Vub| was tainted by large errors due to theoretical uncertainties. Because of our inability to calculate hadronic dynamics, we are forced to resort to ad hoc models when making theoretical predictions, hence introduce errors which are very hard to quantify. However, an accurate measurement of |Vub| is very important for testing the Cabbibo-Kobayashi-Maskawa picture of CP violation in the minimal standard model. It is highly desirable to be able to extract |Vub| with well-defined and reasonable theoretical uncertainties. In this dissertation, a strategy to extract |Vub| from the electron energy spectrum of the inclusive semi-leptonic B decays is proposed, without having to model the hadronic dynamics. It is based on the observation that the long distance physics involving hadronization, of which we are ignorant, is insensitive to the short distance interactions. Therefore, the uncalculable part in B → Xuℓn is the same as that in the radiative B decays B → Xsgamma. We are able to write down an analytic expression for Vub2/ V*tsVtb in terms of known functions. The theoretical uncertainty in this method is well-defined and estimated to be less than 10% in | Vub|. We also apply our method to the case of hadronic mass spectrum of the inclusive semi-leptonic decays, which has the virtue that the quark-hadron duality is expected to work better.

A New Optical Scheme for a Polarimetric-Based Glucose Sensor

NASA Technical Reports Server (NTRS)

Ansari, Rafat R.; Boeckle, Stefan; Rovati, Luigi; Salzman, Jack A. (Technical Monitor)

2002-01-01

We describe a new optical scheme to perform polarimetric measurements to detect glucose concentration in the aqueous humor of a model eye. The ultimate aim is to apply this technique in designing a new instrument for measuring glucose levels in diabetic patients routinely, frequently, and non-invasively. The scheme exploits the Brewsterreflection of circularly polarized light off of the lens of the eye. Theoretically, this backreflected linearly polarized light on its way to the detector is expected to rotate its state of polarization due to the presence of glucose molecules in the aqueous humor of patients. An experimental laboratory setup based on this scheme was designed and tested by measuring a range of known concentration of glucose solutions dissolved in water.

Guidelines for preparing high school psychology teachers: course-based and standards-based approaches.

PubMed

2013-01-01

Psychology is one of the most popular elective high school courses. The high school psychology course provides the foundation for students to benefit from psychological perspectives on personal and contemporary issues and learn the rules of evidence and theoretical frameworks of the discipline. The guidelines presented here constitute the second of two reports in this issue of the American Psychologist (January 2013) representing recent American Psychological Association (APA) policies that support high-quality instruction in the teaching of high school psychology. These guidelines, aligned to the standards presented in the preceding report, describe models for the preparation of preservice psychology teachers. The two reports together demonstrate the rigor and competency that should be expected in psychology instruction at the high school level.

Observing the epoch of galaxy formation.

PubMed

Steidel, C C

1999-04-13

Significant observational progress in addressing the question of the origin and early evolution of galaxies has been made in the past few years, allowing for direct comparison of the epoch when most of the stars in the universe were forming to prevailing theoretical models. There is currently broad consistency between theoretical expectations and the observations, but rapid improvement in the data will provide much more critical tests of theory in the coming years.

Low Loss Flexible Dielectric Waveguide for Millimeter-Wave Transmission and Its Application to Devices.

DTIC Science & Technology

1981-03-01

2 ±1 x 10-2 -agree reasonably well with a simple theoretical fit to the far-infrared lattice absorptions of TLBr and TECt at about 1400 CHz. The...available for TXI, but we would expect it to be similar, and thus the admixture of TUI to TlBr (giving KRS-5) is also expected tn be comparable. It appears

Properties of the ion-ion hybrid resonator in fusion plasmas

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

Morales, George J.

2015-10-06

The project developed theoretical and numerical descriptions of the properties of ion-ion hybrid Alfvén resonators that are expected to arise in the operation of a fusion reactor. The methodology and theoretical concepts were successfully compared to observations made in basic experiments in the LAPD device at UCLA. An assessment was made of the excitation of resonator modes by energetic alpha particles for burning plasma conditions expected in the ITER device. The broader impacts included the generation of basic insight useful to magnetic fusion and space science researchers, defining new avenues for exploration in basic laboratory experiments, establishing broader contacts betweenmore » experimentalists and theoreticians, completion of a Ph.D. dissertation, and promotion of interest in science through community outreach events and classroom instruction.« less

Expectations Do Not Alter Early Sensory Processing during Perceptual Decision-Making.

PubMed

Rungratsameetaweemana, Nuttida; Itthipuripat, Sirawaj; Salazar, Annalisa; Serences, John T

2018-06-13

Two factors play important roles in shaping perception: the allocation of selective attention to behaviorally relevant sensory features, and prior expectations about regularities in the environment. Signal detection theory proposes distinct roles of attention and expectation on decision-making such that attention modulates early sensory processing, whereas expectation influences the selection and execution of motor responses. Challenging this classic framework, recent studies suggest that expectations about sensory regularities enhance the encoding and accumulation of sensory evidence during decision-making. However, it is possible, that these findings reflect well documented attentional modulations in visual cortex. Here, we tested this framework in a group of male and female human participants by examining how expectations about stimulus features (orientation and color) and expectations about motor responses impacted electroencephalography (EEG) markers of early sensory processing and the accumulation of sensory evidence during decision-making (the early visual negative potential and the centro-parietal positive potential, respectively). We first demonstrate that these markers are sensitive to changes in the amount of sensory evidence in the display. Then we show, counter to recent findings, that neither marker is modulated by either feature or motor expectations, despite a robust effect of expectations on behavior. Instead, violating expectations about likely sensory features and motor responses impacts posterior alpha and frontal theta oscillations, signals thought to index overall processing time and cognitive conflict. These findings are inconsistent with recent theoretical accounts and suggest instead that expectations primarily influence decisions by modulating post-perceptual stages of information processing. SIGNIFICANCE STATEMENT Expectations about likely features or motor responses play an important role in shaping behavior. Classic theoretical frameworks posit that expectations modulate decision-making by biasing late stages of decision-making including the selection and execution of motor responses. In contrast, recent accounts suggest that expectations also modulate decisions by improving the quality of early sensory processing. However, these effects could instead reflect the influence of selective attention. Here we examine the effect of expectations about sensory features and motor responses on a set of electroencephalography (EEG) markers that index early sensory processing and later post-perceptual processing. Counter to recent empirical results, expectations have little effect on early sensory processing but instead modulate EEG markers of time-on-task and cognitive conflict. Copyright © 2018 the authors 0270-6474/18/385632-17$15.00/0.

The Safety Culture Enactment Questionnaire (SCEQ): Theoretical model and empirical validation.

PubMed

de Castro, Borja López; Gracia, Francisco J; Tomás, Inés; Peiró, José M

2017-06-01

This paper presents the Safety Culture Enactment Questionnaire (SCEQ), designed to assess the degree to which safety is an enacted value in the day-to-day running of nuclear power plants (NPPs). The SCEQ is based on a theoretical safety culture model that is manifested in three fundamental components of the functioning and operation of any organization: strategic decisions, human resources practices, and daily activities and behaviors. The extent to which the importance of safety is enacted in each of these three components provides information about the pervasiveness of the safety culture in the NPP. To validate the SCEQ and the model on which it is based, two separate studies were carried out with data collection in 2008 and 2014, respectively. In Study 1, the SCEQ was administered to the employees of two Spanish NPPs (N=533) belonging to the same company. Participants in Study 2 included 598 employees from the same NPPs, who completed the SCEQ and other questionnaires measuring different safety outcomes (safety climate, safety satisfaction, job satisfaction and risky behaviors). Study 1 comprised item formulation and examination of the factorial structure and reliability of the SCEQ. Study 2 tested internal consistency and provided evidence of factorial validity, validity based on relationships with other variables, and discriminant validity between the SCEQ and safety climate. Exploratory Factor Analysis (EFA) carried out in Study 1 revealed a three-factor solution corresponding to the three components of the theoretical model. Reliability analyses showed strong internal consistency for the three scales of the SCEQ, and each of the 21 items on the questionnaire contributed to the homogeneity of its theoretically developed scale. Confirmatory Factor Analysis (CFA) carried out in Study 2 supported the internal structure of the SCEQ; internal consistency of the scales was also supported. Furthermore, the three scales of the SCEQ showed the expected correlation patterns with the measured safety outcomes. Finally, results provided evidence of discriminant validity between the SCEQ and safety climate. We conclude that the SCEQ is a valid, reliable instrument supported by a theoretical framework, and it is useful to measure the enactment of safety culture in NPPs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Determinants of life expectancy in eastern mediterranean region: a health production function.

PubMed

Bayati, Mohsen; Akbarian, Reza; Kavosi, Zahra

2013-06-01

Determinants of health or health production function in health economics literature constitute noticeable issues in health promotion. This study aimed at estimating a health production function for East Mediterranean Region (EMR) based on the Grossman theoretical model. This ecological study was performed using the econometric methods. The panel data model was used in order to determine the relationship between life expectancy and socioeconomic factors. The data for 21 EMR countries between 1995 and 2007 were used. Fixed-effect-model was employed to estimate the parameters based on Hausman test. In estimating the health production function, factors such as income per capita (β=0.05, P<0.001), education index (β=0.07, P<0.001), food availability (β=0.01, P<0.001), level of urbanisation (β=0.10, P<0.001), and employment ratio (β=0.11, P<0.001) were specified as determinants of health status, proxied by life expectancy at birth. A notable result was the elasticity of life expectancy with respect to the employment rate and its significance level was different between males (β=0.13, P<0.001) and females (β=0.08, P>0.001). In order to improve the health status in EMR countries, health policymakers should focus on the factors which lie outside the healthcare system. These factors are mainly associated with economic growth and development level. Thus, the economic stabilisation policies with the aim of increasing the productivity, economic growth, and reducing unemployment play significant roles in the health status of the people of the region.

Lung Morphometry with Hyperpolarized 129Xe: Theoretical Background

PubMed Central

Sukstanskii, A.L.; Yablonskiy, D.A.

2011-01-01

The 3He lung morphometry technique, based on MRI measurements of hyperpolarized 3He gas diffusion in lung airspaces, provides unique information on the lung microstructure at the alveolar level. In vivo 3D tomographic images of standard morphological parameters (airspace chord length, lung parenchyma surface-to-volume ratio, number of alveoli per unit volume) can be generated from a rather short (several seconds) MRI scan. The technique is based on a theory of gas diffusion in lung acinar airways and experimental measurements of diffusion attenuated MRI signal. The present work aims at developing the theoretical background of a similar technique based on hyperpolarized 129Xe gas. As the diffusion coefficient and gyromagnetic ratio of 129Xe gas are substantially different from those of 3He gas, the specific details of the theory and experimental measurements with 129Xe should be amended. We establish phenomenological relationships between acinar airway geometrical parameters and the diffusion attenuated MR signal for human and small animal lungs, both normal lungs and lungs with mild emphysema. Optimal diffusion times are shown to be about 5 ms for human and 1.3 ms for small animals. The expected uncertainties in measuring main morphometrical parameters of the lungs are estimated in the framework of Bayesian probability theory. PMID:21713985

Quantitative interpretation of heavy ion effects: Comparison of different systems and endpoints

NASA Astrophysics Data System (ADS)

Kiefer, J.

For a quantitative interpretation of biological heavy ion action the following parameters have to be taken into account: variations of energy depositions in microscopical sites, the dependence of primary lesion formation on local energy density and changes in repairability. They can be studied in objects of different size and with different sensitivities. Results on survival and mutation induction in yeast and in mammalian cells will be compared with theoretical predictions. It is shown that shouldered survival curves of diploid yeast can be adequately described if the final slope is adjusted according to the varying production of primary lesions. This is not the case for mammalian cells where the experiments show a rapid loss of the shoulder with LET, contrary to theoretical expectations. This behaviour is interpreted to mean that the repairability of heavy ion lesions is different in the two systems. Mutation induction is theoretically expected to decrease with higher LET. This is found in yeast but not in mammalian cells where it actually increases. These results suggest a higher rate of misrepair in mammalian cells.

From lists of behaviour change techniques (BCTs) to structured hierarchies: comparison of two methods of developing a hierarchy of BCTs.

PubMed

Cane, James; Richardson, Michelle; Johnston, Marie; Ladha, Ruhina; Michie, Susan

2015-02-01

Behaviour change technique (BCT) Taxonomy v1 is a hierarchically grouped, consensus-based taxonomy of 93 BCTs for reporting intervention content. To enhance the use and understanding of BCTs, the aims of the present study were to (1) quantitatively examine the 'bottom-up' hierarchical structure of Taxonomy v1, (2) identify whether BCTs can be reliably mapped to theoretical domains using a 'top-down' theoretically driven approach, and (3) identify any overlap between the 'bottom-up' and 'top-down' groupings. The 'bottom-up' structure was examined for higher-order groupings using a dendrogram derived from hierarchical cluster analysis. For the theory-based 'top-down' structure, 18 experts sorted BCTs into 14 theoretical domains. Discriminant Content Validity was used to identify groupings, and chi-square tests and Pearson's residuals were used to examine the overlap between groupings. Behaviour change techniques relating to 'Reward and Punishment' and 'Cues and Cue Responses' were perceived as markedly different to other BCTs. Fifty-nine of the BCTs were reliably allocated to 12 of the 14 theoretical domains; 47 were significant and 12 were of borderline significance. Thirty-four of 208 'bottom-up' × 'top-down' pairings showed greater overlap than expected by chance. However, only six combinations achieved satisfactory evidence of similarity. The moderate overlap between the groupings indicates some tendency to implicitly conceptualize BCTs in terms of the same theoretical domains. Understanding the nature of the overlap will aid the conceptualization of BCTs in terms of theory and application. Further research into different methods of developing a hierarchical taxonomic structure of BCTs for international, interdisciplinary work is now required. Statement of contribution What is already known on this subject? Behaviour change interventions are effective in improving health care and health outcomes. The 'active' components of these interventions are behaviour change techniques and over 93 have been identified. Taxonomies of behaviour change techniques require structure to enable potential applications. What does this study add? This study identifies groups of BCTs to aid the recall of BCTs for intervention coding and design. It compares two methods of grouping--'bottom-up' and theory-based 'top-down'--and finds a moderate overlap. Building on identified BCT groups, it examines relationships between theoretical domains and BCTs. © 2014 The British Psychological Society.

How Victim Sensitivity leads to Uncooperative Behavior via Expectancies of Injustice

PubMed Central

Maltese, Simona; Baumert, Anna; Schmitt, Manfred J.; MacLeod, Colin

2016-01-01

According to the Sensitivity-to-mean-intentions model, dispositional victim sensitivity involves a suspicious mindset that is activated by situational cues and guides subsequent information processing and behavior like a schema. Study 1 tested whether victim-sensitive persons are more prone to form expectancies of injustice in ambiguous situations and whether these expectancies mediate the relationship between victim sensitivity and cooperation behavior in a trust game. Results show an indirect effect of victim sensitivity on cooperation after unfair treatment (vs. control condition), mediated by expectancies of injustice. In Study 2 we directly manipulated the tendency to form expectancies of injustice in ambiguous situations to test for causality. Results confirmed that the readiness to expect unjust outcomes led to lower cooperation, compared to a control condition. These findings provide direct evidence that expectancy tendencies are implicated in elevated victim sensitivity and are of theoretical and practical relevance. PMID:26793163

The Hispanic Americans Baseline Alcohol Survey (HABLAS): predictors of alcohol attitudes and expectancies in Hispanic national groups.

PubMed

Mills, Britain A; Caetano, Raul

2010-05-01

Multiple theoretical frameworks identify attitudes and expectancies as important predictors of alcohol behavior. Few studies have examined demographic predictors of these evaluative and belief-based cognitive mediators in the general population, and none have examined them in large-scale studies of Hispanics, a group at higher risk for drinking behavior and problems. This study probes the extent to which dimensions of attitudes and expectancies share common demographic predictors in a large sample of Puerto Ricans, Cuban-Americans, Mexican-Americans, and South/Central Americans. The 2006 Hispanic Americans Baseline Alcohol Survey (HABLAS) used a multistage cluster sample design to interview 5,224 individuals randomly selected from households in Miami, New York, Philadelphia, Houston, and Los Angeles. This study focused on 2,773 respondents self-identified as current drinkers. Multiple linear regression was used to identify predictors of positive and negative dimensions of attitudes and expectancies, controlling for various background variables. Religious affiliation selectively predicted alcohol attitudes, with Catholics having more positive and fewer negative attitudes than other religious groups. Hispanic group selectively predicted alcohol expectancies, with Cuban-Americans having less positive and less negative expectancies than other groups. Being U.S.-born or male predicted more positive attitudes and expectancies, but birthplace and gender did not predict negative dimensions of attitudes or expectancies. Higher acculturation and more education were linked to a decreased tendency to agree with any item. Age was positively and negatively associated with negative expectancies and positive attitudes, respectively, and having never been married, higher income, and unemployment were each linked to fewer negative attitudes. Although there is some overlap, attitudes and expectancies are influenced by different sociodemographic variables. Positive and negative dimensions of those constructs also show distinct patterns of relations. Prevention and treatment programs targeting cognitive mediators of behavior should be mindful of these differential determinants and future modeling endeavors should incorporate them.

The Hispanic Americans Baseline Alcohol Survey (HABLAS): Predictors of alcohol attitudes and expectancies in Hispanic national groups

PubMed Central

Mills, Britain A.; Caetano, Raul

2012-01-01

Background Multiple theoretical frameworks identify attitudes and expectancies as important predictors of alcohol behavior. Few studies have examined demographic predictors of these evaluative and belief-based cognitive mediators in the general population, and none have examined them in large-scale studies of Hispanics, a group at higher risk for drinking behavior and problems. This study probes the extent to which dimensions of attitudes and expectancies share common demographic predictors in a large sample of Puerto Ricans, Cuban-Americans, Mexican-Americans, and South/Central Americans. Methods The 2006 Hispanic Americans Baseline Alcohol Survey (HABLAS) used a multistage cluster sample design to interview 5,224 individuals randomly selected from households in Miami, New York, Philadelphia, Houston, and Los Angeles. This study focused on 2,773 respondents self-identified as current drinkers. Multiple linear regression was used to identify predictors of positive and negative dimensions of attitudes and expectancies, controlling for various background variables. Results Religious affiliation selectively predicted alcohol attitudes, with Catholics having more positive and fewer negative attitudes than other religious groups. Hispanic group selectively predicted alcohol expectancies, with Cuban-Americans having less positive and less negative expectancies than other groups. Being U.S.-born or male predicted more positive attitudes and expectancies, but birthplace and gender did not predict negative dimensions of attitudes or expectancies. Higher acculturation and more education were linked to a decreased tendency to agree with any item. Age was positively and negatively associated with negative expectancies and positive attitudes, respectively, and having never been married, higher income, and unemployment were each linked to fewer negative attitudes. Conclusions Although there is some overlap, attitudes and expectancies are influenced by different sociodemographic variables. Positive and negative dimensions of those constructs also show distinct patterns of relations. Prevention and treatment programs targeting cognitive mediators of behavior should be mindful of these differential determinants and future modeling endeavors should incorporate them. PMID:20184565

Ab Initio Computations and Active Thermochemical Tables Hand in Hand: Heats of Formation of Core Combustion Species.

PubMed

Klippenstein, Stephen J; Harding, Lawrence B; Ruscic, Branko

2017-09-07

The fidelity of combustion simulations is strongly dependent on the accuracy of the underlying thermochemical properties for the core combustion species that arise as intermediates and products in the chemical conversion of most fuels. High level theoretical evaluations are coupled with a wide-ranging implementation of the Active Thermochemical Tables (ATcT) approach to obtain well-validated high fidelity predictions for the 0 K heat of formation for a large set of core combustion species. In particular, high level ab initio electronic structure based predictions are obtained for a set of 348 C, N, O, and H containing species, which corresponds to essentially all core combustion species with 34 or fewer electrons. The theoretical analyses incorporate various high level corrections to base CCSD(T)/cc-pVnZ analyses (n = T or Q) using H 2 , CH 4 , H 2 O, and NH 3 as references. Corrections for the complete-basis-set limit, higher-order excitations, anharmonic zero-point energy, core-valence, relativistic, and diagonal Born-Oppenheimer effects are ordered in decreasing importance. Independent ATcT values are presented for a subset of 150 species. The accuracy of the theoretical predictions is explored through (i) examination of the magnitude of the various corrections, (ii) comparisons with other high level calculations, and (iii) through comparison with the ATcT values. The estimated 2σ uncertainties of the three methods devised here, ANL0, ANL0-F12, and ANL1, are in the range of ±1.0-1.5 kJ/mol for single-reference and moderately multireference species, for which the calculated higher order excitations are 5 kJ/mol or less. In addition to providing valuable references for combustion simulations, the subsequent inclusion of the current theoretical results into the ATcT thermochemical network is expected to significantly improve the thermochemical knowledge base for less-well studied species.

Ab Initio Computations and Active Thermochemical Tables Hand in Hand: Heats of Formation of Core Combustion Species

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

Klippenstein, Stephen J.; Harding, Lawrence B.; Ruscic, Branko

Here, the fidelity of combustion simulations is strongly dependent on the accuracy of the underlying thermochemical properties for the core combustion species that arise as intermediates and products in the chemical conversion of most fuels. High level theoretical evaluations are coupled with a wide-ranging implementation of the Active Thermochemical Tables (ATcT) approach to obtain well-validated high fidelity predictions for the 0 K heat of formation for a large set of core combustion species. In particular, high level ab initio electronic structure based predictions are obtained for a set of 348 C, N, O, and H containing species, which corresponds tomore » essentially all core combustion species with 34 or fewer electrons. The theoretical analyses incorporate various high level corrections to base CCSD(T)/cc-pVnZ analyses (n = T or Q) using H 2, CH 4, H 2O, and NH 3 as references. Corrections for the complete-basis-set limit, higher-order excitations, anharmonic zeropoint energy, core–valence, relativistic, and diagonal Born–Oppenheimer effects are ordered in decreasing importance. Independent ATcT values are presented for a subset of 150 species. The accuracy of the theoretical predictions is explored through (i) examination of the magnitude of the various corrections, (ii) comparisons with other high level calculations, and (iii) through comparison with the ATcT values. The estimated 2σ uncertainties of the three methods devised here, ANL0, ANL0-F12, and ANL1, are in the range of ±1.0–1.5 kJ/mol for single-reference and moderately multireference species, for which the calculated higher order excitations are 5 kJ/mol or less. In addition to providing valuable references for combustion simulations, the subsequent inclusion of the current theoretical results into the ATcT thermochemical network is expected to significantly improve the thermochemical knowledge base for less-well studied species.« less

Ab Initio Computations and Active Thermochemical Tables Hand in Hand: Heats of Formation of Core Combustion Species

DOE PAGES

Klippenstein, Stephen J.; Harding, Lawrence B.; Ruscic, Branko

2017-07-31

Here, the fidelity of combustion simulations is strongly dependent on the accuracy of the underlying thermochemical properties for the core combustion species that arise as intermediates and products in the chemical conversion of most fuels. High level theoretical evaluations are coupled with a wide-ranging implementation of the Active Thermochemical Tables (ATcT) approach to obtain well-validated high fidelity predictions for the 0 K heat of formation for a large set of core combustion species. In particular, high level ab initio electronic structure based predictions are obtained for a set of 348 C, N, O, and H containing species, which corresponds tomore » essentially all core combustion species with 34 or fewer electrons. The theoretical analyses incorporate various high level corrections to base CCSD(T)/cc-pVnZ analyses (n = T or Q) using H 2, CH 4, H 2O, and NH 3 as references. Corrections for the complete-basis-set limit, higher-order excitations, anharmonic zeropoint energy, core–valence, relativistic, and diagonal Born–Oppenheimer effects are ordered in decreasing importance. Independent ATcT values are presented for a subset of 150 species. The accuracy of the theoretical predictions is explored through (i) examination of the magnitude of the various corrections, (ii) comparisons with other high level calculations, and (iii) through comparison with the ATcT values. The estimated 2σ uncertainties of the three methods devised here, ANL0, ANL0-F12, and ANL1, are in the range of ±1.0–1.5 kJ/mol for single-reference and moderately multireference species, for which the calculated higher order excitations are 5 kJ/mol or less. In addition to providing valuable references for combustion simulations, the subsequent inclusion of the current theoretical results into the ATcT thermochemical network is expected to significantly improve the thermochemical knowledge base for less-well studied species.« less

Content-oriented Approach to Organization of Theories and Its Utilization

NASA Astrophysics Data System (ADS)

Hayashi, Yusuke; Bourdeau, Jacqueline; Mizoguch, Riichiro

In spite of the fact that the relation between theory and practice is a foundation of scientific and technological development, the trend of increasing the gap between theory and practice accelerates in these years. The gap embraces a risk of distrust of science and technology. Ontological engineering as the content-oriented research is expected to contribute to the resolution of the gap. This paper presents the feasibility of organization of theoretical knowledge on ontological engineering and new-generation intelligent systems based on it through an application of ontological engineering in the area of learning/instruction support. This area also has the problem of the gap between theory and practice, and its resolution is strongly required. So far we proposed OMNIBUS ontology, which is a comprehensive ontology that covers different learning/instructional theories and paradigms, and SMARTIES, which is a theory-aware and standard-compliant authoring system for making learning/instructional scenarios based on OMNIBUS ontology. We believe the theory-awareness and standard-compliance bridge the gap between theory and practice because it links theories to practical use of standard technologies and enables practitioners to easily enjoy theoretical support while using standard technologies in practice. The following goals are set in order to achieve it; computers (1) understand a variety of learning/instructional theories based on the organization of them, (2) utilize the understanding for helping authors' learning/instructional scenario making and (3) make such theoretically sound scenarios interoperable within the framework of standard technologies. This paper suggests an ontological engineering solution to the achievement of these three goals. Although the evaluation is far from complete in terms of practical use, we believe that the results of this study address high-level technical challenges from the viewpoint of the current state of the art in the research area of artificial intelligence not only in education but also in general, and therefore we hope that constitute a substantial contribution for organization of theoretical knowledge in many other areas.

Religion-based emotional social support mediates the relationship between intrinsic religiosity and mental health.

PubMed

Hovey, Joseph D; Hurtado, Gabriela; Morales, Lori R A; Seligman, Laura D

2014-01-01

Although previous research suggests that increased religiosity is associated with better mental health and many authors have conjectured that religion-based social support may help explain this connection, scant research has directly examined whether religion-based support mediates religiosity and mental health. The present study examined whether various dimensions of religion-based support (social interaction, instrumental, and emotional) mediated the relationship between religiosity and mental health in college students in the Midwest United States. As expected, of the support dimensions, perceived emotional support was the strongest predictor of decreased hopelessness, depression, and suicide behaviors; and the relationships among intrinsic religiosity and the mental health variables were fully mediated by emotional support. These findings provide strong support to the notion that the relationship between religiosity and mental health can be reduced to mediators such as social support. Research and theoretical implications are discussed.

Characterization and Modeling of Nonfilamentary Ta/TaOx/TiO2/Ti Analog Synaptic Device

PubMed Central

Wang, Yu-Fen; Lin, Yen-Chuan; Wang, I-Ting; Lin, Tzu-Ping; Hou, Tuo-Hung

2015-01-01

A two-terminal analog synaptic device that precisely emulates biological synaptic features is expected to be a critical component for future hardware-based neuromorphic computing. Typical synaptic devices based on filamentary resistive switching face severe limitations on the implementation of concurrent inhibitory and excitatory synapses with low conductance and state fluctuation. For overcoming these limitations, we propose a Ta/TaOx/TiO2/Ti device with superior analog synaptic features. A physical simulation based on the homogeneous (nonfilamentary) barrier modulation induced by oxygen ion migration accurately reproduces various DC and AC evolutions of synaptic states, including the spike-timing-dependent plasticity and paired-pulse facilitation. Furthermore, a physics-based compact model for facilitating circuit-level design is proposed on the basis of the general definition of memristor devices. This comprehensive experimental and theoretical study of the promising electronic synapse can facilitate realizing large-scale neuromorphic systems. PMID:25955658

Guidelines for clinical supervision in health service psychology.

PubMed

2015-01-01

This document outlines guidelines for supervision of students in health service psychology education and training programs. The goal was to capture optimal performance expectations for psychologists who supervise. It is based on the premises that supervisors (a) strive to achieve competence in the provision of supervision and (b) employ a competency-based, meta-theoretical approach to the supervision process. The Guidelines on Supervision were developed as a resource to inform education and training regarding the implementation of competency-based supervision. The Guidelines on Supervision build on the robust literatures on competency-based education and clinical supervision. They are organized around seven domains: supervisor competence; diversity; relationships; professionalism; assessment/evaluation/feedback; problems of professional competence, and ethical, legal, and regulatory considerations. The Guidelines on Supervision represent the collective effort of a task force convened by the American Psychological Association (APA) Board of Educational Affairs (BEA). PsycINFO Database Record (c) 2015 APA, all rights reserved.

SERS detection of R6G based on a novel graphene oxide/silver nanoparticles/silicon pyramid arrays structure.

PubMed

Zhang, C; Jiang, S Z; Huo, Y Y; Liu, A H; Xu, S C; Liu, X Y; Sun, Z C; Xu, Y Y; Li, Z; Man, B Y

2015-09-21

We present a novel surface-enhanced Raman scattering (SERS) substrate based on graphene oxide/silver nanoparticles/silicon pyramid arrays structure (GO/Ag/PSi). The SERS behaviors are discussed and compared by the detection of R6G. Based on the contrast experiments with PSi, GO/PSi, Ag/PSi and GO/AgA/PSi as SERS substrate, the perfect bio-compatibility, good homogeneity and chemical stability were confirmed. We also calculated the electric field distributions using Finite-difference time-domain (FDTD) analysis to further understand the GO/Ag/PSi structure as a perfect SERS platform. These experimental and theoretical results imply that the GO/Ag/PSi with regular pyramids array is expected to be an effective substrate for label-free sensitive SERS detections in areas of medicine, food safety and biotechnology.

Individual-based modelling and control of bovine brucellosis

NASA Astrophysics Data System (ADS)

Nepomuceno, Erivelton G.; Barbosa, Alípio M.; Silva, Marcos X.; Perc, Matjaž

2018-05-01

We present a theoretical approach to control bovine brucellosis. We have used individual-based modelling, which is a network-type alternative to compartmental models. Our model thus considers heterogeneous populations, and spatial aspects such as migration among herds and control actions described as pulse interventions are also easily implemented. We show that individual-based modelling reproduces the mean field behaviour of an equivalent compartmental model. Details of this process, as well as flowcharts, are provided to facilitate the reproduction of the presented results. We further investigate three numerical examples using real parameters of herds in the São Paulo state of Brazil, in scenarios which explore eradication, continuous and pulsed vaccination and meta-population effects. The obtained results are in good agreement with the expected behaviour of this disease, which ultimately showcases the effectiveness of our theory.

Design of plate directional heat transmission structure based on layered thermal metamaterials

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

Sun, L. K.; Yu, Z. F.; Huang, J., E-mail: slk-0-1999@163.com

2016-02-15

Invisibility cloaks based on transformation optics are often closed structures; however, such a structure limits the kinds of objects that can be placed in the cloak. In this work, we adopt a transformation thermodynamics approach to design an “open cloak”, called a plate directional heat transmission structure, which is capable of guiding heat fluxes to the flank region of the metamaterial device. The most fascinating and unique feature of the device is that the lower surface can remain at a lower temperature compared with the SiO{sub 2} aerogel thermal insulation material. Our results are expected to markedly enhance capabilities inmore » thermal protection, thermal-energy utilization, and domains beyond. In addition to the theoretical analysis, the present design is demonstrated in numerical simulations based on finite element calculations.« less

Perceived legitimacy of normative expectations motivates compliance with social norms when nobody is watching

PubMed Central

Andrighetto, Giulia; Grieco, Daniela; Tummolini, Luca

2015-01-01

Three main motivations can explain compliance with social norms: fear of peer punishment, the desire for others' esteem and the desire to meet others' expectations. Though all play a role, only the desire to meet others' expectations can sustain compliance when neither public nor private monitoring is possible. Theoretical models have shown that such desire can indeed sustain social norms, but empirical evidence is lacking. Moreover it is unclear whether this desire ranges over others' “empirical” or “normative” expectations. We propose a new experimental design to isolate this motivation and to investigate what kind of expectations people are inclined to meet. Results indicate that, when nobody can assign either material or immaterial sanctions, the perceived legitimacy of others' normative expectations can motivate a significant number of people to comply with costly social norms. PMID:26500568

Modeling Theory of Mind and Cognitive Appraisal with Decision-Theoretic Agents

DTIC Science & Technology

2011-04-07

following key factors: Consistency: People expect, prefer, and are driven to maintain consistency, and avoid cognitive dissonance , be- tween beliefs...Modeling Theory of Mind and Cognitive Appraisal with Decision-Theoretic Agents David V. Pynadath1, Mei Si2, and Stacy C. Marsella1 1Institute for...capacity in appraisal and social emotions, as well as arguing for a uniform process for emotion and cognition . 1 Report Documentation Page Form

Observing the epoch of galaxy formation

PubMed Central

Steidel, Charles C.

1999-01-01

Significant observational progress in addressing the question of the origin and early evolution of galaxies has been made in the past few years, allowing for direct comparison of the epoch when most of the stars in the universe were forming to prevailing theoretical models. There is currently broad consistency between theoretical expectations and the observations, but rapid improvement in the data will provide much more critical tests of theory in the coming years. PMID:10200244

Statistical modeling, detection, and segmentation of stains in digitized fabric images

NASA Astrophysics Data System (ADS)

Gururajan, Arunkumar; Sari-Sarraf, Hamed; Hequet, Eric F.

2007-02-01

This paper will describe a novel and automated system based on a computer vision approach, for objective evaluation of stain release on cotton fabrics. Digitized color images of the stained fabrics are obtained, and the pixel values in the color and intensity planes of these images are probabilistically modeled as a Gaussian Mixture Model (GMM). Stain detection is posed as a decision theoretic problem, where the null hypothesis corresponds to absence of a stain. The null hypothesis and the alternate hypothesis mathematically translate into a first order GMM and a second order GMM respectively. The parameters of the GMM are estimated using a modified Expectation-Maximization (EM) algorithm. Minimum Description Length (MDL) is then used as the test statistic to decide the verity of the null hypothesis. The stain is then segmented by a decision rule based on the probability map generated by the EM algorithm. The proposed approach was tested on a dataset of 48 fabric images soiled with stains of ketchup, corn oil, mustard, ragu sauce, revlon makeup and grape juice. The decision theoretic part of the algorithm produced a correct detection rate (true positive) of 93% and a false alarm rate of 5% on these set of images.

Far-from-equilibrium bidirectional transport system with constrained entrances competing for pool of limited resources

NASA Astrophysics Data System (ADS)

Verma, Atul Kumar; Sharma, Natasha; Gupta, Arvind Kumar

2018-02-01

Motivated by the wide occurrence of limited resources in many real-life systems, we investigate two-lane totally asymmetric simple exclusion process with constrained entrances under finite supply of particles. We analyze the system within the framework of mean-field theory and examine various complex phenomena, including phase separation, phase transition, and symmetry breaking. Based on the theoretical analysis, we analytically derive the phase boundaries for various symmetric as well as asymmetric phases. It has been observed that the symmetry-breaking phenomenon initiates even for very small number of particles in the system. The phases with broken symmetry originates as shock-low density phase under limited resources, which is in contrast to the scenario with infinite number of particles. As expected, the symmetry breaking continues to persist even for higher values of system particles. Seven stationary phases are observed, with three of them exhibiting symmetry-breaking phenomena. The critical values of a total number of system particles, beyond which various symmetrical and asymmetrical phases appear and disappear are identified. Theoretical outcomes are supported by extensive Monte Carlo simulations. Finally, the size-scaling effect and symmetry-breaking phenomenon on the simulation results have also been examined based on particle density histograms.

Resource Letter GrW-1: Gravitational Waves

NASA Technical Reports Server (NTRS)

White, Nicholas E. (Technical Monitor); Centrella, Joan M.

2003-01-01

The phenomenon of gravitational radiation was one of the first predictions of Einstein's general theory of relativity. Progress in understanding this radiation theoretically was slow at first, owing to the difficulty of the nonlinear field equations and the subtleties of their physical effects. The experimental side of this subject also has taken a long time to develop, with efforts at detection severely challenged by the extreme weakness of the waves impinging on the Earth. However, as the 21st century begins, observations of the gravitational waves from astrophysical sources such as black holes, neutron stars, and stellar collapse are expected to open a new window on the universe. Vigorous experimental programs centered on ground-based detectors are being carried out worldwide, and a space-based detector is in the planning stages. On the theoretical side, much effort is being expended to produce robust models of the astrophysical sources and accurate calculations of the waveforms they produce. In this Resource Letter, a set of basic references will be presented first, to provide a general introduction to and overview of the literature in this field. The focus then will shift to highlighting key resources in more specialized areas at the forefront of current research.

Planning a multilevel intervention to prevent hearing loss among farmworkers and managers: a systematic approach.

PubMed

Fernandez, M E; Bartholomew, L K; Alterman, T

2009-01-01

Noise-induced hearing loss (NIHL) is the second most prevalent self-reported occupational illness or injury in the U.S., and agricultural workers experience high rates of hearing loss. This article uses Intervention Mapping (IM), a systematic approach to intervention development, to make recommendations for a program to improve hearing loss protection among farmworkers and managers. Final recommendations, based on previous work in the literature on hearing loss prevention, qualitative formative research, and theoretical considerations, include a specification of a multilevel theory- and evidence-based hearing protection program for farmworkers and farm managers. Twelve performance objectives (e.g., "monitor hearing and hearing loss with regular hearing testing") are specified and crossed with six relevant determinants (knowledge and behavioral capability; perceived exposure and susceptibility and noise annoyance; outcome expectations; barriers; social influence; skills and self-efficacy) to create a highly detailed matrix of change objectives for farmworkers and for their managers. These change objectives are then grouped into five categories: two for both farmworkers and their managers (noticing exposures, taking action) and three only for the latter (surveying and planning, implementation and evaluation, and communication). Theoretical methods and practical strategies, including program materials and activities, are then delineated.

Thermal conductivity model for powdered materials under vacuum based on experimental studies

NASA Astrophysics Data System (ADS)

Sakatani, N.; Ogawa, K.; Iijima, Y.; Arakawa, M.; Honda, R.; Tanaka, S.

2017-01-01

The thermal conductivity of powdered media is characteristically very low in vacuum, and is effectively dependent on many parameters of their constituent particles and packing structure. Understanding of the heat transfer mechanism within powder layers in vacuum and theoretical modeling of their thermal conductivity are of great importance for several scientific and engineering problems. In this paper, we report the results of systematic thermal conductivity measurements of powdered media of varied particle size, porosity, and temperature under vacuum using glass beads as a model material. Based on the obtained experimental data, we investigated the heat transfer mechanism in powdered media in detail, and constructed a new theoretical thermal conductivity model for the vacuum condition. This model enables an absolute thermal conductivity to be calculated for a powder with the input of a set of powder parameters including particle size, porosity, temperature, and compressional stress or gravity, and vice versa. Our model is expected to be a competent tool for several scientific and engineering fields of study related to powders, such as the thermal infrared observation of air-less planetary bodies, thermal evolution of planetesimals, and performance of thermal insulators and heat storage powders.

Signal-to-noise ratio comparison of encoding methods for hyperpolarized noble gas MRI

NASA Technical Reports Server (NTRS)

Zhao, L.; Venkatesh, A. K.; Albert, M. S.; Panych, L. P.

2001-01-01

Some non-Fourier encoding methods such as wavelet and direct encoding use spatially localized bases. The spatial localization feature of these methods enables optimized encoding for improved spatial and temporal resolution during dynamically adaptive MR imaging. These spatially localized bases, however, have inherently reduced image signal-to-noise ratio compared with Fourier or Hadamad encoding for proton imaging. Hyperpolarized noble gases, on the other hand, have quite different MR properties compared to proton, primarily the nonrenewability of the signal. It could be expected, therefore, that the characteristics of image SNR with respect to encoding method will also be very different from hyperpolarized noble gas MRI compared to proton MRI. In this article, hyperpolarized noble gas image SNRs of different encoding methods are compared theoretically using a matrix description of the encoding process. It is shown that image SNR for hyperpolarized noble gas imaging is maximized for any orthonormal encoding method. Methods are then proposed for designing RF pulses to achieve normalized encoding profiles using Fourier, Hadamard, wavelet, and direct encoding methods for hyperpolarized noble gases. Theoretical results are confirmed with hyperpolarized noble gas MRI experiments. Copyright 2001 Academic Press.

Infrared super-resolution imaging based on compressed sensing

NASA Astrophysics Data System (ADS)

Sui, Xiubao; Chen, Qian; Gu, Guohua; Shen, Xuewei

2014-03-01

The theoretical basis of traditional infrared super-resolution imaging method is Nyquist sampling theorem. The reconstruction premise is that the relative positions of the infrared objects in the low-resolution image sequences should keep fixed and the image restoration means is the inverse operation of ill-posed issues without fixed rules. The super-resolution reconstruction ability of the infrared image, algorithm's application area and stability of reconstruction algorithm are limited. To this end, we proposed super-resolution reconstruction method based on compressed sensing in this paper. In the method, we selected Toeplitz matrix as the measurement matrix and realized it by phase mask method. We researched complementary matching pursuit algorithm and selected it as the recovery algorithm. In order to adapt to the moving target and decrease imaging time, we take use of area infrared focal plane array to acquire multiple measurements at one time. Theoretically, the method breaks though Nyquist sampling theorem and can greatly improve the spatial resolution of the infrared image. The last image contrast and experiment data indicate that our method is effective in improving resolution of infrared images and is superior than some traditional super-resolution imaging method. The compressed sensing super-resolution method is expected to have a wide application prospect.

[The path of continuity of care between hospital and territory in patients with severe brain injury. The expectations of caregivers and professionals].

PubMed

Feiroli, Raffaele; Bolzani, Monica; Cornelli, Maria Cristina; Ghirardi, Lida; Guizzardi, Loris; Onesti, Roberta; Dovani, Antonella; Davolo, Andrea; Artioli, Giovanna; Mancini, Tiziana

2013-01-01

The present study analyses how continuity of care is perceived by health professionals and GRACER (Gravi Cerebrolesioni Acquisite Emilia Romagna) patients' caregivers, in order to investigate where the gap between expectations and reality is more heavily felt and which dimension of the continuity of care is the most important both for health professionals and GRACER patients' caregivers. The study has been developed following the Gap Analysis theoretical model. A questionnaire, based on ServQual model, was used to collect data about the three dimensions of the construct of continuity of care related to information, management and relation, declined along the lines of expectations and perception of reality. The questionnaire was administered to health professionals and caregivers of GRACER patients (12-36 months after the event) inside 4 healthcare institutes in Emilia Romagna. The PAI (Piano Assistenziale Individuale) approach was the methodology applied in these 4 sites. To both groups the relational continuity was the most important dimension, followed at a long distance by the informational and the management ones. It has also been noted that to professionals reality is always worse than expectations, with the exception of only two items in the dimension of management continuity. To caregivers reality is worse than expectations in some items in the dimensions of information and management The study has shown that the relational dimension of continuity of care should be more investigated, as confirmed by literature. More research is needed about the professionals' dissatisfaction generated by the negative balance between expectations and perception of reality.

Caffeinated Alcohol Consumption Profiles and Associations with Use Severity and Outcome Expectancies

PubMed Central

Lau-Barraco, Cathy; Milletich, Robert J.; Linden, Ashley N.

2014-01-01

Growing evidence suggests that the consumption of caffeinated alcoholic beverages (CAB) may be riskier than alcohol alone. Efforts to identify patterns of CAB use and the correlates of such drinking patterns could further our conceptualization of and intervention for this health issue. Consequently, the current study aimed to (1) identify distinct classes of CAB users, (2) examine differences between classes on measures of alcohol and caffeine problems, and (3) compare distinct classes of CAB users on caffeine and alcohol outcome expectancies. Participants were 583 (31% men) undergraduate students from a psychology research pool. Latent profile analysis models were derived using four indicators: CAB use quantity, CAB use frequency, alcohol use quantity, and alcohol use frequency. Finding revealed four classes of drinkers: High Alcohol/High CAB (6.00%), High Alcohol/Moderate CAB (5.15%), High Alcohol/Low CAB (22.99%), and Low Alcohol/Low CAB (65.87%). The Low Alcohol/Low CAB class reported the lowest relative levels of caffeine dependence symptoms, caffeine withdrawal, alcohol use problems, and heavy episodic drinking frequency. Further, results indicated differential expectancy endorsement based on use profiles. CAB users in the High Alcohol/Low CAB class endorsed more positive alcohol expectancies than the Low Alcohol/Low CAB group. Those in the High Alcohol/High CAB class endorsed stronger withdrawal symptoms caffeine expectancies than all other classes. Inclusion of substance-specific expectancies into larger theoretical frameworks in future work of CAB use may be beneficial. Findings may inform intervention efforts for those at greatest risk related to CAB consumption. PMID:24210683

Caffeinated alcohol consumption profiles and associations with use severity and outcome expectancies.

PubMed

Lau-Barraco, Cathy; Milletich, Robert J; Linden, Ashley N

2014-01-01

Growing evidence suggests that the consumption of caffeinated alcoholic beverages (CAB) may be riskier than alcohol alone. Efforts to identify patterns of CAB use and the correlates of such drinking patterns could further our conceptualization of and intervention for this health issue. Consequently, the current study aimed to (1) identify distinct classes of CAB users, (2) examine differences between classes on measures of alcohol and caffeine problems, and (3) compare distinct classes of CAB users on caffeine and alcohol outcome expectancies. Participants were 583 (31% men) undergraduate students from a psychology research pool. Latent profile analysis models were derived using four indicators: CAB use quantity, CAB use frequency, alcohol use quantity, and alcohol use frequency. Finding revealed four classes of drinkers: High Alcohol/High CAB (6.00%), High Alcohol/Moderate CAB (5.15%), High Alcohol/Low CAB (22.99%), and Low Alcohol/Low CAB (65.87%). The Low Alcohol/Low CAB class reported the lowest relative levels of caffeine dependence symptoms, caffeine withdrawal, alcohol use problems, and heavy episodic drinking frequency. Further, results indicated differential expectancy endorsement based on use profiles. CAB users in the High Alcohol/Low CAB class endorsed more positive alcohol expectancies than the Low Alcohol/Low CAB group. Those in the High Alcohol/High CAB class endorsed stronger withdrawal symptom caffeine expectancies than all other classes. Inclusion of substance-specific expectancies into larger theoretical frameworks in future work of CAB use may be beneficial. Findings may inform intervention efforts for those at greatest risk related to CAB consumption. © 2013.

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

Callear, Samantha K.; Imberti, Silvia; Johnston, Andrew

The aqueous solution of dopamine hydrochloride has been investigated using neutron and X-ray total scattering data together with Monte-Carlo based modelling using Empirical Potential Structure Refinement. The conformation of the protonated dopamine molecule is presented and the results compared to the conformations found in crystal structures, dopamine-complexed protein crystal structures and predicted from theoretical calculations and pharmacophoric models. It is found that protonated dopamine adopts a range of conformations in solution, highlighting the low rotational energy barrier between different conformations, with the preferred conformation being trans-perpendicular. The interactions between each of the species present (protonated dopamine molecules, water molecules, andmore » chloride anions) have been determined and are discussed with reference to interactions observed in similar systems both in the liquid and crystalline state, and predicted from theoretical calculations. The expected strong hydrogen bonds between the strong hydrogen bond donors and acceptors are observed, together with evidence of weaker CH hydrogen bonds and π interactions also playing a significant role in determining the arrangement of adjacent molecules.« less

Progress in Developing a New Field-theoretical Crossover Equation-of-State

NASA Technical Reports Server (NTRS)

Rudnick, Joseph; Barmatz, M.; Zhong, Fang

2003-01-01

A new field-theoretical crossover equation-of-state model is being developed. This model of a liquid-gas critical point provides a bridge between the asymptotic equation-of-state behavior close to the transition, obtained by the Guida and Zinn-Justin parametric model [J. Phys. A: Math. Gen. 31, 8103 (1998)], and the expected mean field behavior farther away. The crossover is based on the beta function for the renormalized fourth-order coupling constant and incorporates the correct crossover exponents and critical amplitude ratios in both regimes. A crossover model is now being developed that is consistent with predictions along the critical isochore and along the coexistence curve of the minimal subtraction renormalization approach developed by Dohm and co-workers and recently applied to the O(1) universality class [Phys. Rev. E, 67, 021106 (2003)]. Experimental measurements of the heat capacity at constant volume, isothermal susceptibility, and coexistence curve near the He-3 critical point are being compared to the predictions of this model. The results of these comparisons will be presented.

[Basic theory and research method of urban forest ecology].

PubMed

He, Xingyuan; Jin, Yingshan; Zhu, Wenquan; Xu, Wenduo; Chen, Wei

2002-12-01

With the development of world economy and the increment of urban population, the urban environment problem hinders the urban sustainable development. Now, more and more people realized the importance of urban forests in improving the quality of urban ecology. Therefore, a new subject, urban forest ecology, and correlative new concept frame in the field formed. The theoretic foundation of urban forest ecology derived from the mutual combination of theory relating to forest ecology, landscape ecology, landscape architecture ecology and anthrop-ecology. People survey the development of city from the view of ecosystem, and regard the environment, a colony of human, animals and plants, as main factors of the system. The paper introduces systematically the urban forest ecology as follows: 1) the basic concept of urban forest ecology; 2) the meaning of urban forest ecology; 3) the basic principle and theoretic base of urban forest ecology; 4) the research method of urban forest ecology; 5) the developmental expectation of urban forest ecology.

Physical realization of a quantum spin liquid based on a complex frustration mechanism

NASA Astrophysics Data System (ADS)

Reuther, Johannes; Balz, Christian; Lake, Bella

Unlike conventional magnets where the spins undergo magnetic long-range order in the ground state, in a quantum spin liquid they remain disordered down to the lowest temperatures without breaking local symmetries. Here, we investigate the novel, unexplored bilayer-kagome magnet Ca10Cr7O28, which has a complex Hamiltonian consisting of isotropic antiferromagnetic and ferromagnetic interactions where the ferromagnetic couplings are the dominant ones. We show both experimentally and theoretically that this compound displays all the features expected of a quantum spin liquid. In particular, experiments rule out static magnetic order down to 19mK and reveal a diffuse spinon-like excitation spectrum. Numerically simulating this material using the pseudo fermion functional renormalization group (PFFRG) method, we theoretically confirm the non-magnetic ground state of the system and qualitatively reproduce the measured spin correlation profile. By tuning the model parameters away from those realized in Ca10Cr7O28 we further show that the spin-liquid phase is of remarkable stability.

Something's got to give: the effects of dual-goal difficulty, goal progress, and expectancies on resource allocation.

PubMed

Schmidt, Aaron M; Dolis, Chad M

2009-05-01

The current study developed and tested a model of the interplay among goal difficulty, goal progress, and expectancy over time in influencing resource allocation toward competing demands. The results provided broad support for the theoretical model. As predicted, dual-goal expectancy-the perceived likelihood of meeting both goals in competition-played a central role, moderating the relationship between relative goal progress and resource allocation. Dual-goal difficulty was also found to exert an important influence on multiple-goal self-regulation. Although it did not influence total productivity across both tasks combined, it did combine with other model components to influence the relative emphasis of one task over another. These results suggest that the cumulative demands placed by multiple difficult goals may exceed individuals' perceived capabilities and may lead to partial or total abandonment of 1 goal to ensure attainment of the other. The model helps shed light on some of the conflicting theoretical propositions and empirical results obtained in prior work. Implications for theory and research regarding multiple-goal self-regulation are discussed. (c) 2009 APA, all rights reserved.

Asymmetric affective forecasting errors and their correlation with subjective well-being

PubMed Central

2018-01-01

Aims Social scientists have postulated that the discrepancy between achievements and expectations affects individuals' subjective well-being. Still, little has been done to qualify and quantify such a psychological effect. Our empirical analysis assesses the consequences of positive and negative affective forecasting errors—the difference between realized and expected subjective well-being—on the subsequent level of subjective well-being. Data We use longitudinal data on a representative sample of 13,431 individuals from the German Socio-Economic Panel. In our sample, 52% of individuals are females, average age is 43 years, average years of education is 11.4 and 27% of our sample lives in East Germany. Subjective well-being (measured by self-reported life satisfaction) is assessed on a 0–10 discrete scale and its sample average is equal to 6.75 points. Methods We develop a simple theoretical framework to assess the consequences of positive and negative affective forecasting errors—the difference between realized and expected subjective well-being—on the subsequent level of subjective well-being, properly accounting for the endogenous adjustment of expectations to positive and negative affective forecasting errors, and use it to derive testable predictions. Given the theoretical framework, we estimate two panel-data equations, the first depicting the association between positive and negative affective forecasting errors and the successive level of subjective well-being and the second describing the correlation between subjective well-being expectations for the future and hedonic failures and successes. Our models control for individual fixed effects and a large battery of time-varying demographic characteristics, health and socio-economic status. Results and conclusions While surpassing expectations is uncorrelated with subjective well-being, failing to match expectations is negatively associated with subsequent realizations of subjective well-being. Expectations are positively (negatively) correlated to positive (negative) forecasting errors. We speculate that in the first case the positive adjustment in expectations is strong enough to cancel out the potential positive effects on subjective well-being of beaten expectations, while in the second case it is not, and individuals persistently bear the negative emotional consequences of not achieving expectations. PMID:29513685

Motivations for Providing a Secure Base: Links with Attachment Orientation and Secure Base Support Behavior

PubMed Central

Feeney, Brooke C.; Collins, Nancy L.; Van Vleet, Meredith; Tomlinson, Jennifer

2015-01-01

This investigation examined the importance of underlying motivations in predicting secure base support behavior, as well as the extent to which support motivations are predicted by individual differences in attachment orientation. Participants were 189 married couples who participated in two laboratory sessions: During a questionnaire session, couples completed assessments of their underlying motivations for providing, and for not providing, support for their partner's exploration (i.e., goal-strivings), as well as assessments of their typical secure base support behavior. In an observational session, couples engaged in a discussion of one member's personal goals, during which the partner's secure base support was assessed. Results revealed a variety of distinct motivations for providing, and for not providing, secure base support to one's partner, as well as theoretically expected links between these motivations and both secure base behavior and attachment orientation. This work establishes motivations as important mechanisms that underlie the effective or ineffective provision of relational support. PMID:23581972

Synergistic Effects of Expectancy and Value on Homework Engagement: The Case for a Within-Person Perspective.

PubMed

Nagengast, Benjamin; Trautwein, Ulrich; Kelava, Augustin; Lüdtke, Oliver

2013-05-01

Historically, expectancy-value models of motivation assumed a synergistic relation between expectancy and value: motivation is high only when both expectancy and value are high. Motivational processes were studied from a within-person perspective, with expectancies and values being assessed or experimentally manipulated across multiple domains and the focus being placed on intraindividual differences. In contrast, contemporary expectancy-value models in educational psychology concentrate almost exclusively on linear effects of expectancy and value on motivational outcomes, with a focus on between-person differences. Recent advances in latent variable methodology allow both issues to be addressed in observational studies. Using the expectancy-value model of homework motivation as a theoretical framework, this study estimated multilevel structural equation models with latent interactions in a sample of 511 secondary school students and found synergistic effects between domain-specific homework expectancy and homework value in predicting homework engagement in 6 subjects. This approach not only brings the "×" back into expectancy-value theory but also reestablishes the within-person perspective as the appropriate level of analysis for latent expectancy-value models.

Idiosyncratic risk in the Dow Jones Eurostoxx50 Index

NASA Astrophysics Data System (ADS)

Daly, Kevin; Vo, Vinh

2008-07-01

Recent evidence by Campbell et al. [J.Y. Campbell, M. Lettau B.G. Malkiel, Y. Xu, Have individual stocks become more volatile? An empirical exploration of idiosyncratic risk, The Journal of Finance (February) (2001)] shows an increase in firm-level volatility and a decline of the correlation among stock returns in the US. In relation to the Euro-Area stock markets, we find that both aggregate firm-level volatility and average stock market correlation have trended upwards. We estimate a linear model of the market risk-return relationship nested in an EGARCH(1, 1)-M model for conditional second moments. We then show that traditional estimates of the conditional risk-return relationship, that use ex-post excess-returns as the conditioning information set, lead to joint tests of the theoretical model (usually the ICAPM) and of the Efficient Market Hypothesis in its strong form. To overcome this problem we propose alternative measures of expected market risk based on implied volatility extracted from traded option prices and we discuss the conditions under which implied volatility depends solely on expected risk. We then regress market excess-returns on lagged market implied variance computed from implied market volatility to estimate the relationship between expected market excess-returns and expected market risk.We investigate whether, as predicted by the ICAPM, the expected market risk is the main factor in explaining the market risk premium and the latter is independent of aggregate idiosyncratic risk.

What motivates dentists to work in prisons? A qualitative exploration.

PubMed

Smith, P A; Themessl-Huber, M; Akbar, T; Richards, D; Freeman, R

2011-08-26

To explore what motivates dentists to work in prisons using Vroom's theoretical model of motivation as an explanatory framework. In-depth interviews were conducted with ten of the 15 dentists working in Scottish prisons. The focus was to explore their motivations to work in Scottish prisons. The data were analysed using a thematic framework based on the three motivational dimensions of expectancy, instrumentality and valence. The dentists had the skills to help improve their prisoner-patients' oral health but their efforts were often hindered by institutional rationing and the requirement to fit in with prison routines and procedures (expectancy). Despite these institutional difficulties the dentists experienced work rewards associated with the improvement in the prisoners' oral health (instrumentality). Finally, the dentists experienced a feeling of personal worth and a sense of commitment to providing care to Scottish prisoners (valence). The dentists' motivation to work in Scottish prisons may be explained by Vroom's Expectancy Theory. The dentists' motivation is characterised by their beliefs that their work will improve clinical outcomes which will be rewarded by the satisfaction experienced when they overcome environmental obstacles and provide oral health care for their prisoner-patients.

Themes of grief.

PubMed

Carter, S L

1989-01-01

A thematic analysis of 30 narrative accounts of bereavement revealed nine themes that included five core themes in bereavement--being stopped, hurting, missing, holding, and seeking; three meta-themes about bereavement--change, expectations, and inexpressibility; and a contextual theme--personal history. The themes were compared with three theoretical perspectives on bereavement by Freud, Kübler-Ross, and one defined as existential-phenomenological. Features of bereavement that are dissimilar or unaddressed by the theoretical perspectives were: (a) the quality of grief's changing character, including "waves" and intense pain which may be triggered years after the death; (b) holding, an individual process of preserving the fact and meaning of the loved one's existence; (c) expectations, both social and personal, as to how the bereaved should be overlaying the experience; and (d) the critical importance of personal history in affecting the quality and meaning of individual bereavement.

Simple radiative transfer model for relationships between canopy biomass and reflectance

NASA Technical Reports Server (NTRS)

Park, J. K.; Deering, D. W.

1982-01-01

A modified Kubelka-Munk model has been utilized to derive useful equations for the analysis of apparent canopy reflectance. Based on the solution to the model simple working equations were formulated by employing reflectance characteristic parameters. The relationships derived show the asymptotic nature of reflectance data that is typically observed in remote sensing studies of plant biomass. They also establish the range of expected apparent canopy reflectance values for specific plant canopy types. The usefulness of the simplified equations was demonstrated by the exceptionally close fit of the theoretical curves to two separately acquired data sets for alfalfa and shortgrass prairie canopies.

Experimental observation of the 1/3 magnetization plateau in the diamond-chain compound Cu3(CO3)2(OH)2.

PubMed

Kikuchi, H; Fujii, Y; Chiba, M; Mitsudo, S; Idehara, T; Tonegawa, T; Okamoto, K; Sakai, T; Kuwai, T; Ohta, H

2005-06-10

The magnetic susceptibility, high field magnetization, and specific heat measurements of Cu3(CO3)2(OH)2, which is a model substance for the frustrating diamond spin chain model, have been performed using single crystals. Two broad peaks are observed at around 20 and 5 K in both magnetic susceptibility and specific heat results. The magnetization curve has a clear plateau at one third of the saturation magnetization. The experimental results are examined in terms of theoretical expectations based on exact diagonalization and density matrix renormalization group methods. An origin of magnetic anisotropy is also discussed.

Flowing together: a longitudinal study of collective efficacy and collective flow among workgroups.

PubMed

Salanova, Marisa; Rodríguez-Sánchez, Alma M; Schaufeli, Wilmar B; Cifre, Eva

2014-01-01

The aim of this study is to extend the Channel Model of Flow (Csikszentmihalyi, 1975, 1990) at the collective level (workgroups) by including collective efficacy beliefs as a predictor of collective flow based on the Social Cognitive Theory (Bandura, 1997, 2001). A two-wave longitudinal lab study was conducted with 250 participants working in 52 small groups. Longitudinal results from Structural Equation Modeling with data aggregated at the group level showed, as expected, that collective efficacy beliefs predict collective flow over time, both being related reciprocally. Findings and their theoretical and practical implications in the light of Social Cognitive Theory are discussed.

A high resolution electron microscopy investigation of curvature in carbon nanotubes

NASA Astrophysics Data System (ADS)

Weldon, D. N.; Blau, W. J.; Zandbergen, H. W.

1995-07-01

Evidence for heptagon inclusion in multi-walled carbon nanotubes was sought in arc-produced carbon deposits. Transmission electron microscopy revealed many curved nanotubes although their relative abundance was low. Close examination of the micrographs in the regions of expected heptagon inclusion shows that the curvature is accomplished by folding or fracture of the lattice planes. This observed phenomenon contradicts the theoretical modelling studies which predict stable structures with negative curvature accomplished by heptagon/pentagon pairs. A possible explanation for curvature in single-walled tubes is presented based on a molecular mechanics geometry optimisation study of spa inclusion in a graphite sheet.

A quantum framework for likelihood ratios

NASA Astrophysics Data System (ADS)

Bond, Rachael L.; He, Yang-Hui; Ormerod, Thomas C.

The ability to calculate precise likelihood ratios is fundamental to science, from Quantum Information Theory through to Quantum State Estimation. However, there is no assumption-free statistical methodology to achieve this. For instance, in the absence of data relating to covariate overlap, the widely used Bayes’ theorem either defaults to the marginal probability driven “naive Bayes’ classifier”, or requires the use of compensatory expectation-maximization techniques. This paper takes an information-theoretic approach in developing a new statistical formula for the calculation of likelihood ratios based on the principles of quantum entanglement, and demonstrates that Bayes’ theorem is a special case of a more general quantum mechanical expression.

Laboratory study of the spectrum of highly ionized calcium in the 100-250 A range applied to solar flare diagnostics

NASA Technical Reports Server (NTRS)

Lippmann, S.; Finkenthal, M.; Huang, L. K.; Moos, H. W.; Stratton, B. C.; Yu, T. L.; Bhatia, A. K.

1987-01-01

Calcium was introduced into the TEXT tokamak, and its spectral emission was recorded in the 50-360 A range by an absolutely calibrated grazing incidence spectrometer. These observations of highly ionized species of calcium at known conditions of plasma electron temperature and density allow testing of line brightness ratio predictions based on theoretical values of temperature-dependent electron excitation rates. The confirmation of the expected ratios in Be I-like to O I-like calcium allows more confident use of these ratios as a density diagnostic of remote astrophysical sources such as solar flares.

Application of nonlinear pulse shaping of femtosecond pulse generation in a fiber amplifier at 500 MHz repetition rate

NASA Astrophysics Data System (ADS)

Liu, Yang; Luo, Daping; Wang, Chao; Zhu, Zhiwei; Li, Wenxue

2018-03-01

We numerically and experimentally demonstrate that a nonlinear pulse shaping technique based on pre-chirping management in a short gain fiber can be exploited to improve the quality of a compressed pulse. With prior tuning of the pulse chirp, the amplified pulse express different nonlinear propagating processes. A spectrum with s flat top and more smooth wings, showing a similariton feature, generates with the optimal initial pulse chirp, and the shortest pulses with minimal pulse pedestals are obtained. Experimental results show the ability of nonlinear pulse shaping to enhance the quality of compressed pulses, as theoretically expected.

Emergent spin electromagnetism induced by magnetization textures in the presence of spin-orbit interaction (invited)

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

Tatara, Gen, E-mail: gen.tatara@riken.jp; Nakabayashi, Noriyuki; Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397 Japan

2014-05-07

Emergent electromagnetic field which couples to electron's spin in ferromagnetic metals is theoretically studied. Rashba spin-orbit interaction induces spin electromagnetic field which is in the linear order in gradient of magnetization texture. The Rashba-induced effective electric and magnetic fields satisfy in the absence of spin relaxation the Maxwell's equations as in the charge-based electromagnetism. When spin relaxation is taken into account besides spin dynamics, a monopole current emerges generating spin motive force via the Faraday's induction law. The monopole is expected to play an important role in spin-charge conversion and in the integration of spintronics into electronics.

Analyzing systemic risk using non-linear marginal expected shortfall and its minimum spanning tree

NASA Astrophysics Data System (ADS)

Song, Jae Wook; Ko, Bonggyun; Chang, Woojin

2018-02-01

The aim of this paper is to propose a new theoretical framework for analyzing the systemic risk using the marginal expected shortfall (MES) and its correlation-based minimum spanning tree (MST). At first, we develop two parametric models of MES with their closed-form solutions based on the Capital Asset Pricing Model. Our models are derived from the non-symmetric quadratic form, which allows them to consolidate the non-linear relationship between the stock and market returns. Secondly, we discover the evidences related to the utility of our models and the possible association in between the non-linear relationship and the emergence of severe systemic risk by considering the US financial system as a benchmark. In this context, the evolution of MES also can be regarded as a reasonable proxy of systemic risk. Lastly, we analyze the structural properties of the systemic risk using the MST based on the computed series of MES. The topology of MST conveys the presence of sectoral clustering and strong co-movements of systemic risk leaded by few hubs during the crisis. Specifically, we discover that the Depositories are the majority sector leading the connections during the Non-Crisis period, whereas the Broker-Dealers are majority during the Crisis period.

Prior expectations facilitate metacognition for perceptual decision.

PubMed

Sherman, M T; Seth, A K; Barrett, A B; Kanai, R

2015-09-01

The influential framework of 'predictive processing' suggests that prior probabilistic expectations influence, or even constitute, perceptual contents. This notion is evidenced by the facilitation of low-level perceptual processing by expectations. However, whether expectations can facilitate high-level components of perception remains unclear. We addressed this question by considering the influence of expectations on perceptual metacognition. To isolate the effects of expectation from those of attention we used a novel factorial design: expectation was manipulated by changing the probability that a Gabor target would be presented; attention was manipulated by instructing participants to perform or ignore a concurrent visual search task. We found that, independently of attention, metacognition improved when yes/no responses were congruent with expectations of target presence/absence. Results were modeled under a novel Bayesian signal detection theoretic framework which integrates bottom-up signal propagation with top-down influences, to provide a unified description of the mechanisms underlying perceptual decision and metacognition. Copyright © 2015 Elsevier Inc. All rights reserved.

On the Achievable Throughput Over TVWS Sensor Networks

PubMed Central

Caleffi, Marcello; Cacciapuoti, Angela Sara

2016-01-01

In this letter, we study the throughput achievable by an unlicensed sensor network operating over TV white space spectrum in presence of coexistence interference. Through the letter, we first analytically derive the achievable throughput as a function of the channel ordering. Then, we show that the problem of deriving the maximum expected throughput through exhaustive search is computationally unfeasible. Finally, we derive a computational-efficient algorithm characterized by polynomial-time complexity to compute the channel set maximizing the expected throughput and, stemming from this, we derive a closed-form expression of the maximum expected throughput. Numerical simulations validate the theoretical analysis. PMID:27043565

The Bragg gap vanishing phenomena in one-dimensional photonic crystals.

PubMed

Zhang, Hui; Chen, Xi; Li, Youquan; Fu, Yunqi; Yuan, Naichang

2009-05-11

We theoretically deduce the Bragg gap vanishing conditions in one-dimensional photonic crystals and experimentally demonstrate the m=0 band-gap vanishing phenomena at microwave frequencies. In the case of mismatched impedance, the Bragg gap will vanish as long as the discrete modes appear in photonic crystals containing dispersive materials, while for the matched impedance cases, Bragg gaps will always disappear. The experimental results and the simulations agree extremely well with the theoretical expectation.

Comment on "Propionaldehyde infrared cross-sections and band strengths" by B. Köroğlu et al. [1

NASA Astrophysics Data System (ADS)

Richter, Wagner Eduardo; Bruns, Roy Edward

2016-08-01

The propionaldehyde infrared regional integrated area reported by Köroğlu et al. were re-examined. Even though the spectrum seems to be recorded correctly, the comparison between their values with the data obtained by the integration of the propionaldehyde spectrum available in the PNNL database suggests that a scaling factor of 2.3025 (the ratio between ln and log bases) is the reason for their results being lower than those expected based on other literature values and quantum chemical estimates. Revised values were then reported for the four spectral regions evaluated by these authors, resulting in a much better agreement between both theoretical and experimental results for not only for this molecule but also for others like acetone and acetaldehyde.

Application-oriented computational studies on a series of D-π-A structured porphyrin sensitizers with different electron-donor groups.

PubMed

Fan, Chencheng; Zhang, Bao; Li, Yuanchao; Liang, Yuxia; Xue, Xiaodong; Feng, Yaqing

2015-11-11

A series of D-π-A zinc porphyrin sensitizers bearing a substituted iminodibenzyl group at the porphyrin meso position, which is expected to have different electron-donating abilities, were designed. Theoretical studies were performed to examine the photovoltaic properties of these molecules in dye-sensitized solar cells (DSSCs). In particular, the important concepts, the Fukui function and the extended condensed Fukui function, are employed to describe the electron-donating abilities accurately at the quantitative level. Tangui Le Bahers model was adopted to analyze charge transfer (CT) during electron transition. A correlation between the electron donating abilities of the derived iminodibenzyl group and CT was built to evaluate the cell performance based on sensitizers . The theoretical studies showed that porphyrins bearing an extremely strong electron-donating group (EDG) would fail in the generation of photocurrent in the closed circuit when applied in DSSCs due to the higher level of the HOMO energy than the redox potential of the redox couple (I(-)/I3(-)). The one with a weaker EDG () is expected to show better photovoltaic performance than porphyrin with an unsubstituted iminodibenzyl group. This study demonstrates a reliable method involving the employment of the Fukui function, the extended condensed Fukui function and the Tangui Le Bahers model for the evaluation of newly designed D-π-A type porphyrin sensitizers for use in DSSCs, and as guidance for future molecular design.

The Role of Trait Emotional Intelligence in Academic Performance: Theoretical Overview and Empirical Update.

PubMed

Perera, Harsha N

2016-01-01

Considerable debate still exists among scholars over the role of trait emotional intelligence (TEI) in academic performance. The dominant theoretical position is that TEI should be orthogonal or only weakly related to achievement; yet, there are strong theoretical reasons to believe that TEI plays a key role in performance. The purpose of the current article is to provide (a) an overview of the possible theoretical mechanisms linking TEI with achievement and (b) an update on empirical research examining this relationship. To elucidate these theoretical mechanisms, the overview draws on multiple theories of emotion and regulation, including TEI theory, social-functional accounts of emotion, and expectancy-value and psychobiological model of emotion and regulation. Although these theoretical accounts variously emphasize different variables as focal constructs, when taken together, they provide a comprehensive picture of the possible mechanisms linking TEI with achievement. In this regard, the article redresses the problem of vaguely specified theoretical links currently hampering progress in the field. The article closes with a consideration of directions for future research.

Social-cognitive antecedents of hand washing: Action control bridges the planning-behaviour gap.

PubMed

Reyes Fernández, Benjamín; Knoll, Nina; Hamilton, Kyra; Schwarzer, Ralf

2016-08-01

To examine motivational and volitional factors for hand washing in young adults, using the Health Action Process Approach (HAPA) as a theoretical framework. In a longitudinal design with two measurement points, six weeks apart, university students (N = 440) completed paper-based questionnaires. Prior hand washing frequency, self-efficacy, outcome expectancies, intention and action planning were measured at baseline, and coping planning, action control and hand washing frequency were measured at follow-up. A theory-based structural equation model was specified. In line with the HAPA, the motivational factors of self-efficacy and outcome expectancies predicted intention, whereas the volitional factors of planning and action control mediated between intention and changes in hand washing frequency. Action control was confirmed as the most proximal factor on hand washing behaviour, thus representing a bridge of the planning-behaviour gap. Both motivational and volitional processes are important to consider in the improvement of hand hygiene practices. Moreover, the statistically significant effects for planning and action control illustrate the importance of these key self-regulatory factors in the prediction of hand hygiene. The current study highlights the importance of adopting models that account for motivational and volitional factors to better understand hand washing behaviour.

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.

Biodegradable mucus-penetrating nanoparticles composed of diblock copolymers of polyethylene glycol and poly(lactic-co-glycolic acid)

PubMed Central

Yu, Tao; Wang, Ying-Ying; Yang, Ming; Schneider, Craig; Zhong, Weixi; Pulicare, Sarah; Choi, Woo-Jin; Mert, Olcay; Fu, Jie; Lai, Samuel K.; Hanes, Justin

2013-01-01

Mucus secretions coating entry points to the human body that are not covered by skin efficiently trap and clear conventional drug carriers, limiting controlled drug delivery at mucosal surfaces. To overcome this challenge, we recently engineered nanoparticles that readily penetrate a variety of human mucus secretions, which we termed mucus-penetrating particles (MPP). Here, we report a new biodegradable MPP formulation based on diblock copolymers of poly(lactic-co-glycolic acid) and poly(ethylene glycol) (PLGA-PEG). PLGA-PEG nanoparticles prepared by a solvent diffusion method rapidly diffused through fresh, undiluted human cervicovaginal mucus (CVM) with an average speed only eightfold lower than their theoretical speed in water. In contrast, PLGA nanoparticles were slowed more than 12,000-fold in the same CVM secretions. Based on the measured diffusivities, as much as 75% of the PLGA-PEG nanoparticles are expected to penetrate a 10-μm-thick mucus layer within 30 min, whereas virtually no PLGA nanoparticles are expected to do so over the same duration. These results encourage further development of PLGA-PEG nanoparticles as mucus-penetrating drug carriers for improved drug and gene delivery to mucosal surfaces. PMID:24205449

Biomolecularmodeling and simulation: a field coming of age

PubMed Central

Schlick, Tamar; Collepardo-Guevara, Rosana; Halvorsen, Leif Arthur; Jung, Segun; Xiao, Xia

2013-01-01

We assess the progress in biomolecular modeling and simulation, focusing on structure prediction and dynamics, by presenting the field’s history, metrics for its rise in popularity, early expressed expectations, and current significant applications. The increases in computational power combined with improvements in algorithms and force fields have led to considerable success, especially in protein folding, specificity of ligand/biomolecule interactions, and interpretation of complex experimental phenomena (e.g. NMR relaxation, protein-folding kinetics and multiple conformational states) through the generation of structural hypotheses and pathway mechanisms. Although far from a general automated tool, structure prediction is notable for proteins and RNA that preceded the experiment, especially by knowledge-based approaches. Thus, despite early unrealistic expectations and the realization that computer technology alone will not quickly bridge the gap between experimental and theoretical time frames, ongoing improvements to enhance the accuracy and scope of modeling and simulation are propelling the field onto a productive trajectory to become full partner with experiment and a field on its own right. PMID:21226976

The value of identity: olfactory notes on orbitofrontal cortex function.

PubMed

Gottfried, Jay A; Zelano, Christina

2011-12-01

Neuroscientific research has emphatically promoted the idea that the key function of the orbitofrontal cortex (OFC) is to encode value. Associative learning studies indicate that OFC representations of stimulus cues reflect the predictive value of expected outcomes. Neuroeconomic studies suggest that the OFC distills abstract representations of value from discrete commodities to optimize choice. Although value-based models provide good explanatory power for many different findings, these models are typically disconnected from the very stimuli and commodities giving rise to those value representations. Little provision is made, either theoretically or empirically, for the necessary cooperative role of object identity, without which value becomes orphaned from its source. As a step toward remediating the value of identity, this review provides a focused olfactory survey of OFC research, including new work from our lab, to highlight the elemental involvement of this region in stimulus-specific predictive coding of both perceptual outcomes and expected values. © 2011 New York Academy of Sciences.

Evaluation of Fibre Lifetime in Optical Ground Wire Transmission Lines

NASA Astrophysics Data System (ADS)

Grunvalds, R.; Ciekurs, A.; Porins, J.; Supe, A.

2017-06-01

In the research, measurements of polarisation mode dispersion of two OPGWs (optical ground wire transmission lines), in total four fibres, have been carried out, and the expected lifetime of the infrastructure has been assessed on the basis of these measurements. The cables under consideration were installed in 1995 and 2011, respectively. Measurements have shown that polarisation mode dispersion values for cable installed in 1995 are four times higher than that for cable installed in 2011, which could mainly be explained by technological differences in fibre production and lower fibre polarisation mode dispersion requirements in 1995 due to lack of high-speed (over 10 Gbit/s) optical transmission systems. The calculation methodology of non-refusal work and refusal probabilities, using the measured polarisation mode dispersion parameters, is proposed in the paper. Based on reliability calculations, the expected lifetime is then predicted, showing that all measured fibres most likely will be operational within minimum theoretical service life of 25 years accepted by the industry.

Dynamical Mass Segregation Versus Disruption of Binary Stars in Dense Stellar Systems

NASA Astrophysics Data System (ADS)

de Grijs, Richard; Li, C.; Deng, L.

2013-01-01

Upon their formation, dynamically cool (collapsing) star clusters will, within only a few million years, achieve stellar mass segregation for stars down to a few solar masses due to gravitational two-body encounters. Since binary systems are, on average, more massive than single stars, one would expect them to also rapidly mass segregate dynamically. Contrary to these expectations and based on high-resolution Hubble Space Telescope observations, we show that the compact, 15-30 Myr-old Large Magellanic Cloud cluster NGC 1818 is characterized by an increasing fraction of F-star binary systems (with combined masses of 1.3-1.6 solar masses) with increasing distance from the cluster center. This offers unprecedented support of the theoretically predicted but thus far unobserved dynamical disruption processes of the significant population of "soft" binary systems (with relatively low binding energies compared to the kinetic energy of their stellar members) in star clusters, which we could unravel by virtue of the cluster's unique combination of youth and high stellar density.

A thermal/nonthermal model for solar microwave bursts

NASA Technical Reports Server (NTRS)

Benka, Stephen G.; Holman, Gordon D.

1992-01-01

A theoretical framework is developed for modeling high-resolution spectra of microwave bursts from the Owens Valley Radio Observatory which can account for departures from expectations based on simple thermal or nonthermal models. Specifically, 80 percent of the events show more than one spectral peak; many bursts have a low-side spectral index steeper than the maximum expected slope; and the peak frequency stays relatively constant and changes intensity in concert with the secondary peaks throughout a given event's solution. It is shown that the observed spectral features can be explained through gyrosynchrotron radiation. The 'secondary' components seen on the LF side of many spectra are nonthermal enhancements superposed upon thermal radiation, occurring between the thermal harmonics. A steep optically thick slope is accounted for by the thermal absorption of nonthermal radiation. If the coexistence of thermal and nonthermal particles is interpreted in terms of electron heating and acceleration in current sheets, a changing electric field strength can account for the gross evolution of the microwave spectra.

REVIEWS OF TOPICAL PROBLEMS: Relic gravitational waves and cosmology

NASA Astrophysics Data System (ADS)

Grishchuk, Leonid P.

2005-12-01

The paper begins with a brief recollection of interactions of the author with Ya B Zeldovich in the context of the study of relic gravitational waves. The principles and early results on the quantum-mechanical generation of cosmological perturbations are then summarized. The expected amplitudes of relic gravitational waves differ in various frequency windows, and therefore the techniques and prospects of their detection are distinct. One section of the paper describes the present state of efforts in direct detection of relic gravitational waves. Another section is devoted to indirect detection via the anisotropy and polarization measurements of the cosmic microwave background (CMB) radiation. It is emphasized throughout the paper that the inference about the existence and expected amount of relic gravitational waves is based on a solid theoretical foundation and the best available cosmological observations. It is also explained in great detail what went wrong with the so-called 'inflationary gravitational waves', whose amount is predicted by inflationary theorists to be negligibly small, thus depriving them of any observational significance.

A comparison of SAR ATR performance with information theoretic predictions

NASA Astrophysics Data System (ADS)

Blacknell, David

2003-09-01

Performance assessment of automatic target detection and recognition algorithms for SAR systems (or indeed any other sensors) is essential if the military utility of the system / algorithm mix is to be quantified. This is a relatively straightforward task if extensive trials data from an existing system is used. However, a crucial requirement is to assess the potential performance of novel systems as a guide to procurement decisions. This task is no longer straightforward since a hypothetical system cannot provide experimental trials data. QinetiQ has previously developed a theoretical technique for classification algorithm performance assessment based on information theory. The purpose of the study presented here has been to validate this approach. To this end, experimental SAR imagery of targets has been collected using the QinetiQ Enhanced Surveillance Radar to allow algorithm performance assessments as a number of parameters are varied. In particular, performance comparisons can be made for (i) resolutions up to 0.1m, (ii) single channel versus polarimetric (iii) targets in the open versus targets in scrubland and (iv) use versus non-use of camouflage. The change in performance as these parameters are varied has been quantified from the experimental imagery whilst the information theoretic approach has been used to predict the expected variation of performance with parameter value. A comparison of these measured and predicted assessments has revealed the strengths and weaknesses of the theoretical technique as will be discussed in the paper.

Quantitative photoacoustic assessment of red blood cell aggregation under pulsatile blood flow: experimental and theoretical approaches

NASA Astrophysics Data System (ADS)

Bok, Tae-Hoon; Hysi, Eno; Kolios, Michael C.

2017-03-01

In the present paper, the optical wavelength dependence on the photoacoustic (PA) assessment of the pulsatile blood flow was investigated by means of the experimental and theoretical approaches analyzing PA radiofrequency spectral parameters such as the spectral slope (SS) and mid-band fit (MBF). For the experimental approach, the pulsatile flow of human whole blood at 60 bpm was imaged using the VevoLAZR system (40-MHz-linear-array probe, 700-900 nm illuminations). For the theoretical approach, a Monte Carlo simulation for the light transmit into a layered tissue phantom and a Green's function based method for the PA wave generation was implemented for illumination wavelengths of 700, 750, 800, 850 and 900 nm. The SS and MBF for the experimental results were compared to theoretical ones as a function of the illumination wavelength. The MBF increased with the optical wavelength in both theory and experiments. This was expected because the MBF is representative of the PA magnitude, and the PA signal from red blood cell (RBC) is dependent on the molar extinction coefficient of oxyhemoglobin. On the other hand, the SS decreased with the wavelength, even though the RBC size (absorber size which is related to the SS) cannot depend on the illumination wavelength. This conflicting result can be interpreted by means of the changes of the fluence pattern for different illumination wavelengths. The SS decrease with the increasing illumination wavelength should be further investigated.

The evolving concept of "patient-centeredness" in patient-physician communication research.

PubMed

Ishikawa, Hirono; Hashimoto, Hideki; Kiuchi, Takahiro

2013-11-01

Over the past few decades, the concept of "patient-centeredness" has been intensively studied in health communication research on patient-physician interaction. Despite its popularity, this concept has often been criticized for lacking a unified definition and operationalized measurement. This article reviews how health communication research on patient-physician interaction has conceptualized and operationalized patient-centered communication based on four major theoretical perspectives in sociology (i.e., functionalism, conflict theory, utilitarianism, and social constructionism), and discusses the agenda for future research in this field. Each theory addresses different aspects of the patient-physician relationship and communication from different theoretical viewpoints. Patient-centeredness is a multifaceted construct with no single theory that can sufficiently define the whole concept. Different theoretical perspectives of patient-centered communication can be selectively adopted according to the context and nature of problems in the patient-physician relationship that a particular study aims to explore. The present study may provide a useful framework: it offers an overview of the differing models of patient-centered communication and the expected roles and goals in each model; it does so toward identifying a communication model that fits the patient and the context and toward theoretically reconstructing existing measures of patient-centered communication. Furthermore, although patient-centered communication has been defined mainly from the viewpoint of physician's behaviors aimed at achieving patient-centered care, patient competence is also required for patient-centered communication. This needs to be examined in current medical practice. Copyright © 2013 Elsevier Ltd. All rights reserved.

Limiting similarity of competitive species and demographic stochasticity

NASA Astrophysics Data System (ADS)

Zheng, Xiu-Deng; Deng, Ling-Ling; Qiang, Wei-Ya; Cressman, Ross; Tao, Yi

2017-04-01

The limiting similarity of competitive species and its relationship with the competitive exclusion principle is still one of the most important concepts in ecology. In the 1970s, May [R. M. May, Stability and Complexity in Model Ecosystems (Princeton University, Princeton, NJ, 1973)] developed a concise theoretical framework to investigate the limiting similarity of competitive species. His theoretical results show that no limiting similarity threshold of competitive species can be identified in the deterministic model system whereby species more similar than this threshold never coexist. Theoretically, for competitive species coexisting in an unvarying environment, deterministic interspecific interactions and demographic stochasticity can be considered two sides of a coin. To investigate how the "tension" between these two forces affects the coexistence of competing species, a simple two-species competitive system based only on May's model system is transformed into an equivalent replicator equation. The effect of demographic stochasticity on the system stability is measured by the expected drift of the Lyapunov function. Our main results show that the limiting similarity of competitive species should not be considered to be an absolute measure. Specifically, very similar competitive species should be able to coexist in an environment with a high productivity level but big differences between competitive species should be necessary in an ecosystem with a low productivity level.

Laboratory Activity Worksheet to Train High Order Thinking Skill of Student on Surface Chemistry Lecture

NASA Astrophysics Data System (ADS)

Yonata, B.; Nasrudin, H.

2018-01-01

A worksheet has to be a set with activity which is help students to arrange their own experiments. For this reason, this research is focused on how to train students’ higher order thinking skills in laboratory activity by developing laboratory activity worksheet on surface chemistry lecture. To ensure that the laboratory activity worksheet already contains aspects of the higher order thinking skill, it requires theoretical and empirical validation. From the data analysis results, it shows that the developed worksheet worth to use. The worksheet is worthy of theoretical and empirical feasibility. This conclusion is based on the findings: 1) Assessment from the validators about the theoretical feasibility aspects in the category is very feasible with an assessment range of 95.24% to 97.92%. 2) students’ higher thinking skill from N Gain values ranges from 0.50 (enough) to 1.00 (high) so it can be concluded that the laboratory activity worksheet on surface chemistry lecture is empirical in terms of worth. The empirical feasibility is supported by the responses of the students in very reasonable categories. It is expected that the laboratory activity worksheet on surface chemistry lecture can train students’ high order thinking skills for students who program surface chemistry lecture.

Understanding controlled drug release from mesoporous silicates: theory and experiment.

PubMed

Ukmar, T; Maver, U; Planinšek, O; Kaučič, V; Gaberšček, M; Godec, A

2011-11-07

Based on the results of carefully designed experiments upgraded with appropriate theoretical modeling, we present clear evidence that the release curves from mesoporous materials are significantly affected by drug-matrix interactions. In experimental curves, these interactions are manifested as a non-convergence at long times and an inverse dependence of release kinetics on pore size. Neither of these phenomena is expected in non-interacting systems. Although both phenomena have, rather sporadically, been observed in previous research, they have not been explained in terms of a general and consistent theoretical model. The concept is demonstrated on a model drug indomethacin embedded into SBA-15 and MCM-41 porous silicates. The experimental release curves agree exceptionally well with theoretical predictions in the case of significant drug-wall attractions. The latter are described using a 2D Fokker-Planck equation. One could say that the interactions affect the relative cross-section of pores where the local flux has a non-vanishing axial component and in turn control the effective transfer of drug into bulk solution. Finally, we identify the critical parameters determining the pore size dependence of release kinetics and construct a dynamic phase diagram of the various resulting transport regimes. Copyright © 2011 Elsevier B.V. All rights reserved.

Change-related expectations and commitment to change of nurses: the role of leadership and communication.

PubMed

Portoghese, Igor; Galletta, Maura; Battistelli, Adalgisa; Saiani, Luisa; Penna, Maria Pietronilla; Allegrini, Elisabetta

2012-07-01

The purpose of this study was to test a theoretical model linking the impact of expectations on commitment to change and to explore whether change-related communication is a mediating variable between leader-member exchange and expectations. Expectations for change outcomes are an important condition to increase nurses' commitment to change. To understand the role of leadership and communication in expectations development is crucial to promote commitment to change. A predictive, non-experimental design was used in a random sample of 395 nurses. Structural equation modelling was used to analyse the hypothesized model. Positive expectations had a direct effect on affective commitment to change, whereas negative expectation had a direct effect on continuance commitment to change. Leader-member exchange and communication influenced nurse's expectations about change. Communication partially mediated the relationship between Leader-member exchange and expectations. These findings suggested that nurses' expectation about change were strongly linked to commitment to change. Furthermore, the enhancement of communication and relationship with leader contributed to the development of positive and negative expectations. Strategies to promote commitment to change include developing positive expectations about change outcomes and building high-quality leadership style oriented to the communication. © 2011 Blackwell Publishing Ltd.

Aligning professional skills and active learning methods: an application for information and communications technology engineering

NASA Astrophysics Data System (ADS)

Llorens, Ariadna; Berbegal-Mirabent, Jasmina; Llinàs-Audet, Xavier

2017-07-01

Engineering education is facing new challenges to effectively provide the appropriate skills to future engineering professionals according to market demands. This study proposes a model based on active learning methods, which is expected to facilitate the acquisition of the professional skills most highly valued in the information and communications technology (ICT) market. The theoretical foundations of the study are based on the specific literature on active learning methodologies. The Delphi method is used to establish the fit between learning methods and generic skills required by the ICT sector. An innovative proposition is therefore presented that groups the required skills in relation to the teaching method that best develops them. The qualitative research suggests that a combination of project-based learning and the learning contract is sufficient to ensure a satisfactory skills level for this profile of engineers.

Modeling Minor Constituents of Europa's Atmosphere

NASA Astrophysics Data System (ADS)

Cassidy, T. A.; Johnson, R. E.

2007-12-01

A spacecraft orbiting Jupiter's moon Europa, of the sort considered by both ESA and NASA, would provide an opportunity to determine the composition and morphology of its tenuous atmosphere. Europa's atmosphere, though tenuous, has been detected by Earth-based telescopes. Its O2 atmosphere was detected from Earth orbit and its much thinner alkali atmosphere was detected by ground-based telescopes. Many other species are expected based on surface reflectance spectra, such as H2O, Sn, SO2, CO2, H2O2. I will discuss the issues involved in the modeling of these as-yet-undetected components. Previous theoretical studies and observations of the atmosphere produced important conclusions about the surface and its interaction with the Jovian magnetosphere. The modeling and detection of minor components could reveal much more. Of particular interest is the detectability of these species with an orbiting mass spectrometer or more distant light spectrometer.

Theory of the high base resistivity n(+)pp(+) silicon solar cell and its application to radiation damage effects

NASA Technical Reports Server (NTRS)

Goradia, C.; Weinberg, I.

1985-01-01

Particulate radiation in space is a principal source of silicon solar cell degradation, and an investigation of cell radiation damage at higher base resistivities appears to have implication toward increasing solar cell and, therefore, useful satellite lifetimes in the space environment. However, contrary to expectations, it has been found that for cells with resistivities of 84 and 1250 ohm cm, the radiation resistance decreases as cell base resistivity increases. An analytical solar-cell computer model was developed with the objective to determine the reasons for this unexpected behavior. The present paper has the aim to describe the analytical model and its use in interpreting the behavior, under irradiation, of high-resistivity solar cells. Attention is given to boundary conditions at the space-charge region edges, cell currents, cell voltages, the generation of the theoretical I-V characteristic, experimental results, and computer calculations.

Electron-impact vibrational excitation of the hydroxyl radical in the nighttime upper atmosphere

NASA Astrophysics Data System (ADS)

Campbell, Laurence; Brunger, Michael J.

2018-02-01

Chemical processes produce vibrationally excited hydroxyl (OH) in a layer centred at an altitude of about 87 km in the Earth's atmosphere. Observations of this layer are used to deduce temperatures in the mesosphere and to observe the passage of atmospheric gravity waves. Due to the low densities and energies at night of electrons at the relevant altitude, it is not expected that electron-impact excitation of OH would be significant. However, there are unexplained characteristics of OH densities and radiative emissions that might be explained by electron impact. These are measurements of higher than expected densities of OH above 90 km and of emissions at higher energies that cannot be explained by the chemical production processes. This study simulates the role of electron impact in these processes, using theoretical cross sections for electron-impact excitation of OH. The simulations show that electron impact, even in a substantial aurora, cannot fully explain these phenomena. However, in the process of this investigation, apparent inconsistencies in the theoretical cross sections and reaction rates were found, indicating that measurements of electron-impact excitation of OH are needed to resolve these problems and scale the theoretical predictions to allow more accurate simulations.

A Game Theoretical Approach to Hacktivism: Is Attack Likelihood a Product of Risks and Payoffs?

PubMed

Bodford, Jessica E; Kwan, Virginia S Y

2018-02-01

The current study examines hacktivism (i.e., hacking to convey a moral, ethical, or social justice message) through a general game theoretic framework-that is, as a product of costs and benefits. Given the inherent risk of carrying out a hacktivist attack (e.g., legal action, imprisonment), it would be rational for the user to weigh these risks against perceived benefits of carrying out the attack. As such, we examined computer science students' estimations of risks, payoffs, and attack likelihood through a game theoretic design. Furthermore, this study aims at constructing a descriptive profile of potential hacktivists, exploring two predicted covariates of attack decision making, namely, peer prevalence of hacking and sex differences. Contrary to expectations, results suggest that participants' estimations of attack likelihood stemmed solely from expected payoffs, rather than subjective risks. Peer prevalence significantly predicted increased payoffs and attack likelihood, suggesting an underlying descriptive norm in social networks. Notably, we observed no sex differences in the decision to attack, nor in the factors predicting attack likelihood. Implications for policymakers and the understanding and prevention of hacktivism are discussed, as are the possible ramifications of widely communicated payoffs over potential risks in hacking communities.

Teaching light scattering spectroscopy: the dimension and shape of tobacco mosaic virus.

PubMed Central

Santos, N C; Castanho, M A

1996-01-01

The tobacco mosaic virus is used as a model molecular assembly to illustrate the basic potentialities of light scattering techniques (both static and dynamic) to undergraduates. The work has two objectives: a pedagogic one (introducing light scattering to undergraduate students) and a scientific one (stabilization of the virus molecular assembly structure by the nucleic acid). Students are first challenged to confirm the stabilization of the cylindrical shape of the virus by the nucleic acid, at pH and ionic strength conditions where the coat proteins alone do not self-assemble. The experimental intramolecular scattering factor is compared with the theoretical ones for several model geometries. The data clearly suggest that the geometry is, in fact, a rod. Comparing the experimental values of gyration radius and hydrodynamic radius with the theoretical expectations further confirms this conclusion. Moreover, the rod structure is maintained over a wider range of pH and ionic strength than that valid for the coat proteins alone. The experimental values of the diffusion coefficient and radius of gyration are compared with the theoretical expectations assuming the dimensions detected by electron microscopy techniques. In fact, both values are in agreement (length approximately 300 nm, radius approximately 20 nm). PMID:8874039

Expectations and Decisions in the Volunteer’s Dilemma: Effects of Social Distance and Social Projection

PubMed Central

Krueger, Joachim I.; Ullrich, Johannes; Chen, Leonard J.

2016-01-01

In a Volunteer’s Dilemma (VoD) one individual needs to bear a cost so that a public good can be provided. Expectations regarding what others will do play a critical role because they would ideally be negatively correlated with own decisions; yet, a social-projection heuristic generates positive correlations. In a series of 2-person-dilemma studies with over 1,000 participants, we find that expectations are indeed correlated with own choice, and that people tend to volunteer more than game-theoretic benchmarks and their own expectations would allow. We also find strong evidence for a social-distance heuristic, according to which a person’s own probability to volunteer and the expectation that others will volunteer decrease as others become socially more remote. Experimentally induced expectations make opposite behavior more likely, but respondents underweight these expectations. As a result, there is a small but systematic effect of over-volunteering among psychologically close individuals. PMID:28018257

Religiousness and hazardous alcohol use: a conditional indirect effects model.

PubMed

Jankowski, Peter J; Hardy, Sam A; Zamboanga, Byron L; Ham, Lindsay S

2013-08-01

The current study examined a conditional indirect effects model of the association between religiousness and adolescents' hazardous alcohol use. In doing so, we responded to the need to include both mediators and moderators, and the need for theoretically informed models when examining religiousness and adolescents' alcohol use. The sample consisted of 383 adolescents, aged 15-18, who completed an online questionnaire. Results of structural equation modeling supported the proposed model. Religiousness was indirectly associated with hazardous alcohol use through both positive alcohol expectancy outcomes and negative alcohol expectancy valuations. Significant moderating effects for alcohol expectancy valuations on the association between alcohol expectancies and alcohol use were also found. The effects for alcohol expectancy valuations confirm valuations as a distinct construct to that of alcohol expectancy outcomes, and offer support for the protective role of internalized religiousness on adolescents' hazardous alcohol use as a function of expectancy valuations. Copyright © 2013 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Gambler's ruin problem on Erdős-Rényi graphs

NASA Astrophysics Data System (ADS)

Néda, Zoltán; Davidova, Larissa; Újvári, Szeréna; Istrate, Gabriel

2017-02-01

A multiagent ruin-game is studied on Erdős-Rényi type graphs. Initially the players have the same wealth. At each time step a monopolist game is played on all active links (links that connect nodes with nonzero wealth). In such a game each player puts a unit wealth in the pot and the pot is won with equal probability by one of the players. The game ends when there are no connected players such that both of them have non-zero wealth. In order to characterize the final state for dense graphs a compact formula is given for the expected number of the remaining players with non-zero wealth and the wealth distribution among these players. Theoretical predictions are given for the expected duration of the ruin game. The dynamics of the number of active players is also investigated. Validity of the theoretical predictions is investigated by Monte Carlo experiments.

On convergence of the unscented Kalman-Bucy filter using contraction theory

NASA Astrophysics Data System (ADS)

Maree, J. P.; Imsland, L.; Jouffroy, J.

2016-06-01

Contraction theory entails a theoretical framework in which convergence of a nonlinear system can be analysed differentially in an appropriate contraction metric. This paper is concerned with utilising stochastic contraction theory to conclude on exponential convergence of the unscented Kalman-Bucy filter. The underlying process and measurement models of interest are Itô-type stochastic differential equations. In particular, statistical linearisation techniques are employed in a virtual-actual systems framework to establish deterministic contraction of the estimated expected mean of process values. Under mild conditions of bounded process noise, we extend the results on deterministic contraction to stochastic contraction of the estimated expected mean of the process state. It follows that for the regions of contraction, a result on convergence, and thereby incremental stability, is concluded for the unscented Kalman-Bucy filter. The theoretical concepts are illustrated in two case studies.

Gravity-darkening exponents in semi-detached binary systems from their photometric observations. II.

NASA Astrophysics Data System (ADS)

Djurašević, G.; Rovithis-Livaniou, H.; Rovithis, P.; Georgiades, N.; Erkapić, S.; Pavlović, R.

2006-01-01

This second part of our study concerning gravity-darkening presents the results for 8 semi-detached close binary systems. From the light-curve analysis of these systems the exponent of the gravity-darkening (GDE) for the Roche lobe filling components has been empirically derived. The method used for the light-curve analysis is based on Roche geometry, and enables simultaneous estimation of the systems' parameters and the gravity-darkening exponents. Our analysis is restricted to the black-body approximation which can influence in some degree the parameter estimation. The results of our analysis are: 1) For four of the systems, namely: TX UMa, β Per, AW Cam and TW Cas, there is a very good agreement between empirically estimated and theoretically predicted values for purely convective envelopes. 2) For the AI Dra system, the estimated value of gravity-darkening exponent is greater, and for UX Her, TW And and XZ Pup lesser than corresponding theoretical predictions, but for all mentioned systems the obtained values of the gravity-darkening exponent are quite close to the theoretically expected values. 3) Our analysis has proved generally that with the correction of the previously estimated mass ratios of the components within some of the analysed systems, the theoretical predictions of the gravity-darkening exponents for stars with convective envelopes are highly reliable. The anomalous values of the GDE found in some earlier studies of these systems can be considered as the consequence of the inappropriate method used to estimate the GDE. 4) The empirical estimations of GDE given in Paper I and in the present study indicate that in the light-curve analysis one can apply the recent theoretical predictions of GDE with high confidence for stars with both convective and radiative envelopes.

Longitudinal analyses of adoptive parents' expectations and depressive symptoms.

PubMed

Foli, Karen J; Lim, Eunjung; South, Susan C

2017-12-01

Grounded in a theoretical model specific to adoptive parents, we examined the relationship between parental expectations and depressive symptoms across time. Assessments of 129 adoptive parents of 64 children were performed at three time points before and after placement of an adopted child with the family: 4-6 weeks pre-placement and 4-6 weeks and 5-6 months post-placement. Expectations were assessed in four dimensions: expectations of self as parents, of the child, of family and friends, and of society. Depressive symptoms were assessed with the Center for Epidemiologic Studies-Depression scale. Associations between parental expectations and depressive symptoms were analyzed, and longitudinal multilevel modeling was conducted to explore influences on expectations over time. Parental expectations changed from pre- to post-placement. With the exception of expectations of self as parent, adoptive parents' pre-adoption expectations were affirmed in the post-adoption time periods. In each expectation dimension, higher affirmation of expectations was correlated with decreased depressive symptoms before and after placement of a child. While parental expectations are not unique to adoptive parents, the essence and characteristics of certain expectations are unique to these parents. When working with adoptive parents, nurses who care for families should assess expectations both pre- and post-placement with awareness of their relationship to depressive symptoms. © 2017 Wiley Periodicals, Inc.

Improved pulse laser ranging algorithm based on high speed sampling

NASA Astrophysics Data System (ADS)

Gao, Xuan-yi; Qian, Rui-hai; Zhang, Yan-mei; Li, Huan; Guo, Hai-chao; He, Shi-jie; Guo, Xiao-kang

2016-10-01

Narrow pulse laser ranging achieves long-range target detection using laser pulse with low divergent beams. Pulse laser ranging is widely used in military, industrial, civil, engineering and transportation field. In this paper, an improved narrow pulse laser ranging algorithm is studied based on the high speed sampling. Firstly, theoretical simulation models have been built and analyzed including the laser emission and pulse laser ranging algorithm. An improved pulse ranging algorithm is developed. This new algorithm combines the matched filter algorithm and the constant fraction discrimination (CFD) algorithm. After the algorithm simulation, a laser ranging hardware system is set up to implement the improved algorithm. The laser ranging hardware system includes a laser diode, a laser detector and a high sample rate data logging circuit. Subsequently, using Verilog HDL language, the improved algorithm is implemented in the FPGA chip based on fusion of the matched filter algorithm and the CFD algorithm. Finally, the laser ranging experiment is carried out to test the improved algorithm ranging performance comparing to the matched filter algorithm and the CFD algorithm using the laser ranging hardware system. The test analysis result demonstrates that the laser ranging hardware system realized the high speed processing and high speed sampling data transmission. The algorithm analysis result presents that the improved algorithm achieves 0.3m distance ranging precision. The improved algorithm analysis result meets the expected effect, which is consistent with the theoretical simulation.

Observation of top quark pairs in the dilepton decay channel using electrons, muons, and taus

NASA Astrophysics Data System (ADS)

Hohlmann, Marcus

This thesis presents a search for top quark pair production via the process pp → tt + X → W+W/sp-b/bar b + X → (l+νl)/ (/ell/sp-/barνl) bb + X, where l is either e,/ /mu, or /tau. Using a sample of 109 ± 7 pb-1 of pp collisons at /sqrt[s] = 1.8 TeV collected by the CDF detector at the Fermilab Tevatron we find a clear signal for tt production in the ee, μmu, and e/mu dilepton channels. We observe 9 events where we expect 3.9 ± 0.7 tt events (based on the theoretical production cross section) and 2.1 ± 0.4 background events. The tt production cross section measured from this channel is σt/bar t = 8.5-3.3+4.1(stat)- 0.8+1.6(syst) pb. Using a method developed in this thesis to identify hadronically decaying τ leptons we also search for e/tau and μtau dilepton events from tt production and decay. We observe 4 events and expect 2.5 ± 0.4 background events. In 3 of the 4 events at least one jet is tagged as due to a b quark decay. We expect 0.28 ± 0.02 tagged events from background processes. Based on the 4 tau dilepton events we calculate the tt production cross section to be σt/bar t = 10.2- 10.2+16.3(stat) /pm/ 1.6(syst) pb. The kinematics and topology of the candidate events are generally consistent with the expectations, with two exceptions. Five of the 14 candidate events have unusually large missing transverse energy. One e/mu event contains an electron with very high ET (182 GeV) and an additional high-ET (23 GeV) isolated positron. In 109 pb-1 we expect (2.4 ± 0.9) × 10- 6 such 'trilepton' events from tt production and decay.

Nuclear-bound quarkonia and heavy-flavor hadrons

NASA Astrophysics Data System (ADS)

Krein, G.; Thomas, A. W.; Tsushima, K.

2018-05-01

In our quest to win a deeper understanding of how QCD actually works, the study of the binding of heavy quarkonia and heavy-flavor hadrons to atomic nuclei offers enormous promise. Modern experimental facilities such as FAIR, Jefferson Lab at 12 GeV and J-PARC offer exciting new experimental opportunities to study such systems. These experimental advances are complemented by new theoretical approaches and predictions, which will both guide these experimental efforts and be informed and improved by them. This review will outline the main theoretical approaches, beginning with QCD itself, summarize recent theoretical predictions and relate them both to past experiments and those from which we may expect results in the near future.

Lidar determination of the composition of atmosphere aerosols

NASA Technical Reports Server (NTRS)

Wright, M. L.

1980-01-01

Theoretical and experimental studies of the feasibility of using DIfferential SCatter (DISC) lidar to measure the composition of atmospheric aerosols are described. This technique involves multiwavelength measurements of the backscatter cross section of aerosols in the middle infrared, where a number of materials display strong restrahlen features that significantly modulate the backscatter spectrum. The theoretical work indicates that a number of materials of interest, including sulfuric acid, ammonium sulfate, and silicates, can be discriminated among with a CO2 lidar. An initial evaluation of this procedure was performed in which cirrus clouds and lower altitude tropospheric aerosols were developed. The observed ratio spectrum of the two types of aerosol displays structure that is in crude accord with theoretical expectations.

An integrated model of decision-making in health contexts: the role of science education in health education

NASA Astrophysics Data System (ADS)

Arnold, Julia C.

2018-03-01

Health education is to foster health literacy, informed decision-making and to promote health behaviour. To date, there are several models that seek to explain health behaviour (e.g. the Theory of Planned Behaviour or the Health Belief Model). These models include motivational factors (expectancies and values) that play a role in decision-making in health contexts. In this theoretical paper, it is argued that none of these models makes consequent use of expectancy-value pairs. It is further argued that in order to make these models fruitful for science education and for informed decision-making, models should systematically incorporate knowledge as part of the decision-making process. To fill this gap, this theoretical paper introduces The Integrated Model of Decision-Making in Health Contexts. This model includes three types of knowledge (system health knowledge, action-related health knowledge and effectiveness health knowledge) as influencing factors for motivational factors (perceived health threat, attitude towards health action, attitude towards health outcome and subjective norm) that are formed of expectancy-value pairs and lead to decisions. The model's potential for health education in science education as well as research implications is discussed.

Asymmetric nanoparticle may go "active" at room temperature

NASA Astrophysics Data System (ADS)

Sheng, Nan; Tu, YuSong; Guo, Pan; Wan, RongZheng; Wang, ZuoWei; Fang, HaiPing

2017-04-01

Using molecular dynamics simulations, we show that an asymmetrically shaped nanoparticle in dilute solution possesses a spontaneously curved trajectory within a finite time interval, instead of the generally expected random walk. This unexpected dynamic behavior has a similarity to that of active matters, such as swimming bacteria, cells, or even fish, but is of a different physical origin. The key to the curved trajectory lies in the non-zero resultant force originated from the imbalance of the collision forces acted by surrounding solvent molecules on the asymmetrically shaped nanoparticle during its orientation regulation. Theoretical formulae based on microscopic observations have been derived to describe this non-zero force and the resulting motion of the asymmetrically shaped nanoparticle.

Narrative meaning making and integration: Toward a better understanding of the way falling ill influences quality of life.

PubMed

Hartog, Iris; Scherer-Rath, Michael; Kruizinga, Renske; Netjes, Justine; Henriques, José; Nieuwkerk, Pythia; Sprangers, Mirjam; van Laarhoven, Hanneke

2017-09-01

Falling seriously ill is often experienced as a life event that causes conflict with people's personal goals and expectations in life and evokes existential questions. This article presents a new humanities approach to the way people make meaning of such events and how this influences their quality of life. Incorporating theories on contingency, narrative identity, and quality of life, we developed a theoretical model entailing the concepts life event, worldview, ultimate life goals, experience of contingency, narrative meaning making, narrative integration, and quality of life. We formulate testable hypotheses and describe the self-report questionnaire that was developed based on the model.

A quasi-likelihood approach to non-negative matrix factorization

PubMed Central

Devarajan, Karthik; Cheung, Vincent C.K.

2017-01-01

A unified approach to non-negative matrix factorization based on the theory of generalized linear models is proposed. This approach embeds a variety of statistical models, including the exponential family, within a single theoretical framework and provides a unified view of such factorizations from the perspective of quasi-likelihood. Using this framework, a family of algorithms for handling signal-dependent noise is developed and its convergence proven using the Expectation-Maximization algorithm. In addition, a measure to evaluate the goodness-of-fit of the resulting factorization is described. The proposed methods allow modeling of non-linear effects via appropriate link functions and are illustrated using an application in biomedical signal processing. PMID:27348511

Dynamic Models and Coordination Analysis of Reverse Supply Chain with Remanufacturing

NASA Astrophysics Data System (ADS)

Yan, Nina

In this paper, we establish a reverse chain system with one manufacturer and one retailer under demand uncertainties. Distinguishing between the recycling process of the retailer and the remanufacturing process of the manufacturer, we formulate a two-stage dynamic model for reverse supply chain based on remanufacturing. Using buyback contract as coordination mechanism and applying dynamic programming the optimal decision problems for each stage are analyzed. It concluded that the reverse supply chain system could be coordinated under the given condition. Finally, we carry out numerical calculations to analyze the expected profits for the manufacturer and the retailer under different recovery rates and recovery prices and the outcomes validate the theoretical analyses.

A Sorrow Shared is a Sorrow Halved: The Search for Empathetic Understanding of Family Members of a Person with Early-Onset Dementia.

PubMed

Hoppe, Silke

2018-03-01

In this article, I explore how family members of a person with early-onset dementia in the Netherlands attempt to achieve empathetic understanding from significant others, and the barriers they encounter in the process. Based on qualitative interviews, I show that the type of relationship shapes the choices people have to communicate their suffering and their expectations regarding the reactions of others. This article builds on theoretical work on empathy and problematises the notion of shared experiences. It focuses on empathy between family members and significant others, arguing that empathetic understanding between these people is a field of study thus far insufficiently explored.

Forces between permanent magnets: experiments and model

NASA Astrophysics Data System (ADS)

González, Manuel I.

2017-03-01

This work describes a very simple, low-cost experimental setup designed for measuring the force between permanent magnets. The experiment consists of placing one of the magnets on a balance, attaching the other magnet to a vertical height gauge, aligning carefully both magnets and measuring the load on the balance as a function of the gauge reading. A theoretical model is proposed to compute the force, assuming uniform magnetisation and based on laws and techniques accessible to undergraduate students. A comparison between the model and the experimental results is made, and good agreement is found at all distances investigated. In particular, it is also found that the force behaves as r -4 at large distances, as expected.

Accuracy of a class of concurrent algorithms for transient finite element analysis

NASA Technical Reports Server (NTRS)

Ortiz, Michael; Sotelino, Elisa D.; Nour-Omid, Bahram

1988-01-01

The accuracy of a new class of concurrent procedures for transient finite element analysis is examined. A phase error analysis is carried out which shows that wave retardation leading to unacceptable loss of accuracy may occur if a Courant condition based on the dimensions of the subdomains is violated. Numerical tests suggest that this Courant condition is conservative for typical structural applications and may lead to a marked increase in accuracy as the number of subdomains is increased. Theoretical speed-up ratios are derived which suggest that the algorithms under consideration can be expected to exhibit a performance superior to that of globally implicit methods when implemented on parallel machines.

Anomalous I-V curve for mono-atomic carbon chains

NASA Astrophysics Data System (ADS)

Song, Bo; Sanvito, Stefano; Fang, Haiping

2010-10-01

The electronic transport properties of mono-atomic carbon chains were studied theoretically using a combination of density functional theory and the non-equilibrium Green's functions method. The I-V curves for the chains composed of an even number of atoms and attached to gold electrodes through sulfur exhibit two plateaus where the current becomes bias independent. In contrast, when the number of carbon atoms in the chain is odd, the electric current simply increases monotonically with bias. This peculiar behavior is attributed to dimerization of the chains, directly resulting from their one-dimensional nature. The finding is expected to be helpful in designing molecular devices, such as carbon-chain-based transistors and sensors, for nanoscale and biological applications.

High-Q resonant cavities for terahertz quantum cascade lasers.

PubMed

Campa, A; Consolino, L; Ravaro, M; Mazzotti, D; Vitiello, M S; Bartalini, S; De Natale, P

2015-02-09

We report on the realization and characterization of two different designs for resonant THz cavities, based on wire-grid polarizers as input/output couplers, and injected by a continuous-wave quantum cascade laser (QCL) emitting at 2.55 THz. A comparison between the measured resonators parameters and the expected theoretical values is reported. With achieved quality factor Q ≈ 2.5 × 10(5), these cavities show resonant peaks as narrow as few MHz, comparable with the typical Doppler linewidth of THz molecular transitions and slightly broader than the free-running QCL emission spectrum. The effects of the optical feedback from one cavity to the QCL are examined by using the other cavity as a frequency reference.

Which stocks are profitable? A network method to investigate the effects of network structure on stock returns

NASA Astrophysics Data System (ADS)

Chen, Kun; Luo, Peng; Sun, Bianxia; Wang, Huaiqing

2015-10-01

According to asset pricing theory, a stock's expected returns are determined by its exposure to systematic risk. In this paper, we propose a new method for analyzing the interaction effects among industries and stocks on stock returns. We construct a complex network based on correlations of abnormal stock returns and use centrality and modularity, two popular measures in social science, to determine the effect of interconnections on industry and stock returns. Supported by previous studies, our findings indicate that a relationship exists between inter-industry closeness and industry returns and between stock centrality and stock returns. The theoretical and practical contributions of these findings are discussed.

Continuous multispectral imaging of surface phonon polaritons on silicon carbide with an external cavity quantum cascade laser

NASA Astrophysics Data System (ADS)

Dougakiuchi, Tatsuo; Kawada, Yoichi; Takebe, Gen

2018-03-01

We demonstrate the continuous multispectral imaging of surface phonon polaritons (SPhPs) on silicon carbide excited by an external cavity quantum cascade laser using scattering-type scanning near-field optical microscopy. The launched SPhPs were well characterized via the confirmation that the theoretical dispersion relation and measured in-plane wave vectors are in excellent agreement in the entire measurement range. The proposed scheme, which can excite and observe SPhPs with an arbitrary wavelength that effectively covers the spectral gap of CO2 lasers, is expected to be applicable for studies of near-field optics and for various applications based on SPhPs.

Assessing Repetitive Negative Thinking Using Categorical and Transdiagnostic Approaches: A Comparison and Validation of Three Polish Language Adaptations of Self-Report Questionnaires.

PubMed

Kornacka, Monika; Buczny, Jacek; Layton, Rebekah L

2016-01-01

Repetitive negative thinking (RNT) is a transdiagnostic process involved in the risk, maintenance, and relapse of serious conditions including mood disorders, anxiety, eating disorders, and addictions. Processing mode theory provides a theoretical model to assess, research, and treat RNT using a transdiagnostic approach. Clinical researchers also often employ categorical approaches to RNT, including a focus on depressive rumination or worry, for similar purposes. Three widely used self-report questionnaires have been developed to assess these related constructs: the Ruminative Response Scale (RRS), the Perseverative Thinking Questionnaire (PTQ), and the Mini-Cambridge Exeter Repetitive Thought Scale (Mini-CERTS). Yet these scales have not previously been used in conjunction, despite useful theoretical distinctions only available in Mini-CERTS. The present validation of the methods in a Polish speaking population provides psychometric parameters estimates that contribute to current efforts to increase reliable replication of theoretical outcomes. Moreover, the following study aims to present particular characteristics and a comparison of the three methods. Although there has been some exploration of a categorical approach, the comparison of transdiagnostic methods is still lacking. These methods are particularly relevant for developing and evaluating theoretically based interventions like concreteness training, an emerging field of increasing interest, which can be used to address the maladaptive processing mode in RNT that can lead to depression and other disorders. Furthermore, the translation of these measures enables the examination of possible cross-cultural structural differences that may lead to important theoretical progress in the measurement and classification of RNT. The results support the theoretical hypothesis. As expected, the dimensions of brooding, general repetitive negative thinking, as well as abstract analytical thinking, can all be classified as unconstructive repetitive thinking. The particular characteristics of each scale and potential practical applications in clinical and research are discussed.

One-step fabrication of 3D silver paste electrodes into microfluidic devices for enhanced droplet-based cell sorting

NASA Astrophysics Data System (ADS)

Rao, Lang; Cai, Bo; Yu, Xiao-Lei; Guo, Shi-Shang; Liu, Wei; Zhao, Xing-Zhong

2015-05-01

3D microelectrodes are one-step fabricated into a microfluidic droplet separator by filling conductive silver paste into PDMS microchambers. The advantages of 3D silver paste electrodes in promoting droplet sorting accuracy are systematically demonstrated by theoretical calculation, numerical simulation and experimental validation. The employment of 3D electrodes also helps to decrease the droplet sorting voltage, guaranteeing that cells encapsulated in droplets undergo chip-based sorting processes are at better metabolic status for further potential cellular assays. At last, target droplet containing single cell are selectively sorted out from others by an appropriate electric pulse. This method provides a simple and inexpensive alternative to fabricate 3D electrodes, and it is expected our 3D electrode-integrated microfluidic droplet separator platform can be widely used in single cell operation and analysis.

[Problem-based learning in cardiopulmonary resuscitation: basic life support].

PubMed

Sardo, Pedro Miguel Garcez; Dal Sasso, Grace Terezinha Marcon

2008-12-01

Descriptive and exploratory study, aimed to develop an educational practice of Problem-Based Learning in CPR/BLS with 24 students in the third stage of the Nursing Undergraduate Course in a University in the Southern region of Brazil. The study used the PBL methodology, focused on problem situations of cardiopulmonary arrest, and was approved by the CONEP. The methodological strategies for data collection, such as participative observation and questionnaires to evaluate the learning, the educational practices and their methodology, allowed for grouping the results in: students' expectations; group activities; individual activities; practical activities; evaluation of the meetings and their methodology. The study showed that PBL allows the educator to evaluate the academic learning process in several dimensions, functioning as a motivating factor for both the educator and the student, because it allows the theoretical-practical integration in an integrated learning process.

Radiation damage of gallium arsenide production cells

NASA Technical Reports Server (NTRS)

Mardesich, N.; Garlick, G. F. J.

1987-01-01

High-efficiency gallium arsenide cells, made by the liquid epitaxy method (LPE), have been irradiated with 1-MeV electrons up to fluences of 10 to the 16th e/sq cm. Measurements have been made of cell spectral response and dark and light-excited current-voltage characteristics and analyzed using computer-based models to determine underlying parameters such as damage coefficients. It is possible to use spectral response to sort out damage effects in the different cell component layers. Damage coefficients are similar to other reported in the literature for the emitter and buffer (base). However, there is also a damage effect in the window layer and possibly at the window emitter interface similar to that found for proton-irradiated liquid-phase epitaxy-grown cells. Depletion layer recombination is found to be less than theoretically expected at high fluence.

Anomalous interface adhesion of graphene membranes

PubMed Central

He, Y.; Chen, W. F.; Yu, W. B.; Ouyang, G.; Yang, G. W.

2013-01-01

In order to understand the anomalous interface adhesion properties between graphene membranes and their substrates, we have developed a theoretical method to calibrate the interface adhesion energy of monolayer and multilayer graphene on substrates based on the bond relaxation consideration. Four kinds of interfaces, including graphene/SiO2, graphene/Cu, graphene/Cu/Ni and Cu/graphene/Ni, were taken into account. It was found that the membrane thickness and the interface confinement condition determine the adhesion energy. The relationship between the critical interface separation and the graphene thickness showed that the interface separation in the self-equilibrium state drops with decreasing membrane thickness. The size-dependent Young's modulus of graphene membrane and the interfacial condition were responsible for the novel interface adhesion energy. The proposed theory was expected to be applied to the design of graphene-based devices. PMID:24036502

New optical scheme for a polarimetric-based glucose sensor

NASA Technical Reports Server (NTRS)

Ansari, Rafat R.; Bockle, Stefan; Rovati, Luigi

2004-01-01

A new optical scheme to detect glucose concentration in the aqueous humor of the eye is presented. The ultimate aim is to apply this technique in designing a new instrument for, routinely and frequently, noninvasively monitoring blood glucose levels in diabetic patients without contact (no index matching) between the eye and the instrument. The optical scheme exploits the Brewster reflection of circularly polarized light off of the lens of the eye. Theoretically, this reflected linearly polarized light on its way to the detector is expected to rotate its state of polarization, owing to the presence of glucose molecules in the aqueous humor of a patient's eye. An experimental laboratory setup based on this scheme was designed and tested by measuring a range of known concentrations of glucose solutions dissolved in water. (c) 2004 Society of Photo-Optical Instrumentation Engineers.

Sharp plasma pinnacle structure based on shockwave for an improved laser wakefield accelerator

NASA Astrophysics Data System (ADS)

Fang, Ming; Zhang, Zhijun; Wang, Wentao; Liu, Jiansheng; Li, Ruxin

2018-07-01

We created a sharp plasma pinnacle structure for localized electron injection and controlled acceleration in a laser wakefield accelerator. The formation of this shockwave-based pinnacle structure was investigated using aerodynamic theory. Details and scaling laws for the shockwave angle, shock position, shock width, and density ratio were experimentally and theoretically presented. Such work is crucial to yielding an expected plasma density distribution in a laser–plasma experiment but has had little discussion in the literature. Compared with the commonly used shock downramp structure, the particle-in-cell simulations demonstrated that the e beam injected in the created pinnacle structure could be accelerated to higher energy with much smaller root-mean-square relative energy spread. Moreover, this study indicated that the beam charge and transverse emittance can be tuned by the shock angle.

Model-Based IN SITU Parameter Estimation of Ultrasonic Guided Waves in AN Isotropic Plate

NASA Astrophysics Data System (ADS)

Hall, James S.; Michaels, Jennifer E.

2010-02-01

Most ultrasonic systems employing guided waves for flaw detection require information such as dispersion curves, transducer locations, and expected propagation loss. Degraded system performance may result if assumed parameter values do not accurately reflect the actual environment. By characterizing the propagating environment in situ at the time of test, potentially erroneous a priori estimates are avoided and performance of ultrasonic guided wave systems can be improved. A four-part model-based algorithm is described in the context of previous work that estimates model parameters whereby an assumed propagation model is used to describe the received signals. This approach builds upon previous work by demonstrating the ability to estimate parameters for the case of single mode propagation. Performance is demonstrated on signals obtained from theoretical dispersion curves, finite element modeling, and experimental data.

Peak clustering in two-dimensional gas chromatography with mass spectrometric detection based on theoretical calculation of two-dimensional peak shapes: the 2DAid approach.

PubMed

van Stee, Leo L P; Brinkman, Udo A Th

2011-10-28

A method is presented to facilitate the non-target analysis of data obtained in temperature-programmed comprehensive two-dimensional (2D) gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-ToF-MS). One main difficulty of GC×GC data analysis is that each peak is usually modulated several times and therefore appears as a series of peaks (or peaklets) in the one-dimensionally recorded data. The proposed method, 2DAid, uses basic chromatographic laws to calculate the theoretical shape of a 2D peak (a cluster of peaklets originating from the same analyte) in order to define the area in which the peaklets of each individual compound can be expected to show up. Based on analyte-identity information obtained by means of mass spectral library searching, the individual peaklets are then combined into a single 2D peak. The method is applied, amongst others, to a complex mixture containing 362 analytes. It is demonstrated that the 2D peak shapes can be accurately predicted and that clustering and further processing can reduce the final peak list to a manageable size. Copyright © 2011 Elsevier B.V. All rights reserved.

Magnetic interactions in a quasi-one-dimensional antiferromagnet Cu(H{sub 2}O){sub 2}(en)SO{sub 4}

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

Sýkora, Rudolf, E-mail: rudolf.sykora@vsb.cz; Legut, Dominik

A theoretical ab-initio investigation of exchange interaction between Cu atoms in an insulating antiferromagnet Cu(H{sub 2}O){sub 2}(en)SO{sub 4}, en = C{sub 2}H{sub 8}N{sub 2}, is reported. While the previous experimental studies described the system's magnetism to be quasi-two-dimensional, our results, based on a mapping of the system onto an effective Heisenberg model, rather support a quasi-one-dimensional character with the exchange coupling between the Cu atoms being propagated mainly along a zigzag line lying in the crystal's bc plane and connecting the Cu atoms through the N atoms. Further, the direction of magnetic moments on the Cu atoms is suggested to be nearlymore » along the crystal's a axis. A check of the change in the exchange constants induced either by external pressure or by various values of U in the GGA + U approximation is made. Finally, based on experimental values of positions of broad maxima in magnetic-susceptibility and specific-heat curves and using theoretical expressions available in the literature a relevant value of the U parameter and related expected value of the electronic gap are estimated to be about 5 eV and 2 eV, respectively.« less

Transition path time distribution and the transition path free energy barrier.

PubMed

Pollak, Eli

2016-10-19

The recent experimental measurement of the transition path time distributions of proteins presents several challenges to theory. Firstly, why do the fits of the experimental data to a theoretical expression lead to barrier heights which are much lower than the free energies of activation of the observed transitions? Secondly, there is the theoretical question of determining the transition path time distribution, without invoking the Smoluchowski limit. In this paper, we derive an exact expression for a transition path time distribution which is valid for arbitrary memory friction using the normal mode transformation which underlies Kramers' rate theory. We then recall that for low barriers, there is a noticeable difference between the transition path time distribution obtained with absorbing boundary conditions and free boundary conditions. For the former, the transition times are shorter, since recrossings of the boundaries are disallowed. As a result, if one uses the distribution based on absorbing boundary conditions to fit the experimental data, one will find that the transition path barrier will be larger than the values found based on a theory with free boundary conditions. We then introduce the paradigm of a transition path barrier height, and show that one should always expect it to be much smaller than the activation energy.

Optical dosimetry of radiotherapy beams using Cherenkov radiation: the relationship between light emission and dose.

PubMed

Glaser, Adam K; Zhang, Rongxiao; Gladstone, David J; Pogue, Brian W

2014-07-21

Recent studies have proposed that light emitted by the Cherenkov effect may be used for a number of radiation therapy dosimetry applications. There is a correlation between the captured light and expected dose under certain conditions, yet discrepancies have also been observed and a complete examination of the theoretical differences has not been done. In this study, a fundamental comparison between the Cherenkov emission and absorbed dose was explored for x-ray photons, electrons, and protons using both a theoretical and Monte Carlo-based analysis. Based on the findings of where dose correlates with Cherenkov emission, it was concluded that for x-ray photons the light emission would be optimally suited for narrow beam stereotactic radiation therapy and surgery validation studies, for verification of dynamic intensity-modulated and volumetric modulated arc therapy treatment plans in water tanks, near monoenergetic sources (e.g., Co-60 and brachy therapy sources) and also for entrance and exit surface imaging dosimetry of both narrow and broad beams. For electron use, Cherenkov emission was found to be only suitable for surface dosimetry applications. Finally, for proton dosimetry, there exists a fundamental lack of Cherenkov emission at the Bragg peak, making the technique of little use, although post-irradiation detection of light emission from radioisotopes could prove to be useful.

Fair opportunities, social productivity and wellbeing in disability: Towards a theoretical foundation.

PubMed

Siegrist, Johannes; Fekete, Christine

2016-06-13

Theory-based approaches provide explanations of the impact of components of the International Classification of Functioning, Disability and Health (ICF) classification on outcomes such as health and wellbeing. Here, one such approach is proposed, focusing on social participation and its association with wellbeing. In addition to elaborating a theoretical approach, a narrative review of research on labour market participation of persons with severe disability, spinal cord injury, is conducted to illustrate the utility of the proposed approach. Availability and good quality of productive activities, in particular paid work, are expected to improve wellbeing by strengthening favourable experiences of personal control and social recognition. As these opportunities are restricted among persons with disabilities, conditions that enable full social participation need to be strengthened. Research identified several such conditions at the individual (e.g. coping, social support, educational skills) and the contextual socio-political level (e.g. quality of care, medical and vocational rehabilitation), although their potential of improving wellbeing has not yet been sufficiently explored. In conclusion, supplementing the established ICF classification by theory-based approaches may advance explanations of adverse effects of reduced functioning and wellbeing in disability. This new knowledge can guide the development of interventions to improve participation in general and social productivity in particular.

Design, Construction and Testing of Annular Diffusers for High Speed Civil Transportation Combustor Applications

NASA Technical Reports Server (NTRS)

Okhio, Cyril B.

1996-01-01

A theoretical and an experimental design study of subsonic flow through curved-wall annular diffusers has been initiated under this award in order to establish the most pertinent design parameters and hence performance characteristics for such devices, an the implications of their application in the design of engine components in the aerospace industries. The diffusers under this study are expected to contain appreciable regions of stall and the effects of swirl on their performance are being studied. The experimental work involves the application of Computer Aided Design software tool to the development of a suitable annular diffuse geometry and the subsequent downloading of such data to a CNC machine at Central State University (CSU). Two experimental run segments have been completed so far during FY-95 involving flow visualization and diffuser performance evaluation based on Kinetic Energy Dissipation. The method of calculation of the performance of diffusers based on pressure recovery coefficient has been shown to have some shortcomings and so the kinetic energy dissipation approach has been introduced in the run segment two with some success. The application of the discretized, full Navier Stokes and Continuity equations to the numerical study of the problem described above for the time-mean flow is expected to follow. Various models of turbulence are being evaluated for adoption throughout the study and comparisons would be made with experimental data where they exist. Assessment of diffuser performance based on the dissipated mechanical energy would also be made. The result of the investigations are expected to indicate that more cost effective component design of such devices as diffusers which normally contain complex flows can still be achieved.

Specific Barriers and Drivers in Different Stages of Decision-Making about Energy Efficiency Upgrades in Private Homes

PubMed Central

Klöckner, Christian A.; Nayum, Alim

2016-01-01

Energy efficiency upgrades of privately owned homes like adding to the insulation layers in the walls, roof or floor, or replacing windows with more efficiently insulated versions can contribute significantly to reducing the energy impact of the building sector and thus also the CO2 footprint of a household. However, even in countries like Norway that have a rather high rate of renovation, energy upgrades are not always integrated into such a refurbishment project. This study tests which structural and internal psychological barriers hinder and which drivers foster decision-making to implement such measures, once a renovation project is planned. With a theoretical background in stage-based models of decision-making 24 barriers and drivers were tested for their specific effect in the stages of decision-making. The four stages of decision-making assumed in this study were (1) “not being in a decision mode,” (2) “deciding what to do,” (3) “deciding how to do it,” and (4) “planning implementation.” Based on an online survey of 3787 Norwegian households, it was found that the most important barriers toward deciding to implement energy efficiency upgrades were not owning the dwelling and feeling the right time had not come yet. The most important drivers of starting to decide were higher expected comfort levels, better expected living conditions, and an expected reduction of energy costs. For the transition from deciding what to do to how to do it, not managing to make a decision and feeling the right point in time has not come yet were the strongest barriers, easily accessible information and an expected reduction of energy costs were the most important drivers. The final transition from deciding how to do the upgrades to planning implementation was driven by expecting a payoff within a reasonable time frame and higher expected comfort levels; the most important barriers were time demands for supervising contractors and—again—a feeling that the right point in time has not come yet. Implications for policy-making and marketing are discussed. PMID:27660618

Specific Barriers and Drivers in Different Stages of Decision-Making about Energy Efficiency Upgrades in Private Homes.

PubMed

Klöckner, Christian A; Nayum, Alim

2016-01-01

Energy efficiency upgrades of privately owned homes like adding to the insulation layers in the walls, roof or floor, or replacing windows with more efficiently insulated versions can contribute significantly to reducing the energy impact of the building sector and thus also the CO2 footprint of a household. However, even in countries like Norway that have a rather high rate of renovation, energy upgrades are not always integrated into such a refurbishment project. This study tests which structural and internal psychological barriers hinder and which drivers foster decision-making to implement such measures, once a renovation project is planned. With a theoretical background in stage-based models of decision-making 24 barriers and drivers were tested for their specific effect in the stages of decision-making. The four stages of decision-making assumed in this study were (1) "not being in a decision mode," (2) "deciding what to do," (3) "deciding how to do it," and (4) "planning implementation." Based on an online survey of 3787 Norwegian households, it was found that the most important barriers toward deciding to implement energy efficiency upgrades were not owning the dwelling and feeling the right time had not come yet. The most important drivers of starting to decide were higher expected comfort levels, better expected living conditions, and an expected reduction of energy costs. For the transition from deciding what to do to how to do it, not managing to make a decision and feeling the right point in time has not come yet were the strongest barriers, easily accessible information and an expected reduction of energy costs were the most important drivers. The final transition from deciding how to do the upgrades to planning implementation was driven by expecting a payoff within a reasonable time frame and higher expected comfort levels; the most important barriers were time demands for supervising contractors and-again-a feeling that the right point in time has not come yet. Implications for policy-making and marketing are discussed.

Reliability analysis based on the losses from failures.

PubMed

Todinov, M T

2006-04-01

The conventional reliability analysis is based on the premise that increasing the reliability of a system will decrease the losses from failures. On the basis of counterexamples, it is demonstrated that this is valid only if all failures are associated with the same losses. In case of failures associated with different losses, a system with larger reliability is not necessarily characterized by smaller losses from failures. Consequently, a theoretical framework and models are proposed for a reliability analysis, linking reliability and the losses from failures. Equations related to the distributions of the potential losses from failure have been derived. It is argued that the classical risk equation only estimates the average value of the potential losses from failure and does not provide insight into the variability associated with the potential losses. Equations have also been derived for determining the potential and the expected losses from failures for nonrepairable and repairable systems with components arranged in series, with arbitrary life distributions. The equations are also valid for systems/components with multiple mutually exclusive failure modes. The expected losses given failure is a linear combination of the expected losses from failure associated with the separate failure modes scaled by the conditional probabilities with which the failure modes initiate failure. On this basis, an efficient method for simplifying complex reliability block diagrams has been developed. Branches of components arranged in series whose failures are mutually exclusive can be reduced to single components with equivalent hazard rate, downtime, and expected costs associated with intervention and repair. A model for estimating the expected losses from early-life failures has also been developed. For a specified time interval, the expected losses from early-life failures are a sum of the products of the expected number of failures in the specified time intervals covering the early-life failures region and the expected losses given failure characterizing the corresponding time intervals. For complex systems whose components are not logically arranged in series, discrete simulation algorithms and software have been created for determining the losses from failures in terms of expected lost production time, cost of intervention, and cost of replacement. Different system topologies are assessed to determine the effect of modifications of the system topology on the expected losses from failures. It is argued that the reliability allocation in a production system should be done to maximize the profit/value associated with the system. Consequently, a method for setting reliability requirements and reliability allocation maximizing the profit by minimizing the total cost has been developed. Reliability allocation that maximizes the profit in case of a system consisting of blocks arranged in series is achieved by determining for each block individually the reliabilities of the components in the block that minimize the sum of the capital, operation costs, and the expected losses from failures. A Monte Carlo simulation based net present value (NPV) cash-flow model has also been proposed, which has significant advantages to cash-flow models based on the expected value of the losses from failures per time interval. Unlike these models, the proposed model has the capability to reveal the variation of the NPV due to different number of failures occurring during a specified time interval (e.g., during one year). The model also permits tracking the impact of the distribution pattern of failure occurrences and the time dependence of the losses from failures.

Concept maps: A tool for knowledge management and synthesis in web-based conversational learning.

PubMed

Joshi, Ankur; Singh, Satendra; Jaswal, Shivani; Badyal, Dinesh Kumar; Singh, Tejinder

2016-01-01

Web-based conversational learning provides an opportunity for shared knowledge base creation through collaboration and collective wisdom extraction. Usually, the amount of generated information in such forums is very huge, multidimensional (in alignment with the desirable preconditions for constructivist knowledge creation), and sometimes, the nature of expected new information may not be anticipated in advance. Thus, concept maps (crafted from constructed data) as "process summary" tools may be a solution to improve critical thinking and learning by making connections between the facts or knowledge shared by the participants during online discussion This exploratory paper begins with the description of this innovation tried on a web-based interacting platform (email list management software), FAIMER-Listserv, and generated qualitative evidence through peer-feedback. This process description is further supported by a theoretical construct which shows how social constructivism (inclusive of autonomy and complexity) affects the conversational learning. The paper rationalizes the use of concept map as mid-summary tool for extracting information and further sense making out of this apparent intricacy.

Translational behavioral medicine for population and individual health: gaps, opportunities, and vision for practice-based translational behavior change research.

PubMed

Ma, Jun; Lewis, Megan A; Smyth, Joshua M

2018-04-12

In this commentary, we propose a vision for "practice-based translational behavior change research," which we define as clinical and public health practice-embedded research on the implementation, optimization, and fundamental mechanisms of behavioral interventions. This vision intends to be inclusive of important research elements for behavioral intervention development, testing, and implementation. We discuss important research gaps and conceptual and methodological advances in three key areas along the discovery (development) to delivery (implementation) continuum of evidence-based interventions to improve behavior and health that could help achieve our vision of practice-based translational behavior change research. We expect our proposed vision to be refined and evolve over time. Through highlighting critical gaps that can be addressed by integrating modern theoretical and methodological approaches across disciplines in behavioral medicine, we hope to inspire the development and funding of innovative research on more potent and implementable behavior change interventions for optimal population and individual health.

Patient-Therapist Value Congruence and Ratings of Client Improvement

ERIC Educational Resources Information Center

Martini, Janie L.

1978-01-01

It can be concluded from the results of the two studies described here that value similarity between client and therapist is related to therapists' ratings of client improvement. This phenomenon can be expected in therapies irrespective of theoretical orientation. (Author)

The Clustering of Galaxies and Dark Matter at Intermediate Redshifts

NASA Technical Reports Server (NTRS)

Jain, Bhuvnesh; Szalay, Alexander

2003-01-01

Theoretical work in the study of weak lensing was begun while the Scientific PI (Jain) was at the Johns Hopkins University. A new postdoctoral fellow, Rita Kim, was hired to work for 0.5 years on the proposed research. She was unable to join JHU until March 2001 owing to delays in her PhD work. Meanwhile PI Jain moved to the University of Pennsylvania in January 2001. Owing to the above circumstances, the work for the proposed research was delayed and was expected to be carried out in the remainder of 2001. New measures of lensing based on the magnification effect were to be investigated by Drs. Jain and Kim. The simulations needed to test the analytical computations were already in place; hence the work was expected to proceed fairly rapidly. Owing to the close proximity of JHU and UPenn, the collaborative work was expected to proceed smoothly. It was requested therefore that the funds for the first grant year (2000-2001) be transferred to the second year. Part of the funding was spent at JHU on the salary for the Postdoctoral Fellow, Rita Kim, and the remainder at the University of Pennsylvania. The work from this grant is incomplete and will be continued under another grant.

The harmonic force field of benzene. A local density functional study

NASA Astrophysics Data System (ADS)

Bérces, Attila; Ziegler, Tom

1993-03-01

The harmonic force field of benzene has been calculated by a method based on local density functional theory (LDF). The calculations were carried out employing a triple zeta basis set with triple polarization on hydrogen and double polarization on carbon. The LDF force field was compared to the empirical field due to Ozkabak, Goodman, and Thakur [A. G. Ozkabak, L. Goodman, and S. N. Thakur, J. Phys. Chem. 95, 9044 (1991)], which has served as a benchmark for theoretical calculations as well as the theoretical field based on scaled Hartree-Fock ab initio calculation due to Pulay, Fogarasi, and Boggs [P. Pulay, G. Fogarasi, and J. E. Boggs, J. Chem. Phys. 74, 3999 (1981)]. The calculated LDF force field is in excellent qualitative and very good quantitative agreement with the theoretical field proposed by Pulay, Fogarasi, and Boggs as well as the empirical field due to Ozkabak, Goodman, and Thakur. The LDF field is closest to the values of Pulay and co-workers in those cases where the force constants due to Pulay, Fogarasi, and Boggs and to Ozkabak, Goodman, and Thakur differ in sign or magnitude. The accuracy of the LDF force field was investigated by evaluating a number of eigenvalue and eigenfunction dependent quantities from the the LDF force constants. The quantities under investigation include vibrational frequencies of seven isotopomers, isotopic shifts, as well as absorption intensities. The calculations were performed at both theoretical optimized and approximate equilibrium reference geometries. The predicted frequencies are usually within 1%-2% compared to the empirical harmonic frequencies. The least accurate frequency deviates by 5% from the experimental value. The average deviations from the empirical harmonic frequencies of C6H6 and C6D6 are 16.7 cm-1 (1.5%) and 15.2 cm-1 (1.7%), respectively, not including CH stretching frequencies, in the case where a theoretical reference geometry was used. The accuracy of the out-of-plane force field is especially remarkable; the average deviations for the C6H6 and C6D6 frequencies, based on the LDF force field, are 9.4 cm-1 (1.2%) and 7.3 cm-1 (1.2%), respectively. The absorption intensities were not predicted as accurately as it was expected based on the size of the basis set applied. An analysis is provided to ensure that the force constants are not significantly affected by numerical errors due to the numerical integration scheme employed.

Theoretical study on the electronic and optical properties of bulk and surface (001) InxGa1-xAs

NASA Astrophysics Data System (ADS)

Liu, XueFei; Ding, Zhao; Luo, ZiJiang; Zhou, Xun; Wei, JieMin; Wang, Yi; Guo, Xiang; Lang, QiZhi

2018-05-01

The optical properties of surface and bulk InxGa1-xAs materials are compared systematically first time in this paper. The band structures, density of states and optical properties including dielectric function, reflectivity, absorption coefficient, loss function and refractive index of bulk and surface InxGa1-xAs materials are investigated by first-principles based on plane-wave pseudo-potentials method within the LDA approximation. The results agree well with the available theoretical and experimental studies and indicate that the electronic and optical properties of bulk and surface InxGa1-xAs materials are much different, and the results show that the considered optical properties of the both materials vary with increasing indium composition in an opposite way. The calculations show that the optical properties of surface In0.75Ga0.25As material are unexpected to be far from the other two indium compositions of surface InxGa1-xAs materials while the optical properties of bulk InxGa1-xAs materials vary with increasing indium composition in an expected regular way.

A framework for the study of coping, illness behaviour and outcomes.

PubMed

Shaw, C

1999-05-01

This paper presents a theoretical framework for the study of coping, illness attribution, health behaviour and outcomes. It is based upon models developed within health psychology and aims to provide a theoretical basis for nurse researchers to utilize psychosocial variables. It is an interactionist model which views outcomes as dependent upon both situation and person variables. The situation is viewed as the health threat or illness symptoms as well as the psychosocial context within which the person is operating. This context includes socio-economic factors, social support, social norms, and external factors such as the mass media. The experience of health threat is dependent upon individual appraisal, and the framework incorporates Folkman and Lazarus' transactional model of stress, as well as Leventhal's illness representation model. Behaviour and the perception of threat are also dependent upon outcome expectancies and the appraisal of one's own coping resources, and so the concepts of locus of control and self-efficacy are also incorporated. This framework allows one to identify determinants of behaviour and outcome, and will aid nurses in identifying areas for psycho-social intervention.

On the equivalence of spherical splines with least-squares collocation and Stokes's formula for regional geoid computation

NASA Astrophysics Data System (ADS)

Ophaug, Vegard; Gerlach, Christian

2017-11-01

This work is an investigation of three methods for regional geoid computation: Stokes's formula, least-squares collocation (LSC), and spherical radial base functions (RBFs) using the spline kernel (SK). It is a first attempt to compare the three methods theoretically and numerically in a unified framework. While Stokes integration and LSC may be regarded as classic methods for regional geoid computation, RBFs may still be regarded as a modern approach. All methods are theoretically equal when applied globally, and we therefore expect them to give comparable results in regional applications. However, it has been shown by de Min (Bull Géod 69:223-232, 1995. doi: 10.1007/BF00806734) that the equivalence of Stokes's formula and LSC does not hold in regional applications without modifying the cross-covariance function. In order to make all methods comparable in regional applications, the corresponding modification has been introduced also in the SK. Ultimately, we present numerical examples comparing Stokes's formula, LSC, and SKs in a closed-loop environment using synthetic noise-free data, to verify their equivalence. All agree on the millimeter level.

Estimation of π-π Electronic Couplings from Current Measurements.

PubMed

Trasobares, J; Rech, J; Jonckheere, T; Martin, T; Aleveque, O; Levillain, E; Diez-Cabanes, V; Olivier, Y; Cornil, J; Nys, J P; Sivakumarasamy, R; Smaali, K; Leclere, P; Fujiwara, A; Théron, D; Vuillaume, D; Clément, N

2017-05-10

The π-π interactions between organic molecules are among the most important parameters for optimizing the transport and optical properties of organic transistors, light-emitting diodes, and (bio-) molecular devices. Despite substantial theoretical progress, direct experimental measurement of the π-π electronic coupling energy parameter t has remained an old challenge due to molecular structural variability and the large number of parameters that affect the charge transport. Here, we propose a study of π-π interactions from electrochemical and current measurements on a large array of ferrocene-thiolated gold nanocrystals. We confirm the theoretical prediction that t can be assessed from a statistical analysis of current histograms. The extracted value of t ≈35 meV is in the expected range based on our density functional theory analysis. Furthermore, the t distribution is not necessarily Gaussian and could be used as an ultrasensitive technique to assess intermolecular distance fluctuation at the subangström level. The present work establishes a direct bridge between quantum chemistry, electrochemistry, organic electronics, and mesoscopic physics, all of which were used to discuss results and perspectives in a quantitative manner.

Proton-induced knockout reactions with polarized and unpolarized beams

NASA Astrophysics Data System (ADS)

Wakasa, T.; Ogata, K.; Noro, T.

2017-09-01

Proton-induced knockout reactions provide a direct means of studying the single particle or cluster structures of target nuclei. In addition, these knockout reactions are expected to play a unique role in investigations of the effects of the nuclear medium on nucleon-nucleon interactions as well as the properties of nucleons and mesons. However, due to the nature of hadron probes, these reactions can suffer significant disturbances from the nuclear surroundings and the quantitative theoretical treatment of such processes can also be challenging. In this article, we review the experimental and theoretical progress in this field, particularly focusing on the use of these reactions as a spectroscopic tool and as a way to examine the medium modification of nucleon-nucleon interactions. With regard to the former aspect, the review presents a semi-quantitative evaluation of these reactions based on existing experimental data. In terms of the latter point, we introduce a significant body of evidence that suggests, although does not conclusively prove, the existence of medium effects. In addition, this paper also provides information and comments on other related subjects.

Theoretical studies in support of the 3M-vapor transport (PVTOS-) experiments

NASA Technical Reports Server (NTRS)

Rosner, Daniel E.; Keyes, David E.

1989-01-01

Results are reported for a preliminary theoretical study of the coupled mass-, momentum-, and heat-transfer conditions expected within small ampoules used to grow oriented organic solid (OS-) films, by physical vapor transport (PVT) in microgravity environments. It is show that previous studies made restrictive assumptions (e.g., smallness of delta T/T, equality of molecular diffusivities) not valid under PVTOS conditions, whereas the important phenomena of sidewall gas creep, Soret transport of the organic vapor, and large vapor phase supersaturations associated with the large prevailing temperature gradients were not previously considered. Rational estimates are made of the molecular transport properties relevant to copper-phthalocyanine monomeric vapor in a gas mixture containing H2(g) and Xe(g). Efficient numerical methods have been developed and are outlined/illustrated here to making steady axisymmetric gas flow calculations within such ampoules, allowing for realistic realistic delta T/T(sub)w-values, and even corrections to Navier-Stokes-Fourier 'closure' for the governing continuum differential equations. High priority follow-on studies are outlined based on these new results.

Plant delta 15N correlates with the transpiration efficiency of nitrogen acquisition in tropical trees.

PubMed

Cernusak, Lucas A; Winter, Klaus; Turner, Benjamin L

2009-11-01

Based upon considerations of a theoretical model of (15)N/(14)N fractionation during steady-state nitrate uptake from soil, we hypothesized that, for plants grown in a common soil environment, whole-plant delta(15)N (deltaP) should vary as a function of the transpiration efficiency of nitrogen acquisition (F(N)/v) and the difference between deltaP and root delta(15)N (deltaP - deltaR). We tested these hypotheses with measurements of several tropical tree and liana species. Consistent with theoretical expectations, both F(N)/v and deltaP - deltaR were significant sources of variation in deltaP, and the relationship between deltaP and F(N)/v differed between non-N(2)-fixing and N(2)-fixing species. We interpret the correlation between deltaP and F(N)/v as resulting from variation in mineral nitrogen efflux-to-influx ratios across plasma membranes of root cells. These results provide a simple explanation of variation in delta(15)N of terrestrial plants and have implications for understanding nitrogen cycling in ecosystems.

From the Immoral to the Incorruptible: How Prescriptive Expectations Turn the Powerful Into Paragons of Virtue.

PubMed

Hu, Miao; Rucker, Derek D; Galinsky, Adam D

2016-06-01

Ample evidence documents that power increases unethical behavior. This article introduces a new theoretical framework for understanding when power leads to more versus less unethical behavior. Our key proposition is that people hold expectations about power that are both descriptive (how the powerful do behave) and prescriptive (how the powerful should behave). People hold descriptive beliefs that the powerful do behave more unethically than the powerless, but they hold prescriptive beliefs that the powerful should behave more ethically than the powerless. Whichever expectation-descriptive or prescriptive-is salient affects how power influences one's behavior. Three experiments demonstrate that activating descriptive expectations for power leads the powerful to cheat more than the powerless, whereas activating prescriptive expectations leads the powerful to cheat less than the powerless. The current work offers new ideas for curbing unethical behavior by those with power: focus their attention on prescriptive expectations for power. © 2016 by the Society for Personality and Social Psychology, Inc.

An integrated theoretical approach to substance use and risky sexual behavior among men who have sex with men.

PubMed

Wells, Brooke E; Golub, Sarit A; Parsons, Jeffrey T

2011-04-01

Research demonstrates a consistent association between substance use and sexual risk, particularly among men who have sex with men (MSM). The present study builds upon two existing theories (Cognitive Escape Theory and Expectancy Theory) to examine the synergistic role of sexual conflict (surrounding unsafe sex) and expectancies in sexual behavior among 135 MSM. Two conflicts were examined: (1) The conflict between motivation to practice safer sex and temptation for unprotected sex; and (2) The conflict between motivation to practice safer sex and perceived benefits of unprotected sex. Factorial ANOVAs (2 × 2; high versus low expectancies and conflict versus no conflict) revealed a significant interaction between conflict and expectancies-individuals who reported high levels of conflict were more sensitive to the effect of expectancies than were those experiencing low levels of sexual conflict. Results demonstrate the synergistic effects of conflict and expectancies and highlight the importance of integrating existing theories to more fully consider the intrapsychic operation and experience of sexual conflicts.

Predictions of dental pain: the fear of any expected evil, is worse than the evil itself.

PubMed

Arntz, A; van Eck, M; Heijmans, M

1990-01-01

In a study of 40 subjects, who twice underwent extensive dental treatment, the relationships between expectations and experiences of pain and of anxiety were investigated. Inaccurate expectations were adjusted in the same way as observed in the laboratory. Especially anxious subjects expected more pain and anxiety than they experienced, and they appeared to need more experiences before their predictions became accurate. In the course of time, the expectations (and memories) of anxious subjects returned to their original more inaccurate level of prediction. The results suggest that the old schema is ultimately reinstated if disconfirmations are few and far between. Anxious subjects did not experience more pain, but they did experience more anxiety than fearless subjects. Detailed investigation of processes of change after disconfirmation showed that anxiety experienced during treatment is a factor that plays a part in maintaining the problem of inaccurate expectations and fear of treatment. Theoretical and clinical implications of these findings are discussed.

Theoretical Prediction of Microgravity Ignition Delay of Polymeric Fuels in Low Velocity Flows

NASA Technical Reports Server (NTRS)

Fernandez-Pello, A. C.; Torero, J. L.; Zhou, Y. Y.; Walther, D.; Ross, H. D.

2001-01-01

A new flammability apparatus and protocol, FIST (Forced Flow Ignition and Flame Spread Test), is under development. Based on the LIFT (Lateral Ignition and Flame Spread Test) protocol, FIST better reflects the environments expected in spacebased facilities. The final objective of the FIST research is to provide NASA with a test methodology that complements the existing protocol and provides a more comprehensive assessment of material flammability of practical materials for space applications. Theoretical modeling, an extensive normal gravity data bank and a few validation space experiments will support the testing methodology. The objective of the work presented here is to predict the ignition delay and critical heat flux for ignition of solid fuels in microgravity at airflow velocities below those induced in normal gravity. This is achieved through the application of a numerical model previously developed of piloted ignition of solid polymeric materials exposed to an external radiant heat flux. The model predictions will provide quantitative results about ignition of practical materials in the limiting conditions expected in space facilities. Experimental data of surface temperature histories and ignition delay obtained in the KC-135 aircraft are used to determine the critical pyrolysate mass flux for ignition and this value is subsequently used to predict the ignition delay and the critical heat flux for ignition of the material. Surface temperature and piloted ignition delay calculations for Polymethylmethacrylate (PMMA) and a Polypropylene/Fiberglass (PP/GL) composite were conducted under both reduced and normal gravity conditions. It was found that ignition delay times are significantly shorter at velocities below those induced by natural convection.

Orbital motion in T Tauri binary systems

NASA Astrophysics Data System (ADS)

Woitas, J.; Köhler, R.; Leinert, Ch.

2001-04-01

Using speckle-interferometry we have carried out repeated measurements of relative positions for the components of 34 T Tauri binary systems. The projected separation of these components is low enough that orbital motion is expected to be observable within a few years. In most cases orbital motion has indeed been detected. The observational data is discussed in a manner similar to Ghez et al. (\\cite{Ghez95}). However, we extend their study to a larger number of objects and a much longer timespan. The database presented in this paper is valuable for future visual orbit determinations. It will yield empirical masses for T Tauri stars that now are only poorly known. The available data is however not sufficient to do this at the present time. Instead, we use short series of orbital data and statistical distributions of orbital parameters to derive an average system mass that is independent of theoretical assumptions about the physics of PMS stars. For our sample this mass is 2.0 Msun and thus in the order of magnitude one expects for the mass sum of two T Tauri stars. It is also comparable to mass estimates obtained for the same systems using theoretical PMS evolutionary models. Based on observations collected at the German-Spanish Astronomical Center on Calar Alto, Spain, and at the European Southern Observatory, La Silla, Chile. Table A.1 is only available in electronic form at the CDS, via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5), or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/369/249

When theory and biology differ: The relationship between reward prediction errors and expectancy.

PubMed

Williams, Chad C; Hassall, Cameron D; Trska, Robert; Holroyd, Clay B; Krigolson, Olave E

2017-10-01

Comparisons between expectations and outcomes are critical for learning. Termed prediction errors, the violations of expectancy that occur when outcomes differ from expectations are used to modify value and shape behaviour. In the present study, we examined how a wide range of expectancy violations impacted neural signals associated with feedback processing. Participants performed a time estimation task in which they had to guess the duration of one second while their electroencephalogram was recorded. In a key manipulation, we varied task difficulty across the experiment to create a range of different feedback expectancies - reward feedback was either very expected, expected, 50/50, unexpected, or very unexpected. As predicted, the amplitude of the reward positivity, a component of the human event-related brain potential associated with feedback processing, scaled inversely with expectancy (e.g., unexpected feedback yielded a larger reward positivity than expected feedback). Interestingly, the scaling of the reward positivity to outcome expectancy was not linear as would be predicted by some theoretical models. Specifically, we found that the amplitude of the reward positivity was about equivalent for very expected and expected feedback, and for very unexpected and unexpected feedback. As such, our results demonstrate a sigmoidal relationship between reward expectancy and the amplitude of the reward positivity, with interesting implications for theories of reinforcement learning. Copyright © 2017 Elsevier B.V. All rights reserved.

Game theoretic analysis of physical protection system design

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

Canion, B.; Schneider, E.; Bickel, E.

The physical protection system (PPS) of a fictional small modular reactor (SMR) facility have been modeled as a platform for a game theoretic approach to security decision analysis. To demonstrate the game theoretic approach, a rational adversary with complete knowledge of the facility has been modeled attempting a sabotage attack. The adversary adjusts his decisions in response to investments made by the defender to enhance the security measures. This can lead to a conservative physical protection system design. Since defender upgrades were limited by a budget, cost benefit analysis may be conducted upon security upgrades. One approach to cost benefitmore » analysis is the efficient frontier, which depicts the reduction in expected consequence per incremental increase in the security budget.« less

Experimental and theoretical double differential cross sections for electron impact ionization of methane

NASA Astrophysics Data System (ADS)

Yavuz, Murat; Ozer, Zehra Nur; Ulu, Melike; Champion, Christophe; Dogan, Mevlut

2016-04-01

Experimental and theoretical double differential cross sections (DDCSs) for electron-induced ionization of methane (CH4) are here reported for primary energies ranging from 50 eV to 350 eV and ejection angles between 25° and 130°. Experimental DDCSs are compared with theoretical predictions performed within the first Born approximation Coulomb wave. In this model, the initial molecular state is described by using single center wave functions, the incident (scattered) electron being described by a plane wave, while a Coulomb wave function is used for modeling the secondary ejected electron. A fairly good agreement may be observed between theory and experiment with nevertheless an expected systematic overestimation of the theory at low-ejection energies (<50 eV).

Dissolved-solids loads discharged from irrigated areas near Manila, Utah, May 2007-October 2012, and relation of loads to selected variables

USGS Publications Warehouse

Thiros, Susan A.; Gerner, Steven J.

2015-01-01

Irrigation improvements began to be implemented in 2007 to reduce dissolved-solids loads discharged from the MWSP area. The theoretical annual net dissolved-solids load where the cumulative NRCS calculated dissolved-solids load reduction is added to the net MWSP dissolved-solids load is what would be expected if there was no irrigation improvement in the area associated with the MWSP. The theoretical data points lie very near the baseline representing the pre-MWSP dissolved-solids load to canal streamflow relation. The proximity of the theoretical data points to the baseline shows that the NRCS calculations of reduction in dissolved-solids load are generally supported by the data collected during this study.

Theoretical and experimental investigation of optical absorption anisotropy in β-Ga2O3.

PubMed

Ricci, F; Boschi, F; Baraldi, A; Filippetti, A; Higashiwaki, M; Kuramata, A; Fiorentini, V; Fornari, R

2016-06-08

The question of optical bandgap anisotropy in the monoclinic semiconductor β-Ga2O3 was revisited by combining accurate optical absorption measurements with theoretical analysis, performed using different advanced computation methods. As expected, the bandgap edge of bulk β-Ga2O3 was found to be a function of light polarization and crystal orientation, with the lowest onset occurring at polarization in the ac crystal plane around 4.5-4.6 eV; polarization along b unambiguously shifts the onset up by 0.2 eV. The theoretical analysis clearly indicates that the shift in the b onset is due to a suppression of the transition matrix elements of the three top valence bands at Γ point.

Radiofrequency recombination lines as diagnostics of the cool interstellar medium.

NASA Technical Reports Server (NTRS)

Dupree, A. K.

1971-01-01

Quantitative details are given of a new diagnostic technique for the carbon and hydrogen (H I) recombination lines. Theoretical results are presented for conditions expected in H I clouds, and are compared with available observations for Orion A and NGC 2024.

Losses from effluent taxes and quotas under uncertainty

USGS Publications Warehouse

Watson, W.D.; Ridker, R.G.

1984-01-01

Recent theoretical papers by Adar and Griffin (J. Environ. Econ. Manag.3, 178-188 (1976)), Fishelson (J. Environ. Econ. Manag.3, 189-197 (1976)), and Weitzman (Rev. Econ. Studies41, 477-491 (1974)) show that,different expected social losses arise from using effluent taxes and quotas as alternative control instruments when marginal control costs are uncertain. Key assumptions in these analyses are linear marginal cost and benefit functions and an additive error for the marginal cost function (to reflect uncertainty). In this paper, empirically derived nonlinear functions and more realistic multiplicative error terms are used to estimate expected control and damage costs and to identify (empirically) the mix of control instruments that minimizes expected losses. ?? 1984.

Structural and optical properties of (Ag,Cu)(In,Ga)Se{sub 2} polycrystalline thin film alloys

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

Boyle, J. H.; Shafarman, W. N.; Birkmire, R. W.

2014-06-14

The structural and optical properties of pentenary alloy (Ag,Cu)(In,Ga)Se{sub 2} polycrystalline thin films were characterized over the entire compositional range at a fixed (Cu + Ag)/(In + Ga) ratio. Films deposited at 550 °C on bare and molybdenum coated soda-lime glass by elemental co-evaporation in a single-stage process with constant incident fluxes exhibit single phase chalcopyrite structure, corresponding to 122 spacegroup (I-42d) over the entire compositional space. Unit cell refinement of the diffraction patterns show that increasing Ag substitution for Cu, the refined a{sub o} lattice constant, (Ag,Cu)-Se bond length, and anion displacement increase in accordance with the theoretical model proposed by Jaffe, Wei, andmore » Zunger. However, the refined c{sub o} lattice constant and (In,Ga)-Se bond length deviated from theoretical expectations for films with mid-range Ag and Ga compositions and are attributed to influences from crystallographic bond chain ordering or cation electronegativity. The optical band gap, derived from transmission and reflection measurements, widened with increasing Ag and Ga content, due to influences from anion displacement and cation electronegativity, as expected from theoretical considerations for pseudo-binary chalcopyrite compounds.« less

Field-theoretic approach to fluctuation effects in neural networks

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

Buice, Michael A.; Cowan, Jack D.; Mathematics Department, University of Chicago, Chicago, Illinois 60637

A well-defined stochastic theory for neural activity, which permits the calculation of arbitrary statistical moments and equations governing them, is a potentially valuable tool for theoretical neuroscience. We produce such a theory by analyzing the dynamics of neural activity using field theoretic methods for nonequilibrium statistical processes. Assuming that neural network activity is Markovian, we construct the effective spike model, which describes both neural fluctuations and response. This analysis leads to a systematic expansion of corrections to mean field theory, which for the effective spike model is a simple version of the Wilson-Cowan equation. We argue that neural activity governedmore » by this model exhibits a dynamical phase transition which is in the universality class of directed percolation. More general models (which may incorporate refractoriness) can exhibit other universality classes, such as dynamic isotropic percolation. Because of the extremely high connectivity in typical networks, it is expected that higher-order terms in the systematic expansion are small for experimentally accessible measurements, and thus, consistent with measurements in neocortical slice preparations, we expect mean field exponents for the transition. We provide a quantitative criterion for the relative magnitude of each term in the systematic expansion, analogous to the Ginsburg criterion. Experimental identification of dynamic universality classes in vivo is an outstanding and important question for neuroscience.« less

Website Quality, Expectation, Confirmation, and End User Satisfaction: The Knowledge-Intensive Website of the Korean National Cancer Information Center

PubMed Central

Koo, Chulmo; Wati, Yulia; Park, Keeho

2011-01-01

Background The fact that patient satisfaction with primary care clinical practices and physician-patient communications has decreased gradually has brought a new opportunity to the online channel as a supplementary service to provide additional information. Objective In this study, our objectives were to examine the process of cognitive knowledge expectation-confirmation from eHealth users and to recommend the attributes of a “knowledge-intensive website.”. Knowledge expectation can be defined as users’ existing attitudes or beliefs regarding expected levels of knowledge they may gain by accessing the website. Knowledge confirmation is the extent to which user’s knowledge expectation of information systems use is realized during actual use. In our hypothesized research model, perceived information quality, presentation and attractiveness as well as knowledge expectation influence knowledge confirmation, which in turn influences perceived usefulness and end user satisfaction, which feeds back to knowledge expectation. Methods An empirical study was conducted at the National Cancer Center (NCC), Republic of Korea (South Korea), by evaluating its official website. A user survey was administered containing items to measure subjectively perceived website quality and expectation-confirmation attributes. A study sample of 198 usable responses was used for further analysis. We used the structural equation model to test the proposed research model. Results Knowledge expectation exhibited a positive effect on knowledge confirmation (beta = .27, P < .001). The paths from information quality, information presentation, and website attractiveness to knowledge confirmation were also positive and significant (beta = .24, P < .001; beta = .29, P < .001; beta = .18, P < .001, respectively). Moreover, the effect of knowledge confirmation on perceived usefulness was also positively significant (beta = .64, P < .001). Knowledge expectation together with knowledge confirmation and perceived usefulness also significantly affected end user satisfaction (beta = .22 P < .001; beta = .39, P < .001; beta = .25, P < .001, respectively). Conclusions Theoretically, this study has (1) identified knowledge-intensive website attributes, (2) enhanced the theoretical foundation of eHealth from the information systems (IS) perspective by adopting the expectation-confirmation theory (ECT), and (3) examined the importance of information and knowledge attributes and explained their impact on user satisfaction. Practically, our empirical results suggest that perceived website quality (ie, information quality, information presentation, and website attractiveness) is a core requirement for knowledge building. In addition, our study has also shown that knowledge confirmation has a greater effect on satisfaction than both knowledge expectation and perceived usefulness. PMID:22047810

The likelihood ratio as a random variable for linked markers in kinship analysis.

PubMed

Egeland, Thore; Slooten, Klaas

2016-11-01

The likelihood ratio is the fundamental quantity that summarizes the evidence in forensic cases. Therefore, it is important to understand the theoretical properties of this statistic. This paper is the last in a series of three, and the first to study linked markers. We show that for all non-inbred pairwise kinship comparisons, the expected likelihood ratio in favor of a type of relatedness depends on the allele frequencies only via the number of alleles, also for linked markers, and also if the true relationship is another one than is tested for by the likelihood ratio. Exact expressions for the expectation and variance are derived for all these cases. Furthermore, we show that the expected likelihood ratio is a non-increasing function if the recombination rate increases between 0 and 0.5 when the actual relationship is the one investigated by the LR. Besides being of theoretical interest, exact expressions such as obtained here can be used for software validation as they allow to verify the correctness up to arbitrary precision. The paper also presents results and advice of practical importance. For example, we argue that the logarithm of the likelihood ratio behaves in a fundamentally different way than the likelihood ratio itself in terms of expectation and variance, in agreement with its interpretation as weight of evidence. Equipped with the results presented and freely available software, one may check calculations and software and also do power calculations.

Quantitative analysis of H-species in anisotropic minerals by polarized infrared spectroscopy along three orthogonal directions

NASA Astrophysics Data System (ADS)

Shuai, Kang; Yang, Xiaozhi

2017-03-01

Infrared spectroscopy is a powerful technique for probing H-species in nominally anhydrous minerals, and a particular goal of considerable efforts has been providing a simple yet accurate method for the quantification. The available methods, with either polarized or unpolarized analyses, are usually time-consuming or, in some cases, subjected to larger uncertainty than theoretically expected. It is shown here that an empirical approach for measuring the concentration, by determining three polarized infrared spectra along any three mutually perpendicular directions, is theoretically and in particular experimentally correct. The theoretical background is established by considering the integrated absorbance, and the experimental measurements are based on a careful evaluation of the species and content of H in a series of gem-quality orthogonal, monoclinic and triclinic crystals, including olivine, orthopyroxene, clinopyroxene, orthoclase and albite (natural and H-annealed). The results demonstrate that the sum of the integrated absorbance from two polarized spectra along two perpendicular directions in any given plane is a constant, and that the sum of the integrated absorbance from three polarized spectra along any three orthogonal directions is of essentially the same accuracy as that along the principal axes. It is also shown that this method works well, with a relative accuracy within 10%, even at some extreme cases where the sample absorption bands are both intense and strongly anisotropic.

Development and evaluation of social cognitive measures related to adolescent physical activity.

PubMed

Dewar, Deborah L; Lubans, David Revalds; Morgan, Philip James; Plotnikoff, Ronald C

2013-05-01

This study aimed to develop and evaluate the construct validity and reliability of modernized social cognitive measures relating to physical activity behaviors in adolescents. An instrument was developed based on constructs from Bandura's Social Cognitive Theory and included the following scales: self-efficacy, situation (perceived physical environment), social support, behavioral strategies, and outcome expectations and expectancies. The questionnaire was administered in a sample of 171 adolescents (age = 13.6 ± 1.2 years, females = 61%). Confirmatory factor analysis was employed to examine model-fit for each scale using multiple indices, including chi-square index, comparative-fit index (CFI), goodness-of-fit index (GFI), and the root mean square error of approximation (RMSEA). Reliability properties were also examined (ICC and Cronbach's alpha). Each scale represented a statistically sound measure: fit indices indicated each model to be an adequate-to-exact fit to the data; internal consistency was acceptable to good (α = 0.63-0.79); rank order repeatability was strong (ICC = 0.82-0.91). Results support the validity and reliability of social cognitive scales relating to physical activity among adolescents. As such, the developed scales have utility for the identification of potential social cognitive correlates of youth physical activity, mediators of physical activity behavior changes and the testing of theoretical models based on Social Cognitive Theory.

Influence of Multiple Infection and Relatedness on Virulence: Disease Dynamics in an Experimental Plant Population and Its Castrating Parasite

PubMed Central

Buono, Lorenza; López-Villavicencio, Manuela; Shykoff, Jacqui A.; Snirc, Alodie; Giraud, Tatiana

2014-01-01

The level of parasite virulence, i.e., the decrease in host's fitness due to a pathogen, is expected to depend on several parameters, such as the type of the disease (e.g., castrating or host-killing) and the prevalence of multiple infections. Although these parameters have been extensively studied theoretically, few empirical data are available to validate theoretical predictions. Using the anther smut castrating disease on Silene latifolia caused by Microbotryum lychnidis-dioicae, we studied the dynamics of multiple infections and of different components of virulence (host death, non-recovery and percentage of castrated stems) during the entire lifespan of the host in an experimental population. We monitored the number of fungal genotypes within plants and their relatedness across five years, using microsatellite markers, as well as the rates of recovery and host death in the population. The mean relatedness among genotypes within plants remained at a high level throughout the entire host lifespan despite the dynamics of the disease, with recurrent new infections. Recovery was lower for plants with multiple infections compared to plants infected by a single genotype. As expected for castrating parasites, M. lychnidis-dioicae did not increase host mortality. Mortality varied across years but was generally lower for plants that had been diseased the preceding year. This is one of the few studies to have empirically verified theoretical expectations for castrating parasites, and to show particularly i) that castrated hosts live longer, suggesting that parasites can redirect resources normally used in reproduction to increase host lifespan, lengthening their transmission phase, and ii) that multiple infections increase virulence, here in terms of non-recovery and host castration. PMID:24892951

Reconceptualizing Agency within the Life Course: The Power of Looking Ahead1

PubMed Central

Hitlin, Steven; Johnson, Monica Kirkpatrick

2015-01-01

Empirical treatments of agency have not caught up with theoretical explication; empirical projects almost always focus on concurrent beliefs about one’s ability to act successfully without sufficiently attending to temporality. We suggest that understanding the modern life course necessitates a multidimensional understanding of subjective agency involving a) perceived capacities and b) perceived life-chances, or expectations about what life holds in store. We also suggest that a proper understanding of agency’s potential power within a life course necessitates moving beyond the domain-specific expectations more typical of past sociological work. Utilizing the Youth Development Study (YDS), we employ a scale of general life expectations in adolescence to explore the potential influence of a general sense of optimistic life-expectations in addition to the traditional agency-as-efficacy approach on a range of important outcomes. PMID:26166833

Dopamine Receptor-Specific Contributions to the Computation of Value.

PubMed

Burke, Christopher J; Soutschek, Alexander; Weber, Susanna; Raja Beharelle, Anjali; Fehr, Ernst; Haker, Helene; Tobler, Philippe N

2018-05-01

Dopamine is thought to play a crucial role in value-based decision making. However, the specific contributions of different dopamine receptor subtypes to the computation of subjective value remain unknown. Here we demonstrate how the balance between D1 and D2 dopamine receptor subtypes shapes subjective value computation during risky decision making. We administered the D2 receptor antagonist amisulpride or placebo before participants made choices between risky options. Compared with placebo, D2 receptor blockade resulted in more frequent choice of higher risk and higher expected value options. Using a novel model fitting procedure, we concurrently estimated the three parameters that define individual risk attitude according to an influential theoretical account of risky decision making (prospect theory). This analysis revealed that the observed reduction in risk aversion under amisulpride was driven by increased sensitivity to reward magnitude and decreased distortion of outcome probability, resulting in more linear value coding. Our data suggest that different components that govern individual risk attitude are under dopaminergic control, such that D2 receptor blockade facilitates risk taking and expected value processing.

Investigation on the performance of a viscoelastic dielectric elastomer membrane generator.

PubMed

Zhou, Jianyou; Jiang, Liying; Khayat, Roger E

2015-04-21

Dielectric elastomer generators (DEGs), as a recent transduction technology, harvest electrical energy by scavenging mechanical energy from diverse sources. Their performance is affected by various material properties and failure modes of the dielectric elastomers. This work presents a theoretical analysis on the performance of a dielectric elastomer membrane generator under equi-biaxial loading conditions. By comparing our simulation results with the experimental observations existing in the literature, this work considers the fatigue life of DE-based devices under cyclic loading for the first time. From the simulation results, it is concluded that the efficiency of the DEG can be improved by raising the deforming rate and the prescribed maximum stretch ratio, and applying an appropriate bias voltage. However, the fatigue life expectancy compromises the efficiency improvement of the DEG. With the consideration of the fatigue life, applying an appropriate bias voltage appears to be a more desirable way to improve the DEG performance. The general framework developed in this work is expected to provide an increased understanding on the energy harvesting mechanisms of the DEGs and benefit their optimal design.

Cognitive Rehabilitation for Schizophrenia and the Putative Role of Motivation and Expectancies

PubMed Central

Velligan, Dawn I.; Kern, Robert S.; Gold, James M.

2006-01-01

Cognitive rehabilitation (CR) approaches seek to enhance cognitive processes or to circumvent cognitive impairments in schizophrenia in an effort to improve functional outcome. In this review we examine the research findings on the 8 evidence-based approaches to cognitive remediation listed in the 2005 Training Grid Outlining Best Practices for Recovery and Improved Outcomes for People With Serious Mental Illness, developed by the American Psychological Association Committee for the Advancement of Professional Practice. Though the approaches vary widely in theoretical orientation and methods of intervention, the results are, for the most part, encouraging. Improvements in attention, memory, and executive functioning have been reported. However, many persons with schizophrenia are more impaired in real-world functioning than one would expect given the magnitude of their cognitive deficits. We may need to look beyond cognition to other targets such as motivation to identify the reasons that many persons with schizophrenia demonstrate such marked levels of disability. Although a number of current CR approaches address motivation to varying degrees, treating motivation as a primary target may be needed to maximize CR outcomes. PMID:16641424

Data Analysis & Statistical Methods for Command File Errors

NASA Technical Reports Server (NTRS)

Meshkat, Leila; Waggoner, Bruce; Bryant, Larry

2014-01-01

This paper explains current work on modeling for managing the risk of command file errors. It is focused on analyzing actual data from a JPL spaceflight mission to build models for evaluating and predicting error rates as a function of several key variables. We constructed a rich dataset by considering the number of errors, the number of files radiated, including the number commands and blocks in each file, as well as subjective estimates of workload and operational novelty. We have assessed these data using different curve fitting and distribution fitting techniques, such as multiple regression analysis, and maximum likelihood estimation to see how much of the variability in the error rates can be explained with these. We have also used goodness of fit testing strategies and principal component analysis to further assess our data. Finally, we constructed a model of expected error rates based on the what these statistics bore out as critical drivers to the error rate. This model allows project management to evaluate the error rate against a theoretically expected rate as well as anticipate future error rates.

Integration of lateral porous silicon membranes into planar microfluidics.

PubMed

Leïchlé, Thierry; Bourrier, David

2015-02-07

In this work, we present a novel fabrication process that enables the monolithic integration of lateral porous silicon membranes into single-layer planar microchannels. This fabrication technique relies on the patterning of local electrodes to guide pore formation horizontally within the membrane and on the use of silicon-on-insulator substrates to spatially localize porous silicon within the channel depth. The feasibility of our approach is studied by current flow analysis using the finite element method and supported by creating 10 μm long mesoporous membranes within 20 μm deep microchannels. The fabricated membranes are demonstrated to be potentially useful for dead-end microfiltration by adequately retaining 300 nm diameter beads while macromolecules such as single-stranded DNA and immunoglobulin G permeate the membrane. The experimentally determined fluidic resistance is in accordance with the theoretical value expected from the estimated pore size and porosity. The work presented here is expected to greatly simplify the integration of membranes capable of size exclusion based separation into fluidic devices and opens doors to the use of porous silicon in planar lab on a chip devices.

Distributed Time-Varying Formation Robust Tracking for General Linear Multiagent Systems With Parameter Uncertainties and External Disturbances.

PubMed

Hua, Yongzhao; Dong, Xiwang; Li, Qingdong; Ren, Zhang

2017-05-18

This paper investigates the time-varying formation robust tracking problems for high-order linear multiagent systems with a leader of unknown control input in the presence of heterogeneous parameter uncertainties and external disturbances. The followers need to accomplish an expected time-varying formation in the state space and track the state trajectory produced by the leader simultaneously. First, a time-varying formation robust tracking protocol with a totally distributed form is proposed utilizing the neighborhood state information. With the adaptive updating mechanism, neither any global knowledge about the communication topology nor the upper bounds of the parameter uncertainties, external disturbances and leader's unknown input are required in the proposed protocol. Then, in order to determine the control parameters, an algorithm with four steps is presented, where feasible conditions for the followers to accomplish the expected time-varying formation tracking are provided. Furthermore, based on the Lyapunov-like analysis theory, it is proved that the formation tracking error can converge to zero asymptotically. Finally, the effectiveness of the theoretical results is verified by simulation examples.

The early bird gets the worm: foraging strategies of wild songbirds lead to the early discovery of food sources

PubMed Central

Farine, Damien R.; Lang, Stephen D. J.

2013-01-01

Animals need to manage the combined risks of predation and starvation in order to survive. Theoretical and empirical studies have shown that individuals can reduce predation risk by delaying feeding (and hence fat storage) until late afternoon. However, little is known about how individuals manage the opposing pressures of resource uncertainty and predation risks. We suggest that individuals should follow a two-part strategy: prioritizing the discovery of food early in the day and exploiting the best patch late in the day. Using automated data loggers, we tested whether a temporal component exists in the discovery of novel foraging locations by individuals in a mixed-species foraging guild. We found that food deployed in the morning was discovered significantly more often than food deployed in the afternoon. Based on the diurnal activity patterns in this population, overall rates of new arrivals were also significantly higher than expected in the morning and significantly lower than expected in the afternoon. These results align with our predictions of a shift from patch discovery to exploitation over the course of the day. PMID:24108676

Explicit Content Caching at Mobile Edge Networks with Cross-Layer Sensing

PubMed Central

Chen, Lingyu; Su, Youxing; Luo, Wenbin; Hong, Xuemin; Shi, Jianghong

2018-01-01

The deployment density and computational power of small base stations (BSs) are expected to increase significantly in the next generation mobile communication networks. These BSs form the mobile edge network, which is a pervasive and distributed infrastructure that can empower a variety of edge/fog computing applications. This paper proposes a novel edge-computing application called explicit caching, which stores selective contents at BSs and exposes such contents to local users for interactive browsing and download. We formulate the explicit caching problem as a joint content recommendation, caching, and delivery problem, which aims to maximize the expected user quality-of-experience (QoE) with varying degrees of cross-layer sensing capability. Optimal and effective heuristic algorithms are presented to solve the problem. The theoretical performance bounds of the explicit caching system are derived in simplified scenarios. The impacts of cache storage space, BS backhaul capacity, cross-layer information, and user mobility on the system performance are simulated and discussed in realistic scenarios. Results suggest that, compared with conventional implicit caching schemes, explicit caching can better exploit the mobile edge network infrastructure for personalized content dissemination. PMID:29565313

Explicit Content Caching at Mobile Edge Networks with Cross-Layer Sensing.

PubMed

Chen, Lingyu; Su, Youxing; Luo, Wenbin; Hong, Xuemin; Shi, Jianghong

2018-03-22

The deployment density and computational power of small base stations (BSs) are expected to increase significantly in the next generation mobile communication networks. These BSs form the mobile edge network, which is a pervasive and distributed infrastructure that can empower a variety of edge/fog computing applications. This paper proposes a novel edge-computing application called explicit caching, which stores selective contents at BSs and exposes such contents to local users for interactive browsing and download. We formulate the explicit caching problem as a joint content recommendation, caching, and delivery problem, which aims to maximize the expected user quality-of-experience (QoE) with varying degrees of cross-layer sensing capability. Optimal and effective heuristic algorithms are presented to solve the problem. The theoretical performance bounds of the explicit caching system are derived in simplified scenarios. The impacts of cache storage space, BS backhaul capacity, cross-layer information, and user mobility on the system performance are simulated and discussed in realistic scenarios. Results suggest that, compared with conventional implicit caching schemes, explicit caching can better exploit the mobile edge network infrastructure for personalized content dissemination.

Compressive sensing imaging through a drywall barrier at sub-THz and THz frequencies in transmission and reflection modes

NASA Astrophysics Data System (ADS)

Takan, Taylan; Özkan, Vedat A.; Idikut, Fırat; Yildirim, Ihsan Ozan; Şahin, Asaf B.; Altan, Hakan

2014-10-01

In this work sub-terahertz imaging using Compressive Sensing (CS) techniques for targets placed behind a visibly opaque barrier is demonstrated both experimentally and theoretically. Using a multiplied Schottky diode based millimeter wave source working at 118 GHz, metal cutout targets were illuminated in both reflection and transmission configurations with and without barriers which were made out of drywall. In both modes the image is spatially discretized using laser machined, 10 × 10 pixel metal apertures to demonstrate the technique of compressive sensing. The images were collected by modulating the source and measuring the transmitted flux through the apertures using a Golay cell. Experimental results were compared to simulations of the expected transmission through the metal apertures. Image quality decreases as expected when going from the non-obscured transmission case to the obscured transmission case and finally to the obscured reflection case. However, in all instances the image appears below the Nyquist rate which demonstrates that this technique is a viable option for Through the Wall Reflection Imaging (TWRI) applications.

Cognitive rehabilitation for schizophrenia and the putative role of motivation and expectancies.

PubMed

Velligan, Dawn I; Kern, Robert S; Gold, James M

2006-07-01

Cognitive rehabilitation (CR) approaches seek to enhance cognitive processes or to circumvent cognitive impairments in schizophrenia in an effort to improve functional outcome. In this review we examine the research findings on the 8 evidence-based approaches to cognitive remediation listed in the 2005 Training Grid Outlining Best Practices for Recovery and Improved Outcomes for People With Serious Mental Illness, developed by the American Psychological Association Committee for the Advancement of Professional Practice. Though the approaches vary widely in theoretical orientation and methods of intervention, the results are, for the most part, encouraging. Improvements in attention, memory, and executive functioning have been reported. However, many persons with schizophrenia are more impaired in real-world functioning than one would expect given the magnitude of their cognitive deficits. We may need to look beyond cognition to other targets such as motivation to identify the reasons that many persons with schizophrenia demonstrate such marked levels of disability. Although a number of current CR approaches address motivation to varying degrees, treating motivation as a primary target may be needed to maximize CR outcomes.

Global positive expectancies in adolescence and health-related behaviours: Longitudinal models of latent growth and cross-lagged effects

PubMed Central

Carvajal, Scott C.

2015-01-01

Constructs representative of global positive expectancies (GPE) such as dispositional optimism and hope have been theoretically and empirically linked to many positive mental and physical health outcomes. However such expectancies’ health implications for adolescents, as well as their trajectory over time, are less well understood than for adult populations. This study tested whether GPE predict the key indicators of adolescents’ future physical health status, their health-related behaviours. A prospective longitudinal study design was employed whereby a diverse population-based cohort (N = 744; mean age at baseline = 12) completed three surveys over approximately 18 months. Rigorous tests of causal predominance and reciprocal effects were conducted through latent growth and cross-panel structural equation models. Results showed GPE systematically decreased during the course of the study, yet higher initial levels of GPE predicted less alcohol drinking, healthier food choice and greater physical activity over time. GPE’s protective relationships towards health protective behaviours (vs. health risk behaviours that also included tobacco smoking) appear more independent from depressive symptomatology, and the primary findings were robust across socio-demographic groups. PMID:22149606

Difference or disorder? Cultural issues in understanding neurodevelopmental disorders.

PubMed

Norbury, Courtenay Frazier; Sparks, Alison

2013-01-01

Developmental disorders, such as autism spectrum disorder and specific language impairment, are biologically based disorders that currently rely on behaviorally defined criteria for diagnosis and treatment. Specific behaviors that are included in diagnostic frameworks and the point at which individual differences in behavior constitute abnormality are largely arbitrary decisions. Such decisions are therefore likely to be strongly influenced by cultural values and expectations. This is evident in the dramatically different prevalence rates of autism spectrum disorder across countries and across different ethnic groups within the same country. In this article, we critically evaluate the understanding of developmental disorders from a cultural perspective. We specifically consider the challenges of applying diagnostic methods across cultural contexts, the influence of cultural values and expectations on the identification and treatment of children with suspected disorders, and how cross-cultural studies can help to refine cognitive theories of disorder that have been derived exclusively from Western North American and European investigations. Our review synthesizes clinical, cultural, and theoretical work in this area, highlighting potential universals of disorder and concluding with recommendations for future research and practice.

Stochastic ecological network occupancy (SENO) models: a new tool for modeling ecological networks across spatial scales

USGS Publications Warehouse

Lafferty, Kevin D.; Dunne, Jennifer A.

2010-01-01

Stochastic ecological network occupancy (SENO) models predict the probability that species will occur in a sample of an ecological network. In this review, we introduce SENO models as a means to fill a gap in the theoretical toolkit of ecologists. As input, SENO models use a topological interaction network and rates of colonization and extinction (including consumer effects) for each species. A SENO model then simulates the ecological network over time, resulting in a series of sub-networks that can be used to identify commonly encountered community modules. The proportion of time a species is present in a patch gives its expected probability of occurrence, whose sum across species gives expected species richness. To illustrate their utility, we provide simple examples of how SENO models can be used to investigate how topological complexity, species interactions, species traits, and spatial scale affect communities in space and time. They can categorize species as biodiversity facilitators, contributors, or inhibitors, making this approach promising for ecosystem-based management of invasive, threatened, or exploited species.

Gender and Orientations toward the Future: Links to Motivation

ERIC Educational Resources Information Center

Greene, Barbara A.; DeBacker, Teresa K.

2004-01-01

Literature on future orientation and motivation was examined for gender differences. Research revealed gender differences from five theoretical orientations: achievement motivation, future time orientation, possible selves, expectancy-value, and social-cognitive. Some of those differences seemed best explained in terms of generational differences…

How beauty works. Theoretical mechanisms and two empirical applications on students' evaluation of teaching.

PubMed

Wolbring, Tobias; Riordan, Patrick

2016-05-01

Plenty of studies show that the physical appearance of a person affects a variety of outcomes in everyday life. However, due to an incomplete theoretical explication and empirical problems in disentangling different beauty effects, it is unclear which mechanisms are at work. To clarify how beauty works we present explanations from evolutionary theory and expectation states theory and show where both perspectives differ and where interlinkage appears promising. Using students' evaluations of teaching we find observational and experimental evidence for the different causal pathways of physical attractiveness. First, independent raters strongly agree over the physical attractiveness of a person. Second, attractive instructors receive better student ratings. Third, students attend classes of attractive instructors more frequently - even after controlling for teaching quality. Fourth, we find no evidence that attractiveness effects become stronger if rater and ratee are of the opposite sex. Finally, the beauty premium turns into a penalty if an attractive instructor falls short of students' expectations. Copyright © 2016 Elsevier Inc. All rights reserved.

Punishment diminishes the benefits of network reciprocity in social dilemma experiments

PubMed Central

Li, Xuelong; Wang, Zhen; Li, Huijia; Shi, Lei; Podobnik, Boris; Havlin, Shlomo; Boccaletti, Stefano

2018-01-01

Network reciprocity has been widely advertised in theoretical studies as one of the basic cooperation-promoting mechanisms, but experimental evidence favoring this type of reciprocity was published only recently. When organized in an unchanging network of social contacts, human subjects cooperate provided the following strict condition is satisfied: The benefit of cooperation must outweigh the total cost of cooperating with all neighbors. In an attempt to relax this condition, we perform social dilemma experiments wherein network reciprocity is aided with another theoretically hypothesized cooperation-promoting mechanism—costly punishment. The results reveal how networks promote and stabilize cooperation. This stabilizing effect is stronger in a smaller-size neighborhood, as expected from theory and experiments. Contrary to expectations, punishment diminishes the benefits of network reciprocity by lowering assortment, payoff per round, and award for cooperative behavior. This diminishing effect is stronger in a larger-size neighborhood. An immediate implication is that the psychological effects of enduring punishment override the rational response anticipated in quantitative models of cooperation in networks. PMID:29259113

Thickness of the Magnetic Crust of Mars from Magneto-Spectral Analysis

NASA Technical Reports Server (NTRS)

Voorhies, Coerte V.

2006-01-01

Previous analysis of the magnetic spectrum of Mars showed only a crustal source field. The observational spectrum was fairly well fitted by the spectrum expected from random dipolar sources scattered on a spherical shell about 46 plus or minus 10 km below Mars' 3389.5 km mean radius. This de-correlation depth overestimates the typical depth of extended magnetized structures, and so was judged closer to mean source layer thickness than twice its value. To better estimate the thickness of the magnetic crust of Mars, six different magnetic spectra were fitted with the theoretical spectrum expected from a novel, bimodal distribution of magnetic sources. This theoretical spectrum represents both compact and extended, laterally correlated sources, so source shell depth is doubled to obtain layer thickness. The typical magnetic crustal thickness is put at 47.8 plus or minus 8.2 km. The extended sources are enormous, typically 650 km across, and account for over half the magnetic energy at low degrees. How did such vast regions form?

Modeling habitat split: landscape and life history traits determine amphibian extinction thresholds.

PubMed

Fonseca, Carlos Roberto; Coutinho, Renato M; Azevedo, Franciane; Berbert, Juliana M; Corso, Gilberto; Kraenkel, Roberto A

2013-01-01

Habitat split is a major force behind the worldwide decline of amphibian populations, causing community change in richness and species composition. In fragmented landscapes, natural remnants, the terrestrial habitat of the adults, are frequently separated from streams, the aquatic habitat of the larvae. An important question is how this landscape configuration affects population levels and if it can drive species to extinction locally. Here, we put forward the first theoretical model on habitat split which is particularly concerned on how split distance - the distance between the two required habitats - affects population size and persistence in isolated fragments. Our diffusive model shows that habitat split alone is able to generate extinction thresholds. Fragments occurring between the aquatic habitat and a given critical split distance are expected to hold viable populations, while fragments located farther away are expected to be unoccupied. Species with higher reproductive success and higher diffusion rate of post-metamorphic youngs are expected to have farther critical split distances. Furthermore, the model indicates that negative effects of habitat split are poorly compensated by positive effects of fragment size. The habitat split model improves our understanding about spatially structured populations and has relevant implications for landscape design for conservation. It puts on a firm theoretical basis the relation between habitat split and the decline of amphibian populations.

Placebo Response is Driven by UCS Revaluation: Evidence, Neurophysiological Consequences and a Quantitative Model

PubMed Central

Puviani, Luca; Rama, Sidita

2016-01-01

Despite growing scientific interest in the placebo effect and increasing understanding of neurobiological mechanisms, theoretical modeling of the placebo response remains poorly developed. The most extensively accepted theories are expectation and conditioning, involving both conscious and unconscious information processing. However, it is not completely understood how these mechanisms can shape the placebo response. We focus here on neural processes which can account for key properties of the response to substance intake. It is shown that placebo response can be conceptualized as a reaction of a distributed neural system within the central nervous system. Such a reaction represents an integrated component of the response to open substance administration (or to substance intake) and is updated through “unconditioned stimulus (UCS) revaluation learning”. The analysis leads to a theorem, which proves the existence of two distinct quantities coded within the brain, these are the expected or prediction outcome and the reactive response. We show that the reactive response is updated automatically by implicit revaluation learning, while the expected outcome can also be modulated through conscious information processing. Conceptualizing the response to substance intake in terms of UCS revaluation learning leads to the theoretical formulation of a potential neuropharmacological treatment for increasing unlimitedly the effectiveness of a given drug. PMID:27436417

Placebo Response is Driven by UCS Revaluation: Evidence, Neurophysiological Consequences and a Quantitative Model.

PubMed

Puviani, Luca; Rama, Sidita

2016-07-20

Despite growing scientific interest in the placebo effect and increasing understanding of neurobiological mechanisms, theoretical modeling of the placebo response remains poorly developed. The most extensively accepted theories are expectation and conditioning, involving both conscious and unconscious information processing. However, it is not completely understood how these mechanisms can shape the placebo response. We focus here on neural processes which can account for key properties of the response to substance intake. It is shown that placebo response can be conceptualized as a reaction of a distributed neural system within the central nervous system. Such a reaction represents an integrated component of the response to open substance administration (or to substance intake) and is updated through "unconditioned stimulus (UCS) revaluation learning". The analysis leads to a theorem, which proves the existence of two distinct quantities coded within the brain, these are the expected or prediction outcome and the reactive response. We show that the reactive response is updated automatically by implicit revaluation learning, while the expected outcome can also be modulated through conscious information processing. Conceptualizing the response to substance intake in terms of UCS revaluation learning leads to the theoretical formulation of a potential neuropharmacological treatment for increasing unlimitedly the effectiveness of a given drug.

Can Optimism, Pessimism, Hope, Treatment Credibility and Treatment Expectancy Be Distinguished in Patients Undergoing Total Hip and Total Knee Arthroplasty?

PubMed Central

Haanstra, Tsjitske M.; Tilbury, Claire; Kamper, Steven J.; Tordoir, Rutger L.; Vliet Vlieland, Thea P. M.; Nelissen, Rob G. H. H.; Cuijpers, Pim; de Vet, Henrica C. W.; Dekker, Joost; Knol, Dirk L.; Ostelo, Raymond W.

2015-01-01

Objectives The constructs optimism, pessimism, hope, treatment credibility and treatment expectancy are associated with outcomes of medical treatment. While these constructs are grounded in different theoretical models, they nonetheless show some conceptual overlap. The purpose of this study was to examine whether currently available measurement instruments for these constructs capture the conceptual differences between these constructs within a treatment setting. Methods Patients undergoing Total Hip and Total Knee Arthroplasty (THA and TKA) (Total N = 361; 182 THA; 179 TKA), completed the Life Orientation Test-Revised for optimism and pessimism, the Hope Scale, the Credibility Expectancy Questionnaire for treatment credibility and treatment expectancy. Confirmatory factor analysis was used to examine whether the instruments measure distinct constructs. Four theory-driven models with one, two, four and five latent factors were evaluated using multiple fit indices and Δχ2 tests, followed by some posthoc models. Results The results of the theory driven confirmatory factor analysis showed that a five factor model in which all constructs loaded on separate factors yielded the most optimal and satisfactory fit. Posthoc, a bifactor model in which (besides the 5 separate factors) a general factor is hypothesized accounting for the commonality of the items showed a significantly better fit than the five factor model. All specific factors, except for the hope factor, showed to explain a substantial amount of variance beyond the general factor. Conclusion Based on our primary analyses we conclude that optimism, pessimism, hope, treatment credibility and treatment expectancy are distinguishable in THA and TKA patients. Postdoc, we determined that all constructs, except hope, showed substantial specific variance, while also sharing some general variance. PMID:26214176

Can Optimism, Pessimism, Hope, Treatment Credibility and Treatment Expectancy Be Distinguished in Patients Undergoing Total Hip and Total Knee Arthroplasty?

PubMed

Haanstra, Tsjitske M; Tilbury, Claire; Kamper, Steven J; Tordoir, Rutger L; Vliet Vlieland, Thea P M; Nelissen, Rob G H H; Cuijpers, Pim; de Vet, Henrica C W; Dekker, Joost; Knol, Dirk L; Ostelo, Raymond W

2015-01-01

The constructs optimism, pessimism, hope, treatment credibility and treatment expectancy are associated with outcomes of medical treatment. While these constructs are grounded in different theoretical models, they nonetheless show some conceptual overlap. The purpose of this study was to examine whether currently available measurement instruments for these constructs capture the conceptual differences between these constructs within a treatment setting. Patients undergoing Total Hip and Total Knee Arthroplasty (THA and TKA) (Total N = 361; 182 THA; 179 TKA), completed the Life Orientation Test-Revised for optimism and pessimism, the Hope Scale, the Credibility Expectancy Questionnaire for treatment credibility and treatment expectancy. Confirmatory factor analysis was used to examine whether the instruments measure distinct constructs. Four theory-driven models with one, two, four and five latent factors were evaluated using multiple fit indices and Δχ2 tests, followed by some posthoc models. The results of the theory driven confirmatory factor analysis showed that a five factor model in which all constructs loaded on separate factors yielded the most optimal and satisfactory fit. Posthoc, a bifactor model in which (besides the 5 separate factors) a general factor is hypothesized accounting for the commonality of the items showed a significantly better fit than the five factor model. All specific factors, except for the hope factor, showed to explain a substantial amount of variance beyond the general factor. Based on our primary analyses we conclude that optimism, pessimism, hope, treatment credibility and treatment expectancy are distinguishable in THA and TKA patients. Postdoc, we determined that all constructs, except hope, showed substantial specific variance, while also sharing some general variance.

Top-Down Prioritization of Salient Items May Produce the So-Called Stimulus-Driven Capture

PubMed Central

Benoni, Hanna

2018-01-01

The current study proposes that top-down attentional prioritization of salient items may produce the so-called stimulus-driven capture. To test this proposal, the “expectation-based paradigm” was designed on the basis of a visual search task. In Experiment 1, a task-irrelevant singleton frame was presented at the same location in 70% of the trials. The target was either presented at chance level within the singleton location, or away from it. In line with the singleton capture phenomenon, participants were faster in identifying the target when it appeared in the singleton location compared to non-singleton locations. However, leaving out the singleton frame in 30% of the trials led to a similar effect; participants were faster in identifying the target when it appeared in the expected singleton location compared to expected non-singletons locations (a “quasi-capture” effect). These results suggest that the participants allocated their attention to the expected singleton location, rather than that the singleton itself captured attention. In Experiment 2, the same task-irrelevant color singleton was presented in a random position in 70% of the trials. This color frame was shown as a non-singleton in all of the 30% singleton-absent multicolored trials. A similar facilitation effect was obtained when the target appeared in the expected singleton color frame compared to other frames, in singleton-absent trials as in singleton-present trials. These results further support the idea that instances of singleton capture can be explained by top-down attentional shifts toward singleton items. Theoretical implications of these results are discussed. Mostly, the study calls to consider the possibility that all sources of attentional control may be represented by a continuous variable of top-down control, including the category of “physical salience.” PMID:29599731

Temporal expectancy in the context of a theory of visual attention.

PubMed

Vangkilde, Signe; Petersen, Anders; Bundesen, Claus

2013-10-19

Temporal expectation is expectation with respect to the timing of an event such as the appearance of a certain stimulus. In this paper, temporal expectancy is investigated in the context of the theory of visual attention (TVA), and we begin by summarizing the foundations of this theoretical framework. Next, we present a parametric experiment exploring the effects of temporal expectation on perceptual processing speed in cued single-stimulus letter recognition with unspeeded motor responses. The length of the cue-stimulus foreperiod was exponentially distributed with one of six hazard rates varying between blocks. We hypothesized that this manipulation would result in a distinct temporal expectation in each hazard rate condition. Stimulus exposures were varied such that both the temporal threshold of conscious perception (t0 ms) and the perceptual processing speed (v letters s(-1)) could be estimated using TVA. We found that the temporal threshold t0 was unaffected by temporal expectation, but the perceptual processing speed v was a strikingly linear function of the logarithm of the hazard rate of the stimulus presentation. We argue that the effects on the v values were generated by changes in perceptual biases, suggesting that our perceptual biases are directly related to our temporal expectations.

Excited state properties of naphtho-homologated xxDNA bases and effect of methanol solution, deoxyribose, and base pairing.

PubMed

Zhang, Laibin; Ren, Tingqi; Tian, Jianxiang; Yang, Xiuqin; Zhou, Liuzhu; Li, Xiaoming

2013-04-18

Design and synthesis of fluorescent nucleobase analogues for studying structures and dynamics of nucleic acids have attracted much attention in recent years. In the present work, a comprehensive theoretical study of electronic transitions of naphtho-homologated base analogues, namely, xxC, xxT, xxA, and xxG, was performed. The nature of the low-lying excited states was discussed, and the results were compared with those of x-bases. Geometrical characteristics of the lowest excited singlet ππ* states were explored using the CIS method. The calculated excitation maxima are 423, 397, 383, and 357 nm for xxA, xxG, xxC, and xxT, respectively, and they are greatly red-shifted compared with x-bases and natural bases, allowing them to be selectively excited in the presence of the natural bases. In the gas phase, the fluorescence from them would be expected to occur around 497, 461, 457, and 417 nm, respectively. The effects of methanol solution, deoxyribose, and base paring with their complementary natural bases on the relevant absorption and emission spectra of these modified bases were also examined.

Demonstration of a Novel Method for Measuring Mass-loss Rates for Massive Stars

NASA Astrophysics Data System (ADS)

Kobulnicky, Henry A.; Chick, William T.; Povich, Matthew S.

2018-03-01

The rate at which massive stars eject mass in stellar winds significantly influences their evolutionary path. Cosmic rates of nucleosynthesis, explosive stellar phenomena, and compact object genesis depend on this poorly known facet of stellar evolution. We employ an unexploited observational technique for measuring the mass-loss rates of O and early-B stars. Our approach, which has no adjustable parameters, uses the principle of pressure equilibrium between the stellar wind and the ambient interstellar medium for a high-velocity star generating an infrared bow shock nebula. Results for 20 bow-shock-generating stars show good agreement with two sets of theoretical predictions for O5–O9.5 main-sequence stars, yielding \\dot{M} = 1.3 × 10‑6 to 2 × 10‑9 {M}ȯ {yr}}-1. Although \\dot{M} values derived for this sample are smaller than theoretical expectations by a factor of about two, this discrepancy is greatly reduced compared to canonical mass-loss methods. Bow-shock-derived mass-loss rates are factors of 10 smaller than Hα-based measurements (uncorrected for clumping) for similar stellar types and are nearly an order of magnitude larger than P4+ and some other diagnostics based on UV absorption lines. Ambient interstellar densities of at least several cm‑3 appear to be required for formation of a prominent infrared bow shock nebula. Measurements of \\dot{M} for early-B stars are not yet compelling owing to the small number in our sample and the lack of clear theoretical predictions in the regime of lower stellar luminosities. These results may constitute a partial resolution of the extant “weak-wind problem” for late-O stars. The technique shows promise for determining mass-loss rates in the weak-wind regime.

Application of classical simulations for the computation of vibrational properties of free molecules.

PubMed

Tikhonov, Denis S; Sharapa, Dmitry I; Schwabedissen, Jan; Rybkin, Vladimir V

2016-10-12

In this study, we investigate the ability of classical molecular dynamics (MD) and Monte-Carlo (MC) simulations for modeling the intramolecular vibrational motion. These simulations were used to compute thermally-averaged geometrical structures and infrared vibrational intensities for a benchmark set previously studied by gas electron diffraction (GED): CS 2 , benzene, chloromethylthiocyanate, pyrazinamide and 9,12-I 2 -1,2-closo-C 2 B 10 H 10 . The MD sampling of NVT ensembles was performed using chains of Nose-Hoover thermostats (NH) as well as the generalized Langevin equation thermostat (GLE). The performance of the theoretical models based on the classical MD and MC simulations was compared with the experimental data and also with the alternative computational techniques: a conventional approach based on the Taylor expansion of potential energy surface, path-integral MD and MD with quantum-thermal bath (QTB) based on the generalized Langevin equation (GLE). A straightforward application of the classical simulations resulted, as expected, in poor accuracy of the calculated observables due to the complete neglect of quantum effects. However, the introduction of a posteriori quantum corrections significantly improved the situation. The application of these corrections for MD simulations of the systems with large-amplitude motions was demonstrated for chloromethylthiocyanate. The comparison of the theoretical vibrational spectra has revealed that the GLE thermostat used in this work is not applicable for this purpose. On the other hand, the NH chains yielded reasonably good results.

Experimental and Theoretical Studies of Interstellar Grains. Ph.D. Thesis - Maryland Univ., College Park, 1982

NASA Technical Reports Server (NTRS)

Nuth, J. A., III

1981-01-01

Steady state vibrational populations of SiO and CO in dilute black body radiation fields were calculated as a function of total pressure, kinetic temperature and chemical composition of the gas. Approximate calculations for polyatomic molecules are presented. Vibrational disequilibrium becomes increasingly significant as total pressure and radiation density decrease. Many regions of postulated grain formation are found to be far from thermal equilibrium before the onset of nucleation. Calculations based upon classical nucleation theory or equilibrium thermodynamics are expected to be of dubious value in such regions. Laboratory measurements of the extinction of small iron and magnetite grains were made from 195 nm to 830 nm and found to be consistent with predictions based upon published optical constants. This implies that small iron particles are not responsible for the 220 nm interstellar extinction features. Additional measurements are discussed.

The ODD protocol: A review and first update

USGS Publications Warehouse

Grimm, Volker; Berger, Uta; DeAngelis, Donald L.; Polhill, J. Gary; Giske, Jarl; Railsback, Steve F.

2010-01-01

The 'ODD' (Overview, Design concepts, and Details) protocol was published in 2006 to standardize the published descriptions of individual-based and agent-based models (ABMs). The primary objectives of ODD are to make model descriptions more understandable and complete, thereby making ABMs less subject to criticism for being irreproducible. We have systematically evaluated existing uses of the ODD protocol and identified, as expected, parts of ODD needing improvement and clarification. Accordingly, we revise the definition of ODD to clarify aspects of the original version and thereby facilitate future standardization of ABM descriptions. We discuss frequently raised critiques in ODD but also two emerging, and unanticipated, benefits: ODD improves the rigorous formulation of models and helps make the theoretical foundations of large models more visible. Although the protocol was designed for ABMs, it can help with documenting any large, complex model, alleviating some general objections against such models.

The Emergence of Social Capital in Low-Income Latino Elementary Schools

PubMed Central

Shoji, Megan N.; Haskins, Anna R.; Rangel, David E.; Sorensen, Kia N.

2014-01-01

Scholars suggest that racial/ethnic and class disparities in school-based social capital contribute to educational inequalities. Previous studies demonstrate that social capital (relations of trust, mutual expectations, and shared values) between parents and schools supports children's development. Yet we know little about the emergence of social capital, that is, the processes through which it develops. In this study, we explore mechanisms of social capital emergence in predominantly low-income Latino school communities. We draw data from an experimental study that manipulated social capital through an after-school family engagement program. Based on interviews and focus groups with participating parents, teachers, and program staff in two elementary schools, we identified four types of interactions that act as mechanisms of social capital emergence: (1) responsive communication; (2) reciprocal communication; (3) shared experiences; and (4) institutional linkage. The article connects these mechanisms to theoretically linked sources of social capital and discusses implications for theory and practice. PMID:25246729

Research on Performance of Wire-controlled Hydraulic Steering System Based on Four-wheel Steering

NASA Astrophysics Data System (ADS)

Tao, P.; Jin, X. H.

2018-05-01

In this paper, the steering stability and control strategy of forklift are put forward. Drive based on yawing moment distribution of rotary torque coordination control method, through analyzing the linear two degree of freedom model of forklift truck, forklift yawing angular velocity and mass center side-slip Angle of expectations, as the control target parameters system, using fuzzy controller output driving forklift steering the yawing moment, to drive rotary torque distribution, make the forklift truck to drive horizontal pendulum angular velocity and side-slip Angle tracking reference model very well. In this paper, the lateral stability control system were designed, the joint simulation in MATLAB/Simulink, the simulation results show that under the different partial load, the control system can effectively to control side forklift lateral stability, enhanced the forklift driving safety, for the side forklift steering stability study provides a theoretical basis.

High-quality infrared imaging with graphene photodetectors at room temperature.

PubMed

Guo, Nan; Hu, Weida; Jiang, Tao; Gong, Fan; Luo, Wenjin; Qiu, Weicheng; Wang, Peng; Liu, Lu; Wu, Shiwei; Liao, Lei; Chen, Xiaoshuang; Lu, Wei

2016-09-21

Graphene, a two-dimensional material, is expected to enable broad-spectrum and high-speed photodetection because of its gapless band structure, ultrafast carrier dynamics and high mobility. We demonstrate a multispectral active infrared imaging by using a graphene photodetector based on hybrid response mechanisms at room temperature. The high-quality images with optical resolutions of 418 nm, 657 nm and 877 nm and close-to-theoretical-limit Michelson contrasts of 0.997, 0.994, and 0.996 have been acquired for 565 nm, 1550 nm, and 1815 nm light imaging measurements by using an unbiased graphene photodetector, respectively. Importantly, by carefully analyzing the results of Raman mapping and numerical simulations for the response process, the formation of hybrid photocurrents in graphene detectors is attributed to the synergistic action of photovoltaic and photo-thermoelectric effects. The initial application to infrared imaging will help promote the development of high performance graphene-based infrared multispectral detectors.

Highly selective covalent organic functionalization of epitaxial graphene

NASA Astrophysics Data System (ADS)

Bueno, Rebeca A.; Martínez, José I.; Luccas, Roberto F.; Del Árbol, Nerea Ruiz; Munuera, Carmen; Palacio, Irene; Palomares, Francisco J.; Lauwaet, Koen; Thakur, Sangeeta; Baranowski, Jacek M.; Strupinski, Wlodek; López, María F.; Mompean, Federico; García-Hernández, Mar; Martín-Gago, José A.

2017-05-01

Graphene functionalization with organics is expected to be an important step for the development of graphene-based materials with tailored electronic properties. However, its high chemical inertness makes difficult a controlled and selective covalent functionalization, and most of the works performed up to the date report electrostatic molecular adsorption or unruly functionalization. We show hereafter a mechanism for promoting highly specific covalent bonding of any amino-terminated molecule and a description of the operating processes. We show, by different experimental techniques and theoretical methods, that the excess of charge at carbon dangling-bonds formed on single-atomic vacancies at the graphene surface induces enhanced reactivity towards a selective oxidation of the amino group and subsequent integration of the nitrogen within the graphene network. Remarkably, functionalized surfaces retain the electronic properties of pristine graphene. This study opens the door for development of graphene-based interfaces, as nano-bio-hybrid composites, fabrication of dielectrics, plasmonics or spintronics.

An active acoustic tripwire for simultaneous detection and localization of multiple underwater intruders.

PubMed

Folegot, Thomas; Martinelli, Giovanna; Guerrini, Piero; Stevenson, J Mark

2008-11-01

An algorithm allowing simultaneous detection and localization of multiple submerged targets crossing an acoustic tripwire based on forward scattering is described and then evaluated based upon data collected at sea. This paper quantifies the agreement between the theoretical performance and the results obtained from processing data gathered at sea for crossings at several depths and ranges. Targets crossing the acoustic field produce shadows on each side of the barrier, for specific sensors and for specific acoustic paths. In post-processing, a model is invoked to associate expected paths with the observed shadows. This process allows triangulation of the target's position inside the acoustic field. Precise localization is achieved by taking advantage of the multipath propagation structure of the received signal, together with the diversity of the source and receiver locations. Environmental robustness is demonstrated using simulations and can be explained by the use of an array of sources spatially distributed through the water column.

Synthetic Sediments and Stochastic Groundwater Hydrology

NASA Astrophysics Data System (ADS)

Wilson, J. L.

2002-12-01

For over twenty years the groundwater community has pursued the somewhat elusive goal of describing the effects of aquifer heterogeneity on subsurface flow and chemical transport. While small perturbation stochastic moment methods have significantly advanced theoretical understanding, why is it that stochastic applications use instead simulations of flow and transport through multiple realizations of synthetic geology? Allan Gutjahr was a principle proponent of the Fast Fourier Transform method for the synthetic generation of aquifer properties and recently explored new, more geologically sound, synthetic methods based on multi-scale Markov random fields. Focusing on sedimentary aquifers, how has the state-of-the-art of synthetic generation changed and what new developments can be expected, for example, to deal with issues like conceptual model uncertainty, the differences between measurement and modeling scales, and subgrid scale variability? What will it take to get stochastic methods, whether based on moments, multiple realizations, or some other approach, into widespread application?

Neonatal Feeding Behavior as a Complex Dynamical System.

PubMed

Goldfield, Eugene C; Perez, Jennifer; Engstler, Katherine

2017-04-01

The requirements of evidence-based practice in 2017 are motivating new theoretical foundations and methodological tools for characterizing neonatal feeding behavior. Toward that end, this article offers a complex dynamical systems perspective. A set of critical concepts from this perspective frames challenges faced by speech-language pathologists and allied professionals: when to initiate oral feeds, how to determine the robustness of neonatal breathing during feeding and appropriate levels of respiratory support, what instrumental assessments of swallow function to use with preterm neonates, and whether or not to introduce thickened liquids. In the near future, we can expect vast amounts of new data to guide evidence-based practice. But unless practitioners are able to frame these issues in a systems context larger than the individual child, the availability of "big data" will not be effectively translated to clinical practice. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

How much does participatory flood management contribute to stakeholders' social capacity building? Empirical findings based on a triangulation of three evaluation approaches

NASA Astrophysics Data System (ADS)

Buchecker, M.; Menzel, S.; Home, R.

2013-06-01

Recent literature suggests that dialogic forms of risk communication are more effective to build stakeholders' hazard-related social capacities. In spite of the high theoretical expectations, there is a lack of univocal empirical evidence on the relevance of these effects. This is mainly due to the methodological limitations of the existing evaluation approaches. In our paper we aim at eliciting the contribution of participatory river revitalisation projects on stakeholders' social capacity building by triangulating the findings of three evaluation studies that were based on different approaches: a field-experimental, a qualitative long-term ex-post and a cross-sectional household survey approach. The results revealed that social learning and avoiding the loss of trust were more relevant benefits of participatory flood management than acceptance building. The results suggest that stakeholder involvements should be more explicitly designed as tools for long-term social learning.

Conceptual Research of Lunar-based Earth Observation for Polar Glacier Motion

NASA Astrophysics Data System (ADS)

Ruan, Zhixing; Liu, Guang; Ding, Yixing

2016-07-01

The ice flow velocity of glaciers is important for estimating the polar ice sheet mass balance, and it is of great significance for studies into rising sea level under the background of global warming. However so far the long-term and global measurements of these macro-scale motion processes of the polar glaciers have hardly been achieved by Earth Observation (EO) technique from the ground, aircraft or satellites in space. This paper, facing the demand for space technology for large-scale global environmental change observation,especially the changes of polar glaciers, and proposes a new concept involving setting up sensors on the lunar surface and using the Moon as a platform for Earth observation, transmitting the data back to Earth. Lunar-based Earth observation, which enables the Earth's large-scale, continuous, long-term dynamic motions to be measured, is expected to provide a new solution to the problems mentioned above. According to the pattern and characteristics of polar glaciers motion, we will propose a comprehensive investigation of Lunar-based Earth observation with synthetic aperture radar (SAR). Via theoretical modeling and experimental simulation inversion, intensive studies of Lunar-based Earth observation for the glacier motions in the polar regions will be implemented, including the InSAR basics theory, observation modes of InSAR and optimization methods of their key parameters. It will be of a great help to creatively expand the EO technique system from space. In addition, they will contribute to establishing the theoretical foundation for the realization of the global, long-term and continuous observation for the glacier motion phenomena in the Antarctic and the Arctic.

Experimental study of the constituents of space wash water

NASA Technical Reports Server (NTRS)

Putnam, D. F.; Colombo, G. V.

1975-01-01

This report presents experimental data, obtained under controlled conditions, which quantify the various constituents of human origin that may be expected in space wash water. The experiments were conducted with a simulated crew of two male and two female subjects. The data show that the expected wash water contaminants originating from human secretions are substantially lower than theoretical projections indicated. The data presented are immediately useful and may have considerable impact on the tradeoff comparisons among various unit processes and systems under consideration by NASA for recycling space wash water.

Managing Space Situational Awareness Using the Space Surveillance Network

DTIC Science & Technology

2013-11-14

This  report examines  the  use   of  utility metrics  from  two  forms  of  expected  information  gain for each object‐sensor pair as well as the...examines the use of utility metrics from two forms of expected information gain for each object-sensor pair as well as the approximated stability of the...estimation errors in order to work towards a tasking strategy. The information theoretic approaches use the calculation of Fisher information gain

Thermo-electric transport in gauge/gravity models with momentum dissipation

NASA Astrophysics Data System (ADS)

Amoretti, Andrea; Braggio, Alessandro; Maggiore, Nicola; Magnoli, Nicodemo; Musso, Daniele

2014-09-01

We present a systematic definition and analysis of the thermo-electric linear response in gauge/gravity systems focusing especially on models with massive gravity in the bulk and therefore momentum dissipation in the dual field theory. A precise treatment of finite counter-terms proves to be essential to yield a consistent physical picture whose hydrodynamic and beyond-hydrodynamics behaviors noticeably match with field theoretical expectations. The model furnishes a possible gauge/gravity description of the crossover from the quantum-critical to the disorder-dominated Fermi-liquid behaviors, as expected in graphene.

[Problem-based learning, description of a pedagogical method leading to evidence-based medicine].

PubMed

Chalon, P; Delvenne, C; Pasleau, F

2000-04-01

Problem-Based Learning is an educational method which uses health care scenarios to provide a context for learning and to elaborate knowledge through discussion. Additional expectations are to stimulate critical thinking and problem-solving skills, and to develop clinical reasoning taking into account the patient's psychosocial environment and preferences, the economic requirements as well as the best evidence from biomedical research. Appearing at the end of the 60's, it has been adopted by 10% of medical schools world-wide. PBL follows the same rules as Evidence-Based Medicine but is student-centered and provides the information-seeking skills necessary for self-directed life long learning. In this short article, we review the theoretical basis and process of PBL, emphasizing the teacher-student relationship and discussing the suggested advantages and disadvantages of this curriculum. Students in PBL programs make greater use of self-selected references and online searching. From this point of view, PBL strengthens the role of health libraries in medical education, and prepares the future physician for Evidence-Based Medicine.

The Midplane of the Main Asteroid Belt and Its Warps

NASA Astrophysics Data System (ADS)

Cambioni, Saverio; Malhotra, Renu

2017-10-01

It has been recognized for a long time that the orbital planes of asteroids are surprisingly highly dispersed about the mean plane of the solar system, and likely memorialize dynamical events over the ancient history of the solar system. But how well do we know the mean plane of the asteroid belt? Since the time of the first measurements of their mean plane (Plummer 1916; Shor & Yagudina 1991), the number of known main belt asteroids (MBAs) has dramatically increased; the large size of this population now allows measuring its mean plane at much higher accuracy than in previous studies and also allows to compare it with theoretical expectations. The theoretically expected mean plane is defined by the forced solution of the secular perturbation theory for the inclinations and nodes (e.g., Murray & Dermott 1999); this forced plane varies with semi-major axis. We measure the mean plane by analyzing the observational data and we compare it with the theoretical prediction. Our observationally nearly complete sample consists of 89,216 numbered, non-collisional family asteroids of absolute magnitude below 15.5. For the population as a whole, we find that the mean plane differs significantly from previous measurements: the mean plane’s inclination is I = 0.929 (+0.042, -0.042) degrees and its longitude of ascending node is Ω = 87.60 (+2.58, -2.58) degrees. When measured in small semi-major axis bins between 2.15 and 3.25 AU, the mean plane is found to be largely consistent with secular perturbation theory predictions, deviating not more than (1-2)-σ from the theoretically expected values. A warp near the inner edge, due to the ν16 secular resonance, is visible in the data. Our analysis reveals the way to a novel method for the computation of the free or “proper” inclinations of the MBAs, by computing asteroid inclinations relative to the measured mean plane at that location in semi-major axis.This study used the catalogs of osculating elements for the minor planets and collisional family membership available on the AstDys-2 website (http://hamilton.dm.unipi.it/astdys/). We are grateful for research funding from NSF (grant AST-1312498).

Linker-mediated assembly of gold nanoparticles into multimeric motifs

NASA Astrophysics Data System (ADS)

Sikora, Mateusz; Szymczak, Piotr; Thompson, Damien; Cieplak, Marek

2011-11-01

We present a theoretical description of linker-mediated self-assembly of gold nanoparticles (Au-NP). Using mesoscale simulations with a coarse-grained model for the Au NPs and dirhenium-based linker molecules, we investigate the conditions under which large clusters can grow and construct a phase diagram that identifies favorable growth conditions in terms of floating and bound linker concentrations. The findings can be considered as generic, as we expect other NP-linker systems to behave in a qualitatively similar way. In particular, we also discuss the case of antibody-functionalised Au NPs connected by the C-reactive proteins (CRPs). We extract some general rules for NP linking that may aid the production of size- and shape-specific NP clusters for technology applications.

Probabilistic objective functions for sensor management

NASA Astrophysics Data System (ADS)

Mahler, Ronald P. S.; Zajic, Tim R.

2004-08-01

This paper continues the investigation of a foundational and yet potentially practical basis for control-theoretic sensor management, using a comprehensive, intuitive, system-level Bayesian paradigm based on finite-set statistics (FISST). In this paper we report our most recent progress, focusing on multistep look-ahead -- i.e., allocation of sensor resources throughout an entire future time-window. We determine future sensor states in the time-window using a "probabilistically natural" sensor management objective function, the posterior expected number of targets (PENT). This objective function is constructed using a new "maxi-PIMS" optimization strategy that hedges against unknowable future observation-collections. PENT is used in conjuction with approximate multitarget filters: the probability hypothesis density (PHD) filter or the multi-hypothesis correlator (MHC) filter.

Terahertz-induced photothermoelectric response in graphene-metal contact structures

NASA Astrophysics Data System (ADS)

Deng, Xiangquan; Wang, Yingxin; Zhao, Ziran; Chen, Zhiqiang; Sun, Jia-Lin

2016-10-01

We report on the photoresponse of a graphene-metal contact device under terahertz (THz) illumination. The device has an extremely simple structure consisting of a large-area monolayer graphene stripe contacted with two gold electrodes. A significant position-dependent photovoltage is observed across the device by THz excitation, exhibiting a linear relationship with the incident beam power. Experimental results show that the graphene channel length and the substrate thermal conductivity have obvious influence on the photovoltage amplitude and response time, which is consistent with the photothermoelectric mechanism. This compact and powerless device is expected to have a promising application in THz detection. Our work provides theoretical and experimental evidence for the development of high-performance graphene-based THz photodetectors.

Line shape analysis of the K β transition in muonic hydrogen

NASA Astrophysics Data System (ADS)

Covita, Daniel S.; Anagnostopoulos, Dimitrios F.; Fuhrmann, Hermann; Gorke, Hubert; Gotta, Detlev; Gruber, Alexander; Hirtl, Albert; Ishiwatari, Tomoichi; Indelicato, Paul; Jensen, Thomas S.; Le Bigot, Eric-Olivier; Markushin, Valeri E.; Nekipelov, Michael; Pomerantsev, Vladimir N.; Popov, Vladimir P.; dos Santos, Joaquim M. F.; Schmid, Philipp; Simons, Leopold M.; Theisen, Marian; Trassinelli, Martino; Veloso, Joao F. C. A.; Zmeskal, Johann

2018-04-01

The K β transition in muonic hydrogen was measured with a high-resolution crystal spectrometer. The spectrum is shown to be sensitive to the ground-state hyperfine splitting, the corresponding triplet-to-singlet ratio, and the kinetic energy distribution in the 3 p state. The hyperfine splitting and triplet-to-singlet ratio are found to be consistent with the values expected from theoretical and experimental investigations and, therefore, were fixed accordingly in order to reduce the uncertainties in the further reconstruction of the kinetic energy distribution. The presence of high-energetic components was established and quantified in both a phenomenological, i.e. cascade-model-free fit, and in a direct deconvolution of the Doppler broadening based on the Bayesian method.

Development of a High-Resolution, Single-Photon X-Ray Detector

NASA Technical Reports Server (NTRS)

Seidel, George M.

1996-01-01

Research on the development of a low-temperature, magnetic bolometer for x-ray detection is reported. The principal accomplishments during the first phase of this research are as follows. (1) We have constructed SQUID magnetometers and detected both 122 keV and 6 keV x-rays in relatively larger metallic samples with high quantum efficiency. (2) The magnetic properties of a metal sample with localized paramagnetic spins have been measured and found to agree with theoretical expectations. (3) The size of the magnetic response of the sample to x-rays is in agreement with predictions based on the properties of the sample and sensitivity of the magnetometer, supporting the prediction that a resolution of 1 eV at 10 keV should be achievable.

Coupled wave model for large magnet coils

NASA Technical Reports Server (NTRS)

Gabriel, G. J.

1980-01-01

A wave coupled model based on field theory is evolved for analysis of fast electromagnetic transients on superconducting coils. It is expected to play a useful role in the design of protection methods against damage due to high voltages or any adverse effects that might arise from unintentional transients. The significant parameters of the coil are identified to be the turn to turn wave coupling coefficients and the travel time of an electromagnetic disturbance around a single turn. Unlike circuit theoretic inductor, the coil response evolves in discrete steps having durations equal to this travel time. It is during such intervals that high voltages are likely to occur. The model also bridges the gap between the low and high ends of the frequency spectrum.

Neuroeconomics: cross-currents in research on decision-making.

PubMed

Sanfey, Alan G; Loewenstein, George; McClure, Samuel M; Cohen, Jonathan D

2006-03-01

Despite substantial advances, the question of how we make decisions and judgments continues to pose important challenges for scientific research. Historically, different disciplines have approached this problem using different techniques and assumptions, with few unifying efforts made. However, the field of neuroeconomics has recently emerged as an inter-disciplinary effort to bridge this gap. Research in neuroscience and psychology has begun to investigate neural bases of decision predictability and value, central parameters in the economic theory of expected utility. Economics, in turn, is being increasingly influenced by a multiple-systems approach to decision-making, a perspective strongly rooted in psychology and neuroscience. The integration of these disparate theoretical approaches and methodologies offers exciting potential for the construction of more accurate models of decision-making.

Optimal versus observed vegetation responses to CO2 over the last 40 years

NASA Astrophysics Data System (ADS)

Roderick, M. L.; Yang, Y.; Donohue, R. J.; Farquhar, G. D.; McVicar, T.

2016-12-01

The ongoing increase in atmospheric CO2 presents an interesting opportunity for primary producers. Understanding the impacts on agriculture, natural ecological communities and water resources presents considerable challenges. We investigate this problem using a Budyko-type framework based around two end-members: (i) warm arid environments (e.g. warm deserts) and (ii) warm wet environments (e.g. tropical rainforests). We first make predictions of the effect of a change in atmospheric CO2 on the partitioning of precipitation between evapotranspiration and streamflow. We then use satellite observation of greenness and in-situ streamflow data to assess the predictions. We finish by contrasting the observed responses against those expected from a purely theoretical construct: the so-called optimal vegetation.

Emergent loop-nodal s(±)-wave superconductivity in CeCu(2)Si(2): similarities to the iron-based superconductors.

PubMed

Ikeda, Hiroaki; Suzuki, Michi-To; Arita, Ryotaro

2015-04-10

Heavy-fermion superconductors are prime candidates for novel electron-pairing states due to the spin-orbital coupled degrees of freedom and electron correlations. Superconductivity in CeCu_{2}Si_{2} discovered in 1979, which is a prototype of unconventional (non-BCS) superconductors in strongly correlated electron systems, still remains unsolved. Here we provide the first report of superconductivity based on the advanced first-principles theoretical approach. We find that the promising candidate is an s_{±}-wave state with loop-shaped nodes on the Fermi surface, different from the widely expected line-nodal d-wave state. The dominant pairing glue is magnetic but high-rank octupole fluctuations. This system shares the importance of multiorbital degrees of freedom with the iron-based superconductors. Our findings reveal not only the long-standing puzzle in this material, but also urge us to reconsider the pairing states and mechanisms in all heavy-fermion superconductors.

How Effective Is Example Generation for Learning Declarative Concepts?

ERIC Educational Resources Information Center

Rawson, Katherine A.; Dunlosky, John

2016-01-01

Declarative concepts (i.e., key terms and corresponding definitions for abstract concepts) represent foundational knowledge that students learn in many content domains. Thus, investigating techniques to enhance concept learning is of critical importance. Various theoretical accounts support the expectation that example generation will serve this…

Jealousy and Trust: Unexplored Dimensions of Social Exchange Dynamics.

ERIC Educational Resources Information Center

McDonald, Gerald W.; Osmond, Marie Withers

Little effort has been made to systematically assess the determinants and consequences of marital jealousy which affect marital, familial and extra-familial expectations, interactions and behavior. A preliminary attempt to rectify this omission provides a conceptual/theoretical perspective on jealousy dynamics in marriage. Marital jealousy, a…

The gravitational properties of antimatter

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

Goldman, T.; Hughes, R.J.; Nieto, M.M.

1986-09-01

It is argued that a determination of the gravitational acceleration of antimatter towards the earth is capable of imposing powerful constraints on modern quantum gravity theories. Theoretical reasons to expect non-Newtonian non-Einsteinian effects of gravitational strength and experimental suggestions of such effects are reviewed. 41 refs. (LEW)

Factors Influencing Student Participation in College Study Abroad Programs

ERIC Educational Resources Information Center

Bandyopadhyay, Soumava; Bandyopadhyay, Kakoli

2015-01-01

This paper proposes a theoretical framework to investigate the factors that influence student participation in college study abroad programs. The authors posit that students' general perceptions regarding the study abroad experience and their expectations of intercultural awareness from study abroad programs will impact their perceptions of…

Explaining the harmonic sequence paradox.

PubMed

Schmidt, Ulrich; Zimper, Alexander

2012-05-01

According to the harmonic sequence paradox, an expected utility decision maker's willingness to pay for a gamble whose expected payoffs evolve according to the harmonic series is finite if and only if his marginal utility of additional income becomes zero for rather low payoff levels. Since the assumption of zero marginal utility is implausible for finite payoff levels, expected utility theory - as well as its standard generalizations such as cumulative prospect theory - are apparently unable to explain a finite willingness to pay. This paper presents first an experimental study of the harmonic sequence paradox. Additionally, it demonstrates that the theoretical argument of the harmonic sequence paradox only applies to time-patient decision makers, whereas the paradox is easily avoided if time-impatience is introduced. ©2011 The British Psychological Society.

Why emotions matter: expectancy violation and affective response mediate the emotional victim effect.

PubMed

Ask, Karl; Landström, Sara

2010-10-01

The mechanisms behind the 'emotional victim effect' (i.e., that the emotionality of a rape victim's demeanor affects perceived credibility) are relatively unexplored. In this article, a previously neglected mechanism--observers' affective response to the victim--is proposed as an alternative to the traditional expectancy-violation account. The emotional victim effect was replicated in an experiment with a sample of police trainees (N = 189), and cognitive load was found to increase the magnitude of the effect. Importantly, both compassionate affective response and expectancy violation actively mediated the emotional victim effect when the other mechanism was controlled for. These findings extend previous research on credibility judgments by introducing a 'hot' cognitive component in the judgment process. Theoretical and practical implications are discussed.

The role of expectations, hype and ethics in neuroimaging and neuromodulation futures

PubMed Central

Rusconi, Elena; Mitchener-Nissen, Timothy

2014-01-01

The production of expectations or future-goals for the development of techniques which “read” and modulate brain function, represent an important practical tool for neuroscientists. These visions-of-the-future assist scientists by providing focus for both individual and cross-disciplinary research programs; they encourage the development of new industrial sectors, are used to justify the allocation of government resources and funding, and via the media can help capture the imagination and support of the public. However, such expectations need to be tempered by reality. Over-hyping brain imaging and modulation will lead to disappointment; disappointment that in turn can undermine its potential. Similarly, if neuroscientists focus their attention narrowly on the science without concomitant consideration of its future ethical, legal and social implications, then their expectations may remain unrealized. To develop these arguments herein we introduce the theoretical concept of expectations and the practical consequences of expectations. We contextualize these reflections by referring to brain imaging and modulation studies on deception, which encompass the measurement-suppression-augmentation range. PMID:25400557

Theoretical electric dipole moments of SiH, GeH and SnH

NASA Technical Reports Server (NTRS)

Pettersson, L. G. M.; Langhoff, S. R.

1986-01-01

Accurate theoretical dipole moments have been computed for the X2Pi ground states of Si(-)H(+) (0.118 D), Ge(+)H(-) (0.085 D), and Sn(+)H(-) (0.357 D). The trend down the periodic table is regular and follows that expected from the electronegativities of the group IV atoms. The dipole moment of 1.24 + or - 0.1 D for GeH recently derived by Brown, Evenson and Sears (1985) from the relative intensities of electric and magnetic dipole transitions in the 10-micron spectrum of the X2Pi state is seriously questioned.

Theoretical Electric Dipole Moments of SiH, GeH and SnH

NASA Technical Reports Server (NTRS)

Pettersson, Lars G. M.; Langhoff, Stephen R.

1986-01-01

Accurate theoretical dipole moments (mu(sub c) have been computed for the X(exp 2)Pi ground states of Si(-)H(+)(0.118 D), Ge(+)H(-)(0.085 D) and Sn(+)H(-)(0.357 D). The trend down the periodic table is regular and follows that expected from the electronegativities of the group IV atoms. The dipole moment of 1.24 +/- 0.1 D for GeH recently derived by Brown, Evenson and Sears from the relative intensities of electric and magnetic dipole transitions in the 10 microns spectrum of the X(exp 2)Pi state is seriously questioned.

Theoretical analysis of a new class of optical bistability due to noncoherent coupling within a twin-laser system

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

Kuszelewicz, R.; Oudar, J.L.

1987-04-01

A new class of optical bistable devices, relying on the mutual quenching of two identical lasers, is theoretically analyzed. Conditions for achieving adequate competition between an external injected beam and the intracavity field through a noncoherent coupling (NCC) are discussed. Steady-state and transient behaviours are analyzed and lead to fast electrical or optical switching ( <100 ps ) and low commutation energy ( <10 pH). High efficiency, compactness, and technological compatibility with other integrated devices are expected. In addition, the emissive properties of these devices should considerably simplify their use in cascaded configurations.

Hydrogen bonding interactions in nicotinamide Ionic Liquids: A comparative spectroscopic and DFT studies

NASA Astrophysics Data System (ADS)

Shukla, Madhulata

2017-03-01

Being biodegradable in nature nicotinamide based Ionic Liquids (ILs) are gaining much attention now a day. Nicotinamide iodide (i.e 1-methyl-3ethoxy carbonyl pyridinium iodide (mNicI)) and 1-methyl-3ethoxy carbonyl pyridinium trifilimide (mNicNTf2) new ILs has been synthesized and has been characterized using different spectroscopic techniques like NMR, UV visible and infrared spectroscopy. Theoretical studies have been performed on several nicotinamide ILs. Geometry and spectral features were further characterized by Density Functional Theory (DFT) calculation. NBO charge distribution and electrostatic potential diagram presents in depth knowledge about interactions between cation and anion. A comparative theoretical study between mNicI and its other analogues i. e 1-methyl-3 ethoxy carbonyl pyridinium chloride and bromide i. e mNicCl and mNicBr has also been performed. Csbnd H⋯X hydrogen bonding along with C⋯X interaction has been reported for the first time for the nicotinamide based ILs. C2sbnd H stretching frequency shifts to higher wavenumber with change to a lesser electronegative anion. mNicCl and mNicBr are expected to be solid in nature with the evidence from the red shift in stretching frequency as compared to mNicI. TD-DFT calculation of mNicI proved that pale yellow color of liquid is due to inherent transition from anion to cation.

Development and evaluation of theory-based diabetes support services.

PubMed

Guo, Sophie Huey-Ming; Lin, Yung-Hsiu; Chen, Rong-Rong; Kao, Shu-Fen; Chang, Her-Kun

2013-01-01

Technology-enabled support services for diabetes can fulfill patient demand to care for diabetes independently. Patients benefit from such services after greater adoption of the services in healthcare systems. Unfortunately, conventional service development fails to thoroughly understand patient care support, making it difficult to achieve the desired design, and posing substantial challenges in adopting these services. Thus, previously developed services in many cases are not as patients expected, as evidenced by their low acceptance among patients. To solve this problem, adequate strategies must be developed by incorporating theoretical knowledge as a solid foundation in order to improve service design. This study develops technology-enabled diabetes support services based on the self-care theory. A set of self-care service scenarios is also established and combined with theoretical concepts. The developed services consist of a nurse-led consultation service and a mobile application service. Additionally, user acceptance is confirmed by assessing patient perceptions of the diabetes support services in a group of patients with diabetes (N=27). Results of analysis reveal that patients respond favorably toward the services. Patient preference and perceived ease of use attest to their intention to use the services. Greater adoption of the services can be anticipated, owing to a higher levels of preference and higher perceived ease of use. This study demonstrated that the self-care theory can be linked to nursing informatics research and chronic care clinical practices.

Direct surface magnetometry with photoemission magnetic x-ray dichroism

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

Tobin, J.G.; Goodman, K.W.; Schumann, F.O.

1997-04-01

Element specific surface magnetometry remains a central goal of synchrotron radiation based studies of nanomagnetic structures. One appealing possibility is the combination of x-ray absorption dichroism measurements and the theoretical framework provided by the {open_quotes}sum rules.{close_quotes} Unfortunately, sum rule analysis are hampered by several limitations including delocalization of the final state, multi-electronic phenomena and the presence of surface dipoles. An alternative experiment, Magnetic X-Ray Dichroism in Photoelectron Spectroscopy, holds out promise based upon its elemental specificity, surface sensitivity and high resolution. Computational simulations by Tamura et al. demonstrated the relationship between exchange and spin orbit splittings and experimental data ofmore » linear and circular dichroisms. Now the authors have developed an analytical framework which allows for the direct extraction of core level exchange splittings from circular and linear dichroic photoemission data. By extending a model initially proposed by Venus, it is possible to show a linear relation between normalized dichroism peaks in the experimental data and the underlying exchange splitting. Since it is reasonable to expect that exchange splittings and magnetic moments track together, this measurement thus becomes a powerful new tool for direct surface magnetometry, without recourse to time consuming and difficult spectral simulations. The theoretical derivation will be supported by high resolution linear and circular dichroism data collected at the Spectromicroscopy Facility of the Advanced Light Source.« less

Spectral Optical Readout of Rectangular–Miniature Hollow Glass Tubing for Refractive Index Sensing

PubMed Central

Rigamonti, Giulia; Bello, Valentina

2018-01-01

For answering the growing demand of innovative micro-fluidic devices able to measure the refractive index of samples in extremely low volumes, this paper presents an overview of the performances of a micro-opto-fluidic sensing platform that employs rectangular, miniature hollow glass tubings. The operating principle is described by showing the analytical model of the tubing, obtained as superposition of different optical cavities, and the optical readout method based on spectral reflectivity detection. We have analyzed, in particular, the theoretical and experimental optical features of rectangular tubings with asymmetrical geometry, thus with channel depth larger than the thickness of the glass walls, though all of them in the range of a few tens of micrometers. The origins of the complex line-shape of the spectral response in reflection, due to the different cavities formed by the tubing flat walls and channel, have been investigated using a Fourier transform analysis. The implemented instrumental configuration, based on standard telecom fiberoptic components and a semiconductor broadband optical source emitting in the near infrared wavelength region centered at 1.55 µm, has allowed acquisition of reflectivity spectra for experimental verification of the expected theoretical behavior. We have achieved detection of refractive index variations related to the change of concentration of glucose-water solutions flowing through the tubing by monitoring the spectral shift of the optical resonances. PMID:29462907

Spectral Optical Readout of Rectangular-Miniature Hollow Glass Tubing for Refractive Index Sensing.

PubMed

Rigamonti, Giulia; Bello, Valentina; Merlo, Sabina

2018-02-16

For answering the growing demand of innovative micro-fluidic devices able to measure the refractive index of samples in extremely low volumes, this paper presents an overview of the performances of a micro-opto-fluidic sensing platform that employs rectangular, miniature hollow glass tubings. The operating principle is described by showing the analytical model of the tubing, obtained as superposition of different optical cavities, and the optical readout method based on spectral reflectivity detection. We have analyzed, in particular, the theoretical and experimental optical features of rectangular tubings with asymmetrical geometry, thus with channel depth larger than the thickness of the glass walls, though all of them in the range of a few tens of micrometers. The origins of the complex line-shape of the spectral response in reflection, due to the different cavities formed by the tubing flat walls and channel, have been investigated using a Fourier transform analysis. The implemented instrumental configuration, based on standard telecom fiberoptic components and a semiconductor broadband optical source emitting in the near infrared wavelength region centered at 1.55 µm, has allowed acquisition of reflectivity spectra for experimental verification of the expected theoretical behavior. We have achieved detection of refractive index variations related to the change of concentration of glucose-water solutions flowing through the tubing by monitoring the spectral shift of the optical resonances.

REVIEWS OF TOPICAL PROBLEMS: Gravitational wave astronomy: in anticipation of first sources to be detected

NASA Astrophysics Data System (ADS)

Grishchuk, Leonid P.; Lipunov, V. M.; Postnov, Konstantin A.; Prokhorov, Mikhail E.; Sathyaprakash, B. S.

2001-01-01

The first generation of long-baseline laser interferometric detectors of gravitational waves will start collecting data in 2001 - 2003. We carefully analyse their planned performance and compare it with the expected strengths of astrophysical sources. The scientific importance of the anticipated discovery of various gravitational wave signals and the reliability of theoretical predictions are taken into account in our analysis. We try to be conservative in evaluating both the theoretical uncertainties in the parameters of the source and the prospects of its detection. Upon considering many possible sources, we place our emphasis on (i) inspiraling binaries consisting of stellar mass black holes and (ii) relic gravitational waves. We conclude that inspiraling binary black holes are likely to be detected by the early ground-based interferometers first. We estimate that the first interferometers will see 2 - 3 events per year from black hole binaries with component masses of 10 - 15M\\odot, with a signal-to-noise ratio of about 3, in a network of detectors consisting of GEO, VIRGO and two LIGOs. It appears that other possible sources, including coalescing neutron stars, are unlikely to be detected by the early instruments. We also argue that relic gravitational waves may be discovered by space-based interferometers in the frequency interval 2 × 10-3 - 10-2 Hz, at a signal-to-noise ratio level of about 3.

Approximating local observables on projected entangled pair states

NASA Astrophysics Data System (ADS)

Schwarz, M.; Buerschaper, O.; Eisert, J.

2017-06-01

Tensor network states are for good reasons believed to capture ground states of gapped local Hamiltonians arising in the condensed matter context, states which are in turn expected to satisfy an entanglement area law. However, the computational hardness of contracting projected entangled pair states in two- and higher-dimensional systems is often seen as a significant obstacle when devising higher-dimensional variants of the density-matrix renormalization group method. In this work, we show that for those projected entangled pair states that are expected to provide good approximations of such ground states of local Hamiltonians, one can compute local expectation values in quasipolynomial time. We therefore provide a complexity-theoretic justification of why state-of-the-art numerical tools work so well in practice. We finally turn to the computation of local expectation values on quantum computers, providing a meaningful application for a small-scale quantum computer.

Self-organized Segregation on the Grid

NASA Astrophysics Data System (ADS)

Omidvar, Hamed; Franceschetti, Massimo

2018-02-01

We consider an agent-based model with exponentially distributed waiting times in which two types of agents interact locally over a graph, and based on this interaction and on the value of a common intolerance threshold τ , decide whether to change their types. This is equivalent to a zero-temperature ising model with Glauber dynamics, an asynchronous cellular automaton with extended Moore neighborhoods, or a Schelling model of self-organized segregation in an open system, and has applications in the analysis of social and biological networks, and spin glasses systems. Some rigorous results were recently obtained in the theoretical computer science literature, and this work provides several extensions. We enlarge the intolerance interval leading to the expected formation of large segregated regions of agents of a single type from the known size ɛ >0 to size ≈ 0.134. Namely, we show that for 0.433< τ < 1/2 (and by symmetry 1/2<τ <0.567), the expected size of the largest segregated region containing an arbitrary agent is exponential in the size of the neighborhood. We further extend the interval leading to expected large segregated regions to size ≈ 0.312 considering "almost segregated" regions, namely regions where the ratio of the number of agents of one type and the number of agents of the other type vanishes quickly as the size of the neighborhood grows. In this case, we show that for 0.344 < τ ≤ 0.433 (and by symmetry for 0.567 ≤ τ <0.656) the expected size of the largest almost segregated region containing an arbitrary agent is exponential in the size of the neighborhood. This behavior is reminiscent of supercritical percolation, where small clusters of empty sites can be observed within any sufficiently large region of the occupied percolation cluster. The exponential bounds that we provide also imply that complete segregation, where agents of a single type cover the whole grid, does not occur with high probability for p=1/2 and the range of intolerance considered.

Eye Color as a Predictor of Outcomes in Behavior Therapy.

ERIC Educational Resources Information Center

Markle, Allan; And Others

1984-01-01

Examined the relationship between outcomes of behaviorally oriented treatment for children (N=366) and eye color. Findings were consistent with theoretical expectations: Dark-eyed children and teenagers responded better to reactive treatment programs than their light-eyed counterparts, while the reverse was true for self-paced treatment programs.…

Education Fever: Korean Parents' Aspirations for Their Children's Schooling and Future Career

ERIC Educational Resources Information Center

Kim, Jin-Sook; Bang, Hyeyoung

2017-01-01

Korean parents set high academic expectations for their children. Utilising Takeuchi's and Clark's theoretical framework and Q methodology, this study explores Korean parents' "education fever" as aspiration for their children's schooling, and how socio-economic status influences this phenomenon. Thirty-six parents in Busan, South Korea,…

Cultivating Teachers' Morality and the Pedagogy of Emotional Rationality

ERIC Educational Resources Information Center

Kim, Minkang

2013-01-01

Teachers are expected to act ethically and provide moral role models in performing their duties, even though teacher education has often relegated the cultivation of teachers' ethical awareness and moral development to the margins. When it is addressed, the main theoretical assumptions have relied heavily on the cognitivist developmental theories…

The Morphosyntax of Discontinuous Exponence

ERIC Educational Resources Information Center

Campbell, Amy Melissa

2012-01-01

This thesis offers a systematic treatment of discontinuous exponence, a pattern of inflection in which a single feature or a set of features bundled in syntax is expressed by multiple, distinct morphemes. This pattern is interesting and theoretically relevant because it represents a deviation from the expected one-to-one relationship between…

Task Values, Achievement Goals, and Interest: An Integrative Analysis

ERIC Educational Resources Information Center

Hulleman, Chris S.; Durik, Amanda M.; Schweigert, Shaun B.; Harackiewicz, Judith M.

2008-01-01

The research presented in this article integrates 3 theoretical perspectives in the field of motivation: expectancy-value, achievement goals, and interest. The authors examined the antecedents (initial interest, achievement goals) and consequences (interest, performance) of task value judgments in 2 learning contexts: a college classroom and a…

The Space Telescope Observatory

NASA Technical Reports Server (NTRS)

Bahcall, J. N.; Odell, C. R.

1979-01-01

A convenient guide to the expected characteristics of the Space Telescope Observatory for astronomers and physicists is presented. An attempt is made to provide enough detail so that a professional scientist, observer or theorist, can plan how the observatory may be used to further his observing programs or to test theoretical models.

Simple Strategies for Reflecting on and Responding to Common Criticisms of PBIS

ERIC Educational Resources Information Center

Bruhn, Allison; Gorsh, Jay; Hannan, Chloe; Hirsch, Shanna Eisner

2014-01-01

Schools implementing Positive Behavior Interventions and Supports (PBIS) are often confronted with concerns from a variety of educational stakeholders about school climate, teaching behavioral expectations, the role of reinforcement, and labeling students. Administrators should be prepared to respond to these concerns with theoretical and…

Selecting Items for Criterion-Referenced Tests.

ERIC Educational Resources Information Center

Mellenbergh, Gideon J.; van der Linden, Wim J.

1982-01-01

Three item selection methods for criterion-referenced tests are examined: the classical theory of item difficulty and item-test correlation; the latent trait theory of item characteristic curves; and a decision-theoretic approach for optimal item selection. Item contribution to the standardized expected utility of mastery testing is discussed. (CM)

Inflationary Cosmology: Is Our Universe Part of a Multiverse?

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

Guth, Alan

2008-11-06

In this talk, Guth explains the inflationary theory and reviews the features that make it scientifically plausible. In addition, he discusses the biggest mystery in cosmology: Why is the value of the cosmological constant, sometimes called the "anti-gravity" effect, so remarkably small compared to theoretical expectations?

Over-Education and Assortative Matching in Partnerships: A Theoretical Analysis

ERIC Educational Resources Information Center

Tampieri, Alessandro

2016-01-01

This paper argues that assortative matching may explain over-education. Education determines individuals' income and, due to the presence of assortative matching, the quality of partners in personal, social and working life. Thus, an individual acquires education to improve the expected partners' quality. However, since every individual of the…

Word Reading Fluency as a Serial Naming Task

ERIC Educational Resources Information Center

Protopapas, Athanassios; Katopodi, Katerina; Altani, Angeliki; Georgiou, George K.

2018-01-01

Word list reading fluency is theoretically expected to depend on single word reading speed. Yet the correlation between the two diminishes with increasing fluency, while fluency remains strongly correlated to serial digit naming. We hypothesized that multi-element sequence processing is an important component of fluency. We used confirmatory…

How To Manage the Emerging Generational Divide in the Contemporary Knowledge-Rich Workplace.

ERIC Educational Resources Information Center

Novicevic, Milorad M.; Buckley, M. Ronald

2001-01-01

Addresses the manager's dilemmas and options in resolving emerging latent intergenerational conflict in the contemporary knowledge-rich workplace. Topics include a theoretical framework for generational divide management; the polarization in task requirements; social and environmental factors; differences in employee needs and expectations; and…

Debating Nuclear Energy: Theories of Risk and Purposes of Communication.

ERIC Educational Resources Information Center

Mirel, Barbara

1994-01-01

Applies theoretical principles of risk perception and communication (from various psychological, social, political, and cultural dynamics) to a sample risk communication on nuclear energy to determine realistic expectations for persuasive risk communications. Stresses that rhetorical researchers need to explore and test the extent to which written…

Ideological and Historical Challenges in Business Education

ERIC Educational Resources Information Center

Nino, Lana

2011-01-01

Business schools bear a central mission in our society and are responsible for training business managers who work in, lead, and indeed control our corporations and drive our economy's wealth. Historical and ideological challenges have influenced business education and steered it off the expected path. Several theoretical frameworks such as…

Training Transfer, Metacognition Skills, and Performance Outcomes in Blended versus Traditional Training Programs

ERIC Educational Resources Information Center

Giovengo, Rick D.

2014-01-01

The military instituted blended e-learning training programs to reduce manpower requirements and to lower training costs by leveraging technology, but success in this relationship has not been studied specifically. Working within theoretical constructs of motivation, expectancy, and social cognition this quasi-experimental study examined the…

Optimization Techniques for College Financial Aid Managers

ERIC Educational Resources Information Center

Bosshardt, Donald I.; Lichtenstein, Larry; Palumbo, George; Zaporowski, Mark P.

2010-01-01

In the context of a theoretical model of expected profit maximization, this paper shows how historic institutional data can be used to assist enrollment managers in determining the level of financial aid for students with varying demographic and quality characteristics. Optimal tuition pricing in conjunction with empirical estimation of…

How Drug Treatment Courts Work: An Analysis of Mediators

ERIC Educational Resources Information Center

Gottfredson, Denise C.; Kearley, Brook W.; Najaka, Stacy S.; Rocha, Carlos M.

2007-01-01

This study examines program elements related to reductions in drug use and crime among Drug Treatment Courts (DTC) participants as well as theoretical mechanisms--increased social controls and improved perceptions of procedural justice--expected to mediate the effects of DTC on these outcomes. Data are from 157 research participants interviewed…

Rethinking the longitudinal stream temperature paradigm: region-wide comparison of thermal infrared imagery reveals unexpected complexity of river temperatures

EPA Science Inventory

We used an extensive dataset of remotely sensed summertime river temperature to compare longitudinal profiles (temperature versus distance) for 54 rivers in the Pacific Northwest. We evaluated (1) how often profiles fit theoretical expectations of asymptotic downstream warming, a...

Principles of Course Design for Language Teaching. New Directions in Language Teaching.

ERIC Educational Resources Information Center

Yalden, Janice

An introduction to contemporary views of second/foreign language course design is intended for even relatively inexperienced teachers wishing to meet the somewhat sophisticated current expectations for language training. First, it provides theoretical background concerning the concepts of communicative competence and second language proficiency,…

The Moral and the Political in Global Citizenship: Appreciating Differences in Education

ERIC Educational Resources Information Center

Veugelers, Wiel

2011-01-01

Schools are expected to pay attention to citizenship education, including for the global world. The concept global citizenship can get different meanings. In our theoretical orientation, we distinguish between three forms of modern global citizenship: Open global citizenship; Moral global citizenship; Social-political global citizenship. In an…

The Development of a Professional Statistics Teaching Identity

ERIC Educational Resources Information Center

Whitaker, Douglas

2016-01-01

Motivated by the increased statistics expectations for students and their teachers because of the widespread adoption of the Common Core State Standards for Mathematics, this study explores exemplary, in-service statistics teachers' professional identities using a theoretical framework informed by Gee (2000) and communities of practice (Lave &…

To kill a kangaroo: understanding the decision to pursue high-risk/high-gain resources.

PubMed

Jones, James Holland; Bird, Rebecca Bliege; Bird, Douglas W

2013-09-22

In this paper, we attempt to understand hunter-gatherer foraging decisions about prey that vary in both the mean and variance of energy return using an expected utility framework. We show that for skewed distributions of energetic returns, the standard linear variance discounting (LVD) model for risk-sensitive foraging can produce quite misleading results. In addition to creating difficulties for the LVD model, the skewed distributions characteristic of hunting returns create challenges for estimating probability distribution functions required for expected utility. We present a solution using a two-component finite mixture model for foraging returns. We then use detailed foraging returns data based on focal follows of individual hunters in Western Australia hunting for high-risk/high-gain (hill kangaroo) and relatively low-risk/low-gain (sand monitor) prey. Using probability densities for the two resources estimated from the mixture models, combined with theoretically sensible utility curves characterized by diminishing marginal utility for the highest returns, we find that the expected utility of the sand monitors greatly exceeds that of kangaroos despite the fact that the mean energy return for kangaroos is nearly twice as large as that for sand monitors. We conclude that the decision to hunt hill kangaroos does not arise simply as part of an energetic utility-maximization strategy and that additional social, political or symbolic benefits must accrue to hunters of this highly variable prey.

The Value of Heterogeneity for Cost-Effectiveness Subgroup Analysis

PubMed Central

Manca, Andrea; Claxton, Karl; Sculpher, Mark J.

2014-01-01

This article develops a general framework to guide the use of subgroup cost-effectiveness analysis for decision making in a collectively funded health system. In doing so, it addresses 2 key policy questions, namely, the identification and selection of subgroups, while distinguishing 2 sources of potential value associated with heterogeneity. These are 1) the value of revealing the factors associated with heterogeneity in costs and outcomes using existing evidence (static value) and 2) the value of acquiring further subgroup-related evidence to resolve the uncertainty given the current understanding of heterogeneity (dynamic value). Consideration of these 2 sources of value can guide subgroup-specific treatment decisions and inform whether further research should be conducted to resolve uncertainty to explain variability in costs and outcomes. We apply the proposed methods to a cost-effectiveness analysis for the management of patients with acute coronary syndrome. This study presents the expected net benefits under current and perfect information when subgroups are defined based on the use and combination of 6 binary covariates. The results of the case study confirm the theoretical expectations. As more subgroups are considered, the marginal net benefit gains obtained under the current information show diminishing marginal returns, and the expected value of perfect information shows a decreasing trend. We present a suggested algorithm that synthesizes the results to guide policy. PMID:24944196

The value of heterogeneity for cost-effectiveness subgroup analysis: conceptual framework and application.

PubMed

Espinoza, Manuel A; Manca, Andrea; Claxton, Karl; Sculpher, Mark J

2014-11-01

This article develops a general framework to guide the use of subgroup cost-effectiveness analysis for decision making in a collectively funded health system. In doing so, it addresses 2 key policy questions, namely, the identification and selection of subgroups, while distinguishing 2 sources of potential value associated with heterogeneity. These are 1) the value of revealing the factors associated with heterogeneity in costs and outcomes using existing evidence (static value) and 2) the value of acquiring further subgroup-related evidence to resolve the uncertainty given the current understanding of heterogeneity (dynamic value). Consideration of these 2 sources of value can guide subgroup-specific treatment decisions and inform whether further research should be conducted to resolve uncertainty to explain variability in costs and outcomes. We apply the proposed methods to a cost-effectiveness analysis for the management of patients with acute coronary syndrome. This study presents the expected net benefits under current and perfect information when subgroups are defined based on the use and combination of 6 binary covariates. The results of the case study confirm the theoretical expectations. As more subgroups are considered, the marginal net benefit gains obtained under the current information show diminishing marginal returns, and the expected value of perfect information shows a decreasing trend. We present a suggested algorithm that synthesizes the results to guide policy. © The Author(s) 2014.

In search of a theoretical structure for understanding motivation in schizophrenia.

PubMed

Medalia, Alice; Brekke, John

2010-09-01

This themed issue considers different ways to conceptualize the motivational impairment that is a core negative symptom of schizophrenia. Motivational impairment has been linked to poor functional outcome, thus it is important to understand the nature and causes of motivational impairment in order to develop better treatment strategies to enhance motivation and engage patients in the process of recovery. Motivation refers to the processes whereby goal-directed activities are instigated and sustained and can be thought of as the product of a complex interaction of physiological processes and social contextual variables. In this issue, the physiological processes of motivation are the focus of Barch and Dowd, who highlight the role of prefrontal and subcortical mesolimbic dopamine systems in incentive-based learning and the difficulties people with schizophrenia have using internal representations of relevant experiences and goals to drive the behavior that should allow them to obtain desired outcomes. The articles in this issue by Choi et al., Nakagami et al., and Silverstein, focus on social contextual or environmental variables that can shape behavior and motivation. Together, these articles highlight the impact of external cues and goal properties on the expectations and values attached to goal outcomes. Expectancy-value and Self-Determination theories provide an overarching framework to accommodate the perspectives and data provided in all these articles. In the following introduction we show how the articles in this themed issue both support the role of expectancies and value in motivation in schizophrenia and elucidate possible deficiencies in the way expectations and value get assigned.

In Search of a Theoretical Structure for Understanding Motivation in Schizophrenia

PubMed Central

Medalia, Alice; Brekke, John

2010-01-01

This themed issue considers different ways to conceptualize the motivational impairment that is a core negative symptom of schizophrenia. Motivational impairment has been linked to poor functional outcome, thus it is important to understand the nature and causes of motivational impairment in order to develop better treatment strategies to enhance motivation and engage patients in the process of recovery. Motivation refers to the processes whereby goal-directed activities are instigated and sustained and can be thought of as the product of a complex interaction of physiological processes and social contextual variables. In this issue, the physiological processes of motivation are the focus of Barch and Dowd, who highlight the role of prefrontal and subcortical mesolimbic dopamine systems in incentive-based learning and the difficulties people with schizophrenia have using internal representations of relevant experiences and goals to drive the behavior that should allow them to obtain desired outcomes. The articles in this issue by Choi et al., Nakagami et al., and Silverstein, focus on social contextual or environmental variables that can shape behavior and motivation. Together, these articles highlight the impact of external cues and goal properties on the expectations and values attached to goal outcomes. Expectancy-value and Self-Determination theories provide an overarching framework to accommodate the perspectives and data provided in all these articles. In the following introduction we show how the articles in this themed issue both support the role of expectancies and value in motivation in schizophrenia and elucidate possible deficiencies in the way expectations and value get assigned. PMID:20595203

Unmet needs in health training among nurses in rural Chinese township health centers: a cross-sectional hospital-based study.

PubMed

Mo, Yan; Hu, Guijie; Yi, Yanhua; Ying, Yanping; Huang, Huiqiao; Huang, Zhongxian; Lin, Jiafeng

2017-01-01

Maintaining a sufficient and competent rural nursing workforce is an important goal of the Chinese health delivery system. However, few studies have investigated the health training status or conducted a needs assessment of rural Chinese nurses during this time of great transformations in health policy. This study was conducted to explore the current health training status of nurses working in rural Chinese township health centers (THCs) and to ascertain their perceived needs. A cross-sectional survey using a self-administered structured questionnaire was conducted among 240 THC nurses in Guangxi Zhuang Autonomous Region, China from March 2014 to August 2014. The survey questionnaire was adapted from the Second Chinese Survey of Demographic Data and Training Demand for Health Professionals in THCs developed by the Ministry of Education. The nurses in THCs were young, with a low educational level. Their perceived needs for health training included further clinical studies at city-level hospitals to improve their skills and theoretical studies at medical universities in emergency medicine and general practice. Overall, 71.9% of the nurses with a secondary technical school background expected to pursue junior college studies, and 68.5% of the nurses with a junior college education expected to pursue a bachelor's degree. A decentralized program with theoretical studies at medical universities and practical studies at county hospitals was regarded as feasible by 66.9% of the respondents. Health-training programs for nurses in Chinese THCs must be improved in terms of coverage, delivery mode, and content. A decentralized degree-linked training program in which medical universities and city hospitals collaborate would be an appropriate mode of delivery.

Designing a Health-Game Intervention Supporting Health Literacy and a Tobacco-Free Life in Early Adolescence.

PubMed

Parisod, Heidi; Pakarinen, Anni; Axelin, Anna; Danielsson-Ojala, Riitta; Smed, Jouni; Salanterä, Sanna

2017-08-01

The purpose of this study was to explore the design of a health game that aims to both support tobacco-related health literacy and a tobacco-free life in early adolescence and to meet adolescents' expectations. Data were collected from adolescents using an open-ended questionnaire (n = 83) and focus groups (n = 39) to obtain their view of a health game used for tobacco-related health education. The data were analyzed using thematic analysis. A group of experts combined the adolescents' views with theoretical information on health literacy and designed and produced the first version of the game. Adolescents (session 1, n = 16; session 3, n = 10; and session 4, n = 44) and health promotion professionals (session 2, n = 3) participated in testing the game. Feedback from testing sessions 3 and 4 was analyzed using descriptive statistics. Adolescents pointed out that the health game needs to approach the topic of tobacco delicately and focus on the adolescents' perspective and on the positive sides of a tobacco-free life rather than only on the negative consequences of tobacco. The adolescents expected the game to be of high quality, stimulating, and intellectually challenging and to offer possibilities for individualization. Elements from the adolescents' view and theoretical modelling were embedded into the design of a game called Fume. Feedback on the game was promising, but some points were highlighted for further development. Investing especially in high-quality design features, such as graphics and versatile content, using humoristic or otherwise stimulating elements, and maintaining sufficiently challenging gameplay would promote the acceptability of theory-based health games among adolescents.

An expectancy-value model of emotion regulation: implications for motivation, emotional experience, and decision making.

PubMed

Tamir, Maya; Bigman, Yochanan E; Rhodes, Emily; Salerno, James; Schreier, Jenna

2015-02-01

According to expectancy-value models of self-regulation, people are motivated to act in ways they expect to be useful to them. For instance, people are motivated to run when they believe running is useful, even when they have nothing to run away from. Similarly, we propose an expectancy-value model of emotion regulation, according to which people are motivated to emote in ways they expect to be useful to them, regardless of immediate contextual demands. For instance, people may be motivated to get angry when they believe anger is useful, even when there is nothing to be angry about. In 5 studies, we demonstrate that leading people to expect an emotion to be useful increased their motivation to experience that emotion (Studies 1-5), led them to up-regulate the experience of that emotion (Studies 3-4), and led to emotion-consistent behavior (Study 4). Our hypotheses were supported when we manipulated the expected value of anxiety (Study 1) and anger (Studies 2-5), both consciously (Studies 1-4) and unconsciously (Study 5). We discuss the theoretical and pragmatic implications of the proposed model. PsycINFO Database Record (c) 2015 APA, all rights reserved.

Methods for simulating nutritional requirement and response studies with all organisms to increase research efficiency.

PubMed

Vedenov, Dmitry; Alhotan, Rashed A; Wang, Runlian; Pesti, Gene M

2017-02-01

Nutritional requirements and responses of all organisms are estimated using various models representing the response to different dietary levels of the nutrient in question. To help nutritionists design experiments for estimating responses and requirements, we developed a simulation workbook using Microsoft Excel. The objective of the present study was to demonstrate the influence of different numbers of nutrient levels, ranges of nutrient levels and replications per nutrient level on the estimates of requirements based on common nutritional response models. The user provides estimates of the shape of the response curve, requirements and other parameters and observation to observation variation. The Excel workbook then produces 1-1000 randomly simulated responses based on the given response curve and estimates the standard errors of the requirement (and other parameters) from different models as an indication of the expected power of the experiment. Interpretations are based on the assumption that the smaller the standard error of the requirement, the more powerful the experiment. The user can see the potential effects of using one or more subjects, different nutrient levels, etc., on the expected outcome of future experiments. From a theoretical perspective, each organism should have some enzyme-catalysed reaction whose rate is limited by the availability of some limiting nutrient. The response to the limiting nutrient should therefore be similar to enzyme kinetics. In conclusion, the workbook eliminates some of the guesswork involved in designing experiments and determining the minimum number of subjects needed to achieve desired outcomes.

Developing a theoretical foundation to change road user behavior and improve traffic safety: Driving under the influence of cannabis (DUIC).

PubMed

Ward, Nicholas J; Schell, William; Kelley-Baker, Tara; Otto, Jay; Finley, Kari

2018-05-19

This study explored a theoretical model to assess the influence of culture on willingness and intention to drive under the influence of cannabis (DUIC). This model is expected to guide the design of strategies to change future DUIC behavior in road users. This study used a survey methodology to obtain a nationally representative sample (n = 941) from the AmeriSpeak Panel. Survey items were designed to measure aspects of a proposed definition of traffic safety culture and a predictive model of its relationship to DUIC. Although the percentage of reported past DUIC behaviors was relatively low (8.5%), this behavior is still a significant public health issue-especially for younger drivers (18-29 years), who reported more DUIC than expected. Findings suggest that specific cultural components (attitudes, norms) reliably predict past DUIC behavior, general DUIC willingness, and future DUIC intention. Most DUIC behavior appears to be deliberate, related significantly to willingness and intention. Intention and willingness both appear to fully moderate the relationship between traffic safety culture and DUIC behavior. This study explored a theoretical model to understand road user behavior involving drug (cannabis)-impaired driving as a significant risk factor for traffic safety. By understanding the cultural factors that increase DUIC behavior, we can create strategies to transform this culture and sustain safer road user behavior.

Results from Binary Black Hole Simulations in Astrophysics Applications

NASA Technical Reports Server (NTRS)

Baker, John G.

2007-01-01

Present and planned gravitational wave observatories are opening a new astronomical window to the sky. A key source of gravitational waves is the merger of two black holes. The Laser Interferometer Space Antenna (LISA), in particular, is expected to observe these events with signal-to-noise ratio's in the thousands. To fully reap the scientific benefits of these observations requires a detailed understanding, based on numerical simulations, of the predictions of General Relativity for the waveform signals. New techniques for simulating binary black hole mergers, introduced two years ago, have led to dramatic advances in applied numerical simulation work. Over the last two years, numerical relativity researchers have made tremendous strides in understanding the late stages of binary black hole mergers. Simulations have been applied to test much of the basic physics of binary black hole interactions, showing robust results for merger waveform predictions, and illuminating such phenomena as spin-precession. Calculations have shown that merging systems can be kicked at up to 2500 km/s by the thrust from asymmetric emission. Recently, long lasting simulations of ten or more orbits allow tests of post-Newtonian (PN) approximation results for radiation from the last orbits of the binary's inspiral. Already, analytic waveform models based PN techniques with incorporated information from numerical simulations may be adequate for observations with current ground based observatories. As new advances in simulations continue to rapidly improve our theoretical understanding of the systems, it seems certain that high-precision predictions will be available in time for LISA and other advanced ground-based instruments. Future gravitational wave observatories are expected to make precision.

Self-assembling hybrid diamond-biological quantum devices

NASA Astrophysics Data System (ADS)

Albrecht, A.; Koplovitz, G.; Retzker, A.; Jelezko, F.; Yochelis, S.; Porath, D.; Nevo, Y.; Shoseyov, O.; Paltiel, Y.; Plenio, M. B.

2014-09-01

The realization of scalable arrangements of nitrogen vacancy (NV) centers in diamond remains a key challenge on the way towards efficient quantum information processing, quantum simulation and quantum sensing applications. Although technologies based on implanting NV-centers in bulk diamond crystals or hybrid device approaches have been developed, they are limited by the achievable spatial resolution and by the intricate technological complexities involved in achieving scalability. We propose and demonstrate a novel approach for creating an arrangement of NV-centers, based on the self-assembling capabilities of biological systems and their beneficial nanometer spatial resolution. Here, a self-assembled protein structure serves as a structural scaffold for surface functionalized nanodiamonds, in this way allowing for the controlled creation of NV-structures on the nanoscale and providing a new avenue towards bridging the bio-nano interface. One-, two- as well as three-dimensional structures are within the scope of biological structural assembling techniques. We realized experimentally the formation of regular structures by interconnecting nanodiamonds using biological protein scaffolds. Based on the achievable NV-center distances of 11 nm, we evaluate the expected dipolar coupling interaction with neighboring NV-centers as well as the expected decoherence time. Moreover, by exploiting these couplings, we provide a detailed theoretical analysis on the viability of multiqubit quantum operations, suggest the possibility of individual addressing based on the random distribution of the NV intrinsic symmetry axes and address the challenges posed by decoherence and imperfect couplings. We then demonstrate in the last part that our scheme allows for the high-fidelity creation of entanglement, cluster states and quantum simulation applications.

Improved relocatable over-the-horizon radar detection and tracking using the maximum likelihood adaptive neural system algorithm

NASA Astrophysics Data System (ADS)

Perlovsky, Leonid I.; Webb, Virgil H.; Bradley, Scott R.; Hansen, Christopher A.

1998-07-01

An advanced detection and tracking system is being developed for the U.S. Navy's Relocatable Over-the-Horizon Radar (ROTHR) to provide improved tracking performance against small aircraft typically used in drug-smuggling activities. The development is based on the Maximum Likelihood Adaptive Neural System (MLANS), a model-based neural network that combines advantages of neural network and model-based algorithmic approaches. The objective of the MLANS tracker development effort is to address user requirements for increased detection and tracking capability in clutter and improved track position, heading, and speed accuracy. The MLANS tracker is expected to outperform other approaches to detection and tracking for the following reasons. It incorporates adaptive internal models of target return signals, target tracks and maneuvers, and clutter signals, which leads to concurrent clutter suppression, detection, and tracking (track-before-detect). It is not combinatorial and thus does not require any thresholding or peak picking and can track in low signal-to-noise conditions. It incorporates superresolution spectrum estimation techniques exceeding the performance of conventional maximum likelihood and maximum entropy methods. The unique spectrum estimation method is based on the Einsteinian interpretation of the ROTHR received energy spectrum as a probability density of signal frequency. The MLANS neural architecture and learning mechanism are founded on spectrum models and maximization of the "Einsteinian" likelihood, allowing knowledge of the physical behavior of both targets and clutter to be injected into the tracker algorithms. The paper describes the addressed requirements and expected improvements, theoretical foundations, engineering methodology, and results of the development effort to date.

Impact of a Tutored Theoretical-Practical Training to Develop Undergraduate Students’ Skills for the Detection of Caries Lesions: Study Protocol for a Multicenter Controlled Randomized Study

PubMed Central

Ferreira, Fernanda Rosche; Mendes, Fausto Medeiros; Raggio, Daniela Prócida; Imparato, José Carlos; Bonecker, Marcelo; Magalhães, Ana Carolina; Wang, Linda; Rios, Daniela; Pessan, Juliano Pelim; Duque, Cristiane; Rebelo, Maria Augusta Bessa; Alves Filho, Ary Oliveira; Lima, Marina De Deus Moura; Moura, Marcoeli Silva; De Carli, Alessandro Diogo; Sanabe, Mariane Emi; Cenci, Maximiliano Sergio; Oliveira, Elenara Ferreira; Correa, Marcos Britto; Rocha, Rachel Oliveira; Zenkner, Julio Eduardo; Murisí, Pedroza Uribe; Martignon, Stefania; Lara, Juan Sebastian; Aquino, Fatima Gabriela; Carrillo, Alfredo; Chu, Chun Hung; Deery, Chris; Ricketts, David; Melo, Paulo; Antunes, José Leopoldo Ferreira; Ekstrand, Kim Rud

2017-01-01

Background Tutored laboratorial activities could be a manner of improving the competency development of students. However, its impact over conventional theoretical classes has not yet been tested. Additionally, different university contexts could influence this issue and should be explored. Objective To assess the impact of a tutored theoretical-practical training for teaching undergraduate students to detect caries lesions as compared with theoretical teaching activities. The impact of these teaching/learning activities will be assessed in terms of efficacy, cost/benefit, retention of knowledge/acquired competences, and student acceptability. Methods Sixteen centers (7 centers from Brazil and 9 centers from other countries throughout the world) are involved in the inclusion of subjects for this protocol. A randomized controlled study with parallel groups will be conducted. One group (control) will be exposed to a 60- to 90-minute conventional theoretical class and the other group (test) will be exposed to the same theoretical class and also a 90-minute laboratory class, including exercises and discussions based on the evaluation of a pool of images and extracted teeth. The mentioned outcomes will be evaluated immediately after the teaching activities and also in medium- and long-term analyses. To compare the long-term outcomes, students who enrolled in the university before the participating students will be interviewed for data collection and these data will be used as a control and compared with the trained group. This stage will be a nonrandomized phase of this study, nested in the main study. Appropriate statistical analysis will be performed according to the aims of this study. Variables related to the centers will also be analyzed and used to model adjustment as possible sources of variability among results. Results This ongoing study is funded by a Brazilian national funding agency (CNPq- 400736/2014-4). We expect that the tutored theoretical-practical training will improve the undergraduate students’ performance in the detection of caries lesions and subsequent treatment decisions, mainly in terms of long-term retention of knowledge. Our hypothesis is that tutored theoretical-practical training is a more cost-effective option for teaching undergraduate students to detect caries lesions. Conclusions If our hypothesis is confirmed, the use of laboratory training in conjunction with theoretical classes could be used as an educational strategy in Cariology to improve the development of undergraduate students’ skills in the detection of caries lesions and clinical decision-making. PMID:28814381