The sine-Gordon model in the presence of defects

International Nuclear Information System (INIS)

Avan, Jean; Doikou, Anastasia

2013-01-01

The sine-Gordon model in the presence of dynamical integrable defects is investigated. This is an application of the algebraic formulation introduced for integrable defects in earlier works. The quantities in involution as well as the associated Lax pairs are explicitly extracted. Integrability i also shown using certain sewing constraints, which emerge as suitable continuity conditions.

Assessment of the Clinical Trainer as a Role Model: A Role Model Apperception Tool (RoMAT)

NARCIS (Netherlands)

Jochemsen-van der Leeuw, H. G. A. Ria; van Dijk, Nynke; Wieringa-de Waard, Margreet

2014-01-01

Purpose Positive role modeling by clinical trainers is important for helping trainees learn professional and competent behavior. The authors developed and validated an instrument to assess clinical trainers as role models: the Role Model Apperception Tool (RoMAT). Method On the basis of a 2011

Role Model, Hero or Champion? Children's Views Concerning Role Models

Science.gov (United States)

Bricheno, Patricia; Thornton, Mary

2007-01-01

Background: Claims that male role models can improve the behaviour and achievement of boys are familiar and persistent. However, research has not confirmed such a link; recent UK studies indicate that peers and relatives may be far more important to boys than their teachers. Given the seemingly relentless reference to male teachers as role models…

Model-based control of observer bias for the analysis of presence-only data in ecology.

Directory of Open Access Journals (Sweden)

David I Warton

Full Text Available Presence-only data, where information is available concerning species presence but not species absence, are subject to bias due to observers being more likely to visit and record sightings at some locations than others (hereafter "observer bias". In this paper, we describe and evaluate a model-based approach to accounting for observer bias directly--by modelling presence locations as a function of known observer bias variables (such as accessibility variables in addition to environmental variables, then conditioning on a common level of bias to make predictions of species occurrence free of such observer bias. We implement this idea using point process models with a LASSO penalty, a new presence-only method related to maximum entropy modelling, that implicitly addresses the "pseudo-absence problem" of where to locate pseudo-absences (and how many. The proposed method of bias-correction is evaluated using systematically collected presence/absence data for 62 plant species endemic to the Blue Mountains near Sydney, Australia. It is shown that modelling and controlling for observer bias significantly improves the accuracy of predictions made using presence-only data, and usually improves predictions as compared to pseudo-absence or "inventory" methods of bias correction based on absences from non-target species. Future research will consider the potential for improving the proposed bias-correction approach by estimating the observer bias simultaneously across multiple species.

Role of transverse hopping in a two-coupled-chains model

International Nuclear Information System (INIS)

Fabrizio, M.

1993-01-01

We study the effect of a transverse hopping t perpendicular in two chains of both spinless and spinning repulsively interacting fermions, by means of renormalization group and bosonization techniques. We show that, independent of the presence of spin, t perpendicular strongly modifies the asymptotic long-wavelength behavior of the two chains, opening gaps in the excitation spectra. The origin of the instability of the gapless Luttinger-liquid behavior is identified in the flavor (==chain index) anisotropy induced by t perpendicular . In the case of spinning fermions, it leads to dominant pair fluctuations, in spite of the repulsive interaction. The role of spin is further analyzed in a model of two coupled chains showing, in the absence of t perpendicular , spin-charge separation without anomalous exponents. We solve this model exactly by the bosonization technique, and we find that the interesting analytical properties induced by spin-charge separation persist in the presence of transverse hopping, although t perpendicular does modify the shape of the Fermi surface. The asymptotic expression of the single-particle Green function is also obtained

Mentoring and role models in recruitment and retention: a study of junior medical faculty perceptions.

Science.gov (United States)

Steele, Margaret M; Fisman, Sandra; Davidson, Brenda

2013-05-01

This study explored the views of junior faculty toward informing mentorship program development. Mixed sampling methodologies including questionnaires (n = 175), focus groups (female, n = 4; male, n = 4), and individual interviews (female n = 10; male, n = 9) of junior faculty were conducted in clinical departments at one academic health sciences center. Questionnaire results indicated that having role models increased commitment to an academic career; mentorship experience during residency training was a high incentive to pursue an academic career; and junior faculty did have identifiable mentorship experiences. Focus group results revealed that mentoring as well as the presence of role models a few years ahead of the junior faculty would promote career development. Females preferred similar age role models who spoke the same language, particularly in the area of promotion. Females identified several challenges and issues including a lack of researcher role models, a range of perceptions regarding the merits of formal versus informal mentoring, and the idea that mentors should provide advice on promotion and grants. Males valued advice on finances while females wanted advice on work-life balance. Mentorship emerged as an important factor in academic faculty recruitment and retention, with varying perceptions of how it should be institutionalized. Role models were viewed as important for retention, and a paucity of mid-career, female researcher role models suggests a gap to be filled in future programmatic efforts.

Dynamic modeling of presence of occupants using inhomogeneous Markov chains

DEFF Research Database (Denmark)

Andersen, Philip Hvidthøft Delff; Iversen, Anne; Madsen, Henrik

2014-01-01

on time of day, and by use of a filter of the observations it is able to capture per-employee sequence dynamics. Simulations using this method are compared with simulations using homogeneous Markov chains and show far better ability to reproduce key properties of the data. The method is based...... on inhomogeneous Markov chains with where the transition probabilities are estimated using generalized linear models with polynomials, B-splines, and a filter of passed observations as inputs. For treating the dispersion of the data series, a hierarchical model structure is used where one model is for low presence...

Deflection modeling of permanent magnet spherical chains in the presence of external magnetic fields

Energy Technology Data Exchange (ETDEWEB)

O' Donoghue, Kilian, E-mail: kilianod@rennes.ucc.ie; Cantillon-Murphy, Pádraig, E-mail: padraig@alum.mit.edu

2013-10-15

This work examines the interaction of permanently magnetised spheres in the presence of external magnetic fields at the millimetre scale. Static chain formation and deflection models are described for N spheres in the presence of an external magnetic field. Analytical models are presented for the two sphere case by neglecting the effects of magnetocrystalline anisotropy while details of a numerical approach to solve a chain of N spheres are shown. The model is experimentally validated using chain deflections in 4.5 mm diameter spheres in groups of 2, 3 and 4 magnets in the presence of uniform magnetic fields, neglecting gravitational effects, with good agreement between the theoretical model and experimental results. This spherical chain structure could be used as an end effector for catheters as a deflection mechanism for magnetic guidance. The spherical point contacts result in large deflections for navigation around tight corners in endoluminal minimally invasive clinical applications. - Highlights: • We model the interaction of magnetic spheres with uniform external fields. • Analytical models are presented for two spheres interacting with an external field. • Numerical methods are used to model the interaction of N spheres in chain formations. • These models are tested experimentally. • We report good agreement between experiment and theory.

Deflection modeling of permanent magnet spherical chains in the presence of external magnetic fields

International Nuclear Information System (INIS)

O'Donoghue, Kilian; Cantillon-Murphy, Pádraig

2013-01-01

This work examines the interaction of permanently magnetised spheres in the presence of external magnetic fields at the millimetre scale. Static chain formation and deflection models are described for N spheres in the presence of an external magnetic field. Analytical models are presented for the two sphere case by neglecting the effects of magnetocrystalline anisotropy while details of a numerical approach to solve a chain of N spheres are shown. The model is experimentally validated using chain deflections in 4.5 mm diameter spheres in groups of 2, 3 and 4 magnets in the presence of uniform magnetic fields, neglecting gravitational effects, with good agreement between the theoretical model and experimental results. This spherical chain structure could be used as an end effector for catheters as a deflection mechanism for magnetic guidance. The spherical point contacts result in large deflections for navigation around tight corners in endoluminal minimally invasive clinical applications. - Highlights: • We model the interaction of magnetic spheres with uniform external fields. • Analytical models are presented for two spheres interacting with an external field. • Numerical methods are used to model the interaction of N spheres in chain formations. • These models are tested experimentally. • We report good agreement between experiment and theory

Role model and prototype matching

DEFF Research Database (Denmark)

Lykkegaard, Eva; Ulriksen, Lars

2016-01-01

’ meetings with the role models affected their thoughts concerning STEM students and attending university. The regular self-to-prototype matching process was shown in real-life role-models meetings to be extended to a more complex three-way matching process between students’ self-perceptions, prototype...

Development of artificial neural network models for supercritical fluid solvency in presence of co-solvents

Energy Technology Data Exchange (ETDEWEB)

Shokir, Eissa Mohamed El-Moghawry; El-Midany, Ayman Abdel-Hamid [Cairo University, Giza (Egypt); Al-Homadhi, Emad Souliman; Al-Mahdy, Osama [King Saud University, Riyadh (Saudi Arabia)

2014-08-15

This paper presents the application of artificial neural networks (ANN) to develop new models of liquid solvent dissolution of supercritical fluids with solutes in the presence of cosolvents. The neural network model of the liquid solvent dissolution of CO{sub 2} was built as a function of pressure, temperature, and concentrations of the solutes and cosolvents. Different experimental measurements of liquid solvent dissolution of supercritical fluids (CO{sub 2}) with solutes in the presence of cosolvents were collected. The collected data are divided into two parts. The first part was used in building the models, and the second part was used to test and validate the developed models against the Peng- Robinson equation of state. The developed ANN models showed high accuracy, within the studied variables range, in predicting the solubility of the 2-naphthol, anthracene, and aspirin in the supercritical fluid in the presence and absence of co-solvents compared to (EoS). Therefore, the developed ANN models could be considered as a good tool in predicting the solubility of tested solutes in supercritical fluid.

Modeling hydrate formation conditions in the presence of electrolytes and polar inhibitor solutions

International Nuclear Information System (INIS)

Osfouri, Shahriar; Azin, Reza; Gholami, Reza; Izadpanah, Amir Abbas

2015-01-01

Highlights: • A new predictive model is proposed for prediction of hydrate formation pressures. • A new local composition model was used to evaluate water activity in the presence of electrolyte. • MEG, DEG and TEG were used to test ability of the proposed model in the presence of polar inhibitors. • Cage occupancies by methane for the small cage were higher than carbon dioxide for gas mixtures. • The proposed model gives better match with experimental data in mixed electrolyte solutions. - Abstract: In this paper, a new predictive model is proposed for prediction of gas hydrate formation conditions in the presence of single and mixed electrolytes and solutions containing both electrolyte and a polar inhibitor such as monoethylene glycol (MEG), diethylene glycol (DEG) and triethylene glycol (TEG). The proposed model is based on the γ–φ approach, which uses modified Patel–Teja equation of state (VPT EOS) for characterizing the vapor phase, the solid solution theory by van der Waals and Platteeuw for modeling the hydrate phase, the non-electrolyte NRTL-NRF local composition model and Pitzer–Debye–Huckel equation as short-range and long-range contributions to calculate water activity in single electrolyte solutions. Also, the Margules equation was used to determine the activity of water in solutions containing polar inhibitor (glycols). The model predictions are in acceptable agreement with experimental data. For single electrolyte solutions, the model predictions are similar to available models, while for mixtures of electrolytes and mixtures of electrolytes and inhibitors, the proposed model gives significantly better predictions. In addition, the absolute average deviation of hydrate formation pressures (AADP) for 144 experimental data in solutions containing single electrolyte is 5.86% and for 190 experimental data in mixed electrolytes solutions is 5.23%. Furthermore, the proposed model has an AADP of 14.13%, 5.82% and 5.28% in solutions

Microplastics play a minor role in tetracycline sorption in the presence of dissolved organic matter.

Science.gov (United States)

Xu, Baile; Liu, Fei; Brookes, Philip C; Xu, Jianming

2018-05-02

Microplastics have a great potential to sorb organic pollutants from the adjacent environment. In this study, the sorption of tetracycline, a polar and ionizable antibiotic, on three types of microplastics (polyethylene (PE), polypropylene (PP) and polystyrene (PS)) were investigated in batch sorption experiments. The sorption isotherms were well fitted by the Langmuir model, indicating that not only hydrophobic interactions but also other interactions (e.g. electrostatic interactions) played important roles in the sorption process. PS had the maximum sorption capacity, following the order PS > PP > PE, which can be attributed to polar interactions and π-π interactions. The sorption of tetracycline on microplastics was significantly influenced by pH, with sorption capacity increasing gradually, peaking at pH 6.0 and then decreasing, likely due to the influence of tetracycline speciation with the change of pH. Fulvic acid was selected as representative dissolved organic matter (DOM) to examine the effect on sorption. The increasing concentration of fulvic acid inhibited the sorption of tetracycline on three microplastics, decreasing them by more than 90% at the fulvic acid concentration of 20 mg/L, which implied a greater affinity of tetracycline to fulvic acid than to microplastics. Increasing salinity from 0.05 to 3.5% had negligible effects on the sorption of tetracycline on the three microplastics. Our results highlight the importance of pH and DOM on the sorption of tetracycline on microplastics, and suggest the relatively minor role of microplastics in the fate and transport of tetracycline in the aquatic environment in the presence of DOM. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Direct Adaptive Control Approach in the Presence of Model Mismatch

Science.gov (United States)

Joshi, Suresh M.; Tao, Gang; Khong, Thuan

2009-01-01

This paper considers the problem of direct model reference adaptive control when the plant-model matching conditions are violated due to abnormal changes in the plant or incorrect knowledge of the plant's mathematical structure. The approach consists of direct adaptation of state feedback gains for state tracking, and simultaneous estimation of the plant-model mismatch. Because of the mismatch, the plant can no longer track the state of the original reference model, but may be able to track a new reference model that still provides satisfactory performance. The reference model is updated if the estimated plant-model mismatch exceeds a bound that is determined via robust stability and/or performance criteria. The resulting controller is a hybrid direct-indirect adaptive controller that offers asymptotic state tracking in the presence of plant-model mismatch as well as parameter deviations.

The role of presence in virtual reality exposure therapy

OpenAIRE

Price, Matthew; Anderson, Page

2006-01-01

A growing body of literature suggests that virtual reality is a successful tool for exposure therapy in the treatment of anxiety disorders. Virtual reality (VR) researchers posit the construct of presence, defined as the interpretation of an artificial stimulus as if it were real, to be a presumed factor that enables anxiety to be felt during virtual reality exposure therapy (VRE). However, a handful of empirical studies on the relation between presence and anxiety in VRE have yielded mixed f...

Health promotion messages: the role of social presence for food choices.

Science.gov (United States)

Bittner, Jenny V; Kulesz, Micaela M

2015-04-01

We investigated whether social presence cues encourage consumers to self-regulate and select healthier food products. In the first experiment, workers completed food choices in an e-commerce environment. After the activation of health-related goals, they saw a social presence cue and were asked to choose between healthy and unhealthy food options. The analyses revealed main effects of social presence and health goal activation on food choices. These effects were additive, such that the combination of social presence and health goals induced significantly healthier choices compared with the control group. The second experiment further examined social presence cues that were presented on a menu. The results showed significant effects on food choices and on the perceived self-regulatory success in dieting. These findings indicate that social presence cues could be employed to increase healthful eating and, furthermore, that it may be useful to co-activate multiple cues in health promotion messages. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bayesian models for cost-effectiveness analysis in the presence of structural zero costs.

Science.gov (United States)

Baio, Gianluca

2014-05-20

Bayesian modelling for cost-effectiveness data has received much attention in both the health economics and the statistical literature, in recent years. Cost-effectiveness data are characterised by a relatively complex structure of relationships linking a suitable measure of clinical benefit (e.g. quality-adjusted life years) and the associated costs. Simplifying assumptions, such as (bivariate) normality of the underlying distributions, are usually not granted, particularly for the cost variable, which is characterised by markedly skewed distributions. In addition, individual-level data sets are often characterised by the presence of structural zeros in the cost variable. Hurdle models can be used to account for the presence of excess zeros in a distribution and have been applied in the context of cost data. We extend their application to cost-effectiveness data, defining a full Bayesian specification, which consists of a model for the individual probability of null costs, a marginal model for the costs and a conditional model for the measure of effectiveness (given the observed costs). We presented the model using a working example to describe its main features. © 2013 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd.

On estimating probability of presence from use-availability or presence-background data.

Science.gov (United States)

Phillips, Steven J; Elith, Jane

2013-06-01

A fundamental ecological modeling task is to estimate the probability that a species is present in (or uses) a site, conditional on environmental variables. For many species, available data consist of "presence" data (locations where the species [or evidence of it] has been observed), together with "background" data, a random sample of available environmental conditions. Recently published papers disagree on whether probability of presence is identifiable from such presence-background data alone. This paper aims to resolve the disagreement, demonstrating that additional information is required. We defined seven simulated species representing various simple shapes of response to environmental variables (constant, linear, convex, unimodal, S-shaped) and ran five logistic model-fitting methods using 1000 presence samples and 10 000 background samples; the simulations were repeated 100 times. The experiment revealed a stark contrast between two groups of methods: those based on a strong assumption that species' true probability of presence exactly matches a given parametric form had highly variable predictions and much larger RMS error than methods that take population prevalence (the fraction of sites in which the species is present) as an additional parameter. For six species, the former group grossly under- or overestimated probability of presence. The cause was not model structure or choice of link function, because all methods were logistic with linear and, where necessary, quadratic terms. Rather, the experiment demonstrates that an estimate of prevalence is not just helpful, but is necessary (except in special cases) for identifying probability of presence. We therefore advise against use of methods that rely on the strong assumption, due to Lele and Keim (recently advocated by Royle et al.) and Lancaster and Imbens. The methods are fragile, and their strong assumption is unlikely to be true in practice. We emphasize, however, that we are not arguing against

The catalytic ozonization of model lignin compounds in the presence of Fe(III) ions

Science.gov (United States)

Ben'ko, E. M.; Mukovnya, A. V.; Lunin, V. V.

2007-05-01

The ozonization of several model lignin compounds (guaiacol, 2,6-dimethoxyphenol, phenol, and vanillin) was studied in acid media in the presence of iron(III) ions. It was found that Fe3+ did not influence the initial rate of the reactions between model phenols and ozone but accelerated the oxidation of intermediate ozonolysis products. The metal concentration dependences of the total ozone consumption and effective rate constants of catalytic reaction stages were determined. Data on reactions in the presence of oxalic acid as a competing chelate ligand showed that complex formation with Fe3+ was the principal factor that accelerated the ozonolysis of model phenols at the stage of the oxidation of carboxylic dibasic acids and C2 aldehydes formed as intermediate products.

Statistical Modeling of Extreme Values and Evidence of Presence of Dragon King (DK) in Solar Wind

Science.gov (United States)

Gomes, T.; Ramos, F.; Rempel, E. L.; Silva, S.; C-L Chian, A.

2017-12-01

The solar wind constitutes a nonlinear dynamical system, presenting intermittent turbulence, multifractality and chaotic dynamics. One characteristic shared by many such complex systems is the presence of extreme events, that play an important role in several Geophysical phenomena and their statistical characterization is a problem of great practical relevance. This work investigates the presence of extreme events in time series of the modulus of the interplanetary magnetic field measured by Cluster spacecraft on February 2, 2002. One of the main results is that the solar wind near the Earth's bow shock can be modeled by the Generalized Pareto (GP) and Generalized Extreme Values (GEV) distributions. Both models present a statistically significant positive shape parameter which implyies a heavy tail in the probability distribution functions and an unbounded growth in return values as return periods become too long. There is evidence that current sheets are the main responsible for positive values of the shape parameter. It is also shown that magnetic reconnection at the interface between two interplanetary magnetic flux ropes in the solar wind can be considered as Dragon Kings (DK), a class of extreme events whose formation mechanisms are fundamentally different from others. As long as magnetic reconnection can be classified as a Dragon King, there is the possibility of its identification and even its prediction. Dragon kings had previously been identified in time series of financial crashes, nuclear power generation accidents, stock market and so on. It is believed that they are associated with the occurrence of extreme events in dynamical systems at phase transition, bifurcation, crises or tipping points.

A comprehensive study on the role of the Yersinia pestis virulence markers in an animal model of pneumonic plague

NARCIS (Netherlands)

W.E. Kaman (Wendy); S. Hawkey; D. van der Kleij (Desiree); M.P. Broekhuijsen; N.J. Silman; F.J. Bikker (Floris)

2011-01-01

textabstractWe determined the role of Yersinia pestis virulence markers in an animal model of pneumonic plague. Eleven strains of Y. pestis were characterized using PCR assays to detect the presence of known virulence genes both encoded by the three plasmids as well as chromosomal markers. The

Range bagging: a new method for ecological niche modelling from presence-only data.

Science.gov (United States)

Drake, John M

2015-06-06

The ecological niche is the set of environments in which a population of a species can persist without introduction of individuals from other locations. A good mathematical or computational representation of the niche is a prerequisite to addressing many questions in ecology, biogeography, evolutionary biology and conservation. A particularly challenging question for ecological niche modelling is the problem of presence-only modelling. That is, can an ecological niche be identified from records drawn only from the set of niche environments without records from non-niche environments for comparison? Here, I introduce a new method for ecological niche modelling from presence-only data called range bagging. Range bagging draws on the concept of a species' environmental range, but was inspired by the empirical performance of ensemble learning algorithms in other areas of ecological research. This paper extends the concept of environmental range to multiple dimensions and shows that range bagging is computationally feasible even when the number of environmental dimensions is large. The target of the range bagging base learner is an environmental tolerance of the species in a projection of its niche and is therefore an ecologically interpretable property of a species' biological requirements. The computational complexity of range bagging is linear in the number of examples, which compares favourably with the main alternative, Qhull. In conclusion, range bagging appears to be a reasonable choice for niche modelling in applications in which a presence-only method is desired and may provide a solution to problems in other disciplines where one-class classification is required, such as outlier detection and concept learning.

Role of inflammatory cells and adenosine in lung ischemia reoxygenation injury using a model of lung donation after cardiac death.

Science.gov (United States)

Smail, Hassiba; Baste, Jean-Marc; Gay, Arnaud; Begueret, Hugues; Noël, Romain; Morin, Jean-Paul; Litzler, Pierre-Yves

2016-04-01

The objective of this study is to analyze the role of inflammation in the lung ischemia reperfusion (IR) injury and determine the protective role of adenosine in an in vitro lung transplantation model. We used a hybrid model of lung donor after cardiac death, with warm ischemia in corpo of varying duration (2 h, 4 h) followed by in vitro lung slices culture for reoxygenation (1 h, 4 h and 24 h), in the presence or not of lymphocytes and of adenosine. To quantify the inflammatory lesions, we performed TNFα, IL2 assays, and histological analysis. In this model of a nonblood perfused system, the addition of lymphocytes during reoxygenation lead to higher rates of TNFα and IL2 after 4 h than after 2 h of warm ischemia (P < .05). These levels increased with the duration of reoxygenation and were maximum at 24 h (P < .05). In the presence of adenosine TNFα and IL2 decreased. After 2 h of warm ischemia, we observed a significant inflammatory infiltration, alveolar thickening and a necrosis of the bronchiolar cells. After 4 h of warm ischemia, alveolar cells necrosis was associated. This model showed that lymphocytes increased the inflammatory response and the histological lesions after 4 h of warm ischemia and that adenosine could have an anti-inflammatory role with potential reconditioning action when used in the pneumoplegia solution.

A comprehensive study on the role of the Yersinia pestis virulence markers in an animal model of pneumonic plague

NARCIS (Netherlands)

Kaman, W.E.; Hawkey, S.; Kleij, D. van der; Broekhuijsen, M.P.; Silman, N.J.; Bikker, F.J.

2011-01-01

We determined the role of Yersinia pestis virulence markers in an animal model of pneumonic plague. Eleven strains of Y. pestis were characterized using PCR assays to detect the presence of known virulence genes both encoded by the three plasmids as well as chromosomal markers. The virulence of all

Models and role models.

Science.gov (United States)

ten Cate, Jacob M

2015-01-01

Developing experimental models to understand dental caries has been the theme in our research group. Our first, the pH-cycling model, was developed to investigate the chemical reactions in enamel or dentine, which lead to dental caries. It aimed to leverage our understanding of the fluoride mode of action and was also utilized for the formulation of oral care products. In addition, we made use of intra-oral (in situ) models to study other features of the oral environment that drive the de/remineralization balance in individual patients. This model addressed basic questions, such as how enamel and dentine are affected by challenges in the oral cavity, as well as practical issues related to fluoride toothpaste efficacy. The observation that perhaps fluoride is not sufficiently potent to reduce dental caries in the present-day society triggered us to expand our knowledge in the bacterial aetiology of dental caries. For this we developed the Amsterdam Active Attachment biofilm model. Different from studies on planktonic ('single') bacteria, this biofilm model captures bacteria in a habitat similar to dental plaque. With data from the combination of these models, it should be possible to study separate processes which together may lead to dental caries. Also products and novel agents could be evaluated that interfere with either of the processes. Having these separate models in place, a suggestion is made to design computer models to encompass the available information. Models but also role models are of the utmost importance in bringing and guiding research and researchers. 2015 S. Karger AG, Basel

Cellular Automata Models of Traffic Behavior in Presence of Speed Breaking Structures

International Nuclear Information System (INIS)

Ramachandran, Parthasarathy

2009-01-01

In this article, we study traffic flow in the presence of speed breaking structures. The speed breakers are typically used to reduce the local speed of vehicles near certain institutions such as schools and hospitals. Through a cellular automata model we study the impact of such structures on global traffic characteristics. The simulation results indicate that the presence of speed breakers could reduce the global flow under moderate global densities. However, under low and high global density traffic regime the presence of speed breakers does not have an impact on the global flow. Further the speed limit enforced by the speed breaker creates a phase distinction. For a given global density and slowdown probability, as the speed limit enforced by the speed breaker increases, the traffic moves from the reduced flow phase to maximum flow phase. This underlines the importance of proper design of these structures to avoid undesired flow restrictions. (general)

Role modeling excellence in clinical nursing practice.

Science.gov (United States)

Perry, R N Beth

2009-01-01

Role modeling excellence in clinical nursing practice is the focus of this paper. The phenomenological research study reported involved a group of 8 nurses identified by their colleagues as exemplary. The major theme revealed in this study was that these exemplary nurses were also excellent role models in the clinical setting. This paper details approaches used by these nurses that made them excellent role models. Specifically, the themes of attending to the little things, making connections, maintaining a light-hearted attitude, modeling, and affirming others are presented. These themes are discussed within the framework of Watson [Watson, J., 1989. Human caring and suffering: a subjective model for health services. In: Watson, J., Taylor, R. (Eds.), They Shall Not Hurt: Human Suffering and Human Caring. Colorado University, Boulder, CO] "transpersonal caring" and [Bandura, A., 1997. Social Learning Theory. Prentice Hall, Englewood Cliffs, NJ] "Social Learning Theory." Particular emphasis in the discussion is on how positive role modeling by exemplary practitioners can contribute to the education of clinical nurses in the practice setting.

Can role models boost entrepreneurial attitudes?

Science.gov (United States)

Fellnhofer, Katharina; Puumalainen, Kaisu

2017-01-01

This multi-country study used role models to boost perceptions of entrepreneurial feasibility and desirability. The results of a structural equation model based on a sample comprising 426 individuals who were primarily from Austria, Finland and Greece revealed a significant positive influence on perceived entrepreneurial desirability and feasibility. These findings support the argument for embedding entrepreneurial role models in entrepreneurship education courses to promote entrepreneurial activities. This direction is not only relevant for the academic community but also essential for nascent entrepreneurs, policymakers and society at large.

A Diverging View of Role Modeling in Medical Education

Directory of Open Access Journals (Sweden)

Gurjit Sandhu

2015-03-01

Full Text Available Research in the area of role modeling has primarily focused on the qualities and attributes of exceptional role models, and less attention has been given to the act of role modeling itself (Elzubeir & Rizk, 2001; Jochemsen-van der Leeuw, van Dijk, van Etten-Jamaludin, & Wieringa-de Waard, 2013; Wright, 1996; Wright, Wong, & Newill, 1997. A standardized understanding of role modeling in medical education remains elusive (Kenny, Mann, & MacLeod, 2003. This is problematic given that role modeling is pervasively documented as an approach to teaching (Reuler & Nardone, 1994. Our study attempts to fill a void in this body of research by looking at what faculty are thinking, saying, and doing when they say they are role modeling. Individual semi-structured interviews with faculty members were conducted in the Department of General Surgery at Queen’s University, Kingston, Ontario, Canada. Interviews were recorded, transcribed, and analyzed using qualitative methods for themes surrounding teaching and role modeling. Three major themes emerged from the data: (1 faculty members think they are teaching when they are acting professionally; (2 faculty members become aware of teaching opportunities and act on them; and (3 faculty members employ evidence-based teaching methods, but they are incorrectly labeling them as “role modeling.” As a whole, our findings should help distinguish between role modeling as roles and responsibilities enacted while doing one’s job well, and teaching as facilitated instruction that helps connect knowledge with action (Clayton, 2006; Fassbinder, 2007. Contributing to a better understanding of how teaching is separate from role modeling has the potential to improve the scope and quality of teaching, ultimately enhancing the learning experience for trainees.

Modelling the fathering role: Experience in the family of origin and father involvement

Directory of Open Access Journals (Sweden)

Mihić Ivana

2012-01-01

Full Text Available The study presented in this paper deals with the effects of experiences with father in the family of origin on the fathering role in the family of procreation. The results of the studies so far point to great importance of such experiences in parental role modelling, while recent approaches have suggested the concept of introjected notion or an internal working model of the fathering role as the way to operationalise the transgenerational transfer. The study included 247 two-parent couple families whose oldest child attended preschool education. Fathers provided information on self-assessed involvement via the Inventory of father involvement, while both fathers and mothers gave information on introjected experiences from the family of origin via the inventory Presence of the father in the family of origin. It was shown that father’s experiences from the family of origin had significant direct effects on his involvement in child-care. Very important experiences were those of negative emotional exchange, physical closeness and availability of the father, as well as beliefs about the importance of the father as a parent. Although maternal experiences from the family of origin did not contribute significantly to father involvement, shared beliefs about father’s importance as a parent in the parenting alliance had an effect on greater involvement in child-care. The data provide confirmation of the hypotheses on modelling of the fathering role, but also open the issue of the factor of intergenerational maintenance of traditional forms of father involvement in families in Serbia.

Surface complexation modeling of U(VI) sorption on GMZ bentonite in the presence of fulvic acid

Energy Technology Data Exchange (ETDEWEB)

Zheng, Jie [Lanzhou Univ. (China). Radiochemistry Laboratory; Ministry of Industry and Information Technology, Guangzhou (China). The 5th Electronics Research Inst.; Luo, Daojun [Ministry of Industry and Information Technology, Guangzhou (China). The 5th Electronics Research Inst.; Qiao, Yahua; Wang, Liang; Zhang, Chunming [Ministry of Environmental Protection, Beijing (China). Nuclear and Radiation Safety Center; Wu, Wangsuo [Lanzhou Univ. (China). Radiochemistry Laboratory; Ye, Yuanlv [Ministry of Environmental Protection, Beijing (China). Nuclear and Radiation Safety Center; Lanzhou Univ. (China). Radiochemistry Laboratory

2017-03-01

In this work, experiments and modeling for the interactions between uranyl ion and GMZ bentonite in the presence of fulvic acid are presented. The results demonstrated that FA is strongly bound to GMZ bentonite, and these molecules have a very large effect on the U(VI) sorption. The results also demonstrated that U(VI) sorption to GMZ bentonite in the presence and absence of sorbed FA can be well predicted by combining SHM and DLM. According to the model calculations, the nature of the interactions between FA with U(VI) at GMZ bentonite surface is mainly surface complex. The first attempt to simulate clay interaction with humus by the SHM model.

Stability of biological father presence as a proxy for family stability: cross-racial associations with the longitudinal development of emotion regulation in toddlerhood.

Science.gov (United States)

Bocknek, Erika London; Brophy-Herb, Holly E; Fitzgerald, Hiram E; Schiffman, Rachel F; Vogel, Cheri

2014-01-01

The current study, utilizing data from the National Early Head Start Research and Evaluation Project (Love et al., 2005) explored the relationship between biological father presence and emotion regulation over toddlerhood among children from low-income families. Conceptualizing biological father presence as a proxy for family role development, results are interpreted from a role development theoretical perspective. The latent growth curve model was compared based on child ethnoracial status (African American, Caucasian, Hispanic) and child gender. Consistent biological father presence was associated with toddlers' regulatory development across toddlerhood, and this relationship was most robust among Caucasian toddlers as compared to African American toddlers. Findings for Hispanic toddlers were not significantly different from those of Caucasian or African American families. Results bolster the literature on father presence and child outcomes. Analyses address consistency in father presence as a proxy for coherent role development and define a link between consistent father presence and children's regulatory development, demonstrating ethnoracial differences which are likely attributed to the social construction of family roles. © 2014 Michigan Association for Infant Mental Health.

Defining role models for staff orientation.

Science.gov (United States)

Kinley, H

This article examines the need for a formal role model to help integrate new staff within a unit. While acknowledging the range of titles and functions ascribed to such a role in the literature, the author suggests that the essence of the role and its formal recognition has benefits for experienced staff and orientees alike.

Presence-only Species Distribution Modeling for King Mackerel (Scomberomorus cavalla) and its 31 Prey Species in the Gulf of Mexico

Science.gov (United States)

Cai, X.; Simons, J.; Carollo, C.; Sterba-Boatwright, B.; Sadovski, A.

2016-02-01

Ecosystem based fisheries management has been broadly recognized throughout the world as a way to achieve better conservation. Therefore, there is a strong need for mapping of multi-species interactions or spatial distributions. Species distribution models are widely applied since information regarding the presence of species is usually only available for limited locations due to the high cost of fisheries surveys. Instead of regular presence and absence records, a large proportion of the fisheries survey data have only presence records. This makes the modeling problem one of one-class classification (presence only), which is much more complex than the regular two-class classification (presence/absence). In this study, four different presence-only species distribution algorithms (Bioclim, Domain, Mahal and Maxent) were applied using 13 environmental parameters (e.g., depth, DO, bottom types) as predictors to model the distribution of king mackerel (Scomberomorus cavalla) and its 31 prey species in the Gulf of Mexico (a total of 13625 georeferenced presence records from OBIS and GBIF were used). Five-fold cross validations were applied for each of the 128 (4 algorithms × 32 species) models. Area under curve (AUC) and correlation coefficient (R) were used to evaluate the model performances. The AUC of the models based on these four algorithms were 0.83±0.14, 0.77±0.16, 0.94±0.06 and 0.94±0.06, respectively; while R for the models were 0.47±0.27, 0.43±0.24, 0.27±0.16 and 0.76±0.16, respectively. Post hoc with Tukey's test showed that AUC for the Maxent-based models were significantly (pMexico to help managers better manage related fisheries resources.

A model of film boiling in the presence of electric fields

Energy Technology Data Exchange (ETDEWEB)

Carrica, P.M.; Masson, V.; Clausse, A. [Centro Atomico Bariloche and Instituto Balseiro, Barilochi (Argentina)

1995-09-01

Recently it was found that, when a strong electric field is applied around a heated wire, two distinct film boiling heat transfer regimes are observed. In this paper, a semi-empirical model is derived to analyze the pool boiling process in the presence of non uniform electric field. The model takes into account the dielectrophoretic force acting on the bubbles as they grow and the effect of the electric field on the most dangerous wavelength. It is shown how the transition between the two film boiling regimes is possible for high strength electric fields. The threshold voltage for transition, transition heat fluxes and hysteresis values are compared with experimental outcomes showing a satisfactory agreement.

Towards A Model of Identity and Role Exit

Directory of Open Access Journals (Sweden)

Jason S. Milne

2011-11-01

Full Text Available Explanations of role exit often focus on how factors associated with a specific role that affect whether the individual will exit a role or not. Other research explains how identities affect our performance in a role. However, no one has yet to demonstrate the connection between role-set factors and identities, and role exit. Using data from a survey of 940 current and former soccer referees, this paper provides a model of role exit that involves a complex of processes that include role-set factors (structural and cultural factors associated with a specific role and identity processes. Specifically, this paper demonstrates that, other than role conflict, identity processes explain the relationship between role-set factors and role exit. The model provides a beginning method for understanding the connection between identities and role exit.

Calibration plots for risk prediction models in the presence of competing risks

DEFF Research Database (Denmark)

Gerds, Thomas A; Andersen, Per K; Kattan, Michael W

2014-01-01

A predicted risk of 17% can be called reliable if it can be expected that the event will occur to about 17 of 100 patients who all received a predicted risk of 17%. Statistical models can predict the absolute risk of an event such as cardiovascular death in the presence of competing risks...... prediction model is well calibrated. The first is lack of independent validation data, the second is right censoring, and the third is that when the risk scale is continuous, the estimation problem is as difficult as density estimation. To deal with these problems, we propose to estimate calibration curves...

Benefits of Dominance over Additive Models for the Estimation of Average Effects in the Presence of Dominance

Directory of Open Access Journals (Sweden)

Pascal Duenk

2017-10-01

Full Text Available In quantitative genetics, the average effect at a single locus can be estimated by an additive (A model, or an additive plus dominance (AD model. In the presence of dominance, the AD-model is expected to be more accurate, because the A-model falsely assumes that residuals are independent and identically distributed. Our objective was to investigate the accuracy of an estimated average effect (α^ in the presence of dominance, using either a single locus A-model or AD-model. Estimation was based on a finite sample from a large population in Hardy-Weinberg equilibrium (HWE, and the root mean squared error of α^ was calculated for several broad-sense heritabilities, sample sizes, and sizes of the dominance effect. Results show that with the A-model, both sampling deviations of genotype frequencies from HWE frequencies and sampling deviations of allele frequencies contributed to the error. With the AD-model, only sampling deviations of allele frequencies contributed to the error, provided that all three genotype classes were sampled. In the presence of dominance, the root mean squared error of α^ with the AD-model was always smaller than with the A-model, even when the heritability was less than one. Remarkably, in the absence of dominance, there was no disadvantage of fitting dominance. In conclusion, the AD-model yields more accurate estimates of average effects from a finite sample, because it is more robust against sampling deviations from HWE frequencies than the A-model. Genetic models that include dominance, therefore, yield higher accuracies of estimated average effects than purely additive models when dominance is present.

Creating Role models for Japanese Learners

OpenAIRE

Brown, Howard

2009-01-01

English classes in Japan are often taught through the medium of Japanese. This sends the message that English is a subject of study rather than a means of communication. A great deal of recent research and pedagogical work has gone into encouraging more classroom English use by Japanese Teachers of English in order to provide positive role models of language use to students. Along with this, other content area faculty members can become role models for students' English success. Results of th...

A Landscape-based model for predicting Mycobacterium ulcerans infection (Buruli Ulcer disease) presence in Benin, West Africa.

Science.gov (United States)

Wagner, Tyler; Benbow, M Eric; Burns, Meghan; Johnson, R Christian; Merritt, Richard W; Qi, Jiaguo; Small, Pamela L C

2008-03-01

Mycobacterium ulcerans infection (Buruli ulcer [BU] disease) is an emerging tropical disease that causes severe morbidity in many communities, especially those in close proximity to aquatic environments. Research and control efforts are severely hampered by the paucity of data regarding the ecology of this disease; for example, the vectors and modes of transmission remain unknown. It is hypothesized that BU presence is associated with altered landscapes that perturb aquatic ecosystems; however, this has yet to be quantified over large spatial scales. We quantified relationships between land use/land cover (LULC) characteristics surrounding individual villages and BU presence in Benin, West Africa. We also examined the effects of other village-level characteristics which we hypothesized to affect BU presence, such as village distance to the nearest river. We found that as the percent urban land use in a 50-km buffer surrounding a village increased, the probability of BU presence decreased. Conversely, as the percent agricultural land use in a 20-km buffer surrounding a village increased, the probability of BU presence increased. Landscape-based models had predictive ability when predicting BU presence using validation data sets from Benin and Ghana, West Africa. Our analyses suggest that relatively small amounts of urbanization are associated with a decrease in the probability of BU presence, and we hypothesize that this is due to the increased availability of pumped water in urban environments. Our models provide an initial approach to predicting the probability of BU presence over large spatial scales in Benin and Ghana, using readily available land use data.

The influence of role models in undergraduate nurse education.

Science.gov (United States)

Jack, Kirsten; Hamshire, Claire; Chambers, Alison

2017-12-01

To explore the concept of role modelling in undergraduate nurse education and its effect on the personal and professional development of student nurses. Effective educative strategies are important for student nurses, who have to cope with learning in both clinical and university settings. Given the contemporary issues facing nurse education and practice in the United Kingdom (UK), it is timely and important to undertake pedagogical research into the concept of role modelling as an effective educative method. A descriptive narrative approach. Unstructured interviews were conducted with 14 current/recently discontinued students from Adult and Mental Health branches of nursing degree programmes in the north-west region of England, United Kingdom (UK). Data were thematically analysed. Students valued exposure to positive role models in clinical and university settings and viewed them as beneficial to their learning. Exposure to negative role models occurred, and this provided students with opportunities to consider the type of nurse they aspired to become. In some cases, students' exposure to perceived poor practice had an adverse effect on their learning and led to negative feelings about nursing work. Clinical staff might be perceived as more relevant role models than those in the university setting although there were still opportunities for academic staff to model professional behaviours. The study found that role modelling is an effective way to support learning and led to student satisfaction across both clinical and university settings. The findings support the use of role models in nurse education, and further research about conscious positive modelling of practice is required. Exploring the use of role models is important when examining ways in which the quality of nurse education might be developed. © 2017 John Wiley & Sons Ltd.

Benefits of dominance over additive models for the estimation of average effects in the presence of dominance

NARCIS (Netherlands)

Duenk, Pascal; Calus, Mario P.L.; Wientjes, Yvonne C.J.; Bijma, Piter

2017-01-01

In quantitative genetics, the average effect at a single locus can be estimated by an additive (A) model, or an additive plus dominance (AD) model. In the presence of dominance, the AD-model is expected to be more accurate, because the A-model falsely assumes that residuals are independent and

A two-stage model in a Bayesian framework to estimate a survival endpoint in the presence of confounding by indication.

Science.gov (United States)

Bellera, Carine; Proust-Lima, Cécile; Joseph, Lawrence; Richaud, Pierre; Taylor, Jeremy; Sandler, Howard; Hanley, James; Mathoulin-Pélissier, Simone

2018-04-01

Background Biomarker series can indicate disease progression and predict clinical endpoints. When a treatment is prescribed depending on the biomarker, confounding by indication might be introduced if the treatment modifies the marker profile and risk of failure. Objective Our aim was to highlight the flexibility of a two-stage model fitted within a Bayesian Markov Chain Monte Carlo framework. For this purpose, we monitored the prostate-specific antigens in prostate cancer patients treated with external beam radiation therapy. In the presence of rising prostate-specific antigens after external beam radiation therapy, salvage hormone therapy can be prescribed to reduce both the prostate-specific antigens concentration and the risk of clinical failure, an illustration of confounding by indication. We focused on the assessment of the prognostic value of hormone therapy and prostate-specific antigens trajectory on the risk of failure. Methods We used a two-stage model within a Bayesian framework to assess the role of the prostate-specific antigens profile on clinical failure while accounting for a secondary treatment prescribed by indication. We modeled prostate-specific antigens using a hierarchical piecewise linear trajectory with a random changepoint. Residual prostate-specific antigens variability was expressed as a function of prostate-specific antigens concentration. Covariates in the survival model included hormone therapy, baseline characteristics, and individual predictions of the prostate-specific antigens nadir and timing and prostate-specific antigens slopes before and after the nadir as provided by the longitudinal process. Results We showed positive associations between an increased prostate-specific antigens nadir, an earlier changepoint and a steeper post-nadir slope with an increased risk of failure. Importantly, we highlighted a significant benefit of hormone therapy, an effect that was not observed when the prostate-specific antigens trajectory was

Ice formation in model biological membranes in the presence of cryoprotectors

Energy Technology Data Exchange (ETDEWEB)

Kiselev, M.A. E-mail: kiselev@nf.jinr.ru; Lesieur, P.; Kisselev, A.M.; Ollivon, M

2000-06-21

Ice formation in model biological membranes is studied by SAXS and WAXS in the presence of cryoprotectors: dimethyl sulfoxide and glycerol. Three types of phospholipid membranes: DPPC, DMPC, DSPC are chosen for the investigation as well-studied model biological membranes. A special cryostat is used for sample cooling from 14.1 deg. C to -55.4 deg. C. The ice formation is detected only by WAXS in binary phospholipid/water and ternary phospholipid/cryoprotector/water systems in the condition of excess solvent. Ice formation in a binary phospholipid/water system creates an abrupt decrease of the membrane repeat distance by {delta}d, the so-called ice-induced dehydration of intermembrane space. The value of {delta}d decreases as the cryoprotector concentration increases. The formation of ice does not influence the membrane structure ({delta}d=0) for cryoprotector mole fractions higher than 0.05.

Hidden Markov model for improved ultrasound-based presence detection

NARCIS (Netherlands)

Jaramillo Garcia, P.A.; Linnartz, J.P.M.G.

2015-01-01

Adaptive lighting systems typically use a presence detector to save energy by switching off lights in unoccupied rooms. However, it is highly annoying when lights are erroneously turned off while a user is present (false negative, FN). This paper focuses on the estimation of presence, using a Hidden

The Role of Work-Related Skills and Career Role Models in Adolescent Career Maturity.

Science.gov (United States)

Flouri, Eirini; Buchanan, Ann

2002-01-01

Using data for 2,722 British adolescents explores whether work-related skills and career role models are associated with career maturity when sociodemographic characteristics, family support, and personal characteristics are controlled. Having work-related skills and having a career role model were positively associated with career maturity.…

Dual role of delay effects in a tumour-immune system.

Science.gov (United States)

Yu, Min; Dong, Yueping; Takeuchi, Yasuhiro

2017-08-01

In this paper, a previous tumour-immune interaction model is simplified by neglecting a relatively weak direct immune activation by the tumour cells, which can still keep the essential dynamics properties of the original model. As the immune activation process is not instantaneous, we now incorporate one delay for the activation of the effector cells (ECs) by helper T cells (HTCs) into the model. Furthermore, we investigate the stability and instability regions of the tumour-presence equilibrium state of the delay-induced system with respect to two parameters, the activation rate of ECs by HTCs and the HTCs stimulation rate by the presence of identified tumour antigens. We show the dual role of this delay that can induce stability switches exhibiting destabilization as well as stabilization of the tumour-presence equilibrium. Besides, our results reveal that an appropriate immune activation time delay plays a significant role in control of tumour growth.

Science teacher candidates' perceptions about roles and nature of scientific models

Science.gov (United States)

Yenilmez Turkoglu, Ayse; Oztekin, Ceren

2016-05-01

Background: Scientific models have important roles in science and science education. For scientists, they provide a means for generating new knowledge or function as an accessible summary of scientific studies. In science education, on the other hand, they are accessible representations of abstract concepts, and are also organizational frameworks to teach and learn inaccessible facts. As being indispensable parts of learning and doing science, use of scientific models in science classes should be reinforced. At this point, uncovering pre-service science teachers' (PSTs) understandings of scientific models are of great importance since they will design and conduct teaching situations for their students. Purpose: The study aimed to provide an answer to the research question: What understandings do PSTs possess about scientific models? Sample: The sample of the study consisted of 14 PSTs enrolled in an Elementary Science Education program in a public university in Ankara, Turkey. Design and methods: Data were collected by using an open-item instrument and semi-structured interviews, and were analyzed by using qualitative data analysis methods. Results: Findings showed that PSTs held fragmented views of models by having informed views in some aspects while having naïve views on others. That is, although they displayed a constructivist orientation by acknowledging the presence of multiple models for the same phenomenon depending on scientists' perspectives or creativity involved in the production of scientific knowledge, PSTs also expressed logical positivist views by believing that models should be close to the real phenomena that they represent. Findings further revealed that PSTs generally conceptualized models' materialistic uses, yet they did not think much about their theoretical and conceptual uses. It was observed that roles like reifying and visualizing were overestimated and models were dominantly characterized as three-dimensional representations

A Spatial Faithful Cooperative System Based on Mixed Presence Groupware Model

Science.gov (United States)

Wang, Wei; Wang, Xiangyu; Wang, Rui

Traditional groupware platforms are found restrained and cumbersome for supporting geographically dispersed design collaboration. This paper starts with two groupware models, which are Single Display Groupware and Mixed Presence Groupware, and then discusses some of the limitations and argues how these limitations could possibly impair efficient communication among remote designers. Next, it suggests that the support for spatial faithfulness and Tangible User Interface (TUI) could help fill the gap between Face-to-Face (F2F) collaboration and computer-mediated remote collaboration. A spatial faithful groupware with TUI support is then developed to illustrate this concept.

Role modelling in medical education: the importance of teaching skills.

Science.gov (United States)

Burgess, Annette; Oates, Kim; Goulston, Kerry

2016-04-01

By observation of role models, and participation in activities, students develop their attitudes, values and professional competencies. Literature suggests that clinical skills and knowledge, personality, and teaching skills are three main areas that students consider central to the identification of positive role models. The aim of this study was to explore junior medical students' opinions of the ideal attributes of a good role model in clinical tutors. The study was conducted with one cohort (n = 301) of students who had completed year 1 of the medical programme in 2013. All students were asked to complete a questionnaire regarding the ideal attributes of a good role model in a clinical tutor. The questionnaire consisted of seven closed items and one open-ended question. The response rate to the questionnaire was 265/301 (88%). Although students found all three key areas important in a good role model, students emphasised the importance of excellence in teaching skills. Specifically, students see good role models as being able to provide a constructive learning environment, a good understanding of the curriculum and an ability to cater to the learning needs of all students. Students see good role models as being able to provide a constructive learning environment While acknowledging the importance of a patient-centred approach, as well as clinical knowledge and skills, our findings reinforce the importance of the actual teaching abilities of role models within medical education. © 2015 John Wiley & Sons Ltd.

The role of money in modern macro models

OpenAIRE

Seitz, Franz; Schmidt, Markus A.

2013-01-01

This paper is the starting point of a series of analyses aiming at re-discovering the role of money for monetary policy purposes. It provides an overview of the role of money in modern macro models. In particular, we are focussing on New Keynesian and New Monetarist models to investigate their main findings and most significant shortcomings in considering money properly. As a further step, we ask about the role of financial intermediaries in this respect. In dealing with these issues, we dist...

Assessment of the MELCOR 1.8.6 condensation heat transfer model under the presence of noncondensable gases

Energy Technology Data Exchange (ETDEWEB)

Yoo, Ji Min; Lee, Dong Hun; Jeong, Jae Jun [Pusan National University, Busan (Korea, Republic of)

2016-05-15

Condensation heat transfer under the presence of noncondensable gases (NCGs) is an important issue in nuclear safety because the presence of even a small quantity of NC gases in the vapor largely reduces the condensation rate. The extensive assessment of the condensation model of the safety analysis codes has been also performed. When NCGs are present, the condensation phenomenon is largely reduced by accumulated NCGs near the condensing surface. Since the total pressure remains constant, the partial pressure of vapor at the liquid-vapor interface is lower than that in the bulk mixture, providing the driving force for vapor diffusion towards the liquid-vapor interface. The main objective of the present study is the assessment of the condensation heat transfer model of the severe accident code MELCOR 1.8.6 under the presence of NCGs. In this study, the condensation heat transfer model of the MELCOR 1.8.6 is assessed using various experiments which have 4 different types of geometry. Through the comparison of the results, it was shown that the MELCOR code generally under-predicts the condensation heat transfer except the condensation on outer surface of vertical pipes and improvement is needed for other geometries.

Phase structure of Gross-Neveu model with compactification in the presence of external magnetic field

International Nuclear Information System (INIS)

Zhokhov, R.N.; Kolmakov, P. B.; Zhukovsky, V.Ch.; Klimenko, K.G.

2016-01-01

In the paper there have been studied Gross-Neveu model in (2+1)-dimensional space-time with one compactified dimension in presence of external magnetic field at finite temperature. Magnetic field is directed along the uncompactified dimension that is along the axis of the cylinder on which the system lives. Chiral symmetry breaking and corresponding phase structure of the model is investigated in the leading order of (1/N) expansion

Good mentors and role models

Indian Academy of Sciences (India)

Lawrence

Today, as a teacher and researcher, I look forward to my day ... essential for women, and that it would prove to be more valuable ... mentors, who have been my role models. ... benefit to make the workplace gender friendly by including more.

Phase transitions in the random field Ising model in the presence of a transverse field

Energy Technology Data Exchange (ETDEWEB)

Dutta, A.; Chakrabarti, B.K. [Saha Institute of Nuclear Physics, Bidhannagar, Calcutta (India); Stinchcombe, R.B. [Saha Institute of Nuclear Physics, Bidhannagar, Calcutta (India); Department of Physics, Oxford (United Kingdom)

1996-09-07

We have studied the phase transition behaviour of the random field Ising model in the presence of a transverse (or tunnelling) field. The mean field phase diagram has been studied in detail, and in particular the nature of the transition induced by the tunnelling (transverse) field at zero temperature. Modified hyper-scaling relation for the zero-temperature transition has been derived using the Suzuki-Trotter formalism and a modified 'Harris criterion'. Mapping of the model to a randomly diluted antiferromagnetic Ising model in uniform longitudinal and transverse field is also given. (author)

Role of fluctuations in the phase transitions of coupled plaquette spin models of glasses

Directory of Open Access Journals (Sweden)

Giulio Biroli, Charlotte Rulquin, Gilles Tarjus, Marco Tarzia

2016-10-01

Full Text Available We study the role of fluctuations on the thermodynamic glassy properties of plaquette spin models, more specifically on the transition involving an overlap order parameter in the presence of an attractive coupling between different replicas of the system. We consider both short-range fluctuations associated with the local environment on Bethe lattices and long-range fluctuations that distinguish Euclidean from Bethe lattices with the same local environment. We find that the phase diagram in the temperature-coupling plane is very sensitive to the former but, at least for the $3$-dimensional (square pyramid model, appears qualitatively or semi-quantitatively unchanged by the latter. This surprising result suggests that the mean-field theory of glasses provides a reasonable account of the glassy thermodynamics of models otherwise described in terms of the kinetically constrained motion of localized defects and taken as a paradigm for the theory of dynamic facilitation. We discuss the possible implications for the dynamical behavior.

Model reference adaptive control of flexible robots in the presence of sudden load changes

Science.gov (United States)

Steinvorth, Rodrigo; Kaufman, Howard; Neat, Gregory

1991-01-01

Direct command generator tracker based model reference adaptive control (MRAC) algorithms are applied to the dynamics for a flexible-joint arm in the presence of sudden load changes. Because of the need to satisfy a positive real condition, such MRAC procedures are designed so that a feedforward augmented output follows the reference model output, thus, resulting in an ultimately bounded rather than zero output error. Thus, modifications are suggested and tested that: (1) incorporate feedforward into the reference model's output as well as the plant's output, and (2) incorporate a derivative term into only the process feedforward loop. The results of these simulations give a response with zero steady state model following error, and thus encourage further use of MRAC for more complex flexibile robotic systems.

Role model identification by medical radiation science practitioners - a pilot study

International Nuclear Information System (INIS)

Lewis, S.J.; Robinson, J.W.

2003-01-01

Purpose: The objective of this study was to address the paucity of research in role modeling and to develop a greater understanding of role modeling within the occupations of diagnostic radiography and radiation therapy. It can be postulated that the shaping of professional growth may rest with the behavioural models accepted by the workplace or the individuals themselves; thus, role modeling is a vital ingredient in professionalization. The benefits of this research are to advance the attainment of professional development and awareness by diagnostic radiographers and radiation therapists through the processes of identification, classification and construction of generic role models. Method: A study was conducted with eight target centres representing diagnostic and therapy workplaces. The centres ranged from large teaching hospitals to small community hospitals with the inclusion of two large private practices; and geographically, these centres were all located within the Sydney Area Health Services. The research methodology consisted of a structured interview and a short written task. A hierarchical percentage of participants, ranging from chief/manager, senior/charge, junior to recently graduated diagnostic radiographers and radiation therapists were invited to participate in the study. Results and discussion: The results indicated that the generic role models were established for both diagnostic radiographers and radiation therapists despite their varying clinical roles. Also similar was the participants' identification of attributes while viewing themselves as suitable role models. The selection of choice of workplace role model was different for the two occupations. Interestingly, the results indicate a mismatch between the ideal characteristic composition of a role model and the self-perception of the participants as professional role models on the subject of ethical conduct

Role model identification by medical radiation science practitioners - a pilot study

Energy Technology Data Exchange (ETDEWEB)

Lewis, S.J. E-mail: s.lewis@cchs.usyd.edu.au; Robinson, J.W

2003-02-01

Purpose: The objective of this study was to address the paucity of research in role modeling and to develop a greater understanding of role modeling within the occupations of diagnostic radiography and radiation therapy. It can be postulated that the shaping of professional growth may rest with the behavioural models accepted by the workplace or the individuals themselves; thus, role modeling is a vital ingredient in professionalization. The benefits of this research are to advance the attainment of professional development and awareness by diagnostic radiographers and radiation therapists through the processes of identification, classification and construction of generic role models. Method: A study was conducted with eight target centres representing diagnostic and therapy workplaces. The centres ranged from large teaching hospitals to small community hospitals with the inclusion of two large private practices; and geographically, these centres were all located within the Sydney Area Health Services. The research methodology consisted of a structured interview and a short written task. A hierarchical percentage of participants, ranging from chief/manager, senior/charge, junior to recently graduated diagnostic radiographers and radiation therapists were invited to participate in the study. Results and discussion: The results indicated that the generic role models were established for both diagnostic radiographers and radiation therapists despite their varying clinical roles. Also similar was the participants' identification of attributes while viewing themselves as suitable role models. The selection of choice of workplace role model was different for the two occupations. Interestingly, the results indicate a mismatch between the ideal characteristic composition of a role model and the self-perception of the participants as professional role models on the subject of ethical conduct.

Role models and occupational ambitions of in-school male adolescents

Directory of Open Access Journals (Sweden)

Suhail Ahmad Azmi

2014-01-01

Full Text Available Background: A role model is perceived as worthy of imitation, their selection can indicate significant elements of psychosocial health and self-projection in adolescents. Patterns of behavior and lifestyle choices established during adolescence can have immediate and lasting effects on health. Materials and Methods: Cross-sectional study was undertaken in the schools of Aligarh, Uttar Pradesh, India. The sample frame was 2347, out of which a sample of 390 students was studied. Data collected were entered and analyzed by SPSS for Windows version 10%. Results: Majority (62.7% of adolescents revealed that their role models were Film Star (34.8% and their Teachers (27.9%, Parents (14.3%, Sportsman (12.0%. Politicians as the role models were opted by least proportion (1.2%. Desire of future occupation was Businessmen (27.9%, Doctor (18.6, and Engineer (14.4%. Conclusion: Nearly all adolescents had a role model. There is greater impact of cinema on the minds of adolescents, which resulted in choosing film actors as their role model. Aspiration of future occupation was not related to the characteristics of the role model.

Modeling the Role of the Glymphatic Pathway and Cerebral Blood Vessel Properties in Alzheimer's Disease Pathogenesis.

Science.gov (United States)

Kyrtsos, Christina Rose; Baras, John S

2015-01-01

Alzheimer's disease (AD) is the most common cause of dementia in the elderly, affecting over 10% population over the age of 65 years. Clinically, AD is described by the symptom set of short term memory loss and cognitive decline, changes in mentation and behavior, and eventually long-term memory deficit as the disease progresses. On imaging studies, significant atrophy with subsequent increase in ventricular volume have been observed. Pathology on post-mortem brain specimens demonstrates the classic findings of increased beta amyloid (Aβ) deposition and the presence of neurofibrillary tangles (NFTs) within affected neurons. Neuroinflammation, dysregulation of blood-brain barrier transport and clearance, deposition of Aβ in cerebral blood vessels, vascular risk factors such as atherosclerosis and diabetes, and the presence of the apolipoprotein E4 allele have all been identified as playing possible roles in AD pathogenesis. Recent research has demonstrated the importance of the glymphatic system in the clearance of Aβ from the brain via the perivascular space surrounding cerebral blood vessels. Given the variety of hypotheses that have been proposed for AD pathogenesis, an interconnected, multilayer model offers a unique opportunity to combine these ideas into a single unifying model. Results of this model demonstrate the importance of vessel stiffness and heart rate in maintaining adequate clearance of Aβ from the brain.

The intriguing role of fibroblasts and c-Jun in the chemopreventive and therapeutic effect of finasteride on xenograft models of prostate cancer

Directory of Open Access Journals (Sweden)

Yi-Nong Niu

2016-01-01

Full Text Available In a large clinical trial, finasteride reduced the rate of low-grade prostate cancer (PCa while increasing the incidence of high-grade cancer. Whether finasteride promotes the development of high-grade tumors remains controversial. We demonstrated the role of fibroblasts and c-Jun in chemopreventive and therapeutic effect of finasteride on xenograft models of PCa. LNCaP (PC3 cells or recombinants of cancer cells and fibroblasts were implanted in male athymic nude mice treated with finasteride. Tumor growth, cell proliferation, apoptosis, p-Akt, and p-ERK1/2 were evaluated. In LNCaP (PC3 mono-grafted models, finasteride did not change the tumor growth. In recombinant-grafted models, fibroblasts and c-Jun promoted tumor growth; finasteride induced proliferation of LNCaP cells and repressed PC3 cell apoptosis. When c-Jun was knocked out, fibroblasts and/or finasteride did not promote the tumor growth. Finasteride inhibited p-Akt and p-ERK1/2 in mono-culture cancer cells while stimulating the same signaling molecules in the presence of fibroblasts. Reduced p-Akt and p-ERK1/2 were noted in the presence of c-Jun−/− fibroblasts. Fibroblasts and c-Jun promote PCa growth; finasteride further stimulates tumor growth with promoted proliferation, repressed apoptosis, and up-regulated pro-proliferative molecular pathway in the presence of fibroblasts and c-Jun. Stromal-epithelial interactions play critical roles in finasteride′s therapeutic effects on PCa. Our findings have preliminary implications in using finasteride as a chemopreventive or therapeutic agent for PCa patients.

Modeling brook trout presence and absence from landscape variables using four different analytical methods

Science.gov (United States)

Steen, Paul J.; Passino-Reader, Dora R.; Wiley, Michael J.

2006-01-01

As a part of the Great Lakes Regional Aquatic Gap Analysis Project, we evaluated methodologies for modeling associations between fish species and habitat characteristics at a landscape scale. To do this, we created brook trout Salvelinus fontinalis presence and absence models based on four different techniques: multiple linear regression, logistic regression, neural networks, and classification trees. The models were tested in two ways: by application to an independent validation database and cross-validation using the training data, and by visual comparison of statewide distribution maps with historically recorded occurrences from the Michigan Fish Atlas. Although differences in the accuracy of our models were slight, the logistic regression model predicted with the least error, followed by multiple regression, then classification trees, then the neural networks. These models will provide natural resource managers a way to identify habitats requiring protection for the conservation of fish species.

Role Modeling for Clinical Educators.

Science.gov (United States)

Ettinger, Ellen Richter

1991-01-01

To become better role models, higher educators in institutions of clinical education should be conscious of the behaviors they demonstrate and the broad range of activities and attitudes that students observe and emulate, including clinical competence, professional demeanor, doctor-patient interactions, ethical values, and social consciousness.…

Presence within a mixed reality environment.

Science.gov (United States)

van Schaik, Paul; Turnbull, Triece; van Wersch, Anna; Drummond, Sarah

2004-10-01

Mixed reality environments represent a new approach to creating technology-mediated experiences. However, there is a lack of empirical research investigating users' actual experience. The aim of the current exploratory, non-experimental study was to establish levels of and identify factors associated with presence, within the framework of Schubert et al.'s model of presence. Using questionnaire and interview methods, the experience of the final performance of the Desert Rain mixed reality environment was investigated. Levels of general and spatial presence were relatively high, but levels of involvement and realness were not. Overall, intrinsic motivation, confidence and intention to re-visit Desert Rain were high. However, age was negatively associated with both spatial presence and confidence to play. Furthermore, various problems in navigating the environment were identified. Results are discussed in terms of Schubert's model and other theoretical perspectives. Implications for system design are presented.

The Role of Participatory Modeling in Landscape Approaches to Reconcile Conservation and Development

Directory of Open Access Journals (Sweden)

Marieke Sandker

2010-06-01

Full Text Available Conservation organizations are increasingly turning to landscape approaches to achieve a balance between conservation and development goals. We use six case studies in Africa and Asia to explore the role of participatory modeling with stakeholders as one of the steps towards implementing a landscape approach. The modeling was enthusiastically embraced by some stakeholders and led to impact in some cases. Different stakeholders valued the modeling exercise differently. Noteworthy was the difference between those stakeholders connected to the policy process and scientists; the presence of the former in the modeling activities is key to achieving policy impacts, and the latter were most critical of participatory modeling. Valued aspects of the modeling included stimulating cross-sector strategic thinking, and helping participants to confront the real drivers of change and to recognize trade-offs. The modeling was generally considered to be successful in building shared understanding of issues. This understanding was gained mainly in the discussions held in the process of building the model rather than in the model outputs. The model itself reflects but a few of the main elements of the usually rich discussions that preceded its finalization. Problems emerged when models became too complex. Key lessons for participatory modeling are the need for good facilitation in order to maintain a balance between "models as stories" and technical modeling, and the importance of inviting the appropriate stakeholders to achieve impact.

Towards a Definition of Role-related Concepts for Business Modeling

NARCIS (Netherlands)

Meertens, Lucas Onno; Iacob, Maria Eugenia; Nieuwenhuis, Lambertus Johannes Maria

2010-01-01

Abstract—While several role-related concepts play an important role in business modeling, their definitions, relations, and use differ greatly between languages, papers, and reports. Due to this, the knowledge captured by models is not transferred correctly, and models are incomparable. In this

Adding intrapreneurial role in HR business partner model: (an extension in the HR business partner model)

OpenAIRE

Bashir, Jibran; Afzal, Sara

2009-01-01

Purpose: The Purpose of this paper is to introduce a concept, whereby extending the Dave Ulrich’s HR business partner model by adding fifth Role – The HR Intrapreneur Role – in the existing model. This will be done by combining two separate concepts “Four Roles HR Business Partner Model” and “Intrapreneurial HR”, resulting in a five roles HR Business Partner Model. Design/methodology/approach: This paper is introducing a new concept through theoretical research. Findings: H...

Calibration plots for risk prediction models in the presence of competing risks.

Science.gov (United States)

Gerds, Thomas A; Andersen, Per K; Kattan, Michael W

2014-08-15

A predicted risk of 17% can be called reliable if it can be expected that the event will occur to about 17 of 100 patients who all received a predicted risk of 17%. Statistical models can predict the absolute risk of an event such as cardiovascular death in the presence of competing risks such as death due to other causes. For personalized medicine and patient counseling, it is necessary to check that the model is calibrated in the sense that it provides reliable predictions for all subjects. There are three often encountered practical problems when the aim is to display or test if a risk prediction model is well calibrated. The first is lack of independent validation data, the second is right censoring, and the third is that when the risk scale is continuous, the estimation problem is as difficult as density estimation. To deal with these problems, we propose to estimate calibration curves for competing risks models based on jackknife pseudo-values that are combined with a nearest neighborhood smoother and a cross-validation approach to deal with all three problems. Copyright © 2014 John Wiley & Sons, Ltd.

Development of a novel kinetic model for the analysis of PAH biodegradation in the presence of lead and cadmium co-contaminants

Energy Technology Data Exchange (ETDEWEB)

Deary, Michael E., E-mail: michael.deary@northumbria.ac.uk [Department of Geography,Faculty of Engineering and Environment, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST (United Kingdom); Ekumankama, Chinedu C. [Department of Geography,Faculty of Engineering and Environment, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST (United Kingdom); Cummings, Stephen P. [Faculty of Health and Life Sciences, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST (United Kingdom)

2016-04-15

Highlights: • 40 week study of the biodegradation of 16 US EPA priority PAHs in a soil with high organic matter. • Effects of cadmium, lead and mercury co-contaminants studied. • Novel kinetic approach developed. • Biodegradation of lower molecular weight PAHs relatively unaffected by Cd or Pb. • Soil organic matter plays a key role in the PAH removal mechanism. - Abstract: We report on the results of a 40 week study in which the biodegradation of 16 US EPA polycyclic aromatic hydrocarbons (PAHs) was followed in microcosms containing soil of high organic carbon content (11%) in the presence and absence of lead and cadmium co-contaminants. The total spiked PAH concentration was 2166 mg/kg. Mercury amendment was also made to give an abiotic control. A novel kinetic model has been developed to explain the observed biphasic nature of PAH degradation. The model assumes that PAHs are distributed across soil phases of varying degrees of bioaccessibility. The results of the analysis suggest that overall percentage PAH loss is dependent on the respective rates at which the PAHs (a) are biodegraded by soil microorganisms in pore water and bioaccessible soil phases and (b) migrate from bioaccessible to non-bioaccessible soil phases. In addition, migration of PAHs to non-bioaccessible and non-Soxhlet-extractable soil phases associated with the humin pores gives rise to an apparent removal process. The presence of metal co-contaminants shows a concentration dependent inhibition of the biological degradation processes that results in a reduction in overall degradation. Lead appears to have a marginally greater inhibitory effect than cadmium.

Role models in pathology. A new look at an old issue.

Science.gov (United States)

Vance, R P

1989-01-01

Recent trends indicate that pathology is becoming a less attractive specialty to US medical graduates. This article discusses role models as an important but underutilized tool in medical education, and pathology education, in particular. Historically, the term role model has been used to describe a hero or a good teacher. Social scientists who study specialty choices in medicine, however, consider role model to be a much more heterogeneous concept. The information gained from these studies, therefore, needs to be sorted out carefully if erroneous conclusions about role models are to be avoided. For example, personality traits and attitudinal assessment studies encourage, unfortunately, either a totally passive stance toward recruitment, or a selective approach to those students who fit the specialty profile. However, there is no available evidence to support such approaches in pathology. Indeed, faculty role models have consistently been found to be influential recruiters into specialties that are not well known to the students (eg, pathology). Many different types of role models are present in pathology. Two important types are clinical consultants and physician-researchers. Positive faculty role models are an effective way to remove false impressions and negative assumptions about the practice of pathology, and they should be used more explicitly in recruiting efforts.

Current practices related to family presence during acute deterioration in adult emergency department patients.

Science.gov (United States)

Youngson, Megan J; Currey, Judy; Considine, Julie

2017-11-01

To explore the characteristics of and interactions between clinicians, patients and family members during management of the deteriorating adult patient in the emergency department. Previous research into family presence during resuscitation has identified many positive outcomes when families are included. However, over the last three decades the epidemiology of acute clinical deterioration has changed, with a decrease in in-hospital cardiac arrests and an increase in acute clinical deterioration. Despite the decrease in cardiac arrests, research related to family presence continues to focus on care during resuscitation rather than care during acute deterioration. Descriptive exploratory study using nonparticipatory observation. Five clinical deterioration episodes were observed within a 50-bed, urban, Australian emergency department. Field notes were taken using a semistructured tool to allow for thematic analysis. Presence, roles and engagement describe the interactions between clinicians, family members and patients while family are present during a patient's episode of deterioration. Presence was classified as no presence, physical presence and therapeutic presence. Clinicians and family members moved through primary, secondary and tertiary roles during patients' deterioration episode. Engagement was observed to be superficial or deep. There was a complex interplay between presence, roles and engagement with each influencing which form the other could take. Current practices of managing family during episodes of acute deterioration are complex and multifaceted. There is fluid interplay between presence, roles and engagement during a patient's episode of deterioration. This study will contribute to best practice, provide a strong foundation for clinician education and present opportunities for future research. © 2017 John Wiley & Sons Ltd.

Modeling of ITER edge plasma in the presence of resonant magnetic perturbations

Energy Technology Data Exchange (ETDEWEB)

Rozhansky, V.; Kaveeva, E.; Veselova, I.; Voskoboynikov, S. [Peter the Great St. Petersburg Polytechnic University, St. Petersburg (Russian Federation); Coster, D. [Max-Planck Institut fur Plasmaphysik, EURATOM Association, Garching (Germany)

2016-08-15

The modeling of the ITER edge is performed with the use of the code B2SOLPS5.2 in the presence of the electron conductivity caused by RMPs as well as for the reference case with the same input parameters but without RMPs. The radial electric field close to the neoclassical one is obtained without RMPs. Even the modest level of RMPs changes the direction of the electric field and causes the toroidal spin-up of the edge plasma. At the same time the pump-out effect is small. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Ising model with competing axial interactions in the presence of a field

International Nuclear Information System (INIS)

Yokoi, C.S.O.; Salinas, S.R.A.; Coutinho Filho, M.D.

1980-09-01

A layered Ising model is studied with competing interactions between nearest and next-nearest layers in the presence of a magnetic field. The analysis is carried out in the mean-field approximation with one effective field for each layer. The high-temperature region is studied analytically. The low-temperature region is studied numerically. T-H phase diagrams are constructed, which exhibit a variety of modulated phases, for various values of the ratio of the strength of the competing interactions. Numerical evidence of the devil's staircase behavior is found either as a function of temperature or applied magnetic field. (Author) [pt

Neutrophils Release Metalloproteinases during Adhesion in the Presence of Insulin, but Cathepsin G in the Presence of Glucagon

Directory of Open Access Journals (Sweden)

Natalia V. Fedorova

2018-01-01

Full Text Available In patients with reperfusion after ischemia and early development of diabetes, neutrophils can attach to blood vessel walls and release their aggressive bactericide agents, which damage the vascular walls. Insulin and 17β-estradiol (E2 relieve the vascular complications observed in metabolic disorders. In contrast, glucagon plays an essential role in the pathophysiology of diabetes. We studied the effect of hormones on neutrophil secretion during adhesion to fibronectin. Amino acid analysis revealed that proteins secreted by neutrophils are characterized by a stable amino acid profile enriched with glutamate, leucine, lysine, and arginine. The total amount of secreted proteins defined as the sum of detected amino acids was increased in the presence of insulin and reduced in the presence of glucagon. E2 did not affect the amount of protein secretion. Proteome analysis showed that in the presence of insulin and E2, neutrophils secreted metalloproteinases MMP-9 and MMP-8 playing a key role in modulation of the extracellular matrix. In contrast, glucagon induced the secretion of cathepsin G, a key bactericide protease of neutrophils. Cathepsin G can promote the development of vascular complications because of its proinflammatory activity and ability to stimulate neutrophil adhesion via the proteolysis of surface receptors.

Performance of nonlinear mixed effects models in the presence of informative dropout.

Science.gov (United States)

Björnsson, Marcus A; Friberg, Lena E; Simonsson, Ulrika S H

2015-01-01

Informative dropout can lead to bias in statistical analyses if not handled appropriately. The objective of this simulation study was to investigate the performance of nonlinear mixed effects models with regard to bias and precision, with and without handling informative dropout. An efficacy variable and dropout depending on that efficacy variable were simulated and model parameters were reestimated, with or without including a dropout model. The Laplace and FOCE-I estimation methods in NONMEM 7, and the stochastic simulations and estimations (SSE) functionality in PsN, were used in the analysis. For the base scenario, bias was low, less than 5% for all fixed effects parameters, when a dropout model was used in the estimations. When a dropout model was not included, bias increased up to 8% for the Laplace method and up to 21% if the FOCE-I estimation method was applied. The bias increased with decreasing number of observations per subject, increasing placebo effect and increasing dropout rate, but was relatively unaffected by the number of subjects in the study. This study illustrates that ignoring informative dropout can lead to biased parameters in nonlinear mixed effects modeling, but even in cases with few observations or high dropout rate, the bias is relatively low and only translates into small effects on predictions of the underlying effect variable. A dropout model is, however, crucial in the presence of informative dropout in order to make realistic simulations of trial outcomes.

Adolescents of the U.S. National Longitudinal Lesbian Family Study: male role models, gender role traits, and psychological adjustment

NARCIS (Netherlands)

Bos, H.; Goldberg, N.; van Gelderen, L.; Gartrell, N.

2012-01-01

This article focuses on the influence of male role models on the lives of adolescents (N = 78) in the U.S. National Longitudinal Lesbian Family Study. Half of the adolescents had male role models; those with and those without male role models had similar scores on the feminine and masculine scales

Predicting the Presence of Scyphozoan Jellyfish in the Gulf of Mexico Using a Biophysical Model

Science.gov (United States)

Aleksa, K. T.; Nero, R. W.; Wiggert, J. D.; Graham, W. M.

2016-02-01

The study and quantification of jellyfish (cnidarian medusae and ctenophores) is difficult due to their fragile body plan and a composition similar to their environment. The development of a predictive biophysical jellyfish model would be the first of its kind for the Gulf of Mexico and could provide assistance in ecological research and human interactions. In this study, the collection data of two scyphozoan medusae, Chrysaora quinquecirrha and Aurelia spp., were extracted from SEAMAP trawling surveys and were used to determine biophysical predictors for the presence of large jellyfish medusae in the Gulf of Mexico. Both in situ and remote sensing measurements from 2003 to 2013 were obtained. Logistic regressions were then applied to 27 biophysical parameters derived from these data to explore and determine significant predictors for the presence of medusae. Significant predictors identified by this analysis included water temperature, chlorophyll a, turbidity, distance from shore, and salinity. Future application for this model include foraging assessment of gelatinous predators as well as possible near real time monitoring of the distribution and movement of these medusae in the Gulf of Mexico.

Modeling the Role of the Glymphatic Pathway and Cerebral Blood Vessel Properties in Alzheimer's Disease Pathogenesis.

Directory of Open Access Journals (Sweden)

Christina Rose Kyrtsos

Full Text Available Alzheimer's disease (AD is the most common cause of dementia in the elderly, affecting over 10% population over the age of 65 years. Clinically, AD is described by the symptom set of short term memory loss and cognitive decline, changes in mentation and behavior, and eventually long-term memory deficit as the disease progresses. On imaging studies, significant atrophy with subsequent increase in ventricular volume have been observed. Pathology on post-mortem brain specimens demonstrates the classic findings of increased beta amyloid (Aβ deposition and the presence of neurofibrillary tangles (NFTs within affected neurons. Neuroinflammation, dysregulation of blood-brain barrier transport and clearance, deposition of Aβ in cerebral blood vessels, vascular risk factors such as atherosclerosis and diabetes, and the presence of the apolipoprotein E4 allele have all been identified as playing possible roles in AD pathogenesis. Recent research has demonstrated the importance of the glymphatic system in the clearance of Aβ from the brain via the perivascular space surrounding cerebral blood vessels. Given the variety of hypotheses that have been proposed for AD pathogenesis, an interconnected, multilayer model offers a unique opportunity to combine these ideas into a single unifying model. Results of this model demonstrate the importance of vessel stiffness and heart rate in maintaining adequate clearance of Aβ from the brain.

Predictive modelling using neuroimaging data in the presence of confounds.

Science.gov (United States)

Rao, Anil; Monteiro, Joao M; Mourao-Miranda, Janaina

2017-04-15

When training predictive models from neuroimaging data, we typically have available non-imaging variables such as age and gender that affect the imaging data but which we may be uninterested in from a clinical perspective. Such variables are commonly referred to as 'confounds'. In this work, we firstly give a working definition for confound in the context of training predictive models from samples of neuroimaging data. We define a confound as a variable which affects the imaging data and has an association with the target variable in the sample that differs from that in the population-of-interest, i.e., the population over which we intend to apply the estimated predictive model. The focus of this paper is the scenario in which the confound and target variable are independent in the population-of-interest, but the training sample is biased due to a sample association between the target and confound. We then discuss standard approaches for dealing with confounds in predictive modelling such as image adjustment and including the confound as a predictor, before deriving and motivating an Instance Weighting scheme that attempts to account for confounds by focusing model training so that it is optimal for the population-of-interest. We evaluate the standard approaches and Instance Weighting in two regression problems with neuroimaging data in which we train models in the presence of confounding, and predict samples that are representative of the population-of-interest. For comparison, these models are also evaluated when there is no confounding present. In the first experiment we predict the MMSE score using structural MRI from the ADNI database with gender as the confound, while in the second we predict age using structural MRI from the IXI database with acquisition site as the confound. Considered over both datasets we find that none of the methods for dealing with confounding gives more accurate predictions than a baseline model which ignores confounding, although

Modeling On-Body DTN Packet Routing Delay in the Presence of Postural Disconnections

Directory of Open Access Journals (Sweden)

Taghizadeh Mahmoud

2011-01-01

Full Text Available This paper presents a stochastic modeling framework for store-and-forward packet routing in Wireless Body Area Networks (WBAN with postural partitioning. A prototype WBANs has been constructed for experimentally characterizing and capturing on-body topology disconnections in the presence of ultrashort range radio links, unpredictable RF attenuation, and human postural mobility. Delay modeling techniques for evaluating single-copy on-body DTN routing protocols are then developed. End-to-end routing delay for a series of protocols including opportunistic, randomized, and two other mechanisms that capture multiscale topological localities in human postural movements have been evaluated. Performance of the analyzed protocols are then evaluated experimentally and via simulation to compare with the results obtained from the developed model. Finally, a mechanism for evaluating the topological importance of individual on-body sensor nodes is developed. It is shown that such information can be used for selectively reducing the on-body sensor-count without substantially sacrificing the packet delivery delay.

Modeling On-Body DTN Packet Routing Delay in the Presence of Postural Disconnections.

Science.gov (United States)

Quwaider, Muhannad; Taghizadeh, Mahmoud; Biswas, Subir

2011-01-01

This paper presents a stochastic modeling framework for store-and-forward packet routing in Wireless Body Area Networks ( WBAN ) with postural partitioning. A prototype WBANs has been constructed for experimentally characterizing and capturing on-body topology disconnections in the presence of ultrashort range radio links, unpredictable RF attenuation, and human postural mobility. Delay modeling techniques for evaluating single-copy on-body DTN routing protocols are then developed. End-to-end routing delay for a series of protocols including opportunistic, randomized, and two other mechanisms that capture multiscale topological localities in human postural movements have been evaluated. Performance of the analyzed protocols are then evaluated experimentally and via simulation to compare with the results obtained from the developed model. Finally, a mechanism for evaluating the topological importance of individual on-body sensor nodes is developed. It is shown that such information can be used for selectively reducing the on-body sensor-count without substantially sacrificing the packet delivery delay.

Economic Models of OPEC Behaviour and the Role of Saudi Arabia

OpenAIRE

Nourah A. Al-Yousef

1998-01-01

Previous studies of OPEC have suggested ways of explaining the behaviour of OPEC as a group. The specific role of Saudi Arabia in the market and within OPEC has received attention from some authors. This study analyses the role of Saudi Arabia in these models and tries to find how much they explain the role of Saudi Arabia in the period from 1973 to the present. Models of OPEC behaviour are divided into four sets. The first set of models does not address the role of Saudi Arabia; they include...

A New Simple Model for Underwater Wireless Optical Channels in the Presence of Air Bubbles

KAUST Repository

Zedini, Emna

2018-01-15

A novel statistical model is proposed to characterize turbulence-induced fading in underwater wireless optical channels in the presence of air bubbles for fresh and salty waters, based on experimental data. In this model, the channel irradiance fluctuations are characterized by the mixture Exponential-Gamma distribution. We use the expectation maximization (EM) algorithm to obtain the maximum likelihood parameter estimation of the new model. Interestingly, the proposed model is shown to provide a perfect fit with the measured data under all the channel conditions for both types of water. The major advantage of the new model is that it has a simple mathematical form making it attractive from a performance analysis point of view. Indeed, the application of the Exponential-Gamma model leads to closed-form and analytically tractable expressions for key system performance metrics such as the outage probability and the average bit-error rate.

A New Simple Model for Underwater Wireless Optical Channels in the Presence of Air Bubbles

KAUST Repository

Zedini, Emna; Oubei, Hassan M.; Kammoun, Abla; Hamdi, Mounir; Ooi, Boon S.; Alouini, Mohamed-Slim

2018-01-01

A novel statistical model is proposed to characterize turbulence-induced fading in underwater wireless optical channels in the presence of air bubbles for fresh and salty waters, based on experimental data. In this model, the channel irradiance fluctuations are characterized by the mixture Exponential-Gamma distribution. We use the expectation maximization (EM) algorithm to obtain the maximum likelihood parameter estimation of the new model. Interestingly, the proposed model is shown to provide a perfect fit with the measured data under all the channel conditions for both types of water. The major advantage of the new model is that it has a simple mathematical form making it attractive from a performance analysis point of view. Indeed, the application of the Exponential-Gamma model leads to closed-form and analytically tractable expressions for key system performance metrics such as the outage probability and the average bit-error rate.

Medical students on the value of role models for developing 'soft skills'

African Journals Online (AJOL)

Adele

of medical students, especially their doctor-patient interaction skills and .... how they adapted their own personalities with patients…] ... students learning from role models. Students .... Role models and the learning environment: essential elements in ... Paice E, Heard S, Moss F. How important are role models in making.

A New Model for Describing the Rheological Behavior of Heavy and Extra Heavy Crude Oils in the Presence of Nanoparticles

Directory of Open Access Journals (Sweden)

Esteban A. Taborda

2017-12-01

Full Text Available The present work proposes for the first time a mathematical model for describing the rheological behavior of heavy and extra-heavy crude oils in the presence of nanoparticles. This model results from the combination of two existing mathematical models. The first one applies to the rheology of pseudoplastic substances, i.e., the Herschel-Bulkley model. The second one was previously developed by our research group to model the rheology of suspensions, namely the modified Pal and Rhodes model. The proposed model is applied to heavy and extra heavy crude oils in the presence of nanoparticles, considering the effects of nanoparticles concentration and surface chemical nature, temperature, and crude oil type. All the experimental data evaluated exhibited compelling goodness of fitting, and the physical parameters in the model follow correlate well with variations in viscosity. The new model is dependent of share rate and opens new possibilities for phenomenologically understanding viscosity reduction in heavy crude by adding solid nanoparticles and favoring the scale-up in enhanced oil recovery (EOR and/or improved oil recovery (IOR process.

Presence

Directory of Open Access Journals (Sweden)

Pamela Renee Boeck

2014-03-01

Full Text Available Healthy therapeutic relationships enhance wholeness and healing; they are the key to effective health promotion. Therapeutic nursing presence demonstrates caring, empathy, and connection, qualities required to build rapport and trust between nurse and patient. This concept analysis’ purpose was to illuminate the various forms of the meanings of presence and the value placed on them. The science of nursing often precedes the art and spirituality of nursing. This is due to focusing primarily on the high acuity of the patients being seen in conjunction with shortage of personnel and resources. Patient dissatisfaction continues to be a growing concern. The nursing shortage crisis continues along with more nurses experiencing moral distress, compassion fatigue, and/or burnout. In nurses’ haste to complete their duties, are we facing the risk of overlooking one of the original gifts of the nursing profession? This would be the gift of genuine presence. This concept analysis aims to identify the attributes that are essential to the concept of presence, and to clarify its nursing usage, by following the strategy suggested by Walker and Avant. It is important to reflect on various ways of providing presence in the clinical setting. By exploring the spiritual, literary, psychological, and nursing literature, there is a diverse yet similar interconnectivity of what presence may represent. Observations and experiences of a range of sensatory and kinesthetic perceptions are revealed to ascertain the attributes discerning commonalities and themes of presence. Nursing presence is considered to be an essential state of holistic nursing as well as a core competency in contemporary nursing. Clarifying the significance of presence in nursing invites the prospect of additional evidence-based research that may place the intrinsic value of presence as a continuing theoretical foundation.

Rethinking presence: a grounded theory of nurses and teleconsultation.

Science.gov (United States)

Barrett, David

2017-10-01

To develop a theory that offered an evidence-based insight into the use of teleconsultation by nurses. Teleconsultation is the use of video to facilitate real-time, remote interaction between healthcare practitioners and patients. Although its popularity is growing, there is little understanding of how teleconsultation impacts on the role of nurses. The study adopted a constructivist grounded theory method, supplemented by the use of Straussian analytical approaches. Using selective and theoretical approaches, registered nurses with experience of using video in health care were sampled. Data were collected using semi-structured interviews exploring experiences, knowledge and feelings surrounding teleconsultation. Interviews were recorded, transcribed and subjected to three-stage, nonlinear manual analysis (open, axial and selective coding). Theoretical saturation occurred after 17 interviews. The core category identified from the data was 'nursing presence' Four subcategories of nursing presence were identified: operational, clinical, therapeutic and social. The degree to which presence could be achieved was dependent upon three influencing factors - enablers, constraints and compensation. Nurses provide different types of presence during teleconsultation, with the degree of presence dependent on specific characteristics of video-mediated communication. Where the use of video constrains the delivery of presence, nurses use a range of compensatory mechanisms to enhance patient care. Teleconsultation provides an innovative approach to enhancing the delivery of health care. This study provides nurses with insight into the impact of teleconsultation on their professional role, and an understanding of how best to use video-mediated communication to support patient care. © 2016 John Wiley & Sons Ltd.

Role Models on Dope

DEFF Research Database (Denmark)

Christiansen, Ask Vest; Gleaves, John

2014-01-01

Compared to football-players cyclists are virtuous role models. Yes, Lance Armstrong, Michael Rasmussen and other riders have doped, and because of this they have received the predicate as the most immoral athletes in the sporting world. But if morality is not only a question of whether a person ...... has enhanced his or hers performances by the use of various drugs (and lied about it), but also is about human beings’ relations and interactions, then cycling isn’t as depraved as we like to tell each other. Football is much worse....

On Inertial Body Tracking in the Presence of Model Calibration Errors.

Science.gov (United States)

Miezal, Markus; Taetz, Bertram; Bleser, Gabriele

2016-07-22

In inertial body tracking, the human body is commonly represented as a biomechanical model consisting of rigid segments with known lengths and connecting joints. The model state is then estimated via sensor fusion methods based on data from attached inertial measurement units (IMUs). This requires the relative poses of the IMUs w.r.t. the segments-the IMU-to-segment calibrations, subsequently called I2S calibrations-to be known. Since calibration methods based on static poses, movements and manual measurements are still the most widely used, potentially large human-induced calibration errors have to be expected. This work compares three newly developed/adapted extended Kalman filter (EKF) and optimization-based sensor fusion methods with an existing EKF-based method w.r.t. their segment orientation estimation accuracy in the presence of model calibration errors with and without using magnetometer information. While the existing EKF-based method uses a segment-centered kinematic chain biomechanical model and a constant angular acceleration motion model, the newly developed/adapted methods are all based on a free segments model, where each segment is represented with six degrees of freedom in the global frame. Moreover, these methods differ in the assumed motion model (constant angular acceleration, constant angular velocity, inertial data as control input), the state representation (segment-centered, IMU-centered) and the estimation method (EKF, sliding window optimization). In addition to the free segments representation, the optimization-based method also represents each IMU with six degrees of freedom in the global frame. In the evaluation on simulated and real data from a three segment model (an arm), the optimization-based method showed the smallest mean errors, standard deviations and maximum errors throughout all tests. It also showed the lowest dependency on magnetometer information and motion agility. Moreover, it was insensitive w.r.t. I2S position and

Are Universities Role Models for Communities? A Gender Perspective

OpenAIRE

Felicia Cornelia MACARIE; Octavian MOLDOVAN

2012-01-01

The present paper explores the degree in which universities could/should serve as role models for communities from the perspective of gender integration. Although the theoretical/ moral answer would be affirmative (universities should be in such a position that would allow local communities to regard them as role models of gender integration), the primary empirical analysis leads to another conclusion. A brief theoretical review (that connects gender discrimination, sustainable development, u...

Multiscale modeling of the solidification microstructure evolution in the presence of ultrasonic stirring

International Nuclear Information System (INIS)

Nastac, Laurentiu

2012-01-01

Ultrasonic treatment (UST) was studied to improve the quality of cast ingots as well as to control the solidification microstructure evolution. Ultrasonically-induced cavitation consists of the formation of small cavities (bubbles) in the molten metal followed by their growth, pulsation and collapse. These cavities are created by the tensile stresses that are produced by acoustic waves in the rarefaction phase. The cavitation threshold pressure for nucleation of the bubbles may decrease with increasing the amount of dissolved gases and especially with the amount of inclusions in the melt. A UST model was developed to predict the ultrasonic cavitation and acoustic streaming. The developed UST modeling approach is based on the numerical solution of Lilley model (that is founded on Lighthills's acoustic analogy), fluid flow, and heat transfer equations, and mesoscopic modeling of the grain structure. The UST model was applied to study the solidification of Al-based alloys) under the presence of ultrasound. It is found that the predicted ultrasonic cavitation region is relatively small, the acoustic streaming is strong and thus the created/survived bubbles/nuclei are transported into the bulk liquid quickly. The predicted grain size under UST condition is at least one order of magnitude lower than that without UST, which is in excellent agreement with the experimental data.

Task-role-based Access Control Model in Smart Health-care System

Directory of Open Access Journals (Sweden)

Wang Peng

2015-01-01

Full Text Available As the development of computer science and smart health-care technology, there is a trend for patients to enjoy medical care at home. Taking enormous users in the Smart Health-care System into consideration, access control is an important issue. Traditional access control models, discretionary access control, mandatory access control, and role-based access control, do not properly reflect the characteristics of Smart Health-care System. This paper proposes an advanced access control model for the medical health-care environment, task-role-based access control model, which overcomes the disadvantages of traditional access control models. The task-role-based access control (T-RBAC model introduces a task concept, dividing tasks into four categories. It also supports supervision role hierarchy. T-RBAC is a proper access control model for Smart Health-care System, and it improves the management of access rights. This paper also proposes an implementation of T-RBAC, a binary two-key-lock pair access control scheme using prime factorization.

An Overview on the Role of α -Synuclein in Experimental Models of Parkinson's Disease from Pathogenesis to Therapeutics.

Science.gov (United States)

Javed, Hayate; Kamal, Mohammad Amjad; Ojha, Shreesh

2016-01-01

Parkinson's disease (PD) is a devastating and progressive movement disorder characterized by symptoms of muscles rigidity, tremor, postural instability and slow physical movements. Biochemically, PD is characterized by lack of dopamine production and its action due to loss of dopaminergic neurons and neuropathologically by the presence of intracytoplasmic inclusions known as Lewy bodies, which mainly consist of presynaptic neuronal protein, α-synuclein (α-syn). It is believed that alteration in α-syn homeostasis leads to increased accumulation and aggregation of α-syn in Lewy body. Based on the important role of α-syn from pathogenesis to therapeutics, the recent researches are mainly focused on deciphering the critical role of α-syn at advanced level. Being a major protein in Lewy body that has a key role in pathogenesis of PD, several model systems including immortalized cell lines (SH-SY5Y), primary neuronal cultures, yeast (saccharomyces cerevisiae), drosophila (fruit flies), nematodes (Caenorhabditis elegans) and rodents are being employed to understand the PD pathogenesis and treatment. In order to study the etiopathogensis and develop novel therapeutic target for α -syn aggregation, majority of investigators rely on toxin (rotenone, 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine, 6-hydroxydopamine, paraquat)-induced animal models of PD as a tool for basic research. Whereas, cell and tissue based models are mostly utilized to elucidate the mechanistic and molecular pathways underlying the α -syn induced toxicity and therapeutic approaches in PD. Gene modified mouse models based on α-syn expression are fascinating for modeling familial PD and toxin induced models provide a suitable approach for sporadic PD. The purpose of this review is to provide a summary and a critical review of the involvement of α-syn in various in vitro and in vivo models of PD based on use of neurotoxins as well as genetic modifications.

Modeling the Role of the Glymphatic Pathway and Cerebral Blood Vessel Properties in Alzheimer’s Disease Pathogenesis

Science.gov (United States)

Kyrtsos, Christina Rose; Baras, John S.

2015-01-01

Alzheimer’s disease (AD) is the most common cause of dementia in the elderly, affecting over 10% population over the age of 65 years. Clinically, AD is described by the symptom set of short term memory loss and cognitive decline, changes in mentation and behavior, and eventually long-term memory deficit as the disease progresses. On imaging studies, significant atrophy with subsequent increase in ventricular volume have been observed. Pathology on post-mortem brain specimens demonstrates the classic findings of increased beta amyloid (Aβ) deposition and the presence of neurofibrillary tangles (NFTs) within affected neurons. Neuroinflammation, dysregulation of blood-brain barrier transport and clearance, deposition of Aβ in cerebral blood vessels, vascular risk factors such as atherosclerosis and diabetes, and the presence of the apolipoprotein E4 allele have all been identified as playing possible roles in AD pathogenesis. Recent research has demonstrated the importance of the glymphatic system in the clearance of Aβ from the brain via the perivascular space surrounding cerebral blood vessels. Given the variety of hypotheses that have been proposed for AD pathogenesis, an interconnected, multilayer model offers a unique opportunity to combine these ideas into a single unifying model. Results of this model demonstrate the importance of vessel stiffness and heart rate in maintaining adequate clearance of Aβ from the brain. PMID:26448331

Rethinking board role performance: Towards an integrative model

Directory of Open Access Journals (Sweden)

Babić Verica M.

2011-01-01

Full Text Available This research focuses on the board role evolution analysis which took place simultaneously with the development of different corporate governance theories and perspectives. The purpose of this paper is to provide understanding of key factors that make a board effective in the performance of its role. We argue that analysis of board role performance should incorporate both structural and process variables. This paper’s contribution is the development of an integrative model that aims to establish the relationship between the board structure and processes on the one hand, and board role performance on the other.

Empowering Effective STEM Role Models to Promote STEM Equity in Local Communities

Science.gov (United States)

Harte, T.; Taylor, J.

2017-12-01

Empowering Effective STEM Role Models, a three-hour training developed and successfully implemented by NASA Langley Research Center's Science Directorate, is an effort to encourage STEM professionals to serve as role models within their community. The training is designed to help participants reflect on their identity as a role model and provide research-based strategies to effectively engage youth, particularly girls, in STEM (science, technology, engineering, and mathematics). Research shows that even though girls and boys do not demonstrate a significant difference in their ability to be successful in mathematics and science, there is a significant difference in their confidence level when participating in STEM subject matter and pursuing STEM careers. The Langley training model prepares professionals to disrupt this pattern and take on the habits and skills of effective role models. The training model is based on other successful models and resources for role modeling in STEM including SciGirls; the National Girls Collaborative; and publications by the American Association of University Women and the National Academies. It includes a significant reflection component, and participants walk through situation-based scenarios to practice a focused suite of research-based strategies. These strategies can be implemented in a variety of situations and adapted to the needs of groups that are underrepresented in STEM fields. Underpinning the training and the discussions is the fostering of a growth mindset and promoting perseverance. "The Power of Yet" becomes a means whereby role models encourage students to believe in themselves, working toward reaching their goals and dreams in the area of STEM. To provide additional support, NASA Langley role model trainers are available to work with a champion at other organizations to facilitate the training. This champion helps recruit participants, seeks leadership buy-in, and helps provide valuable insights for needs and

Parental presence or absence during paediatric burn wound care procedures.

Science.gov (United States)

Egberts, Marthe R; de Jong, Alette E E; Hofland, Helma W C; Geenen, Rinie; Van Loey, Nancy E E

2017-12-18

Differing views on benefits and disadvantages of parental presence during their child's wound care after burn injury leave the topic surrounded by controversies. This study aimed to describe and explain parents' experiences of their presence or absence during wound care. Shortly after the burn event, 22 semi-structured interviews were conducted with parents of children (0-16 years old) that underwent hospitalization in one of the three Dutch burn centers. Eighteen of these parents also participated in follow-up interviews three to six months after discharge. Interviews were analyzed using grounded theory methodology. Analyses resulted in themes that were integrated into a model, summarizing key aspects of parental presence during wound care. These aspects include parental cognitions and emotions (e.g., shared distress during wound care), parental abilities and needs (e.g., controlling own emotions, being responsive, and gaining overall control) and the role of burn care professionals. Findings emphasize the distressing nature of wound care procedures. Despite the distress, parents expressed their preference to be present. The abilities to control their own emotions and to be responsive to the child's needs were considered beneficial for both the child and the parent. Importantly, being present increased a sense of control in parents that helped them to cope with the situation. For parents not present, the professional was the intermediary to provide information about the healing process that helped parents to deal with the situation. In sum, the proposed model provides avenues for professionals to assess parents' abilities and needs on a daily basis and to adequately support the child and parent during wound care. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

Cartographic modeling: The role and importance

Directory of Open Access Journals (Sweden)

Ikonović Vesna

2007-01-01

Full Text Available Aim and sense of cartographic modeling is to represent essential, typical and characteristically attributes of mapping territory. Cartographic modeling is applying in two phases: 1. trough theoretical modeling and creating mind models (by notice relevant factors of space, modeling is in cartographer’s mind and 2. trough practical modeling and making prototype model (continuing and objectification of mind model which one has bigger degree of concrezation and experimented role. The maps are mathematical and logical models, which are not just representing the contents of the real space, but also their specific and relational traits which can’t be seen at first sight. Atlas is modeled contexture contents of treated thematic of space on optimal map union. Atlases are higher form of cartography. Modern computer's technology and specific software make possible better and faster making of all kinds of maps, atlases and spatial analysis connections and relationships among all elements of contents from concrete space which is, until now, demand much more time or they can not imagine.

Bi-dimensional null model analysis of presence-absence binary matrices.

Science.gov (United States)

Strona, Giovanni; Ulrich, Werner; Gotelli, Nicholas J

2018-01-01

Comparing the structure of presence/absence (i.e., binary) matrices with those of randomized counterparts is a common practice in ecology. However, differences in the randomization procedures (null models) can affect the results of the comparisons, leading matrix structural patterns to appear either "random" or not. Subjectivity in the choice of one particular null model over another makes it often advisable to compare the results obtained using several different approaches. Yet, available algorithms to randomize binary matrices differ substantially in respect to the constraints they impose on the discrepancy between observed and randomized row and column marginal totals, which complicates the interpretation of contrasting patterns. This calls for new strategies both to explore intermediate scenarios of restrictiveness in-between extreme constraint assumptions, and to properly synthesize the resulting information. Here we introduce a new modeling framework based on a flexible matrix randomization algorithm (named the "Tuning Peg" algorithm) that addresses both issues. The algorithm consists of a modified swap procedure in which the discrepancy between the row and column marginal totals of the target matrix and those of its randomized counterpart can be "tuned" in a continuous way by two parameters (controlling, respectively, row and column discrepancy). We show how combining the Tuning Peg with a wise random walk procedure makes it possible to explore the complete null space embraced by existing algorithms. This exploration allows researchers to visualize matrix structural patterns in an innovative bi-dimensional landscape of significance/effect size. We demonstrate the rational and potential of our approach with a set of simulated and real matrices, showing how the simultaneous investigation of a comprehensive and continuous portion of the null space can be extremely informative, and possibly key to resolving longstanding debates in the analysis of ecological

Roles of nuclear power system in the presence of uncertainties from global warming

International Nuclear Information System (INIS)

Kiriyama, Eriko; Iwata, Shuichi

2005-01-01

Environmental 'bads' like carbon dioxide are not simply incorporated in the market system. The costs involved, however, do not really reflect the inherent value of the environment, or what it is worth to them. This study focuses on the uncertainty of CO 2 emission credits. Assigning economic values to environmental goods and services is complex, but it is an area that is receiving considerable attention from environmental economists. The purpose of this study is to analyze the value of an investment in power generation assets that do not emit CO 2 . To deal with the CO 2 emission credit, we built new models based on the real option model by Pindyck (2000). In the modern, market-based financial systems that dominate the global economy, the value of a resource is represented by the price that an individual or a group is willing to pay for it. Managing CO 2 emission limitations will be a critical aspect of power generation systems. And it will be increasingly so as the emphasis on global environmental issues continues to rise. In order to secure the effectiveness of measures against global warming, we should reconsider the role of nuclear power systems. (author)

MODEL ROLE PLAYING DALAM PEMBELAJARAN SIKLUS AKUNTANSI PERUSAHAAN DAGANG

Directory of Open Access Journals (Sweden)

Jarot Tri Tri Bowo Santoso

2011-06-01

Full Text Available Accounting lesson is considered as a difficult lesson by most students in SMK/SMA. It is even sometimes worse with the less ability of accounting teachers to select learning methods thatcan attract students’ attention and thought. Therefore, it is necessary to find an alternative learning which can help students to involve in the real situation which is fun and memorable. The learning model which can fulfill the fun situation is the role playing. The steps to implement this model in the learning of accounting cycle for trade firm are to divide students in groups and to give each of them an opportunity to play a role. In practice, each student changers the role weekly based on the order. The model makesstuents easier to understand the basic accounting and leads the teachers evaluate the materials if the lack of conformity occurs during the learning.

A new role-model for the future humanities?

DEFF Research Database (Denmark)

Caviglia, Francesco; Pedersen, Alex Young

The Knowledge Building approach (henceforth, KB) is a constructionist approach to learn-ing that builds on a Popperian epistemology and the idea of bringing to education “both the goals and the processes of knowledge-creating organizations – as represented, for instance, in scientific research...... of citizens” who work together to design solutions for living better together, which the authors suggest being an equally productive role-model as the idea of a “scientific research groups and industrial design teams”, which is the standard role-model for KB prac-tice. The authors sees this alternative model...... groups and industrial design teams” (Scardamalia & Bereiter, 2014). KB is becoming a signature pedagogy (Shulman, 2005) for scientific disciplines, with nearly all educational interventions quoted by Scardamalia & Bereiter (2014) or presented at con-ferences focusing on natural sciences. Although...

Electron cyclotron waves in the presence of parallel electric fields in the Earth's auroral plasma

Directory of Open Access Journals (Sweden)

S. Kumar

1997-01-01

Full Text Available The electron cyclotron waves that originate at low altitudes (<0.5 RE and observed by ground facilities have been studied in the presence of a weak parallel electric field in auroral magnetoplasma consisting of trapped energetic auroral electrons and cold background electrons of ionospheric origin. The model distribution for auroral trapped electrons is taken as Maxwellian ring distribution. An expression for the growth rate has been obtained in the presence of parallel electric field assuming that the real frequency in the whistler mode is not affected by the presence of the electric field. The results show that waves grow (or damp in amplitude for a parallel (or antiparallel electric field. The influence of the electric field is more pronounced at a shorter wavelength spectrum. An increase in population of energetic electrons increases the growth rate and thus, plays a significant role in the wave excitation process in the auroral regions.

Task-and-role-based access-control model for computational grid

Institute of Scientific and Technical Information of China (English)

LONG Tao; HONG Fan; WU Chi; SUN Ling-li

2007-01-01

Access control in a grid environment is a challenging issue because the heterogeneous nature and independent administration of geographically dispersed resources in grid require access control to use fine-grained policies. We established a task-and-role-based access-control model for computational grid (CG-TRBAC model), integrating the concepts of role-based access control (RBAC) and task-based access control (TBAC). In this model, condition restrictions are defined and concepts specifically tailored to Workflow Management System are simplified or omitted so that role assignment and security administration fit computational grid better than traditional models; permissions are mutable with the task status and system variables, and can be dynamically controlled. The CG-TRBAC model is proved flexible and extendible. It can implement different control policies. It embodies the security principle of least privilege and executes active dynamic authorization. A task attribute can be extended to satisfy different requirements in a real grid system.

The Potential Role of the Philippines in U.S. Naval Forward Presence

National Research Council Canada - National Science Library

Garcia, Thomas

2001-01-01

.... Naval forward presence in the Asia-Pacific region. With the shift of defense focus from the European to the Asia-Pacific region, and the current "War on Terrorism," the problem of finding more secure bases for U.S...

Ocular hemodynamics and glaucoma: the role of mathematical modeling.

Science.gov (United States)

Harris, Alon; Guidoboni, Giovanna; Arciero, Julia C; Amireskandari, Annahita; Tobe, Leslie A; Siesky, Brent A

2013-01-01

To discuss the role of mathematical modeling in studying ocular hemodynamics, with a focus on glaucoma. We reviewed recent literature on glaucoma, ocular blood flow, autoregulation, the optic nerve head, and the use of mathematical modeling in ocular circulation. Many studies suggest that alterations in ocular hemodynamics play a significant role in the development, progression, and incidence of glaucoma. Although there is currently a limited number of studies involving mathematical modeling of ocular blood flow, regulation, and diseases (such as glaucoma), preliminary modeling work shows the potential of mathematical models to elucidate the mechanisms that contribute most significantly to glaucoma progression. Mathematical modeling is a useful tool when used synergistically with clinical and laboratory data in the study of ocular blood flow and glaucoma. The development of models to investigate the relationship between ocular hemodynamic alterations and glaucoma progression will provide a unique and useful method for studying the pathophysiology of glaucoma.

Scientists as role models in space science outreach

Science.gov (United States)

Alexander, D.

The direct participation of scientists significantly enhances the impact of any E/PO effort. This is particularly true when the scientists come from minority or traditionally under-represented groups and, consequently, become role models for a large number of students while presenting positive counter-examples to the usual stereotypes. In this paper I will discuss the impact of scientists as role models through the successful implementation of a set of space physics games and activities, called Solar Week. Targetted at middle-school girls, the key feature of Solar Week is the "Ask a Scientist" section enabling direct interaction between participating students and volunteer scientists. All of the contributing scientists are women, serving as experts in their field and providing role models to whom the students can relate. Solar Week has completed four sessions with a total of some 140 edcuators and 12,000+ students in over 28 states and 9 countries. A major success of the Solar Week program has been the ability of the students to learn more about the scientists as people, through online biographies, and to discuss a variety of topics ranging from science, to careers and common hobbies.

Trends in the Presence and Roles of Women Physicists in Serbia

Science.gov (United States)

Kapor, Agneš; Savić, Ilija; Davidović, Milena; Knezević, Dragica; Božić, Mirjana

2009-04-01

In general, the portion of women in physics has been increasing in recent years in Serbia, as well as their presence in research and academic institutions. The percentage of women who earned BSc degrees in physics is greater than men. In this respect the situation in Serbia is different from most other countries. But more men than women earned MSc and PhD degrees.

Detection of HPV and the role of p16INK4A overexpression as a surrogate marker for the presence of functional HPV oncoprotein E7 in colorectal cancer

Directory of Open Access Journals (Sweden)

Lardon Filip

2010-03-01

Full Text Available Abstract Background Based on the well-recognized etiological role of human papillomavirus (HPV in cervical, anogenital and oropharyngeal carcinogenesis, a potential role of HPV in colorectal carcinogenesis has been suggested. For that reason, the aim of the present study was to investigate the presence of HPV DNA in colorectal carcinomas (CRC and to study overexpression of p16INK4A as a marker for the presence of an active HPV oncoprotein E7. These findings were correlated with clinical and pathological prognostic factors of CRC. Methods The presence of HPV was assessed using a multiplex PCR system of 10 non-biotinylated primers. The amplified fragments of HPV positive samples were further analyzed by a highly sensitive, broad spectrum SPF10 PCR and subsequently genotyped using reverse hybridization in a line probe assay. P16INK4A protein expression was investigated in a subset of 90 (30 HPV positive and 60 HPV negative CRC samples by immunohistochemistry. Results HPV DNA was found in 14.2% of the CRC samples with HPV16 as the most prevalent type. No significant differences in clinical and pathological variables were found between HPV positive and negative CRCs, except for age. HPV positive patients were significantly younger (p = 0.05. There was no significant correlation between the presence of HPV and overexpression of p16INK4A (p = 0.325. Conclusions In conclusion, the presence of oncogenic HPV DNA in a small cohort of CRC samples may suggest that HPV may be involved in the carcinogenesis of some CRC. However, contrary to what has been observed in head and neck squamous cell cancer and cancer of the uterine cervix, p16INK4A does not seem to be a surrogate marker for an active HPV infection in CRC. Therefore, further functional analyses are necessary to elucidate the role of HPV in CRC.

The roles of the micro-organisms and chromium content in the corrosion of iron-chromium steels in the presence of sulfate-reducing bacteria

International Nuclear Information System (INIS)

Ferrante, V.

1991-09-01

If it is widely accepted that the presence of sulfate-reducing bacteria can increase the aqueous corrosion of steels, the induced mechanisms are still not definitively established. The aim of this work is to specify the roles, for corrosion, of the presence of bacteria (D. Vulgaris) in one part and of chemical parameters as the composition of the material and the accumulation of sulfides in another part. The use of experimental techniques coming from microbiology, electrochemistry or chemical analysis has revealed the interdependence which exists between the bacteria and the material, and the importance of the steel composition towards the adhesion of microorganisms and the generalized corrosion. The bacteria and the dissolved sulfides do not seem to influence remarkably the generalized corrosion. Nevertheless, the alterations of the surface state they induce could be the cause of localized corrosion phenomena. (O.M.)

Parasocial interaction with my avatar: effects of interdependent self-construal and the mediating role of self-presence in an avatar-based console game, Wii.

Science.gov (United States)

Jin, Seung-A Annie; Park, Namkee

2009-12-01

The "self" concept has grown increasingly important in interactive media environments. This study investigated self-related processes in an avatar-based game console, Wii. A key feature of the Wii is its motion-sensing capability that empowers players to manipulate and interact with items on-screen via movement. The present study examined the effects of video game players' self-construal on parasocial interaction with their avatars and feelings of self-presence. In this study, parasocial interaction was operationally defined as the extent of game players' interpersonal involvement with their avatar and the extent to which game players perceive themselves as interacting with the avatar. Self-presence was defined as the degree to which video game players feel as if their avatar on the screen were their real self. Based on an experiment, the study discovered that game players with high interdependent self-construal showed closer parasocial interaction and higher level of self-presence than those with low interdependent self-construal. Results also showed that self-presence mediated the effects of interdependent self-construal on the parasocial relationship with game players' avatars. Thus, the study discovered an important individual difference factor, interdependent self-construal, affecting the degree to which people form a parasocial relationship with their virtual self that is visually manifested in the form of an avatar. In addition, the present study added empirical evidence about the mediating role played by self-presence in avatar-based video games.

Analysis of a Fishery Model with two competing prey species in the presence of a predator species for Optimal Harvesting

Science.gov (United States)

Sutimin; Khabibah, Siti; Munawwaroh, Dita Anis

2018-02-01

A harvesting fishery model is proposed to analyze the effects of the presence of red devil fish population, as a predator in an ecosystem. In this paper, we consider an ecological model of three species by taking into account two competing species and presence of a predator (red devil), the third species, which incorporates the harvesting efforts of each fish species. The stability of the dynamical system is discussed and the existence of biological and bionomic equilibrium is examined. The optimal harvest policy is studied and the solution is derived in the equilibrium case applying Pontryagin's maximal principle. The simulation results is presented to simulate the dynamical behavior of the model and show that the optimal equilibrium solution is globally asymptotically stable. The results show that the optimal harvesting effort is obtained regarding to bionomic and biological equilibrium.

Enhancement of Presence in a Virtual Sailing Environment through Localized Wind Simulation

NARCIS (Netherlands)

Verlinden, J.C.; Mulder, F.A.; Vergeest, J.S.; De Jonge, A.; Krutiy, D.; Nagy, Z.; Logeman, B.J.; Schouten, P.

2013-01-01

In the context of sailing, wind plays an important role. However, there is little knowledge on how wind influences presence – the sense of “being there” - while immersed in a virtual setting. This article explores several wind parameters and presents a wind array to explore presence in a sail

Role model and prototype matching: Upper-secondary school students’ meetings with tertiary STEM students

Directory of Open Access Journals (Sweden)

Eva Lykkegaard

2016-04-01

Full Text Available Previous research has found that young people’s prototypes of science students and scientists affect their inclination to choose tertiary STEM programs (Science, Technology, Engineering and Mathematics. Consequently, many recruitment initiatives include role models to challenge these prototypes. The present study followed 15 STEM-oriented upper-secondary school students from university-distant backgrounds during and after their participation in an 18-months long university-based recruitment and outreach project involving tertiary STEM students as role models. The analysis focusses on how the students’ meetings with the role models affected their thoughts concerning STEM students and attending university. The regular self-to-prototype matching process was shown in real-life role-models meetings to be extended to a more complex three-way matching process between students’ self-perceptions, prototype images and situation-specific conceptions of role models. Furthermore, the study underlined the positive effect of prolonged role-model contact, the importance of using several role models and that traditional school subjects catered more resistant prototype images than unfamiliar ones did.

A role based coordination model in agent systems

Institute of Scientific and Technical Information of China (English)

ZHANG Ya-ying; YOU Jin-yuan

2005-01-01

Coordination technology addresses the construction of open, flexible systems from active and independent software agents in concurrent and distributed systems. In most open distributed applications, multiple agents need interaction and communication to achieve their overall goal. Coordination technologies for the Internet typically are concerned with enabling interaction among agents and helping them cooperate with each other.At the same time, access control should also be considered to constrain interaction to make it harmless. Access control should be regarded as the security counterpart of coordination. At present, the combination of coordination and access control remains an open problem. Thus, we propose a role based coordination model with policy enforcement in agent application systems. In this model, coordination is combined with access control so as to fully characterize the interactions in agent systems. A set of agents interacting with each other for a common global system task constitutes a coordination group. Role based access control is applied in this model to prevent unauthorized accesses. Coordination policy is enforced in a distributed manner so that the model can be applied to the open distributed systems such as Intemet. An Internet online auction system is presented as a case study to illustrate the proposed coordination model and finally the performance analysis of the model is introduced.

Topography of Spoil Heaps and Its Role in Plant Succession and Soil Fauna Presence

Directory of Open Access Journals (Sweden)

Walmsley A.

2017-03-01

Full Text Available The spoil heaps from brown coal mining without technical reclamation are interesting specific sites for ecological relationships observation. This research was aimed at investigating whether topographic features, which determine soil nutrient and moisture distribution, in combination with soil fauna (wireworm and earthworm presence, affect plant community composition at a spontaneously revegetated post mining area with an undulating surface. Two sites of different age with three types of topographic features were selected, soil moisture and nutrient contents were measured, and plant community composition and soil macrofauna community were sampled at each position. Wireworms were present at all positions and were most abundant at the bottoms of waves at the younger site; their presence was correlated with the presence of several plant species with high palatability for wireworms, but the direction of the interaction is not clear. Earthworms were only present at the older site and had the highest abundance at flat sections. Earthworm presence affected the amount of nitrogen in soil - the highest nitrogen content was at the site with the highest earthworm density and was followed by a higher diversity of plant community. The plant community composition was generally correlated with plant available nutrient content - especially P and N. We infer that topographic features affect nutrient and soil fauna distribution, which consequently influences the plant community composition.

Predicting Intentions to Read Suicide Awareness Stories. The Role of Depression and Characteristics of the Suicidal Role Model.

Science.gov (United States)

Niederkrotenthaler, Thomas; Arendt, Florian; Till, Benedikt

2015-01-01

Research on factors that influence the intention to read suicide awareness material is lacking. To identify how social and state similarities between the featured protagonist of a suicide awareness story and the audience impact on the intent to read similar stories. Laboratory experiment with n = 104 students. Participants were randomly assigned to study groups. In the first group, the role model provided his personal story of crisis and was a student. In the second group, the content was identical but the model was socially dissimilar. The third group read about a topic unrelated to suicide. Depression, identification, and exposure intent were measured after the experiment. Conditional process analysis was carried out. In the group featuring a once-suicidal role model with high social similarity, depression in the audience increased the intention to read similar material in the future via identification with the role model; 82% of individuals wanted to read similar material in the future, but only 50% wanted to do so in the group featuring a dissimilar person. Exposure intention increases via identification when role model and audience characteristics align regarding social traits and the experience of depression. These factors are relevant when developing campaigns targeting individuals with stories of recovery.

Wanted: role models - medical students’ perceptions of professionalism

Directory of Open Access Journals (Sweden)

Byszewski Anna

2012-11-01

Full Text Available Abstract Background Transformation of medical students to become medical professionals is a core competency required for physicians in the 21st century. Role modeling was traditionally the key method of transmitting this skill. Medical schools are developing medical curricula which are explicit in ensuring students develop the professional competency and understand the values and attributes of this role. The purpose of this study was to determine student perception of professionalism at the University of Ottawa and gain insights for improvement in promotion of professionalism in undergraduate medical education. Methods Survey on student perception of professionalism in general, the curriculum and learning environment at the University of Ottawa, and the perception of student behaviors, was developed by faculty and students and sent electronically to all University of Ottawa medical students. The survey included both quantitative items including an adapted Pritzker list and qualitative responses to eight open ended questions on professionalism at the Faculty of Medicine, University of Ottawa. All analyses were performed using SAS version 9.1 (SAS Institute Inc. Cary, NC, USA. Chi-square and Fischer’s exact test (for cell count less than 5 were used to derive p-values for categorical variables by level of student learning. Results The response rate was 45.6% (255 of 559 students for all four years of the curriculum. 63% of the responses were from students in years 1 and 2 (preclerkship. Students identified role modeling as the single most important aspect of professionalism. The strongest curricular recommendations included faculty-led case scenario sessions, enhancing interprofessional interactions and the creation of special awards to staff and students to “celebrate” professionalism. Current evaluation systems were considered least effective. The importance of role modeling and information on how to report lapses and breaches was

Measuring presence in a collaborative physics learning activity in Second Life

DEFF Research Database (Denmark)

Vrellis, Ioannis; Papachristos, Nikiforos; Natsis, Antonios

2010-01-01

interacting with and via virtual environments and seems to play an important role in learning. This paper presents empirical data gathered from an exploratory study regarding a problem-based physics learning activity in Second Life (SL). Our aim is to gain knowledge and experience about the sense of presence...... found between dimensions of presence, subjective computer expertise and tendency to become involved in activities....

Disentangling the Role of Domain-Specific Knowledge in Student Modeling

Science.gov (United States)

Ruppert, John; Duncan, Ravit Golan; Chinn, Clark A.

2017-08-01

This study explores the role of domain-specific knowledge in students' modeling practice and how this knowledge interacts with two domain-general modeling strategies: use of evidence and developing a causal mechanism. We analyzed models made by middle school students who had a year of intensive model-based instruction. These models were made to explain a familiar but unstudied biological phenomenon: late onset muscle pain. Students were provided with three pieces of evidence related to this phenomenon and asked to construct a model to account for this evidence. Findings indicate that domain-specific resources play a significant role in the extent to which the models accounted for provided evidence. On the other hand, familiarity with the situation appeared to contribute to the mechanistic character of models. Our results indicate that modeling strategies alone are insufficient for the development of a mechanistic model that accounts for provided evidence and that, while learners can develop a tentative model with a basic familiarity of the situation, scaffolding certain domain-specific knowledge is necessary to assist students with incorporating evidence in modeling tasks.

The role of a convective surface in models of the radiative heat transfer in nanofluids

Energy Technology Data Exchange (ETDEWEB)

Rahman, M.M., E-mail: mansurdu@yahoo.com; Al-Mazroui, W.A.; Al-Hatmi, F.S.; Al-Lawatia, M.A.; Eltayeb, I.A.

2014-08-15

Highlights: • The role of a convective surface in modelling with nanofluids is investigated over a wedge. • Surface convection significantly controls the rate of heat transfer in nanofluid. • Increased volume fraction of nanoparticles to the base-fluid may not always increase the rate of heat transfer. • Effect of nanoparticles solid volume fraction depends on the types of constitutive materials. • Higher heat transfer in nanofluids is found in a moving wedge rather than in a static wedge. - Abstract: Nanotechnology becomes the core of the 21st century. Nanofluids are important class of fluids which help advancing nanotechnology in various ways. Convection in nanofluids plays a key role in enhancing the rate of heat transfer either for heating or cooling nanodevices. In this paper, we investigate theoretically the role of a convective surface on the heat transfer characteristics of water-based nanofluids over a static or moving wedge in the presence of thermal radiation. Three different types of nanoparticles, namely copper Cu, alumina Al{sub 2}O{sub 3} and titanium dioxide TiO{sub 2} are considered in preparation of nanofluids. The governing nonlinear partial differential equations are made dimensionless with the similarity transformations. Numerical simulations are carried out through the very robust computer algebra software MAPLE 13 to investigate the effects of various pertinent parameters on the flow field. The obtained results presented graphically as well as in tabular form and discussed from physical and engineering points of view. The results show that the rate of heat transfer in a nanofluid in the presence of thermal radiation significantly depends on the surface convection parameter. If the hot fluid side surface convection resistance is lower than the cold fluid side surface convection resistance, then increased volume fraction of the nanoparticles to the base fluid may reduces the heat transfer rate rather than increases from the surface of

Role Model Influencers of Nontraditional Professional Women.

Science.gov (United States)

Lunneborg, Patricia W.

1982-01-01

Tested the influence of a supportive family on 142 women employed in or studying for nontraditional careers. Results showed the importance of emotional support by parents, siblings, peers and teachers. Suggests counselors encourage women to locate role models and mentors if preparing for nontraditional careers. (Author/JAC)

A dynamic model for infectious diseases: The role of vaccination and treatment

International Nuclear Information System (INIS)

Raja Sekhara Rao, P.; Naresh Kumar, M.

2015-01-01

Understanding dynamics of an infectious disease helps in designing appropriate strategies for containing its spread in a population. Recent mathematical models are aimed at studying dynamics of some specific types of infectious diseases. In this paper we propose a new model for infectious diseases spread having susceptible, infected, and recovered populations and study its dynamics in presence of incubation delays and relapse of the disease. The influence of treatment and vaccination efforts on the spread of infection in presence of time delays are studied. Sufficient conditions for local stability of the equilibria and change of stability are derived in various cases. The problem of global stability is studied for an important special case of the model. Simulations carried out in this study brought out the importance of treatment rate in controlling the disease spread. It is observed that incubation delays have influence on the system even under enhanced vaccination. The present study has clearly brought out the fact that treatment rate even in presence of time delays would contain the disease as compared to popular belief that eradication can only be done through vaccination

Scientist Role Models in the Classroom: How Important Is Gender Matching?

Science.gov (United States)

Conner, Laura D. Carsten; Danielson, Jennifer

2016-01-01

Gender-matched role models are often proposed as a mechanism to increase identification with science among girls, with the ultimate aim of broadening participation in science. While there is a great deal of evidence suggesting that role models can be effective, there is mixed support in the literature for the importance of gender matching. We used…

Spatial Downscaling of Alien Species Presences Using Machine Learning

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Ioannis N. Daliakopoulos

2017-07-01

Full Text Available Spatially explicit assessments of alien species environmental and socio-economic impacts, and subsequent management interventions for their mitigation, require large scale, high-resolution data on species presence distribution. However, these data are often unavailable. This paper presents a method that relies on Random Forest (RF models to distribute alien species presence counts at a finer resolution grid, thus achieving spatial downscaling. A bootstrapping scheme is designed to account for sub-setting uncertainty, and subsets are used to train a sufficiently large number of RF models. RF results are processed to estimate variable importance and model performance. The method is tested with an ~8 × 8 km2 grid containing floral alien species presence and several potentially exploratory indices of climatic, habitat, land use, and soil property covariates for the Mediterranean island of Crete, Greece. Alien species presence is aggregated at 16 × 16 km2 and used as a predictor of presence at the original resolution, thus simulating spatial downscaling. Uncertainty assessment of the spatial downscaling of alien species' occurrences was also performed and true/false presences and absences were quantified. The approach is promising for downscaling alien species datasets of larger spatial scale but coarse resolution, where the underlying environmental information is available at a finer resolution. Furthermore, the RF architecture allows for tuning toward operationally optimal sensitivity and specificity, thus providing a decision support tool for designing a resource efficient alien species census.

Application of density functional theory to the nitric oxide heterogeneous reduction mechanism in the presence of hydroxyl and carbonyl groups

International Nuclear Information System (INIS)

Zhang, Hai; Jiang, Xiumin; Liu, Jiaxun; Shen, Jun

2014-01-01

Highlights: • The role of hydroxyl and carbonyl groups are studied on two modified zigzag models. • Energetics and kinetics for the proposed pathways are chiefly investigated. • New active sites are beneficial for NO adsorption and N-O bond dissociation. • The highly exothermicity of C(NCO) formation is helpful for CO 2 and N 2 elimination. - Abstract: Comprehensive theoretical calculations are carried out to investigate the nitric oxide (NO) heterogeneous reduction mechanism in the presence of hydroxyl (-OH) and carbonyl (>C=O) groups. Energetics (activation energy and thermochemistry data) and kinetics (thermal rate constant) for the proposed pathways are provided by density functional theory (DFT) and conventional transition state theory (TST), respectively. The role played by -OH and >C=O has been clarified. In the presence of -OH, four stepwise reactions with the highest energy barrier of 251.7 kJ/mol are found to produce new active sites. Subsequently, a number of elementary reactions with energy barrier below 116.1 kJ/mol take place to reduce NO. The role of > C=O is to yield NCO intermediate. The formation of NCO is highly exothermic with 709.4 kJ/mol, which contributes to the elimination of carbon dioxide (CO 2 ) and nitrogen (N 2 ). The discovered mechanism is consistent with previous experimental observation that NO heterogeneous reduction is enhanced due to the presence of oxygen

Entrepreneurship education revisited: perceived entrepreneurial role models increase perceived behavioural control

Science.gov (United States)

Fellnhofer, Katharina

2017-01-01

Relying on Bandura’s (1986) social learning theory, Ajzen’s (1988) theory of planned behaviour (TPB), and Dyer’s (1994) model of entrepreneurial careers, this study aims to highlight the potential of entrepreneurial role models to entrepreneurship education. The results suggest that entrepreneurial courses would greatly benefit from real-life experiences, either positive or negative. The results of regression analysis based on 426 individuals, primarily from Austria, Finland, and Greece, show that role models increase learners’ entrepreneurial perceived behaviour control (PBC) by increasing their self-efficacy. This study can inform the research and business communities and governments about the importance of integrating entrepreneurs into education to stimulate entrepreneurial PBC. This study is the first of its kind using its approach, and its results warrant more in-depth studies of storytelling by entrepreneurial role models in the context of multimedia entrepreneurship education. PMID:29104604

Entrepreneurship education revisited: perceived entrepreneurial role models increase perceived behavioural control.

Science.gov (United States)

Fellnhofer, Katharina

2017-01-01

Relying on Bandura's (1986) social learning theory, Ajzen's (1988) theory of planned behaviour (TPB), and Dyer's (1994) model of entrepreneurial careers, this study aims to highlight the potential of entrepreneurial role models to entrepreneurship education. The results suggest that entrepreneurial courses would greatly benefit from real-life experiences, either positive or negative. The results of regression analysis based on 426 individuals, primarily from Austria, Finland, and Greece, show that role models increase learners' entrepreneurial perceived behaviour control (PBC) by increasing their self-efficacy. This study can inform the research and business communities and governments about the importance of integrating entrepreneurs into education to stimulate entrepreneurial PBC. This study is the first of its kind using its approach, and its results warrant more in-depth studies of storytelling by entrepreneurial role models in the context of multimedia entrepreneurship education.

State of the Art Report On Condensation Phenomena Within Tubes in the Presence of Noncondensable Gas

International Nuclear Information System (INIS)

Polo, J.

1998-01-01

Condensation phenomena play an important role in many industrial applications; in particular; the nuclear industry uses such processes in different systems for both operation and safety aspects. Thus most of the engineering safety features in the current Light Water Reactor (LWR) plants as well as in the new advanced/passive type design are based on the condensation phenomena inside tubes to reduce the system pressure and to remove the decay heat released under accidental conditions. Regarding the new advanced/passive plant designs such a systems must ensure their capabilities under severe accident conditions, that means, under the presence of non-condensable gas an even aerosol particles. The presence of even a small quantity of non condensable gas in liquid-vapour has profound influence on the resistance to heat transfer at the liquid-vapour interface leading to reduce in the heat transfer rate. In consequence, the safety analysis of the Simplified Boiling Water Reactor (SBWR) promoted in increase in the modelling, model development and experimental research on the gas mixtures condensing inside vertical tubes. This report summarises the last models developed as well as the experimental findings on such processes. (Author) 51 refs

Promoting success or preventing failure: cultural differences in motivation by positive and negative role models.

Science.gov (United States)

Lockwood, Penelope; Marshall, Tara C; Sadler, Pamela

2005-03-01

In two studies, cross-cultural differences in reactions to positive and negative role models were examined. The authors predicted that individuals from collectivistic cultures, who have a stronger prevention orientation, would be most motivated by negative role models, who highlight a strategy of avoiding failure; individuals from individualistic cultures, who have a stronger promotion focus, would be most motivated by positive role models, who highlight a strategy of pursuing success. In Study 1, the authors examined participants' reported preferences for positive and negative role models. Asian Canadian participants reported finding negative models more motivating than did European Canadians; self-construals and regulatory focus mediated cultural differences in reactions to role models. In Study 2, the authors examined the impact of role models on the academic motivation of Asian Canadian and European Canadian participants. Asian Canadians were motivated only by a negative model, and European Canadians were motivated only by a positive model.

The Role of Teaching Presence and Student Participation in Spanish Blended Courses

Science.gov (United States)

Rubio, Fernando; Thomas, Jonathan M.; Li, Qin

2018-01-01

This chapter describes a study of a blended language course that combines face-to-face (F2F) instructional time with an online component. The purpose of the study is to understand how teachers and students exploit the complementarity of the two delivery formats to improve the learning experience. The study first examines how the presence of an…

Reconciling professional identity: A grounded theory of nurse academics' role modelling for undergraduate students.

Science.gov (United States)

Baldwin, A; Mills, J; Birks, M; Budden, L

2017-12-01

Role modelling by experienced nurses, including nurse academics, is a key factor in the process of preparing undergraduate nursing students for practice, and may contribute to longevity in the workforce. A grounded theory study was undertaken to investigate the phenomenon of nurse academics' role modelling for undergraduate students. The study sought to answer the research question: how do nurse academics role model positive professional behaviours for undergraduate students? The aims of this study were to: theorise a process of nurse academic role modelling for undergraduate students; describe the elements that support positive role modelling by nurse academics; and explain the factors that influence the implementation of academic role modelling. The study sample included five second year nursing students and sixteen nurse academics from Australia and the United Kingdom. Data was collected from observation, focus groups and individual interviews. This study found that in order for nurse academics to role model professional behaviours for nursing students, they must reconcile their own professional identity. This paper introduces the theory of reconciling professional identity and discusses the three categories that comprise the theory, creating a context for learning, creating a context for authentic rehearsal and mirroring identity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Role of Stat in Skin Carcinogenesis: Insights Gained from Relevant Mouse Models

International Nuclear Information System (INIS)

Macias, E.; Rao, D.; DiGiovanni, J.; DiGiovanni, J.; DiGiovanni, J.

2013-01-01

Signal transducer and activator of transcription 3 (Stat) is a cytoplasmic protein that is activated in response to cytokines and growth factors and acts as a transcription factor. Stat plays critical roles in various biological activities including cell proliferation, migration, and survival. Studies using keratinocyte-specific Stat-deficient mice have revealed that Stat plays an important role in skin homeostasis including keratinocyte migration, wound healing, and hair follicle growth. Use of both constitutive and inducible keratinocyte-specific Stat-deficient mouse models has demonstrated that Stat is required for both the initiation and promotion stages of multistage skin carcinogenesis. Further studies using a transgenic mouse model with a gain of function mutant of Stat (Stat3C) expressed in the basal layer of the epidermis revealed a novel role for Stat in skin tumor progression. Studies using similar Stat-deficient and gain-of-function mouse models have indicated its similar roles in ultraviolet B (UVB) radiation-mediated skin carcinogenesis. This paper summarizes the use of these various mouse models for studying the role and underlying mechanisms for the function of Stat in skin carcinogenesis. Given its significant role throughout the skin carcinogenesis process, Stat is an attractive target for skin cancer prevention and treatment.

The Managerial Roles of Academic Library Directors: The Mintzberg Model.

Science.gov (United States)

Moskowitz, Michael Ann

1986-01-01

A study based on a model developed by Henry Mintzberg examined the internal and external managerial roles of 126 New England college and university library directors. Survey results indicate that the 97 responding directors were primarily involved with internal managerial roles and work contacts. (CDD)

An SOA model for toluene oxidation in the presence of inorganic aerosols.

Science.gov (United States)

Cao, Gang; Jang, Myoseon

2010-01-15

A predictive model for secondary organic aerosol (SOA) formation including both partitioning and heterogeneous reactions is explored for the SOA produced from the oxidation of toluene in the presence of inorganic seed aerosols. The predictive SOA model comprises the explicit gas-phase chemistry of toluene, gas-particle partitioning, and heterogeneous chemistry. The resulting products from the explicit gas phase chemistry are lumped into several classes of chemical species based on their vapor pressure and reactivity for heterogeneous reactions. Both the gas-particle partitioning coefficient and the heterogeneous reaction rate constant of each lumped gas-phase product are theoretically determined using group contribution and molecular structure-reactivity. In the SOA model, the predictive SOA mass is decoupled into partitioning (OM(P)) and heterogeneous aerosol production (OM(H)). OM(P) is estimated from the SOA partitioning model developed by Schell et al. (J. Geophys. Res. 2001, 106, 28275-28293 ) that has been used in a regional air quality model (CMAQ 4.7). OM(H) is predicted from the heterogeneous SOA model developed by Jang et al. (Environ. Sci. Technol. 2006, 40, 3013-3022 ). The SOA model is evaluated using a number of the experimental SOA data that are generated in a 2 m(3) indoor Teflon film chamber under various experimental conditions (e.g., humidity, inorganic seed compositions, NO(x) concentrations). The SOA model reasonably predicts not only the gas-phase chemistry, such as the ozone formation, the conversion of NO to NO(2), and the toluene decay, but also the SOA production. The model predicted that the OM(H) fraction of the total toluene SOA mass increases as NO(x) concentrations decrease: 0.73-0.83 at low NO(x) levels and 0.17-0.47 at middle and high NO(x) levels for SOA experiments with high initial toluene concentrations. Our study also finds a significant increase in the OM(H) mass fraction in the SOA generated with low initial toluene

A kinetic model for low pressure glow discharges in the presence of dust particles

International Nuclear Information System (INIS)

Wang Dezhen; Dong, J.Q.; Mahajan, S.M.

1996-05-01

A kinetic model for electrons in dusty plasmas is developed. The Boltzmann and the dust charging balance equations are solved self-consistently. The dependence of the dust particle surface potential on plasma parameters and the effects of particulate contamination on electron energy distribution are investigated for direct-current argon glow discharges. It is shown that the dust particle surface potential obtained from this model is higher than that obtained for a Maxwellian electron distribution, and that the higher energy portion of the electron distribution is reduced in the presence of dust particles. Electron-dust collection and electron-atom inelastic collision are the main electron energy loss processes, and the electron energy loss due to electron-dust elastic collision is negligibly small for 10 -16 V cm 2 -15 V cm 2 under the discharge conditions considered in this work, where E is the externally applied electric field and N is the argon atom density. (author). 16 refs, 8 figs

The complexity of role balance: support for the Model of Juggling Occupations.

Science.gov (United States)

Evans, Kiah L; Millsteed, Jeannine; Richmond, Janet E; Falkmer, Marita; Falkmer, Torbjorn; Girdler, Sonya J

2014-09-01

This pilot study aimed to establish the appropriateness of the Model of Juggling Occupations in exploring the complex experience of role balance amongst working women with family responsibilities living in Perth, Australia. In meeting this aim, an evaluation was conducted of a case study design, where data were collected through a questionnaire, time diary, and interview. Overall role balance varied over time and across participants. Positive indicators of role balance occurred frequently in the questionnaires and time diaries, despite the interviews revealing a predominance of negative evaluations of role balance. Between-role balance was achieved through compatible role overlap, buffering, and renewal. An exploration of within-role balance factors demonstrated that occupational participation, values, interests, personal causation, and habits were related to role balance. This pilot study concluded that the Model of Juggling Occupations is an appropriate conceptual framework to explore the complex and dynamic experience of role balance amongst working women with family responsibilities. It was also confirmed that the case study design, including the questionnaire, time diary, and interview methods, is suitable for researching role balance from this perspective.

Understanding DNA Under Oxidative Stress and Sensitization: The Role of Molecular Modeling

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Antonio eMonari

2015-07-01

Full Text Available DNA is constantly exposed to damaging threats coming from oxidative stress, i.e. from the presence of free radicals and reactive oxygen species. Sensitization from exogenous and endogenous compounds that strongly enhance the frequency of light-induced lesions also plays an important role. The experimental determination of DNA lesions, though a difficult subject, is somehow well established and allows to elucidate even extremely rare DNA lesions. In parallel, molecular modeling has become fundamental to clearly understand the fine mechanisms related to DNA defects induction. Indeed, it offers an unprecedented possibility to get access to an atomistic or even electronic resolution. Ab initio molecular dynamics may also describe the time-evolution of the molecular system and its reactivity. Yet the modeling of DNA (photo-reactions does necessitate elaborate multi-scale methodologies to tackle a damage induction reactivity that takes place in a complex environment. The double-stranded DNA environment is first characterized by a very high flexibility, that dynamical effects are to be taken into account, but also a strongly inhomogeneous electrostatic embedding. Additionally, one aims at capturing more subtle effects, such as the sequence selectivity which is of critical important for DNA damage. The structure and dynamics of the DNA/sensitizers complexes, as well as the photo-induced electron- and energy-transfer phenomena taking place upon sensitization, should be carefully modeled. Finally the factors inducing different repair ratios for different lesions should also be rationalized.In this review we will critically analyze the different computational strategies used to model DNA lesions. A clear picture of the complex interplay between reactivity and structural factors will be sketched. The use of proper multi-scale modeling leads to the in-depth comprehension of DNA lesions mechanism and also to the rational design of new chemo-therapeutic agents.

The Role of Aggregates of Therapeutic Protein Products in Immunogenicity: An Evaluation by Mathematical Modeling

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Liusong Yin

2015-01-01

Full Text Available Therapeutic protein products (TPP have been widely used to treat a variety of human diseases, including cancer, hemophilia, and autoimmune diseases. However, TPP can induce unwanted immune responses that can impact both drug efficacy and patient safety. The presence of aggregates is of particular concern as they have been implicated in inducing both T cell-independent and T cell-dependent immune responses. We used mathematical modeling to evaluate several mechanisms through which aggregates of TPP could contribute to the development of immunogenicity. Modeling interactions between aggregates and B cell receptors demonstrated that aggregates are unlikely to induce T cell-independent immune responses by cross-linking B cell receptors because the amount of signal transducing complex that can form under physiologically relevant conditions is limited. We systematically evaluate the role of aggregates in inducing T cell-dependent immune responses using a recently developed multiscale mechanistic mathematical model. Our analysis indicates that aggregates could contribute to T cell-dependent immune response by inducing high affinity epitopes which may not be present in the nonaggregated TPP and/or by enhancing danger signals to break tolerance. In summary, our computational analysis is suggestive of novel insights into the mechanisms underlying aggregate-induced immunogenicity, which could be used to develop mitigation strategies.

Penerapan Model Pembelajaran Bermain Peran (Role Playing dalam Meningkatkan Hasil Belajar Ekonomi

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Tri Hartati

2012-06-01

Full Text Available Berdasarkan observasi di SMA N 1 Wadaslintang proses pembelajararan masih didominasi guru, ini membuat siswa pasif sehingga hasil belajar rendah. Upaya mencapai kompetensi pembelajaran adalah melakukan perbaikan dengan menerapkan model pembelajaran Role playing. Permasalahan: (1 apakah keaktifan siswa dengan penerapan model pembelajaran Role Playing dapat meningkatkan hasil belajar?, (2 bagaimana respon/tanggapan siswa dengan penerapan model Role Playing?. Tujuan: (1 mengetahui aktifitas siswa yang dapat meningkatkan hasil belajar, (2 mengetahui respon/tanggapan siswa terhadap model Role Playing. Penelitian ini merupakan penelitian tindakan kelas yang dilaksanakan dalam 2 siklus, masing-masing siklus dua kali pertemuan dan beberapa tahap yaitu perencanaan, pelaksanaan, pengamatan dan refleksi. Data yang diperoleh dalam penelitian ini meliputi: keaktifan siswa, hasil belajar, dan respon siswa. Siklus I aktifitas siswa sebesar 57,82% (cukup aktif, rata-rata nilai hasil belajar 72 ketuntasan klasikal 68,18% dan respon siswa 64,58% (positif. Siklus II keaktifan siswa menjadi 78,9% (aktif, rata-rata nilai hasil belajar 84 ketuntasan klasikal 95,45% dan respon siswa meningkat menjadi 77,56% (positif. Simpulan dari penelitian ini adalah (1 meningkatnya keaktifan siswa dengan model pembelajaran Role Playing dapat meningkatkan hasil belajar siswa, (2 respon/tanggapan siswa menunjukan respon positif selama proses pembelajaran. Saran dari penelitian ini yaitu (1 Pembelajaran menggunakan model role playing dapat disesuaikan dengan materi yang ada dengan catatan guru harus menerangkan terlebih dahulu materi yang akan dipelajari, (2 model pembelajaran role playing memerlukan penguasaan materi yang baik jadi sebelum melakukan proses role playing disarankan siswa lebih banyak membaca materi agar proses pembelajaran lebih aktif. � Based on observation, economic teacher at SMA N 1 Wadaslintang implement teacher center learning, student being pasive and student

A two-compartment mechanochemical model of the roles of transforming growth factor and tissue tension in dermal wound healing

KAUST Repository

Murphy, Kelly E.

2011-03-01

The repair of dermal tissue is a complex process of interconnected phenomena, where cellular, chemical and mechanical aspects all play a role, both in an autocrine and in a paracrine fashion. Recent experimental results have shown that transforming growth factor -β (TGF β) and tissue mechanics play roles in regulating cell proliferation, differentiation and the production of extracellular materials. We have developed a 1D mathematical model that considers the interaction between the cellular, chemical and mechanical phenomena, allowing the combination of TGF β and tissue stress to inform the activation of fibroblasts to myofibroblasts. Additionally, our model incorporates the observed feature of residual stress by considering the changing zero-stress state in the formulation for effective strain. Using this model, we predict that the continued presence of TGF β in dermal wounds will produce contractures due to the persistence of myofibroblasts; in contrast, early elimination of TGF β significantly reduces the myofibroblast numbers resulting in an increase in wound size. Similar results were obtained by varying the rate at which fibroblasts differentiate to myofibroblasts and by changing the myofibroblast apoptotic rate. Taken together, the implication is that elevated levels of myofibroblasts is the key factor behind wounds healing with excessive contraction, suggesting that clinical strategies which aim to reduce the myofibroblast density may reduce the appearance of contractures. © 2010 Elsevier Ltd.

A two-compartment mechanochemical model of the roles of transforming growth factor and tissue tension in dermal wound healing

KAUST Repository

Murphy, Kelly E.; Hall, Cameron L.; McCue, Scott W.; Sean McElwain, D.L.

2011-01-01

The repair of dermal tissue is a complex process of interconnected phenomena, where cellular, chemical and mechanical aspects all play a role, both in an autocrine and in a paracrine fashion. Recent experimental results have shown that transforming growth factor -β (TGF β) and tissue mechanics play roles in regulating cell proliferation, differentiation and the production of extracellular materials. We have developed a 1D mathematical model that considers the interaction between the cellular, chemical and mechanical phenomena, allowing the combination of TGF β and tissue stress to inform the activation of fibroblasts to myofibroblasts. Additionally, our model incorporates the observed feature of residual stress by considering the changing zero-stress state in the formulation for effective strain. Using this model, we predict that the continued presence of TGF β in dermal wounds will produce contractures due to the persistence of myofibroblasts; in contrast, early elimination of TGF β significantly reduces the myofibroblast numbers resulting in an increase in wound size. Similar results were obtained by varying the rate at which fibroblasts differentiate to myofibroblasts and by changing the myofibroblast apoptotic rate. Taken together, the implication is that elevated levels of myofibroblasts is the key factor behind wounds healing with excessive contraction, suggesting that clinical strategies which aim to reduce the myofibroblast density may reduce the appearance of contractures. © 2010 Elsevier Ltd.

Crucial roles of the protein kinases MK2 and MK3 in a mouse model of glomerulonephritis.

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Adam J Guess

Full Text Available Elevated mitogen-activated protein kinase p38 (p38 MAPK signaling has been implicated in various experimental and human glomerulopathies, and its inhibition has proven beneficial in animal models of these diseases. p38 MAPK signaling is partially mediated through MK2 and MK3, two phylogenetically related protein kinases that are its direct substrates. The current study was designed to determine the specific roles of MK2 and MK3 in a mouse model of acute proliferative glomerulonephritis, using mice with disrupted MK2 and/or MK3 genes. We found that the absence of MK3 alone worsened the disease course and increased mortality slightly compared to wild-type mice, whereas the absence of MK2 alone exhibited no significant effect. However, in an MK3-free background, the disease course depended on the presence of MK2 in a gene dosage-dependent manner, with double knock-out mice being most susceptible to disease induction. Histological and renal functional analyses confirmed kidney damage following disease induction. Because the renal stress response plays a crucial role in kidney physiology and disease, we analyzed the stress response pattern in this disease model. We found that renal cortices of diseased mice exhibited a pronounced and specific pattern of expression and/or phosphorylation of stress proteins and other indicators of the stress response (HSPB1, HSPB6, HSPB8, CHOP, eIF2α, partially in a MK2/MK3 genotype-specific manner, and without induction of a general stress response. Similarly, the expression and activation patterns of other protein kinases downstream of p38 MAPK (MNK1, MSK1 depended partially on the MK2/MK3 genotype in this disease model. In conclusion, MK2 and MK3 together play crucial roles in the regulation of the renal stress response and in the development of glomerulonephritis, which can potentially be exploited to develop novel therapeutic approaches to treat glomerular disease.

Presence and Positioning as Components of Online Instructor Persona

Science.gov (United States)

Dennen, Vanessa Paz

2007-01-01

Instructor persona in online discussion may set the tone for a variety of course outcomes. Instructors establish persona via both presence (amount of instructor posts) and position (interaction relative to those in the student role). In this paper, three online classes were studied using positioning theory as a grounding framework to elicit ways…

Growing up and Role Modeling: A Theory in Iranian Nursing Students? Education

OpenAIRE

Nouri, Jamileh Mokhtari; Ebadi, Abbas; Alhani, Fatemeh; Rejeh, Nahid

2014-01-01

One of the key strategies in students? learning is being affected by models. Understanding the role-modeling process in education will help to make greater use of this training strategy. The aim of this grounded theory study was to explore Iranian nursing students and instructors? experiences about role modeling process. Data was analyzed by Glaserian?s Grounded Theory methodology through semi-structured interviews with 7 faculty members, 2 nursing students; the three focus group discussions ...

Anomalous resonance of the symmetric single-impurity Anderson model in the presence of pairing fluctuations

International Nuclear Information System (INIS)

Guang-Ming Zhang; Lu Yu

1998-10-01

We consider the symmetric single-impurity Anderson model in the presence of pairing fluctuations. In the isotropic limit, the degrees of freedom of the local impurity are separated into hybridizing and non-hybridizing modes. The self-energy for the hybridizing modes can be obtained exactly, leading to two subbands centered at ±U/2. For the non-hybridizing modes, the second order perturbation yields a singular resonance of the marginal Fermi liquid form. By multiplicative renormalization, the self-energy is derived exactly, showing the resonance is pinned at the Fermi level, while its strength is weakened by renormalization. (author)

Enduring Influence of Stereotypical Computer Science Role Models on Women's Academic Aspirations

Science.gov (United States)

Cheryan, Sapna; Drury, Benjamin J.; Vichayapai, Marissa

2013-01-01

The current work examines whether a brief exposure to a computer science role model who fits stereotypes of computer scientists has a lasting influence on women's interest in the field. One-hundred undergraduate women who were not computer science majors met a female or male peer role model who embodied computer science stereotypes in appearance…

Modeling the Role of Networks and Individual Differences in Inter-Group Violence.

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Alexander Isakov

Full Text Available There is significant heterogeneity within and between populations in their propensity to engage in conflict. Most research has neglected the role of within-group effects in social networks in contributing to between-group violence and focused instead on the precursors and consequences of violence, or on the role of between-group ties. Here, we explore the role of individual variation and of network structure within a population in promoting and inhibiting group violence towards other populations. Motivated by ethnographic observations of collective behavior in a small-scale society, we describe a model with differentiated roles for individuals embedded within friendship networks. Using a simple model based on voting-like dynamics, we explore several strategies for influencing group-level behavior. When we consider changing population level attitude changes and introducing control nodes separately, we find that a particularly effective control strategy relies on exploiting network degree. We also suggest refinements to our model such as tracking fine-grained information spread dynamics that can lead to further enrichment in using evolutionary game theory models for sociological phenomena.

Immobilization of uranium in the presence of Fe0(s): Model development and simulation of contrasting experimental conditions

International Nuclear Information System (INIS)

Wang Yong; Salvage, Karen

2005-01-01

A geochemical model is developed for the immobilization of U in the presence of metallic Fe. Zero-valent iron (ZVI) serves as a reducing agent inducing the reductive-precipitation of U, and ZVI corrosion products can serve as absorbing agents for U. The numerical model developed allows the complex interactions of U in solution in differing concentrations to be examined, under variable pH and redox conditions, with or without carbonate, in the presence of ZVI of different size and surface area. It incorporates Fe corrosion, Fe(II) and Fe(III) corrosion product formation, reductive-precipitation of U from the soluble U(VI) valence to the poorly soluble U(IV) valence, adsorption/de-sorption of U onto the Fe oxide corrosion products, and aqueous speciation. The processes of Fe corrosion and reductive precipitation of U are simulated as non-equilibrium, an improvement over other geochemical models. The reductive-precipitation process may use either ZVI or Fe(II) as the reducing agent. The model is calibrated using 3 separate sets of experimental data from published literature that cover a wide range of redox conditions. Sensitivity of the model predictions to variations in input parameters is examined. The simulation results show that the different published experimental results can be explained by different solution chemistries in the studies, specifically O 2 and CO 2 availability and pH, and the amount and surface area of the metallic Fe. With this numerical model the behavior of U in ZVI containing systems over a range of conditions realistic for groundwater can be investigated. By synthesizing observations across several experimental studies, it will lead to a broader understanding of the processes controlling U immobilization under varied geochemical conditions

A Stage-Structured Prey-Predator Fishery Model In The Presence Of Toxicity With Taxation As A Control Parameter of Harvesting Effort

Directory of Open Access Journals (Sweden)

Sumit Kaur Bhatia

2017-08-01

Full Text Available In this paper we have considered stage-structured fishery model in the presence of toxicity, which is diminishing due to the current excessive use of fishing efforts resulting in devastating consequences. The purpose of this study is to propose a bio-economic mathematical model by introducing taxes to the profit per unit biomass of the harvested fish of each species with the intention of controlling fishing efforts in the presence of toxicity. We obtained both boundary and interior equilibrium points along with the conditions ensuring their validity. Local stability for the interior equilibrium point has been found by the trace-determinant criterion and global stability has been analyzed through a suitable Lyapunov function. We have also obtained the optimal harvesting policy with the help of Pontryagin's maximum principle. Lastly, numerical simulation with the help of MATLAB have been done and thus, the results of the formulated model have been established.

I can do that: the impact of implicit theories on leadership role model effectiveness.

Science.gov (United States)

Hoyt, Crystal L; Burnette, Jeni L; Innella, Audrey N

2012-02-01

This research investigates the role of implicit theories in influencing the effectiveness of successful role models in the leadership domain. Across two studies, the authors test the prediction that incremental theorists ("leaders are made") compared to entity theorists ("leaders are born") will respond more positively to being presented with a role model before undertaking a leadership task. In Study 1, measuring people's naturally occurring implicit theories of leadership, the authors showed that after being primed with a role model, incremental theorists reported greater leadership confidence and less anxious-depressed affect than entity theorists following the leadership task. In Study 2, the authors demonstrated the causal role of implicit theories by manipulating participants' theory of leadership ability. They replicated the findings from Study 1 and demonstrated that identification with the role model mediated the relationship between implicit theories and both confidence and affect. In addition, incremental theorists outperformed entity theorists on the leadership task.

Presence of Social Presence during Disasters

DEFF Research Database (Denmark)

Mukkamala, Alivelu Manga; Beck, Roman

2017-01-01

During emergencies, affected people use social media platforms for interaction and collaboration. Social media is used to ask for help, provide moral support, and to help each other, without direct face-to-face interactions. From a social presence point of view, we analyzed Twitter messages...... to understand how people cooperate and collaborate with each other during heavy rains and subsequent floods in Chennai, India. We conducted a manual content analysis to build social presence classifiers comprising intimacy and immediacy concepts which we used to train a machine learning approach to subsequently...

Aberrant Behaviours of Reaction Diffusion Self-organisation Models on Growing Domains in the Presence of Gene Expression Time Delays

KAUST Repository

Seirin Lee, S.

2010-03-23

Turing\\'s pattern formation mechanism exhibits sensitivity to the details of the initial conditions suggesting that, in isolation, it cannot robustly generate pattern within noisy biological environments. Nonetheless, secondary aspects of developmental self-organisation, such as a growing domain, have been shown to ameliorate this aberrant model behaviour. Furthermore, while in-situ hybridisation reveals the presence of gene expression in developmental processes, the influence of such dynamics on Turing\\'s model has received limited attention. Here, we novelly focus on the Gierer-Meinhardt reaction diffusion system considering delays due the time taken for gene expression, while incorporating a number of different domain growth profiles to further explore the influence and interplay of domain growth and gene expression on Turing\\'s mechanism. We find extensive pathological model behaviour, exhibiting one or more of the following: temporal oscillations with no spatial structure, a failure of the Turing instability and an extreme sensitivity to the initial conditions, the growth profile and the duration of gene expression. This deviant behaviour is even more severe than observed in previous studies of Schnakenberg kinetics on exponentially growing domains in the presence of gene expression (Gaffney and Monk in Bull. Math. Biol. 68:99-130, 2006). Our results emphasise that gene expression dynamics induce unrealistic behaviour in Turing\\'s model for multiple choices of kinetics and thus such aberrant modelling predictions are likely to be generic. They also highlight that domain growth can no longer ameliorate the excessive sensitivity of Turing\\'s mechanism in the presence of gene expression time delays. The above, extensive, pathologies suggest that, in the presence of gene expression, Turing\\'s mechanism would generally require a novel and extensive secondary mechanism to control reaction diffusion patterning. © 2010 Society for Mathematical Biology.

Are Universities Role Models for Communities? A Gender Perspective

Directory of Open Access Journals (Sweden)

Felicia Cornelia MACARIE

2012-12-01

Full Text Available The present paper explores the degree in which universities could/should serve as role models for communities from the perspective of gender integration. Although the theoretical/ moral answer would be affirmative (universities should be in such a position that would allow local communities to regard them as role models of gender integration, the primary empirical analysis leads to another conclusion. A brief theoretical review (that connects gender discrimination, sustainable development, universities and local communities is followed by an empirical analysis that compares the management structures of 12 Romanian Universities of Advanced Research and Education (the best Romanian universities according to a national ranking with those of four local communities where they are located (as geographic proximity would lead to a better diffusion of best practices. Contrary to initial expectations, even in higher education institutions, women are underrepresented both in executive and legislative positions. Since universities are subject to the same major patterns of gender discrimination (such as role theory, glass ceiling and glass elevator as private and public organizations, they lose the moral high ground that theory would suggest. However, medicine and pharmacy universities that can be connected with the traditional roles attributed to women provide better gender integration, but glass escalator phenomena remain present even in these limited fields.

Ethical Presence in the Psychoanalytic Encounter and the Role of Apology.

Science.gov (United States)

Weiss, Micha

2018-03-01

This paper discusses aspects of ethical presence in psychoanalysis, and the possible use of apology in the therapeutic process. The author roughly delineates two periods in the history of psychoanalysis regarding the ethical dimension-the early classical period which is influenced by Freud's ethics of honesty, which gradually evolves towards the more recent intersubjectively-influenced period, necessitating the assimilation of an ethics of relationships. It is suggested that explicit theorizing of the ethical dimension into psychoanalysis offers added value to its effectiveness, and a framework is presented for combining relational, intersubjectively informed ethical dialogue, with contributions of classical technique, enriching the therapeutic potential of psychoanalytic work.

Dynamic model of minimax control over economic security state of the region in the presence of risks

Directory of Open Access Journals (Sweden)

Andrey Fedorovich Shorikov

2012-06-01

Full Text Available Investigation and solution of management of economic security state in the region (MESSR requires development of a dynamic economic-mathematical model that takes into account the presence of control actions, uncontrolled parameters (risk modeling errors, etc. and availability of information deficit. At the same time, the existing approaches to solving such problems are based primarily on static models and the use of stochastic modeling of the device, which is required for the application of knowledge of the probability characteristics of the main model parameters and special conditions for the realization of the process. We should note that to use the apparatus of stochastic modeling, very strict conditions are required, which in practice are usually not feasible in advance In this paper, we propose to use a deterministic approach for modeling and solving the original problem in the form of a dynamic programming problem of minimax control (optimization of a guaranteed result MESSR at the determined point of time, taking into account the availability of risks of deterministic and stochastic nature (combined risks model. At thesametime, under therisks in thesocial and economic system we understand thefactors that negatively catastrophically affect the results of the reviewed processes inside it. For an effective use, a technique of prediction and assessment of time rows and stochastic risks in MESSR optimization process is presented, which can serve as a basis for the development of appropriate computer software. To solve the problem of program minimax control MESSR in the presence of risks, we propose a method which is reduced to the realization of a finite number of solutions of linear and convex mathematical programming and discrete optimization problem. The proposed method makes it possible to develop efficient numerical procedures to implement computer simulation of the dynamics of the problem, build program minimax control and gain optimal

Defining the role of polyamines in colon carcinogenesis using mouse models

Directory of Open Access Journals (Sweden)

Natalia A Ignatenko

2011-01-01

Full Text Available Genetics and diet are both considered important risk determinants for colorectal cancer, a leading cause of death in the US and worldwide. Genetically engineered mouse (GEM models have made a significant contribution to the characterization of colorectal cancer risk factors. Reliable, reproducible, and clinically relevant animal models help in the identification of the molecular events associated with disease progression and in the development of effictive treatment strategies. This review is focused on the use of mouse models for studying the role of polyamines in colon carcinogenesis. We describe how the available mouse models of colon cancer such as the multiple intestinal neoplasia (Min mice and knockout genetic models facilitate understanding of the role of polyamines in colon carcinogenesis and help in the development of a rational strategy for colon cancer chemoprevention.

Growing up and role modeling: a theory in Iranian nursing students' education.

Science.gov (United States)

Mokhtari Nouri, Jamileh; Ebadi, Abbas; Alhani, Fatemeh; Rejeh, Nahid

2014-11-16

One of the key strategies in students' learning is being affected by models. Understanding the role-modeling process in education will help to make greater use of this training strategy. The aim of this grounded theory study was to explore Iranian nursing students and instructors' experiences about role modeling process. Data was analyzed by Glaserian's Grounded Theory methodology through semi-structured interviews with 7 faculty members, 2 nursing students; the three focus group discussions with 20 nursing students based on purposive and theoretical sampling was done for explaining role modeling process from four nursing faculties in Tehran. Through basic coding, an effort to comprehensive growth and excellence was made with the basic social process consisting the core category and through selective coding three phases were identified as: realizing and exposure to inadequate human and professional growth, facilitating human and professional growth and evolution. The role modeling process is taking place unconscious, involuntary, dynamic and with positive progressive process in order to facilitate overall growth in nursing student. Accordingly, the design and implementation of the designed model can be used to make this unconscious to conscious, active and voluntarily processes a process to help education administrators of nursing colleges and supra organization to prevent threats to human and professional in nursing students' education and promote nursing students' growth.

Sickness presence, sick leave and adjustment latitude

Directory of Open Access Journals (Sweden)

Joachim Gerich

2014-10-01

Full Text Available Objectives: Previous research on the association between adjustment latitude (defined as the opportunity to adjust work efforts in case of illness and sickness absence and sickness presence has produced inconsistent results. In particular, low adjustment latitude has been identified as both a risk factor and a deterrent of sick leave. The present study uses an alternative analytical strategy with the aim of joining these results together. Material and Methods: Using a cross-sectional design, a random sample of employees covered by the Upper Austrian Sickness Fund (N = 930 was analyzed. Logistic and ordinary least square (OLS regression models were used to examine the association between adjustment latitude and days of sickness absence, sickness presence, and an estimator for the individual sickness absence and sickness presence propensity. Results: A high level of adjustment latitude was found to be associated with a reduced number of days of sickness absence and sickness presence, but an elevated propensity for sickness absence. Conclusions: Employees with high adjustment latitude experience fewer days of health complaints associated with lower rates of sick leave and sickness presence compared to those with low adjustment latitude. In case of illness, however, high adjustment latitude is associated with a higher pro­bability of taking sick leave rather than sickness presence.

Experimental study and thermodynamic modeling of CO2 gas hydrate formation in presence of zinc oxide nanoparticles

International Nuclear Information System (INIS)

Mohammadi, Mohsen; Haghtalab, Ali; Fakhroueian, Zahra

2016-01-01

Highlights: • Nanofluids enhance heat and mass transfer and affect on kinetic and thermodynamics. • The ZnO nanoparticles in liquid affect on kinetics and P-T curve of CO 2 hydrate. • ZnO nanoparticles enhance the growth rate and gas storage in CO 2 hydrate. • A thermodynamic modeling of CO 2 hydrate proposed in the presence of nanoparticles. • Water activity in ZnO + nanofluid was affected by enhancement of the CO 2 solubility. - Abstract: The effect of synthesized zinc oxide (ZnO) nanoparticles was investigated on the kinetic and thermodynamic equilibrium conditions of CO 2 hydrate formation. The amount of the gas consumption was measured and compared for the four sample fluids: pure water, aqueous solution of sodium dodecyl sulfate (SDS), water-based ZnO-nanofluid and water-based ZnO-nanofluid in the presence of SDS (0.001 mass fraction). The time of hydrate growth decreased and the amount of the storage gas enhanced in the presence of nanoparticles. Moreover, the nanoparticles size effect besides the CO 2 solubility enhancement in ZnO-nanofluid led to the reduction of water activity, so that the equilibrium curve of hydrate formation was shifted to higher pressures. A new correlation for Henry’s law constant was obtained using CO 2 -solubility data in ZnO-nanofluid. Finally using this correlation, the water activity was calculated through the Chen–Guo approach to propose a thermodynamic method for prediction of the equilibrium hydrate formation conditions in the presence of the nanoparticles.

Assessment of MELCOR condensation models with the presence of noncondensable gas in natural convection flow regime

International Nuclear Information System (INIS)

Yoon, Dhongik S; Jo, HangJin; Corradini, Michael L

2017-01-01

Condensation of steam vapor is an important mode of energy removal from the reactor containment. The presence of noncondensable gas complicates the process and makes it difficult to model. MELCOR, one of the more widely used system codes for containment analyses, uses the heat and mass transfer analogy to model condensation heat transfer. To investigate previously reported nodalization-dependence in natural convection flow regime, MELCOR condensation model as well as other models are studied. The nodalization-dependence issue is resolved by using physical length from the actual geometry rather than node size of each control volume as the characteristic length scale for MELCOR containment analyses. At the transition to turbulent natural convection regime, the McAdams correlation for convective heat transfer produces a better prediction compared to the original MELCOR model. The McAdams correlation is implemented in MELCOR and the prediction is validated against a set of experiments on a scaled AP600 containment. The MELCOR with our implemented model produces improved predictions. For steam molar fractions in the gas mixture greater than about 0.58, the predictions are within the uncertainty margin of the measurements. The simulation results still underestimate the heat transfer from the gas-steam mixture, implying that conservative predictions are provided.

Causal role of thalamic interneurons on brain state transitions: a study using a neural mass model implementing synaptic kinetics

Directory of Open Access Journals (Sweden)

Basabdatta Sen Bhattacharya

2016-11-01

Full Text Available Experimental studies on the Lateral Geniculate Nucleus (LGN of mammals and rodents show that the inhibitory interneurons (IN receive around 47.1% of their afferents from the retinal spiking neurons, and constitute around 20 - 25% of the LGN cell population. However, there is a definite gap in knowledge about the role and impact of IN on thalamocortical dynamics in both experimental and model-based research. We use a neural mass computational model of the LGN with three neural populations viz. IN, thalamocortical relay (TCR, thalamic reticular nucleus (TRN, to study the causality of IN on LGN oscillations and state-transitions. The synaptic information transmission in the model is implemented with kinetic modelling, facilitating the linking of low-level cellular attributes with high-level population dynamics. The model is parameterised and tuned to simulate both Local Field Potential (LFP of LGN and electroencephalogram (EEG of visual cortex in an awake resting state with eyes closed and dominant frequency within the alpha (8-13 Hz band. The results show that: First, the response of the TRN is suppressed in the presence of IN in the circuit; disconnecting the IN from the circuit effects a dramatic change in the model output, displaying high amplitude synchronous oscillations within the alpha band in both TCR and TRN. These observations conform to experimental reports implicating the IN as the primary inhibitory modulator of LGN dynamics in a cognitive state, and that reduced cognition is achieved by suppressing the TRN response. Second, the model validates steady state visually evoked potential response in humans corresponding to periodic input stimuli; however, when the IN is disconnected from the circuit, the output power spectra do not reflect the input frequency. This agrees with experimental reports underpinning the role of IN in efficient retino-geniculate information transmission. Third, a smooth transition from alpha to theta band is

Modelling the presence of myelin and oedema in the brain based on multi-parametric quantitative MRI

Directory of Open Access Journals (Sweden)

Marcel eWarntjes

2016-02-01

Full Text Available The aim of this study was to present a model that uses multi-parametric quantitative MRI to estimate the presence of myelin and oedema in the brain. The model relates simultaneous measurement of R1 and R2 relaxation rates and proton density to four partial volume compartments, consisting of myelin partial volume, cellular partial volume, free water partial volume and excess parenchymal water partial volume. The model parameters were obtained using spatially normalised brain images of a group of 20 healthy controls. The pathological brain was modelled in terms of the reduction of myelin content and presence of excess parenchymal water, which indicates the degree of oedema. The method was tested on spatially normalised brain images of a group of 20 age-matched multiple sclerosis (MS patients. Clear differences were observed with respect to the healthy controls: the MS group had a 79 mL smaller brain volume (1069 vs. 1148 mL, a 38 mL smaller myelin volume (119 vs. 157 mL and a 21 mL larger excess parenchymal water volume (78 vs. 57 mL. Template regions of interest of various brain structures indicated that the myelin partial volume in the MS group was 1.6±1.5% lower for grey matter (GM structures and 2.8±1.0% lower for white matter (WM structures. The excess parenchymal water partial volume was 9±10% larger for GM and 5±2% larger for WM. Manually placed ROIs indicated that the results using the template ROIs may have suffered from loss of anatomical detail due to the spatial normalization process. Examples of the application of the method on high-resolution images are provided for three individual subjects, a 45-year-old healthy subject, a 72-year-old healthy subject and a 45-year-old MS patient. The observed results agreed with the expected behaviour considering both age and disease. In conclusion, the proposed model may provide clinically important parameters such as the total brain volume, degree of myelination and degree of oedema, based on

Estimating genetic effect sizes under joint disease-endophenotype models in presence of gene-environment interactions

Directory of Open Access Journals (Sweden)

Alexandre eBureau

2015-07-01

Full Text Available Effects of genetic variants on the risk of complex diseases estimated from association studies are typically small. Nonetheless, variants may have important effects in presence of specific levels of environmental exposures, and when a trait related to the disease (endophenotype is either normal or impaired. We propose polytomous and transition models to represent the relationship between disease, endophenotype, genotype and environmental exposure in family studies. Model coefficients were estimated using generalized estimating equations and were used to derive gene-environment interaction effects and genotype effects at specific levels of exposure. In a simulation study, estimates of the effect of a genetic variant were substantially higher when both an endophenotype and an environmental exposure modifying the variant effect were taken into account, particularly under transition models, compared to the alternative of ignoring the endophenotype. Illustration of the proposed modeling with the metabolic syndrome, abdominal obesity, physical activity and polymorphisms in the NOX3 gene in the Quebec Family Study revealed that the positive association of the A allele of rs1375713 with the metabolic syndrome at high levels of physical activity was only detectable in subjects without abdominal obesity, illustrating the importance of taking into account the abdominal obesity endophenotype in this analysis.

The presence of APGWamide in Octopus vulgaris: a possible role in the reproductive behavior

NARCIS (Netherlands)

Di Cristo, C.; van Minnen, J.; Di Cosmo, A.

2005-01-01

The concerted action of many neuropeptides has been implicated in the nervous control of specific behaviors in many molluscs. In the present study, the presence of amidated tetrapeptide Ala-Pro-Gly-Trp-NH

The impact of perception and presence on emotional reactions: a review of research in virtual reality.

Science.gov (United States)

Diemer, Julia; Alpers, Georg W; Peperkorn, Henrik M; Shiban, Youssef; Mühlberger, Andreas

2015-01-01

Virtual reality (VR) has made its way into mainstream psychological research in the last two decades. This technology, with its unique ability to simulate complex, real situations and contexts, offers researchers unprecedented opportunities to investigate human behavior in well controlled designs in the laboratory. One important application of VR is the investigation of pathological processes in mental disorders, especially anxiety disorders. Research on the processes underlying threat perception, fear, and exposure therapy has shed light on more general aspects of the relation between perception and emotion. Being by its nature virtual, i.e., simulation of reality, VR strongly relies on the adequate selection of specific perceptual cues to activate emotions. Emotional experiences in turn are related to presence, another important concept in VR, which describes the user's sense of being in a VR environment. This paper summarizes current research into perception of fear cues, emotion, and presence, aiming at the identification of the most relevant aspects of emotional experience in VR and their mutual relations. A special focus lies on a series of recent experiments designed to test the relative contribution of perception and conceptual information on fear in VR. This strand of research capitalizes on the dissociation between perception (bottom-up input) and conceptual information (top-down input) that is possible in VR. Further, we review the factors that have so far been recognized to influence presence, with emotions (e.g., fear) being the most relevant in the context of clinical psychology. Recent research has highlighted the mutual influence of presence and fear in VR, but has also traced the limits of our current understanding of this relationship. In this paper, the crucial role of perception on eliciting emotional reactions is highlighted, and the role of arousal as a basic dimension of emotional experience is discussed. An interoceptive attribution model of

The impact of perception and presence on emotional reactions: a review of research in virtual reality

Science.gov (United States)

Diemer, Julia; Alpers, Georg W.; Peperkorn, Henrik M.; Shiban, Youssef; Mühlberger, Andreas

2015-01-01

Virtual reality (VR) has made its way into mainstream psychological research in the last two decades. This technology, with its unique ability to simulate complex, real situations and contexts, offers researchers unprecedented opportunities to investigate human behavior in well controlled designs in the laboratory. One important application of VR is the investigation of pathological processes in mental disorders, especially anxiety disorders. Research on the processes underlying threat perception, fear, and exposure therapy has shed light on more general aspects of the relation between perception and emotion. Being by its nature virtual, i.e., simulation of reality, VR strongly relies on the adequate selection of specific perceptual cues to activate emotions. Emotional experiences in turn are related to presence, another important concept in VR, which describes the user’s sense of being in a VR environment. This paper summarizes current research into perception of fear cues, emotion, and presence, aiming at the identification of the most relevant aspects of emotional experience in VR and their mutual relations. A special focus lies on a series of recent experiments designed to test the relative contribution of perception and conceptual information on fear in VR. This strand of research capitalizes on the dissociation between perception (bottom–up input) and conceptual information (top-down input) that is possible in VR. Further, we review the factors that have so far been recognized to influence presence, with emotions (e.g., fear) being the most relevant in the context of clinical psychology. Recent research has highlighted the mutual influence of presence and fear in VR, but has also traced the limits of our current understanding of this relationship. In this paper, the crucial role of perception on eliciting emotional reactions is highlighted, and the role of arousal as a basic dimension of emotional experience is discussed. An interoceptive attribution

The role of topographic structure and soil macrofauna presence at spoil heaps during spontaneous succession.

Science.gov (United States)

Walmsley, Alena; Vachová, Pavla; Vach, Marek

2016-04-01

This research was investigating whether topographic features, which determine soil nutrient and moisture distribution, in combination with soil fauna (wireworm and earthworm) presence, affect plant community composition at a spontaneously revegetated post mining area with an undulating surface. Two sites of different age with 3 types of topographic features were selected, soil moisture and nutrient content were measured, plant community composition and soil macrofauna community was sampled at each position. Wireworms were present at all positions and were most abundant at bottoms of waves at the younger site; their presence was correlated with several plant species, but the direction of the interaction isn't clear. Earthworms were only present at the older site and had highest abundance at flat sections. Earthworm presence affected the amount of nitrogen in soil - the most nitrogen content was at the site with highest earthworm density and was followed by higher diversity of plant community. The plant community composition was generally correlated with plant available nutrient content - especially P and N. We infer that topographic features affect nutrient and soil fauna distribution, which consequently influences plant community composition.

A two-compartment mechanochemical model of the roles of transforming growth factor β and tissue tension in dermal wound healing.

Science.gov (United States)

Murphy, Kelly E; Hall, Cameron L; McCue, Scott W; Sean McElwain, D L

2011-03-07

The repair of dermal tissue is a complex process of interconnected phenomena, where cellular, chemical and mechanical aspects all play a role, both in an autocrine and in a paracrine fashion. Recent experimental results have shown that transforming growth factor -β (TGFβ) and tissue mechanics play roles in regulating cell proliferation, differentiation and the production of extracellular materials. We have developed a 1D mathematical model that considers the interaction between the cellular, chemical and mechanical phenomena, allowing the combination of TGFβ and tissue stress to inform the activation of fibroblasts to myofibroblasts. Additionally, our model incorporates the observed feature of residual stress by considering the changing zero-stress state in the formulation for effective strain. Using this model, we predict that the continued presence of TGFβ in dermal wounds will produce contractures due to the persistence of myofibroblasts; in contrast, early elimination of TGFβ significantly reduces the myofibroblast numbers resulting in an increase in wound size. Similar results were obtained by varying the rate at which fibroblasts differentiate to myofibroblasts and by changing the myofibroblast apoptotic rate. Taken together, the implication is that elevated levels of myofibroblasts is the key factor behind wounds healing with excessive contraction, suggesting that clinical strategies which aim to reduce the myofibroblast density may reduce the appearance of contractures. Copyright © 2010 Elsevier Ltd. All rights reserved.

Business model change : Managerial roles and tactics in decision-making

NARCIS (Netherlands)

van den Oever, Koen; Martin, Xavier; Baden-Fuller, Charles; Mangematin, Vincent

2015-01-01

We study the decision-making process behind business model change, focusing specifically on the tactics managers employ to gain support for such changes. We first argue for the prominent role of middle management in business model change, and second, we revisit the literature on issue selling and

Turing patterns induced by cross-diffusion in a predator-prey system in presence of habitat complexity

International Nuclear Information System (INIS)

Ghorai, Santu; Poria, Swarup

2016-01-01

In this paper, we have investigated the phenomena of Turing pattern formation in a predator-prey model with habitat complexity in presence of cross diffusion. Using the linear stability analysis, the conditions for the existence of stationary pattern and the existence of Hopf bifurcation are obtained. It is shown analytically that the presence of cross diffusion in the system supports the formation of Turing pattern. Two parameter bifurcation analysis are done analytically and corresponding bifurcation diagrams are presented numerically. A series of simulation results are plotted for different biologically meaningful parameter values. Effects of variation of habitat complexity and the predator mortality rate and birth rate of prey on pattern formation are also reported. It is shown that cross-diffusion can lead to a wide variety of spatial and spatiotemporal pattern formation. It is found that the model exhibits spot and stripe pattern, and coexistence of both spot and strip patterns under the zero flux boundary condition. It is observed that cross-diffusion, habitat complexity, birth rate of prey and predator’s mortality rate play a significant role in the pattern formation of a distributed population system of predator-prey type.

Irradiation of polyethylene in the presence of antioxidants

Science.gov (United States)

Jaworska, E.; Kałuska, I.; Strzelczak-Burlińska, G.; Michalik, J.

The radiation induced reactions in LDPE in the presence of phenolic type antioxidants have been studied. It was shown that various antioxidants can influence the polyethylene network formation and the radical yield in different ways. The dependence of network structure on absorbed doses was determined by gel analysis, hot-set test and extraction of antioxidants for samples irradiated with accelerated electrons. It was found that the antioxidants eluated from polyethylene in higher percentage influence polymer crosslinking to a smaller degree. The ESR studies of γ-irradiated blends of polyethylene with antioxidant indicate the presence of alkyl and phenoxyl radicals. The role of antioxidant molecules on radiation induced reactions in polyethylene-antioxidant systems is considered. The correlation between the network structure and the type of additive in polyethylene is also discussed.

Consistency maintenance for constraint in role-based access control model

Institute of Scientific and Technical Information of China (English)

韩伟力; 陈刚; 尹建伟; 董金祥

2002-01-01

Constraint is an important aspect of role-based access control and is sometimes argued to be the principal motivation for role-based access control (RBAC). But so far few authors have discussed consistency maintenance for constraint in RBAC model. Based on researches of constraints among roles and types of inconsistency among constraints, this paper introduces corresponding formal rules, rule-based reasoning and corresponding methods to detect, avoid and resolve these inconsistencies. Finally, the paper introduces briefly the application of consistency maintenance in ZD-PDM, an enterprise-oriented product data management (PDM) system.

Consistency maintenance for constraint in role-based access control model

Institute of Scientific and Technical Information of China (English)

韩伟力; 陈刚; 尹建伟; 董金祥

2002-01-01

Constraint is an important aspect of role-based access control and is sometimes argued to be the principal motivation for role-based access control (RBAC). But so far'few authors have discussed consistency maintenance for constraint in RBAC model. Based on researches of constraints among roles and types of inconsistency among constraints, this paper introduces correaponding formal rules, rulebased reasoning and corresponding methods to detect, avoid and resolve these inconsistencies. Finally,the paper introduces briefly the application of consistency maintenance in ZD-PDM, an enterprise-ori-ented product data management (PDM) system.

An Approach to Enforcing Clark-Wilson Model in Role-based Access Control Model

Institute of Scientific and Technical Information of China (English)

LIANGBin; SHIWenchang; SUNYufang; SUNBo

2004-01-01

Using one security model to enforce another is a prospective solution to multi-policy support. In this paper, an approach to the enforcing Clark-Wilson data integrity model in the Role-based access control (RBAC) model is proposed. An enforcement construction with great feasibility is presented. In this construction, a direct way to enforce the Clark-Wilson model is provided, the corresponding relations among users, transformation procedures, and constrained data items are strengthened; the concepts of task and subtask are introduced to enhance the support to least-privilege. The proposed approach widens the applicability of RBAC. The theoretical foundation for adopting Clark-Wilson model in a RBAC system with small cost is offered to meet the requirements of multi-policy support and policy flexibility.

Model Dependency of TMAO's Counteracting Effect Against Action of Urea: Kast Model versus Osmotic Model of TMAO.

Science.gov (United States)

Borgohain, Gargi; Paul, Sandip

2016-03-10

Classical molecular dynamics simulation of GB1 peptide (a 16-residue β-hairpin) in different osmotic environments is studied. Urea is used for denaturation of the peptide, and trimethylamine-N-oxide (TMAO) is used to offset the effect of urea. Protein-urea electrostatic interactions are found to play a major role in protein-denaturation. To emphasize on protein protecting action of TMAO against urea, two different models of TMAO are used, viz., the Kast model and the Osmotic model. We observe that the Osmotic model of TMAO gives the best protection to counteract urea's action when used in ratio 1:2 of urea:TMAO (i.e., reverse ratio). This is because the presence of TMAO makes urea-protein electrostatic interactions more unfavorable. Preferential solvation of TMAO molecules by urea (and water) molecules is also observed, which causes depletion in the number of urea molecules in the vicinity of the protein. The calculations of intraprotein hydrogen bonds between different residues of protein further reveal the breaking of backbone hydrogen bonds of residues 2 and 15 in the presence of urea, and the same is preserved in the presence of TMAO. Free energy landscapes show that the narrowest distribution is obtained for the osmotic TMAO model when used in reverse ratio.

Setting a good example: supervisors as work-life-friendly role models within the context of boundary management.

Science.gov (United States)

Koch, Anna R; Binnewies, Carmen

2015-01-01

This multisource, multilevel study examined the importance of supervisors as work-life-friendly role models for employees' boundary management. Particularly, we tested whether supervisors' work-home segmentation behavior represents work-life-friendly role modeling for their employees. Furthermore, we tested whether work-life-friendly role modeling is positively related to employees' work-home segmentation behavior. Also, we examined whether work-life-friendly role modeling is positively related to employees' well-being in terms of feeling less exhausted and disengaged. In total, 237 employees and their 75 supervisors participated in our study. Results from hierarchical linear models revealed that supervisors who showed more segmentation behavior to separate work and home were more likely perceived as work-life-friendly role models. Employees with work-life-friendly role models were more likely to segment between work and home, and they felt less exhausted and disengaged. One may conclude that supervisors as work-life-friendly role models are highly important for employees' work-home segmentation behavior and gatekeepers to implement a work-life-friendly organizational culture. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Presence Management and Merging Presence Information for NGN Services

Science.gov (United States)

Schumann, Sebastian; Mikoczy, Eugen; Podhradsky, Pavol; Muruchi, Feliciano; Maruschke, Michael

This paper describes an approach for interworking scenarios between Session Initiation Protocol (SIP) based and non SIP based frameworks (e.g. web services) in case of the presence management service. The characteristics of the concept of a centralized presence management will be introduced.

Experimental and computational analysis of steam condensation in the presence of air and helium

International Nuclear Information System (INIS)

Bucci, M.

2010-01-01

Among the different phenomena expected to occur within nuclear reactor containments during a postulated loss of coolant accident, condensation on containment walls plays a major role, since it represents an important heat sink for evacuating the energy released by the discharge of the primary water. Nevertheless, condensation strongly affects other relevant phenomena, like containment atmosphere mixing, that influences the distribution of non-condensable gases hypothetically delivered in severe accident conditions. In this scenario, the role of condensation is not obvious, since it can locally aid the hydrogen produced by the oxidation of the core claddings to concentrate and reach flammability limits, providing a dangerous effect instead of a positive one. The understanding of condensation in the presence of air and hydrogen is therefore a fundamental task for the safety analyses of reactor containments. This research has been carried out with the aim to contribute to the understanding of these phenomena. A double strategy has been adopted, including complementary experimental and computational activities. Novel data have been made available by the CONAN facility, investigating the effects induced by light non-condensable gases in experimental configurations that were scarcely investigated in past studies. Computational fluid dynamics (CFD) condensation models have been developed and validated. The suitability of helium as a substitute for hydrogen in experimental activities has been investigated by theoretical and computational analyses allowing to establish simple criteria for the scaling of condensation tests in the presence of a light non-condensable gas. (authors)

An empirical test of a mediation model of the impact of the traditional male gender role on suicidal behavior in men.

Science.gov (United States)

Houle, Janie; Mishara, Brian L; Chagnon, François

2008-04-01

Men die by suicide three to four times more often than women in Western countries. The adverse impact of the traditional male gender role as well as men's reluctance to seek help are possible explanations of this gender gap, but these hypotheses have not been well documented empirically. This study compares two groups of men who experienced comparable severely stressful life events during the preceding 12 months: 40 men admitted to hospital emergency following suicide attempts, and 40 men with no history of suicide attempts. Structured interviews were conducted to measure adherence to the traditional male gender role, help seeking behaviour, social support, suicide acceptability and mental health. ANOVAS indicated that attempters are more likely to adhere to the traditional masculine gender role and regression analysis revealed that this relationship persists even when the presence of mental disorders is statistically controlled. Sequential regression analysis support the mediation model and show that the effects of the traditional male gender role on suicidal behavior are mediated through protective and risk factors for suicide, namely mental state, help seeking and social support. The traditional male gender role appears to increase the risk of suicidal behavior in men by undermining their mental state and by inhibiting the protective factors of help seeking and social support. This study underscores the importance of encouraging men to seek help.

Gender and work-family conflict: testing the rational model and the gender role expectations model in the Spanish cultural context.

Science.gov (United States)

Calvo-Salguero, Antonia; Martínez-de-Lecea, José-María Salinas; del Carmen Aguilar-Luzón, María

2012-01-01

Gutek, Searle, and Klepa (1991) proposed two models to explain the gender differences in work-family conflict: the rational model and the gender role expectations model. Both models have mostly been tested on American and Canadian samples, and have obtained partial support. Given the cultural differences between North American countries and Spain, we should question whether the two models are equally applicable to Spanish society or whether one of them captures Spanish men and women's experience of work-family conflict better than the other. So, the aim of this study is to test which of the models better explains the gender differences in work-family conflict in the Spanish cultural context (or if, indeed, the two models apply equally well). Given the typical cultural dimensions of Spanish society, we expected to find greater support for the gender role expectations model than for the rational model. However, the results obtained in this study indicated that, while the rational model can explain the gender differences that were found, the gender role expectations model cannot capture Spanish people's work-family conflict experiences. The results are interpreted in terms of cultural dimensions characteristic of the Spanish context.

Thermal analysis of continuous and patterned multilayer films in the presence of a nanoscale hot spot

Science.gov (United States)

Juang, Jia-Yang; Zheng, Jinglin

2016-10-01

Thermal responses of multilayer films play essential roles in state-of-the-art electronic systems, such as photo/micro-electronic devices, data storage systems, and silicon-on-insulator transistors. In this paper, we focus on the thermal aspects of multilayer films in the presence of a nanoscale hot spot induced by near field laser heating. The problem is set up in the scenario of heat assisted magnetic recording (HAMR), the next-generation technology to overcome the data storage density limit imposed by superparamagnetism. We characterized thermal responses of both continuous and patterned multilayer media films using transient thermal modeling. We observed that material configurations, in particular, the thermal barriers at the material layer interfaces crucially impact the temperature field hence play a key role in determining the hot spot geometry, transient response and power consumption. With a representative generic media model, we further explored the possibility of optimizing thermal performances by designing layers of heat sink and thermal barrier. The modeling approach demonstrates an effective way to characterize thermal behaviors of micro and nano-scale electronic devices with multilayer thin film structures. The insights into the thermal transport scheme will be critical for design and operations of such electronic devices.

Simulation modelling: educational development roles for learning technologists

Directory of Open Access Journals (Sweden)

David Riley

2002-12-01

Full Text Available Simulation modelling was in the mainstream of CAL development in the 1980s when the late David Squires introduced this author to the Dynamic Modelling System. Since those early days, it seems that simulation modelling has drifted into a learning technology backwater to become a member of Laurillard's underutilized, 'adaptive and productive' media. Referring to her Conversational Framework, Laurillard constructs a pedagogic case for modelling as a productive student activity but provides few references to current practice and available resources. This paper seeks to complement her account by highlighting the pioneering initiatives of the Computers in the Curriculum Project and more recent developments in systems modelling within geographic and business education. The latter include improvements to system dynamics modelling programs such as STELLA®, the publication of introductory textbooks, and the emergence of online resources. The paper indicates several ways in which modelling activities may be approached and identifies some educational development roles for learning technologists. The paper concludes by advocating simulation modelling as an exemplary use of learning technologies - one that realizes their creative-transformative potential.

Dissolving decision making? : Models and their roles in decision-making processes and policy at large

NARCIS (Netherlands)

Zeiss, Ragna; van Egmond, S.

2014-01-01

This article studies the roles three science-based models play in Dutch policy and decision making processes. Key is the interaction between model construction and environment. Their political and scientific environments form contexts that shape the roles of models in policy decision making.

Presence and Effects of Chemical Toxin on Feeding of Cowpea ...

African Journals Online (AJOL)

These varieties along with one susceptible variety (Tvu.76(Prima) were used for conducting two experiments together to find out the presence of a chemical and their role in aphid's feeding and survival. Comparative studies of the number of honey dew drops produced on varieties used in the experiment, and the reaction of ...

A General Attribute and Rule Based Role-Based Access Control Model

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

Growing numbers of users and many access control policies which involve many different resource attributes in service-oriented environments bring various problems in protecting resource. This paper analyzes the relationships of resource attributes to user attributes in all policies, and propose a general attribute and rule based role-based access control(GAR-RBAC) model to meet the security needs. The model can dynamically assign users to roles via rules to meet the need of growing numbers of users. These rules use different attribute expression and permission as a part of authorization constraints, and are defined by analyzing relations of resource attributes to user attributes in many access policies that are defined by the enterprise. The model is a general access control model, and can support many access control policies, and also can be used to wider application for service. The paper also describes how to use the GAR-RBAC model in Web service environments.

Parent presence, delayed dispersal, and territory acquisition in the Seychelles warbler

NARCIS (Netherlands)

Eikenaar, C.; Richardson, D. S.; Komdeur, J.

2007-01-01

The presence of parents in the natal territory may play an important, but often overlooked, role in natal dispersal and the consequent acquisition of a territory. Living with parents in a territory may confer a fitness advantage to subordinates through, for example, the nepotistic behavior of the

Role of erosion and isostasy in the Cordillera Blanca uplift: Insights from landscape evolution modeling (northern Peru, Andes)

Science.gov (United States)

Margirier, Audrey; Braun, Jean; Robert, Xavier; Audin, Laurence

2018-03-01

The processes driving uplift and exhumation of the highest Peruvian peaks (the Cordillera Blanca) are not well understood. Uplift and exhumation seem closely linked to the formation and movement on the Cordillera Blanca normal fault (CBNF) that delimits and shapes the western flank of the Cordillera Blanca. Several models have been proposed to explain the presence of this major normal fault in a compressional setting, but the CBNF and the Cordillera Blanca recent rapid uplift remain enigmatic. Whereas the Cordillera Blanca morphology demonstrates important erosion and thus a significant mass of rocks removal, the impact of erosion and isostasy on the evolution of the Cordillera Blanca uplift rates has never been explored. We address the role of erosion and associated flexural rebound in the uplift and exhumation of the Cordillera Blanca with numerical modeling of landscape evolution. We perform inversions of the broad features of the present-day topography, total exhumation and thermochronological data using a landscape evolution model (FastScape) to provide constraints on the erosion efficiency factor, the uplift rate and the temperature gradient. Our results evidence the not negligible contribution of erosion and associated flexural rebound to the uplift of the Cordillera Blanca and allow us to question the models previously proposed for the formation of the CBNF.

Role of Speaker Cues in Attention Inference

OpenAIRE

Jin Joo Lee; Cynthia Breazeal; David DeSteno

2017-01-01

Current state-of-the-art approaches to emotion recognition primarily focus on modeling the nonverbal expressions of the sole individual without reference to contextual elements such as the co-presence of the partner. In this paper, we demonstrate that the accurate inference of listeners’ social-emotional state of attention depends on accounting for the nonverbal behaviors of their storytelling partner, namely their speaker cues. To gain a deeper understanding of the role of speaker cues in at...

Disk and circumsolar radiances in the presence of ice clouds

Directory of Open Access Journals (Sweden)

P. Haapanala

2017-06-01

Full Text Available The impact of ice clouds on solar disk and circumsolar radiances is investigated using a Monte Carlo radiative transfer model. The monochromatic direct and diffuse radiances are simulated at angles of 0 to 8° from the center of the sun. Input data for the model are derived from measurements conducted during the 2010 Small Particles in Cirrus (SPARTICUS campaign together with state-of-the-art databases of optical properties of ice crystals and aerosols. For selected cases, the simulated radiances are compared with ground-based radiance measurements obtained by the Sun and Aureole Measurements (SAM instrument. First, the sensitivity of the radiances to the ice cloud properties and aerosol optical thickness is addressed. The angular dependence of the disk and circumsolar radiances is found to be most sensitive to assumptions about ice crystal roughness (or, more generally, non-ideal features of ice crystals and size distribution, with ice crystal habit playing a somewhat smaller role. Second, in comparisons with SAM data, the ice cloud optical thickness is adjusted for each case so that the simulated radiances agree closely (i.e., within 3 % with the measured disk radiances. Circumsolar radiances at angles larger than ≈ 3° are systematically underestimated when assuming smooth ice crystals, whereas the agreement with the measurements is better when rough ice crystals are assumed. Our results suggest that it may well be possible to infer the particle roughness directly from ground-based SAM measurements. In addition, the results show the necessity of correcting the ground-based measurements of direct radiation for the presence of diffuse radiation in the instrument's field of view, in particular in the presence of ice clouds.

Role model and prototype matching: Upper-secondary school students’ meetings with tertiary STEM students

DEFF Research Database (Denmark)

Lykkegaard, Eva; Ulriksen, Lars

2016-01-01

concerning STEM students and attending university. The regular self-to-prototype matching process was shown in real-life role-models meetings to be extended to a more complex three-way matching process between students’ self-perceptions, prototype images and situation-specific conceptions of role models...

A test of the California competency-based differentiated role model.

Science.gov (United States)

Keating, Sarah B; Rutledge, Dana N; Sargent, Arlene; Walker, Polly

2003-01-01

To address the incongruence between the expectations of nursing service and education in California, the Education Industry Interface Task Force of the California Strategic Planning Committee for Nursing developed descriptions to assist employers and educators in clearly differentiating practice and educational competencies. The completion of the Competency-Based Role Differentiation Model resulted in the need to test the model for its utility in the service setting, in education, and for career planning for nurses. Three alpha demonstration sites were selected based on representative geographical regions of California. The sites were composed of tri-partnerships consisting of a medical center, an associate degree in nursing program, and a baccalaureate nursing program. Observers rated senior students and new graduates in medical-surgical units on their behaviors in teacher and leadership care provider and care coordinator roles. The alpha demonstration study results were as expected. That is, senior students practice predominantly at a novice level in teacher and management/leadership care provider functions and new graduates practice predominately at the competent level. New graduates are more likely to take on novice and competent care coordinator roles. The CBRDM may be useful for practice and education settings to evaluate student and nurse performance, to define role expectations, and to identify the preparation necessary for the roles. It is useful for all of nursing as it continues to define its levels of practice and their relationship to on-the-job performance, curriculum development, and carrier planning.

Role modelling of clinical tutors: a focus group study among medical students.

Science.gov (United States)

Burgess, Annette; Goulston, Kerry; Oates, Kim

2015-02-14

Role modelling by clinicians assists in development of medical students' professional competencies, values and attitudes. Three core characteristics of a positive role model include 1) clinical attributes, 2) teaching skills, and 3) personal qualities. This study was designed to explore medical students' perceptions of their bedside clinical tutors as role models during the first year of a medical program. The study was conducted with one cohort (n = 301) of students who had completed Year 1 of the Sydney Medical Program in 2013. A total of nine focus groups (n = 59) were conducted with medical students following completion of Year 1. Data were transcribed verbatim. Thematic analysis was used to code and categorise data into themes. Students identified both positive and negative characteristics and behaviour displayed by their clinical tutors. Characteristics and behaviour that students would like to emulate as medical practitioners in the future included: 1) Clinical attributes: a good knowledge base; articulate history taking skills; the ability to explain and demonstrate skills at the appropriate level for students; and empathy, respect and genuine compassion for patients. 2) Teaching skills: development of a rapport with students; provision of time towards the growth of students academically and professionally; provision of a positive learning environment; an understanding of the student curriculum and assessment requirements; immediate and useful feedback; and provision of patient interaction. 3) Personal qualities: respectful interprofessional staff interactions; preparedness for tutorials; demonstration of a passion for teaching; and demonstration of a passion for their career choice. Excellence in role modelling entails demonstration of excellent clinical care, teaching skills and personal characteristics. Our findings reinforce the important function of clinical bedside tutors as role models, which has implications for faculty development and

Entrepreneurial Women in Radiology: Role Models of Success.

Science.gov (United States)

Anzai, Yoshimi; Meltzer, Carolyn C; DeStigter, Kristen K; Destounis, Stamatia; Pawley, Barbara K; Oates, M Elizabeth

2016-11-01

Radiology is undeniably male dominated. Alongside surgery and orthopedic surgery, academic radiology ranks near the bottom in having the lowest proportion of full-time female faculty members. Despite many efforts to recruit talented women, the pipeline entering the radiologic disciplines continues to flow at a trickle. One factor is the relative lack of role models for female medical students. Entrepreneurial women in radiology can lead the field with their innovation and creativity, courage, and commitment. In this article, the authors highlight two entrepreneurial female radiologists who shared their success stories at the American Association for Women Radiologists' session at the 2015 ACR annual meeting. Their successes underscore the potential for such women to serve as role models to female medical students and even college undergraduates. Despite the gender gap in radiology, the field has yielded some exceptional women who can take on challenges, overcome barriers and assume risks, create strategies and processes to operationalize their visions, secure funding, and expand their enterprises to make sustainable impacts both at home and abroad. As we move toward more patient- and family-centered care models and become increasingly visible to diverse populations, there is no better time for female leaders in radiology to inspire the next generation to join our essential and rewarding specialty. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Modeling and Testing of EVs - Preliminary Study and Laboratory Development

DEFF Research Database (Denmark)

Yang, Guang-Ya; Marra, Francesco; Nielsen, Arne Hejde

2010-01-01

Electric vehicles (EVs) are expected to play a key role in the future energy management system to stabilize both supply and consumption with the presence of high penetration of renewable generation. A reasonably accurate model of battery is a key element for the study of EVs behavior and the grid...... tests, followed by the suggestions towards a feasible battery model for further studies.......Electric vehicles (EVs) are expected to play a key role in the future energy management system to stabilize both supply and consumption with the presence of high penetration of renewable generation. A reasonably accurate model of battery is a key element for the study of EVs behavior and the grid...... impact at different geographical areas, as well as driving and charging patterns. Electric circuit model is deployed in this work to represent the electrical properties of a lithium-ion battery. This paper reports the preliminary modeling and validation work based on manufacturer data sheet and realistic...

Elucidating the role of recovery experiences in the job demands-resources model.

Science.gov (United States)

Moreno-Jiménez, Bernardo; Rodríguez-Muñoz, Alfredo; Sanz-Vergel, Ana Isabel; Garrosa, Eva

2012-07-01

Based on the Job Demands-Resources (JD-R) model, the current study examined the moderating role of recovery experiences (i.e., psychological detachment from work, relaxation, mastery experiences, and control over leisure time) on the relationship between one job demand (i.e., role conflict) and work- and health-related outcomes. Results from our sample of 990 employees from Spain showed that psychological detachment from work and relaxation buffered the negative impact of role conflict on some of the proposed outcomes. Contrary to our expectations, we did not find significant results for mastery and control regarding moderating effects. Overall, findings suggest a differential pattern of the recovery experiences in the health impairment process proposed by the JD-R model.

Experimental study and thermodynamic modelling of methane clathrate hydrate dissociation conditions in silica gel porous media in the presence of methanol aqueous solution

International Nuclear Information System (INIS)

Hashemi, Hamed; Javanmardi, Jafar; Zarifi, Mojdeh; Eslamimanesh, Ali; Mohammadi, Amir H.

2012-01-01

Highlights: ► Phase equilibria of hydrates of methane in confined silica gel pores are reported. ► Dissociation data in the presences of methanol aqueous solution are also measured. ► A thermodynamic model is developed for prediction of the obtained data. ► Acceptable agreement is found between the obtained data and the predicted results. - Abstract: In this work, the phase equilibria of clathrate hydrates of methane in the presence of pure water and 0.035 mass fraction of methanol aqueous solution in confined silica gel pores with (10 and 15) nm mean diameters are measured and reported. A thermodynamic model is also developed for prediction of the obtained experimental hydrate dissociation data. The Valderrama–Patel–Teja (VPT-EoS) equation of state (EoS) accompanied with the non-density dependent (NDD) mixing rules coupled with a previously developed activity model are applied to evaluate the fugacity of the species present and the activity coefficient of water in methanol aqueous solution. Acceptable agreement between the reported data and the predicted results using the proposed model and an existing method reported in the literature demonstrates the reliability of the presented model.

In Vitro Evidence of the Presence of Mesenchymal Stromal Cells in Cervical Cancer and Their Role in Protecting Cancer Cells from Cytotoxic T Cell Activity

Science.gov (United States)

Montesinos, Juan J.; Mora-García, María de L.; Mayani, Héctor; Flores-Figueroa, Eugenia; García-Rocha, Rosario; Fajardo-Orduña, Guadalupe R.; Castro-Manrreza, Marta E.; Weiss-Steider, Benny

2013-01-01

Mesenchymal stromal cells (MSCs) have been isolated from different tumors and it has been suggested that they support tumor growth through immunosuppression processes that favor tumor cell evasion from the immune system. To date, however, the presence of MSCs in cervical cancer (CeCa) and their possible role in tumor growth remains unknown. Herein we report on the presence of MSCs in cervical tissue, both in normal conditions (NCx-MSCs) and in CeCa (CeCa-MSCs), and described several biological properties of such cells. Our study showed similar patterns of cell surface antigen expression, but distinct differentiation potentials, when we compared both cervical MSC populations to MSCs from normal bone marrow (BM-MSCs, the gold standard). Interestingly, CeCa-MSCs were negative for the presence of human papiloma virus, indicating that these cells are not infected by such a viral agent. Also, interestingly, and in contrast to NCx-MSCs, CeCa-MSCs induced significant downregulation of surface HLA class I molecules (HLA-A*0201) on CaSki cells and other CeCa cell lines. We further observed that CeCa-MSCs inhibited antigen-specific T cell recognition of CaSki cells by cytotoxic T lymphocytes (CTLs). HLA class I downregulation on CeCa cells correlated with the production of IL-10 in cell cocultures. Importantly, this cytokine strongly suppressed recognition of CeCa cells by CTLs. In summary, this study demonstrates the presence of MSCs in CeCa and suggests that tumor-derived MSCs may provide immune protection to tumor cells by inducing downregulation of HLA class I molecules. This mechanism may have important implications in tumor growth. PMID:23656504

The Role of Top-down Attention in the Cocktail Party: Revisiting Cherry's Experiment after Sixty Years

DEFF Research Database (Denmark)

Marchegiani, Letizia; Karadogan, Seliz; Andersen, Taja

2011-01-01

We investigate the role of top-down task drive attention in the cocktail party problem. In a recently proposed computational model of top-down attention it is possible to simulate the cocktail party problem and make predictions about sensitivity to confounders under different levels of attention....... Based on such simulations we expect that under strong top-down attention pattern recognition is improved as the model can compensate for noise and confounders. We next investigate the role of temporal and spectral overlaps and speech intelligibility in humans, and how the presence of a task influences...... computational top-down attention model....

Surface complexation modeling of uranium (Vi) retained onto zirconium diphosphate in presence of organic acids

International Nuclear Information System (INIS)

Almazan T, M. G.; Garcia G, N.; Ordonez R, E.

2010-10-01

In the field of nuclear waste disposal, predictions regarding radionuclide migration through the geosphere, have to take account the effects of natural organic matter. This work presents an investigation of interaction mechanisms between U (Vi) and zirconium diphosphate (ZrP 2 O 7 ) in presence of organic acids (citric acid and oxalic acid). The retention reactions were previously examined using a batch equilibrium method. Previous results showed that U (Vi) retention was more efficient when citric acid or oxalic acid was present in solid surface at lower ph values. In order to determine the retention equilibria for both systems studied, a phosphorescence spectroscopy study was carried out. The experimental data were then fitted using the Constant Capacitance Model included in the FITEQL4.0 code. Previous results concerning surface characterization of ZrP 2 O 7 (surface sites density and surface acidity constants) were used to constraint the modeling. The best fit for U (Vi)/citric acid/ZrP 2 O 7 and U (Vi)/oxalic acid/ZrP 2 O 7 systems considered the formation of a ternary surface complex. (Author)

Repeatability of a 3D multi-segment foot model protocol in presence of foot deformities.

Science.gov (United States)

Deschamps, Kevin; Staes, Filip; Bruyninckx, Herman; Busschots, Ellen; Matricali, Giovanni A; Spaepen, Pieter; Meyer, Christophe; Desloovere, Kaat

2012-07-01

Repeatability studies on 3D multi-segment foot models (3DMFMs) have mainly considered healthy participants which contrasts with the widespread application of these models to evaluate foot pathologies. The current study aimed at establishing the repeatability of the 3DMFM described by Leardini et al. in presence of foot deformities. Foot kinematics of eight adult participants were analyzed using a repeated-measures design including two therapists with different levels of experience. The inter-trial variability was higher compared to the kinematics of healthy subjects. Consideration of relative angles resulted in the lowest inter-session variability. The absolute 3D rotations between the Sha-Cal and Cal-Met seem to have the lowest variability in both therapists. A general trend towards higher σ(sess)/σ(trial) ratios was observed when the midfoot was involved. The current study indicates that not only relative 3D rotations and planar angles can be measured consistently in patients, also a number of absolute parameters can be consistently measured serving as basis for the decision making process. Copyright © 2012 Elsevier B.V. All rights reserved.

Mechanistic model of stress corrosion cracking (scc) of carbon steel in acidic solution with the presence of H2s

International Nuclear Information System (INIS)

Asmara, Y P; Juliawati, A; Sulaiman, A; Jamiluddin

2013-01-01

In oil and gas industrial environments, H 2 S gas is one of the corrosive species which should be a main concern in designing infrastructure made of carbon steel. Combination between the corrosive environment and stress condition will cause degradation of carbon steel increase unpredictably due to their simultaneous effects. This paper will design a model that involves electrochemical and mechanical theories to study crack growth rate under presence of H 2 S gas. Combination crack and corrosion propagation of carbon steel, with different hydrogen concentration has been investigated. The results indicated that high concentration of hydrogen ions showed a higher crack propagation rate. The comparison between corrosion prediction models and corrosion model developed by researchers used to verify the model accuracy showed a good agreement

The density of states for the Bi-dimensional Anderson model in the presence of a magnetic field with quantum plaque flux

International Nuclear Information System (INIS)

Kuehl, N.M.

1987-01-01

The regularity properties of the integrated density of states and the state density of the Anderson bidimensional tight-binding model, in the presence of a uniform magnetic field, perpendicular to the plane of the system by means of quantum flux with plaques, are studied. (A.C.A.S.) [pt

Being a Deaf Role Model: Deaf People's Experiences of Working with Families and Deaf Young People

Science.gov (United States)

Rogers, Katherine D.; Young, Alys M.

2011-01-01

The experiences of being a deaf role model have been little explored in the literature. This paper explores the role of the deaf role model as perceived by d/Deaf adults who carried out this role, when working with deaf young people, parents of deaf children, and professionals who work with them. The data were collected from part of the evaluation…

Parental role modeling of fruits and vegetables at meals and snacks is associated with children's adequate consumption.

Science.gov (United States)

Draxten, Michelle; Fulkerson, Jayne A; Friend, Sarah; Flattum, Colleen F; Schow, Robin

2014-07-01

Research has shown that parental role modeling of healthful eating behaviors is positively correlated to children's dietary intake and fruit and vegetable (F&V) preferences. The purpose of this study is to (1) examine associations between parent and child report of parental role modeling of F&V consumption at snacks and dinner and (2) determine whether parental role modeling is associated with children meeting daily F&V recommendations. Parent-child dyads (N = 160) participating in the HOME Plus study completed baseline surveys on parental role modeling of F&V at snacks and dinner. Children also completed 24-hour dietary recalls. Spearman correlations and chi-square/Fisher's exact tests were used to examine relationships between parent and child report of parental role modeling of F&V at snacks and dinner and whether children met daily recommendations. On average, children consumed less than three daily servings of F&V with only 23% consuming the recommended servings. Statistically significant correlations were seen between parent and child report of parental role modeling fruit at dinner and green salad at dinner. Children who reported parental role modeling of vegetables at snack and salad at dinner were significantly more likely, than those who did not, to meet daily F&V recommendations. Parents who reported role modeling fruit at snack were significantly more likely to have children who met daily F&V recommendations. Results indicate that children are aware of their parents' eating behaviors and on occasion report this behavior similarly to their parents. Parents should be encouraged to utilize the opportunity to role model healthful dietary intake, especially at snacks, where consumption of F&V appears low. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Role of Career Competencies in the Job Demands-Resources Model

NARCIS (Netherlands)

Akkermans, J.; Schaufeli, W.B.; Brenninkmeijer, V.; Blonk, R.W.B.

2013-01-01

This study investigated the role of career competencies as a mediator in the Job Demands - Resources model. Structural equation modeling with data from 305 young employed persons aged 16-30 years showed that career competencies are positively related to job resources and work engagement, but not to

Entrepreneurship Education Revisited: Perceived Entrepreneurial Role Models Increase Perceived Behavioural Control

Science.gov (United States)

Fellnhofer, Katharina

2017-01-01

Relying on Bandura's (1986) social learning theory, Ajzen's (1988) theory of planned behaviour (TPB), and Dyer's (1994) model of entrepreneurial careers, this study aims to highlight the potential of entrepreneurial role models to entrepreneurship education. The results suggest that entrepreneurial courses would greatly benefit from real-life…

Factors Affecting the Choice of Professors as a Role Model from the Viewpoint of Medical Students

Directory of Open Access Journals (Sweden)

Masome Rahimi

2018-01-01

Full Text Available The role of professors as a model can have a beneficial impact on the mental, psychological and educational conditions of medical students. This also plays an important role in improving professionalism and academic achievements among medical students. Therefore, the present study was aimed at evaluating the standpoint of students on factors influencing the selection of professors as a role model. This descriptive cross-sectional study was conducted on the students of different disciplines studying in Jahrom University of Medical Sciences in 2016. A randomized sampling method was conducted on 217 students. Their viewpoints were collected using a 30- question researcher-made questionnaire. The questionnaire consisted of three parts, each containing ten items. In addition, this questionnaire was distributed among 20 people (as a pilot survey, the alpha coefficient of which was equal to 0.88; and its measurement was based on Likert scale "from very low to very high". Data were analyzed using SPSS 18 and descriptive statistics. Most respondents were nursing students and the highest influence of professors as a role model was associated with their role as a research leader (future specialized courses in the clinical choices and selection of future specialized fields. The factors influencing the selection of professors as a role model included their respectful attitude toward students, and the high level of their knowledge and skills. On the other hand, the most important factors that caused professors not to be regarded as a role model included their inappropriate relationship with the students and refusing to listen to them. Role model professors can have a beneficial impact on the future of students and scientific communities, as far as the science and education is concerned. Therefore, it is necessary for professors to pay particular attention to strengthening their role as a model at universities.

The impact of social roles on trait judgments: a critical reexamination.

Science.gov (United States)

Bosak, Janine; Sczesny, Sabine; Eagly, Alice H

2012-04-01

Consistent with social role theory's assumption that the role behavior of men and women shapes gender stereotypes, earlier experiments have found that men's and women's occupancy of the same role eliminated gender-stereotypical judgments of greater agency and lower communion in men than women. The shifting standards model raises the question of whether a shift to within-sex standards in judgments of men and women in roles could have masked underlying gender stereotypes. To examine this possibility, two experiments obtained judgments of men and women using measures that do or do not restrain shifts to within-sex standards. This measure variation did not affect the social role pattern of smaller perceived sex differences in the presence of role information. These findings thus support the social role theory claim that designations of identical roles for subgroups of men and women eliminate or reduce perceived sex differences.

The effect of patient-centeredness and gender of professional role models on trainees' mentalization responses. Implications for film-aided education.

Science.gov (United States)

Bálint, Katalin; Nagy, Tamás; Csabai, Márta

2014-10-01

To examine how certain characteristics of film-presented practitioner role-models influence trainees' mentalization. In an experimental setting, psychology students watched four film clips presenting a patient-practitioner session; the clips varied in the practitioner's patient-centeredness (positive vs. negative) and gender. Participants commented on the practitioner's thoughts, emotions and intentions through the session. Analysis of 116 comments focused on the effect of patient-centeredness and gender variables on mentalization and judgment utterances. Negative role-models and female role-models induced higher levels of mentalization compared to positive and male role-models. There was no gender difference in the level of mentalization; however male participants gave more judgmental responses than female participants. The patient-centeredness had a larger effect on mentalization when trainees described the opposite gender role-model. In a systematic comparison, students' capacity for mentalization differed according to role-models' patient-centeredness and gender, as well as the gender-match of students with role-models. When working with film-presented role-models, educators should be aware of the differences in the level of mentalization elicited by positive and male role-models, as opposed to negative and female role-models. Educators should also consider the gender-match between trainees and role-models, therefore students should be exposed to both cross- and same-gender role-models. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The role of non-epistemic values in engineering models

NARCIS (Netherlands)

Diekmann, S.; Peterson, M.B.

2013-01-01

We argue that non-epistemic values, including moral ones, play an important role in the construction and choice of models in science and engineering. Our main claim is that non-epistemic values are not only "secondary values" that become important just in case epistemic values leave some issues

The Power of Passion in Entrepreneurship Education: Entrepreneurial Role Models Encourage Passion?

Science.gov (United States)

Fellnhofer, Katharina

2018-01-01

This study of Entrepreneurship Education (EE) centers on the impact of entrepreneurial role models on entrepreneurial passion, which also is expected to influence entrepreneurial intention. Based on 426 individuals recruited primarily from Austria, Finland, and Greece, Structural Equation Modeling (SEM) reveals the significant direct and indirect effects of entrepreneurial role models on entrepreneurial intention, mediated by entrepreneurial passion. These effects were found to be stronger following multimedia presentation of entrepreneurial stories, confirming the fruitful spillover effects of the innovative educational use of computers on entrepreneurial intentions among nascent entrepreneurs. Drawing on the theory of planned behavior (TPB) and social learning theory, this study confirms both the positive impact of entrepreneurial role models and significant short-term effects of web-based multimedia in the context of EE. This narrative approach is shown to be an effective pedagogical instrument in enhancing individual orientation toward entrepreneurship to facilitate entrepreneurial intention. This study identifies the great potential of these pioneering methods and tools, both for further research in the academic community and for entrepreneurship educators who hope to promote entrepreneurial intention in aspiring entrepreneurs. The findings are also relevant for policy makers designing effective instruments to achieve long-term goals. PMID:29877516

The Power of Passion in Entrepreneurship Education: Entrepreneurial Role Models Encourage Passion?

Science.gov (United States)

Fellnhofer, Katharina

2017-07-01

This study of Entrepreneurship Education (EE) centers on the impact of entrepreneurial role models on entrepreneurial passion, which also is expected to influence entrepreneurial intention. Based on 426 individuals recruited primarily from Austria, Finland, and Greece, Structural Equation Modeling (SEM) reveals the significant direct and indirect effects of entrepreneurial role models on entrepreneurial intention, mediated by entrepreneurial passion. These effects were found to be stronger following multimedia presentation of entrepreneurial stories, confirming the fruitful spillover effects of the innovative educational use of computers on entrepreneurial intentions among nascent entrepreneurs. Drawing on the theory of planned behavior (TPB) and social learning theory, this study confirms both the positive impact of entrepreneurial role models and significant short-term effects of web-based multimedia in the context of EE. This narrative approach is shown to be an effective pedagogical instrument in enhancing individual orientation toward entrepreneurship to facilitate entrepreneurial intention. This study identifies the great potential of these pioneering methods and tools, both for further research in the academic community and for entrepreneurship educators who hope to promote entrepreneurial intention in aspiring entrepreneurs. The findings are also relevant for policy makers designing effective instruments to achieve long-term goals.

The role of career competencies in the Job Demands: Resources model

NARCIS (Netherlands)

Akkermans, J.; Schaufeli, W.B.; Brenninkmeijer, V.; Blonk, R.W.B.

2013-01-01

This study investigated the role of career competencies as a mediator in the Job Demands — Resources model. Structural equation modeling with data from 305 young employed persons aged 16–30 years showed that career competencies are positively related to job resources and work engagement, but not to

Modality effects in Second Life: the mediating role of social presence and the moderating role of product involvement.

Science.gov (United States)

Jin, Seung-A Annie

2009-12-01

The rapid growth of virtual worlds is one of the most recent Internet trends. Some distinguishing features of virtual environments include the employment of avatars and multimodal communication among avatars. This study examined the effects of the modality (text vs. audio) of message presentation on people's evaluation of spokes-avatar credibility and the informational value of promotional messages in avatar-based advertising inside 3D virtual environments. An experiment was conducted in the virtual Apple retail store inside Second Life, the most popular and fastest growing virtual world. The author designed a two-group (textual advertisement vs. auditory advertisement) comparison experiment by manipulating the modality of conveying advertisement messages. The author also created a spokes-avatar that represents a real-life organization (Apple) and presents promotional messages about its innovative product, the iPhone. Data analyses showed that (a) textual modality (vs. auditory modality) resulted in greater source expertise, informational value of the advertisement message, and social presence; and that (b) high product involvement (vs. low product involvement) resulted in a more positive attitude toward the product, higher buying intention, and a higher level of perceived interactivity. In addition to the main effects of product involvement and modality, results showed significant interaction between involvement and modality. Modality effects were stronger for people with low product involvement than for those with high product involvement, thus confirming the moderating effects of product involvement. Results of a path analysis also showed that social presence mediated the effects of modality on the perceived informational value of the advertisement message.

Poleward propagation of boreal summer intraseasonal oscillations in a coupled model: role of internal processes

Energy Technology Data Exchange (ETDEWEB)

Ajayamohan, R.S. [University of Victoria, Canadian Centre for Climate Modelling and Analysis, P.O. Box 3065, Victoria, BC (Canada); Annamalai, H.; Hafner, Jan [University of Hawaii, International Pacific Research Center, Honolulu (United States); Luo, Jing-Jia [Japan Agency for Marine-Earth Science and Technology, Frontier Research Centre for Global Change, Yokohama (Japan); Yamagata, Toshio [Japan Agency for Marine-Earth Science and Technology, Frontier Research Centre for Global Change, Yokohama (Japan); The University of Tokyo, Department of Earth and Planetary Science, Tokyo (Japan)

2011-09-15

The study compares the simulated poleward migration characteristics of boreal summer intraseasonal oscillations (BSISO) in a suite of coupled ocean-atmospheric model sensitivity integrations. The sensitivity experiments are designed in such a manner to allow full coupling in specific ocean basins but forced by temporally varying monthly climatological sea surface temperature (SST) adopted from the fully coupled model control runs (ES10). While the local air-sea interaction is suppressed in the tropical Indian Ocean and allowed in the other oceans in the ESdI run, it is suppressed in the tropical Pacific and allowed in the other oceans in the ESdP run. Our diagnostics show that the basic mean state in precipitation and easterly vertical shear as well as the BSISO properties remain unchanged due to either inclusion or exclusion of local air-sea interaction. In the presence of realistic easterly vertical shear, the continuous emanation of Rossby waves from the equatorial convection is trapped over the monsoon region that enables the poleward propagation of BSISO anomalies in all the model sensitivity experiments. To explore the internal processes that maintain the tropospheric moisture anomalies ahead of BSISO precipitation anomalies, moisture and moist static energy budgets are performed. In all model experiments, advection of anomalous moisture by climatological winds anchors the moisture anomalies that in turn promote the northward migration of BSISO precipitation. While the results indicate the need for realistic simulation of all aspects of the basic state, our model results need to be taken with caution because in the ECHAM family of coupled models the internal variance at intraseasonal timescales is indeed very high, and therefore local air-sea interactions may not play a pivotal role. (orig.)

Enhancement of the glass corrosion in the presence of clay minerals: testing experimental results with an integrated glass dissolution model

International Nuclear Information System (INIS)

Godon, N.; Vernaz, E.Y.

1992-01-01

Recent glass dissolution experiments, conducted at 90 deg C in the presence of potential backfill materials, indicate remarkably faster glass corrosion in the presence of clay, compared to tests where the glass is leached either alone or with alternative backfill materials. This effect correlates with the clay content in the backfill, and may be attributed to the removal of silica from solution. Scorpion, or dissolution with reprecipitation of a silica-rich clay, have been proposed as possible mechanisms for the silica consumption. The results of some experiments have been tested against a glass dissolution model, in which a widely used kinetic equation for glass corrosion is coupled with diffusive silica transport through a single porosity, linearly sorbing medium, which represents the backfilling. Because the glass corrosion rates imposed by the kinetic equation are inversely proportional to the silicic acid concentration of the leachant contacting the glass, the model predicts enhanced glass dissolution if silica is sorbed by the porous medium. The experimental data proved to be consistent with the predicted enhancement of the glass dissolution. Moreover, the model-estimated distribution coefficients for silica sorption (K d ) fall within the range of values extracted from available literature data, thus supporting the hypothesis that the observed high corrosion rates are due to sorption of silica on the clay mineral surfaces. (author)

Presence and enactment as a vehicle of psychotherapeutic change.

Science.gov (United States)

Viederman, M

1999-01-01

This article addresses an aspect of psychoanalytic and psychotherapeutic process that leads to change. Focusing on an aspect of the patient-therapist interaction that the author calls "presence" of the therapist, it demonstrates how the experience of this may lead the patient to unconscious enactment of early wishful fantasies concerning the good parent. The gratification of these wishes implicit in the interaction influences the therapist-patient relationship and plays a significant role in change.

[Husband's presence at childbirth in light of obstetric psychoprophylaxis].

Science.gov (United States)

Sioma-Markowska, Urszula; Sipiński, Adam; Majerczyk, Iwona; Selwet, Monika; Kuna, Anna; Machura, Mariola

2004-01-01

Contemporary obstetric psychoprophylaxis gives prospective parents wide opportunities to prepare to the pregnancy period and delivery. It is educationally-minded and points the importance to modify the life style, introduces exercises accompanied by the relative during the pregnancy and delivery. The survey portrays husband's--child father's role in obstetric psychoprophylaxis. The importance to continue the psychoprophylaxis in the delivery room was spotted in the survey, too. The continuation might be reached by close relative's presence.

The Impact of Role Modeling on Proteges' Personal Learning and Work-to-Family Enrichment

Science.gov (United States)

Kwan, Ho Kwong; Mao, Yina; Zhang, Haina

2010-01-01

The present study investigates the impact of role modeling as perceived by proteges on their personal learning (i.e., relational job learning and personal skill development) and work-to-family enrichment (WFE). Results from a two-wave field survey of 173 proteges in the People's Republic of China indicate that role modeling positively affects…

The inadequacy of role models for educating medical students in ethics with some reflections on virtue theory.

Science.gov (United States)

Erde, E L

1997-01-01

Persons concerned with medical education sometimes argued that medical students need no formal education in ethics. They contended that if admissions were restricted to persons of good character and those students were exposed to good role models, the ethics of medicine would take care of itself. However, no one seems to give much philosophic attention to the ideas of model or role model. In this essay, I undertake such an analysis and add an analysis of role. I show the weakness in relying on role models exclusively and draw implications from these for appeals to virtue theory. Furthermore, I indicate some of the problems about how virtue theory is invoked as the ethical theory that would most closely be associated to the role model rhetoric and consider some of the problems with virtue theory. Although Socrates was interested in the character of the (young) persons with whom he spoke, Socratic education is much more than what role modeling and virtue theory endorse. It-that is, philosophy-is invaluable for ethics education.

Theoretical modeling of condensation of steam outside different vertical geometries (tube, flat plates) in the presence of noncondensable gases like air and helium

International Nuclear Information System (INIS)

Ganguli, Arijit; Patel, A.G.; Maheshwari, N.K.; Pandit, A.B.

2008-01-01

Condensation of steam coming out from the coolant pipe during a loss of coolant accident (LOCA) plays a key role in removing heat from the primary containment of the advanced nuclear reactor (ANR). The presence of large mass fractions of air (W air = 0.25-0.9) and a small mass fraction of helium (W He = 0.017-0.083) reduces the overall heat transfer coefficient (HTC) substantially. The present work emphasizes on the issue that modeling the diffusion of water-vapor through the gas-liquid interface is the key to give good predictions in HTC. In this, condensation conductivity and effective diffusivity plays a key role. Therefore, modifications have been made in the derivation for calculation of condensation conductivity in the case of steam-air mixture and effective diffusivity (in the case of multicomponent mixture). The model validation has been done with the experimental data of Dehbi et al. [Dehbi, A.A., Golay, M.W., Kazimi, M.S., 1991. National Conference of Heat Transfer AIChE Symposium Series, pp. 19-28] and Anderson et al. [Anderson, M.H., Herranz, L.E., Corradini, M.L., 1998. Experimental analysis of heat transfer within the AP600 containment under postulated accident conditions. Nucl. Eng. Des. 185, 153-172] and other analytical models available in the literature [Herranz, L.E., Anderson, M.H., Corradini, M.H., 1998a. The effect of light gases in noncondensable mixtures on condensation heat transfer. Nucl. Eng. Des. 183, 133-150; Herranz, L.E., Anderson, M.H., Corradini, M.L., 1998b. A diffusion layer model for steam condensation within the AP600 containment. Nucl. Eng. Des. 185, 153-172; Peterson, P.F., Schrock, Y.E., Kageyama, T., 1993. Diffusion layer theory for turbulent vapor condensation with noncondensable gases. J. Heat Transf., 115; Dehbi, A.A., Golay, M.W., Kazimi, M.S., 1991. National Conference of Heat Transfer AIChE Symposium Series, pp. 19-28]. Since the validations of the results were found satisfactory, the datasets [Dehbi, A.A., Golay, M

Female Leaders: Injurious or Inspiring Role Models for Women?

Science.gov (United States)

Hoyt, Crystal L.; Simon, Stefanie

2011-01-01

The impact of female role models on women's leadership aspirations and self-perceptions after a leadership task were assessed across two laboratory studies. These studies tested the prediction that upward social comparisons to high-level female leaders will have a relatively detrimental impact on women's self-perceptions and leadership aspirations…

Teacher’s role model ingender education of students

Directory of Open Access Journals (Sweden)

Elvira Dode

2015-07-01

Full Text Available Gender education as an important part of education, affects by the role and attitudes of teachers. Including gender perspective in schools is a prerequisite in alienable of human development, instead insuring gender equality it is considered as respecting human rights. Elimination of the gender stereotypes has a two-fold significance since itemsurest gender equality not only in the school system but even in the society as a whole. Gender stereotype messages, regardless by hidden or displayed form, unilaterally influence the development of the personality in its appearance as well as the formation of the individual. Children learn about gender identity simply by observing what happens in different circumstances around. In education exist gender disparities, which can be assessed by means of measurable indicators. So, the content of the curricula and instructive texts, the interactive relationships teacher-students, the institutional ambiance, etc. play an important role into the preservation and transmission of the gender disparity stereotypes through the messages they convey. The purpose of thestudy is to perform a systematic research in order to show the scale and shape in which gender stereotypes are portrayed and shown in social life, even through the role model of teacher and their affecting the education for a democratic society. To achieve this goal, we use the method of studying the existing literature; a detailed analysis of the questionnaires and interviews content with school directors and teachers of pre-university education in city: Shkodër, Tiranë, Elbasan, Pogradec, Korçë. Parents and teachers attitudes, seems to be a role model and affect the education of students. Therefore it is necessary before to teach students about gender equality, teachers need to be careful in their behavior about gender equality as an integral part of thinking. Need to have successful teacher, to get successful students otherwise should be successful

Spatial Downscaling of Alien Species Presences using Machine Learning

Science.gov (United States)

Daliakopoulos, Ioannis N.; Katsanevakis, Stelios; Moustakas, Aristides

2017-07-01

Large scale, high-resolution data on alien species distributions are essential for spatially explicit assessments of their environmental and socio-economic impacts, and management interventions for mitigation. However, these data are often unavailable. This paper presents a method that relies on Random Forest (RF) models to distribute alien species presence counts at a finer resolution grid, thus achieving spatial downscaling. A sufficiently large number of RF models are trained using random subsets of the dataset as predictors, in a bootstrapping approach to account for the uncertainty introduced by the subset selection. The method is tested with an approximately 8×8 km2 grid containing floral alien species presence and several indices of climatic, habitat, land use covariates for the Mediterranean island of Crete, Greece. Alien species presence is aggregated at 16×16 km2 and used as a predictor of presence at the original resolution, thus simulating spatial downscaling. Potential explanatory variables included habitat types, land cover richness, endemic species richness, soil type, temperature, precipitation, and freshwater availability. Uncertainty assessment of the spatial downscaling of alien species’ occurrences was also performed and true/false presences and absences were quantified. The approach is promising for downscaling alien species datasets of larger spatial scale but coarse resolution, where the underlying environmental information is available at a finer resolution than the alien species data. Furthermore, the RF architecture allows for tuning towards operationally optimal sensitivity and specificity, thus providing a decision support tool for designing a resource efficient alien species census.

Parental role modeling of fruits and vegetables at meals and snacks is associated with children’s adequate consumption

Science.gov (United States)

Draxten, Michelle; Fulkerson, Jayne A.; Friend, Sarah; Flattum, Colleen F.; Schow, Robin

2014-01-01

Parental role modeling of healthful eating behaviors has been shown to be positively correlated to children’s dietary intake and preference for fruits and vegetables. However, no study to date has utilized both parent and child report of parental role modeling and assessed role modeling at snacks and dinner. The purpose of this study is to 1) examine associations between parent and child report of parental role modeling of fruit and vegetable consumption at snacks and dinner and 2) determine whether parental role modeling is associated with children meeting daily fruit and vegetable recommendations. Parent-child dyads (N=160) participating in the Healthy Home Offerings via the Mealtime Environment (HOME) Plus study completed baseline surveys that included questions regarding parental role modeling of fruits and vegetables at dinner and snacks. Children also completed 24-hour dietary recalls. Spearman correlations and chi-square/Fisher’s exact test were used to examine relationships between parent and child report of parental role modeling of fruit and vegetable consumption at snacks and dinner and whether children met daily recommended servings of fruits and vegetables. On average, children consumed less than three servings of fruits and vegetables per day with only 23% of children consuming the recommended four daily servings. Similarities between parent and child reports of parental role modeling of fruits and vegetables at snacks and dinner varied by food type (e.g., fruit versus green salad) and whether the role modeling behavior was at snack or dinner. Statistically significant correlations were seen between parent and child report of parental role modeling consumption of fruit at dinner and green salad at dinner. Children who reported parental role modeling of vegetable consumption at snack and green salad at dinner were significantly more likely, than those who did not, to meet the daily fruit and vegetable consumption recommendations. Parents who

Effects of rare-earths additions on the breakdown of protective oxide scales in the presence of sulfur

International Nuclear Information System (INIS)

Srinivasan, V.; Goodman, D.E.

1989-01-01

Minor additions of rare-earths improve oxide scale adhesion in simple oxidation at high temperatures. The efficacy of such improvements and the role of such additions are not well understood in the presence of sulfur at 500-700 degrees C. Therefore, mixed gas corrosion tests were performed on model Fe-based alloys, with minor additions of rare-earths in an H 2 /H 2 S/H 2 O/Ar gas mixture at 700 degrees C up to 192 hours. The scale breakdown mechanisms were studied on preoxidized samples. The scales and the substrates were characterized by SEM/EDS, and scanning Auger microscopy (AES). The results are discussed

Modeling the role of environment in addiction.

Science.gov (United States)

Caprioli, Daniele; Celentano, Michele; Paolone, Giovanna; Badiani, Aldo

2007-11-15

The aim of this review is to provide an overview of the main types of animal models used to investigate the modulatory role of environment on drug addiction. The environment can alter the responsiveness to addictive drugs in at least three major ways. First, adverse life experiences can make an individual more vulnerable to develop drug addiction or to relapse into drug seeking. Second, neutral environmental cues can acquire, through Pavlovian conditioning, the ability to trigger drug seeking even after long periods of abstinence. Third, the environment immediately surrounding drug taking can alter the behavioral, subjective, and rewarding effects of a given drug, thus influencing the propensity to use the same drug again. We have focused in particular on the results obtained using an animal model we have developed to study the latter type of drug-environment interaction.

ANP (Atrial Natriuretic Peptide presence in the heart of a tunicate, Ciona intestinalis.

Directory of Open Access Journals (Sweden)

Aldo Gerbino

2010-06-01

Full Text Available Atrial natriuretic peptide was found in the heart of vertebrates, we studied the ANP presence in the heart of Ciona intestinalis. This is animal is very important because of the its evolutionary position between invertebrates and vertebrates. ANP presence was only revealed in myoepithelial cells of the myocardium. Results suggest the hypothesis that ANP is present not only in the vertebrates but also in the invertebrates and in Ciona heart ANP might play a similar role like in the heart of vertebrates.

Modelling cholera epidemics: the role of waterways, human mobility and sanitation.

Science.gov (United States)

Mari, L; Bertuzzo, E; Righetto, L; Casagrandi, R; Gatto, M; Rodriguez-Iturbe, I; Rinaldo, A

2012-02-07

We investigate the role of human mobility as a driver for long-range spreading of cholera infections, which primarily propagate through hydrologically controlled ecological corridors. Our aim is to build a spatially explicit model of a disease epidemic, which is relevant to both social and scientific issues. We present a two-layer network model that accounts for the interplay between epidemiological dynamics, hydrological transport and long-distance dissemination of the pathogen Vibrio cholerae owing to host movement, described here by means of a gravity-model approach. We test our model against epidemiological data recorded during the extensive cholera outbreak occurred in the KwaZulu-Natal province of South Africa during 2000-2001. We show that long-range human movement is fundamental in quantifying otherwise unexplained inter-catchment transport of V. cholerae, thus playing a key role in the formation of regional patterns of cholera epidemics. We also show quantitatively how heterogeneously distributed drinking water supplies and sanitation conditions may affect large-scale cholera transmission, and analyse the effects of different sanitation policies.

Modelling cholera epidemics: the role of waterways, human mobility and sanitation

Science.gov (United States)

Mari, L.; Bertuzzo, E.; Righetto, L.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

2012-01-01

We investigate the role of human mobility as a driver for long-range spreading of cholera infections, which primarily propagate through hydrologically controlled ecological corridors. Our aim is to build a spatially explicit model of a disease epidemic, which is relevant to both social and scientific issues. We present a two-layer network model that accounts for the interplay between epidemiological dynamics, hydrological transport and long-distance dissemination of the pathogen Vibrio cholerae owing to host movement, described here by means of a gravity-model approach. We test our model against epidemiological data recorded during the extensive cholera outbreak occurred in the KwaZulu-Natal province of South Africa during 2000–2001. We show that long-range human movement is fundamental in quantifying otherwise unexplained inter-catchment transport of V. cholerae, thus playing a key role in the formation of regional patterns of cholera epidemics. We also show quantitatively how heterogeneously distributed drinking water supplies and sanitation conditions may affect large-scale cholera transmission, and analyse the effects of different sanitation policies. PMID:21752809

Weak-value amplification and optimal parameter estimation in the presence of correlated noise

Science.gov (United States)

Sinclair, Josiah; Hallaji, Matin; Steinberg, Aephraim M.; Tollaksen, Jeff; Jordan, Andrew N.

2017-11-01

We analytically and numerically investigate the performance of weak-value amplification (WVA) and related parameter estimation methods in the presence of temporally correlated noise. WVA is a special instance of a general measurement strategy that involves sorting data into separate subsets based on the outcome of a second "partitioning" measurement. Using a simplified correlated noise model that can be analyzed exactly together with optimal statistical estimators, we compare WVA to a conventional measurement method. We find that WVA indeed yields a much lower variance of the parameter of interest than the conventional technique does, optimized in the absence of any partitioning measurements. In contrast, a statistically optimal analysis that employs partitioning measurements, incorporating all partitioned results and their known correlations, is found to yield an improvement—typically slight—over the noise reduction achieved by WVA. This result occurs because the simple WVA technique is not tailored to any specific noise environment and therefore does not make use of correlations between the different partitions. We also compare WVA to traditional background subtraction, a familiar technique where measurement outcomes are partitioned to eliminate unknown offsets or errors in calibration. Surprisingly, for the cases we consider, background subtraction turns out to be a special case of the optimal partitioning approach, possessing a similar typically slight advantage over WVA. These results give deeper insight into the role of partitioning measurements (with or without postselection) in enhancing measurement precision, which some have found puzzling. They also resolve previously made conflicting claims about the usefulness of weak-value amplification to precision measurement in the presence of correlated noise. We finish by presenting numerical results to model a more realistic laboratory situation of time-decaying correlations, showing that our conclusions hold

Aberrant Behaviours of Reaction Diffusion Self-organisation Models on Growing Domains in the Presence of Gene Expression Time Delays

KAUST Repository

Seirin  Lee, S.; Gaffney, E. A.

2010-01-01

domains in the presence of gene expression (Gaffney and Monk in Bull. Math. Biol. 68:99-130, 2006). Our results emphasise that gene expression dynamics induce unrealistic behaviour in Turing's model for multiple choices of kinetics and thus such aberrant

Using a mathematical model to analyze the role of probiotics and inflammation in necrotizing enterocolitis.

Directory of Open Access Journals (Sweden)

Julia C Arciero

2010-04-01

Full Text Available Necrotizing enterocolitis (NEC is a severe disease of the gastrointestinal tract of pre-term babies and is thought to be related to the physiological immaturity of the intestine and altered levels of normal flora in the gut. Understanding the factors that contribute to the pathology of NEC may lead to the development of treatment strategies aimed at re-establishing the integrity of the epithelial wall and preventing the propagation of inflammation in NEC. Several studies have shown a reduced incidence and severity of NEC in neonates treated with probiotics (beneficial bacteria species.The objective of this study is to use a mathematical model to predict the conditions under which probiotics may be successful in promoting the health of infants suffering from NEC. An ordinary differential equation model is developed that tracks the populations of pathogenic and probiotic bacteria in the intestinal lumen and in the blood/tissue region. The permeability of the intestinal epithelial layer is treated as a variable, and the role of the inflammatory response is included. The model predicts that in the presence of probiotics health is restored in many cases that would have been otherwise pathogenic. The timing of probiotic administration is also shown to determine whether or not health is restored. Finally, the model predicts that probiotics may be harmful to the NEC patient under very specific conditions, perhaps explaining the detrimental effects of probiotics observed in some clinical studies.The reduced, experimentally motivated mathematical model that we have developed suggests how a certain general set of characteristics of probiotics can lead to beneficial or detrimental outcomes for infants suffering from NEC, depending on the influences of probiotics on defined features of the inflammatory response.

Transverse kink oscillations in the presence of twist

Science.gov (United States)

Terradas, J.; Goossens, M.

2012-12-01

Context. Magnetic twist is thought to play an important role in coronal loops. The effects of magnetic twist on stable magnetohydrodynamic (MHD) waves is poorly understood because they are seldom studied for relevant cases. Aims: The goal of this work is to study the fingerprints of magnetic twist on stable transverse kink oscillations. Methods: We numerically calculated the eigenmodes of propagating and standing MHD waves for a model of a loop with magnetic twist. The azimuthal component of the magnetic field was assumed to be small in comparison to the longitudinal component. We did not consider resonantly damped modes or kink instabilities in our analysis. Results: For a nonconstant twist the frequencies of the MHD wave modes are split, which has important consequences for standing waves. This is different from the degenerated situation for equilibrium models with constant twist, which are characterised by an azimuthal component of the magnetic field that linearly increases with the radial coordinate. Conclusions: In the presence of twist standing kink solutions are characterised by a change in polarisation of the transverse displacement along the tube. For weak twist, and in the thin tube approximation, the frequency of standing modes is unaltered and the tube oscillates at the kink speed of the corresponding straight tube. The change in polarisation is linearly proportional to the degree of twist. This has implications with regard to observations of kink modes, since the detection of this variation in polarisation can be used as an indirect method to estimate the twist in oscillating loops.

The role of computer modelling in participatory integrated assessments

International Nuclear Information System (INIS)

Siebenhuener, Bernd; Barth, Volker

2005-01-01

In a number of recent research projects, computer models have been included in participatory procedures to assess global environmental change. The intention was to support knowledge production and to help the involved non-scientists to develop a deeper understanding of the interactions between natural and social systems. This paper analyses the experiences made in three projects with the use of computer models from a participatory and a risk management perspective. Our cross-cutting analysis of the objectives, the employed project designs and moderation schemes and the observed learning processes in participatory processes with model use shows that models play a mixed role in informing participants and stimulating discussions. However, no deeper reflection on values and belief systems could be achieved. In terms of the risk management phases, computer models serve best the purposes of problem definition and option assessment within participatory integrated assessment (PIA) processes

Adapting to change: The role of the right hemisphere in mental model building and updating.

Science.gov (United States)

Filipowicz, Alex; Anderson, Britt; Danckert, James

2016-09-01

We recently proposed that the right hemisphere plays a crucial role in the processes underlying mental model building and updating. Here, we review the evidence we and others have garnered to support this novel account of right hemisphere function. We begin by presenting evidence from patient work that suggests a critical role for the right hemisphere in the ability to learn from the statistics in the environment (model building) and adapt to environmental change (model updating). We then provide a review of neuroimaging research that highlights a network of brain regions involved in mental model updating. Next, we outline specific roles for particular regions within the network such that the anterior insula is purported to maintain the current model of the environment, the medial prefrontal cortex determines when to explore new or alternative models, and the inferior parietal lobule represents salient and surprising information with respect to the current model. We conclude by proposing some future directions that address some of the outstanding questions in the field of mental model building and updating. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Using probability modelling and genetic parentage assignment to test the role of local mate availability in mating system variation.

Science.gov (United States)

Blyton, Michaela D J; Banks, Sam C; Peakall, Rod; Lindenmayer, David B

2012-02-01

The formal testing of mating system theories with empirical data is important for evaluating the relative importance of different processes in shaping mating systems in wild populations. Here, we present a generally applicable probability modelling framework to test the role of local mate availability in determining a population's level of genetic monogamy. We provide a significance test for detecting departures in observed mating patterns from model expectations based on mate availability alone, allowing the presence and direction of behavioural effects to be inferred. The assessment of mate availability can be flexible and in this study it was based on population density, sex ratio and spatial arrangement. This approach provides a useful tool for (1) isolating the effect of mate availability in variable mating systems and (2) in combination with genetic parentage analyses, gaining insights into the nature of mating behaviours in elusive species. To illustrate this modelling approach, we have applied it to investigate the variable mating system of the mountain brushtail possum (Trichosurus cunninghami) and compared the model expectations with the outcomes of genetic parentage analysis over an 18-year study. The observed level of monogamy was higher than predicted under the model. Thus, behavioural traits, such as mate guarding or selective mate choice, may increase the population level of monogamy. We show that combining genetic parentage data with probability modelling can facilitate an improved understanding of the complex interactions between behavioural adaptations and demographic dynamics in driving mating system variation. © 2011 Blackwell Publishing Ltd.

The effect of hydroxyapatite presence on the degree of conversion and polymerization rate in a model self-etching adhesive

Science.gov (United States)

Zhang, Ying; Wang, Yong

2011-01-01

Objective The effect of hydroxyapatite (HAp) content on photopolymerization of a model self-etching adhesive was studied by using attenuated total reflectance Fourier transform infrared (ATR/FT-IR) spectroscopy. Materials and methods The model adhesive contained two monomers: bis[2-(methacryloyloxy)ethyl] phosphate (2MP) and 2-hydroxyethyl methacrylate (HEMA) using a 1:1 mass ratio, representing an acidic formulation. Camphorquinone and ethyl 4-dimethylaminobenzoate were added to enable visible light photopolymerization in a constant concentration of 0.022 mmol per gram monomer. HAp [Ca10(OH)2(PO4)6] powder were added to the test solutions to obtain mass fraction of 0, 1, 2, 3, 4 wt%. The degree of conversion (DC) and the polymerization rate (PR) with/without HAp were determined using ATR/FT-IR with a time-based spectrum analysis. Results Monomer DC and PR were significantly enhanced by addition of HAp. Incorporation of 4 wt% of HAp increased DC from 20.8 (±0.3) % to 93.4 (±1.1) %, and PR from 0.42 (±0.01) %/s to 3.21 (±0.07) %/s. The pH of adhesive solutions was measured and correlated with DC and PR. The pH of test solutions was also controlled using a base (sodium hydroxide, NaOH) to similar values as when using HAp. Results indicated that both the DC and PR increased with increasing pH, regardless of additive, confirming the role of pH on polymerization. From the IR spectral comparison, changes in molecular structures of the self-etching adhesive after the addition of HAp were observed, which were correlated with the specific interaction between 2MP and HAp. The effect of viscosity was also proposed to be another possible reason for the improved polymerization. Significance The photopolymerization of a self-etching adhesive was enhanced / accelerated in the presence of HAp. The results provide the critical information for understanding the interactions/bonding between self-etching adhesives and tooth substrates. PMID:22032933

Food Safety Management in a Global Environment: The Role of Risk Assessment Models

OpenAIRE

Fuentes-Pila, Joaquin; Jimeno, Vicente; Manzano, Amparo; Rodriguez Monroy, Carlos; Mar Fernandez, Maria Del

2006-01-01

Quantitative risk assessment models are playing a minor role in the development of the new EU legal framework for food safety. There is a tendency of the EU institutions to apply the precautionary principle versus the predisposition of the USA institutions to rely on risk analysis. This paper provides a comparison of the role played by quantitative risk assessment models in the development of new policies on food safety in the EU and in the USA, focusing on a study case: the supply chain of s...

The importance of antibiotic residues presence detection in milk

Directory of Open Access Journals (Sweden)

Dubravka Samaržija

2002-01-01

Full Text Available Antibiotic residues are the most present inhibitory substances in milkhaving undesirable effect on human health, technological characteristics and the quality of milk and dairy products. In order to protect consumer's health and to ensure high quality milk production, European Union (EU regulation 2377/90 sets a maximum permitted levels for antibiotic residues in milk. Although the presence of antibiotic residues in milk can be due to animal diseases treatment, and in the case of milking animals, they are mostly present after mastitis treatment. The aim of this work is to stress the importance of the continuous control on antibiotic residues presence in milk, due to the role that milk and dairy products have in human nutrition. In this paper, different groups of antibiotics, mechanisms of theirs action, mistakes occurring in dairy products manufacture as well as the methods for theirs detection are described.

Unexpected strong attraction in the presence of continuum bound state

International Nuclear Information System (INIS)

Delfino, A.; Frederico, T.

1992-06-01

The result of few-particle ground-state calculation employing a two-particle non-local potential supporting a continuum bound state in addition to a negative-energy bound state has occasionally revealed unexpected large attraction in producing a very strongly bound ground state. In the presence of the continuum bound state the difference of phase shift between zero and infinite energies has an extra jump of φ as in the presence of an additional bound state. The wave function of the continuum bound state is identical with that of a strongly bound negative-energy state, which leads us to postulate a pseudo bound state in the two-particle system in order to explain the unexpected attraction. The role of the Pauli forbidden states is expected to be similar to these pseudo states. (author)

Building new roles and relationships in research: a model of patient engagement research.

Science.gov (United States)

Marlett, Nancy; Shklarov, Svetlana; Marshall, Deborah; Santana, Maria Jose; Wasylak, Tracy

2015-05-01

Patient engagement is influenced by institutional ideologies, professional attitudes and patient readiness to accept new, engaged roles. This article provides an opportunity to consider a new role for patients who are trained to conduct patient experience research using qualitative methods. The emergence of the role of patient engagement researcher was studied using a grounded theory with 21 patients over one-year internship and 125 research participants. Data were collected using tape recordings, field notes and student assignments. These were analyzed using open and selective coding, memoing, categorizing themes. Patients' education level (from high school to PhD), cultural background (immigrant experience, seniors), employment (employed full or part time, receiving disability benefits or retired), age (late 30 s-75) and gender (17 women and four men) were diverse. Main categories (emancipating patient experience; qualifying for research; leading sitting down; working data together; seeding change) are organized by the dialectic of co-creation as the roles of patient and researcher merge. A theoretical model is proposed. The theoretical model provides a glimpse into the process of merging two distinct roles of patient and researcher and in the process unleashes a force for change. The emergence of a dialectic from polar opposite roles is difficult to locate in health or other institutions where power differentials exist but there are indications that this new role might become a template for other merged roles in patient-led medical teams.

Genetics and presence of non-syndromic supernumerary teeth: A mystery case report and review of literature

Directory of Open Access Journals (Sweden)

Neha Khambete

2012-01-01

Full Text Available Presence of supernumerary teeth is well-recognized clinical phenomenon. However, it is uncommon to find multiple supernumeraries in individuals with no other associated disease or syndrome. Presence of multiple supernumerary teeth is thought to have genetic component. We report a rare case where multiple supernumerary teeth were seen without presence of any other syndrome in 3 generations; father, son, and two grandsons. We also present a review of similar cases published in literature till date. The role of genetics in development of supernumerary teeth is highlighted.

A Massively Scalable Architecture for Instant Messaging & Presence

NARCIS (Netherlands)

Schippers, Jorrit; Remke, Anne Katharina Ingrid; Punt, Henk; Wegdam, M.; Haverkort, Boudewijn R.H.M.; Thomas, N.; Bradley, J.; Knottenbelt, W.; Dingle, N.; Harder, U.

2010-01-01

This paper analyzes the scalability of Instant Messaging & Presence (IM&P) architectures. We take a queueing-based modelling and analysis approach to ��?nd the bottlenecks of the current IM&P architecture at the Dutch social network Hyves, as well as of alternative architectures. We use the

Reactions of model compounds in the presence of pyrene and MoS sub 2 to simulate coprocessing

Energy Technology Data Exchange (ETDEWEB)

Ting, P.-S.; Curtis, C.W.; Cronauer, D.C. (Auburn University, Auburn, AL (USA). Chemical Engineering Dept.)

Catalytic reactions of pyrene using in situ generated MoS{sub 2} from molybdenum naphthenate and excess sulfur were evaluated in the presence of added model species, both hydrocarbons and heteroatomic species. The added hydrocarbons and heteroatomic compounds containing oxygen and sulfur had little effect on the hydrogenation of pyrene at either 400 or 425{degree}C, but quinoline at 400{degree}C reduced the hydrogenation of pyrene by half. Reactions at 425{degree}C also reduced the hydrogenation of pyrene by half regardless of the added model species. The added model species underwent different degrees of reaction: the hydrocarbons underwent little or no reaction, dibenzofuran showed little hydrodeoxygenation, dibenzothiophene yielded substantial hydrodesulfurization and quinoline was almost totally hydrodenitrogenated. The addition of quinoline at increasing concentration resulted in substantial lowering of pyrene hydrogenation and quinoline hydrodenitrogenation. Introduction of quinoline at a low concentration of 0.4 wt% gave a pyrene hydrogenation rate constant of 0.073 min{sup -1} at 400{degree}C while an increase in quinoline to 10.0 wt% yielded a rate constant of 0.020 min{sup -1}. 21 refs., 7 figs., 6 tabs.

Role-modeling and conversations about giving in the socialization of adolescent charitable giving and volunteering.

Science.gov (United States)

Ottoni-Wilhelm, Mark; Estell, David B; Perdue, Neil H

2014-01-01

This study investigated the relationship between the monetary giving and volunteering behavior of adolescents and the role-modeling and conversations about giving provided by their parents. The participants are a large nationally-representative sample of 12-18 year-olds from the Panel Study of Income Dynamics' Child Development Supplement (n = 1244). Adolescents reported whether they gave money and whether they volunteered. In a separate interview parents reported whether they talked to their adolescent about giving. In a third interview, parents reported whether they gave money and volunteered. The results show that both role-modeling and conversations about giving are strongly related to adolescents' giving and volunteering. Knowing that both role-modeling and conversation are strongly related to adolescents' giving and volunteering suggests an often over-looked way for practitioners and policy-makers to nurture giving and volunteering among adults: start earlier, during adolescence, by guiding parents in their role-modeling of, and conversations about, charitable giving and volunteering. Copyright © 2013 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Gender role models in fictional novels for emerging adult lesbians.

Science.gov (United States)

Cook, Jennifer R; Rostosky, Sharon S; Riggle, Ellen D B

2013-01-01

Novels provide role models for young adult lesbians and thus may influence their identity development. This study focused on 16 lesbian protagonists identified in 11 young adult novels that received 2011 Lambda Literary Award nominations. Content analyses revealed six themes. Three themes defied traditional gender stereotypes: Asserting Oneself, Pursuing Intimacy with Another Woman, and Breaking Free of Constraints to Authentic Self-Expression. Three themes reinforced gender stereotypes: Negative Emotional Experiences Associated with Lesbian Identity, Traditional Masculine Gender Expression, and Traditional Gender Role-Based Sexual Scripts. Each theme is discussed in light of its possible contribution to lesbian identity development.

Homeostatic role of heterosynaptic plasticity: Models and experiments

Directory of Open Access Journals (Sweden)

Marina eChistiakova

2015-07-01

Full Text Available Homosynaptic Hebbian-type plasticity provides a cellular mechanism of learning and refinement of connectivity during development in a variety of biological systems. In this review we argue that a complimentary form of plasticity - heterosynaptic plasticity - represents a necessary cellular component for homeostatic regulation of synaptic weights and neuronal activity. The required properties of a homeostatic mechanism which acutely constrains the runaway dynamics imposed by Hebbian associative plasticity have been well-articulated by theoretical and modeling studies. Such mechanism(s should robustly support the stability of operation of neuronal networks and synaptic competition, include changes at non-active synapses, and operate on a similar time scale to Hebbian-type plasticity. The experimentally observed properties of heterosynaptic plasticity have introduced it as a strong candidate to fulfill this homeostatic role. Subsequent modeling studies which incorporate heterosynaptic plasticity into model neurons with Hebbian synapses (utilizing an STDP learning rule have confirmed its ability to robustly provide stability and competition. In contrast, properties of homeostatic synaptic scaling, which is triggered by extreme and long lasting (hours and days changes of neuronal activity, do not fit two crucial requirements for a hypothetical homeostatic mechanism needed to provide stability of operation in the face of on-going synaptic changes driven by Hebbian-type learning rules. Both the trigger and the time scale of homeostatic synaptic scaling are fundamentally different from those of the Hebbian-type plasticity. We conclude that heterosynaptic plasticity, which is triggered by the same episodes of strong postsynaptic activity and operates on the same time scale as Hebbian-type associative plasticity, is ideally suited to serve homeostatic role during on-going synaptic plasticity.

The role of water chemistry and geomorphic control in the presence of Didymosphenia geminata in Quebec

Science.gov (United States)

Gillis, C.; Gabor, R. S.; Cullis, J. D.; Ran, L.; Hassan, M. A.

2010-12-01

Didymosphenia geminata (didymo), an invasive diatom, was first officially observed and identified in the Matapedia River in Eastern Quebec in July 2006. This Atlantic salmon fishing river has several characteristics shown to favor didymo's ability to form thick, extensive benthic mats, including stable flow and oligotrophic nutrient conditions. Since the incursion, rapid colonization and inter-catchment transfer processes were observed, notably in surrounding watersheds on the Gaspé Peninsula as well as in northern New-Brunswick. All affected watersheds share favorable characteristics for didymo growth, including high light, low nutrient waters, and stable substrate. The nearby North Shore of the St. Lawrence, which also contains rivers with conditions that would favor didymo growth, has not yet shown didymo presence. This system provides a comparison to identify necessary parameters for didymo growth, with differences primarily due to geology-driven water chemistry. Pre-incursion water chemistry was compared between the two regions. Rivers in the region where didymo is present displayed a high alkalinity and corresponding higher pH, due to increases concentrations of magnesium and calcium, than rivers in regions where didymo has not appeared. Also, rivers with didymo show a lower amount of color-causing compounds, such as organic carbon, and clearer water, which supports the theory that high light levels encourage didymo growth. In addition to water chemistry, channel morphology, bed stability and flow patterns are also believed to be key elements in determining the presence of this benthic diatom. In 2007, channel morphology, bed texture, bankfull depth and width, local bed slope and didymo presence were surveyed on a 65 km stretch of the Matapedia River. Relative frequency of didymo presence showed that didymo blooms are most likely to appear in cobble-riffles than in any other morphologies. In fact, cobble riffles promote didymo establishment due to shallow

Effects of work-family-school role conflicts and role-related social support on burnout in Registered Nurses: a structural equation modelling approach.

Science.gov (United States)

Goong, Hwasoo; Xu, Lijuan; Li, Chun-Yu

2016-11-01

To examine the effects of work-family-school role conflicts and role-related social support (RRSS) on burnout of nurses pursuing an advanced degree. A predictive correlational cross-sectional study design was used. Nurses were found to be a high-risk group for burnout, even more so among nurses pursuing an advanced degree. When nurses with a professional career marry and decide to become students, inter-role conflicts and burnout are possible outcomes of the resulting multiple roles. Using convenience sampling, data were collected from October 2011-May 2012. A questionnaire about work-family-school role conflicts, RRSS, burnout and general information was completed by 286 nurses pursuing an advanced degree at 12 hospitals in Korea. Data were analysed using SPSS and structural equation modelling with the Analysis of Moment Structures program. The proposed model provided a good fit to the obtained data. Work-family-school role conflicts and social support exerted significant effects on burnout. Role-related social support was found to play a partial mediating role between work-family-school role conflicts and burnout. The findings of this study imply that RRSS significantly directly and indirectly influences burnout among the nurses pursuing an advanced degree. It is necessary for nursing managers to consider implementing family- and school-friendly policies (e.g. flexible work schedules) to help nurses to manage their multiple roles and thereby decrease their burnout rate. © 2016 John Wiley & Sons Ltd.

Presence and distribution of leptin and leptin receptor in the canine gallbladder.

Science.gov (United States)

Lee, Sungin; Lee, Aeri; Kweon, Oh-Kyeong; Kim, Wan Hee

2016-09-01

The hormone leptin is produced by mature adipocytes and plays an important role in regulating food intake and energy metabolism through its interaction with the leptin receptor. In addition to roles in obesity and obesity-related diseases, leptin has been reported to affect the components and secretion of bile in leptin-deficient mice. Furthermore, gallbladder diseases such as cholelithiasis are known to be associated with serum leptin concentrations in humans. We hypothesized that the canine gallbladder is a source of leptin and that the leptin receptor may be localized in the gallbladder, where it plays a role in regulating the function of this organ. The aim of this study was to demonstrate the presence and expression patterns of leptin and its receptors in normal canine gallbladders using reverse transcriptase-PCR (RT-PCR) and immunohistochemistry. Clinically normal gallbladder tissue samples were obtained from four healthy beagle dogs with similar body condition scores. RT-PCR and sequencing of the amplified PCR products revealed the presence of leptin mRNA and its receptors in the gallbladder. Immunohistochemical investigations demonstrated the expression of leptin and its receptors in the luminal single columnar and tubuloalveolar glandular epithelial cells. In conclusion, the results of this study demonstrated the presence of leptin and its receptors in the gallbladders of dogs. Leptin and its receptor were both localized throughout the cytoplasm of luminal and glandular epithelial cells. These results suggested that the gallbladder is not only a source of leptin, but also a target of leptin though autocrine/paracrine mechanisms. The results of this study could increase the understanding of both the normal physiological functions of the gallbladder and the pathophysiological mechanisms of gallbladder diseases characterized by leptin system dysfunction. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

The roles of the micro-organisms and chromium content in the corrosion of iron-chromium steels in the presence of sulfate-reducing bacteria

International Nuclear Information System (INIS)

Ferrante, V.

1991-12-01

Although the ability of sulfate-reducing bacteria to enhance the corrosion of steel is now widely accepted, the actual processes involved in such phenomena are still discussed. This work is dedicated to the study of the exact roles played in corrosion processes firstly, by the presence of D. vulgaris cells and, secondly, by chemical factors such as the material composition and the accumulation of sulfide ions in the solution. The use of microbiological, electrochemical and analytical experimental techniques lead to results that show the interdependence of the bacteria and the material as well as the importance of the steel composition in the adhesion of the micro-organisms and the general corrosion rates. The bacteria cells and dissolved sulfide ions do not markedly influence the general corrosion rates. They however induce surface state modifications that can result in localized corrosion phenomena

Sonic Virtuality, Environment, and Presence

DEFF Research Database (Denmark)

Grimshaw, Mark

2018-01-01

The article presents a brief introduction to the concept of sonic virtuality, a view of sound as a multi-modal, emergent perception that provides a framework that has since been used to provide an explanation of the formation of environments. Additionally, the article uses such concepts to explain...... the phenomenon of presence, not only in virtual worlds but also in actual worlds. The view put forward is that environment is an emergent perception, formed from the hypothetical modelling of salient worlds of sensory things, and it is in the environment that we feel present. The article ends with some thoughts...

Presence-only approach to assess landslide triggering-thickness susceptibility. A test for the Mili catchment (North-Eastern Sicily, Italy)

Science.gov (United States)

Lombardo, Luigi; Fubelli, Giandomenico; Amato, Gabriele; Bonasera, Mauro; Hochschild, Volker; Rotigliano, Edoardo

2015-04-01

This study aims at comparing the performances of a presence only approach, namely Maximum Entropy, in assessing landslide triggering-thickness susceptibility within the Mili catchment, located in the north-eastern Sicily, Italy. This catchment has been recently exposed to three main meteorological extreme events, resulting in the activation of multiple fast landslides, which occurred on the 1st October 2009, 10th March 2010 and 1st March 2011. Differently from the 2009 event, which only marginally hit the catchment, the 2010 and 2011 storms fully involved the area of the Mili catchment. Detailed field data was collected to associate the thickness of mobilised materials at the triggering zone to each mass movement within the catchment. This information has been used to model the landslide susceptibility for two classes of processes clustered into shallow failures for maximum depths of 0.5m and deep ones in case of values equal or greater than 0.5m. As the authors believed that the peculiar geomorphometry of this narrow and steep catchment played a fundamental role in generating two distinct patterns of landslide thicknesses during the initiation phase, a HRDEM was used to extract topographic attributes to express near-triggering geomorphological conditions. On the other hand, medium resolution vegetation indexes derived from ASTER scenes were used as explanatory variables pertaining to a wider spatial neighbourhood, whilst a revised geological map, the land use from CORINE and a tectonic map were used to convey an even wider area connected to the slope instability. The choice of a presence-only approach allowed to effectively discriminate between the two types of landslide thicknesses at the triggering zone, producing outstanding prediction skills associated with relatively low variances across a set of 20 randomly generated replicates. The validation phase produced indeed average AUC values of 0.91 with a standard deviation of 0.03 for both the modelled landslide

Interaction quench dynamics in the Kondo model in the presence of a local magnetic field.

Science.gov (United States)

Heyl, M; Kehrein, S

2010-09-01

In this work we investigate the quench dynamics in the Kondo model on the Toulouse line in the presence of a local magnetic field. It is shown that this setup can be realized by either applying the local magnetic field directly or by preparing the system in a macroscopically spin-polarized initial state. In the latter case, the magnetic field results from a subtlety in applying the bosonization technique where terms that are usually referred to as finite-size corrections become important in the present non-equilibrium setting. The transient dynamics are studied by analyzing exact analytical results for the local spin dynamics. The timescale for the relaxation of the local dynamical quantities turns out to be exclusively determined by the Kondo scale. In the transient regime, one observes damped oscillations in the local correlation functions with a frequency set by the magnetic field.

Models and role models

NARCIS (Netherlands)

ten Cate, J.M.

2015-01-01

Developing experimental models to understand dental caries has been the theme in our research group. Our first, the pH-cycling model, was developed to investigate the chemical reactions in enamel or dentine, which lead to dental caries. It aimed to leverage our understanding of the fluoride mode of

A simple model of HIV epidemic in Italy: The role of the antiretroviral treatment.

Science.gov (United States)

Papa, Federico; Binda, Francesca; Felici, Giovanni; Franzetti, Marco; Gandolfi, Alberto; Sinisgalli, Carmela; Balotta, Claudia

2018-02-01

In the present paper we propose a simple time-varying ODE model to describe the evolution of HIV epidemic in Italy. The model considers a single population of susceptibles, without distinction of high-risk groups within the general population, and accounts for the presence of immigration and emigration, modelling their effects on both the general demography and the dynamics of the infected subpopulations. To represent the intra-host disease progression, the untreated infected population is distributed over four compartments in cascade according to the CD4 counts. A further compartment is added to represent infected people under antiretroviral therapy. The per capita exit rate from treatment, due to voluntary interruption or failure of therapy, is assumed variable with time. The values of the model parameters not reported in the literature are assessed by fitting available epidemiological data over the decade 2003÷2012. Predictions until year 2025 are computed, enlightening the impact on the public health of the early initiation of the antiretroviral therapy. The benefits of this change in the treatment eligibility consist in reducing the HIV incidence rate, the rate of new AIDS cases, and the rate of death from AIDS. Analytical results about properties of the model in its time-invariant form are provided, in particular the global stability of the equilibrium points is established either in the absence and in the presence of infected among immigrants.

A Role Model Mother/caregiver Programme to Expand Home-based ...

African Journals Online (AJOL)

In Nigeria, a Role Model Mother/Caregiver (RMM/C) programme was initiated by the National Malaria Control Programme (NMCP) to provide home-based management of malaria. Criteria for RMM/C selection were developed centrally by the Nigerian NMCP for community use. RMM/Cs were identified and recruited by the ...

Improved workflow modelling using role activity diagram-based modelling with application to a radiology service case study.

Science.gov (United States)

Shukla, Nagesh; Keast, John E; Ceglarek, Darek

2014-10-01

The modelling of complex workflows is an important problem-solving technique within healthcare settings. However, currently most of the workflow models use a simplified flow chart of patient flow obtained using on-site observations, group-based debates and brainstorming sessions, together with historic patient data. This paper presents a systematic and semi-automatic methodology for knowledge acquisition with detailed process representation using sequential interviews of people in the key roles involved in the service delivery process. The proposed methodology allows the modelling of roles, interactions, actions, and decisions involved in the service delivery process. This approach is based on protocol generation and analysis techniques such as: (i) initial protocol generation based on qualitative interviews of radiology staff, (ii) extraction of key features of the service delivery process, (iii) discovering the relationships among the key features extracted, and, (iv) a graphical representation of the final structured model of the service delivery process. The methodology is demonstrated through a case study of a magnetic resonance (MR) scanning service-delivery process in the radiology department of a large hospital. A set of guidelines is also presented in this paper to visually analyze the resulting process model for identifying process vulnerabilities. A comparative analysis of different workflow models is also conducted. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The Effect of Parental Modeling on Child Pain Responses: The Role of Parent and Child Sex.

Science.gov (United States)

Boerner, Katelynn E; Chambers, Christine T; McGrath, Patrick J; LoLordo, Vincent; Uher, Rudolf

2017-06-01

Social modeling is a process by which pain behaviors are learned, and research has found parents act as models for their children's behavior. Despite social learning theory predicting that same-sex models have greater effect, no experimental investigation to date has examined the role of sex of the model or observer in social learning of pediatric pain. The present study recruited 168 parent-child dyads (equal father-son, father-daughter, mother-son, and mother-daughter dyads) in which children were generally healthy and 6 to 8 years old. Unbeknownst to their child, parents were randomly assigned to exaggerate their expression of pain, minimize their expression of pain, or act naturally during the cold pressor task (CPT). Parents completed the CPT while their child observed, then children completed the CPT themselves. Children whose parents were in the exaggerate condition reported higher anxiety than children of parents in the minimize condition. Additionally, girls in the exaggerate condition rated their overall pain intensity during the CPT significantly higher than boys in the same condition. No child sex differences were observed in pain intensity for the control or minimize conditions. Parent expressions of pain affects children's anxiety, and sex-specific effects of parental exaggerated pain expression on children's own subsequent pain experience are present. This article describes how parental expressions of pain influence children's pain and anxiety, specifically examining the relevance of parent and child sex in this process. These findings have implications for children of parents with chronic pain, or situations in which parents experience pain in the presence of their child (eg, vaccinations). Copyright © 2017 American Pain Society. Published by Elsevier Inc. All rights reserved.

The role of networks in business model innovation : three shaping processes supporting cognitive shifts

NARCIS (Netherlands)

Oskam, Inge; de Man, Ard-Pieter; Bossink, Bart

2017-01-01

Stakeholders and in particular customers are an important source for business model innovation. Especially for sustainable business models, stakeholder integration may radically change the business logic and help to revise the business model. In this process cognition plays a central role,

A bridge role metric model for nodes in software networks.

Directory of Open Access Journals (Sweden)

Bo Li

Full Text Available A bridge role metric model is put forward in this paper. Compared with previous metric models, our solution of a large-scale object-oriented software system as a complex network is inherently more realistic. To acquire nodes and links in an undirected network, a new model that presents the crucial connectivity of a module or the hub instead of only centrality as in previous metric models is presented. Two previous metric models are described for comparison. In addition, it is obvious that the fitting curve between the Bre results and degrees can well be fitted by a power law. The model represents many realistic characteristics of actual software structures, and a hydropower simulation system is taken as an example. This paper makes additional contributions to an accurate understanding of module design of software systems and is expected to be beneficial to software engineering practices.

Black holes in the presence of dark energy

International Nuclear Information System (INIS)

Babichev, E O; Dokuchaev, V I; Eroshenko, Yu N

2013-01-01

The new, rapidly developing field of theoretical research—studies of dark energy interacting with black holes (and, in particular, accreting onto black holes)–—is reviewed. The term 'dark energy' is meant to cover a wide range of field theory models, as well as perfect fluids with various equations of state, including cosmological dark energy. Various accretion models are analyzed in terms of the simplest test field approximation or by allowing back reaction on the black-hole metric. The behavior of various types of dark energy in the vicinity of Schwarzschild and electrically charged black holes is examined. Nontrivial effects due to the presence of dark energy in the black hole vicinity are discussed. In particular, a physical explanation is given of why the black hole mass decreases when phantom energy is being accreted, a process in which the basic energy conditions of the famous theorem of nondecreasing horizon area in classical black holes are violated. The theoretical possibility of a signal escaping from beneath the black hole event horizon is discussed for a number of dark energy models. Finally, the violation of the laws of thermodynamics by black holes in the presence of noncanonical fields is considered. (reviews of topical problems)

A Theoretical Framework and Model towards Media-Rich Social Presence Design Practices

Science.gov (United States)

Elwood, Susan; McCaleb, Karen; Fernandez, Mary; Keengwe, Jared

2014-01-01

Educators are seeing rapid developments in online instruction with regard to not only available technologies, but also in design and teaching practices. Developing and maintaining social presence in an online environment is paramount to the success of a learning environment. This article touches upon some historical perspectives of social presence…

Non-equilibrium modeling of UV laser induced plasma on a copper target in the presence of Cu{sup 2+}

Energy Technology Data Exchange (ETDEWEB)

Ait Oumeziane, Amina, E-mail: a.aitoumeziane@gmail.com; Liani, Bachir [Laboratoire de Physique Théorique, Abou Beker Blekaid University (Algeria); Parisse, Jean-Denis [IUSTI UMR CNRS 7343, Aix-Marseille University (France); French Air School, Salon de Provence (France)

2016-03-15

This work is a contribution to the understanding of UV laser ablation of a copper sample in the presence of Cu{sup 2+} species as well as electronic non-equilibrium in the laser induced plasma. This particular study extends a previous paper and develops a 1D hydrodynamic model to describe the behavior of the laser induced plume, including the thermal non-equilibrium between electrons and heavy particles. Incorporating the formation of doubly charged ions (Cu{sup 2+}) in such an approach has not been considered previously. We evaluate the effect of the presence of doubly ionized species on the characteristics of the plume, i.e., temperature, pressure, and expansion velocity, and on the material itself by evaluating the ablation depth and plasma shielding effects. This study evaluates the effects of the doubly charged species using a non-equilibrium hydrodynamic approach which comprises a contribution to the understanding of the governing processes of the interaction of ultraviolet nanosecond laser pulses with metals and the parameter optimization depending on the intended application.

Modeling back-relaxation in ionic polymer metal composites: The role of steric effects and composite layers

Science.gov (United States)

Porfiri, Maurizio; Sharghi, Hesam; Zhang, Peng

2018-01-01

Ionic polymer metal composites (IPMCs) are a new class of active materials that are gaining traction as soft actuators in medical and industrial applications. IPMCs can undergo large deformations under modest voltage inputs, in dry and wet environments. Past studies have demonstrated that physical and geometric properties of all the IPMC constituents (ionomer, electrodes, and counterions) may all influence the time scales of the transient response and severity of the back-relaxation. In this study, we present a detailed mathematical model to investigate how the finite size of the counterions and the presence of metal particles in the vicinity of the electrodes modulate IPMC actuation. We build on previous work by our group on thermodynamically consistent modeling of IPMC mechanics and electrochemistry, which attributes IPMC actuation to the interplay between Maxwell stress and osmotic forces. To gain insight into the role of physical and geometric parameters, the resulting nonlinear partial differential equations are solved semianalytically using the method of matched asymptotic expansions, for the initial transient and the steady-state. A numerical solution in COMSOL Multiphysics® is developed to verify semianalytical findings and further explore IPMC actuation. Our model can successfully predict the entire response of IPMCs, from the initial bending toward the anode to the steady-state toward the cathode. We find that the steric effect can abolish the back-relaxation of IPMCs by restraining the counterions' concentration near the electrodes. We also find that increasing the thickness of the ionomer-metal composite layers may enhance IPMC actuation through increased osmotic forces and Maxwell stress.

The Dynamics of an HIV/AIDS Model with Screened Disease Carriers

Directory of Open Access Journals (Sweden)

S. D. Hove-Musekwa

2009-01-01

Full Text Available The presence of carriers usually complicates the dynamics and prevention of a disease. They are not recognized as disease cases themselves unless they are screened and they usually spread the infection without them being aware. We argue that this has been one of the major causes of the spread of human immunodeficiency virus (HIV. We propose, in this paper, a model for the heterogeneous transmission of HIV/acquired immunodeficiency syndrome in the presence of disease carriers. The model allows us to assess the role of screening, as an intervention program that can slow the epidemic. A threshold value ψ*, for the screening rate is obtained. It is shown numerically that if 80% or more of the carrier population is screened, the epidemic can be contained. The qualitative analysis is done in terms of the model reproduction number R. The model has two equilibria, the disease free equilibrium and a unique endemic equilibrium. The disease free equilibrium is globally stable of R  1. A detailed discussion of the model reproduction number is given and numerical simulations are done to show the role of some of the important model parameters.

Asteroid thermal modeling in the presence of reflected sunlight

Science.gov (United States)

Myhrvold, Nathan

2018-03-01

A new derivation of simple asteroid thermal models is presented, investigating the need to account correctly for Kirchhoff's law of thermal radiation when IR observations contain substantial reflected sunlight. The framework applies to both the NEATM and related thermal models. A new parameterization of these models eliminates the dependence of thermal modeling on visible absolute magnitude H, which is not always available. Monte Carlo simulations are used to assess the potential impact of violating Kirchhoff's law on estimates of physical parameters such as diameter and IR albedo, with an emphasis on NEOWISE results. The NEOWISE papers use ten different models, applied to 12 different combinations of WISE data bands, in 47 different combinations. The most prevalent combinations are simulated and the accuracy of diameter estimates is found to be depend critically on the model and data band combination. In the best case of full thermal modeling of all four band the errors in an idealized model the 1σ (68.27%) confidence interval is -5% to +6%, but this combination is just 1.9% of NEOWISE results. Other combinations representing 42% of the NEOWISE results have about twice the CI at -10% to +12%, before accounting for errors due to irregular shape or other real world effects that are not simulated. The model and data band combinations found for the majority of NEOWISE results have much larger systematic and random errors. Kirchhoff's law violation by NEOWISE models leads to errors in estimation accuracy that are strongest for asteroids with W1, W2 band emissivity ɛ12 in both the lowest (0.605 ≤ɛ12 ≤ 0 . 780), and highest decile (0.969 ≤ɛ12 ≤ 0 . 988), corresponding to the highest and lowest deciles of near-IR albedo pIR. Systematic accuracy error between deciles ranges from a low of 5% to as much as 45%, and there are also differences in the random errors. Kirchhoff's law effects also produce large errors in NEOWISE estimates of pIR, particularly for high

Selective degradation of model pollutants in the presence of core@shell TiO{sub 2}@SiO{sub 2} photocatalyst

Energy Technology Data Exchange (ETDEWEB)

Nadrah, Peter, E-mail: peter.nadrah@zag.si [Slovenian National Building and Civil Engineering Institute, Dimičeva ul. 12, SI-1000 Ljubljana (Slovenia); Gaberšček, Miran [National Institute of Chemistry, Hajdrihova ul. 19, SI-1000 Ljubljana (Slovenia); Sever Škapin, Andrijana [Slovenian National Building and Civil Engineering Institute, Dimičeva ul. 12, SI-1000 Ljubljana (Slovenia)

2017-05-31

Highlights: • TiO{sub 2} encapsulated in mesoporous silica exhibits selective photocatalytic degradation of low-molecular-weight molecules. • Core@shell photocatalyst degrades rhodamine B in presence of fivefold mass concentration of starch, while pure TiO{sub 2} does not. • Potential use for removing water pollutants, while retaining non-harmful and beneficial macromolecules. - Abstract: Photocatalytic TiO{sub 2} degrades organic matter unselectively. However, in certain applications, such as degradation of pollutants, selectivity towards pollutants is beneficial. We synthesized core@shell TiO{sub 2}@SiO{sub 2} nanoparticles with photocatalytic activity featuring a significantly faster preferential degradation of model pollutant (rhodamine B) in presence of abundant concentration of natural organic matter compared to pure TiO{sub 2} (P25). The material’s photocatalytic activity was tested in aqueous medium. The selectivity of prepared effect of core@shell materials is explained based on transmission electron microscopy, nitrogen adsorption, X-ray powder diffraction and zeta potential measurements.

The role of emotion regulation in situational empathy-related responding and prosocial behaviour in the presence of negative affect.

Science.gov (United States)

Hein, Sascha; Röder, Mandy; Fingerle, Michael

2016-12-15

Empathy and prosocial behaviour are crucial factors for children's positive social adjustment. Contemporary models of empathy highlight the capacity to regulate vicariously experienced emotions as a precursor to empathy-related responses (e.g., prosocial behaviour). The goal of this study was to examine the role of emotion regulation (ER) in situational empathy-related responding and prosocial behaviour. A sample of 157 children (76 boys and 81 girls; M age = 9.94 years) participated in a two-tiered interview procedure that utilised vignettes to assess empathy and prosocial behaviour. Between both phases of the interview, a negative affect was induced to investigate the influence of ER on the change between the two phases. Results from a latent change model showed that ER strategies positively predicted change scores, that is, children with higher abilities to regulate emotions showed a higher increase in empathy and prosocial behaviour. Implications for the promotion of social-emotional learning in school are discussed. © 2016 International Union of Psychological Science.

The role of feedback and social presence in an online peer coaching program for student teachers

NARCIS (Netherlands)

Thurlings, M.C.G.; Vermeulen, M.; Bastiaens, T.J.; Stijnen, P.J.J.

2014-01-01

Feedback is essential in any kind of learning. This study focused on feedback in online learning and conceptualized feedback as a social interaction process. Online learning rests on social interaction, which is affected by feelings of social presence. Therefore, we investigated received and

The role of feedback and social presence in an online peer coaching program for student teachers

NARCIS (Netherlands)

Thurlings, Marieke; Vermeulen, Marjan; Bastiaens, Theo; Stijnen, Sjef

2018-01-01

Feedback is essential in any kind of learning. This study focused on feedback in online learning and conceptualized feedback as a social interaction process. Online learning rests on social interaction, which is affected by feelings of social presence. Therefore, we investigated received and

Task-role-based Access Control Model in Smart Health-care System

OpenAIRE

Wang Peng; Jiang Lingyun

2015-01-01

As the development of computer science and smart health-care technology, there is a trend for patients to enjoy medical care at home. Taking enormous users in the Smart Health-care System into consideration, access control is an important issue. Traditional access control models, discretionary access control, mandatory access control, and role-based access control, do not properly reflect the characteristics of Smart Health-care System. This paper proposes an advanced access control model for...

Modelling cholera epidemics: the role of waterways, human mobility and sanitation

OpenAIRE

Mari, L.; Bertuzzo, E.; Righetto, L.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

2011-01-01

We investigate the role of human mobility as a driver for long-range spreading of cholera infections, which primarily propagate through hydrologically controlled ecological corridors. Our aim is to build a spatially explicit model of a disease epidemic, which is relevant to both social and scientific issues. We present a two-layer network model that accounts for the interplay between epidemiological dynamics, hydrological transport and long-distance dissemination of the pathogen Vibrio choler...

Investigation of actinides speciation within the presence of ligands of interest for decorporation

International Nuclear Information System (INIS)

Bonin, L.

2008-01-01

Data about the behaviour of actinides in biological media are required in order to investigate their decorporation. Those data are obtained through in vivo experiments and the study of chemical speciation of actinides within the presence of biological constituents. A part of this work consists in the development of a method leading to the determination of the speciation of actinides at the oxidation state +IV within the presence of a complexing species, as well as its structure. The method was applied to two types of ligands: 1) a constituent of blood plasma: the citrate anion. The various complexes formed were investigated and their formation constants were quantified. The coordination mode of the ligand was then clarified through a structural study of the complexes, underlining the role of only one carboxylic site and of the alcohol function. 2) chelating agents used for decorporation. The formation constants of complexes of An(IV) with NTA and DTPA were determined. The coordination number of the metallic cation in those complexes as well as the role of the nitrogen atom were proved. Lastly, the behaviour of Pu(IV) within the presence of LIHOPO was investigated. This chelating agent, more efficient than DTPA in the case of in vivo decorporation of Np, forms very stable complexes with the metallic cation. One of those complexes can be assumed to present a stoichiometry 2:3. (author)

Probability Models Based on Soil Properties for Predicting Presence-Absence of Pythium in Soybean Roots.

Science.gov (United States)

Zitnick-Anderson, Kimberly K; Norland, Jack E; Del Río Mendoza, Luis E; Fortuna, Ann-Marie; Nelson, Berlin D

2017-10-01

Associations between soil properties and Pythium groups on soybean roots were investigated in 83 commercial soybean fields in North Dakota. A data set containing 2877 isolates of Pythium which included 26 known spp. and 1 unknown spp. and 13 soil properties from each field were analyzed. A Pearson correlation analysis was performed with all soil properties to observe any significant correlation between properties. Hierarchical clustering, indicator spp., and multi-response permutation procedures were used to identify groups of Pythium. Logistic regression analysis using stepwise selection was employed to calculate probability models for presence of groups based on soil properties. Three major Pythium groups were identified and three soil properties were associated with these groups. Group 1, characterized by P. ultimum, was associated with zinc levels; as zinc increased, the probability of group 1 being present increased (α = 0.05). Pythium group 2, characterized by Pythium kashmirense and an unknown Pythium sp., was associated with cation exchange capacity (CEC) (α < 0.05); as CEC increased, these spp. increased. Group 3, characterized by Pythium heterothallicum and Pythium irregulare, were associated with CEC and calcium carbonate exchange (CCE); as CCE increased and CEC decreased, these spp. increased (α = 0.05). The regression models may have value in predicting pathogenic Pythium spp. in soybean fields in North Dakota and adjacent states.

'Presence' of the past in the presence (Hans Ulrich Gumbrecht, Eelco Runia)

NARCIS (Netherlands)

ter Schure, L

2006-01-01

In recent writings historian Eelco Runia (Groningen) and literary theorist Hans Ulrich Gumbrecht (Stanford) have introduced the notion of presence, a new and promising way of thinking about history. Although there are differences between the two authors, both think of presence as the antithesis of

The Power of Presence Unlock Your Potential to Influence and Engage Others

CERN Document Server

HEDGES, Kristi

2011-01-01

Everyone recognizes leaders with ôpresence.ö They stand out for their seemingly innate ability to command attention and inspire commitment. But what is this secret quality they exude, exactly? Executive and CEO coach Kristi Hedges demystifies this elusive trait, revealing that presence is the intersection of outward influencing skills and internal mental conditioning. Using her I-Presence model, the author shows how anyoneùregardless of position or personalityùcan strengthen their impact. Readers will learn how to build trust as the foundation for leadership, eschew perfectionism for authentic

CENTRAL EUROPE: Role models

Energy Technology Data Exchange (ETDEWEB)

Anon.

1993-12-15

Hungary is one of the newcomers to the CERN fold, having joined in 1992. The country's contributions are naturally in line with its slender resources and are not as immediately visible as those of the major Western European Member States. However the approach used and its consequent successes provide a good role model for a smaller nation in an international research environment. This was reflected on 24 September at a meeting of the European Committee for Future Accelerators (ECFA) convened in Budapest, continuing an ECFA tradition of holding meetings in national centres to learn more about the physics programmes of different countries. This tradition started with visits to major West European Centres, but last year ECFA held a meeting in Warsaw, its first in a central European country. By far the largest Hungarian population centre, Budapest is also a hub for national research in this sector, with university centres and the KFKI Research Institute for Particle and Nuclear Physics of the National Academy of Sciences. However important research work is also carried out in the eastern city of Debrecen. Hungarians look back to the classic investigations of Eotvos early this century as the starting point of their national tradition in fundamental physics. (In the mid-80s, these experiments briefly came back into vogue when there was a suggestion of an additional 'fifth force' contribution to nuclear masses.)

Association of ficolin-3 with abdominal aortic aneurysm presence and progression

DEFF Research Database (Denmark)

Fernandez-García, C-E; Burillo, E; Lindholt, J S

2017-01-01

Essentials Abdominal aortic aneurysm (AAA) is asymptomatic and its evolution unpredictable. To find novel potential biomarkers of AAA, microvesicles are an excellent source of biomarkers. Ficolin-3 is increased in microvesicles obtained from activated platelets and AAA tissue. Increased ficolin-3...... plasma levels are associated with AAA presence and progression. SUMMARY: Background Abdominal aortic aneurysm (AAA) patients are usually asymptomatic and AAA evolution is unpredictable. Ficolin-3, mainly synthesized by the liver, is a molecule of the lectin complement-activation pathway involved in AAA...... pathophysiology. Objectives To define extra-hepatic sources of ficolin-3 in AAA and investigate the role of ficolin-3 as a biomarker of the presence and progression of AAA. Methods Microvesicles (exosomes and microparticles) were isolated from culture-conditioned medium of ADP-activated platelets, as well as from...

Increasing women's aspirations and achievement in science: The effect of role models on implicit cognitions

Science.gov (United States)

Phelan, Julie E.

This research investigated the role of implicit science beliefs in the gender gap in science aspirations and achievement, with the goal of testing identification with a female role model as a potential intervention strategy for increasing women's representation in science careers. At Time 1, women's implicit science stereotyping (i.e., associating men more than women with science) was linked to more negative (implicit and explicit) attitudes towards science and less identification with science. For men, stereotypes were either non-significantly or positively related to science attitudes and identification. Time 2 examined the influence of implicit and explicit science cognitions on students' science aspirations and achievement, and found that implicit stereotyping, attitudes, and identification were all unique predictors of science aspirations, but not achievement. Of more importance, Time 2 examined the influence of science role models, and found that identification with a role model of either gender reduced women's implicit science stereotyping and increased their positive attitudes toward science. Implications for decreasing the gender gap in advanced science achievement are discussed.

Concentration polarization effects on the macromolecular transport in the presence of non-uniform magnetic field: A numerical study using a lumen-wall model

Energy Technology Data Exchange (ETDEWEB)

Mohammadpourfard, M., E-mail: Mohammadpour@azaruniv.edu [Department of Mechanical Engineering, Azarbaijan Shahid Madani University, Tabriz 53751-71379 (Iran, Islamic Republic of); Aminfar, H., E-mail: hh_aminfar@tabrizu.ac.ir [Faculty of Mechanical Engineering, University of Tabriz, Tabriz (Iran, Islamic Republic of); Khajeh, K., E-mail: khajeh.k.2005@gmail.com [Faculty of Mechanical Engineering, University of Tabriz, Tabriz (Iran, Islamic Republic of)

2014-04-01

In this paper, the concentration polarization phenomena in a two dimensional tube under steady state conditions containing ferrofluid (blood and 4 vol% Fe{sub 3}O{sub 4}) is reported in the presence of non-uniform magnetic field. Lumen-wall model has been used for solving the mass transport equation. Hemodynamics parameters such as flow rate, viscosity, wall shear stress (WSS) and the macromolecules surface concentration which accumulate on the blood vessel wall, influenced the formation and progression of atherosclerosis disease. Effective parameters on the low density lipoprotein (LDL) surface concentration (LSC) such as: the wall filtration velocity, inlet Reynolds number and WSS under applied non-uniform magnetic field have been examined. Numerical solution of governing equations of the flow field have been obtained by using the single-phase model and the control volume technique. Magnetic field is generated by an electric current going through a thin and straight wire oriented perpendicular to the tube. Results show WSS in the vicinity of magnetic field source increased and LSC decreased along the wall. - Highlights: • In this paper the concentration polarization phenomena of blood flow is reported in the presence of non-uniform magnetic field. • In presence of non-uniform magnetic field LSC will decrease along the wall due to the increasing the velocity gradients near the magnetic source. • When non-uniform magnetic field intensity increases, LSC along the wall becomes lower. • Non-uniform magnetic field can affects the flow more in low Reynolds numbers.

Does leader-affective presence influence communication of creative ideas within work teams?

Science.gov (United States)

Madrid, Hector P; Totterdell, Peter; Niven, Karen

2016-09-01

Affective presence is a novel, emotion-related personality trait, supported in experimental studies, concerning the extent to which a person makes his or her interaction partners feel the same way (Eisenkraft & Elfenbein, 2010). Applying this concept to an applied teamwork context, we proposed that team-leader-affective presence would influence team members' communication of creative ideas. Multilevel modeling analysis of data from a survey study conducted with teams from a consultancy firm confirmed that team-leader-affective presence interacted with team-member creative idea generation to predict inhibition of voicing their ideas. Specifically, withholding of ideas was less likely when team members generated creative ideas and their team leader had higher positive affective presence or lower negative affective presence. These findings contribute to emotion research by showing affective presence as a trait with interpersonal meaning, which can shape how cognition is translated into social behavior in applied performance contexts, such as teamwork in organizations. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Performative Pedagogy and the Creation of Desire: The Indigenous Athlete/Role Model and Implications for Learning

Science.gov (United States)

Coram, Stella

2007-01-01

The athlete role model has emerged as the new pastor invested with the task of leading young people classed "at-risk" from entering into self-destructive pathways. The logic invested in the athlete role model is that young people identify with their sporting heroes and in the process try to emulate them. This holds for the major sporting…

Presence of antiseptic resistance genes in porcine methicillin-resistant Staphylococcus aureus.

Science.gov (United States)

Wong, T Z; Zhang, M; O'Donoghue, M; Boost, M

2013-03-23

Numerous studies have documented the presence of methicillin-resistant Staphylococcus aureus (MRSA) in meat-producing animals, which has led to concern about its spread into the community. Disinfectants play an important role in reduction of contamination in both animal husbandry and food-preparation, helping control spread of organisms from foodstuffs, including raw meat. Plasmid-borne antiseptic resistance (AR) genes increasing tolerance to several disinfectants have been reported in S. aureus of human origin (qacA/B and smr) and from bovine, equine, and caprine staphylococcal isolates (qacG, qacH, and qacJ). This study investigated the presence of AR genes in porcine MRSA isolates. Plasmid DNA from 100 MRSA ST9 strains isolated from pig carcasses was amplified for the presence of AR genes. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) to benzalkonium chloride (BC) and chlorhexidine gluconate (CHX) were determined in AR gene-positive isolates. qacG was present in 45 strains, eight of which also harbored smr. No strains carried qacA/B, qacH or qacJ. Presence of smr increased MICs to both BC and CHX and MBCs of CHX, but qacG presence only resulted in elevated MBC for CHX. This is the first report of AR genes from a porcine source. AR gene positivity has previously been associated with methicillin resistance and AR gene presence in these strains may increase their ability to persist in the environment. Improved implementation of hygiene measures during transportation and pre- and post-slaughter should be considered to prevent spread in the community. Copyright © 2012 Elsevier B.V. All rights reserved.

Mechanism of alkylation of isobutane by olefins in the presence of sulfuric acid

Energy Technology Data Exchange (ETDEWEB)

Baiburskii, V.L.; Khadzhiev, S.N.; Ovsyannikov, V.P.

1992-05-10

The authors attempted here to examine the mechanism of alkylation of isobutane by olefins in the presence of sulfuric acid in terms of an initial stage of activation of isoparaffin. The version of formation of tert-alkyl cations and the role of the catalyst in this stage were analyzed. 10 refs., 1 fig., 1 tab.

Effects of children on parental sex-role orientation.

Science.gov (United States)

Ganong, L H; Coleman, M

1987-09-01

The predominant theories of gender-role development have focused primarily on childhood; socialization processes for gender roles are explained from birth through adolescence. The assumption appears to be that gender roles are developed in childhood and implemented, basically unchanged, in adulthood. There is evidence, however, that gender-role self-perceptions change in adulthood. This study investigates the effects of sex of children on parental sex-role orientation. More specifically, an attempt is made to determine if the presence of sons affects sex-role self-concept of parents more than the presence of daughters. The Bem Sex Role Inventory was administered to 153 parental dyads who had daughters only (n=41), sons only (n=41), or an equal number of both sons and daughters (n=71). Sex of child, especially sons, did appear to have an effect on parents' femininity. Fathers with sons have lower femininity scores than fathers with daughters only, and mothers with sons have higher femininity scores than mothers with daughters only.

Presence of insoluble Tau following rotenone exposure ameliorates basic pathways associated with neurodegeneration

Directory of Open Access Journals (Sweden)

Rodrigo S. Chaves

2016-12-01

Full Text Available Protein aggregation is an important feature of neurodegenerative disorders. In Alzheimer's disease (AD protein aggregates are composed of hyperphosphorylated Tau and amyloid beta peptide (Aβ. Despite the involvement and identification of the molecular composition of these aggregates, their role in AD pathophysiology is not fully understood. However, depositions of these insoluble aggregates are typically reported as pathogenic and toxic for cell homeostasis. New evidences suggest that the deposition of these aggregates is a protective mechanism that preserves cell from toxic insults associated with the early stages of neurodegenerative diseases. To better understand the biological role of the protein aggregation with regard its effects in cellular homeostasis, the present study investigated the role of insoluble Tau and Tau aggregates on crucial cellular parameters such as redox homeostasis, proteasome activity and autophagy in hippocampal cell cultures and hippocampus of aged Lewis rats using a rotenone-induced aggregation model. Neurons were exposed to rotenone in different concentrations and exposure times aiming to determine the interval required for Tau aggregation. Our experimental design allowed us to demonstrate that rotenone exposure induces Tau hyperphosphorylation and aggregation in a concentration and time-dependent manner. Oxidative stress triggered by rotenone exposure was observed with the absence of Tau aggregates and was reduced or absent when Tau aggregates were present. This reduction of oxidative stress along with the presence of insoluble Tau was independent of alterations in antioxidant enzymes activities or cell death. In addition, rotenone induced oxidative stress was mainly associated with decrease in proteasome activity and autophagy flux. Conversely, when insoluble Tau appeared, autophagy turns to be overactivated while proteasome activity remained low. Our studies significantly advance the understanding that Tau

Human presence diminishes the importance of climate in driving fire activity across the United States

Science.gov (United States)

Syphard, Alexandra D.; Keeley, Jon E.; Pfaff, Anne Hopkins; Ferschweiler, Ken

2017-01-01

Growing human and ecological costs due to increasing wildfire are an urgent concern in policy and management, particularly given projections of worsening fire conditions under climate change. Thus, understanding the relationship between climatic variation and fire activity is a critically important scientific question. Different factors limit fire behavior in different places and times, but most fire-climate analyses are conducted across broad spatial extents that mask geographical variation. This could result in overly broad or inappropriate management and policy decisions that neglect to account for regionally specific or other important factors driving fire activity. We developed statistical models relating seasonal temperature and precipitation variables to historical annual fire activity for 37 different regions across the continental United States and asked whether and how fire-climate relationships vary geographically, and why climate is more important in some regions than in others. Climatic variation played a significant role in explaining annual fire activity in some regions, but the relative importance of seasonal temperature or precipitation, in addition to the overall importance of climate, varied substantially depending on geographical context. Human presence was the primary reason that climate explained less fire activity in some regions than in others. That is, where human presence was more prominent, climate was less important. This means that humans may not only influence fire regimes but their presence can actually override, or swamp out, the effect of climate. Thus, geographical context as well as human influence should be considered alongside climate in national wildfire policy and management.

Shared presence in physician-patient communication: A graphic representation.

Science.gov (United States)

Ventres, William B; Frankel, Richard M

2015-09-01

Shared presence is a state of being in which physicians and patients enter into a deep sense of trust, respect, and knowing that facilitates healing. Communication between physicians and patients (and, in fact, all providers and recipients of health care) is the medium through which shared presence occurs, regardless of the presenting problem, time available, location of care, or clinical history of the patient. Conceptualizing how communication leads to shared presence has been a challenging task, however. Pathways of this process have been routinely lumped together as the biopsychosocial model or patient, person, and relationship-centered care--all deceptive in their simplicity but, in fact, highly complex--or reduced to descriptive explications of one constituent element (e.g., empathy). In this article, we reconcile these pathways and elements by presenting a graphic image for clinicians and teachers in medical education. This conceptual image serves as a framework to synthesize the vast literature on physician-patient communication. We place shared presence, the fundamental characteristic of effective clinical communication, at the center of our figure. Around this focal point, we locate four elemental factors that either contribute to or result from shared presence, including interpersonal skills, relational contexts, actions in clinical encounters, and healing outcomes. By visually presenting various known and emergent theories of physician-patient communication, outlining the flow of successful encounters between physicians and patients, and noting how such encounters can improve outcomes, physicians, other health care professionals, and medical educators can better grasp the complexity, richness, and potential for achieving shared presence with their patients. (c) 2015 APA, all rights reserved).

PARTICIPATION OF TLR4 IN ENGULFMENT OF ESCHERICHIA COLI BY HUMAN BLOOD NEUTROPHILS IN PRESENCE OF LIPOPOLYSACCHARIDES

Directory of Open Access Journals (Sweden)

S. V. Zubova

2012-01-01

Full Text Available Abstract. TLR4 is a key player in signaling system of host cells. Possible role of TLR4 is actively discussed, e.g. its significance for phagocytosis. A capacity of neutrophils to engulf FITC-labeled E. coli bacteria upon activation with LPS of different origin was studied in presence of anti-TLR4 Mab’s (HTA125 clone. It was shown that, in whole blood, TLR4 does not play any essential role in engulfment of bacteria by the neutrophils. Phagocytic activity of neutrophils in blood increases increased after their priming with E. coli endotoxins. LPS from Rb. сapsulatus did not affect phagocytosis. In presence of endotoxins, the degree of TLR4 involvement in neutrophil phagocytosis depends on LPS structure.

The explicit treatment of model uncertainties in the presence of aleatory and epistemic parameter uncertainties in risk and reliability analysis

International Nuclear Information System (INIS)

Ahn, Kwang Il; Yang, Joon Eon

2003-01-01

In the risk and reliability analysis of complex technological systems, the primary concern of formal uncertainty analysis is to understand why uncertainties arise, and to evaluate how they impact the results of the analysis. In recent times, many of the uncertainty analyses have focused on parameters of the risk and reliability analysis models, whose values are uncertain in an aleatory or an epistemic way. As the field of parametric uncertainty analysis matures, however, more attention is being paid to the explicit treatment of uncertainties that are addressed in the predictive model itself as well as the accuracy of the predictive model. The essential steps for evaluating impacts of these model uncertainties in the presence of parameter uncertainties are to determine rigorously various sources of uncertainties to be addressed in an underlying model itself and in turn model parameters, based on our state-of-knowledge and relevant evidence. Answering clearly the question of how to characterize and treat explicitly the forgoing different sources of uncertainty is particularly important for practical aspects such as risk and reliability optimization of systems as well as more transparent risk information and decision-making under various uncertainties. The main purpose of this paper is to provide practical guidance for quantitatively treating various model uncertainties that would often be encountered in the risk and reliability modeling process of complex technological systems

The role of initial values in nonstationary fractional time series models

DEFF Research Database (Denmark)

Johansen, Søren; Nielsen, Morten Ørregaard

We consider the nonstationary fractional model $\\Delta^{d}X_{t}=\\varepsilon _{t}$ with $\\varepsilon_{t}$ i.i.d.$(0,\\sigma^{2})$ and $d>1/2$. We derive an analytical expression for the main term of the asymptotic bias of the maximum likelihood estimator of $d$ conditional on initial values, and we...... discuss the role of the initial values for the bias. The results are partially extended to other fractional models, and three different applications of the theoretical results are given....

Female role models in physics education in Ireland

Science.gov (United States)

Chormaic, Síle Nic; Fee, Sandra; Tobin, Laura; Hennessy, Tara

2013-03-01

In this paper we consider the statistics on undergraduate student representation in Irish universities and look at student numbers in secondary (high) schools in one region in Ireland. There seems to be no significant change in female participation in physics from 2002 to 2011. Additionally, we have studied the influence of an educator's gender on the prevalence of girls studying physics in secondary schools in Co. Louth, Ireland, and at the postgraduate level in Irish universities. It would appear that strong female role models have a positive influence and lead to an increase in girls' participation in physics.

Modeling data for pancreatitis in presence of a duodenal diverticula using logistic regression

Science.gov (United States)

Dineva, S.; Prodanova, K.; Mlachkova, D.

2013-12-01

The presence of a periampullary duodenal diverticulum (PDD) is often observed during upper digestive tract barium meal studies and endoscopic retrograde cholangiopancreatography (ERCP). A few papers reported that the diverticulum had something to do with the incidence of pancreatitis. The aim of this study is to investigate if the presence of duodenal diverticula predisposes to the development of a pancreatic disease. A total 3966 patients who had undergone ERCP were studied retrospectively. They were divided into 2 groups-with and without PDD. Patients with a duodenal diverticula had a higher rate of acute pancreatitis. The duodenal diverticula is a risk factor for acute idiopathic pancreatitis. A multiple logistic regression to obtain adjusted estimate of odds and to identify if a PDD is a predictor of acute or chronic pancreatitis was performed. The software package STATISTICA 10.0 was used for analyzing the real data.

CENTRAL EUROPE: Role models

International Nuclear Information System (INIS)

Anon.

1993-01-01

Hungary is one of the newcomers to the CERN fold, having joined in 1992. The country's contributions are naturally in line with its slender resources and are not as immediately visible as those of the major Western European Member States. However the approach used and its consequent successes provide a good role model for a smaller nation in an international research environment. This was reflected on 24 September at a meeting of the European Committee for Future Accelerators (ECFA) convened in Budapest, continuing an ECFA tradition of holding meetings in national centres to learn more about the physics programmes of different countries. This tradition started with visits to major West European Centres, but last year ECFA held a meeting in Warsaw, its first in a central European country. By far the largest Hungarian population centre, Budapest is also a hub for national research in this sector, with university centres and the KFKI Research Institute for Particle and Nuclear Physics of the National Academy of Sciences. However important research work is also carried out in the eastern city of Debrecen. Hungarians look back to the classic investigations of Eotvos early this century as the starting point of their national tradition in fundamental physics. (In the mid-80s, these experiments briefly came back into vogue when there was a suggestion of an additional 'fifth force' contribution to nuclear masses.)

Linear support vector regression and partial least squares chemometric models for determination of Hydrochlorothiazide and Benazepril hydrochloride in presence of related impurities: A comparative study

Science.gov (United States)

Naguib, Ibrahim A.; Abdelaleem, Eglal A.; Draz, Mohammed E.; Zaazaa, Hala E.

2014-09-01

Partial least squares regression (PLSR) and support vector regression (SVR) are two popular chemometric models that are being subjected to a comparative study in the presented work. The comparison shows their characteristics via applying them to analyze Hydrochlorothiazide (HCZ) and Benazepril hydrochloride (BZ) in presence of HCZ impurities; Chlorothiazide (CT) and Salamide (DSA) as a case study. The analysis results prove to be valid for analysis of the two active ingredients in raw materials and pharmaceutical dosage form through handling UV spectral data in range (220-350 nm). For proper analysis a 4 factor 4 level experimental design was established resulting in a training set consisting of 16 mixtures containing different ratios of interfering species. An independent test set consisting of 8 mixtures was used to validate the prediction ability of the suggested models. The results presented indicate the ability of mentioned multivariate calibration models to analyze HCZ and BZ in presence of HCZ impurities CT and DSA with high selectivity and accuracy of mean percentage recoveries of (101.01 ± 0.80) and (100.01 ± 0.87) for HCZ and BZ respectively using PLSR model and of (99.78 ± 0.80) and (99.85 ± 1.08) for HCZ and BZ respectively using SVR model. The analysis results of the dosage form were statistically compared to the reference HPLC method with no significant differences regarding accuracy and precision. SVR model gives more accurate results compared to PLSR model and show high generalization ability, however, PLSR still keeps the advantage of being fast to optimize and implement.

PENGEMBANGAN MODEL KOLABORASI JIGSAW ROLE PLAYING SEBAGAI UPAYA PENINGKATAN KEMAMPUAN BEKERJASAMA SISWA KELAS V SD PADA PELAJARAN IPS

Directory of Open Access Journals (Sweden)

Ika Ari Pratiwi

2015-11-01

Full Text Available Penelitian bertujuan untuk mengembangkan model kolaborasi jigsaw, role playing untuk meningkatkan kemampuan bekerjasama siswa yang valid, efektif dan praktis. Metode penelitian adalah penelitian dan pengembangan (R&D. Tahap uji coba pengembangan terdiri atas uji coba ahli, uji coba skala terbatas dan uji coba skala luas. Keefektifan model kolaborasi jigsaw role playing  diperoleh rata-rata 51,83 dalam kategori baik diterapkan dalam pelajaran IPS, peningkatan kemampuan bekerjasama siswa hasil N-gain = 0,56 dengan kategori sedang, peningkatan hasil belajar IPS N-gain = 0,50 dengan kategori sedang dan hasil ketuntasan klasikal pembelajaran IPS 97,14%.  Hasil respon guru dan siswa terhadap model yang digunakan adalah berkriteria baik. Model final penelitian ini menghasilkan model kolaborasi jigsaw role playing yang dikemas dalam suatu buku pedoman.

Smectite clays in Mars soil - Evidence for their presence and role in Viking biology experimental results

Science.gov (United States)

Banin, A.; Rishpon, J.

1979-01-01

Evidence for the presence of smectite clays in Martian soils is reviewed and results of experiments with certain active clays simulating the Viking biology experiments are reported. Analyses of Martian soil composition by means of X-ray fluorescence spectrometry and dust storm spectroscopy and Martian geological history strongly suggest the presence of a mixture of weathered ferro-silicate minerals, mainly nontronite and montmorillonite, accompanied by soluble sulphate salts, as major constituents. Samples of montmorillonite and nontronite incubated with (C-14)-formate or the radioactive nutrient medium solution used in the Viking Labeled Release experiment, were found to produce patterns of release of radioactive gas very similar to those observed in the Viking experiments, indicating the iron-catalyzed decomposition of formate as the reaction responsible for the Viking results. The experimental results of Hubbard (1979) simulating the results of the Viking Pyrolytic Release experiment using iron montmorillonites are pointed out, and it is concluded that many of the results of the Viking biology experiments can be explained in terms of the surface activity of smectite clays in catalysis and adsorption.

"We Don't Need Another Hero:" Heroes and Role Models in Germany and Israel

Science.gov (United States)

Yair, Gad; Girsh, Yaron; Alayan, Samira; Hues, Henning; Or, Elad

2014-01-01

This study provides insights about attitudes toward heroes and role models in Germany and Israel. We expected German and Israeli school textbooks and teachers to provide varying renditions for the traumatic effects of World War II and the Holocaust, and for students to express different attitudes about the role of heroes in their lives. In…

Understanding the Role of Chemokines and Cytokines in Experimental Models of Herpes Simplex Keratitis

Directory of Open Access Journals (Sweden)

Tayaba N. Azher

2017-01-01

Full Text Available Herpes simplex keratitis is a disease of the cornea caused by HSV-1. It is a leading cause of corneal blindness in the world. Underlying molecular mechanism is still unknown, but experimental models have helped give a better understanding of the underlying molecular pathology. Cytokines and chemokines are small proteins released by cells that play an important proinflammatory or anti-inflammatory role in modulating the disease process. Cytokines such as IL-17, IL-6, IL-1α, and IFN-γ and chemokines such as MIP-2, MCP-1, MIP-1α, and MIP-1β have proinflammatory role in the destruction caused by HSV including neutrophil infiltration and corneal inflammation, and other chemokines and cytokines such as IL-10 and CCL3 can have a protective role. Most of the damage results from neutrophil infiltration and neovascularization. While many more studies are needed to better understand the role of these molecules in both experimental models and human corneas, current studies indicate that these molecules hold potential to be targets of future therapy.

A Technology-Neutral Role-Based Collaboration Model for Software Ecosystems

DEFF Research Database (Denmark)

Stanciulescu, Stefan; Rabiser, Daniela; Seidl, Christoph

2016-01-01

by contributing a role-based collaboration model for software ecosystems to make such implicit similarities explicit and to raise awareness among developers during their ongoing efforts. We extract this model based on realization artifacts in a specific programming language located in a particular source code......In large-scale software ecosystems, many developers contribute extensions to a common software platform. Due to the independent development efforts and the lack of a central steering mechanism, similar functionality may be developed multiple times by different developers. We tackle this problem...... efforts and information of ongoing development efforts. Finally, using the collaborations defined in the formalism we model real artifacts from Marlin, a firmware for 3D printers, and we show that for the selected scenarios, the five collaborations were sufficient to raise awareness and make implicit...

The Role of Economic Strain on Adolescent Delinquency: A Microsocial Process Model

OpenAIRE

Low, Sabina; Sinclair, Ryan; Shortt, Joann Wu

2012-01-01

The current study examines the role of economic strain as a moderator of the microsocial processes influencing younger siblings’ delinquency (externalizing behavior and substance use) in a longitudinal design. The younger siblings (122 younger brothers and 122 younger sisters) were from 244 families with same-sex biological siblings. Structural equation modeling was utilized to examine a process model whereby mothers’ harsh/inconsistent parenting and older sibling delinquency influence younge...

Frequent occurrence of mitochondrial DNA mutations in Barrett's metaplasia without the presence of dysplasia.

Directory of Open Access Journals (Sweden)

Soong Lee

Full Text Available BACKGROUND: Barrett's esophagus (BE is one of the most common premalignant lesions and can progress to esophageal adenocarcinoma (EA. The numerous molecular events may play a role in the neoplastic transformation of Barrett's mucosa such as the change of DNA ploidy, p53 mutation and alteration of adhesion molecules. However, the molecular mechanism of the progression of BE to EA remains unclear and most studies of mitochondrial DNA (mtDNA mutations in BE have performed on BE with the presence of dysplasia. METHODS/FINDINGS: Thus, the current study is to investigate new molecular events (Barrett's esophageal tissue-specific-mtDNA alterations/instabilities in mitochondrial genome and causative factors for their alterations using the corresponding adjacent normal mucosal tissue (NT and tissue (BT from 34 patients having Barrett's metaplasia without the presence of dysplasia. Eighteen patients (53% exhibited mtDNA mutations which were not found in adjacent NT. mtDNA copy number was about 3 times higher in BT than in adjacent NT. The activity of the mitochondrial respiratory chain enzyme complexes in tissues from Barrett's metaplasia without the presence of dysplasia was impaired. Reactive oxygen species (ROS level in BT was significantly higher than those in corresponding samples. CONCLUSION/SIGNIFICANCE: High ROS level in BT may contribute to the development of mtDNA mutations, which may play a crucial role in disease progression and tumorigenesis in BE.

The role of economic strain on adolescent delinquency: a microsocial process model.

Science.gov (United States)

Low, Sabina; Sinclair, Ryan; Shortt, Joann Wu

2012-08-01

The current study examines the role of economic strain as a moderator of the microsocial processes influencing younger siblings' delinquency (externalizing behavior and substance use) in a longitudinal design. The younger siblings (122 younger brothers and 122 younger sisters) were from 244 families with same-sex biological siblings. Structural equation modeling was utilized to examine a process model whereby mothers' harsh/inconsistent parenting and older sibling delinquency influence younger siblings' delinquent behavior via sibling aggression and delinquent peer affiliation. Findings suggest that indirect mechanisms vary as a function of economic strain, with sibling aggression having a stronger, more detrimental effect on adolescent delinquency in economically strained families. Data suggest that familial economic conditions contextualize the relative roles of parenting, sibling, and peer processes in the transmission of risk to adolescent delinquency. PsycINFO Database Record (c) 2012 APA, all rights reserved.

A role for interleukins in ochronosis in a chondrocyte in vitro model of alkaptonuria.

Science.gov (United States)

Mistry, J B; Jackson, D J; Bukhari, M; Taylor, A M

2016-07-01

Alkaptonuria is a rare autosomal recessive condition resulting from inability to breakdown homogentisic acid (HGA), an intermediate in tyrosine degradation. The condition has a triad of clinical features, the most damaging of which is ochronotic osteoarthropathy. HGA is elevated from birth, but pigmentation takes many years. We hypothesise that interleukins play a role in initiation and progression of ochronotic osteoarthropathy. C20/A4 cells were cultured and maintained in 9-cm petri dishes containing either HGA at 0.33 mM, a single interleukin (IL-1β, IL-6 or IL-10) at 1 ng/ml or a combination of HGA and a single interleukin. Statistical analysis of pigment deposits and cell viability was performed using analysis of variance with Newman-Keuls post-test. All cultures containing HGA showed a significant increase in pigment deposition compared to control and IL cultures alone. The cultures containing HGA and IL-6 showed a significant increase in pigment deposits compared to HGA alone. The cell viability counts across all cultures on day 10 demonstrated a significant decrease in cultures containing HGA compared to those which did not. There was no significant difference between cultures containing just HGA or those combined with an interleukin. This work demonstrates a role for cytokines present in the joint(s) in the pigmentation process, particularly IL-6, and that the presence of HGA in joint tissues appears more detrimental to chondrocytes than the presence of any of the interleukins found in response to joint injury, trauma and osteoarthritis (OA). This further supports the evidence that the arthropathy in alkaptonuria is much more severe and rapidly progressing.

Role of frameworks, models, data, and judgment in human reliability analysis

Energy Technology Data Exchange (ETDEWEB)

Hannaman, G W

1986-05-01

Many advancements in the methods for treating human interactions in PRA studies have occurred in the last decade. These advancements appear to increase the capability of PRAs to extend beyond just the assessment of the human's importance to safety. However, variations in the application of these advanced models, data, and judgements in recent PRAs make quantitative comparisons among studies extremely difficult. This uncertainty in the analysis diminishes the usefulness of the PRA study for upgrading procedures, enhancing traning, simulator design, technical specification guidance, and for aid in designing the man-machine interface. Hence, there is a need for a framework to guide analysts in incorporating human interactions into the PRA systems analyses so that future users of a PRA study will have a clear understanding of the approaches, models, data, and assumptions which were employed in the initial study. This paper describes the role of the systematic human action reliability procedure (SHARP) in providing a road map through the complex terrain of human reliability that promises to improve the reproducibility of such analysis in the areas of selecting the models, data, representations, and assumptions. Also described is the role that a human cognitive reliability model can have in collecting data from simulators and helping analysts assign human reliability parameters in a PRA study. Use of these systematic approaches to perform or upgrade existing PRAs promises to make PRA studies more useful as risk management tools.

Modeling metal binding to soils: the role of natural organic matter.

Science.gov (United States)

Gustafsson, Jon Petter; Pechová, Pavlina; Berggren, Dan

2003-06-15

The use of mechanistically based models to simulate the solution concentrations of heavy metals in soils is complicated by the presence of different sorbents that may bind metals. In this study, the binding of Zn, Pb, Cu, and Cd by 14 different Swedish soil samples was investigated. For 10 of the soils, it was found that the Stockholm Humic Model (SHM) was able to describe the acid-base characteristics, when using the concentrations of "active" humic substances and Al as fitting parameters. Two additional soils could be modeled when ion exchange to clay was also considered, using a component additivity approach. For dissolved Zn, Cd, Ca, and Mg reasonable model fits were produced when the metal-humic complexation parameters were identical for the 12 soils modeled. However, poor fits were obtained for Pb and Cu in Aquept B horizons. In two of the soil suspensions, the Lund A and Romfartuna Bhs, the calculated speciation agreed well with results obtained by using cation-exchange membranes. The results suggest that organic matter is an important sorbent for metals in many surface horizons of soils in temperate and boreal climates, and the necessity of properly accounting for the competition from Al in simulations of dissolved metal concentrations is stressed.

Role of equipotential and equidensity surfaces for constructing models of galaxies

International Nuclear Information System (INIS)

Kutuzov, S.A.; Osipkov, L.P.

1987-01-01

The role played by the specification of the equipotential surfaces and equidensity surfaces in the general problem of constructing models of galaxies is examined. If the equipotential surfaces are specified, Poisson's equation makes it possible to find the spatial density from the circular velocity. The problem of determining the potential and the spatial density from the equatorial density is considered. If equidensity surfaces are specified, then the kernel of the integral equation that relates the density to the circular velocity can be determined. The corresponding expressions for known models are obtained

What role can simulation model predictions play in environmental decisions: carbon dioxide as an example

International Nuclear Information System (INIS)

Emanuel, W.R.

1979-01-01

Frequently, when an environmental issue requiring quantitative analysis surfaces, the development of a model synthesizing all aspects of the problem and applicable at each stage of the decision process is proposed. A more desirable alternative is to generate models specifically designed to meet the requirements of each level in decision making and which can be adapted in response to the changing status of the environmental issue. Various models of the global carbon cycle constructed to predict levels of CO 2 in the atmosphere as a result of man's activities are described to illustrate this point. In summary, the progression of models developed to analyze the global carbon cycle in resolving the CO 2 /climate issue indicates the changing character of models depending on the immediate role they play in environmental decision making. The dominant and successful role served by models in the carbon cycle problem points to the desirability of this flexible approach

A modified model of pharmacists' job stress: the role of organizational, extra-role, and individual factors on work-related outcomes.

Science.gov (United States)

Gaither, Caroline A; Kahaleh, Abir A; Doucette, William R; Mott, David A; Pederson, Craig A; Schommer, Jon C

2008-09-01

Understanding the effects of job stress continues to be a concern for health-care providers as workload and personnel needs increase. The overall objective of this study was to test a direct effects model of job stress that examines the characteristics of the organizational environment (interpersonal interactions, environmental aspects, the level of compensation and advancement, role stress, and availability of alternative jobs); extra-role factors (work-home conflict); job stress; individual factors (career commitment); and the work-related psychological outcomes of job satisfaction, organizational commitment, and job turnover intention. A cross-sectional mail survey was sent to a nationwide random sample of 4895 licensed pharmacists in the United States. Previously validated summated Likert-type scales measured each of the study variables. Data analyses included descriptive statistics, and exploratory and confirmatory factor analyses. Structural equation modeling was used to estimate the final model. A response rate of 46% was achieved. Psychometric analyses indicated acceptable reliability and validity. The study model fit the data well (CFI[comparative fit index] = 0.90, RMSEA[root mean square error of approximation] = 0.05). Organizational factors in the form of role overload (standardized beta = 0.45) and conflict (0.31) and ease of finding a job with better interpersonal characteristics (0.26) had the largest effects on job stress. Interpersonal characteristics were also one of the strongest predictors of job satisfaction (-0.61) and organizational commitment (-0.70). Work-home conflict directly affected job turnover intention (0.11) and career commitment (-0.16). Other significant, but sometimes, opposite direct effects were found. Job satisfaction and organizational commitment directly affected job turnover intention. Given the increased demand for pharmacy services, health-care organizations will benefit from increasing positive and reducing negative work

Does Leader-Affective Presence Influence Communication of Creative Ideas Within Work Teams?

OpenAIRE

Madrid, H.P.; Totterdell, P.; Niven, K.

2016-01-01

Affective presence is a novel, emotion-related personality trait, supported in experimental studies, concerning the extent to which a person makes his or her interaction partners feel the same way (Eisenkraft & Elfenbein, 2010). Applying this concept to an applied teamwork context, we proposed that team-leader-affective presence would influence team members' communication of creative ideas. Multilevel modeling analysis of data from a survey study conducted with teams from a consultancy firm c...

Role, ownership and presence of domestic animals in peri-urban households of Kisumu, Kenya.

Science.gov (United States)

Barnes, A N; Mumma, J; Cumming, O

2018-02-01

Low- and middle-income countries are experiencing rapid urban population growth, particularly in peri-urban informal settlements. In these urban areas, animal husbandry remains a valuable source of income and protein-rich foods but may also present a risk of zoonotic disease threat. To date, there have been studies that have assessed the prevalence and nature of animal ownership in these communities. This cross-sectional survey assessed the geographical, sociocultural and economic factors behind the presence, ownership and purpose of domestic animals in three informal peri-urban communities of Kisumu, Kenya. A majority (n = 587) of the study households exhibited domestic animal presence in the living space yet only 32% of households reported animal ownership (n = 252). The purposes of ownership included: for meat/eggs (55%); for income, sale or trade (43%); for milk production (31%); and as companions/pets (31%). Among households that owned animals, 76% reported that at least one animal slept in the house at night. In multivariate logistic regression, the following factors were significantly associated with household animal ownership: ownership of agricultural land (OR = 1.94, 95% CI = 1.12, 3.35), perceiving a strong community bond (OR = 2.28, 95% CI = 1.25, 4.16), and household membership in a community group (OR = 1.64, 95% CI = 1.04, 2.60). This research demonstrates the high prevalence of animal ownership in a low-income and high-density peri-urban neighbourhood of an African city, which may facilitate zoonotic disease transmission. Further research should assess if and to what extent animal ownership in such communities is associated with disease risk. © 2017 The Authors. Zoonoses and Public Health Published by Blackwell Verlag GmbH.

Factors influencing residents' evaluations of clinical faculty member teaching qualities and role model status.

Science.gov (United States)

Arah, Onyebuchi A; Heineman, Maas J; Lombarts, Kiki M J M H

2012-04-01

  Evaluations of faculty members are widely used to identify excellent or substandard teaching performance. In order to enable such evaluations to be properly interpreted and used in faculty development, it is essential to understand the factors that influence resident doctors' (residents) evaluations of the teaching qualities of faculty members and their perceptions of faculty members as role-model specialists.   We carried out a cross-sectional survey within a longitudinal study of the System for Evaluation of Teaching Qualities (SETQ) of clinical teachers. The study sample included 889 residents and 1014 faculty members in 61 teaching programmes spanning 22 specialties in 20 hospitals in the Netherlands. Main outcome measures included residents' (i) global and (ii) specific ratings of faculty member teaching qualities, and (iii) global ratings of faculty members as role-model specialists. Statistical analysis was conducted using adjusted multivariable logistic generalised estimating equations.   In total, 690 residents (77.6%) completed 6485 evaluations of 962 faculty members, 848 (83.6%) of whom also self-evaluated. More recently certified faculty members, those who had attended a teacher training programme, and those who spent more time teaching than seeing patients or conducting research were more likely to score highly on most teaching qualities. However, faculty members who had undergone teacher training were less likely to be seen as role models (odds ratio [OR] 0.72, 95% confidence interval [CI] 0.59-0.88). In addition, faculty members were evaluated slightly higher by male than female residents on core teaching domains and overall teaching quality, but were less likely to be seen as role models by male residents (OR 0.80, 95% CI 0.67-0.97). Lastly, faculty members had higher odds of receiving top scores in specific teaching domains from residents in the first 4 years of residency and were less likely to be considered as role models by more

Training presence: the importance of virtual reality experience on the "sense of being there".

Science.gov (United States)

Gamito, Pedro; Oliveira, Jorge; Morais, Diogo; Baptista, André; Santos, Nuno; Soares, Fábio; Saraiva, Tomaz; Rosa, Pedro

2010-01-01

Nature and origin of presence are still unclear. Although it can be characterized, under a neurophysiological perspective, as a process resulting from a synchrony between cognitive and perceptive systems, the multitude of associated processes reduces the chances of brain mapping presence. In this way, our study was designed in order to understand the possible role of VR experience on presence in a virtual environment. For our study, 16 participants (M=28.39 years; SD=13.44) of both genders without computer experience were selected. The study design consisted of two assessments (initial and final), where the participants were evaluated with BFI, PQ, ITQ, QC, MCSDS-SF, STAI, visual attention and behavioral measures after playing an first person shooter (FPS) game. In order to manipulate the level of VR experience the participants were trained on, a different FPS was used during the 12 weekly sessions of 30 minutes. Results revealed significant differences between the first and final assessment for presence (F(1,15)=11.583; MSE=775.538; p<01) and immersion scores (F(1,15)=6.234; MSE=204.962; p<05), indicating higher levels of presence and immersion in the final assessment. No statistical significant results were obtained for cybersickness or the behavioral measures. In summary, our results showed that training and the subsequent higher computer experience levels can increase immersion and presence.

The Role of Neutrophil Myeloperoxidase in Models of Lung Tumor Development

International Nuclear Information System (INIS)

Rymaszewski, Amy L.; Tate, Everett; Yimbesalu, Joannes P.; Gelman, Andrew E.; Jarzembowski, Jason A.; Zhang, Hao; Pritchard, Kirkwood A. Jr.; Vikis, Haris G.

2014-01-01

Chronic inflammation plays a key tumor-promoting role in lung cancer. Our previous studies in mice demonstrated that neutrophils are critical mediators of tumor promotion in methylcholanthrene (MCA)-initiated, butylated hydroxytoluene (BHT)-promoted lung carcinogenesis. In the present study we investigated the role of neutrophil myeloperoxidase (MPO) activity in this inflammation promoted model. Increased levels of MPO protein and activity were present in the lungs of mice administered BHT. Treatment of mice with N-acetyl lysyltyrosylcysteine amide (KYC), a novel tripeptide inhibitor of MPO, during the inflammatory stage reduced tumor burden. In a separate tumor model, KYC treatment of a Lewis Lung Carcinoma (LLC) tumor graft in mice had no effect on tumor growth, however, mice genetically deficient in MPO had significantly reduced LLC tumor growth. Our observations suggest that MPO catalytic activity is critical during the early stages of tumor development. However, during the later stages of tumor progression, MPO expression independent of catalytic activity appears to be required. Our studies advocate for the use of MPO inhibitors in a lung cancer prevention setting

The role of neutrophil myeloperoxidase in models of lung tumor development.

Science.gov (United States)

Rymaszewski, Amy L; Tate, Everett; Yimbesalu, Joannes P; Gelman, Andrew E; Jarzembowski, Jason A; Zhang, Hao; Pritchard, Kirkwood A; Vikis, Haris G

2014-05-09

Chronic inflammation plays a key tumor-promoting role in lung cancer. Our previous studies in mice demonstrated that neutrophils are critical mediators of tumor promotion in methylcholanthrene (MCA)-initiated, butylated hydroxytoluene (BHT)-promoted lung carcinogenesis. In the present study we investigated the role of neutrophil myeloperoxidase (MPO) activity in this inflammation promoted model. Increased levels of MPO protein and activity were present in the lungs of mice administered BHT. Treatment of mice with N-acetyl lysyltyrosylcysteine amide (KYC), a novel tripeptide inhibitor of MPO, during the inflammatory stage reduced tumor burden. In a separate tumor model, KYC treatment of a Lewis Lung Carcinoma (LLC) tumor graft in mice had no effect on tumor growth, however, mice genetically deficient in MPO had significantly reduced LLC tumor growth. Our observations suggest that MPO catalytic activity is critical during the early stages of tumor development. However, during the later stages of tumor progression, MPO expression independent of catalytic activity appears to be required. Our studies advocate for the use of MPO inhibitors in a lung cancer prevention setting.

The Role of Neutrophil Myeloperoxidase in Models of Lung Tumor Development

Energy Technology Data Exchange (ETDEWEB)

Rymaszewski, Amy L.; Tate, Everett; Yimbesalu, Joannes P. [Department of Pharmacology and Toxicology and MCW Cancer Center, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Gelman, Andrew E. [Department of Surgery, Washington University in St. Louis, St. Louis, MO 63130 (United States); Jarzembowski, Jason A. [Department of Pathology, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Zhang, Hao; Pritchard, Kirkwood A. Jr. [Department of Surgery and MCW Cancer Center, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Vikis, Haris G., E-mail: hvikis@mcw.edu [Department of Pharmacology and Toxicology and MCW Cancer Center, Medical College of Wisconsin, Milwaukee, WI 53226 (United States)

2014-05-09

Chronic inflammation plays a key tumor-promoting role in lung cancer. Our previous studies in mice demonstrated that neutrophils are critical mediators of tumor promotion in methylcholanthrene (MCA)-initiated, butylated hydroxytoluene (BHT)-promoted lung carcinogenesis. In the present study we investigated the role of neutrophil myeloperoxidase (MPO) activity in this inflammation promoted model. Increased levels of MPO protein and activity were present in the lungs of mice administered BHT. Treatment of mice with N-acetyl lysyltyrosylcysteine amide (KYC), a novel tripeptide inhibitor of MPO, during the inflammatory stage reduced tumor burden. In a separate tumor model, KYC treatment of a Lewis Lung Carcinoma (LLC) tumor graft in mice had no effect on tumor growth, however, mice genetically deficient in MPO had significantly reduced LLC tumor growth. Our observations suggest that MPO catalytic activity is critical during the early stages of tumor development. However, during the later stages of tumor progression, MPO expression independent of catalytic activity appears to be required. Our studies advocate for the use of MPO inhibitors in a lung cancer prevention setting.

The Role of Neutrophil Myeloperoxidase in Models of Lung Tumor Development

Directory of Open Access Journals (Sweden)

Amy L. Rymaszewski

2014-05-01

Full Text Available Chronic inflammation plays a key tumor-promoting role in lung cancer. Our previous studies in mice demonstrated that neutrophils are critical mediators of tumor promotion in methylcholanthrene (MCA-initiated, butylated hydroxytoluene (BHT-promoted lung carcinogenesis. In the present study we investigated the role of neutrophil myeloperoxidase (MPO activity in this inflammation promoted model. Increased levels of MPO protein and activity were present in the lungs of mice administered BHT. Treatment of mice with N-acetyl lysyltyrosylcysteine amide (KYC, a novel tripeptide inhibitor of MPO, during the inflammatory stage reduced tumor burden. In a separate tumor model, KYC treatment of a Lewis Lung Carcinoma (LLC tumor graft in mice had no effect on tumor growth, however, mice genetically deficient in MPO had significantly reduced LLC tumor growth. Our observations suggest that MPO catalytic activity is critical during the early stages of tumor development. However, during the later stages of tumor progression, MPO expression independent of catalytic activity appears to be required. Our studies advocate for the use of MPO inhibitors in a lung cancer prevention setting.

Silver release from nanocomposite Ag/alginate hydrogels in the presence of chloride ions: experimental results and mathematical modeling

Energy Technology Data Exchange (ETDEWEB)

Kostic, Danijela, E-mail: dkostic@tmf.bg.ac.rs [Innovation Center of the Faculty of Technology and Metallurgy (Serbia); Vidovic, Srđan, E-mail: srdjanhi@gmail.com; Obradovic, Bojana, E-mail: bojana@tmf.bg.ac.rs [University of Belgrade, Faculty of Technology and Metallurgy (Serbia)

2016-03-15

A stepwise experimental and mathematical modeling approach was used to assess silver release from nanocomposite Ag/alginate microbeads in wet and dried forms into water and into normal saline solution chosen as a simplified model for certain biological fluids (e.g., blood plasma, wound exudates, sweat, etc). Three phenomena were connected and mathematically described: diffusion of silver nanoparticles (AgNPs) within the alginate hydrogel, AgNP oxidation/dissolution and reaction with chloride ions, and diffusion of the resultant silver-chloride species. Mathematical modeling results agreed well with the experimental data with the AgNP diffusion coefficient estimated as 1.3 × 10{sup −18} m{sup 2} s{sup −1}, while the first-order kinetic rate constant of AgNP oxidation/dissolution and diffusivity of silver-chloride species were shown to be inversely related. In specific, rapid rehydration and swelling of dry Ag/alginate microbeads induced fast AgNP oxidation/dissolution reaction with Cl{sup −} and AgCl precipitation within the microbeads with the lowest diffusivity of silver-chloride species compared to wet microbeads in normal saline. The proposed mathematical model provided an insight into the phenomena related to silver release from nanocomposite Ca-alginate hydrogels relevant for use of antimicrobial devices and established, at the same time, a basis for further in-depth studies of AgNP interactions in hydrogels in the presence of chloride ions.

Comparing Video Modeling and Graduated Guidance Together and Video Modeling Alone for Teaching Role Playing Skills to Children with Autism

Science.gov (United States)

Akmanoglu, Nurgul; Yanardag, Mehmet; Batu, E. Sema

2014-01-01

Teaching play skills is important for children with autism. The purpose of the present study was to compare effectiveness and efficiency of providing video modeling and graduated guidance together and video modeling alone for teaching role playing skills to children with autism. The study was conducted with four students. The study was conducted…

Show us you are real: the effect of human-versus-organizational presence on online relationship building through social networking sites.

Science.gov (United States)

Park, Hyojung; Lee, Hyunmin

2013-04-01

This study examined how creating a human presence in organizational online communication affects organization-public relationships and publics' favorable behavioral intentions to engage in word-of-mouth (WOM) and dialogic communications. Four hypotheses were tested in the context of Twitter through a 2×2 (presence: human vs. organizational×organization type: nonprofit vs. for-profit) within-subjects design. The results revealed that conversational human voice was perceived to be higher for Twitter pages of organizations with a human presence than for those with an organizational presence. Providing a human presence on social media through the use of social media managers' avatars and names appeared to promote favorable organization-public relationships and positive WOM communication. However, dialogic communication intentions did not significantly differ between organizations incorporating a human presence versus an organizational presence into their Twitter pages. The proposed dynamic role of human presence versus organizational presence adds a new perspective as to how organizations can take better advantage of interpersonal aspects of social media.

Cross-sectional serosurvey of avian influenza antibodies presence in domestic ducks of Kathmandu, Nepal.

Science.gov (United States)

Karki, S; Lupiani, B; Budke, C M; Manandhar, S; Ivanek, R

2014-09-01

Kathmandu, Nepal has been classified as a high-risk area for highly pathogenic avian influenza (HPAI) by the Nepali Government. While ducks have an important role in the transmission of avian influenza viruses (AIV), including HPAI, seroprevalence of antibodies to AIV in domestic ducks of Kathmandu has never been assessed. The objectives of this study were (i) to estimate the prevalence of seroconversion to AIV in domestic ducks in major duck-raising areas of Kathmandu and (ii) to assess the effect of age, sex, presence of swine and the number of ducks on the farm on the carriage of antibodies to AIV in these ducks. From April through July of 2011, a cross-sectional study was conducted and a total of 310 ducks in the major duck-raising areas of Kathmandu were sampled. The estimated prevalence of AIV antibodies was 27.2% [95% confidence interval (CI): 24.6-29.5]. Of 62 enrolled farms, 42% had at least one seropositive duck. Half of the enrolled farms also kept pigs of which 52% had at least one seropositive duck. Bivariate analysis indicated association between ducks' seroconversion to AIV and their age, sex and farm size. However, the final multivariable model, after controlling for clustering of ducks within farms, identified age as the only significant risk factor. Based on this model, ducks older than 1 year of age were more likely to be seropositive compared to ducks ducks in the major duck-raising areas of Kathmandu and identify a high-risk group that can be targeted in surveillance activities. Future studies should be conducted to differentiate the subtypes of AIV present among domestic ducks in Kathmandu, with particular interest in the presence of HPAI viruses. © 2014 Blackwell Verlag GmbH.

Presurgical Unilateral Cleft Lip Anthropometrics and the Presence of Dental Anomalies.

Science.gov (United States)

Antonarakis, Gregory S; Fisher, David M

2015-07-01

To investigate associations between cleft lip anthropometrics and dental anomalies in the permanent dentition in unilateral cleft lip patients. Retrospective cross-sectional study. Children with unilateral clefts of the lip, with or without cleft palate. Anthropometric lip measurements, made immediately prior to lip repair, were available for each patient. The presence of dental anomalies in the permanent dentition was assessed radiographically. The presence of associations between anthropometric lip measurements and prevalence rates of different dental anomalies were determined using logistic regression analyses. In the 122 included patients, the cleft lateral lip element was deficient in height in 80% and in transverse length in 84% of patients. Patients with more deficient cleft side lateral lip height and less deficient cleft side lateral lip transverse length were more likely to present with cleft side maxillary lateral incisor agenesis. On the other hand, patients with a less deficient cleft side lateral lip height and more deficient cleft side lateral lip transverse length were more likely to present with a cleft side supernumerary maxillary lateral incisor. When looking only at incomplete clefts, the cleft side lateral lip transverse length deficiency was more predictive of the presence of supernumerary maxillary lateral incisors (P = .030), while for complete clefts, the cleft side lateral lip height deficiency was more predictive of the presence of maxillary lateral incisor agenesis (P = .035). In patients with unilateral clefts, cleft lip anthropometrics have a predictive role in determining the occurrence of dental anomalies.

Growth hormone in the presence of laminin modulates interaction of human thymic epithelial cells and thymocytes in vitro

Directory of Open Access Journals (Sweden)

Marvin Paulo Lins

Full Text Available BACKGROUND: Several evidences indicate that hormones and neuropeptides function as immunomodulators. Among these, growth hormone (GH is known to act on the thymic microenvironment, supporting its role in thymocyte differentiation. The aim of this study was to evaluate the effect of GH on human thymocytes and thymic epithelial cells (TEC in the presence of laminin. RESULTS: GH increased thymocyte adhesion on BSA-coated and further on laminin-coated surfaces. The number of migrating cells in laminin-coated membrane was higher in GH-treated thymocyte group. In both results, VLA-6 expression on thymocytes was constant. Also, treatment with GH enhanced laminin production by TEC after 24 h in culture. However, VLA-6 integrin expression on TEC remained unchanged. Finally, TEC/thymocyte co-culture model demonstrated that GH elevated absolute number of double-negative (CD4-CD8- and single-positive CD4+ and CD8+ thymocytes. A decrease in cell number was noted in double-positive (CD4+CD8+ thymocytes. CONCLUSIONS: The results of this study demonstrate that GH is capable of enhancing the migratory capacity of human thymocytes in the presence of laminin and promotes modulation of thymocyte subsets after co-culture with TEC.

Empathy for Adolescents' Role Model Selection and Learning of DVD Content

Science.gov (United States)

Calvert, Sandra L.; Strouse, Gabrielle A.; Murray, Katherine J.

2006-01-01

Male and female high school and college students viewed a DVD about a love story. Youth who more readily empathized with media characters were more likely to perceive same-sex characters as role models and were better able to understand the story content. The findings suggest that fantasy empathy, in which viewers become deeply involved in…

Chaos-assisted tunneling in the presence of Anderson localization.

Science.gov (United States)

Doggen, Elmer V H; Georgeot, Bertrand; Lemarié, Gabriel

2017-10-01

Tunneling between two classically disconnected regular regions can be strongly affected by the presence of a chaotic sea in between. This phenomenon, known as chaos-assisted tunneling, gives rise to large fluctuations of the tunneling rate. Here we study chaos-assisted tunneling in the presence of Anderson localization effects in the chaotic sea. Our results show that the standard tunneling rate distribution is strongly modified by localization, going from the Cauchy distribution in the ergodic regime to a log-normal distribution in the strongly localized case, for both a deterministic and a disordered model. We develop a single-parameter scaling description which accurately describes the numerical data. Several possible experimental implementations using cold atoms, photonic lattices, or microwave billiards are discussed.

The role of neuroticism, perfectionism and depression in chronic fatigue syndrome. A structural equation modeling approach.

Science.gov (United States)

Valero, Sergi; Sáez-Francàs, Naia; Calvo, Natalia; Alegre, José; Casas, Miquel

2013-10-01

Previous studies have reported consistent associations between Neuroticism, maladaptive perfectionism and depression with severity of fatigue in Chronic Fatigue Syndrome (CFS). Depression has been considered a mediator factor between maladaptive perfectionism and fatigue severity, but no studies have explored the role of neuroticism in a comparable theoretical framework. This study aims to examine for the first time, the role of neuroticism, maladaptive perfectionism and depression on the severity of CFS, analyzing several explanation models. A sample of 229 CFS patients were studied comparing four structural equation models, testing the role of mediation effect of depression severity in the association of Neuroticism and/or Maladaptive perfectionism on fatigue severity. The model considering depression severity as mediator factor between Neuroticism and fatigue severity is the only one of the explored models where all the structural modeling indexes have fitted satisfactorily (Chi square=27.01, p=0.079; RMSE=0.047, CFI=0.994; SRMR=0.033). Neuroticism is associated with CFS by the mediation effect of depression severity. This personality variable constitutes a more consistent factor than maladaptive perfectionism in the conceptualization of CFS severity. Copyright © 2013 Elsevier Inc. All rights reserved.

The Role of Flow Diagnostic Techniques in Fan and Open Rotor Noise Modeling

Science.gov (United States)

Envia, Edmane

2016-01-01

A principal source of turbomachinery noise is the interaction of the rotating and stationary blade rows with the perturbations in the airstream through the engine. As such, a lot of research has been devoted to the study of the turbomachinery noise generation mechanisms. This is particularly true of fan and open rotors, both of which are the major contributors to the overall noise output of modern aircraft engines. Much of the research in fan and open rotor noise has been focused on developing theoretical models for predicting their noise characteristics. These models, which run the gamut from the semi-empirical to fully computational ones, are, in one form or another, informed by the description of the unsteady flow-field in which the propulsors (i.e., the fan and open rotors) operate. Not surprisingly, the fidelity of the theoretical models is dependent, to a large extent, on capturing the nuances of the unsteady flowfield that have a direct role in the noise generation process. As such, flow diagnostic techniques have proven to be indispensible in identifying the shortcoming of theoretical models and in helping to improve them. This presentation will provide a few examples of the role of flow diagnostic techniques in assessing the fidelity and robustness of the fan and open rotor noise prediction models.

A new turbine model for enhancing convective heat transfer in the presence of low volume concentration of Ag-Oil Nanofluids

Science.gov (United States)

Jafarimoghaddam, Amin; Aberoumand, Sadegh; Jafarimoghaddam, Reza

2018-05-01

This study aims to experimentally investigate and introduce a new model for enhancing convective heat transfer in the presence of Ag/ oil nanofluid. An annular tube was designed with a turbine element attached to the inner tube. The inner tube was a bearing shaft which could rotate with the rotation of turbine element. As the previous works by authors, the setup was conducted with a fully developed laminar flow regime with the Reynolds numbers less than 160. The outer surface of the annular tube was heated by an element with constant heat flux of 204 W. Ag/ oil nanofluid was used in different volume concentrations of 0.011%, 0.044% and 0.171%. The new model could enhance the convective heat transfer coefficient up to 54% (compared to the simple annular tube in the case of base fluid) for the best studied case (nanofluid with the volume concentration of 0.171%) while the friction factor remained low. The new model can be applied for related applications regarding Ag/ oil nanofluid as a new step in enhancing the convective heat transfer coefficient.

Exploring a two-dimensional model of mentor teacher roles in mentoring dialogues

NARCIS (Netherlands)

Dr. F.J.A.J. Crasborn; Dr. Paul Hennissen; Dr. Niels Brouwer; Prof. Dr. Fred Korthagen; Prof. Dr. Theo Bergen

2011-01-01

The extent to which mentor teachers are able to address mentees' individual needs is an important factor in the success of mentoring. A two-dimensional model of mentor teacher roles in mentoring dialogues, entitled MERID, is explored empirically. Data regarding five aspects of mentoring dialogues

Exploring a two-dimensional model of mentor teacher roles in mentoring dialogues

NARCIS (Netherlands)

Crasborn, F.J.A.J.; Hennissen, P.P.M.; Brouwer, C.N.; Korthagen, F.A.J.; Bergen, T.C.M.

2011-01-01

In this study, a two-dimensional model of mentor teacher roles in mentoring dialogues, entitled MERID, is explored empirically. Data regarding five aspects of mentoring dialogues were collected, using a sample of 20 transcriptions of mentoring dialogues, in which 112 topics were discussed and 440

Modelling and simulation in nuclear safety and the role of experiment

International Nuclear Information System (INIS)

Baek, W-P.

2015-01-01

'Full text:' Modeling and simulation (M&S) technology is a key element in assuring and enhancing the safety of nuclear installations. The M&S technology has been progressed continuously with the introduction of new designs, improved understanding on relevant physical processes, and the improvement of computing environment. This presentation covers the role, progresses and prospect of M&S technology relevant to nuclear safety. Special attention is given to the effective interaction between M&S and experiment. The expected role of experiment to motivate the advancement of M&S technology is emphasized with some typical examples. Finally, relevant R&D activities of Korea are introduced for thermal-hydraulics and severe accident safety. (author)

Incorporation of thymidine into onion root meristematic cell nuclei in presence of hydroxyurea and its role in recovery of mitotic activity

International Nuclear Information System (INIS)

Habdas, H.

1977-01-01

Hydroxyurea treatment of onion roots induced mitotic block which was released by transfer of bulbs to water, and also to some extent by addition of cold or 3 H-thymidine to hydroxyurea solutions. In presence of hydroxyurea there was noted very intense incorporation of 3 H-thymidine into cell nuclei, giving labelling index of 40-70%. However, all the mitotic figures appearing in presence of hydroxyurea and 3 H-thymidine were unlabelled. On the other hand, labelled mitotic figures were obtained when roots incubated with 3 H-thymidine in presence of hydroxyurea had been transferred to water. Incorporation of 3 H-uridine was unaffected by hydroxyurea. The results show that hydroxyurea arrests onion root meristematic cells, either in the S phase and the G 2 phase. Enhanced incorporation of 3 H-thymidine in the presence of hydroxyurea, and release by added thymidine of the mitotic block indicate that hydroxyurea induces in onion root meristematic cells a particular shortage of thymidylate. (author)

A CFD study of wave influence on film steam condensation in the presence of non-condensable gas

Energy Technology Data Exchange (ETDEWEB)

Wang, Xianmao, E-mail: xm-wang11@mails.tsinghua.edu.cn [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Chang, Huajian, E-mail: changhj@tsinghua.edu.cn [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Corradini, Michael, E-mail: corradini@engr.wisc.edu [Department of Engineering Physics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, WI 53706 (United States)

2016-08-15

Highlights: • A condensation model is incorporated in the ANSYS FLUENT. • Different turbulence models are evaluated for flows over wavy surfaces. • Wavy surfaces with and without moving velocities are used to model the wave. • Various wavy surfaces with different wave heights and wavelengths are selected. • Wave influence on film steam condensation is investigated. - Abstract: Steam condensation plays an important role in removing heat from the containment of a nuclear plant during postulated accidents. However, due to the presence of non-condensable gases such as air and hydrogen in the containment, the condensation rate can decrease dramatically. Under certain conditions, the condensate film on the cold containment walls can affect the overall heat transfer rate. The wavy interface of the condensate film is a factor and is usually believed to enhance the condensation rate, since the waves can both increase the interfacial area and disturb the non-condensable gas boundary layer. However, it is not clear how to properly account for this factor and what is its quantitative influence in experiments. In this work, a CFD approach is applied to study the wave effects on film condensation in the presence of non-condensable gas. Wavy surfaces with and without moving velocities are used to replace the wavy interface of the falling film. A condensation model is incorporated in the ANSYS FLUENT simulation and a realizable k–ε turbulence model is applied. Various wavy surfaces with different wave heights and wavelengths are selected to conduct numerical experiments with a wide range of gas velocities. The results show that the wave structure can enhance condensation rate up to ten percent mainly due to the alteration of local flow structures in the gas phase. The increments of the condensation rate due to the wavy interface can vary with different gas velocities. The investigation shows that a multiplication factor accounts for the wave effects on film

An Efficient Role and Object Based Access Control Model Implemented in a PDM System

Institute of Scientific and Technical Information of China (English)

HUANG Xiaowen; TAN Jian; HUANG Xiangguo

2006-01-01

An effective and reliable access control is crucial to a PDM system. This article has discussed the commonly used access control models, analyzed their advantages and disadvantages, and proposed a new Role and Object based access control model that suits the particular needs of a PDM system. The new model has been implemented in a commercial PDM system, which has demonstrated enhanced flexibility and convenience.

Modeling of sonochemistry in water in the presence of dissolved carbon dioxide.

Science.gov (United States)

Authier, Olivier; Ouhabaz, Hind; Bedogni, Stefano

2018-07-01

CO 2 capture and utilization (CCU) is a process that captures CO 2 emissions from sources such as fossil fuel power plants and reuses them so that they will not enter the atmosphere. Among the various ways of recycling CO 2 , reduction reactions are extensively studied at lab-scale. However, CO 2 reduction by standard methods is difficult. Sonochemistry may be used in CO 2 gas mixtures bubbled through water subjected to ultrasound waves. Indeed, the sonochemical reduction of CO 2 in water has been already investigated by some authors, showing that fuel species (CO and H 2 ) are obtained in the final products. The aim of this work is to model, for a single bubble, the close coupling of the mechanisms of bubble dynamics with the kinetics of gas phase reactions in the bubble that can lead to CO 2 reduction. An estimation of time-scales is used to define the controlling steps and consequently to solve a reduced model. The calculation of the concentration of free radicals and gases formed in the bubble is undertaken over many cycles to look at the effects of ultrasound frequency, pressure amplitude, initial bubble radius and bubble composition in CO 2 . The strong effect of bubble composition on the CO 2 reduction rate is confirmed in accordance with experimental data from the literature. When the initial fraction of CO 2 in the bubble is low, bubble growth and collapse are slightly modified with respect to simulation without CO 2 , and chemical reactions leading to CO 2 reduction are promoted. However, the peak collapse temperature depends on the thermal properties of the CO 2 and greatly decreases as the CO 2 increases in the bubble. The model shows that initial bubble radius, ultrasound frequency and pressure amplitude play a critical role in CO 2 reduction. Hence, in the case of a bubble with an initial radius of around 5 μm, CO 2 reduction appears to be more favorable at a frequency around 300 kHz than at a low frequency of around 20 kHz. Finally, the

Computer simulation models as a tool to investigate the role of microRNAs in osteoarthritis.

Directory of Open Access Journals (Sweden)

Carole J Proctor

Full Text Available The aim of this study was to show how computational models can be used to increase our understanding of the role of microRNAs in osteoarthritis (OA using miR-140 as an example. Bioinformatics analysis and experimental results from the literature were used to create and calibrate models of gene regulatory networks in OA involving miR-140 along with key regulators such as NF-κB, SMAD3, and RUNX2. The individual models were created with the modelling standard, Systems Biology Markup Language, and integrated to examine the overall effect of miR-140 on cartilage homeostasis. Down-regulation of miR-140 may have either detrimental or protective effects for cartilage, indicating that the role of miR-140 is complex. Studies of individual networks in isolation may therefore lead to different conclusions. This indicated the need to combine the five chosen individual networks involving miR-140 into an integrated model. This model suggests that the overall effect of miR-140 is to change the response to an IL-1 stimulus from a prolonged increase in matrix degrading enzymes to a pulse-like response so that cartilage degradation is temporary. Our current model can easily be modified and extended as more experimental data become available about the role of miR-140 in OA. In addition, networks of other microRNAs that are important in OA could be incorporated. A fully integrated model could not only aid our understanding of the mechanisms of microRNAs in ageing cartilage but could also provide a useful tool to investigate the effect of potential interventions to prevent cartilage loss.

Tobacco Truths: The Impact of Role Models on Children's Attitudes toward Smoking.

Science.gov (United States)

Meier, Kathryn S.

1991-01-01

A survey of 1,085 seventh and eleventh graders assessed the impact of parents, peers, siblings, advertising, and sponsorship as role models influencing attitudes toward smoking and smoking behavior. Results suggest that intervention programs need to address nicotine addiction and be in place before grade seven. (JOW)

PresenceRemote

DEFF Research Database (Denmark)

Sokoler, Tomas; Svensson, Marcus Sanchez

2008-01-01

how these technologies can accommodate the specific challenges related to the everyday life of elderly people. In particular, using an example concept – the PresenceRemote – we will discuss how the stigma associated with being lonely, an inherent part of senior living, can be addressed by leaving room...

The Interactions between Facilitator Identity, Conflictual Presence, and Social Presence in Peer-Moderated Online Collaborative Learning

Science.gov (United States)

Xie, Kui; Lu, Lin; Cheng, Sheng-Lun; Izmirli, Serkan

2017-01-01

Research has focused on the significance of social presence in online learning. However, peer interaction does not always result in positive emotions and feelings; it can trigger tension, distress, and anger within a learning community. Therefore, conflictual presence, as a carrier of negative valence within presence, is also a critical element…

Potential role of biotic transport models in low-level-waste management

International Nuclear Information System (INIS)

Kennedy, W.E. Jr.; Soldat, J.K.; Cadwell, L.L.; McKenzie, D.H.

1982-01-01

This paper is a summary of the initial results of a study being conducted for the US Nuclear Regulatory Commission (NRC) to determine the relevance of biotic pathways to the regulation of nuclear waste disposal. Biotic transport is defined as the actions of plants and animals that result in the transport of radioactive materials from a LLW burial ground to a location where they can enter exposure pathways to man. A critical review of the role of modeling in evaluating biotic transport is given. Both current applications and the need for future modeling development are discussed

An Evaluation of Ad Hoc Presence-Only Data in Explaining Patterns of Distribution: Cetacean Sightings from Whale-Watching Vessels

Directory of Open Access Journals (Sweden)

Louisa K. Higby

2012-01-01

Full Text Available The analysis of presence-only data is a problem in determining species distributions and accurately determining population sizes. The collection of such data is common from unequal or nonrandomised effort surveys, such as those surveys conducted by citizen scientists. However, causative regression-based methods have been less well examined using presence-only data. In this study, we examine a range of predictive factors which might influence Cetacean sightings (specifically minke whale sightings from whale-watching vessels in Faxaflói Bay in Iceland. In this case, environmental variables were collected regularly regardless of whether sightings were recorded. Including absences as well as presence in the analysis resulted in a multiple-generalised linear regression model with significantly more explanatory power than when data were presence only. However, by including extra information on the sightings of the whales, in this case, their observed behaviour when the sighting occurred resulted in a significantly improved model over the presence-only data model. While there are limitations of conducting nonrandomised surveys for the use of predictive models such as regression, presence-only data should not be considered as worthless, and the scope of collection of these data by citizen scientists using modern technology should not be underestimated.

Tumour control in ion beam radiotherapy with different ions in the presence of hypoxia: an oxygen enhancement ratio model based on the microdosimetric kinetic model

Science.gov (United States)

Strigari, L.; Torriani, F.; Manganaro, L.; Inaniwa, T.; Dalmasso, F.; Cirio, R.; Attili, A.

2018-03-01

Few attempts have been made to include the oxygen enhancement ratio (OER) in treatment planning for ion beam therapy, and systematic studies to evaluate the impact of hypoxia in treatment with the beam of different ion species are sorely needed. The radiobiological models used to quantify the OER in such studies are mainly based on the dose-averaged LET estimates, and do not explicitly distinguish between the ion species and fractionation schemes. In this study, a new type of OER modelling, based on the microdosimetric kinetic model, taking into account the specificity of the different ions, LET spectra, tissues and fractionation schemes, has been developed. The model has been benchmarked with published in vitro data, HSG, V79 and CHO cells in aerobic and hypoxic conditions, for different ion irradiation. The model has been included in the simulation of treatments for a clinical case (brain tumour) using proton, lithium, helium, carbon and oxygen ion beams. A study of the tumour control probability (TCP) as a function of oxygen partial pressure, dose per fraction and primary ion type has been performed. The modelled OER depends on both the LET and ion type, also showing a decrease for an increased dose per fraction with a slope that depends on the LET and ion type, in good agreement with the experimental data. In the investigated clinical case, a significant increase in TCP has been found upon increasing the ion charge. Higher OER variations as a function of dose per fraction have also been found for low-LET ions (up to 15% varying from 2 to 8 Gy(RBE) for protons). This model could be exploited in the identification of treatment condition optimality in the presence of hypoxia, including fractionation and primary particle selection.

The role of models in managing the uncertainty of software-intensive systems

International Nuclear Information System (INIS)

Littlewood, Bev; Neil, Martin; Ostrolenk, Gary

1995-01-01

It is increasingly argued that uncertainty is an inescapable feature of the design and operational behaviour of software-intensive systems. This paper elaborates the role of models in managing such uncertainty, in relation to evidence and claims for dependability. Personal and group models are considered with regard to abstraction, consensus and corroboration. The paper focuses on the predictive property of models, arguing for the need for empirical validation of their trustworthiness through experimentation and observation. The impact on trustworthiness of human fallibility, formality of expression and expressiveness is discussed. The paper identifies two criteria for deciding the degree of trust to be placed in a model, and hence also for choosing between models, namely accuracy and informativeness. Finally, analogy and reuse are proposed as the only means by which empirical evidence can be established for models in software engineering

Sparrowhawk movement, calling, and presence of dead conspecifics differentially impact blue tit (Cyanistes caeruleus) vocal and behavioral mobbing responses.

Science.gov (United States)

Carlson, Nora V; Pargeter, Helen M; Templeton, Christopher N

2017-01-01

Many animals alter their anti-predator behavior in accordance to the threat level of a predator. While much research has examined variation in mobbing responses to different predators, few studies have investigated how anti-predator behavior is affected by changes in a predator's own state or behavior. We examined the effect of sparrowhawk ( Accipiter nisus ) behavior on the mobbing response of wild blue tits ( Cyanistes caeruleus ) using robotic taxidermy sparrowhawks. We manipulated whether the simulated predator moved its head, produced vocalizations, or held a taxidermy blue tit in its talons. When any sparrowhawk model was present, blue tits decreased foraging and increased anti-predator behavior and vocalizations. Additionally, each manipulation of the model predator's state (moving, vocalizing, or the presence of a dead conspecific) impacted different types of blue tit anti-predator behavior and vocalizations. These results indicate that different components of mobbing vary according to the specific state of a given predator-beyond its presence or absence-and suggest that each might play a different role in the overall mobbing response. Last, our results indicate that using more life-like predator stimuli-those featuring simple head movements and audio playback of vocalizations-changes how prey respond to the predator; these 'robo-raptor' models provide a powerful tool to provide increased realism in simulated predator encounters without sacrificing experimental control. Anti-predatory behavior is often modulated by the threat level posed by a particular predator. While much research has tested how different types of predators change prey behavior, few experiments have examined how predator behavior affects anti-predatory responses of prey. By experimentally manipulating robotic predators, we show that blue tits not only respond to the presence of a sparrowhawk, by decreasing feeding and increasing anti-predator behavior and vocalizations, but that they vary

Presence While Watching Movies

Directory of Open Access Journals (Sweden)

Tom Troscianko

2011-05-01

Full Text Available “Presence” is the illusion of being in a mediated experience rather than simply being an observer. It is a concept often applied to the question of realism of virtual environments. However, it is equally applicable to the act of watching a movie. A movie provides a markedly different visual environment to that given by the natural world—particularly because of frequent edits. And yet, the audience in a movie achieves high levels of presence. We investigate the relationship between presence and the optical and temporal parameters of movies. We find effects of mean shot length, colour/b&w, and 3D/2D. We find that short shots, while being unnatural, are associated with high levels of presence. We consider why such artificial stimuli should appear so real and immersive.

Radiation effects on methane in the presence of molecular sieves

International Nuclear Information System (INIS)

Shimizu, Y.; Nagai, S.; Hatada, M.

1983-01-01

Product analysis has been carried out for the radiation-induced reaction of methane in the presence of molecular sieves (MS) 3A, 4A, 5A and 13X. Irradiation of methane over MS 4A selectively produces C 2 hydrocarbons, while the use of MS 5A leads to C 2 and C 3 hydrocarbons. The selectivity and yields of these hydrocarbons, however, decrease with irradiation time, owing to deposition of carbonaceous solid produced from methane on the surface of the molecular sieves. The carbonaceous solid is decomposed to low-molecular-weight hydrocarbons when irradiated in an H 2 atmosphere. Material balance estimated for the radiation-chemical reaction of argon containing 2 mol% methane over MS 5A reveals that the carbonaceous solid is highly abundant in carbon atoms. On the other hand the formation of carbonaceous solids plays a less important role in the radiation-chemical reaction of methane in the presence of silica gel, which is found to exhibit greater activity for the formation of hydrocarbons than the molecular sieves. (author)

Aromatic metabolism of filamentous fungi in relation to the presence of aromatic compounds in plant biomass

NARCIS (Netherlands)

Mäkelä, Miia R; Marinović, Mila; Nousiainen, Paula; Liwanag, April J M; Benoit, Isabelle; Sipilä, Jussi; Hatakka, Annele; de Vries, Ronald P; Hildén, Kristiina S

2015-01-01

The biological conversion of plant lignocellulose plays an essential role not only in carbon cycling in terrestrial ecosystems but also is an important part of the production of second generation biofuels and biochemicals. The presence of the recalcitrant aromatic polymer lignin is one of the major

Attraction of Rhagoletis indifferens (Diptera: Tephitidae) to white light in the presence and absence of ammonia

Science.gov (United States)

Attraction of tephritid fruit flies to light and its role in fly biology and management has received little attention. Here, the objective was to show that western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), is attracted to white light in the presence and absence of ammo...

Ejaculation as a Source of Proteinuria Regardless of the Presence or Absence of Sperm in Semen

NARCIS (Netherlands)

Sadri-Ardekani, Hooman; Soltanghoraee, Halleh; Taheri, Arman; Kashi, Tahereh; Akhondi, Mehdi A.

2009-01-01

Objectives: The presence of protein in urine samples without any background leads to subsequent unnecessary tests. The objective of this paper was to assess protein in urine before and after semen sampling in azoospermic and non-azoospermic men to determine the role of semen proteins or spermatozoa

Role of Polycarboxylate-ether superplasticizers on cement hydration kinetics and microstructural development

Directory of Open Access Journals (Sweden)

Valentini L.

2018-01-01

Full Text Available Polycarboxylate-ether (PCE superplasticizers are a fundamental constituent of modern cementbased materials due to their impact on the rheology of the fresh mix and mechanical performance of the hardened material. The effect of PCEs on cement hydration kinetics has been known since their introduction in the early 1980s. However, detailed knowledge of the role played by PCE macromolecules on the basic mechanisms of cement hydration (dissolution, diffusion, precipitation is still lacking. A better understanding of how such mechanisms are influenced by the addition of PCE is no doubt beneficial to the design of novel superplasticizing admixtures. Here, I report on some recent findings about the role of PCE superplasticizers on cement hydration kinetics and microstructural development. The interaction between PCE and C3S pastes was investigated by an ad-hoc kinetic model based on a combination of generalized forms of the Avrami and BNG (Boundary Nucleation and Growth models. The model is used to fit the rate of C-S-H precipitation measured by in-situ X-ray powder diffraction combined with mass balance calculations. The results show that a switch from heterogeneous to homogeneous C-S-H nucleation occurs in the presence of PCEs and that the C-S-H growth rate decreases proportionally to the amount of PCE used. The predicted switch to homogeneous nucleation is in agreement with experimental results obtained by XRD-enhanced micro-tomography imaging, showing that, in the presence of PCE, C-S-H preferentially forms in the pore space rather than at the surface of clinker particles.

Melatonin: a possible link between the presence of artificial light at night and reductions in biological fitness

Science.gov (United States)

Jones, Therésa M.; Durrant, Joanna; Michaelides, Ellie B.; Green, Mark P.

2015-01-01

The mechanisms underpinning the ecological impacts of the presence of artificial night lighting remain elusive. One suspected underlying cause is that the presence of light at night (LAN) supresses nocturnal production of melatonin, a key driver of biological rhythm and a potent antioxidant with a proposed role in immune function. Here, we briefly review the evidence for melatonin as the link between LAN and changes in behaviour and physiology. We then present preliminary data supporting the potential for melatonin to act as a recovery agent mitigating the negative effects of LAN in an invertebrate. Adult crickets (Teleogryllus commodus), exposed to constant illumination, were provided with dietary melatonin (concentrations: 0, 10 or 100 µg ml−1) in their drinking water. We then compared survival, lifetime fecundity and, over a 4-week period, immune function (haemocyte concentration, lysozyme-like and phenoloxidase (PO) activity). Melatonin supplementation was able only partially to mitigate the detrimental effects of LAN: it did not improve survival or fecundity or PO activity, but it had a largely dose-dependent positive effect on haemocyte concentration and lysozyme-like activity. We discuss the implications of these relationships, as well as the usefulness of invertebrates as model species for future studies that explore the effects of LAN. PMID:25780235

Simple analytical model reveals the functional role of embodied sensorimotor interaction in hexapod gaits

Science.gov (United States)

Aoi, Shinya; Nachstedt, Timo; Manoonpong, Poramate; Wörgötter, Florentin; Matsuno, Fumitoshi

2018-01-01

Insects have various gaits with specific characteristics and can change their gaits smoothly in accordance with their speed. These gaits emerge from the embodied sensorimotor interactions that occur between the insect’s neural control and body dynamic systems through sensory feedback. Sensory feedback plays a critical role in coordinated movements such as locomotion, particularly in stick insects. While many previously developed insect models can generate different insect gaits, the functional role of embodied sensorimotor interactions in the interlimb coordination of insects remains unclear because of their complexity. In this study, we propose a simple physical model that is amenable to mathematical analysis to explain the functional role of these interactions clearly. We focus on a foot contact sensory feedback called phase resetting, which regulates leg retraction timing based on touchdown information. First, we used a hexapod robot to determine whether the distributed decoupled oscillators used for legs with the sensory feedback generate insect-like gaits through embodied sensorimotor interactions. The robot generated two different gaits and one had similar characteristics to insect gaits. Next, we proposed the simple model as a minimal model that allowed us to analyze and explain the gait mechanism through the embodied sensorimotor interactions. The simple model consists of a rigid body with massless springs acting as legs, where the legs are controlled using oscillator phases with phase resetting, and the governed equations are reduced such that they can be explained using only the oscillator phases with some approximations. This simplicity leads to analytical solutions for the hexapod gaits via perturbation analysis, despite the complexity of the embodied sensorimotor interactions. This is the first study to provide an analytical model for insect gaits under these interaction conditions. Our results clarified how this specific foot contact sensory

Tests of Financial Models in the Presence of Overlapping Observations.

OpenAIRE

Richardson, Matthew; Smith, Tom

1991-01-01

A general approach to testing serial dependence restrictions implied from financial models is developed. In particular, we discuss joint serial dependence restrictions imposed by random walk, market microstructure, and rational expectations models recently examined in the literature. This approach incorporates more information from the data by explicitly modeling dependencies induced by the use of overlapping observations. Because the estimation problem is sufficiently simple in this framewor...

Presence of indicator plant species as a predictor of wetland vegetation integrity

Science.gov (United States)

Stapanian, Martin A.; Adams, Jean V.; Gara, Brian

2013-01-01

We fit regression and classification tree models to vegetation data collected from Ohio (USA) wetlands to determine (1) which species best predict Ohio vegetation index of biotic integrity (OVIBI) score and (2) which species best predict high-quality wetlands (OVIBI score >75). The simplest regression tree model predicted OVIBI score based on the occurrence of three plant species: skunk-cabbage (Symplocarpus foetidus), cinnamon fern (Osmunda cinnamomea), and swamp rose (Rosa palustris). The lowest OVIBI scores were best predicted by the absence of the selected plant species rather than by the presence of other species. The simplest classification tree model predicted high-quality wetlands based on the occurrence of two plant species: skunk-cabbage and marsh-fern (Thelypteris palustris). The overall misclassification rate from this tree was 13 %. Again, low-quality wetlands were better predicted than high-quality wetlands by the absence of selected species rather than the presence of other species using the classification tree model. Our results suggest that a species’ wetland status classification and coefficient of conservatism are of little use in predicting wetland quality. A simple, statistically derived species checklist such as the one created in this study could be used by field biologists to quickly and efficiently identify wetland sites likely to be regulated as high-quality, and requiring more intensive field assessments. Alternatively, it can be used for advanced determinations of low-quality wetlands. Agencies can save considerable money by screening wetlands for the presence/absence of such “indicator” species before issuing permits.

Optical absorption in a disk-shaped quantum dot in the presence of an impurity

Energy Technology Data Exchange (ETDEWEB)

Mikhail, I.F.I., E-mail: ifi_mikhail@hotmail.com [Department of Mathematics, Faculty of Science, Ain Shams University, Cairo (Egypt); Shafee, A.M. [Department of Mathematics, Faculty of Girls, Art, Science and Education, Ain Shams University, Cairo (Egypt)

2017-02-15

The linear and third order nonlinear optical absorption coefficients have been calculated in a two dimensional disk quantum dot. The confinement potential has been taken to be a combination of a parabolic and inverse squared part. The study has been performed in the presence of a perpendicular static magnetic field and a central or off-central impurity. The resulting Schrödinger equation has been solved by applying the variational method. It has been found that the presence of impurity causes a huge increase in the square of the transition matrix and in the absorption coefficients, in particular in the third order coefficient. Moreover, the asymmetry which results in the case of off-central impurity has been dealt with carefully by taking into consideration the transition matrices which vanish in other cases. - Highlights: • The optical absorption in a two dimensional disk-shaped quantum dot is investigated. • A static magnetic field is applied perpendicular to the plane of the disk. • The study is performed in the presence of central or off- central impurity. • The variational approach has been applied to find the energies and wave functions. • The presence and location of impurity play effective roles.

Effects of biotic interactions and dispersal on the presence-absence of multiple species

International Nuclear Information System (INIS)

Mohd, Mohd Hafiz; Murray, Rua; Plank, Michael J.; Godsoe, William

2017-01-01

One of the important issues in ecology is to predict which species will be present (or absent) across a geographical region. Dispersal is thought to have an important influence on the range limits of species, and understanding this problem in a multi-species community with priority effects (i.e. initial abundances determine species presence-absence) is a challenging task because dispersal also interacts with biotic and abiotic factors. Here, we propose a simple multi-species model to investigate the joint effects of biotic interactions and dispersal on species presence-absence. Our results show that dispersal can substantially expand species ranges when biotic and abiotic forces are present; consequently, coexistence of multiple species is possible. The model also exhibits ecologically interesting priority effects, mediated by intense biotic interactions. In the absence of dispersal, competitive exclusion of all but one species occurs. We find that dispersal reduces competitive exclusion effects that occur in no-dispersal case and promotes coexistence of multiple species. These results also show that priority effects are still prevalent in multi-species communities in the presence of dispersal process. We also illustrate the existence of threshold values of competitive strength (i.e. transcritical bifurcations), which results in different species presence-absence in multi-species communities with and without dispersal.

Major Histocompatibility Complex, demographic, and environmental predictors of antibody presence in a free-ranging mammal.

Science.gov (United States)

Ruiz-López, María José; Monello, Ryan J; Schuttler, Stephanie G; Lance, Stacey L; Gompper, Matthew E; Eggert, Lori S

2014-12-01

Major Histocompatibility Complex (MHC) variability plays a key role in pathogen resistance, but its relative importance compared to environmental and demographic factors that also influence resistance is unknown. We analyzed the MHC II DRB exon 2 for 165 raccoons (Procyon lotor) in Missouri (USA). For each animal we also determined the presence of immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies to two highly virulent pathogens, canine distemper virus (CDV) and parvovirus. We investigated the role of MHC polymorphism and other demographic and environmental factors previously associated with predicting seroconversion. In addition, using an experimental approach, we studied the relative importance of resource availability and contact rates. We found important associations between IgG antibody presence and several MHC alleles and supertypes but not between IgM antibody presence and MHC. No effect of individual MHC diversity was found. For CDV, supertype S8, one allele within S8 (Prlo-DRB(∗)222), and a second allele (Prlo-DRB(∗)204) were positively associated with being IgG+, while supertype S4 and one allele within the supertype (Prlo-DRB(∗)210) were negatively associated with being IgG+. Age, year, and increased food availability were also positively associated with being IgG+, but allele Prlo-DRB(∗)222 was a stronger predictor. For parvovirus, only one MHC allele was negatively associated with being IgG+ and age and site were stronger predictors of seroconversion. Our results show that negative-frequency dependent selection is likely acting on the raccoon MHC and that while the role of MHC in relation to other factors depends on the pathogen of interest, it may be one of the most important factors predicting successful immune response. Copyright © 2014 Elsevier B.V. All rights reserved.

On the foundation for roles in RM-ODP: contributions from conceptual modelling

NARCIS (Netherlands)

Guizzardi, G.; Andrade Almeida, João; Linington, P.F.; Vallecillo, A.; Wood, B.

2007-01-01

In this paper, we attempt to provide a semantic foundation for the role-related concepts in the RM-ODP. We believe that some theories of conceptual modelling may help us to provide a well-founded underpinning for these concepts, and to harmonize competing proposals for them. As a starting point of

Parents as Role Models: Parental Behavior Affects Adolescents' Plans for Work Involvement

Science.gov (United States)

Wiese, Bettina S.; Freund, Alexandra M.

2011-01-01

This study (N = 520 high-school students) investigates the influence of parental work involvement on adolescents' own plans regarding their future work involvement. As expected, adolescents' perceptions of parental work behavior affected their plans for own work involvement. Same-sex parents served as main role models for the adolescents' own…

Extending the Challenge-Hindrance Model of Occupational Stress: The Role of Appraisal

Science.gov (United States)

Webster, Jennica R.; Beehr, Terry A.; Love, Kevin

2011-01-01

Interest regarding the challenge-hindrance occupational stress model has increased in recent years, however its theoretical foundation has not been tested. Drawing from the transactional theory of stress, this study tests the assumptions made in past research (1) that workload and responsibility are appraised as challenges and role ambiguity and…

Self-consistent modeling of the dynamic evolution of magnetic island growth in the presence of stabilizing electron-cyclotron current drive

International Nuclear Information System (INIS)

Chatziantonaki, Ioanna; Tsironis, Christos; Isliker, Heinz; Vlahos, Loukas

2013-01-01

The most promising technique for the control of neoclassical tearing modes in tokamak experiments is the compensation of the missing bootstrap current with an electron-cyclotron current drive (ECCD). In this frame, the dynamics of magnetic islands has been studied extensively in terms of the modified Rutherford equation (MRE), including the presence of a current drive, either analytically described or computed by numerical methods. In this article, a self-consistent model for the dynamic evolution of the magnetic island and the driven current is derived, which takes into account the island's magnetic topology and its effect on the current drive. The model combines the MRE with a ray-tracing approach to electron-cyclotron wave-propagation and absorption. Numerical results exhibit a decrease in the time required for complete stabilization with respect to the conventional computation (not taking into account the island geometry), which increases by increasing the initial island size and radial misalignment of the deposition. (paper)

Self-consistent modeling of the dynamic evolution of magnetic island growth in the presence of stabilizing electron-cyclotron current drive

Science.gov (United States)

Chatziantonaki, Ioanna; Tsironis, Christos; Isliker, Heinz; Vlahos, Loukas

2013-11-01

The most promising technique for the control of neoclassical tearing modes in tokamak experiments is the compensation of the missing bootstrap current with an electron-cyclotron current drive (ECCD). In this frame, the dynamics of magnetic islands has been studied extensively in terms of the modified Rutherford equation (MRE), including the presence of a current drive, either analytically described or computed by numerical methods. In this article, a self-consistent model for the dynamic evolution of the magnetic island and the driven current is derived, which takes into account the island's magnetic topology and its effect on the current drive. The model combines the MRE with a ray-tracing approach to electron-cyclotron wave-propagation and absorption. Numerical results exhibit a decrease in the time required for complete stabilization with respect to the conventional computation (not taking into account the island geometry), which increases by increasing the initial island size and radial misalignment of the deposition.

Wanted: Active Role Models for Today's Kids | NIH MedlinePlus the Magazine

Science.gov (United States)

... American children more likely to tap a video game controller than bounce a ball, problems of obesity should be no surprise. And with obesity already a growing problem for their parents, kids today need all the active role models they can get. "With childhood obesity at an all-time high, we need ...

The Relationship between Smoker Role Models and Intentions to Smoke among Adolescents

Science.gov (United States)

Wiium, Nora; Breivik, Kyrre; Wold, Bente

2006-01-01

The study examines how adolescents' perceptions of exposure to smoker role models relate to their intentions to smoke, both directly, and indirectly through attitudes, norms, and perceived behavioural control. The data is based on a national representative sample of 15-year-olds (n=1670) in Norway. Path analysis indicates that perceptions of model…

The Role of Emotion in Informal Science Learning: Testing an Exploratory Model

Science.gov (United States)

Staus, Nancy L.; Falk, John H.

2017-01-01

Although there is substantial research on the effect of emotions on educational outcomes in the classroom, relatively little is known about how emotion affects learning in informal science contexts. We examined the role of emotion in the context of an informal science learning experience by utilizing a path model to investigate the relationships…

Changing Lives? Critical Evaluation of a School-Based Athlete Role Model Intervention

Science.gov (United States)

Armour, Kathleen; Duncombe, Rebecca

2012-01-01

There would appear to be an enduring belief that successful sportsmen and women can act as powerful motivational role models for young people, especially disaffected, disadvantaged or disengaged youth. In the UK, for example, this belief has been expressed recently in the development of programmes, such as changingLIVES, the Respect Athlete Mentor…

Quantification of iron in the presence of calcium with dual-energy computed tomography (DECT) in an ex vivo porcine plaque model

International Nuclear Information System (INIS)

Wang Jia; Duan Xinhui; Leng Shuai; Yu Lifeng; McCollough, Cynthia H; Garg, Nitin; Liu Yu; Kantor, Birgit; Ritman, Erik L

2011-01-01

Iron deposits secondary to microbleeds often co-exist with calcium in coronary plaques. The purpose of this study was to quantify iron in the presence of calcium in an ex vivo porcine arterial plaque model using a clinical dual-energy CT (DECT) scanner. A material decomposition method to quantify the mass fractions of iron and calcium within a mixture using DECT was developed. Mixture solutions of known iron and calcium concentrations were prepared to calibrate and validate the DECT-based algorithm. Simulated plaques with co-existing iron and calcium were created by injecting the mixture solutions into the vessel wall of porcine carotid arteries and aortas. These vessel regions were harvested and scanned using a clinical DECT system and iron mass fraction was calculated for each sample. Iron- and calcium-specific staining was conducted on 5 µm thick histological sections of vessel samples to confirm the co-existence of iron and calcium in the simulated plaques. The proposed algorithm accurately quantified iron and calcium amounts in mixture solutions. Maps of iron mass fraction of 60 artery segments were obtained from CT images at two energies. The sensitivity for detecting the presence of iron was 83% and the specificity was 92% using a threshold at an iron mass fraction of 0.25%. Histological analysis confirmed the co-localization of iron and calcium within the simulated plaques. Iron quantification in the presence of calcium was feasible in excised arteries at an iron mass fraction of around 1.5% or higher using current clinical DECT scanners.

Drosophila as a model to study the role of blood cells in inflammation, innate immunity and cancer

Science.gov (United States)

Wang, Lihui; Kounatidis, Ilias; Ligoxygakis, Petros

2014-01-01

Drosophila has a primitive yet effective blood system with three types of haemocytes which function throughout different developmental stages and environmental stimuli. Haemocytes play essential roles in tissue modeling during embryogenesis and morphogenesis, and also in innate immunity. The open circulatory system of Drosophila makes haemocytes ideal signal mediators to cells and tissues in response to events such as infection and wounding. The application of recently developed and sophisticated genetic tools to the relatively simple genome of Drosophila has made the fly a popular system for modeling human tumorigensis and metastasis. Drosophila is now used for screening and investigation of genes implicated in human leukemia and also in modeling development of solid tumors. This second line of research offers promising opportunities to determine the seemingly conflicting roles of blood cells in tumor progression and invasion. This review provides an overview of the signaling pathways conserved in Drosophila during haematopoiesis, haemostasis, innate immunity, wound healing and inflammation. We also review the most recent progress in the use of Drosophila as a cancer research model with an emphasis on the roles haemocytes can play in various cancer models and in the links between inflammation and cancer. PMID:24409421

Industry growth, work role characteristics, and job satisfaction: a cross-level mediation model.

Science.gov (United States)

Ford, Michael T; Wooldridge, Jessica D

2012-10-01

The associations between industry revenue growth, individual work role characteristics, and job satisfaction were examined in this cross-level mediation analysis. Work roles were expected to be more autonomous, involve greater skill variety, and offer more opportunities for growth and development for workers in growing industries than for workers in declining industries. Supervisor support was also hypothesized to be stronger for workers in high-growth industries. Results from a nationally representative (U.S.) sample of service industry workers, using multilevel modeling, supported these propositions and suggest that job enrichment mediates relations between industry growth and job satisfaction. Associations between industry growth and autonomy were also stronger among workers in occupations that are less normatively autonomous, suggesting that industry growth fosters a weakening, and industry decline a strengthening, of traditional differences in autonomy across work roles. These results contribute to a multilevel perspective on organizational environments, individual work roles, and worker attitudes and well-being.

The Active Use of Online Presence, Movies and Gameplay to Improve Classroom Engagement

OpenAIRE

Costain , Sean; Patterson , Dale

2014-01-01

Part 1: Digital Games and Interactive Entertainment; International audience; The online world is filled with rich interactive games, spaces, motion pictures and personas. Despite a rapid growth in online education, the tertiary classroom looks quite different to the entertaining online world it exists within. The design of mobile online resources, both official and unofficial, plays a key role in student engagement and learning. From the teachers perspective designing an online presence and i...

The role of mechanical heterogeneities during continental breakup: a 3D lithospheric-scale modelling approach

Science.gov (United States)

Duclaux, Guillaume; Huismans, Ritske S.; May, Dave

2015-04-01

How and why do continents break? More than two decades of analogue and 2D plane-strain numerical experiments have shown that despite the origin of the forces driving extension, the geometry of continental rifts falls into three categories - or modes: narrow rift, wide rift, or core complex. The mode of extension itself is strongly influenced by the rheology (and rheological behaviour) of the modelled layered system. In every model, an initial thermal or mechanical heterogeneity, such as a weak seed or a notch, is imposed to help localise the deformation and avoid uniform stretching of the lithosphere by pure shear. While it is widely accepted that structural inheritance is a key parameter for controlling rift localisation - as implied by the Wilson Cycle - modelling the effect of lithospheric heterogeneities on the long-term tectonic evolution of an extending plate in full 3D remains challenging. Recent progress in finite-element methods applied to computational tectonics along with the improved accessibility to high performance computers, now enable to switch from plane strain thermo-mechanical experiments to full 3D high-resolution experiments. Here we investigate the role of mechanical heterogeneities on rift opening, linkage and propagation during extension of a layered lithospheric systems with pTatin3d, a geodynamics modeling package utilising the material-point-method for tracking material composition, combined with a multigrid finite-element method to solve heterogeneous, incompressible visco-plastic Stokes problems. The initial model setup consists in a box of 1200 km horizontally by 250 km deep. It includes a 35 km layer of continental crust, underlaid by 85 km of sub-continental lithospheric mantle, and an asthenospheric mantle. Crust and mantle have visco-plastic rheologies with a pressure dependent yielding, which includes strain weakening, and a temperature, stress, strain-rate-dependent viscosity based on wet quartzite rheology for the crust, and wet

Presence : concept, determinants and measurement

NARCIS (Netherlands)

IJsselsteijn, W.A.; Ridder, de H.; Freeman, J.; Avons, S.E.; Rogowitz, B.E.; Pappas, T.N.

2000-01-01

The concept of presence, i.e. the sensation of 'being there' in a mediated environment, has received substantial attention from the virtual reality community, and is becaming increasingly relevant both to broadcasters and display developers. Although research into presence is still at an early stage

A Low-Cost Tele-Presence Wheelchair System

OpenAIRE

Shen, Jiajun; Xu, Bin; Pei, Mingtao; Jia, Yunde

2016-01-01

This paper presents the architecture and implementation of a tele-presence wheelchair system based on tele-presence robot, intelligent wheelchair, and touch screen technologies. The tele-presence wheelchair system consists of a commercial electric wheelchair, an add-on tele-presence interaction module, and a touchable live video image based user interface (called TIUI). The tele-presence interaction module is used to provide video-chatting for an elderly or disabled person with the family mem...

Role-modelling and the hidden curriculum: New graduate nurses' professional socialisation.

Science.gov (United States)

Hunter, Kiri; Cook, Catherine

2018-05-12

To explore new graduate nurses' experiences of professional socialisation by registered nurses in hospital-based practice settings, and identify strategies that support professional identity development. Professionalism is reinforced and stabilised in the clinical environment through the 'hidden curriculum', with major learning coming from practice role-models. New graduates observe attitudes, behaviours, decision-making and skills, and gain feedback from registered nurses, which they translate into their own practice. Professional socialisation occurs through encounters with desirable and undesirable role-modelling; both are significant in professional identity formation. Qualitative descriptive design. Data collection was undertaken through semi-structured interviews with five new graduate nurse participants. A general inductive approach guided analysis. The meaningful descriptions gained provided insight into their experiences. Three main themes identified from the data include: 'Lessons from the wilderness'; 'Life in the wild'; and 'Belonging to a wolf pack'. The data set highlighted the major transitional process from student identity to registered nurse. New graduates' rethinking of beliefs and professional nursing identities were influenced by organisational pressures and experienced nurses role-modelling practices contrary to professional values. Despite encountering a range of professional behaviours, attitudes and dilemmas, new graduates were capable of moral agency and critical thinking. However, they rapidly acculturated and described compromises to cope. To promote high morale and a sense of belonging, a concerted effort is required by all nurses to facilitate the socialisation process to encourage self-authorship. A well-developed professional identity enhances nursing as a profession, contributing towards better healthcare delivery and outcomes. It is critically important how professional values are learnt within the culture of nursing. Tensions in

Role of Neuroinflammation in Evolution of Childhood Epilepsy.

Science.gov (United States)

Koh, Sookyong

2018-01-01

Until a decade ago, epilepsy research had focused mainly on alterations of neuronal activities and excitability. Such neurocentric emphasis has neglected the role of glia and involvement of inflammation in the pathogenesis of epilepsy. It is becoming clear that immune and inflammatory reactions do occur in the brain despite the brain's lack of conventional lymphatic drainage and graft acceptance and the presence of vascular brain barrier that tightly regulates infiltration of blood monocytes and lymphocytes. The critical roles of brain-resident immune mediators and of brain-infiltrating peripheral leukocytes are increasingly recognized. Inflammatory processes, including activation of microglia and astrocytes and production of proinflammatory cytokines and related molecules, occur in human epilepsy as well as in experimental models of epilepsy. Immune mechanism that underlies evolution of drug-resistant epilepsy and epileptic encephalopathy represents a new target and will aid in development of novel immunotherapeutic drugs and therapies against the key constituents in immune pathways.

The role of the leading edge vortex in lift augmentation of steadily revolving wings: a change in perspective.

Science.gov (United States)

Nabawy, Mostafa R A; Crowther, William J

2017-07-01

The presence of a stable leading edge vortex (LEV) on steadily revolving wings increases the maximum lift coefficient that can be generated from the wing and its role is important to understanding natural flyers and flapping wing vehicles. In this paper, the role of LEV in lift augmentation is discussed under two hypotheses referred to as 'additional lift' and 'absence of stall'. The 'additional lift' hypothesis represents the traditional view. It presumes that an additional suction/circulation from the LEV increases the lift above that of a potential flow solution. This behaviour may be represented through either the 'Polhamus leading edge suction' model or the so-called 'trapped vortex' model. The 'absence of stall' hypothesis is a more recent contender that presumes that the LEV prevents stall at high angles of attack where flow separation would normally occur. This behaviour is represented through the so-called 'normal force' model. We show that all three models can be written in the form of the same potential flow kernel with modifiers to account for the presence of a LEV. The modelling is built on previous work on quasi-steady models for hovering wings such that model parameters are determined from first principles, which allows a fair comparison between the models themselves, and the models and experimental data. We show that the two models which directly include the LEV as a lift generating component are built on a physical picture that does not represent the available experimental data. The simpler 'normal force' model, which does not explicitly model the LEV, performs best against data in the literature. We conclude that under steady conditions the LEV as an 'absence of stall' model/mechanism is the most satisfying explanation for observed aerodynamic behaviour. © 2017 The Author(s).

Moduli evolution in the presence of thermal corrections

International Nuclear Information System (INIS)

Barreiro, Tiago; Carlos, Beatriz de; Copeland, Edmund J.; Nunes, Nelson J.

2008-01-01

We study the effect of thermal corrections on the evolution of moduli in effective supergravity models. This is motivated by previous results in the literature suggesting that these corrections could alter and even erase the presence of a minimum in the zero temperature potential, something that would have disastrous consequences in these particular models. We show that, in a representative sample of flux compactification constructions, this need not be the case, although we find that the inclusion of thermal corrections can dramatically decrease the region of initial conditions for which the moduli are stabilized. Moreover, the bounds on the reheating temperature coming from demanding that the full, finite temperature potential, has a minimum can be considerably relaxed given the slow pace at which the evolution proceeds.

Kalman-Takens filtering in the presence of dynamical noise

Science.gov (United States)

Hamilton, Franz; Berry, Tyrus; Sauer, Timothy

2017-12-01

The use of data assimilation for the merging of observed data with dynamical models is becoming standard in modern physics. If a parametric model is known, methods such as Kalman filtering have been developed for this purpose. If no model is known, a hybrid Kalman-Takens method has been recently introduced, in order to exploit the advantages of optimal filtering in a nonparametric setting. This procedure replaces the parametric model with dynamics reconstructed from delay coordinates, while using the Kalman update formulation to assimilate new observations. In this article, we study the efficacy of this method for identifying underlying dynamics in the presence of dynamical noise. Furthermore, by combining the Kalman-Takens method with an adaptive filtering procedure we are able to estimate the statistics of the observational and dynamical noise. This solves a long-standing problem of separating dynamical and observational noise in time series data, which is especially challenging when no dynamical model is specified.

Transgenic mouse models to study the role of the macrophage scavenger receptor class A in atherosclerosis

NARCIS (Netherlands)

de Winther, M. P.; Gijbels, M. J.; van Dijk, K. W.; Havekes, L. M.; Hofker, M. H.

2000-01-01

Several in vivo studies have been performed on the role of the macrophage scavenger receptor class A (SR-A) in atherosclerosis using SR-A knockout mice. The results indicate both an antiatherogenic and a proatherogenic role of SR-A, depending on the nature of the animal model serving as the

The biomechanical role of the chondrocranium and sutures in a lizard cranium.

Science.gov (United States)

Jones, Marc E H; Gröning, Flora; Dutel, Hugo; Sharp, Alana; Fagan, Michael J; Evans, Susan E

2017-12-01

The role of soft tissues in skull biomechanics remains poorly understood. Not least, the chondrocranium, the portion of the braincase which persists as cartilage with varying degrees of mineralization. It also remains commonplace to overlook the biomechanical role of sutures despite evidence that they alter strain distribution. Here, we examine the role of both the sutures and the chondrocranium in the South American tegu lizard Salvator merianae We use multi-body dynamics analysis (MDA) to provide realistic loading conditions for anterior and posterior unilateral biting and a detailed finite element model to examine strain magnitude and distribution. We find that strains within the chondrocranium are greatest during anterior biting and are primarily tensile; also that strain within the cranium is not greatly reduced by the presence of the chondrocranium unless it is given the same material properties as bone. This result contradicts previous suggestions that the anterior portion (the nasal septum) acts as a supporting structure. Inclusion of sutures to the cranium model not only increases overall strain magnitudes but also leads to a more complex distribution of tension and compression rather than that of a beam under sagittal bending. © 2017 The Authors.

Role Models and Mentors in Mid-Pipeline Retention of Geoscience Students, Newark, NJ

Science.gov (United States)

Gates, A. E.; Kalczynski, M. J.

2012-12-01

Undergraduate minority students retained enthusiasm for majoring in the geosciences by a combination of working with advanced minority mentors and role models as well as serving as role models for middle and high school students in Geoscience Education programs in Newark, NJ. An academic year program to interest 8-10th grade students from the Newark Public schools in the Geosciences employs minority undergraduate students from Rutgers University and Essex Community College as assistants. There is an academic year program (Geoexplorers) and a science festival (Dinosaur Day) at the Newark Museum that employs Rutgers University students and a summer program that employs Rutgers and Essex Community College students. All students are members of the Garden State LSAMP and receive any needed academic support from that program. The students receive mentoring from minority graduate students, project personnel and participating Newark Public School teachers, many of whom are from minority groups. The main factor in success and retention, however, is their role as authorities and role models for the K-12 students. The assistants are respected and consulted by the K-12 students for their knowledge and authority in the geosciences. This positive feedback shows them that they can be regarded as geoscientists and reinforces their self-image and enthusiasm. It further reinforces their knowledge of Geoscience concepts. It also binds the assistants together into a self-supporting community that even extends to the non-participating minority students in the Rutgers program. Although the drop-out rate among minority Geoscience majors was high (up to 100%) prior to the initiation of the program, it has dropped to 0% over the past 3 years with 2 participants now in PhD programs and 2 others completing MS degrees this year. Current students are seriously considering graduate education. Prior to this program, only one minority graduate from the program continued to graduate school in the

Occupant-vehicle dynamics and the role of the internal model

Science.gov (United States)

Cole, David J.

2018-05-01

With the increasing need to reduce time and cost of vehicle development there is increasing advantage in simulating mathematically the dynamic interaction of a vehicle and its occupant. The larger design space arising from the introduction of automated vehicles further increases the potential advantage. The aim of the paper is to outline the role of the internal model hypothesis in understanding and modelling occupant-vehicle dynamics, specifically the dynamics associated with direction and speed control of the vehicle. The internal model is the driver's or passenger's understanding of the vehicle dynamics and is thought to be employed in the perception, cognition and action processes of the brain. The internal model aids the estimation of the states of the vehicle from noisy sensory measurements. It can also be used to optimise cognitive control action by predicting the consequence of the action; thus model predictive control (MPC) theory provides a foundation for modelling the cognition process. The stretch reflex of the neuromuscular system also makes use of the prediction of the internal model. Extensions to the MPC approach are described which account for: interaction with an automated vehicle; robust control; intermittent control; and cognitive workload. Further work to extend understanding of occupant-vehicle dynamic interaction is outlined. This paper is based on a keynote presentation given by the author to the 13th International Symposium on Advanced Vehicle Control (AVEC) conference held in Munich, September 2016.

Adsorption Behavior of Vanadium in Presence of alumina with Emphasize on Triple Layer Model Simulation

International Nuclear Information System (INIS)

El-Sayed, A.A.

2006-01-01

Adsorption behavior of vanadium in alumina colloidal solution as simulation for soil-water and/or sediment - water system was investigated. factors affecting this behavior including Ph, humic acid and alumina concentrations were studied. Three stages of vanadium adsorption on alumina were approved due to Ph changes. The first is increasing adsorption with increasing Ph, in the range 1-3. the second is decreasing adsorption with increasing Ph in the range 6-10. the third is constant adsorption at 100% adsorption in Ph range 3-8 at 10 g/l concentration of alumina. However, at 0.2 g/l, the maximum adsorption of vanadium became less than 100%.The effect of humic acid on the adsorption behavior of vanadium (V) was studied and compared with that of vanadium (IV) . Adsorption behaviors were studied at concentration 4.1 E-4 M for vanadium at 0.1 M ionic strength. Triple layer model was used for simulation of vanadium adsorption behavior in presence of alumina under the same working conditions. the results showed good validation and verification to the data practically found. speciation of vanadium in both homogenous and heterogeneous systems was also studied theoretically so as to verify the most abundant elemental species and its impact on the environment

On-farm starling populations and other environmental and management factors associated with the presence of cefotaxime and ciprofloxacin resistant E. coli among dairy cattle in Ohio.

Science.gov (United States)

Medhanie, Genet A; Pearl, David L; McEwen, Scott A; Guerin, Michele T; Jardine, Claire M; Schrock, Jennifer; LeJeune, Jeffrey T

2016-11-01

Wild birds that forage around livestock facilities have been implicated as vectors of antimicrobial resistant organisms. Although antimicrobial resistant bacteria have been isolated from European starlings (Sturnus vulgaris), their role in the dissemination of antimicrobial resistant elements in livestock facilities needs further investigation. To determine whether on-farm starling density and other factors were associated with the presence of cefotaxime and ciprofloxacin resistant E. coli among dairy cows in Ohio, bovine fecal pats from 150 farms were tested for the presence of cefotaxime and ciprofloxacin resistant E. coli. Each farm was visited twice (during the summer and fall of 2007-2009). Multi-level logistic regression models with a random intercept to account for fecal pats collected within a specific visit to a farm were used to assess the associations. The percentage of samples with cefotaxime and ciprofloxacin resistant E. coli was 13.4% and 13.6%, respectively. The percentage of farms having at least one sample testing positive for cefotaxime and ciprofloxacin resistant E. coli was 56.7% and 48.7%, respectively. The odds of detecting cefotaxime and ciprofloxacin resistant E. coli in the samples was significantly higher in 2007 compared to 2008 and 2009, in fall compared to summer, and from farms closer than 60km to starling night roost sites compared to the farms further than 60km. The presence of starlings during the day had a negative association with the likelihood of detecting cefotaxime resistant E. coli. Presence of calves also had a negative association with the likelihood of detecting both cefotaxime and ciprofloxacin resistant E. coli. European starlings might play a role in the dissemination of antimicrobial resistant agents in livestock facilities related to their daily population movements rather than the specific density of birds on farm during the day. Copyright © 2016 Elsevier B.V. All rights reserved.

Model-predictive control based on Takagi-Sugeno fuzzy model for electrical vehicles delayed model

DEFF Research Database (Denmark)

Khooban, Mohammad-Hassan; Vafamand, Navid; Niknam, Taher

2017-01-01

Electric vehicles (EVs) play a significant role in different applications, such as commuter vehicles and short distance transport applications. This study presents a new structure of model-predictive control based on the Takagi-Sugeno fuzzy model, linear matrix inequalities, and a non......-quadratic Lyapunov function for the speed control of EVs including time-delay states and parameter uncertainty. Experimental data, using the Federal Test Procedure (FTP-75), is applied to test the performance and robustness of the suggested controller in the presence of time-varying parameters. Besides, a comparison...... is made between the results of the suggested robust strategy and those obtained from some of the most recent studies on the same topic, to assess the efficiency of the suggested controller. Finally, the experimental results based on a TMS320F28335 DSP are performed on a direct current motor. Simulation...

Geopolitical aspects of Jewish presence in the Romanian principalities during the middle ages

Directory of Open Access Journals (Sweden)

Silviu Costachie

2007-11-01

Full Text Available „Geopolitical aspects of Jewish presence in the Romanian Principalities, during the Middle Ages” is probably one of the very few scientific articles about the geopolitical role of Jewish existence in Romanian territory during the last centuries. Few historians dared to deal with this topic, as it was regarded a very delicate issue. The author is the only geographer that managed to show us some geopolitical aspects regarding the immense role of this ethnic group in the political, economical and social life of the Romanian people during the Middle Ages. Based on various sources of information, and expressing all the facts from a geographical point of view, the author offers us an analytic study of the geopolitical role of Jews who had settled in Romanian territory between XIVth and XVIIIth centuries. Interesting facts are revealed regarding the way Romanian ‘voivodes’ came to the throne and the help they received from the Jews.

Hydrolysis of TBF and TiAP in presence of zirconium

International Nuclear Information System (INIS)

Vladimirova, M.V.; Kulikov, I.A.; Kuprij, A.A.

1992-01-01

Acid hydrolysis of organic solutions of tributyl phosphate (TBP) and tri-iso-amylphosphate (TiAP) in n-paraffin diluent in the presence of zirconium (0.025-0.1 mole/l) at nitric acid concentration of 0.3-1 mole/l is studied. Hydrolysis of extractants in a two-phase system, modelling conditions of spent fuel reprocessing and consisting of 1.1 mole/l TAP, 3 mole/l nitric acid at zirconium concentration in water phase 0.05-0.11 mole/l, at water-organic phase ratio 10:1 and at 60 deg C is also studied. Constants of TAP hydrolysis in organic and water phases are determined. Mechanism of increasing the TAP hydrolysis rate in zirconium presence is discussed. 5 refs., 2 figs., 5 tabs

The role of virtual reality and 3D modelling in built environment education

OpenAIRE

Horne, Margaret; Thompson, Emine Mine

2007-01-01

This study builds upon previous research on the integration of Virtual Reality (VR) within the built environment curriculum and aims to investigate the role of Virtual Reality and three-dimensional (3D) computer modelling on learning and teaching in a school of the built environment. In order to achieve this aim a number of academic experiences were analysed to explore the applicability and viability of 3D computer modelling and Virtual Reality (VR) into built environment subject areas. Altho...

Environmental predictors of ice seal presence in the Bering Sea.

Science.gov (United States)

Miksis-Olds, Jennifer L; Madden, Laura E

2014-01-01

Ice seals overwintering in the Bering Sea are challenged with foraging, finding mates, and maintaining breathing holes in a dark and ice covered environment. Due to the difficulty of studying these species in their natural environment, very little is known about how the seals navigate under ice. Here we identify specific environmental parameters, including components of the ambient background sound, that are predictive of ice seal presence in the Bering Sea. Multi-year mooring deployments provided synoptic time series of acoustic and oceanographic parameters from which environmental parameters predictive of species presence were identified through a series of mixed models. Ice cover and 10 kHz sound level were significant predictors of seal presence, with 40 kHz sound and prey presence (combined with ice cover) as potential predictors as well. Ice seal presence showed a strong positive correlation with ice cover and a negative association with 10 kHz environmental sound. On average, there was a 20-30 dB difference between sound levels during solid ice conditions compared to open water or melting conditions, providing a salient acoustic gradient between open water and solid ice conditions by which ice seals could orient. By constantly assessing the acoustic environment associated with the seasonal ice movement in the Bering Sea, it is possible that ice seals could utilize aspects of the soundscape to gauge their safe distance to open water or the ice edge by orienting in the direction of higher sound levels indicative of open water, especially in the frequency range above 1 kHz. In rapidly changing Arctic and sub-Arctic environments, the seasonal ice conditions and soundscapes are likely to change which may impact the ability of animals using ice presence and cues to successfully function during the winter breeding season.

Environmental predictors of ice seal presence in the Bering Sea.

Directory of Open Access Journals (Sweden)

Jennifer L Miksis-Olds

Full Text Available Ice seals overwintering in the Bering Sea are challenged with foraging, finding mates, and maintaining breathing holes in a dark and ice covered environment. Due to the difficulty of studying these species in their natural environment, very little is known about how the seals navigate under ice. Here we identify specific environmental parameters, including components of the ambient background sound, that are predictive of ice seal presence in the Bering Sea. Multi-year mooring deployments provided synoptic time series of acoustic and oceanographic parameters from which environmental parameters predictive of species presence were identified through a series of mixed models. Ice cover and 10 kHz sound level were significant predictors of seal presence, with 40 kHz sound and prey presence (combined with ice cover as potential predictors as well. Ice seal presence showed a strong positive correlation with ice cover and a negative association with 10 kHz environmental sound. On average, there was a 20-30 dB difference between sound levels during solid ice conditions compared to open water or melting conditions, providing a salient acoustic gradient between open water and solid ice conditions by which ice seals could orient. By constantly assessing the acoustic environment associated with the seasonal ice movement in the Bering Sea, it is possible that ice seals could utilize aspects of the soundscape to gauge their safe distance to open water or the ice edge by orienting in the direction of higher sound levels indicative of open water, especially in the frequency range above 1 kHz. In rapidly changing Arctic and sub-Arctic environments, the seasonal ice conditions and soundscapes are likely to change which may impact the ability of animals using ice presence and cues to successfully function during the winter breeding season.

Capturing Online Presence

DEFF Research Database (Denmark)

de Bakker, Frank; Hellsten, Lina

2013-01-01

The rise of Internet-mediated communication poses possibilities and challenges for organisation studies, also in the area of corporate social responsibility (CSR) and business and society interactions. Although social media are attracting more and more attention in this domain, websites also remain...... an important channel for CSR debate. In this paper, we present an explorative study of activist groups’ online presence via their websites and propose a combination of methods to study both the structural positioning of websites (hyperlink network analysis) and the meanings in these websites (semantic co...... activist networks’ online presence can provide insights into the tactics these networks apply to achieve institutional change on CSR issues. Meanwhile, we identify some notable differences between styles and word use in the two organisations’ websites. We conclude with a set of suggestions for future...

Social influences on smoking in American workers: the role of the presence of smokers in the workplace and in the home.

Science.gov (United States)

Holahan, Carole K; Holahan, Charles J; Li, Xiaoyin; Jung, Sooin

2013-01-01

To examine the relationship between the presence of smokers in the workplace and smokers in the home and current smoking status among employed men and women. Analysis of data from the second wave of the nationally representative Survey of Midlife Development in the United States (2004-2006). Sample of 627 currently employed men and women, aged 34 to 82 (M = 51), who had been regular cigarette smokers at some time. Survey items indexing presence of smokers in the respondents' immediate work area and home and their current smoking status. Multiple logistic regression analyses, controlling for age, gender, education, race, and job type. Examined together, smokers in the workplace (OR = 2.83) and smokers in the home (OR = 6.09) were uniquely associated with current smoking status. Moreover, smokers in the home reduced the association between smokers in the workplace and current smoking. The presence of smokers in the workplace was associated with a more than fourfold increase in current smoking among respondents with no smokers in the home, but was unrelated to current smoking among respondents with smokers in the home. Failure to consider the presence of smokers in the home significantly limits the potential impact of workplace smoking interventions.

Modelling the effect of perceived interdependence among mental healthcare professionals on their work role performance.

Science.gov (United States)

Markon, Marie-Pierre; Chiocchio, François; Fleury, Marie-Josée

2017-07-01

The purpose of mental healthcare system reform was to enhance service efficiency by strengthening primary mental healthcare and increasing service integration in communities. Reinforcing interprofessional teamwork also intended to address the extensive and multidimensional needs of patients with mental disorders by bringing together a broader array of expertise. In this context, mental healthcare professionals (MHCPs) from various health and social care professions are more interdependent in many aspects of their work (tasks, resources, and goals). We wanted to examine the effect of perceived interdependence among MHCPs on their work role performance in the context of mental healthcare. For this purpose, we developed and tested a model coherent with the Input-Mediator-Outcome-Input (IMOI) framework of team effectiveness. Data from questionnaires administered to 315 MHCPs from four local health service networks in Quebec, Canada were analysed through structural equation modelling and mediation analysis. The structural equation model provided a good fit for the data and explained 51% of the variance of work role performance. Perceived collaboration, confidence in the advantages of interprofessional collaboration, involvement in the decision process, knowledge sharing, and satisfaction with the nature of the work partially mediated the effect of perceived interdependence among team members on work role performance. Therefore, perceived interdependence among team members had a positive impact on the work role performance of MHCPs mostly through its effect on favourable team functioning features. This implies, in practice, that increased interdependence of MHCPs would be more likely to truly enhance work role performance if team-based interventions to promote collaborative work and interprofessional teaching and training programs to support work within interprofessional teams were jointly implemented. Participation in the decision process and knowledge sharing should

Migrant remittances in Greece and Portugal: distribution by country of provenance and the role of the banking presence.

Science.gov (United States)

Karafolas, S

1998-01-01

"The article examines migrant remittances per country of origin of remittances for two emigration countries, Greece and Portugal. It also examines the relationship between remittances and the number of banks of the emigration country in the host country. From the analysis it appears that remittances are concentrated in a small number of host countries--the U.S and Germany for the Greek case; France (mainly) and the U.S., Germany and Switzerland for the Portuguese case. Remittances followed similar trends, characterized by especially high growth during the 1970s and also during the second half of the 1980s. For both countries similar trends are observed regarding the relationship between remittances and remittances per migrant with the presence of banks of the home country at the important countries of origin of remittances. The growth of the banking presence in host countries had a significant impact on the growth of migrant remittances." (EXCERPT)

Studies on oxidative radiolysis of ibuprofen in presence of potassium persulfate

International Nuclear Information System (INIS)

Paul, Jhimli; Naik, D.B.; Bhardwaj, Y.K.; Varshney, Lalit

2014-01-01

The radiolysis of ibuprofen (IBP), a model pharmaceutical compound, was studied by gamma irradiation in an aqueous solution in the presence and absence of potassium persulfate (K 2 S 2 O 8 ). The extent of mineralization was investigated by measuring the UV–visible spectra, decrease in the chemical oxygen demand (COD) and the total organic carbon (TOC) content of aqueous IBP solution at different doses. The gamma radiolysis, in the presence of K 2 S 2 O 8 , required much lesser dose compared to in the absence of K 2 S 2 O 8 for the same extent of mineralization of aqueous IBP solution. The pulse radiolysis of IBP was carried out under different radiolytic conditions to understand the mechanism of efficient mineralization of IBP during gamma radiolysis in the presence of K 2 S 2 O 8 . It was found that unlike · OH radical, SO 4 ·− radical preferentially produces benzyl type of radicals via the formation of the benzene radical cation. The results concluded that the gamma radiolysis in presence of K 2 S 2 O 8 could be one of the efficient advanced oxidation processes for degradation of pharmaceutical compounds present in the aqueous solution. - Highlights: • The radiolysis of aqueous solution of Ibuprofen (IBP) was investigated. • The COD and TOC content decreased significantly in presence of K 2 S 2 O 8 . • Pulse radiolysis studies revealed the mechanism of mineralization of IBP. • The presence of K 2 S 2 O 8 increased the efficiency of gamma radiolysis

Presence of Ca2+-dependent K+ channels in chemosensory cilia support a role in odor transduction.

Science.gov (United States)

Delgado, Ricardo; Saavedra, M Veronica; Schmachtenberg, Oliver; Sierralta, Jimena; Bacigalupo, Juan

2003-09-01

Olfactory receptor neurons (ORNs) respond to odorants with changes in the action potential firing rate. Excitatory responses, consisting of firing increases, are mediated by a cyclic AMP cascade that leads to the activation of cationic nonselective cyclic nucleotide-gated (CNG) channels and Ca2+-dependent Cl- (ClCa) channels. This process takes place in the olfactory cilia, where all protein components of this cascade are confined. ORNs from various vertebrate species have also been shown to generate inhibitory odor responses, expressed as decreases in action potential discharges. Odor inhibition appears to rely on Ca2+-dependent K+ (KCa) channels, but the underlying transduction mechanism remains unknown. If these channels are involved in odor transduction, they are expected to be present in the olfactory cilia. We found that a specific antibody against a large conductance KCa recognized a protein of approximately 116 kDa in Western blots of purified rat olfactory ciliary membranes. Moreover, the antibody labeled ORN cilia in isolated ORNs from rat and toad (Caudiverbera caudiverbera). In addition, single-channel recordings from inside-out membrane patches excised from toad chemosensory cilia showed the presence of 4 different types of KCa channels, with unitary conductances of 210, 60, 12, and 29 and 60 pS, high K+-selectivity, and Ca2+ sensitivities in the low micromolar range. Our work demonstrates the presence of K+ channels in the ORN cilia and supports their participation in odor transduction.

Experiential Role of Artefacts in Cooperative Design

OpenAIRE

Vyas, Dhaval; Heylen, Dirk K.J.; Nijholt, Antinus; van der Veer, Gerrit C.; Caroll, J.M.

2009-01-01

The role of material artefacts in supporting distributed and co-located work practices has been well acknowledged within the HCI and CSCW research. In this paper, we show that in addition to their ecological, coordinative and organizational support, artefacts also play an ‘experiential’ role. In this case, artefacts not only improve efficiency or have a purely functional role (e.g. allowing people to complete tasks quickly), but the presence and manifestations of these artefacts bring quality...

Factors influencing presence in virtual worlds.

Science.gov (United States)

Chow, Meyrick C M

2012-01-01

Virtual worlds are showing potential as an effective platform for a variety of activities, including learning. The concept of presence (the sensation of "being there" in a mediated environment) has received substantial attention from the virtual reality community, and the effectiveness of virtual worlds has often been linked to the feelings of presence reported by their users. The present study examined the effects of attitude and perceived ease of use on sense of presence in Second Life, which is one of the most known and used virtual worlds. Based on data from a survey of 206 nursing students, hypotheses are empirically tested. Findings suggest that users' attitude toward using Second Life and their perceived ease of use of it have a positive effect on their sense of presence in the virtual environment. This study advances our understanding of factors influencing presence in virtual worlds.

Evaluation of airborne lidar data to predict vegetation Presence/Absence

Science.gov (United States)

Palaseanu-Lovejoy, M.; Nayegandhi, A.; Brock, J.; Woodman, R.; Wright, C.W.

2009-01-01

This study evaluates the capabilities of the Experimental Advanced Airborne Research Lidar (EAARL) in delineating vegetation assemblages in Jean Lafitte National Park, Louisiana. Five-meter-resolution grids of bare earth, canopy height, canopy-reflection ratio, and height of median energy were derived from EAARL data acquired in September 2006. Ground-truth data were collected along transects to assess species composition, canopy cover, and ground cover. To decide which model is more accurate, comparisons of general linear models and generalized additive models were conducted using conventional evaluation methods (i.e., sensitivity, specificity, Kappa statistics, and area under the curve) and two new indexes, net reclassification improvement and integrated discrimination improvement. Generalized additive models were superior to general linear models in modeling presence/absence in training vegetation categories, but no statistically significant differences between the two models were achieved in determining the classification accuracy at validation locations using conventional evaluation methods, although statistically significant improvements in net reclassifications were observed. ?? 2009 Coastal Education and Research Foundation.

Worldwide Diversity in Funded Pension Plans : Four Role Models on Choice and Participation

NARCIS (Netherlands)

Garcia Huitron, Manuel; Ponds, Eduard

2015-01-01

This paper provides an in-depth comparison of funded pension savings plans around the world. The large variety in plan designs is a reflection of historical, cultural and institutional diversity. We postulate a new classification of four role models of funded pension plans, primarily based on choice

An approach for activity-based DEVS model specification

DEFF Research Database (Denmark)

Alshareef, Abdurrahman; Sarjoughian, Hessam S.; Zarrin, Bahram

2016-01-01

Creation of DEVS models has been advanced through Model Driven Architecture and its frameworks. The overarching role of the frameworks has been to help develop model specifications in a disciplined fashion. Frameworks can provide intermediary layers between the higher level mathematical models...... and their corresponding software specifications from both structural and behavioral aspects. Unlike structural modeling, developing models to specify behavior of systems is known to be harder and more complex, particularly when operations with non-trivial control schemes are required. In this paper, we propose specifying...... activity-based behavior modeling of parallel DEVS atomic models. We consider UML activities and actions as fundamental units of behavior modeling, especially in the presence of recent advances in the UML 2.5 specifications. We describe in detail how to approach activity modeling with a set of elemental...

Continental rift architecture and patterns of magma migration: a dynamic analysis based on centrifuge models.

NARCIS (Netherlands)

Corti, G.; Bonini, M.; Sokoutis, D.; Innocenti, F.; Manetti, P.; Cloetingh, S.A.P.L.; Mulugeta, G.

2004-01-01

Small-scale centrifuge models were used to investigate the role of continental rift structure in controlling patterns of magma migration and emplacement. Experiments considered the reactivation of weakness zones in the lower crust and the presence of magma at Moho depths. Results suggest that

Accurate landmarking of three-dimensional facial data in the presence of facial expressions and occlusions using a three-dimensional statistical facial feature model.

Science.gov (United States)

Zhao, Xi; Dellandréa, Emmanuel; Chen, Liming; Kakadiaris, Ioannis A

2011-10-01

Three-dimensional face landmarking aims at automatically localizing facial landmarks and has a wide range of applications (e.g., face recognition, face tracking, and facial expression analysis). Existing methods assume neutral facial expressions and unoccluded faces. In this paper, we propose a general learning-based framework for reliable landmark localization on 3-D facial data under challenging conditions (i.e., facial expressions and occlusions). Our approach relies on a statistical model, called 3-D statistical facial feature model, which learns both the global variations in configurational relationships between landmarks and the local variations of texture and geometry around each landmark. Based on this model, we further propose an occlusion classifier and a fitting algorithm. Results from experiments on three publicly available 3-D face databases (FRGC, BU-3-DFE, and Bosphorus) demonstrate the effectiveness of our approach, in terms of landmarking accuracy and robustness, in the presence of expressions and occlusions.