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Sample records for exploration model foe

  1. Hit or Run: Exploring Aggressive and Avoidant Reactions to Interpersonal Provocation Using a Novel Fight-or-Escape Paradigm (FOE

    Directory of Open Access Journals (Sweden)

    Frederike Beyer

    2017-10-01

    Full Text Available Interpersonal provocation presents an approach-avoidance conflict to the provoked person: responding aggressively might yield the joy of retribution, whereas withdrawal can provide safety. Experimental aggression studies typically measure only retaliation intensity, neglecting whether individuals want to confront the provocateur at all. To overcome this shortcoming of previous measures, we developed and validated the Fight-or-Escape paradigm (FOE. The FOE is a competitive reaction time (RT task in which the winner can choose the volume of a sound blast to be directed at his/her opponent. Participants face two ostensible opponents who consistently select either high or low punishments. At the beginning of each trial, subjects are given the chance to avoid the encounter for a limited number of times. In a first experiment (n = 27, all women, we found that fear potentiation (FP of the startle response was related to lower scores in a composite measure of aggression and avoidance against the provoking opponent. In a second experiment (n = 34, 13 men, we altered the paradigm such that participants faced the opponents in alternating rather than in random order. Participants completed the FOE as well as the Dot-Probe Task (DPT and the Approach-Avoidance Task (AAT. Subjects with higher approach bias scores in the AAT avoided the provoking opponent less frequently. Hence, individuals with high threat reactivity and low approach motivation displayed more avoidant responses to provocation, whereas participants high in approach motivation were more likely to engage in aggressive interactions when provoked. The FOE is thus a promising laboratory measure of avoidance and aggression.

  2. Exploring social media and admissions decision-making – friends or foes?

    Directory of Open Access Journals (Sweden)

    Marcus Law

    2016-10-01

    Full Text Available Background: Despite the ever-increasing use of social media (e.g., Facebook, Twitter little is known about its use in medical school admissions. This qualitative study explores whether and how social media (SM is used in undergraduate admissions in Canada, and the attitudes of admissions personnel towards such use. Methods: Phone interviews were conducted with admissions deans and nominated admissions personnel. A qualitative descriptive analysis was performed using iterative coding and comparing, and grouping data into themes. Results: Personnel from 15 of 17 Canadian medical schools participated. A sizeable proportion had, at some point, examined social media (SM profiles to acquire information on applicants. Participants did not report using it explicitly to screen all applicants (primary use; however, several did admit to looking at SM to follow up on preliminary indications of misbehaviour (secondary use. Participants articulated concerns, such as validity and equity, about using SM in admissions. Despite no schools having existing policy, participants expressed openness to future use.   Conclusions: While some of the 15 schools had used SM to acquire information on applicants, criteria for formulating judgments were obscure, and participants expressed significant apprehension, based on concerns for fairness and validity. Findings suggest participant ambivalence and ongoing risks associated with “hidden” selection practices.

  3. Exploring social media and admissions decision-making - friends or foes?

    Science.gov (United States)

    Law, Marcus; Mylopoulos, Maria; Veinot, Paula; Miller, Daniel; Hanson, Mark D

    2016-10-01

    Despite the ever-increasing use of social media (e.g., Facebook, Twitter) little is known about its use in medical school admissions. This qualitative study explores whether and how social media (SM) is used in undergraduate admissions in Canada, and the attitudes of admissions personnel towards such use. Phone interviews were conducted with admissions deans and nominated admissions personnel. A qualitative descriptive analysis was performed using iterative coding and comparing, and grouping data into themes. Personnel from 15 of 17 Canadian medical schools participated. A sizeable proportion had, at some point, examined social media (SM) profiles to acquire information on applicants. Participants did not report using it explicitly to screen all applicants (primary use); however, several did admit to looking at SM to follow up on preliminary indications of misbehaviour (secondary use). Participants articulated concerns, such as validity and equity, about using SM in admissions. Despite no schools having existing policy, participants expressed openness to future use. While some of the 15 schools had used SM to acquire information on applicants, criteria for formulating judgments were obscure, and participants expressed significant apprehension, based on concerns for fairness and validity. Findings suggest participant ambivalence and ongoing risks associated with "hidden" selection practices.

  4. Redox Models in Chemistry Textbooks for the Upper Secondary School: Friend or Foe?

    Science.gov (United States)

    Osterlund, Lise-Lotte; Berg, Anders; Ekborg, Margareta

    2010-01-01

    We have investigated how chemistry textbooks use models of redox reactions in different subject areas, how they change models between and within the topics, and how they deal with specific learning difficulties identified in the literature. The textbooks examined were published for use in the natural science programme in Swedish upper secondary…

  5. The Effects of Genetic Background of Mouse Models of Cancer: Friend or Foe?

    Science.gov (United States)

    Reilly, Karlyne M

    2016-03-01

    Over the past century, mice have been selectively bred to give rise to the strains used in biomedical research today. Mouse models of cancer allow researchers to control variables of diet, environment, and genetic heterogeneity to better dissect the role of these factors in cancer in humans. Because of the important role of genetic background in cancer, the strain of the mouse can introduce confounding results in studies of mouse models if not properly controlled. Conversely, genetic variation between strains can also provide important new insights into cancer mechanisms. Here, the sources of genetic heterogeneity in mouse models are reviewed, with an explanation of how heterogeneity modifies cancer phenotypes. © 2016 Cold Spring Harbor Laboratory Press.

  6. Caffeine: Friend or Foe?

    Science.gov (United States)

    Doepker, Candace; Lieberman, Harris R; Smith, Andrew Paul; Peck, Jennifer D; El-Sohemy, Ahmed; Welsh, Brian T

    2016-01-01

    The debate on the safety of and regulatory approaches for caffeine continues among various stakeholders and regulatory authorities. This decision-making process comes with significant challenges, particularly when considering the complexities of the available scientific data, making the formulation of clear science-based regulatory guidance more difficult. To allow for discussions of a number of key issues, the North American Branch of the International Life Sciences Institute (ILSI) convened a panel of subject matter experts for a caffeine-focused session entitled "Caffeine: Friend or Foe?," which was held during the 2015 ILSI Annual Meeting. The panelists' expertise covered topics ranging from the natural occurrence of caffeine in plants and interindividual metabolism of caffeine in humans to specific behavioral, reproductive, and cardiovascular effects related to caffeine consumption. Each presentation highlighted the potential risks, benefits, and challenges that inform whether caffeine exposure warrants concern. This paper aims to summarize the key topics discussed during the session.

  7. Friend-foe Discrimination, Caffeine, and Sentry Duty

    National Research Council Canada - National Science Library

    Johnson, Richard

    1999-01-01

    ...: (a) 200 mg caffeine, foe-only; (b) 200 mg caffeine, friend-foe; (c) placebo, foe-only; and (d) placebo. friend-foe. Participants monitored the target scene of the Weaponeer Rifle Marksmanship Simulator with instructions to fire at enemy targets...

  8. Exploring Children's Data Modeling.

    Science.gov (United States)

    Lehrer, Richard; Romberg, Thomas

    1996-01-01

    Two experiments examined fifth-grade students' reasoning about data modeling: one involved development of hypermedia documents, the other, use of a simple randomization distribution to test students' hypotheses. Found that data construction and analysis provide an opportunity to involve students in the important enterprise of mathematical…

  9. Development of a Geologic Exploration Model foe the Permo-Pennsylvanian Petroleum System in South-Central Montana

    Energy Technology Data Exchange (ETDEWEB)

    David A. Lopez

    2007-06-30

    Eolian sands are the main Pennsylvanian Tensleep Sandstone reservoir rocks, and were deposited in a near-shore environment interbedded with near-shore marine and sabkha calcareous and dolomitic rocks. Within the Tensleep, numerous cycles are characterized by basal marine or sabkha calcareous sandstone or dolomitic sandstone overlain by porous and permeable eolian sandstone, which in turn is capped by marine sandstone. The cycles represent the interplay of near-shore marine, sabkha, and eolian environments. On the west side of the project area, both the lower and upper Tensleep are present and the total thickness reaches a maximum of about 240 ft. The lower Tensleep is 100 to 120 ft thick and consists of a sequence of repeating cycles of limey shallow marine sandstone, sandy limestone, and sandy dolomite. The upper Tensleep is generally characterized by cycles of sandy limestone or dolomite, overlain by light-colored, eolian dune sandstone capped by marine limey sandstone. In the central and eastern parts of the project area, only the lower Tensleep is present, but here eolian sandstones are in cycles much like those in the west in the upper Tensleep. The lower Tensleep is quite variable in thickness, ranging from about 25 ft to over 200 ft. Oil accumulations in the Tensleep are best described as structurally modified paleostratigraphic accumulations. At Frannie Field, the irregular oil column can be explained by a post-Tensleep channel scour on the west flank of the anticline. On the Powder River Basin side of the project area, the Soap Creek and Lodge Grass Fields produce from the Permo-Pennsylvanian system. In these two fields, erosional remnants of eolian sandstone control the production, similar to the situation at Frannie Field. At Soap Creek the trap is enhanced by structural closure. In the Lodge Grass area, Tensleep oil is trapped in preserved dunes in the footwall of a Laramide reverse fault. Oil generation and migration was early. Two hypotheses have been presented: migration occurred (1) before mid-Jurassic erosion produced a major regional unconformity or (2) about 82 million years ago. Migration pre-Laramide occurred because oil in both the Bighorn Basin and the Powder River Basin are part of the same petroleum system. Geochemical analyses of oils from producing fields across the region show the oils are all similar and have the same source and generation history. No Phosphoria source rocks exist in the project area of south-central Montana, requiring that oil migrated from distant source areas, probably in central and southwestern Wyoming. Oil shows and production in the Tensleep are absent in the northern part of the project area. This appears to be controlled by the merging of the top of the Tensleep Sandstone and the Jurassic unconformity (top of the Triassic Chugwater Formation). There should be potential for the discovery of oil in Tensleep stratigraphic traps or combination traps everywhere south of the Jurassic-Pennsylvanian Isopach zero contour except where the Tensleep has been exposed by uplift and erosion. Known Tensleep fields in south-central Montana are generally small in area, which agrees with outcrop studies that show eolian dune sequences are generally quite small in lateral extent, on the order of 10 to 40 acres. Although existing fields are small in area, they are very productive; individual wells will probably make 300,000 to 500,000 barrels of oil. In the project area, hydrodynamic considerations are important. All the existing Tensleep fields have active water drives. In many cases, the reservoir pressure today is as it was when initially discovered. In areas of high structural complexity, such as the Lodge Grass-Crow Agency fault and the Lake Basin fault zone, significant structural closure may be necessary to trap oil because of the strong hydrodynamic influence exerted by the underlying Madison Formation aquifer.

  10. Exploration through Business Model Innovation

    DEFF Research Database (Denmark)

    Knab, Sebastian; Rohrbeck, René

    2015-01-01

    utilities in the emerging virtual power plant market. Based on the behavioral theory of the firm, we study how the cognitive and physical elements of an incumbent’s strategy can be changed and how these changes affect its business model innovation activities in the exploration process. Our preliminary......With this research we aim to enhance our understanding about how incumbents can explore emerging opportunities through business model innovation. Using a multiple-case, longitudinal research design spanning 2008 to 2014 we investigate exploration activities of the four largest German energy...... findings suggest that the use of synergies and probing can lead to changing physical elements and primarily increase business model maturity. CEO change and structural separation can lead to changing cognitive elements and primarily increase business model sophistication....

  11. Media and breastfeeding: Friend or foe?

    Directory of Open Access Journals (Sweden)

    Peuchaud Sheila

    2008-08-01

    Full Text Available Abstract The mass media have the potential to be powerful friends or foes in promoting breastfeeding. The media could help by putting the issue of breastfeeding on policy agendas and by framing breastfeeding as healthy and normative for baby and mother. Currently, however, it looks as if the media are more often contributing to perceptions that breastfeeding is difficult for mothers and potentially dangerous for babies. This paper presents a brief overview of research on the media and breastfeeding, some insights into the market forces and human psychological factors that may play into media representations of breastfeeding, and strategies to help breastfeeding advocates work more effectively with the media.

  12. Multiple Vaccinations: Friend or Foe

    Science.gov (United States)

    Church, Sarah E.; Jensen, Shawn M.; Twitty, Chris; Bahjat, Keith; Hu, Hong-Ming; Urba, Walter J.; Fox, Bernard A.

    2013-01-01

    Few immunotherapists would accept the concept of a single vaccination inducing a therapeutic anti-cancer immune response in a patient with advanced cancer. But what is the evidence to support the “more-is-better” approach of multiple vaccinations? Since we are unaware of trials comparing the effect of a single vaccine versus multiple vaccinations on patient outcome, we considered that an anti-cancer immune response might provide a surrogate measure of the effectiveness of vaccination strategies. Since few large trials include immunological monitoring, the majority of information is gleaned from smaller trials in which an evaluation of immune responses to vaccine or tumor, before and at one or more times following the first vaccine was performed. In some studies there is convincing evidence that repeated administration of a specific vaccine can augment the immune response to antigens contained in the vaccine. In other settings multiple vaccinations can significantly reduce the immune response to one or more targets. Results from three large adjuvant vaccine studies support the potential detrimental effect of multiple vaccinations as clinical outcomes in the control arms were significantly better than that for treatment groups. Recent research has provided insights into mechanisms that are likely responsible for the reduced responses in the studies noted above, but supporting evidence from clinical specimens is generally lacking. Interpretation of these results is further complicated by the possibility that the dominant immune response may evolve to recognize epitopes not present in the vaccine. Nonetheless, the FDA-approval of the first therapeutic cancer vaccine and recent developments from preclinical models and clinical trials provide a substantial basis for optimism and a critical evaluation of cancer vaccine strategies. PMID:21952289

  13. Explorations in Elementary Mathematical Modeling

    Science.gov (United States)

    Shahin, Mazen

    2010-01-01

    In this paper we will present the methodology and pedagogy of Elementary Mathematical Modeling as a one-semester course in the liberal arts core. We will focus on the elementary models in finance and business. The main mathematical tools in this course are the difference equations and matrix algebra. We also integrate computer technology and…

  14. Explorative methods in linear models

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar

    2004-01-01

    The author has developed the H-method of mathematical modeling that builds up the model by parts, where each part is optimized with respect to prediction. Besides providing with better predictions than traditional methods, these methods provide with graphic procedures for analyzing different feat...... features in data. These graphic methods extend the well-known methods and results of Principal Component Analysis to any linear model. Here the graphic procedures are applied to linear regression and Ridge Regression.......The author has developed the H-method of mathematical modeling that builds up the model by parts, where each part is optimized with respect to prediction. Besides providing with better predictions than traditional methods, these methods provide with graphic procedures for analyzing different...

  15. Explorations in Elementary Mathematical Modeling

    Directory of Open Access Journals (Sweden)

    Mazen Shahin

    2010-06-01

    Full Text Available In this paper we will present the methodology and pedagogy of Elementary Mathematical Modeling as a one-semester course in the liberal arts core. We will focus on the elementary models in finance and business. The main mathematical tools in this course are the difference equations and matrix algebra. We also integrate computer technology and cooperative learning into this inquiry-based learning course where students work in small groups on carefully designed activities and utilize available software to support problem solving and understanding of real life situations. We emphasize the use of graphical and numerical techniques, rather than theoretical techniques, to investigate and analyze the behavior of the solutions of the difference equations.As an illustration of our approach, we will show a nontraditional and efficient way of introducing models from finance and economics. We will also present an interesting model of supply and demand with a lag time, which is called the cobweb theorem in economics. We introduce a sample of a research project on a technique of removing chaotic behavior from a chaotic system.

  16. Noradrenaline and the kidney: friends or foes?

    Science.gov (United States)

    Bellomo, Rinaldo; Di Giantomasso, David

    2001-01-01

    Septic shock, systemic inflammation and pharmacological vasodilatation are often complicated by systemic hypotension, despite aggressive fluid resuscitation and an increased cardiac output. If the physician wishes to restore arterial pressure (>80–85 mmHg), with the aim of sustaining organ perfusion pressure, the administration of systemic vasopressor agents, such as noradrenaline, becomes necessary. Because noradrenaline induces vasoconstriction in many vascular beds (visibly in the skin), however, it may decrease renal and visceral blood flow, impairing visceral organ function. This unproven fear has stopped clinicians from using noradrenaline more widely. In vasodilated states, unlike in normal circulatory conditions, however, noradrenaline may actually improve visceral organ blood flow. Animal studies show that the increased organ perfusion pressures achieved with noradrenaline improve the glomerular filtration rate and renal blood flow. There are no controlled human data to define the effects of noradrenaline on the kidney, but many patient series show a positive effect on glomerular filtration rate and urine output. There is no reason to fear the use of noradrenaline. If it is used to support a vasodilated circulation with a normal or increased cardiac output, it is likely to be the kidney's friend not its foe. PMID:11737909

  17. Fever and sickness behavior: Friend or foe?

    Science.gov (United States)

    Harden, L M; Kent, S; Pittman, Q J; Roth, J

    2015-11-01

    Fever has been recognized as an important symptom of disease since ancient times. For many years, fever was treated as a putative life-threatening phenomenon. More recently, it has been recognized as an important part of the body's defense mechanisms; indeed at times it has even been used as a therapeutic agent. The knowledge of the functional role of the central nervous system in the genesis of fever has greatly improved over the last decade. It is clear that the febrile process, which develops in the sick individual, is just one of many brain-controlled sickness symptoms. Not only will the sick individual appear "feverish" but they may also display a range of behavioral changes, such as anorexia, fatigue, loss of interest in usual daily activities, social withdrawal, listlessness or malaise, hyperalgesia, sleep disturbances and cognitive dysfunction, collectively termed "sickness behavior". In this review we consider the issue of whether fever and sickness behaviors are friend or foe during: a critical illness, the common cold or influenza, in pregnancy and in the newborn. Deciding whether these sickness responses are beneficial or harmful will very much shape our approach to the use of antipyretics during illness. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. DMPD: Toll-like receptor 9 in murine lupus: more friend than foe! [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18241699 Toll-like receptor 9 in murine lupus: more friend than foe! Yu P, Musette P, Peng SL. Immunobiology...pus: more friend than foe! Authors Yu P, Musette P, Peng SL. Publication Immunobiology

  19. Non-coding RNAs in polyglutamine disorders: friend or foe?

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences; Volume 33; Issue 2. Non-coding RNAs in polyglutamine disorders: friend or foe? Sonali Sengupta Subramaniam Ganesh. Mini-review Volume 33 Issue 2 June 2008 pp 303-306. Fulltext. Click here to view fulltext PDF. Permanent link:

  20. ong-term trends of foE and geomagnetic activity variations

    Science.gov (United States)

    Mikhailov, A. V.; de La Morena, B. A.

    2003-03-01

    A relationship between foE trends and geomagnetic activity long-term variations has been revealed for the first time. By analogy with earlier obtained results on the foF2 trends it is possible to speak about the geomagnetic control of the foE long-term trends as well. Periods of increasing geomagnetic activity correspond to negative foE trends, while these trends are positive for the decreasing phase of geomagnetic activity. This natural relationship breaks down around 1970 (on some stations later) when pronounced positive foE trends have appeared on most of the stations considered. The dependence of foE trends on geomagnetic activity can be related with nitric oxide variations at the E-layer heights. The positive foE trends that appeared after the break down effect may also be explained by the [NO] decrease which is not related to geomagnetic activity variations. But negative trends or irregular foE variations on some stations for the same time period require some different mechanism. Chemical pollution of the lower thermosphere due to the anthropogenic activity may be responsible for such abnormal foE behavior after the end of the 1960s.

  1. The concept exploration model and an application

    Science.gov (United States)

    Zhang, Yin; Gao, Kening; Zhang, Bin

    2015-03-01

    For a user who is unfamiliar with a target domain, the first step to conduct an exploratory search task is to go over a learning phrase, which means to learn from the search results to acquire basic domain knowledge. Since lots of search results could be returned by a search engine, and usually only a small portion of all the results contain valuable knowledge to the current search task, the user usually needs to read lots of documents and could only learn limited knowledge. This makes the learning phrase a low efficiency, time consuming and easy to fail process. In order to support the learning phrase of the exploratory search process, this paper proposes the concept exploration model which describes how a user reads search results and figures out interesting concepts. The model focuses on how does a user explore related concepts during the learning phrase, and factorizes the concept exploration process as a production of the probability that concepts form a specific relation structure, and the probability that a user is attracted by a concept. In an application example, the concept exploration model is used in a query recommendation task to support exploratory search. We demonstrate how to determine the two probabilistic factors and evaluate the model with a set of metrics. The experiment results show that the application example could help users explore domain concepts more effectively.

  2. Exploration for Understanding in Cognitive Modeling

    Science.gov (United States)

    Gluck, Kevin; Stanley, Clayton; Moore, L.; Reitter, David; Halbrügge, Marc

    2010-12-01

    The cognitive modeling and artificial general intelligence research communities may reap greater scientific return on research investments - may achieve an improved understanding of architectures and models - if there is more emphasis on systematic sensitivity and necessity analyses during model development, evaluation, and comparison. We demonstrate this methodological prescription with two of the models submitted for the Dynamic Stocks and Flows (DSF) Model Comparison Challenge, exploring the complex interactions among architectural mechanisms, knowledge-level strategy variants, and task conditions. To cope with the computational demands of these analyses we use a predictive analytics approach similar to regression trees, combined with parallelization on high performance computing clusters, to enable large scale, simultaneous search and exploration.

  3. Exploring Several Methods of Groundwater Model Selection

    Science.gov (United States)

    Samani, Saeideh; Ye, Ming; Asghari Moghaddam, Asghar

    2017-04-01

    Selecting reliable models for simulating groundwater flow and solute transport is essential to groundwater resources management and protection. This work is to explore several model selection methods for avoiding over-complex and/or over-parameterized groundwater models. We consider six groundwater flow models with different numbers (6, 10, 10, 13, 13 and 15) of model parameters. These models represent alternative geological interpretations, recharge estimates, and boundary conditions at a study site in Iran. The models were developed with Model Muse, and calibrated against observations of hydraulic head using UCODE. Model selection was conducted by using the following four approaches: (1) Rank the models using their root mean square error (RMSE) obtained after UCODE-based model calibration, (2) Calculate model probability using GLUE method, (3) Evaluate model probability using model selection criteria (AIC, AICc, BIC, and KIC), and (4) Evaluate model weights using the Fuzzy Multi-Criteria-Decision-Making (MCDM) approach. MCDM is based on the fuzzy analytical hierarchy process (AHP) and fuzzy technique for order performance, which is to identify the ideal solution by a gradual expansion from the local to the global scale of model parameters. The KIC and MCDM methods are superior to other methods, as they consider not only the fit between observed and simulated data and the number of parameter, but also uncertainty in model parameters. Considering these factors can prevent from occurring over-complexity and over-parameterization, when selecting the appropriate groundwater flow models. These methods selected, as the best model, one with average complexity (10 parameters) and the best parameter estimation (model 3).

  4. Exploring Digital News Publishing Business Models

    DEFF Research Database (Denmark)

    Lindskow, Kasper

    . In order to do so, a theoretical model is developed that is suited for the analysis of the strategic design of business models, including the production networks that support them, in the sectors of the economy that are affected by networked informatization in general and in digital news publishing...... of the traditional business models poses an existential threat to news publishing and has given rise to a continuing struggle among news publishers to design digital business models that will be sustainable in the future. This dissertation argues that a central and underresearched aspect of digital news publishing...... business models concerns the production networks that support the co-production of digital news offerings. To fill this knowledge gap, this dissertation explores the strategic design of the digital news publishing production networks that are associated with HTML-based news offerings on the open Web...

  5. Logistics Modeling for Lunar Exploration Systems

    Science.gov (United States)

    Andraschko, Mark R.; Merrill, R. Gabe; Earle, Kevin D.

    2008-01-01

    The extensive logistics required to support extended crewed operations in space make effective modeling of logistics requirements and deployment critical to predicting the behavior of human lunar exploration systems. This paper discusses the software that has been developed as part of the Campaign Manifest Analysis Tool in support of strategic analysis activities under the Constellation Architecture Team - Lunar. The described logistics module enables definition of logistics requirements across multiple surface locations and allows for the transfer of logistics between those locations. A key feature of the module is the loading algorithm that is used to efficiently load logistics by type into carriers and then onto landers. Attention is given to the capabilities and limitations of this loading algorithm, particularly with regard to surface transfers. These capabilities are described within the context of the object-oriented software implementation, with details provided on the applicability of using this approach to model other human exploration scenarios. Some challenges of incorporating probabilistics into this type of logistics analysis model are discussed at a high level.

  6. Exploring Social Structures in Extended Team Model

    DEFF Research Database (Denmark)

    Zahedi, Mansooreh; Ali Babar, Muhammad

    2013-01-01

    Extended Team Model (ETM) as a type of offshore outsourcing is increasingly becoming popular mode of Global Software Development (GSD). There is little knowledge about the social structures in ETM and their impact on collaboration. Within a large interdisciplinary project to develop the next...... generation of GSD technologies, we are exploring the role of social structures to support collaboration. This paper reports some details of our research design and initial findings about the mechanisms to support social structures and their impact on collaboration in an ETM....

  7. Modeling Operations Costs for Human Exploration Architectures

    Science.gov (United States)

    Shishko, Robert

    2013-01-01

    Operations and support (O&S) costs for human spaceflight have not received the same attention in the cost estimating community as have development costs. This is unfortunate as O&S costs typically comprise a majority of life-cycle costs (LCC) in such programs as the International Space Station (ISS) and the now-cancelled Constellation Program. Recognizing this, the Constellation Program and NASA HQs supported the development of an O&S cost model specifically for human spaceflight. This model, known as the Exploration Architectures Operations Cost Model (ExAOCM), provided the operations cost estimates for a variety of alternative human missions to the moon, Mars, and Near-Earth Objects (NEOs) in architectural studies. ExAOCM is philosophically based on the DoD Architecture Framework (DoDAF) concepts of operational nodes, systems, operational functions, and milestones. This paper presents some of the historical background surrounding the development of the model, and discusses the underlying structure, its unusual user interface, and lastly, previous examples of its use in the aforementioned architectural studies.

  8. Participatory Systems Modeling to Explore Sustainable ...

    Science.gov (United States)

    Decision makers often need assistance in understanding dynamic interactions and linkages among economic, environmental and social systems in coastal watersheds. They also need scientific input to better evaluate potential costs and benefits of alternative policy interventions. The US EPA is applying sustainability science to address these needs. Triple Value (3V) Scoping and Modeling projects bring a systems approach to understand complex environmental problems, incorporate local knowledge, and allow decision-makers to explore policy scenarios. This leads to better understanding of feedbacks and outcomes to both human and environmental systems. The Suffolk County, NY (eastern Long Island) 3V Case uses SES interconnections to explore possible policy options and scenarios for intervention to mitigate the effects of excess nitrogen (N) loading to ground, surface, and estuarine waters. Many of the environmental impacts of N pollution negatively affect social and economic well-being and productivity. Key are loss of enjoyment and recreational use of local beach environments and loss of income and revenues from tourism and local fisheries. Stakeholders generated this Problem Statement: Suffolk County is experiencing widespread degradation to groundwater and the coastal marine environment caused by excess nitrogen. How can local stakeholders and decision makers in Suffolk County arrest and reverse this degradation, restore conditions to support a healthy thriving ecos

  9. Friends and Foes in the Occupational Career. The Influence of Sweet and Sour Social Capital on the Labour Market. Friends and Foes in the Occupa-tional Career.

    NARCIS (Netherlands)

    Moerbeek, Hester Hagar Susan

    2001-01-01

    Will people with friends experience profit and will people with foes experience harm on the labour market? The words ‘friends’ and ‘foes’ mean something else than in every day life, that is people who have helped or hindered someone in the past and/or are willing to do so in the future. From this

  10. Blueberries and Tofu: Friend or Foe?

    Science.gov (United States)

    D'Ascoli, Jennifer; Lee, Susanne

    2004-03-01

    Two flavonoids, naringenin and genistein found in blueberries and soybeans, respectively, scavenge free radicals and exhibit anti- breast and prostate cancer properties. When consumed in foods, these flavonoids usually are subject to heat, yet all biological studies have been performed with unheated molecules. We have explored and will report on the three-dimensional, molecular structure changes we have thermally-induced in naringenin and genistein. We have measured and will discuss the flavonoids' thermodynamic properties as a function of temperature. Several endothermic transformations were observed along with a marked color change that remained when the flavonoids were dissolved in a solvent, indicating their molecular structures had been altered by the heat. Ultraviolet-Visible spectroscopy, and proton and carbon 1-D nuclear magnetic resonance will be presented that show the change was associated with a decrease in electron localization within the molecules. We will explain how such modified structures could scavenge free radicals more effectively and affect breast cancer cell proliferation.

  11. News comments: exploring, modeling, and online prediction

    NARCIS (Netherlands)

    Tsagkias, M.; Weerkamp, W.; de Rijke, M.

    2010-01-01

    Online news agents provide commenting facilities for their readers to express their opinions or sentiments with regards to news stories. The number of user supplied comments on a news article may be indicative of its importance, interestingness, or impact. We explore the news comments space, and

  12. Floods and droughts: friends or foes?

    Science.gov (United States)

    Prudhomme, Christel

    2017-04-01

    Water hazards are some of the biggest threats to lives and livelihoods globally, causing serious damages to society and infrastructure. But floods and droughts are an essential part of the hydrological regime that ensures fundamental ecosystem functions, providing natural ways to bring in nutrients, flush out pollutants and enabling soils, rivers and lakes natural biodiversity to thrive. Traditionally, floods and droughts are too often considered separately, with scientific advance in process understanding, modelling, statistical characterisation and impact assessment are often done independently, possibly delaying the development of innovative methods that could be applied to both. This talk will review some of the key characteristics of floods and droughts, highlighting differences and commonalties, losses and benefits, with the aim of identifying future key research challenges faced by both current and next generation of hydrologists.

  13. Exploring the Standard Model of Particles

    Science.gov (United States)

    Johansson, K. E.; Watkins, P. M.

    2013-01-01

    With the recent discovery of a new particle at the CERN Large Hadron Collider (LHC) the Higgs boson could be about to be discovered. This paper provides a brief summary of the standard model of particle physics and the importance of the Higgs boson and field in that model for non-specialists. The role of Feynman diagrams in making predictions for…

  14. Business Model Exploration for Software Defined Networks

    NARCIS (Netherlands)

    Xu, Yudi; Jansen, Slinger|info:eu-repo/dai/nl/270902902; España, Sergio|info:eu-repo/dai/nl/412500949; Zhang, Dong; Gao, Xuesong

    2017-01-01

    Business modeling is becoming a foundational process in the information technology industry. Many ICT companies are constructing their business models to stay competitive on the cutting edge of the technology world. However, when comes to new technologies or emerging markets, it remains difficult

  15. LIMEPY: Lowered Isothermal Model Explorer in PYthon

    Science.gov (United States)

    Gieles, Mark; Zocchi, Alice

    2017-10-01

    LIMEPY solves distribution function (DF) based lowered isothermal models. It solves Poisson's equation used on input parameters and offers fast solutions for isotropic/anisotropic, single/multi-mass models, normalized DF values, density and velocity moments, projected properties, and generates discrete samples.

  16. Exploring Organic Mechanistic Puzzles with Molecular Modeling

    Science.gov (United States)

    Horowitz, Gail; Schwartz, Gary

    2004-01-01

    The molecular modeling was used to reinforce more general skills such as deducing and drawing reaction mechanisms, analyzing reaction kinetics and thermodynamics and drawing reaction coordinate energy diagrams. This modeling was done through the design of mechanistic puzzles, involving reactions not familiar to the students.

  17. Exploring RNA structure by integrative molecular modelling

    DEFF Research Database (Denmark)

    Masquida, Benoît; Beckert, Bertrand; Jossinet, Fabrice

    2010-01-01

    in three dimensions (3D) and used as building blocks assembled manually during a bioinformatic interactive process. Comparing the models to the corresponding crystal structures has validated the method as being powerful to predict the RNA topology and architecture while being less accurate regarding...... the prediction of base-base interactions. These aspects as well as the necessary steps towards automation will be discussed....

  18. Exploring RNA structure by integrative molecular modelling.

    Science.gov (United States)

    Masquida, Benoît; Beckert, Bertrand; Jossinet, Fabrice

    2010-07-31

    RNA molecular modelling is adequate to rapidly tackle the structure of RNA molecules. With new structured RNAs constituting a central class of cellular regulators discovered every year, the need for swift and reliable modelling methods is more crucial than ever. The pragmatic method based on interactive all-atom molecular modelling relies on the observation that specific structural motifs are recurrently found in RNA sequences. Once identified by a combination of comparative sequence analysis and biochemical data, the motifs composing the secondary structure of a given RNA can be extruded in three dimensions (3D) and used as building blocks assembled manually during a bioinformatic interactive process. Comparing the models to the corresponding crystal structures has validated the method as being powerful to predict the RNA topology and architecture while being less accurate regarding the prediction of base-base interactions. These aspects as well as the necessary steps towards automation will be discussed. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  19. Exploring Yellowstone National Park with Mathematical Modeling

    Science.gov (United States)

    Wickstrom, Megan H.; Carr, Ruth; Lackey, Dacia

    2017-01-01

    Mathematical modeling, a practice standard in the Common Core State Standards for Mathematics (CCSSM) (CCSSI 2010), is a process by which students develop and use mathematics as a tool to make sense of the world around them. Students investigate a real-world situation by asking mathematical questions; along the way, they need to decide how to use…

  20. Human microbiome versus food-borne pathogens: friend or foe.

    Science.gov (United States)

    Josephs-Spaulding, Jonathan; Beeler, Erik; Singh, Om V

    2016-06-01

    As food safety advances, there is a great need to maintain, distribute, and provide high-quality food to a much broader consumer base. There is also an ever-growing "arms race" between pathogens and humans as food manufacturers. The human microbiome is a collective organ of microbes that have found community niches while associating with their host and other microorganisms. Humans play an important role in modifying the environment of these organisms through their life choices, especially through individual diet. The composition of an individual's diet influences the digestive system-an ecosystem with the greatest number and largest diversity of organisms currently known. Organisms living on and within food have the potential to be either friends or foes to the consumer. Maintenance of this system can have multiple benefits, but lack of maintenance can lead to a host of chronic and preventable diseases. Overall, this dynamic system is influenced by intense competition from food-borne pathogens, lifestyle, overall diet, and presiding host-associated microbiota.

  1. Investigating Identity, Ambivalence, Hybridity: A Bhabhaian Reading of J. M. Coetzee's "Foe" and "Disgrace"

    Science.gov (United States)

    Mostafaee, Jalal

    2016-01-01

    The present paper seeks to investigate J.M. Coetzee's "Foe" and "Disgrace" in terms of Homi K. Bhabha's concept of Identities/Subjectivities. Homi K. Bhabha is one of the most important contemporary figure in postcolonial studies; he argues that ambivalence is existed at the site of colonial dominance. He argues that…

  2. Exploring, exploiting and evolving diversity of aquatic ecosystem models

    DEFF Research Database (Denmark)

    Janssen, Annette B. G.; Arhonditsis, George B.; Beusen, Arthur

    2015-01-01

    Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality...... management. In this spirit, numerous models have been developed since the 1970s. We set off to explore model diversity by making an inventory among 42 aquatic ecosystem modellers, by categorizing the resulting set of models and by analysing them for diversity. We then focus on how to exploit model diversity...... by comparing and combining different aspects of existing models. Finally, we discuss how model diversity came about in the past and could evolve in the future. Throughout our study, we use analogies from biodiversity research to analyse and interpret model diversity. We recommend to make models publicly...

  3. Reservoir pressure evolution model during exploration drilling

    Directory of Open Access Journals (Sweden)

    Korotaev B. A.

    2017-03-01

    Full Text Available Based on the analysis of laboratory studies and literature data the method for estimating reservoir pressure in exploratory drilling has been proposed, it allows identify zones of abnormal reservoir pressure in the presence of seismic data on reservoir location depths. This method of assessment is based on developed at the end of the XX century methods using d- and σ-exponentials taking into account the mechanical drilling speed, rotor speed, bit load and its diameter, lithological constant and degree of rocks' compaction, mud density and "regional density". It is known that in exploratory drilling pulsation of pressure at the wellhead is observed. Such pulsation is a consequence of transferring reservoir pressure through clay. In the paper the mechanism for transferring pressure to the bottomhole as well as the behaviour of the clay layer during transmission of excess pressure has been described. A laboratory installation has been built, it has been used for modelling pressure propagation to the bottomhole of the well through a layer of clay. The bulge of the clay layer is established for 215.9 mm bottomhole diameter. Functional correlation of pressure propagation through the layer of clay has been determined and a reaction of the top clay layer has been shown to have bulge with a height of 25 mm. A pressure distribution scheme (balance has been developed, which takes into account the distance from layers with abnormal pressure to the bottomhole. A balance equation for reservoir pressure evaluation has been derived including well depth, distance from bottomhole to the top of the formation with abnormal pressure and density of clay.

  4. Exploring the African business model in relation to entrepreneurial ...

    African Journals Online (AJOL)

    Exploring the African business model in relation to entrepreneurial and business leadership ... African Journal of Social Work ... Africa by analyzing different entrepreneurial and business leadership paradigms from America, Europe and Asia.

  5. Exploration

    Science.gov (United States)

    Wilburn, D.R.

    2001-01-01

    Part of an annual review of mines and mineral resources in the U.S. An overview of nonfuel-mineral exploration in 2000 is presented. Principal exploration target was gold exploration in Latin America, Australia, and the U.S. There was a decrease of 18 percent in the exploration budget for gold as compared with the budget for 1999. Statistical information on nonfuel-mineral exploration worldwide is presented, analyzed, and interpreted.

  6. Mistletoe, friend and foe: synthesizing ecosystem implications of mistletoe infection

    Science.gov (United States)

    Griebel, Anne; Watson, David; Pendall, Elise

    2017-11-01

    Biotic disturbances are affecting a wide range of tree species in all climates, and their occurrence is contributing to increasing rates of tree mortality globally. Mistletoe is a widespread group of parasitic plants that establishes long-lasting relationships with a diverse range of host tree species. With climate change, ecophysiological stress is increasing, potentially making trees more susceptible to mistletoe infection, which in turn leads to higher forest mortality rates. The perception of mistletoe presence in individual trees and forest stands is divided within the scientific community, leading to an ongoing debate regarding its impacts. Forest managers concerned about stand health and carbon sequestration may view mistletoe as a foe that leads to reduced productivity. In contrast, ecologists may see mistletoe as a friend, in light of the wildlife habitat, biodiversity and nutrient cycling it promotes. However, individual studies typically focus on isolated effects of mistletoe presence within their respective research area and lack a balanced, interdisciplinary perspective of mistletoe disturbance. With this conceptual paper we aim to bring together the positive and negative impacts of mistletoe presence on tree physiology, soil nutrient cycling as well as stand health and stand dynamics. We focus on the role of mistletoe-induced tree mortality in ecosystem succession and biodiversity. In addition, we present potential modifications of mistletoe presence on the energy budget and on forest vulnerability to climate change, which could feed back into stand dynamics and disturbance patterns. Lastly, we will identify the most pressing remaining knowledge gaps and highlight priorities for future research on this widespread agent of biotic disturbance.

  7. Investigating Identity, Ambivalence, Hybridity: A Bhabhaian Reading of J. M. Coetzee’s Foe and Disgrace

    Directory of Open Access Journals (Sweden)

    Jalal Mostafaee

    2016-12-01

    Full Text Available The present paper seeks to investigate J.M. Coetzee's Foe and Disgrace in terms of Homi K. Bhabha's concept of Identities/Subjectivities. Homi K.  Bhabha is one of the most important contemporary figure in postcolonial studies; he argues that ‘’there is always ambivalence at the site of colonial dominance. The colonizer aggressively states his superiority to the colonized, but is always anxiously contemplating his own identity, which is never quite as stable as his aggression implies’’. The paper also seeks on the notion of hybridity which indicates that the practices of colonial authority is intermingling other texts and discourses which results in a hybridization that facilitates colonial domination.  Bhabha's reading of Lacan accords well with the ambivalence he traces in various writers. It is what Lacan calls the mirror stage that is central to Bhabha's reading. Bhabha believes that ‘’the mirror stage encapsulates what happens in colonial discourse's stereotyping productions: the mirror stage is at least a good model for the colonial situation’’. Bhabha suggests that like’’ the mirror phase the fullness of the stereotype_ its image as identity_ is always threatened by lack.’’ A telling and recurring idea in Coetzee's fiction is that the force of the colonizer is formative of the identity of the colonized, something to be embraced and this paper aims to investigate this closely by using Bhabha's concepts. Keywords: Ambivalence, Apartheid, Colonial discourse, Hybridity, Marginality, Mimicry, Stereotype, Uncanny

  8. Exploring, exploiting and evolving diversity of aquatic ecosystem models

    NARCIS (Netherlands)

    Janssen, A.B.G.; Arhonditsis, G.B.; Beusen, Arthur; Bolding, Karsten; Bruce, Louise; Bruggeman, Jorn; Couture, Raoul Marie; Downing, Andrea S.; Alex Elliott, J.; Frassl, M.A.; Gal, Gideon; Gerla, Daan J.; Hipsey, M.R.; Hu, Fenjuan; Ives, S.C.; Janse, J.H.; Jeppesen, Erik; Jöhnk, K.D.; Kneis, David; Kong, Xiangzhen; Kuiper, J.J.; Lehmann, M.K.; Lemmen, Carsten; Özkundakci, Deniz; Petzoldt, Thomas; Rinke, Karsten; Robson, B.J.; Sachse, René; Schep, S.A.; Schmid, Martin; Scholten, Huub; Teurlincx, Sven; Trolle, Dennis; Troost, T.A.; Dam, Van A.A.; Gerven, Van L.P.A.; Weijerman, Mariska; Wells, S.A.; Mooij, W.M.

    2015-01-01

    Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality

  9. Styles in business process modeling: an exploration and a model

    NARCIS (Netherlands)

    Pinggera, Jakob; Soffer, Pnina; Fahland, Dirk; Weidlich, Matthias; Zugal, Stefan; Weber, Barbara; Reijers, Hajo A.; Mendling, Jan

    2015-01-01

    Business process models are an important means to design, analyze, implement, and control business processes. As with every type of conceptual model, a business process model has to meet certain syntactic, semantic, and pragmatic quality requirements to be of value. For many years, such quality

  10. Study of parental models: building an instrument for their exploration

    Directory of Open Access Journals (Sweden)

    José Francisco Martínez Licona

    2014-08-01

    Full Text Available Objective: This research presents the construction of an attributional questionnaire concerning the different parental models and factors that are involved in family interactions. Method: A mixed methodology was used as a foundation to develop items and respective pilots that allowed checking the validity and internal consistency of the instrument using expert judgment. Results: An instrument of 36 statements was organized into 12 categories to explore the parental models according to the following factors: parental models, breeding patterns, attachment bonds and guidelines for success, and promoted inside family contexts. Analyzing these factors contributes to the children’s development within the familiar frown, and the opportunity for socio-educational intervention. Conclusion: It is assumed that the family context is as decisive as the school context; therefore, exploring the nature of parental models is required to understand the features and influences that contribute to the development of young people in any social context.

  11. A compositional modelling framework for exploring MPSoC systems

    DEFF Research Database (Denmark)

    Tranberg-Hansen, Anders Sejer; Madsen, Jan

    2009-01-01

    This paper presents a novel compositional framework for system level performance estimation and exploration of Multi-Processor System On Chip (MPSoC) based systems. The main contributions are the definition of a compositional model which allows quantitative performance estimation to be carried out...

  12. Exploring conceptual models for community engagement at higher ...

    African Journals Online (AJOL)

    A critical conceptual analysis of the South African Higher Education context reflects the lack of a structural and functional framework for the conceptualisation of community engagement (CE) in higher education. The purpose of this article is to explore a framework and model for the conceptualisation of CE for a better ...

  13. On Explorative and Integrative Modeling of Biomolecular Complexes

    NARCIS (Netherlands)

    van Zundert, G.C.P.

    2015-01-01

    This thesis introduces and showcases novel approaches for explorative and integrative modeling in the presence of cryo-EM data and distance restraints. In it the PowerFit software is presented, a Python package for fast cross correlation based rigid body fitting of high-resolution structures in

  14. Optical vortex metrology: Are phase singularities foes or friends in optical metrology?

    DEFF Research Database (Denmark)

    Takeda, M.; Wang, W.; Hanson, Steen Grüner

    2008-01-01

    We raise an issue whether phase singularities are foes or friends in optical metrology, and give an answer by introducing the principle and applications of a new technique which we recently proposed for displacement and flow measurements. The technique is called optical vortex metrology because i...... or Laguerre-Gauss transform to the random pattern. © (2008) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only....

  15. Adaptable Authentication Model: Exploring Security with Weaker Attacker Models

    DEFF Research Database (Denmark)

    Ahmed, Naveed; Jensen, Christian D.

    2011-01-01

    Most methods for protocol analysis classify protocols as “broken” if they are vulnerable to attacks from a strong attacker, e.g., assuming the Dolev-Yao attacker model. In many cases, however, exploitation of existing vulnerabilities may not be practical and, moreover, not all applications may...... suffer because of the identified vulnerabilities. Therefore, we may need to analyze a protocol for weaker notions of security. In this paper, we present a security model that supports such weaker notions. In this model, the overall goals of an authentication protocol are broken into a finer granularity......; for each fine level authentication goal, we determine the “least strongest-attacker” for which the authentication goal can be satisfied. We demonstrate that this model can be used to reason about the security of supposedly insecure protocols. Such adaptability is particularly useful in those applications...

  16. Lobbying friends and foes in climate policy: The case of business and environmental interest groups in the European Union

    Energy Technology Data Exchange (ETDEWEB)

    Gullberg, Anne Therese [CICERO, Pb 1129 Blindern, N-0318 Oslo (Norway)

    2008-08-15

    Drawing on two conflicting hypotheses from the theoretical literature on lobbying, I consider the strategies applied by interest groups lobbying to influence climate policy in the European Union (EU). The first hypothesis claims that interest groups lobby their 'friends', decision-makers with positions similar to their own. The second claims that interest groups lobby their 'foes', decision-makers with positions opposed to their own. Using interviews with lobbyists and decision-makers, I demonstrate that in the field of climate policy, interest groups in the EU lobby both friends and foes, but under different conditions. Moreover, I find that the interest groups' motives are not always in line with the theoretical hypotheses. Interest groups lobby their friends on single policy decisions to exchange information, to further a common cause and to exert pressure, and their foes because a foe on one issue might prove to be a friend on another issue. Interest groups direct general lobbying towards both friends and foes. This paper provides a new empirical contribution to a literature that has so far been heavily dominated by studies focusing on lobbying in the US. (author)

  17. Dynamic Decision Making for Graphical Models Applied to Oil Exploration

    CERN Document Server

    Martinelli, Gabriele; Hauge, Ragnar

    2012-01-01

    We present a framework for sequential decision making in problems described by graphical models. The setting is given by dependent discrete random variables with associated costs or revenues. In our examples, the dependent variables are the potential outcomes (oil, gas or dry) when drilling a petroleum well. The goal is to develop an optimal selection strategy that incorporates a chosen utility function within an approximated dynamic programming scheme. We propose and compare different approximations, from simple heuristics to more complex iterative schemes, and we discuss their computational properties. We apply our strategies to oil exploration over multiple prospects modeled by a directed acyclic graph, and to a reservoir drilling decision problem modeled by a Markov random field. The results show that the suggested strategies clearly improve the simpler intuitive constructions, and this is useful when selecting exploration policies.

  18. Framework for the Parametric System Modeling of Space Exploration Architectures

    Science.gov (United States)

    Komar, David R.; Hoffman, Jim; Olds, Aaron D.; Seal, Mike D., II

    2008-01-01

    This paper presents a methodology for performing architecture definition and assessment prior to, or during, program formulation that utilizes a centralized, integrated architecture modeling framework operated by a small, core team of general space architects. This framework, known as the Exploration Architecture Model for IN-space and Earth-to-orbit (EXAMINE), enables: 1) a significantly larger fraction of an architecture trade space to be assessed in a given study timeframe; and 2) the complex element-to-element and element-to-system relationships to be quantitatively explored earlier in the design process. Discussion of the methodology advantages and disadvantages with respect to the distributed study team approach typically used within NASA to perform architecture studies is presented along with an overview of EXAMINE s functional components and tools. An example Mars transportation system architecture model is used to demonstrate EXAMINE s capabilities in this paper. However, the framework is generally applicable for exploration architecture modeling with destinations to any celestial body in the solar system.

  19. The role of somatosensory models in vocal autonomous exploration

    OpenAIRE

    Acevedo Valle, Juan Manuel; Angulo Bahón, Cecilio; Moulin-Frier, Clément; Trejo Ramírez, Karla Andrea

    2016-01-01

    The present work focuses on two main objectives. Firstly, it highlights the relevance of studying the early stages of language development using machines as an approach to contribute to the future of speech recognizers and synthesizers, user interfaces, active learning techniques, and to the field of robotics and artificial intelligence in general. Secondly, this work introduces some results on the study of the role of somatosensory models in vocal autonomous exploration. In previous works, t...

  20. Exploring SMBH assembly with semi-analytic modelling

    Science.gov (United States)

    Ricarte, Angelo; Natarajan, Priyamvada

    2018-02-01

    We develop a semi-analytic model to explore different prescriptions of supermassive black hole (SMBH) fuelling. This model utilizes a merger-triggered burst mode in concert with two possible implementations of a long-lived steady mode for assembling the mass of the black hole in a galactic nucleus. We improve modelling of the galaxy-halo connection in order to more realistically determine the evolution of a halo's velocity dispersion. We use four model variants to explore a suite of observables: the M•-σ relation, mass functions of both the overall and broad-line quasar population, and luminosity functions as a function of redshift. We find that `downsizing' is a natural consequence of our improved velocity dispersion mappings, and that high-mass SMBHs assemble earlier than low-mass SMBHs. The burst mode of fuelling is sufficient to explain the assembly of SMBHs to z = 2, but an additional steady mode is required to both assemble low-mass SMBHs and reproduce the low-redshift luminosity function. We discuss in detail the trade-offs in matching various observables and the interconnected modelling components that govern them. As a result, we demonstrate the utility as well as the limitations of these semi-analytic techniques.

  1. Discovering Planetary Nebula Geometries: Explorations with a Hierarchy of Models

    Science.gov (United States)

    Huyser, Karen A.; Knuth, Kevin H.; Fischer, Bernd; Schumann, Johann; Granquist-Fraser, Domhnull; Hajian, Arsen R.

    2004-01-01

    Astronomical objects known as planetary nebulae (PNe) consist of a shell of gas expelled by an aging medium-sized star as it makes its transition from a red giant to a white dwarf. In many cases this gas shell can be approximately described as a prolate ellipsoid. Knowledge of the physics of ionization processes in this gaseous shell enables us to construct a model in three dimensions (3D) called the Ionization-Bounded Prolate Ellipsoidal Shell model (IBPES model). Using this model we can generate synthetic nebular images, which can be used in conjunction with Hubble Space Telescope (HST) images of actual PNe to perform Bayesian model estimation. Since the IBPES model is characterized by thirteen parameters, model estimation requires the search of a 13-dimensional parameter space. The 'curse of dimensionality,' compounded by a computationally intense forward problem, makes forward searches extremely time-consuming and frequently causes them to become trapped in local solutions. We find that both the speed and of the search can be improved by judiciously reducing the dimensionality of the search space. Our basic approach employs a hierarchy of models of increasing complexity that converges to the IBPES model. Earlier studies establish that a hierarchical sequence converges more quickly, and to a better solution, than a search relying only on the most complex model. Here we report results for a hierarchy of five models. The first three models treat the nebula as a 2D image, while the last two models explore its characteristics as a 3D object and enable us to characterize the physics of the nebula. This five-model hierarchy is applied to HST images of ellipsoidal PNe to estimate their geometric properties and gas density profiles.

  2. Exploring education for digital librarians meaning, modes and models

    CERN Document Server

    Myburgh, Sue

    2013-01-01

    Exploring Education for Digital Librarians provides a refreshing perspective on the discipline and profession of Library and Information Science (LIS), with a focus on preparing students for careers as librarians who can deal with present and future digital information environments. A re-examination of the knowledge base of the field, combined with a proposed theoretical structure for LIS, provide the basis for this work, which also examines competencies for practice as well as some of the international changes in the nature of higher education. The authors finally suggest a model that could b

  3. Theory-guided exploration with structural equation model forests.

    Science.gov (United States)

    Brandmaier, Andreas M; Prindle, John J; McArdle, John J; Lindenberger, Ulman

    2016-12-01

    Structural equation model (SEM) trees, a combination of SEMs and decision trees, have been proposed as a data-analytic tool for theory-guided exploration of empirical data. With respect to a hypothesized model of multivariate outcomes, such trees recursively find subgroups with similar patterns of observed data. SEM trees allow for the automatic selection of variables that predict differences across individuals in specific theoretical models, for instance, differences in latent factor profiles or developmental trajectories. However, SEM trees are unstable when small variations in the data can result in different trees. As a remedy, SEM forests, which are ensembles of SEM trees based on resamplings of the original dataset, provide increased stability. Because large forests are less suitable for visual inspection and interpretation, aggregate measures provide researchers with hints on how to improve their models: (a) variable importance is based on random permutations of the out-of-bag (OOB) samples of the individual trees and quantifies, for each variable, the average reduction of uncertainty about the model-predicted distribution; and (b) case proximity enables researchers to perform clustering and outlier detection. We provide an overview of SEM forests and illustrate their utility in the context of cross-sectional factor models of intelligence and episodic memory. We discuss benefits and limitations, and provide advice on how and when to use SEM trees and forests in future research. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  4. Exploring Bayesian model selection methods for effective field theory expansions

    Science.gov (United States)

    Schaffner, Taylor; Yamauchi, Yukari; Furnstahl, Richard

    2017-09-01

    A fundamental understanding of the microscopic properties and interactions of nuclei has long evaded physicists due to the complex nature of quantum chromodynamics (QCD). One approach to modeling nuclear interactions is known as chiral effective field theory (EFT). Today, the method's greatest limitation lies in the approximation of interaction potentials and their corresponding uncertainties. Computing EFT expansion coefficients, known as Low-Energy Constants (LECs), from experimental data reduces to a problem of statistics and fitting. In the conventional approach, the fitting is done using frequentist methods that fail to evaluate the quality of the model itself (e.g., how many orders to use) in addition to its fit to the data. By utilizing Bayesian statistical methods for model selection, the model's quality can be taken into account, providing a more controlled and robust EFT expansion. My research involves probing different Bayesian model checking techniques to determine the most effective means for use with estimating the values of LECs. In particular, we are using model problems to explore the Bayesian calculation of an EFT expansion's evidence and an approximation to this value known as the WAIC (Widely Applicable Information Criterion). This work was supported in part by the National Science Foundation under Grant No. PHY-1306250.

  5. Friends or foes? Relational dissonance and adolescent psychological wellbeing.

    Science.gov (United States)

    Bond, Lyndal; Lusher, Dean; Williams, Ian; Butler, Helen

    2014-01-01

    The interaction of positive and negative relationships (i.e. I like you, but you dislike me - referred to as relational dissonance) is an underexplored phenomenon. Further, it is often only poor (or negative) mental health that is examined in relation to social networks, with little regard for positive psychological wellbeing. Finally, these issues are compounded by methodological constraints. This study explores a new concept of relational dissonance alongside mutual antipathies and friendships and their association with mental health using multivariate exponential random graph models with an Australian sample of secondary school students. Results show male students with relationally dissonant ties have lower positive mental health measures. Girls with relationally dissonant ties have lower depressed mood, but those girls being targeted by negative ties are more likely to have depressed mood. These findings have implications for the development of interventions focused on promoting adolescent wellbeing and consideration of the appropriate measurement of wellbeing and mental illness.

  6. Friends or foes? Relational dissonance and adolescent psychological wellbeing.

    Directory of Open Access Journals (Sweden)

    Lyndal Bond

    Full Text Available The interaction of positive and negative relationships (i.e. I like you, but you dislike me - referred to as relational dissonance is an underexplored phenomenon. Further, it is often only poor (or negative mental health that is examined in relation to social networks, with little regard for positive psychological wellbeing. Finally, these issues are compounded by methodological constraints. This study explores a new concept of relational dissonance alongside mutual antipathies and friendships and their association with mental health using multivariate exponential random graph models with an Australian sample of secondary school students. Results show male students with relationally dissonant ties have lower positive mental health measures. Girls with relationally dissonant ties have lower depressed mood, but those girls being targeted by negative ties are more likely to have depressed mood. These findings have implications for the development of interventions focused on promoting adolescent wellbeing and consideration of the appropriate measurement of wellbeing and mental illness.

  7. Lunar exploration and development--a sustainable model.

    Science.gov (United States)

    Williamson, Mark

    2005-01-01

    A long-term goal of space exploration is the development of a lunar settlement that will not only be largely self-sufficient but also contribute to the economy of the Earth-Moon system. Proposals for lunar mining and materials processing developments, as well as tourism-based applications, have appeared in the literature for many years. However, so great are the technical and financial difficulties associated with sustained lunar development that, more than 30 years after the end of the Apollo programme, there have been no practical advances towards this goal. While this may soon be remedied by a series of proposed unmanned orbiters, landers and rovers, the philosophy of lunar exploration and development remains the same as it has for decades: conquer, exploit, and ignore the consequences. By contrasting the well-recognised problems of Earth orbital debris and the barely recognised issue of intentional spacecraft impacts on the lunar surface, this paper illustrates the need for a new model for lunar exploration and development. This new paradigm would assign a value to the lunar environment and provide a balance between protection and exploitation, creating, in effect, a philosophy of sustainable development for the Moon. It is suggested that this new philosophy should be an integral part of any future strategy for lunar colonisation. c2005 Elsevier Ltd. All rights reserved.

  8. Lunar exploration and development—A sustainable model

    Science.gov (United States)

    Williamson, Mark

    2005-07-01

    A long-term goal of space exploration is the development of a lunar settlement that will not only be largely self-sufficient but also contribute to the economy of the Earth Moon system. Proposals for lunar mining and materials processing developments, as well as tourism-based applications, have appeared in the literature for many years. However, so great are the technical and financial difficulties associated with sustained lunar development that, more than 30 years after the end of the Apollo programme, there have been no practical advances towards this goal. While this may soon be remedied by a series of proposed unmanned orbiters, landers and rovers, the philosophy of lunar exploration and development remains the same as it has for decades: conquer, exploit, and ignore the consequences. By contrasting the well-recognised problems of Earth orbital debris and the barely recognised issue of intentional spacecraft impacts on the lunar surface, this paper illustrates the need for a new model for lunar exploration and development. This new paradigm would assign a value to the lunar environment and provide a balance between protection and exploitation, creating, in effect, a philosophy of sustainable development for the Moon. It is suggested that this new philosophy should be an integral part of any future strategy for lunar colonisation.

  9. Exploring host–microbiota interactions in animal models and humans

    Science.gov (United States)

    Kostic, Aleksandar D.; Howitt, Michael R.; Garrett, Wendy S.

    2013-01-01

    The animal and bacterial kingdoms have coevolved and coadapted in response to environmental selective pressures over hundreds of millions of years. The meta'omics revolution in both sequencing and its analytic pipelines is fostering an explosion of interest in how the gut microbiome impacts physiology and propensity to disease. Gut microbiome studies are inherently interdisciplinary, drawing on approaches and technical skill sets from the biomedical sciences, ecology, and computational biology. Central to unraveling the complex biology of environment, genetics, and microbiome interaction in human health and disease is a deeper understanding of the symbiosis between animals and bacteria. Experimental model systems, including mice, fish, insects, and the Hawaiian bobtail squid, continue to provide critical insight into how host–microbiota homeostasis is constructed and maintained. Here we consider how model systems are influencing current understanding of host–microbiota interactions and explore recent human microbiome studies. PMID:23592793

  10. Experimental exploration of diffusion panel labyrinth in scale model

    Science.gov (United States)

    Vance, Mandi M.

    Small rehearsal and performance venues often lack the rich reverberation found in larger spaces. Higini Arau-Puchades has designed and implemented a system of diffusion panels in the Orchestra Rehearsal Room at the Great Theatre Liceu and the Tonhalle St. Gallen that lengthen the reverberation time. These panels defy traditional room acoustics theory which holds that adding material to a room will shorten the reverberation time. This work explores several versions of Arau-Puchades' panels and room characteristics in scale model. Reverberation times are taken from room impulse response measurements in order to better understand the unusual phenomenon. Scale modeling enables many tests but has limitations in its accuracy due to the higher frequency range involved. Further investigations are necessary to establish how the sound energy interacts with the diffusion panels and confirm their validity in a range of applications.

  11. Exploring Hallucinogen Pharmacology and Psychedelic Medicine with Zebrafish Models.

    Science.gov (United States)

    Kyzar, Evan J; Kalueff, Allan V

    2016-10-01

    After decades of sociopolitical obstacles, the field of psychiatry is experiencing a revived interest in the use of hallucinogenic agents to treat brain disorders. Along with the use of ketamine for depression, recent pilot studies have highlighted the efficacy of classic serotonergic hallucinogens, such as lysergic acid diethylamide and psilocybin, in treating addiction, post-traumatic stress disorder, and anxiety. However, many basic pharmacological and toxicological questions remain unanswered with regard to these compounds. In this study, we discuss psychedelic medicine as well as the behavioral and toxicological effects of hallucinogenic drugs in zebrafish. We emphasize this aquatic organism as a model ideally suited to assess both the potential toxic and therapeutic effects of major known classes of hallucinogenic compounds. In addition, novel drugs with hallucinogenic properties can be efficiently screened using zebrafish models. Well-designed preclinical studies utilizing zebrafish can contribute to the reemerging treatment paradigm of psychedelic medicine, leading to new avenues of clinical exploration for psychiatric disorders.

  12. Designing tools for oil exploration using nuclear modeling

    Science.gov (United States)

    Mauborgne, Marie-Laure; Allioli, Françoise; Manclossi, Mauro; Nicoletti, Luisa; Stoller, Chris; Evans, Mike

    2017-09-01

    When designing nuclear tools for oil exploration, one of the first steps is typically nuclear modeling for concept evaluation and initial characterization. Having an accurate model, including the availability of accurate cross sections, is essential to reduce or avoid time consuming and costly design iterations. During tool response characterization, modeling is benchmarked with experimental data and then used to complement and to expand the database to make it more detailed and inclusive of more measurement environments which are difficult or impossible to reproduce in the laboratory. We present comparisons of our modeling results obtained using the ENDF/B-VI and ENDF/B-VII cross section data bases, focusing on the response to a few elements found in the tool, borehole and subsurface formation. For neutron-induced inelastic and capture gamma ray spectroscopy, major obstacles may be caused by missing or inaccurate cross sections for essential materials. We show examples of the benchmarking of modeling results against experimental data obtained during tool characterization and discuss observed discrepancies.

  13. Designing tools for oil exploration using nuclear modeling

    Directory of Open Access Journals (Sweden)

    Mauborgne Marie-Laure

    2017-01-01

    Full Text Available When designing nuclear tools for oil exploration, one of the first steps is typically nuclear modeling for concept evaluation and initial characterization. Having an accurate model, including the availability of accurate cross sections, is essential to reduce or avoid time consuming and costly design iterations. During tool response characterization, modeling is benchmarked with experimental data and then used to complement and to expand the database to make it more detailed and inclusive of more measurement environments which are difficult or impossible to reproduce in the laboratory. We present comparisons of our modeling results obtained using the ENDF/B-VI and ENDF/B-VII cross section data bases, focusing on the response to a few elements found in the tool, borehole and subsurface formation. For neutron-induced inelastic and capture gamma ray spectroscopy, major obstacles may be caused by missing or inaccurate cross sections for essential materials. We show examples of the benchmarking of modeling results against experimental data obtained during tool characterization and discuss observed discrepancies.

  14. Requirements for high level models supporting design space exploration in model-based systems engineering

    NARCIS (Netherlands)

    Haveman, Steven; Bonnema, Gerrit Maarten

    2013-01-01

    Most formal models are used in detailed design and focus on a single domain. Few effective approaches exist that can effectively tie these lower level models to a high level system model during design space exploration. This complicates the validation of high level system requirements during

  15. Exploring Explanations of Subglacial Bedform Sizes Using Statistical Models.

    Directory of Open Access Journals (Sweden)

    John K Hillier

    Full Text Available Sediments beneath modern ice sheets exert a key control on their flow, but are largely inaccessible except through geophysics or boreholes. In contrast, palaeo-ice sheet beds are accessible, and typically characterised by numerous bedforms. However, the interaction between bedforms and ice flow is poorly constrained and it is not clear how bedform sizes might reflect ice flow conditions. To better understand this link we present a first exploration of a variety of statistical models to explain the size distribution of some common subglacial bedforms (i.e., drumlins, ribbed moraine, MSGL. By considering a range of models, constructed to reflect key aspects of the physical processes, it is possible to infer that the size distributions are most effectively explained when the dynamics of ice-water-sediment interaction associated with bedform growth is fundamentally random. A 'stochastic instability' (SI model, which integrates random bedform growth and shrinking through time with exponential growth, is preferred and is consistent with other observations of palaeo-bedforms and geophysical surveys of active ice sheets. Furthermore, we give a proof-of-concept demonstration that our statistical approach can bridge the gap between geomorphological observations and physical models, directly linking measurable size-frequency parameters to properties of ice sheet flow (e.g., ice velocity. Moreover, statistically developing existing models as proposed allows quantitative predictions to be made about sizes, making the models testable; a first illustration of this is given for a hypothesised repeat geophysical survey of bedforms under active ice. Thus, we further demonstrate the potential of size-frequency distributions of subglacial bedforms to assist the elucidation of subglacial processes and better constrain ice sheet models.

  16. Exploring healthcare communication models in private physiotherapy practice.

    Science.gov (United States)

    Hiller, Amy; Guillemin, Marilys; Delany, Clare

    2015-10-01

    This project explored whether models of healthcare communication are evident within patient-physiotherapist communication in the private practice setting. Using qualitative ethnographic methods, fifty-two patient-physiotherapist treatment sessions were observed and interviews with nine physiotherapists were undertaken. Data were analyzed using thematic analysis. In these clinical encounters physiotherapists led the communication. The communication was structured and focussed on physical aspects of the patient's presentation. These features were mediated via casual conversation and the use of touch to respond to the individual patient. Physiotherapists did not explicitly link their therapeutic communication style to established communication models. However, they described a purposeful approach to how they communicated within the treatment encounter. The communication occurring in the private practice physiotherapy treatment encounter is predominantly representative of a 'practitioner-centred' model. However, the subtle use of touch and casual conversation implicitly communicate competence and care, representative of a patient-centred model. Physiotherapists do not explicitly draw from theories of communication to inform their practice. Physiotherapists may benefit from further education to achieve patient-centred communication. Equally, the incorporation of casual conversation and the use of touch into theory of physiotherapy patient-centred communication would highlight these specific skills that physiotherapists already utilize in practice. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Numerical modeling of regional stress distributions for geothermal exploration

    Science.gov (United States)

    Guillon, Theophile; Peter-Borie, Mariane; Gentier, Sylvie; Blaisonneau, Arnold

    2017-04-01

    Any high-enthalpy unconventional geothermal projectcan be jeopardized by the uncertainty on the presence of the geothermal resource at depth. Indeed, for the majority of such projects the geothermal resource is deeply seated and, with the drilling costs increasing accordingly, must be located as precisely as possible to increase the chance of their economic viability. In order to reduce the "geological risk", i.e., the chance to poorly locate the geothermal resource, a maximum amount of information must be gathered prior to any drilling of exploration and/or operational well. Cross-interpretation from multiple disciplines (e.g., geophysics, hydrology, geomechanics …) should improve locating the geothermal resource and so the position of exploration wells ; this is the objective of the European project IMAGE (grant agreement No. 608553), under which the work presented here was carried out. As far as geomechanics is concerned, in situ stresses can have a great impact on the presence of a geothermal resource since they condition both the regime within the rock mass, and the state of the major fault zones (and hence, the possible flow paths). In this work, we propose a geomechanical model to assess the stress distribution at the regional scale (characteristic length of 100 kilometers). Since they have a substantial impact on the stress distributions and on the possible creation of regional flow paths, the major fault zones are explicitly taken into account. The Distinct Element Method is used, where the medium is modeled as fully deformable blocks representing the rock mass interacting through mechanically active joints depicting the fault zones. The first step of the study is to build the model geometry based on geological and geophysical evidences. Geophysical and structural geology results help positioning the major fault zones in the first place. Then, outcrop observations, structural models and site-specific geological knowledge give information on the fault

  18. Ergonomics-inspired Reshaping and Exploration of Collections of Models

    KAUST Repository

    Zheng, Youyi

    2015-06-22

    This paper examines the following question: given a collection of man-made shapes, e.g., chairs, can we effectively explore and rank the shapes with respect to a given human body – in terms of how well a candidate shape fits the specified human body? Answering this question requires identifying which shapes are more suitable for a prescribed body, and how to alter the input geometry to better fit the shapes to a given human body. The problem links physical proportions of the human body and its interaction with object geometry, which is often expressed as ergonomics guidelines. We present an interactive system that allows users to explore shapes using different avatar poses, while, at the same time providing interactive previews of how to alter the shapes to fit the user-specified body and pose. We achieve this by first constructing a fuzzy shape-to-body map from the ergonomic guidelines to multi-contacts geometric constraints; and then, proposing a novel contact-preserving deformation paradigm to realize a reshaping to adapt the input shape. We evaluate our method on collections of models from different categories and validate the results through a user study.

  19. A Management Model for International Participation in Space Exploration Missions

    Science.gov (United States)

    George, Patrick J.; Pease, Gary M.; Tyburski, Timothy E.

    2005-01-01

    This paper proposes an engineering management model for NASA's future space exploration missions based on past experiences working with the International Partners of the International Space Station. The authors have over 25 years of combined experience working with the European Space Agency, Japan Aerospace Exploration Agency, Canadian Space Agency, Italian Space Agency, Russian Space Agency, and their respective contractors in the design, manufacturing, verification, and integration of their elements electric power system into the United States on-orbit segment. The perspective presented is one from a specific sub-system integration role and is offered so that the lessons learned from solving issues of technical and cultural nature may be taken into account during the formulation of international partnerships. Descriptions of the types of unique problems encountered relative to interactions between international partnerships are reviewed. Solutions to the problems are offered, taking into consideration the technical implications. Through the process of investigating each solution, the important and significant issues associated with working with international engineers and managers are outlined. Potential solutions are then characterized by proposing a set of specific methodologies to jointly develop spacecraft configurations that benefits all international participants, maximizes mission success and vehicle interoperability while minimizing cost.

  20. Investigation of international energy economics. [Use of econometric model EXPLOR

    Energy Technology Data Exchange (ETDEWEB)

    Deonigi, D.E.; Clement, M.; Foley, T.J.; Rao, S.A.

    1977-03-01

    The Division of International Affairs of the Energy Research and Development Administration is assessing the long-range economic effects of energy research and development programs in the U.S. and other countries, particularly members of the International Energy Agency (IEA). In support of this effort, a program was designed to coordinate the capabilities of five research groups--Rand, Virginia Polytechnic Institute, Brookhaven National Laboratory, Lawrence Livermore Laboratory, and Pacific Northwest Laboratory. The program could evaluate the international economics of proposed or anticipated sources of energy. This program is designed to be general, flexible, and capable of evaluating a diverse collection of potential energy (nuclear and nonnuclear) related problems. For example, the newly developed methodology could evaluate the international and domestic economic impact of nuclear-related energy sources, but also existing nonnuclear and potential energy sources such as solar, geothermal, wind, etc. Major items to be included would be the cost of exploration, cost of production, prices, profit, market penetration, investment requirements and investment goods, economic growth, change in balance of payments, etc. In addition, the changes in cost of producing all goods and services would be identified for each new energy source. PNL developed (1) a means of estimating the demands for major forms of energy by country, and (2) a means of identifying results or impacts on each country. The results for each country were then to be compared to assess relative advantages. PNL relied on its existing general econometric model, EXPLOR, to forecast the demand for energy by country. (MCW)

  1. Exploring the lambda model of the hybrid superstring

    Energy Technology Data Exchange (ETDEWEB)

    Schmidtt, David M. [Instituto de Física Teórica IFT/UNESP,Rua Dr. Bento Teobaldo Ferraz 271, Bloco II, CEP 01140-070, São Paulo-SP (Brazil)

    2016-10-26

    The purpose of this contribution is to initiate the study of integrable deformations for different superstring theory formalisms that manifest the property of (classical) integrability. In this paper we choose the hybrid formalism of the superstring in the background AdS{sub 2}×S{sup 2} and explore in detail the most immediate consequences of its λ-deformation. The resulting action functional corresponds to the λ-model of the matter part of the fairly more sophisticated pure spinor formalism, which is also known to be classical integrable. In particular, the deformation preserves the integrability and the one-loop conformal invariance of its parent theory, hence being a marginal deformation.

  2. Exploring a Parasite-Host Model with Monte Carlo Simulations

    Science.gov (United States)

    Breecher, Nyles; Dong, Jiajia

    2011-03-01

    We explore parasite-host interactions, a less investigated subset of the well-established predator-prey model. In particular, it is not well known how the numerous parameters of the system affect its characteristics. Parasite-host systems rely on their spatial interaction, as a parasite must make physical contact with the host to reproduce. Using C++ to program a Monte Carlo simulation, we study how the speed and type of movement of the host affect the spatial and temporal distribution of the parasites. By drawing on mean-field theoretics, we find the exact solution for the parasite distribution with a stationary host at the center and analyze the distributions for a moving host. The findings of the study provide rich behavior of a non-equilibrium system and bring insights to pest-control and, on a larger scale, epidemics spreading.

  3. Exploring the Model Design Space for Battery Health Management

    Science.gov (United States)

    Saha, Bhaskar; Quach, Cuong Chi; Goebel, Kai Frank

    2011-01-01

    Battery Health Management (BHM) is a core enabling technology for the success and widespread adoption of the emerging electric vehicles of today. Although battery chemistries have been studied in detail in literature, an accurate run-time battery life prediction algorithm has eluded us. Current reliability-based techniques are insufficient to manage the use of such batteries when they are an active power source with frequently varying loads in uncertain environments. The amount of usable charge of a battery for a given discharge profile is not only dependent on the starting state-of-charge (SOC), but also other factors like battery health and the discharge or load profile imposed. This paper presents a Particle Filter (PF) based BHM framework with plug-and-play modules for battery models and uncertainty management. The batteries are modeled at three different levels of granularity with associated uncertainty distributions, encoding the basic electrochemical processes of a Lithium-polymer battery. The effects of different choices in the model design space are explored in the context of prediction performance in an electric unmanned aerial vehicle (UAV) application with emulated flight profiles.

  4. Exploring the critical quality attributes and models of smart homes.

    Science.gov (United States)

    Ted Luor, Tainyi; Lu, Hsi-Peng; Yu, Hueiju; Lu, Yinshiu

    2015-12-01

    Research on smart homes has significantly increased in recent years owing to their considerably improved affordability and simplicity. However, the challenge is that people have different needs (or attitudes toward smart homes), and provision should be tailored to individuals. A few studies have classified the functions of smart homes. Therefore, the Kano model is first adopted as a theoretical base to explore whether the functional classifications of smart homes are attractive or necessary, or both. Second, three models and test user attitudes toward three function types of smart homes are proposed. Based on the Kano model, the principal results, namely, two "Attractive Quality" and nine "Indifferent Quality" items, are found. Verification of the hypotheses also indicates that the entertainment, security, and automation functions are significantly correlated with the variables "perceive useful" and "attitude." Cost consideration is negatively correlated with attitudes toward entertainment and automation. Results suggest that smart home providers should survey user needs for their product instead of merely producing smart homes based on the design of the builder or engineer. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. "Friends" and "Foes" in the Social Space of the Tatar Ethnic Group

    Directory of Open Access Journals (Sweden)

    Nataliia O. Khazieva

    2017-10-01

    Full Text Available The history of the World Culture is a demonstration of the "war" between the two opposites: on the one hand, we see a trend towards unification of all aspects of life on a global scale, and on the other, there is a clear confrontation between different groups of mankind. Of the many causes of the disunity of the people, the authors' focus at the opposition "friend – foe" as a metaphysical principle of formation of social space wasn't chosen by accident. The fact is that any culture, in principle, is dichotomous, and the opposition "friend – foe" is the fullest incarnation of this dichotomy. As a universal principle of the formation and functioning of the cultures, it originally manifests itself in every one of them. And, as the authors of the study suggest: this opposition could either "work" in general on the cross-cultural cooperation and unity or be one of the confrontation sources. The main result of the study is that history has prepared and put forward the Tartars for carrying out a special mission, to unite peoples and cultures. But the revolutionary social upheavals that take place in the modern world pose a threat (in the circumstances of forced migration of peoples, the growth of national consciousness of the former Soviet Union space, and especially in the face of Islamic fundamentalism on fulfilling this function.

  6. Exploring New Physics Beyond the Standard Model: Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Liantao [Univ. of Chicago, IL (United States)

    2016-10-17

    This grant in 2015 to 2016 was for support in the area of theoretical High Energy Physics. The research supported focused mainly on the energy frontier, but it also has connections to both the cosmic and intensity frontiers. Lian-Tao Wang (PI) focused mainly on signal of new physics at colliders. The year 2015 - 2016, covered by this grant, has been an exciting period of digesting the influx of LHC data, understanding its meaning, and using it to refine strategies for deeper exploration. The PI proposed new methods of searching for new physics at the LHC, such as for the compressed stops. He also investigated in detail the signal of composite Higgs models, focusing on spin-1 composite resonances in the di-boson channel. He has also considered di-photon as a probe for such models. He has also made contributions in formulating search strategies of dark matter at the LHC, resulting in two documents with recommendations. The PI has also been active in studying the physics potential of future colliders, including Higgs factories and 100 TeV pp colliders. He has given comprehensive overview of the physics potential of the high energy proton collider, and outline its luminosity targets. He has also studied the use of lepton colliders to probe fermionic Higgs portal and bottom quark couplings to the Z boson.

  7. Exploring the nap paradox: are mid-day sleep bouts a friend or foe?

    Science.gov (United States)

    Mantua, Janna; Spencer, Rebecca M C

    2017-09-01

    The mid-day nap, sometimes called a siesta, is a ubiquitous occurrence across the lifespan. It is well established that in addition to reducing sleepiness, mid-day naps offer a variety of benefits: memory consolidation, preparation for subsequent learning, executive functioning enhancement, and a boost in emotional stability. These benefits are present even if a sufficient amount of sleep is obtained during the night prior. However, we present a paradox: in spite of these reported benefits of naps, frequent napping has also been associated with numerous negative outcomes (eg, cognitive decline, hypertension, diabetes), particularly in older populations. This association exists even when statistically controlling for relevant health- and sleep-affecting determinants. An emerging hypothesis suggests inflammation is a mediator between mid-day naps and poor health outcomes, yet further research is necessary. Given this, it may be premature to 'prescribe' naps as a health enhancer. Herein, we aggregate findings from several branches of sleep research (eg, developmental neuroscience, cognitive neuroscience, sleep medicine) to critically examine the paradoxical role of naps in cognitive and somatic health. This review uncovers gaps in the literature to guide research opportunities in the field. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Orebody Modelling for Exploration: The Western Mineralisation, Broken Hill, NSW

    Energy Technology Data Exchange (ETDEWEB)

    Lotfolah Hamedani, Mohammad, E-mail: mlotfham@gmail.com; Plimer, Ian Rutherford [University of Adelaide, School of Earth and Environmental Sciences (Australia); Xu Chaoshui [University of Adelaide, School of Civil, Environmental and Mining Engineering (Australia)

    2012-09-15

    The Western Mineralisation in the Broken Hill deposit was studied to identify the zonation sequence of lithogeochemical haloes along and across the strike of the orebody. Samples used are from 77 drill holes and the samples were assayed for Pb, Zn, Fe, S, Cu, Ag, Cd, Sb, Bi and As. Variogram analyses were calculated for all the elements and kriging was used to construct the 3D block model. Analysis of cross sections along and across the strike of the orebody shows that Bi and Sb form broader halos around sulphide masses and this suggests that they are pathfinder elements for the Pb and Zn elements of this orebody. The threshold concentrations (minimum anomaly) of the 10 elements were determined using the concentration-area analysis. On east-west vertical cross sections, the values of linear productivity, variability gradient and zonality index were calculated for each element. Based on the maximum zonality index of each element, the sequence of geochemical zonation pattern was determined from top to bottom of the orebody. The result shows that S, Pb, Zn and Cd tend to concentrate in the upper part of the mineralisation whereas Ag, Cu, Bi and As have a tendency to concentrate in the lower part of the mineralised rocks. Also, an empirical product ratio index was developed based on the position of the elements in the zonation sequence. The methods and results of this research are applicable to exploration of similar Zn and Pb sulphide ore deposits.

  9. The Business of Art Education: Friend or Foe?

    Science.gov (United States)

    Shin, Ryan

    2012-01-01

    Franchised art instruction businesses are not necessarily the enemy of the art educator, and can even provide a mutually beneficial way to enrich school art education programs. This article explores the status of art education businesses as creative enterprises that offer art curricula for children as clients, beyond the traditional school and…

  10. Surface models and gradually peeled volume model to explore hand structures.

    Science.gov (United States)

    Chung, Beom Sun; Kwon, Koojoo; Shin, Byeong-Seok; Chung, Min Suk

    2017-05-01

    This study was intended to confirm whether simultaneous examination of surface and volume models contributes to learning of hand structures. Outlines of the skin, muscles, and bones of the right hand were traced in sectioned images of a male cadaver to create surface models of the structures. After the outlines were filled with selected colors, the color-filled sectioned images were stacked to produce a volume model of the hand, from which the skin was gradually peeled. The surface models provided locational orientation of the hand structures such as extrinsic and intrinsic hand muscles, while the peeled volume model revealed the depth of the individual hand structures. In addition, the characteristic appearances of the radial artery and the wrist joint were confirmed. The exploration of the volume model accompanied by equivalent surface models is synergistically helpful for understanding the morphological properties of hand structures. Copyright © 2017 Elsevier GmbH. All rights reserved.

  11. Career Exploration for High School Women: A Model.

    Science.gov (United States)

    Birk, Janice M.; Tanney, Mary Faith

    Designed for high school women at the sophomore level, this program is intended to act as a catalyst for exploration of career goals with a heightened awareness of the influence of sexism and stereotypic attitudes regarding women's roles. Together with three special activity periods, there is continued assistance by the high school counselor in…

  12. The stainless steel crown debate: friend or foe?

    Science.gov (United States)

    Uston, Karen A; Estrella, Maria Regina P

    2011-01-01

    In this article, we will explore the use of the stainless steel crown (SSC) in dentistry today. For the pediatric population, many factors can affect the choice of restoration, such as the variations between primary and permanent tooth morphology, oral environment, and patient selection. The current literature and dentistry guidelines encourage dentists to make an informed decision when determining the restoration recommended for a carious primary molar. To further help educate dental providers on the topic of SSCs the following items will be reviewed: the indications; techniques for placement; advantages; and drawbacks when compared to alternative restorative materials. Regardless of personal opinion, the SSC should continue to be recognized for its efficiency, cost-effectiveness, and successful treatment modality.

  13. Friends, family, and foes: the influence of father's social networks.

    Science.gov (United States)

    Murphy, Alexandrea Danielle; Gordon, Derrick; Sherrod, Hans; Dancy, Victoria; Kershaw, Trace

    2013-05-01

    Fathers can play an important role in child development and family functioning. However, little is known about the influence of paternal perceptions of fatherhood involvement or the influence of fathers' peer networks. We explored the network characteristics (density, closeness, and degree centrality) and peer norms regarding sex, fatherhood, and other risk behaviors of 52 urban adult males in New Haven, Connecticut. Results identify that engagement in high-risk sexual behavior was associated with fatherhood involvement, with 88% of less involved fathers engaging in high-risk sexual behavior (p = .004). Denser networks were positively correlated with unfavorable peer norms such as cheating on a partner or drinking or using drugs (p networks are important to father's health and behavior and that father's behaviors may be affected by peer norms. Interventions designed for men may be strengthened by including peers in programming and by addressing norms and norm changing.

  14. Exploring the Limits of the Geometric Copolymerization Model

    Directory of Open Access Journals (Sweden)

    Martin S. Engler

    2017-03-01

    Full Text Available The geometric copolymerization model is a recently introduced statistical Markov chain model. Here, we investigate its practicality. First, several approaches to identify the optimal model parameters from observed copolymer fingerprints are evaluated using Monte Carlo simulated data. Directly optimizing the parameters is robust against noise but has impractically long running times. A compromise between robustness and running time is found by exploiting the relationship between monomer concentrations calculated by ordinary differential equations and the geometric model. Second, we investigate the applicability of the model to copolymerizations beyond living polymerization and show that the model is useful for copolymerizations involving termination and depropagation reactions.

  15. Testing the Standard Model with the Primordial Inflation Explorer

    Science.gov (United States)

    Kogut, Alan J.

    2011-01-01

    The Primordial Inflation Explorer is an Explorer-class mission to measure the gravity-wave signature of primordial inflation through its distinctive imprint on the linear polarization of the cosmic microwave background. PIXIE uses an innovative optical design to achieve background-limited sensitivity in 400 spectral channels spanning 2.5 decades in frequency from 30 GHz to 6 THz (1 cm to 50 micron wavelength). The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r < 10A{-3) at 5 standard deviations. The rich PIXIE data set will also constrain physical processes ranging from Big Bang cosmology to the nature of the first stars to physical conditions within the interstellar medium of the Galaxy. I describe the PIXIE instrument and mission architecture needed to detect the inflationary signature using only 4 semiconductor bolometers.

  16. Tactile Teaching: Exploring Protein Structure/Function Using Physical Models

    Science.gov (United States)

    Herman, Tim; Morris, Jennifer; Colton, Shannon; Batiza, Ann; Patrick, Michael; Franzen, Margaret; Goodsell, David S.

    2006-01-01

    The technology now exists to construct physical models of proteins based on atomic coordinates of solved structures. We review here our recent experiences in using physical models to teach concepts of protein structure and function at both the high school and the undergraduate levels. At the high school level, physical models are used in a…

  17. A consolidation based extruder model to explore GAME process configurations

    NARCIS (Netherlands)

    Willems, P.; Kuipers, N.J.M.; de Haan, A.B.

    2009-01-01

    A mathematical model from literature was adapted to predict the pressure profile and oil yield for canola in a lab-scale extruder. Changing the description of the expression process from filtration to consolidation significantly improved the performance and physical meaning of the model. The model

  18. Computerised modelling for developmental biology : an exploration with case studies

    NARCIS (Netherlands)

    Bertens, Laura M.F.

    2012-01-01

    Many studies in developmental biology rely on the construction and analysis of models. This research presents a broad view of modelling approaches for developmental biology, with a focus on computational methods. An overview of modelling techniques is given, followed by several case studies. Using

  19. Exploring component-based approaches in forest landscape modeling

    Science.gov (United States)

    H. S. He; D. R. Larsen; D. J. Mladenoff

    2002-01-01

    Forest management issues are increasingly required to be addressed in a spatial context, which has led to the development of spatially explicit forest landscape models. The numerous processes, complex spatial interactions, and diverse applications in spatial modeling make the development of forest landscape models difficult for any single research group. New...

  20. Educational Inclusion and Critical Neuroscience: Friends or Foes?

    Science.gov (United States)

    Billington, Tom

    2017-01-01

    Momentum is continuing to grow in the circulation of neuroscientific discourse, informing aspects of how we live but affecting too how we think about education and learning. Neurologically informed intrusions into education frequently align with psychology which has until now largely adopted a "medical model", supporting policies and…

  1. Trade liberalization: Poverty's friend or foe? | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2011-01-31

    Jan 31, 2011 ... By changing variables, researchers can develop “what if ” scenarios to assess the outcome of proposed policy changes and to identify the important channels through which the changes act. But any model is only as good as the data available to put in it and the assumptions on which it is based. While the ...

  2. Terrain modelling and motion planning for an autonomous exploration rover

    Science.gov (United States)

    Richard, F.; Benoliel, S.; Faugeras, O.; Grandjean, P.; Hayard, M.; Simeon, T.

    1994-01-01

    To assess the feasibility of planetary exploration missions using rovers, the French national agency CNES, with a consortium of European laboratories and industrial concerns, has initiated the Eureka project, 'Illustration of an Autonomous Robot for the Exploration of Space' (IARES). IARES is a demonstrator composed of a rover and a ground station, linked by telemetry and telecommand. It is aimed at verifying, on earth, robotic concepts developed by the RISP group of French laboratories (LAAS, INRIA, CERT, LETI) to perform scientific missions such as autonomous terrain sample collecting over large areas. To cope with the actual needs of planet exploration, IARES suitability is assessed through constraints on limited bandwidth, time delay and on-board resources. This autonomy relies heavily on robust onboard trajectory generation capabilities. This paper presents the main functions of the IARES navigation sub-system and shows how they are combined to allow movement in Mars-like environments. Section 2 gives an overall description of the IARES system. Section 3 details the functions of the Navigation sub-system, and finally, section 4 illustrates with a simple example the use of these functions.

  3. Endothelial Progenitor Cells in Diabetic Microvascular Complications: Friends or Foes?

    Directory of Open Access Journals (Sweden)

    Cai-Guo Yu

    2016-01-01

    Full Text Available Despite being featured as metabolic disorder, diabetic patients are largely affected by hyperglycemia-induced vascular abnormality. Accumulated evidence has confirmed the beneficial effect of endothelial progenitor cells (EPCs in coronary heart disease. However, antivascular endothelial growth factor (anti-VEGF treatment is the main therapy for diabetic retinopathy and nephropathy, indicating the uncertain role of EPCs in the pathogenesis of diabetic microvascular disease. In this review, we first illustrate how hyperglycemia induces metabolic and epigenetic changes in EPCs, which exerts deleterious impact on their number and function. We then discuss how abnormal angiogenesis develops in eyes and kidneys under diabetes condition, focusing on “VEGF uncoupling with nitric oxide” and “competitive angiopoietin 1/angiopoietin 2” mechanisms that are shared in both organs. Next, we dissect the nature of EPCs in diabetic microvascular complications. After we overview the current EPCs-related strategies, we point out new EPCs-associated options for future exploration. Ultimately, we hope that this review would uncover the mysterious nature of EPCs in diabetic microvascular disease for therapeutics.

  4. Exploring mental health students' perceptions of role models.

    Science.gov (United States)

    Illingworth, Paul

    This article describes and reflects on a qualitative study that attempted to develop further understanding of the concept of role models, using the experiences of third-year students undertaking mental health nurse education. Although there is a wealth of literature regarding role models, little exists that acknowledges what, in this case, students want of a role model, or how the students identify the positive attributes of a significant role model. The researcher used a qualitative approached based on phenomenological methods. The research question used, was: 'From the viewpoint of a third-year student undertaking mental health nurse education, what is the phenomenon referred to as role model?'

  5. Exploring EFL Teachers’ Cognitive Models Through Metaphor Analysis

    Directory of Open Access Journals (Sweden)

    Hui Xiong

    2015-10-01

    Full Text Available This study aims to investigate how a group of Chinese university teachers developed their cognitive models by using “English as a Foreign Language (EFL teachers” metaphors. The research method includes an open-ended questionnaire, a checklist questionnaire, and verbal reports. The goal for this research is twofold. First, we will present those metaphors we believe to be the most frequently used or most central in shaping the thoughts or ideas they have had for EFL teaching and learning. Second, we will provide a description of their internal process of developing cognitive models, as well as factors that could account for such models. The findings showed that (a most of us had three ways of understanding EFL teachers in terms of the educational journey metaphor, the educational building metaphor, and the educational conduit metaphor; (b we used such a cluster of converging cognitive models as the instructor model, the transmitter model, and the builder model to construct definitions for EFL teachers, with the instructor model as a central model; and (c metaphor can actually serve as a useful, effective, and analytic tool for making us aware of the cognitive model underlying our conceptual framework.

  6. Exploring Neural Network Models with Hierarchical Memories and Their Use in Modeling Biological Systems

    Science.gov (United States)

    Pusuluri, Sai Teja

    Energy landscapes are often used as metaphors for phenomena in biology, social sciences and finance. Different methods have been implemented in the past for the construction of energy landscapes. Neural network models based on spin glass physics provide an excellent mathematical framework for the construction of energy landscapes. This framework uses a minimal number of parameters and constructs the landscape using data from the actual phenomena. In the past neural network models were used to mimic the storage and retrieval process of memories (patterns) in the brain. With advances in the field now, these models are being used in machine learning, deep learning and modeling of complex phenomena. Most of the past literature focuses on increasing the storage capacity and stability of stored patterns in the network but does not study these models from a modeling perspective or an energy landscape perspective. This dissertation focuses on neural network models both from a modeling perspective and from an energy landscape perspective. I firstly show how the cellular interconversion phenomenon can be modeled as a transition between attractor states on an epigenetic landscape constructed using neural network models. The model allows the identification of a reaction coordinate of cellular interconversion by analyzing experimental and simulation time course data. Monte Carlo simulations of the model show that the initial phase of cellular interconversion is a Poisson process and the later phase of cellular interconversion is a deterministic process. Secondly, I explore the static features of landscapes generated using neural network models, such as sizes of basins of attraction and densities of metastable states. The simulation results show that the static landscape features are strongly dependent on the correlation strength and correlation structure between patterns. Using different hierarchical structures of the correlation between patterns affects the landscape features

  7. Comparison of four nonlinear growth models for effective exploration ...

    African Journals Online (AJOL)

    This study was conducted to compare the effectiveness for non-linear growth models designated as Chapman-Richards, Gompertz, Logistic and von Bertalanffy for selection of fast-growing fish strain of turbot Scophthalmus maximus. These models were compared using the goodness of fit (the coefficient of determination ...

  8. Exploring the interdependencies between parameters in a material model.

    Energy Technology Data Exchange (ETDEWEB)

    Silling, Stewart Andrew; Fermen-Coker, Muge

    2014-01-01

    A method is investigated to reduce the number of numerical parameters in a material model for a solid. The basis of the method is to detect interdependencies between parameters within a class of materials of interest. The method is demonstrated for a set of material property data for iron and steel using the Johnson-Cook plasticity model.

  9. Exploring Mental Models of Learning and Instruction in Teacher Education

    Science.gov (United States)

    Wilke, Ryan A.; Losh, Susan Carol

    2012-01-01

    The authors examine conceptual change in preservice teachers through a synthesis and application of mental models theory. They analyzed longitudinal data in the form of lesson plans, interviews, and written rationales from eight, social science preservice teachers. Findings that illustrate how preservice teachers' mental models changed during…

  10. Animal Models Used to Explore Abdominal Aortic Aneurysms

    DEFF Research Database (Denmark)

    Lysgaard Poulsen, J; Stubbe, J; Lindholt, J S

    2016-01-01

    OBJECTIVE: Experimental animal models have been used to investigate the formation, development, and progression of abdominal aortic aneurysms (AAAs) for decades. New models are constantly being developed to imitate the mechanisms of human AAAs and to identify treatments that are less risky than t...

  11. Exploring Term Dependences in Probabilistic Information Retrieval Model.

    Science.gov (United States)

    Cho, Bong-Hyun; Lee, Changki; Lee, Gary Geunbae

    2003-01-01

    Describes a theoretic process to apply Bahadur-Lazarsfeld expansion (BLE) to general probabilistic models and the state-of-the-art 2-Poisson model. Through experiments on two standard document collections, one in Korean and one in English, it is demonstrated that incorporation of term dependences using BLE significantly contributes to performance…

  12. Exploring First-Year Academic Achievement through Structural Equation Modelling

    Science.gov (United States)

    McKenzie, Kirsten; Gow, Kathryn; Schweitzer, Robert

    2004-01-01

    The purpose of this research was to develop and test a multicausal model of the individual characteristics associated with academic success in first-year Australian university students. This model comprised the constructs of: previous academic performance, achievement motivation, self-regulatory learning strategies, and personality traits, with…

  13. Developing Alternative Frameworks for Exploring Intercultural Learning: A Critique of Hofstede's Cultural Difference Model

    Science.gov (United States)

    Signorini, Paola; Wiesemes, Rolf; Murphy, Roger

    2009-01-01

    Hofstede's model of cultural difference has been used widely for exploring aspects of culture in educational settings. In this paper, we review Hofstede's model and explore some of its limitations, particularly in relation to the field of higher education. These limitations include an oversimplification of cultural differences, inconsistencies…

  14. Beta-blockers: friend or foe in asthma?

    Directory of Open Access Journals (Sweden)

    Arboe B

    2013-07-01

    Full Text Available Bente Arboe, Charlotte Suppli UlrikDepartment of Pulmonary Medicine, Hvidovre Hospital and University of Copenhagen, Hvidovre, DenmarkBackground and aim: Recently, β-blockers have been suggested as a potential maintenance treatment option for asthma. The aim of this review is to provide an overview of the current knowledge of the potential benefits and risks of β-blocker therapy for asthma.Method: Systematic literature review.Results: No significant increase in the number of patients requiring rescue oral corticosteroid for an exacerbation of asthma has been observed after initiation of β-blocker treatment. Patients with mild to moderate reactive airway disease, probably both asthma and chronic obstructive pulmonary disease, may have a limited fall in forced expiratory volume in 1 second (FEV1 following single-dose administration of β-blocker, whereas no change in FEV1 has been reported following long-term administration. In a murine model of asthma, long-term administration of β-blockers resulted in a decrease in airway hyperresponsiveness, suggesting an anti-inflammatory effect. In keeping with this, long-term administration of a nonselective β-blocker to steroid-naïve asthma patients has shown a dose-dependent improvement in airway hyperresponsiveness, and either an asymptomatic fall in FEV1 or no significant change in FEV1. Furthermore, available studies show that bronchoconstriction induced by inhaled methacholine is reversed by salbutamol in patients on regular therapy with a β-blocker. On the other hand, a recent placebo-controlled trial of propranolol and tiotropium bromide added to inhaled corticosteroids revealed no effect on airway hyperresponsiveness and a small, not statistically significant, fall in FEV1 in patients classified as having mild to moderate asthma.Conclusion: The available, although limited, evidence suggests that a dose-escalating model of β-blocker therapy to patients with asthma is well tolerated, does not

  15. An FE model of a cellular polypropylene: exploring mechanical properties

    Science.gov (United States)

    Sgardelis, Pavlos; Pozzi, Michele

    2017-05-01

    Several analytical models have been suggested to describe the changes in the electromechanical properties of Cellular Polypropylene (Cell-PP) due to charging. However, there is a limited number of studies considering the non-linear dependence of the piezoelectric coefficient d33 on the mechanical load applied. One of the main reasons for this nonlinearity is the stiffness of the film that increases proportionally to the applied mechanical load. Moreover the size and shape distribution of the enclosed voids is an important determinant of the electromechanical properties. In this work, the geometry of a 3D model of Cell-PP is designed on the basis of analytical Splines. Both the manufacturing procedure of Cell-PP films (bi-axial stretching) and the pressure expansion treatment were simulated in order to account for a realistic void distribution. The FEA is done on a 2D cross-section of the modelled film. The modelled mechanical response is analysed based on increasing mechanical load applied. The load-deflection curves obtained from the analysis are then compared to the experimental results acquired via Dynamical Mechanical Analyzer (DMA) to validate the model. Four types of Cell-PP films, expanded at different pressures, were used in this validation. The aim is to develop a model that describes the effect of morphological parameters on the stiffness of the films by simulating the manufacturing procedure.

  16. Innate Immunity and Biomaterials at the Nexus: Friends or Foes

    Directory of Open Access Journals (Sweden)

    Susan N. Christo

    2015-01-01

    Full Text Available Biomaterial implants are an established part of medical practice, encompassing a broad range of devices that widely differ in function and structural composition. However, one common property amongst biomaterials is the induction of the foreign body response: an acute sterile inflammatory reaction which overlaps with tissue vascularisation and remodelling and ultimately fibrotic encapsulation of the biomaterial to prevent further interaction with host tissue. Severity and clinical manifestation of the biomaterial-induced foreign body response are different for each biomaterial, with cases of incompatibility often associated with loss of function. However, unravelling the mechanisms that progress to the formation of the fibrotic capsule highlights the tightly intertwined nature of immunological responses to a seemingly noncanonical “antigen.” In this review, we detail the pathways associated with the foreign body response and describe possible mechanisms of immune involvement that can be targeted. We also discuss methods of modulating the immune response by altering the physiochemical surface properties of the biomaterial prior to implantation. Developments in these areas are reliant on reproducible and effective animal models and may allow a “combined” immunomodulatory approach of adapting surface properties of biomaterials, as well as treating key immune pathways to ultimately reduce the negative consequences of biomaterial implantation.

  17. Lecithin:cholesterol acyltransferase: old friend or foe in atherosclerosis?

    Science.gov (United States)

    Kunnen, Sandra; Van Eck, Miranda

    2012-01-01

    Lecithin:cholesterol acyltransferase (LCAT) is a key enzyme that catalyzes the esterification of free cholesterol in plasma lipoproteins and plays a critical role in high-density lipoprotein (HDL) metabolism. Deficiency leads to accumulation of nascent preβ-HDL due to impaired maturation of HDL particles, whereas enhanced expression is associated with the formation of large, apoE-rich HDL1 particles. In addition to its function in HDL metabolism, LCAT was believed to be an important driving force behind macrophage reverse cholesterol transport (RCT) and, therefore, has been a subject of great interest in cardiovascular research since its discovery in 1962. Although half a century has passed, the importance of LCAT for atheroprotection is still under intense debate. This review provides a comprehensive overview of the insights that have been gained in the past 50 years on the biochemistry of LCAT, the role of LCAT in lipoprotein metabolism and the pathogenesis of atherosclerosis in animal models, and its impact on cardiovascular disease in humans. PMID:22566575

  18. Hypothermia in bleeding trauma: a friend or a foe?

    Directory of Open Access Journals (Sweden)

    Kochanek Ashley R

    2009-12-01

    Full Text Available Abstract The induction of hypothermia for cellular protection is well established in several clinical settings. Its role in trauma patients, however, is controversial. This review discusses the benefits and complications of induced hypothermia--emphasizing the current state of knowledge and potential applications in bleeding patients. Extensive pre-clinical data suggest that in advanced stages of shock, rapid cooling can protect cells during ischemia and reperfusion, decrease organ damage, and improve survival. Yet hypothermia is a double edged sword; unless carefully managed, its induction can be associated with a number of complications. Appropriate patient selection requires a thorough understanding of the pre-clinical literature. Clinicians must also appreciate the enormous influence that temperature modulation exerts on various cellular mechanisms. This manuscript aims to provide a balanced view of the published literature on this topic. While many of the advantageous molecular and physiological effects of induced hypothermia have been outlined in animal models, rigorous clinical investigations are needed to translate these promising findings into clinical practice.

  19. Lactate and the injured brain: friend or foe?

    Science.gov (United States)

    Bouzat, Pierre; Oddo, Mauro

    2014-04-01

    Energy metabolism is increasingly recognized as a key factor in the pathogenesis of acute brain injury (ABI). We review the role of cerebral lactate metabolism and summarize evidence showing that lactate may act as supplemental fuel after ABI. The role of cerebral lactate has shifted from a waste product to a potentially preferential fuel and signaling molecule. According to the astrocyte-neuron lactate shuttle model, glycolytic lactate might act as glucose-sparing substrate. Lactate also is emerging as a key signal to regulate cerebral blood flow (CBF) and a neuroprotective agent after experimental ABI. Clinical investigation using cerebral microdialysis shows the existence of two main lactate patterns, ischemic - from anaerobic metabolism - and nonischemic, from activated glycolysis, whereby lactate can be used as supplemental energy fuel. Preliminary clinical data suggests hypertonic lactate solutions improve cerebral energy metabolism and are an effective treatment for elevated intracranial pressure (ICP) after ABI. Lactate can be a supplemental fuel for the injured brain and is important to regulate glucose metabolism and CBF. Exogenous lactate supplementation may be neuroprotective after experimental ABI. Recent clinical data from ABI patients suggest hypertonic lactate solutions may be a valid therapeutic option for secondary energy dysfunction and elevated ICP.

  20. Innate Immunity and Biomaterials at the Nexus: Friends or Foes

    Science.gov (United States)

    Christo, Susan N.; Diener, Kerrilyn R.; Bachhuka, Akash; Vasilev, Krasimir; Hayball, John D.

    2015-01-01

    Biomaterial implants are an established part of medical practice, encompassing a broad range of devices that widely differ in function and structural composition. However, one common property amongst biomaterials is the induction of the foreign body response: an acute sterile inflammatory reaction which overlaps with tissue vascularisation and remodelling and ultimately fibrotic encapsulation of the biomaterial to prevent further interaction with host tissue. Severity and clinical manifestation of the biomaterial-induced foreign body response are different for each biomaterial, with cases of incompatibility often associated with loss of function. However, unravelling the mechanisms that progress to the formation of the fibrotic capsule highlights the tightly intertwined nature of immunological responses to a seemingly noncanonical “antigen.” In this review, we detail the pathways associated with the foreign body response and describe possible mechanisms of immune involvement that can be targeted. We also discuss methods of modulating the immune response by altering the physiochemical surface properties of the biomaterial prior to implantation. Developments in these areas are reliant on reproducible and effective animal models and may allow a “combined” immunomodulatory approach of adapting surface properties of biomaterials, as well as treating key immune pathways to ultimately reduce the negative consequences of biomaterial implantation. PMID:26247017

  1. [Exploration and research of community management model for asthmatic children].

    Science.gov (United States)

    Li, Jingpeng; Wei, Hong; Li, Xuejun; Wang, Mengmeng; Wang, Genxiang; Zhao, Shunying

    2014-05-01

    To study the efficacy of community management model of bronchial asthma in children. Through community outreach and clinic, 120 cases of children with asthma were enrolled from the 11 000 children aged 0 to 14 in Zhanlanlu area, and a community management model of asthma was established according to the Global Initiative for Asthma requirements combined with the actual situation of the community, both physicians and patients participated in case identification, file creation, and long-term standardized management. Through repeated medical education, the telephone hotline and interactive network of asthma among physicians, children and parents, a physician-patient relationship was established. The data of standardized medication, scheduled re-visit to the hospital, frequency of asthma attacks, antibiotic use, medical expenses, the loss of parents work hours etc. before and after the implementation of community management model were analyzed and compared. After implementation of community management model, the use of systemic corticosteroids (19.4%), oral medication (31.6%) was significantly lower than those before implementation (68.3% and 90.0%) (χ(2) = 51.9, 41.1, P management level (10.0%), χ(2) = 106.0, P management, eventually the dropout rate was 9.2%. Enrollment of children with bronchial asthma into community management model made the children adhere to the management regularly and a standardized management was achieved.

  2. Exploring new models in all detail with SARAH

    CERN Document Server

    Staub, Florian

    2015-01-01

    I give an overview about the features the Mathematica package SARAH provides to study new models. In general, SARAH can handle a wide range of models beyond the MSSM coming with additional chiral superfields, extra gauge groups, or distinctive features like Dirac gaugino masses. All of these models can be implemented in a compact form in SARAH and are easy to use: SARAH extracts all analytical properties of the given model like two-loop renormalization group equations, tadpole equations, mass matrices and vertices. Also one- and two-loop corrections to tadpoles and self-energies can be obtained. For numerical calculations SARAH can be interfaced to other tools to get the mass spectrum, to check flavour or dark matter constraints, and to test the vacuum stability, or to perform collider studies. In particular, the interface to SPheno allows a precise prediction of the Higgs mass in a given model comparable to MSSM precision by incorporating the important two-loop corrections. I show in great detail at the exam...

  3. Plant lessons: exploring ABCB functionality through structural modeling

    Directory of Open Access Journals (Sweden)

    Aurélien eBailly

    2012-01-01

    Full Text Available In contrast to mammalian ABCB1 proteins, narrow substrate specificity has been extensively documented for plant orthologs shown to catalyze the transport of the plant hormone, auxin. Using the crystal structures of the multidrug exporters Sav1866 and MmABCB1 as templates, we have developed structural models of plant ABCB proteins with a common architecture. Comparisons of these structures identified kingdom-specific candidate substrate-binding regions within the translocation chamber formed by the transmembrane domains of ABCBs from the model plant Arabidopsis. These results suggest an early evolutionary divergence of plant and mammalian ABCBs. Validation of these models becomes a priority for efforts to elucidate ABCB function and manipulate this class of transporters to enhance plant productivity and quality.

  4. Plant Lessons: Exploring ABCB Functionality Through Structural Modeling

    Science.gov (United States)

    Bailly, Aurélien; Yang, Haibing; Martinoia, Enrico; Geisler, Markus; Murphy, Angus S.

    2012-01-01

    In contrast to mammalian ABCB1 proteins, narrow substrate specificity has been extensively documented for plant orthologs shown to catalyze the transport of the plant hormone, auxin. Using the crystal structures of the multidrug exporters Sav1866 and MmABCB1 as templates, we have developed structural models of plant ABCB proteins with a common architecture. Comparisons of these structures identified kingdom-specific candidate substrate-binding regions within the translocation chamber formed by the transmembrane domains of ABCBs from the model plant Arabidopsis. These results suggest an early evolutionary divergence of plant and mammalian ABCBs. Validation of these models becomes a priority for efforts to elucidate ABCB function and manipulate this class of transporters to enhance plant productivity and quality. PMID:22639627

  5. A new mouse model to explore therapies for preeclampsia.

    Directory of Open Access Journals (Sweden)

    Abdulwahab Ahmed

    Full Text Available BACKGROUND: Pre-eclampsia, a pregnancy-specific multisystemic disorder is a leading cause of maternal and perinatal mortality and morbidity. This syndrome has been known to medical science since ancient times. However, despite considerable research, the cause/s of preeclampsia remain unclear, and there is no effective treatment. Development of an animal model that recapitulates this complex pregnancy-related disorder may help to expand our understanding and may hold great potential for the design and implementation of effective treatment. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that the CBA/J x DBA/2 mouse model of recurrent miscarriage is also a model of immunologically-mediated preeclampsia (PE. DBA/J mated CBA/J females spontaneously develop many features of human PE (primigravidity, albuminuria, endotheliosis, increased sensitivity to angiotensin II and increased plasma leptin levels that correlates with bad pregnancy outcomes. We previously reported that antagonism of vascular endothelial growth factor (VEGF signaling by soluble VEGF receptor 1 (sFlt-1 is involved in placental and fetal injury in CBA/J x DBA/2 mice. Using this animal model that recapitulates many of the features of preeclampsia in women, we found that pravastatin restores angiogenic balance, ameliorates glomerular injury, diminishes hypersensitivity to angiotensin II and protects pregnancies. CONCLUSIONS/SIGNIFICANCE: We described a new mouse model of PE, were the relevant key features of human preeclampsia develop spontaneously. The CBA/J x DBA/2 model, that recapitulates this complex disorder, helped us identify pravastatin as a candidate therapy to prevent preeclampsia and its related complications. We recognize that these studies were conducted in mice and that clinical trials are needed to confirm its application to humans.

  6. Comparison of four nonlinear growth models for effective exploration ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-10-05

    Oct 5, 2016 ... 4Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology,. Qingdao 266071, China. Received 24 May, 2016; Accepted 15 September, 2016. This study was conducted to compare the effectiveness for non-linear growth models designated as.

  7. Exploring Arthur's Pass Topographic Map and Model Interpretation.

    Science.gov (United States)

    Fastier, Murray; Macaulay, John

    1995-01-01

    Provides instructional materials, tasks, and activities to supplement a unit on map reading. Presents a two-page color topographical map of Arthur's Pass (New Zealand). Includes learning activities covering reading grid references, estimating distances, cross-sections, and sketch mapping. Briefly discusses and illustrates digital terrain models.…

  8. A Model for Exploring Student Understandings of Plagiarism

    Science.gov (United States)

    Sutton, Anna; Taylor, David; Johnston, Carol

    2014-01-01

    A clear understanding of how students view plagiarism is needed if the extensive efforts devoted to helping them engage in high-quality scholarship are to be worthwhile. There are a variety of views on this topic, but theoretical models to integrate the literature, take account of international differences and guide practitioners are limited.…

  9. JTorX: Exploring Model-Based Testing

    NARCIS (Netherlands)

    Belinfante, Axel

    2014-01-01

    The overall goal of the work described in this thesis is: ``To design a flexible tool for state-of-the-art model-based derivation and automatic application of black-box tests for reactive systems, usable both for education and outside an academic context.'' From this goal, we derive functional and

  10. Model-Based Exploration of Societal Aging in the Netherlands

    NARCIS (Netherlands)

    Pruyt, E.; Logtens, T.W.A.

    2015-01-01

    Mismanagement of societal aging is an important threat to health care, social security, and the economy of many nations. A System Dynamics simulation model related to societal aging in the Netherlands and its implications for the Dutch welfare system is used here to generate exploratory scenarios

  11. Exploration Of Deep Learning Algorithms Using Openacc Parallel Programming Model

    KAUST Repository

    Hamam, Alwaleed A.

    2017-03-13

    Deep learning is based on a set of algorithms that attempt to model high level abstractions in data. Specifically, RBM is a deep learning algorithm that used in the project to increase it\\'s time performance using some efficient parallel implementation by OpenACC tool with best possible optimizations on RBM to harness the massively parallel power of NVIDIA GPUs. GPUs development in the last few years has contributed to growing the concept of deep learning. OpenACC is a directive based ap-proach for computing where directives provide compiler hints to accelerate code. The traditional Restricted Boltzmann Ma-chine is a stochastic neural network that essentially perform a binary version of factor analysis. RBM is a useful neural net-work basis for larger modern deep learning model, such as Deep Belief Network. RBM parameters are estimated using an efficient training method that called Contrastive Divergence. Parallel implementation of RBM is available using different models such as OpenMP, and CUDA. But this project has been the first attempt to apply OpenACC model on RBM.

  12. Preliminary Exploration of Adaptive State Predictor Based Human Operator Modeling

    Science.gov (United States)

    Trujillo, Anna C.; Gregory, Irene M.

    2012-01-01

    Control-theoretic modeling of the human operator dynamic behavior in manual control tasks has a long and rich history. In the last two decades, there has been a renewed interest in modeling the human operator. There has also been significant work on techniques used to identify the pilot model of a given structure. The purpose of this research is to attempt to go beyond pilot identification based on collected experimental data and to develop a predictor of pilot behavior. An experiment was conducted to quantify the effects of changing aircraft dynamics on an operator s ability to track a signal in order to eventually model a pilot adapting to changing aircraft dynamics. A gradient descent estimator and a least squares estimator with exponential forgetting used these data to predict pilot stick input. The results indicate that individual pilot characteristics and vehicle dynamics did not affect the accuracy of either estimator method to estimate pilot stick input. These methods also were able to predict pilot stick input during changing aircraft dynamics and they may have the capability to detect a change in a subject due to workload, engagement, etc., or the effects of changes in vehicle dynamics on the pilot.

  13. Interactive exploration of coastal restoration modeling in virtual environments

    Science.gov (United States)

    Gerndt, Andreas; Miller, Robert; Su, Simon; Meselhe, Ehab; Cruz-Neira, Carolina

    2009-02-01

    Over the last decades, Louisiana has lost a substantial part of its coastal region to the Gulf of Mexico. The goal of the project depicted in this paper is to investigate the complex ecological and geophysical system not only to find solutions to reverse this development but also to protect the southern landscape of Louisiana for disastrous impacts of natural hazards like hurricanes. This paper sets a focus on the interactive data handling of the Chenier Plain which is only one scenario of the overall project. The challenge addressed is the interactive exploration of large-scale time-depending 2D simulation results and of terrain data with a high resolution that is available for this region. Besides data preparation, efficient visualization approaches optimized for the usage in virtual environments are presented. These are embedded in a complex framework for scientific visualization of time-dependent large-scale datasets. To provide a straightforward interface for rapid application development, a software layer called VRFlowVis has been developed. Several architectural aspects to encapsulate complex virtual reality aspects like multi-pipe vs. cluster-based rendering are discussed. Moreover, the distributed post-processing architecture is investigated to prove its efficiency for the geophysical domain. Runtime measurements conclude this paper.

  14. Model-Based Exploration of Societal Aging in the Netherlands

    OpenAIRE

    Erik Pruyt; Tom Logtens

    2015-01-01

    Mismanagement of societal aging is an important threat to health care, social security, and the economy of many nations. A System Dynamics simulation model related to societal aging in the Netherlands and its implications for the Dutch welfare system is used here to generate exploratory scenarios and to test policy robustness across many scenarios. Key concerns derived from this research are (i) the existence of plausible scenarios with severe labor scarcity, especially in health care, (ii) u...

  15. Petroleum geology of Cook Inlet basin - an exploration model

    Science.gov (United States)

    Magoon, L.B.; Claypool, G.E.

    1981-01-01

    Oil exploration commenced onshore adjacent to lower Cook Inlet on the Iniskin Peninsula in 1900, shifted with considerable success to upper Cook Inlet from 1957 through 1965, then returned to lower Cook Inlet in 1977 with the COST well and Federal OCS sale. Lower Cook Inlet COST No. 1 well, drilled to a total depth of 3,775.6 m, penetrated basinwide unconformities at the tops of Upper Cretaceous, Lower Cretaceous, and Upper Jurassic strata at 797.1, 1,540.8, and 2,112.3 m, respectively. Sandstone of potential reservoir quality is present in the Cretaceous and lower Tertiary rocks. All siltstones and shales analyzed are low (0 to 0.5 wt. %) in oil-prone organic matter, and only coals are high in humic organic matter. At total depth, vitrinite readings reached a maximum ave age reflectance of 0.65. Several indications of hydrocarbons were present. Oil analyses suggest that oils from the major fields of the Cook Inlet region, most of which produce from the Tertiary Hemlock Conglomerate, have a common source. More detailed work on stable carbon isotope ratios and the distribution of gasoline-range and heavy (C12+) hydrocarbons confirms this genetic relation among the major fields. In addition, oils from Jurassic rocks under the Iniskin Peninsula and from the Hemlock Conglomerate at the southwestern tip of the Kenai lowland are members of the same or a very similar oil family. The Middle Jurassic strata of the Iniskin Peninsula are moderately rich in organic carbon (0.5 to 1.5 wt. %) and yield shows of oil and of gas in wells and in surface seeps. Extractable hydrocarbons from this strata are similar in chemi al and isotopic composition to the Cook Inlet oils. Organic matter in Cretaceous and Tertiary rocks is thermally immature in all wells analyzed. Oil reservoirs in the major producing fields are of Tertiary age and unconformably overlie Jurassic rocks; the pre-Tertiary unconformity may be significant in exploration for new oil reserves. The unconformable relation

  16. Exploring Animal Models That Resemble Idiopathic Pulmonary Fibrosis

    Directory of Open Access Journals (Sweden)

    Jun Tashiro

    2017-07-01

    Full Text Available Large multicenter clinical trials have led to two recently approved drugs for patients with idiopathic pulmonary fibrosis (IPF; yet, both of these therapies only slow disease progression and do not provide a definitive cure. Traditionally, preclinical trials have utilized mouse models of bleomycin (BLM-induced pulmonary fibrosis—though several limitations prevent direct translation to human IPF. Spontaneous pulmonary fibrosis occurs in other animal species, including dogs, horses, donkeys, and cats. While the fibrotic lungs of these animals share many characteristics with lungs of patients with IPF, current veterinary classifications of fibrotic lung disease are not entirely equivalent. Additional studies that profile these examples of spontaneous fibroses in animals for similarities to human IPF should prove useful for both human and animal investigators. In the meantime, studies of BLM-induced fibrosis in aged male mice remain the most clinically relevant model for preclinical study for human IPF. Addressing issues such as time course of treatment, animal size and characteristics, clinically irrelevant treatment endpoints, and reproducibility of therapeutic outcomes will improve the current status of preclinical studies. Elucidating the mechanisms responsible for the development of fibrosis and disrepair associated with aging through a collaborative approach between researchers will promote the development of models that more accurately represent the realm of interstitial lung diseases in humans.

  17. Exploring female mice interstrain differences relevant for models of depression

    Directory of Open Access Journals (Sweden)

    Daniela de Sá Calçada

    2015-12-01

    Full Text Available Depression is an extremely heterogeneous disorder. Diverse molecular mechanisms have been suggested to underlie its etiology. To understand the molecular mechanisms responsible for this complex disorder, researchers have been using animal models extensively, namely mice from various genetic backgrounds and harboring distinct genetic modifications. The use of numerous mouse models has contributed to enrich our knowledge on depression. However, accumulating data also revealed that the intrinsic characteristics of each mouse strain might influence the experimental outcomes, which may justify some conflicting evidence reported in the literature. To further understand the impact of the genetic background we performed a multimodal comparative study encompassing the most relevant parameters commonly addressed in depression in three of the most widely used mouse strains: Balb/c, C57BL/6 and CD-1. Moreover, female mice were selected for this study taken into account the higher prevalence of depression in woman and the fewer animal studies using this gender. Our results show that Balb/c mice have a more pronounced anxious-like behavior than CD-1 and C57BL/6 mice, whereas C57BL/6 animals present the strongest depressive-like trait. Furthermore, C57BL/6 mice display the highest rate of proliferating cells and brain-derived neurotrophic factor expression levels in the hippocampus, while hippocampal dentate granular neurons of Balb/c mice show smaller dendritic lengths and fewer ramifications. Of notice, the expression levels of inducible nitric oxide synthase (iNos predict 39,5% of the depressive-like behavior index, which suggests a key role of hippocampal iNOS in depression.Overall, this study reveals important interstrain differences in several behavioral dimensions and molecular and cellular parameters that should be considered when preparing and analyzing experiments addressing depression using mouse models. It further contributes to the literature by

  18. Exploring the Application of Capital Facility Investment Justification Model

    Directory of Open Access Journals (Sweden)

    Marijan Karić

    2013-07-01

    Full Text Available For decades now, the models for identifying and quantifying the level of risk of investment projects and investment justification evaluation have been the subject of investigation by members of professional and research communities. It is important to quantify the level of risk because by evaluating investment justification in terms of the risks involved, the decision-maker (investor is able to choose from available alternatives the one that will achieve the most favourable ratio of expected profit to the assumed risk. In this way, the economic entity can raise its productivity, profitability and the quality of business operation in general. The aim of this paper was to investigate the extent to which medium and large companies have been using modern methods of investment justification evaluation in their decision-making process and determine the level of quality of the application of the selected methods in practice. The study was conducted on a sample of medium and large enterprises in the eastern Croatia during 2011 and 2012, and it was established that despite the fact that a large number of modern investment project profitability and risk assessment models have been developed, the level of their application in practice is not high enough. The analyzed investment proposals included only basic methods of capital budgeting without risk assessment. Hence, it was concluded that individual investors were presented with low-quality and incomplete investment justification evaluation results on the basis of which the decisions of key importance for the development of the economic entity as a whole were made. This paper aims to underline the need for financial managers to get informed and educate themselves about contemporary investment project profitability and risk assessment models as well as the need to create educational programmes and computer solutions that will encourage key people in companies to acquire new knowledge and apply modern

  19. Exploration of models for a cargo assembly planning problem

    OpenAIRE

    Belov, G.; Boland, N.; Savelsbergh, M.W.P.; Stuckey, P. J.

    2015-01-01

    We consider a real-world cargo assembly planning problem arising in a coal supply chain. The cargoes are built on the stockyard at a port terminal from coal delivered by trains. Then the cargoes are loaded onto vessels. Only a limited number of arriving vessels is known in advance. The goal is to minimize the average delay time of the vessels over a long planning period. We model the problem in the MiniZinc constraint programming language and design a large neighbourhood search scheme. The ef...

  20. Adaptable Authentication Model - for Exploring the Weaker Notions of Security

    DEFF Research Database (Denmark)

    Ahmed, Naveed; Jensen, Christian D.

    operational environment. In past, this often caused increasing the power of attacker model, for instance, now a days we also consider privacy concerns and side channel leakage beside the classic Dolev-Yao attacker. A protocol is labeled as insecure protocol once an effective attack or flaw is found in it...... and sometimes with additional capabilities such as dynamic corruption of communicating nodes. Then, one tries to show that the protocol achieves its objective under this specific attacker. Naturally there are three possibilities: one may succeed in constructing a security proof; one may fail in proving security...

  1. Exploring bird aerodynamics using radio-controlled models

    Energy Technology Data Exchange (ETDEWEB)

    Hoey, Robert G, E-mail: bobh@antelecom.ne [Air Force Flight Test Center, Edwards AFB, CA (United States)

    2010-12-15

    A series of radio-controlled glider models was constructed by duplicating the aerodynamic shape of soaring birds (raven, turkey vulture, seagull and pelican). Controlled tests were conducted to determine the level of longitudinal and lateral-directional static stability, and to identify the characteristics that allowed flight without a vertical tail. The use of tail-tilt for controlling small bank-angle changes, as observed in soaring birds, was verified. Subsequent tests, using wing-tip ailerons, inferred that birds use a three-dimensional flow pattern around the wing tip (wing tip vortices) to control adverse yaw and to create a small amount of forward thrust in gliding flight.

  2. Exploring persistence in science in CEGEP: Toward a motivational model

    Science.gov (United States)

    Simon, Rebecca A.

    There is currently a shortage of science teachers in North America and continually decreasing rates of enrollment in science programs. Science continues to be the academic domain that sees the highest attrition rates, particularly for women. The purpose of the present study was to examine male and female students' experiences in mathematics and science courses during a crucial time in their academic development in an attempt to explain the high attrition rates in science between the last year of high school and the first year of CEGEP (junior college). In line with self-determination theory (Deci & Ryan, 1985), as well as achievement-goal theory (Pintrich & Schunk, 1996) and research on academic emotions, the study examined the relation between a set of motivational variables (i.e., perceptions of autonomy-support, self-efficacy, achievement goals, and intrinsic motivation), affect, achievement, and persistence. A secondary objective was to test a motivational model of student persistence in science using structural equation modeling (SEM). The sample consisted of 603 male and 706 female students from four English-language CEGEPs in the greater Montreal area. Just prior to beginning CEGEP, participants completed a questionnaire that asked about the learning environment in high school mathematics and science classes as well as student characteristics including sources of motivation, personal achievement goals, and feelings of competence. All students expressed an initial interest in pursuing a career in science by enrolling in optional advanced mathematics and science courses during high school. Multivariate analysis of variance was used to examine differences among male and female students across the variables measured. Structural equation modeling was used to test the validity of a questionnaire designed specifically to gather information about CEGEP students' experiences with mathematics and science, and to evaluate the fit of a model designed to reflect the

  3. Exploring bird aerodynamics using radio-controlled models.

    Science.gov (United States)

    Hoey, Robert G

    2010-12-01

    A series of radio-controlled glider models was constructed by duplicating the aerodynamic shape of soaring birds (raven, turkey vulture, seagull and pelican). Controlled tests were conducted to determine the level of longitudinal and lateral-directional static stability, and to identify the characteristics that allowed flight without a vertical tail. The use of tail-tilt for controlling small bank-angle changes, as observed in soaring birds, was verified. Subsequent tests, using wing-tip ailerons, inferred that birds use a three-dimensional flow pattern around the wing tip (wing tip vortices) to control adverse yaw and to create a small amount of forward thrust in gliding flight.

  4. Human Factors Research for Space Exploration: Measurement, Modeling, and Mitigation

    Science.gov (United States)

    Kaiser, Mary K.; Allen, Christopher S.; Barshi, Immanuel; Billman, Dorrit; Holden, Kritina L.

    2010-01-01

    As part of NASA's Human Research Program, the Space Human Factors Engineering Project serves as the bridge between Human Factors research and Human Spaceflight applications. Our goal is to be responsive to the operational community while addressing issues at a sufficient level of abstraction to ensure that our tools and solutions generalize beyond the point design. In this panel, representatives from four of our research domains will discuss the challenges they face in solving current problems while also enabling future capabilities. Historically, engineering-dominated organizations have tended to view good Human Factors (HF) as a desire rather than a requirement in system design and development. Our field has made significant gains in the past decade, however; the Department of Defense, for example, now recognizes Human-System Integration (HSI), of which HF is a component, as an integral part of their divisions hardware acquisition processes. And our own agency was far more accepting of HF/HSI requirements during the most recent vehicle systems definition than in any prior cycle. Nonetheless, HF subject matter experts at NASA often find themselves in catch up mode... coping with legacy systems (hardware and software) and procedures that were designed with little regard for the human element, and too often with an attitude of we can deal with any operator issues during training. Our challenge, then, is to segregate the true knowledge gaps in Space Human Factors from the prior failures to incorporate best (or even good) HF design principles. Further, we strive to extract the overarching core HF issues from the point-design-specific concerns that capture the operators (and managers) attention. Generally, our approach embraces a 3M approach to Human Factors: Measurement, Modeling, and Mitigation. Our first step is to measure human performance, to move from subjective anecdotes to objective, quantified data. Next we model the phenomenon, using appropriate methods in

  5. An Idealized Meteorological-Hydrodynamic Model for Exploring Extreme Storm Surge Statistics in the North Sea

    NARCIS (Netherlands)

    Van Ledden, M.; Van den Berg, N.J.F.; De Jong, M.S.; Van Gelder, P.H.A.J.M.; Den Heijer, C.; Vrijling, J.K.; Jonkman, S.N.; Roos, P.C.; Hulscher, S.J.M.H.; Lansen, A.J.

    2014-01-01

    This paper explores an alternative method to determine extreme surge levels at the Dutch Coast. For this exploration, specific focus is on the extreme water level at Hoek van Holland, The Netherlands. The alternative method has been based on a joint probability model of the storm characteristics at

  6. Exploring Higher Education Governance: Analytical Models and Heuristic Frameworks

    Directory of Open Access Journals (Sweden)

    Burhan FINDIKLI

    2017-08-01

    Full Text Available Governance in higher education, both at institutional and systemic levels, has experienced substantial changes within recent decades because of a range of world-historical processes such as massification, growth, globalization, marketization, public sector reforms, and the emergence of knowledge economy and society. These developments have made governance arrangements and decision-making processes in higher education more complex and multidimensional more than ever and forced scholars to build new analytical and heuristic tools and strategies to grasp the intricacy and diversity of higher education governance dynamics. This article provides a systematic discussion of how and through which tools prominent scholars of higher education have analyzed governance in this sector by examining certain heuristic frameworks and analytical models. Additionally, the article shows how social scientific analysis of governance in higher education has proceeded in a cumulative way with certain revisions and syntheses rather than radical conceptual and theoretical ruptures from Burton R. Clark’s seminal work to the present, revealing conceptual and empirical junctures between them.

  7. Exploring manual asymmetries during grasping: a dynamic causal modeling approach.

    Directory of Open Access Journals (Sweden)

    Chiara eBegliomini

    2015-02-01

    Full Text Available Recording of neural activity during grasping actions in macaques showed that grasp-related sensorimotor transformations are accomplished in a circuit constituted by the anterior part of the intraparietal sulcus (AIP, the ventral (F5 and the dorsal (F2 region of the premotor area. In humans, neuroimaging studies have revealed the existence of a similar circuit, involving the putative homolog of macaque areas AIP, F5 and F2. These studies have mainly considered grasping movements performed with the right dominant hand and only a few studies have measured brain activity associated with a movement performed with the left non-dominant hand. As a consequence of this gap, how the brain controls for grasping movement performed with the dominant and the non-dominant hand still represents an open question. A functional resonance imaging experiment (fMRI has been conducted, and effective connectivity (Dynamic Causal Modelling, DCM was used to assess how connectivity among grasping-related areas is modulated by hand (i.e., left and right during the execution of grasping movements towards a small object requiring precision grasping. Results underlined boosted inter-hemispheric couplings between dorsal premotor cortices during the execution of movements performed with the left rather than the right dominant hand. More specifically, they suggest that the dorsal premotor cortices may play a fundamental role in monitoring the configuration of fingers when grasping movements are performed by either the right and the left hand. This role becomes particularly evident when the hand less-skilled (i.e., the left hand to perform such action is utilized. The results are discussed in light of recent theories put forward to explain how parieto-frontal connectivity is modulated by the execution of prehensile movements.

  8. Multiscale Modeling of Complex Molecular Structure and Dynamics with MBN Explorer

    DEFF Research Database (Denmark)

    Solov'yov, Ilia A.; Korol, Andrei V.; Solov'yov, Andrey V.

    efficiency of MBN Explorer is comparable to that of other, more specialized software packages, making it a viable multi-purpose alternative for the computational modeling of complex molecular systems. A number of detailed case studies presented in the second part of this book demonstrate MBN Explorer......This book introduces readers to MesoBioNano (MBN) Explorer - a multi-purpose software package designed to model molecular systems at various levels of size and complexity. In addition, it presents a specially designed multi-task toolkit and interface - the MBN Studio - which enables the set......, and guides readers through its applications in numerous areas of research in bio- and chemical physics and material science - ranging from the nano- to the mesoscale. MBN Explorer is particularly suited to computing the system's energy, to optimizing molecular structure, and to exploring the various facets...

  9. Evidence of chemical stimulation of hepatic metabolism by an experimental acetanilide (FOE 5043) indirectly mediating reductions in circulating thyroid hormone levels in the male rat.

    Science.gov (United States)

    Christenson, W R; Becker, B D; Wahle, B S; Moore, K D; Dass, P D; Lake, S G; Van Goethem, D L; Stuart, B P; Sangha, G K; Thyssen, J H

    1996-02-01

    N-(4-Fluorophenyl)-N-(1-methylethyl)-2-[[5-(trifluoromethyl)-1,3, 4-thiadiazol-2-yl]oxy]acetamide (FOE 5043) is a new acetanilide-type herbicide undergoing regulatory testing. Previous work in this laboratory suggested that FOE 5043-induced reductions in serum thyroxine (T4) levels were mediated via an extrathyroidal site of action. The possibility that the alterations in circulating T4 levels were due to chemical induction of hepatic thyroid hormone metabolism was investigated. Treatment with FOE 5043 at a rate of 1000 ppm as a dietary admixture was found to significantly increase the clearance of [125I]T4 from the serum, suggesting an enhanced excretion of the hormone. In the liver, the activity of hepatic uridine glucuronosyl transferase, a major pathway of thyroid hormone biotransformation in the rat, increased in a statistically significant and dose-dependent manner; conversely, hepatic 5'-monodeiodinase activity trended downward with dose. Bile flow as well as the hepatic uptake and biliary excretion of [125I]T4 were increased following exposure to FOE 5043. Thyroidal function, as measured by the discharge of iodide ion in response to perchlorate, and pituitary function, as measured by the capacity of the pituitary to secrete thyrotropin in response to an exogenous challenge by hypothalamic thyrotropin releasing hormone, were both unchanged from the controlled response. These data suggest that the functional status of the thyroid and pituitary glands has not been altered by treatment with FOE 5043 and that reductions in circulating levels of T4 are being mediated indirectly through an increase in the biotransformation and excretion of thyroid hormone in the liver.

  10. A spiking Basal Ganglia model of synchrony, exploration and decision making.

    Science.gov (United States)

    Mandali, Alekhya; Rengaswamy, Maithreye; Chakravarthy, V Srinivasa; Moustafa, Ahmed A

    2015-01-01

    To make an optimal decision we need to weigh all the available options, compare them with the current goal, and choose the most rewarding one. Depending on the situation an optimal decision could be to either "explore" or "exploit" or "not to take any action" for which the Basal Ganglia (BG) is considered to be a key neural substrate. In an attempt to expand this classical picture of BG function, we had earlier hypothesized that the Indirect Pathway (IP) of the BG could be the subcortical substrate for exploration. In this study we build a spiking network model to relate exploration to synchrony levels in the BG (which are a neural marker for tremor in Parkinson's disease). Key BG nuclei such as the Sub Thalamic Nucleus (STN), Globus Pallidus externus (GPe) and Globus Pallidus internus (GPi) were modeled as Izhikevich spiking neurons whereas the Striatal output was modeled as Poisson spikes. The model is cast in reinforcement learning framework with the dopamine signal representing reward prediction error. We apply the model to two decision making tasks: a binary action selection task (similar to one used by Humphries et al., 2006) and an n-armed bandit task (Bourdaud et al., 2008). The model shows that exploration levels could be controlled by STN's lateral connection strength which also influenced the synchrony levels in the STN-GPe circuit. An increase in STN's lateral strength led to a decrease in exploration which can be thought as the possible explanation for reduced exploratory levels in Parkinson's patients. Our simulations also show that on complete removal of IP, the model exhibits only Go and No-Go behaviors, thereby demonstrating the crucial role of IP in exploration. Our model provides a unified account for synchronization, action section, and explorative behavior.

  11. Numerical Modelling of Thermal Convection Related to Fracture Permeability - Implications for Geothermal Exploration and Basin Modelling

    Science.gov (United States)

    Lipsey, Lindsay; van Wees, Jan-Diederik; Pluymaekers, Maarten; Cloetingh, Sierd

    2015-04-01

    the fracture network geometry within the aquifer. In summary, convective upwellings can create significant temperature enhancements relative to conductive profile and in agreement with the observations in the LTG-01 carbonates. This enhancement is critically dependent on the aquifer thickness and geothermal gradient. Given a gradient of 39°C/km and aquifer thickness of 600 m, a temperature of 203°C can be obtained at a depth of 4500 m directly above upwelling zones. Contrarily, downwelling zones result in a temperature of 185°C at the same depth. This demonstrates the strong spatial variability of thermal anomalies in convective fractured aquifers at large depth and can have strong effects on exploration opportunity and risk of prospective areas. Numerical models can facilitate in exploration workflows to assess thermal variation and location of upwelling zones.

  12. Gamma-delta (γδ) T cells: friend or foe in cancer development?

    Science.gov (United States)

    Zhao, Yijing; Niu, Chao; Cui, Jiuwei

    2018-01-10

    γδ T cells are a distinct subgroup of T cells containing T cell receptors (TCRs) γ and TCR δ chains with diverse structural and functional heterogeneity. As a bridge between the innate and adaptive immune systems, γδ T cells participate in various immune responses during cancer progression. Because of their direct/indirect antitumor cytotoxicity and strong cytokine production ability, the use of γδ T cells in cancer immunotherapy has received a lot of attention over the past decade. Despite the promising potential of γδ T cells, the efficacy of γδ T cell immunotherapy is limited, with an average response ratio of only 21%. In addition, research over the past 2 years has shown that γδ T cells could also promote cancer progression by inhibiting antitumor responses, and enhancing cancer angiogenesis. As a result, γδ T cells have a dual effect and can therefore be considered as being both "friends" and "foes" of cancer. In order to solve the sub-optimal efficiency problem of γδ T cell immunotherapy, we review recent observations regarding the antitumor and protumor activities of major structural and functional subsets of human γδ T cells, describing how these subsets are activated and polarized, and how these events relate to subsequent effects in cancer immunity. A mixture of both antitumor or protumor γδ T cells used in adoptive immunotherapy, coupled with the fact that γδ T cells can be polarized from antitumor cells to protumor cells appear to be the likely reasons for the mild efficacy seen with γδ T cells. The future holds the promise of depleting the specific protumor γδ T cell subgroup before therapy, choosing multi-immunocyte adoptive therapy, modifying the cytokine balance in the cancer microenvironment, and using a combination of γδ T cells adoptive immunotherapy with immune checkpoint inhibitors.

  13. AGEs, RAGEs and s-RAGE; friend or foe for cancer.

    Science.gov (United States)

    Ahmad, Saheem; Khan, Hamda; Siddiqui, Zeba; Khan, Mohd Yasir; Rehman, Shahnawaz; Shahab, Uzma; Godovikova, Tatyana; Silnikov, Vladimir; Moinuddin

    2017-07-13

    Impaired awareness of glycation biology in cancer initiation and progression is one of the fundamental reasons for its meticulous investigation of the molecules involved in signalling pathway. Glycation of biological macromolecules results in the progression of advanced glycation end-products (AGEs) that proliferates the process of carcinogenesis by activation of transcription factors and release of cytokines. The receptor for advanced glycation end-products (RAGEs) with the binding of its different ligands like; AGEs, HMGB1 and S100 activate the signalling arrays. The activation of downstream signalling pathway ultimately leads to the pathophysiological conditions of diabetes, ageing, neurological disorders and cancers as well as a result of the activation of transcription factors which is discussed in the main body text of this review. However, there might be a likelihood of the positive effect of the HMGB1 and S100 proteins in cancer. Still, some untouched mechanisms might be responsible for the establishment of the function of AGE-RAGE or AGE-sRAGE axis activation that leads to the friend-foe association with the cancers. The levels of RAGE and s-RAGE may be a useful biomarker of ligand-RAGE pathway activation and cancer. Thus, the possibility of providing a potential complement to carcinogenesis is very high which might be an interesting target for therapeutic interventions. This article is an insightful assessment on AGE, RAGE and s-RAGE for its possible role in cancer onset and progression. The novel therapeutic targets for cancer prevention or inhibition are also explained in brief in relation to AGE and RAGE. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Teachers' Use of Computational Tools to Construct and Explore Dynamic Mathematical Models

    Science.gov (United States)

    Santos-Trigo, Manuel; Reyes-Rodriguez, Aaron

    2011-01-01

    To what extent does the use of computational tools offer teachers the possibility of constructing dynamic models to identify and explore diverse mathematical relations? What ways of reasoning or thinking about the problems emerge during the model construction process that involves the use of the tools? These research questions guided the…

  15. Using maximum topology matching to explore differences in species distribution models

    Science.gov (United States)

    Poco, Jorge; Doraiswamy, Harish; Talbert, Marian; Morisette, Jeffrey; Silva, Claudio

    2015-01-01

    Species distribution models (SDM) are used to help understand what drives the distribution of various plant and animal species. These models are typically high dimensional scalar functions, where the dimensions of the domain correspond to predictor variables of the model algorithm. Understanding and exploring the differences between models help ecologists understand areas where their data or understanding of the system is incomplete and will help guide further investigation in these regions. These differences can also indicate an important source of model to model uncertainty. However, it is cumbersome and often impractical to perform this analysis using existing tools, which allows for manual exploration of the models usually as 1-dimensional curves. In this paper, we propose a topology-based framework to help ecologists explore the differences in various SDMs directly in the high dimensional domain. In order to accomplish this, we introduce the concept of maximum topology matching that computes a locality-aware correspondence between similar extrema of two scalar functions. The matching is then used to compute the similarity between two functions. We also design a visualization interface that allows ecologists to explore SDMs using their topological features and to study the differences between pairs of models found using maximum topological matching. We demonstrate the utility of the proposed framework through several use cases using different data sets and report the feedback obtained from ecologists.

  16. A service based component model for composing and exploring MPSoC platforms

    DEFF Research Database (Denmark)

    Tranberg-Hansen, Anders Sejer; Madsen, Jan

    2008-01-01

    This paper presents an abstract service based modelling method for use in performance estimation and design space exploration of Multi Processor System On Chip (MPSoC) based systems. The method provides the infrastructure for composing abstract hardware and software models of stream based systems...

  17. Exploring Undergraduate Students' Mental Models of the Environment: Are They Related to Environmental Affect and Behavior?

    Science.gov (United States)

    Liu, Shu-Chiu; Lin, Huann-shyang

    2015-01-01

    A draw-and-explain task and questionnaire were used to explore Taiwanese undergraduate students' mental models of the environment and whether and how they relate to their environmental affect and behavioral commitment. We found that students generally held incomplete mental models of the environment, focusing on objects rather than on processes or…

  18. Aggregation of spatial units in linear programming models to explore land use options.

    NARCIS (Netherlands)

    Hijmans, R.J.; Ittersum, van M.K.

    1996-01-01

    Consequences of aggregating spatial units in an interactive multiple-goal linear programming (IMGLP) model are analysed for a schematized and an existing IMGLP model (GOAL) exploring land use options for the European Union. A discrimination was made between effects on objective functions for the

  19. Exploring the Neural Basis of Fairness: A Model of Neuro-Organizational Justice

    Science.gov (United States)

    Beugre, Constant D.

    2009-01-01

    Drawing from the literature in neuroeconomics, organizational justice, and social cognitive neuroscience, I propose a model of neuro-organizational justice that explores the role of the brain in how people form fairness judgments and react to situations of fairness and/or unfairness in organizations. The model integrates three levels of analysis:…

  20. A spiking Basal Ganglia model of synchrony, exploration and decision making

    Directory of Open Access Journals (Sweden)

    Alekhya eMandali

    2015-05-01

    Full Text Available To make an optimal decision we need to weigh all the available options, compare them with the current goal, and choose the most rewarding one. Depending on the situation an optimal decision could be to either ‘explore’ or ‘exploit’ or ‘not to take any action’ for which the Basal Ganglia (BG is considered to be a key neural substrate. In an attempt to expand this classical picture of BG function, we had earlier hypothesized that the Indirect Pathway (IP of the BG could be the subcortical substrate for exploration. In this study we build a spiking network model to relate exploration to synchrony levels in the BG (which are a neural marker for tremor in Parkinson’s disease. Key BG nuclei such as the Sub Thalamic Nucleus (STN, Globus Pallidus externus (GPe and Globus Pallidus internus (GPi were modeled as Izhikevich spiking neurons whereas the Striatal output was modeled as Poisson spikes. The model is cast in reinforcement learning framework with the dopamine signal representing reward prediction error. We apply the model to two decision making tasks: a binary action selection task (similar to one used by Humphries et al. 2006 and an n-armed bandit task (Bourdaud et al. 2008. The model shows that exploration levels could be controlled by STN’s lateral connection strength which also influenced the synchrony levels in the STN-GPe circuit. An increase in STN’s lateral strength led to a decrease in exploration which can be thought as the possible explanation for reduced exploratory levels in Parkinson’s patients. Our simulations also show that on complete removal of IP, the model exhibits only Go and No-Go behaviors, thereby demonstrating the crucial role of IP in exploration. Our model provides a unified account for synchronization, action section, and explorative behavior.

  1. Modeling Oxygen Prebreathe Protocols for Exploration Extravehicular Activities Using Variable Pressure Suits

    Science.gov (United States)

    Abercromby, Andrew F. J.; Conkin, Johnny; Gernhardt, Michael L.

    2017-01-01

    Exploration missions are expected to use variable pressure extravehicular activity (EVA) spacesuits as well as a spacecraft "exploration atmosphere" of 56.5 kPa (8.2 psia), 34% O2, both of which provide the possibility of reducing the oxygen prebreathe times necessary to reduce decompression sickness (DCS) risk. Previous modeling work predicted 8.4% DCS risk for an EVA beginning at the exploration atmosphere, followed by 15 minutes of in-suit O2 prebreathe, and 6 hours of EVA at 29.6 kPa (4.3 psia). In this study we model notional prebreathe protocols for a variable pressure suit where the exploration atmosphere is unavailable.

  2. NOAA Ship Okeanos Explorer: Evolving Models Enabling Remote Science Participation via Telepresence

    Science.gov (United States)

    Elliott, K.; Potter, J.; Martinez, C.; Pinner, W.; Russell, C. W.; Verplanck, N.

    2014-12-01

    Since 2005 NOAA's Office of Ocean Exploration and Research (OER) and partners have tested and developed uses of telepresence to extend ocean exploration expeditions to shore-based scientists and students in real-time. Telepresence increases the potential pace and scope of ocean exploration by enabling experts to join an expedition from anywhere, providing unlimited access to intellectual capital, while simultaneously expanding the reach of ocean science expeditions to public audiences worldwide. "America's Ship for Ocean Exploration", NOAA Ship Okeanos Explorer, is the first and only federal vessel purpose-outfitted for conducting telepresence-enabled ocean exploration. As a platform for testing new technologies and methodologies, her primary operating paradigm focuses on using telepresence to enable the majority of expedition scientists to participate and guide explorations from shore in real-time. Between 2010-2014, NOAA and partners implemented different models to conduct telepresence-enabled ocean exploration on NOAA Ship Okeanos Explorer, all with the majority of the participating expedition scientists located on shore. These expeditions tested different scientist participation models, communication technologies, operating procedures, internet video streams, data distribution methods, and internet-based collaboration tools, and provided varying levels of real-time access to ongoing expeditions. Each expedition provided new insights into what makes remote science participation "work", and identified challenges that remain to be overcome. This presentation will provide an overview of the different methods and tools used by NOAA's Okeanos Explorer Program to enable remote science participation in expeditions over the last five years, highlighting successes, lessons learned, and challenges for the future.

  3. Exploring Bioeconomy Growth through the Public Release of the Biomass Scenario Model

    Energy Technology Data Exchange (ETDEWEB)

    Newes, Emily K [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Biddy, Mary J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bush, Brian W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Inman, Daniel J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vimmerstedt, Laura J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Peterson, Steve [Lexidyne, LLC

    2017-08-02

    The Biomass Scenario Model (BSM) is an important tool for exploring vibrant future bioeconomy scenarios that leverage domestic resources. Developed by NREL and BETO, this model of the domestic biofuels supply chain has been used to explore success strategies for BETO's activities towards bioeconomy growth. The BSM offers a robust test bed for detailed exploration of effects of BETO activities within the complex context of resource availability; physical, technological, and economic constraints; behavior; and policy. The public release of the model in 2017 will allow broad engagement with the theme of the conference as model users can analyze bioeconomy growth, domestic biomass resource use, and associated effects. The BSM is a carefully validated, state-of-the-art, dynamic model of the biomass to biofuels supply chain. Using a system dynamics simulation modeling approach, the model tracks long-term deployment of biofuels given technology development and investment, considering land availability, the competing oil market, consumer demand, and government policies over time. Sample outputs include biofuels production, feedstock use, capital investment, incentives, and costs of feedstocks and fuels. BSM scenarios reveal technological, economic, and policy challenges, as well as opportunities for dynamic growth of the bioeconomy with strategic public and private investment at key points in the system. The model logic and results have been reviewed extensively, through collaborative analysis, expert reviews and external publications (https://www.zotero.org/groups/bsm_publications/).

  4. Interactive exploration and modeling of large data sets: a case study with Venus light scattering data

    NARCIS (Netherlands)

    J.J. van Wijk (Jack); H.J.W. Spoelder; W.-J.J. Knibbe; K.E. Shahroudi

    1997-01-01

    textabstractWe present a system where visualization and the control of the simulation are integrated to facilitate interactive exploration and modeling of large data sets. The system was developed to estimate properties of the atmosphere of Venus from comparison between measured and simulated data.

  5. Exploring Student Characteristics of Retention That Lead to Graduation in Higher Education Using Data Mining Models

    Science.gov (United States)

    Raju, Dheeraj; Schumacker, Randall

    2015-01-01

    The study used earliest available student data from a flagship university in the southeast United States to build data mining models like logistic regression with different variable selection methods, decision trees, and neural networks to explore important student characteristics associated with retention leading to graduation. The decision tree…

  6. Exploring Demographic Shifts : Aging and Migration Exploratory Group Model Specification & Simulation

    NARCIS (Netherlands)

    Pruyt, E.; Logtens, T.; Gijsbers, G.

    2011-01-01

    Plausible dynamics of a major demographic shift –(societal) aging– is studied in this paper, both from a global perspective and from a national perspective. Several economic, political and social implications of aging and aging-related demographic shifts are explored using System Dynamics models as

  7. Modelling dishes and exploring culinary 'precisions': the two issues of molecular gastronomy.

    Science.gov (United States)

    This, Hervé

    2005-04-01

    The scientific strategy of molecular gastronomy includes modelling 'culinary definitions' and experimental explorations of 'culinary precisions'. A formalism that describes complex dispersed systems leads to a physical classification of classical sauces, as well as to the invention of an infinite number of new dishes.

  8. Exploring Reading Comprehension Skill Relationships through the G-DINA Model

    Science.gov (United States)

    Chen, Huilin; Chen, Jinsong

    2016-01-01

    By analysing the test data of 1029 British secondary school students' performance on 20 Programme for International Student Assessment English reading items through the generalised deterministic input, noisy "and" gate (G-DINA) model, the study conducted two investigations on exploring the relationships among the five reading…

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

    NARCIS (Netherlands)

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

    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

  10. Teaching Tip: Using Rapid Game Prototyping for Exploring Requirements Discovery and Modeling

    Science.gov (United States)

    Dalal, Nikunj

    2012-01-01

    We describe the use of rapid game prototyping as a pedagogic technique to experientially explore and learn requirements discovery, modeling, and specification in systems analysis and design courses. Students have a natural interest in gaming that transcends age, gender, and background. Rapid digital game creation is used to build computer games…

  11. Effective Classroom Management and Instruction: An Exploration of Models. Executive Summary of Final Report.

    Science.gov (United States)

    Evertson, Carolyn M.; And Others

    A summary is presented of the final report, "Effective Classroom Management and Instruction: An Exploration of Models." The final report presents a set of linked investigations of the effects of training teachers in effective classroom management practices in a series of school-based workshops. Four purposes were addressed by the study: (1) to…

  12. Comparing Management Models of Secondary Schools in Tamaulipas, Mexico: An Exploration with a Delphi Method

    Science.gov (United States)

    Navarro-Leal, Marco Aurelio; Garcia, Concepcion Nino; Saldivar, Luisa Caballero

    2012-01-01

    For a preliminary exploration of management models between two secondary schools, a Delphi method was used in order to identify and focus relevant topics for a larger research. A first approximation with this method proved to be a heuristic tool to focus and define some categories and guidelines of enquiry. It was found that in both of the schools…

  13. Exploring a model for finding meaning in the changing world of work (Part 2

    Directory of Open Access Journals (Sweden)

    Daniel H. Burger

    2012-01-01

    Full Text Available Orientation: This article explores the role that meaning, as logotherapy conceptualises it, can play to facilitate organisational changes.Research purpose: The purpose of this study is to explore further a model an earlier paper proposed for using employees’ experiences of meaning in work contexts to facilitate changes.Motivation for the study: The researchers could not find a comprehensive model in the literature for addressing employees’ experiences of meaning in, or at, work during organisational changes. A previous paper proposed such a model, but it addressed only one component fully. This article seeks to explore this model further to address this apparent gap in the literature.Research design, approach and method: The researchers used a literature review to conduct the study. The components of the model directed this review in order to find meaning at work.Main findings: The actions of organisations, which aim to create positive organisational contexts (through practices for improving meaning at work and transcendence and to frame changes using ‘Logo-OD’, can improve employees’ experiences of meaning during organisational changes.Practical/managerial implications: Understanding the relationship between meaning and organisational change, and applying the model this article presents, can contribute to the overall success of change initiatives.Contribution/value-add: This study’s primary contribution stems from the novel framework it presents for organisations to use the knowledge about how employees search for meaning to facilitate changes.

  14. Prospectivity Modeling of Karstic Groundwater Using a Sequential Exploration Approach in Tepal Area, Iran

    Science.gov (United States)

    Sharifi, Fereydoun; Arab-Amiri, Ali Reza; Kamkar-Rouhani, Abolghasem; Yousefi, Mahyar; Davoodabadi-Farahani, Meysam

    2017-09-01

    The purpose of this study is water prospectivity modeling (WPM) for recognizing karstic water-bearing zones by using analyses of geo-exploration data in Kal-Qorno valley, located in Tepal area, north of Iran. For this, a sequential exploration method applied on geo-evidential data to delineate target areas for further exploration. In this regard, two major exploration phases including regional and local scales were performed. In the first phase, indicator geological features, structures and lithological units, were used to model groundwater prospectivity as a regional scale. In this phase, for karstic WPM, fuzzy lithological and structural evidence layers were generated and combined using fuzzy operators. After generating target areas using WPM, in the second phase geophysical surveys including gravimetry and geoelectrical resistivity were carried out on the recognized high potential zones as a local scale exploration. Finally the results of geophysical analyses in the second phase were used to select suitable drilling locations to access and extract karstic groundwater in the study area.

  15. Exploring uncertainty and model predictive performance concepts via a modular snowmelt-runoff modeling framework

    Science.gov (United States)

    Tyler Jon Smith; Lucy Amanda. Marshall

    2010-01-01

    Model selection is an extremely important aspect of many hydrologic modeling studies because of the complexity, variability, and uncertainty that surrounds the current understanding of watershed-scale systems. However, development and implementation of a complete precipitation-runoff modeling framework, from model selection to calibration and uncertainty analysis, are...

  16. The effectiveness of snow cube throwing learning model based on exploration

    Science.gov (United States)

    Sari, Nenden Mutiara

    2017-08-01

    This study aimed to know the effectiveness of Snow Cube Throwing (SCT) and Cooperative Model in Exploration-Based Math Learning in terms of the time required to complete the teaching materials and student engagement. This study was quasi-experimental research was conducted at SMPN 5 Cimahi, Indonesia. All student in grade VIII SMPN 5 Cimahi which consists of 382 students is used as population. The sample consists of two classes which had been chosen randomly with purposive sampling. First experiment class consists of 38 students and the second experiment class consists of 38 students. Observation sheet was used to observe the time required to complete the teaching materials and record the number of students involved in each meeting. The data obtained was analyzed by independent sample-t test and used the chart. The results of this study: SCT learning model based on exploration are more effective than cooperative learning models based on exploration in terms of the time required to complete teaching materials based on exploration and student engagement.

  17. Random Testing and Model Checking: Building a Common Framework for Nondeterministic Exploration

    Science.gov (United States)

    Groce, Alex; Joshi, Rajeev

    2008-01-01

    Two popular forms of dynamic analysis, random testing and explicit-state software model checking, are perhaps best viewed as search strategies for exploring the state spaces introduced by nondeterminism in program inputs. We present an approach that enables this nondeterminism to be expressed in the SPIN model checker's PROMELA language, and then lets users generate either model checkers or random testers from a single harness for a tested C program. Our approach makes it easy to compare model checking and random testing for models with precisely the same input ranges and probabilities and allows us to mix random testing with model checking's exhaustive exploration of non-determinism. The PROMELA language, as intended in its design, serves as a convenient notation for expressing nondeterminism and mixing random choices with nondeterministic choices. We present and discuss a comparison of random testing and model checking. The results derive from using our framework to test a C program with an effectively infinite state space, a module in JPL's next Mars rover mission. More generally, we show how the ability of the SPIN model checker to call C code can be used to extend SPIN's features, and hope to inspire others to use the same methods to implement dynamic analyses that can make use of efficient state storage, matching, and backtracking.

  18. Theoretical Models of Optical Transients. I. A Broad Exploration of the Duration-Luminosity Phase Space

    Science.gov (United States)

    Villar, V. Ashley; Berger, Edo; Metzger, Brian D.; Guillochon, James

    2017-11-01

    The duration-luminosity phase space (DLPS) of optical transients is used, mostly heuristically, to compare various classes of transient events, to explore the origin of new transients, and to influence optical survey observing strategies. For example, several observational searches have been guided by intriguing voids and gaps in this phase space. However, we should ask, do we expect to find transients in these voids given our understanding of the various heating sources operating in astrophysical transients? In this work, we explore a broad range of theoretical models and empirical relations to generate optical light curves and to populate the DLPS. We explore transients powered by adiabatic expansion, radioactive decay, magnetar spin-down, and circumstellar interaction. For each heating source, we provide a concise summary of the basic physical processes, a physically motivated choice of model parameter ranges, an overall summary of the resulting light curves and their occupied range in the DLPS, and how the various model input parameters affect the light curves. We specifically explore the key voids discussed in the literature: the intermediate-luminosity gap between classical novae and supernovae, and short-duration transients (≲ 10 days). We find that few physical models lead to transients that occupy these voids. Moreover, we find that only relativistic expansion can produce fast and luminous transients, while for all other heating sources events with durations ≲ 10 days are dim ({M}{{R}}≳ -15 mag). Finally, we explore the detection potential of optical surveys (e.g., Large Synoptic Survey Telescope) in the DLPS and quantify the notion that short-duration and dim transients are exponentially more difficult to discover in untargeted surveys.

  19. Exploring alternative models of rostral-caudal patterning in the zebrafish neurectoderm with computer simulations.

    Science.gov (United States)

    Chitnis, Ajay B; Itoh, Motoyuki

    2004-08-01

    The StarLogo and NetLogo programming environments allow developmental biologists to build computer models of cell-cell interactions in an epithelium and visualize emergent properties of hypothetical genetic regulatory networks operating in the cells. These environments were used to explore alternative models that show how a posteriorizing morphogen gradient might define gene-expression domains along the rostral-caudal axis in the zebrafish neurectoderm. The models illustrate how a hypothetical genetic network based on auto-activation and cross-repression could lead to establishment of discrete non-overlapping gene-expression domains. Copyright 2004 Elsevier Ltd.

  20. Exploring the Impact of Students' Learning Approach on Collaborative Group Modeling of Blood Circulation

    Science.gov (United States)

    Lee, Shinyoung; Kang, Eunhee; Kim, Heui-Baik

    2015-04-01

    This study aimed to explore the effect on group dynamics of statements associated with deep learning approaches (DLA) and their contribution to cognitive collaboration and model development during group modeling of blood circulation. A group was selected for an in-depth analysis of collaborative group modeling. This group constructed a model in a similar fashion to a target model and demonstrated within-group dialogic interaction patterns. It was found that statements associated with DLA contributed to the collaborative group dynamics by providing cognitive scaffolding and enabling critical monitoring, which together facilitated model development and students' participation and understanding. In the model generation phase, the skills demonstrated indicated the use of statements associated with DLA as one student focused on the principles of blood circulation, thereby providing scaffolding for the other students. These students then generated another sub-model. In the model elaboration phase, statements associated with DLA elements such as request information of mechanism (AQ-a) and resolve discrepancies in knowledge (AQ-b) provided students with metacognitive scaffolding and enabled them to show their deep cognitive participation. Moreover, statements associated with DLA elements such as asking questions or metacognitive activity enabled the students to monitor others' models or ideas critically, showing that active cognitive interaction was taking place within the group. These findings reveal that individual learning approaches will bring a synergistic effect to a group modeling process and can lead to practical educational insights for educators seeking to use lessons based on group modeling.

  1. Balanced Exploration and Exploitation Model search for efficient epipolar geometry estimation.

    Science.gov (United States)

    Goshen, Liran; Shimshoni, Ilan

    2008-07-01

    The estimation of the epipolar geometry is especially difficult when the putative correspondences include a low percentage of inlier correspondences and/or a large subset of the inliers is consistent with a degenerate configuration of the epipolar geometry that is totally incorrect. This work presents the Balanced Exploration and Exploitation Model Search (BEEM) algorithm that works very well especially for these difficult scenes. The algorithm handles these two problems in a unified manner. It includes the following main features: (1) Balanced use of three search techniques: global random exploration, local exploration near the current best solution and local exploitation to improve the quality of the model. (2) Exploits available prior information to accelerate the search process. (3) Uses the best found model to guide the search process, escape from degenerate models and to define an efficient stopping criterion. (4) Presents a simple and efficient method to estimate the epipolar geometry from two SIFT correspondences. (5) Uses the locality-sensitive hashing (LSH) approximate nearest neighbor algorithm for fast putative correspondences generation. The resulting algorithm when tested on real images with or without degenerate configurations gives quality estimations and achieves significant speedups compared to the state of the art algorithms.

  2. Design of Mobility System for Ground Model of Planetary Exploration Rover

    Directory of Open Access Journals (Sweden)

    Younkyu Kim

    2012-12-01

    Full Text Available In recent years, a number of missions have been planned and conducted worldwide on the planets such as Mars, which involves the unmanned robotic exploration with the use of rover. The rover is an important system for unmanned planetary exploration, performing the locomotion and sample collection and analysis at the exploration target of the planetary surface designated by the operator. This study investigates the development of mobility system for the rover ground model necessary to the planetary surface exploration for the benefit of future planetary exploration mission in Korea. First, the requirements for the rover mobility system are summarized and a new mechanism is proposed for a stable performance on rough terrain which consists of the passive suspension system with 8 wheeled double 4-bar linkage (DFBL, followed by the performance evaluation for the mechanism of the mobility system based on the shape design and simulation. The proposed mobility system DFBL was compared with the Rocker-Bogie suspension system of US space agency National Aeronautics and Space Administration and 8 wheeled mobility system CRAB8 developed in Switzerland, using the simulation to demonstrate the superiority with respect to the stability of locomotion. On the basis of the simulation results, a general system configuration was proposed and designed for the rover manufacture.

  3. Exploring implementation and sustainability of models of care: can theory help?

    Directory of Open Access Journals (Sweden)

    Forster Della A

    2011-11-01

    Full Text Available Abstract Objective Research on new models of care in health service provision is complex, as is the introduction and embedding of such models, and positive research findings are only one factor in whether a new model of care will be implemented. In order to understand why this is the case, research design must not only take account of proposed changes in the clinical encounter, but the organisational context that must sustain and normalise any changed practices. We use two case studies where new models of maternity care were implemented and evaluated via randomised controlled trials (RCTs to discuss how (or whether the use of theory might inform implementation and sustainability strategies. The Normalisation Process Model is proposed as a suitable theoretical framework, and a comparison made using the two case studies – one where a theoretical framework was used, the other where it was not. Context and approach In the maternity sector there is considerable debate about which model of care provides the best outcomes for women, while being sustainable in the organisational setting. We explore why a model of maternity care – team midwifery (where women have a small group of midwives providing their care – that was implemented and tested in an RCT was not continued after the RCT’s conclusion, despite showing the same or better outcomes for women in the intervention group compared with women allocated to usual care. We then discuss the conceptualisation and rationale leading to the use of the ‘Normalisation Process Model' as an aid to exploring aspects of implementation of a caseload midwifery model (where women are allocated a primary midwife for their care that has recently been evaluated by RCT. Discussion We demonstrate how the Normalisation Process Model was applied in planning of the evaluation phases of the RCT as a means of exploring the implementation of the caseload model of care. We argue that a theoretical understanding of

  4. Exploring the Process of Implementing Healthy Workplace Initiatives: Mapping to Kotter's Leading Change Model.

    Science.gov (United States)

    Chappell, Stacie; Pescud, Melanie; Waterworth, Pippa; Shilton, Trevor; Roche, Dee; Ledger, Melissa; Slevin, Terry; Rosenberg, Michael

    2016-10-01

    The aim of this study was to use Kotter's leading change model to explore the implementation of workplace health and wellbeing initiatives. Qualitative interviews were conducted with 31 workplace representatives with a healthy workplace initiative. None of the workplaces used a formal change management model when implementing their healthy workplace initiatives. Not all of the steps in Kotter model were considered necessary and the order of the steps was challenged. For example, interviewees perceived that communicating the vision, developing the vision, and creating a guiding coalition were integral parts of the process, although there was less emphasis on the importance of creating a sense of urgency and consolidating change. Although none of the workplaces reported using a formal organizational change model when implementing their healthy workplace initiatives, there did appear to be perceived merit in using the steps in Kotter's model.

  5. Exploring the potential of multivariate depth-damage and rainfall-damage models

    DEFF Research Database (Denmark)

    van Ootegem, Luc; van Herck, K.; Creten, T.

    2018-01-01

    In Europe, floods are among the natural catastrophes that cause the largest economic damage. This article explores the potential of two distinct types of multivariate flood damage models: ‘depth-damage’ models and ‘rainfall-damage’ models. We use survey data of 346 Flemish households that were...... victim of pluvial floods complemented with rainfall data from both rain gauges and weather radars. In the econometrical analysis, a Tobit estimation technique is used to deal with the issue of zero damage observations. The results show that in the ‘depth-damage’ models flood depth has a significant...... impact on the damage. In the ‘rainfall-damage’ models there is a significant impact of rainfall accumulation on the damage when using the gauge rainfall data as predictor, but not when using the radar rainfall data. Finally, non-hazard indicators are found to be important for explaining pluvial flood...

  6. Exploring magnetized liner inertial fusion with a semi-analytic model

    Energy Technology Data Exchange (ETDEWEB)

    McBride, R. D.; Slutz, S. A.; Vesey, R. A.; Gomez, M. R.; Sefkow, A. B.; Hansen, S. B.; Knapp, P. F.; Schmit, P. F.; Geissel, M.; Harvey-Thompson, A. J.; Jennings, C. A.; Harding, E. C.; Awe, T. J.; Rovang, D. C.; Hahn, K. D.; Martin, M. R.; Cochrane, K. R.; Peterson, K. J.; Rochau, G. A.; Porter, J. L. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); and others

    2016-01-15

    In this paper, we explore magnetized liner inertial fusion (MagLIF) [S. A. Slutz et al., Phys. Plasmas 17, 056303 (2010)] using a semi-analytic model [R. D. McBride and S. A. Slutz, Phys. Plasmas 22, 052708 (2015)]. Specifically, we present simulation results from this model that: (a) illustrate the parameter space, energetics, and overall system efficiencies of MagLIF; (b) demonstrate the dependence of radiative loss rates on the radial fraction of the fuel that is preheated; (c) explore some of the recent experimental results of the MagLIF program at Sandia National Laboratories [M. R. Gomez et al., Phys. Rev. Lett. 113, 155003 (2014)]; (d) highlight the experimental challenges presently facing the MagLIF program; and (e) demonstrate how increases to the preheat energy, fuel density, axial magnetic field, and drive current could affect future MagLIF performance.

  7. Modeling and Simulation for Exploring Human-Robot Team Interaction Requirements

    Energy Technology Data Exchange (ETDEWEB)

    Dudenhoeffer, Donald Dean; Bruemmer, David Jonathon; Davis, Midge Lee

    2001-12-01

    Small-sized and micro-robots will soon be available for deployment in large-scale forces. Consequently, the ability of a human operator to coordinate and interact with largescale robotic forces is of great interest. This paper describes the ways in which modeling and simulation have been used to explore new possibilities for human-robot interaction. The paper also discusses how these explorations have fed implementation of a unified set of command and control concepts for robotic force deployment. Modeling and simulation can play a major role in fielding robot teams in actual missions. While live testing is preferred, limitations in terms of technology, cost, and time often prohibit extensive experimentation with physical multi-robot systems. Simulation provides insight, focuses efforts, eliminates large areas of the possible solution space, and increases the quality of actual testing.

  8. 3D MODELLING AND MAPPING FOR VIRTUAL EXPLORATION OF UNDERWATER ARCHAEOLOGY ASSETS

    Directory of Open Access Journals (Sweden)

    F. Liarokapis

    2017-02-01

    Full Text Available This paper investigates immersive technologies to increase exploration time in an underwater archaeological site, both for the public, as well as, for researchers and scholars. Focus is on the Mazotos shipwreck site in Cyprus, which is located 44 meters underwater. The aim of this work is two-fold: (a realistic modelling and mapping of the site and (b an immersive virtual reality visit. For 3D modelling and mapping optical data were used. The underwater exploration is composed of a variety of sea elements including: plants, fish, stones, and artefacts, which are randomly positioned. Users can experience an immersive virtual underwater visit in Mazotos shipwreck site and get some information about the shipwreck and its contents for raising their archaeological knowledge and cultural awareness.

  9. D Modelling and Mapping for Virtual Exploration of Underwater Archaeology Assets

    Science.gov (United States)

    Liarokapis, F.; Kouřil, P.; Agrafiotis, P.; Demesticha, S.; Chmelík, J.; Skarlatos, D.

    2017-02-01

    This paper investigates immersive technologies to increase exploration time in an underwater archaeological site, both for the public, as well as, for researchers and scholars. Focus is on the Mazotos shipwreck site in Cyprus, which is located 44 meters underwater. The aim of this work is two-fold: (a) realistic modelling and mapping of the site and (b) an immersive virtual reality visit. For 3D modelling and mapping optical data were used. The underwater exploration is composed of a variety of sea elements including: plants, fish, stones, and artefacts, which are randomly positioned. Users can experience an immersive virtual underwater visit in Mazotos shipwreck site and get some information about the shipwreck and its contents for raising their archaeological knowledge and cultural awareness.

  10. A multicriteria decision model for selecting a portfolio of oil and gas exploration projects

    Directory of Open Access Journals (Sweden)

    Yuri Gama Lopes

    2013-12-01

    Full Text Available As well as exploratory activity being at the heart of and guiding the future of the oil industry, it is fundamental that there be a comprehensive analysis covering the various factors and nuances that arise in the selection of exploration projects. Moreover, it is essential that a decision model enables the decisionmaker's preferences to be addressed in a structured (and methodologically correct way, and one which is easy to understand and to apply in a real-world. Therefore, this paper proposes a multicriteria decision model which underpins using a deterministic procedure for selecting a portfolio of oil and gas exploration projects and thereafter a reality-based application is set out, based on a decision making context within Petrobras.

  11. Explorations in combining cognitive models of individuals and system dynamics models of groups.

    Energy Technology Data Exchange (ETDEWEB)

    Backus, George A.

    2008-07-01

    This report documents a demonstration model of interacting insurgent leadership, military leadership, government leadership, and societal dynamics under a variety of interventions. The primary focus of the work is the portrayal of a token societal model that responds to leadership activities. The model also includes a linkage between leadership and society that implicitly represents the leadership subordinates as they directly interact with the population. The societal model is meant to demonstrate the efficacy and viability of using System Dynamics (SD) methods to simulate populations and that these can then connect to cognitive models depicting individuals. SD models typically focus on average behavior and thus have limited applicability to describe small groups or individuals. On the other hand, cognitive models readily describe individual behavior but can become cumbersome when used to describe populations. Realistic security situations are invariably a mix of individual and population dynamics. Therefore, the ability to tie SD models to cognitive models provides a critical capability that would be otherwise be unavailable.

  12. Exploring a capability-demand interaction model for inclusive design evaluation

    OpenAIRE

    Persad, Umesh

    2012-01-01

    Designers are required to evaluate their designs against the needs and capabilities of their target user groups in order to achieve successful, inclusive products. This dissertation presents exploratory research into the specific problem of supporting analytical design evaluation for Inclusive Design. The analytical evaluation process involves evaluating products with user data rather than testing with actual users. The work focuses on the exploration of a capability-demand model of product i...

  13. Exploring Pre-Service Elementary Teachers’ Mental Models of the Environment

    OpenAIRE

    TASKIN-EKICI, Fatma; Erhan EKICI; COKADAR, Hulusi

    2015-01-01

    Abstract This study aims to explore pre-service elementary teachers’ understandings of the environment. A survey method was carried out in this study. A close-ended questionnaire and Draw-An-Environment Test (DAET) are administered to pre-service teachers (N=255) after instruction of an Environmental Education course. A rubric (DAET-R) is used for assessing the mental models or images of the environment held by pre-service teachers. Results of this study suggest that the...

  14. Using Scenario-based Business Modelling to Explore the 5G Telecommunication Market

    DEFF Research Database (Denmark)

    Moqaddamerad, Sara; Ahokangas, Petri; Matinmikko, Marja

    2017-01-01

    Innovative technologies often alter established value chains and make traditional strategic planning methods inadequate. In this paper, we present the use of scenario-based business modelling to explore the market for the fifth generation mobile communication networks (5G). We discuss four...... to integrate multi-dimensional change, from technology, regulation, value-chain dynamics, and value proposition evolution. We further conclude that the approach is particularly valuable in environments that are characterized by a high level of uncertainty and complexity....

  15. A Multi-rhythmic Oscillator Model that Can Integrate Motion Stabilization with Motion Exploration

    Science.gov (United States)

    Owaki, Dai; Sakai, Yoshiyuki; Ishida, Satoshi; Tero, Atsushi; Ishiguro, Akio

    Central pattern generators (CPGs) have been increasingly attracting roboticists in the hope that they enable robots to realize truly supple and agile locomotion under real world constraints. Thus far, various CPG models have been proposed, particularly in terms of motion stabilization against external perturbations, i.e., limit cycle behavior. On the other hand, biological CPGs have another crucial aspect that cannot be neglected, i.e., motion exploration. Here, note that motion stabilization and motion exploration should be performed in different time-scales. Now the following questions arise: how can different time-scales be embedded into a single CPG effectively?; and what is a good mathematical tool for describing the coexistence of different time-scales? To overcome these problems, this paper introduces a novel oscillator model in which the two functions of motion stabilization and motion exploration can be seamlessly integrated by exploiting the concept of multi-rhythmicity, without relying on any hierarchical structure, which in turn enables that learning is an integral part of the motor control system. We applied this model to the learning of hopping motion as a practical example. Simulation results indicate that the robot can successfully perform online learning without the need for a separation between learning and performance phases.

  16. Exploring electrical resistance: a novel kinesthetic model helps to resolve some misconceptions

    Science.gov (United States)

    Cottle, Dan; Marshall, Rick

    2016-09-01

    A simple ‘hands on’ physical model is described which displays analogous behaviour to some aspects of the free electron theory of metals. Using it students can get a real feel for what is going on inside a metallic conductor. Ohms Law, the temperature dependence of resistivity, the dependence of resistance on geometry, how the conduction electrons respond to a potential difference and the concepts of mean free path and drift speed of the conduction electrons can all be explored. Some quantitative results obtained by using the model are compared with the predictions of Drude’s free electron theory of electrical conduction.

  17. Computer Simulation and Modeling of CO2 Removal Systems for Exploration 2013-2014

    Science.gov (United States)

    Coker, R.; Knox, J.; Gomez, C.

    2015-01-01

    The Atmosphere Revitalization Recovery and Environmental Monitoring (ARREM) project was initiated in September of 2011 as part of the Advanced Exploration Systems (AES) program. Under the ARREM project and the follow-on Life Support Systems (LSS) project, testing of sub-scale and full-scale systems has been combined with multiphysics computer simulations for evaluation and optimization of subsystem approaches. In particular, this paper will describes the testing and 1-D modeling of the combined water desiccant and carbon dioxide sorbent subsystems of the carbon dioxide removal assembly (CDRA). The goal is a full system predictive model of CDRA to guide system optimization and development.

  18. A novel case-control subsampling approach for rapid model exploration of large clustered binary data.

    Science.gov (United States)

    Wright, Stephen T; Ryan, Louise M; Pham, Tung

    2017-12-11

    In many settings, an analysis goal is the identification of a factor, or set of factors associated with an event or outcome. Often, these associations are then used for inference and prediction. Unfortunately, in the big data era, the model building and exploration phases of analysis can be time-consuming, especially if constrained by computing power (ie, a typical corporate workstation). To speed up this model development, we propose a novel subsampling scheme to enable rapid model exploration of clustered binary data using flexible yet complex model set-ups (GLMMs with additive smoothing splines). By reframing the binary response prospective cohort study into a case-control-type design, and using our knowledge of sampling fractions, we show one can approximate the model estimates as would be calculated from a full cohort analysis. This idea is extended to derive cluster-specific sampling fractions and thereby incorporate cluster variation into an analysis. Importantly, we demonstrate that previously computationally prohibitive analyses can be conducted in a timely manner on a typical workstation. The approach is applied to analysing risk factors associated with adverse reactions relating to blood donation. Copyright © 2017 John Wiley & Sons, Ltd.

  19. Precambrian uranium-bearing quartz-pebble conglomerates: exploration model and United States resource potential

    Energy Technology Data Exchange (ETDEWEB)

    Houston, R.S.; Karlstrom, K.E.

    1979-11-01

    Uranium has been discovered in fluvial quartz-pebble conglomerates in most of the Precambrian shield areas of the world, including the Canadian, African, South American, Indian, Baltic, and Australian shields. Occurrences in these and other areas are shown. Two of these occurrences, the Huronian supergroup of Canada and the Witwatersrand deposit of South Africa contain 20 to 30 percent of the planet's known uranium reserves. Thus it is critical that we understand the origin of these deposits and develop exploration models that can aid in finding new deposits. Inasmuch as these uranium-bearing conglomerates are confined almost entirely to rocks of Precambrian age, Part I of this review begins with a discussion of Precambrian geology as it applies to the conglomerates. This is followed by a discussion of genetic concepts, a discussion of unresolved problems, and finally a suggested exploration model. Part II summarizes known and potential occurrences of Precambrian fossil placers in the world and evaluates them in terms of the suggested exploration model. Part III discusses the potential for important Precambrian fossil-placer uranium deposits in the United States and includes suggestions that may be helpful in establishing an exploration program in this country. Part III also brings together new (1975-1978) data on uranium occurrences in the Precambrian of the Wyoming Province. Part IV is a complete bibliography of Precambrian fossil placers, divided according to geographical areas. In total, this paper is designed to be a comprehensive review of Precambrian uranium-bearing fossil placers which will be of use to uranium explorationists and to students of Precambrian geology.

  20. Models and Simulations as a Service: Exploring the Use of Galaxy for Delivering Computational Models.

    Science.gov (United States)

    Walker, Mark A; Madduri, Ravi; Rodriguez, Alex; Greenstein, Joseph L; Winslow, Raimond L

    2016-03-08

    We describe the ways in which Galaxy, a web-based reproducible research platform, can be used for web-based sharing of complex computational models. Galaxy allows users to seamlessly customize and run simulations on cloud computing resources, a concept we refer to as Models and Simulations as a Service (MaSS). To illustrate this application of Galaxy, we have developed a tool suite for simulating a high spatial-resolution model of the cardiac Ca(2+) spark that requires supercomputing resources for execution. We also present tools for simulating models encoded in the SBML and CellML model description languages, thus demonstrating how Galaxy's reproducible research features can be leveraged by existing technologies. Finally, we demonstrate how the Galaxy workflow editor can be used to compose integrative models from constituent submodules. This work represents an important novel approach, to our knowledge, to making computational simulations more accessible to the broader scientific community. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  1. Evaluation of a Porcine Model for Exploration of Endodontic Regeneration Strategies Using Mineral Trioxide Aggregate and Biodentine

    Science.gov (United States)

    2016-06-14

    a Porcine Model for Exploration of Endodontic Regeneration Strategies Using Mineral Trioxide Aggregate and Biodentine . ~ is appropriately... Biodentine . 1. Your request for Publication Clearance has been reviewed in accordance with established regulations and approved effective July 06, 2016...Other 6. Title: Evaluation of a Porcine Model for Exploration of Endodonlic Regeneration Strategies Using Mineral Trioxide Aggregate and Biodentine

  2. A cognitive map model based on spatial and goal-oriented mental exploration in rodents.

    Science.gov (United States)

    Zhu, Qing; Wang, Rubin; Wang, Ziyin

    2013-11-01

    The rodent hippocampus has been used to represent the spatial environment as a cognitive map. Classical theories suggest that the cognitive map is a consequence of assignment of different spatial regions to variant cell populations in the framework of rate coding. The current study constructs a novel computational neural model of the cognitive map based on firing rate coding, as widely appears in associative memory, thus providing an explanation for formation and function of the two types of cognitive maps: the spatial vector map, responsible for self localization and simultaneous updating of detailed information; and the goal-oriented vector map, important in route finding. A proposed intermediate between these two map types was constructed by combining the spatial vector and goal-orientation maps to form an effective and efficient path finding mechanism. Application of such novel cognitive map based path finding methods to a mental exploration model was explored. With adaptation as a driving force, the basic knowledge of the location relationships in the spatial cognitive map was reformed and sent to the goal-oriented cognitive map, thus solving a series of new path problems through mental exploration. This method allows for rapid identification of suitable paths under variant conditions, thus providing a simpler and safer resource for path finding. Additionally, this method also provides an improved basis for potential robotic path finding applications. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  3. ACTIVIS: Visual Exploration of Industry-Scale Deep Neural Network Models.

    Science.gov (United States)

    Kahng, Minsuk; Andrews, Pierre Y; Kalro, Aditya; Polo Chau, Duen Horng

    2017-08-30

    While deep learning models have achieved state-of-the-art accuracies for many prediction tasks, understanding these models remains a challenge. Despite the recent interest in developing visual tools to help users interpret deep learning models, the complexity and wide variety of models deployed in industry, and the large-scale datasets that they used, pose unique design challenges that are inadequately addressed by existing work. Through participatory design sessions with over 15 researchers and engineers at Facebook, we have developed, deployed, and iteratively improved ACTIVIS, an interactive visualization system for interpreting large-scale deep learning models and results. By tightly integrating multiple coordinated views, such as a computation graph overview of the model architecture, and a neuron activation view for pattern discovery and comparison, users can explore complex deep neural network models at both the instance- and subset-level. ACTIVIS has been deployed on Facebook's machine learning platform. We present case studies with Facebook researchers and engineers, and usage scenarios of how ACTIVIS may work with different models.

  4. A fractal growth model: Exploring the connection pattern of hubs in complex networks

    Science.gov (United States)

    Li, Dongyan; Wang, Xingyuan; Huang, Penghe

    2017-04-01

    Fractal is ubiquitous in many real-world networks. Previous researches showed that the strong disassortativity between the hub-nodes on all length scales was the key principle that gave rise to the fractal architecture of networks. Although fractal property emerged in some models, there were few researches about the fractal growth model and quantitative analyses about the strength of the disassortativity for fractal model. In this paper, we proposed a novel inverse renormalization method, named Box-based Preferential Attachment (BPA), to build the fractal growth models in which the Preferential Attachment was performed at box level. The proposed models provided a new framework that demonstrated small-world-fractal transition. Also, we firstly demonstrated the statistical characteristic of connection patterns of the hubs in fractal networks. The experimental results showed that, given proper growing scale and added edges, the proposed models could clearly show pure small-world or pure fractal or both of them. It also showed that the hub connection ratio showed normal distribution in many real-world networks. At last, the comparisons of connection pattern between the proposed models and the biological and technical networks were performed. The results gave useful reference for exploring the growth principle and for modeling the connection patterns for real-world networks.

  5. Probabilistic reliability modeling for oil exploration & production (E&P) facilities in the tallgrass prairie preserve.

    Science.gov (United States)

    Zambrano, Lyda; Sublette, Kerry; Duncan, Kathleen; Thoma, Greg

    2007-10-01

    The aging domestic oil production infrastructure represents a high risk to the environment because of the type of fluids being handled (oil and brine) and the potential for accidental release of these fluids into sensitive ecosystems. Currently, there is not a quantitative risk model directly applicable to onshore oil exploration and production (E&P) facilities. We report on a probabilistic reliability model created for onshore exploration and production (E&P) facilities. Reliability theory, failure modes and effects analysis (FMEA), and event trees were used to develop the model estimates of the failure probability of typical oil production equipment. Monte Carlo simulation was used to translate uncertainty in input parameter values to uncertainty in the model output. The predicted failure rates were calibrated to available failure rate information by adjusting probability density function parameters used as random variates in the Monte Carlo simulations. The mean and standard deviation of normal variate distributions from which the Weibull distribution characteristic life was chosen were used as adjustable parameters in the model calibration. The model was applied to oil production leases in the Tallgrass Prairie Preserve, Oklahoma. We present the estimated failure probability due to the combination of the most significant failure modes associated with each type of equipment (pumps, tanks, and pipes). The results show that the estimated probability of failure for tanks is about the same as that for pipes, but that pumps have much lower failure probability. The model can provide necessary equipment reliability information for proactive risk management at the lease level by providing quantitative information to base allocation of maintenance resources to high-risk equipment that will minimize both lost production and ecosystem damage.

  6. Exploring Third-Grade Student Model-Based Explanations about Plant Relationships within an Ecosystem

    Science.gov (United States)

    Zangori, Laura; Forbes, Cory T.

    2015-12-01

    Elementary students should have opportunities to develop scientific models to reason and build understanding about how and why plants depend on relationships within an ecosystem for growth and survival. However, scientific modeling practices are rarely included within elementary science learning environments and disciplinary content is often treated as discrete pieces separate from scientific practice. Elementary students have few, if any, opportunities to reason about how individual organisms, such as plants, hold critical relationships with their surrounding environment. The purpose of this design-based research study is to build a learning performance to identify and explore the third-grade students' baseline understanding of and their reasoning about plant-ecosystem relationships when engaged in the practices of modeling. The developed learning performance integrated scientific content and core scientific activity to identify and measure how students build knowledge about the role of plants in ecosystems through the practices of modeling. Our findings indicate that the third-grade students' ideas about plant growth include abiotic and biotic relationships. Further, they used their models to reason about how and why these relationships were necessary to maintain plant stasis. However, while the majority of the third-grade students were able to identify and reason about plant-abiotic relationships, a much smaller group reasoned about plant-abiotic-animal relationships. Implications from the study suggest that modeling serves as a tool to support elementary students in reasoning about system relationships, but they require greater curricular and instructional support in conceptualizing how and why ecosystem relationships are necessary for plant growth and development. This paper is based on data from a doctoral dissertation. An earlier version of this paper was presented at the 2015 international conference for the National Association for Research in Science

  7. Using multifractal modeling as a standard tool in geochemical exploration for predicting mineralized areas

    Science.gov (United States)

    Gonçalves, Mario A.

    2015-04-01

    It has been 20 years since the pioneering work of Cheng et al (1994) first proposed a quantitative relationship for the areas enclosing concentration values of an element above given thresholds and their distribution in the field, known as concentration-area (CA) method, which is based in multifractal theory. The method allows the definition of geochemical anomalies in wide set of geological backgrounds but it took nearly 15 years before it became a widely used methodology for mineral exploration. The method was also extended to 1D and 3D data sets. It is worth noting the variety of methods that spanned from the theory of fractals. Building on previous models, including multiplicative cascades and size-grade relationships, increasing evidence points to the powerful tools of fractal theory to describe and model ore deposit distribution and formation. However, while much of these approaches become complex and not easy to use, the CA method is remarkable for its utter simplicity and disarming results obtained when confronted with the geological reality in the field. This is most valued by companies and professionals undertaking geochemical exploration surveys for the characterization or refining of potential ore targets or known mineralized areas. Several approaches have combined the CA method with geostatistic modeling and simulation and other established statistical techniques in order to enhance anomalous threshold identification. Examples are not restricted to geochemical exploration alone, other applications being studies on environmental change. Some of these examples will be addressed as they have been applied to different regions in the world, but particular emphasis will be put on geochemical exploration surveys in different geotectonic units of the Variscan basement in the Iberian Peninsula. These include quartz-vein gold mineralization in Northern Portugal and several surveys for base metals over two wide areas, which served to re-evaluate much of the

  8. Multiscale Modeling of Complex Molecular Structure and Dynamics with MBN Explorer

    DEFF Research Database (Denmark)

    Solov'yov, Ilia A.; Korol, Andrei V.; Solov'yov, Andrey V.

    This book introduces readers to MesoBioNano (MBN) Explorer - a multi-purpose software package designed to model molecular systems at various levels of size and complexity. In addition, it presents a specially designed multi-task toolkit and interface - the MBN Studio - which enables the set......-up of input files, controls the simulations, and supports the subsequent visualization and analysis of the results obtained. The book subsequently provides a systematic description of the capabilities of this universal and powerful software package within the framework of computational molecular science...... practicalities. MBN Studio enables users to easily construct initial geometries for the molecular, liquid, crystalline, gaseous and hybrid systems that serve as input for the subsequent simulations of their physical and chemical properties using MBN Explorer. Despite its universality, the computational...

  9. Forest processes from stands to landscapes: exploring model forecast uncertainties using cross-scale model comparison

    Science.gov (United States)

    Michael J. Papaik; Andrew Fall; Brian Sturtevant; Daniel Kneeshaw; Christian Messier; Marie-Josee Fortin; Neal. Simon

    2010-01-01

    Forest management practices conducted primarily at the stand scale result in simplified forests with regeneration problems and low structural and biological diversity. Landscape models have been used to help design management strategies to address these problems. However, there remains a great deal of uncertainty that the actual management practices result in the...

  10. The Exploration of Models Regarding E-Learning Readiness: Reference Model Suggestions

    Science.gov (United States)

    Demir, Ömer; Yurdugül, Halil

    2015-01-01

    Many studies have been conducted about readiness for e-learning, yet it is quite hard to decide which work of research from the literature to use in a specific context. Therefore, the aim of this study is to identify of which components models consist and for which stakeholders they were developed by investigating the most comprehensive and…

  11. Exploring nonlinear relations: models of clinical decision making by regression with optimal scaling.

    Science.gov (United States)

    Hartmann, Armin; Van Der Kooij, Anita J; Zeeck, Almut

    2009-07-01

    In explorative regression studies, linear models are often applied without questioning the linearity of the relations between the predictor variables and the dependent variable, or linear relations are taken as an approximation. In this study, the method of regression with optimal scaling transformations is demonstrated. This method does not require predefined nonlinear functions and results in easy-to-interpret transformations that will show the form of the relations. The method is illustrated using data from a German multicenter project on the indication criteria for inpatient or day clinic psychotherapy treatment. The indication criteria to include in the regression model were selected with the Lasso, which is a tool for predictor selection that overcomes the disadvantages of stepwise regression methods. The resulting prediction model indicates that treatment status is (approximately) linearly related to some criteria and nonlinearly related to others.

  12. Exploring causal networks of bovine milk fatty acids in a multivariate mixed model context

    DEFF Research Database (Denmark)

    Bouwman, Aniek C; Valente, Bruno D; Janss, Luc L G

    2014-01-01

    Knowledge regarding causal relationships among traits is important to understand complex biological systems. Structural equation models (SEM) can be used to quantify the causal relations between traits, which allow prediction of outcomes to interventions applied to such a network. Such models...... are fitted conditionally on a causal structure among traits, represented by a directed acyclic graph and an Inductive Causation (IC) algorithm can be used to search for causal structures. The aim of this study was to explore the space of causal structures involving bovine milk fatty acids and to select...... a network supported by data as the structure of a SEM. Results: The IC algorithm adapted to mixed models settings was applied to study 14 correlated bovine milk fatty acids, resulting in an undirected network. The undirected pathway from C4:0 to C12:0 resembled the de novo synthesis pathway of short...

  13. Validating Human Performance Models of the Future Orion Crew Exploration Vehicle

    Science.gov (United States)

    Wong, Douglas T.; Walters, Brett; Fairey, Lisa

    2010-01-01

    NASA's Orion Crew Exploration Vehicle (CEV) will provide transportation for crew and cargo to and from destinations in support of the Constellation Architecture Design Reference Missions. Discrete Event Simulation (DES) is one of the design methods NASA employs for crew performance of the CEV. During the early development of the CEV, NASA and its prime Orion contractor Lockheed Martin (LM) strived to seek an effective low-cost method for developing and validating human performance DES models. This paper focuses on the method developed while creating a DES model for the CEV Rendezvous, Proximity Operations, and Docking (RPOD) task to the International Space Station. Our approach to validation was to attack the problem from several fronts. First, we began the development of the model early in the CEV design stage. Second, we adhered strictly to M&S development standards. Third, we involved the stakeholders, NASA astronauts, subject matter experts, and NASA's modeling and simulation development community throughout. Fourth, we applied standard and easy-to-conduct methods to ensure the model's accuracy. Lastly, we reviewed the data from an earlier human-in-the-loop RPOD simulation that had different objectives, which provided us an additional means to estimate the model's confidence level. The results revealed that a majority of the DES model was a reasonable representation of the current CEV design.

  14. Exploring the Validity of Proposed Transgenic Animal Models of Attention-Deficit Hyperactivity Disorder (ADHD).

    Science.gov (United States)

    de la Peña, June Bryan; Dela Peña, Irene Joy; Custodio, Raly James; Botanas, Chrislean Jun; Kim, Hee Jin; Cheong, Jae Hoon

    2017-05-22

    Attention-deficit/hyperactivity disorder (ADHD) is a common, behavioral, and heterogeneous neurodevelopmental condition characterized by hyperactivity, impulsivity, and inattention. Symptoms of this disorder are managed by treatment with methylphenidate, amphetamine, and/or atomoxetine. The cause of ADHD is unknown, but substantial evidence indicates that this disorder has a significant genetic component. Transgenic animals have become an essential tool in uncovering the genetic factors underlying ADHD. Although they cannot accurately reflect the human condition, they can provide insights into the disorder that cannot be obtained from human studies due to various limitations. An ideal animal model of ADHD must have face (similarity in symptoms), predictive (similarity in response to treatment or medications), and construct (similarity in etiology or underlying pathophysiological mechanism) validity. As the exact etiology of ADHD remains unclear, the construct validity of animal models of ADHD would always be limited. The proposed transgenic animal models of ADHD have substantially increased and diversified over the years. In this paper, we compiled and explored the validity of proposed transgenic animal models of ADHD. Each of the reviewed transgenic animal models has strengths and limitations. Some fulfill most of the validity criteria of an animal model of ADHD and have been extensively used, while there are others that require further validation. Nevertheless, these transgenic animal models of ADHD have provided and will continue to provide valuable insights into the genetic underpinnings of this complex disorder.

  15. Exploring Model-to-Model Transformations for RIA Architectures by means of a Systematic Mapping Study

    Directory of Open Access Journals (Sweden)

    Daniel Bonhaure

    2017-12-01

    From an initial set of 132 papers, we selected 30 papers first. Then, thanks to experts' suggestion, we added 3 additional papers. Therefore, we considered 33 research papers. The performed analysis led to various considerations. Among the important ones, we can mention: there are many newly proposed methods, the scarcity of rigorous and formal validation of such methods, the problem of the portability of Platform Independent Models -- PIM, and the low number of tools available for MDD.

  16. Allosteric transitions of supramolecular systems explored by network models: application to chaperonin GroEL.

    Directory of Open Access Journals (Sweden)

    Zheng Yang

    2009-04-01

    Full Text Available Identification of pathways involved in the structural transitions of biomolecular systems is often complicated by the transient nature of the conformations visited across energy barriers and the multiplicity of paths accessible in the multidimensional energy landscape. This task becomes even more challenging in exploring molecular systems on the order of megadaltons. Coarse-grained models that lend themselves to analytical solutions appear to be the only possible means of approaching such cases. Motivated by the utility of elastic network models for describing the collective dynamics of biomolecular systems and by the growing theoretical and experimental evidence in support of the intrinsic accessibility of functional substates, we introduce a new method, adaptive anisotropic network model (aANM, for exploring functional transitions. Application to bacterial chaperonin GroEL and comparisons with experimental data, results from action minimization algorithm, and previous simulations support the utility of aANM as a computationally efficient, yet physically plausible, tool for unraveling potential transition pathways sampled by large complexes/assemblies. An important outcome is the assessment of the critical inter-residue interactions formed/broken near the transition state(s, most of which involve conserved residues.

  17. Lévy-like behaviour in deterministic models of intelligent agents exploring heterogeneous environments

    Science.gov (United States)

    Boyer, D.; Miramontes, O.; Larralde, H.

    2009-10-01

    Many studies on animal and human movement patterns report the existence of scaling laws and power-law distributions. Whereas a number of random walk models have been proposed to explain observations, in many situations individuals actually rely on mental maps to explore strongly heterogeneous environments. In this work, we study a model of a deterministic walker, visiting sites randomly distributed on the plane and with varying weight or attractiveness. At each step, the walker minimizes a function that depends on the distance to the next unvisited target (cost) and on the weight of that target (gain). If the target weight distribution is a power law, p(k) ~ k-β, in some range of the exponent β, the foraging medium induces movements that are similar to Lévy flights and are characterized by non-trivial exponents. We explore variations of the choice rule in order to test the robustness of the model and argue that the addition of noise has a limited impact on the dynamics in strongly disordered media.

  18. Altered explorative strategies and reactive coping style in the FSL rat model of depression

    Directory of Open Access Journals (Sweden)

    Salvatore eMagara

    2015-04-01

    Full Text Available Modeling depression in animals is based on the observation of behaviors interpreted as analogue to human symptoms. Typical tests used in experimental depression research are designed to evoke an either-or outcome. It is known that explorative and coping strategies are relevant for depression, however these aspects are generally not considered in animal behavioral testing. Here we investigate the Flinders Sensitive Line (FSL, a rat model of depression, compared to the Sprague-Dawley (SD rat in three independent tests where the animals are allowed to express a more extensive behavioral repertoire. The multivariate concentric square field™ (MCSF and the novel cage tests evoke exploratory behaviors in a novel environment and the home cage change test evokes social behaviors in the re-establishment of a social hierarchy. In the MCSF test, FSL rats exhibited less exploratory drive and more risk-assessment behavior compared to SD rats. When re-exposed to the arena, FSL, but not SD rats, increased their exploratory behavior compared to the first trial and displayed risk-assessment behavior to the same extent as SD rats. Thus, the behavior of FSL rats was more similar to that of SDs when the rats were familiar with the arena. In the novel cage test FSL rats exhibited a reactive coping style, consistent with the reduced exploration observed in the MCSF. Reactive coping is associated with less aggressive behavior. Accordingly, FSL rats displayed less aggressive behavior in the home cage change test. Taken together, our data show that FSL rats express altered explorative behavior and reactive coping style. Reduced interest is a core symptom of depression, and individuals with a reactive coping style are more vulnerable to the disease. Our results support the use of FSL rats as an animal model of depression and increase our understanding of the FSL rat beyond the behavioral dimensions targeted by the traditional depression-related tests.

  19. Modeling Goal-Directed User Exploration in Human-Computer Interaction

    Science.gov (United States)

    2011-02-01

    and use. A more contemporary example is the World-Wide-Web (WWW or Web), where users may be skilled in general website navigation, but lack prior...Hornof (2008) began to investigate the effect of semantic grouping on visual search by using meaningful group and text labels (e.g. “ jewelry ”, “anklet...as AutoCWW also used the same, the TASA corpus may no longer be suitable for more contemporary tasks. Imagine using CogTool-Explorer to model a

  20. Dynamics of Aviation Biofuel Investment, Incentives, and Market Growth: An Exploration Using the Biomass Scenario Model

    Energy Technology Data Exchange (ETDEWEB)

    Vimmerstedt, Laura; Newes, Emily

    2016-10-25

    The Federal Aviation Administration promotes the development of an aviation biofuel market, and has pursued a goal of 1 billion gallons of production annually by 2018. Although this goal is unlikely to be met, this analysis applies the Biomass Scenario Model to explore conditions affecting market growth, and identifies policy incentive and oil price conditions under which this level of production might occur, and by what year. Numerous combinations of conditions that are more favorable than current conditions can reach the goal before 2030.

  1. Djinn Lite: a tool for customised gene transcript modelling, annotation-data enrichment and exploration

    Science.gov (United States)

    Teber, Erdahl T; Crawford, Edward; Bolton, Kent B; Van Dyk, Derek; Schofield, Peter R; Kapoor, Vimal; Church, W Bret

    2006-01-01

    Background There is an ever increasing rate of data made available on genetic variation, transcriptomes and proteomes. Similarly, a growing variety of bioinformatic programs are becoming available from many diverse sources, designed to identify a myriad of sequence patterns considered to have potential biological importance within inter-genic regions, genes, transcripts, and proteins. However, biologists require easy to use, uncomplicated tools to integrate this information, visualise and print gene annotations. Integrating this information usually requires considerable informatics skills, and comprehensive knowledge of the data format to make full use of this information. Tools are needed to explore gene model variants by allowing users the ability to create alternative transcript models using novel combinations of exons not necessarily represented in current database deposits of mRNA/cDNA sequences. Results Djinn Lite is designed to be an intuitive program for storing and visually exploring of custom annotations relating to a eukaryotic gene sequence and its modelled gene products. In particular, it is helpful in developing hypothesis regarding alternate splicing of transcripts by allowing the construction of model transcripts and inspection of their resulting translations. It facilitates the ability to view a gene and its gene products in one synchronised graphical view, allowing one to drill down into sequence related data. Colour highlighting of selected sequences and added annotations further supports exploration, visualisation of sequence regions and motifs known or predicted to be biologically significant. Conclusion Gene annotating remains an ongoing and challengingtask that will continue as gene structures, gene transcription repertoires, disease loci, protein products and their interactions become moreprecisely defined. Djinn Lite offers an accessible interface to help accumulate, enrich, and individualise sequence annotations relating to a gene, its

  2. Djinn Lite: a tool for customised gene transcript modelling, annotation-data enrichment and exploration

    Directory of Open Access Journals (Sweden)

    Van Dyk Derek

    2006-01-01

    Full Text Available Abstract Background There is an ever increasing rate of data made available on genetic variation, transcriptomes and proteomes. Similarly, a growing variety of bioinformatic programs are becoming available from many diverse sources, designed to identify a myriad of sequence patterns considered to have potential biological importance within inter-genic regions, genes, transcripts, and proteins. However, biologists require easy to use, uncomplicated tools to integrate this information, visualise and print gene annotations. Integrating this information usually requires considerable informatics skills, and comprehensive knowledge of the data format to make full use of this information. Tools are needed to explore gene model variants by allowing users the ability to create alternative transcript models using novel combinations of exons not necessarily represented in current database deposits of mRNA/cDNA sequences. Results Djinn Lite is designed to be an intuitive program for storing and visually exploring of custom annotations relating to a eukaryotic gene sequence and its modelled gene products. In particular, it is helpful in developing hypothesis regarding alternate splicing of transcripts by allowing the construction of model transcripts and inspection of their resulting translations. It facilitates the ability to view a gene and its gene products in one synchronised graphical view, allowing one to drill down into sequence related data. Colour highlighting of selected sequences and added annotations further supports exploration, visualisation of sequence regions and motifs known or predicted to be biologically significant. Conclusion Gene annotating remains an ongoing and challengingtask that will continue as gene structures, gene transcription repertoires, disease loci, protein products and their interactions become moreprecisely defined. Djinn Lite offers an accessible interface to help accumulate, enrich, and individualise sequence

  3. Dynamic Modeling and Soil Mechanics for Path Planning of the Mars Exploration Rovers

    Science.gov (United States)

    Trease, Brian; Arvidson, Raymond; Lindemann, Randel; Bennett, Keith; Zhou, Feng; Iagnemma, Karl; Senatore, Carmine; Van Dyke, Lauren

    2011-01-01

    To help minimize risk of high sinkage and slippage during drives and to better understand soil properties and rover terramechanics from drive data, a multidisciplinary team was formed under the Mars Exploration Rover (MER) project to develop and utilize dynamic computer-based models for rover drives over realistic terrains. The resulting tool, named ARTEMIS (Adams-based Rover Terramechanics and Mobility Interaction Simulator), consists of the dynamic model, a library of terramechanics subroutines, and the high-resolution digital elevation maps of the Mars surface. A 200-element model of the rovers was developed and validated for drop tests before launch, using MSC-Adams dynamic modeling software. Newly modeled terrain-rover interactions include the rut-formation effect of deformable soils, using the classical Bekker-Wong implementation of compaction resistances and bull-dozing effects. The paper presents the details and implementation of the model with two case studies based on actual MER telemetry data. In its final form, ARTEMIS will be used in a predictive manner to assess terrain navigability and will become part of the overall effort in path planning and navigation for both Martian and lunar rovers.

  4. Exploring the Red Sea seasonal ecosystem functioning using a three-dimensional biophysical model

    KAUST Repository

    Triantafyllou, G.

    2014-03-01

    The Red Sea exhibits complex hydrodynamic and biogeochemical dynamics, which vary both in time and space. These dynamics have been explored through the development and application of a 3-D ecosystem model. The simulation system comprises two off-line coupled submodels: the MIT General Circulation Model (MITgcm) and the European Regional Seas Ecosystem Model (ERSEM), both adapted for the Red Sea. The results from an annual simulation under climatological forcing are presented. Simulation results are in good agreement with satellite and in situ data illustrating the role of the physical processes in determining the evolution and variability of the Red Sea ecosystem. The model was able to reproduce the main features of the Red Sea ecosystem functioning, including the exchange with the Gulf of Aden, which is a major driving mechanism for the whole Red Sea ecosystem and the winter overturning taking place in the north. Some model limitations, mainly related to the dynamics of the extended reef system located in the southern part of the Red Sea, which is not currently represented in the model, still need to be addressed.

  5. Exploring Mixed Membership Stochastic Block Models via Non-negative Matrix Factorization

    KAUST Repository

    Peng, Chengbin

    2014-12-01

    Many real-world phenomena can be modeled by networks in which entities and connections are represented by nodes and edges respectively. When certain nodes are highly connected with each other, those nodes forms a cluster, which is called community in our context. It is usually assumed that each node belongs to one community only, but evidences in biology and social networks reveal that the communities often overlap with each other. In other words, one node can probably belong to multiple communities. In light of that, mixed membership stochastic block models (MMB) have been developed to model those networks with overlapping communities. Such a model contains three matrices: two incidence matrices indicating in and out connections and one probability matrix. When the probability of connections for nodes between communities are significantly small, the parameter inference problem to this model can be solved by a constrained non-negative matrix factorization (NMF) algorithm. In this paper, we explore the connection between the two models and propose an algorithm based on NMF to infer the parameters of MMB. The proposed algorithms can detect overlapping communities regardless of knowing or not the number of communities. Experiments show that our algorithm can achieve a better community detection performance than the traditional NMF algorithm. © 2014 IEEE.

  6. Multiscale modeling of complex molecular structure and dynamics with MBN Explorer

    CERN Document Server

    Solov’yov, Ilia A; Solov’yov, Andrey V

    2017-01-01

    This book introduces readers to MesoBioNano (MBN) Explorer – a multi-purpose software package designed to model molecular systems at various levels of size and complexity. In addition, it presents a specially designed multi-task toolkit and interface – the MBN Studio – which enables the set-up of input files, controls the simulations, and supports the subsequent visualization and analysis of the results obtained. The book subsequently provides a systematic description of the capabilities of this universal and powerful software package within the framework of computational molecular science, and guides readers through its applications in numerous areas of research in bio- and chemical physics and material science – ranging from the nano- to the meso-scale. MBN Explorer is particularly suited to computing the system’s energy, to optimizing molecular structure, and to exploring the various facets of molecular and random walk dynamics. The package allows the use of a broad variety of interatomic potenti...

  7. A foodweb model to explore uncertainties in the South Georgia shelf pelagic ecosystem

    Science.gov (United States)

    Hill, Simeon L.; Keeble, Kathryn; Atkinson, Angus; Murphy, Eugene J.

    2012-01-01

    Foodweb models provide a useful framework for compiling data on biomass, production, consumption and feeding relationships. They are particularly useful for identifying gaps and inconsistencies in the data, and for exploring plausible scenarios of change. We compiled data on the pelagic foodweb of the South Georgia shelf, which is one of the most intensively studied areas in the Southern Ocean. The data suggest that current average annual copepod production is three times that of Antarctic krill and that flying seabirds and fish are, respectively, responsible for 25% and 21% of local krill consumption. The most striking inconsistency was that estimated consumption of fish was 5 times their estimated production. We developed a static mass balance model of the foodweb representing one of many possible solutions to the inconsistencies in the data. The model included sufficient fish biomass to balance the original consumption estimate, and consequently fish became the main krill consumers. Nonetheless, only 74% of local krill production was consumed by predators, suggesting that there are additional mortality sources that we did not explicitly model. We developed further models to explore scenarios incorporating plausible climate-driven reductions in krill biomass. In scenarios with unchanged predator diets, an 80% reduction in krill biomass resulted in a 73% reduction in vertebrate biomass. However, when predators with diverse diets were able to switch to feeding on alternative zooplankton prey, total vertebrate biomass was maintained at current levels. Scenarios in which 80% of krill biomass was replaced with copepod biomass required 28% more primary production because the estimated consumption rate of copepods is higher than that of krill. The additional copepod biomass did not alter the consequences for vertebrates. These scenarios illustrate the wide range of potential consequences of a shift from a krill to a copepod dominated system in a warming climate. They

  8. An Emerging Role for Numerical Modelling in Wildfire Behavior Research: Explorations, Explanations, and Hypothesis Development

    Science.gov (United States)

    Linn, R.; Winterkamp, J.; Canfield, J.; Sauer, J.; Dupuy, J. L.; Finney, M.; Hoffman, C.; Parsons, R.; Pimont, F.; Sieg, C.; Forthofer, J.

    2014-12-01

    The human capacity for altering the water cycle has been well documented and given the expected change due to population, income growth, biofuels, climate, and associated land use change, there remains great uncertainty in both the degree of increased pressure on land and water resources and in our ability to adapt to these changes. Alleviating regional shortages in water supply can be carried out in a spatial hierarchy through i) direct trade of water between all regions, ii) development of infrastructure to improve water availability within regions (e.g. impounding rivers), iii) via inter-basin hydrological transfer between neighboring regions and, iv) via virtual water trade. These adaptation strategies can be managed via market trade in water and commodities to identify those strategies most likely to be adopted. This work combines the physically-based University of New Hampshire Water Balance Model (WBM) with the macro-scale Purdue University Simplified International Model of agricultural Prices Land use and the Environment (SIMPLE) to explore the interaction of supply and demand for fresh water globally. In this work we use a newly developed grid cell-based version of SIMPLE to achieve a more direct connection between the two modeling paradigms of physically-based models with optimization-driven approaches characteristic of economic models. We explore questions related to the global and regional impact of water scarcity and water surplus on the ability of regions to adapt to future change. Allowing for a variety of adaptation strategies such as direct trade of water and expanding the built water infrastructure, as well as indirect trade in commodities, will reduce overall global water stress and, in some regions, significantly reduce their vulnerability to these future changes.

  9. Application of the Viterbi Algorithm in Hidden Markov Models for Exploring Irrigation Decision Series

    Science.gov (United States)

    Andriyas, S.; McKee, M.

    2014-12-01

    Anticipating farmers' irrigation decisions can provide the possibility of improving the efficiency of canal operations in on-demand irrigation systems. Although multiple factors are considered during irrigation decision making, for any given farmer there might be one factor playing a major role. Identification of that biophysical factor which led to a farmer deciding to irrigate is difficult because of high variability of those factors during the growing season. Analysis of the irrigation decisions of a group of farmers for a single crop can help to simplify the problem. We developed a hidden Markov model (HMM) to analyze irrigation decisions and explore the factor and level at which the majority of farmers decide to irrigate. The model requires observed variables as inputs and the hidden states. The chosen model inputs were relatively easily measured, or estimated, biophysical data, including such factors (i.e., those variables which are believed to affect irrigation decision-making) as cumulative evapotranspiration, soil moisture depletion, soil stress coefficient, and canal flows. Irrigation decision series were the hidden states for the model. The data for the work comes from the Canal B region of the Lower Sevier River Basin, near Delta, Utah. The main crops of the region are alfalfa, barley, and corn. A portion of the data was used to build and test the model capability to explore that factor and the level at which the farmer takes the decision to irrigate for future irrigation events. Both group and individual level behavior can be studied using HMMs. The study showed that the farmers cannot be classified into certain classes based on their irrigation decisions, but vary in their behavior from irrigation-to-irrigation across all years and crops. HMMs can be used to analyze what factor and, subsequently, what level of that factor on which the farmer most likely based the irrigation decision. The study shows that the HMM is a capable tool to study a process

  10. Plant resistance to parasitic plants: molecular approaches to an old foe.

    Science.gov (United States)

    Rispail, N; Dita, M-A; González-Verdejo, C; Pérez-de-Luque, A; Castillejo, M-A; Prats, E; Román, B; Jorrín, J; Rubiales, D

    2007-01-01

    Parasitic weeds pose severe constraint on major agricultural crops. Varying levels of resistance have been identified and exploited in the breeding programmes of several crops. However, the level of protection achieved to date is either incomplete or ephemeral. Resistance is mainly determined by the coexistence of several mechanisms controlled by multigenic and quantitative systems. Efficient control of the parasite requires a better understanding of the interaction and their associated resistance mechanisms at the histological, genetic and molecular levels. Application of postgenomic technologies and the use of model plants should improve the understanding of the plant-parasitic plant interaction and drive not only breeding programmes through either marker-assisted selection (MAS) or transgenesis but also the development of alternative methods to control the parasite. This review presents the current approaches targeting the characterization of resistance mechanisms and explores their potentiality to control parasitic plants.

  11. Exploring the influence of a social ecological model on school-based physical activity.

    Science.gov (United States)

    Langille, Jessie-Lee D; Rodgers, Wendy M

    2010-12-01

    Among rising rates of overweight and obesity, schools have become essential settings to promote health behaviors, such as physical activity (PA). As schools exist within a broader environment, the social ecological model (SEM) provided a framework to consider how different levels interact and influence PA. The purpose of this study was to provide insight on school-based PA promotion by investigating the integration between different levels of Emmons's SEM within one public school board in a large Canadian city. Interviews were conducted with participants from the government (n = 4), the public school board (n = 3), principals (n = 3), and teachers (n = 4) and analyzed to explore perspectives on the various levels of the model. The results suggested that higher level policies "trickled down" into the organizational level of the SEM but there was pivotal responsibility for schools to determine how to implement PA strategies. Furthermore, schools have difficulty implementing PA because of the continued priority of academic achievement.

  12. Applying a system dynamics modelling approach to explore policy options for improving neonatal health in Uganda.

    Science.gov (United States)

    Semwanga, Agnes Rwashana; Nakubulwa, Sarah; Adam, Taghreed

    2016-05-04

    The most recent reports on global trends in neonatal mortality continue to show alarmingly slow progress on improvements in neonatal mortality rates, with sub-Saharan Africa still lagging behind. This emphasised the urgent need to innovatively employ alternative solutions that take into account the intricate complexities of neonatal health and the health systems in which the various strategies operate. In our first paper, we empirically explored the causes of the stagnating neonatal mortality in Uganda using a dynamic synthesis methodology (DSM) approach. In this paper, we completed the last three stages of DSM, which involved the development of a quantitative (simulation) model, using STELLA modelling software. We used statistical data to populate the model. Through brainstorming sessions with stakeholders, iterations to test and validate the model were undertaken. The different strategies and policy interventions that could possibly lower neonatal mortality rates were tested using what-if analysis. Sensitivity analysis was used to determine the strategies that could have a great impact on neonatal mortality. We developed a neonatal health simulation model (NEOSIM) to explore potential interventions that could possibly improve neonatal health within a health system context. The model has four sectors, namely population, demand for services, health of the mothers and choices of clinical care. It tests the effects of various interventions validated by a number of Ugandan health practitioners, including health education campaigns, free delivery kits, motorcycle coupons, kangaroo mother care, improving neonatal resuscitation and labour management skills, and interventions to improve the mothers health, i.e. targeting malaria, anaemia and tetanus. Among the tested interventions, the package with the highest impact on reducing neonatal mortality rates was a combination of the free delivery kits in a setting where delivery services were free and motorcycle coupons to

  13. Thermo-mechanical models of the European lithosphere for geothermal exploration

    Science.gov (United States)

    Limberger, Jon; van Wees, Jan-Diederik; Tesauro, Magdala; Bonté, Damien; Lipsey, Lindsay; Beekman, Fred; Cloetingh, Sierd

    2015-04-01

    One of the critical exploration parameters for geothermal systems is the subsurface temperature. Temperature data are reliable up to a depth of 1 km in most parts of Europe. Accordingly, the robustness of temperature estimation rapidly decreases with depth, as temperature data from wells become sparser and unevenly distributed. We developed a two-layer temperature model for assessing the prospective resource base of enhanced geothermal systems in Europe. The surface heat flow and the Moho depth were used to constrain the radiogenic heat production in the upper crust. Only conduction was considered for heat transfer. The most recent and comprehensive regional temperature models and maps available were directly used to constrain the 3D temperature distribution up to a depth of 6 km. The model shows high average geothermal gradients of up to 60 °C in volcanically active regions such as Iceland, parts of Italy, Greece and Turkey. Temperatures at 5 km depth range between 40 °C and 310 °C and at 10 km depth between 80 °C and 590 °C. However, this direct use of regional models is not fully consistent with the calculated and observed heat flow. Furthermore, only fixed thermal conductivity values were assigned to the sediments and the crystalline basement. As part of the EU FP7-funded Integrated Methods for Advanced Geothermal Exploration (IMAGE) project we are going to develop a methodology to obtain a more advanced 3D lithosphere-scale thermal model of Europe. This will include a more realistic distribution of thermal properties, according with lithological variations of the European crust. Further improvements of the thermal model, aiming at consistency between temperature and heat flow observations and tectonic model predictions, will be obtained by adopting data assimilation techniques derived from reservoir engineering best practices. The newly derived thermal model of the European lithosphere together with compositional data will be used to estimate the strength

  14. Biomass burning at Cape Grim: exploring photochemistry using multi-scale modelling

    Science.gov (United States)

    Lawson, Sarah J.; Cope, Martin; Lee, Sunhee; Galbally, Ian E.; Ristovski, Zoran; Keywood, Melita D.

    2017-10-01

    We have tested the ability of a high-resolution chemical transport model (CTM) to reproduce biomass burning (BB) plume strikes and ozone (O3) enhancements observed at Cape Grim in Tasmania, Australia, from the Robbins Island fire. The CTM has also been used to explore the contribution of near-field BB emissions and background sources to O3 observations under conditions of complex meteorology. Using atmospheric observations, we have tested model sensitivity to meteorology, BB emission factors (EFs) corresponding to low, medium, and high modified combustion efficiency (MCE), and spatial variability. The use of two different meteorological models (TAPM-CTM and CCAM-CTM) varied the first (BB1) plume strike time by up to 15 h and the duration of impact between 12 and 36 h, and it varied the second (BB2) plume duration between 50 and 57 h. Meteorology also had a large impact on simulated O3, with one model (TAPM-CTM) simulating four periods of O3 enhancement, while the other model (CCAM) simulating only one period. Varying the BB EFs, which in turn varied the non-methane organic compound (NMOC) / oxides of nitrogen (NOx) ratio, had a strongly non-linear impact on simulated O3 concentration, with either destruction or production of O3 predicted in different simulations. As shown in previous work (Lawson et al., 2015), minor rainfall events have the potential to significantly alter EF due to changes in combustion processes. Models that assume fixed EF for O3 precursor species in an environment with temporally or spatially variable EF may be unable to simulate the behaviour of important species such as O3. TAPM-CTM is used to further explore the contribution of the Robbins Island fire to the observed O3 enhancements during BB1 and BB2. Overall, TAPM-CTM suggests that the dominant source of O3 observed at Cape Grim was aged urban air (age = 2 days), with a contribution of O3 formed from local BB emissions. This work shows the importance of assessing model sensitivity to

  15. The Patterning Cascade Model and Carabelli's trait expression in metameres of the mixed human dentition: exploring a morphogenetic model.

    Science.gov (United States)

    Paul, Kathleen S; Astorino, Claudia M; Bailey, Shara E

    2017-01-01

    The Patterning Cascade Model (PCM) provides an evolutionary developmental framework for exploring diversity in tooth crown form. According to the model, proximity of secondary enamel knots and tooth germ size track underlying developmental processes that dictate ultimate crown morphology (i.e., cusp number, accessory cusp presence/size). Previous research has shown the model to successfully predict variation in Carabelli's trait expression between antimeric and metameric pairs of human permanent molars. In this study, we quantify Carabelli's trait expression for metameres of the mixed dentition (dm2 and M1) and assess the PCM's potential for explaining differences in expression between the two elements. Crown dimensions, intercusp distances, and Carabelli's trait expression were collected from 49 subadults possessing observable dm2/M1 pairs. Wilcoxon signed-rank tests and paired t-tests were performed to assess whether metameres differ significantly in morphometric variables. We explored the relationships between relative intercusp distances (RICDs) and Carabelli's trait expression using proportional odds logistic regression. Intra-individual dm2/M1 pairs differed significantly in Carabelli's trait expression (p = 0.01), with dm2 exhibiting higher grades of expression more commonly despite its smaller crown size. Paired molars differed in only one statistically significant RICD: metacone-hypocone (p < 0.01). Most RICDs shared the predicted negative relationship with Carabelli's trait expression, but this relationship was only statistically significant for three RICDs in the dm2 (mean, protocone-paracone, metacone-hypocone). We found mixed support for the PCM's ability to explain differences in Carabelli's trait expression between metameres of the mixed molar row. Results suggest that protocone-paracone enamel knot spacing has the greatest influence on Carabelli's trait expression. Lack of statistical significance for many of the relationships explored may

  16. Dynamic Modeling and Soil Mechanics for Path Planning of the Mars Exploration Rovers

    Science.gov (United States)

    Trease, Brian

    2011-01-01

    To help minimize risk of high sinkage and slippage during drives and to better understand soil properties and rover terramechanics from drive data, a multidisciplinary team was formed under the Mars Exploration Rover project to develop and utilize dynamic computer-based models for rover drives over realistic terrains. The resulting system, named ARTEMIS (Adams-based Rover Terramechanics and Mobility Interaction System), consists of the dynamic model, a library of terramechanics subroutines, and the high-resolution digital elevation maps of the Mars surface. A 200-element model of the rovers was developed and validated for drop tests before launch, using Adams dynamic modeling software. The external library was built in Fortran and called by Adams to model the wheel-soil interactions include the rut-formation effect of deformable soils, lateral and longitudinal forces, bull-dozing effects, and applied wheel torque. The paper presents the details and implementation of the system. To validate the developed system, one study case is presented from a realistic drive on Mars of the Opportunity rover. The simulation results match well from the measurement of on-board telemetry data. In its final form, ARTEMIS will be used in a predictive manner to assess terrain navigability and will become part of the overall effort in path planning and navigation for both Martian and lunar rovers.

  17. Exploring the predictive power of interaction terms in a sophisticated risk equalization model using regression trees.

    Science.gov (United States)

    van Veen, S H C M; van Kleef, R C; van de Ven, W P M M; van Vliet, R C J A

    2017-05-23

    This study explores the predictive power of interaction terms between the risk adjusters in the Dutch risk equalization (RE) model of 2014. Due to the sophistication of this RE-model and the complexity of the associations in the dataset (N = ~16.7 million), there are theoretically more than a million interaction terms. We used regression tree modelling, which has been applied rarely within the field of RE, to identify interaction terms that statistically significantly explain variation in observed expenses that is not already explained by the risk adjusters in this RE-model. The interaction terms identified were used as additional risk adjusters in the RE-model. We found evidence that interaction terms can improve the prediction of expenses overall and for specific groups in the population. However, the prediction of expenses for some other selective groups may deteriorate. Thus, interactions can reduce financial incentives for risk selection for some groups but may increase them for others. Furthermore, because regression trees are not robust, additional criteria are needed to decide which interaction terms should be used in practice. These criteria could be the right incentive structure for risk selection and efficiency or the opinion of medical experts. Copyright © 2017 John Wiley & Sons, Ltd.

  18. Correlation of experimentally measured atomic scale properties of EUV photoresist to modeling performance: an exploration

    Science.gov (United States)

    Kandel, Yudhishthir; Chandonait, Jonathan; Melvin, Lawrence S.; Marokkey, Sajan; Yan, Qiliang; Grzeskowiak, Steven; Painter, Benjamin; Denbeaux, Gregory

    2017-03-01

    Extreme ultraviolet (EUV) lithography at 13.5 nm stands at the crossroads of next generation patterning technology for high volume manufacturing of integrated circuits. Photo resist models that form the part of overall pattern transform model for lithography play a vital role in supporting this effort. The physics and chemistry of these resists must be understood to enable the construction of accurate models for EUV Optical Proximity Correction (OPC). In this study, we explore the possibility of improving EUV photo-resist models by directly correlating the parameters obtained from experimentally measured atomic scale physical properties; namely, the effect of interaction of EUV photons with photo acid generators in standard chemically amplified EUV photoresist, and associated electron energy loss events. Atomic scale physical properties will be inferred from the measurements carried out in Electron Resist Interaction Chamber (ERIC). This study will use measured physical parameters to establish a relationship with lithographically important properties, such as line edge roughness and CD variation. The data gathered from these measurements is used to construct OPC models of the resist.

  19. Exploring nursing e-learning systems success based on information system success model.

    Science.gov (United States)

    Chang, Hui-Chuan; Liu, Chung-Feng; Hwang, Hsin-Ginn

    2011-12-01

    E-learning is thought of as an innovative approach to enhance nurses' care service knowledge. Extensive research has provided rich information toward system development, courses design, and nurses' satisfaction with an e-learning system. However, a comprehensive view in understanding nursing e-learning system success is an important but less focused-on topic. The purpose of this research was to explore net benefits of nursing e-learning systems based on the updated DeLone and McLean's Information System Success Model. The study used a self-administered questionnaire to collected 208 valid nurses' responses from 21 of Taiwan's medium- and large-scale hospitals that have implemented nursing e-learning systems. The result confirms that the model is sufficient to explore the nurses' use of e-learning systems in terms of intention to use, user satisfaction, and net benefits. However, while the three exogenous quality factors (system quality, information quality, and service quality) were all found to be critical factors affecting user satisfaction, only information quality showed a direct effect on the intention to use. This study provides useful insights for evaluating nursing e-learning system qualities as well as an understanding of nurses' intentions and satisfaction related to performance benefits.

  20. More Similar than Different? Exploring Cultural Models of Depression among Latino Immigrants in Florida

    Directory of Open Access Journals (Sweden)

    Dinorah (Dina Martinez Tyson

    2011-01-01

    Full Text Available The Surgeon General's report, “Culture, Race, and Ethnicity: A Supplement to Mental Health,” points to the need for subgroup specific mental health research that explores the cultural variation and heterogeneity of the Latino population. Guided by cognitive anthropological theories of culture, we utilized ethnographic interviewing techniques to explore cultural models of depression among foreign-born Mexican (n=30, Cuban (n=30, Columbian (n=30, and island-born Puerto Ricans (n=30, who represent the largest Latino groups in Florida. Results indicate that Colombian, Cuban, Mexican, and Puerto Rican immigrants showed strong intragroup consensus in their models of depression causality, symptoms, and treatment. We found more agreement than disagreement among all four groups regarding core descriptions of depression, which was largely unexpected but can potentially be explained by their common immigrant experiences. Findings expand our understanding about Latino subgroup similarities and differences in their conceptualization of depression and can be used to inform the adaptation of culturally relevant interventions in order to better serve Latino immigrant communities.

  1. Exploring Interface Problems in Taiwan’s Construction Projects Using Structural Equation Modeling

    Directory of Open Access Journals (Sweden)

    Chien-Liang Lin

    2017-05-01

    Full Text Available Construction projects are complex systems that inherently contain complex interface problems. This study explored the root causes of interface problems in construction projects using structural equation modeling. This technique is a systematic approach that combines factor analysis and path analysis to investigate the causal relationships among multidimensional factors. The literature on construction interface problems was reviewed, and a questionnaire survey was conducted in Taiwan to identify 27 initial factors that cause interface problems in three dimensions: owner, design, and construction. Then, a series of structural equation models (SEMs was developed to further explore the root causes of the interface problems and their causal relationships. This study has three main findings: (1 poor design causes interface problems; (2 ineffective communication and coordination among the owner, design, and construction dimensions are the main factors that cause construction interface problems; and (3 a lack of communication and coordination has a greater influence on the construction dimension than on the owner and design dimensions. The above findings can be used as important references and sustainable management strategies for academia and decision-makers in the construction industry.

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

    Science.gov (United States)

    Holman, I.

    2014-12-01

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

  3. Exploring noctilucent cloud variability using the nudged and extended version of the Canadian Middle Atmosphere Model

    Science.gov (United States)

    Kuilman, Maartje; Karlsson, Bodil; Benze, Susanne; Megner, Linda

    2017-11-01

    Ice particles in the summer mesosphere - such as those connected to noctilucent clouds and polar mesospheric summer echoes - have since their discovery contributed to the uncovering of atmospheric processes on various scales ranging from interactions on molecular levels to global scale circulation patterns. While there are numerous model studies on mesospheric ice microphysics and how the clouds relate to the background atmosphere, there are at this point few studies using comprehensive global climate models to investigate observed variability and climatology of noctilucent clouds. In this study it is explored to what extent the large-scale inter-annual characteristics of noctilucent clouds are captured in a 30-year run - extending from 1979 to 2009 - of the nudged and extended version of the Canadian Middle Atmosphere Model (CMAM30). To construct and investigate zonal mean inter-seasonal variability in noctilucent cloud occurrence frequency and ice mass density in both hemispheres, a simple cloud model is applied in which it is assumed that the ice content is solely controlled by the local temperature and water vapor volume mixing ratio. The model results are compared to satellite observations, each having an instrument-specific sensitivity when it comes to detecting noctilucent clouds. It is found that the model is able to capture the onset dates of the NLC seasons in both hemispheres as well as the hemispheric differences in NLCs, such as weaker NLCs in the SH than in the NH and differences in cloud height. We conclude that the observed cloud climatology and zonal mean variability are well captured by the model.

  4. A continuous latitudinal energy balance model to explore non-uniform climate engineering strategies

    Science.gov (United States)

    Bonetti, F.; McInnes, C. R.

    2016-12-01

    Current concentrations of atmospheric CO2 exceed measured historical levels in modern times, largely attributed to anthropogenic forcing since the industrial revolution. The required decline in emissions rates has never been achieved leading to recent interest in climate engineering for future risk-mitigation strategies. Climate engineering aims to offset human-driven climate change. It involves techniques developed both to reduce the concentration of CO2 in the atmosphere (Carbon Dioxide Removal (CDR) methods) and to counteract the radiative forcing that it generates (Solar Radiation Management (SRM) methods). In order to investigate effects of SRM technologies for climate engineering, an analytical model describing the main dynamics of the Earth's climate has been developed. The model is a time-dependent Energy Balance Model (EBM) with latitudinal resolution and allows for the evaluation of non-uniform climate engineering strategies. A significant disadvantage of climate engineering techniques involving the management of solar radiation is regional disparities in cooling. This model offers an analytical approach to design multi-objective strategies that counteract climate change on a regional basis: for example, to cool the Artic and restrict undesired impacts at mid-latitudes, or to control the equator-to-pole temperature gradient. Using the Green's function approach the resulting partial differential equation allows for the computation of the surface temperature as a function of time and latitude when a 1% per year increase in the CO2 concentration is considered. After the validation of the model through comparisons with high fidelity numerical models, it will be used to explore strategies for the injection of the aerosol precursors in the stratosphere. In particular, the model involves detailed description of the optical properties of the particles, the wash-out dynamics and the estimation of the radiative cooling they can generate.

  5. Exploring life expectancy limits: First exit time modeling, parameter analysis and forecasts

    Science.gov (United States)

    Skiadas, Christos H.; Skiadas, Charilaos

    In this paper we explore the life expectancy limits by based on the stochastic modeling of mortality and applying the first exit or hitting time theory of a stochastic process. The main assumption is that the health state or the "vitality", according to Strehler and Mildvan, of an individual is a stochastic variable and thus it was introduced and applied a first exit time density function to mortality data. The model is used to estimate the development of mortality rates in the late stages of the human life span, to make better fitting to population mortality data including the infant mortality, to compare it with the classical Gompertz curve, and to make comparisons between the Carey medfly data and the population mortality data estimating the health state or "vitality" functions. Furthermore, we apply the model to the life table data of Italy, France, USA, Canada, Sweden, Norway and Japan, and we analyze the characteristic parameters of the model and make forecasts. The case of female mortality in Sweden is extensively studied and forecasts to 2025 and 2050 are presented.

  6. An exploration for research-oriented teaching model in biology teaching.

    Science.gov (United States)

    Xing, Wanjin; Mo, Morigen; Su, Huimin

    2014-07-01

    Training innovative talents, as one of the major aims for Chinese universities, needs to reform the traditional teaching methods. The research-oriented teaching method has been introduced and its connotation and significance for Chinese university teaching have been discussed for years. However, few practical teaching methods for routine class teaching were proposed. In this paper, a comprehensive and concrete research-oriented teaching model with contents of reference value and evaluation method for class teaching was proposed based on the current teacher-guiding teaching model in China. We proposed that the research-oriented teaching model should include at least seven aspects on: (1) telling the scientific history for the skills to find out scientific questions; (2) replaying the experiments for the skills to solve scientific problems; (3) analyzing experimental data for learning how to draw a conclusion; (4) designing virtual experiments for learning how to construct a proposal; (5) teaching the lesson as the detectives solve the crime for learning the logic in scientific exploration; (6) guiding students how to read and consult the relative references; (7) teaching students differently according to their aptitude and learning ability. In addition, we also discussed how to evaluate the effects of the research-oriented teaching model in examination.

  7. Exploration of Serum Proteomic Profiling and Diagnostic Model That Differentiate Crohn's Disease and Intestinal Tuberculosis.

    Directory of Open Access Journals (Sweden)

    Fenming Zhang

    Full Text Available To explore the diagnostic models of Crohn's disease (CD, Intestinal tuberculosis (ITB and the differential diagnostic model between CD and ITB by analyzing serum proteome profiles.Serum proteome profiles from 30 CD patients, 21 ITB patients and 30 healthy controls (HCs were analyzed by using weak cationic magnetic beads combined with MALDI-TOF-MS technique to detect the differentially expressed proteins of serum samples. Three groups were made and compared accordingly: group of CD patients and HCs, group of ITB patients and HCs, group of CD patients and ITB patients. Wilcoxon rank sum test was used to screen the ten most differentiated protein peaks (P < 0.05. Genetic algorithm combining with support vector machine (SVM was utilized to establish the optimal diagnostic models for CD, ITB and the optimal differential diagnostic model between CD and ITB. The predictive effects of these models were evaluated by Leave one out (LOO cross validation method.There were 236 protein peaks differently expressed between group of CD patients and HCs, 305 protein peaks differently expressed between group of ITB patients and HCs, 332 protein peaks differently expressed between group of CD patients and ITB patients. Ten most differentially expressed peaks were screened out between three groups respectively (P < 0.05 to establish diagnostic models and differential diagnostic model. A diagnostic model comprising of four protein peaks (M/Z 4964, 3029, 2833, 2900 can well distinguish CD patients and HCs, with a specificity and sensitivity of 96.7% and 96.7% respectively. A diagnostic model comprising four protein peaks (M/Z 3030, 2105, 2545, 4210 can well distinguish ITB patients and HCs, with a specificity and sensitivity of 93.3% and 95.2% respectively. A differential diagnostic model comprising three potential biomarkers protein peaks (M/Z 4267, 4223, 1541 can well distinguish CD patients and ITB patients, with a specificity and sensitivity of 76.2% and 80

  8. A review of models in support of oil and gas exploration off the north coast of British Columbia

    National Research Council Canada - National Science Library

    Foreman, M. G. G

    2005-01-01

    A state-of-the-art review of numerical models that would be needed to address scientific and environmental issues related to removing the moratorium on offshore oil and gas exploration for the waters...

  9. Exploring Shifts in Middle School Learners' Modeling Activity While Generating Drawings, Animations, and Computational Simulations of Molecular Diffusion

    Science.gov (United States)

    Wilkerson-Jerde, Michelle H.; Gravel, Brian E.; Macrander, Christopher A.

    2015-01-01

    Modeling and using technology are two practices of particular interest to K-12 science educators. These practices are inextricably linked among professionals, who engage in modeling activity with and across a variety of representational technologies. In this paper, we explore the practices of five sixth-grade girls as they generated models of…

  10. Difficult Dialogues, Privilege and Social Justice: Uses of the Privileged Identity Exploration (PIE) Model in Student Affairs Practice

    Science.gov (United States)

    Watt, Sherry K.

    2007-01-01

    This article will introduce the Privileged Identity Exploration (PIE) Model. This model identifies eight (8) defense modes associated with behaviors individuals display when engaged in difficult dialogues about social justice issues. Implications for the model and ways it can be used to assist facilitators as they engage participants in…

  11. A computational model to explore the role of angiogenic impairment on endochondral ossification during fracture healing.

    Science.gov (United States)

    OReilly, Adam; Hankenson, Kurt D; Kelly, Daniel J

    2016-10-01

    While it is well established that an adequate blood supply is critical to successful bone regeneration, it remains poorly understood how progenitor cell fate is affected by the altered conditions present in fractures with disrupted vasculature. In this study, computational models were used to explore how angiogenic impairment impacts oxygen availability within a fracture callus and hence regulates mesenchymal stem cell (MSC) differentiation and bone regeneration. Tissue differentiation was predicted using a previously developed algorithm which assumed that MSC fate is governed by oxygen tension and substrate stiffness. This model was updated based on the hypothesis that cell death, chondrocyte hypertrophy and endochondral ossification are regulated by oxygen availability. To test this, the updated model was used to simulate the time course of normal fracture healing, where it successfully predicted the observed quantity and spatial distribution of bone and cartilage at 10 and 20 days post-fracture (dpf). It also predicted the ratio of cartilage which had become hypertrophic at 10 dpf. Following this, three models of fracture healing with increasing levels of angiogenic impairment were developed. Under mild impairment, the model predicted experimentally observed reductions in hypertrophic cartilage at 10 dpf as well as the persistence of cartilage at 20 dpf. Models of more severe impairment predicted apoptosis and the development of fibrous tissue. These results provide insight into how factors specific to an ischemic callus regulate tissue regeneration and provide support for the hypothesis that chondrocyte hypertrophy and endochondral ossification during tissue regeneration are inhibited by low oxygen.

  12. Lithosphere temperature model and resource assessment for deep geothermal exploration in Hungary

    Science.gov (United States)

    Bekesi, Eszter; van Wees, Jan-Diederik; Vrijlandt, Mark; Lenkey, Laszlo; Horvath, Ferenc

    2017-04-01

    The demand for deep geothermal energy has increased considerably over the past years. To reveal potential areas for geothermal exploration, it is crucial to have an insight into the subsurface temperature distribution. Hungary is one of the most suitable countries in Europe for geothermal development, as a result of Early and Middle Miocene extension and subsequent thinning of the lithosphere. Hereby we present the results of a new thermal model of Hungary extending from the surface down to the lithosphere-astenosphere boundary (LAB). Subsurface temperatures were calculated through a regular 3D grid with a horizontal resolution of 2.5 km, a vertical resolution of 200 m for the uppermost 7 km, and 3 km down to the depth of the LAB The model solves the heat equation in steady-state, assuming conduction as the main heat transfer mechanism. At the base, it adopts a constant basal temperature or heat flow condition. For the calibration of the model, more than 5000 temperature measurements were collected from the Geothermal Database of Hungary. The model is built up by five sedimentary layers, upper crust, lower crust, and lithospheric mantle, where each layer has its own thermal properties. The prior thermal properties and basal condition of the model is updated through the ensemble smoother with multiple data assimilation technique. The conductive model shows misfits with the observed temperatures, which cannot be explained by neglected transient effects related to lithosphere extension. These anomalies are explained mostly by groundwater flow in Mesozoic carbonates and other porous sedimentary rocks. To account for the effect of heat convection, we use a pseudo-conductive approach by adjusting the thermal conductivity of the layers where fluid flow may occur. After constructing the subsurface temperature model of Hungary, the resource base for EGS (Enhanced Geothermal Systems) is quantified. To this end, we applied a cash-flow model to translate the geological

  13. POEM APPRECIATION LEARNING MODEL IN INDONESIA EXPLORATION STUDY AND NEEDS ANALYSIS

    Directory of Open Access Journals (Sweden)

    Sukini

    2016-12-01

    Full Text Available Poem Appreciation is a compulsary course at Indonesian Language and Literature Education Department of higher education. This exploratory research aimed at exploring problems and needs encountered by lecturers and students in Poem Appreciation course in the areas of Surakarta ex-residency and Yogyakarta Special Region. The research subjects were lecturers and students involved in poem learning in those areas. Observation, interview, document analysis, and questionnaire were used as data collection techniques. Related to Poem Appreciation course, the problems and needs for lecturers are: (1 the arrangement of lesson plan and syllabus; (2 the implementation of its procedure; (3 the evaluation of its learning; whereas those for students include the use of strategy and learning models which are innovative, effective, and students-centered. Inquiry-Based Learning (IBL is necessarily needed by lecturers and students in Poem Appreciation course.

  14. Exploring the free energy landscape of a model β-hairpin peptide and its isoform.

    Science.gov (United States)

    Narayanan, Chitra; Dias, Cristiano L

    2014-10-01

    Secondary structural transitions from α-helix to β-sheet conformations are observed in several misfolding diseases including Alzheimer's and Parkinson's. Determining factors contributing favorably to the formation of each of these secondary structures is therefore essential to better understand these disease states. β-hairpin peptides form basic components of anti-parallel β-sheets and are suitable model systems for characterizing the fundamental forces stabilizing β-sheets in fibrillar structures. In this study, we explore the free energy landscape of the model β-hairpin peptide GB1 and its E2 isoform that preferentially adopts α-helical conformations at ambient conditions. Umbrella sampling simulations using all-atom models and explicit solvent are performed over a large range of end-to-end distances. Our results show the strong preference of GB1 and the E2 isoform for β-hairpin and α-helical conformations, respectively, consistent with previous studies. We show that the unfolded states of GB1 are largely populated by misfolded β-hairpin structures which differ from each other in the position of the β-turn. We discuss the energetic factors contributing favorably to the formation of α-helix and β-hairpin conformations in these peptides and highlight the energetic role of hydrogen bonds and non-bonded interactions. © 2014 Wiley Periodicals, Inc.

  15. Exploring biological relationships between calving traits in primiparous cattle with a Bayesian recursive model.

    Science.gov (United States)

    de Maturana, Evangelina López; Wu, Xiao-Lin; Gianola, Daniel; Weigel, Kent A; Rosa, Guilherme J M

    2009-01-01

    Structural equation models (SEMs) of a recursive type with heterogeneous structural coefficients were used to explore biological relationships between gestation length (GL), calving difficulty (CD), and perinatal mortality, also known as stillbirth (SB), in cattle, with the last two traits having categorical expression. An acyclic model was assumed, where recursive effects existed from the GL phenotype to the liabilities (latent variables) to CD and SB and from the liability to CD to that of SB considering four periods regarding GL. The data contained GL, CD, and SB records from 90,393 primiparous cows, sired by 1122 bulls, distributed over 935 herd-calving year classes. Low genetic correlations between GL and the other calving traits were found, whereas the liabilities to CD and SB were high and positively correlated, genetically. The model indicated that gestations of approximately 274 days of length (3 days shorter than the average) would lead to the lowest CD and SB and confirmed the existence of an intermediate optimum of GL with respect to these traits.

  16. Field and modeling studies of cyclic carbonates: a predictive tool for petroleum exploration

    Energy Technology Data Exchange (ETDEWEB)

    Read, J.F.

    1989-03-01

    In cyclic sequences containing large numbers of 1 to 10-m carbonate cycles, lack of well-defined markers generally prevents construction of detailed stratigraphic cross sections showing detailed facies changes. Fischer plots that graph cumulative cycle thickness corrected for linear subsidence using average cycle period can be used to correlate sections and show relation of individual cycle types to third-order sea level cycles. Interaction between simple or complex sea level curves defined by various frequencies and amplitudes; the sediment-surface, water-depth dependent sedimentation rate; lag time; and subsidence through time can be shown using one-dimensional models. Isostatically balanced two-dimensional models that incorporate the above variables, plus initial platform slope and thermotectonic subsidence (divided into rotational and regional components), can be used to construct detailed cyclic facies cross sections of carbonate platforms. These can be used to define regional relations between cycles; likely vertical and lateral facies changes; distribution of disconformities, conformities, and tidal-flat caps; relative water depths of facies likely to be developed on the platform; as well as likely location of early diagenesis. The integration of field and modeling studies provides a rigorous analysis of cycle deposition that could be of great predictive value in the exploration and development of petroleum reservoirs.

  17. A mathematical model to explore the interdependence between the serotonin and orexin/hypocretin systems.

    Science.gov (United States)

    Joshi, Alok; Wong-Lin, KongFatt; McGinnity, T Martin; Prasad, Girijesh

    2011-01-01

    Among their multitude of physiological and behavioral effects, the neurochemicals serotonin (5-HT) and orexin (Ox) have been closely linked to major depressive disorders (MDD) and sleep alterations. The dorsal raphe nucleus (DRN) and the lateral hypothalamus area (LHA) are brain regions that are sources of 5-HT and Ox, and there is evidence that suggests a reciprocal interaction between them. This lends support to the hypothesis of a close relationship between MDD and sleep disorders. Based on various experimental data, and appropriate assumptions, we construct a mathematical model of the coupled DRN-LHA neural circuit. Our model relates the dynamics of four important variables that can be experimentally measured: (i) the firing rate of 5-HT-containing neurons in DRN, (ii) the firing rate of Ox-containing neurons in the LHA, (iii) 5-HT concentration level in LHA, and (iv) Ox concentration level in DRN. Simulations show that our model supports the co-existence of baseline activities and concentration levels as observed in various separate experiments. It also allows circuit-level exploration of various parameters not yet identified experimentally, e.g. the rise and decay of Ox concentration levels due to Ox neural activity, and the exact dependence of Ox neural activity on 5-HT level. Finally we have made some model predictions regarding the effects of the 5-HT antagonist on the circuit. Our model, which can be subjected to verification and refinement as new experimental data accumulates, provides unified quantitative relationships and predictions between two important connected brain regions strongly tied to MDD and sleep disorders.

  18. Exploring calibration strategies of the SEDD model in two olive orchard catchments

    Science.gov (United States)

    Burguet, María; Taguas, Encarnación V.; Gómez, José Alfonso

    2017-08-01

    To optimize soil conservation strategies in catchments, it is required an accurate diagnosis of the areas contributing to soil erosion by using models such as SEDD (Sediment Delivery Distributed model). In this study, different calibration strategies of the SEDD model were explored to adapt its use in two olive catchments with different environmental features and managements. A data series of rainfall-runoff-sediment load, collected in the catchments for 6 years was used: i) to evaluate calibration strategies for different management and flow conditions through the analysis of the C and R factors, and ii) to describe the temporal patterns of sediment delivery ratio (SDR) at the event and annual scales. Different results and calibration approaches were derived from contrasting soil features and sediment dynamics in the catchments. A good model performance with simple calibration procedure was obtained for the catchment with clayey soil and a very active gully, whereas the model parameterisation was adapted to event features in the catchment with sandy soil where the importance of concentrated flow was minor. Mean annual values of SDR at the watershed scale (SDRw) were 110.1% for the catchment with clayey soil and 64.1% for that with sandy soils. SDRw values greater than 100% occurred in very humid years with precipitations 30% above the mean annual values. At the event scale, similar behaviours of SDR were observed. SDR > 100% were associated with the gully exporting sediments out from the clayey catchment, whereas this was done by rills and an ephemeral gully in the sandy catchment.

  19. Decision analytic model exploring the cost and cost-offset implications of street triage

    Science.gov (United States)

    Heslin, Margaret; Callaghan, Lynne; Packwood, Martin; Badu, Vincent; Byford, Sarah

    2016-01-01

    Objectives To determine if street triage is effective at reducing the total number of people with mental health needs detained under section 136, and is associated with cost savings compared to usual police response. Design Routine data from a 6-month period in the year before and after the implementation of a street triage scheme were used to explore detentions under section 136, and to populate a decision analytic model to explore the impact of street triage on the cost to the NHS and the criminal justice sector of supporting people with a mental health need. Setting A predefined area of Sussex, South East England, UK. Participants All people who were detained under section 136 within the predefined area or had contact with the street triage team. Interventions The street triage model used here was based on a psychiatric nurse attending incidents with a police constable. Primary and secondary outcome measures The primary outcome was change in the total number of detentions under section 136 between the before and after periods assessed. Secondary analysis focused on whether the additional costs of street triage were offset by cost savings as a result of changes in detentions under section 136. Results Detentions under section 136 in the street triage period were significantly lower than in the usual response period (118 vs 194 incidents, respectively; χ2 (1df) 18.542, ptriage period compared to £1077 in the usual response period. Conclusions Investment in street triage was offset by savings as a result of reduced detentions under section 136, particularly detentions in custody. Data available did not include assessment of patient outcomes, so a full economic evaluation was not possible. PMID:26868943

  20. Global climate modeling of Saturn's atmosphere: exploration of seasonal variability and stratospheric dynamics

    Science.gov (United States)

    Spiga, A.; Guerlet, S.; Millour, E.; Sylvestre, M.; Fouchet, T.; Wordsworth, R.; Leconte, J.; Forget, F.; Hourdin, F.

    2013-12-01

    A leap forward on our knowledge of Saturn's stratosphere has resulted from the combination of orbital observations on board the Cassini spacecraft and state-of-the-art ground-based observations. Maps of temperature and hydrocarbons in Saturn's stratosphere revealed puzzling anomalies: equatorial oscillations with a period of about half a Saturn year, meridional circulations affecting the hydrocarbons' distribution, including possible effects of rings shadowing, "beacons" associated with the powerful 2010 Great White Spot. Those signatures, reminiscent of fundamental wave-driven phenomena in the Earth's middle atmosphere (e.g., Quasi-Biennal Oscillation, Brewer-Dobson circulation), cannot be reproduced by 1D photochemical and radiative models. This motivated us to develop a complete 3D General Circulation Model (GCM) for Saturn, based on the LMDz hydrodynamical core, to explore the circulation, seasonal variability, and wave activity in Saturn's atmosphere. In order to closely reproduce Saturn's radiative forcing, a particular emphasis was put in obtaining fast and accurate radiative transfer calculations. Our radiative model uses correlated-k distributions and spectral discretization tailored for Saturn's atmospheric composition (methane, ethane, acetylene). In addition to this, we include CIA absorption (hydrogen and helium), internal heat flux, ring shadowing, and aerosols. A systematic study is carried out on the sensitivity of the model to spectral discretization, spectroscopic databases, and aerosol scenarios (varying particle sizes, opacities and vertical structures). Temperature fields obtained with this new radiative equilibrium model are compared to that inferred from Cassini/CIRS observations. In the troposphere, our model reproduces the observed temperature knee caused by heating at the top of the tropospheric aerosol layer. In the lower stratosphere, the overall meridional gradient between the summer and the winter hemispheres agrees with observations

  1. Landscape fragmentation and pollinator movement within agricultural environments: a modelling framework for exploring foraging and movement ecology

    Directory of Open Access Journals (Sweden)

    Sean A. Rands

    2014-02-01

    Full Text Available Pollinator decline has been linked to landscape change, through both habitat fragmentation and the loss of habitat suitable for the pollinators to live within. One method for exploring why landscape change should affect pollinator populations is to combine individual-level behavioural ecological techniques with larger-scale landscape ecology. A modelling framework is described that uses spatially-explicit individual-based models to explore the effects of individual behavioural rules within a landscape. The technique described gives a simple method for exploring the effects of the removal of wild corridors, and the creation of wild set-aside fields: interventions that are common to many national agricultural policies. The effects of these manipulations on central-place nesting pollinators are varied, and depend upon the behavioural rules that the pollinators are using to move through the environment. The value of this modelling framework is discussed, and future directions for exploration are identified.

  2. Landscape fragmentation and pollinator movement within agricultural environments: a modelling framework for exploring foraging and movement ecology.

    Science.gov (United States)

    Rands, Sean A

    2014-01-01

    Pollinator decline has been linked to landscape change, through both habitat fragmentation and the loss of habitat suitable for the pollinators to live within. One method for exploring why landscape change should affect pollinator populations is to combine individual-level behavioural ecological techniques with larger-scale landscape ecology. A modelling framework is described that uses spatially-explicit individual-based models to explore the effects of individual behavioural rules within a landscape. The technique described gives a simple method for exploring the effects of the removal of wild corridors, and the creation of wild set-aside fields: interventions that are common to many national agricultural policies. The effects of these manipulations on central-place nesting pollinators are varied, and depend upon the behavioural rules that the pollinators are using to move through the environment. The value of this modelling framework is discussed, and future directions for exploration are identified.

  3. Exploring causal networks of bovine milk fatty acids in a multivariate mixed model context.

    Science.gov (United States)

    Bouwman, Aniek C; Valente, Bruno D; Janss, Luc L G; Bovenhuis, Henk; Rosa, Guilherme J M

    2014-01-17

    Knowledge regarding causal relationships among traits is important to understand complex biological systems. Structural equation models (SEM) can be used to quantify the causal relations between traits, which allow prediction of outcomes to interventions applied to such a network. Such models are fitted conditionally on a causal structure among traits, represented by a directed acyclic graph and an Inductive Causation (IC) algorithm can be used to search for causal structures. The aim of this study was to explore the space of causal structures involving bovine milk fatty acids and to select a network supported by data as the structure of a SEM. The IC algorithm adapted to mixed models settings was applied to study 14 correlated bovine milk fatty acids, resulting in an undirected network. The undirected pathway from C4:0 to C12:0 resembled the de novo synthesis pathway of short and medium chain saturated fatty acids. By using prior knowledge, directions were assigned to that part of the network and the resulting structure was used to fit a SEM that led to structural coefficients ranging from 0.85 to 1.05. The deviance information criterion indicated that the SEM was more plausible than the multi-trait model. The IC algorithm output pointed towards causal relations between the studied traits. This changed the focus from marginal associations between traits to direct relationships, thus towards relationships that may result in changes when external interventions are applied. The causal structure can give more insight into underlying mechanisms and the SEM can predict conditional changes due to such interventions.

  4. Phylogeography and palaeodistribution modelling of Nassauvia subgenus Strongyloma (Asteraceae): exploring phylogeographical scenarios in the Patagonian steppe.

    Science.gov (United States)

    Nicola, Marcela V; Sede, Silvana M; Pozner, Raúl; Johnson, Leigh A

    2014-11-01

    The Patagonian steppe is an immense, cold, arid region, yet phylogeographically understudied. Nassauvia subgen. Strongyloma is a characteristic element of the steppe, exhibiting a continuum of morphological variation. This taxon provides a relevant phylogeographical model not only to understand how past environmental changes shaped the genetic structure of its populations, but also to explore phylogeographical scenarios at the large geographical scale of the Patagonian steppe. Here, we (1) assess demographic processes and historical events that shaped current geographic patterns of haplotypic diversity; (2) analyze hypotheses of isolation in refugia, fragmentation of populations, and/or colonization of available areas during Pleistocene glaciations; and (3) model extant and palaeoclimatic distributions to support inferred phylogeographical patterns. Chloroplast intergenic spacers, rpl32-trnL and trnQ-5'rps16, were sequenced for 372 individuals from 63 populations. Nested clade analysis, analyses of molecular variance, and neutrality tests were performed to assess genetic structure and range expansion. The present potential distribution was modelled and projected onto a last glacial maximum (LGM) model. Of 41 haplotypes observed, ten were shared among populations associated with different morphological variants. Populations with highest haplotype diversity and private haplotypes were found in central-western and south-eastern Patagonia, consistent with long-term persistence in refugia during Pleistocene. Palaeomodelling suggested a shift toward the palaeoseashore during LGM; new available areas over the exposed Atlantic submarine platform were colonized during glaciations with postglacial retraction of populations. A scenario of fragmentation and posterior range expansion may explain the observed patterns in the center of the steppe, which is supported by palaeomodelling. Northern Patagonian populations were isolated from southern populations by the Chubut and the

  5. Geotechnical modelling, classification and exploration for safe and efficient mine layout and tunnel support design

    Energy Technology Data Exchange (ETDEWEB)

    Bigby, D.; Cassie, J.; Kent, L. (and others) [Rock Mechanics Technology, Burton upon Trent (United Kingdom)

    2008-07-01

    Developments and improvements in geochemical modelling, classification and exploration for safe and efficient mine layout and tunnel support design were achieved through rock mass classification, rock testing, underground measurements, seismic system development, improved numerical modelling techniques and application at field study sites. In geotechnical modelling, new constitutive models were proposed for rock creep and stiffness properties. Further advances in rock property representation were achieved for rock mass deformability, definition of the susceptibility of a rock to burning failure and the strength of ground that has failed and then been reconsolidated by grout injection. Approaches were developed to reduce the time necessary to construct 3D modes and to represent pre-tensioning of reinforcement elements and the placement of trusses in roadway reinforcement designs. These improvements were applied within the numerical codes FLAC, FLAC3D and MAP3D. A practical rock mass classification system was developed using data from exploratory drilling and face mapping incorporating the effects of faulting. Using this rock mass classification and measured gate road deformation, a methodology was developed for the predication of roadway deformation. Tests within a 3D laser scanner showed the technology was applicable to recording roadway deformation and geotechnical rock mass classification data although use was restricted as it was not intrinsically safe. A practical seismic system was developed to detect geological disturbances up to 50 m ahead of an advancing roadway. At the case study site where exploratory drilling ahead of the face was undertaken the seismic results correlated well with the location of waster filled disturbances encountered. 76 refs., 83 figs., 15 tabs., 1 app.

  6. Exploration of the seasonal variation of organic aerosol composition using an explicit modeling approach

    Science.gov (United States)

    Ouzebidour, Farida; Camredon, Marie; Stéphanie La, Yuyi; Madronich, Sasha; Taylor, Julia Lee; Hodzic, Alma; Beekmann, Matthias; Siour, Guillaume; Aumont, Bernard

    2014-05-01

    Organic compounds account for a major fraction of fine aerosols in the atmosphere. This organic fraction is dominated by secondary organic aerosol (SOA). Processes leading to SOA formation are however still uncertain and SOA composition is far from being fully characterized. The goals of this study are to evaluate our current understanding of SOA formation and explore its composition. For this purpose, a box-model that describes explicitly processes involved in SOA formation has been developed. This model includes the emission of 183 gaseous and particulate organic compounds. The oxidation of these emitted organic compounds is described using the Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A). Gas/particle partitioning has been implemented considering an ideal homogeneous condensed phase. The generated chemical scheme contains 500,000 species and the gas/particle partitioning is performed for 90,000 of them. Simulations have been performed for summer and winter scenarios representative of continental and urban conditions. NOx and ozone simulated concentrations reproduce the expected winter and summer diurnal evolutions. The predicted organic aerosol composition is a mixture of primary and secondary organic aerosols during the winter and is largely dominated by SOA during the summer.

  7. Exploring the management of bone metastasis according to the Roy Adaptation Model.

    Science.gov (United States)

    Maxwell, T; Givant, E; Kowalski, M O

    2001-08-01

    To explore bone metastasis using Roy's Adaptation Model as a conceptual framework. Published articles, conference abstracts, recent texts, and prescribing information. Bone metastasis has a significant impact on the patient's ability to maintain physical and psychosocial functions. Primary (self), secondary (family and occupation), and tertiary (community) roles, as identified by the Roy Adaptation Model, may be impaired as a result of bone metastasis. Patient education is a nursing intervention that frequently is used, as it allows an individual to interpret an aversive event and take action, thus promoting adaptation to illness. Medications for the underlying disease, bone metastasis, pain, and other symptoms warrant consideration. Active interventions, such as relaxation therapy, guided imagery, music, meditation, and therapeutic touch, also promote adaptation. Bone is a common and potentially debilitating site of metastasis. The presence of bone metastasis indicates progressive and, almost always, incurable disease. Patient adaptation can be enhanced through the proper use of palliative therapies and other nursing measures. Oncology nurses can assist in the physical and psychosocial adaptation of patients with bone metastasis through assessment, patient education, and symptom management.

  8. An Exploration of Scenarios to Support Sustainable Land Management Using Integrated Environmental Socio-economic Models

    Science.gov (United States)

    Fleskens, L.; Nainggolan, D.; Stringer, L. C.

    2014-11-01

    Scenario analysis constitutes a valuable deployment method for scientific models to inform environmental decision-making, particularly for evaluating land degradation mitigation options, which are rarely based on formal analysis. In this paper we demonstrate such an assessment using the PESERA-DESMICE modeling framework with various scenarios for 13 global land degradation hotspots. Starting with an initial assessment representing land degradation and productivity under current conditions, options to combat instances of land degradation are explored by determining: (1) Which technologies are most biophysically appropriate and most financially viable in which locations; we term these the "technology scenarios"; (2) how policy instruments such as subsidies influence upfront investment requirements and financial viability and how they lead to reduced levels of land degradation; we term these the "policy scenarios"; and (3) how technology adoption affects development issues such as food production and livelihoods; we term these the "global scenarios". Technology scenarios help choose the best technology for a given area in biophysical and financial terms, thereby outlining where policy support may be needed to promote adoption; policy scenarios assess whether a policy alternative leads to a greater extent of technology adoption; while global scenarios demonstrate how implementing technologies may serve wider sustainable development goals. Scenarios are applied to assess spatial variation within study sites as well as to compare across different sites. Our results show significant scope to combat land degradation and raise agricultural productivity at moderate cost. We conclude that scenario assessment can provide informative input to multi-level land management decision-making processes.

  9. Theoretical Model of God: The Key to Correct Exploration of the Universe

    Science.gov (United States)

    Kalanov, Temur Z.

    2007-04-01

    The problem of the correct approach to exploration of the Universe cannot be solved if there is no solution of the problem of existence of God (Creator, Ruler) in science. In this connection, theoretical proof of existence of God is proposed. The theoretical model of God -- as scientific proof of existence of God -- is the consequence of the system of the formulated axioms. The system of the axioms contains, in particular, the following premises: (1) all objects formed (synthesized) by man are characterized by the essential property: namely, divisibility into aspects; (2) objects which can be mentally divided into aspects are objects formed (synthesized); (3) the system ``Universe'' is mentally divided into aspects. Consequently, the Universe represents the system formed (synthesized); (4) the theorem of existence of God (i.e. Absolute, Creator, Ruler) follows from the principle of logical completeness of system of concepts: if the formed (synthesized) system ``Universe'' exists, then God exists as the Absolute, the Creator, the Ruler of essence (i.e. information) and phenomenon (i.e. material objects). Thus, the principle of existence of God -- the content of the theoretical model of God -- must be a starting-point and basis of correct gnosiology and science of 21 century.

  10. The Race to Nourish: Exploring resource equity in a coupled human coastline model

    Science.gov (United States)

    Williams, Z. C.; McNamara, D.; Murray, A.; Smith, M.

    2011-12-01

    Many coastal communities are faced with eroding shorelines due to gradients in the alongshore transport of sediment and rising sea level. These communities often employ a beach nourishment mitigation strategy to counter erosion from natural forces. These nourishment activities provide economic benefits in the form of protection from storms and enhanced recreation on the stabilized beach. Previous work has shown that economically optimal nourishment decisions indicate that rising nourishment costs can lead to more frequent nourishment. Given that the cost of nourishing is likely to rise as offshore sediment borrow sites become more scarce, this suggests a positive feedback whereby nourishment that dwindles offshore borrow sites causes more frequent nourishment. We explore the dynamics of this feedback in a coupled economic-coastline model and how resulting long term shoreline and economic patterns respond to forcing changes in the form of increased sea level rise and changing storminess along both a straight shoreline and a cuspate Carolina like shoreline. The economic model utilizes myopic manager agents that inform a community of the optimal nourishment interval based on the current cost of sand and locally observed erosion rate since the last nourishment episode. Communities nourish independently but can affect the erosion rate of adjacent communities through alongshore sediment transport dynamics. The coastline model tracks large-scale coastline change via alongshore sediment transport calculations and erosion due to rising sea level. Model experiments show that when the economic model is coupled to a flat coastline, the feedback in sand cost leads to resource inequity as communities that become caught in the feedback nourish frequently while adjacent communities maintain coastline position by "free riding" on these neighbor towns. Model experiments also show that on cuspate coastlines, the emergent cuspate features enhance the cost feedback and create unequal

  11. Exploring southern African Plateau uplift with landscape evolution model inversion and erosion history data

    Science.gov (United States)

    Stanley, Jessica; Braun, Jean; Flowers, Rebecca; Guillocheau, François; Robin, Cécile; Baby, Guillaume

    2017-04-01

    The southern African plateau is a dominant feature of African topography but there is considerable debate about when and how it formed. Cretaceous kimberlite activity and the presence of a large low shear seismic velocity province (LLSVP) in the deep mantle below southern Africa have lead many to propose uplift related to mantle processes. Better constraints on the timing of uplift have the potential to constrain the nature of the LLSVP and the source of support for southern Africa's anomalous elevations. However, surface uplift is difficult to detect directly in the geologic record and the relationships between mantle-sourced uplift and erosion are not necessarily direct. Here, we use a landscape evolution model combined with data constraining the spatiotemporal erosion patterns across southern Africa to explore how topographic development and erosion are related. This is an ideal location to utilize this approach because several recent studies have helped to constrain the erosion history of this region over different spatial and temporal scales but the uplift history is still widely debated. We integrate a highly efficient landscape evolution model (FastScape, Braun and Willett, 2013) and a thermal module with a large low temperature thermochronology dataset, sedimentary flux volumes for the major offshore basins, and geologic observations to address these questions. We used inversion methods based on the Neighborhood Algorithm to investigate how data is best simulated by the model while varying model parameters related to plateau uplift and the physical characteristics of the eroding material. This is a powerful approach because we are able to compare model outputs to many aspects of topographic shape and constraints on the erosion history simultaneously. Results from the inversions show that the data are sufficient to constrain many model parameters. Additionally, we show that the combination of different types of data, and in particular the spatiotemporal

  12. Exploring optimal air ambulance base locations in Norway using advanced mathematical modelling.

    Science.gov (United States)

    Røislien, Jo; van den Berg, Pieter L; Lindner, Thomas; Zakariassen, Erik; Aardal, Karen; van Essen, J Theresia

    2017-02-01

    Helicopter emergency medical services are an important part of many healthcare systems. Norway has a nationwide physician staffed air ambulance service with 12 bases servicing a country with large geographical variations in population density. The aim of the study was to estimate optimal air ambulance base locations. We used high resolution population data for Norway from 2015, dividing Norway into >300 000 1 km×1 km cells. Inhabited cells had a median (5-95 percentile) of 13 (1-391) inhabitants. Optimal helicopter base locations were estimated using the maximal covering location problem facility location optimisation model, exploring the number of bases needed to cover various fractions of the population for time thresholds 30 and 45 min, both in green field scenarios and conditioning on the current base structure. We reanalysed on municipality level data to explore the potential information loss using coarser population data. For a 45 min threshold, 90% of the population could be covered using four bases, and 100% using nine bases. Given the existing bases, the calculations imply the need for two more bases to achieve full coverage. Decreasing the threshold to 30 min approximately doubles the number of bases needed. Results using municipality level data were remarkably similar to those using fine grid information. The whole population could be reached in 45 min or less using nine optimally placed bases. The current base structure could be improved by moving or adding one or two select bases. Municipality level data appears sufficient for proper analysis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  13. Using the socioecological model to explore factors affecting health-seeking behaviours of older Korean immigrants.

    Science.gov (United States)

    Chung, Jane; Seo, Jin Young; Lee, Jongwon

    2017-10-30

    The purpose of this study was to explore multilevel factors affecting older Korean immigrants' health-seeking behaviours. Although studies have documented significant issues related to healthcare access and utilisation issues among older immigrants, a noted limitation of current research is its failure to explore multiple factors related to their health-seeking behaviours. A qualitative study using interview data from two previous studies. We performed a qualitative analysis of focus groups and individual interviews using inductive coding methods. The socioecological model provided a useful framework to guide this study. The sample included 17 community-dwelling older Korean immigrants aged ≥65 years living in the metropolitan area of Seattle, WA, USA. Findings revealed various factors at the individual (e.g., perception of health and illness, mistrust, cultural values and norms, length of residency in the United States, language barriers and ageing experiences), interpersonal (e.g., peers, family and primary care physicians), community (e.g., ethnic community centres and organisations, home care helpers and interpretation services) and policy (e.g., lack of affordability and health benefits coverage) levels. Each of these factors played a role as either a barrier to or facilitator of older Korean immigrants' health-seeking behaviours. Several factors, such as language barriers and lack of available information, were intertwined. Findings indicate the importance of considering four major areas when designing culturally appropriate, community-based interventions for older immigrants. Also, utilising peers or trusted human resources in the community is critical to the design and implementation of health promotion interventions for older immigrants. Examining intrapersonal, interpersonal, community, and policy level factors that affect older immigrants' health-seeking behaviours informs the design of community-based health promotion interventions for older

  14. Exploring the Causes of Distal Volcano-Tectonic (dVT) Seismicity Using Hydrothermal Modeling

    Science.gov (United States)

    Ingebritsen, S.; Coulon, C.; Hsieh, P. A.; White, R. A.; Lowenstern, J. B.

    2016-12-01

    Based on observation of 111 volcanic eruptions, White and McCausland (JVGR, 2016) found that distal volcano-tectonic (dVT) seismicity typically preceded eruption at long-dormant volcanoes by days to years. They hypothesized that precursory dVT seismicity reflects magma-induced fluid-pressure pulses that intersect critically stressed faults. We explored this idea using the USGS HYDROTHERM model, an open-source magmatic-hydrothermal code that simulates multiphase fluid and heat transport over the temperature range 0 to 1200oC. We examined fluid pressure changes caused by a small (0.04 km3) intrusion into host rock, and explored the effects of coordinate systems (Cartesian vs. radial), magma devolatilization rates (0-15 kg/s), and intrusion depths (5 and 7.5 km, above and below the brittle-ductile transition). Magma and host-rock permeabilities were key controlling parameters and we tested a wide range of permeability (k) and permeability anisotropies (kh/kv), including k constant, k(depth), k(T), and k(depth,T,P) distributions. We examined a total of 1500 realizations to explore the parameter space. Propagation of pressure changes (∆P≥0.1 bars) to the mean dVT location (6 km lateral distance, 6 km depth) was favored by focused fluid flow (i.e. Cartesian geometries), high devolatilization rates, and permeabilities similar to those found in geothermal reservoirs (k 10-16 to 10-13 m2). In Cartesian coordinates we found cases of ∆P ≥ 0.1 bars for every permeability in the range 10-16 to 10-13 m2, whereas in radial coordinates with no devolatilization, ∆P < 0.1 bars occurred for all permeabilities. Changes in distal fluid pressure transpired before proximal changes given modest anisotropies (kh/kv 10-100) typical of layered volcanic rocks. Invoking k(depth,T,P) and high, sustained devolatilization rates caused large dynamic fluctuations in k and P in the near-magma environment but had little effect on pressure changes at the distal dVT location. Intrusion below

  15. Exploring Early Angiosperm Fire Feedbacks using Coupled Experiments and Modelling Approaches to Estimate Cretaceous Palaeofire Behaviour

    Science.gov (United States)

    Belcher, Claire; Hudpsith, Victoria

    2016-04-01

    Using the fossil record we are typically limited to exploring linkages between palaeoecological changes and palaeofire activity by assessing the abundance of charcoals preserved in sediments. However, it is the behaviour of fires that primarily governs their ecological effects. Therefore, the ability to estimate variations in aspects of palaeofire behaviour such as palaeofire intensity and rate of spread would be of key benefit toward understanding the coupled evolutionary history of ecosystems and fire. The Cretaceous Period saw major diversification in land plants. Previously, conifers (gymnosperms) and ferns (pteridophytes) dominated Earth's ecosystems until flowering plants (angiosperms) appear in the fossil record of the Early Cretaceous (~135Ma). We have created surface fire behaviour estimates for a variety of angiosperm invasion scenarios and explored the influence of Cretaceous superambient atmospheric oxygen levels on the fire behaviour occurring in these new Cretaceous ecosystems. These estimates are then used to explore the hypothesis that the early spread of the angiosperms was promoted by the novel fire regimes that they created. In order to achieve this we tested the flammability of Mesozoic analogue fuel types in controlled laboratory experiments using an iCone calorimeter, which measured the ignitability as well as the effective heat of combustion of the fuels. We then used the BehavePlus fire behaviour modelling system to scale up our laboratory results to the ecosystem scale. Our results suggest that fire-angiosperm feedbacks may have occurred in two phases: The first phase being a result of weedy angiosperms providing an additional easily ignitable fuel that enhanced both the seasonality and frequency of surface fires. In the second phase, the addition of shrubby understory fuels likely expanded the number of ecosystems experiencing more intense surface fires, resulting in enhanced mortality and suppressed post-fire recruitment of gymnosperms

  16. Thermal Modelling of Amagmatic Heat Sources as an Exploration Tool for Hot Rock Geothermal Systems

    Science.gov (United States)

    Lescinsky, D. T.; Budd, A. R.; Champion, D. C.; Gerner, E. J.; Kirkby, A. L.

    2012-12-01

    Geothermal resources in Australia are amagmatic, "Hot Rock" systems, and unrelated to active volcanism or plate margin collision. Instead, these resources are typically associated with heat from radioactive decay in high-heat-producing (HHP) granites (granites containing high concentrations of U, Th and K), coupled with thermal insulation from a thick sediment cover. A greater understanding of the ideal geological components of the Hot Rock system is needed to assist geothermal exploration and reduce risk. Existing geothermal data for Australia (borehole temperatures and heat flow determinations) are limited and collection of additional data is both time consuming and restricted to accessing wells drilled for other purposes. To aid in targeting and prioritizing areas for further study (i.e., evaluations of permeabilities and flow rates), GA has undertaken synthetic thermal modelling, constrained by available geological and geophysical datasets. 150,000 discrete numerical simulations were performed using the SHEMAT computer code. The models were designed to explore the range of geological conditions present in Australia and include variations in intrusive geometry and heat production, sediment thickness and thermal conductivity, basement heat production and basal heat flow. In order to facilitate computation and analysis, plutons were modelled as radially symmetrical cylinders and advective heat transfer was considered to be negligible. The results of the synthetic modelling indicate that significant heat can be generated by granites and trapped in geologically realistic conditions. Temperatures >160°C can be produced with heat production values as low as 2.0 μW/m3, but these scenarios require either unusually large pluton diameters (>50 km), low sediment thermal conductivity (0.05 W/m2). The most geologically reasonable conditions that result in temperatures >160°C, are: pluton diameters 30-40 km; heat production of 4.0-5.0 μW/m3; a basal heat flow of 0.04 W/m2

  17. Exploring Host-Microbiome Interactions using an in Silico Model of Biomimetic Robots and Engineered Living Cells.

    Science.gov (United States)

    Heyde, Keith C; Ruder, Warren C

    2015-07-16

    The microbiome's underlying dynamics play an important role in regulating the behavior and health of its host. In order to explore the details of these interactions, we created an in silico model of a living microbiome, engineered with synthetic biology, that interfaces with a biomimetic, robotic host. By analytically modeling and computationally simulating engineered gene networks in these commensal communities, we reproduced complex behaviors in the host. We observed that robot movements depended upon programmed biochemical network dynamics within the microbiome. These results illustrate the model's potential utility as a tool for exploring inter-kingdom ecological relationships. These systems could impact fields ranging from synthetic biology and ecology to biophysics and medicine.

  18. Molecular dynamics simulation: a tool for exploration and discovery using simple models

    Science.gov (United States)

    Rapaport, D. C.

    2014-12-01

    Emergent phenomena share the fascinating property of not being obvious consequences of the design of the system in which they appear. This characteristic is no less relevant when attempting to simulate such phenomena, given that the outcome is not always a foregone conclusion. The present survey focuses on several simple model systems that exhibit surprisingly rich emergent behavior, all studied by molecular dynamics (MD) simulation. The examples are taken from the disparate fields of fluid dynamics, granular matter and supramolecular self-assembly. In studies of fluids modeled at the detailed microscopic level using discrete particles, the simulations demonstrate that complex hydrodynamic phenomena in rotating and convecting fluids—the Taylor-Couette and Rayleigh-Bénard instabilities—can not only be observed within the limited length and time scales accessible to MD, but even allow quantitative agreement to be achieved. Simulation of highly counter-intuitive segregation phenomena in granular mixtures, again using MD methods, but now augmented by forces producing damping and friction, leads to results that resemble experimentally observed axial and radial segregation in the case of a rotating cylinder and to a novel form of horizontal segregation in a vertically vibrated layer. Finally, when modeling self-assembly processes analogous to the formation of the polyhedral shells that package spherical viruses, simulation of suitably shaped particles reveals the ability to produce complete, error-free assembly and leads to the important general observation that reversible growth steps contribute to the high yield. While there are limitations to the MD approach, both computational and conceptual, the results offer a tantalizing hint of the kinds of phenomena that can be explored and what might be discovered when sufficient resources are brought to bear on a problem.

  19. Exploring a Multiresolution Modeling Approach within the Shallow-Water Equations

    Energy Technology Data Exchange (ETDEWEB)

    Ringler, Todd D.; Jacobsen, Doug; Gunzburger, Max; Ju, Lili; Duda, Michael; Skamarock, William

    2011-11-01

    The ability to solve the global shallow-water equations with a conforming, variable-resolution mesh is evaluated using standard shallow-water test cases. While the long-term motivation for this study is the creation of a global climate modeling framework capable of resolving different spatial and temporal scales in different regions, the process begins with an analysis of the shallow-water system in order to better understand the strengths and weaknesses of the approach developed herein. The multiresolution meshes are spherical centroidal Voronoi tessellations where a single, user-supplied density function determines the region(s) of fine- and coarsemesh resolution. The shallow-water system is explored with a suite of meshes ranging from quasi-uniform resolution meshes, where the grid spacing is globally uniform, to highly variable resolution meshes, where the grid spacing varies by a factor of 16 between the fine and coarse regions. The potential vorticity is found to be conserved to within machine precision and the total available energy is conserved to within a time-truncation error. This result holds for the full suite of meshes, ranging from quasi-uniform resolution and highly variable resolution meshes. Based on shallow-water test cases 2 and 5, the primary conclusion of this study is that solution error is controlled primarily by the grid resolution in the coarsest part of the model domain. This conclusion is consistent with results obtained by others.When these variable-resolution meshes are used for the simulation of an unstable zonal jet, the core features of the growing instability are found to be largely unchanged as the variation in the mesh resolution increases. The main differences between the simulations occur outside the region of mesh refinement and these differences are attributed to the additional truncation error that accompanies increases in grid spacing. Overall, the results demonstrate support for this approach as a path toward

  20. Explorable Three-Dimensional Digital Model of the Female Pelvis, Pelvic Contents, and Perineum for Anatomical Education

    Science.gov (United States)

    Sergovich, Aimee; Johnson, Marjorie; Wilson, Timothy D.

    2010-01-01

    The anatomy of the pelvis is complex, multilayered, and its three-dimensional organization is conceptually difficult for students to grasp. The aim of this project was to create an explorable and projectable stereoscopic, three-dimensional (3D) model of the female pelvis and pelvic contents for anatomical education. The model was created using…

  1. Methylglyoxal, the foe and friend of glyoxalase and Trx/TrxR systems in HT22 nerve cells.

    Science.gov (United States)

    Dafre, A L; Goldberg, J; Wang, T; Spiegel, D A; Maher, P

    2015-12-01

    Methylglyoxal (MGO) is a major glycating agent that reacts with basic residues of proteins and promotes the formation of advanced glycation end products (AGEs) which are believed to play key roles in a number of pathologies, such as diabetes, Alzheimer's disease, and inflammation. Here, we examined the effects of MGO on immortalized mouse hippocampal HT22 nerve cells. The endpoints analyzed were MGO and thiol status, the glyoxalase system, comprising glyoxalase 1 and 2 (GLO1/2), and the cytosolic and mitochondrial Trx/TrxR systems, as well as nuclear Nrf2 and its target genes. We found that nuclear Nrf2 is induced by MGO treatment in HT22 cells, as corroborated by induction of the Nrf2-controlled target genes and proteins glutamate cysteine ligase and heme oxygenase 1. Nrf2 knockdown prevented MGO-dependent induction of glutamate cysteine ligase and heme oxygenase 1. The cystine/glutamate antiporter, system xc(-), which is also controlled by Nrf2, was also induced. The increased cystine import (system xc(-)) activity and GCL expression promoted GSH synthesis, leading to increased levels of GSH. The data indicate that MGO can act as both a foe and a friend of the glyoxalase and the Trx/TrxR systems. At low concentrations of MGO (0.3mM), GLO2 is strongly induced, but at high MGO (0.75 mM) concentrations, GLO1 is inhibited and GLO2 is downregulated. The cytosolic Trx/TrxR system is impaired by MGO, where Trx is downregulated yet TrxR is induced, but strong MGO-dependent glycation may explain the loss in TrxR activity. We propose that Nrf2 can be the unifying element to explain the observed upregulation of GSH, GCL, HO1, TrxR1, Trx2, TrxR2, and system xc(-) system activity. Copyright © 2015. Published by Elsevier Inc.

  2. Surface heterogeneity: a friend or foe of protein adsorption - insights from theoretical simulations.

    Science.gov (United States)

    Penna, Matthew; Ley, Kamron; Maclaughlin, Shane; Yarovsky, Irene

    2016-10-06

    A lack in the detailed understanding of mechanisms through which proteins adsorb or are repelled at various solid/liquid interfaces limits the capacity to rationally design and produce more sophisticated surfaces with controlled protein adsorption in both biomedical and industrial settings. To date there are three main approaches to achieve anti biofouling efficacy, namely chemically adjusting the surface hydrophobicity and introducing various degrees of surface roughness, or a combination of both. More recently, surface nanostructuring has been shown to have an effect on protein adsorption. However, the current resolution of experimental techniques makes it difficult to investigate these three phase systems at the molecular level. In this molecular dynamics study we explore in all-atom detail the adsorption process of one of the most surface active proteins, EAS hydrophobin, known for its versatile ability to self-assemble on both hydrophobic and hydrophilic surfaces forming stable monolayers that facilitate further biofilm growth. We model the adsorption of this protein on organic ligand protected silica surfaces with varying degrees of chemical heterogeneity and roughness, including fully homogenous hydrophobic and hydrophilic surfaces for comparison. We present a detailed characterisation of the functionalised surface structure and dynamics for each of these systems, and the effect the ligands have on interfacial water, the adsorption process and conformational rearrangements of the protein. Results suggest that the ligand arrangement that produces the highest hydrophilic chain mobility and the lack of significant hydrophobic patches shows the most promising anti-fouling efficacy toward hydrophobin. However, the presence on the protein surface of a flexible loop with amphipathic character (the Cys3-Cys4 loop) is seen to facilitate EAS adsorption on all surfaces by enabling the protein to match the surface pattern.

  3. Agenda Setting for Health Promotion: Exploring an Adapted Model for the Social Media Era

    Science.gov (United States)

    2015-01-01

    Background The foundation of best practice in health promotion is a robust theoretical base that informs design, implementation, and evaluation of interventions that promote the public’s health. This study provides a novel contribution to health promotion through the adaptation of the agenda-setting approach in response to the contribution of social media. This exploration and proposed adaptation is derived from a study that examined the effectiveness of Twitter in influencing agenda setting among users in relation to road traffic accidents in Saudi Arabia. Objective The proposed adaptations to the agenda-setting model to be explored reflect two levels of engagement: agenda setting within the social media sphere and the position of social media within classic agenda setting. This exploratory research aims to assess the veracity of the proposed adaptations on the basis of the hypotheses developed to test these two levels of engagement. Methods To validate the hypotheses, we collected and analyzed data from two primary sources: Twitter activities and Saudi national newspapers. Keyword mentions served as indicators of agenda promotion; for Twitter, interactions were used to measure the process of agenda setting within the platform. The Twitter final dataset comprised 59,046 tweets and 38,066 users who contributed by tweeting, replying, or retweeting. Variables were collected for each tweet and user. In addition, 518 keyword mentions were recorded from six popular Saudi national newspapers. Results The results showed significant ratification of the study hypotheses at both levels of engagement that framed the proposed adaptions. The results indicate that social media facilitates the contribution of individuals in influencing agendas (individual users accounted for 76.29%, 67.79%, and 96.16% of retweet impressions, total impressions, and amplification multipliers, respectively), a component missing from traditional constructions of agenda-setting models. The influence

  4. Agenda Setting for Health Promotion: Exploring an Adapted Model for the Social Media Era.

    Science.gov (United States)

    Albalawi, Yousef; Sixsmith, Jane

    2015-01-01

    The foundation of best practice in health promotion is a robust theoretical base that informs design, implementation, and evaluation of interventions that promote the public's health. This study provides a novel contribution to health promotion through the adaptation of the agenda-setting approach in response to the contribution of social media. This exploration and proposed adaptation is derived from a study that examined the effectiveness of Twitter in influencing agenda setting among users in relation to road traffic accidents in Saudi Arabia. The proposed adaptations to the agenda-setting model to be explored reflect two levels of engagement: agenda setting within the social media sphere and the position of social media within classic agenda setting. This exploratory research aims to assess the veracity of the proposed adaptations on the basis of the hypotheses developed to test these two levels of engagement. To validate the hypotheses, we collected and analyzed data from two primary sources: Twitter activities and Saudi national newspapers. Keyword mentions served as indicators of agenda promotion; for Twitter, interactions were used to measure the process of agenda setting within the platform. The Twitter final dataset comprised 59,046 tweets and 38,066 users who contributed by tweeting, replying, or retweeting. Variables were collected for each tweet and user. In addition, 518 keyword mentions were recorded from six popular Saudi national newspapers. The results showed significant ratification of the study hypotheses at both levels of engagement that framed the proposed adaptions. The results indicate that social media facilitates the contribution of individuals in influencing agendas (individual users accounted for 76.29%, 67.79%, and 96.16% of retweet impressions, total impressions, and amplification multipliers, respectively), a component missing from traditional constructions of agenda-setting models. The influence of organizations on agenda setting is

  5. Differentiation and Exploration of Model MACP for HE VER 1.0 on Prototype Performance Measurement Application for Higher Education

    Directory of Open Access Journals (Sweden)

    Akbar R. Reza El

    2018-01-01

    Full Text Available Model MACP for HE ver.1. Is a model that describes how to perform measurement and monitoring performance for Higher Education. Based on a review of the research related to the model, there are several parts of the model component to develop in further research, so this research has four main objectives. The first objective is to differentiate the CSF (critical success factor components in the previous model, the two key KPI (key performance indicators exploration in the previous model, the three based on the previous objective, the new and more detailed model design. The final goal is the fourth designed prototype application for performance measurement in higher education, based on a new model created. The method used is explorative research method and application design using prototype method. The results of this study are first, forming a more detailed new model for measurement and monitoring of performance in higher education, differentiation and exploration of the Model MACP for HE Ver.1. The second result compiles a dictionary of college performance measurement by re-evaluating the existing indicators. The third result is the design of prototype application of performance measurement in higher education.

  6. Meteorological predictions for Mars 2020 Exploration Rover high-priority landing sites throug MRAMS Mesoscale Modeling

    Science.gov (United States)

    Pla-García, Jorge; Rafkin, Scot C. R.

    2015-04-01

    The Mars Regional Atmospheric Modeling System (MRAMS) is used to predict meteorological conditions that are likely to be encountered by the Mars 2020 Exploration Rover at several proposed landing sites during entry, descent, and landing (EDL). The meteorology during the EDL window at most of the sites is dynamic. The intense heating of the lower atmosphere drives intense thermals and mesoscale thermal circulations. Moderate mean winds, wind shear, turbulence, and vertical air currents associated with convection are present and potentially hazardous to EDL [1]. Nine areas with specific high-priority landing ellipses of the 2020 Rover, are investigated: NE Syrtis, Nili Fossae, Nili Fossae Carbonates, Jezero Crater Delta, Holden Crater, McLaughlin Crater, Southwest Melas Basin, Mawrth Vallis and East Margaritifer Chloride. MRAMS was applied to the landing site regions using nested grids with a spacing of 330 meters on the innermost grid that is centered over each landing site. MRAMS is ideally suited for this investigation; the model is explicitly designed to simulate Mars' atmospheric thermal circulations at the mesoscale and smaller with realistic, high-resolution surface properties [2, 3]. Horizontal wind speeds, both vertical profiles and vertical cross-sections wind speeds, are studied. For some landing sites simulations, two example configurations -including and not including Hellas basin in the mother domain- were generated, in order to study how the basin affects the innermost grids circulations. Afternoon circulations at all sites pose some risk entry, descent, and landing. Most of the atmospheric hazards are not evident in current observational data and general circulation model simulations and can only be ascertained through mesoscale modeling of the region. Decide where to go first and then design a system that can tolerate the environment would greatly minimize risk. References: [1] Rafkin, S. C. R., and T. I. Michaels (2003), J. Geophys. Res., 108(E12

  7. Exploring the relationship between sustainability and project success - conceptual model and expected relationships

    Directory of Open Access Journals (Sweden)

    Gilbert Silvius

    2016-01-01

    Full Text Available Sustainability is one of the most important challenges of our time. Companies are integrating sustainability in their marketing, communication and their actions. Sustainability has more recently also been linked to project management. The logic behind this link is that sustainability needs change and projects are realizing change. Several studies explored how the concept of sustainability impact project management. The research project reported in this paper elaborates on these works by studying how sustainability affects project success. Project managers, logically, strive for project success and considering sustainability may influence this success. Based upon a review of relevant literature, the paper develops a conceptual model that provides a more detailed understanding of how considering different dimensions of sustainability may affect the individual criteria of project success. The study also provides a conceptual mapping of the different relationships between dimensions of sustainability and criteria of project success. This mapping shows that the most positive relationships are expected for the relationship between sustainability and the success criteria stakeholder satisfaction, future readiness and controlled project execution. The expected relationship between considering sustainability and completing the project on schedule and within budget is uncertain.

  8. Exploring Two-Field Inflation in the Wess-Zumino Model

    CERN Document Server

    Ellis, John; Mulryne, David J

    2014-01-01

    We explore inflation via the effective potential of the minimal Wess-Zumino model, considering both the real and imaginary components of the complex field. Using transport techniques, we calculate the full allowed range of $n_s$, $r$ and $f_{\\rm NL}$ for different choices of the single free parameter, $v$, and present the probability distribution of these signatures given a simple choice for the prior distribution of initial conditions. Our work provides a case study of multi-field inflation in a simple but realistic setting, with important lessons that are likely to apply more generally. For example, we find that there are initial conditions consistent with observations of $n_s$ and $r$ for values of $v$ that would be excluded if only evolutions in the real field direction were to be considered, and that these may yield enhanced values of $f_{\\rm NL}$. Moreover, we find that initial conditions fixed at high energy density, where the potential is close to quartic in form, can still lead to evolutions in a con...

  9. Parental monitoring, parental warmth, and minority youths' academic outcomes: exploring the integrative model of parenting.

    Science.gov (United States)

    Lowe, Katie; Dotterer, Aryn M

    2013-09-01

    Guided by the integrative model of parenting, the present study investigated the relationship between parental monitoring and racial/ethnic minority adolescents' school engagement and academic motivation as a function of parental warmth, and explored whether these associations varied for boys and girls. Participants (60 % female) were 208 sixth through eighth grade students (63 % African American, 19 % Latino, 18 % Multiracial) from an urban middle school in the Midwestern United States. Youth completed an in-school survey with items on parenting (parental monitoring, mothers'/fathers' warmth), cognitive engagement (school self-esteem), behavioral engagement (school trouble), and academic motivation (intrinsic motivation). As hypothesized, mothers' warmth enhanced the association between parental monitoring and youths' engagement and motivation. No gender differences in these associations emerged. Fathers' warmth strengthened the negative association between parental monitoring and school trouble, and this association was stronger for boys. Implications regarding the importance of sustaining a high level of monitoring within the context of warm parent-adolescent relationships to best support academic outcomes among minority youth are discussed.

  10. Estimation of subsurface dielectric target depth for GPR planetary exploration: Laboratory measurements and modeling

    Science.gov (United States)

    Lauro, Sebastian Emanuel; Mattei, Elisabetta; Barone, Pier Matteo; Pettinelli, Elena; Vannaroni, Giuliano; Valerio, Guido; Comite, Davide; Galli, Alessandro

    2013-06-01

    In order to test the accuracy of Ground Penetrating Radar (GPR) in the detection of subsurface targets for planetary exploration, a laboratory scale experiment is performed based on a 'sand box' setup using two different bistatic GPR commercial instruments. Specific attention is paid to the challenging case of buried dielectric scatterers whose location and dimensions are of the same order of magnitude of the GPR antenna separation and signal wavelengths. The target depth is evaluated by using the wave propagation velocity measured with Time Domain Reflectometry (TDR). By means of a proper modeling of the different wave-propagation contributions to the gathered signal, the position of buried targets is correctly estimated with both GPRs even for rather shallow and small-size scatterers in near-field conditions. In this frame, relevant results for a basalt block buried in a silica soil are discussed. The experimental configuration is also simulated with an ad-hoc numerical code, whose synthetic radar sections fully confirm the measured results. The acquired information is of paramount importance for the analysis of various scenarios involving GPR on-site application in future space missions.

  11. An exploration of role model influence on adult nursing students' professional development: A phenomenological research study.

    Science.gov (United States)

    Felstead, Ian S; Springett, Kate

    2016-02-01

    Patients' expectations of being cared for by a nurse who is caring, competent, and professional are particularly pertinent in current health and social care practice. The current drive for NHS values-based recruitment serves to strengthen this. How nursing students' development of professionalism is shaped is not fully known, though it is acknowledged that their practice experience strongly shapes behaviour. This study (in 2013-14) explored twelve adult nursing students' lived experiences of role modelling through an interpretive phenomenological analysis approach, aiming to understand the impact on their development as professional practitioners. Clinical nurses influenced student development consistently. Some students reported that their experiences allowed them to learn how not to behave in practice; a productive learning experience despite content. Students also felt senior staff influence on their development to be strong, citing 'leading by example.' The impact of patients on student professional development was also a key finding. Through analysing information gained, identifying and educating practice-based mentors who are ready, willing, and able to role model professional attributes appear crucial to developing professionalism in nursing students. Those involved in nurse education, whether service providers or universities, may wish to acknowledge the influence of clinical nurse behaviour observed by students both independent of and in direct relation to care delivery and the impact on student nurse professional development. A corollary relates to how students should be guided and briefed/debriefed to work with a staff to ensure their exposure to a variety of practice behaviours. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Exploring EFL Learners’ Attitudes toward the Application of a Model of Writing E-portfolio

    Directory of Open Access Journals (Sweden)

    Aliasghar Yousefi Azarfam

    2016-05-01

    Full Text Available This study aimed to explore the attitudes of two groups of EFL learners toward the application of a model of writing e-portfolio in developing their writing skill. It was a follow-up study to an experiment on the effectiveness of this model on the writing performance of Iranian EFL learners. One group had used certain strategies based on the analytic traits of writing, while the other group had not used such strategies in the writing process. Four class members from each writing e-portfolio group were selected purposively for conducting the semi-structured interviews in this research. The findings showed that members of the group that used strategies based on analytic traits of writing had acquired a sort of awareness towards the different qualities of writing, claiming that knowing about the analytic traits of writing caused them to understand the necessity of paying attention to all aspects of writing and not just the usage and mechanical correctness of it. They referred to the role of Peer Checklist in reminding them of the writing qualities to be considered in their self- and peer-assessment. The results of the learners’ feedback in both e-portfolio groups further revealed that the electronic environment of e-portfolios can play a significant role in facilitating the writing task performance of the learners and consequently improving their writing skill in both e-portfolio groups.  On the whole, the student self-reports indicated that the use of strategies based on analytical traits was able to heighten awareness regarding important aspects of writing.

  13. Cooperation and dialogical modeling for designing a safe Human space exploration mission to Mars

    Science.gov (United States)

    Grès, Stéphane; Tognini, Michel; Le Cardinal, Gilles; Zalila, Zyed; Gueydan, Guillaume

    2014-11-01

    This paper proposes an approach for a complex and innovative project requiring international contributions from different communities of knowledge and expertise. Designing a safe and reliable architecture for a manned mission to Mars or the Asteroids necessitates strong cooperation during the early stages of design to prevent and reduce risks for the astronauts at each step of the mission. The stake during design is to deal with the contradictions, antagonisms and paradoxes of the involved partners for the definition and modeling of a shared project of reference. As we see in our research which analyses the cognitive and social aspects of technological risks in major accidents, in such a project, the complexity of the global organization (during design and use) and the integration of a wide and varie d range of sciences and innovative technologies is likely to increase systemic risks as follows: human and cultural mistakes, potential defaults, failures and accidents. We identify as the main danger antiquated centralized models of organization and the operational limits of interdisciplinarity in the sciences. Beyond this, we can see that we need to take carefully into account human cooperation and the quality of relations between heterogeneous partners. Designing an open, self-learning and reliable exploration system able to self-adapt in dangerous and unforeseen situations implies a collective networked intelligence led by a safe process that organizes interaction between the actors and the aims of the project. Our work, supported by the CNES (French Space Agency), proposes an innovative approach to the coordination of a complex project.

  14. Exploring the usefulness of a simple linear regression model for understanding price movements of selected recycled materials in UK.

    OpenAIRE

    Angus, Andrew; Rivas Casado, Monica; Fitzsimons, D

    2012-01-01

    The price volatility of recycled materials exposes many different organisations to financial and regulatory risk. These risks can be partially mitigated by improved understanding of price volatility using econometric models, although these have tended to be sophisticated autoregressive models, beyond the analytical capability or cost structure of the average market participant. In this context, this study explores the use of a simple linearregression model to understand the ...

  15. Water ice clouds on Mars: Exploring processes through modeling and laboratory work

    Science.gov (United States)

    Santiago-Materese, Delia Liza

    Water ice clouds on Mars are an important component of the hydrologic cycle as well as the overall climate system of the planet. The goal of this research is to better understand water ice cloud formation and behavior on Mars. We use modeling and laboratory experiments to explore different processes related to water ice cloud formation and evolution. The first goal of this work is to examine how well the Martian water cycle is simulated by the NASA Ames Mars General Circulation Model. The simulation predicts atmospheric water vapor amounts approximately half of those observed, globally. We identify water ice clouds as being a major contributor to this discrepancy. The model closely reproduces the convective aphelion cloud belt at the equator, but deviates substantially from observations over the North Polar Cap region. Modifying the nucleation scheme within the cloud microphysical model brings model results closer to observations and affects the surface radiative balance, which affects the annual cycle of sublimation and deposition of water ice at the residual North Polar Cap. The most realistic global water vapor and cloud patterns come from limiting the nucleation rate of particles at the poles. Our simulations show that the North Polar Cap region exhibits atmospheric dynamics where stratiform clouds form. We hypothesize that the modified nucleation scheme compensates for biases in the radiative properties of the stratiform clouds expected over the North Polar Cap. More broadly, this study illustrates the strong sensitivity of the Martian global water cycle to clouds over the North Polar Cap region. The second goal of this work is to assess the ability of various salts to serve as water ice cloud condensation nuclei under Martian conditions. We use a vacuum chamber to simulate the cold, lower pressure atmospheric conditions on Mars and find the critical saturation ratios at which the substrates nucleate water ice. We find no significant difference between sodium

  16. Management interventions in dairy herds: exploring within herd uncertainty using an integrated Bayesian model.

    Science.gov (United States)

    Green, Martin J; Medley, Graham F; Bradley, Andrew J; Browne, William J

    2010-01-01

    Knowledge of the efficacy of an intervention for disease control on an individual farm is essential to make good decisions on preventive healthcare, but the uncertainty in outcome associated with undertaking a specific control strategy has rarely been considered in veterinary medicine. The purpose of this research was to explore the uncertainty in change in disease incidence and financial benefit that could occur on different farms, when two effective farm management interventions are undertaken. Bovine mastitis was used as an example disease and the research was conducted using data from an intervention study as prior information within an integrated Bayesian simulation model. Predictions were made of the reduction in clinical mastitis within 30 days of calving on 52 farms, attributable to the application of two herd interventions previously reported as effective; rotation of dry cow pasture and differential dry cow therapy. Results indicated that there were important degrees of uncertainty in the predicted reduction in clinical mastitis for individual farms when either intervention was undertaken; the magnitude of the 95% credible intervals for reduced clinical mastitis incidence were substantial and of clinical relevance. The large uncertainty associated with the predicted reduction in clinical mastitis attributable to the interventions resulted in important variability in possible financial outcomes for each farm. The uncertainty in outcome associated with farm control measures illustrates the difficulty facing a veterinary clinician when making an on-farm decision and highlights the importance of iterative herd health procedures (continual evaluation, reassessment and adjusted interventions) to optimise health in an individual herd. INRA, EDP Sciences, 2009

  17. Exploration of Novel Human Tyrosinase Inhibitors by Molecular Modeling, Docking and Simulation Studies.

    Science.gov (United States)

    Hassan, Mubashir; Ashraf, Zaman; Abbas, Qamar; Raza, Hussain; Seo, Sung-Yum

    2016-04-21

    Research studies on human tyrosinase inhibitors and exploration for better cytotoxic agents remain an important line in drug discovery and development at the present time. Recently, multiple inhibitors are being used to cure melanogenesis by targeting human tyrosinase. A series of coumarin (C1-C9)-, thymol (T1-T8)- and vanillin (V1-V8)-based derivatives have been theoretically analyzed for their inhibitory effects against human tyrosinase. The crystal structure of human tyrosinase is not available in Protein Data Bank. Therefore, homology modeling approach was used to predict three-dimensional (3D) crystal structure of human tyrosinase. The reliability and efficacy of predicted 3D structure were validated by using Ramachandran plots which indicate that 95.01 % residues are present in favored regions. Moreover, multiple computational approaches such as molecular docking and molecular dynamic (MD) simulation along with various online tools were employed to screen the best inhibitor against melanogenesis. The results revealed that V7 and C9 compounds showed significant binding energy values (-7.79 and -7.40 kcal/mol, respectively) compared with the standard drugs such as kojic acid (-4.21 kcal/mol) and arbutin (-4.62 kcal/mol). Moreover, MD simulation results also justified that V7 showed little fluctuations throughout the simulation period as depicted by the root mean square deviation and root mean square fluctuation graphs. Thus, the present in silico study provides a deeper insight into the structural attributes of V7 compound and its overall molecular interactions against human tyrosinase and gives a hypothetical gateway to use this compound as a potential inhibitor against melanogenesis.

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

    Science.gov (United States)

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

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

  19. The development of a mouse model to explore resistance and susceptibility to early Ascaris suum infection.

    Science.gov (United States)

    Lewis, R; Behnke, J M; Stafford, P; Holland, C V

    2006-02-01

    Ascaris suum and Ascaris lumbricoides exhibit an over-dispersed frequency distribution in their host populations in both the adult and larval stages. The impact of host factors on this observed distribution is still poorly understood and difficult to investigate in the natural host populations. The use of a mouse model has been supported by the observations that the larval migratory pattern, in this host, mimics the pattern observed in the pig. We explored the extrinsic factors that might affect the quantitative recovery of larvae during this migration in order to standardize a model system facilitating accurate future assessment of host genetic variation on this phase of the infection. In Exp. 1 larvae accumulated in the livers of both C57BL/6j and BALB/c mice up to and including days 4-5 p.i. and then declined in both strains until day 9. Loss of larvae from the livers corresponded to arrival in the lungs and maximum accumulation on day 7 p.i. but recovery was considerably higher in C57BL/6j mice. It was concluded that day 7 recoveries gave the best indication of relative resistance/susceptibility to this parasite. In Exp. 2 A/J, BALB/c, CBA/Ca, C57BL/6j, C3H/HeN, DBA/2, NIH, SJL, and SWR mice were compared. C57BL/6j mice were identified as the most susceptible strain and CBA/Ca mice as having the most contrasting phenotype, but with a similar kinetic pattern of migration. Finally, in Exp. 3, a strong positive correlation between the size of the inoculum and the mean worm recovery from the lungs was found in CBA/Ca and C57BL/6j mice, but the difference between these strains was highly consistent, 66.6-80%, regardless of the initial dose. These results demonstrate that, using our protocols for infection and recovery, between-experiment variation in A. suum worm burdens is minimal, and that C57BL/6j mice are highly susceptible to infection compared to other strains. The mechanistic basis of this susceptibility in relation to the resistance of other strains is

  20. Friends or foes ? : predictors of treatment outcome of cognitieve behavioral therapy for childhood anxiety disorders

    NARCIS (Netherlands)

    Liber, Juliëtte Margo

    2008-01-01

    The present dissertation had as its central focus the prediction of outcome of the treatment of childhood anxiety disorders. In the present study a selection of variables that were thought to have prognostic validity for successful cognitive behavioral treatment (CBT) outcome were explored in a

  1. Neural-network-based prediction techniques for single station modeling and regional mapping of the foF2 and M(3000F2 ionospheric characteristics

    Directory of Open Access Journals (Sweden)

    T. D. Xenos

    2002-01-01

    Full Text Available In this work, Neural-Network-based single-station hourly daily foF2 and M(3000F2 modelling of 15 European ionospheric stations is investigated. The data used are neural networks and hourly daily values from the period 1964- 1988 for training the neural networks and from the period 1989-1994 for checking the prediction accuracy. Two types of models are presented for the F2-layer critical frequency prediction and two for the propagation factor M(3000F2. The first foF2 model employs the E-layer local noon calculated daily critical frequency (foE12 and the local noon F2- layer critical frequency of the previous day. The second foF2 model, which introduces a new regional mapping technique, employs the Juliusruh neural network model and uses the E-layer local noon calculated daily critical frequency (foE12, and the previous day F2-layer critical frequency measured at Juliusruh at noon. The first M(3000F2 model employs the E-layer local noon calculated daily critical frequency (foE12, its ± 3 h deviations and the local noon cosine of the solar zenith angle (cos c12. The second model, which introduces a new M(3000F2 mapping technique, employs Juliusruh neural network model and uses the E-layer local noon calculated daily critical frequency (foE12, and the previous day F2-layer critical frequency measured at Juliusruh at noon.

  2. Exploring the relationship of threshold concepts and Hodges’ model of care from the individual to populations and global health

    Directory of Open Access Journals (Sweden)

    Peter Jones

    2017-09-01

    How to cite this article: Jones P. Exploring the relationship of threshold concepts and Hodges’ model of care from the individual to populations and global health. Rev Cuid. 2017; 8(3: 1697-720.  http://dx.doi.org/10.15649/cuidarte.v8i3.464

  3. Exploration of the Growing Trend of Electric Vehicles in Beijing with System Dynamics method and Vensim model

    NARCIS (Netherlands)

    Zhang, C.; Qin, C.

    2014-01-01

    This research is conducted to explore the growing trend of private vehicles in Beijing, China, in the coming 25 years using the system dynamics (SD) method. The vensim software is used to build the SD model and do simulations. First, the paper introduces the background of the private vehicles in

  4. Exploring options for sustainable farming systems development for vegetable family farmers in Uruguay using a modeling toolkit

    NARCIS (Netherlands)

    Casagrande, M.; Dogliotti, S.; Groot, J.C.J.; Aguerre, V.; Abbas, A.; Albin, A.; Claassen, G.D.H.; Chilibroste, P.; Rossing, W.A.H.

    2010-01-01

    Economic and environmental sustainability of family-based vegetable production systems in south Uruguay are seriously compromised after two decades of net decreasing prices and strategies based on specialization and intensification. This paper presents a model-based exploration of alternative

  5. Individual differences in teacher development : An exploration of the applicability of a stage model to assess individual teachers

    NARCIS (Netherlands)

    van der Lans, Rikkert M.; van de Grift, Wim J.C.M.; van Veen, Klaas

    Researchers have recently become interested in exploring cumulative order in teachers’ use of teaching practices, which they argue may reflect stages in teacher development. However, to validly apply stage models to individuals, it is necessary to determine whether all teachers fit the stage order.

  6. Exploring the Effects of Managerial Ownership on the Decision to Go Private: A Behavioral Agency Model Approach

    Science.gov (United States)

    Valenti, Alix; Schneider, Marguerite

    2012-01-01

    This paper utilizes the behavioral agency model to investigate why many formerly public companies have been converted to privately held corporations. Using a matched pairs sample and categorical binary regression, and controlling for effects found in previous studies, we explore how the equity ownership of those entrusted to manage firms, the…

  7. Exploring the Attitudes of Parents of Young Children with Autism Towards the TEACCH Conceptual Model: A Narrative Case Study

    Science.gov (United States)

    Powell, Natalie Lynne

    2012-01-01

    The purpose of this dissertation is to explore the attitudes of parents of young children with autism towards the Treatment and Education of Autistic and related Communication Handicapped Children Program's (TEACCH) conceptual model, known as the Culture of Autism. One primary research question guided the study: What are the attitudes of…

  8. Exploring the MACH Model's Potential as a Metacognitive Tool to Help Undergraduate Students Monitor Their Explanations of Biological Mechanisms

    Science.gov (United States)

    Trujillo, Caleb M.; Anderson, Trevor R.; Pelaez, Nancy J.

    2016-01-01

    When undergraduate biology students learn to explain biological mechanisms, they face many challenges and may overestimate their understanding of living systems. Previously, we developed the MACH model of four components used by expert biologists to explain mechanisms: Methods, Analogies, Context, and How. This study explores the implementation of…

  9. Coupled economic-ecological models for ecosystem-based fishery management: Exploration of trade-offs between model complexity and management needs

    DEFF Research Database (Denmark)

    Thunberg, Eric; Holland, Dan; Nielsen, J. Rasmus

    2012-01-01

    and parameterize them is greater and these models tend to require trade-offs such as the inability to quantify uncertainty or model human behaviour as accurately as can be done with models of individual fisheries. The theme session was organized as a moderated panel format representing a progression of economic......Ecosystem based fishery management has moved beyond rhetorical statements calling for a more holistic approach to resource management, to implementing decisions on resource use that are compatible with goals of maintaining ecosystem health and resilience. Coupled economic-ecological models...... are a primary tool for informing these decisions. Recognizing the importance of these models, the International Council for the Exploration of the Seas (ICES) formed a Study Group on Integration of Economics, Stock Assessment and Fisheries Management (SGIMM) to explore alternative modelling approaches...

  10. A review of models in support of oil and gas exploration off the north coast of British Columbia

    Energy Technology Data Exchange (ETDEWEB)

    Foreman, M.G.G.; Beauchemin, L.; Cherniawsky, J.Y.; Pena, M.A.; Cummins, P.F.; Sutherland, G.

    2005-07-01

    This report presents a timely review of numerical models that are needed to address scientific and environmental issues pertaining to the removal of the moratorium on offshore oil and gas exploration in northern British Columbia. Comprehensive ocean measurements and computer models are needed to obtain information of oceanic flows for the waters off British Columbia where the coastline is highly irregular with a variable bathymetry and a circulation that is driven by tides, wind and buoyancy forces. Numerical ocean models can clarify ocean processes by interpolating these observations and by providing a detailed and realistic view of the ocean. One of the challenges facing ocean modelling within the coastal environment is sub-grid scale parameterization. The objectives for modelling ocean circulation are to represent past events, predict future events and provide a better understanding of the underlying dynamics. The candidate circulation models presented in this report are the Princeton Ocean Model, the Eulerian-Lagrangian Circulation and Semi-Implicit Eulerian-Lagrangian Finite Element model, and the Regional Ocean Modeling System. Forecasting models are needed in the event that sufficient hydrocarbon reserves are found to warrant production. Specific recommendations are made for circulation, ecosystem, oil spill and drilling mud models. The models predict the physical, chemical and biological interactions that will alter the properties of oil or drilling muds once they are introduced into the ocean, as wells as the pathways by which they move in the environment. The report also pursues complementary needs for more observations to validate these modes and for the development of both high resolution surface wave model and a high resolution atmosphere model. It is expected that these recommendations will assist in the development of future science programs associated with oil and gas exploration. 179 refs., 2 tabs., 7 figs., 2 appendices.

  11. Modeling, construction and experimental validation of actuated rolling dynamics of the cylindrical Transforming Roving-Rolling Explorer (TRREx)

    Science.gov (United States)

    Edwin, L.; Mazzoleni, A.; Gemmer, T.; Ferguson, S.

    2017-03-01

    Planetary surface exploration technology over the past few years has seen significant advancements on multiple fronts. Robotic exploration platforms are becoming more sophisticated and capable of embarking on more challenging missions. More unconventional designs, particularly transforming architectures that have multiple modes of locomotion, are being studied. This work explores the capabilities of one such novel transforming rover called the Transforming Roving-Rolling Explorer (TRREx). Biologically inspired by the armadillo and the golden-wheel spider, the TRREx has two modes of locomotion: it can traverse on six wheels like a conventional rover on benign terrain, but can transform into a sphere when necessary to negotiate steep rugged slopes. The ability to self-propel in the spherical configuration, even in the absence of a negative gradient, increases the TRREx's versatility and its concept value. This paper describes construction and testing of a prototype cylindrical TRREx that demonstrates that "actuated rolling" can be achieved, and also presents a dynamic model of this prototype version of the TRREx that can be used to investigate the feasibility and value of such self-propelled locomotion. Finally, we present results that validate our dynamic model by comparing results from computer simulations made using the dynamic model to experimental results acquired from test runs using the prototype.

  12. A Grammar-based Approach for Modeling User Interactions and Generating Suggestions During the Data Exploration Process.

    Science.gov (United States)

    Dabek, Filip; Caban, Jesus J

    2017-01-01

    Despite the recent popularity of visual analytics focusing on big data, little is known about how to support users that use visualization techniques to explore multi-dimensional datasets and accomplish specific tasks. Our lack of models that can assist end-users during the data exploration process has made it challenging to learn from the user's interactive and analytical process. The ability to model how a user interacts with a specific visualization technique and what difficulties they face are paramount in supporting individuals with discovering new patterns within their complex datasets. This paper introduces the notion of visualization systems understanding and modeling user interactions with the intent of guiding a user through a task thereby enhancing visual data exploration. The challenges faced and the necessary future steps to take are discussed; and to provide a working example, a grammar-based model is presented that can learn from user interactions, determine the common patterns among a number of subjects using a K-Reversible algorithm, build a set of rules, and apply those rules in the form of suggestions to new users with the goal of guiding them along their visual analytic process. A formal evaluation study with 300 subjects was performed showing that our grammar-based model is effective at capturing the interactive process followed by users and that further research in this area has the potential to positively impact how users interact with a visualization system.

  13. Models of Recognition, Repetition Priming, and Fluency : Exploring a New Framework

    Science.gov (United States)

    Berry, Christopher J.; Shanks, David R.; Speekenbrink, Maarten; Henson, Richard N. A.

    2012-01-01

    We present a new modeling framework for recognition memory and repetition priming based on signal detection theory. We use this framework to specify and test the predictions of 4 models: (a) a single-system (SS) model, in which one continuous memory signal drives recognition and priming; (b) a multiple-systems-1 (MS1) model, in which completely…

  14. Exploring Pre-Service Elementary Teachers' Mental Models of the Environment

    Science.gov (United States)

    Taskin-Ekici, Fatma; Ekici, Erhan; Cokadar, Hulusi

    2015-01-01

    This study aims to explore pre-service elementary teachers' understandings of the environment. A survey method was carried out in this study. A close-ended questionnaire and Draw-An-Environment Test (DAET) are administered to pre-service teachers (N = 255) after instruction of an Environmental Education course. A rubric (DAET-R) is used for…

  15. Beliefs, Practices, and Reflection: Exploring a Science Teacher's Classroom Assessment through the Assessment Triangle Model

    Science.gov (United States)

    Lyon, Edward G.

    2011-01-01

    This paper describes the Assessment Practices Framework and how I used it to study a high school Chemistry teacher as she designed, implemented, and learned from a chemistry lab report. The framework consists of exploring three teacher-centered components of classroom assessment (assessment beliefs, practices, and reflection) and analyzing…

  16. A reanalysis of a behavioral intervention to prevent incident HIV infections: including indirect effects in modeling outcomes of Project EXPLORE.

    Science.gov (United States)

    Eaton, Lisa A; Kalichman, Seth C; Kenny, David A; Harel, Ofer

    2013-01-01

    Project EXPLORE - a large-scale, behavioral intervention tested among men who have sex with men (MSM) at-risk for HIV infection - was generally deemed as ineffective in reducing HIV incidence. Using novel and more precise data analytic techniques we reanalyzed Project EXPLORE by including both direct and indirect paths of intervention effects. Data from 4296 HIV-negative MSM who participated in Project EXPLORE, which included 10 sessions of behavioral risk reduction counseling completed from 1999 to 2005, were included in the analysis. We reanalyzed the data to include parameters that estimate the over-time effects of the intervention on unprotected anal (UA) sex and the over-time effects of the intervention on HIV status mediated by UA sex simultaneously in a single model. We found the indirect effect of intervention on HIV infection through UA sex to be statistically significant up through 12-month post-intervention, OR = 0.83, 95% CI = 0.72-0.95. Furthermore, the intervention significantly reduced UA sex up through 18-month post-intervention, OR = 0.79, 95% CI = 0.63-0.99. Our results reveal effects not tested in the original model that offer new insight into the effectiveness of a behavioral intervention for reducing HIV incidence. Project EXPLORE demonstrated that when tested against an evidence-based, effective control condition can result in reductions in rates of HIV acquisition at one year follow-up. Findings highlight the critical role of addressing behavioral risk reduction counseling in HIV prevention.

  17. How much cryosphere model complexity is just right? Exploration using the conceptual cryosphere hydrology framework

    Directory of Open Access Journals (Sweden)

    T. M. Mosier

    2016-09-01

    Full Text Available Making meaningful projections of the impacts that possible future climates would have on water resources in mountain regions requires understanding how cryosphere hydrology model performance changes under altered climate conditions and when the model is applied to ungaged catchments. Further, if we are to develop better models, we must understand which specific process representations limit model performance. This article presents a modeling tool, named the Conceptual Cryosphere Hydrology Framework (CCHF, that enables implementing and evaluating a wide range of cryosphere modeling hypotheses. The CCHF represents cryosphere hydrology systems using a set of coupled process modules that allows easily interchanging individual module representations and includes analysis tools to evaluate model outputs. CCHF version 1 (Mosier, 2016 implements model formulations that require only precipitation and temperature as climate inputs – for example variations on simple degree-index (SDI or enhanced temperature index (ETI formulations – because these model structures are often applied in data-sparse mountain regions, and perform relatively well over short periods, but their calibration is known to change based on climate and geography. Using CCHF, we implement seven existing and novel models, including one existing SDI model, two existing ETI models, and four novel models that utilize a combination of existing and novel module representations. The novel module representations include a heat transfer formulation with net longwave radiation and a snowpack internal energy formulation that uses an approximation of the cold content. We assess the models for the Gulkana and Wolverine glaciated watersheds in Alaska, which have markedly different climates and contain long-term US Geological Survey benchmark glaciers. Overall we find that the best performing models are those that are more physically consistent and representative, but no single model performs

  18. Beneficial effects of magnesium in chronic renal failure: a foe no longer.

    Science.gov (United States)

    Tzanakis, Ioannis P; Oreopoulos, Dimitrios G

    2009-01-01

    Magnesium plays a critical role in cellular physiology in humans, regulating many fundamental functions. In the general population its deficiency is associated with many disorders, the most significant being cardiovascular diseases. The role of magnesium in many aspects of end-stage renal disease (ESRD) may be also very important, although this has not been explored in depth. The most significant of these roles are use of magnesium salts as phosphate binders and its ability to inhibit the development or progression of vascular calcification. Moreover, serum magnesium suppresses parathyroid hormone excretion, whereas high magnesium dialysate may result in intradialytic hemodynamic stability. Data provided by recent studies on these issues have promoted promising renewed interest in the role of magnesium in ESRD and its possible favorable therapeutic application in these patients. Further large studies are needed to establish its efficacy and safety, and, probably, to re-evaluate its appropriate concentration in hemodialysis and continuous ambulatory peritoneal dialysis (CAPD) fluids.

  19. Positive feedback : exploring current approaches in iterative travel demand model implementation.

    Science.gov (United States)

    2012-01-01

    Currently, the models that TxDOTs Transportation Planning and Programming Division (TPP) developed are : traditional three-step models (i.e., trip generation, trip distribution, and traffic assignment) that are sequentially : applied. A limitation...

  20. Exploring the Relationship Between Business Model Innovation, Corporate Sustainability, and Organisational Values within the Fashion Industry

    DEFF Research Database (Denmark)

    Pedersen, Esben Rahbek Gjerdrum; Gwozdz, Wencke; Hvass, Kerli Kant

    2016-01-01

    The objective of this paper is to examine the relationship between business model innovation, corporate sustainability, and the underlying organisational values. Moreover, the paper examines how the three dimensions correlate with corporate financial performance. It is concluded that companies...... with innovative business models are more likely to address corporate sustainability and that business model innovation and corporate sustainability alike are typically found in organisations rooted in values of flexibility and discretion. Business model innovation and corporate sustainability thus seem to have...

  1. Future extreme events in European climate: An exploration of regional climate model projections

    DEFF Research Database (Denmark)

    Beniston, M.; Stephenson, D.B.; Christensen, O.B.

    2007-01-01

    regions of Holland, Germany and Denmark, in particular. These results are found to depend to different degrees on model formulation. While the responses of heat waves are robust to model formulation, the magnitudes of changes in precipitation and wind speed are sensitive to the choice of regional model...

  2. Exploring nonlinear subgrid-scale models and new characteristic length scales for large-eddy simulation

    NARCIS (Netherlands)

    Silvis, Maurits H.; Trias, F. Xavier; Abkar, M.; Bae, H.J.; Lozano-Duran, A.; Verstappen, R.W.C.P.; Moin, Parviz; Urzay, Javier

    2016-01-01

    We study subgrid-scale modeling for large-eddy simulation of anisotropic turbulent flows on anisotropic grids. In particular, we show how the addition of a velocity-gradient-based nonlinear model term to an eddy viscosity model provides a better representation of energy transfer. This is shown to

  3. Applying a system dynamics modelling approach to explore policy options for improving neonatal health in Uganda

    OpenAIRE

    Semwanga, Agnes Rwashana; Nakubulwa, Sarah; Adam, Taghreed

    2016-01-01

    Background The most recent reports on global trends in neonatal mortality continue to show alarmingly slow progress on improvements in neonatal mortality rates, with sub-Saharan Africa still lagging behind. This emphasised the urgent need to innovatively employ alternative solutions that take into account the intricate complexities of neonatal health and the health systems in which the various strategies operate. Methods In our first paper, we empirically explored the causes of the stagnating...

  4. Agenda Setting for Health Promotion: Exploring an Adapted Model for the Social Media Era

    OpenAIRE

    Albalawi, Yousef; Sixsmith, Jane

    2015-01-01

    Background The foundation of best practice in health promotion is a robust theoretical base that informs design, implementation, and evaluation of interventions that promote the public?s health. This study provides a novel contribution to health promotion through the adaptation of the agenda-setting approach in response to the contribution of social media. This exploration and proposed adaptation is derived from a study that examined the effectiveness of Twitter in influencing agenda setting ...

  5. Drilling Load Model of an Inchworm Boring Robot for Lunar Subsurface Exploration

    OpenAIRE

    Weiwei Zhang; Shengyuan Jiang; Dewei Tang; Huazhi Chen; Jieneng Liang

    2017-01-01

    In the past decade, the wireline robot has received increasing attention due to the advantages of light weight, low cost, and flexibility compared to the traditional drilling instruments in space missions. For the lunar subsurface in situ exploration mission, we proposed a type of wireline robot named IBR (Inchworm Boring Robot) drawing inspiration from the inchworm. Two auger tools are utilized to remove chips for IBR, which directly interacted with the lunar regolith in the drilling process...

  6. A Review of the Experimental and Modeling Development of a Water Phase Change Heat Exchanger for Future Exploration Support Vehicles

    Science.gov (United States)

    Cognata, Thomas; Leimkuehler, Thomas; Ramaswamy, Balasubramaniam; Nayagam, Vedha; Hasan, Mohammad; Stephan, Ryan

    2011-01-01

    Water affords manifold benefits for human space exploration. Its properties make it useful for the storage of thermal energy as a Phase Change Material (PCM) in thermal control systems, in radiation shielding against Solar Particle Events (SPE) for the protection of crew members, and it is indisputably necessary for human life support. This paper envisions a single application for water which addresses these benefits for future exploration support vehicles and it describes recent experimental and modeling work that has been performed in order to arrive at a description of the thermal behavior of such a system. Experimental units have been developed and tested which permit the evaluation of the many parameters of design for such a system with emphasis on the latent energy content, temperature rise, mass, and interstitial material geometry. The experimental results are used to develop a robust and well correlated model which is intended to guide future design efforts toward the multi-purposed water PCM heat exchanger envisioned.

  7. Exploration concept and characteristic of the dinarides stratigraphic and structural model in the Croatian offshore area

    Energy Technology Data Exchange (ETDEWEB)

    Grandic, S. (Western Geophysical, Isleworth, Middlesex (United Kingdom)); Susterciv, M.; Balas, E. (Ina-Naftaplin, Zagreb (Croatia))

    1993-09-01

    The Dinarides Mesozoic carbonate platform constitutes an extensive paleogeographic unit of the Neo-Tethys platform system. Despite a large sedimentary complex within the platform displaying good hydrocarbon potential, no economic oil accumulations have as yet been discovered. A detailed study of the latest seismic and well data from the Kornati block and other relevant areas suggests, however, that a modified exploration scenario, based on the following elements, could be proposed: (1) Systematic lateral distribution of potential petroliferous facies between the Istrian-Dalmatian marginal zones and the central zone of the external Dinarides. Also, evidence of regular facies changes during platform evolution. (2) Paleotectonic control of varying depositional environments. These range from extremely restricted (anoxic) conditions, to high-energy zones on the platform margins and the edges of intraplatform basins and lagoons. (3) A link between the structural style of the final platform carbonates and the underlying Permian-Triassic halokinetic deposits. This relationship occurred during the Apulia microplate collision and shearing. (4) Differential platform subsidence and burial of potential source rock during platform evolution. Also, post-platform flysch and Molasse sedimentation. (5) Rotational displacement of potential hydrocarbon reservoirs away from the conventional target of exploratory drilling. An acceptance of the above-mentioned elements, particularly the rotation concept, could contribute toward developing a more effective exploration strategy. This should involve seismostratigraphic and other refined exploration methods in many zones of the Neo-Tethys carbonate platform system characterized by similar rotational displacement.

  8. A Model of Dewey’s Moral Imagination for Service Learning: Theoretical Explorations and Implications for Practice in Higher Education

    OpenAIRE

    You, Zhuran; Rud, A. G.

    2010-01-01

    Abstract: While John Dewey’s learning theory has been widely credited as the essential theoretical underpinnings of service-learning, lesser attention has been paid to his concept of moral imagination regarding its immense potentials in nurturing college students’ moral growth in service-learning. This article explores Dewey’s framework of moral imagination and its implications for moral education in college service-learning programs to construct a moral imagination model that could enrich cu...

  9. Exploring behaviors of stochastic differential equation models of biological systems using change of measures

    Directory of Open Access Journals (Sweden)

    Jha Sumit

    2012-04-01

    Full Text Available Abstract Stochastic Differential Equations (SDE are often used to model the stochastic dynamics of biological systems. Unfortunately, rare but biologically interesting behaviors (e.g., oncogenesis can be difficult to observe in stochastic models. Consequently, the analysis of behaviors of SDE models using numerical simulations can be challenging. We introduce a method for solving the following problem: given a SDE model and a high-level behavioral specification about the dynamics of the model, algorithmically decide whether the model satisfies the specification. While there are a number of techniques for addressing this problem for discrete-state stochastic models, the analysis of SDE and other continuous-state models has received less attention. Our proposed solution uses a combination of Bayesian sequential hypothesis testing, non-identically distributed samples, and Girsanov's theorem for change of measures to examine rare behaviors. We use our algorithm to analyze two SDE models of tumor dynamics. Our use of non-identically distributed samples sampling contributes to the state of the art in statistical verification and model checking of stochastic models by providing an effective means for exposing rare events in SDEs, while retaining the ability to compute bounds on the probability that those events occur.

  10. Space physiology IV: mathematical modeling of the cardiovascular system in space exploration.

    Science.gov (United States)

    Keith Sharp, M; Batzel, Jerry Joseph; Montani, Jean-Pierre

    2013-08-01

    Mathematical modeling represents an important tool for analyzing cardiovascular function during spaceflight. This review describes how modeling of the cardiovascular system can contribute to space life science research and illustrates this process via modeling efforts to study postflight orthostatic intolerance (POI), a key issue for spaceflight. Examining this application also provides a context for considering broader applications of modeling techniques to the challenges of bioastronautics. POI, which affects a large fraction of astronauts in stand tests upon return to Earth, presents as dizziness, fainting and other symptoms, which can diminish crew performance and cause safety hazards. POI on the Moon or Mars could be more critical. In the field of bioastronautics, POI has been the dominant application of cardiovascular modeling for more than a decade, and a number of mechanisms for POI have been investigated. Modeling approaches include computational models with a range of incorporated factors and hemodynamic sophistication, and also physical models tested in parabolic and orbital flight. Mathematical methods such as parameter sensitivity analysis can help identify key system mechanisms. In the case of POI, this could lead to more effective countermeasures. Validation is a persistent issue in modeling efforts, and key considerations and needs for experimental data to synergistically improve understanding of cardiovascular responses are outlined. Future directions in cardiovascular modeling include subject-specific assessment of system status, as well as research on integrated physiological responses, leading, for instance, to assessment of subject-specific susceptibility to POI or effects of cardiovascular alterations on muscular, vision and cognitive function.

  11. Carbon cycle confidence and uncertainty: Exploring variation among soil biogeochemical models.

    Science.gov (United States)

    Wieder, William R; Hartman, Melannie D; Sulman, Benjamin N; Wang, Ying-Ping; Koven, Charles D; Bonan, Gordon B

    2017-11-09

    Emerging insights into factors responsible for soil organic matter stabilization and decomposition are being applied in a variety of contexts, but new tools are needed to facilitate the understanding, evaluation, and improvement of soil biogeochemical theory and models at regional to global scales. To isolate the effects of model structural uncertainty on the global distribution of soil carbon stocks and turnover times we developed a soil biogeochemical testbed that forces three different soil models with consistent climate and plant productivity inputs. The models tested here include a first-order, microbial implicit approach (CASA-CNP), and two recently developed microbially explicit models that can be run at global scales (MIMICS and CORPSE). When forced with common environmental drivers, the soil models generated similar estimates of initial soil carbon stocks (roughly 1,400 Pg C globally, 0-100 cm), but each model shows a different functional relationship between mean annual temperature and inferred turnover times. Subsequently, the models made divergent projections about the fate of these soil carbon stocks over the 20th century, with models either gaining or losing over 20 Pg C globally between 1901 and 2010. Single-forcing experiments with changed inputs, temperature, and moisture suggest that uncertainty associated with freeze-thaw processes as well as soil textural effects on soil carbon stabilization were larger than direct temperature uncertainties among models. Finally, the models generated distinct projections about the timing and magnitude of seasonal heterotrophic respiration rates, again reflecting structural uncertainties that were related to environmental sensitivities and assumptions about physicochemical stabilization of soil organic matter. By providing a computationally tractable and numerically consistent framework to evaluate models we aim to better understand uncertainties among models and generate insights about factors regulating the

  12. Galectin-3: A Friend but Not a Foe during Trypanosoma cruzi Experimental Infection

    Directory of Open Access Journals (Sweden)

    Aline A. da Silva

    2017-11-01

    Full Text Available Trypanosoma cruzi interacts with host cells, including cardiomyocytes, and induces the production of cytokines, chemokines, metalloproteinases, and glycan-binding proteins. Among the glycan-binding proteins is Galectin-3 (Gal-3, which is upregulated after T. cruzi infection. Gal-3 is a member of the lectin family with affinity for β-galactose containing molecules; it can be found in both the nucleus and the cytoplasm and can be either membrane-associated or secreted. This lectin is involved in several immunoregulatory and parasite infection process. Here, we explored the consequences of Gal-3 deficiency during acute and chronic T. cruzi experimental infection. Our results demonstrated that lack of Gal-3 enhanced in vitro replication of intracellular parasites, increased in vivo systemic parasitaemia, and reduced leukocyte recruitment. Moreover, we observed decreased secretion of pro-inflammatory cytokines in spleen and heart of infected Gal-3 knockout mice. Lack of Gal-3 also led to elevated mast cell recruitment and fibrosis of heart tissue. In conclusion, galectin-3 expression plays a pivotal role in controlling T. cruzi infection, preventing heart damage and fibrosis.

  13. Agent-based modeling as a research method for exploring joint decision making in organizations – a distributed cognition perspective

    DEFF Research Database (Denmark)

    Thomsen, Svend Erik

    2017-01-01

    This paper proposes an agent-based model to explore aspects of decision making in organizations from a distributed cognition perspective. Within distributed cognition research cognition is conceptualized as a process that takes place - not only within individuals’ minds but also between them...... decision making and distributed cognition......., as they interact with each other. This means that the interactions between individuals impact both the outcome of the decision process and the individuals’ cognition, which in turn will impact their subsequent decisions. The paper outlines how this dynamic and complex task can be modeled taking into account...

  14. A Stochastic Tick-Borne Disease Model: Exploring the Probability of Pathogen Persistence.

    Science.gov (United States)

    Maliyoni, Milliward; Chirove, Faraimunashe; Gaff, Holly D; Govinder, Keshlan S

    2017-07-13

    We formulate and analyse a stochastic epidemic model for the transmission dynamics of a tick-borne disease in a single population using a continuous-time Markov chain approach. The stochastic model is based on an existing deterministic metapopulation tick-borne disease model. We compare the disease dynamics of the deterministic and stochastic models in order to determine the effect of randomness in tick-borne disease dynamics. The probability of disease extinction and that of a major outbreak are computed and approximated using the multitype Galton-Watson branching process and numerical simulations, respectively. Analytical and numerical results show some significant differences in model predictions between the stochastic and deterministic models. In particular, we find that a disease outbreak is more likely if the disease is introduced by infected deer as opposed to infected ticks. These insights demonstrate the importance of host movement in the expansion of tick-borne diseases into new geographic areas.

  15. Bayesian inference for partially identified models exploring the limits of limited data

    CERN Document Server

    Gustafson, Paul

    2015-01-01

    Introduction Identification What Is against Us? What Is for Us? Some Simple Examples of Partially Identified ModelsThe Road Ahead The Structure of Inference in Partially Identified Models Bayesian Inference The Structure of Posterior Distributions in PIMs Computational Strategies Strength of Bayesian Updating, Revisited Posterior MomentsCredible Intervals Evaluating the Worth of Inference Partial Identification versus Model Misspecification The Siren Call of Identification Comp

  16. Development of a Conceptual Model in International Sport Tourism: Exploring Pre-and Post- Consumption Factors

    OpenAIRE

    Danny Woo-Sik Choi; David J. Shonk; Gonzalo Bravo

    2016-01-01

    The purpose is to develop a model of consumer behavior in international sport tourism that examines both pre-and post-consumption factors in international sport tourism. A secondary purpose is to address international visitation by introducing national culture as an important component of the model. The proposed model suggests that certain cultural characteristics influence an international sport tourist and these cultural characteristics impact both motivation and travel constraints. Motivat...

  17. Modeling and Simulating Moral Emotions in Organizations: exploring its impact on collaboration

    OpenAIRE

    Teran Villegas, Oswaldo Ramon; Sibertin-Blanc, Christophe; Gaudou, Benoit

    2014-01-01

    International audience; The paper presents how moral sensitivity and emotions are modeled in organizational setting by using the SocLab formal framework. Additionally simulation results, including an interesting tendency for a Free Rider model, will be given. SocLab is a platform for the modeling, simulation and analysis of cooperation relationships within social organizations - and more generally Sys-tems of Organized Action. Taking into account the fact that decision-making processes are no...

  18. Business models of sharing economy companies : exploring features responsible for sharing economy companies’ internationalization

    OpenAIRE

    Kosintceva, Aleksandra

    2016-01-01

    This paper is dedicated to the sharing economy business models and their features responsible for internationalization. The study proposes derived definitions for the concepts of “sharing economy” and “business model” and first generic sharing economy business models typology. The typology was created through the qualitative analysis of secondary data on twenty sharing economy companies from nine different industries. The outlined categories of sharing economy business models a...

  19. An upgradeable agent-based model to explore non-linearity and intangibles in peacekeeping operations

    OpenAIRE

    Lehmann, Wolfgang

    2006-01-01

    Peacekeeping operations (PKO) have become a significant challenge to the German Armed Forces. For the development of tactics, techniques, procedures and equipment with combat operations, agent-based models have been developed, used and exploited for many years. Modeling and simulation of PKO, however, is still in a very early stage. This thesis develops an agent-based model to analyze PKO. Unlike many other multi-agent systems (MAS), it implements the rules of discrete event simulation. The c...

  20. Exploring the Effects of Sampling Locations for Calibrating the Huff Model Using Mobile Phone Location Data

    Directory of Open Access Journals (Sweden)

    Shiwei Lu

    2017-01-01

    Full Text Available The introduction of the Huff model is of critical significance in many fields, including urban transport, optimal location planning, economics and business analysis. Moreover, parameters calibration is a crucial procedure before using the model. Previous studies have paid much attention to calibrating the spatial interaction model for human mobility research. However, are whole sampling locations always the better solution for model calibration? We use active tracking data of over 16 million cell phones in Shenzhen, a metropolitan city in China, to evaluate the calibration accuracy of Huff model. Specifically, we choose five business areas in this city as destinations and then randomly select a fixed number of cell phone towers to calibrate the parameters in this spatial interaction model. We vary the selected number of cell phone towers by multipliers of 30 until we reach the total number of towers with flows to the five destinations. We apply the least square methods for model calibration. The distribution of the final sum of squared error between the observed flows and the estimated flows indicates that whole sampling locations are not always better for the outcomes of this spatial interaction model. Instead, fewer sampling locations with higher volume of trips could improve the calibration results. Finally, we discuss implications of this finding and suggest an approach to address the high-accuracy model calibration solution.

  1. The System Dynamics Model User Sustainability Explorer (SD-MUSE): a user-friendly tool for interpreting system dynamic models

    Science.gov (United States)

    System Dynamics (SD) models are useful for holistic integration of data to evaluate indirect and cumulative effects and inform decisions. Complex SD models can provide key insights into how decisions affect the three interconnected pillars of sustainability. However, the complexi...

  2. Exploring business process modelling paradigms and design-time to run-time transitions

    Science.gov (United States)

    Caron, Filip; Vanthienen, Jan

    2016-09-01

    The business process management literature describes a multitude of approaches (e.g. imperative, declarative or event-driven) that each result in a different mix of process flexibility, compliance, effectiveness and efficiency. Although the use of a single approach over the process lifecycle is often assumed, transitions between approaches at different phases in the process lifecycle may also be considered. This article explores several business process strategies by analysing the approaches at different phases in the process lifecycle as well as the various transitions.

  3. Exploring the Utility of Logistic Mixed Modeling Approaches to Simultaneously Investigate Item and Testlet DIF on Testlet-based Data.

    Science.gov (United States)

    Fukuhara, Hirotaka; Paek, Insu

    2016-01-01

    This study explored the utility of logistic mixed models for the analysis of differential item functioning when item response data were testlet-based. Decomposition of differential item functioning (DIF) into item level and testlet level for the testlet-based data was introduced to separate possible sources of DIF: (1) an item, (2) a testlet, and (3) both the item and the testlet. Simulation study was conducted to investigate the performance of several logistic mixed models as well as the Mantel-Haenszel method under the conditions, in which the item-related DIF and testlet-related DIF were present simultaneously. The results revealed that a new DIF model based on a logistic mixed model with random item effects and item covariates could capture the item-related DIF and testlet-related DIF well under certain conditions.

  4. Random regret minimization : Exploration of a new choice model for environmental and resource economics

    NARCIS (Netherlands)

    Thiene, M.; Boeri, M.; Chorus, C.G.

    2011-01-01

    This paper introduces the discrete choice model-paradigm of Random Regret Minimization (RRM) to the field of environmental and resource economics. The RRM-approach has been very recently developed in the context of travel demand modelling and presents a tractable, regret-based alternative to the

  5. Multiculturalism's Narratives in Singapore and Canada: Exploring a Model for Comparative Multiculturalism and Multicultural Education

    Science.gov (United States)

    Bokhorst-Heng, Wendy D.

    2007-01-01

    This paper examines the diverse nature of multiculturalism. Although there is no lack of literature on multiculturalism, it is dominated by a Western paradigm and perspectives. This paper offers a model that takes a pluralistic perspective on diversity by locating multiculturalism within the imaginings of the nation. This model uses the concept of…

  6. Neuroscience Meets Music Education: Exploring the Implications of Neural Processing Models on Music Education Practice

    Science.gov (United States)

    Collins, Anita

    2013-01-01

    Over the past two decades, neuroscientists have been fascinated by the way the brain processes music. Using new technologies, neuroscientists offer us a better understanding of the human brain's structures and functions. They have further proposed explanatory models for how the brain processes music. While these models shed light on how the…

  7. Exploring the Argumentation Pattern in Modeling-Based Learning about Apparent Motion of Mars

    Science.gov (United States)

    Park, Su-Kyeong

    2016-01-01

    This study proposed an analytic framework for coding students' dialogic argumentation and investigated the characteristics of the small-group argumentation pattern observed in modeling-based learning. The participants were 122 second grade high school students in South Korea divided into an experimental and a comparison group. Modeling-based…

  8. Exploring Middle School Students' Understanding of Three Conceptual Models in Genetics

    Science.gov (United States)

    Bresler Freidenreich, Hava; Golan Duncan, Ravit; Shea, Nicole

    2011-11-01

    Genetics is the cornerstone of modern biology and a critical aspect of scientific literacy. Research has shown, however, that many high school graduates lack fundamental understandings in genetics necessary to make informed decisions about issues and emerging technologies in this domain, such as genetic screening, genetically modified foods, etc. Genetic literacy entails understanding three interrelated models: a genetic model that describes patterns of genetic inheritance, a meiotic model that describes the process by which genes are segregated into sex cells, and a molecular model that describes the mechanisms that link genotypes to phenotypes within an individual. Currently, much of genetics instruction, especially in terms of the molecular model, occurs at the high school level, and we know little about the ways in which middle school students can reason about these models. Furthermore, we do not know the extent to which carefully designed instruction can help younger students develop coherent and interrelated understandings in genetics. In this paper, we discuss a research study aimed at elucidating middle school students' abilities to reason about the three genetic models. As part of our research, we designed an eight-week inquiry unit that was implemented in a combined sixth- to eighth-grade science classroom. We describe our instructional design and report results based on an analysis of written assessments, clinical interviews, and artifacts of the unit. Our findings suggest that middle school students are able to successfully reason about all three genetic models.

  9. Using the ADDIE Model to Create an Online Strength Training Program: An Exploration

    Science.gov (United States)

    Brook, Rebekah L.

    2014-01-01

    The purpose of this design and development research was to investigate whether the ADDIE model can be used to design online modules that teach psychomotor skills. The overarching research question was: How can the ADDIE Model of Instructional Design be used to create an online module that teaches safe and effective movement for psychomotor skills?…

  10. Using a cellular model to explore human-facilitated spread of risk of EAB in Minnesota

    Science.gov (United States)

    Anantha Prasad; Louis Iverson; Matthew Peters; Steve. Matthews

    2011-01-01

    The Emerald Ash Borer has made inroads to Minnesota in the past two years, killing ash trees. We use our spatially explicit cell based model called EAB-SHIFT to calculate the risk of infestation owing to flight characteristics and short distance movement of the insect (insect flight model, IFM), and the human facilitated agents like roads, campgrounds etc. (insect ride...

  11. Origami: A Versatile Modeling System for Visualising Chemical Structure and Exploring Molecular Function

    Science.gov (United States)

    Davis, James; Leslie, Ray; Billington, Susan; Slater, Peter R.

    2010-01-01

    The use of "Origami" is presented as an accessible and transferable modeling system through which to convey the intricacies of molecular shape and highlight structure-function relationships. The implementation of origami has been found to be a versatile alternative to conventional ball-and-stick models, possessing the key advantages of being both…

  12. Exploring Parameter Tuning for Analysis and Optimization of a Computational Model

    NARCIS (Netherlands)

    Mollee, J.S.; Fernandes de Mello Araujo, E.; Klein, M.C.A.

    2017-01-01

    Computational models of human processes are used for many different purposes and in many different types of applications. A common challenge in using such models is to find suitable parameter values. In many cases, the ideal parameter values are those that yield the most realistic simulation

  13. Community, conflict and land: exploring the strategic partnership model of South African land restitution

    NARCIS (Netherlands)

    Basu, Soutrik

    2016-01-01

    The Strategic Partnership (SP) model was implemented in the South African land restitution programme. The model prematurely ended in a fiasco that left the community with huge debts and intractable conflicts. This paper aims at understanding the implementation process by taking up the issue of how

  14. An Indigenous Model of Career Satisfaction: Exploring the Role of Workplace Cultural Wellbeing

    Science.gov (United States)

    Haar, Jarrod M.; Brougham, Dave M.

    2013-01-01

    Despite career satisfaction models being well established, little is understood about the career satisfaction of indigenous employees. Using a sample of 172 Maori employees, the indigenous people of New Zealand, we tested a career satisfaction model with a cultural wellbeing factor over and above established factors of human capital,…

  15. Exploring the role of fire, succession, climate, and weather on landscape dynamics using comparative modeling

    Science.gov (United States)

    Robert E. Keane; Geoffrey J. Cary; Mike D. Flannigan; Russell A. Parsons; Ian D. Davies; Karen J. King; Chao Li; Ross A. Bradstock; Malcolm Gill

    2013-01-01

    An assessment of the relative importance of vegetation change and disturbance as agents of landscape change under current and future climates would (1) provide insight into the controls of landscape dynamics, (2) help inform the design and development of coarse scale spatially explicit ecosystem models such as Dynamic Global Vegetation Models (DGVMs), and (3) guide...

  16. My neighbors made me do it: an exploration of a neighborhood network model of activism

    Science.gov (United States)

    Lewis, Michael A.; Noguchi, Eri

    2008-08-01

    Social scientists have allocated a great deal of time to trying to understand the determinants of civic/political engagement. They, along with physicists, have also shown some interest in social networks, some in the question of the association between such networks and civic/political engagement. This paper builds on this work by exploring the extent to which the association between one's neighborhood network and the chance that one has taken part in a march, boycott, or demonstration varies by gender. We did several types of analyses. Initially, we used conditional probabilities to explore the relationship between neighborhood network and the chance that one has taken part in a march, boycott, or demonstration. After pointing out the problems with these conditional probabilities, we conducted logistic regression on a data set of 1897 females and 1521 males from the United States. We found that males whose neighbors give them a sense of community had about one and a half times the odds of having taken part in a march, boycott, or demonstration over the previous twelve months compared to males whose neighbors do not give them such a sense. For females, there appeared to be no such association between neighborhood network and the chance of having taken part in a march, boycott, or demonstration.

  17. Reforging the Wedding Ring: Exploring a Semi-Artificial Model of Population for the United Kingdom with Gaussian process emulators

    Directory of Open Access Journals (Sweden)

    Viet Dung Cao

    2013-10-01

    Full Text Available Background: We extend the "Wedding Ring‟ agent-based model of marriage formation to include some empirical information on the natural population change for the United Kingdom together with behavioural explanations that drive the observed nuptiality trends. Objective: We propose a method to explore statistical properties of agent-based demographic models. By coupling rule-based explanations driving the agent-based model with observed data we wish to bring agent-based modelling and demographic analysis closer together. Methods: We present a Semi-Artificial Model of Population, which aims to bridge demographic micro-simulation and agent-based traditions. We then utilise a Gaussian process emulator - a statistical model of the base model - to analyse the impact of selected model parameters on two key model outputs: population size and share of married agents. A sensitivity analysis is attempted, aiming to assess the relative importance of different inputs. Results: The resulting multi-state model of population dynamics has enhanced predictive capacity as compared to the original specification of the Wedding Ring, but there are some trade-offs between the outputs considered. The sensitivity analysis allows identification of the most important parameters in the modelled marriage formation process. Conclusions: The proposed methods allow for generating coherent, multi-level agent-based scenarios aligned with some aspects of empirical demographic reality. Emulators permit a statistical analysis of their properties and help select plausible parameter values. Comments: Given non-linearities in agent-based models such as the Wedding Ring, and the presence of feedback loops, the uncertainty in the model may not be directly computable by using traditional statistical methods. The use of statistical emulators offers a way forward.

  18. Exploring large-scale phenomena in composite membranes through an efficient implicit-solvent model

    Science.gov (United States)

    Laradji, Mohamed; Kumar, P. B. Sunil; Spangler, Eric J.

    2016-07-01

    Several microscopic and mesoscale models have been introduced in the past to investigate various phenomena in lipid membranes. Most of these models account for the solvent explicitly. Since in a typical molecular dynamics simulation, the majority of particles belong to the solvent, much of the computational effort in these simulations is devoted for calculating forces between solvent particles. To overcome this problem, several implicit-solvent mesoscale models for lipid membranes have been proposed during the last few years. In the present article, we review an efficient coarse-grained implicit-solvent model we introduced earlier for studies of lipid membranes. In this model, lipid molecules are coarse-grained into short semi-flexible chains of beads with soft interactions. Through molecular dynamics simulations, the model is used to investigate the thermal, structural and elastic properties of lipid membranes. We will also review here few studies, based on this model, of the phase behavior of nanoscale liposomes, cytoskeleton-induced blebbing in lipid membranes, as well as nanoparticles wrapping and endocytosis by tensionless lipid membranes. Topical Review article submitted to the Journal of Physics D: Applied Physics, May 9, 2016

  19. An anthology of theories and models of design philosophy, approaches and empirical explorations

    CERN Document Server

    Blessing, Lucienne

    2014-01-01

    While investigations into both theories and models has remained a major strand of engineering design research, current literature sorely lacks a reference book that provides a comprehensive and up-to-date anthology of theories and models, and their philosophical and empirical underpinnings; An Anthology of Theories and Models of Design fills this gap. The text collects the expert views of an international authorship, covering: ·         significant theories in engineering design, including CK theory, domain theory, and the theory of technical systems; ·         current models of design, from a function behavior structure model to an integrated model; ·         important empirical research findings from studies into design; and ·         philosophical underpinnings of design itself. For educators and researchers in engineering design, An Anthology of Theories and Models of Design gives access to in-depth coverage of theoretical and empirical developments in this area; for pr...

  20. Exploring social representations of adapting to climate change using topic modeling and Bayesian networks

    Directory of Open Access Journals (Sweden)

    Timothy Lynam

    2016-12-01

    In this paper I describe the methods and results of applying topic modeling to 660 micronarratives collected from Australian academics / researchers, government employees, and members of the public in 2010-2011. The narrative fragments focused on adaptation to climate change (CC and hence provide an example of Australian society making sense of an emerging and conflict ridden phenomena. The results of the topic modeling reflect elements of SRs of adaptation to CC that are consistent with findings in the literature as well as being reasonably robust predictors of classes of action in response to CC. Bayesian Network (BN modeling was used to identify relationships among the topics (SR elements and in particular to identify relationships among topics, sentiment, and action. Finally the resulting model and topic modeling results are used to highlight differences in the salience of SR elements among social groups. The approach of linking topic modeling and BN modeling offers a new and encouraging approach to analysis for ongoing research on SRs.

  1. Exploring the use of multiple analogical models when teaching and learning chemical equilibrium

    Science.gov (United States)

    Harrison, Allan G.; de Jong, Onno

    2005-12-01

    This study describes the multiple analogical models used to introduce and teach Grade 12 chemical equilibrium. We examine the teacher's reasons for using models, explain each model's development during the lessons, and analyze the understandings students derived from the models. A case study approach was used and the data were drawn from the observation of three consecutive Grade 12 lessons on chemical equilibrium, pre- and post-lesson interviews, and delayed student interviews. The key analogical models used in teaching were: the school dance; the sugar in a teacup; the pot of curry; and the busy highway. The lesson and interview data were subject to multiple, independent analyses and yielded the following outcomes: The teacher planned to use the students' prior knowledge wherever possible and he responded to student questions with stories and extended and enriched analogies. He planned to discuss where each analogy broke down but did not. The students enjoyed the teaching but built variable mental models of equilibrium and some of their analogical mappings were unreliable. A female student disliked masculine analogies, other students tended to see elements of the multiple models in isolation, and some did not recognize all the analogical mappings embedded in the teaching plan. Most students learned that equilibrium reactions are dynamic, occur in closed systems, and the forward and reverse reactions are balanced. We recommend the use of multiple analogies like these and insist that teachers always show where the analogy breaks down and carefully negotiate the conceptual outcomes.

  2. Strengthen forensic entomology in court--the need for data exploration and the validation of a generalised additive mixed model.

    Science.gov (United States)

    Baqué, Michèle; Amendt, Jens

    2013-01-01

    Developmental data of juvenile blow flies (Diptera: Calliphoridae) are typically used to calculate the age of immature stages found on or around a corpse and thus to estimate a minimum post-mortem interval (PMI(min)). However, many of those data sets don't take into account that immature blow flies grow in a non-linear fashion. Linear models do not supply a sufficient reliability on age estimates and may even lead to an erroneous determination of the PMI(min). According to the Daubert standard and the need for improvements in forensic science, new statistic tools like smoothing methods and mixed models allow the modelling of non-linear relationships and expand the field of statistical analyses. The present study introduces into the background and application of these statistical techniques by analysing a model which describes the development of the forensically important blow fly Calliphora vicina at different temperatures. The comparison of three statistical methods (linear regression, generalised additive modelling and generalised additive mixed modelling) clearly demonstrates that only the latter provided regression parameters that reflect the data adequately. We focus explicitly on both the exploration of the data--to assure their quality and to show the importance of checking it carefully prior to conducting the statistical tests--and the validation of the resulting models. Hence, we present a common method for evaluating and testing forensic entomological data sets by using for the first time generalised additive mixed models.

  3. Mental health service use among those with depression: an exploration using Andersen's Behavioral Model of Health Service Use.

    Science.gov (United States)

    Graham, Annette; Hasking, Penelope; Brooker, Joanne; Clarke, David; Meadows, Graham

    2017-01-15

    Despite positive effects on prognosis, less than half of the people diagnosed with depression access mental health services. Knowledge of what promotes such service use is limited. There is dispute about whether the receipt of mental illness related information encourages or discourages service use among those with depression. Accurate service use models are needed to inform programs designed to facilitate service use by those who would benefit most. We examine the appropriateness of Andersen's Behavioral Model of Health Service Use in this context. Data from 451 adults identified through the Australian National Survey of Mental Health and Wellbeing as meeting International Classification of Diseases Ten (ICD-10) criteria for depression were used. Confirmatory factor analysis failed to verify Andersen's model. Thus, an empirically derived service use model was developed using exploratory factor analysis and then structural equation modelling. Mental health need was the strongest predictor of service use and the model suggested the importance of social connectedness in promoting service use. Participants who had received helpful mental illness information were significantly more likely to have accessed mental health services than those who had not. The cross-sectional design and lack of replication preclude definitive conclusions CONCLUSION: Andersen's model is a useful starting point for the exploration of service use among people with depression. It is necessary, however, to develop specific models for this population. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Exploration of a physiologically-inspired hearing-aid algorithm using a computer model mimicking impaired hearing.

    Science.gov (United States)

    Jürgens, Tim; Clark, Nicholas R; Lecluyse, Wendy; Meddis, Ray

    2016-01-01

    To use a computer model of impaired hearing to explore the effects of a physiologically-inspired hearing-aid algorithm on a range of psychoacoustic measures. A computer model of a hypothetical impaired listener's hearing was constructed by adjusting parameters of a computer model of normal hearing. Absolute thresholds, estimates of compression, and frequency selectivity (summarized to a hearing profile) were assessed using this model with and without pre-processing the stimuli by a hearing-aid algorithm. The influence of different settings of the algorithm on the impaired profile was investigated. To validate the model predictions, the effect of the algorithm on hearing profiles of human impaired listeners was measured. A computer model simulating impaired hearing (total absence of basilar membrane compression) was used, and three hearing-impaired listeners participated. The hearing profiles of the model and the listeners showed substantial changes when the test stimuli were pre-processed by the hearing-aid algorithm. These changes consisted of lower absolute thresholds, steeper temporal masking curves, and sharper psychophysical tuning curves. The hearing-aid algorithm affected the impaired hearing profile of the model to approximate a normal hearing profile. Qualitatively similar results were found with the impaired listeners' hearing profiles.

  5. Exploring the critiques of the social model of disability: the transformative possibility of Arendt's notion of power.

    Science.gov (United States)

    Owens, Janine

    2015-03-01

    The social model of disability has demonstrated political success for disabled people in society. At the same time, it has been labelled an outdated ideology in need of further development. While the social model of disability has been used successfully for political activism, it has simultaneously created conflict and tensions in disability studies, sociology and the sociology of the body. This article sheds light on the confusion surrounding the social model of disability by discussing the historical emergence of its different forms. It then proceeds to analyse and evaluate key criticisms of the social model of disability. The article then goes on to explore the relevance of different forms of power to the current discourse on disability before proceeding to explore in depth what might be gained from the approach of one particular theorist on power; Hannah Arendt. It suggests that there may be merit in drawing on Arendt and illustrates some of the benefits of a more nuanced idea of a pluralistic body and experiences. © 2014 Foundation for the Sociology of Health & Illness.

  6. Exploring mechanisms for mobilising industrial sustainability models across different industrial locations

    DEFF Research Database (Denmark)

    Jacobsen, Ole Morten Noel Brings

    2009-01-01

    Industrial symbiosis is a model of sustainability which suggests that agglomerations of industries can achieve considerable environmental benefits by engaging in inter-organisational waste recycling, energy cascading and water recovery. This article considers how such a complex inter......-organisational model for environmental management can be mobilised across different industrial localities. It is suggested that companies engaged in industrial symbiosis activities at one production locality may be more inclined to engage in symbiotic activities when entering a new production locality. The industrial...... symbiosis model may in this way be mobilised across industrial localities as part of the global corporate search for marked access and cost reductions. This suggestion is supported by an illustrative case study shedding some light on the mechanisms for mobilising sustainability models across localities....

  7. Novel Methods for Surface EMG Analysis and Exploration Based on Multi-Modal Gaussian Mixture Models

    National Research Council Canada - National Science Library

    Vögele, Anna Magdalena; Zsoldos, Rebeka R; Krüger, Björn; Licka, Theresia

    2016-01-01

    .... It is based on fitting Gaussian mixture models (GMMs) to surface EMG data (sEMG). This approach enables researchers/users to isolate parts of the overall muscle activation within locomotion EMG data...

  8. An exploration of scenarios to support sustainable land management using integrated environmental socio-economic models

    NARCIS (Netherlands)

    Fleskens, L.; Nainggolan, D.; Stringer, L.C.

    2014-01-01

    Scenario analysis constitutes a valuable deployment method for scientific models to inform environmental decision-making, particularly for evaluating land degradation mitigation options, which are rarely based on formal analysis. In this paper we demonstrate such an assessment using the

  9. Exploring the Nature and Implementation Process of User-Centric Business Models

    DEFF Research Database (Denmark)

    Hienerth, Christoph; Keinz, Peter; Lettl, Christopher

    2011-01-01

    integrated users into their core business processes, and find that implementing user-centric business models successfully requires a comprehensive approach encompassing an appropriate social software design, a transparent intellectual property policy, proper incentive systems, evolutional learning...... users in core business processes, and (2) effective strategies to overcome internal resistance at established companies wishing to introduce user-centric business models. We apply a multi-case comparison methodology between three well-known companies (LEGO, IBM and Coloplast) which have successfully...

  10. Exploring predictive and reproducible modeling with the single-subject FIAC dataset.

    Science.gov (United States)

    Chen, Xu; Pereira, Francisco; Lee, Wayne; Strother, Stephen; Mitchell, Tom

    2006-05-01

    Predictive modeling of functional magnetic resonance imaging (fMRI) has the potential to expand the amount of information extracted and to enhance our understanding of brain systems by predicting brain states, rather than emphasizing the standard spatial mapping. Based on the block datasets of Functional Imaging Analysis Contest (FIAC) Subject 3, we demonstrate the potential and pitfalls of predictive modeling in fMRI analysis by investigating the performance of five models (linear discriminant analysis, logistic regression, linear support vector machine, Gaussian naive Bayes, and a variant) as a function of preprocessing steps and feature selection methods. We found that: (1) independent of the model, temporal detrending and feature selection assisted in building a more accurate predictive model; (2) the linear support vector machine and logistic regression often performed better than either of the Gaussian naive Bayes models in terms of the optimal prediction accuracy; and (3) the optimal prediction accuracy obtained in a feature space using principal components was typically lower than that obtained in a voxel space, given the same model and same preprocessing. We show that due to the existence of artifacts from different sources, high prediction accuracy alone does not guarantee that a classifier is learning a pattern of brain activity that might be usefully visualized, although cross-validation methods do provide fairly unbiased estimates of true prediction accuracy. The trade-off between the prediction accuracy and the reproducibility of the spatial pattern should be carefully considered in predictive modeling of fMRI. We suggest that unless the experimental goal is brain-state classification of new scans on well-defined spatial features, prediction alone should not be used as an optimization procedure in fMRI data analysis.

  11. Hunting Solomonoff's Swans: Exploring the Boundary Between Physics and Statistics in Hydrological Modeling

    Science.gov (United States)

    Nearing, G. S.

    2014-12-01

    Statistical models consistently out-perform conceptual models in the short term, however to account for a nonstationary future (or an unobserved past) scientists prefer to base predictions on unchanging and commutable properties of the universe - i.e., physics. The problem with physically-based hydrology models is, of course, that they aren't really based on physics - they are based on statistical approximations of physical interactions, and we almost uniformly lack an understanding of the entropy associated with these approximations. Thermodynamics is successful precisely because entropy statistics are computable for homogeneous (well-mixed) systems, and ergodic arguments explain the success of Newton's laws to describe systems that are fundamentally quantum in nature. Unfortunately, similar arguments do not hold for systems like watersheds that are heterogeneous at a wide range of scales. Ray Solomonoff formalized the situation in 1968 by showing that given infinite evidence, simultaneously minimizing model complexity and entropy in predictions always leads to the best possible model. The open question in hydrology is about what happens when we don't have infinite evidence - for example, when the future will not look like the past, or when one watershed does not behave like another. How do we isolate stationary and commutable components of watershed behavior? I propose that one possible answer to this dilemma lies in a formal combination of physics and statistics. In this talk I outline my recent analogue (Solomonoff's theorem was digital) of Solomonoff's idea that allows us to quantify the complexity/entropy tradeoff in a way that is intuitive to physical scientists. I show how to formally combine "physical" and statistical methods for model development in a way that allows us to derive the theoretically best possible model given any given physics approximation(s) and available observations. Finally, I apply an analogue of Solomonoff's theorem to evaluate the

  12. Aesthetic Perception of Visual Textures: A Holistic Exploration using Texture Analysis, Psychological Experiment and Perception Modeling

    Directory of Open Access Journals (Sweden)

    Jianli eLiu

    2015-11-01

    Full Text Available Modeling human aesthetic perception of visual textures is important and valuable in numerous industrial domains, such as product design, architectural design and decoration. Based on results from a semantic differential rating experiment, we modeled the relationship between low-level basic texture features and aesthetic properties involved in human aesthetic texture perception. First, we compute basic texture features from textural images using four classical methods. These features are neutral, objective and independent of the socio-cultural context of the visual textures. Then, we conduct a semantic differential rating experiment to collect from evaluators their aesthetic perceptions of selected textural stimuli. In semantic differential rating experiment, eights pairs of aesthetic properties are chosen, which are strongly related to the socio-cultural context of the selected textures and to human emotions. They are easily understood and connected to everyday life. We propose a hierarchical feed-forward layer model of aesthetic texture perception and assign 8 pairs of aesthetic properties to different layers. Finally, we describe the generation of multiple linear and nonlinear regression models for aesthetic prediction by taking dimensionality-reduced texture features and aesthetic properties of visual textures as dependent and independent variables, respectively. Our experimental results indicate that the relationships between each layer and its neighbors in the hierarchical feed-forward layer model of aesthetic texture perception can be fitted well by linear functions, and the models thus generated can successfully bridge the gap between computational texture features and aesthetic texture properties.

  13. Aesthetic perception of visual textures: a holistic exploration using texture analysis, psychological experiment, and perception modeling.

    Science.gov (United States)

    Liu, Jianli; Lughofer, Edwin; Zeng, Xianyi

    2015-01-01

    Modeling human aesthetic perception of visual textures is important and valuable in numerous industrial domains, such as product design, architectural design, and decoration. Based on results from a semantic differential rating experiment, we modeled the relationship between low-level basic texture features and aesthetic properties involved in human aesthetic texture perception. First, we compute basic texture features from textural images using four classical methods. These features are neutral, objective, and independent of the socio-cultural context of the visual textures. Then, we conduct a semantic differential rating experiment to collect from evaluators their aesthetic perceptions of selected textural stimuli. In semantic differential rating experiment, eights pairs of aesthetic properties are chosen, which are strongly related to the socio-cultural context of the selected textures and to human emotions. They are easily understood and connected to everyday life. We propose a hierarchical feed-forward layer model of aesthetic texture perception and assign 8 pairs of aesthetic properties to different layers. Finally, we describe the generation of multiple linear and non-linear regression models for aesthetic prediction by taking dimensionality-reduced texture features and aesthetic properties of visual textures as dependent and independent variables, respectively. Our experimental results indicate that the relationships between each layer and its neighbors in the hierarchical feed-forward layer model of aesthetic texture perception can be fitted well by linear functions, and the models thus generated can successfully bridge the gap between computational texture features and aesthetic texture properties.

  14. Exploring uncertainty in glacier mass balance modelling with Monte Carlo simulation

    Directory of Open Access Journals (Sweden)

    H. Machguth

    2008-12-01

    Full Text Available By means of Monte Carlo simulations we calculated uncertainty in modelled cumulative mass balance over 400 days at one particular point on the tongue of Morteratsch Glacier, Switzerland, using a glacier energy balance model of intermediate complexity. Before uncertainty assessment, the model was tuned to observed mass balance for the investigated time period and its robustness was tested by comparing observed and modelled mass balance over 11 years, yielding very small deviations. Both systematic and random uncertainties are assigned to twelve input parameters and their respective values estimated from the literature or from available meteorological data sets. The calculated overall uncertainty in the model output is dominated by systematic errors and amounts to 0.7 m w.e. or approximately 10% of total melt over the investigated time span. In order to provide a first order estimate on variability in uncertainty depending on the quality of input data, we conducted a further experiment, calculating overall uncertainty for different levels of uncertainty in measured global radiation and air temperature. Our results show that the output of a well calibrated model is subject to considerable uncertainties, in particular when applied for extrapolation in time and space where systematic errors are likely to be an important issue.

  15. Model Development and Experimental Validation of the Fusible Heat Sink Design for Exploration Vehicles

    Science.gov (United States)

    Cognata, Thomas J.; Leimkuehler, Thomas; Sheth, Rubik; Le, Hung

    2013-01-01

    The Fusible Heat Sink is a novel vehicle heat rejection technology which combines a flow through radiator with a phase change material. The combined technologies create a multi-function device able to shield crew members against Solar Particle Events (SPE), reduce radiator extent by permitting sizing to the average vehicle heat load rather than to the peak vehicle heat load, and to substantially absorb heat load excursions from the average while constantly maintaining thermal control system setpoints. This multi-function technology provides great flexibility for mission planning, making it possible to operate a vehicle in hot or cold environments and under high or low heat load conditions for extended periods of time. This paper describes the modeling and experimental validation of the Fusible Heat Sink technology. The model developed was intended to meet the radiation and heat rejection requirements of a nominal MMSEV mission. Development parameters and results, including sizing and model performance will be discussed. From this flight-sized model, a scaled test-article design was modeled, designed, and fabricated for experimental validation of the technology at Johnson Space Center thermal vacuum chamber facilities. Testing showed performance comparable to the model at nominal loads and the capability to maintain heat loads substantially greater than nominal for extended periods of time.

  16. A comprehensive approach to dark matter studies: exploration of simplified top-philic models

    Energy Technology Data Exchange (ETDEWEB)

    Arina, Chiara; Backović, Mihailo [Centre for Cosmology, Particle Physics and Phenomenology (CP3),Université catholique de Louvain, Chemin du Cyclotron 2, B-1348 Louvain-la-Neuve (Belgium); Conte, Eric [Groupe de Recherche de Physique des Hautes Énergies (GRPHE), Université de Haute-Alsace,IUT Colmar, F-68008 Colmar Cedex (France); Fuks, Benjamin [Sorbonne Universités, UPMC University Paris 06, UMR 7589, LPTHE, F-75005, Paris (France); CNRS, UMR 7589, LPTHE, F-75005, Paris (France); Guo, Jun [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics,Chinese Academy of Sciences, Beijing 100190 (China); Institut Pluridisciplinaire Hubert Curien/Département Recherches Subatomiques,Université de Strasbourg/CNRS-IN2P3, F-67037 Strasbourg (France); Heisig, Jan [Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University,Sommerfeldstr. 16, D-52056 Aachen (Germany); Hespel, Benoît [Centre for Cosmology, Particle Physics and Phenomenology (CP3),Université catholique de Louvain, Chemin du Cyclotron 2, B-1348 Louvain-la-Neuve (Belgium); Krämer, Michael [Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University,Sommerfeldstr. 16, D-52056 Aachen (Germany); Maltoni, Fabio; Martini, Antony [Centre for Cosmology, Particle Physics and Phenomenology (CP3),Université catholique de Louvain, Chemin du Cyclotron 2, B-1348 Louvain-la-Neuve (Belgium); Mawatari, Kentarou [Laboratoire de Physique Subatomique et de Cosmologie, Université Grenoble-Alpes,CNRS/IN2P3, 53 Avenue des Martyrs, F-38026 Grenoble (France); Theoretische Natuurkunde and IIHE/ELEM, Vrije Universiteit Brussel andInternational Solvay Institutes, Pleinlaan 2, B-1050 Brussels (Belgium); Pellen, Mathieu [Universität Würzburg, Institut für Theoretische Physik und Astrophysik,Emil-Hilb-Weg 22, 97074 Würzburg (Germany); Vryonidou, Eleni [Centre for Cosmology, Particle Physics and Phenomenology (CP3),Université catholique de Louvain, Chemin du Cyclotron 2, B-1348 Louvain-la-Neuve (Belgium)

    2016-11-21

    Studies of dark matter lie at the interface of collider physics, astrophysics and cosmology. Constraining models featuring dark matter candidates entails the capability to provide accurate predictions for large sets of observables and compare them to a wide spectrum of data. We present a framework which, starting from a model Lagrangian, allows one to consistently and systematically make predictions, as well as to confront those predictions with a multitude of experimental results. As an application, we consider a class of simplified dark matter models where a scalar mediator couples only to the top quark and a fermionic dark sector (i.e. the simplified top-philic dark matter model). We study in detail the complementarity of relic density, direct/indirect detection and collider searches in constraining the multi-dimensional model parameter space, and efficiently identify regions where individual approaches to dark matter detection provide the most stringent bounds. In the context of collider studies of dark matter, we point out the complementarity of LHC searches in probing different regions of the model parameter space with final states involving top quarks, photons, jets and/or missing energy. Our study of dark matter production at the LHC goes beyond the tree-level approximation and we show examples of how higher-order corrections to dark matter production processes can affect the interpretation of the experimental results.

  17. Data Cache-Energy and Throughput Models: Design Exploration for Embedded Processors

    Directory of Open Access Journals (Sweden)

    Qadri MuhammadYasir

    2009-01-01

    Full Text Available Abstract Most modern 16-bit and 32-bit embedded processors contain cache memories to further increase instruction throughput of the device. Embedded processors that contain cache memories open an opportunity for the low-power research community to model the impact of cache energy consumption and throughput gains. For optimal cache memory configuration mathematical models have been proposed in the past. Most of these models are complex enough to be adapted for modern applications like run-time cache reconfiguration. This paper improves and validates previously proposed energy and throughput models for a data cache, which could be used for overhead analysis for various cache types with relatively small amount of inputs. These models analyze the energy and throughput of a data cache on an application basis, thus providing the hardware and software designer with the feedback vital to tune the cache or application for a given energy budget. The models are suitable for use at design time in the cache optimization process for embedded processors considering time and energy overhead or could be employed at runtime for reconfigurable architectures.

  18. Data Cache-Energy and Throughput Models: Design Exploration for Embedded Processors

    Directory of Open Access Journals (Sweden)

    Muhammad Yasir Qadri

    2009-01-01

    Full Text Available Most modern 16-bit and 32-bit embedded processors contain cache memories to further increase instruction throughput of the device. Embedded processors that contain cache memories open an opportunity for the low-power research community to model the impact of cache energy consumption and throughput gains. For optimal cache memory configuration mathematical models have been proposed in the past. Most of these models are complex enough to be adapted for modern applications like run-time cache reconfiguration. This paper improves and validates previously proposed energy and throughput models for a data cache, which could be used for overhead analysis for various cache types with relatively small amount of inputs. These models analyze the energy and throughput of a data cache on an application basis, thus providing the hardware and software designer with the feedback vital to tune the cache or application for a given energy budget. The models are suitable for use at design time in the cache optimization process for embedded processors considering time and energy overhead or could be employed at runtime for reconfigurable architectures.

  19. Exploring residents' communication learning process in the workplace: a five-phase model.

    Science.gov (United States)

    van den Eertwegh, Valerie; van der Vleuten, Cees; Stalmeijer, Renée; van Dalen, Jan; Scherpbier, Albert; van Dulmen, Sandra

    2015-01-01

    Competency-based education is a resurgent paradigm in professional medical education. However, more specific knowledge is needed about the learning process of such competencies, since they consist of complex skills. We chose to focus on the competency of skilled communication and want to further explore its learning process, since it is regarded as a main competency in medical education. This study aims to explore in more detail the learning process that residents in general practice go through during workplace-based learning in order to become skilled communicators. A qualitative study was conducted in which twelve GP residents were observed during their regular consultations, and were interviewed in-depth afterwards. Analysis of the data resulted in the construction of five phases and two overall conditions to describe the development towards becoming a skilled communicator: Confrontation with (un)desired behaviour or clinical outcomes was the first phase. Becoming conscious of one's own behaviour and changing the underlying frame of reference formed the second phase. The third phase consisted of the search for alternative behaviour. In the fourth phase, personalization of the alternative behaviour had to occur, this was perceived as difficult and required much time. Finally, the fifth phase concerned full internalization of the new behaviour, which by then had become an integrated part of the residents' clinical repertoire. Safety and cognitive & emotional space were labelled as overall conditions influencing this learning process. Knowledge and awareness of these five phases can be used to adjust medical working and learning environments in such a way that development of skilled medical communication can come to full fruition and its benefits are more fully reaped.

  20. Exploring Residents’ Communication Learning Process in the Workplace: A Five-Phase Model

    Science.gov (United States)

    Scherpbier, Albert; van Dulmen, Sandra

    2015-01-01

    Context Competency-based education is a resurgent paradigm in professional medical education. However, more specific knowledge is needed about the learning process of such competencies, since they consist of complex skills. We chose to focus on the competency of skilled communication and want to further explore its learning process, since it is regarded as a main competency in medical education. Objective This study aims to explore in more detail the learning process that residents in general practice go through during workplace-based learning in order to become skilled communicators. Methods A qualitative study was conducted in which twelve GP residents were observed during their regular consultations, and were interviewed in-depth afterwards. Results Analysis of the data resulted in the construction of five phases and two overall conditions to describe the development towards becoming a skilled communicator: Confrontation with (un)desired behaviour or clinical outcomes was the first phase. Becoming conscious of one’s own behaviour and changing the underlying frame of reference formed the second phase. The third phase consisted of the search for alternative behaviour. In the fourth phase, personalization of the alternative behaviour had to occur, this was perceived as difficult and required much time. Finally, the fifth phase concerned full internalization of the new behaviour, which by then had become an integrated part of the residents’ clinical repertoire. Safety and cognitive & emotional space were labelled as overall conditions influencing this learning process. Conclusions Knowledge and awareness of these five phases can be used to adjust medical working and learning environments in such a way that development of skilled medical communication can come to full fruition and its benefits are more fully reaped. PMID:26000767

  1. Mind the Gap: Exploring the Underground of the NASA Space Cancer Risk Model

    Science.gov (United States)

    Chappell, L. J.; Elgart, S. R.; Milder, C. M.; Shavers, M. R.; Semones, E. J.; Huff, J. L.

    2017-01-01

    The REID quantifies the lifetime risk of death from radiation-induced cancer in an exposed astronaut. The NASA Space Cancer Risk (NSCR) 2012 mode incorporates elements from physics, biology, epidemiology, and statistics to generate the REID distribution. The current model quantifies the space radiation environment, radiation quality, and dose-rate effects to estimate a NASA-weighted dose. This weighted dose is mapped to the excess risk of radiation-induced cancer mortality from acute exposures to gamma rays and then transferred to an astronaut population. Finally, the REID is determined by integrating this risk over the individual's lifetime. The calculated upper 95% confidence limit of the REID is used to restrict an astronaut's permissible mission duration (PMD) for a proposed mission. As a statistical quantity characterized by broad, subjective uncertainties, REID estimates for space missions result in wide distributions. Currently, the upper 95% confidence level is over 350% larger than the mean REID value, which can severely limit an astronaut's PMD. The model incorporates inputs from multiple scientific disciplines in the risk estimation process. Physics and particle transport models calculate how radiation moves through space, penetrates spacecraft, and makes its way to the human beings onboard. Epidemiological studies of exposures from atomic bombings, medical treatments, and power plants are used to quantify health risks from acute and chronic low linear energy transfer (LET) ionizing radiation. Biological studies in cellular and animal models using radiation at various LETs and energies inform quality metrics for ions present in space radiation. Statistical methodologies unite these elements, controlling for mathematical and scientific uncertainty and variability. Despite current progress, these research platforms contain knowledge gaps contributing to the large uncertainties still present in the model. The NASA Space Radiation Program Element (SRPE

  2. Exploring the effect of absence selection on landslide susceptibility models: A case study in Sicily, Italy

    Science.gov (United States)

    Conoscenti, Christian; Rotigliano, Edoardo; Cama, Mariaelena; Caraballo-Arias, Nathalie Almaru; Lombardo, Luigi; Agnesi, Valerio

    2016-05-01

    A statistical approach was employed to model the spatial distribution of rainfall-triggered landslides in two areas in Sicily (Italy) that occurred during the winter of 2004-2005. The investigated areas are located within the Belice River basin and extend for 38.5 and 10.3 km2, respectively. A landslide inventory was established for both areas using two Google Earth images taken on October 25th 2004 and on March 18th 2005, to map slope failures activated or reactivated during this interval. Geographic Information Systems (GIS) were used to prepare 5 m grids of the dependent variables (absence/presence of landslide) and independent variables (lithology and 13 DEM-derivatives). Multivariate Adaptive Regression Splines (MARS) were applied to model landslide susceptibility whereas receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were used to evaluate model performance. To evaluate the robustness of the whole procedure, we prepared 10 different samples of positive (landslide presence) and negative (landslide absence) cases for each area. Absences were selected through two different methods: (i) extraction from randomly distributed circles with a diameter corresponding to the mean width of the landslide source areas; and (ii) selection as randomly distributed individual grid cells. A comparison was also made between the predictive performances of models including and not including the lithology parameter. The models trained and tested on the same area demonstrated excellent to outstanding fit (AUC > 0.8). On the other hand, predictive skill decreases when measured outside the calibration area, although most of the landslides occur where susceptibility is high and the overall model performance is acceptable (AUC > 0.7). The results also showed that the accuracy of the landslide susceptibility models is higher when lithology is included in the statistical analysis. Models whose absences were selected using random circles showed a

  3. A probabilistic model for hydrokinetic turbine collision risks: exploring impacts on fish.

    Directory of Open Access Journals (Sweden)

    Linus Hammar

    Full Text Available A variety of hydrokinetic turbines are currently under development for power generation in rivers, tidal straits and ocean currents. Because some of these turbines are large, with rapidly moving rotor blades, the risk of collision with aquatic animals has been brought to attention. The behavior and fate of animals that approach such large hydrokinetic turbines have not yet been monitored at any detail. In this paper, we conduct a synthesis of the current knowledge and understanding of hydrokinetic turbine collision risks. The outcome is a generic fault tree based probabilistic model suitable for estimating population-level ecological risks. New video-based data on fish behavior in strong currents are provided and models describing fish avoidance behaviors are presented. The findings indicate low risk for small-sized fish. However, at large turbines (≥5 m, bigger fish seem to have high probability of collision, mostly because rotor detection and avoidance is difficult in low visibility. Risks can therefore be substantial for vulnerable populations of large-sized fish, which thrive in strong currents. The suggested collision risk model can be applied to different turbine designs and at a variety of locations as basis for case-specific risk assessments. The structure of the model facilitates successive model validation, refinement and application to other organism groups such as marine mammals.

  4. A probabilistic model for hydrokinetic turbine collision risks: exploring impacts on fish.

    Science.gov (United States)

    Hammar, Linus; Eggertsen, Linda; Andersson, Sandra; Ehnberg, Jimmy; Arvidsson, Rickard; Gullström, Martin; Molander, Sverker

    2015-01-01

    A variety of hydrokinetic turbines are currently under development for power generation in rivers, tidal straits and ocean currents. Because some of these turbines are large, with rapidly moving rotor blades, the risk of collision with aquatic animals has been brought to attention. The behavior and fate of animals that approach such large hydrokinetic turbines have not yet been monitored at any detail. In this paper, we conduct a synthesis of the current knowledge and understanding of hydrokinetic turbine collision risks. The outcome is a generic fault tree based probabilistic model suitable for estimating population-level ecological risks. New video-based data on fish behavior in strong currents are provided and models describing fish avoidance behaviors are presented. The findings indicate low risk for small-sized fish. However, at large turbines (≥5 m), bigger fish seem to have high probability of collision, mostly because rotor detection and avoidance is difficult in low visibility. Risks can therefore be substantial for vulnerable populations of large-sized fish, which thrive in strong currents. The suggested collision risk model can be applied to different turbine designs and at a variety of locations as basis for case-specific risk assessments. The structure of the model facilitates successive model validation, refinement and application to other organism groups such as marine mammals.

  5. Application of a catchment characterization hydrologic model for exploring parameter sensitivities in a boreal forest, discontinuous permafrost ecosystem

    Science.gov (United States)

    Morton, D.; Bolton, W. R.; Young, J.; Hinzman, L. D.

    2013-12-01

    Many of the expected climate-driven changes in sub-arctic ecosystems, such as increased temperature and precipitation, decreased permafrost extent, tree-line expansion and vegetation composition, have been identified as potential mechanisms that may lead to shifts in the Arctic Ocean freshwater budget. Understanding the feedback mechanisms of the water cycle are paramount, in that small changes may result in dramatic threshold changes in the hydrology, ecology and surface energy balance. As part of a study on how vegetation water use and permafrost dynamics impact stream flow in the boreal forest discontinuous permafrost zone, we are integrating a vegetation water use model and a simple, first-order, non-linear hydrological model, utilizing a Bayesian analysis approach to fully account for and propagate uncertainty through this modeling system. With an overall goal of improving parameterizations of large-scale hydrological models, we are constructing a simple and portable hydrologic model within a Bayesian framework. Thus, uncertainty associated with the evaporation (E), transpiration (T), precipitation (P), and streamflow (Q) submodels will be propagated into the final hydrology model. An immediate application of the modeling system will be used to explore the hydrological impacts of different vegetation distributions found in the boreal forest. In this work, we describe the basic structure of this flexible, object-oriented model and test its performance against collected basin data from headwater catchments of varying permafrost extent and ecosystem structure (deciduous versus coniferous vegetation). We will also do analyses to assess model sensitivity to each parameter (E, T, P, Q) and to different climate scenarios. This model is a major advancement for hydrological models that will aid in assessing sources of uncertainty in boreal hydrological systems.

  6. Using a Mixed Model to Explore Evaluation Criteria for Bank Supervision: A Banking Supervision Law Perspective.

    Directory of Open Access Journals (Sweden)

    Sang-Bing Tsai

    Full Text Available Financial supervision means that monetary authorities have the power to supervise and manage financial institutions according to laws. Monetary authorities have this power because of the requirements of improving financial services, protecting the rights of depositors, adapting to industrial development, ensuring financial fair trade, and maintaining stable financial order. To establish evaluation criteria for bank supervision in China, this study integrated fuzzy theory and the decision making trial and evaluation laboratory (DEMATEL and proposes a fuzzy-DEMATEL model. First, fuzzy theory was applied to examine bank supervision criteria and analyze fuzzy semantics. Second, the fuzzy-DEMATEL model was used to calculate the degree to which financial supervision criteria mutually influenced one another and their causal relationship. Finally, an evaluation criteria model for evaluating bank and financial supervision was established.

  7. Using a Mixed Model to Explore Evaluation Criteria for Bank Supervision: A Banking Supervision Law Perspective.

    Science.gov (United States)

    Tsai, Sang-Bing; Chen, Kuan-Yu; Zhao, Hongrui; Wei, Yu-Min; Wang, Cheng-Kuang; Zheng, Yuxiang; Chang, Li-Chung; Wang, Jiangtao

    2016-01-01

    Financial supervision means that monetary authorities have the power to supervise and manage financial institutions according to laws. Monetary authorities have this power because of the requirements of improving financial services, protecting the rights of depositors, adapting to industrial development, ensuring financial fair trade, and maintaining stable financial order. To establish evaluation criteria for bank supervision in China, this study integrated fuzzy theory and the decision making trial and evaluation laboratory (DEMATEL) and proposes a fuzzy-DEMATEL model. First, fuzzy theory was applied to examine bank supervision criteria and analyze fuzzy semantics. Second, the fuzzy-DEMATEL model was used to calculate the degree to which financial supervision criteria mutually influenced one another and their causal relationship. Finally, an evaluation criteria model for evaluating bank and financial supervision was established.

  8. Using a Mixed Model to Explore Evaluation Criteria for Bank Supervision: A Banking Supervision Law Perspective

    Science.gov (United States)

    Tsai, Sang-Bing; Chen, Kuan-Yu; Zhao, Hongrui; Wei, Yu-Min; Wang, Cheng-Kuang; Zheng, Yuxiang; Chang, Li-Chung; Wang, Jiangtao

    2016-01-01

    Financial supervision means that monetary authorities have the power to supervise and manage financial institutions according to laws. Monetary authorities have this power because of the requirements of improving financial services, protecting the rights of depositors, adapting to industrial development, ensuring financial fair trade, and maintaining stable financial order. To establish evaluation criteria for bank supervision in China, this study integrated fuzzy theory and the decision making trial and evaluation laboratory (DEMATEL) and proposes a fuzzy-DEMATEL model. First, fuzzy theory was applied to examine bank supervision criteria and analyze fuzzy semantics. Second, the fuzzy-DEMATEL model was used to calculate the degree to which financial supervision criteria mutually influenced one another and their causal relationship. Finally, an evaluation criteria model for evaluating bank and financial supervision was established. PMID:27992449

  9. Computational exploration of metaphor comprehension processes using a semantic space model.

    Science.gov (United States)

    Utsumi, Akira

    2011-03-01

    Recent metaphor research has revealed that metaphor comprehension involves both categorization and comparison processes. This finding has triggered the following central question: Which property determines the choice between these two processes for metaphor comprehension? Three competing views have been proposed to answer this question: the conventionality view (Bowdle & Gentner, 2005), aptness view (Glucksberg & Haught, 2006b), and interpretive diversity view (Utsumi, 2007); these views, respectively, argue that vehicle conventionality, metaphor aptness, and interpretive diversity determine the choice between the categorization and comparison processes. This article attempts to answer the question regarding which views are plausible by using cognitive modeling and computer simulation based on a semantic space model. In the simulation experiment, categorization and comparison processes are modeled in a semantic space constructed by latent semantic analysis. These two models receive word vectors for the constituent words of a metaphor and compute a vector for the metaphorical meaning. The resulting vectors can be evaluated according to the degree to which they mimic the human interpretation of the same metaphor; the maximum likelihood estimation determines which of the two models better explains the human interpretation. The result of the model selection is then predicted by three metaphor properties (i.e., vehicle conventionality, aptness, and interpretive diversity) to test the three views. The simulation experiment for Japanese metaphors demonstrates that both interpretive diversity and vehicle conventionality affect the choice between the two processes. On the other hand, it is found that metaphor aptness does not affect this choice. This result can be treated as computational evidence supporting the interpretive diversity and conventionality views. Copyright © 2010 Cognitive Science Society, Inc.

  10. A hybrid computational model to explore the topological characteristics of epithelial tissues.

    Science.gov (United States)

    González-Valverde, Ismael; García-Aznar, José Manuel

    2017-11-01

    Epithelial tissues show a particular topology where cells resemble a polygon-like shape, but some biological processes can alter this tissue topology. During cell proliferation, mitotic cell dilation deforms the tissue and modifies the tissue topology. Additionally, cells are reorganized in the epithelial layer and these rearrangements also alter the polygon distribution. We present here a computer-based hybrid framework focused on the simulation of epithelial layer dynamics that combines discrete and continuum numerical models. In this framework, we consider topological and mechanical aspects of the epithelial tissue. Individual cells in the tissue are simulated by an off-lattice agent-based model, which keeps the information of each cell. In addition, we model the cell-cell interaction forces and the cell cycle. Otherwise, we simulate the passive mechanical behaviour of the cell monolayer using a material that approximates the mechanical properties of the cell. This continuum approach is solved by the finite element method, which uses a dynamic mesh generated by the triangulation of cell polygons. Forces generated by cell-cell interaction in the agent-based model are also applied on the finite element mesh. Cell movement in the agent-based model is driven by the displacements obtained from the deformed finite element mesh of the continuum mechanical approach. We successfully compare the results of our simulations with some experiments about the topology of proliferating epithelial tissues in Drosophila. Our framework is able to model the emergent behaviour of the cell monolayer that is due to local cell-cell interactions, which have a direct influence on the dynamics of the epithelial tissue. Copyright © 2017 John Wiley & Sons, Ltd.

  11. Pain expressiveness and altruistic behavior: an exploration using agent-based modeling.

    Science.gov (United States)

    de C Williams, Amanda C; Gallagher, Elizabeth; Fidalgo, Antonio R; Bentley, Peter J

    2016-03-01

    Predictions which invoke evolutionary mechanisms are hard to test. Agent-based modeling in artificial life offers a way to simulate behaviors and interactions in specific physical or social environments over many generations. The outcomes have implications for understanding adaptive value of behaviors in context. Pain-related behavior in animals is communicated to other animals that might protect or help, or might exploit or predate. An agent-based model simulated the effects of displaying or not displaying pain (expresser/nonexpresser strategies) when injured and of helping, ignoring, or exploiting another in pain (altruistic/nonaltruistic/selfish strategies). Agents modeled in MATLAB interacted at random while foraging (gaining energy); random injury interrupted foraging for a fixed time unless help from an altruistic agent, who paid an energy cost, speeded recovery. Environmental and social conditions also varied, and each model ran for 10,000 iterations. Findings were meaningful in that, in general, contingencies that evident from experimental work with a variety of mammals, over a few interactions, were replicated in the agent-based model after selection pressure over many generations. More energy-demanding expression of pain reduced its frequency in successive generations, and increasing injury frequency resulted in fewer expressers and altruists. Allowing exploitation of injured agents decreased expression of pain to near zero, but altruists remained. Decreasing costs or increasing benefits of helping hardly changed its frequency, whereas increasing interaction rate between injured agents and helpers diminished the benefits to both. Agent-based modeling allows simulation of complex behaviors and environmental pressures over evolutionary time.

  12. Interactive effects of nanoparticles with other contaminants in aquatic organisms: Friend or foe?

    Science.gov (United States)

    Canesi, L; Ciacci, C; Balbi, T

    2015-10-01

    The increasing production and use of nanoparticles (NPs) will lead to their release into the aquatic environment, posing a potential threat to the health of aquatic organisms. Both in the water phase and in the sediments NPs could mix and interact with other pollutants, such as organic xenobiotics and heavy metals, leading to possible changes in their bioavailability/bioconcentration/toxicity. However, whether these interactive effects may lead to increased harmful effects in marine organisms is largely unknown. In this work, available data mainly obtained on carbon based NPs and n-TiO2, as examples of widespread NPs, in aquatic organisms are reviewed. Moreover, data are summarized on the interactive effects of n-TiO2 with 2,3,7,8-TCDD and Cd(2+), chosen as examples of common and persistent organic and inorganic contaminants, respectively, in the model marine bivalve Mytilus. The results reveal complex and often unexpected interactive responses of NPs with other pollutants, depending on type of contaminant and the endpoint measured, as well as differences in bioaccumulation. The results are discussed in relation with data obtained in freshwater organisms. Overall, information available so far indicate that interactive effects of NPs with other contaminants do not necessarily lead to increased toxicity or harmful effects in aquatic organisms. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. From Immunodeficiency to Humanization: The Contribution of Mouse Models to Explore HTLV-1 Leukemogenesis

    Directory of Open Access Journals (Sweden)

    Eléonore Pérès

    2015-12-01

    Full Text Available The first discovered human retrovirus, Human T-Lymphotropic Virus type 1 (HTLV-1, is responsible for an aggressive form of T cell leukemia/lymphoma. Mouse models recapitulating the leukemogenesis process have been helpful for understanding the mechanisms underlying the pathogenesis of this retroviral-induced disease. This review will focus on the recent advances in the generation of immunodeficient and human hemato-lymphoid system mice with a particular emphasis on the development of mouse models for HTLV-1-mediated pathogenesis, their present limitations and the challenges yet to be addressed.

  14. From Immunodeficiency to Humanization: The Contribution of Mouse Models to Explore HTLV-1 Leukemogenesis.

    Science.gov (United States)

    Pérès, Eléonore; Bagdassarian, Eugénie; This, Sébastien; Villaudy, Julien; Rigal, Dominique; Gazzolo, Louis; Duc Dodon, Madeleine

    2015-12-07

    The first discovered human retrovirus, Human T-Lymphotropic Virus type 1 (HTLV-1), is responsible for an aggressive form of T cell leukemia/lymphoma. Mouse models recapitulating the leukemogenesis process have been helpful for understanding the mechanisms underlying the pathogenesis of this retroviral-induced disease. This review will focus on the recent advances in the generation of immunodeficient and human hemato-lymphoid system mice with a particular emphasis on the development of mouse models for HTLV-1-mediated pathogenesis, their present limitations and the challenges yet to be addressed.

  15. Friend or foe: genetic and functional characterization of plant endophytic Pseudomonas aeruginosa.

    Science.gov (United States)

    Kumar, A; Munder, A; Aravind, R; Eapen, S J; Tümmler, B; Raaijmakers, J M

    2013-03-01

    Endophytic Pseudomonas aeruginosa strain BP35 was originally isolated from black pepper grown in the rain forest in Kerala, India. Strain PaBP35 was shown to provide significant protection to black pepper against infections by Phytophthora capsici and Radopholus similis. For registration and implementation in disease management programmes, several traits of PaBP35 were investigated including its endophytic behaviour, biocontrol activity, phylogeny and toxicity to mammals. The results showed that PaBP35 efficiently colonized black pepper shoots and displayed a typical spatiotemporal pattern in its endophytic movement with concomitant suppression of Phytophthora rot. Confocal laser scanning microscopy revealed high populations of PaBP35::gfp2 inside tomato plantlets, supporting its endophytic behaviour in other plant species. Polyphasic approaches to genotype PaBP35, including BOX-PCR, recN sequence analysis, multilocus sequence typing and comparative genome hybridization analysis, revealed its uniqueness among P. aeruginosa strains representing clinical habitats. However, like other P. aeruginosa strains, PaBP35 exhibited resistance to antibiotics, grew at 25-41°C and produced rhamnolipids and phenazines. PaBP35 displayed strong type II secretion effectors-mediated cytotoxicity on mammalian A549 cells. Coupled with pathogenicity in a murine airway infection model, we conclude that this plant endophytic strain is as virulent as clinical P. aeruginosa strains. Safety issues related to the selection of plant endophytic bacteria for crop protection are discussed. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  16. Amylin and its Analogs: A Friend or Foe for the Treatment of Alzheimer’s Disease?

    Directory of Open Access Journals (Sweden)

    Wei Qiao (Wendy eQiu

    2014-07-01

    Full Text Available Amylin, a gut-brain axis hormone, and amyloid-beta peptides (Aβ, a major component of the Alzheimer’s disease (AD brain, share several features, including similar β-sheet secondary structures, binding to the same receptor and being degraded by the same protease, insulin degrading enzyme (IDE. However, while amylin readily crosses the blood brain barrier (BBB and mediates several activities including improving glucose metabolism, relaxing cerebrovascular structure, modulating inflammatory reaction and perhaps enhancing neural regeneration, Aβ has no known physiological functions. Thus, abundant Aβ in the AD brain could block or interfere with the binding of amylin to its receptor and hinder its functions. Recent studies using AD animal models demonstrate that amylin and its analog reduce the AD pathology in the brain and improve cognitive impairment in AD. Given that, in addition to amyloid plaques and neurofibrillary tangles, perturbed cerebral glucose metabolism and cerebrovascular damage are the hallmarks of the AD brain, we propose that giving exogenous amylin type peptides have the potential to become a new avenue for the diagnosis and therapeutic of AD. Although amylin’s property of self-aggregation may be a limitation to developing it as a therapeutic for AD, its clinical analog, pramlintide containing 3 amino acid differences from amylin, does not aggregate like human amylin, but more potently mediates amylin’s activities in the brain. Pramlintide is an effective drug for diabetes with a favorable profile of safety. Thus a randomized, double-blind, placebo-controlled clinical trial should be conducted to examine the efficacy of pramlintide for AD. This review summarizes the knowledge and findings on amylin type peptides and discuss pros and cons for their potential for AD.

  17. Students Explore Fossil Creatures of the Cambrian Period Burgess Shale through Model-Making

    Science.gov (United States)

    Anderson, Andrea E.; Zhbanova, Ksenia; Gray, Phyllis; Teske, Jolene K.; Rule, Audrey C.

    2016-01-01

    This practical article features an arts-integrated science unit on fossils of the Burgess Shale for fourteen elementary/middle school students at a weeklong summer day camp. The day camp had a theme of recycling, reduction and reuse; all of the fossil models had substantial recycled components to support this theme. Next Generation Science…

  18. Leadership Development in Higher Education: Exploring Model Impact among Students and Alumni

    Science.gov (United States)

    Bommarito, Michael S.

    2012-01-01

    The purpose of this study was to investigate the impact of an institution-wide leadership development model on students at a private Christian university. The university being studied in this research made a significant commitment to the principles of servant-leadership as well as Kouzes and Posner's (2002) Leadership Challenge development…

  19. Empathy in Medical Students: Exploring the Impact of a Longitudinal Integrated Clerkship Model

    Science.gov (United States)

    Bergstresser, Kara

    2017-01-01

    Empathy is considered a significant factor in the physician-patient relationship. The current study examined the impact of a Longitudinal Integrated Clerkship (LIC) model on empathy and patient-centered attitude in medical students. Archival data were examined from 186 medical students at a medical college in the mid-Atlantic region of the United…

  20. Exploring a Method for Improving Turbulent Separated-Flow Predictions with kappa-omega Models

    Science.gov (United States)

    Rumsey, Christopher L.

    2009-01-01

    A particular failing of Reynolds-averaged Navier-Stokes separated turbulent flow computations is addressed within the context of a kappa-omega two-equation turbulence model. The failing is the tendency for turbulence models to under-predict turbulent shear stress in the shear layers of some separation bubbles, yielding late boundary layer reattachment and recovery. Inspired by unpublished work of Volker, Langtry, and Menter, the author undertook an independent investigation in an attempt to improve the ability of the Menter shear stress transport (SST) model to predict flowfield characteristics in and downstream of separation bubbles. The fix is an ad hoc term that is a function of the local ratio of turbulent production to dissipation; it is used to multiply the omega-destruction term, increasing eddy viscosity in separated regions. With this fix, several flowfields are investigated. Results show that, although the "separation fix" can provide dramatic improvement in some cases, it is not consistently good for all flows. Thus, although it may prove helpful in many situations in its current form, this model may benefit from further refinements, including better sensitization to the energetics of turbulence in the separated region.

  1. Exploration of the molecular basis of blast injury in a biofidelic model of traumatic brain injury

    Science.gov (United States)

    Thielen, P.; Mehoke, T.; Gleason, J.; Iwaskiw, A.; Paulson, J.; Merkle, A.; Wester, B.; Dymond, J.

    2017-10-01

    Biological response to blast overpressure is complex and results in various and potentially non-concomitant acute and long-term deficits to exposed individuals. Clinical links between blast severity and injury outcomes remain elusive and have yet to be fully described, resulting in a critical inability to develop associated protection and mitigation strategies. Further, experimental models frequently fail to reproduce observed physiological phenomena and/or introduce artifacts that confound analysis and reproducibility. New models are required that employ consistent mechanical inputs, scale with biological analogs and known clinical data, and permit high-throughput examination of biological responses for a range of environmental and battlefield- relevant exposures. Here we describe a novel, biofidelic headform capable of integrating complex biological samples for blast exposure studies. We additionally demonstrate its utility in detecting acute transcriptional responses in the model organism Caenorhabditis elegans after exposure to blast overpressure. This approach enables correlation between mechanical exposure and biological outcome, permitting both the enhancement of existing surrogate and computational models and the high-throughput biofidelic testing of current and future protection systems.

  2. Exploring the backward swimming ability of a robotic fish: Combining modelling and experiments

    National Research Council Canada - National Science Library

    Li, Liang; Wang, Chen; Fan, Ruifeng; Xie, Guangming

    2016-01-01

    .... After a series of online optimal experiments, we find several locomotion gaits that can make the robotic fish swim backward, and the corresponding fixed points are similarly located near the tail. The backward swimming velocity is strongly correlated with the fixed point position along the robotic fish body, which verifies the effectiveness of our fixed-point model.

  3. Exploring the applicability of a sustainable smallholder sourcing model in the black soybean case in Java

    NARCIS (Netherlands)

    Sjauw-Koen-Fa, August R.; Blok, Vincent; Omta, Onno

    2017-01-01

    Food and agribusiness multinational enterprises are redesigning their sourcing strategies to tap into the underused food production potential of small-scale farms in a way that improve farmers' livelihood. The problem is that current widely applied sourcing models do not include improvement of

  4. The Postsecondary Resource Trinity Model: Exploring the Interaction between Socioeconomic, Academic, and Institutional Resources

    Science.gov (United States)

    Giani, Matt S.

    2015-01-01

    The purpose of this study is to revisit the widely held assumption that the impact of socioeconomic background declines steadily across educational transitions, particularly at the postsecondary level. Sequential logit modeling, a staple methodological approach for estimating the relative impact of SES across educational stages, is applied to a…

  5. Science Inquiry into Local Animals: Structure and Function Explored through Model Making

    Science.gov (United States)

    Rule, Audrey C.; Tallakson, Denise A.; Glascock, Alex L.; Chao, Astoria

    2015-01-01

    This article describes an arts- and spatial thinking skill--integrated inquiry project applied to life science concepts from the Next Generation Science Standards for fourth grade students that focuses on two unifying or crosscutting themes: (1) structure (or "form") and function and (2) use of models. Students made observations and…

  6. Modeling low-carbon US electricity futures to explore impacts on national and regional water use

    Science.gov (United States)

    Clemmer, S.; Rogers, J.; Sattler, S.; Macknick, J.; Mai, T.

    2013-03-01

    The US electricity sector is currently responsible for more than 40% of both energy-related carbon dioxide emissions and total freshwater withdrawals for power plant cooling (EIA 2012a Annual Energy Outlook 2012 (Washington, DC: US Department of Energy), Kenny et al 2009 Estimated Use of Water in the United States 2005 (US Geological Survey Circular vol 1344) (Reston, VA: US Geological Survey)). Changes in the future electricity generation mix in the United States will have important implications for water use, particularly given the changing water availability arising from competing demands and climate change and variability. However, most models that are used to make long-term projections of the electricity sector do not have sufficient regional detail for analyzing water-related impacts and informing important electricity- and water-related decisions. This paper uses the National Renewable Energy Laboratory’s Regional Energy Deployment System (ReEDS) to model a range of low-carbon electricity futures nationally that are used to calculate changes in national water use (a sample result, on water consumption, is included here). The model also produces detailed sub-regional electricity results through 2050 that can be linked with basin-level water modeling. The results will allow for sufficient geographic resolution and detail to be relevant from a water management perspective.

  7. An Exploration of the System Dynamics Field : A Model-Based Policy Analysis

    NARCIS (Netherlands)

    Rose, A.C.

    2014-01-01

    This report presents a first look study at the field of System Dynamics. The objective of the study is to perform a model-based policy analysis in order to investigate the future advancement of the System Dynamics field. The aim of this investigation is to determine what this advancement should look

  8. Using the Mixture Rasch Model to Explore Knowledge Resources Students Invoke in Mathematic and Science Assessments

    Science.gov (United States)

    Zhang, Danhui; Orrill, Chandra; Campbell, Todd

    2015-01-01

    The purpose of this study was to investigate whether mixture Rasch models followed by qualitative item-by-item analysis of selected Programme for International Student Assessment (PISA) mathematics and science items offered insight into knowledge students invoke in mathematics and science separately and combined. The researchers administered an…

  9. Inquiry through Modeling: Exploring the Tensions between Natural & Sexual Selection Using Crickets

    Science.gov (United States)

    Bouwma-Gearhart, Jana; Bouwma, Andrew

    2015-01-01

    The "Next Generation Science Standards" (NGSS Lead States, 2013) recommend that science courses engage communities of students in scientific practices that include building accurate conceptual models of phenomena central to the understanding of scientific disciplines. We offer a set of activities, implemented successfully at both the…

  10. Exploring Gains in Reading and Mathematics Achievement among Regular and Exceptional Students Using Growth Curve Modeling

    Science.gov (United States)

    Shin, Tacksoo; Davison, Mark L.; Long, Jeffrey D.; Chan, Chi-Keung; Heistad, David

    2013-01-01

    Using four-wave longitudinal reading and mathematics data (4th to 7th grades) from a large urban school district, growth curve modeling was used as a tool for examining three research questions: Are achievement gaps closing in reading and mathematics? What are the associations between prior-achievement and growth across the reading and mathematics…

  11. Exploring Alternative Characteristic Curve Approaches to Linking Parameter Estimates from the Generalized Partial Credit Model.

    Science.gov (United States)

    Roberts, James S.; Bao, Han; Huang, Chun-Wei; Gagne, Phill

    Characteristic curve approaches for linking parameters from the generalized partial credit model were examined for cases in which common (anchor) items are calibrated separately in two groups. Three of these approaches are simple extensions of the test characteristic curve (TCC), item characteristic curve (ICC), and operating characteristic curve…

  12. Hybrid Methods and Atomistic Models to Explore Free Energies, Rates and Pathways of Protein Shape Changes

    DEFF Research Database (Denmark)

    Wang, Yong

    When I just joined the Lindor-Larsen group as a fresh PhD student, the Nobel Prize in Chemistry that year was awarded for the development of multiscale models for complex chemical systems" to prize the pioneering works of Martin Karplus, Michael Levitt and Arieh Warshel. As a computational biolog...

  13. Modelling with Difference Equations Supported by GeoGebra: Exploring the Kepler Problem

    Science.gov (United States)

    Kovacs, Zoltan

    2010-01-01

    The use of difference and differential equations in the modelling is a topic usually studied by advanced students in mathematics. However difference and differential equations appear in the school curriculum in many direct or hidden ways. Difference equations first enter in the curriculum when studying arithmetic sequences. Moreover Newtonian…

  14. Exploring Temporal Frameworks for Constructing Longitudinal Instance-Specific Models from Clinical Data

    Science.gov (United States)

    Watt, Emily

    2012-01-01

    The prevalence of the EMR in biomedical research is growing, the EMR being regarded as a source of contextually rich, longitudinal data for computation and statistical/trend analysis. However, models trained with data abstracted from the EMR often (1) do not capture all features needed to accurately predict the patient's future state and to…

  15. 2D lattice model of a lipid bilayer: Microscopic derivation and thermodynamic exploration

    Science.gov (United States)

    Hakobyan, Davit; Heuer, Andreas

    2017-02-01

    Based on all-atom Molecular Dynamics (MD) simulations of a lipid bilayer we present a systematic mapping on a 2D lattice model. Keeping the lipid type and the chain order parameter as key variables we derive a free energy functional, containing the enthalpic interaction of adjacent lipids as well as the tail entropy. The functional form of both functions is explicitly determined for saturated and polyunsaturated lipids. By studying the lattice model via Monte Carlo simulations it is possible to reproduce the temperature dependence of the distribution of order parameters of the pure lipids, including the prediction of the gel transition. Furthermore, application to a mixture of saturated and polyunsaturated lipids yields the correct phase separation behavior at lower temperatures with a simulation time reduced by approximately 7 orders of magnitude as compared to the corresponding MD simulations. Even the time-dependence of the de-mixing is reproduced on a semi-quantitative level. Due to the generality of the approach we envisage a large number of further applications, ranging from modeling larger sets of lipids, sterols, and solvent proteins to predicting nucleation barriers for the melting of lipids. Particularly, from the properties of the 2D lattice model one can directly read off the enthalpy and entropy change of the 1,2-dipalmitoyl-sn-glycero-3-phosphocholine gel-to-liquid transition in excellent agreement with experimental and MD results.

  16. Exploring causal networks of bovine milk fatty acids in a multivariate mixed model context

    NARCIS (Netherlands)

    Bouwman, A.C.; Valente, B.D.; Janss, L.L.G.; Bovenhuis, H.; Rosa, G.J.

    2014-01-01

    BACKGROUND: Knowledge regarding causal relationships among traits is important to understand complex biological systems. Structural equation models (SEM) can be used to quantify the causal relations between traits, which allow prediction of outcomes to interventions applied to such a network. Such

  17. Exploring topic-based language models for effective web information retrieval

    NARCIS (Netherlands)

    Li, R.; Kaptein, R.; Hiemstra, D.; Kamps, J.

    2008-01-01

    The main obstacle for providing focused search is the relative opaqueness of search request—searchers tend to express their complex information needs in only a couple of keywords. Our overall aim is to find out if, and how, topic-based language models can leads to more effective web information

  18. Exploring Topic-based Language Models for Effective Web Information Retrieval

    NARCIS (Netherlands)

    Li, R.; Kaptein, Rianne; Hiemstra, Djoerd; Kamps, Jaap; Hoenkamp, E.; De Cock, M.; Hoste, V.

    2008-01-01

    The main obstacle for providing focused search is the relative opaqueness of search request -- searchers tend to express their complex information needs in only a couple of keywords. Our overall aim is to find out if, and how, topic-based language models can lead to more effective web information

  19. Transcriptome and proteome exploration to model translation efficiency and protein stability in Lactococcus lactis.

    Directory of Open Access Journals (Sweden)

    Clémentine Dressaire

    2009-12-01

    Full Text Available This genome-scale study analysed the various parameters influencing protein levels in cells. To achieve this goal, the model bacterium Lactococcus lactis was grown at steady state in continuous cultures at different growth rates, and proteomic and transcriptomic data were thoroughly compared. Ratios of mRNA to protein were highly variable among proteins but also, for a given gene, between the different growth conditions. The modeling of cellular processes combined with a data fitting modeling approach allowed both translation efficiencies and degradation rates to be estimated for each protein in each growth condition. Estimated translational efficiencies and degradation rates strongly differed between proteins and were tested for their biological significance through statistical correlations with relevant parameters such as codon or amino acid bias. These efficiencies and degradation rates were not constant in all growth conditions and were inversely proportional to the growth rate, indicating a more efficient translation at low growth rate but an antagonistic higher rate of protein degradation. Estimated protein median half-lives ranged from 23 to 224 min, underlying the importance of protein degradation notably at low growth rates. The regulation of intracellular protein level was analysed through regulatory coefficient calculations, revealing a complex control depending on protein and growth conditions. The modeling approach enabled translational efficiencies and protein degradation rates to be estimated, two biological parameters extremely difficult to determine experimentally and generally lacking in bacteria. This method is generic and can now be extended to other environments and/or other micro-organisms.

  20. Prostitution and Human Trafficking : A model-based exploration and policy analysis

    NARCIS (Netherlands)

    Kovari, A.; Pruyt, E.

    2012-01-01

    The meeting of the oldest profession with modern slavery is the topic of this paper. After a brief introduction to prostitution and prostitution-related human trafficking, this paper focuses on the Dutch policy debate. A System Dynamics simulation model related to the Dutch situation developed to

  1. Exploring Use of New Media in Environmental Education Contexts: Introducing Visitors' Technology Use in Zoos Model

    Science.gov (United States)

    Yocco, Victor; Danter, Elizabeth H.; Heimlich, Joseph E.; Dunckel, Betty A.; Myers, Chris

    2011-01-01

    Modern zoological gardens have invested substantial resources in technology to deliver environmental education concepts to visitors. Investment in these media reflects a currently unsubstantiated belief that visitors will both use and learn from these media alongside more traditional and less costly displays. This paper proposes a model that…

  2. Exploring Environmental Factors in Nursing Workplaces That Promote Psychological Resilience: Constructing a Unified Theoretical Model.

    Science.gov (United States)

    Cusack, Lynette; Smith, Morgan; Hegney, Desley; Rees, Clare S; Breen, Lauren J; Witt, Regina R; Rogers, Cath; Williams, Allison; Cross, Wendy; Cheung, Kin

    2016-01-01

    Building nurses' resilience to complex and stressful practice environments is necessary to keep skilled nurses in the workplace and ensuring safe patient care. A unified theoretical framework titled Health Services Workplace Environmental Resilience Model (HSWERM), is presented to explain the environmental factors in the workplace that promote nurses' resilience. The framework builds on a previously-published theoretical model of individual resilience, which identified the key constructs of psychological resilience as self-efficacy, coping and mindfulness, but did not examine environmental factors in the workplace that promote nurses' resilience. This unified theoretical framework was developed using a literary synthesis drawing on data from international studies and literature reviews on the nursing workforce in hospitals. The most frequent workplace environmental factors were identified, extracted and clustered in alignment with key constructs for psychological resilience. Six major organizational concepts emerged that related to a positive resilience-building workplace and formed the foundation of the theoretical model. Three concepts related to nursing staff support (professional, practice, personal) and three related to nursing staff development (professional, practice, personal) within the workplace environment. The unified theoretical model incorporates these concepts within the workplace context, linking to the nurse, and then impacting on personal resilience and workplace outcomes, and its use has the potential to increase staff retention and quality of patient care.

  3. The MeLiM Minipig: An Original Spontaneous Model to Explore Cutaneous Melanoma Genetic Basis

    Directory of Open Access Journals (Sweden)

    Emmanuelle Bourneuf

    2017-10-01

    Full Text Available Melanoma is the deadliest skin cancer and is a major public health concern with a growing incidence worldwide. As for other complex diseases, animal models are needed in order to better understand the mechanisms leading to pathology, identify potential biomarkers to be used in the clinics, and eventually molecular targets for therapeutic solutions. Cutaneous melanoma, arising from skin melanocytes, is mainly caused by environmental factors such as UV radiation; however a significant genetic component participates in the etiology of the disease. The pig is a recognized model for spontaneous development of melanoma with features similar to the human ones, followed by a complete regression and a vitiligo-like depigmentation. Three different pig models (MeLiM, Sinclair, and MMS-Troll have been maintained through the last decades, and different genetic studies have evidenced a complex inheritance of the disease. As in humans, pigmentation seems to play a prominent role, notably through MC1R and MITF signaling. Conversely, cell cycle genes as CDKN2A and CDK4 have been excluded as predisposing for melanoma in MeLiM. So far, only sparse studies have focused on somatic changes occurring during oncogenesis, and have revealed major cytological changes and a potential dysfunction of the telomere maintenance system. Finally, the spontaneous tumor progression and regression occurring in these models could shed light on the interplay between endogenous retroviruses, melanomagenesis, and adaptive immune response.

  4. Exploring the Darkside of Courtship: A Test of a Model of Male Premarital Sexual Aggression.

    Science.gov (United States)

    Christopher, F. Scott; And Others

    1993-01-01

    Tested model of male premarital sexual aggressiveness among 184 single men. Analysis supported inclusion of sexual promiscuity and lack of empathy as exogenous variables, and violent attitudes, hostility toward women, anger, and negative relationship experiences as endogenous variables. Second study involving 249 single males cross-validated…

  5. Exploration of a leadership competency model for medical school faculties in Korea.

    Science.gov (United States)

    Lee, Yong Seok; Oh, Dong Keun; Kim, Myungun; Lee, Yoon Seong; Shin, Jwa Seop

    2010-12-01

    To adapt to rapid and turbulent changes in the field of medicine, education, and society, medical school faculties need appropriate leadership. To develop leadership competencies through education, coaching, and mentoring, we need a leadership competency model. The purpose of this study was to develop a new leadership competency model that is suitable for medical school faculties in Korea. To collect behavioral episodes with regard to leadership, we interviewed 54 subjects (faculties, residents, nurses) and surveyed 41 faculties with open-ended questionnaires. We classified the behavioral episodes based on Quinn and Cameron's leadership competency model and developed a Likert scale questionnaire to perform a confirmatory factor analysis. Two hundred seven medical school faculties responded to the questionnaire. The competency clusters that were identified by factor analysis were professionalism, citizenship, leadership, and membership to an organization. Accordingly, each cluster was linked with a dimension: self, society, team (that he/she is leading), and organization (to which he/she belongs). The clusters of competencies were: professional ability, ethics/morality, self-management, self-development, and passion; public interest, networking, social participation, and active service; motivating, caring, promoting teamwork, nurturing, conflict management, directing, performance management, and systems thinking; organizational orientation, collaboration, voluntary participation, and cost-benefit orientation. This competency model that fits medical school faculties in Korea can be used to design and develop selection plans, education programs, feedback tools, diagnostic evaluation tools, and career plan support programs.

  6. Exploring into the New Model Procedure in Translation: Wafting as a Case in Point

    Science.gov (United States)

    Akbari, Alireza

    2013-01-01

    Choosing the near equivalence for translator is of great concern nowadays. While it seems more commitment has been given to this issue, yet there are still rooms for more attention to innovative methods of Translation Studies in this direction. The idea of wafting procedure in Intermediacy model of translation comes from a book by Alireza Akbari…

  7. Exploring the Postgraduate Research Climate and the Postgraduate Research Experience: A Conceptual Model

    Science.gov (United States)

    Govender, K. K.

    2011-01-01

    The objective of this article is to develop a conceptual model aimed at improving the postgraduate research students' experience. Since postgraduate students "vote with their feet" an improved understanding of the postgraduate research service encounter may result in improving the quality of the encounter and so increasing throughput and…

  8. Integrated health impact assessment of travel behaviour: model exploration and application to a fuel price increase.

    Science.gov (United States)

    Dhondt, Stijn; Kochan, Bruno; Beckx, Carolien; Lefebvre, Wouter; Pirdavani, Ali; Degraeuwe, Bart; Bellemans, Tom; Int Panis, Luc; Macharis, Cathy; Putman, Koen

    2013-01-01

    Transportation policy measures often aim to change travel behaviour towards more efficient transport. While these policy measures do not necessarily target health, these could have an indirect health effect. We evaluate the health impact of a policy resulting in an increase of car fuel prices by 20% on active travel, outdoor air pollution and risk of road traffic injury. An integrated modelling chain is proposed to evaluate the health impact of this policy measure. An activity-based transport model estimated movements of people, providing whereabouts and travelled kilometres. An emission- and dispersion model provided air quality levels (elemental carbon) and a road safety model provided the number of fatal and non-fatal traffic victims. We used kilometres travelled while walking or cycling to estimate the time in active travel. Differences in health effects between the current and fuel price scenario were expressed in Disability Adjusted Life Years (DALY). A 20% fuel price increase leads to an overall gain of 1650 (1010-2330) DALY. Prevented deaths lead to a total of 1450 (890-2040) Years Life Gained (YLG), with better air quality accounting for 530 (180-880) YLG, fewer road traffic injuries for 750 (590-910) YLG and active travel for 170 (120-250) YLG. Concerning morbidity, mostly road safety led to 200 (120-290) fewer Years Lived with Disability (YLD), while air quality improvement only had a minor effect on cardiovascular hospital admissions. Air quality improvement and increased active travel mainly had an impact at older age, while traffic safety mainly affected younger and middle-aged people. This modelling approach illustrates the feasibility of a comprehensive health impact assessment of changes in travel behaviour. Our results suggest that more is needed than a policy rising car fuel prices by 20% to achieve substantial health gains. While the activity-based model gives an answer on what the effect of a proposed policy is, the focus on health may make

  9. Using High-Level RTOS Models for HW/SW Embedded Architecture Exploration: Case Study on Mobile Robotic Vision

    Directory of Open Access Journals (Sweden)

    Verdier François

    2008-01-01

    Full Text Available Abstract We are interested in the design of a system-on-chip implementing the vision system of a mobile robot. Following a biologically inspired approach, this vision architecture belongs to a larger sensorimotor loop. This regulation loop both creates and exploits dynamics properties to achieve a wide variety of target tracking and navigation objectives. Such a system is representative of numerous flexible and dynamic applications which are more and more encountered in embedded systems. In order to deal with all of the dynamic aspects of these applications, it appears necessary to embed a dedicated real-time operating system on the chip. The presence of this on-chip custom executive layer constitutes a major scientific obstacle in the traditional hardware and software design flows. Classical exploration and simulation tools are particularly inappropriate in this case. We detail in this paper the specific mechanisms necessary to build a high-level model of an embedded custom operating system able to manage such a real-time but flexible application. We also describe our executable RTOS model written in SystemC allowing an early simulation of our application on top of its specific scheduling layer. Based on this model, a methodology is discussed and results are given on the exploration and validation of a distributed platform adapted to this vision system.

  10. Exploring Systematic Yield Risk and Its Strengthening Factors for Apple Product in Iran: Application of Spatial Autoregressive Models

    Directory of Open Access Journals (Sweden)

    habib salami

    2014-03-01

    Full Text Available The presence of yield systematic risk in agricultural sector is one of the main reasons for facing this sector with huge damages and is one of the restricting factors in developing agricultural insurance in Iran. This study explores the presence of systematic yield risk and the extent and severity of yield spatial dependence for apple production in Iran. To this end, the apple production regions were grouped into two climatic regions based on their thermal regimes. In the second step, systematic yield risk was explored using the first order spatial autoregressive (FAR model in each of the two climatic regions.Finally, the effects of climatic variables on the yield of apple have been estimated using more general spatial autoregressive models. Results indicate that apple production regions can be classified into two mountainous and plain regions. Apple yields are correlated across space in each of the two regions. Frost in the first region and drought in the second region is accounted for the presence of systematic yield risk in apple production in Iran. Results from more general models revealed that one year lag of drought, the occurrence of frost in March, average of temperature in June and July, total annual precipitation, and variation of precipitation are important climate variables that affect apple yield in Iran.

  11. Knowledge-driven GIS modeling technique for gold exploration, Bulghah gold mine area, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Ahmed A. Madani

    2011-12-01

    Full Text Available This research aims to generate a favorability map for gold exploration at the Bulghah gold mine area using integration of geo-datasets within a GIS environment. Spatial data analyses and integration of different geo-datasets are carried out based on knowledge-driven and weighting technique. The integration process involves the weighting and scoring of different layers affecting the gold mineralization at the study area using the index overlay method within PCI Geomatica environment. Generation of the binary predictor maps for lithology, lineaments, faults and favorable contacts precede the construction of the favorability map. About 100 m buffer zones are generated for favorable contacts, lineaments and major faults layers. Internal weighting is assigned to each layer based on favorability for gold mineralization. The scores for lithology, major faults, lineaments and favorable contacts layers in the constructed favorability map are 50%, 25%, 10% and 15%, respectively. Final favorability map for the Bulghah gold mine area shows the recording of two new sites for gold mineralization located at the northern and southern extensions of tonalite–diorite intrusions. The northern new site is now exploited for gold from the Bulghah North mine. The southern new site is narrow and small; its rocks resemble those of the Bulghah gold mine.

  12. Exploring Mathematics Achievement Goals Using Kolb’s Learning Style Model

    Directory of Open Access Journals (Sweden)

    Avelino G. Ignacio Jr.

    2017-02-01

    Full Text Available This research work is an exploration of causality connection of learning styles to mathematics achievement goals. The objectives of the study are as follows: (1 to identify the mathematics achievement goal of students when grouped according to preferred learning style (2 to identify the learning style of students when grouped according to preferred mathematics achievement goal and (3 to determine if there is a significant difference in each mathematics achievement goal when grouped according to learning style. The researcher used explanatory cross-sectional design. The Revised Achievement Goal Questionnaire and Kolb’s Learning Style Inventory 3.1 were utilized to collect data. Results show that respondents hold mastery-approach achievement goals regardless of learning styles. Also, students with approach type of mathematics achievement goals hold assimilative learning style which operates on reflective observation and abstract conceptualization; and students with avoidance type of mathematics achievement goals hold accommodative learning style which operates on active experimentation and concrete experimentation. Furthermore, findings show that there is no significant difference in the mathematics achievement goals based on learning style. Exploratory research is recommended to understand why students with approach type of mathematics achievement goals hold assimilative learning style and why students with avoidance type of mathematics achievement goals hold accommodative learning style.

  13. Planning ahead for asteroid and comet hazard mitigation, phase 1: parameter space exploration and scenario modeling

    Energy Technology Data Exchange (ETDEWEB)

    Plesko, Catherine S [Los Alamos National Laboratory; Clement, R Ryan [Los Alamos National Laboratory; Weaver, Robert P [Los Alamos National Laboratory; Bradley, Paul A [Los Alamos National Laboratory; Huebner, Walter F [Los Alamos National Laboratory

    2009-01-01

    The mitigation of impact hazards resulting from Earth-approaching asteroids and comets has received much attention in the popular press. However, many questions remain about the near-term and long-term, feasibility and appropriate application of all proposed methods. Recent and ongoing ground- and space-based observations of small solar-system body composition and dynamics have revolutionized our understanding of these bodies (e.g., Ryan (2000), Fujiwara et al. (2006), and Jedicke et al. (2006)). Ongoing increases in computing power and algorithm sophistication make it possible to calculate the response of these inhomogeneous objects to proposed mitigation techniques. Here we present the first phase of a comprehensive hazard mitigation planning effort undertaken by Southwest Research Institute and Los Alamos National Laboratory. We begin by reviewing the parameter space of the object's physical and chemical composition and trajectory. We then use the radiation hydrocode RAGE (Gittings et al. 2008), Monte Carlo N-Particle (MCNP) radiation transport (see Clement et al., this conference), and N-body dynamics codes to explore the effects these variations in object properties have on the coupling of energy into the object from a variety of mitigation techniques, including deflection and disruption by nuclear and conventional munitions, and a kinetic impactor.

  14. The Exploration of an Objective Model for Roughness With Several Acoustic Markers.

    Science.gov (United States)

    Latoszek, Ben Barsties V; De Bodt, Marc; Gerrits, Ellen; Maryn, Youri

    2017-05-29

    In voice assessment, the evaluation of voice quality is a major component in which roughness has received wide acceptance as a major subtype of abnormal voice quality. The aim of the present study was to develop a new multivariate acoustic model for the evaluation of roughness. In total, 970 participants with dysphonia and 88 participants with normal voice were included. Concatenated voice samples of continuous speech and sustained vowel [a:] were perceptually judged on roughness severity. Acoustic analyses were conducted on the voiced segments of the continuous speech sample plus sustained vowel as well. A stepwise multiple linear regression analysis was applied to construct an acoustic model of the best acoustic predictors. Concurrent validity, diagnostic accuracy, and cross-validation were verified on the basis of Spearman correlation coefficient (r s ), several estimates of the receiver operating characteristics plus the likelihood ratio, and iterated internal cross-correlations. Six experts were included for perceptual analysis based on acceptable rater reliability. Stepwise multiple regression analysis yielded a 12-variable acoustic model. A marked correlation was identified between the model and the perceptual judgment (r s  = 0.731, P = 0.000). The cross-correlations confirmed a high comparable degree of association. However, the receiver operating characteristics and likelihood ratio results showed the best diagnostic outcome at a threshold of 2.92, with a sensitivity of 51.9% and a specificity of 94.9%. Currently, the newly developed roughness model is not recommended for clinical practice. Further research is needed to detect the acoustic complexity of roughness (eg, multiplophonia, irregularity, chaotic structure, glottal fry, etc). Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  15. Using Google Earth to Explore Strain Rate Models of Southern California

    Science.gov (United States)

    Richard, G. A.; Bell, E. A.; Holt, W. E.

    2007-12-01

    A series of strain rate models for the Transverse Ranges of southern California were developed based on Quaternary fault slip data and geodetic data from high precision GPS stations in southern California. Pacific-North America velocity boundary conditions are applied for all models. Topography changes are calculated using the model dilatation rates, which predict crustal thickness changes under the assumption of Airy isostasy and a specified rate of crustal volume loss through erosion. The models were designed to produce graphical and numerical output representing the configuration of the region from 3 million years ago to 3 million years into the future at intervals of 50 thousand years. Using a North American reference frame, graphical output for the topography and faults and numerical output for locations of faults and points on the crust marked by the locations on cities were used to create data in KML format that can be used in Google Earth to represent time intervals of 50 thousand years. As markers familiar to students, the cities provide a geographic context that can be used to quantify crustal movement, using the Google Earth ruler tool. By comparing distances that markers for selected cities have moved in various parts of the region, students discover that the greatest amount of crustal deformation has occurred in the vicinity of the boundary between the North American and Pacific plates. Students can also identify areas of compression or extension by finding pairs of city markers that have converged or diverged, respectively, over time. The Google Earth layers also reveal that faults that are not parallel to the plate boundary have tended to rotate clockwise due to the right lateral motion along the plate boundary zone. KML TimeSpan markup was added to two versions of the model, enabling the layers to be displayed in an automatic sequenced loop for a movie effect. The data is also available as QuickTime (.mov) and Graphics Interchange Format (.gif

  16. The multi-component model of working memory: explorations in experimental cognitive psychology.

    Science.gov (United States)

    Repovs, G; Baddeley, A

    2006-04-28

    There are a number of ways one can hope to describe and explain cognitive abilities, each of them contributing a unique and valuable perspective. Cognitive psychology tries to develop and test functional accounts of cognitive systems that explain the capacities and properties of cognitive abilities as revealed by empirical data gathered by a range of behavioral experimental paradigms. Much of the research in the cognitive psychology of working memory has been strongly influenced by the multi-component model of working memory [Baddeley AD, Hitch GJ (1974) Working memory. In: Recent advances in learning and motivation, Vol. 8 (Bower GA, ed), pp 47-90. New York: Academic Press; Baddeley AD (1986) Working memory. Oxford, UK: Clarendon Press; Baddeley A. Working memory: Thought and action. Oxford: Oxford University Press, in press]. By expanding the notion of a passive short-term memory to an active system that provides the basis for complex cognitive abilities, the model has opened up numerous questions and new lines of research. In this paper we present the current revision of the multi-component model that encompasses a central executive, two unimodal storage systems: a phonological loop and a visuospatial sketchpad, and a further component, a multimodal store capable of integrating information into unitary episodic representations, termed episodic buffer. We review recent empirical data within experimental cognitive psychology that has shaped the development of the multicomponent model and the understanding of the capacities and properties of working memory. Research based largely on dual-task experimental designs and on neuropsychological evidence has yielded valuable information about the fractionation of working memory into independent stores and processes, the nature of representations in individual stores, the mechanisms of their maintenance and manipulation, the way the components of working memory relate to each other, and the role they play in other

  17. Friend or Foe? Flipped Classroom for Undergraduate Electrocardiogram Learning: a Randomized Controlled Study.

    Science.gov (United States)

    Rui, Zeng; Lian-Rui, Xiang; Rong-Zheng, Yue; Jing, Zeng; Xue-Hong, Wan; Chuan, Zuo

    2017-03-07

    Interpreting an electrocardiogram (ECG) is not only one of the most important parts of clinical diagnostics but also one of the most difficult topics to teach and learn. In order to enable medical students to master ECG interpretation skills in a limited teaching period, the flipped teaching method has been recommended by previous research to improve teaching effect on undergraduate ECG learning. A randomized controlled trial for ECG learning was conducted, involving 181 junior-year medical undergraduates using a flipped classroom as an experimental intervention, compared with Lecture-Based Learning (LBL) as a control group. All participants took an examination one week after the intervention by analysing 20 ECGs from actual clinical cases and submitting their ECG reports. A self-administered questionnaire was also used to evaluate the students' attitudes, total learning time, and conditions under each teaching method. The students in the experimental group scored significantly higher than the control group (8.72 ± 1.01 vs 8.03 ± 1.01, t = 4.549, P = 0.000) on ECG interpretation. The vast majority of the students in the flipped classroom group held positive attitudes toward the flipped classroom method and also supported LBL. There was no significant difference (4.07 ± 0.96 vs 4.16 ± 0.89, Z = - 0.948, P = 0.343) between the groups. Prior to class, the students in the flipped class group devoted significantly more time than those in the control group (42.33 ± 22.19 vs 30.55 ± 10.15, t = 4.586, P = 0.000), whereas after class, the time spent by the two groups were not significantly different (56.50 ± 46.80 vs 54.62 ± 31.77, t = 0.317, P = 0.752). Flipped classroom teaching can improve medical students' interest in learning and their self-learning abilities. It is an effective teaching model that needs to be further studied and promoted.

  18. Integrating social capital theory, social cognitive theory, and the technology acceptance model to explore a behavioral model of telehealth systems.

    Science.gov (United States)

    Tsai, Chung-Hung

    2014-05-07

    Telehealth has become an increasingly applied solution to delivering health care to rural and underserved areas by remote health care professionals. This study integrated social capital theory, social cognitive theory, and the technology acceptance model (TAM) to develop a comprehensive behavioral model for analyzing the relationships among social capital factors (social capital theory), technological factors (TAM), and system self-efficacy (social cognitive theory) in telehealth. The proposed framework was validated with 365 respondents from Nantou County, located in Central Taiwan. Structural equation modeling (SEM) was used to assess the causal relationships that were hypothesized in the proposed model. The finding indicates that elderly residents generally reported positive perceptions toward the telehealth system. Generally, the findings show that social capital factors (social trust, institutional trust, and social participation) significantly positively affect the technological factors (perceived ease of use and perceived usefulness respectively), which influenced usage intention. This study also confirmed that system self-efficacy was the salient antecedent of perceived ease of use. In addition, regarding the samples, the proposed model fitted considerably well. The proposed integrative psychosocial-technological model may serve as a theoretical basis for future research and can also offer empirical foresight to practitioners and researchers in the health departments of governments, hospitals, and rural communities.

  19. Integrating Social Capital Theory, Social Cognitive Theory, and the Technology Acceptance Model to Explore a Behavioral Model of Telehealth Systems

    Science.gov (United States)

    Tsai, Chung-Hung

    2014-01-01

    Telehealth has become an increasingly applied solution to delivering health care to rural and underserved areas by remote health care professionals. This study integrated social capital theory, social cognitive theory, and the technology acceptance model (TAM) to develop a comprehensive behavioral model for analyzing the relationships among social capital factors (social capital theory), technological factors (TAM), and system self-efficacy (social cognitive theory) in telehealth. The proposed framework was validated with 365 respondents from Nantou County, located in Central Taiwan. Structural equation modeling (SEM) was used to assess the causal relationships that were hypothesized in the proposed model. The finding indicates that elderly residents generally reported positive perceptions toward the telehealth system. Generally, the findings show that social capital factors (social trust, institutional trust, and social participation) significantly positively affect the technological factors (perceived ease of use and perceived usefulness respectively), which influenced usage intention. This study also confirmed that system self-efficacy was the salient antecedent of perceived ease of use. In addition, regarding the samples, the proposed model fitted considerably well. The proposed integrative psychosocial-technological model may serve as a theoretical basis for future research and can also offer empirical foresight to practitioners and researchers in the health departments of governments, hospitals, and rural communities. PMID:24810577

  20. Integrating Social Capital Theory, Social Cognitive Theory, and the Technology Acceptance Model to Explore a Behavioral Model of Telehealth Systems

    Directory of Open Access Journals (Sweden)

    Chung-Hung Tsai

    2014-05-01

    Full Text Available Telehealth has become an increasingly applied solution to delivering health care to rural and underserved areas by remote health care professionals. This study integrated social capital theory, social cognitive theory, and the technology acceptance model (TAM to develop a comprehensive behavioral model for analyzing the relationships among social capital factors (social capital theory, technological factors (TAM, and system self-efficacy (social cognitive theory in telehealth. The proposed framework was validated with 365 respondents from Nantou County, located in Central Taiwan. Structural equation modeling (SEM was used to assess the causal relationships that were hypothesized in the proposed model. The finding indicates that elderly residents generally reported positive perceptions toward the telehealth system. Generally, the findings show that social capital factors (social trust, institutional trust, and social participation significantly positively affect the technological factors (perceived ease of use and perceived usefulness respectively, which influenced usage intention. This study also confirmed that system self-efficacy was the salient antecedent of perceived ease of use. In addition, regarding the samples, the proposed model fitted considerably well. The proposed integrative psychosocial-technological model may serve as a theoretical basis for future research and can also offer empirical foresight to practitioners and researchers in the health departments of governments, hospitals, and rural communities.

  1. Exploration and Modeling of Structural changes in Waste Glass Under Corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Pantano, Carlos; Ryan, Joseph; Strachan, Denis

    2013-11-10

    Vitrification is currently the world-wide treatment of choice for the disposition of high-level nuclear wastes. In glasses, radionuclides are atomistically bonded into the solid, resulting in a highly durable product, with borosilicate glasses exhibiting particularly excellent durability in water. Considering that waste glass is designed to retain the radionuclides within the waste form for long periods, it is important to understand the long-term stability of these materials when they react in the environment, especially in the presence of water. Based on a number of previous studies, there is general consensus regarding the mechanisms controlling the initial rate of nuclear waste glass dissolution. Agreement regarding the cause of the observed decrease in dissolution rate at extended times, however, has been elusive. Two general models have been proposed to explain this behavior, and it has been concluded that both concepts are valid and must be taken into account when considering the decrease in dissolution rate. Furthermore, other processes such as water diffusion, ion exchange, and precipitation of mineral phases onto the glass surface may occur in parallel with dissolution of the glass and can influence long-term performance. Our proposed research will address these issues through a combination of aqueous-phase dissolution/reaction experiments and probing of the resulting surface layers with state-of-the-art analytical methods. These methods include solid-state nuclear magnetic resonance (SSNMR) and time-of-flight secondary ion mass spectrometry (TOF-SIMS). The resulting datasets will then be coupled with computational chemistry and reaction-rate modeling to address the most persistent uncertainties in the understanding of glass corrosion, which indeed have limited the performance of the best corrosion models to date. With an improved understanding of corrosion mechanisms, models can be developed and improved that, while still conservative, take advantage of

  2. Hydrologic Predictions in the Anthropocene: Exploration with Co-evolutionary Socio-hydrologic Models

    Science.gov (United States)

    Sivapalan, Murugesu; Tian, Fuqiang; Liu, Dengfeng

    2013-04-01

    Socio-hydrology studies the co-evolution and self-organization of humans in the hydrologic landscape, which requires a thorough understanding of the complex interactions between humans and water. On the one hand, the nature of water availability greatly impacts the development of society. On the other hand, humans can significantly alter the spatio-temporal distribution of water and in this way provide feedback to the society itself. The human-water system functions underlying such complex human-water interactions are not well understood. Exploratory models with the appropriate level of simplification in any given area can be valuable to understand these functions and the self-organization associated with socio-hydrology. In this study, a simple coupled modeling framework for socio-hydrology co-evolution is developed, and is used to illustrate the explanatory power of such models. In the Tarim River, humans depend heavily on agricultural production (other industries can be ignored for a start), and the social processes can be described principally by two variables, i.e., irrigated-area and human population. The eco-hydrological processes are expressed in terms of area under natural vegetation and stream discharge. The study area is the middle and the lower reaches of the Tarim River, which is divided into two modeling units, i.e. middle reach and lower reach. In each modeling unit, four ordinary differential equations are used to simulate the dynamics of the hydrological system represented by stream discharge, ecological system represented by area under natural vegetation, the economic system represented by irrigated area under agriculture and social system represented by human population. The four dominant variables are coupled together by several internal variables. For example, the stream discharge is coupled to irrigated area by the colonization rate and mortality rate of the irrigated area in the middle reach and the irrigated area is coupled to stream

  3. Developing Terrestrial Trophic Models for Petroleum and Natural Gas Exploration and Production Sites: The Oklahoma Tallgrass Prairie Preserve Example

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, M; Coty, J; Stewart, J; Carlsen, T; Callaham, M

    2001-01-26

    This document details procedures to be used when constructing a conceptual terrestrial trophic model for natural gas and oil exploration and production sites. A site conceptual trophic model is intended for use in evaluating ecological impacts of oil and brine releases at E&P sites from a landscape or ecosystem perspective. The terrestrial trophic model protocol was developed using an example site, the Tallgrass Prairie Preserve (TPP) in Oklahoma. The procedure focuses on developing a terrestrial trophic model using information found in the primary literature, and augmented using site-specific research where available. Although the TPP has been the subject of considerable research and public interest since the high-profile reintroduction of bison (Bison bison) in 1993, little formal work has been done to develop a food web for the plant and animal communities found at the preserve. We describe how to divide species into guilds using explicit criteria on the basis of resource use and spatial distribution. For the TPP, sixteen guilds were developed for use in the trophic model, and the relationships among these guilds were analyzed. A brief discussion of the results of this model is provided, along with considerations for its use and areas for further study.

  4. Use of Danish Heat Atlas and energy system models for exploring renewable energy scenarios

    DEFF Research Database (Denmark)

    Petrovic, Stefan; Karlsson, Kenneth Bernard

    2013-01-01

    networks in relation with significant heat saving measures that are capital intensive infrastructure investments require highly detailed decision - support tools. The Heat Atlas for Denmark provides a highly detailed database and includes heat demand and possible heat savings for about 2.5 million...... buildings with associated costs included. Energy systems modelling tools that incorporate economic, environmental, energy and engineering analysis of future energy systems are considered crucial for quantitative assessment of transitional scenarios towards future milestones, such as (i) EU 2020 goals...... of reducing greenhouse gas emissions, increasing share of renewable energy and improving energy efficiency and (ii) Denmark’s 2050 goals of covering entire energy supply by renewable energy. Optimization and simulation energy system models are currently used in Denmark. The present paper tends to provide...

  5. Exploring public bus service quality in South Africa: A structural equation modelling approach

    Directory of Open Access Journals (Sweden)

    Ayanda M. Vilakazi

    2014-03-01

    Full Text Available This study, which is a deviation from the usual practice of using SERVQUAL or an adaptedversion thereof, uses McKnight, Pagano and Paaswell’s (1986 service quality dimensions,namely reliability; extent of service; comfort; safety; and affordability (RECSA and structuralequation modelling to determine commuters’ perception of public bus service quality in amajor city in South Africa. The RECSA model was adapted and fitted to the data collectedfrom a convenience sample of bus commuters in Johannesburg, using structural equationmodelling. It was ascertained that reliability, service, comfort and safety influenced thepublic bus commuters’ perception of the overall service quality. The implications of theaforementioned findings for providers of public bus services are explained.

  6. An exploration of measures for comparing measurements with the results from meteorological models for Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Williams, M.D.; Brown, M.J.

    1995-12-31

    Los Alamos National Laboratory and Instituto Mexicano del Petroleo have completed a joint study of options for improving air quality in Mexico City. We used a three-dimensional, prognostic, higher-order turbulence model for atmospheric circulation (HOTMAC) to treat domains that include an urbanized area. We tested the model against routine measurements and those of a major field program. During the field program, measurements included: (1) lidar measurements of aerosol transport and dispersion, (2) aircraft measurements of winds, turbulence, and chemical species aloft, (3) aircraft measurements of skin temperatures, and (4) Tethersonde measurements of winds and ozone. We made both graphical and statistical comparisons and we have reported some of the comparisons to provide insight into the meaning of statistical parameters including the index of agreement.

  7. Exploring the dynamics of collective cognition using a computational model of cognitive dissonance

    Science.gov (United States)

    Smart, Paul R.; Sycara, Katia; Richardson, Darren P.

    2013-05-01

    The socially-distributed nature of cognitive processing in a variety of organizational settings means that there is increasing scientific interest in the factors that affect collective cognition. In military coalitions, for example, there is a need to understand how factors such as communication network topology, trust, cultural differences and the potential for miscommunication affects the ability of distributed teams to generate high quality plans, to formulate effective decisions and to develop shared situation awareness. The current paper presents a computational model and associated simulation capability for performing in silico experimental analyses of collective sensemaking. This model can be used in combination with the results of human experimental studies in order to improve our understanding of the factors that influence collective sensemaking processes.

  8. Exploring competing density order in the ionic Hubbard model with ultracold fermions.

    Science.gov (United States)

    Messer, Michael; Desbuquois, Rémi; Uehlinger, Thomas; Jotzu, Gregor; Huber, Sebastian; Greif, Daniel; Esslinger, Tilman

    2015-09-11

    We realize and study the ionic Hubbard model using an interacting two-component gas of fermionic atoms loaded into an optical lattice. The bipartite lattice has a honeycomb geometry with a staggered energy offset that explicitly breaks the inversion symmetry. Distinct density-ordered phases are identified using noise correlation measurements of the atomic momentum distribution. For weak interactions the geometry induces a charge density wave. For strong repulsive interactions we detect a strong suppression of doubly occupied sites, as expected for a Mott insulating state, and the externally broken inversion symmetry is not visible anymore in the density distribution. The local density distributions in different configurations are characterized by measuring the number of doubly occupied lattice sites as a function of interaction and energy offset. We further probe the excitations of the system using direction dependent modulation spectroscopy and discover a complex spectrum, which we compare with a theoretical model.

  9. Exploring Interacting Topological Insulators with Ultracold Atoms: The Synthetic Creutz-Hubbard Model

    Directory of Open Access Journals (Sweden)

    J. Jünemann

    2017-09-01

    Full Text Available Understanding the robustness of topological phases of matter in the presence of strong interactions and synthesizing novel strongly correlated topological materials lie among the most important and difficult challenges of modern theoretical and experimental physics. In this work, we present a complete theoretical analysis of the synthetic Creutz-Hubbard ladder, which is a paradigmatic model that provides a neat playground to address these challenges. We give special attention to the competition of correlated topological phases and orbital quantum magnetism in the regime of strong interactions. These results are, furthermore, confirmed and extended by extensive numerical simulations. Moreover, we propose how to experimentally realize this model in a synthetic ladder made of two internal states of ultracold fermionic atoms in a one-dimensional optical lattice. Our work paves the way towards quantum simulators of interacting topological insulators with cold atoms.

  10. Exploring the quantitative nature of empathy, systemising and autistic traits using factor mixture modelling.

    Science.gov (United States)

    Grove, Rachel; Baillie, Andrew; Allison, Carrie; Baron-Cohen, Simon; Hoekstra, Rosa A

    2015-11-01

    Autism research has previously focused on either identifying a latent dimension or searching for subgroups. Research assessing the concurrently categorical and dimensional nature of autism is needed. To investigate the latent structure of autism and identify meaningful subgroups in a sample spanning the full spectrum of genetic vulnerability. Factor mixture models were applied to data on empathy, systemising and autistic traits from individuals on the autism spectrum, parents and general population controls. A two-factor three-class model was identified, with two factors measuring empathy and systemising. Class one had high systemising and low empathy scores and primarily consisted of individuals with autism. Mainly comprising controls and parents, class three displayed high empathy scores and lower systemising scores, and class two showed balanced scores on both measures of systemising and empathy. Autism is best understood as a dimensional construct, but meaningful subgroups can be identified based on empathy, systemising and autistic traits. © The Royal College of Psychiatrists 2015.

  11. Well-log based prediction of temperature models in the exploration of sedimentary settings

    DEFF Research Database (Denmark)

    Fuchs, Sven; Förster, Andrea; Wonik, Thomas

    these measurements are not available or only measured to a certain depth so that a temperature model needs to developed. A prerequisite for such a model is the knowledge of the regional heat flow and the geological conditions translated into lithology and thermal rock properties. For the determination of continuous...... borehole temperature profiles we propose a two-step procedure: (1) the use of standard petrophysical well logs and (2) the inversion of predicted TC to temperature gradients by applying Fourier’s law of heat conduction. The prediction of TC is solved by using set of equations (Fuchs & Förster, 2014......) developed for matrix TC of sedimentary rocks. The equations resulted from a statistical analysis of an artificial set of mineral assemblages (consisting of 15 rock-forming minerals) typical for the different types of sedimentary rocks. The matrix TC was transformed into bulk TC by using a well-log derived...

  12. Hybrid Methods and Atomistic Models to Explore Free Energies, Rates and Pathways of Protein Shape Changes

    DEFF Research Database (Denmark)

    Wang, Yong

    , for example, accurately quantifying the free energy differences and transition times of protein conformational exchanges and their dependence on sequence modications, we are still at the early stages. In this dissertation, I present a number of new methodological improvements and applications for protein...... folding, conformational exchange and binding with ligands at long time scales. In Chapter 2, we benchmarked how well the current force elds and molecular dynamics (MD) simulations could model changes in structure, dynamics, free energy and kinetics for an extensively studied protein called T4 lysozyme (T4......", and subsequently used to estimate the free energy dierences based on a twostate assumption. To show its practical utility, we applied this approach by taking T4L-benzene system as the model system in which binding free energies from kinetics, free energy perturbation and experiments are all in good agreement...

  13. Exploring the Tripartite Influence Model of body dissatisfaction in postpartum women.

    Science.gov (United States)

    Lovering, Meghan E; Rodgers, Rachel F; George, Jessica Edwards; Franko, Debra L

    2017-12-16

    Pregnancy and childbirth result in dramatic changes in a woman's body shape, which can be associated with body image concerns. To date, however, little is known about how sociocultural factors may influence body dissatisfaction in postpartum women. This study aimed to test a sociocultural model of body image and eating concerns among a sample of postpartum women. A sample of N = 474 women, mean (SD) age = 30.6 (4.8), having given birth during the last year, completed an online survey and reported on sociocultural pressures from media, peers, family and partners, thin-ideal internalization, appearance comparison, body dissatisfaction, and psychological functioning. Structural equation modeling analyses revealed a good fit to the data, χ2 (49) = 220.20, p body shapes/sizes during the post-pregnancy period, contributing to their body image concerns. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Exploring the inequality-mortality relationship in the US with Bayesian spatial modeling

    Science.gov (United States)

    Yang, Tse-Chuan; Jensen, Leif

    2014-01-01

    While there is evidence to suggest that socioeconomic inequality within places is associated with mortality rates among people living within them, the empirical connection between the two remains unsettled as potential confounders associated with racial and social structure are overlooked. This study seeks to test this relationship, to determine whether it is due to differential levels of deprivation and social capital, and does so with intrinsically conditional autoregressive Bayesian spatial modeling that effectively addresses the bias introduced by spatial dependence. We find that deprivation and social capital partly but not completely account for why inequality is positively associated with mortality and that spatial modeling generates more accurate predictions than does the traditional approach. We advance the literature by unveiling the intervening roles of social capital and deprivation in the inequality-mortality relationship and offering new evidence that inequality matters in US county mortality rates. PMID:26166920

  15. The Spirit and the meal as a model for Charismatic worship: A practical-theological exploration

    Directory of Open Access Journals (Sweden)

    Lindie Denny

    2013-01-01

    Full Text Available The purpose of this article is to present one aspect of a larger research project. The Spirit tradition (Charismatic and its liturgical rituals as well as the Meal tradition (Liturgical Movement and its liturgical rituals through history were researched as well as the concomitant theology. The aim was to gain a better understanding of whether the future of Charismatic worship can benefit from a somewhat closer integration of aspects of the meal tradition, especially the celebration of the Lord’s Supper. This article will mostly be focused on the empirical research done in this project within three Charismatic churches in Gauteng, South Africa. This research seeks to contribute to Robert Webber’s model of bringing old and new together in synergy. In the end, this article poses a new model for Charismatic worship when liturgical-rituals of the Spirit are combined with the celebration of communion in a way that worshippers experience as being more meaningful.

  16. An Exploration of the Role of Cellular Neuroplasticity in Large Scale Models of Biological Neural Networks

    OpenAIRE

    Skorheim, Steven W.

    2014-01-01

    Cellular level learning is vital to almost all brain function, and extensive homeostatic plasticity is required to maintain brain functionality. While much has been learned about cellular level plasticity in vivo, how these mechanisms affect higher level functionality is not readily apparent. The cellular level circuitry of most networks that process information is unknown. A variety of models were developed to better understand plasticity in both learning and homeostasis. Spike time dependen...

  17. Exploring Firm Location Beyond Simple Growth Models: A Double Hurdle Application

    OpenAIRE

    Davis Reum, Alison; Harris, Thomas R.

    2006-01-01

    Firm location decisions are typically influenced by economic, demographic, environmental, and social factors. This research extends the current literature by investigating the factors thought to influence the total number of manufacturing firms within a given region. Given the large number of regions without any manufacturing firms, a double hurdle model is employed to account for excess zeros. The results suggest that there are certain industry input variables, such as population and educati...

  18. Exploring the mitigation potential role of legumes in European agriculture – a modelling approach

    OpenAIRE

    Angelopoulos, Nikolaos G.

    2015-01-01

    The increasing atmospheric concentration of greenhouse gases (GHG) has direct consequences on humans and threatens the sustainability of natural and managed ecosystems. The European Union has set high targets for reducing their emissions by 80‐95% of the 1990 levels by 2050 and is working progressively to achieve these reductions. Legumes are an important group of crop species as they have the potential to reduce N2O emissions. Biogeochemical modelling can provide a valuable...

  19. Seismic Inversion for Hydrocarbon Exploration, Crustal Structure and Whole Earth Modeling

    Science.gov (United States)

    Sen, M. K.

    2005-05-01

    Seismic inversion employing travel time, amplitudes and full waveform attributes is a challenging task. In order to maintain accuracy and computational speed, it is important to make judicial choice of optimization methods, onstraints, a priori information, forward modeling operator and data. We have applied seismic inversion to a variety of applications including (1) full waveform inversion for estimating rock properties within a hydrocarbon reservoir, (2) joint inversion of seismic travel time and gravity data for delineating plate boundaries and crustal structure offshore Taiwan, (3) crustal velocity structure from waveform inversion of shear-couple PL waves, and (4) anisotropic structure of the core-mantle transition zone. Although all these applications make use of the same forward modeling algorithms and optimization routines, they are carefully designed to address the disparate scale and data types. For example, a semi-analytic approach for differential seismogram calculation is used for full waveform inversion in the first application while arc-parameter basis functions are used to represent the subsurface in the joint inversion of seismic and gravity data. Forward caculation is tailored to rapidly compute the response of the crustal structure for the shear coupled PL waves. To model anisotropic D" layer, we pre-compute the respose of the crust and the mantle layers (without D") for use in each iteration of the waveform inversion. In addition to deriving best fit models we also estimate parameter uncertainty and tradeoff between different parametes using Bayesian statistics. Such results are interpreted in terms of the physics of the problem being investigated.

  20. Development and exploration of the gratitude model of body appreciation in women.

    Science.gov (United States)

    Homan, Kristin J; Tylka, Tracy L

    2018-02-08

    Although researchers and clinicians recognize the importance of positive body image for women's well-being, development of theoretical frameworks for understanding positive body image has not kept pace with research documenting its many benefits. The present study proposed and tested a comprehensive model linking gratitude, contingent self-worth, social comparison, body appreciation, and intuitive eating. Path analysis indicated that this model fit the data for a sample of college and online community women (N = 263). Gratitude was indirectly linked to body appreciation via lower investment in self-worth based on appearance and others' approval, and via lower engagement in eating and body comparison. Gratitude had a strong direct effect on body appreciation, and body appreciation accounted for a large portion (88%) of gratitude's relationship with intuitive eating. These results provide strong preliminary support for the model, revealing that gratitude, which can be improved via intervention, plays a key role in body appreciation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Exploring molecular genetics of bladder cancer: lessons learned from mouse models

    Directory of Open Access Journals (Sweden)

    Imran Ahmad

    2012-05-01

    Full Text Available Urothelial cell carcinoma (UCC of the bladder is one of the most common malignancies worldwide, causing considerable morbidity and mortality. It is unusual among the epithelial carcinomas because tumorigenesis can occur by two distinct pathways: low-grade, recurring papillary tumours usually contain oncogenic mutations in FGFR3 or HRAS, whereas high-grade, muscle-invasive tumours with metastatic potential generally have defects in the pathways controlled by the tumour suppressors p53 and retinoblastoma (RB. Over the past 20 years, a plethora of genetically engineered mouse (GEM models of UCC have been developed, containing deletions or mutations of key tumour suppressor genes or oncogenes. In this review, we provide an up-to-date summary of these GEM models, analyse their flaws and weaknesses, discuss how they have advanced our understanding of UCC at the molecular level, and comment on their translational potential. We also highlight recent studies supporting a role for dysregulated Wnt signalling in UCC and the development of mouse models that recapitulate this dysregulation.

  2. Coupling Agent-Based and Groundwater Modeling to Explore Demand Management Strategies for Shared Resources

    Science.gov (United States)

    Al-Amin, S.

    2015-12-01

    Municipal water demands in growing population centers in the arid southwest US are typically met through increased groundwater withdrawals. Hydro-climatic uncertainties attributed to climate change and land use conversions may also alter demands and impact the replenishment of groundwater supply. Groundwater aquifers are not necessarily confined within municipal and management boundaries, and multiple diverse agencies may manage a shared resource in a decentralized approach, based on individual concerns and resources. The interactions among water managers, consumers, and the environment influence the performance of local management strategies and regional groundwater resources. This research couples an agent-based modeling (ABM) framework and a groundwater model to analyze the effects of different management approaches on shared groundwater resources. The ABM captures the dynamic interactions between household-level consumers and policy makers to simulate water demands under climate change and population growth uncertainties. The groundwater model is used to analyze the relative effects of management approaches on reducing demands and replenishing groundwater resources. The framework is applied for municipalities located in the Verde River Basin, Arizona that withdraw groundwater from the Verde Formation-Basin Fill-Carbonate aquifer system. Insights gained through this simulation study can be used to guide groundwater policy-making under changing hydro-climatic scenarios for a long-term planning horizon.

  3. An Integrated Simulation Model for Dynamically Exploring the Optimal Solution to Mitigating Water Scarcity and Pollution

    Directory of Open Access Journals (Sweden)

    Wei Yang

    2015-02-01

    Full Text Available An integrated optimization simulation model has been developed based on an input-output approach to mitigate water pollution and water scarcity through embedding environmental economic policies and applicable technologies into a complex environ-economic system to obtain an optimal set of policies and technologies that promotes the maximization of the regional economy under the constraints of water pollutant discharge and water availability. An empirical study is undertaken with the Source Region of Liao River as the target area to verify the performance of the model. The relationships between the water environment and socio-economic systems are presented by clarifying the trends in economic development, water pollutant discharge and water supply and demand during a time horizon from 2011 to 2020. The endogenously-formed optimal set of policies and industrial restructuring simultaneously facilitate the reduction of water pollutant discharge and water consumption and increase the water supply. The extent of the mitigation of water pollution and water scarcity via applied policies and technologies promoted by the subsidies provided by the government are specified, and the mechanism of the policy application and subsidization distribution is explained. This model has applicability for other regions in terms of giving an optimal solution via comprehensive assessment of all of the proposed sustainability-related policies with sufficient data accessibility to achieve regional sustainable development.

  4. Exploring Drell-Yan signals from the 4D Composite Higgs Model at the LHC

    Science.gov (United States)

    Barducci, D.; Belyaev, A.; De Curtis, S.; Moretti, S.; Pruna, G. M.

    2013-04-01

    We study the phenomenology of Drell-Yan processes at the Large Hadron Collider for the case of both the neutral and charged current channels within a recently proposed 4-Dimensional formulation of the Minimal Composite Higgs Model. We estimate the integrated and differential event rates at the CERN machine, assuming 14 TeV and data samples of {O} (100 fb-1), as at lower energy and/or luminosity event rates are prohibitively small. We pay particular attention to the presence of multiple resonances in either channel, by showing that in certain region of parameter space some of these can be distinguishable and experimentally accessible in the invariant and/or transverse mass distribution, sampled in either the cross section, the forward-backward asymmetry or both. At the same time, we assess the indirect impact onto the line-shape of the emerging gauge boson resonances, both neutral and charged, of additional heavy fermionic states present in the spectrum of the model. Finally, we show how to exploit in the kinematic selection the fact that the extra neutral and charged gauge boson resonances in composite Higgs models are correlated in mass. Such results rely on a parton level study including a statistical error analysis.

  5. A new hybrid model for exploring the adoption of online nursing courses.

    Science.gov (United States)

    Tung, Feng-Cheng; Chang, Su-Chao

    2008-04-01

    With the advancement in educational technology and internet access in recent years, nursing academia is searching for ways to widen nurses' educational opportunities. The online nursing courses are drawing more attention as well. The online nursing courses are very important e-learning tools for nursing students. The research combines the innovation diffusion theory and technology acceptance model, and adds two research variables, perceived financial cost and computer self-efficacy to propose a new hybrid technology acceptance model to study nursing students' behavioral intentions to use the online nursing courses. Based on 267 questionnaires collected from six universities in Taiwan, the research finds that studies strongly support this new hybrid technology acceptance model in predicting nursing students' behavioral intentions to use the online nursing courses. This research finds that compatibility, perceived usefulness, perceived ease of use, perceived financial cost and computer self-efficacy are critical factors for nursing students' behavioral intentions to use the online nursing courses. By explaining nursing students' behavioral intentions from a user's perspective, the findings of this research help to develop more user friendly online nursing courses and also provide insight into the best way to promote new e-learning tools for nursing students. This research finds that compatibility is the most important research variable that affects the behavioral intention to use the online nursing courses.

  6. Influence of warmth and competence on the promotion of safe in-group selection: Stereotype content model and social categorization of faces.

    Science.gov (United States)

    Ponsi, G; Panasiti, M S; Scandola, M; Aglioti, S M

    2016-01-01

    Categorizing an individual as a friend or foe plays a pivotal role in navigating the social world. According to the stereotype content model (SCM), social perception relies on two fundamental dimensions, warmth and competence, which allow us to process the intentions of others and their ability to enact those intentions, respectively. Social cognition research indicates that, in categorization tasks, people tend to classify other individuals as more likely to belong to the out-group than the in-group (in-group overexclusion effect, IOE) when lacking diagnostic information, probably with the aim of protecting in-group integrity. Here, we explored the role of warmth and competence in group-membership decisions by testing 62 participants in a social-categorization task consisting of 150 neutral faces. We assessed whether (a) warmth and competence ratings could predict the in-group/out-group categorization, and (b) the reliance on these two dimensions differed in low-IOE versus high-IOE participants. Data showed that high ratings of warmth and competence were necessary to categorize a face as in-group. Moreover, while low-IOE participants relied on warmth, high-IOE participants relied on competence. This finding suggests that the proneness to include/exclude unknown identities in/from one's own in-group is related to individual differences in the reliance on SCM social dimensions. Furthermore, the primacy of the warmth effect seems not to represent a universal phenomenon adopted in the context of social evaluation.

  7. Recent Advances in Ionospheric Modeling for Mars Exploration using Ground Penetrating Radars

    Science.gov (United States)

    Restano, Marco; Picardi, Giovanni; Seu, Roberto

    2013-04-01

    Orbiting ground penetrating radars (GPRs) as the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) and the Shallow Radar (SHARAD) currently operating on Mars need a fine ionospheric correction in order to deliver products useful for geological investigations. Ionosphere influence can be assessed using a new approach based on the finite-difference time-domain (FDTD) method. The proposed work aims to underline the errors introduced by a not perfect knowledge of the ionosphere electron density profile on the transmitted chirp signal. Such effect has a great impact on the data inversion process that aims to estimate the permittivity of the subsurface detected interfaces. Data inversion is accomplished by evaluating, via a two channels approach, quantities related to crust attenuation, surface/subsurface geometry and power scattered by the detected interfaces. The final product delivered after SAR processing is highly dependent on the ionosphere compensation. Ionosphere phase related distortions have been theoretically modelled using the Chapman density function. They introduce an S/N and a side lobe level (SLL) degradation after matched filtering along with a delay and a pulse shape distortion. Since several data acquired over smooth surfaces do not present a pulse shape verifying the backscattering models introduced for MARSIS and SHARAD and based on Kirchhoff approximation it is important to provide a different approach for the ionosphere compensation in order to obtain more reliable products. Not perfectly compensated data would provide erroneous power levels and a wrong geometric interpretation jeopardizing the entire data inversion process. The finite-difference time-domain (FDTD) method can be used to study the propagation of a MARSIS/SHARAD chirp signal into a plasma modelled according to a desired electron density profile adding a new important benefit to the simulation methods available to understand GPR signals in this context. A 1D

  8. Syndromes of the global water crisis - exploring the emergent dynamics through socio-hydrological modeling

    Science.gov (United States)

    Kuil, Linda; Levy, Morgan; Pavao-Zuckerman, Mitch; Penny, Gopal; Scott, Christopher; Srinivasan, Veena; Thompson, Sally; Troy, Tara

    2014-05-01

    There is a great variety of human water systems at the global scale due to the types and timing of water supply/availability, and the high diversity in water use, management, and abstraction methods. Importantly, this is largely driven by differences in welfare, social values, institutional frameworks, and cultural traditions of communities. The observed trend of a growing world population in combination with changing habits that generally increase our water consumption per capita implies that an increasing number of communities will face water scarcity. Over the years much research has been done in order to increase our understanding of human water systems and their associated water problems, using both top-down and bottom-up approaches. Despite these efforts, the challenge has remained to generalize findings beyond the areas of interests and to establish a common framework in order to compare and learn from different cases as a basis for finding solutions. In a recent analysis of multiple interdisciplinary subnational water resources case studies, it was shown that a suite of distinct resources utilization patterns leading to a water crisis can be identified, namely: 1) groundwater depletion, 2) ecological destruction, 3) drought-driven conflicts, 4) unmet subsistence needs, 5) resource capture by elite and 6) water reallocation to nature (Srinivasan et al., 2012). The effects of these syndromes on long-lasting human wellbeing can be grouped in the following outcomes: unsustainability, vulnerability, chronic scarcity and adaptation. The aim of this group collaboration is to build on this work through the development of a socio-hydrological model that is capable of reproducing the above syndromes and outcomes, ultimately giving insight in the different pathways leading to the syndromes. The resulting model will be distinct compared to existing model frameworks for two reasons. First of all, feedback loops between the hydrological, the environmental and the human

  9. Mars Rover Model Celebration: Using Planetary Exploration To Enrich STEM Teaching In Elementary And Middle School

    Science.gov (United States)

    Bering, E. A.; Ramsey, J.; Dominey, W.; Kapral, A.; Carlson, C.; Konstantinidis, I.; James, J.; Sweaney, S.; Mendez, R.

    2011-12-01

    The present aerospace engineering and science workforce is ageing. It is not clear that the US education system will produce enough qualified replacements to meet the need in the near future. Unfortunately, by the time many students get to high school, it is often too late to get them pointed toward an engineering or science career. Since some college programs require 6 units of high school mathematics for admission, students need to begin consciously preparing for a science or engineering curriculum as early as 6th or 7th grade. The challenge for educators is to convince elementary school students that science and engineering are both exciting, relevant and accessible career paths. The recent NASA Mars Rover missions capture the imagination of children, as NASA missions have done for decades. The University of Houston is in the process of developing a prototype of a flexible program that offers children an in-depth educational experience culminating in the design and construction of their own model rover. The existing prototype program is called the Mars Rover Model Celebration. It focuses on students, teachers and parents in grades 3-8. Students will design and build a model of a Mars rover to carry out a student selected science mission on the surface of Mars. The model will be a mock-up, constructed at a minimal cost from art supplies. The students will build the models as part of a project on Mars. The students will be given design criteria for a rover and will do basic research on Mars that will determine the objectives and features of their rover. This project may be used either informally as an after school club or youth group activity or formally as part of a class studying general science, earth science, solar system astronomy or robotics, or as a multi-disciplinary unit for a gifted and talented program. The program culminates in a capstone event held at the University of Houston (or other central location in the other communities that will be involved

  10. The Financial Coaching Advice Model: An Exploration into how it Satisfies Expectations of Quality Advice

    Directory of Open Access Journals (Sweden)

    Julie Knutsen

    2012-11-01

    Full Text Available For 20 years, the financial planning sector in Australia has been transitioning from a sales-orientated force to aprofession of qualified and skilled practitioners. Today, the potential for professional financial planning adviceto benefit Australians financially, economically and psychologically is recognised by government. Financially,these benefits include increased savings, less interest expense through faster debt reduction, higher investmentreturns and appropriate levels of insurance. Economically, a more financially literate society has the potentialfor less reliance on an already burdened social security system. Psychologically, the benefits include the peaceof mind that comes from an individual being confident in financial matters. However, despite this level ofrecognition and development, national surveys have reported that only a small percentage of the populationactually seek professional financial advice. The factors attributing to these low percentages included the gapsin financial literacy limiting an individual’s engagement in financial matters and consumer’s current mistrust ofthe financial advice business models that remain dominated by commission-driven product sales. Thesedeficiencies have led some financial planning firms to break from financial product sales as the primary advicemodel and focus on financial coaching. Exploratory interviews with the practitioners and clients of a selectedfinancial planning firm have generated insightful discussion into how a financial coaching advice model isachieving the financial, economic and psychological benefits recognised by government as the potentialoutcomes of professional financial advice. The aim of this paper is to present the findings from that discussionand demonstrate the opportunities embedded within a financial coaching advice model. It is argued that thisdiscussion offers a foundation for future research direction in an area currently under researched in

  11. Exploring hydrogeological controls on river and groundwater vulnerability to droughts using synthetic models

    Science.gov (United States)

    Carlier, Claire; Wirth, Stefanie B.; Cochand, Fabien; Hunkeler, Daniel; Brunner, Philip

    2017-04-01

    Characterising the vulnerability of watersheds to droughts is essential to guarantee water supply under changing climatic conditions. Numerous studies have analysed watershed processes under dry conditions focusing on surface flows. However, hydrological catchment dynamics, and especially river low-flows, are strongly dependent on the surrounding hydrogeological settings. We thus propose an integrated quantification of the impact of prolonged dry periods on both surface water and groundwater. To achieve this, we consider various catchment properties representative of a wide range of geological and topographical environments. The relationship between these physical parameters and low-flow dynamics in a catchment is highly complex, and no straightforward correlation can be obtained by analysing easily measurable catchment properties such as slope or main geological units. A modelling approach is therefore developed to systematically and independently quantify the control mechanisms of catchment parameters on river and groundwater dynamics. The physically based numerical model HydroGeoSphere is used, which simulates surface water and groundwater in a fully coupled way. More than 200 synthetic models are designed with systematically varying geometrical parameters such as river and hill slopes, as well as hydraulic conductivities and porosities of the main geological units. A clear correlation between the porous storage volume in a catchment and the resilience to drought of both streamflow and groundwater is observed. An attempt to link these results to real watersheds is made by analysing the flows, the geology and the hydrogeological properties of a selection of catchments. The validation of the synthetic results with observations will allow the development of drought sensitivity indicators applicable to both groundwater and river low-flows based solely on watershed physical properties.

  12. Exploring Climate Science with WV Educators: A Regional Model for Teacher Professional Development

    Science.gov (United States)

    Ruberg, L. F.; Calinger, M.

    2014-12-01

    The National Research Council Framework for K-12 Science Literacy reports that children reared in rural agricultural communities, who experience regular interactions with plants and animals, develop more sophisticated understanding of ecology and biological systems than do urban and suburban children of the same age. West Virginia (WV) is a rural state. The majority of its residents live in communities of fewer than 2,500 people. Based on the features of the population being served and their unique strengths, this presentation focuses on a regional model for teacher professional development that addresses agricultural and energy vulnerabilities and adaptations to climate change in WV. The professional development model outlined shows how to guide teachers to use a problem-based learning approach to introduce climate data and analysis techniques within a scenario context that is locally meaningful. This strategy engages student interest by focusing on regional and community concerns. Climate science standards are emphasized in the Next Generation Science Standards, but WV has not provided its teachers with appropriate instructional resources to meet those standards. The authors addressed this need by offering a series of climate science education workshops followed by online webinars offered to WV science educators free of charge with funding by the West Virginia Space Grant Consortium. The authors report on findings from this series of professional development workshops conducted in partnership with the West Virginia Science Teachers Association. The goal was to enhance grades 5-12 teaching and learning about climate change through problem-based learning. Prior to offering the climate workshops, all WV science educators were asked to complete a short questionnaire. As Figure 1 shows, over 40% of the teacher respondents reported being confident in teaching climate science content. For comparison post workshops surveys measure teacher confidence in climate science

  13. Exploring storage and runoff generation processes for urban flooding through a physically based watershed model

    Science.gov (United States)

    Smith, B. K.; Smith, J. A.; Baeck, M. L.; Miller, A. J.

    2015-03-01

    A physically based model of the 14 km2 Dead Run watershed in Baltimore County, MD was created to test the impacts of detention basin storage and soil storage on the hydrologic response of a small urban watershed during flood events. The Dead Run model was created using the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) algorithms and validated using U.S. Geological Survey stream gaging observations for the Dead Run watershed and 5 subbasins over the largest 21 warm season flood events during 2008-2012. Removal of the model detention basins resulted in a median peak discharge increase of 11% and a detention efficiency of 0.5, which was defined as the percent decrease in peak discharge divided by percent detention controlled area. Detention efficiencies generally decreased with increasing basin size. We tested the efficiency of detention basin networks by focusing on the "drainage network order," akin to the stream order but including storm drains, streams, and culverts. The detention efficiency increased dramatically between first-order detention and second-order detention but was similar for second and third-order detention scenarios. Removal of the soil compacted layer, a common feature in urban soils, resulted in a 7% decrease in flood peak discharges. This decrease was statistically similar to the flood peak decrease caused by existing detention. Current soil storage within the Dead Run watershed decreased flood peak discharges by a median of 60%. Numerical experiment results suggested that detention basin storage and increased soil storage have the potential to substantially decrease flood peak discharges.

  14. Simulation study using 3-D wavefield modeling for oil and gas exploration; Sanjigen hadoba modeling wo mochiita sekiyu tanko no simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Sato, T.; Matsuoka, T. [Japan Petroleum Exploration Corp., Tokyo (Japan); Saeki, T. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

    1997-05-27

    As the surroundings of objects of oil exploration grow more complicated, seismic survey methods have turned 3-dimensional and, in this report, several models are examined using the 3-dimensional simulation technology. The result obtained by the conventional wave tracking method is different from actual wavefields, and is unrealistic. The difference method among the fullwave modelling methods demands an exorbitantly long computation time and high cost. A pseudospectral method has been developed which is superior to the difference method, and has been put to practical use thanks to the advent of parallel computers. It is found that a 3-dimensional survey is mandatory in describing faults. After examining the SEG/EAGE Salt model, it is learned that the salt is well-developed and that 3-dimensional depth migration is required for sub-salt exploration. It is also found through simulation of the EAGE/S Overthrust model, which is an elastic model, that no quality records are available on thrust zones in complicated terrains. The records are poor in quality since the actually measured wavefield is regarded as an acoustic wavefield when it is an elastic wavefield. 1 refs., 18 figs., 2 tabs.

  15. The Zebrafish Models to Explore Genetic and Epigenetic Impacts on Evolutionary Developmental Origins of Aging

    Science.gov (United States)

    Kishi, Shuji

    2014-01-01

    hand, unexpected senescence-related genes might also be involved in the early developmental process and its regulation. The ease of manipulation using the zebrafish system allows us to conduct an exhaustive exploration of novel genes/genotypes and epigenotype that can be linked to the senescence phenotype, and thereby facilitates searching for the evolutionary and developmental origins of aging in vertebrates. PMID:24239812

  16. Exploring the gain of function contribution of AKT to mammary tumorigenesis in mouse models.

    Directory of Open Access Journals (Sweden)

    Carmen Blanco-Aparicio

    Full Text Available Elevated expression of AKT has been noted in a significant percentage of primary human breast cancers, mainly as a consequence of the PTEN/PI3K pathway deregulation. To investigate the mechanistic basis of the AKT gain of function-dependent mechanisms of breast tumorigenesis, we explored the phenotype induced by activated AKT transgenes in a quantitative manner. We generated several transgenic mice lines expressing different levels of constitutively active AKT in the mammary gland. We thoroughly analyzed the preneoplastic and neoplastic mammary lesions of these mice and correlated the process of tumorigenesis to AKT levels. Finally, we analyzed the impact that a possible senescent checkpoint might have in the tumor promotion inhibition observed, crossing these lines to mammary specific p53(R172H mutant expression, and to p27 knock-out mice. We analyzed the benign, premalignant and malignant lesions extensively by pathology and at molecular level analysing the expression of proteins involved in the PI3K/AKT pathway and in cellular senescence. Our findings revealed an increased preneoplastic phenotype depending upon AKT signaling which was not altered by p27 or p53 loss. However, p53 inactivation by R172H point mutation combined with myrAKT transgenic expression significantly increased the percentage and size of mammary carcinoma observed, but was not sufficient to promote full penetrance of the tumorigenic phenotype. Molecular analysis suggest that tumors from double myrAKT;p53(R172H mice result from acceleration of initiated p53(R172H tumors and not from bypass of AKT-induced oncogenic senescence. Our work suggests that tumors are not the consequence of the bypass of senescence in MIN. We also show that AKT-induced oncogenic senescence is dependent of pRb but not of p53. Finally, our work also suggests that the cooperation observed between mutant p53 and activated AKT is due to AKT-induced acceleration of mutant p53-induced tumors. Finally, our

  17. Reaction-diffusion finite element model of lateral line primordium migration to explore cell leadership.

    Science.gov (United States)

    Allena, R; Maini, P K

    2014-12-01

    Collective cell migration plays a fundamental role in many biological phenomena such as immune response, embryogenesis and tumorigenesis. In the present work, we propose a reaction-diffusion finite element model of the lateral line primordium migration in zebrafish. The population is modelled as a continuum with embedded discrete motile cells, which are assumed to be viscoelastic and able to undergo large deformations. The Wnt/ß-catenin-FGF and cxcr4b-cxcr7b signalling pathways inside the cohort regulating the migration are described through coupled reaction-diffusion equations. The coupling between mechanics and the molecular scenario occurs in two ways. Firstly, the intensity of the protrusion-contraction movement of the cells depends on the cxcr4b concentration. Secondly, the intra-synchronization between the active deformations and the adhesion forces inside each cell is triggered by the cxcr4b-cxcr7b polarity. This influences the inter-synchronization between the cells and results in two main modes of migration: uncoordinated and coordinated. The main objectives of the work were (i) to validate our assumptions with respect to the experimental observations and (ii) to decipher the mechanical conditions leading to efficient migration of the primordium. To achieve the second goal, we will specifically focus on the role of the leader cells and their position inside the population.

  18. Exploration of (super-)heavy elements using the Skyrme-Hartree-Fock model

    Energy Technology Data Exchange (ETDEWEB)

    Erler, Jochen

    2011-01-31

    Motivated by the steadily increasing number of known nuclei and nuclear properties, theories of nuclear structure are presently a field of intense research. This work concentrates on the self-consistent description of nuclei in terms of the Skyrme-Hartree-Fock (SHF) approach. The extrapolation of nuclear shell structure to the region of super-heavy elements (SHE) using the SHF model, the dependence on different parameterization and the influence of collective correlation will be studied. The general scope of this work are large scale calculation for a global survey of properties of SHE like binding energies, separation energies and decay characteristics and lifetimes. These calculations were done in a collaboration with the theory group of the GSI in Darmstadt and have the aim to develop a database of lifetimes and reaction rates for {alpha}, {beta}-decay and spontaneous fission in a very wide range with proton numbers 86 {<=} Z {<=} 120 and neutron numbers up to N {approx} 260 relevant for the astrophysical r-process. The results of this study for example predictions of a possible islands of very stable nuclei and information of favored decay mode for each nuclei are also applicable in the recent experimental synthesis of exotic SHE. For these calculation a framework to calculate {beta}-decay half-lives within the SHF model has been developed and the existing axial SHF code has been extended to compute {beta}-transition matrix elements and so to provide an estimation of half-lives. (orig.)

  19. Extending Validated Human Performance Models to Explore NextGen Concepts

    Science.gov (United States)

    Gore, Brian Francis; Hooey, Becky Lee; Mahlstedt, Eric; Foyle, David C.

    2012-01-01

    To meet the expected increases in air traffic demands, NASA and FAA are researching and developing Next Generation Air Transportation System (NextGen) concepts. NextGen will require substantial increases in the data available to pilots on the flight deck (e.g., weather,wake, traffic trajectory predictions, etc.) to support more precise and closely coordinated operations (e.g., self-separation, RNAV/RNP, and closely spaced parallel operations, CSPOs). These NextGen procedures and operations, along with the pilot's roles and responsibilities, must be designed with consideration of the pilot's capabilities and limitations. Failure to do so will leave the pilots, and thus the entire aviation system, vulnerable to error. A validated Man-machine Integration and design Analysis System (MIDAS) v5 model was extended to evaluate anticipated changes to flight deck and controller roles and responsibilities in NextGen approach and Land operations. Compared to conditions when the controllers are responsible for separation on decent to land phase of flight, the output from these model predictions suggest that the flight deck response time to detect the lead aircraft blunder will decrease, pilot scans to the navigation display will increase, and workload will increase.

  20. Exploring charge density analysis in crystals at high pressure: data collection, data analysis and advanced modelling.

    Science.gov (United States)

    Casati, Nicola; Genoni, Alessandro; Meyer, Benjamin; Krawczuk, Anna; Macchi, Piero

    2017-08-01

    The possibility to determine electron-density distribution in crystals has been an enormous breakthrough, stimulated by a favourable combination of equipment for X-ray and neutron diffraction at low temperature, by the development of simplified, though accurate, electron-density models refined from the experimental data and by the progress in charge density analysis often in combination with theoretical work. Many years after the first successful charge density determination and analysis, scientists face new challenges, for example: (i) determination of the finer details of the electron-density distribution in the atomic cores, (ii) simultaneous refinement of electron charge and spin density or (iii) measuring crystals under perturbation. In this context, the possibility of obtaining experimental charge density at high pressure has recently been demonstrated [Casati et al. (2016). Nat. Commun. 7, 10901]. This paper reports on the necessities and pitfalls of this new challenge, focusing on the species syn-1,6:8,13-biscarbonyl[14]annulene. The experimental requirements, the expected data quality and data corrections are discussed in detail, including warnings about possible shortcomings. At the same time, new modelling techniques are proposed, which could enable specific information to be extracted, from the limited and less accurate observations, like the degree of localization of double bonds, which is fundamental to the scientific case under examination.

  1. Exploring the Inert Doublet Model through the dijet plus missing transverse energy channel at the LHC

    Directory of Open Access Journals (Sweden)

    P. Poulose

    2017-02-01

    Full Text Available In this study of the Inert Doublet Model (IDM, we propose that the dijet + missing transverse energy channel at the Large Hadron Collider (LHC will be an effective way of searching for the scalar particles of the IDM. This channel receives contributions from gauge boson fusion, and t-channel production, along with contributions from H+ associated production. We perform the analysis including study of the Standard Model (SM background with assumed systematic uncertainty, and optimise the selection criteria employing suitable cuts on the kinematic variables to maximise the signal significance. We find that with high luminosity option of the LHC, this channel has the potential to probe the IDM in the mass range of up to about 400 GeV, which is not accessible through other leptonic channels. In a scenario with light dark matter of mass about 65 GeV, charged Higgs in the mass range of around 200 GeV provides the best possibility with a signal significance of about 2σ at an integrated luminosity of about 3000 fb−1.

  2. On the Modeling of Electrical Effects Experienced by Space Explorers During Extra Vehicular Activities: Intracorporal Currents, Resistances, and Electric Fields

    Science.gov (United States)

    Cela, Carlos J.; Loizos, Kyle; Lazzi, Gianluca; Hamilton, Douglas; Lee, Raphael C.

    2011-01-01

    Recent research has shown that space explorers engaged in Extra Vehicular Activities (EVAs) may be exposed, under certain conditions, to undesired electrical currents. This work focuses on determining whether these undesired induced electrical currents could be responsible for involuntary neuromuscular activity in the subjects, possibly caused by either large diameter peripheral nerve activation or reflex activity from cutaneous afferent stimulation. An efficient multiresolution variant of the admittance method along with a millimeter-resolution model of a male human body were used to calculate induced electric fields, resistance between contact electrodes used to simulate the potential exposure condition, and currents induced in the human body model. Results show that, under realistic exposure conditions using a 15V source, current density magnitudes and total current injected are well above previously reported startle reaction thresholds. This indicates that, under the considered conditions, the subjects could experience involuntary motor response.

  3. Exploring the relation between masculinity and mental illness stigma using the stereotype content model and BIAS map.

    Science.gov (United States)

    Boysen, Guy A

    2017-01-01

    The current research explored the association of masculinity and stigma toward mental illness using theoretical predictions stemming from the stereotype content model and BIAS map. Two correlational studies (Ns = 245, 163) measured stereotypes, emotions, and behavioral intentions in relation to masculine, feminine, and gender-neutral disorders. Participants perceived masculine disorders as lacking personal warmth and competence. Masculine disorders also elicited more negative emotions and behavioral intentions. Two experimental studies (Ns = 161, 431) manipulated personal warmth, sex, and type of disorder in descriptions of people with mental illness. Low warmth and stereotypically masculine disorders consistently elicited negative emotions and behavioral intentions, but sex had limited effects. Overall, the results supported the theoretical models and illustrated the importance of warmth and symptomatic behavior in explaining the masculinity-stigma relation.

  4. Exploring historical and future urban climate in the Earth System Modeling framework: 1. Model development and evaluation

    Science.gov (United States)

    Li, Dan; Malyshev, Sergey; Shevliakova, Elena

    2016-06-01

    A number of recent studies investigated impacts of Land-Use and Land-Cover Changes (LULCC) on climate with global Earth System Models (ESMs). Yet many ESMs are still missing a representation of the most extreme form of natural landscape modification - urban settlements. Moreover, long-term (i.e., decades to century) transitions between build-up and other land cover types due to urbanization and de-urbanization have not been examined in the literature. In this study we evaluate a new urban canopy model (UCM) that characterizes urban physical and biogeochemical processes within the subgrid tiling framework of the Geophysical Fluid Dynamics Laboratory (GFDL) land model, LM3. The new model LM3-UCM is based on the urban canyon concept and simulates exchange of energy, water (liquid and solid), and carbon between urban land and the atmosphere. LM3-UCM has several unique features, including explicit treatment of vegetation inside the urban canyon and dynamic transition between urban, agricultural and unmanaged tiles. The model is evaluated using observational data sets collected at three urban sites: Marseille in France, Basel in Switzerland and Baltimore in the United States. It is found that LM3-UCM satisfactorily reproduces canyon air temperature, surface temperatures, radiative fluxes, and turbulent heat fluxes at the three urban sites. LM3-UCM can capture urban features in a computationally efficient manner and is incorporated into the land component of GFDL ESMs. This new capability will enable improved understanding of climate change effects on cities and the impacts of urbanization on climate.

  5. 3D modelling of an aero-gravity and -magnetic survey as an first exploration step in a frontier basin

    Science.gov (United States)

    Köther, Nils; Eckard, Marcel; Götze, Hans-Jürgen

    2010-05-01

    The West African Taoudeni basin covers a desert area of about 1.8 million km² and is one of the last frontier basins worldwide. Here Wintershall Holding AG holds acreage of about 68000 km². During 2005-2007 geological surveys and an aero-gravity and -magnetic survey were conducted in this area. The potential field modelling should contribute first insight about the subsurface to plan an economic seismic survey. 2D models lead to poor results. 2008 the results of an internship (NK) were 3D subsurface models, which were enhanced during the following diploma thesis (Köther, 2009). Complex igneous rocks and sparsely distributed constraints lead to an ambiguous interpretation. Therefore, several simple 3D models were compiled with the in-house software IGMAS+, which base on geological ideas of the underground and fit well the measured data. These basic models allow a geophysical evaluation of different geological theories about the subsurface. Also, for a thorough interpretation field transformations (Euler, Curvature, and Derivatives) were calculated. These results led to new constraints for further interpretation of the basin structures and therefore they are important contributions for future exploration e.g. the planning of seismic surveys.

  6. Exploration of optimal dosing regimens of vancomycin in patients infected with methicillin-resistant Staphylococcus aureus by modeling and simulation.

    Science.gov (United States)

    Lim, H-S; Chong, Y P; Noh, Y-H; Jung, J-A; Kim, Y S

    2014-04-01

    Vancomycin is the drug of choice for methicillin-resistant Staphylococcus aureus (MRSA) infection and shows time-dependent bacterial killing. The current study evaluated the pharmacokinetics (PK) and pharmacodynamics (PD) of vancomycin and explored its optimal dosing regimens by modeling and simulation. Pharmacokinetics study was performed for 20 patients who were treated with vancomycin intravenously, 1000 mg, every 12 h, and blood for PK was randomly drawn within prespecified time windows. PD study was in vitro time-kill experiment for vancomycin against 20 MRSA strains independent of the PK study, where bacterial titre was measured at 0, 2, 4, 8, 24 h after the beginning of vancomycin exposure at 0, 1, 2, 4, 8, 16, 32× minimum inhibitory concentrations. PK and PD models were built from each data set, and simulation for MRSA titre changes over time in human body was performed for various vancomycin dosing regimens using NONMEM(®) . Vancomycin followed a two-compartment PK model, and creatinine clearance was the significant covariate affecting the clearance of vancomycin. PD model described the in vitro time-kill data well. The PK/PD model predicted clear dose-response relationships of vancomycin. The therapeutic dosing regimens of vancomycin, suggested by the simulation studies, showed good agreement with the current clinical practice guidance, which indicates that this PK/PD modeling and simulation approach could prove useful for identifying optimal dosing regimens of other antibiotics and expediting novel antibiotic development. Using PD model from in vitro time-kill study and human PK model from phase 1 study, we could predict whether the drug is going to be efficacious or obtain insight into the optimal dosing regimens for a novel antibiotic agent in the early phases of drug development process. © 2014 John Wiley & Sons Ltd.

  7. Water and Productivity of Floodplain Grasslands: Exploring Linkages through Experimentations and Models in the Tana River Delta, Kenya

    Science.gov (United States)

    Leauthaud, C.; Musila, W.; Kergoat, L.; Hiernaux, P.; Manuela, G.; Duvail, S.

    2014-12-01

    Floodplain grasslands have one of the highest productivities of non-cultivated ecosystems on Earth. They procure a wide variety of benefits to human beings. In Eastern Africa, grasslands of Echinochloa stagnina are primordial for pastoralists as highly productive dry-season grazing zones. Regular flooding is a critical property in maintaining their productivity and resulting services. Yet, construction of hydrologic infrastructure modifies the flooding regime of rivers and the consequences on downstream floodplain grasslands need to be assessed. This presentation focuses on quantifying the productivity of the floodplain grasslands in the Tana River Delta, Kenya, in order to assess potential changes under varying flooding regimes. The interactions between growth and floods are explored firstly at an experimental site, then through the construction of a process-based plant growth model adapted to floodplain grasslands. The 15-month experiment consisted in quantifying daily growth rates under various rainfall, irrigation, cutting and flooding regimes . Floods increased growth rates three-folds, and high productivities were maintained after the floods. The cutting regime and contribution of non-flood water also influenced productivity. Modelling allowed exploring the underlying processes explaining such behaviour. In an exploratory endeavour, the productivity of the grassland at the ecosystem scale was assessed with the model for a variety of flood and non-flooded scenarios. Decreasing floods led to a drop in annual productivity that could have serious consequences for the livestock keeping activities of the zone. This research highlights the importance of floods in the maintenance of high productivities for a floodplain grassland typical of East Africa, and maybe of the Sahelian band. The model, once further validated, could be used on other floodplain grasslands, such as those of the Niger delta. Results for the Tana River Delta would need to be discussed with the

  8. MARSCAPE: Exploring the Martian Landscape through PARM (Projected Augmented Relief Model)

    Science.gov (United States)

    Sprinks, James; Wardlaw, Jessica; Priestnall, Gary

    2017-04-01

    In the past decade through the proliferation of digital technologies, citizen science has grown in popularity and is now used as a data analysis tool across a range of disciplines. Due to the abundance of instruments currently collecting data, planetary science has become a prime candidate for, and adaptor of, citizen science platforms (Sprinks et al., 2015). Current projects (planetfour.org, moonzoo.org etc.) take a Virtual Citizen Science (VCS) approach (Reed et al., 2012), gathering scientific analysis from remotely sensed imagery that's presented to the public through a website interface. However, in presenting the data 'on screen' in a 2D form, issues regarding interpretation and context arise - for instance, depending on the angle of the Sun when the picture was taken, images of craters taken from overhead (i.e. from orbit) may appear to be a mountain. In order to address such issues regarding context and interpretation, we present MARSCAPE, an engaging and informative display that communicates key aspects of the Martian landscape to the public, including the nature and scale of landscape forms, using a unique combination of physical landscape models and synchronised 3D perspective views. It combines the proven power of physical relief models for providing overviews of landscape and discerning more subtle spatial forms and relationships, with first person game-like perspectives on the ground. It also includes the capability of projecting data 'overlays' onto the physical model of surface, such as imagery, geological mapping, or comparison examples from Earth to provide context. The aims of the MARSCAPE project are not only to solve the issues regarding context and interpretation when studying the Martian surface, but also to educate the observer in regards to the geophysical processes that occur on Mars and how they relate to those that are happening on Earth. Through using a physical display presented in a public space citizen science can be moved from an

  9. Exploring a Model of Symbolic Social Communication: The Case of ‘Magic’ Johnson

    Science.gov (United States)

    FLORA, JUNE A.; SCHOOLER, CAROLINE; MAYS, VICKIE M.; COCHRAN, SUSAN D.

    2009-01-01

    We propose a model of symbolic social communication to explain the process whereby sociocultural identity mediates relationships among receivers, sources and messages to shape message effects. This exploratory study examines how two at-risk groups of African American men responded to various HIV prevention messages delivered by celebrity and professional sources. We interviewed 47 men from a homeless shelter and 50 male college students. Members of both groups were likely to select Johnson as the best person to deliver HIV prevention messages among a list of African American celebrity and professional sources. Results suggest the symbolic meanings embedded in celebrities and message topics are important and enduring influences on message effects. The images and ideas that a source represents are transferred to the advocated behavior, attitude or knowledge change and thus shape how messages are interpreted and received. Further understanding of how culture influences the effects of persuasive messages is critical for the improvement of health-communication campaigns. PMID:22011997

  10. An atomic charge model for graphene oxide for exploring its bioadhesive properties in explicit water

    Energy Technology Data Exchange (ETDEWEB)

    Stauffer, D.; Dragneva, N.; Floriano, W. B.; Rubel, O. [Thunder Bay Regional Research Institute, 290 Munro St, Thunder Bay, Ontario P7B 6V4 (Canada); Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7A 7T1 (Canada); Mawhinney, R. C. [Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7A 7T1 (Canada); Fanchini, G. [Physics and Astronomy, University of Western Ontario, 1151 Richmond St, London, Ontario N6A 3K7 (Canada); French, S. [University of Calgary, South Health Campus, 4448 Front St. SE, Calgary, Alberta T3M 1M4 (Canada)

    2014-07-28

    Graphene Oxide (GO) has been shown to exhibit properties that are useful in applications such as biomedical imaging, biological sensors, and drug delivery. The binding properties of biomolecules at the surface of GO can provide insight into the potential biocompatibility of GO. Here we assess the intrinsic affinity of amino acids to GO by simulating their adsorption onto a GO surface. The simulation is done using Amber03 force-field molecular dynamics in explicit water. The emphasis is placed on developing an atomic charge model for GO. The adsorption energies are computed using atomic charges obtained from an ab initio electrostatic potential based method. The charges reported here are suitable for simulating peptide adsorption to GO.

  11. An Exploration of Wind Stress Calculation Techniques in Hurricane Storm Surge Modeling

    Directory of Open Access Journals (Sweden)

    Kyra M. Bryant

    2016-09-01

    Full Text Available As hurricanes continue to threaten coastal communities, accurate storm surge forecasting remains a global priority. Achieving a reliable storm surge prediction necessitates accurate hurricane intensity and wind field information. The wind field must be converted to wind stress, which represents the air-sea momentum flux component required in storm surge and other oceanic models. This conversion requires a multiplicative drag coefficient for the air density and wind speed to represent the air-sea momentum exchange at a given location. Air density is a known parameter and wind speed is a forecasted variable, whereas the drag coefficient is calculated using an empirical correlation. The correlation’s accuracy has brewed a controversy of its own for more than half a century. This review paper examines the lineage of drag coefficient correlations and their acceptance among scientists.

  12. Exploring the isopycnal mixing and helium–heat paradoxes in a suite of Earth system models

    Directory of Open Access Journals (Sweden)

    A. Gnanadesikan

    2015-07-01

    this paper we show that this is not the case. In a suite of models with different spatially constant and spatially varying values of ARedi the distribution of radiocarbon and helium isotopes is sensitive to the value of ARedi. However, away from strong helium sources in the southeastern Pacific, the relationship between the two is not sensitive, indicating that large-scale advection is the limiting process for removing helium and radiocarbon from the deep ocean. The helium isotopes, in turn, suggest a higher value of ARedi below the thermocline than is seen in theoretical parameterizations based on baroclinic growth rates. We argue that a key part of resolving the isopycnal mixing paradox is to abandon the idea that ARedi has a direct relationship to local baroclinic instability and to the so-called "thickness" mixing coefficient AGM.

  13. Twin studies as a model for exploring the aetiology of autoimmune thyroid disease

    DEFF Research Database (Denmark)

    Brix, Thomas Heiberg; Hegedüs, Laszlo

    2012-01-01

    , these studies have provided valid and unbiased information regarding the influence of genetic and environmental factors in the aetiology of autoimmune thyroid disease (AITD). The comparison of concordance rates between monozygotic (MZ) and dizygotic twins provides irrefutable evidence of a genetic component......, and biometric twin modelling shows that approximately 75% of the total phenotypic variance in AITD is because of genetic effects. On the other hand, the lack of complete concordance in MZ twin pairs is proof of environmental and/or epigenetic factors also playing an important role. The impact of environmental....... Future twin studies should incorporate information on genetic, epigenetic and environmental variation thereby enhancing our ability to quantify the precise effect of specific risk factors....

  14. Exploring entropic uncertainty relation in the Heisenberg XX model with inhomogeneous magnetic field

    Science.gov (United States)

    Huang, Ai-Jun; Wang, Dong; Wang, Jia-Ming; Shi, Jia-Dong; Sun, Wen-Yang; Ye, Liu

    2017-08-01

    In this work, we investigate the quantum-memory-assisted entropic uncertainty relation in a two-qubit Heisenberg XX model with inhomogeneous magnetic field. It has been found that larger coupling strength J between the two spin-chain qubits can effectively reduce the entropic uncertainty. Besides, we observe the mechanics of how the inhomogeneous field influences the uncertainty, and find out that when the inhomogeneous field parameter b1. Intriguingly, the entropic uncertainty can shrink to zero when the coupling coefficients are relatively large, while the entropic uncertainty only reduces to 1 with the increase of the homogeneous magnetic field. Additionally, we observe the purity of the state and Bell non-locality and obtain that the entropic uncertainty is anticorrelated with both the purity and Bell non-locality of the evolution state.

  15. Measurement and Exploration of Individual Beliefs About the Consequences of Building Information Modelling Use

    DEFF Research Database (Denmark)

    Davies, Richard; Harty, Chris

    2013-01-01

    of the consequences of ICT use predict subsequent usage. We describe the development of scales to measure beliefs about the consequences of building information modelling (BIM) and their use in a survey of employees of a large construction contracting organization in the United Kingdom. Scales for performance......Information and communication technology (ICT) is becoming increasingly important in construction although the rate of adoption is considered slow and the industry faces specific implementation challenges. Mainstream information systems research has shown that individuals’ beliefs and expectations...... the consequences of BIM use were broadly favourable although there is a need for more data for comparisons. The structure of the responses showed that expectations that BIM would enhance job performance were strongly related to expectations that BIM use was compatible with preferred and existing ways of working...

  16. Numerical modeling of cold magmatic CO2 flux measurements for the exploration of hidden geothermal systems

    Science.gov (United States)

    Peiffer, Loïc.; Wanner, Christoph; Pan, Lehua

    2015-10-01

    The most accepted conceptual model to explain surface degassing of cold magmatic CO2 in volcanic-geothermal systems involves the presence of a gas reservoir. In this study, numerical simulations using the TOUGH2-ECO2N V2.0 package are performed to get quantitative insights into how cold CO2 soil flux measurements are related to reservoir and fluid properties. Although the modeling is based on flux data measured at a specific geothermal site, the Acoculco caldera (Mexico), some general insights have been gained. Both the CO2 fluxes at the surface and the depth at which CO2 exsolves are highly sensitive to the dissolved CO2 content of the deep fluid. If CO2 mainly exsolves above the reservoir within a fracture zone, the surface CO2 fluxes are not sensitive to the reservoir size but depend on the CO2 dissolved content and the rock permeability. For gas exsolution below the top of the reservoir, surface CO2 fluxes also depend on the gas saturation of the deep fluid as well as the reservoir size. The absence of thermal anomalies at the surface is mainly a consequence of the low enthalpy of CO2. The heat carried by CO2 is efficiently cooled down by heat conduction and to a certain extent by isoenthalpic volume expansion depending on the temperature gradient. Thermal anomalies occur at higher CO2 fluxes (>37,000 g m-2 d-1) when the heat flux of the rising CO2 is not balanced anymore. Finally, specific results are obtained for the Acoculco area (reservoir depth, CO2 dissolved content, and gas saturation state).

  17. Comparative exploration of multidimensional flow cytometry software: a model approach evaluating T cell polyfunctional behavior.

    Science.gov (United States)

    Spear, Timothy T; Nishimura, Michael I; Simms, Patricia E

    2017-08-01

    Advancement in flow cytometry reagents and instrumentation has allowed for simultaneous analysis of large numbers of lineage/functional immune cell markers. Highly complex datasets generated by polychromatic flow cytometry require proper analytical software to answer investigators' questions. A problem among many investigators and flow cytometry Shared Resource Laboratories (SRLs), including our own, is a lack of access to a flow cytometry-knowledgeable bioinformatics team, making it difficult to learn and choose appropriate analysis tool(s). Here, we comparatively assess various multidimensional flow cytometry software packages for their ability to answer a specific biologic question and provide graphical representation output suitable for publication, as well as their ease of use and cost. We assessed polyfunctional potential of TCR-transduced T cells, serving as a model evaluation, using multidimensional flow cytometry to analyze 6 intracellular cytokines and degranulation on a per-cell basis. Analysis of 7 parameters resulted in 128 possible combinations of positivity/negativity, far too complex for basic flow cytometry software to analyze fully. Various software packages were used, analysis methods used in each described, and representative output displayed. Of the tools investigated, automated classification of cellular expression by nonlinear stochastic embedding (ACCENSE) and coupled analysis in Pestle/simplified presentation of incredibly complex evaluations (SPICE) provided the most user-friendly manipulations and readable output, evaluating effects of altered antigen-specific stimulation on T cell polyfunctionality. This detailed approach may serve as a model for other investigators/SRLs in selecting the most appropriate software to analyze complex flow cytometry datasets. Further development and awareness of available tools will help guide proper data analysis to answer difficult biologic questions arising from incredibly complex datasets. © Society

  18. Exploring quadrangulations

    KAUST Repository

    Peng, Chihan

    2014-01-01

    Here we presented a framework to explore quad mesh topologies. The core of our work is a systematic enumeration algorithm that can generate all possible quadrangular meshes inside a defined boundary with an upper limit of v3-v5 pairs. The algorithm is orders of magnitude more efficient than previous work. The combination of topological enumeration and shape-space exploration demonstrates that mesh topology has a powerful influence on geometry. The Fig. 18. A gallery of different quadrilateral meshes for a Shuriken. The quadrilaterals of the model were colored in a postprocess. Topological variations have distinctive, interesting patterns of mesh lines. © 2014 ACM 0730-0301/2014/01-ART3 15.00.

  19. Wikipedia: Friend, Not Foe

    Science.gov (United States)

    Crovitz, Darren; Smoot, W. Scott

    2009-01-01

    As online research has become an increasingly standard activity for middle school and high school students, Wikipedia (http://www.wikipedia.org) has simultaneously emerged as the bane of many teachers who include research-focused assignments in their courses. An online encyclopedia that allows anyone to edit its entries, Wikipedia has educators…

  20. GPS & Galileo. Friendly Foes?

    Science.gov (United States)

    2007-04-01

    used around the world today.60 “Experts said that the system is operating well and has played a significant role in cartography, telecoms , water...concerns of China’s involvement and partnered with Russia on GLONASS. Similar agreements were signed with Ukraine in June 2005, with Morocco in