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Sample records for modeling human syllogistic

  1. Teaching Syllogistics Using Conceptual Graphs

    DEFF Research Database (Denmark)

    Øhrstrøm, Peter; Sandborg-Petersen, Ulrik; Thorvaldsen, Steiner

    2014-01-01

    It has for centuries been commonly believed that syllogistic reasoning is an essential part of human rationality. For this reason, Aristotelian syllogistics has since the rise of the European university been a standard component of logic teaching. During the medieval period syllogistic validity......, implemented using the Prolog programming language as embodied in a Java implementation called Prolog+CG. The aim of the present paper is to study some interesting conceptual aspects of syllogistic reasoning and to investigate whether CG formalism can be helpful in order to obtain a better understanding...... of syllogistic reasoning in general and the system of Aristotelian syllogisms conceived as a deductive (axiomatic) structure in particular. Some prototypes of tools for basic logic teaching have been developed using Prolog+CG, and various preliminary tests of the tools have been carried out....

  2. Effects of belief and logic on syllogistic reasoning: Eye-movement evidence for selective processing models.

    Science.gov (United States)

    Ball, Linden J; Phillips, Peter; Wade, Caroline N; Quayle, Jeremy D

    2006-01-01

    Studies of syllogistic reasoning have demonstrated a nonlogical tendency for people to endorse more believable conclusions than unbelievable ones. This belief bias effect is more dominant on invalid syllogisms than valid ones, giving rise to a logic by belief interaction. We report an experiment in which participants' eye movements were recorded in order to provide insights into the nature and time course of the reasoning processes associated with manipulations of conclusion validity and believability. Our main dependent measure was people's inspection times for syllogistic premises, and we tested predictions deriving from three contemporary mental-models accounts of the logic by belief interaction. Results supported recent "selective processing" theories of belief bias (e.g., Evans, 2000; Klauer, Musch, & Naumer, 2000), which assume that the believability of a conclusion biases model construction processes, rather than biasing the search for falsifying models (e.g., Oakhill & Johnson-Laird, 1985) or a response stage of reasoning arising from subjective uncertainty (e.g., Quayle & Ball, 2000). We conclude by suggesting that the eye-movement analyses in reasoning research may provide a useful adjunct to other process-tracing techniques such as verbal protocol analysis.

  3. Phonological and visual distinctiveness effects in syllogistic reasoning: implications for mental models theory.

    Science.gov (United States)

    Ball, Linden J; Quayle, Jeremy D

    2009-09-01

    Two experiments are reported in which the representational distinctiveness of terms within categorical syllogisms was manipulated in order to examine the assumption of mental models theory that abstract, spatially based representations underpin deduction. In Experiment 1, participants evaluated conclusion validity for syllogisms containing either phonologically distinctive terms (e.g., harks, paps, and fids) or phonologically nondistinctive terms (e.g., fuds, fods, and feds). Logical performance was enhanced with the distinctive contents, suggesting that the phonological properties of syllogism terms can play an important role in deduction. In Experiment 2, participants received either the phonological materials from Experiment 1 or syllogisms involving distinctive or nondistinctive visual contents. Logical inference was again enhanced for the distinctive contents, whether phonological or visual in nature. Our findings suggest a broad involvement of multimodal information in syllogistic reasoning and question the assumed primacy of abstract, spatially organized representations in deduction, as is claimed by mental models theorists.

  4. Leibniz' First Formalization of Syllogistics

    DEFF Research Database (Denmark)

    Robering, Klaus

    2014-01-01

    In his Dissertatio de Arte Combinatoria from 1666 Leibniz provides a formal presentation of syllogistics within the framework of his general-combinatoric program. He does not set up an axiomatic system for the derivation of all valid syllogistic mode, rather he formulates a set of rules which...... distinguish the valid modes among all possible ones. Leibniz' coding of syllogistic modi by combinations of letters and his distinction between possible and useful ("utiles") modes suggests to reconstruct the characterization of the valid modes as the problem of determining among the possible combination...... of letters just those which belong to the useful, i.e., valid, modes. The set of codes of valid modes turns out to be a so-called "regular" language (in the sense of formal-language-theory). Leibniz' formalization of syllogistics in his Dissertatio thus contains an estimation of the computational complexity...

  5. The Hamiltonian Syllogistic

    CERN Document Server

    Pratt-Hartmann, Ian

    2010-01-01

    This paper undertakes a re-examination of Sir William Hamilton's doctrine of the quantification of the predicate. Hamilton's doctrine comprises two theses. First, the predicates of traditional syllogistic sentence-forms contain implicit existential quantifiers, so that, for example, "All p are q" is to be understood as "All p are some q". Second, these implicit quantifiers can be meaningfully dualized to yield novel sentence-forms, such as, for example, "All p are all q". Hamilton attempted to provide a deductive system for his language, along the lines of the classical syllogisms. We show, using techniques unavailable to Hamilton, that such a system does exist, though with qualifications that distinguish it from its classical counterpart.

  6. CASCADED FUNZZY SYSTEM AND ITS ROBUST ANALYSIS BASED ON SYLLOGISTIC FUZZY REASONING

    Institute of Scientific and Technical Information of China (English)

    Wang Shitong; Korris F. L. Chung

    2004-01-01

    Syllogistic fuzzy reasoning is introduced into fizzy system, and the new Cascaded Fuzzy System(CFS) is presented. The thoroughly theoretical analysis and experimental results show that syllogistic fuzzy reasoning is more robust than all other implication inferences for noise data and that CFS has better robustness than conventional fuzzy systems, which provide the solid foundation for CFS's potential application in fuzzy control and modeling and so on.

  7. Teaching Syllogistics Through Gamification and Interactive Proofs

    DEFF Research Database (Denmark)

    Øhrstrøm, Peter; Sandborg-Petersen, Ulrik; Thorvaldsen, Steinar

    2015-01-01

    This paper is a continuation of earlier studies involving experiments with Communication students using a Java-Applet running in the student’s browser, developed using the Prolog programming language as embodied in a Java implementation called Prolog+CG. This makes it possible to support logic...... be helpful in logic teaching in order to obtain a better understanding of syllogistic reasoning....

  8. Teaching Syllogistics Using E-learning Tools

    DEFF Research Database (Denmark)

    Øhrstrøm, Peter; Sandborg-Petersen, Ulrik; Thorvaldsen, Steinar

    2016-01-01

    This paper is a study of various strategies for teaching syllogistics as part of a course in basic logic. It is a continuation of earlier studies involving practical experiments with students of Communication using the Syllog system, which makes it possible to develop e-learning tools and to do l...... involving different teaching methods will be compared.......This paper is a study of various strategies for teaching syllogistics as part of a course in basic logic. It is a continuation of earlier studies involving practical experiments with students of Communication using the Syllog system, which makes it possible to develop e-learning tools and to do...... learning analytics based on log-data. The aim of the present paper is to investigate whether the Syllog e-learning tools can be helpful in logic teaching in order to obtain a better understanding of logic and argumentation in general and syllogisms in particular. Four versions of a course in basic logic...

  9. Teaching Syllogistics Using E-learning Tools

    DEFF Research Database (Denmark)

    Øhrstrøm, Peter; Sandborg-Petersen, Ulrik; Thorvaldsen, Steinar

    2016-01-01

    This paper is a study of various strategies for teaching syllogistics as part of a course in basic logic. It is a continuation of earlier studies involving practical experiments with students of Communication using the Syllog system, which makes it possible to develop e-learning tools and to do...... learning analytics based on log-data. The aim of the present paper is to investigate whether the Syllog e-learning tools can be helpful in logic teaching in order to obtain a better understanding of logic and argumentation in general and syllogisms in particular. Four versions of a course in basic logic...... involving different teaching methods will be compared....

  10. Physarum Polycephalum Syllogistic L-Systems and Judaic Roots of Unconventional Computing

    Directory of Open Access Journals (Sweden)

    Schumann Andrew

    2016-03-01

    Full Text Available We show that in Kabbalah, the esoteric teaching of Judaism, there were developed ideas of unconventional automata in which operations over characters of the Hebrew alphabet can simulate all real processes producing appropriate strings in accordance with some algorithms. These ideas may be used now in a syllogistic extension of Lindenmayer systems (L-systems, where we deal also with strings in the Kabbalistic-Leibnizean meaning. This extension is illustrated by the behavior of Physarum polycephalum plasmodia which can implement, first, the Aristotelian syllogistic and, second, a Talmudic syllogistic by qal wa-homer.

  11. A successive-conditionalization approach to disjunctive and syllogistic reasoning.

    Science.gov (United States)

    Liu, In-Mao; Chou, Ting-Hsi

    2012-09-01

    With p and q each standing for a familiar event, a disjunctive statement, "either p or q", seems quite different from its material conditional, "if not p then q". The notions of sufficiency and necessity seem specific to conditional statements. It is surprising, however, to find that perceived sufficiency and necessity affect disjunctive reasoning in the way they affect conditional reasoning. With B and C each standing for a category name, a universal statement, "all B are C", seems stronger than its logically equivalent conditional statement, "if B then C". However, the effects of perceived sufficiency or necessity were found to be as pronounced in conditional reasoning as in syllogistic reasoning. Furthermore, two experiments also showed that (a) MP (modus ponens)-comparable disjunctive reasoning was as difficult as MT (modus tollens)-comparable disjunctive reasoning, and that (b) MT-comparable syllogisms were easier to solve than MT problems in conditional reasoning.

  12. Logic and belief across the lifespan: the rise and fall of belief inhibition during syllogistic reasoning.

    Science.gov (United States)

    De Neys, Wim; Van Gelder, Elke

    2009-01-01

    Popular reasoning theories postulate that the ability to inhibit inappropriate beliefs lies at the heart of the human reasoning engine. Given that people's inhibitory capacities are known to rise and fall across the lifespan, we predicted that people's deductive reasoning performance would show similar curvilinear age trends. A group of children (12-year-olds), young adults (20-year-olds), and older adults (65+-year-olds) were presented with a classic syllogistic reasoning task and a decision-making questionnaire. Results indicated that on syllogisms where beliefs and logic conflicted, reasoning performance showed the expected curvilinear age trend: Reasoning performance initially increased from childhood to early adulthood but declined again in later life. On syllogisms where beliefs and logic were consistent and sound reasoning did not require belief inhibition, however, age did not affect performance. Furthermore, across the lifespan we observed that the better people were at resisting intuitive temptations in the decision-making task, the less they were biased by their beliefs on the conflict syllogisms. As with the effect of age, one's ability to override intuitions in the decision-making task did not mediate reasoning performance on the no-conflict syllogisms. Results lend credence to the postulated central role of inhibitory processing in those situations where beliefs and logic conflict.

  13. Negations in syllogistic reasoning: evidence for a heuristic-analytic conflict.

    Science.gov (United States)

    Stupple, Edward J N; Waterhouse, Eleanor F

    2009-08-01

    An experiment utilizing response time measures was conducted to test dominant processing strategies in syllogistic reasoning with the expanded quantifier set proposed by Roberts (2005). Through adding negations to existing quantifiers it is possible to change problem surface features without altering logical validity. Biases based on surface features such as atmosphere, matching, and the probability heuristics model (PHM; Chater & Oaksford, 1999; Wetherick & Gilhooly, 1995) would not be expected to show variance in response latencies, but participant responses should be highly sensitive to changes in the surface features of the quantifiers. In contrast, according to analytic accounts such as mental models theory and mental logic (e.g., Johnson-Laird & Byrne, 1991; Rips, 1994) participants should exhibit increased response times for negated premises, but not be overly impacted upon by the surface features of the conclusion. Data indicated that the dominant response strategy was based on a matching heuristic, but also provided evidence of a resource-demanding analytic procedure for dealing with double negatives. The authors propose that dual-process theories offer a stronger account of these data whereby participants employ competing heuristic and analytic strategies and fall back on a heuristic response when analytic processing fails.

  14. Syllogistic System for the Propagation of Parasites. The Case of Schistosomatidae (Trematoda: Digenea

    Directory of Open Access Journals (Sweden)

    Schumann Andrew

    2015-03-01

    Full Text Available In the paper, a new syllogistic system is built up. This system simulates a massive-parallel behavior in the propagation of collectives of parasites. In particular, this system simulates the behavior of collectives of trematode larvae (miracidia and cercariae.

  15. Does Logic Feel Good? Testing for Intuitive Detection of Logicality in Syllogistic Reasoning

    Science.gov (United States)

    Klauer, Karl Christoph; Singmann, Henrik

    2013-01-01

    Recent research on syllogistic reasoning suggests that the logical status (valid vs. invalid) of even difficult syllogisms can be intuitively detected via small changes in affective state (Morsanyi & Handley, 2012). In a series of 6 experiments, we replicated effects of logical status on liking ratings of difficult syllogisms (although their…

  16. The neural basis of syllogistic reasoning: An event-related potential study.

    Science.gov (United States)

    Qiu, Jiang; Li, Hong; Luo, Yuejia; Zhang, Qinglin; Tu, Shen

    2009-06-01

    The spatiotemporal analysis of brain activation during syllogistic reasoning, and the execution of 1 baseline task (BST) were performed in 14 healthy adult participants using high-density event-related brain potentials (ERPs). The following results were obtained: First, the valid syllogistic reasoning task (VSR) elicited a greater positive ERP deflection than the invalid syllogistic reasoning task (ISR) and BST between 300 and 400 ms after the onset of the minor premise. Dipole source analysis of the difference waves (VSR-BST and VSR-ISR) indicated that the positive components were localized in the vicinity of the occipito-temporal cortex, possibly related to visual premise processing. Second, VSR and ISR demonstrated greater negativity than BST developed at 600-700 ms. Dipole source analysis of difference waves (VSR-BST and ISR-BST) indicated that the negative components were mainly localized near the medial frontal cortex/the anterior cingulate cortex, possibly related to the manipulation and integration of premise information. Third, both VSR and ISR elicited a more positive ERP deflection than BST between 2500 and 3000 ms. Voltage maps of the difference waves (VSR-BST and VSR-ISR) demonstrated strong activity in the right frontal scalp regions. Results indicate that the reasoning tasks may require more mental effort to spatial processing of working memory.

  17. Correlates of syllogistic reasoning skills in middle childhood and early adolescence.

    Science.gov (United States)

    Galotti, K M; Komatsu, L K

    1988-02-01

    Sixth, eighth, tenth, and twelfth graders, and college students, were given a preliminary test of categorical syllogistic reasoning ability. In a subsequent session, subjects were given other categorical syllogisms and asked to depict as many of the possible relationships between the A, B, and C terms of the syllogism as they could. The number of possible relationships, and the time it took to decide if other relationships were possible, did not differ among the noncollege groups. The results indicated, however, that the correlates of reasoning proficiency differed for those subjects younger and those older than about age 13.

  18. Syllogistic reasoning in fuzzy logic and its application to usuality and reasoning with dispositions

    Science.gov (United States)

    Zadeh, L. A.

    1985-01-01

    A fuzzy syllogism in fuzzy logic is defined to be an inference schema in which the major premise, the minor premise and the conclusion are propositions containing fuzzy quantifiers. A basic fuzzy syllogism in fuzzy logic is the intersection/product syllogism. Several other basic syllogisms are developed that may be employed as rules of combination of evidence in expert systems. Among these is the consequent conjunction syllogism. Furthermore, it is shown that syllogistic reasoning in fuzzy logic provides a basis for reasoning with dispositions; that is, with propositions that are preponderantly but not necessarily always true. It is also shown that the concept of dispositionality is closely related to the notion of usuality and serves as a basis for what might be called a theory of usuality - a theory which may eventually provide a computational framework for commonsense reasoning.

  19. Does logic feel good? Testing for intuitive detection of logicality in syllogistic reasoning.

    Science.gov (United States)

    Klauer, Karl Christoph; Singmann, Henrik

    2013-07-01

    Recent research on syllogistic reasoning suggests that the logical status (valid vs. invalid) of even difficult syllogisms can be intuitively detected via small changes in affective state (Morsanyi & Handley, 2012). In a series of 6 experiments, we replicated effects of logical status on liking ratings of difficult syllogisms (although their shape differs from that reported by Morsanyi and Handley), and we tested 2 alternative accounts of our and Morsanyi and Handley's findings in terms of surface features accidentally confounded with logical status: the partial-repetition hypothesis and the content-effects hypothesis. The results support the content-effects hypothesis, according to which the effects of logical status reflect differences in mean liking for the presented conclusions rather than effects of logical status itself.

  20. A Modern Syllogistic Method in Intuitionistic Fuzzy Logic with Realistic Tautology

    Directory of Open Access Journals (Sweden)

    Ali Muhammad Rushdi

    2015-01-01

    Full Text Available The Modern Syllogistic Method (MSM of propositional logic ferrets out from a set of premises all that can be concluded from it in the most compact form. The MSM combines the premises into a single function equated to 1 and then produces the complete product of this function. Two fuzzy versions of MSM are developed in Ordinary Fuzzy Logic (OFL and in Intuitionistic Fuzzy Logic (IFL with these logics augmented by the concept of Realistic Fuzzy Tautology (RFT which is a variable whose truth exceeds 0.5. The paper formally proves each of the steps needed in the conversion of the ordinary MSM into a fuzzy one. The proofs rely mainly on the successful replacement of logic 1 (or ordinary tautology by an RFT. An improved version of Blake-Tison algorithm for generating the complete product of a logical function is also presented and shown to be applicable to both crisp and fuzzy versions of the MSM. The fuzzy MSM methodology is illustrated by three specific examples, which delineate differences with the crisp MSM, address the question of validity values of consequences, tackle the problem of inconsistency when it arises, and demonstrate the utility of the concept of Realistic Fuzzy Tautology.

  1. Negative valence can evoke a liberal response bias in syllogistic reasoning.

    Science.gov (United States)

    Vartanian, Oshin; Nakashima, Ann; Bouak, Fethi; Smith, Ingrid; Baranski, Joseph V; Cheung, Bob

    2013-03-01

    Recently, studies have demonstrated that negative valence reduces the magnitude of the belief-bias effect in syllogistic reasoning. This effect has been localized in the reasoning stage, in the form of increased deliberation on trials where validity and conclusion believability are incongruent. Here, using signal detection theory, we show that the attenuation of belief bias observed when valence was negative can also be evoked by a liberal response bias at the decision stage. Indeed, when valence was negative participants adopted a more liberal criterion for judging syllogisms as "valid," and were overconfident in their judgments. They also displayed less sensitivity in distinguishing between valid and invalid syllogisms. Our findings dovetail with recent evidence from memory research suggesting that negative valence can evoke a liberal response bias without improving performance. Our novel contribution is the demonstration that the attenuating effect of negative valence on belief bias can take multiples routes--by influencing the decision stage as was the case here, the reasoning stage as has been demonstrated elsewhere, and potentially both stages.

  2. A Modern Syllogistic Method in Intuitionistic Fuzzy Logic with Realistic Tautology.

    Science.gov (United States)

    Rushdi, Ali Muhammad; Zarouan, Mohamed; Alshehri, Taleb Mansour; Rushdi, Muhammad Ali

    2015-01-01

    The Modern Syllogistic Method (MSM) of propositional logic ferrets out from a set of premises all that can be concluded from it in the most compact form. The MSM combines the premises into a single function equated to 1 and then produces the complete product of this function. Two fuzzy versions of MSM are developed in Ordinary Fuzzy Logic (OFL) and in Intuitionistic Fuzzy Logic (IFL) with these logics augmented by the concept of Realistic Fuzzy Tautology (RFT) which is a variable whose truth exceeds 0.5. The paper formally proves each of the steps needed in the conversion of the ordinary MSM into a fuzzy one. The proofs rely mainly on the successful replacement of logic 1 (or ordinary tautology) by an RFT. An improved version of Blake-Tison algorithm for generating the complete product of a logical function is also presented and shown to be applicable to both crisp and fuzzy versions of the MSM. The fuzzy MSM methodology is illustrated by three specific examples, which delineate differences with the crisp MSM, address the question of validity values of consequences, tackle the problem of inconsistency when it arises, and demonstrate the utility of the concept of Realistic Fuzzy Tautology.

  3. Logic feels so good-I like it! Evidence for intuitive detection of logicality in syllogistic reasoning.

    Science.gov (United States)

    Morsanyi, Kinga; Handley, Simon J

    2012-05-01

    When people evaluate syllogisms, their judgments of validity are often biased by the believability of the conclusions of the problems. Thus, it has been suggested that syllogistic reasoning performance is based on an interplay between a conscious and effortful evaluation of logicality and an intuitive appreciation of the believability of the conclusions (e.g., Evans, Newstead, Allen, & Pollard, 1994). However, logic effects in syllogistic reasoning emerge even when participants are unlikely to carry out a full logical analysis of the problems (e.g., Shynkaruk & Thompson, 2006). There is also evidence that people can implicitly detect the conflict between their beliefs and the validity of the problems, even if they are unable to consciously produce a logical response (e.g., De Neys, Moyens, & Vansteenwegen, 2010). In 4 experiments we demonstrate that people intuitively detect the logicality of syllogisms, and this effect emerges independently of participants' conscious mindset and their cognitive capacity. This logic effect is also unrelated to the superficial structure of the problems. Additionally, we provide evidence that the logicality of the syllogisms is detected through slight changes in participants' affective states. In fact, subliminal affective priming had an effect on participants' subjective evaluations of the problems. Finally, when participants misattributed their emotional reactions to background music, this significantly reduced the logic effect.

  4. Scalability of human models

    NARCIS (Netherlands)

    Rodarius, C.; Rooij, L. van; Lange, R. de

    2007-01-01

    The objective of this work was to create a scalable human occupant model that allows adaptation of human models with respect to size, weight and several mechanical parameters. Therefore, for the first time two scalable facet human models were developed in MADYMO. First, a scalable human male was

  5. Computational human body models

    NARCIS (Netherlands)

    Wismans, J.S.H.M.; Happee, R.; Dommelen, J.A.W. van

    2005-01-01

    Computational human body models are widely used for automotive crashsafety research and design and as such have significantly contributed to a reduction of traffic injuries and fatalities. Currently crash simulations are mainly performed using models based on crash-dummies. However crash dummies dif

  6. Computational human body models

    NARCIS (Netherlands)

    Wismans, J.S.H.M.; Happee, R.; Dommelen, J.A.W. van

    2005-01-01

    Computational human body models are widely used for automotive crashsafety research and design and as such have significantly contributed to a reduction of traffic injuries and fatalities. Currently crash simulations are mainly performed using models based on crash-dummies. However crash dummies

  7. Human migraine models

    DEFF Research Database (Denmark)

    Iversen, Helle Klingenberg

    2001-01-01

    The need for experimental models is obvious. In animal models it is possible to study vascular responses, neurogenic inflammation, c-fos expression etc. However, the pathophysiology of migraine remains unsolved, why results from animal studies not directly can be related to the migraine attack......, which is a human experience. A set-up for investigations of experimental headache and migraine in humans, has been evaluated and headache mechanisms explored by using nitroglycerin and other headache-inducing agents. Nitric oxide (NO) or other parts of the NO activated cascade seems to be responsible...

  8. Human Factors Model

    Science.gov (United States)

    1993-01-01

    Jack is an advanced human factors software package that provides a three dimensional model for predicting how a human will interact with a given system or environment. It can be used for a broad range of computer-aided design applications. Jack was developed by the computer Graphics Research Laboratory of the University of Pennsylvania with assistance from NASA's Johnson Space Center, Ames Research Center and the Army. It is the University's first commercial product. Jack is still used for academic purposes at the University of Pennsylvania. Commercial rights were given to Transom Technologies, Inc.

  9. The Development and Evaluation of a Model for Teaching Science in the Elementary School.

    Science.gov (United States)

    Schiele, Paul Ellsworth, Jr.

    A model for teaching science in elementary school was developed and evaluated for its effectiveness. The model clarified the philosophical bases, the organizational structure, the curriculum content, and the type of activities to be performed in the classroom. The model was tested for grades one through six in eight schools. A syllogistic approach…

  10. Logic and Belief across the Lifespan: The Rise and Fall of Belief Inhibition during Syllogistic Reasoning

    Science.gov (United States)

    De Neys, Wim; Van Gelder, Elke

    2009-01-01

    Popular reasoning theories postulate that the ability to inhibit inappropriate beliefs lies at the heart of the human reasoning engine. Given that people's inhibitory capacities are known to rise and fall across the lifespan, we predicted that people's deductive reasoning performance would show similar curvilinear age trends. A group of children…

  11. Modeling human color categorization

    NARCIS (Netherlands)

    van den Broek, Egon; Schouten, Th.E.; Kisters, P.M.F.

    2008-01-01

    A unique color space segmentation method is introduced. It is founded on features of human cognition, where 11 color categories are used in processing color. In two experiments, human subjects were asked to categorize color stimuli into these 11 color categories, which resulted in markers for a Colo

  12. Modeling human color categorization

    NARCIS (Netherlands)

    van den Broek, Egon; Schouten, Th.E.; Kisters, P.M.F.

    A unique color space segmentation method is introduced. It is founded on features of human cognition, where 11 color categories are used in processing color. In two experiments, human subjects were asked to categorize color stimuli into these 11 color categories, which resulted in markers for a

  13. Integrated Environmental Modelling: human decisions, human challenges

    Science.gov (United States)

    Glynn, Pierre D.

    2015-01-01

    Integrated Environmental Modelling (IEM) is an invaluable tool for understanding the complex, dynamic ecosystems that house our natural resources and control our environments. Human behaviour affects the ways in which the science of IEM is assembled and used for meaningful societal applications. In particular, human biases and heuristics reflect adaptation and experiential learning to issues with frequent, sharply distinguished, feedbacks. Unfortunately, human behaviour is not adapted to the more diffusely experienced problems that IEM typically seeks to address. Twelve biases are identified that affect IEM (and science in general). These biases are supported by personal observations and by the findings of behavioural scientists. A process for critical analysis is proposed that addresses some human challenges of IEM and solicits explicit description of (1) represented processes and information, (2) unrepresented processes and information, and (3) accounting for, and cognizance of, potential human biases. Several other suggestions are also made that generally complement maintaining attitudes of watchful humility, open-mindedness, honesty and transparent accountability. These suggestions include (1) creating a new area of study in the behavioural biogeosciences, (2) using structured processes for engaging the modelling and stakeholder communities in IEM, and (3) using ‘red teams’ to increase resilience of IEM constructs and use.

  14. Mathematical models of human behavior

    DEFF Research Database (Denmark)

    Møllgaard, Anders Edsberg

    data set, along with work on other behavioral data. The overall goal is to contribute to a quantitative understanding of human behavior using big data and mathematical models. Central to the thesis is the determination of the predictability of different human activities. Upper limits are derived......, thereby implying that interactions between spreading processes are driving forces of attention dynamics. Overall, the thesis contributes to a quantitative understanding of a wide range of different human behaviors by applying mathematical modeling to behavioral data. There can be no doubt......During the last 15 years there has been an explosion in human behavioral data caused by the emergence of cheap electronics and online platforms. This has spawned a whole new research field called computational social science, which has a quantitative approach to the study of human behavior. Most...

  15. Effects of aging on hemispheric asymmetry in inferior frontal cortex activity during belief-bias syllogistic reasoning: a near-infrared spectroscopy study.

    Science.gov (United States)

    Tsujii, Takeo; Okada, Mitsuhiro; Watanabe, Shigeru

    2010-07-11

    The belief-bias effect in syllogistic reasoning refers to the tendency for subjects to be erroneously biased when logical conclusions are incongruent with beliefs about the world. This study examined age-related differences in inferior frontal cortex (IFC) activity associated with belief-bias reasoning using near-infrared spectroscopy (NIRS). The subjects were 32 older (mean age, 68.53 years) and 32 young adult volunteers (mean age, 21.50 years). They performed belief-congruent and incongruent reasoning trials while right and left IFC activities were being measured by NIRS. Behavioral analysis found that older adults exhibited a larger belief-bias than young adults. NIRS analysis showed that the right IFC was more activated than the left IFC in young adults, while there was no significant hemispheric difference in older adults. On correlation analysis, there was a significant positive correlation between reasoning accuracy and IFC activation in both hemispheres for older adults, while in young adults, the correlation was significant only in the right hemisphere. These correlation patterns suggest that the right IFC is critical for resolving conflicting reasoning in young adults, but that older adults may further recruit the left IFC to compensate for the age-related decline in the inhibitory control functions. Thus, we demonstrate, for the first time, age-related differences in neural activity associated with belief-bias reasoning.

  16. A natural human hand model

    NARCIS (Netherlands)

    Van Nierop, O.A.; Van der Helm, A.; Overbeeke, K.J.; Djajadiningrat, T.J.P.

    2007-01-01

    We present a skeletal linked model of the human hand that has natural motion. We show how this can be achieved by introducing a new biology-based joint axis that simulates natural joint motion and a set of constraints that reduce an estimated 150 possible motions to twelve. The model is based on obs

  17. Mathematical models of human behavior

    DEFF Research Database (Denmark)

    Møllgaard, Anders Edsberg

    During the last 15 years there has been an explosion in human behavioral data caused by the emergence of cheap electronics and online platforms. This has spawned a whole new research field called computational social science, which has a quantitative approach to the study of human behavior. Most...... studies have considered data sets with just one behavioral variable such as email communication. The Social Fabric interdisciplinary research project is an attempt to collect a more complete data set on human behavior by providing 1000 smartphones with pre-installed data collection software to students...... data set, along with work on other behavioral data. The overall goal is to contribute to a quantitative understanding of human behavior using big data and mathematical models. Central to the thesis is the determination of the predictability of different human activities. Upper limits are derived...

  18. Flexible Bayesian Human Fecundity Models.

    Science.gov (United States)

    Kim, Sungduk; Sundaram, Rajeshwari; Buck Louis, Germaine M; Pyper, Cecilia

    2012-12-01

    Human fecundity is an issue of considerable interest for both epidemiological and clinical audiences, and is dependent upon a couple's biologic capacity for reproduction coupled with behaviors that place a couple at risk for pregnancy. Bayesian hierarchical models have been proposed to better model the conception probabilities by accounting for the acts of intercourse around the day of ovulation, i.e., during the fertile window. These models can be viewed in the framework of a generalized nonlinear model with an exponential link. However, a fixed choice of link function may not always provide the best fit, leading to potentially biased estimates for probability of conception. Motivated by this, we propose a general class of models for fecundity by relaxing the choice of the link function under the generalized nonlinear model framework. We use a sample from the Oxford Conception Study (OCS) to illustrate the utility and fit of this general class of models for estimating human conception. Our findings reinforce the need for attention to be paid to the choice of link function in modeling conception, as it may bias the estimation of conception probabilities. Various properties of the proposed models are examined and a Markov chain Monte Carlo sampling algorithm was developed for implementing the Bayesian computations. The deviance information criterion measure and logarithm of pseudo marginal likelihood are used for guiding the choice of links. The supplemental material section contains technical details of the proof of the theorem stated in the paper, and contains further simulation results and analysis.

  19. The Shigella human challenge model.

    Science.gov (United States)

    Porter, C K; Thura, N; Ranallo, R T; Riddle, M S

    2013-02-01

    Shigella is an important bacterial cause of infectious diarrhoea globally. The Shigella human challenge model has been used since 1946 for a variety of objectives including understanding disease pathogenesis, human immune responses and allowing for an early assessment of vaccine efficacy. A systematic review of the literature regarding experimental shigellosis in human subjects was conducted. Summative estimates were calculated by strain and dose. While a total of 19 studies evaluating nine strains at doses ranging from 10 to 1 × 1010 colony-forming units were identified, most studies utilized the S. sonnei strain 53G and the S. flexneri strain 2457T. Inoculum solution and pre-inoculation buffering has varied over time although diarrhoea attack rates do not appear to increase above 75-80%, and dysentery rates remain fairly constant, highlighting the need for additional dose-ranging studies. Expansion of the model to include additional strains from different serotypes will elucidate serotype and strain-specific outcome variability.

  20. Modeling of Human Joint Structures.

    Science.gov (United States)

    1982-09-01

    Radial Lateral " epicondyle Olecranon Radius Ulna Figure 3. Lateral aspect of the right elbow joint. -17- Annular Ligament This strong band encircles... elbow joint, knee joint, human joints, shoulder joint, ankle joint, joint models, hip joint, ligaments. 20. ABSTRACT (Continue on reverse side If...ligaments. -A rather extended discussion of the articulations and anatomical descriptions of the elbow , shoulder, hip, knee and ankle joints are

  1. Human Thermal Model Evaluation Using the JSC Human Thermal Database

    Science.gov (United States)

    Bue, Grant; Makinen, Janice; Cognata, Thomas

    2012-01-01

    Human thermal modeling has considerable long term utility to human space flight. Such models provide a tool to predict crew survivability in support of vehicle design and to evaluate crew response in untested space environments. It is to the benefit of any such model not only to collect relevant experimental data to correlate it against, but also to maintain an experimental standard or benchmark for future development in a readily and rapidly searchable and software accessible format. The Human thermal database project is intended to do just so; to collect relevant data from literature and experimentation and to store the data in a database structure for immediate and future use as a benchmark to judge human thermal models against, in identifying model strengths and weakness, to support model development and improve correlation, and to statistically quantify a model s predictive quality. The human thermal database developed at the Johnson Space Center (JSC) is intended to evaluate a set of widely used human thermal models. This set includes the Wissler human thermal model, a model that has been widely used to predict the human thermoregulatory response to a variety of cold and hot environments. These models are statistically compared to the current database, which contains experiments of human subjects primarily in air from a literature survey ranging between 1953 and 2004 and from a suited experiment recently performed by the authors, for a quantitative study of relative strength and predictive quality of the models.

  2. Modeling Forces on the Human Body.

    Science.gov (United States)

    Pagonis, Vasilis; Drake, Russel; Morgan, Michael; Peters, Todd; Riddle, Chris; Rollins, Karen

    1999-01-01

    Presents five models of the human body as a mechanical system which can be used in introductory physics courses: human arms as levers, humans falling from small heights, a model of the human back, collisions during football, and the rotating gymnast. Gives ideas for discussions and activities, including Interactive Physics (TM) simulations. (WRM)

  3. Modelling the scaling properties of human mobility

    Science.gov (United States)

    Song, Chaoming; Koren, Tal; Wang, Pu; Barabási, Albert-László

    2010-10-01

    Individual human trajectories are characterized by fat-tailed distributions of jump sizes and waiting times, suggesting the relevance of continuous-time random-walk (CTRW) models for human mobility. However, human traces are barely random. Given the importance of human mobility, from epidemic modelling to traffic prediction and urban planning, we need quantitative models that can account for the statistical characteristics of individual human trajectories. Here we use empirical data on human mobility, captured by mobile-phone traces, to show that the predictions of the CTRW models are in systematic conflict with the empirical results. We introduce two principles that govern human trajectories, allowing us to build a statistically self-consistent microscopic model for individual human mobility. The model accounts for the empirically observed scaling laws, but also allows us to analytically predict most of the pertinent scaling exponents.

  4. Human Performance Modeling for Dynamic Human Reliability Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Boring, Ronald Laurids [Idaho National Laboratory; Joe, Jeffrey Clark [Idaho National Laboratory; Mandelli, Diego [Idaho National Laboratory

    2015-08-01

    Part of the U.S. Department of Energy’s (DOE’s) Light Water Reac- tor Sustainability (LWRS) Program, the Risk-Informed Safety Margin Charac- terization (RISMC) Pathway develops approaches to estimating and managing safety margins. RISMC simulations pair deterministic plant physics models with probabilistic risk models. As human interactions are an essential element of plant risk, it is necessary to integrate human actions into the RISMC risk framework. In this paper, we review simulation based and non simulation based human reliability analysis (HRA) methods. This paper summarizes the founda- tional information needed to develop a feasible approach to modeling human in- teractions in RISMC simulations.

  5. Intuitive logic revisited: new data and a Bayesian mixed model meta-analysis.

    Science.gov (United States)

    Singmann, Henrik; Klauer, Karl Christoph; Kellen, David

    2014-01-01

    Recent research on syllogistic reasoning suggests that the logical status (valid vs. invalid) of even difficult syllogisms can be intuitively detected via differences in conceptual fluency between logically valid and invalid syllogisms when participants are asked to rate how much they like a conclusion following from a syllogism (Morsanyi & Handley, 2012). These claims of an intuitive logic are at odds with most theories on syllogistic reasoning which posit that detecting the logical status of difficult syllogisms requires effortful and deliberate cognitive processes. We present new data replicating the effects reported by Morsanyi and Handley, but show that this effect is eliminated when controlling for a possible confound in terms of conclusion content. Additionally, we reanalyze three studies (n = 287) without this confound with a Bayesian mixed model meta-analysis (i.e., controlling for participant and item effects) which provides evidence for the null-hypothesis and against Morsanyi and Handley's claim.

  6. Humanized in vivo Model for Autoimmune Diabetes

    Science.gov (United States)

    2009-02-01

    AWARD NUMBER: W81XWH-07-1-0121 TITLE: Humanized in vivo Model for Autoimmune Diabetes PRINCIPAL INVESTIGATOR: Gerald T Nepom, M.D., Ph.D...4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER Humanized in vivo Model for Autoimmune Diabetes Sb. GRANT NUMBER W81XWH-07-1-0121 Sc. PROGRAM ELEMENT...therapies. This research study entails using humanized mice manifesting type 1 diabetes (T1 D)-associated human HLA molecules to address the fate and

  7. Human mammary microenvironment better regulates the biology of human breast cancer in humanized mouse model.

    Science.gov (United States)

    Zheng, Ming-Jie; Wang, Jue; Xu, Lu; Zha, Xiao-Ming; Zhao, Yi; Ling, Li-Jun; Wang, Shui

    2015-02-01

    During the past decades, many efforts have been made in mimicking the clinical progress of human cancer in mouse models. Previously, we developed a human breast tissue-derived (HB) mouse model. Theoretically, it may mimic the interactions between "species-specific" mammary microenvironment of human origin and human breast cancer cells. However, detailed evidences are absent. The present study (in vivo, cellular, and molecular experiments) was designed to explore the regulatory role of human mammary microenvironment in the progress of human breast cancer cells. Subcutaneous (SUB), mammary fat pad (MFP), and HB mouse models were developed for in vivo comparisons. Then, the orthotopic tumor masses from three different mouse models were collected for primary culture. Finally, the biology of primary cultured human breast cancer cells was compared by cellular and molecular experiments. Results of in vivo mouse models indicated that human breast cancer cells grew better in human mammary microenvironment. Cellular and molecular experiments confirmed that primary cultured human breast cancer cells from HB mouse model showed a better proliferative and anti-apoptotic biology than those from SUB to MFP mouse models. Meanwhile, primary cultured human breast cancer cells from HB mouse model also obtained the migratory and invasive biology for "species-specific" tissue metastasis to human tissues. Comprehensive analyses suggest that "species-specific" mammary microenvironment of human origin better regulates the biology of human breast cancer cells in our humanized mouse model of breast cancer, which is more consistent with the clinical progress of human breast cancer.

  8. Genetically Modified Pig Models for Human Diseases

    Institute of Scientific and Technical Information of China (English)

    Nana Fan; Liangxue Lai

    2013-01-01

    Genetically modified animal models are important for understanding the pathogenesis of human disease and developing therapeutic strategies.Although genetically modified mice have been widely used to model human diseases,some of these mouse models do not replicate important disease symptoms or pathology.Pigs are more similar to humans than mice in anatomy,physiology,and genome.Thus,pigs are considered to be better animal models to mimic some human diseases.This review describes genetically modified pigs that have been used to model various diseases including neurological,cardiovascular,and diabetic disorders.We also discuss the development in gene modification technology that can facilitate the generation of transgenic pig models for human diseases.

  9. 3-D Human Modeling and Animation

    CERN Document Server

    Ratner, Peter

    2012-01-01

    3-D Human Modeling and Animation Third Edition All the tools and techniques you need to bring human figures to 3-D life Thanks to today's remarkable technology, artists can create and animate realistic, three-dimensional human figures that were not possible just a few years ago. This easy-to-follow book guides you through all the necessary steps to adapt your own artistic skill in figure drawing, painting, and sculpture to this exciting digital canvas. 3-D Human Modeling and Animation, Third Edition starts you off with simple modeling, then prepares you for more advanced techniques for crea

  10. Presentation Format and Syllogistic Reasoning

    Science.gov (United States)

    Espino, Orlando; Santamaria, Carlos

    2013-01-01

    Figural effect is a response bias that depends on the arrangement of the terms in syllogisms. The usual pattern in construction tasks is that participants tend to give A-C responses when the syllogisms are in figure 4(A-B/B-C), while the majority of their conclusions are in the opposite direction (C-A) for syllogisms in figure 1 (B-A/C-B). We…

  11. Human hand modelling: kinematics, dynamics, applications

    NARCIS (Netherlands)

    Gustus, A.; Stillfried, G.; Visser, J.; Jörntell, H.; Van der Smagt, P.

    2012-01-01

    An overview of mathematical modelling of the human hand is given. We consider hand models from a specific background: rather than studying hands for surgical or similar goals, we target at providing a set of tools with which human grasping and manipulation capabilities can be studied, and hand funct

  12. Hidden Markov Models for Human Genes

    DEFF Research Database (Denmark)

    Baldi, Pierre; Brunak, Søren; Chauvin, Yves

    1997-01-01

    We analyse the sequential structure of human genomic DNA by hidden Markov models. We apply models of widely different design: conventional left-right constructs and models with a built-in periodic architecture. The models are trained on segments of DNA sequences extracted such that they cover...

  13. Human Centered Hardware Modeling and Collaboration

    Science.gov (United States)

    Stambolian Damon; Lawrence, Brad; Stelges, Katrine; Henderson, Gena

    2013-01-01

    In order to collaborate engineering designs among NASA Centers and customers, to in clude hardware and human activities from multiple remote locations, live human-centered modeling and collaboration across several sites has been successfully facilitated by Kennedy Space Center. The focus of this paper includes innovative a pproaches to engineering design analyses and training, along with research being conducted to apply new technologies for tracking, immersing, and evaluating humans as well as rocket, vehic le, component, or faci lity hardware utilizing high resolution cameras, motion tracking, ergonomic analysis, biomedical monitoring, wor k instruction integration, head-mounted displays, and other innovative human-system integration modeling, simulation, and collaboration applications.

  14. Human Exposure Modeling - Databases to Support Exposure Modeling

    Science.gov (United States)

    Human exposure modeling relates pollutant concentrations in the larger environmental media to pollutant concentrations in the immediate exposure media. The models described here are available on other EPA websites.

  15. Human Operator Control Strategy Model.

    Science.gov (United States)

    1980-04-01

    fashion. HOPE reflects the two-store theory of memory current in the psycho- logical literature ( Atkinson & Shiffrin , 1968; Broadbent, 1971). Two...uncertainty. In P.M.A. Rabbit & S. Dornic (Eds.), Attention and performance V. New York: Academic Press, 1975. Atkinson , R. C., & Shiffrin , R. M. Human...48 2. The Perception Process ... ............... 50 3. The Command Memory and Command Selection Process

  16. Human Adaptive Mechatronics and Human-System Modelling

    Directory of Open Access Journals (Sweden)

    Satoshi Suzuki

    2013-03-01

    Full Text Available Several topics in projects for mechatronics studies, which are 'Human Adaptive Mechatronics (HAM' and 'Human-System Modelling (HSM', are presented in this paper. The main research theme of the HAM project is a design strategy for a new intelligent mechatronics system, which enhances operators' skills during machine operation. Skill analyses and control system design have been addressed. In the HSM project, human modelling based on hierarchical classification of skills was studied, including the following five types of skills: social, planning, cognitive, motion and sensory-motor skills. This paper includes digests of these research topics and the outcomes concerning each type of skill. Relationships with other research activities, knowledge and information that will be helpful for readers who are trying to study assistive human-mechatronics systems are also mentioned.

  17. Human body modeling in injury biomechanics

    NARCIS (Netherlands)

    Happee, R.; Morsink, P.L.J.; Horst, M.J. van der; Wismans, J.S.H.M.

    1999-01-01

    Mathematical modelling is widely used for crash-safety research and design. However, most occupant models used in crash simulations are based on crash dummies and thereby inherit their apparent limitations. This paper describes a mathematical model of the real human body for impact loading. A combin

  18. Modeling human operator involvement in robotic systems

    NARCIS (Netherlands)

    Wewerinke, P.H.

    1991-01-01

    A modeling approach is presented to describe complex manned robotic systems. The robotic system is modeled as a (highly) nonlinear, possibly time-varying dynamic system including any time delays in terms of optimal estimation, control and decision theory. The role of the human operator(s) is modeled

  19. Cognitive modelling of human temporal reasoning

    NARCIS (Netherlands)

    ter Meulen, AGB

    2003-01-01

    Modelling human reasoning characterizes the fundamental human cognitive capacity to describe our past experience and use it to form expectations as well as plan and direct our future actions. Natural language semantics analyzes dynamic forms of reasoning in which the real-time order determines the

  20. Murine models of human wound healing.

    Science.gov (United States)

    Chen, Jerry S; Longaker, Michael T; Gurtner, Geoffrey C

    2013-01-01

    In vivo wound healing experiments remain the most predictive models for studying human wound healing, allowing an accurate representation of the complete wound healing environment including various cell types, environmental cues, and paracrine interactions. Small animals are economical, easy to maintain, and allow researchers to take advantage of the numerous transgenic strains that have been developed to investigate the specific mechanisms involved in wound healing and regeneration. Here we describe three reproducible murine wound healing models that recapitulate the human wound healing process.

  1. Animal Models of Human Placentation - A Review

    DEFF Research Database (Denmark)

    Carter, Anthony Michael

    2007-01-01

    This review examines the strengths and weaknesses of animal models of human placentation and pays particular attention to the mouse and non-human primates. Analogies can be drawn between mouse and human in placental cell types and genes controlling placental development. There are, however...... and endometrium is similar in macaques and baboons, as is the subsequent lacunar stage. The absence of interstitial trophoblast cells in the monkey is an important difference from human placentation. However, there is a strong resemblance in the way spiral arteries are invaded and transformed in the macaque...

  2. The Human-Artifact Model

    DEFF Research Database (Denmark)

    Bødker, Susanne; Klokmose, Clemens Nylandsted

    2011-01-01

    Although devices of all shapes and sizes currently dominate the technological landscape, human–computer interaction (HCI) as a field is not yet theoretically equipped to match this reality. In this article we develop the human–artifact model, which has its roots in activity theoretical HCI....... By reinterpreting the activity theoretical foundation, we present a framework that helps addressing the analysis of individual interactive artifacts while embracing that they are part of a larger ecology of artifacts. We show how the human–artifact model helps structuring the understanding of an artifact's action......-possibilities in relation to the artifact ecology surrounding it. Essential to the model is that it provides four interconnected levels of analysis and addresses the possibilities and problems at these four levels. Artifacts and their use are constantly developing, and we address development in, and of, use. The framework...

  3. Finite element modeling of the human pelvis

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, B.

    1995-11-01

    A finite element model of the human pelvis was created using a commercial wire frame image as a template. To test the final mesh, the model`s mechanical behavior was analyzed through finite element analysis and the results were displayed graphically as stress concentrations. In the future, this grid of the pelvis will be integrated with a full leg model and used in side-impact car collision simulations.

  4. Computational Intelligence in a Human Brain Model

    Directory of Open Access Journals (Sweden)

    Viorel Gaftea

    2016-06-01

    Full Text Available This paper focuses on the current trends in brain research domain and the current stage of development of research for software and hardware solutions, communication capabilities between: human beings and machines, new technologies, nano-science and Internet of Things (IoT devices. The proposed model for Human Brain assumes main similitude between human intelligence and the chess game thinking process. Tactical & strategic reasoning and the need to follow the rules of the chess game, all are very similar with the activities of the human brain. The main objective for a living being and the chess game player are the same: securing a position, surviving and eliminating the adversaries. The brain resolves these goals, and more, the being movement, actions and speech are sustained by the vital five senses and equilibrium. The chess game strategy helps us understand the human brain better and easier replicate in the proposed ‘Software and Hardware’ SAH Model.

  5. Computational Intelligence in a Human Brain Model

    Directory of Open Access Journals (Sweden)

    Viorel Gaftea

    2016-06-01

    Full Text Available This paper focuses on the current trends in brain research domain and the current stage of development of research for software and hardware solutions, communication capabilities between: human beings and machines, new technologies, nano-science and Internet of Things (IoT devices. The proposed model for Human Brain assumes main similitude between human intelligence and the chess game thinking process. Tactical & strategic reasoning and the need to follow the rules of the chess game, all are very similar with the activities of the human brain. The main objective for a living being and the chess game player are the same: securing a position, surviving and eliminating the adversaries. The brain resolves these goals, and more, the being movement, actions and speech are sustained by the vital five senses and equilibrium. The chess game strategy helps us understand the human brain better and easier replicate in the proposed ‘Software and Hardware’ SAH Model.

  6. Mathematical human modelling for impact loading

    NARCIS (Netherlands)

    Happee, R.; Hoof, J.F.A.M. van; Lange, R. de

    2001-01-01

    Mathematical modeling of the human body is widely used for automotive crash-safety research and design. Simulations have contributed to a reduction of injury numbers by optimization of vehicle structures and restraint systems. Currently, such simulations are largely performed using occupant models b

  7. Mathematical human modelling for impact loading

    NARCIS (Netherlands)

    Happee, R.; Hoof, J.F.A.M. van; Lange, R. de

    2001-01-01

    Mathematical modeling of the human body is widely used for automotive crash-safety research and design. Simulations have contributed to a reduction of injury numbers by optimization of vehicle structures and restraint systems. Currently, such simulations are largely performed using occupant models

  8. Mathematical human body modelling for impact loading

    NARCIS (Netherlands)

    Happee, R.; Morsink, P.L.J.; Wismans, J.S.H.M.

    1999-01-01

    Mathematical modelling of the human body is widely used for automotive crash safety research and design. Simulations have contributed to a reduction of injury numbers by optimisation of vehicle structures and restraint systems. Currently such simulations are largely performed using occupant models

  9. Complex Systems and Human Performance Modeling

    Science.gov (United States)

    2013-12-01

    constitute a cognitive architecture or decomposing the work flows and resource constraints that characterize human-system interactions, the modeler...also explored the generation of so-called “ fractal ” series from simple task network models where task times are the calculated by way of a moving

  10. Models of the Human in Tantric Hinduism

    DEFF Research Database (Denmark)

    Olesen, Bjarne Wernicke; Flood, Gavin

    2018-01-01

    This research project explores the origins, developments and transformations of yogic models of the human (e.g. kundalini yoga, the cakra system and ritual sex) in the tantric goddess traditions or what might be called Śāktism of medieval India. These Śākta models of esoteric anatomy originating...

  11. Mathematical human body modelling for impact loading

    NARCIS (Netherlands)

    Happee, R.; Morsink, P.L.J.; Wismans, J.S.H.M.

    1999-01-01

    Mathematical modelling of the human body is widely used for automotive crash safety research and design. Simulations have contributed to a reduction of injury numbers by optimisation of vehicle structures and restraint systems. Currently such simulations are largely performed using occupant models b

  12. Interior Design Research: A Human Ecosystem Model.

    Science.gov (United States)

    Guerin, Denise A.

    1992-01-01

    The interior ecosystems model illustrates effects on the human organism of the interaction of the natural, behavioral, and built environment. Examples of interior lighting and household energy consumption show the model's flexibility for organizing study variables in interior design research. (SK)

  13. A Model of the Human Eye

    Science.gov (United States)

    Colicchia, G.; Wiesner, H.; Waltner, C.; Zollman, D.

    2008-01-01

    We describe a model of the human eye that incorporates a variable converging lens. The model can be easily constructed by students with low-cost materials. It shows in a comprehensible way the functionality of the eye's optical system. Images of near and far objects can be focused. Also, the defects of near and farsighted eyes can be demonstrated.

  14. Interior Design Research: A Human Ecosystem Model.

    Science.gov (United States)

    Guerin, Denise A.

    1992-01-01

    The interior ecosystems model illustrates effects on the human organism of the interaction of the natural, behavioral, and built environment. Examples of interior lighting and household energy consumption show the model's flexibility for organizing study variables in interior design research. (SK)

  15. Human Muscle Fatigue Model in Dynamic Motions

    CERN Document Server

    Ma, Ruina; Bennis, Fouad; Ma, Liang

    2012-01-01

    Human muscle fatigue is considered to be one of the main reasons for Musculoskeletal Disorder (MSD). Recent models have been introduced to define muscle fatigue for static postures. However, the main drawbacks of these models are that the dynamic effect of the human and the external load are not taken into account. In this paper, each human joint is assumed to be controlled by two muscle groups to generate motions such as push/pull. The joint torques are computed using Lagrange's formulation to evaluate the dynamic factors of the muscle fatigue model. An experiment is defined to validate this assumption and the result for one person confirms its feasibility. The evaluation of this model can predict the fatigue and MSD risk in industry production quickly.

  16. Mathematical models of human african trypanosomiasis epidemiology.

    Science.gov (United States)

    Rock, Kat S; Stone, Chris M; Hastings, Ian M; Keeling, Matt J; Torr, Steve J; Chitnis, Nakul

    2015-03-01

    Human African trypanosomiasis (HAT), commonly called sleeping sickness, is caused by Trypanosoma spp. and transmitted by tsetse flies (Glossina spp.). HAT is usually fatal if untreated and transmission occurs in foci across sub-Saharan Africa. Mathematical modelling of HAT began in the 1980s with extensions of the Ross-Macdonald malaria model and has since consisted, with a few exceptions, of similar deterministic compartmental models. These models have captured the main features of HAT epidemiology and provided insight on the effectiveness of the two main control interventions (treatment of humans and tsetse fly control) in eliminating transmission. However, most existing models have overestimated prevalence of infection and ignored transient dynamics. There is a need for properly validated models, evolving with improved data collection, that can provide quantitative predictions to help guide control and elimination strategies for HAT.

  17. Human models of acute lung injury

    Directory of Open Access Journals (Sweden)

    Alastair G. Proudfoot

    2011-03-01

    Full Text Available Acute lung injury (ALI is a syndrome that is characterised by acute inflammation and tissue injury that affects normal gas exchange in the lungs. Hallmarks of ALI include dysfunction of the alveolar-capillary membrane resulting in increased vascular permeability, an influx of inflammatory cells into the lung and a local pro-coagulant state. Patients with ALI present with severe hypoxaemia and radiological evidence of bilateral pulmonary oedema. The syndrome has a mortality rate of approximately 35% and usually requires invasive mechanical ventilation. ALI can follow direct pulmonary insults, such as pneumonia, or occur indirectly as a result of blood-borne insults, commonly severe bacterial sepsis. Although animal models of ALI have been developed, none of them fully recapitulate the human disease. The differences between the human syndrome and the phenotype observed in animal models might, in part, explain why interventions that are successful in models have failed to translate into novel therapies. Improved animal models and the development of human in vivo and ex vivo models are therefore required. In this article, we consider the clinical features of ALI, discuss the limitations of current animal models and highlight how emerging human models of ALI might help to answer outstanding questions about this syndrome.

  18. Mathematical modeling of the human knee joint

    Energy Technology Data Exchange (ETDEWEB)

    Ricafort, Juliet [Univ. of Southern California, Los Angeles, CA (United States). Dept. of Biomedical Engineering

    1996-05-01

    A model was developed to determine the forces exerted by several flexor and extensor muscles of the human knee under static conditions. The following muscles were studied: the gastrocnemius, biceps femoris, semitendinosus, semimembranosus, and the set of quadricep muscles. The tibia and fibula were each modeled as rigid bodies; muscles were modeled by their functional lines of action in space. Assumptions based on previous data were used to resolve the indeterminacy.

  19. Conceptual Data Modelling of Modern Human Migration

    Directory of Open Access Journals (Sweden)

    Kosta Sotiroski

    2012-12-01

    Full Text Available The processes of human migrations have been present for ages, since the very beginnings of human history on the planet Earth. Nowadays, these are amplified to a large scale due to the modern means of communication, transportation, information and knowledge exchange, as well as the complex processes of globalization. Knowing the social, demographic, ethnical and educational structure of the migrants, as well as their geographical trajectory and temporal dynamics of their spatial moving across territories, countries and continents, is of a crucial meaning for both national governments and international policies. There is an emphasized need for identifying, acquiring, organizing, storing, retrieving and analyzing data related to human migration processes. The relational databases provide an ultimate solution, whilst the E-R diagram represents a common graphical tool for conceptual data modelling and relational database design. Within the paper we develop and propose a logical data model of the modern human migration.

  20. Preclinical and human surrogate models of itch

    DEFF Research Database (Denmark)

    Hoeck, Emil August; Marker, Jens Broch; Gazerani, Parisa;

    2016-01-01

    Pruritus, or simply itch, is a debilitating symptom that significantly decreases the quality of life in a wide range of clinical conditions. While histamine remains the most studied mediator of itch in humans, treatment options for chronic itch, in particular antihistamine-resistant itch, are lim...... currently applied in animals and humans. This article is protected by copyright. All rights reserved.......Pruritus, or simply itch, is a debilitating symptom that significantly decreases the quality of life in a wide range of clinical conditions. While histamine remains the most studied mediator of itch in humans, treatment options for chronic itch, in particular antihistamine-resistant itch......, are limited. Relevant preclinical and human surrogate models of non-histaminergic itch are needed to accelerate the development of novel antipruritics and diagnostic tools. Advances in basic itch research have facilitated the development of diverse models of itch and associated dysesthesiae. While...

  1. CGRP in human models of primary headaches

    DEFF Research Database (Denmark)

    Ashina, Håkan; Schytz, Henrik Winther; Ashina, Messoud

    2017-01-01

    experiments are likely due to assay variation; therefore, proper validation and standardization of an assay is needed. To what extent CGRP is involved in tension-type headache and cluster headache is unknown. CONCLUSION: Human models of primary headaches have elucidated the role of CGRP in headache......OBJECTIVE: To review the role of CGRP in human models of primary headaches and to discuss methodological aspects and future directions. DISCUSSION: Provocation experiments demonstrated a heterogeneous CGRP migraine response in migraine patients. Conflicting CGRP plasma results in the provocation...... pathophysiology and sparked great interest in developing new treatment strategies using CGRP antagonists and antibodies. Future studies applying more refined human experimental models should identify biomarkers of CGRP-induced primary headache and reveal whether CGRP provocation experiments could be used...

  2. Human Adaptive Mechatronics and Human-System Modelling

    Directory of Open Access Journals (Sweden)

    Satoshi Suzuki

    2013-03-01

    Full Text Available Several topics in projects for mechatronics studies, which are ʹHuman Adaptive Mechatronics (HAMʹ and ʹHuman‐System Modelling (HSMʹ, are presented in this paper. The main research theme of the HAM project is a design strategy for a new intelligent mechatronics system, which enhances operatorsʹ skills during machine operation. Skill analyses and control system design have been addressed. In the HSM project, human modelling based on hierarchical classification of skills was studied, including the following five types of skills: social, planning, cognitive, motion and sensory‐motor skills. This paper includes digests of these research topics and the outcomes concerning each type of skill. Relationships with other research activities, knowledge and information that will be helpful for readers who are trying to study assistive human‐mechatronics systems are also mentioned.

  3. Animal and human models to understand ageing.

    Science.gov (United States)

    Lees, Hayley; Walters, Hannah; Cox, Lynne S

    2016-11-01

    Human ageing is the gradual decline in organ and tissue function with increasing chronological time, leading eventually to loss of function and death. To study the processes involved over research-relevant timescales requires the use of accessible model systems that share significant similarities with humans. In this review, we assess the usefulness of various models, including unicellular yeasts, invertebrate worms and flies, mice and primates including humans, and highlight the benefits and possible drawbacks of each model system in its ability to illuminate human ageing mechanisms. We describe the strong evolutionary conservation of molecular pathways that govern cell responses to extracellular and intracellular signals and which are strongly implicated in ageing. Such pathways centre around insulin-like growth factor signalling and integration of stress and nutritional signals through mTOR kinase. The process of cellular senescence is evaluated as a possible underlying cause for many of the frailties and diseases of human ageing. Also considered is ageing arising from systemic changes that cannot be modelled in lower organisms and instead require studies either in small mammals or in primates. We also touch briefly on novel therapeutic options arising from a better understanding of the biology of ageing. Copyright © 2016. Published by Elsevier Ireland Ltd.

  4. A stochastic model of human gait dynamics

    Science.gov (United States)

    Ashkenazy, Yosef; M. Hausdorff, Jeffrey; Ch. Ivanov, Plamen; Eugene Stanley, H.

    2002-12-01

    We present a stochastic model of gait rhythm dynamics, based on transitions between different “neural centers”, that reproduces distinctive statistical properties of normal human walking. By tuning one model parameter, the transition (hopping) range, the model can describe alterations in gait dynamics from childhood to adulthood-including a decrease in the correlation and volatility exponents with maturation. The model also generates time series with multifractal spectra whose broadness depends only on this parameter. Moreover, we find that the volatility exponent increases monotonically as a function of the width of the multifractal spectrum, suggesting the possibility of a change in multifractality with maturation.

  5. Analisis Model Pengukuran Human Capital dalam Organisasi

    Directory of Open Access Journals (Sweden)

    Cecep Hidayat

    2013-11-01

    Full Text Available Measurement of human capital is not an easy to do because it is dynamic and always changing in accordance with the changing circumstances. Determination of dimensions and indicators of measurement needs to consider various factors such as situations and also the research scopes. This article has objectives to review the concepts, dimensions and measurement models of human capital. The research method used was literature study with a major reference source from current journal articles that discuss the measurement of human capital. Results of the study showed that basically the definition set forth in any dimension containing either explicitly or implicitly. In addition, the result indicated that there are three main categories of equality among researchers regarding the definition of human capital which emphasizes on: economic value/productivity, education, and abilities/competencies. The results also showed that the use of definitions, dimensions, and indicators for measurement of human capital depends on the situation, the scope of research, and the size of the organization. The conclusion of the study indicated that the measurement model and determination of dimensions and indicators of human capital measurement will determine the effectiveness of the measurement, and will have an impact on organizational performance.

  6. Engineering large animal models of human disease.

    Science.gov (United States)

    Whitelaw, C Bruce A; Sheets, Timothy P; Lillico, Simon G; Telugu, Bhanu P

    2016-01-01

    The recent development of gene editing tools and methodology for use in livestock enables the production of new animal disease models. These tools facilitate site-specific mutation of the genome, allowing animals carrying known human disease mutations to be produced. In this review, we describe the various gene editing tools and how they can be used for a range of large animal models of diseases. This genomic technology is in its infancy but the expectation is that through the use of gene editing tools we will see a dramatic increase in animal model resources available for both the study of human disease and the translation of this knowledge into the clinic. Comparative pathology will be central to the productive use of these animal models and the successful translation of new therapeutic strategies.

  7. Bayesian Modeling of a Human MMORPG Player

    CERN Document Server

    Synnaeve, Gabriel

    2010-01-01

    This paper describes an application of Bayesian programming to the control of an autonomous avatar in a multiplayer role-playing game (the example is based on World of Warcraft). We model a particular task, which consists of choosing what to do and to select which target in a situation where allies and foes are present. We explain the model in Bayesian programming and show how we could learn the conditional probabilities from data gathered during human-played sessions.

  8. Bayesian Modeling of a Human MMORPG Player

    Science.gov (United States)

    Synnaeve, Gabriel; Bessière, Pierre

    2011-03-01

    This paper describes an application of Bayesian programming to the control of an autonomous avatar in a multiplayer role-playing game (the example is based on World of Warcraft). We model a particular task, which consists of choosing what to do and to select which target in a situation where allies and foes are present. We explain the model in Bayesian programming and show how we could learn the conditional probabilities from data gathered during human-played sessions.

  9. Human ex vivo wound healing model.

    Science.gov (United States)

    Stojadinovic, Olivera; Tomic-Canic, Marjana

    2013-01-01

    Wound healing is a spatially and temporally regulated process that progresses through sequential, yet overlapping phases and aims to restore barrier breach. To study this complex process scientists use various in vivo and in vitro models. Here we provide step-by-step instructions on how to perform and employ an ex vivo wound healing model to assess epithelization during wound healing in human skin.

  10. Modelling dengue epidemic spreading with human mobility

    Science.gov (United States)

    Barmak, D. H.; Dorso, C. O.; Otero, M.

    2016-04-01

    We explored the effect of human mobility on the spatio-temporal dynamics of Dengue with a stochastic model that takes into account the epidemiological dynamics of the infected mosquitoes and humans, with different mobility patterns of the human population. We observed that human mobility strongly affects the spread of infection by increasing the final size and by changing the morphology of the epidemic outbreaks. When the spreading of the disease is driven only by mosquito dispersal (flight), a main central focus expands diffusively. On the contrary, when human mobility is taken into account, multiple foci appear throughout the evolution of the outbreaks. These secondary foci generated throughout the outbreaks could be of little importance according to their mass or size compared with the largest main focus. However, the coalescence of these foci with the main one generates an effect, through which the latter develops a size greater than the one obtained in the case driven only by mosquito dispersal. This increase in growth rate due to human mobility and the coalescence of the foci are particularly relevant in temperate cities such as the city of Buenos Aires, since they give more possibilities to the outbreak to grow before the arrival of the low-temperature season. The findings of this work indicate that human mobility could be the main driving force in the dynamics of vector epidemics.

  11. AN EFFECTIVE HUMAN LEG MODELING METHOD

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Digital medicine is a new concept in medical field, and the need for digital human body is increasing these years. This paper used Free Form Deformation (FFD) to model the motion of human leg. It presented the motion equations of knee joint on the basis of anatomic structure and motion characters, then transmitted the deformation to the mesh of leg through a simplified FFD that only used two-order B-spline basis function. The experiments prove that this method can simulate the bend of leg and the deformation of muscles fairly well. Compared with the method of curved patches, this method is more convenient and effective. Further more, those equations can be easily applied to other joint models of human body.

  12. Modeling human craniofacial disorders in Xenopus.

    Science.gov (United States)

    Dubey, Aditi; Saint-Jeannet, Jean-Pierre

    2017-03-01

    Craniofacial disorders are among the most common human birth defects and present an enormous health care and social burden. The development of animal models has been instrumental to investigate fundamental questions in craniofacial biology and this knowledge is critical to understand the etiology and pathogenesis of these disorders. The vast majority of craniofacial disorders arise from abnormal development of the neural crest, a multipotent and migratory cell population. Therefore, defining the pathogenesis of these conditions starts with a deep understanding of the mechanisms that preside over neural crest formation and its role in craniofacial development. This review discusses several studies using Xenopus embryos to model human craniofacial conditions, and emphasizes the strength of this system to inform important biological processes as they relate to human craniofacial development and disease.

  13. An Outline Course on Human Performance Modeling

    Science.gov (United States)

    2006-01-01

    complementary or competing tasks: Dario SaIvucci, ??? 46. Bonnie Johns, David Kieras 47. ecological interface design 48. More into modeling human... alarcon 70. Ben Knott 71. Evelyn Rozanski 7.Pete Khooshabeh Optional: If ou would like to be on a mailin list for further seminars lease enter our email

  14. Modeling human muscle disease in zebrafish

    OpenAIRE

    Guyon, Jeffrey R.; Steffen, Leta S; Howell, Melanie H.; Pusack, Timothy J; Lawrence, Chris; Kunkel, Louis M

    2007-01-01

    Modeling human muscle disease in zebrafish correspondence: Corresponding author. Children's Hospital Boston, Enders Bldg, Rm 570, 300 Longwood Ave Boston, MA 02115. Tel.: +1 617 355 7576. (Kunkel, Louis M.) (Kunkel, Louis M.) Program in Genomics and Howard Hughes Medical Institute at Children's Hospital Boston - Boston--> , MA 02115--> - UNITED STATES (Guyon, Jeffrey R.) Program in Genomics a...

  15. Modeling and Simulating Virtual Anatomical Humans

    NARCIS (Netherlands)

    Madehkhaksar, Forough; Luo, Zhiping; Pronost, Nicolas; Egges, Arjan

    2014-01-01

    This chapter presents human musculoskeletal modeling and simulation as a challenging field that lies between biomechanics and computer animation. One of the main goals of computer animation research is to develop algorithms and systems that produce plausible motion. On the other hand, the main chall

  16. Future of human models for crash analysis

    NARCIS (Netherlands)

    Wismans, J.S.H.M.; Happee, R.; Hoof, J.F.A.M. van; Lange, R. de

    2001-01-01

    In the crash safety field mathematical models can be applied in practically all area's of research and development including: reconstruction of actual accidents, design (CAD) of the crash response of vehicles, safety devices and roadside facilities and in support of human impact biomechanical

  17. Future of human models for crash analysis

    NARCIS (Netherlands)

    Wismans, J.S.H.M.; Happee, R.; Hoof, J.F.A.M. van; Lange, R. de

    2001-01-01

    In the crash safety field mathematical models can be applied in practically all area's of research and development including: reconstruction of actual accidents, design (CAD) of the crash response of vehicles, safety devices and roadside facilities and in support of human impact biomechanical studie

  18. Constructing predictive models of human running.

    Science.gov (United States)

    Maus, Horst-Moritz; Revzen, Shai; Guckenheimer, John; Ludwig, Christian; Reger, Johann; Seyfarth, Andre

    2015-02-06

    Running is an essential mode of human locomotion, during which ballistic aerial phases alternate with phases when a single foot contacts the ground. The spring-loaded inverted pendulum (SLIP) provides a starting point for modelling running, and generates ground reaction forces that resemble those of the centre of mass (CoM) of a human runner. Here, we show that while SLIP reproduces within-step kinematics of the CoM in three dimensions, it fails to reproduce stability and predict future motions. We construct SLIP control models using data-driven Floquet analysis, and show how these models may be used to obtain predictive models of human running with six additional states comprising the position and velocity of the swing-leg ankle. Our methods are general, and may be applied to any rhythmic physical system. We provide an approach for identifying an event-driven linear controller that approximates an observed stabilization strategy, and for producing a reduced-state model which closely recovers the observed dynamics. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  19. Model of human visual-motion sensing

    Science.gov (United States)

    Watson, A. B.; Ahumada, A. J., Jr.

    1985-01-01

    A model of how humans sense the velocity of moving images is proposed. The model exploits constraints provided by human psychophysics, notably that motion-sensing elements appear tuned for two-dimensional spatial frequency, and by the frequency spectrum of a moving image, namely, that its support lies in the plane in which the temporal frequency equals the dot product of the spatial frequency and the image velocity. The first stage of the model is a set of spatial-frequency-tuned, direction-selective linear sensors. The temporal frequency of the response of each sensor is shown to encode the component of the image velocity in the sensor direction. At the second stage, these components are resolved in order to measure the velocity of image motion at each of a number of spatial locations and spatial frequencies. The model has been applied to several illustrative examples, including apparent motion, coherent gratings, and natural image sequences. The model agrees qualitatively with human perception.

  20. Space Station crew safety - Human factors model

    Science.gov (United States)

    Cohen, M. M.; Junge, M. K.

    1984-01-01

    A model of the various human factors issues and interactions that might affect crew safety is developed. The first step addressed systematically the central question: How is this Space Station different from all other spacecraft? A wide range of possible issue was identified and researched. Five major topics of human factors issues that interacted with crew safety resulted: Protocols, Critical Habitability, Work Related Issues, Crew Incapacitation and Personal Choice. Second, an interaction model was developed that would show some degree of cause and effect between objective environmental or operational conditions and the creation of potential safety hazards. The intermediary steps between these two extremes of causality were the effects on human performance and the results of degraded performance. The model contains three milestones: stressor, human performance (degraded) and safety hazard threshold. Between these milestones are two countermeasure intervention points. The first opportunity for intervention is the countermeasure against stress. If this countermeasure fails, performance degrades. The second opportunity for intervention is the countermeasure against error. If this second countermeasure fails, the threshold of a potential safety hazard may be crossed.

  1. Development of a realistic human airway model.

    Science.gov (United States)

    Lizal, Frantisek; Elcner, Jakub; Hopke, Philip K; Jedelsky, Jan; Jicha, Miroslav

    2012-03-01

    Numerous models of human lungs with various levels of idealization have been reported in the literature; consequently, results acquired using these models are difficult to compare to in vivo measurements. We have developed a set of model components based on realistic geometries, which permits the analysis of the effects of subsequent model simplification. A realistic digital upper airway geometry except for the lack of an oral cavity has been created which proved suitable both for computational fluid dynamics (CFD) simulations and for the fabrication of physical models. Subsequently, an oral cavity was added to the tracheobronchial geometry. The airway geometry including the oral cavity was adjusted to enable fabrication of a semi-realistic model. Five physical models were created based on these three digital geometries. Two optically transparent models, one with and one without the oral cavity, were constructed for flow velocity measurements, two realistic segmented models, one with and one without the oral cavity, were constructed for particle deposition measurements, and a semi-realistic model with glass cylindrical airways was developed for optical measurements of flow velocity and in situ particle size measurements. One-dimensional phase doppler anemometry measurements were made and compared to the CFD calculations for this model and good agreement was obtained.

  2. Model of the Human Sleep Wake System

    CERN Document Server

    Rogers, Lisa

    2012-01-01

    A model and analysis of the human sleep/wake system is presented. The model is derived using the known neuronal groups, and their various projections, involved with sleep and wake. Inherent in the derivation is the existence of a slow time scale associated with homeostatic regulation, and a faster time scale associated with the dynamics within the sleep phase. A significant feature of the model is that it does not contain a periodic forcing term, common in other models, reflecting the fact that sleep/wake is not dependent upon a diurnal stimulus. Once derived, the model is analyzed using a linearized stability analysis. We then use experimental data from normal sleep-wake systems and orexin knockout systems to verify the physiological validity of the equations.

  3. Computer Modeling of Human Delta Opioid Receptor

    Directory of Open Access Journals (Sweden)

    Tatyana Dzimbova

    2013-04-01

    Full Text Available The development of selective agonists of δ-opioid receptor as well as the model of interaction of ligands with this receptor is the subjects of increased interest. In the absence of crystal structures of opioid receptors, 3D homology models with different templates have been reported in the literature. The problem is that these models are not available for widespread use. The aims of our study are: (1 to choose within recently published crystallographic structures templates for homology modeling of the human δ-opioid receptor (DOR; (2 to evaluate the models with different computational tools; and (3 to precise the most reliable model basing on correlation between docking data and in vitro bioassay results. The enkephalin analogues, as ligands used in this study, were previously synthesized by our group and their biological activity was evaluated. Several models of DOR were generated using different templates. All these models were evaluated by PROCHECK and MolProbity and relationship between docking data and in vitro results was determined. The best correlations received for the tested models of DOR were found between efficacy (erel of the compounds, calculated from in vitro experiments and Fitness scoring function from docking studies. New model of DOR was generated and evaluated by different approaches. This model has good GA341 value (0.99 from MODELLER, good values from PROCHECK (92.6% of most favored regions and MolProbity (99.5% of favored regions. Scoring function correlates (Pearson r = -0.7368, p-value = 0.0097 with erel of a series of enkephalin analogues, calculated from in vitro experiments. So, this investigation allows suggesting a reliable model of DOR. Newly generated model of DOR receptor could be used further for in silico experiments and it will give possibility for faster and more correct design of selective and effective ligands for δ-opioid receptor.

  4. Human physiologically based pharmacokinetic model for propofol

    Directory of Open Access Journals (Sweden)

    Schnider Thomas W

    2005-04-01

    Full Text Available Abstract Background Propofol is widely used for both short-term anesthesia and long-term sedation. It has unusual pharmacokinetics because of its high lipid solubility. The standard approach to describing the pharmacokinetics is by a multi-compartmental model. This paper presents the first detailed human physiologically based pharmacokinetic (PBPK model for propofol. Methods PKQuest, a freely distributed software routine http://www.pkquest.com, was used for all the calculations. The "standard human" PBPK parameters developed in previous applications is used. It is assumed that the blood and tissue binding is determined by simple partition into the tissue lipid, which is characterized by two previously determined set of parameters: 1 the value of the propofol oil/water partition coefficient; 2 the lipid fraction in the blood and tissues. The model was fit to the individual experimental data of Schnider et. al., Anesthesiology, 1998; 88:1170 in which an initial bolus dose was followed 60 minutes later by a one hour constant infusion. Results The PBPK model provides a good description of the experimental data over a large range of input dosage, subject age and fat fraction. Only one adjustable parameter (the liver clearance is required to describe the constant infusion phase for each individual subject. In order to fit the bolus injection phase, for 10 or the 24 subjects it was necessary to assume that a fraction of the bolus dose was sequestered and then slowly released from the lungs (characterized by two additional parameters. The average weighted residual error (WRE of the PBPK model fit to the both the bolus and infusion phases was 15%; similar to the WRE for just the constant infusion phase obtained by Schnider et. al. using a 6-parameter NONMEM compartmental model. Conclusion A PBPK model using standard human parameters and a simple description of tissue binding provides a good description of human propofol kinetics. The major advantage of a

  5. Human Factors Engineering Program Review Model

    Science.gov (United States)

    2004-02-01

    AA NUREG -0711,Rev. 2 Human Factors Engineering Program Review Model 20081009191 I i m To] Bi U.S. Nuclear Regulatory Commission Office of...Material As of November 1999, you may electronically access NUREG -series publications and other NRC records at NRC’s Public Electronic Reading Room at...http://www.nrc.qov/readinq-rm.html. Publicly released records include, to name a few, NUREG -series publications; Federal Register notices; applicant

  6. Human Plague Risk: Spatial-Temporal Models

    Science.gov (United States)

    Pinzon, Jorge E.

    2010-01-01

    This chpater reviews the use of spatial-temporal models in identifying potential risks of plague outbreaks into the human population. Using earth observations by satellites remote sensing there has been a systematic analysis and mapping of the close coupling between the vectors of the disease and climate variability. The overall result is that incidence of plague is correlated to positive El Nino/Southem Oscillation (ENSO).

  7. MODELING HUMAN RELIABILITY ANALYSIS USING MIDAS

    Energy Technology Data Exchange (ETDEWEB)

    Ronald L. Boring; Donald D. Dudenhoeffer; Bruce P. Hallbert; Brian F. Gore

    2006-05-01

    This paper summarizes an emerging collaboration between Idaho National Laboratory and NASA Ames Research Center regarding the utilization of high-fidelity MIDAS simulations for modeling control room crew performance at nuclear power plants. The key envisioned uses for MIDAS-based control room simulations are: (i) the estimation of human error with novel control room equipment and configurations, (ii) the investigative determination of risk significance in recreating past event scenarios involving control room operating crews, and (iii) the certification of novel staffing levels in control rooms. It is proposed that MIDAS serves as a key component for the effective modeling of risk in next generation control rooms.

  8. Behavior genetic modeling of human fertility

    DEFF Research Database (Denmark)

    Rodgers, J L; Kohler, H P; Kyvik, K O

    2001-01-01

    Try) and number of children (NumCh). Behavior genetic models were fitted using structural equation modeling and DF analysis. A consistent medium-level additive genetic influence was found for NumCh, equal across genders; a stronger genetic influence was identified for FirstTry, greater for females than for males......Behavior genetic designs and analysis can be used to address issues of central importance to demography. We use this methodology to document genetic influence on human fertility. Our data come from Danish twin pairs born from 1953 to 1959, measured on age at first attempt to get pregnant (First...

  9. Genetically engineered mouse models and human osteosarcoma

    Directory of Open Access Journals (Sweden)

    Ng Alvin JM

    2012-10-01

    Full Text Available Abstract Osteosarcoma is the most common form of bone cancer. Pivotal insight into the genes involved in human osteosarcoma has been provided by the study of rare familial cancer predisposition syndromes. Three kindreds stand out as predisposing to the development of osteosarcoma: Li-Fraumeni syndrome, familial retinoblastoma and RecQ helicase disorders, which include Rothmund-Thomson Syndrome in particular. These disorders have highlighted the important roles of P53 and RB respectively, in the development of osteosarcoma. The association of OS with RECQL4 mutations is apparent but the relevance of this to OS is uncertain as mutations in RECQL4 are not found in sporadic OS. Application of the knowledge or mutations of P53 and RB in familial and sporadic OS has enabled the development of tractable, highly penetrant murine models of OS. These models share many of the cardinal features associated with human osteosarcoma including, importantly, a high incidence of spontaneous metastasis. The recent development of these models has been a significant advance for efforts to improve our understanding of the genetics of human OS and, more critically, to provide a high-throughput genetically modifiable platform for preclinical evaluation of new therapeutics.

  10. Modeling Oxygen Transport in the Human Placenta

    Science.gov (United States)

    Serov, Alexander; Filoche, Marcel; Salafia, Carolyn; Grebenkov, Denis

    Efficient functioning of the human placenta is crucial for the favorable pregnancy outcome. We construct a 3D model of oxygen transport in the placenta based on its histological cross-sections. The model accounts for both diffusion and convention of oxygen in the intervillous space and allows one to estimate oxygen uptake of a placentone. We demonstrate the existence of an optimal villi density maximizing the uptake and explain it as a trade-off between the incoming oxygen flow and the absorbing villous surface. Calculations performed for arbitrary shapes of fetal villi show that only two geometrical characteristics - villi density and the effective villi radius - are required to predict fetal oxygen uptake. Two combinations of physiological parameters that determine oxygen uptake are also identified: maximal oxygen inflow of a placentone and the Damköhler number. An automatic image analysis method is developed and applied to 22 healthy placental cross-sections demonstrating that villi density of a healthy human placenta lies within 10% of the optimal value, while overall geometry efficiency is rather low (around 30-40%). In a perspective, the model can constitute the base of a reliable tool of post partum oxygen exchange efficiency assessment in the human placenta. Also affiliated with Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90095, USA.

  11. Biomedical Simulation Models of Human Auditory Processes

    Science.gov (United States)

    Bicak, Mehmet M. A.

    2012-01-01

    Detailed acoustic engineering models that explore noise propagation mechanisms associated with noise attenuation and transmission paths created when using hearing protectors such as earplugs and headsets in high noise environments. Biomedical finite element (FE) models are developed based on volume Computed Tomography scan data which provides explicit external ear, ear canal, middle ear ossicular bones and cochlea geometry. Results from these studies have enabled a greater understanding of hearing protector to flesh dynamics as well as prioritizing noise propagation mechanisms. Prioritization of noise mechanisms can form an essential framework for exploration of new design principles and methods in both earplug and earcup applications. These models are currently being used in development of a novel hearing protection evaluation system that can provide experimentally correlated psychoacoustic noise attenuation. Moreover, these FE models can be used to simulate the effects of blast related impulse noise on human auditory mechanisms and brain tissue.

  12. Modelling the evolution of human trail systems

    Science.gov (United States)

    Helbing, Dirk; Keltsch, Joachim; Molnár, Péter

    1997-07-01

    Many human social phenomena, such as cooperation, the growth of settlements, traffic dynamics and pedestrian movement, appear to be accessible to mathematical descriptions that invoke self-organization. Here we develop a model of pedestrian motion to explore the evolution of trails in urban green spaces such as parks. Our aim is to address such questions as what the topological structures of these trail systems are, and whether optimal path systems can be predicted for urban planning. We use an `active walker' model that takes into account pedestrian motion and orientation and the concomitant feedbacks with the surrounding environment. Such models have previously been applied to the study of complex structure formation in physical, chemical and biological systems. We find that our model is able to reproduce many of the observed large-scale spatial features of trail systems.

  13. Optimization of experimental human leukemia models (review

    Directory of Open Access Journals (Sweden)

    D. D. Pankov

    2012-01-01

    Full Text Available Actual problem of assessing immunotherapy prospects including antigenpecific cell therapy using animal models was covered in this review.Describe the various groups of currently existing animal models and methods of their creating – from different immunodeficient mice to severalvariants of tumor cells engraftment in them. The review addresses the possibility of tumor stem cells studying using mouse models for the leukemia treatment with adoptive cell therapy including WT1. Also issues of human leukemia cells migration and proliferation in a mice withdifferent immunodeficiency degree are discussed. To assess the potential immunotherapy efficacy comparison of immunodeficient mouse model with clinical situation in oncology patients after chemotherapy is proposed.

  14. Optimization of experimental human leukemia models (review

    Directory of Open Access Journals (Sweden)

    D. D. Pankov

    2014-07-01

    Full Text Available Actual problem of assessing immunotherapy prospects including antigenpecific cell therapy using animal models was covered in this review.Describe the various groups of currently existing animal models and methods of their creating – from different immunodeficient mice to severalvariants of tumor cells engraftment in them. The review addresses the possibility of tumor stem cells studying using mouse models for the leukemia treatment with adoptive cell therapy including WT1. Also issues of human leukemia cells migration and proliferation in a mice withdifferent immunodeficiency degree are discussed. To assess the potential immunotherapy efficacy comparison of immunodeficient mouse model with clinical situation in oncology patients after chemotherapy is proposed.

  15. Modeling human influenza infection in the laboratory

    Directory of Open Access Journals (Sweden)

    Radigan KA

    2015-08-01

    Full Text Available Kathryn A Radigan,1 Alexander V Misharin,2 Monica Chi,1 GR Scott Budinger11Division of Pulmonary and Critical Care Medicine, 2Division of Rheumatology, Northwestern University Feinberg School of Medicine, Chicago, IL, USAAbstract: Influenza is the leading cause of death from an infectious cause. Because of its clinical importance, many investigators use animal models to understand the biologic mechanisms of influenza A virus replication, the immune response to the virus, and the efficacy of novel therapies. This review will focus on the biosafety, biosecurity, and ethical concerns that must be considered in pursuing influenza research, in addition to focusing on the two animal models – mice and ferrets – most frequently used by researchers as models of human influenza infection.Keywords: mice, ferret, influenza, animal model, biosafety

  16. Modeling learned categorical perception in human vision.

    Science.gov (United States)

    Casey, Matthew C; Sowden, Paul T

    2012-09-01

    A long standing debate in cognitive neuroscience has been the extent to which perceptual processing is influenced by prior knowledge and experience with a task. A converging body of evidence now supports the view that a task does influence perceptual processing, leaving us with the challenge of understanding the locus of, and mechanisms underpinning, these influences. An exemplar of this influence is learned categorical perception (CP), in which there is superior perceptual discrimination of stimuli that are placed in different categories. Psychophysical experiments on humans have attempted to determine whether early cortical stages of visual analysis change as a result of learning a categorization task. However, while some results indicate that changes in visual analysis occur, the extent to which earlier stages of processing are changed is still unclear. To explore this issue, we develop a biologically motivated neural model of hierarchical vision processes consisting of a number of interconnected modules representing key stages of visual analysis, with each module learning to exhibit desired local properties through competition. With this system level model, we evaluate whether a CP effect can be generated with task influence to only the later stages of visual analysis. Our model demonstrates that task learning in just the later stages is sufficient for the model to exhibit the CP effect, demonstrating the existence of a mechanism that requires only a high-level of task influence. However, the effect generalizes more widely than is found with human participants, suggesting that changes to earlier stages of analysis may also be involved in the human CP effect, even if these are not fundamental to the development of CP. The model prompts a hybrid account of task-based influences on perception that involves both modifications to the use of the outputs from early perceptual analysis along with the possibility of changes to the nature of that early analysis itself

  17. Human embryonic stem cell lines model experimental human cytomegalovirus latency.

    Science.gov (United States)

    Penkert, Rhiannon R; Kalejta, Robert F

    2013-05-28

    Herpesviruses are highly successful pathogens that persist for the lifetime of their hosts primarily because of their ability to establish and maintain latent infections from which the virus is capable of productively reactivating. Human cytomegalovirus (HCMV), a betaherpesvirus, establishes latency in CD34(+) hematopoietic progenitor cells during natural infections in the body. Experimental infection of CD34(+) cells ex vivo has demonstrated that expression of the viral gene products that drive productive infection is silenced by an intrinsic immune defense mediated by Daxx and histone deacetylases through heterochromatinization of the viral genome during the establishment of latency. Additional mechanistic details about the establishment, let alone maintenance and reactivation, of HCMV latency remain scarce. This is partly due to the technical challenges of CD34(+) cell culture, most notably, the difficulty in preventing spontaneous differentiation that drives reactivation and renders them permissive for productive infection. Here we demonstrate that HCMV can establish, maintain, and reactivate in vitro from experimental latency in cultures of human embryonic stem cells (ESCs), for which spurious differentiation can be prevented or controlled. Furthermore, we show that known molecular aspects of HCMV latency are faithfully recapitulated in these cells. In total, we present ESCs as a novel, tractable model for studies of HCMV latency.

  18. Computational Models to Synthesize Human Walking

    Institute of Scientific and Technical Information of China (English)

    Lei Ren; David Howard; Laurence Kenney

    2006-01-01

    The synthesis of human walking is of great interest in biomechanics and biomimetic engineering due to its predictive capabilities and potential applications in clinical biomechanics, rehabilitation engineering and biomimetic robotics. In this paper,the various methods that have been used to synthesize humanwalking are reviewed from an engineering viewpoint. This involves a wide spectrum of approaches, from simple passive walking theories to large-scale computational models integrating the nervous, muscular and skeletal systems. These methods are roughly categorized under four headings: models inspired by the concept of a CPG (Central Pattern Generator), methods based on the principles of control engineering, predictive gait simulation using optimisation, and models inspired by passive walking theory. The shortcomings and advantages of these methods are examined, and future directions are discussed in the context of providing insights into the neural control objectives driving gait and improving the stability of the predicted gaits. Future advancements are likely to be motivated by improved understanding of neural control strategies and the subtle complexities of the musculoskeletal system during human locomotion. It is only a matter of time before predictive gait models become a practical and valuable tool in clinical diagnosis, rehabilitation engineering and robotics.

  19. A dynamic model of human physiology

    Science.gov (United States)

    Green, Melissa; Kaplan, Carolyn; Oran, Elaine; Boris, Jay

    2010-11-01

    To study the systems-level transport in the human body, we develop the Computational Man (CMAN): a set of one-dimensional unsteady elastic flow simulations created to model a variety of coupled physiological systems including the circulatory, respiratory, excretory, and lymphatic systems. The model systems are collapsed from three spatial dimensions and time to one spatial dimension and time by assuming axisymmetric vessel geometry and a parabolic velocity profile across the cylindrical vessels. To model the actions of a beating heart or expanding lungs, the flow is driven by user-defined changes to the equilibrium areas of the elastic vessels. The equations are then iteratively solved for pressure, area, and average velocity. The model is augmented with valves and contractions to resemble the biological structure of the different systems. CMAN will be used to track material transport throughout the human body for diagnostic and predictive purposes. Parameters will be adjustable to match those of individual patients. Validation of CMAN has used both higher-dimensional simulations of similar geometries and benchmark measurement from medical literature.

  20. Modeling and simulation of the human eye

    Science.gov (United States)

    Duran, R.; Ventura, L.; Nonato, L.; Bruno, O.

    2007-02-01

    The computational modeling of the human eye has been wide studied for different sectors of the scientific and technological community. One of the main reasons for this increasing interest is the possibility to reproduce eye optic properties by means of computational simulations, becoming possible the development of efficient devices to treat and to correct the problems of the vision. This work explores this aspect still little investigated of the modeling of the visual system, considering a computational sketch that make possible the use of real data in the modeling and simulation of the human visual system. This new approach makes possible the individual inquiry of the optic system, assisting in the construction of new techniques used to infer vital data in medical investigations. Using corneal topography to collect real data from patients, a computational model of cornea is constructed and a set of simulations were build to ensure the correctness of the system and to investigate the effect of corneal abnormalities in retinal image formation, such as Plcido Discs, Point Spread Function, Wave front and the projection of a real image and it's visualization on retina.

  1. Zebrafish Models for Human Acute Organophosphorus Poisoning.

    Science.gov (United States)

    Faria, Melissa; Garcia-Reyero, Natàlia; Padrós, Francesc; Babin, Patrick J; Sebastián, David; Cachot, Jérôme; Prats, Eva; Arick Ii, Mark; Rial, Eduardo; Knoll-Gellida, Anja; Mathieu, Guilaine; Le Bihanic, Florane; Escalon, B Lynn; Zorzano, Antonio; Soares, Amadeu M V M; Raldúa, Demetrio

    2015-10-22

    Terrorist use of organophosphorus-based nerve agents and toxic industrial chemicals against civilian populations constitutes a real threat, as demonstrated by the terrorist attacks in Japan in the 1990 s or, even more recently, in the Syrian civil war. Thus, development of more effective countermeasures against acute organophosphorus poisoning is urgently needed. Here, we have generated and validated zebrafish models for mild, moderate and severe acute organophosphorus poisoning by exposing zebrafish larvae to different concentrations of the prototypic organophosphorus compound chlorpyrifos-oxon. Our results show that zebrafish models mimic most of the pathophysiological mechanisms behind this toxidrome in humans, including acetylcholinesterase inhibition, N-methyl-D-aspartate receptor activation, and calcium dysregulation as well as inflammatory and immune responses. The suitability of the zebrafish larvae to in vivo high-throughput screenings of small molecule libraries makes these models a valuable tool for identifying new drugs for multifunctional drug therapy against acute organophosphorus poisoning.

  2. HLA-Modeler: Automated Homology Modeling of Human Leukocyte Antigens

    Directory of Open Access Journals (Sweden)

    Shinji Amari

    2013-01-01

    Full Text Available The three-dimensional (3D structures of human leukocyte antigen (HLA molecules are indispensable for the studies on the functions at molecular level. We have developed a homology modeling system named HLA-modeler specialized in the HLA molecules. Segment matching algorithm is employed for modeling and the optimization of the model is carried out by use of the PFROSST force field considering the implicit solvent model. In order to efficiently construct the homology models, HLA-modeler uses a local database of the 3D structures of HLA molecules. The structure of the antigenic peptide-binding site is important for the function and the 3D structure is highly conserved between various alleles. HLA-modeler optimizes the use of this structural motif. The leave-one-out cross-validation using the crystal structures of class I and class II HLA molecules has demonstrated that the rmsds of nonhydrogen atoms of the sites between homology models and crystal structures are less than 1.0 Å in most cases. The results have indicated that the 3D structures of the antigenic peptide-binding sites can be reproduced by HLA-modeler at the level almost corresponding to the crystal structures.

  3. HLA-Modeler: Automated Homology Modeling of Human Leukocyte Antigens.

    Science.gov (United States)

    Amari, Shinji; Kataoka, Ryoichi; Ikegami, Takashi; Hirayama, Noriaki

    2013-01-01

    The three-dimensional (3D) structures of human leukocyte antigen (HLA) molecules are indispensable for the studies on the functions at molecular level. We have developed a homology modeling system named HLA-modeler specialized in the HLA molecules. Segment matching algorithm is employed for modeling and the optimization of the model is carried out by use of the PFROSST force field considering the implicit solvent model. In order to efficiently construct the homology models, HLA-modeler uses a local database of the 3D structures of HLA molecules. The structure of the antigenic peptide-binding site is important for the function and the 3D structure is highly conserved between various alleles. HLA-modeler optimizes the use of this structural motif. The leave-one-out cross-validation using the crystal structures of class I and class II HLA molecules has demonstrated that the rmsds of nonhydrogen atoms of the sites between homology models and crystal structures are less than 1.0 Å in most cases. The results have indicated that the 3D structures of the antigenic peptide-binding sites can be reproduced by HLA-modeler at the level almost corresponding to the crystal structures.

  4. Model human heart or brain signals

    CERN Document Server

    Tuncay, Caglar

    2008-01-01

    A new model is suggested and used to mimic various spatial or temporal designs in biological or non biological formations where the focus is on the normal or irregular electrical signals coming from human heart (ECG) or brain (EEG). The electrical activities in several muscles (EMG) or neurons or other organs of human or various animals, such as lobster pyloric neuron, guinea pig inferior olivary neuron, sepia giant axon and mouse neocortical pyramidal neuron and some spatial formations are also considered (in Appendix). In the biological applications, several elements (cells or tissues) in an organ are taken as various entries in a representative lattice (mesh) where the entries are connected to each other in terms of some molecular diffusions or electrical potential differences. The biological elements evolve in time (with the given tissue or organ) in terms of the mentioned connections (interactions) besides some individual feedings. The anatomical diversity of the species (or organs) is handled in terms o...

  5. The quantitative modelling of human spatial habitability

    Science.gov (United States)

    Wise, J. A.

    1985-01-01

    A model for the quantitative assessment of human spatial habitability is presented in the space station context. The visual aspect assesses how interior spaces appear to the inhabitants. This aspect concerns criteria such as sensed spaciousness and the affective (emotional) connotations of settings' appearances. The kinesthetic aspect evaluates the available space in terms of its suitability to accommodate human movement patterns, as well as the postural and anthrometric changes due to microgravity. Finally, social logic concerns how the volume and geometry of available space either affirms or contravenes established social and organizational expectations for spatial arrangements. Here, the criteria include privacy, status, social power, and proxemics (the uses of space as a medium of social communication).

  6. The quantitative modelling of human spatial habitability

    Science.gov (United States)

    Wise, James A.

    1988-01-01

    A theoretical model for evaluating human spatial habitability (HuSH) in the proposed U.S. Space Station is developed. Optimizing the fitness of the space station environment for human occupancy will help reduce environmental stress due to long-term isolation and confinement in its small habitable volume. The development of tools that operationalize the behavioral bases of spatial volume for visual kinesthetic, and social logic considerations is suggested. This report further calls for systematic scientific investigations of how much real and how much perceived volume people need in order to function normally and with minimal stress in space-based settings. The theoretical model presented in this report can be applied to any size or shape interior, at any scale of consideration, for the Space Station as a whole to an individual enclosure or work station. Using as a point of departure the Isovist model developed by Dr. Michael Benedikt of the U. of Texas, the report suggests that spatial habitability can become as amenable to careful assessment as engineering and life support concerns.

  7. MODELING HUMAN COMPREHENSION OF DATA VISUALIZATIONS.

    Energy Technology Data Exchange (ETDEWEB)

    Matzen, Laura E.; Haass, Michael Joseph; Divis, Kristin Marie; Wilson, Andrew T.

    2017-09-01

    This project was inspired by two needs. The first is a need for tools to help scientists and engineers to design effective data visualizations for communicating information, whether to the user of a system, an analyst who must make decisions based on complex data, or in the context of a technical report or publication. Most scientists and engineers are not trained in visualization design, and they could benefit from simple metrics to assess how well their visualization's design conveys the intended message. In other words, will the most important information draw the viewer's attention? The second is the need for cognition-based metrics for evaluating new types of visualizations created by researchers in the information visualization and visual analytics communities. Evaluating visualizations is difficult even for experts. However, all visualization methods and techniques are intended to exploit the properties of the human visual system to convey information efficiently to a viewer. Thus, developing evaluation methods that are rooted in the scientific knowledge of the human visual system could be a useful approach. In this project, we conducted fundamental research on how humans make sense of abstract data visualizations, and how this process is influenced by their goals and prior experience. We then used that research to develop a new model, the Data Visualization Saliency Model, that can make accurate predictions about which features in an abstract visualization will draw a viewer's attention. The model is an evaluation tool that can address both of the needs described above, supporting both visualization research and Sandia mission needs.

  8. Mouse Model of Human Hereditary Pancreatitis

    Science.gov (United States)

    2016-09-01

    models that recapitulate the human disease . Therefore, we introduced mutations in the endogenous mouse T7 cationic trypsinogen gene and obtained several...ACCOMPLISHMENTS: What were the major goals of the project? Our original proposal had three specific aims. Aim 1. Identify and biochemically characterize...pancreatitis in mutant mice which do not develop spontaneous disease (strains T7-D23del-Cre, T7-D23del-Neo, T7-K24R-Cre and T7- K24R-Neo), will be

  9. Liver immune-pathogenesis and therapy of human liver tropic virus infection in humanized mouse models

    OpenAIRE

    Bility, Moses T.; Li, Feng; Cheng, Liang; Su, Lishan

    2013-01-01

    Hepatitis B virus (HBV) and hepatitis C virus (HCV) infect and replicate primarily in human hepatocytes. Few reliable and easy accessible animal models are available for studying the immune system’s contribution to the liver disease progression during hepatitis virus infection. Humanized mouse models reconstituted with human hematopoietic stem cells (HSCs) have been developed to study human immunology, human immunodeficiency virus 1 infection, and immunopathogenesis. However, a humanized mous...

  10. A modular approach to numerical human body modeling

    NARCIS (Netherlands)

    Forbes, P.A.; Griotto, G.; Rooij, L. van

    2007-01-01

    The choice of a human body model for a simulated automotive impact scenario must take into account both accurate model response and computational efficiency as key factors. This study presents a "modular numerical human body modeling" approach which allows the creation of a customized human body mod

  11. A modular approach to numerical human body modeling

    NARCIS (Netherlands)

    Forbes, P.A.; Griotto, G.; Rooij, L. van

    2007-01-01

    The choice of a human body model for a simulated automotive impact scenario must take into account both accurate model response and computational efficiency as key factors. This study presents a "modular numerical human body modeling" approach which allows the creation of a customized human body

  12. Generative models: Human embryonic stem cells and multiple modeling relations.

    Science.gov (United States)

    Fagan, Melinda Bonnie

    2016-04-01

    Model organisms are at once scientific models and concrete living things. It is widely assumed by philosophers of science that (1) model organisms function much like other kinds of models, and (2) that insofar as their scientific role is distinctive, it is in virtue of representing a wide range of biological species and providing a basis for generalizations about those targets. This paper uses the case of human embryonic stem cells (hESC) to challenge both assumptions. I first argue that hESC can be considered model organisms, analogous to classic examples such as Escherichia coli and Drosophila melanogaster. I then discuss four contrasts between the epistemic role of hESC in practice, and the assumptions about model organisms noted above. These contrasts motivate an alternative view of model organisms as a network of systems related constructively and developmentally to one another. I conclude by relating this result to other accounts of model organisms in recent philosophy of science. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Human factors engineering program review model

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    The staff of the Nuclear Regulatory Commission is performing nuclear power plant design certification reviews based on a design process plan that describes the human factors engineering (HFE) program elements that are necessary and sufficient to develop an acceptable detailed design specification and an acceptable implemented design. There are two principal reasons for this approach. First, the initial design certification applications submitted for staff review did not include detailed design information. Second, since human performance literature and industry experiences have shown that many significant human factors issues arise early in the design process, review of the design process activities and results is important to the evaluation of an overall design. However, current regulations and guidance documents do not address the criteria for design process review. Therefore, the HFE Program Review Model (HFE PRM) was developed as a basis for performing design certification reviews that include design process evaluations as well as review of the final design. A central tenet of the HFE PRM is that the HFE aspects of the plant should be developed, designed, and evaluated on the basis of a structured top-down system analysis using accepted HFE principles. The HFE PRM consists of ten component elements. Each element in divided into four sections: Background, Objective, Applicant Submittals, and Review Criteria. This report describes the development of the HFE PRM and gives a detailed description of each HFE review element.

  14. Conditional Lineage Ablation to Model Human Diseases

    Science.gov (United States)

    Lee, Paul; Morley, Gregory; Huang, Qian; Fischer, Avi; Seiler, Stephanie; Horner, James W.; Factor, Stephen; Vaidya, Dhananjay; Jalife, Jose; Fishman, Glenn I.

    1998-09-01

    Cell loss contributes to the pathogenesis of many inherited and acquired human diseases. We have developed a system to conditionally ablate cells of any lineage and developmental stage in the mouse by regulated expression of the diphtheria toxin A (DTA) gene by using tetracycline-responsive promoters. As an example of this approach, we targeted expression of DTA to the hearts of adult mice to model structural abnormalities commonly observed in human cardiomyopathies. Induction of DTA expression resulted in cell loss, fibrosis, and chamber dilatation. As in many human cardiomyopathies, transgenic mice developed spontaneous arrhythmias in vivo, and programmed electrical stimulation of isolated-perfused transgenic hearts demonstrated a strikingly high incidence of spontaneous and inducible ventricular tachycardia. Affected mice showed marked perturbations of cardiac gap junction channel expression and localization, including a subset with disorganized epicardial activation patterns as revealed by optical action potential mapping. These studies provide important insights into mechanisms of arrhythmogenesis and suggest that conditional lineage ablation may have wide applicability for studies of disease pathogenesis.

  15. A human neurodevelopmental model for Williams syndrome.

    Science.gov (United States)

    Chailangkarn, Thanathom; Trujillo, Cleber A; Freitas, Beatriz C; Hrvoj-Mihic, Branka; Herai, Roberto H; Yu, Diana X; Brown, Timothy T; Marchetto, Maria C; Bardy, Cedric; McHenry, Lauren; Stefanacci, Lisa; Järvinen, Anna; Searcy, Yvonne M; DeWitt, Michelle; Wong, Wenny; Lai, Philip; Ard, M Colin; Hanson, Kari L; Romero, Sarah; Jacobs, Bob; Dale, Anders M; Dai, Li; Korenberg, Julie R; Gage, Fred H; Bellugi, Ursula; Halgren, Eric; Semendeferi, Katerina; Muotri, Alysson R

    2016-08-18

    Williams syndrome is a genetic neurodevelopmental disorder characterized by an uncommon hypersociability and a mosaic of retained and compromised linguistic and cognitive abilities. Nearly all clinically diagnosed individuals with Williams syndrome lack precisely the same set of genes, with breakpoints in chromosome band 7q11.23 (refs 1-5). The contribution of specific genes to the neuroanatomical and functional alterations, leading to behavioural pathologies in humans, remains largely unexplored. Here we investigate neural progenitor cells and cortical neurons derived from Williams syndrome and typically developing induced pluripotent stem cells. Neural progenitor cells in Williams syndrome have an increased doubling time and apoptosis compared with typically developing neural progenitor cells. Using an individual with atypical Williams syndrome, we narrowed this cellular phenotype to a single gene candidate, frizzled 9 (FZD9). At the neuronal stage, layer V/VI cortical neurons derived from Williams syndrome were characterized by longer total dendrites, increased numbers of spines and synapses, aberrant calcium oscillation and altered network connectivity. Morphometric alterations observed in neurons from Williams syndrome were validated after Golgi staining of post-mortem layer V/VI cortical neurons. This model of human induced pluripotent stem cells fills the current knowledge gap in the cellular biology of Williams syndrome and could lead to further insights into the molecular mechanism underlying the disorder and the human social brain.

  16. Integrated Human Futures Modeling in Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Passell, Howard D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Aamir, Munaf Syed [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bernard, Michael Lewis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Beyeler, Walter E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Fellner, Karen Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hayden, Nancy Kay [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jeffers, Robert Fredric [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Keller, Elizabeth James Kistin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Malczynski, Leonard A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mitchell, Michael David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Silver, Emily [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tidwell, Vincent C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Villa, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vugrin, Eric D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Engelke, Peter [Atlantic Council, Washington, D.C. (United States); Burrow, Mat [Atlantic Council, Washington, D.C. (United States); Keith, Bruce [United States Military Academy, West Point, NY (United States)

    2016-01-01

    The Integrated Human Futures Project provides a set of analytical and quantitative modeling and simulation tools that help explore the links among human social, economic, and ecological conditions, human resilience, conflict, and peace, and allows users to simulate tradeoffs and consequences associated with different future development and mitigation scenarios. In the current study, we integrate five distinct modeling platforms to simulate the potential risk of social unrest in Egypt resulting from the Grand Ethiopian Renaissance Dam (GERD) on the Blue Nile in Ethiopia. The five platforms simulate hydrology, agriculture, economy, human ecology, and human psychology/behavior, and show how impacts derived from development initiatives in one sector (e.g., hydrology) might ripple through to affect other sectors and how development and security concerns may be triggered across the region. This approach evaluates potential consequences, intended and unintended, associated with strategic policy actions that span the development-security nexus at the national, regional, and international levels. Model results are not intended to provide explicit predictions, but rather to provide system-level insight for policy makers into the dynamics among these interacting sectors, and to demonstrate an approach to evaluating short- and long-term policy trade-offs across different policy domains and stakeholders. The GERD project is critical to government-planned development efforts in Ethiopia but is expected to reduce downstream freshwater availability in the Nile Basin, fueling fears of negative social and economic impacts that could threaten stability and security in Egypt. We tested these hypotheses and came to the following preliminary conclusions. First, the GERD will have an important short-term impact on water availability, food production, and hydropower production in Egypt, depending on the short- term reservoir fill rate. Second, the GERD will have a very small impact on

  17. SVM Model for Identification of human GPCRs

    CERN Document Server

    Shrivastava, Sonal; Malik, M M

    2010-01-01

    G-protein coupled receptors (GPCRs) constitute a broad class of cell-surface receptors in eukaryotes and they possess seven transmembrane a-helical domains. GPCRs are usually classified into several functionally distinct families that play a key role in cellular signalling and regulation of basic physiological processes. We can develop statistical models based on these common features that can be used to classify proteins, to predict new members, and to study the sequence-function relationship of this protein function group. In this study, SVM based classification model has been developed for the identification of human gpcr sequences. Sequences of Level 1 subfamilies of Class A rhodopsin is considered as case study. In the present study, an attempt has been made to classify GPCRs on the basis of species. The present study classifies human gpcr sequences with rest of the species available in GPCRDB. Classification is based on specific information derived from the n-terminal and extracellular loops of the sequ...

  18. Simple models of human brain functional networks.

    Science.gov (United States)

    Vértes, Petra E; Alexander-Bloch, Aaron F; Gogtay, Nitin; Giedd, Jay N; Rapoport, Judith L; Bullmore, Edward T

    2012-04-10

    Human brain functional networks are embedded in anatomical space and have topological properties--small-worldness, modularity, fat-tailed degree distributions--that are comparable to many other complex networks. Although a sophisticated set of measures is available to describe the topology of brain networks, the selection pressures that drive their formation remain largely unknown. Here we consider generative models for the probability of a functional connection (an edge) between two cortical regions (nodes) separated by some Euclidean distance in anatomical space. In particular, we propose a model in which the embedded topology of brain networks emerges from two competing factors: a distance penalty based on the cost of maintaining long-range connections; and a topological term that favors links between regions sharing similar input. We show that, together, these two biologically plausible factors are sufficient to capture an impressive range of topological properties of functional brain networks. Model parameters estimated in one set of functional MRI (fMRI) data on normal volunteers provided a good fit to networks estimated in a second independent sample of fMRI data. Furthermore, slightly detuned model parameters also generated a reasonable simulation of the abnormal properties of brain functional networks in people with schizophrenia. We therefore anticipate that many aspects of brain network organization, in health and disease, may be parsimoniously explained by an economical clustering rule for the probability of functional connectivity between different brain areas.

  19. Delayed Random Walks: Modeling Human Posture Control

    Science.gov (United States)

    Ohira, Toru

    1998-03-01

    We consider a phenomenological description of a noisy trajectory which appears on a stabiliogram platform during human postural sway. We hypothesize that this trajectory arises due to a mixture of uncontrollable noise and a corrective delayed feedback to an upright position. Based on this hypothesis, we model the process with a biased random walk whose transition probability depends on its position at a fixed time delay in the past, which we call a delayed random walk. We first introduce a very simple model (T. Ohira and J. G. Milton, Phys.Rev.E. 52), 3277, (1995), which can nevertheless capture the rough qualitative features of the two--point mean square displacement of experimental data with reasonable estimation of delay time. Then, we discuss two approaches toward better capturing and understanding of the experimental data. The first approach is an extension of the model to include a spatial displacement threshold from the upright position below which no or only weak corrective feedback motion takes place. This can be incorporated into an extended delayed random walk model. Numerical simulations show that this extended model can better capture the three scaling region which appears in the two--point mean square displacement. The other approach studied the autocorrelation function of the experimental data, which shows oscillatory behavior. We recently investigated a delayed random walk model whose autocorrelation function has analytically tractable oscillatory behavior (T. Ohira, Phys.Rev.E. 55), R1255, (1997). We discuss how this analytical understanding and its application to delay estimation (T. Ohira and R. Sawatari, Phys.Rev.E. 55), R2077, (1997) could possibly be used to further understand the postural sway data.

  20. Automatic Modeling of Virtual Humans and Body Clothing

    Institute of Scientific and Technical Information of China (English)

    Nadia Magnenat-Thalmann; Hyewon Seo; Frederic Cordier

    2004-01-01

    Highly realistic virtual human models are rapidly becoming commonplace in computer graphics.These models, often represented by complex shape and requiring labor-intensive process, challenge the problem of automatic modeling. The problem and solutions to automatic modeling of animatable virtual humans are studied. Methods for capturing the shape of real people, parameterization techniques for modeling static shape (the variety of human body shapes) and dynamic shape (how the body shape changes as it moves) of virtual humans are classified, summarized and compared. Finally, methods for clothed virtual humans are reviewed.

  1. The Application of Humanized Mouse Models for the Study of Human Exclusive Viruses.

    Science.gov (United States)

    Vahedi, Fatemeh; Giles, Elizabeth C; Ashkar, Ali A

    2017-01-01

    The symbiosis between humans and viruses has allowed human tropic pathogens to evolve intricate means of modulating the human immune response to ensure its survival among the human population. In doing so, these viruses have developed profound mechanisms that mesh closely with our human biology. The establishment of this intimate relationship has created a species-specific barrier to infection, restricting the virus-associated pathologies to humans. This specificity diminishes the utility of traditional animal models. Humanized mice offer a model unique to all other means of study, providing an in vivo platform for the careful examination of human tropic viruses and their interaction with human cells and tissues. These types of animal models have provided a reliable medium for the study of human-virus interactions, a relationship that could otherwise not be investigated without questionable relevance to humans.

  2. Modeling the human prothrombinase complex components

    Science.gov (United States)

    Orban, Tivadar

    Thrombin generation is the culminating stage of the blood coagulation process. Thrombin is obtained from prothrombin (the substrate) in a reaction catalyzed by the prothrombinase complex (the enzyme). The prothrombinase complex is composed of factor Xa (the enzyme), factor Va (the cofactor) associated in the presence of calcium ions on a negatively charged cell membrane. Factor Xa, alone, can activate prothrombin to thrombin; however, the rate of conversion is not physiologically relevant for survival. Incorporation of factor Va into prothrombinase accelerates the rate of prothrombinase activity by 300,000-fold, and provides the physiological pathway of thrombin generation. The long-term goal of the current proposal is to provide the necessary support for the advancing of studies to design potential drug candidates that may be used to avoid development of deep venous thrombosis in high-risk patients. The short-term goals of the present proposal are to (1) to propose a model of a mixed asymmetric phospholipid bilayer, (2) expand the incomplete model of human coagulation factor Va and study its interaction with the phospholipid bilayer, (3) to create a homology model of prothrombin (4) to study the dynamics of interaction between prothrombin and the phospholipid bilayer.

  3. Animal models for human craniofacial malformations.

    Science.gov (United States)

    Johnston, M C; Bronsky, P T

    1991-01-01

    Holoprosencephaly malformations, of which the fetal alcohol syndrome appears to be a mild form, can result from medial anterior neural plate deficiencies as demonstrated in an ethanol treated animal model. These malformations are associated with more medial positioning of the nasal placodes and resulting underdevelopment or absence of the medial nasal prominences (MNPs) and their derivatives. Malformations seen in the human retinoic acid syndrome (RAS) can be produced by administration of the drug 13-cis-retinoic acid in animals. Primary effects on neural crest cells account for most of these RAS malformations. Many of the malformations seen in the RAS are similar to those of hemifacial microsomia, suggesting similar neural crest involvement. Excessive cell death, apparently limited to trigeminal ganglion neuroblasts of placodal origin, follows 13-cis retinoic acid administration at the time of ganglion formation and leads to malformations virtually identical to those of the Treacher Collins syndrome (TCS). Secondary effects on neural crest cells in the area of the ganglion appear to be responsible for the TCS malformations. Malformations of the DiGeorge Syndrome are similar to those of the RAS and can be produced in mice by ethanol administration or by "knocking out" a homeobox gene (box 1.5). Human and animal studies indicate that cleft lips of multifactorial etiology may be generically susceptible because of small MNP)s or other MNP developmental alterations, such as those found in A/J mice, that make prominence contact more difficult. Experimental maternal hypoxia in mice indicates that cigarette smoking may increase the incidence of cleft lip by interfering with morphogenetic movements. Other human cleft lips may result from the action of a single major gene coding for TGF-alpha variants. A study with mouse palatal shelves in culture and other information suggest that a fusion problem may be involved.

  4. Liver immune-pathogenesis and therapy of human liver tropic virus infection in humanized mouse models.

    Science.gov (United States)

    Bility, Moses T; Li, Feng; Cheng, Liang; Su, Lishan

    2013-08-01

    Hepatitis B virus (HBV) and hepatitis C virus (HCV) infect and replicate primarily in human hepatocytes. Few reliable and easy accessible animal models are available for studying the immune system's contribution to the liver disease progression during hepatitis virus infection. Humanized mouse models reconstituted with human hematopoietic stem cells (HSCs) have been developed to study human immunology, human immunodeficiency virus 1 infection, and immunopathogenesis. However, a humanized mouse model engrafted with both human immune and human liver cells is needed to study infection and immunopathogenesis of HBV/HCV infection in vivo. We have recently developed the humanized mouse model with both human immune and human liver cells (AFC8-hu HSC/Hep) to study immunopathogenesis and therapy of HCV infection in vivo. In this review, we summarize the current models of HBV/HCV infection and their limitations in immunopathogenesis. We will then present our recent findings of HCV infection and immunopathogenesis in the AFC8-hu HSC/Hep mouse, which supports HCV infection, human T-cell response and associated liver pathogenesis. Inoculation of humanized mice with primary HCV isolates resulted in long-term HCV infection. HCV infection induced elevated infiltration of human immune cells in the livers of HCV-infected humanized mice. HCV infection also induced HCV-specific T-cell immune response in lymphoid tissues of humanized mice. Additionally, HCV infection induced liver fibrosis in humanized mice. Anti-human alpha smooth muscle actin (αSMA) staining showed elevated human hepatic stellate cell activation in HCV-infected humanized mice. We discuss the limitation and future improvements of the AFC8-hu HSC/Hep mouse model and its application in evaluating novel therapeutics, as well as studying both HCV and HBV infection, human immune responses, and associated human liver fibrosis and cancer.

  5. Modeling and remodeling of human extraction sockets.

    Science.gov (United States)

    Trombelli, Leonardo; Farina, Roberto; Marzola, Andrea; Bozzi, Leopoldo; Liljenberg, Birgitta; Lindhe, Jan

    2008-07-01

    The available studies on extraction wound repair in humans are affected by significant limitations and have failed to evaluate tissue alterations occurring in all compartments of the hard tissue defect. To monitor during a 6-month period the healing of human extraction sockets and include a semi-quantitative analysis of tissues and cell populations involved in various stages of the processes of modeling/remodeling. Twenty-seven biopsies, representative of the early (2-4 weeks, n=10), intermediate (6-8 weeks, n=6), and late phase (12-24 weeks, n=11) of healing, were collected and analysed. Granulation tissue that was present in comparatively large amounts in the early healing phase of socket healing, was in the interval between the early and intermediate observation phase replaced with provisional matrix and woven bone. The density of vascular structures and macrophages slowly decreased from 2 to 4 weeks over time. The presence of osteoblasts peaked at 6-8 weeks and remained almost stable thereafter; a small number of osteoclasts were present in a few specimens at each observation interval. The present findings demonstrated that great variability exists in man with respect to hard tissue formation within extraction sockets. Thus, whereas a provisional connective tissue consistently forms within the first weeks of healing, the interval during which mineralized bone is laid down is much less predictable.

  6. In Vitro Model of Human Choroidal Neovascular

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Choroidal capillary endothelia cell (CEC) plays a critical role in the development of choroidal neovascularization which is one of the major causes of blindness. An effective method for CEC cultivation was proposed.The isolation of human choroidal CECs using micro dissection followed by the use of superparamagnetic beads (Dynabeads) coated with the CD 31, which selectively binds to the endothelial cell surface. Cells bound to beads were isolated using a magnetic particle concentrator. The CECs were planted into type Ⅳ collagen coated 24 well plates. The results show that the primary cultured CEC is induced to tube formation in collagen Ⅳ coated environment, which can be presented as an in vitro model of choroidal neovascularization.

  7. Molecular Modeling of Prion Transmission to Humans

    Directory of Open Access Journals (Sweden)

    Etienne Levavasseur

    2014-10-01

    Full Text Available Using different prion strains, such as the variant Creutzfeldt-Jakob disease agent and the atypical bovine spongiform encephalopathy agents, and using transgenic mice expressing human or bovine prion protein, we assessed the reliability of protein misfolding cyclic amplification (PMCA to model interspecies and genetic barriers to prion transmission. We compared our PMCA results with in vivo transmission data characterized by attack rates, i.e., the percentage of inoculated mice that developed the disease. Using 19 seed/substrate combinations, we observed that a significant PMCA amplification was only obtained when the mouse line used as substrate is susceptible to the corresponding strain. Our results suggest that PMCA provides a useful tool to study genetic barriers to transmission and to study the zoonotic potential of emerging prion strains.

  8. Design of a Human Reliability Assessment model for structural engineering

    NARCIS (Netherlands)

    De Haan, J.; Terwel, K.C.; Al-Jibouri, S.H.S.

    2013-01-01

    It is generally accepted that humans are the “weakest link” in structural design and construction processes. Despite this, few models are available to quantify human error within engineering processes. This paper demonstrates the use of a quantitative Human Reliability Assessment model within struct

  9. Analysis of rear end impact using mathematical human modelling

    NARCIS (Netherlands)

    Happee, R.; Meijer, R.; Horst, M.J. van der; Ono, K.; Yamazaki, K.

    2000-01-01

    At TNO an omni-directional mathematical human body model has been developed. Until now this human model has been validated for frontal and lateral loading using response data of volunteer and post mortem human subject (PMHS) sled tests. For rearward loading it has been validated for high speed impac

  10. Integrated Human Futures Modeling in Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Passell, Howard D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Aamir, Munaf Syed [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bernard, Michael Lewis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Beyeler, Walter E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Fellner, Karen Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hayden, Nancy Kay [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jeffers, Robert Fredric [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Keller, Elizabeth James Kistin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Malczynski, Leonard A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mitchell, Michael David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Silver, Emily [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tidwell, Vincent C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Villa, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vugrin, Eric D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Engelke, Peter [Atlantic Council, Washington, D.C. (United States); Burrow, Mat [Atlantic Council, Washington, D.C. (United States); Keith, Bruce [United States Military Academy, West Point, NY (United States)

    2016-01-01

    The Integrated Human Futures Project provides a set of analytical and quantitative modeling and simulation tools that help explore the links among human social, economic, and ecological conditions, human resilience, conflict, and peace, and allows users to simulate tradeoffs and consequences associated with different future development and mitigation scenarios. In the current study, we integrate five distinct modeling platforms to simulate the potential risk of social unrest in Egypt resulting from the Grand Ethiopian Renaissance Dam (GERD) on the Blue Nile in Ethiopia. The five platforms simulate hydrology, agriculture, economy, human ecology, and human psychology/behavior, and show how impacts derived from development initiatives in one sector (e.g., hydrology) might ripple through to affect other sectors and how development and security concerns may be triggered across the region. This approach evaluates potential consequences, intended and unintended, associated with strategic policy actions that span the development-security nexus at the national, regional, and international levels. Model results are not intended to provide explicit predictions, but rather to provide system-level insight for policy makers into the dynamics among these interacting sectors, and to demonstrate an approach to evaluating short- and long-term policy trade-offs across different policy domains and stakeholders. The GERD project is critical to government-planned development efforts in Ethiopia but is expected to reduce downstream freshwater availability in the Nile Basin, fueling fears of negative social and economic impacts that could threaten stability and security in Egypt. We tested these hypotheses and came to the following preliminary conclusions. First, the GERD will have an important short-term impact on water availability, food production, and hydropower production in Egypt, depending on the short- term reservoir fill rate. Second, the GERD will have a very small impact on

  11. Genomic responses in mouse models poorly mimic human inflammatory diseases.

    Science.gov (United States)

    Seok, Junhee; Warren, H Shaw; Cuenca, Alex G; Mindrinos, Michael N; Baker, Henry V; Xu, Weihong; Richards, Daniel R; McDonald-Smith, Grace P; Gao, Hong; Hennessy, Laura; Finnerty, Celeste C; López, Cecilia M; Honari, Shari; Moore, Ernest E; Minei, Joseph P; Cuschieri, Joseph; Bankey, Paul E; Johnson, Jeffrey L; Sperry, Jason; Nathens, Avery B; Billiar, Timothy R; West, Michael A; Jeschke, Marc G; Klein, Matthew B; Gamelli, Richard L; Gibran, Nicole S; Brownstein, Bernard H; Miller-Graziano, Carol; Calvano, Steve E; Mason, Philip H; Cobb, J Perren; Rahme, Laurence G; Lowry, Stephen F; Maier, Ronald V; Moldawer, Lyle L; Herndon, David N; Davis, Ronald W; Xiao, Wenzhong; Tompkins, Ronald G

    2013-02-26

    A cornerstone of modern biomedical research is the use of mouse models to explore basic pathophysiological mechanisms, evaluate new therapeutic approaches, and make go or no-go decisions to carry new drug candidates forward into clinical trials. Systematic studies evaluating how well murine models mimic human inflammatory diseases are nonexistent. Here, we show that, although acute inflammatory stresses from different etiologies result in highly similar genomic responses in humans, the responses in corresponding mouse models correlate poorly with the human conditions and also, one another. Among genes changed significantly in humans, the murine orthologs are close to random in matching their human counterparts (e.g., R(2) between 0.0 and 0.1). In addition to improvements in the current animal model systems, our study supports higher priority for translational medical research to focus on the more complex human conditions rather than relying on mouse models to study human inflammatory diseases.

  12. Genomic responses in mouse models poorly mimic human inflammatory diseases

    Science.gov (United States)

    Seok, Junhee; Warren, H. Shaw; Cuenca, Alex G.; Mindrinos, Michael N.; Baker, Henry V.; Xu, Weihong; Richards, Daniel R.; McDonald-Smith, Grace P.; Gao, Hong; Hennessy, Laura; Finnerty, Celeste C.; López, Cecilia M.; Honari, Shari; Moore, Ernest E.; Minei, Joseph P.; Cuschieri, Joseph; Bankey, Paul E.; Johnson, Jeffrey L.; Sperry, Jason; Nathens, Avery B.; Billiar, Timothy R.; West, Michael A.; Jeschke, Marc G.; Klein, Matthew B.; Gamelli, Richard L.; Gibran, Nicole S.; Brownstein, Bernard H.; Miller-Graziano, Carol; Calvano, Steve E.; Mason, Philip H.; Cobb, J. Perren; Rahme, Laurence G.; Lowry, Stephen F.; Maier, Ronald V.; Moldawer, Lyle L.; Herndon, David N.; Davis, Ronald W.; Xiao, Wenzhong; Tompkins, Ronald G.; Abouhamze, Amer; Balis, Ulysses G. J.; Camp, David G.; De, Asit K.; Harbrecht, Brian G.; Hayden, Douglas L.; Kaushal, Amit; O’Keefe, Grant E.; Kotz, Kenneth T.; Qian, Weijun; Schoenfeld, David A.; Shapiro, Michael B.; Silver, Geoffrey M.; Smith, Richard D.; Storey, John D.; Tibshirani, Robert; Toner, Mehmet; Wilhelmy, Julie; Wispelwey, Bram; Wong, Wing H

    2013-01-01

    A cornerstone of modern biomedical research is the use of mouse models to explore basic pathophysiological mechanisms, evaluate new therapeutic approaches, and make go or no-go decisions to carry new drug candidates forward into clinical trials. Systematic studies evaluating how well murine models mimic human inflammatory diseases are nonexistent. Here, we show that, although acute inflammatory stresses from different etiologies result in highly similar genomic responses in humans, the responses in corresponding mouse models correlate poorly with the human conditions and also, one another. Among genes changed significantly in humans, the murine orthologs are close to random in matching their human counterparts (e.g., R2 between 0.0 and 0.1). In addition to improvements in the current animal model systems, our study supports higher priority for translational medical research to focus on the more complex human conditions rather than relying on mouse models to study human inflammatory diseases. PMID:23401516

  13. Modeling bursts and heavy tails in human dynamics

    OpenAIRE

    Vazquez, A.; Oliveira, J. Gama; Dezso, Z.; Goh, K. -I.; Kondor, I.; Barabasi, A. -L.

    2005-01-01

    Current models of human dynamics, used from risk assessment to communications, assume that human actions are randomly distributed in time and thus well approximated by Poisson processes. We provide direct evidence that for five human activity patterns the timing of individual human actions follow non-Poisson statistics, characterized by bursts of rapidly occurring events separated by long periods of inactivity. We show that the bursty nature of human behavior is a consequence of a decision ba...

  14. Modeling human response errors in synthetic flight simulator domain

    Science.gov (United States)

    Ntuen, Celestine A.

    1992-01-01

    This paper presents a control theoretic approach to modeling human response errors (HRE) in the flight simulation domain. The human pilot is modeled as a supervisor of a highly automated system. The synthesis uses the theory of optimal control pilot modeling for integrating the pilot's observation error and the error due to the simulation model (experimental error). Methods for solving the HRE problem are suggested. Experimental verification of the models will be tested in a flight quality handling simulation.

  15. A long term model of circulation. [human body

    Science.gov (United States)

    White, R. J.

    1974-01-01

    A quantitative approach to modeling human physiological function, with a view toward ultimate application to long duration space flight experiments, was undertaken. Data was obtained on the effect of weightlessness on certain aspects of human physiological function during 1-3 month periods. Modifications in the Guyton model are reviewed. Design considerations for bilateral interface models are discussed. Construction of a functioning whole body model was studied, as well as the testing of the model versus available data.

  16. Competency Modeling in Extension Education: Integrating an Academic Extension Education Model with an Extension Human Resource Management Model

    Science.gov (United States)

    Scheer, Scott D.; Cochran, Graham R.; Harder, Amy; Place, Nick T.

    2011-01-01

    The purpose of this study was to compare and contrast an academic extension education model with an Extension human resource management model. The academic model of 19 competencies was similar across the 22 competencies of the Extension human resource management model. There were seven unique competencies for the human resource management model.…

  17. On our best behavior: optimality models in human behavioral ecology.

    Science.gov (United States)

    Driscoll, Catherine

    2009-06-01

    This paper discusses problems associated with the use of optimality models in human behavioral ecology. Optimality models are used in both human and non-human animal behavioral ecology to test hypotheses about the conditions generating and maintaining behavioral strategies in populations via natural selection. The way optimality models are currently used in behavioral ecology faces significant problems, which are exacerbated by employing the so-called 'phenotypic gambit': that is, the bet that the psychological and inheritance mechanisms responsible for behavioral strategies will be straightforward. I argue that each of several different possible ways we might interpret how optimality models are being used for humans face similar and additional problems. I suggest some ways in which human behavioral ecologists might adjust how they employ optimality models; in particular, I urge the abandonment of the phenotypic gambit in the human case.

  18. Diffusion Based Modeling of Human Brain Response to External Stimuli

    CERN Document Server

    Namazi, Hamidreza

    2012-01-01

    Human brain response is the overall ability of the brain in analyzing internal and external stimuli in the form of transferred energy to the mind/brain phase-space and thus, making the proper decisions. During the last decade scientists discovered about this phenomenon and proposed some models based on computational, biological, or neuropsychological methods. Despite some advances in studies related to this area of the brain research there was less effort which have been done on the mathematical modeling of the human brain response to external stimuli. This research is devoted to the modeling of human EEG signal, as an alert state of overall human brain activity monitoring, due to receiving external stimuli, based on fractional diffusion equation. The results of this modeling show very good agreement with the real human EEG signal and thus, this model can be used as a strong representative of the human brain activity.

  19. Modelling Human Emotions for Tactical Decision-Making Games

    Science.gov (United States)

    Visschedijk, Gillian C.; Lazonder, Ard W.; van der Hulst, Anja; Vink, Nathalie; Leemkuil, Henny

    2013-01-01

    The training of tactical decision making increasingly occurs through serious computer games. A challenging aspect of designing such games is the modelling of human emotions. Two studies were performed to investigate the relation between fidelity and human emotion recognition in virtual human characters. Study 1 compared five versions of a virtual…

  20. Modelling human emotions for tactical decision-making games

    NARCIS (Netherlands)

    Visschedijk, G.C.; Lazonder, A.W.; Hulst, A.H. van der; Vink, N.; Leemkuil, H.

    2013-01-01

    The training of tactical decision making increasingly occurs through serious computer games. A challenging aspect of designing such games is the modelling of human emotions. Two studieswere performed to investigate the relation between fidelity and human emotion recognition in virtual human characte

  1. Modelling human emotions for tactical decision-making games

    NARCIS (Netherlands)

    Visschedijk, G.C.; Lazonder, A.W.; Hulst, A.H. van der; Vink, N.; Leemkuil, H.

    2013-01-01

    The training of tactical decision making increasingly occurs through serious computer games. A challenging aspect of designing such games is the modelling of human emotions. Two studieswere performed to investigate the relation between fidelity and human emotion recognition in virtual human characte

  2. Research on Dynamic Model of the Human Body

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chun-lin; WANG Guang-quan; LU Dun-yong

    2005-01-01

    After summarizing the current situation of the research on human body modeling, a new dynamic model containing 5 equivalent masses has been proposed and the corresponding dynamic equations has been deduced too. By using this new model, more detailed information about the situation of the human body under impact and vibration can be obtained. The new model solves the problem that transmission functions of forces inside the human body can't be deduced by using 3-equivalent-mass model. It will find its usage in many applications.

  3. Modelling Human Exposure to Chemicals in Food

    NARCIS (Netherlands)

    Slob W

    1993-01-01

    Exposure to foodborne chemicals is often estimated using the average consumption pattern in the human population. To protect the human population instead of the average individual, however, interindividual variability in consumption behaviour must be taken into account. This report shows how food

  4. Dynamics of the two process model of human sleep regulation

    Science.gov (United States)

    Kenngott, Max; McKay, Cavendish

    2011-04-01

    We examine the dynamics of the two process model of human sleep regulation. In this model, sleep propensity is governed by the interaction between a periodic threshold (process C) and a saturating growth/decay (process S). We find that the parameter space of this model admits sleep cycles with a wide variety of characteristics, many of which are not observed in normal human sleepers. We also examine the effects of phase dependent feedback on this model.

  5. Minimizing Human Risk: Human Performance Models in the Space Human Factors and Habitability and Behavioral Health and Performance Elements

    Science.gov (United States)

    Gore, Brian F.

    2016-01-01

    Human space exploration has never been more exciting than it is today. Human presence to outer worlds is becoming a reality as humans are leveraging much of our prior knowledge to the new mission of going to Mars. Exploring the solar system at greater distances from Earth than ever before will possess some unique challenges, which can be overcome thanks to the advances in modeling and simulation technologies. The National Aeronautics and Space Administration (NASA) is at the forefront of exploring our solar system. NASA's Human Research Program (HRP) focuses on discovering the best methods and technologies that support safe and productive human space travel in the extreme and harsh space environment. HRP uses various methods and approaches to answer questions about the impact of long duration missions on the human in space including: gravity's impact on the human body, isolation and confinement on the human, hostile environments impact on the human, space radiation, and how the distance is likely to impact the human. Predictive models are included in the HRP research portfolio as these models provide valuable insights into human-system operations. This paper will provide an overview of NASA's HRP and will present a number of projects that have used modeling and simulation to provide insights into human-system issues (e.g. automation, habitat design, schedules) in anticipation of space exploration.

  6. Numerical Modeling of Electromagnetic Field Effects on the Human Body

    Directory of Open Access Journals (Sweden)

    Zuzana Psenakova

    2006-01-01

    Full Text Available Interactions of electromagnetic field (EMF with environment and with tissue of human beings are still under discussion and many research teams are investigating it. The human simulation models are used for biomedical research in a lot of areas, where it is advantage to replace real human body (tissue by the numerical model. Biological effects of EMF are one of the areas, where numerical models are used with many advantages. On the other side, this research is very specific and it is always quite hard to simulate realistic human tissue. This paper deals with different possibilities of numerical modelling of electromagnetic field effects on the human body (especially calculation of the specific absorption rate (SAR distribution in human body and thermal effect.

  7. Pharmacological migraine provocation: a human model of migraine

    DEFF Research Database (Denmark)

    Ashina, Messoud; Hansen, Jakob Møller

    2010-01-01

    for migraine mechanisms. So far, however, animal models cannot predict the efficacy of new therapies for migraine. Because migraine attacks are fully reversible and can be aborted by therapy, the headache- or migraine-provoking property of naturally occurring signaling molecules can be tested in a human model....... If a naturally occurring substance can provoke migraine in human patients, then it is likely, although not certain, that blocking its effect will be effective in the treatment of acute migraine attacks. To this end, a human in vivo model of experimental headache and migraine in humans has been developed...

  8. Predicting human walking gaits with a simple planar model.

    Science.gov (United States)

    Martin, Anne E; Schmiedeler, James P

    2014-04-11

    Models of human walking with moderate complexity have the potential to accurately capture both joint kinematics and whole body energetics, thereby offering more simultaneous information than very simple models and less computational cost than very complex models. This work examines four- and six-link planar biped models with knees and rigid circular feet. The two differ in that the six-link model includes ankle joints. Stable periodic walking gaits are generated for both models using a hybrid zero dynamics-based control approach. To establish a baseline of how well the models can approximate normal human walking, gaits were optimized to match experimental human walking data, ranging in speed from very slow to very fast. The six-link model well matched the experimental step length, speed, and mean absolute power, while the four-link model did not, indicating that ankle work is a critical element in human walking models of this type. Beyond simply matching human data, the six-link model can be used in an optimization framework to predict normal human walking using a torque-squared objective function. The model well predicted experimental step length, joint motions, and mean absolute power over the full range of speeds.

  9. Multi-agent Model of Trust in a Human Game

    NARCIS (Netherlands)

    Jonker, C.M.; Meijer, S.A.; Tykhonov, D.; Verwaart, D.

    2006-01-01

    Individual-level trust is formalized within the context of a multi-agent system that models human behaviour with respect to trust in the Trust and Tracing Game. This is a trade game on commodity supply chains and networks, designed as a reserach tool and to be played by human players. The model of t

  10. Fuzzy Control Strategies in Human Operator and Sport Modeling

    CERN Document Server

    Ivancevic, Tijana T; Markovic, Sasa

    2009-01-01

    The motivation behind mathematically modeling the human operator is to help explain the response characteristics of the complex dynamical system including the human manual controller. In this paper, we present two different fuzzy logic strategies for human operator and sport modeling: fixed fuzzy-logic inference control and adaptive fuzzy-logic control, including neuro-fuzzy-fractal control. As an application of the presented fuzzy strategies, we present a fuzzy-control based tennis simulator.

  11. An integrated model of human-wildlife interdependence

    Science.gov (United States)

    John, Kun H.; Walsh, Richard G.; Johnson, R. L.

    1994-01-01

    This paper attempts to integrate wildlife-related ecologic and economic variables into an econometric model. The model reveals empirical evidence of the presumed interdependence of human-wildlife and the holistic nature of humanity's relationship to the ecosystem. Human use of biologic resources varies not only with income, education, and population, but also with sustainability of humankind's action relative to the quality and quantity of the supporting ecological base.

  12. Humanized mouse model for assessing the human immune response to xenogeneic and allogeneic decellularized biomaterials.

    Science.gov (United States)

    Wang, Raymond M; Johnson, Todd D; He, Jingjin; Rong, Zhili; Wong, Michelle; Nigam, Vishal; Behfar, Atta; Xu, Yang; Christman, Karen L

    2017-06-01

    Current assessment of biomaterial biocompatibility is typically implemented in wild type rodent models. Unfortunately, different characteristics of the immune systems in rodents versus humans limit the capability of these models to mimic the human immune response to naturally derived biomaterials. Here we investigated the utility of humanized mice as an improved model for testing naturally derived biomaterials. Two injectable hydrogels derived from decellularized porcine or human cadaveric myocardium were compared. Three days and one week after subcutaneous injection, the hydrogels were analyzed for early and mid-phase immune responses, respectively. Immune cells in the humanized mouse model, particularly T-helper cells, responded distinctly between the xenogeneic and allogeneic biomaterials. The allogeneic extracellular matrix derived hydrogels elicited significantly reduced total, human specific, and CD4(+) T-helper cell infiltration in humanized mice compared to xenogeneic extracellular matrix hydrogels, which was not recapitulated in wild type mice. T-helper cells, in response to the allogeneic hydrogel material, were also less polarized towards a pro-remodeling Th2 phenotype compared to xenogeneic extracellular matrix hydrogels in humanized mice. In both models, both biomaterials induced the infiltration of macrophages polarized towards a M2 phenotype and T-helper cells polarized towards a Th2 phenotype. In conclusion, these studies showed the importance of testing naturally derived biomaterials in immune competent animals and the potential of utilizing this humanized mouse model for further studying human immune cell responses to biomaterials in an in vivo environment.

  13. Pearls and pitfalls in human pharmacological models of migraine

    DEFF Research Database (Denmark)

    Ashina, Messoud; Hansen, Jakob Møller; Olesen, Jes

    2013-01-01

    In vitro studies have contributed to the characterization of receptors in cranial blood vessels and the identification of new possible anti-migraine agents. In vivo animal models enable the study of vascular responses, neurogenic inflammation, peptide release and genetic predisposition and thus...... have provided leads in the search for migraine mechanisms. All animal-based results must, however, be validated in human studies because so far no animal models can predict the efficacy of new therapies for migraine. Given the nature of migraine attacks, fully reversible and treatable, the headache....... To this end, a human in vivo model of experimental headache and migraine in humans has been developed. Human models of migraine offer unique possibilities to study mechanisms responsible for migraine and to explore the mechanisms of action of existing and future anti-migraine drugs. The human model has played...

  14. Mice with human immune system components as in vivo models for infections with human pathogens

    OpenAIRE

    Rämer, P C; Chijioke, O; Meixlsperger, S; Leung, C S; Münz, C.

    2011-01-01

    Many pathogens relevant to human disease do not infect other animal species. Therefore, animal models that reconstitute or harbour human tissues are explored as hosts for these. In this review, we will summarize recent advances to utilize mice with human immune system components, reconstituted from hematopoietic progenitor cells in vivo. Such mice can be used to study human pathogens that replicate in leucocytes. In addition to studying the replication of these pathogens, the reconstituted hu...

  15. Variation in calculated human exposure. Comparison of calculations with seven European human exposure models

    NARCIS (Netherlands)

    Swartjes F; ECO

    2003-01-01

    Twenty scenarios, differing with respect to land use, soil type and contaminant, formed the basis for calculating human exposure from soil contaminants with the use of models contributed by seven European countries (one model per country). Here, the human exposures to children and children

  16. Modeling Human Behaviour with Higher Order Logic: Insider Threats

    DEFF Research Database (Denmark)

    Boender, Jaap; Ivanova, Marieta Georgieva; Kammuller, Florian

    2014-01-01

    In this paper, we approach the problem of modeling the human component in technical systems with a view on the difference between the use of model and theory in sociology and computer science. One aim of this essay is to show that building of theories and models for sociology can be compared...... it to the sociological process of logical explanation. As a case study on modeling human behaviour, we present the modeling and analysis of insider threats as a Higher Order Logic theory in Isabelle/HOL. We show how each of the three step process of sociological explanation can be seen in our modeling of insider’s state...

  17. Human Cancer Models Initiative | Office of Cancer Genomics

    Science.gov (United States)

    The Human Cancer Models Initiative (HCMI) is an international consortium that is generating novel human tumor-derived culture models, which are annotated with genomic and clinical data. In an effort to advance cancer research and more fully understand how in vitro findings are related to clinical biology, HCMI-developed models and related data will be available as a community resource for cancer research.

  18. Human surrogate models of neuropathic pain: validity and limitations.

    Science.gov (United States)

    Binder, Andreas

    2016-02-01

    Human surrogate models of neuropathic pain in healthy subjects are used to study symptoms, signs, and the hypothesized underlying mechanisms. Although different models are available, different spontaneous and evoked symptoms and signs are inducible; 2 key questions need to be answered: are human surrogate models conceptually valid, ie, do they share the sensory phenotype of neuropathic pain states, and are they sufficiently reliable to allow consistent translational research?

  19. [Attempt at computer modeling of evolution of human society].

    Science.gov (United States)

    Levchenko, V F; Menshutkin, V V

    2009-01-01

    A model of evolution of human society and biosphere, which is based on the concepts of V. I. Vernadskii about noosphere and of L. N. Gumilev about ethnogenesis is developed and studied. The mathematical apparatus of the model is composition of finite stochastic automata. By using this model, a possibility of the global ecological crisis is demonstrated in the case of preservation of the current tendencies of interaction of the biosphere and the human civilization.

  20. A novel SCID mouse model for studying spontaneous metastasis of human lung cancer to human tissue.

    Science.gov (United States)

    Teraoka, S; Kyoizumi, S; Seyama, T; Yamakido, M; Akiyama, M

    1995-05-01

    We established a novel severe combined immunodeficient (SCID) mouse model for the study of human lung cancer metastasis to human lung. Implantation of both human fetal and adult lung tissue into mammary fat pads of SCID mice showed a 100% rate of engraftment, but only fetal lung implants revealed normal morphology of human lung tissue. Using these chimeric mice, we analyzed human lung cancer metastasis to both mouse and human lungs by subcutaneous inoculation of human squamous cell carcinoma and adenocarcinoma cell lines into the mice. In 60 to 70% of SCID mice injected with human-lung squamous-cell carcinoma, RERF-LC-AI, cancer cells were found to have metastasized to both mouse lungs and human fetal lung implants but not to human adult lung implants 80 days after cancer inoculation. Furthermore, human-lung adenocarcinoma cells, RERF-LC-KJ, metastasized to the human lung implants within 90 days in about 40% of SCID mice, whereas there were no metastases to the lungs of the mice. These results demonstrate the potential of this model for the in vivo study of human lung cancer metastasis.

  1. Detection of Unusual Human Activities Based on Behavior Modeling

    OpenAIRE

    Hiraishi, Kunihiko; Kobayashi, Koichi

    2014-01-01

    A type of services that require human physical actions and intelligent decision making exists in various real fields, such as nursing in hospitals and caregiving in nursing homes. In this paper, we propose new formalism for modeling human behavior in such services. Behavior models are estimated from event-logs, and can be used for analysis of human activities. We show two analysis methods: one is to detect unusual human activities that appear in event-logs, and the other is to find staffs tha...

  2. Mouse models for understanding human developmental anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Generoso, W.M.

    1989-01-01

    The mouse experimental system presents an opportunity for studying the nature of the underlying mutagenic damage and the molecular pathogenesis of this class of anomalies by virtue of the accessibility of the zygote and its descendant blastomeres. Such studies could contribute to the understanding of the etiology of certain sporadic but common human malformations. The vulnerability of the zygotes to mutagens as demonstrated in the studies described in this report should be a major consideration in chemical safety evaluation. It raises questions regarding the danger to human zygotes when the mother is exposed to drugs and environmental chemicals.

  3. Drosophila Melanogaster as an Emerging Translational Model of Human Nephrolithiasis

    Science.gov (United States)

    Miller, Joe; Chi, Thomas; Kapahi, Pankaj; Kahn, Arnold J.; Kim, Man Su; Hirata, Taku; Romero, Michael F.; Dow, Julian A.T.; Stoller, Marshall L.

    2013-01-01

    Purpose The limitations imposed by human clinical studies and mammalian models of nephrolithiasis have hampered the development of effective medical treatments and preventative measures for decades. The simple but elegant Drosophila melanogaster is emerging as a powerful translational model of human disease, including nephrolithiasis and may provide important information essential to our understanding of stone formation. We present the current state of research using D. melanogaster as a model of human nephrolithiasis. Materials and Methods A comprehensive review of the English language literature was performed using PUBMED. When necessary, authoritative texts on relevant subtopics were consulted. Results The genetic composition, anatomic structure and physiologic function of Drosophila Malpighian tubules are remarkably similar to those of the human nephron. The direct effects of dietary manipulation, environmental alteration, and genetic variation on stone formation can be observed and quantified in a matter of days. Several Drosophila models of human nephrolithiasis, including genetically linked and environmentally induced stones, have been developed. A model of calcium oxalate stone formation is among the most recent fly models of human nephrolithiasis. Conclusions The ability to readily manipulate and quantify stone formation in D. melanogaster models of human nephrolithiasis presents the urologic community with a unique opportunity to increase our understanding of this enigmatic disease. PMID:23500641

  4. Current humanized mouse models for studying human immunology and HIV-1 immuno-pathogenesis

    Institute of Scientific and Technical Information of China (English)

    MEISSNER; Eric

    2010-01-01

    A robust animal model for "hypothesis-testing/mechanistic" research in human immunology and immuno-pathology should meet the following criteria.First,it has well-studied hemato-lymphoid organs and target cells similar to those of humans.Second,the human pathogens establish infection and lead to relevant diseases.Third,it is genetically inbred and can be manipulated via genetic,immunological and pharmacological means.Many human-tropic pathogens such as HIV-1 fail to infect murine cells due to the blocks at multiple steps of their life cycle.The mouse with a reconstituted human immune system and other human target organs is a good candidate.A number of human-mouse chimeric models with human immune cells have been developed in the past 20 years,but most with only limited success due to the selective engraftment of xeno-reactive human T cells in hu-PBL-SCID mice or the lack of significant human immune responses in the SCID-hu Thy/Liv mouse.This review summarizes the current understanding of HIV-1 immuno-pathogenesis in human patients and in SIV-infected primate models.It also reviews the recent progress in the development of humanized mouse models with a functional human immune system,especially the recent progress in the immunodeficient mice that carry a defective gammaC gene.NOD/SCID/gammaC-/(NOG or NSG) or the Rag2-/-/gammaC-/double knockout (DKO) mice,which lack NK as well as T and B cells (NTB-null mice),have been used to reconstitute a functional human immune system in central and peripheral lymphoid organs with human CD34+ HSC.These NTB-hu HSC humanized models have been used to investigate HIV-1 infection,immuno-pathogenesis and therapeutic interventions.Such models,with further improvements,will contribute to study human immunology,human-tropic pathogens as well as human stem cell biology in the tissue development and function in vivo.

  5. Mice with human immune system components as in vivo models for infections with human pathogens.

    Science.gov (United States)

    Rämer, Patrick C; Chijioke, Obinna; Meixlsperger, Sonja; Leung, Carol S; Münz, Christian

    2011-03-01

    Many pathogens relevant to human disease do not infect other animal species. Therefore, animal models that reconstitute or harbor human tissues are explored as hosts for these. In this review, we will summarize recent advances to utilize mice with human immune system components, reconstituted from hematopoietic progenitor cells in vivo. Such mice can be used to study human pathogens that replicate in leukocytes. In addition to studying the replication of these pathogens, the reconstituted human immune system components can also be analyzed for initiating immune responses and control against these infections. Moreover, these new animal models of human infectious disease should replicate the reactivity of the human immune system to vaccine candidates and, especially, the adjuvants contained in them, more faithfully.

  6. A novel mouse model for stable engraftment of a human immune system and human hepatocytes.

    Directory of Open Access Journals (Sweden)

    Helene Strick-Marchand

    Full Text Available Hepatic infections by hepatitis B virus (HBV, hepatitis C virus (HCV and Plasmodium parasites leading to acute or chronic diseases constitute a global health challenge. The species tropism of these hepatotropic pathogens is restricted to chimpanzees and humans, thus model systems to study their pathological mechanisms are severely limited. Although these pathogens infect hepatocytes, disease pathology is intimately related to the degree and quality of the immune response. As a first step to decipher the immune response to infected hepatocytes, we developed an animal model harboring both a human immune system (HIS and human hepatocytes (HUHEP in BALB/c Rag2-/- IL-2Rγc-/- NOD.sirpa uPAtg/tg mice. The extent and kinetics of human hepatocyte engraftment were similar between HUHEP and HIS-HUHEP mice. Transplanted human hepatocytes were polarized and mature in vivo, resulting in 20-50% liver chimerism in these models. Human myeloid and lymphoid cell lineages developed at similar frequencies in HIS and HIS-HUHEP mice, and splenic and hepatic compartments were humanized with mature B cells, NK cells and naïve T cells, as well as monocytes and dendritic cells. Taken together, these results demonstrate that HIS-HUHEP mice can be stably (> 5 months and robustly engrafted with a humanized immune system and chimeric human liver. This novel HIS-HUHEP model provides a platform to investigate human immune responses against hepatotropic pathogens and to test novel drug strategies or vaccine candidates.

  7. A novel mouse model for stable engraftment of a human immune system and human hepatocytes.

    Science.gov (United States)

    Strick-Marchand, Helene; Dusséaux, Mathilde; Darche, Sylvie; Huntington, Nicholas D; Legrand, Nicolas; Masse-Ranson, Guillemette; Corcuff, Erwan; Ahodantin, James; Weijer, Kees; Spits, Hergen; Kremsdorf, Dina; Di Santo, James P

    2015-01-01

    Hepatic infections by hepatitis B virus (HBV), hepatitis C virus (HCV) and Plasmodium parasites leading to acute or chronic diseases constitute a global health challenge. The species tropism of these hepatotropic pathogens is restricted to chimpanzees and humans, thus model systems to study their pathological mechanisms are severely limited. Although these pathogens infect hepatocytes, disease pathology is intimately related to the degree and quality of the immune response. As a first step to decipher the immune response to infected hepatocytes, we developed an animal model harboring both a human immune system (HIS) and human hepatocytes (HUHEP) in BALB/c Rag2-/- IL-2Rγc-/- NOD.sirpa uPAtg/tg mice. The extent and kinetics of human hepatocyte engraftment were similar between HUHEP and HIS-HUHEP mice. Transplanted human hepatocytes were polarized and mature in vivo, resulting in 20-50% liver chimerism in these models. Human myeloid and lymphoid cell lineages developed at similar frequencies in HIS and HIS-HUHEP mice, and splenic and hepatic compartments were humanized with mature B cells, NK cells and naïve T cells, as well as monocytes and dendritic cells. Taken together, these results demonstrate that HIS-HUHEP mice can be stably (> 5 months) and robustly engrafted with a humanized immune system and chimeric human liver. This novel HIS-HUHEP model provides a platform to investigate human immune responses against hepatotropic pathogens and to test novel drug strategies or vaccine candidates.

  8. New Metacognitive Model for Human Performance Technology

    Science.gov (United States)

    Turner, John R.

    2011-01-01

    Addressing metacognitive functions has been shown to improve performance at the individual, team, group, and organizational levels. Metacognition is beginning to surface as an added cognate discipline for the field of human performance technology (HPT). Advances from research in the fields of cognition and metacognition offer a place for HPT to…

  9. New Metacognitive Model for Human Performance Technology

    Science.gov (United States)

    Turner, John R.

    2011-01-01

    Addressing metacognitive functions has been shown to improve performance at the individual, team, group, and organizational levels. Metacognition is beginning to surface as an added cognate discipline for the field of human performance technology (HPT). Advances from research in the fields of cognition and metacognition offer a place for HPT to…

  10. Human performance modeling for system of systems analytics.

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, Kevin R.; Lawton, Craig R.; Basilico, Justin Derrick; Longsine, Dennis E. (INTERA, Inc., Austin, TX); Forsythe, James Chris; Gauthier, John Henry; Le, Hai D.

    2008-10-01

    A Laboratory-Directed Research and Development project was initiated in 2005 to investigate Human Performance Modeling in a System of Systems analytic environment. SAND2006-6569 and SAND2006-7911 document interim results from this effort; this report documents the final results. The problem is difficult because of the number of humans involved in a System of Systems environment and the generally poorly defined nature of the tasks that each human must perform. A two-pronged strategy was followed: one prong was to develop human models using a probability-based method similar to that first developed for relatively well-understood probability based performance modeling; another prong was to investigate more state-of-art human cognition models. The probability-based modeling resulted in a comprehensive addition of human-modeling capability to the existing SoSAT computer program. The cognitive modeling resulted in an increased understanding of what is necessary to incorporate cognition-based models to a System of Systems analytic environment.

  11. Understanding What We Do: Emerging Models for Human Rights Education

    Science.gov (United States)

    Tibbitts, Felisa

    2002-07-01

    The author presents three approaches to contemporary human rights education practice: the Values and Awareness Model, the Accountability Model and the Transformational Model. Each model is associated with particular target groups, contents and strategies. The author suggests that these models can lend themselves to theory development and research in what might be considered an emerging educational field. Human rights education can be further strengthened through the appropriate use oflearning theory, as well as through the setting of standards for trainer preparation and program content, and through evaluating the impact of programs in terms of reaching learner goals (knowledge, values and skills) and contributing to social change.

  12. Biostereometric Data Processing In ERGODATA: Choice Of Human Body Models

    Science.gov (United States)

    Pineau, J. C.; Mollard, R.; Sauvignon, M.; Amphoux, M.

    1983-07-01

    The definition of human body models was elaborated with anthropometric data from ERGODATA. The first model reduces the human body into a series of points and lines. The second model is well adapted to represent volumes of each segmentary element. The third is an original model built from the conventional anatomical points. Each segment is defined in space by a tri-angular plane located with its 3-D coordinates. This new model can answer all the processing possibilities in the field of computer-aided design (C.A.D.) in ergonomy but also biomechanics and orthopaedics.

  13. Human Digital Modeling & Hand Scanning Lab

    Data.gov (United States)

    Federal Laboratory Consortium — This laboratory incorporates specialized scanning equipment, computer workstations and software applications for the acquisition and analysis of digitized models of...

  14. Synthetic vision and emotion calculation in intelligent virtual human modeling.

    Science.gov (United States)

    Zhao, Y; Kang, J; Wright, D K

    2007-01-01

    The virtual human technique can already provide vivid and believable human behaviour in more and more scenarios. Virtual humans are expected to replace real humans in hazardous situations to undertake tests and feed back valuable information. This paper will introduce a virtual human with a novel collision-based synthetic vision, short-term memory model and a capability to implement emotion calculation and decision making. The virtual character based on this model can 'see' what is in its field of view (FOV) and remember those objects. After that, a group of affective computing equations have been introduced. These equations have been implemented into a proposed emotion calculation process to enlighten emotion for virtual intelligent humans.

  15. Modelling mutational landscapes of human cancers in vitro

    Science.gov (United States)

    Olivier, Magali; Weninger, Annette; Ardin, Maude; Huskova, Hana; Castells, Xavier; Vallée, Maxime P.; McKay, James; Nedelko, Tatiana; Muehlbauer, Karl-Rudolf; Marusawa, Hiroyuki; Alexander, John; Hazelwood, Lee; Byrnes, Graham; Hollstein, Monica; Zavadil, Jiri

    2014-03-01

    Experimental models that recapitulate mutational landscapes of human cancers are needed to decipher the rapidly expanding data on human somatic mutations. We demonstrate that mutation patterns in immortalised cell lines derived from primary murine embryonic fibroblasts (MEFs) exposed in vitro to carcinogens recapitulate key features of mutational signatures observed in human cancers. In experiments with several cancer-causing agents we obtained high genome-wide concordance between human tumour mutation data and in vitro data with respect to predominant substitution types, strand bias and sequence context. Moreover, we found signature mutations in well-studied human cancer driver genes. To explore endogenous mutagenesis, we used MEFs ectopically expressing activation-induced cytidine deaminase (AID) and observed an excess of AID signature mutations in immortalised cell lines compared to their non-transgenic counterparts. MEF immortalisation is thus a simple and powerful strategy for modelling cancer mutation landscapes that facilitates the interpretation of human tumour genome-wide sequencing data.

  16. Cyberpsychology: a human-interaction perspective based on cognitive modeling.

    Science.gov (United States)

    Emond, Bruno; West, Robert L

    2003-10-01

    This paper argues for the relevance of cognitive modeling and cognitive architectures to cyberpsychology. From a human-computer interaction point of view, cognitive modeling can have benefits both for theory and model building, and for the design and evaluation of sociotechnical systems usability. Cognitive modeling research applied to human-computer interaction has two complimentary objectives: (1) to develop theories and computational models of human interactive behavior with information and collaborative technologies, and (2) to use the computational models as building blocks for the design, implementation, and evaluation of interactive technologies. From the perspective of building theories and models, cognitive modeling offers the possibility to anchor cyberpsychology theories and models into cognitive architectures. From the perspective of the design and evaluation of socio-technical systems, cognitive models can provide the basis for simulated users, which can play an important role in usability testing. As an example of application of cognitive modeling to technology design, the paper presents a simulation of interactive behavior with five different adaptive menu algorithms: random, fixed, stacked, frequency based, and activation based. Results of the simulation indicate that fixed menu positions seem to offer the best support for classification like tasks such as filing e-mails. This research is part of the Human-Computer Interaction, and the Broadband Visual Communication research programs at the National Research Council of Canada, in collaboration with the Carleton Cognitive Modeling Lab at Carleton University.

  17. Modeling Human Behaviour with Higher Order Logic: Insider Threats

    NARCIS (Netherlands)

    Boender, Jaap; Ivanova, Marieta Georgieva; Kammüller, Florian; Primierio, Giuseppe

    2014-01-01

    In this paper, we approach the problem of modeling the human component in technical systems with a view on the difference between the use of model and theory in sociology and computer science. One aim of this essay is to show that building of theories and models for sociology can be compared and imp

  18. Formal modelling techniques in human-computer interaction

    NARCIS (Netherlands)

    Haan, de G.; Veer, van der G.C.; Vliet, van J.C.

    1991-01-01

    This paper is a theoretical contribution, elaborating the concept of models as used in Cognitive Ergonomics. A number of formal modelling techniques in human-computer interaction will be reviewed and discussed. The analysis focusses on different related concepts of formal modelling techniques in hum

  19. Human Spaceflight Architecture Model (HSFAM) Data Dictionary

    Science.gov (United States)

    Shishko, Robert

    2016-01-01

    HSFAM is a data model based on the DoDAF 2.02 data model with some for purpose extensions. These extensions are designed to permit quantitative analyses regarding stakeholder concerns about technical feasibility, configuration and interface issues, and budgetary and/or economic viability.

  20. Behavior genetic modeling of human fertility

    DEFF Research Database (Denmark)

    Rodgers, J L; Kohler, H P; Kyvik, K O;

    2001-01-01

    Try) and number of children (NumCh). Behavior genetic models were fitted using structural equation modeling and DF analysis. A consistent medium-level additive genetic influence was found for NumCh, equal across genders; a stronger genetic influence was identified for FirstTry, greater for females than for males...

  1. Phase transitions in models of human cooperation

    Science.gov (United States)

    Perc, Matjaž

    2016-08-01

    If only the fittest survive, why should one cooperate? Why should one sacrifice personal benefits for the common good? Recent research indicates that a comprehensive answer to such questions requires that we look beyond the individual and focus on the collective behavior that emerges as a result of the interactions among individuals, groups, and societies. Although undoubtedly driven also by culture and cognition, human cooperation is just as well an emergent, collective phenomenon in a complex system. Nonequilibrium statistical physics, in particular the collective behavior of interacting particles near phase transitions, has already been recognized as very valuable for understanding counterintuitive evolutionary outcomes. However, unlike pairwise interactions among particles that typically govern solid-state physics systems, interactions among humans often involve group interactions, and they also involve a larger number of possible states even for the most simplified description of reality. Here we briefly review research done in the realm of the public goods game, and we outline future research directions with an emphasis on merging the most recent advances in the social sciences with methods of nonequilibrium statistical physics. By having a firm theoretical grip on human cooperation, we can hope to engineer better social systems and develop more efficient policies for a sustainable and better future.

  2. Human Engineering Modeling and Performance Lab Study Project

    Science.gov (United States)

    Oliva-Buisson, Yvette J.

    2014-01-01

    The HEMAP (Human Engineering Modeling and Performance) Lab is a joint effort between the Industrial and Human Engineering group and the KAVE (Kennedy Advanced Visualiations Environment) group. The lab consists of sixteen camera system that is used to capture human motions and operational tasks, through te use of a Velcro suit equipped with sensors, and then simulate these tasks in an ergonomic software package know as Jac, The Jack software is able to identify the potential risk hazards.

  3. Human vascular model with defined stimulation medium - a characterization study.

    Science.gov (United States)

    Huttala, Outi; Vuorenpää, Hanna; Toimela, Tarja; Uotila, Jukka; Kuokkanen, Hannu; Ylikomi, Timo; Sarkanen, Jertta-Riina; Heinonen, Tuula

    2015-01-01

    The formation of blood vessels is a vital process in embryonic development and in normal physiology. Current vascular modelling is mainly based on animal biology leading to species-to-species variation when extrapolating the results to humans. Although there are a few human cell based vascular models available these assays are insufficiently characterized in terms of culture conditions and developmental stage of vascular structures. Therefore, well characterized vascular models with human relevance are needed for basic research, embryotoxicity testing, development of therapeutic strategies and for tissue engineering. We have previously shown that the in vitro vascular model based on co-culture of human adipose stromal cells (hASC) and human umbilical vein endothelial cells (HUVEC) is able to induce an extensive vascular-like network with high reproducibility. In this work we developed a defined serum-free vascular stimulation medium (VSM) and performed further characterization in terms of cell identity, maturation and structure to obtain a thoroughly characterized in vitro vascular model to replace or reduce corresponding animal experiments. The results showed that the novel vascular stimulation medium induced intact and evenly distributed vascular-like network with morphology of mature vessels. Electron microscopic analysis assured the three-dimensional microstructure of the network containing lumen. Additionally, elevated expressions of the main human angiogenesis-related genes were detected. In conclusion, with the new defined medium the vascular model can be utilized as a characterized test system for chemical testing as well as in creating vascularized tissue models.

  4. Agency, Values, and Well-Being: A Human Development Model

    Science.gov (United States)

    Welzel, Christian; Inglehart, Ronald

    2010-01-01

    This paper argues that feelings of agency are linked to human well-being through a sequence of adaptive mechanisms that promote human development, once existential conditions become permissive. In the first part, we elaborate on the evolutionary logic of this model and outline why an evolutionary perspective is helpful to understand changes in…

  5. Modelling human actions on lightweight structures: experimental and numerical developments

    Directory of Open Access Journals (Sweden)

    Živanović S.

    2015-01-01

    Full Text Available This paper presents recent, numerical and experimental, developments in modelling dynamic loading generated by humans. As modern structures with exposure to human-induced loading, such as footbridges, building floors and grandstands, are becoming ever lighter and more slender, they are increasingly susceptible to vibration under human-induced dynamic excitation, such as walking, jumping, running and bobbing, and their vibration serviceability assessment is often a deciding factor in the design process. While simplified modelling of the human using a harmonic force was sufficient for assessment of vibration performance of more robust structures a few decades ago, the higher fidelity models are required in the contemporary design. These models are expected not only to describe both temporal and spectral features of the force signal more accurately, but also to capture the influence, psychological and physiological, of human-structure and human-human interaction mechanisms on the human kinematics, and consequently on the force generated and the resulting vibration response. Significant advances have been made in both the research studies and design guidance. This paper reports the key developments and identifies the scope for further research.

  6. How do humans inspect BPMN models: an exploratory study

    DEFF Research Database (Denmark)

    Haisjackl, Cornelia; Soffer, Pnina; Lim, Shao Yi

    2016-01-01

    by humans, what strategies are taken, what challenges arise, and what cognitive processes are involved. This paper contributes toward such an understanding and reports an exploratory study investigating how humans identify and classify quality issues in BPMN process models. Providing preliminary answers...

  7. Relevance of animal models to human tardive dyskinesia

    Directory of Open Access Journals (Sweden)

    Blanchet Pierre J

    2012-03-01

    Full Text Available Abstract Tardive dyskinesia remains an elusive and significant clinical entity that can possibly be understood via experimentation with animal models. We conducted a literature review on tardive dyskinesia modeling. Subchronic antipsychotic drug exposure is a standard approach to model tardive dyskinesia in rodents. Vacuous chewing movements constitute the most common pattern of expression of purposeless oral movements and represent an impermanent response, with individual and strain susceptibility differences. Transgenic mice are also used to address the contribution of adaptive and maladaptive signals induced during antipsychotic drug exposure. An emphasis on non-human primate modeling is proposed, and past experimental observations reviewed in various monkey species. Rodent and primate models are complementary, but the non-human primate model appears more convincingly similar to the human condition and better suited to address therapeutic issues against tardive dyskinesia.

  8. DEVELOPMENT OF 2D HUMAN BODY MODELING USING THINNING ALGORITHM

    Directory of Open Access Journals (Sweden)

    K. Srinivasan

    2010-11-01

    Full Text Available Monitoring the behavior and activities of people in Video surveillance has gained more applications in Computer vision. This paper proposes a new approach to model the human body in 2D view for the activity analysis using Thinning algorithm. The first step of this work is Background subtraction which is achieved by the frame differencing algorithm. Thinning algorithm has been used to find the skeleton of the human body. After thinning, the thirteen feature points like terminating points, intersecting points, shoulder, elbow, and knee points have been extracted. Here, this research work attempts to represent the body model in three different ways such as Stick figure model, Patch model and Rectangle body model. The activities of humans have been analyzed with the help of 2D model for the pre-defined poses from the monocular video data. Finally, the time consumption and efficiency of our proposed algorithm have been evaluated.

  9. Box model for channels of human migration

    CERN Document Server

    Vitanov, Nikolay K

    2016-01-01

    We discuss a mathematical model of migration channel based on the truncated Waring distribution. The truncated Waring distribution is obtained for a more general model of motion of substance through a channel containing finite number of boxes. The model is applied then for case of migrants moving through a channel consisting of finite number of countries or cities. The number of migrants in the channel strongly depends on the number of migrants that enter the channel through the country of entrance. It is shown that if the final destination country is very popular then large percentage of migrants may concentrate there.

  10. A Model of Genetic Variation in Human Social Networks

    CERN Document Server

    Fowler, James H; Christakis, Nicholas A

    2008-01-01

    Social networks influence the evolution of cooperation and they exhibit strikingly systematic patterns across a wide range of human contexts. Both of these facts suggest that variation in the topological attributes of human social networks might have a genetic basis. While genetic variation accounts for a significant portion of the variation in many complex social behaviors, the heritability of egocentric social network attributes is unknown. Here we show that three of these attributes (in-degree, transitivity, and centrality) are heritable. We then develop a "mirror network" method to test extant network models and show that none accounts for observed genetic variation in human social networks. We propose an alternative "attract and introduce" model that generates significant heritability as well as other important network features, and we show that this model with two simple forms of heterogeneity is well suited to the modeling of real social networks in humans. These results suggest that natural selection ...

  11. Pharmacological migraine provocation: a human model of migraine

    DEFF Research Database (Denmark)

    Ashina, Messoud; Hansen, Jakob Møller

    2010-01-01

    In vitro studies have contributed to the characterization of receptors in cranial blood vessels and the identification of possible new antimigraine agents. Animal models enable the study of vascular responses, neurogenic inflammation, and peptide release, and thus have provided leads in the search...... for migraine mechanisms. So far, however, animal models cannot predict the efficacy of new therapies for migraine. Because migraine attacks are fully reversible and can be aborted by therapy, the headache- or migraine-provoking property of naturally occurring signaling molecules can be tested in a human model....... If a naturally occurring substance can provoke migraine in human patients, then it is likely, although not certain, that blocking its effect will be effective in the treatment of acute migraine attacks. To this end, a human in vivo model of experimental headache and migraine in humans has been developed...

  12. Dynamic Human Body Modeling Using a Single RGB Camera

    Directory of Open Access Journals (Sweden)

    Haiyu Zhu

    2016-03-01

    Full Text Available In this paper, we present a novel automatic pipeline to build personalized parametric models of dynamic people using a single RGB camera. Compared to previous approaches that use monocular RGB images, our system can model a 3D human body automatically and incrementally, taking advantage of human motion. Based on coarse 2D and 3D poses estimated from image sequences, we first perform a kinematic classification of human body parts to refine the poses and obtain reconstructed body parts. Next, a personalized parametric human model is generated by driving a general template to fit the body parts and calculating the non-rigid deformation. Experimental results show that our shape estimation method achieves comparable accuracy with reconstructed models using depth cameras, yet requires neither user interaction nor any dedicated devices, leading to the feasibility of using this method on widely available smart phones.

  13. Dynamic Human Body Modeling Using a Single RGB Camera.

    Science.gov (United States)

    Zhu, Haiyu; Yu, Yao; Zhou, Yu; Du, Sidan

    2016-03-18

    In this paper, we present a novel automatic pipeline to build personalized parametric models of dynamic people using a single RGB camera. Compared to previous approaches that use monocular RGB images, our system can model a 3D human body automatically and incrementally, taking advantage of human motion. Based on coarse 2D and 3D poses estimated from image sequences, we first perform a kinematic classification of human body parts to refine the poses and obtain reconstructed body parts. Next, a personalized parametric human model is generated by driving a general template to fit the body parts and calculating the non-rigid deformation. Experimental results show that our shape estimation method achieves comparable accuracy with reconstructed models using depth cameras, yet requires neither user interaction nor any dedicated devices, leading to the feasibility of using this method on widely available smart phones.

  14. Human Communication--A New Model.

    Science.gov (United States)

    McLeish, John

    1978-01-01

    Pavlov's organism-in-the-environment model was adapted to a functional analysis of communication, expecially abstract and symbolic activities. A classification of discrimination response and reinforcement patterns was given. (CP)

  15. Modeling and Mapping of Human Source Data

    Science.gov (United States)

    2011-03-08

    developing a functional framework (and identifying relevant models and algorithms) is to follow the Joint Directors of Laboratories ( JDL ) data fusion...process model ([32], [18]) and explore an analog between traditional fusion processing (at the JDL level 0 and level 1 sub-processes) for physical sensors...this work is shown below. A diagrammatic summary of the analysis is shown in Figures 5 and 6. Figure 4: Information Fusion Hierarchy ( JDL Levels

  16. Human Operator Modeling for Aerial Tracking.

    Science.gov (United States)

    1980-12-01

    SECuRIT CLASSIFICATION OF THIS PAGE(Wh~.n Dwte Enteved) PREFACE This research project was funded by he Air Force Aerospace Medical Research Laboratory...mrad). We assume that the threshold changes gradually around t = 305 sec, where GT decreases from 7 to 4G . These assumption were applied, regardless of...is the subject attained G; (Equation (2.43)) and (; = 4g = minimalA Az mai G;z level, below which human performance is assumed not to be affected

  17. Testing modern human out-of-Africa dispersal models and implications for modern human origins.

    Science.gov (United States)

    Reyes-Centeno, Hugo; Hubbe, Mark; Hanihara, Tsunehiko; Stringer, Chris; Harvati, Katerina

    2015-10-01

    The modern human expansion process out of Africa has important implications for understanding the genetic and phenotypic structure of extant populations. While intensely debated, the primary hypotheses focus on either a single dispersal or multiple dispersals out of the continent. Here, we use the human fossil record from Africa and the Levant, as well as an exceptionally large dataset of Holocene human crania sampled from Asia, to model ancestor-descendant relationships along hypothetical dispersal routes. We test the spatial and temporal predictions of competing out-of-Africa models by assessing the correlation of geographical distances between populations and measures of population differentiation derived from quantitative cranial phenotype data. Our results support a model in which extant Australo-Melanesians are descendants of an initial dispersal out of Africa by early anatomically modern humans, while all other populations are descendants of a later migration wave. Our results have implications for understanding the complexity of modern human origins and diversity.

  18. Inverse Kinematic Analysis of Human Hand Thumb Model

    Science.gov (United States)

    Toth-Tascau, Mirela; Pater, Flavius; Stoia, Dan Ioan; Menyhardt, Karoly; Rosu, Serban; Rusu, Lucian; Vigaru, Cosmina

    2011-09-01

    This paper deals with a kinematic model of the thumb of the human hand. The proposed model has 3 degrees of freedom being able to model the movements of the thumb tip with respect to the wrist joint centre. The kinematic equations are derived based on Denavit-Hartenberg Convention and solved in both direct and inverse way. Inverse kinematic analysis of human hand thumb model reveals multiple and connected solutions which are characteristic to nonlinear systems when the number of equations is greater than number of unknowns and correspond to natural movements of the finger.

  19. Human casualties in earthquakes: modelling and mitigation

    Science.gov (United States)

    Spence, R.J.S.; So, E.K.M.

    2011-01-01

    Earthquake risk modelling is needed for the planning of post-event emergency operations, for the development of insurance schemes, for the planning of mitigation measures in the existing building stock, and for the development of appropriate building regulations; in all of these applications estimates of casualty numbers are essential. But there are many questions about casualty estimation which are still poorly understood. These questions relate to the causes and nature of the injuries and deaths, and the extent to which they can be quantified. This paper looks at the evidence on these questions from recent studies. It then reviews casualty estimation models available, and finally compares the performance of some casualty models in making rapid post-event casualty estimates in recent earthquakes.

  20. Principle Generalized Net Model of a Human Stress Reaction

    Directory of Open Access Journals (Sweden)

    Anthony Shannon

    2008-04-01

    Full Text Available The present study was aimed at investigating the mechanism of a human stress reaction by means of Generalized Nets (GNs. A principle GN-model of the main structures, organs and systems of the human body taking part in the acute and chronic reaction of the organism to a stress stimulus is generated. A possible application of the GN-model of the human stress reaction for testing the effect of known or newly synthesized pharmacological products as well as of food supplements is discussed.

  1. Dynamic inverse models in human-cyber-physical systems

    Science.gov (United States)

    Robinson, Ryan M.; Scobee, Dexter R. R.; Burden, Samuel A.; Sastry, S. Shankar

    2016-05-01

    Human interaction with the physical world is increasingly mediated by automation. This interaction is characterized by dynamic coupling between robotic (i.e. cyber) and neuromechanical (i.e. human) decision-making agents. Guaranteeing performance of such human-cyber-physical systems will require predictive mathematical models of this dynamic coupling. Toward this end, we propose a rapprochement between robotics and neuromechanics premised on the existence of internal forward and inverse models in the human agent. We hypothesize that, in tele-robotic applications of interest, a human operator learns to invert automation dynamics, directly translating from desired task to required control input. By formulating the model inversion problem in the context of a tracking task for a nonlinear control system in control-a_ne form, we derive criteria for exponential tracking and show that the resulting dynamic inverse model generally renders a portion of the physical system state (i.e., the internal dynamics) unobservable from the human operator's perspective. Under stability conditions, we show that the human can achieve exponential tracking without formulating an estimate of the system's state so long as they possess an accurate model of the system's dynamics. These theoretical results are illustrated using a planar quadrotor example. We then demonstrate that the automation can intervene to improve performance of the tracking task by solving an optimal control problem. Performance is guaranteed to improve under the assumption that the human learns and inverts the dynamic model of the altered system. We conclude with a discussion of practical limitations that may hinder exact dynamic model inversion.

  2. Human visual performance model for crewstation design

    Science.gov (United States)

    Larimer, James; Prevost, Michael; Arditi, Aries; Azueta, Steven; Bergen, James; Lubin, Jeffrey

    1991-01-01

    An account is given of a Visibility Modeling Tool (VMT) which furnishes a crew-station designer with the means to assess configurational tradeoffs, with a view to the impact of various options on the unambiguous access of information to the pilot. The interactive interface of the VMT allows the manipulation of cockpit geometry, ambient lighting, pilot ergonomics, and the displayed symbology. Performance data can be displayed in the form of 3D contours into the crewstation graphic model, thereby yielding an indication of the operator's visual capabilities.

  3. Companion animals symposium: humanized animal models of the microbiome.

    Science.gov (United States)

    Gootenberg, D B; Turnbaugh, P J

    2011-05-01

    Humans and other mammals are colonized by trillions of microorganisms, most of which reside in the gastrointestinal tract, that provide key metabolic capabilities, such as the biosynthesis of vitamins and AA, the degradation of dietary plant polysaccharides, and the metabolism of orally administered therapeutics. Although much progress has been made by studying the human microbiome directly, comparing the human microbiome with that of other animals, and constructing in vitro models of the human gut, there remains a need to develop in vivo models where host, microbial, and environmental parameters can be manipulated. Here, we discuss some of the initial results from a promising method that enables the direct manipulation of microbial community structure, environmental exposures, host genotype, and other factors: the colonization of germ-free animals with complex microbial communities, including those from humans or other animal donors. Analyses of these resulting "humanized" gut microbiomes have begun to reveal 1) that key microbial activities can be transferred from the donor to the recipient animal (e.g., microbial reduction of cholesterol and production of equol), 2) that dietary shifts can affect the composition, gene abundance, and gene expression of the gut microbiome, 3) the succession of the microbial community in infants and ex-germ-free adult animals, and 4) the biogeography of these microbes across the length of gastrointestinal tract. Continued studies of humanized and other intentionally colonized animal models stand to provide new insight into not only the human microbiome, but also the microbiomes of our animal companions.

  4. Evaluation of human thorax FE model in various impact scenarios

    Directory of Open Access Journals (Sweden)

    Jansová M.

    2015-06-01

    Full Text Available The study focused on the validation of the 50th percentile male model — a detailed FE model of the thoracic segment of the human body developed within project Development of a Finite Element Model of the Human Thorax and Upper Extremities (THOMO co-funded by the European Commission (7th Framework Programme. The model response was tested in three impact scenarios: frontal, lateral and oblique. The resulting impactor contact force vs. time and chest deflection vs. time responses were compared with experimental results. The strain profile of the 5th rib was checked with lateral and oblique strain profiles from post-mortem human subject (PMHS experiments. The influence of heart and lungs on the mechanical response of the model was assessed and the material data configuration, giving the most biofidelic thorax behaviour, was identified.

  5. Complex human activities recognition using interval temporal syntactic model

    Institute of Scientific and Technical Information of China (English)

    夏利民; 韩芬; 王军

    2016-01-01

    A novel method based on interval temporal syntactic model was proposed to recognize human activities in video flow. The method is composed of two parts: feature extract and activities recognition. Trajectory shape descriptor, speeded up robust features (SURF) and histograms of optical flow (HOF) were proposed to represent human activities, which provide more exhaustive information to describe human activities on shape, structure and motion. In the process of recognition, a probabilistic latent semantic analysis model (PLSA) was used to recognize sample activities at the first step. Then, an interval temporal syntactic model, which combines the syntactic model with the interval algebra to model the temporal dependencies of activities explicitly, was introduced to recognize the complex activities with a time relationship. Experiments results show the effectiveness of the proposed method in comparison with other state-of-the-art methods on the public databases for the recognition of complex activities.

  6. Paralysis recovery in humans and model systems

    Science.gov (United States)

    Edgerton, V. Reggie; Roy, Roland R.

    2002-01-01

    Considerable evidence now demonstrates that extensive functional and anatomical reorganization following spinal cord injury occurs in centers of the brain that have some input into spinal motor pools. This is very encouraging, given the accumulating evidence that new connections formed across spinal lesions may not be initially functionally useful. The second area of advancement in the field of paralysis recovery is in the development of effective interventions to counter axonal growth inhibition. A third area of significant progress is the development of robotic devices to quantify the performance level of motor tasks following spinal cord injury and to 'teach' the spinal cord to step and stand. Advances are being made with robotic devices for mice, rats and humans.

  7. Vibration analysis with MADYMO human models

    NARCIS (Netherlands)

    Verver, M.M.; Hoof, J.F.A.M. van

    2002-01-01

    The importance of comfort for the automotive industry is increasing. Car manufacturers use comfort to distinguish their products from their competitors. However, the development and design of a new car seat or interior is very time consuming and expensive. The introduction of computer models of huma

  8. Modeling human disease using organotypic cultures

    DEFF Research Database (Denmark)

    Schweiger, Pawel J; Jensen, Kim B

    2016-01-01

    Reliable disease models are needed in order to improve quality of healthcare. This includes gaining better understanding of disease mechanisms, developing new therapeutic interventions and personalizing treatment. Up-to-date, the majority of our knowledge about disease states comes from in vivo...

  9. An experimental study of human birth models

    Science.gov (United States)

    Baumer, Alexa; Gossmann, Roseanna; Fauci, Lisa J.; Leftwich, Megan C.

    2016-11-01

    The laboring uterus is a complex and dynamic fluid system. Relatively little is known about the fluid properties in this system. However, the two primary fluids of interest, amniotic fluid and vernix caseosa, likely play integral roles in the force transferred to the fetus during the final stages of parturition. This investigation probes the role of fluid in the force transfer during delivery by considering physical models that determine the role of various components of the full system. The first experimental model represents the fetus passing through the birth canal as concentric cylinders with a fluid filled gap. The rigid, inner cylinder moves through the highly flexible outer cylinder at a prescribed velocity. The geometry of the inner cylinder is varied by aspect ratio and length. A total of five different inner geometries are used to fully investigate the parameter space. As the inner cylinder moves through the outer cylinder, strain measurements are taken. These measurements are converted to force measurements as a function of time and position in the outer cylinder. The results of these experiments are compared with numerical results to form a more complete picture of force transfer. This model can be used as the foundation for predicting the force needed to deliver a fetus in the final stages of parturition. Additionally, more complex models, that incorporate uterine contraction forces, are being developed.

  10. Modeling Human Aesthetic Perception of Visual Textures

    NARCIS (Netherlands)

    Thumfart, Stefan; Jacobs, Richard H. A. H.; Lughofer, Edwin; Eitzinger, Christian; Cornelissen, Frans W.; Groissboeck, Werner; Richter, Roland

    2011-01-01

    Texture is extensively used in areas such as product design and architecture to convey specific aesthetic information. Using the results of a psychological experiment, we model the relationship between computational texture features and aesthetic properties of visual textures. Contrary to previous a

  11. Animal model of human disease. Multiple myeloma

    NARCIS (Netherlands)

    Radl, J.; Croese, J.W.; Zurcher, C.; Enden-Vieveen, M.H.M. van den; Leeuw, A.M. de

    1988-01-01

    Animal models of spontaneous and induced plasmacytomas in some inbred strains of mice have proven to be useful tools for different studies on tumorigenesis and immunoregulation. Their wide applicability and the fact that after their intravenous transplantation, the recipient mice developed bone

  12. Modeling Human Aesthetic Perception of Visual Textures

    NARCIS (Netherlands)

    Thumfart, Stefan; Jacobs, Richard H. A. H.; Lughofer, Edwin; Eitzinger, Christian; Cornelissen, Frans W.; Groissboeck, Werner; Richter, Roland

    2011-01-01

    Texture is extensively used in areas such as product design and architecture to convey specific aesthetic information. Using the results of a psychological experiment, we model the relationship between computational texture features and aesthetic properties of visual textures. Contrary to previous

  13. A human experimental model of episodic pain

    DEFF Research Database (Denmark)

    Petrini, Laura; Hennings, Kristian; Li, Xi

    2014-01-01

    An experimental model of daily episodic pain was developed to investigate peripheral sensitization and cortical reorganization in healthy individuals. Two experiments (A and B) were conducted. Experiments A and B consisted of one and five consecutive days, respectively, in which the participants ...

  14. Lumped parametric model of the human ear for sound transmission.

    Science.gov (United States)

    Feng, Bin; Gan, Rong Z

    2004-09-01

    A lumped parametric model of the human auditoria peripherals consisting of six masses suspended with six springs and ten dashpots was proposed. This model will provide the quantitative basis for the construction of a physical model of the human middle ear. The lumped model parameters were first identified using published anatomical data, and then determined through a parameter optimization process. The transfer function of the middle ear obtained from human temporal bone experiments with laser Doppler interferometers was used for creating the target function during the optimization process. It was found that, among 14 spring and dashpot parameters, there were five parameters which had pronounced effects on the dynamic behaviors of the model. The detailed discussion on the sensitivity of those parameters was provided with appropriate applications for sound transmission in the ear. We expect that the methods for characterizing the lumped model of the human ear and the model parameters will be useful for theoretical modeling of the ear function and construction of the ear physical model.

  15. Modeling and remote sensing of human induced water cycle change

    Science.gov (United States)

    Pokhrel, Yadu N.

    2016-04-01

    The global water cycle has been profoundly affected by human land-water management especially during the last century. Since the changes in water cycle can affect the functioning of a wide range of biophysical and biogeochemical processes of the Earth system, it is essential to account for human land-water management in land surface models (LSMs) which are used for water resources assessment and to simulate the land surface hydrologic processes within Earth system models (ESMs). During the last two decades, noteworthy progress has been made in modeling human impacts on the water cycle but sufficient advancements have not yet been made, especially in representing human factors in large-scale LSMs toward integrating them into ESMs. In this study, an integrated modeling framework of continental-scale water cycle, with explicit representation of climate and human induced forces (e.g., irrigation, groundwater pumping) is developed and used to reconstruct the observed water cycle changes in the past and to attribute the observed changes to climatic and human factors. The new model builds upon two different previously developed models: a global LSM called the Human Impacts and GroundWater in the MATSIRO (HiGW-MAT) and a high-resolution regional groundwater model called the LEAF-Hydro-Flood. The model is used to retro-simulate the hydrologic stores and fluxes in close dialogue with in-situ and GRACE satellite based observations at a wide range of river basin scales around the world, with a particular focus on the changes in groundwater dynamics in northwest India, Pakistan, and the High Plains and Central Valley aquifers in the US.

  16. Human pluripotent stem cells: an emerging model in developmental biology.

    Science.gov (United States)

    Zhu, Zengrong; Huangfu, Danwei

    2013-02-01

    Developmental biology has long benefited from studies of classic model organisms. Recently, human pluripotent stem cells (hPSCs), including human embryonic stem cells and human induced pluripotent stem cells, have emerged as a new model system that offers unique advantages for developmental studies. Here, we discuss how studies of hPSCs can complement classic approaches using model organisms, and how hPSCs can be used to recapitulate aspects of human embryonic development 'in a dish'. We also summarize some of the recently developed genetic tools that greatly facilitate the interrogation of gene function during hPSC differentiation. With the development of high-throughput screening technologies, hPSCs have the potential to revolutionize gene discovery in mammalian development.

  17. Modeling Human Blockers in Millimeter Wave Radio Links

    Institute of Scientific and Technical Information of China (English)

    Jonathan S. Lu; Daniel Steinbach; Patrick Cabrol; Philip Pietraski

    2012-01-01

    In this paper, we investigate the loss caused by multiple humans blocking millimeter wave frequencies. We model human blockers as absorbing screens of infinite height with two knife-edges, We take a physical optics approach to computing the diffraction around the absorbing screens, This approach differs to the geometric optics approach described in much of the literature. The blocking model is validated by measuring the gain from multiple-human blocking configurations on an indoor link. The blocking gains predicted using Piazzi ' s numerical integration method (a physical optics method) agree well with measurements taken from approximately 2.7 dB to -50 dB. Thereofre, this model is suitable for real human blockers, The mean prediction error for the method is approximately -1.2 dB, and the standard deviation is approximately 5 dB.

  18. A novel polar-based human face recognition computational model

    Directory of Open Access Journals (Sweden)

    Y. Zana

    2009-07-01

    Full Text Available Motivated by a recently proposed biologically inspired face recognition approach, we investigated the relation between human behavior and a computational model based on Fourier-Bessel (FB spatial patterns. We measured human recognition performance of FB filtered face images using an 8-alternative forced-choice method. Test stimuli were generated by converting the images from the spatial to the FB domain, filtering the resulting coefficients with a band-pass filter, and finally taking the inverse FB transformation of the filtered coefficients. The performance of the computational models was tested using a simulation of the psychophysical experiment. In the FB model, face images were first filtered by simulated V1- type neurons and later analyzed globally for their content of FB components. In general, there was a higher human contrast sensitivity to radially than to angularly filtered images, but both functions peaked at the 11.3-16 frequency interval. The FB-based model presented similar behavior with regard to peak position and relative sensitivity, but had a wider frequency band width and a narrower response range. The response pattern of two alternative models, based on local FB analysis and on raw luminance, strongly diverged from the human behavior patterns. These results suggest that human performance can be constrained by the type of information conveyed by polar patterns, and consequently that humans might use FB-like spatial patterns in face processing.

  19. Generation and use of human 3D-CAD models

    Science.gov (United States)

    Grotepass, Juergen; Speyer, Hartmut; Kaiser, Ralf

    2002-05-01

    Individualized Products are one of the ten mega trends of the 21st Century with human modeling as the key issue for tomorrow's design and product development. The use of human modeling software for computer based ergonomic simulations within the production process increases quality while reducing costs by 30- 50 percent and shortening production time. This presentation focuses on the use of human 3D-CAD models for both, the ergonomic design of working environments and made to measure garment production. Today, the entire production chain can be designed, individualized models generated and analyzed in 3D computer environments. Anthropometric design for ergonomics is matched to human needs, thus preserving health. Ergonomic simulation includes topics as human vision, reachability, kinematics, force and comfort analysis and international design capabilities. In German more than 17 billions of Mark are moved to other industries, because clothes do not fit. Individual clothing tailored to the customer's preference means surplus value, pleasure and perfect fit. The body scanning technology is the key to generation and use of human 3D-CAD models for both, the ergonomic design of working environments and made to measure garment production.

  20. Modeling aspects of human memory for scientific study.

    Energy Technology Data Exchange (ETDEWEB)

    Caudell, Thomas P. (University of New Mexico); Watson, Patrick (University of Illinois - Champaign-Urbana Beckman Institute); McDaniel, Mark A. (Washington University); Eichenbaum, Howard B. (Boston University); Cohen, Neal J. (University of Illinois - Champaign-Urbana Beckman Institute); Vineyard, Craig Michael; Taylor, Shawn Ellis; Bernard, Michael Lewis; Morrow, James Dan; Verzi, Stephen J.

    2009-10-01

    Working with leading experts in the field of cognitive neuroscience and computational intelligence, SNL has developed a computational architecture that represents neurocognitive mechanisms associated with how humans remember experiences in their past. The architecture represents how knowledge is organized and updated through information from individual experiences (episodes) via the cortical-hippocampal declarative memory system. We compared the simulated behavioral characteristics with those of humans measured under well established experimental standards, controlling for unmodeled aspects of human processing, such as perception. We used this knowledge to create robust simulations of & human memory behaviors that should help move the scientific community closer to understanding how humans remember information. These behaviors were experimentally validated against actual human subjects, which was published. An important outcome of the validation process will be the joining of specific experimental testing procedures from the field of neuroscience with computational representations from the field of cognitive modeling and simulation.

  1. 3D virtual human rapid modeling method based on top-down modeling mechanism

    Directory of Open Access Journals (Sweden)

    LI Taotao

    2017-01-01

    Full Text Available Aiming to satisfy the vast custom-made character demand of 3D virtual human and the rapid modeling in the field of 3D virtual reality, a new virtual human top-down rapid modeling method is put for-ward in this paper based on the systematic analysis of the current situation and shortage of the virtual hu-man modeling technology. After the top-level realization of virtual human hierarchical structure frame de-sign, modular expression of the virtual human and parameter design for each module is achieved gradu-al-level downwards. While the relationship of connectors and mapping restraints among different modules is established, the definition of the size and texture parameter is also completed. Standardized process is meanwhile produced to support and adapt the virtual human top-down rapid modeling practice operation. Finally, the modeling application, which takes a Chinese captain character as an example, is carried out to validate the virtual human rapid modeling method based on top-down modeling mechanism. The result demonstrates high modelling efficiency and provides one new concept for 3D virtual human geometric mod-eling and texture modeling.

  2. Interactive Modelling and Simulation of Human Motion

    DEFF Research Database (Denmark)

    Engell-Nørregård, Morten Pol

    Dansk resumé Denne ph.d.-afhandling beskæftiger sig med modellering og simulation af menneskelig bevægelse. Emnerne i denne afhandling har mindst to ting til fælles. For det første beskæftiger de sig med menneskelig bevægelse. Selv om de udviklede modeller også kan benyttes til andre ting,er det ....... Endvidere kan den anvendes med enhver softbody simuleringsmodel som finite elements eller mass spring systemer. • En kontrol metode til deformerbare legemer baseret på rum tids opti- mering. fremgangsmåden kan anvendes til at styre sammentrækning af muskler i en muskel simulering....

  3. Plant Modeling for Human Supervisory Control

    DEFF Research Database (Denmark)

    Lind, Morten

    1999-01-01

    This paper provides an overview of multilevel flow modelling (MFM) and its application for design of displays for the supervisory control of industrial plant. The problem of designing the inforrrzatian content of sacpervisory displays is discussed and plant representations like MFM using levels...... is also provided by an analysis of the relations between levels of abstraction. It is also described how MFM supparts reazsonin about control actions by defining levels of intervention and by modal distinctions between function enablement and initiation....

  4. Non-rotational aspherical models of the human optical system

    Science.gov (United States)

    Giovanzana, S.; Kasprzak, H. T.; Pałucki, B.; Ţălu, Ş.

    2013-12-01

    The aim of this work was to define three-dimensional (3D) non-rotational aspherical parametric models for the human cornea and lens using computational geometry and CAD representations. The hyperbolic cosine based function is used for the cornea and a parametric model is used for lens modeling. Data analysis and visualization of 3D non-rotational models were made using the Rhinoceros CAD software and MATLAB software was used for numeric computation. We combined, implemented, and evaluated these models with a 3D ray-tracing in order to fully analyze the human eye model. It was found that 3D non-rotational aspherical models for the human eye could be more accurately modeled and rendered for analysis with finite element method. The objective of this study is to present and analyze mathematical models of the cornea and lens and to highlight the potential of optical applications of the eye models containing astigmatic surfaces, which are more close to the real eye than spherosymmetric eye models.

  5. Interactive Modelling and Simulation of Human Motion

    DEFF Research Database (Denmark)

    Engell-Nørregård, Morten Pol

    Dansk resumé Denne ph.d.-afhandling beskæftiger sig med modellering og simulation af menneskelig bevægelse. Emnerne i denne afhandling har mindst to ting til fælles. For det første beskæftiger de sig med menneskelig bevægelse. Selv om de udviklede modeller også kan benyttes til andre ting,er det...... menneskers led, der udviser både ikke-konveksitet og flere frihedsgrader • En generel og alsidig model for aktivering af bløde legemer. Modellen kan anvendes som et animations værktøj, men er lige så velegnet til simulering af menneskelige muskler, da den opfylder de grundlæggende fysiske principper...... primære fokus på at modellere den menneskelige krop. For det andet, beskæftiger de sig alle med simulering som et redskab til at syntetisere bevægelse og dermed skabe animationer. Dette er en vigtigt pointe, da det betyder, at vi ikke kun skaber værktøjer til animatorer, som de kan bruge til at lave sjove...

  6. Meeting Human Reliability Requirements through Human Factors Design, Testing, and Modeling

    Energy Technology Data Exchange (ETDEWEB)

    R. L. Boring

    2007-06-01

    In the design of novel systems, it is important for the human factors engineer to work in parallel with the human reliability analyst to arrive at the safest achievable design that meets design team safety goals and certification or regulatory requirements. This paper introduces the System Development Safety Triptych, a checklist of considerations for the interplay of human factors and human reliability through design, testing, and modeling in product development. This paper also explores three phases of safe system development, corresponding to the conception, design, and implementation of a system.

  7. Humanized Mouse Model of Ebola Virus Disease Mimics the Immune Responses in Human Disease.

    Science.gov (United States)

    Bird, Brian H; Spengler, Jessica R; Chakrabarti, Ayan K; Khristova, Marina L; Sealy, Tara K; Coleman-McCray, JoAnn D; Martin, Brock E; Dodd, Kimberly A; Goldsmith, Cynthia S; Sanders, Jeanine; Zaki, Sherif R; Nichol, Stuart T; Spiropoulou, Christina F

    2016-03-01

    Animal models recapitulating human Ebola virus disease (EVD) are critical for insights into virus pathogenesis. Ebola virus (EBOV) isolates derived directly from human specimens do not, without adaptation, cause disease in immunocompetent adult rodents. Here, we describe EVD in mice engrafted with human immune cells (hu-BLT). hu-BLT mice developed EVD following wild-type EBOV infection. Infection with high-dose EBOV resulted in rapid, lethal EVD with high viral loads, alterations in key human antiviral immune cytokines and chemokines, and severe histopathologic findings similar to those shown in the limited human postmortem data available. A dose- and donor-dependent clinical course was observed in hu-BLT mice infected with lower doses of either Mayinga (1976) or Makona (2014) isolates derived from human EBOV cases. Engraftment of the human cellular immune system appeared to be essential for the observed virulence, as nonengrafted mice did not support productive EBOV replication or develop lethal disease. hu-BLT mice offer a unique model for investigating the human immune response in EVD and an alternative animal model for EVD pathogenesis studies and therapeutic screening.

  8. Tissue-engineered models of human tumors for cancer research

    Science.gov (United States)

    Villasante, Aranzazu; Vunjak-Novakovic, Gordana

    2015-01-01

    Introduction Drug toxicity often goes undetected until clinical trials, which are the most costly and dangerous phase of drug development. Both the cultures of human cells and animal studies have limitations that cannot be overcome by incremental improvements in drug-testing protocols. A new generation of bioengineered tumors is now emerging in response to these limitations, with potential to transform drug screening by providing predictive models of tumors within their tissue context, for studies of drug safety and efficacy. An area that could greatly benefit from these models is cancer research. Areas covered In this review, the authors first describe the engineered tumor systems, using Ewing's sarcoma as an example of human tumor that cannot be predictably studied in cell culture and animal models. Then, they discuss the importance of the tissue context for cancer progression and outline the biomimetic principles for engineering human tumors. Finally, they discuss the utility of bioengineered tumor models for cancer research and address the challenges in modeling human tumors for use in drug discovery and testing. Expert opinion While tissue models are just emerging as a new tool for cancer drug discovery, they are already demonstrating potential for recapitulating, in vitro, the native behavior of human tumors. Still, numerous challenges need to be addressed before we can have platforms with a predictive power appropriate for the pharmaceutical industry. Some of the key needs include the incorporation of the vascular compartment, immune system components, and mechanical signals that regulate tumor development and function. PMID:25662589

  9. Numerical human model for impact and seating comfort

    NARCIS (Netherlands)

    Hoof, J.F.A.M. van; Lange, R. de; Verver, M.M.

    2003-01-01

    This paper presents a detailed numerical model of the human body that can be used to evaluate both safety and comfort aspects of vehicle interiors. The model is based on a combination of rigid body and finite element techniques to provide an optimal combination of computational efficiency and accura

  10. Child human model development: a hybrid validation approach

    NARCIS (Netherlands)

    Forbes, P.A.; Rooij, L. van; Rodarius, C.; Crandall, J.

    2008-01-01

    The current study presents a development and validation approach of a child human body model that will help understand child impact injuries and improve the biofidelity of child anthropometric test devices. Due to the lack of fundamental child biomechanical data needed to fully develop such models a

  11. A Monte Carlo Solution of the Human Ballistic Mortality Model

    Science.gov (United States)

    1978-08-01

    to obtain a damage D for thetotal wound. This addition law is averaged over the total soldier W.B. Beverly, "A Human Balistic Mortalitj Model," to be...January 1970. 𔃽 C.A. Stanley and K. Brown. "A Coniputer Man Anatomica l ModeL ," Balistic Research Laboratory Report ARBL T No. 02080, May 1978

  12. Human strategic reasoning in dynamic games: Experiments, logics, cognitive models

    NARCIS (Netherlands)

    Ghosh, Sujata; Halder, Tamoghna; Sharma, Khyati; Verbrugge, Rineke

    2015-01-01

    © Springer-Verlag Berlin Heidelberg 2015.This article provides a three-way interaction between experiments, logic and cognitive modelling so as to bring out a shared perspective among these diverse areas, aiming towards better understanding and better modelling of human strategic reasoning in

  13. Child human model development: a hybrid validation approach

    NARCIS (Netherlands)

    Forbes, P.A.; Rooij, L. van; Rodarius, C.; Crandall, J.

    2008-01-01

    The current study presents a development and validation approach of a child human body model that will help understand child impact injuries and improve the biofidelity of child anthropometric test devices. Due to the lack of fundamental child biomechanical data needed to fully develop such models a

  14. Growth Modeling of Human Mandibles using Non-Euclidean Metrics

    DEFF Research Database (Denmark)

    Hilger, Klaus Baggesen; Larsen, Rasmus; Wrobel, Mark

    2003-01-01

    From a set of 31 three-dimensional CT scans we model the temporal shape and size of the human mandible. Each anatomical structure is represented using 14851 semi-landmarks, and mapped into Procrustes tangent space. Exploratory subspace analyses are performed leading to linear models of mandible s...

  15. The Various Roles of Animal Models in Understanding Human Development

    Science.gov (United States)

    Gottlieb, Gilbert; Lickliter, Robert

    2004-01-01

    In this article, the authors take a very conservative view of the contribution of animal models to an understanding of human development. We do not think that homologies can be readily documented with even our most closely related relatives' behavior and psychological functioning. The major contribution of animal models is their provision of food…

  16. Numerical human model for impact and seating comfort

    NARCIS (Netherlands)

    Hoof, J.F.A.M. van; Lange, R. de; Verver, M.M.

    2003-01-01

    This paper presents a detailed numerical model of the human body that can be used to evaluate both safety and comfort aspects of vehicle interiors. The model is based on a combination of rigid body and finite element techniques to provide an optimal combination of computational efficiency and

  17. Human strategic reasoning in dynamic games: Experiments, logics, cognitive models

    NARCIS (Netherlands)

    Ghosh, Sujata; Halder, Tamoghna; Sharma, Khyati; Verbrugge, Rineke

    2015-01-01

    © Springer-Verlag Berlin Heidelberg 2015.This article provides a three-way interaction between experiments, logic and cognitive modelling so as to bring out a shared perspective among these diverse areas, aiming towards better understanding and better modelling of human strategic reasoning in dynami

  18. Quantitative Modeling of Human-Environment Interactions in Preindustrial Time

    Science.gov (United States)

    Sommer, Philipp S.; Kaplan, Jed O.

    2017-04-01

    Quantifying human-environment interactions and anthropogenic influences on the environment prior to the Industrial revolution is essential for understanding the current state of the earth system. This is particularly true for the terrestrial biosphere, but marine ecosystems and even climate were likely modified by human activities centuries to millennia ago. Direct observations are however very sparse in space and time, especially as one considers prehistory. Numerical models are therefore essential to produce a continuous picture of human-environment interactions in the past. Agent-based approaches, while widely applied to quantifying human influence on the environment in localized studies, are unsuitable for global spatial domains and Holocene timescales because of computational demands and large parameter uncertainty. Here we outline a new paradigm for the quantitative modeling of human-environment interactions in preindustrial time that is adapted to the global Holocene. Rather than attempting to simulate agency directly, the model is informed by a suite of characteristics describing those things about society that cannot be predicted on the basis of environment, e.g., diet, presence of agriculture, or range of animals exploited. These categorical data are combined with the properties of the physical environment in coupled human-environment model. The model is, at its core, a dynamic global vegetation model with a module for simulating crop growth that is adapted for preindustrial agriculture. This allows us to simulate yield and calories for feeding both humans and their domesticated animals. We couple this basic caloric availability with a simple demographic model to calculate potential population, and, constrained by labor requirements and land limitations, we create scenarios of land use and land cover on a moderate-resolution grid. We further implement a feedback loop where anthropogenic activities lead to changes in the properties of the physical

  19. A human lung xenograft mouse model of Nipah virus infection.

    Directory of Open Access Journals (Sweden)

    Gustavo Valbuena

    2014-04-01

    Full Text Available Nipah virus (NiV is a member of the genus Henipavirus (family Paramyxoviridae that causes severe and often lethal respiratory illness and encephalitis in humans with high mortality rates (up to 92%. NiV can cause Acute Lung Injury (ALI in humans, and human-to-human transmission has been observed in recent outbreaks of NiV. While the exact route of transmission to humans is not known, we have previously shown that NiV can efficiently infect human respiratory epithelial cells. The molecular mechanisms of NiV-associated ALI in the human respiratory tract are unknown. Thus, there is an urgent need for models of henipavirus infection of the human respiratory tract to study the pathogenesis and understand the host responses. Here, we describe a novel human lung xenograft model in mice to study the pathogenesis of NiV. Following transplantation, human fetal lung xenografts rapidly graft and develop mature structures of adult lungs including cartilage, vascular vessels, ciliated pseudostratified columnar epithelium, and primitive "air" spaces filled with mucus and lined by cuboidal to flat epithelium. Following infection, NiV grows to high titers (10(7 TCID50/gram lung tissue as early as 3 days post infection (pi. NiV targets both the endothelium as well as respiratory epithelium in the human lung tissues, and results in syncytia formation. NiV infection in the human lung results in the production of several cytokines and chemokines including IL-6, IP-10, eotaxin, G-CSF and GM-CSF on days 5 and 7 pi. In conclusion, this study demonstrates that NiV can replicate to high titers in a novel in vivo model of the human respiratory tract, resulting in a robust inflammatory response, which is known to be associated with ALI. This model will facilitate progress in the fundamental understanding of henipavirus pathogenesis and virus-host interactions; it will also provide biologically relevant models for other respiratory viruses.

  20. Combined Hand Gesture — Speech Model for Human Action Recognition

    Directory of Open Access Journals (Sweden)

    Sheng-Tzong Cheng

    2013-12-01

    Full Text Available This study proposes a dynamic hand gesture detection technology to effectively detect dynamic hand gesture areas, and a hand gesture recognition technology to improve the dynamic hand gesture recognition rate. Meanwhile, the corresponding relationship between state sequences in hand gesture and speech models is considered by integrating speech recognition technology with a multimodal model, thus improving the accuracy of human behavior recognition. The experimental results proved that the proposed method can effectively improve human behavior recognition accuracy and the feasibility of system applications. Experimental results verified that the multimodal gesture-speech model provided superior accuracy when compared to the single modal versions.

  1. Combined hand gesture--speech model for human action recognition.

    Science.gov (United States)

    Cheng, Sheng-Tzong; Hsu, Chih-Wei; Li, Jian-Pan

    2013-12-12

    This study proposes a dynamic hand gesture detection technology to effectively detect dynamic hand gesture areas, and a hand gesture recognition technology to improve the dynamic hand gesture recognition rate. Meanwhile, the corresponding relationship between state sequences in hand gesture and speech models is considered by integrating speech recognition technology with a multimodal model, thus improving the accuracy of human behavior recognition. The experimental results proved that the proposed method can effectively improve human behavior recognition accuracy and the feasibility of system applications. Experimental results verified that the multimodal gesture-speech model provided superior accuracy when compared to the single modal versions.

  2. MODELING ENERGY EXPENDITURE AND OXYGEN CONSUMPTION IN HUMAN EXPOSURE MODELS: ACCOUNTING FOR FATIGUE AND EPOC

    Science.gov (United States)

    Human exposure and dose models often require a quantification of oxygen consumption for a simulated individual. Oxygen consumption is dependent on the modeled Individual's physical activity level as described in an activity diary. Activity level is quantified via standardized val...

  3. MODELING ENERGY EXPENDITURE AND OXYGEN CONSUMPTION IN HUMAN EXPOSURE MODELS: ACCOUNTING FOR FATIGUE AND EPOC

    Science.gov (United States)

    Human exposure and dose models often require a quantification of oxygen consumption for a simulated individual. Oxygen consumption is dependent on the modeled Individual's physical activity level as described in an activity diary. Activity level is quantified via standardized val...

  4. Modelling human decision-making in coupled human and natural systems

    Science.gov (United States)

    Feola, G.

    2012-12-01

    A solid understanding of human decision-making is essential to analyze the complexity of coupled human and natural systems (CHANS) and inform policies to promote resilience in the face of environmental change. Human decisions drive and/or mediate the interactions and feedbacks, and contribute to the heterogeneity and non-linearity that characterize CHANS. However, human decision-making is usually over-simplistically modeled, whereby human agents are represented deterministically either as dumb or clairvoyant decision-makers. Decision-making models fall short in the integration of both environmental and human behavioral drivers, and concerning the latter, tend to focus on only one category, e.g. economic, cultural, or psychological. Furthermore, these models render a linear decision-making process and therefore fail to account for the recursive co-evolutionary dynamics in CHANS. As a result, these models constitute only a weak basis for policy-making. There is therefore scope and an urgent need for better approaches to human decision-making, to produce the knowledge that can inform vulnerability reduction policies in the face of environmental change. This presentation synthesizes the current state-of-the-art of modelling human decision-making in CHANS, with particular reference to agricultural systems, and delineates how the above mentioned shortcomings can be overcome. Through examples from research on pesticide use and adaptation to climate change, both based on the integrative agent-centered framework (Feola and Binder, 2010), the approach for an improved understanding of human agents in CHANS are illustrated. This entails: integrative approach, focus on behavioral dynamics more than states, feedbacks between individual and system levels, and openness to heterogeneity.

  5. Modeling and simulating human teamwork behaviors using intelligent agents

    Science.gov (United States)

    Fan, Xiaocong; Yen, John

    2004-12-01

    Among researchers in multi-agent systems there has been growing interest in using intelligent agents to model and simulate human teamwork behaviors. Teamwork modeling is important for training humans in gaining collaborative skills, for supporting humans in making critical decisions by proactively gathering, fusing, and sharing information, and for building coherent teams with both humans and agents working effectively on intelligence-intensive problems. Teamwork modeling is also challenging because the research has spanned diverse disciplines from business management to cognitive science, human discourse, and distributed artificial intelligence. This article presents an extensive, but not exhaustive, list of work in the field, where the taxonomy is organized along two main dimensions: team social structure and social behaviors. Along the dimension of social structure, we consider agent-only teams and mixed human-agent teams. Along the dimension of social behaviors, we consider collaborative behaviors, communicative behaviors, helping behaviors, and the underpinning of effective teamwork-shared mental models. The contribution of this article is that it presents an organizational framework for analyzing a variety of teamwork simulation systems and for further studying simulated teamwork behaviors.

  6. Modeling Human Glaucoma: Lessons from the in vitro Models.

    Science.gov (United States)

    Aires, Inês Dinis; Ambrósio, António Francisco; Santiago, Ana Raquel

    2017-01-01

    Glaucoma, a leading cause of blindness worldwide, is a degenerative disease characterized by retinal ganglion cell (RGC) loss and optic nerve atrophy. Elevated intraocular pressure (IOP) is a main risk factor for onset and progression of the disease. Since increased IOP is the only modifiable risk factor, relevant models for glaucoma would comprise RGC and optic nerve damage triggered by ocular hypertension. Animal models of glaucoma have greatly contributed to the understanding of the molecular mechanisms of this pathology, and they have also facilitated the development of new pharmacological interventions. Although animal models of glaucoma have provided valuable information about the disease, there is still no ideal model for studying glaucoma due to its complexity. There is a recognized demand for in vitro models that can replace or reduce the need for animal experiments. Several in vitro models have emerged as a great opportunity in the field of glaucoma research, helping to clarify the mechanisms involved in disease progression. Several types of equipment have been developed to expose cells and tissue cultures to elevated pressures. Herein, we discuss the methodology used to increase pressure, the main findings, and the relevance of in vitro models for the study of the pathophysiology of glaucoma.

  7. Study of Optical Models Regarding the Human Eye

    Directory of Open Access Journals (Sweden)

    Maryam Abolmasoomi

    2011-03-01

    Full Text Available Introduction: Until now, many models have been presented for optical study of the human eye. In recent years, surgery on the anterior section of the eye (such as cataract and photo-refractive surgery has increased, so a study on the optics of the eye and evaluation of vision quality has become more important. Material and Methods: In this article, some of these models are considered. They include models with spherical and conic-section surfaces (for cornea and lens, simple models and new models with complex surfaces. Results: Evaluation of the optical models of the eye provides the possibility of enhancing the representation of human vision and also increasing the accuracy of surgery on the anterior section of the eye to enable higher quality vision.

  8. Modeling Human Behavior to Anticipate Insider Attacks

    Energy Technology Data Exchange (ETDEWEB)

    Greitzer, Frank L.; Hohimer, Ryan E.

    2011-06-09

    The insider threat ranks among the most pressing cybersecurity challenges that threaten government and industry information infrastructures. To date, no systematic methods have been developed that provide a complete and effective approach to prevent data leakage, espionage and sabotage. Current practice is forensic in nature, relegating to the analyst the bulk of the responsibility to monitor, analyze, and correlate an overwhelming amount of data. We describe a predictive modeling framework that integrates a diverse set of data sources from the cyber domain as well as inferred psychological/motivational factors that may underlie malicious insider exploits. This comprehensive threat assessment approach provides automated support for the detection of high-risk behavioral “triggers” to help focus the analyst’s attention and inform the analysis. Designed to be domain independent, the system may be applied to many different threat and warning analysis/sensemaking problems.

  9. Modeling Human Behavior to Anticipate Insider Attacks

    Directory of Open Access Journals (Sweden)

    Ryan E Hohimer

    2011-01-01

    Full Text Available The insider threat ranks among the most pressing cyber-security challenges that threaten government and industry information infrastructures. To date, no systematic methods have been developed that provide a complete and effective approach to prevent data leakage, espionage, and sabotage. Current practice is forensic in nature, relegating to the analyst the bulk of the responsibility to monitor, analyze, and correlate an overwhelming amount of data. We describe a predictive modeling framework that integrates a diverse set of data sources from the cyber domain, as well as inferred psychological/motivational factors that may underlie malicious insider exploits. This comprehensive threat assessment approach provides automated support for the detection of high-risk behavioral "triggers" to help focus the analyst's attention and inform the analysis. Designed to be domain-independent, the system may be applied to many different threat and warning analysis/sense-making problems.

  10. An everlasting role of animal models in understanding human disease

    Institute of Scientific and Technical Information of China (English)

    Xiao Yang; Chonglin Yang

    2010-01-01

    Model organisms have been widely used to dissect important biological phenomena, as well as to explore potential causes and treatments for human disorders. Much of our knowledge on molecular mechanisms underlying the he?redity, development as well as physiology is largely derived from the researches of model organisms.We have witnessed an explosive increase in the development and application of genetic modified model organisms in the last decade.

  11. A human brainstem glioma xenograft model enabled for bioluminescence imaging

    OpenAIRE

    Hashizume, Rintaro; Ozawa, Tomoko; Dinca, Eduard B.; Banerjee, Anuradha; Prados, Michael D.; James, Charles D.; Gupta, Nalin

    2009-01-01

    Despite the use of radiation and chemotherapy, the prognosis for children with diffuse brainstem gliomas is extremely poor. There is a need for relevant brainstem tumor models that can be used to test new therapeutic agents and delivery systems in pre-clinical studies. We report the development of a brainstem-tumor model in rats and the application of bioluminescence imaging (BLI) for monitoring tumor growth and response to therapy as part of this model. Luciferase-modified human glioblastoma...

  12. DigitalHuman (DH): An Integrative Mathematical Model ofHuman Physiology

    Science.gov (United States)

    Hester, Robert L.; Summers, Richard L.; lIescu, Radu; Esters, Joyee; Coleman, Thomas G.

    2010-01-01

    Mathematical models and simulation are important tools in discovering the key causal relationships governing physiological processes and improving medical intervention when physiological complexity is a central issue. We have developed a model of integrative human physiology called DigitalHuman (DH) consisting of -5000 variables modeling human physiology describing cardiovascular, renal, respiratory, endocrine, neural and metabolic physiology. Users can view time-dependent solutions and interactively introduce perturbations by altering numerical parameters to investigate new hypotheses. The variables, parameters and quantitative relationships as well as all other model details are described in XML text files. All aspects of the model, including the mathematical equations describing the physiological processes are written in XML open source, text-readable files. Model structure is based upon empirical data of physiological responses documented within the peer-reviewed literature. The model can be used to understand proposed physiological mechanisms and physiological interactions that may not be otherwise intUitively evident. Some of the current uses of this model include the analyses of renal control of blood pressure, the central role of the liver in creating and maintaining insulin resistance, and the mechanisms causing orthostatic hypotension in astronauts. Additionally the open source aspect of the modeling environment allows any investigator to add detailed descriptions of human physiology to test new concepts. The model accurately predicts both qualitative and more importantly quantitative changes in clinically and experimentally observed responses. DigitalHuman provides scientists a modeling environment to understand the complex interactions of integrative physiology. This research was supported by.NIH HL 51971, NSF EPSCoR, and NASA

  13. The relevance of non-human primate and rodent malaria models for humans

    Directory of Open Access Journals (Sweden)

    Riley Eleanor

    2011-02-01

    Full Text Available Abstract At the 2010 Keystone Symposium on "Malaria: new approaches to understanding Host-Parasite interactions", an extra scientific session to discuss animal models in malaria research was convened at the request of participants. This was prompted by the concern of investigators that skepticism in the malaria community about the use and relevance of animal models, particularly rodent models of severe malaria, has impacted on funding decisions and publication of research using animal models. Several speakers took the opportunity to demonstrate the similarities between findings in rodent models and human severe disease, as well as points of difference. The variety of malaria presentations in the different experimental models parallels the wide diversity of human malaria disease and, therefore, might be viewed as a strength. Many of the key features of human malaria can be replicated in a variety of nonhuman primate models, which are very under-utilized. The importance of animal models in the discovery of new anti-malarial drugs was emphasized. The major conclusions of the session were that experimental and human studies should be more closely linked so that they inform each other, and that there should be wider access to relevant clinical material.

  14. Human Modeling Evaluations in Microgravity Workstation and Restraint Development

    Science.gov (United States)

    Whitmore, Mihriban; Chmielewski, Cynthia; Wheaton, Aneice; Hancock, Lorraine; Beierle, Jason; Bond, Robert L. (Technical Monitor)

    1999-01-01

    The International Space Station (ISS) will provide long-term missions which will enable the astronauts to live and work, as well as, conduct research in a microgravity environment. The dominant factor in space affecting the crew is "weightlessness" which creates a challenge for establishing workstation microgravity design requirements. The crewmembers will work at various workstations such as Human Research Facility (HRF), Microgravity Sciences Glovebox (MSG) and Life Sciences Glovebox (LSG). Since the crew will spend considerable amount of time at these workstations, it is critical that ergonomic design requirements are integral part of design and development effort. In order to achieve this goal, the Space Human Factors Laboratory in the Johnson Space Center Flight Crew Support Division has been tasked to conduct integrated evaluations of workstations and associated crew restraints. Thus, a two-phase approach was used: 1) ground and microgravity evaluations of the physical dimensions and layout of the workstation components, and 2) human modeling analyses of the user interface. Computer-based human modeling evaluations were an important part of the approach throughout the design and development process. Human modeling during the conceptual design phase included crew reach and accessibility of individual equipment, as well as, crew restraint needs. During later design phases, human modeling has been used in conjunction with ground reviews and microgravity evaluations of the mock-ups in order to verify the human factors requirements. (Specific examples will be discussed.) This two-phase approach was the most efficient method to determine ergonomic design characteristics for workstations and restraints. The real-time evaluations provided a hands-on implementation in a microgravity environment. On the other hand, only a limited number of participants could be tested. The human modeling evaluations provided a more detailed analysis of the setup. The issues identified

  15. Avian Models for Human Cognitive Neuroscience: A Proposal.

    Science.gov (United States)

    Clayton, Nicola S; Emery, Nathan J

    2015-06-17

    Research on avian cognitive neuroscience over the past two decades has revealed the avian brain to be a better model for understanding human cognition than previously thought, despite differences in the neuroarchitecture of avian and mammalian brains. The brain, behavior, and cognition of songbirds have provided an excellent model of human cognition in one domain, namely learning human language and the production of speech. There are other important behavioral candidates of avian cognition, however, notably the capacity of corvids to remember the past and plan for the future, as well as their ability to think about another's perspective, and physical reasoning. We review this work and assess the evidence that the corvid brain can support such a cognitive architecture. We propose potential applications of these behavioral paradigms for cognitive neuroscience, including recent work on single-cell recordings and neuroimaging in corvids. Finally, we discuss their impact on understanding human developmental cognition. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Non-Human Primate Models of Orthopoxvirus Infections

    Directory of Open Access Journals (Sweden)

    Anne Schmitt

    2014-06-01

    Full Text Available Smallpox, one of the most destructive diseases, has been successfully eradicated through a worldwide vaccination campaign. Since immunization programs have been stopped, the number of people with vaccinia virus induced immunity is declining. This leads to an increase in orthopoxvirus (OPXV infections in humans, as well as in animals. Additionally, potential abuse of Variola virus (VARV, the causative agent of smallpox, or monkeypox virus, as agents of bioterrorism, has renewed interest in development of antiviral therapeutics and of safer vaccines. Due to its high risk potential, research with VARV is restricted to two laboratories worldwide. Therefore, numerous animal models of other OPXV infections have been developed in the last decades. Non-human primates are especially suitable due to their close relationship to humans. This article provides a review about on non-human primate models of orthopoxvirus infections.

  17. Model-Based approaches to Human-Automation Systems Design

    DEFF Research Database (Denmark)

    Jamieson, Greg A.; Andersson, Jonas; Bisantz, Ann

    2012-01-01

    Human-automation interaction in complex systems is common, yet design for this interaction is often conducted without explicit consideration of the role of the human operator. Fortunately, there are a number of modeling frameworks proposed for supporting this design activity. However, the framewo......Human-automation interaction in complex systems is common, yet design for this interaction is often conducted without explicit consideration of the role of the human operator. Fortunately, there are a number of modeling frameworks proposed for supporting this design activity. However......, the frameworks are often adapted from other purposes, usually applied to a limited range of problems, sometimes not fully described in the open literature, and rarely critically reviewed in a manner acceptable to proponents and critics alike. The present paper introduces a panel session wherein these proponents...

  18. Impact injury prediction by FE human body model

    Directory of Open Access Journals (Sweden)

    Hynčík L.

    2008-12-01

    Full Text Available The biomechanical simulations as powerful instruments are used in many areas such as traffic, medicine, sport, army etc. The simulations are often performed with models, which are based on the Finite Element Method. The great ability of FE deformable models of human bodies is to predict the injuries during accidents. Due to its modular implementation of thorax and abdomen FE models, human articulated rigid body model ROBBY, which was previously developed at the University of West Bohemia in cooperation with ESI Group (Engineering Simulation for Industry, can be used for this purpose. ROBBY model representing average adult man is still being improved to obtain more precise model of human body with the possibility to predict injuries during accidents. Recently, new generated thoracic model was embedded into ROBBY model and this was subsequently satisfactorily validated. In this study the updated ROBBY model was used and injury of head and thorax were investigated during frontal crashes simulated by virtue of two types of sled tests with various types of restraint system (shoulder belt, lap belt and airbag. The results of the simulation were compared with the experimental ones.

  19. Are animal models relevant to key aspects of human parturition?

    Science.gov (United States)

    Mitchell, Bryan F; Taggart, Michael J

    2009-09-01

    Preterm birth remains the most serious complication of pregnancy and is associated with increased rates of infant death or permanent neurodevelopmental disability. Our understanding of the regulation of parturition remains inadequate. The scientific literature, largely derived from rodent animal models, suggests two major mechanisms regulating the timing of parturition: the withdrawal of the steroid hormone progesterone and a proinflammatory response by the immune system. However, available evidence strongly suggests that parturition in the human has significantly different regulators and mediators from those in most of the animal models. Our objectives are to critically review the data and concepts that have arisen from use of animal models for parturition and to rationalize the use of a new model. Many animal models have contributed to advances in our understanding of the regulation of parturition. However, we suggest that those animals dependent on progesterone withdrawal to initiate parturition clearly have a limitation to their translation to the human. In such models, a linear sequence of events (e.g., luteolysis, progesterone withdrawal, uterine activation, parturition) gives rise to the concept of a "trigger" mechanism. Conversely, we propose that human parturition may arise from the concomitant maturation of several systems in parallel. We have termed this novel concept "modular accumulation of physiological systems" (MAPS). We also emphasize the urgency to determine the precise role of the immune system in the process of parturition in situations other than intrauterine infection. Finally, we accentuate the need to develop a nonprimate animal model whose physiology is more relevant to human parturition. We suggest that the guinea pig displays several key physiological characteristics of gestation that more closely resemble human pregnancy than do currently favored animal models. We conclude that the application of novel concepts and new models are

  20. Knock-in human FGFR3 achondroplasia mutation as a mouse model for human skeletal dysplasia

    Science.gov (United States)

    Lee, Yi-Ching; Song, I-Wen; Pai, Ya-Ju; Chen, Sheng-De; Chen, Yuan-Tsong

    2017-01-01

    Achondroplasia (ACH), the most common genetic dwarfism in human, is caused by a gain-of function mutation in fibroblast growth factor receptor 3 (FGFR3). Currently, there is no effective treatment for ACH. The development of an appropriate human-relevant model is important for testing potential therapeutic interventions before human clinical trials. Here, we have generated an ACH mouse model in which the endogenous mouse Fgfr3 gene was replaced with human FGFR3G380R (FGFR3ACH) cDNA, the most common mutation in human ACH. Heterozygous (FGFR3ACH/+) and homozygous (FGFR3ACH/ACH) mice expressing human FGFR3G380R recapitulate the phenotypes observed in ACH patients, including growth retardation, disproportionate shortening of the limbs, round head, mid-face hypoplasia at birth, and kyphosis progression during postnatal development. We also observed premature fusion of the cranial sutures and low bone density in newborn FGFR3G380R mice. The severity of the disease phenotypes corresponds to the copy number of activated FGFR3G380R, and the phenotypes become more pronounced during postnatal skeletal development. This mouse model offers a tool for assessing potential therapeutic approaches for skeletal dysplasias related to over-activation of human FGFR3, and for further studies of the underlying molecular mechanisms. PMID:28230213

  1. Thermodynamic Modeling and Analysis of Human Stress Response

    Science.gov (United States)

    Boregowda, S. C.; Tiwari, S. N.

    1999-01-01

    A novel approach based on the second law of thermodynamics is developed to investigate the psychophysiology and quantify human stress level. Two types of stresses (thermal and mental) are examined. A Unified Stress Response Theory (USRT) is developed under the new proposed field of study called Engineering Psychophysiology. The USRT is used to investigate both thermal and mental stresses from a holistic (human body as a whole) and thermodynamic viewpoint. The original concepts and definitions are established as postulates which form the basis for thermodynamic approach to quantify human stress level. An Objective Thermal Stress Index (OTSI) is developed by applying the second law of thermodynamics to the human thermal system to quantify thermal stress or dis- comfort in the human body. The human thermal model based on finite element method is implemented. It is utilized as a "Computational Environmental Chamber" to conduct series of simulations to examine the human thermal stress responses under different environmental conditions. An innovative hybrid technique is developed to analyze human thermal behavior based on series of human-environment interaction simulations. Continuous monitoring of thermal stress is demonstrated with the help of OTSI. It is well established that the human thermal system obeys the second law of thermodynamics. Further, the OTSI is validated against the experimental data. Regarding mental stress, an Objective Mental Stress Index (OMSI) is developed by applying the Maxwell relations of thermodynamics to the combined thermal and cardiovascular system in the human body. The OMSI is utilized to demonstrate the technique of monitoring mental stress continuously and is validated with the help of series of experimental studies. Although the OMSI indicates the level of mental stress, it provides a strong thermodynamic and mathematical relationship between activities of thermal and cardiovascular systems of the human body.

  2. Human airway xenograft models of epithelial cell regeneration

    Directory of Open Access Journals (Sweden)

    Puchelle Edith

    2000-10-01

    Full Text Available Abstract Regeneration and restoration of the airway epithelium after mechanical, viral or bacterial injury have a determinant role in the evolution of numerous respiratory diseases such as chronic bronchitis, asthma and cystic fibrosis. The study in vivo of epithelial regeneration in animal models has shown that airway epithelial cells are able to dedifferentiate, spread, migrate over the denuded basement membrane and progressively redifferentiate to restore a functional respiratory epithelium after several weeks. Recently, human tracheal xenografts have been developed in immunodeficient severe combined immunodeficiency (SCID and nude mice. In this review we recall that human airway cells implanted in such conditioned host grafts can regenerate a well-differentiated and functional human epithelium; we stress the interest in these humanized mice in assaying candidate progenitor and stem cells of the human airway mucosa.

  3. [Living the birth process in a humanized assistance model].

    Science.gov (United States)

    da Silva, Larissa Mandarano; Barbieri, Márcia; Fustinoni, Suzete Maria

    2011-01-01

    That was a qualitative study with phenomenological approach that aimed at understanding women's post-partum experiences in a humanized assistance. Data were collected in a hospital from São Paulo, SP, Brazil. Eight women in post-partum period were interviewed. From data analysis two themes were extracted: Bearing the labor and Having the opportunity rescuing autonomy, being disclosed the phenomenon: "Living the ambiguity on the birth process in a humanized assistance model". The reports show feelings like pain, fear and anxiety, however, it allowed a participation and rescuing autonomy. Although the study have been realized in a humanized assistance, the women's experiences reveals that they are far from an effective humanization, according to its principles. This study can be used to guide educative actions target to humanization and to generate managerial changes.

  4. Integration of Lightning- and Human-Caused Wildfire Occurrence Models

    DEFF Research Database (Denmark)

    Vilar, Lara; Nieto Solana, Hector; Martín, M. Pilar

    2010-01-01

    Fire risk indices are useful tools for fire prevention actions by fire managers. A fire ignition is either the result of lightning or human activities. In European Mediterranean countries most forest fires are due to human activities. However, lightning is still an important fire ignition source...... in some regions. Integration of lightning and human fire occurrence probability into fire risk indices would be necessary to have a complete picture of the causal agents and their relative importance in fire occurrence. We present two methods for the integration of lightning and human fire occurrence...... probability models at 1 × 1 km grid cell resolution in two regions of Spain: Madrid, which presents a high fire incidence due to human activities; and Aragón, one of the most affected regions in Spain by lightning-fires. For validation, independent fire ignition points were used to compute the Receiver...

  5. Individualized Human CAD Models: Anthropmetric Morphing and Body Tissue Layering

    Science.gov (United States)

    2014-07-31

    torso sub-assembly may have more fat in the abdomen than in the chest. A study 18 that could help refine this feature is being developed by the US...responses to various ensembles being developed, taking 3 into account human characteristics (height, weight, body fat , etc.), physical activity levels...model of the human body in a CAD (Computer- Aided Design) format which includes both surface features as well as internal composition, e.g., the fat

  6. Modeling Human Visual Perception for Target Detection in Military Simulations

    Science.gov (United States)

    2009-06-01

    Human Visual Perception, Visual Attention, Eye Movements, Eye Tracking , Human Behavior Modeling, Target Detection, Visual Search, Semantic Relevance...pertaining my eye - tracking experiment, and also for understand- ing that I considered their eye-tracker to be mine, Tim Chung for the excellent...is through the target, and top-down processing is solely engaged through pre-specifying the target features. Eye - tracking data captured in previous

  7. Modeling Human Graft-Versus-Host Disease in Immunocompromised Mice.

    Science.gov (United States)

    Norelli, Margherita; Camisa, Barbara; Bondanza, Attilio

    2016-01-01

    Hematopoietic stem cell transplantation (HSCT) from an allogeneic donor is an effective form of cancer immunotherapy, especially for acute leukemias. HSCT is however frequently complicated by the occurrence of graft-versus-host disease (GVHD). Immunocompromised mice infused with human T cells often develop a clinical syndrome resembling human GVHD (xenogeneic or X-GVHD). Herein, we describe a method for inducing X-GVHD in a highly reproducible manner. Given the human nature of immune effectors, this xenogeneic model can be routinely adopted for screening the efficacy of new treatments for GVHD.

  8. [Human resources for health in Ecuador's new model of care].

    Science.gov (United States)

    Espinosa, Verónica; de la Torre, Daniel; Acuña, Cecilia; Cadena, Cristina

    2017-06-08

    Describe strategies implemented by Ecuador's Ministry of Public Health (MPH) to strengthen human resources for health leadership and respond to the new model of care, as a part of the reform process in the period 2012-2015. A documentary review was carried out of primary and secondary sources on development of human resources for health before and after the reform. In the study period, Ecuador developed a new institutional and regulatory framework for developing human resources for health to respond to the requirements of a model of care based on primary health care. The MPH consolidated its steering role by forging strategic partnerships, implementing human resources planning methods, and making an unprecedented investment in health worker training, hiring, and wage increases. These elements constitute the initial core for development of human resources for health policy and a health-services study program consistent with the reform's objectives. Within the framework of the reform carried out from 2012 to 2015, intersectoral work by the MPH has led to considerable achievements in development of human resources for health. Notable achievements include strengthening of the steering role, development and implementation of standards and regulatory instruments, creation of new professional profiles, and hiring of professionals to implement the comprehensive health care model, which helped to solve problems carried over from the years prior to the reform.

  9. Human performance modeling for system of systems analytics :soldier fatigue.

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, Craig R.; Campbell, James E.; Miller, Dwight Peter

    2005-10-01

    The military has identified Human Performance Modeling (HPM) as a significant requirement and challenge of future systems modeling and analysis initiatives as can be seen in the Department of Defense's (DoD) Defense Modeling and Simulation Office's (DMSO) Master Plan (DoD 5000.59-P 1995). To this goal, the military is currently spending millions of dollars on programs devoted to HPM in various military contexts. Examples include the Human Performance Modeling Integration (HPMI) program within the Air Force Research Laboratory, which focuses on integrating HPMs with constructive models of systems (e.g. cockpit simulations) and the Navy's Human Performance Center (HPC) established in September 2003. Nearly all of these initiatives focus on the interface between humans and a single system. This is insufficient in the era of highly complex network centric SoS. This report presents research and development in the area of HPM in a system-of-systems (SoS). Specifically, this report addresses modeling soldier fatigue and the potential impacts soldier fatigue can have on SoS performance.

  10. Large animal models of rare genetic disorders: sheep as phenotypically relevant models of human genetic disease.

    Science.gov (United States)

    Pinnapureddy, Ashish R; Stayner, Cherie; McEwan, John; Baddeley, Olivia; Forman, John; Eccles, Michael R

    2015-09-02

    Animals that accurately model human disease are invaluable in medical research, allowing a critical understanding of disease mechanisms, and the opportunity to evaluate the effect of therapeutic compounds in pre-clinical studies. Many types of animal models are used world-wide, with the most common being small laboratory animals, such as mice. However, rodents often do not faithfully replicate human disease, despite their predominant use in research. This discordancy is due in part to physiological differences, such as body size and longevity. In contrast, large animal models, including sheep, provide an alternative to mice for biomedical research due to their greater physiological parallels with humans. Completion of the full genome sequences of many species, and the advent of Next Generation Sequencing (NGS) technologies, means it is now feasible to screen large populations of domesticated animals for genetic variants that resemble human genetic diseases, and generate models that more accurately model rare human pathologies. In this review, we discuss the notion of using sheep as large animal models, and their advantages in modelling human genetic disease. We exemplify several existing naturally occurring ovine variants in genes that are orthologous to human disease genes, such as the Cln6 sheep model for Batten disease. These, and other sheep models, have contributed significantly to our understanding of the relevant human disease process, in addition to providing opportunities to trial new therapies in animals with similar body and organ size to humans. Therefore sheep are a significant species with respect to the modelling of rare genetic human disease, which we summarize in this review.

  11. Improving Saliency Models by Predicting Human Fixation Patches

    KAUST Repository

    Dubey, Rachit

    2015-04-16

    There is growing interest in studying the Human Visual System (HVS) to supplement and improve the performance of computer vision tasks. A major challenge for current visual saliency models is predicting saliency in cluttered scenes (i.e. high false positive rate). In this paper, we propose a fixation patch detector that predicts image patches that contain human fixations with high probability. Our proposed model detects sparse fixation patches with an accuracy of 84 % and eliminates non-fixation patches with an accuracy of 84 % demonstrating that low-level image features can indeed be used to short-list and identify human fixation patches. We then show how these detected fixation patches can be used as saliency priors for popular saliency models, thus, reducing false positives while maintaining true positives. Extensive experimental results show that our proposed approach allows state-of-the-art saliency methods to achieve better prediction performance on benchmark datasets.

  12. A ROBUST ADAPTIVE VIDEO ENCODER BASED ON HUMAN VISUAL MODEL

    Institute of Scientific and Technical Information of China (English)

    Yin Hao; Zhang Jiangshan; Zhu Yaoting; Zhu Guangxi

    2003-01-01

    A Robust Adaptive Video Encoder (RAVE) based on human visual model is proposed. The encoder combines the best features of Fine Granularity Scalable (FGS) coding, framedropping coding, video redundancy coding, and human visual model. According to packet loss and available bandwidth of the network, the encoder adjust the output bit rate by jointly adapting quantization step-size instructed by human visual model, rate shaping, and periodically inserting key frame. The proposed encoder is implemented based on MPEG-4 encoder and is compared with the case of a conventional FGS algorithm. It is shown that RAVE is a very efficient robust video encoder that provides improved visual quality for the receiver and consumes equal or less network resource. Results are confirmed by subjective tests and simulation tests.

  13. A ROBUST ADAPTIVE VIDEO ENCODER BASED ON HUMAN VISUAL MODEL

    Institute of Scientific and Technical Information of China (English)

    YinHao; ZhangJiangshan

    2003-01-01

    A Robust Adaptive Video Encoder (RAVE) based on human visual model is proposed.The encoder combines the best features of Fine Granularity Scalabla (FGS) coding,frame-dropping coding,video redundancy coding,and human visual model.According to packet loss and available bandwidth of the network,the encoder adjust the output bit rate by jointly adapting quantization step-size instructed by human visual model,rate shaping,and periodically inserting key frame.The proposed encoder is implemented based on MPEG-4 encoder and is compared with the case of a conventional FGS algorithm.It is shown that RAVE is a very efficient robust videl encoder that provides improved visual quality for the receiver and consumes equal or less network resource.Results are confirmed by subjective tests and simulation tests.

  14. Modeling for the Dynamics of Human Innovative Behaviors

    CERN Document Server

    Lin, Ying-Ting; Wang, Bing-Hong

    2013-01-01

    How to promote the innovative activities is an important problem for modern society. In this paper, combining with the evolutionary games and information spreading, we propose a lattice model to investigate dynamics of human innovative behaviors based on benefit-driven assumption. Simulations show several properties in agreement with peoples' daily cognition on innovative behaviors, such as slow diffusion of innovative behaviors, gathering of innovative strategy on "innovative centers", and quasi-localized dynamics. Furthermore, our model also emerges rich non-Poisson properties in the temporal-spacial patterns of the innovative status, including the scaling law in the interval time of innovation releases and the bimodal distributions on the spreading range of innovations, which would be universal in human innovative behaviors. Our model provide a basic framework on the study of the issue relevant to the evolution of human innovative behaviors and the promotion measurement of innovative activities.

  15. Modeling human dynamics of face-to-face interaction networks

    CERN Document Server

    Starnini, Michele; Pastor-Satorras, Romualdo

    2013-01-01

    Face-to-face interaction networks describe social interactions in human gatherings, and are the substrate for processes such as epidemic spreading and gossip propagation. The bursty nature of human behavior characterizes many aspects of empirical data, such as the distribution of conversation lengths, of conversations per person, or of inter-conversation times. Despite several recent attempts, a general theoretical understanding of the global picture emerging from data is still lacking. Here we present a simple model that reproduces quantitatively most of the relevant features of empirical face-to-face interaction networks. The model describes agents which perform a random walk in a two dimensional space and are characterized by an attractiveness whose effect is to slow down the motion of people around them. The proposed framework sheds light on the dynamics of human interactions and can improve the modeling of dynamical processes taking place on the ensuing dynamical social networks.

  16. Pre-clinical Orthotopic Murine Model of Human Prostate Cancer.

    Science.gov (United States)

    Shahryari, Varahram; Nip, Hannah; Saini, Sharanjot; Dar, Altaf A; Yamamura, Soichiro; Mitsui, Yozo; Colden, Melissa; Bucay, Nathan; Tabatabai, Laura Z; Greene, Kirsten; Deng, Guoren; Tanaka, Yuichiro; Dahiya, Rajvir; Majid, Shahana

    2016-08-29

    To study the multifaceted biology of prostate cancer, pre-clinical in vivo models offer a range of options to uncover critical biological information about this disease. The human orthotopic prostate cancer xenograft mouse model provides a useful alternative approach for understanding the specific interactions between genetically and molecularly altered tumor cells, their organ microenvironment, and for evaluation of efficacy of therapeutic regimens. This is a well characterized model designed to study the molecular events of primary tumor development and it recapitulates the early events in the metastatic cascade prior to embolism and entry of tumor cells into the circulation. Thus it allows elucidation of molecular mechanisms underlying the initial phase of metastatic disease. In addition, this model can annotate drug targets of clinical relevance and is a valuable tool to study prostate cancer progression. In this manuscript we describe a detailed procedure to establish a human orthotopic prostate cancer xenograft mouse model.

  17. A control-theory model for human decision-making

    Science.gov (United States)

    Levison, W. H.; Tanner, R. B.

    1971-01-01

    A model for human decision making is an adaptation of an optimal control model for pilot/vehicle systems. The models for decision and control both contain concepts of time delay, observation noise, optimal prediction, and optimal estimation. The decision making model was intended for situations in which the human bases his decision on his estimate of the state of a linear plant. Experiments are described for the following task situations: (a) single decision tasks, (b) two-decision tasks, and (c) simultaneous manual control and decision making. Using fixed values for model parameters, single-task and two-task decision performance can be predicted to within an accuracy of 10 percent. Agreement is less good for the simultaneous decision and control situation.

  18. A stochastic evolutionary model for capturing human dynamics

    CERN Document Server

    Fenner, Trevor; Loizou, George

    2015-01-01

    The recent interest in human dynamics has led researchers to investigate the stochastic processes that explain human behaviour in various contexts. Here we propose a generative model to capture the dynamics of survival analysis, traditionally employed in clinical trials and reliability analysis in engineering. We derive a general solution for the model in the form of a product, and then a continuous approximation to the solution via the renewal equation describing age-structured population dynamics. This enables us to model a wide rage of survival distributions, according to the choice of the mortality distribution. We provide empirical evidence for the validity of the model from a longitudinal data set of popular search engine queries over 114 months, showing that the survival function of these queries is closely matched by the solution for our model with power-law mortality.

  19. Simulation Models of Human Decision-Making Processes

    Directory of Open Access Journals (Sweden)

    Nina RIZUN

    2014-10-01

    Full Text Available The main purpose of the paper is presentation of the new concept of human decision-making process modeling via using the analogy with Automatic Control Theory. From the author's point of view this concept allows to develop and improve the theory of decision-making in terms of the study and classification of specificity of the human intellectual processes in different conditions. It was proved that the main distinguishing feature between the Heuristic / Intuitive and Rational Decision-Making Models is the presence of so-called phenomenon of "enrichment" of the input information with human propensity, hobbies, tendencies, expectations, axioms and judgments, presumptions or bias and their justification. In order to obtain additional knowledge about the basic intellectual processes as well as the possibility of modeling the decision results in various parameters characterizing the decision-maker, the complex of the simulation models was developed. These models are based on the assumptions that:  basic intellectual processes of the Rational Decision-Making Model can be adequately simulated and identified by the transient processes of the proportional-integral-derivative controller; basic intellectual processes of the Bounded Rationality and Intuitive Models can be adequately simulated and identified by the transient processes of the nonlinear elements.The taxonomy of the most typical automatic control theory elements and their compliance with certain decision-making models with a point of view of decision-making process specificity and decision-maker behavior during a certain time of professional activity was obtained.

  20. Geometric Modeling and Reasoning of Human-Centered Freeform Products

    CERN Document Server

    Wang, Charlie C L

    2013-01-01

    The recent trend in user-customized product design requires the shape of products to be automatically adjusted according to the human body’s shape, so that people will feel more comfortable when wearing these products.  Geometric approaches can be used to design the freeform shape of products worn by people, which can greatly improve the efficiency of design processes in various industries involving customized products (e.g., garment design, toy design, jewel design, shoe design, and design of medical devices, etc.). These products are usually composed of very complex geometric shapes (represented by free-form surfaces), and are not driven by a parameter table but a digital human model with free-form shapes or part of human bodies (e.g., wrist, foot, and head models).   Geometric Modeling and Reasoning of Human-Centered Freeform Products introduces the algorithms of human body reconstruction, freeform product modeling, constraining and reconstructing freeform products, and shape optimization for improving...

  1. Modeling human decision making behavior in supervisory control

    Science.gov (United States)

    Tulga, M. K.; Sheridan, T. B.

    1977-01-01

    An optimal decision control model was developed, which is based primarily on a dynamic programming algorithm which looks at all the available task possibilities, charts an optimal trajectory, and commits itself to do the first step (i.e., follow the optimal trajectory during the next time period), and then iterates the calculation. A Bayesian estimator was included which estimates the tasks which might occur in the immediate future and provides this information to the dynamic programming routine. Preliminary trials comparing the human subject's performance to that of the optimal model show a great similarity, but indicate that the human skips certain movements which require quick change in strategy.

  2. A Real-Time Model-Based Human Motion Tracking and Analysis for Human-Computer Interface Systems

    Directory of Open Access Journals (Sweden)

    Chung-Lin Huang

    2004-09-01

    Full Text Available This paper introduces a real-time model-based human motion tracking and analysis method for human computer interface (HCI. This method tracks and analyzes the human motion from two orthogonal views without using any markers. The motion parameters are estimated by pattern matching between the extracted human silhouette and the human model. First, the human silhouette is extracted and then the body definition parameters (BDPs can be obtained. Second, the body animation parameters (BAPs are estimated by a hierarchical tritree overlapping searching algorithm. To verify the performance of our method, we demonstrate different human posture sequences and use hidden Markov model (HMM for posture recognition testing.

  3. An Illumination Modeling System for Human Factors Analyses

    Science.gov (United States)

    Huynh, Thong; Maida, James C.; Bond, Robert L. (Technical Monitor)

    2002-01-01

    Seeing is critical to human performance. Lighting is critical for seeing. Therefore, lighting is critical to human performance. This is common sense, and here on earth, it is easily taken for granted. However, on orbit, because the sun will rise or set every 45 minutes on average, humans working in space must cope with extremely dynamic lighting conditions. Contrast conditions of harsh shadowing and glare is also severe. The prediction of lighting conditions for critical operations is essential. Crew training can factor lighting into the lesson plans when necessary. Mission planners can determine whether low-light video cameras are required or whether additional luminaires need to be flown. The optimization of the quantity and quality of light is needed because of the effects on crew safety, on electrical power and on equipment maintainability. To address all of these issues, an illumination modeling system has been developed by the Graphics Research and Analyses Facility (GRAF) and Lighting Environment Test Facility (LETF) in the Space Human Factors Laboratory at NASA Johnson Space Center. The system uses physically based ray tracing software (Radiance) developed at Lawrence Berkeley Laboratories, a human factors oriented geometric modeling system (PLAID) and an extensive database of humans and environments. Material reflectivity properties of major surfaces and critical surfaces are measured using a gonio-reflectometer. Luminaires (lights) are measured for beam spread distribution, color and intensity. Video camera performances are measured for color and light sensitivity. 3D geometric models of humans and the environment are combined with the material and light models to form a system capable of predicting lighting conditions and visibility conditions in space.

  4. Identifying and modeling the structural discontinuities of human interactions

    Science.gov (United States)

    Grauwin, Sebastian; Szell, Michael; Sobolevsky, Stanislav; Hövel, Philipp; Simini, Filippo; Vanhoof, Maarten; Smoreda, Zbigniew; Barabási, Albert-László; Ratti, Carlo

    2017-04-01

    The idea of a hierarchical spatial organization of society lies at the core of seminal theories in human geography that have strongly influenced our understanding of social organization. Along the same line, the recent availability of large-scale human mobility and communication data has offered novel quantitative insights hinting at a strong geographical confinement of human interactions within neighboring regions, extending to local levels within countries. However, models of human interaction largely ignore this effect. Here, we analyze several country-wide networks of telephone calls - both, mobile and landline - and in either case uncover a systematic decrease of communication induced by borders which we identify as the missing variable in state-of-the-art models. Using this empirical evidence, we propose an alternative modeling framework that naturally stylizes the damping effect of borders. We show that this new notion substantially improves the predictive power of widely used interaction models. This increases our ability to understand, model and predict social activities and to plan the development of infrastructures across multiple scales.

  5. Elucidation of xenobiotic metabolism pathways in human skin and human skin models by proteomic profiling.

    Directory of Open Access Journals (Sweden)

    Sven van Eijl

    Full Text Available BACKGROUND: Human skin has the capacity to metabolise foreign chemicals (xenobiotics, but knowledge of the various enzymes involved is incomplete. A broad-based unbiased proteomics approach was used to describe the profile of xenobiotic metabolising enzymes present in human skin and hence indicate principal routes of metabolism of xenobiotic compounds. Several in vitro models of human skin have been developed for the purpose of safety assessment of chemicals. The suitability of these epidermal models for studies involving biotransformation was assessed by comparing their profiles of xenobiotic metabolising enzymes with those of human skin. METHODOLOGY/PRINCIPAL FINDINGS: Label-free proteomic analysis of whole human skin (10 donors was applied and analysed using custom-built PROTSIFT software. The results showed the presence of enzymes with a capacity for the metabolism of alcohols through dehydrogenation, aldehydes through dehydrogenation and oxidation, amines through oxidation, carbonyls through reduction, epoxides and carboxylesters through hydrolysis and, of many compounds, by conjugation to glutathione. Whereas protein levels of these enzymes in skin were mostly just 4-10 fold lower than those in liver and sufficient to support metabolism, the levels of cytochrome P450 enzymes were at least 300-fold lower indicating they play no significant role. Four epidermal models of human skin had profiles very similar to one another and these overlapped substantially with that of whole skin. CONCLUSIONS/SIGNIFICANCE: The proteomics profiling approach was successful in producing a comprehensive analysis of the biotransformation characteristics of whole human skin and various in vitro skin models. The results show that skin contains a range of defined enzymes capable of metabolising different classes of chemicals. The degree of similarity of the profiles of the in vitro models indicates their suitability for epidermal toxicity testing. Overall, these

  6. A computational model for dynamic analysis of the human gait.

    Science.gov (United States)

    Vimieiro, Claysson; Andrada, Emanuel; Witte, Hartmut; Pinotti, Marcos

    2015-01-01

    Biomechanical models are important tools in the study of human motion. This work proposes a computational model to analyse the dynamics of lower limb motion using a kinematic chain to represent the body segments and rotational joints linked by viscoelastic elements. The model uses anthropometric parameters, ground reaction forces and joint Cardan angles from subjects to analyse lower limb motion during the gait. The model allows evaluating these data in each body plane. Six healthy subjects walked on a treadmill to record the kinematic and kinetic data. In addition, anthropometric parameters were recorded to construct the model. The viscoelastic parameter values were fitted for the model joints (hip, knee and ankle). The proposed model demonstrated that manipulating the viscoelastic parameters between the body segments could fit the amplitudes and frequencies of motion. The data collected in this work have viscoelastic parameter values that follow a normal distribution, indicating that these values are directly related to the gait pattern. To validate the model, we used the values of the joint angles to perform a comparison between the model results and previously published data. The model results show a same pattern and range of values found in the literature for the human gait motion.

  7. Coupling of the Models of Human Physiology and Thermal Comfort

    Science.gov (United States)

    Pokorny, J.; Jicha, M.

    2013-04-01

    A coupled model of human physiology and thermal comfort was developed in Dymola/Modelica. A coupling combines a modified Tanabe model of human physiology and thermal comfort model developed by Zhang. The Coupled model allows predicting the thermal sensation and comfort of both local and overall from local boundary conditions representing ambient and personal factors. The aim of this study was to compare prediction of the Coupled model with the Fiala model prediction and experimental data. Validation data were taken from the literature, mainly from the validation manual of software Theseus-FE [1]. In the paper validation of the model for very light physical activities (1 met) indoor environment with temperatures from 12 °C up to 48 °C is presented. The Coupled model predicts mean skin temperature for cold, neutral and warm environment well. However prediction of core temperature in cold environment is inaccurate and very affected by ambient temperature. Evaluation of thermal comfort in warm environment is supplemented by skin wettedness prediction. The Coupled model is designed for non-uniform and transient environmental conditions; it is also suitable simulation of thermal comfort in vehicles cabins. The usage of the model is limited for very light physical activities up to 1.2 met only.

  8. Development of a hydraulic model of the human systemic circulation

    Science.gov (United States)

    Sharp, M. K.; Dharmalingham, R. K.

    1999-01-01

    Physical and numeric models of the human circulation are constructed for a number of objectives, including studies and training in physiologic control, interpretation of clinical observations, and testing of prosthetic cardiovascular devices. For many of these purposes it is important to quantitatively validate the dynamic response of the models in terms of the input impedance (Z = oscillatory pressure/oscillatory flow). To address this need, the authors developed an improved physical model. Using a computer study, the authors first identified the configuration of lumped parameter elements in a model of the systemic circulation; the result was a good match with human aortic input impedance with a minimum number of elements. Design, construction, and testing of a hydraulic model analogous to the computer model followed. Numeric results showed that a three element model with two resistors and one compliance produced reasonable matching without undue complication. The subsequent analogous hydraulic model included adjustable resistors incorporating a sliding plate to vary the flow area through a porous material and an adjustable compliance consisting of a variable-volume air chamber. The response of the hydraulic model compared favorably with other circulation models.

  9. A biokinetic and dosimetric model for ionic indium in humans

    Science.gov (United States)

    Andersson, Martin; Mattsson, Sören; Johansson, Lennart; Leide-Svegborn, Sigrid

    2017-08-01

    This paper reviews biokinetic data for ionic indium, and proposes a biokinetic model for systemic indium in adult humans. The development of parameter values focuses on human data and indium in the form of ionic indium(III), as indium chloride and indium arsenide. The model presented for systemic indium is defined by five different pools: plasma, bone marrow, liver, kidneys and other soft tissues. The model is based on two subsystems: one corresponding to indium bound to transferrin and one where indium is transported back to the plasma, binds to red blood cell transferrin and is then excreted through the kidneys to the urinary bladder. Absorbed doses to several organs and the effective dose are calculated for 111In- and 113mIn-ions. The proposed biokinetic model is compared with previously published biokinetic indium models published by the ICRP. The absorbed doses are calculated using the ICRP/ICRU adult reference phantoms and the effective dose is estimated according to ICRP Publication 103. The effective doses for 111In and 113mIn are 0.25 mSv MBq-1 and 0.013 mSv MBq-1 respectively. The updated biokinetic and dosimetric models presented in this paper take into account human data and new animal data, which represent more detailed and presumably more accurate dosimetric data than that underlying previous models for indium.

  10. More-Realistic Digital Modeling of a Human Body

    Science.gov (United States)

    Rogge, Renee

    2010-01-01

    A MATLAB computer program has been written to enable improved (relative to an older program) modeling of a human body for purposes of designing space suits and other hardware with which an astronaut must interact. The older program implements a kinematic model based on traditional anthropometric measurements that do provide important volume and surface information. The present program generates a three-dimensional (3D) whole-body model from 3D body-scan data. The program utilizes thin-plate spline theory to reposition the model without need for additional scans.

  11. A computational model of human auditory signal processing and perception

    DEFF Research Database (Denmark)

    Jepsen, Morten Løve; Ewert, Stephan D.; Dau, Torsten

    2008-01-01

    A model of computational auditory signal-processing and perception that accounts for various aspects of simultaneous and nonsimultaneous masking in human listeners is presented. The model is based on the modulation filterbank model described by Dau et al. [J. Acoust. Soc. Am. 102, 2892 (1997......)] but includes major changes at the peripheral and more central stages of processing. The model contains outer- and middle-ear transformations, a nonlinear basilar-membrane processing stage, a hair-cell transduction stage, a squaring expansion, an adaptation stage, a 150-Hz lowpass modulation filter, a bandpass...

  12. Recent efforts to model human diseases in vivo in Drosophila.

    Science.gov (United States)

    Pfleger, Cathie M; Reiter, Lawrence T

    2008-01-01

    Upon completion of sequencing the Drosophila genome, it was estimated that 61% of human disease-associated genes had sequence homologs in flies, and in some diseases such as cancer, the number was as high as 68%. We now know that as many as 75% of the genes associated with genetic disease have counterparts in Drosophila. Using better tools for mutation detection, association studies and whole genome analysis the number of human genes associated with genetic disease is steadily increasing. These detection efforts are outpacing the ability to assign function and understand the underlying cause of the disease at the molecular level. Drosophila models can therefore advance human disease research in a number of ways by: establishing the normal role of these gene products during development, elucidating the mechanism underlying disease pathology, and even identifying candidate therapeutic agents for the treatment of human disease. At the 49(th) Annual Drosophila Research Conference in San Diego this year, a number of labs presented their exciting findings on Drosophila models of human disease in both platform presentations and poster sessions. Here we can only briefly review some of these developments, and we apologize that we do not have the time or space to review all of the findings presented which use Drosophila to understand human disease etiology.

  13. [Development of human embryonic stem cell model for toxicity evaluation].

    Science.gov (United States)

    Yu, Guang-yan; Cao, Tong; Ouyang, Hong-wei; Peng, Shuang-qing; Deng, Xu-liang; Li, Sheng-lin; Liu, He; Zou, Xiao-hui; Fu, Xin; Peng, Hui; Wang, Xiao-ying; Zhan, Yuan

    2013-02-18

    The current international standard for toxicity screening of biomedical devices and materials recommend the use of immortalized cell lines because of their homogeneous morphologies and infinite proliferation which provide good reproducibility for in vitro cytotoxicity screening. However, most of the widely used immortalized cell lines are derived from animals and may not be representative of normal human cell behavior in vivo, in particular in terms of the cytotoxic and genotoxic response. Therefore, It is vital to develop a model for toxicity evaluation. In our studies, two Chinese human embryonic stem cell (hESC) lines as toxicity model were established. hESC derived tissue/organ cell model for tissue/organ specific toxicity evaluation were developed. The efficiency and accuracy of using hESC model for cytoxicity, embryotoxicity and genotoxicity evaluation were confirmed. The results indicated that hESCs might be good tools for toxicity testing and biosafety evaluation in vitro.

  14. Animation of 3D Model of Human Head

    Directory of Open Access Journals (Sweden)

    V. Michalcin

    2007-04-01

    Full Text Available The paper deals with the new algorithm of animation of 3D model of the human head in combination with its global motion. The designed algorithm is very fast and with low calculation requirements, because it does not need the synthesis of the input videosequence for estimation of the animation parameters as well as the parameters of global motion. The used 3D model Candide generates different expressions using its animation units which are controlled by the animation parameters. These ones are estimated on the basis of optical flow without the need of extracting of the feature points in the frames of the input videosequence because they are given by the selected vertices of the animation units of the calibrated 3D model Candide. The established multiple iterations inside the designed animation algorithm of 3D model of the human head between two successive frames significantly improved its accuracy above all for the large motion.

  15. Sensitivity analysis techniques for models of human behavior.

    Energy Technology Data Exchange (ETDEWEB)

    Bier, Asmeret Brooke

    2010-09-01

    Human and social modeling has emerged as an important research area at Sandia National Laboratories due to its potential to improve national defense-related decision-making in the presence of uncertainty. To learn about which sensitivity analysis techniques are most suitable for models of human behavior, different promising methods were applied to an example model, tested, and compared. The example model simulates cognitive, behavioral, and social processes and interactions, and involves substantial nonlinearity, uncertainty, and variability. Results showed that some sensitivity analysis methods create similar results, and can thus be considered redundant. However, other methods, such as global methods that consider interactions between inputs, can generate insight not gained from traditional methods.

  16. Introducing Human APOE into Aβ Transgenic Mouse Models

    Directory of Open Access Journals (Sweden)

    Leon M. Tai

    2011-01-01

    Full Text Available Apolipoprotein E (apoE and apoE/amyloid-β (Aβ transgenic (Tg mouse models are critical to understanding apoE-isoform effects on Alzheimer's disease risk. Compared to wild type, apoE−/− mice exhibit neuronal deficits, similar to apoE4-Tg compared to apoE3-Tg mice, providing a model for Aβ-independent apoE effects on neurodegeneration. To determine the effects of apoE on Aβ-induced neuropathology, apoE−/− mice were crossed with Aβ-Tg mice, resulting in a significant delay in plaque deposition. Surprisingly, crossing human-apoE-Tg mice with apoE−/−/Aβ-Tg mice further delayed plaque deposition, which eventually developed in apoE4/Aβ-Tg mice prior to apoE3/Aβ-Tg. One approach to address hAPOE-induced temporal delay in Aβ pathology is an additional insult, like head injury. Another is crossing human-apoE-Tg mice with Aβ-Tg mice that have rapid-onset Aβ pathology. For example, because 5xFAD mice develop plaques by 2 months, the prediction is that human-apoE/5xFAD-Tg mice develop plaques around 6 months and 12 months before other human-apoE/Aβ-Tg mice. Thus, tractable models for human-apoE/Aβ-Tg mice continue to evolve.

  17. A humanized mouse model of anaphylactic peanut allergy.

    Science.gov (United States)

    Burton, Oliver T; Stranks, Amanda J; Tamayo, Jaciel M; Koleoglou, Kyle J; Schwartz, Lawrence B; Oettgen, Hans C

    2017-01-01

    Food allergy is a growing health problem with very limited treatment options. Investigation of the immunologic pathways underlying allergic sensitization to foods in humans has been greatly constrained by the limited availability of intestinal tissue and gut-resident immune cells. Although mouse models have offered insights into pathways of food sensitization, differences between rodent and human immune physiology limit the extension of these findings to our understanding of human disease. We sought to develop a strategy for the generation of mice with humanized adaptive immune systems, complete with tissue engraftment by human mast cells that are competent to mount specific IgE-mediated responses and drive systemic anaphylaxis on ingestion challenge. Nonobese diabetic severe combined immunodeficient mice lacking the cytokine receptor common gamma chain (γc(-/-)) and carrying a human stem cell factor transgene were engrafted with human hematopoietic stem cells. The impact of peanut (PN) feeding and IgE neutralization on the development of immune responses, mast cell homeostasis, and anaphylactic food allergy was assessed in these animals. Humanized nonobese diabetic severe combined immunodeficient common gamma chain-deficient stem cell factor (huNSG) mice exhibited robust engraftment with functional human T and B lymphocytes and human mast cells were found in significant numbers in their tissues, including the intestinal mucosa. Following gavage feeding with PN, they mounted specific antibody responses, including PN-specific IgE. When enterally challenged with PN, they exhibited mast-cell-mediated systemic anaphylaxis, as indicated by hypothermia and increases in plasma tryptase levels. Anti-IgE (omalizumab) treatment ablated this anaphylactic response. huNSG mice provide a novel tool for studying food allergy and IgE-mediated anaphylaxis. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  18. 3D active workspace of human hand anatomical model

    Directory of Open Access Journals (Sweden)

    Ungureanu Loredana

    2007-05-01

    Full Text Available Abstract Background If the model of the human hand is created with accuracy by respecting the type of motion provided by each articulation and the dimensions of articulated bones, it can function as the real organ providing the same motions. Unfortunately, the human hand is hard to model due to its kinematical chains submitted to motion constraints. On the other hand, if an application does not impose a fine manipulation it is not necessary to create a model as complex as the human hand is. But always the hand model has to perform a certain space of motions in imposed workspace architecture no matter what the practical application does. Methods Based on Denavit-Hartenberg convention, we conceived the kinematical model of the human hand, having in mind the structure and the behavior of the natural model. We obtained the kinematical equations describing the motion of every fingertip with respect to the general coordinate system, placed on the wrist. For every joint variable, a range of motion was established. Dividing these joint variables to an appropriate number of intervals and connecting them, the complex surface bordering the active hand model workspace was obtained. Results Using MATLAB 7.0, the complex surface described by fingertips, when hand articulations are all simultaneously moving, was obtained. It can be seen that any point on surface has its own coordinates smaller than the maximum length of the middle finger in static position. Therefore, a sphere having the centre in the origin of the general coordinate system and the radius which equals this length covers the represented complex surface. Conclusion We propose a human hand model that represents a new solution compared to the existing ones. This model is capable to make special movements like power grip and dexterous manipulations. During them, the fingertips do not exceed the active workspace encapsulated by determined surfaces. The proposed kinematical model can help to choose

  19. A validation study of a stochastic model of human interaction

    Science.gov (United States)

    Burchfield, Mitchel Talmadge

    The purpose of this dissertation is to validate a stochastic model of human interactions which is part of a developmentalism paradigm. Incorporating elements of ancient and contemporary philosophy and science, developmentalism defines human development as a progression of increasing competence and utilizes compatible theories of developmental psychology, cognitive psychology, educational psychology, social psychology, curriculum development, neurology, psychophysics, and physics. To validate a stochastic model of human interactions, the study addressed four research questions: (a) Does attitude vary over time? (b) What are the distributional assumptions underlying attitudes? (c) Does the stochastic model, {-}N{intlimitssbsp{-infty}{infty}}varphi(chi,tau)\\ Psi(tau)dtau, have utility for the study of attitudinal distributions and dynamics? (d) Are the Maxwell-Boltzmann, Fermi-Dirac, and Bose-Einstein theories applicable to human groups? Approximately 25,000 attitude observations were made using the Semantic Differential Scale. Positions of individuals varied over time and the logistic model predicted observed distributions with correlations between 0.98 and 1.0, with estimated standard errors significantly less than the magnitudes of the parameters. The results bring into question the applicability of Fisherian research designs (Fisher, 1922, 1928, 1938) for behavioral research based on the apparent failure of two fundamental assumptions-the noninteractive nature of the objects being studied and normal distribution of attributes. The findings indicate that individual belief structures are representable in terms of a psychological space which has the same or similar properties as physical space. The psychological space not only has dimension, but individuals interact by force equations similar to those described in theoretical physics models. Nonlinear regression techniques were used to estimate Fermi-Dirac parameters from the data. The model explained a high degree

  20. Modelling familial dysautonomia in human induced pluripotent stem cells

    OpenAIRE

    Lee, Gabsang; Studer, Lorenz

    2011-01-01

    Induced pluripotent stem (iPS) cells have considerable promise as a novel tool for modelling human disease and for drug discovery. While the generation of disease-specific iPS cells has become routine, realizing the potential of iPS cells in disease modelling poses challenges at multiple fronts. Such challenges include selecting a suitable disease target, directing the fate of iPS cells into symptom-relevant cell populations, identifying disease-related phenotypes and showing reversibility of...

  1. Modeling the effects of physician emigration on human development.

    OpenAIRE

    2011-01-01

    We analyzed the effects of physician emigration on human development indicators in developing countries. First, the geographical distribution of physician brain drain was documented for the period 1991–2004. Second, random and fixed effects models were employed to investigate the effects of physicians in the home countries and abroad on child mortality and vaccination rates. Third, models were estimated to investigate migration-induced incentives in the medical sector that would increase the ...

  2. Network effects in a human capital based economic growth model

    Science.gov (United States)

    Vaz Martins, Teresa; Araújo, Tanya; Augusta Santos, Maria; St Aubyn, Miguel

    2009-06-01

    We revisit a recently introduced agent model [ACS, 11, 99 (2008)], where economic growth is a consequence of education (human capital formation) and innovation, and investigate the influence of the agents’ social network, both on an agent’s decision to pursue education and on the output of new ideas. Regular and random networks are considered. The results are compared with the predictions of a mean field (representative agent) model.

  3. Human Posture and Movement Prediction based on Musculoskeletal Modeling

    DEFF Research Database (Denmark)

    Farahani, Saeed Davoudabadi

    2014-01-01

    Abstract This thesis explores an optimization-based formulation, so-called inverse-inverse dynamics, for the prediction of human posture and motion dynamics performing various tasks. It is explained how this technique enables us to predict natural kinematic and kinetic patterns for human posture...... and motion using AnyBody Modeling System (AMS). AMS uses inverse dynamics to analyze musculoskeletal systems and is, therefore, limited by its dependency on input kinematics. We propose to alleviate this dependency by assuming that voluntary postures and movement strategies in humans are guided by a desire...... investigated, a scaling to the mean height and body mass may be sufficient, while other questions require subject-specific models. The movement is parameterized by means of time functions controlling selected degrees-of-freedom (DOF). Subsequently, the parameters of these functions, usually referred...

  4. Human-centric decision-making models for social sciences

    CERN Document Server

    Pedrycz, Witold

    2014-01-01

    The volume delivers a wealth of effective methods to deal with various types of uncertainty inherently existing in human-centric decision problems. It elaborates on  comprehensive decision frameworks to handle different decision scenarios, which help use effectively the explicit and tacit knowledge and intuition, model perceptions and preferences in a more human-oriented style. The book presents original approaches and delivers new results on fundamentals and applications related to human-centered decision making approaches to business, economics and social systems. Individual chapters cover multi-criteria (multiattribute) decision making, decision making with prospect theory, decision making with incomplete probabilistic information, granular models of decision making and decision making realized with the use of non-additive measures. New emerging decision theories being presented as along with a wide spectrum of ongoing research make the book valuable to all interested in the field of advanced decision-mak...

  5. Human task animation from performance models and natural language input

    Science.gov (United States)

    Esakov, Jeffrey; Badler, Norman I.; Jung, Moon

    1989-01-01

    Graphical manipulation of human figures is essential for certain types of human factors analyses such as reach, clearance, fit, and view. In many situations, however, the animation of simulated people performing various tasks may be based on more complicated functions involving multiple simultaneous reaches, critical timing, resource availability, and human performance capabilities. One rather effective means for creating such a simulation is through a natural language description of the tasks to be carried out. Given an anthropometrically-sized figure and a geometric workplace environment, various simple actions such as reach, turn, and view can be effectively controlled from language commands or standard NASA checklist procedures. The commands may also be generated by external simulation tools. Task timing is determined from actual performance models, if available, such as strength models or Fitts' Law. The resulting action specification are animated on a Silicon Graphics Iris workstation in real-time.

  6. Human nonindependent mate choice: is model female attractiveness everything?

    Science.gov (United States)

    Vakirtzis, Antonios; Roberts, S Craig

    2012-05-06

    Following two decades of research on non-human animals, there has recently been increased interest in human nonindependent mate choice, namely the ways in which choosing women incorporate information about a man's past or present romantic partners ('model females') into their own assessment of the male. Experimental studies using static facial images have generally found that men receive higher desirability ratings from female raters when presented with attractive (compared to unattractive) model females. This phenomenon has a straightforward evolutionary explanation: the fact that female mate value is more dependent on physical attractiveness compared to male mate value. Furthermore, due to assortative mating for attractiveness, men who are paired with attractive women are more likely to be of high mate value themselves. Here, we also examine the possible relevance of model female cues other than attractiveness (personality and behavioral traits) by presenting video recordings of model females to a set of female raters. The results confirm that the model female's attractiveness is the primary cue. Contrary to some earlier findings in the human and nonhuman literature, we found no evidence that female raters prefer partners of slightly older model females. We conclude by suggesting some promising variations on the present experimental design.

  7. Human Nonindependent Mate Choice: Is Model Female Attractiveness Everything?

    Directory of Open Access Journals (Sweden)

    Antonios Vakirtzis

    2012-04-01

    Full Text Available Following two decades of research on non-human animals, there has recently been increased interest in human nonindependent mate choice, namely the ways in which choosing women incorporate information about a man's past or present romantic partners (‘model females’ into their own assessment of the male. Experimental studies using static facial images have generally found that men receive higher desirability ratings from female raters when presented with attractive (compared to unattractive model females. This phenomenon has a straightforward evolutionary explanation: the fact that female mate value is more dependent on physical attractiveness compared to male mate value. Furthermore, due to assortative mating for attractiveness, men who are paired with attractive women are more likely to be of high mate value themselves. Here, we also examine the possible relevance of model female cues other than attractiveness (personality and behavioral traits by presenting video recordings of model females to a set of female raters. The results confirm that the model female's attractiveness is the primary cue. Contrary to some earlier findings in the human and nonhuman literature, we found no evidence that female raters prefer partners of slightly older model females. We conclude by suggesting some promising variations on the present experimental design.

  8. Validation of human physiologically based pharmacokinetic model for vinyl acetate against human nasal dosimetry data.

    Science.gov (United States)

    Hinderliter, P M; Thrall, K D; Corley, R A; Bloemen, L J; Bogdanffy, M S

    2005-05-01

    Vinyl acetate has been shown to induce nasal lesions in rodents in inhalation bioassays. A physiologically based pharmacokinetic (PBPK) model for vinyl acetate has been used in human risk assessment, but previous in vivo validation was conducted only in rats. Controlled human exposures to vinyl acetate were conducted to provide validation data for the application of the model in humans. Five volunteers were exposed to 1, 5, and 10 ppm 13C1,13C2 vinyl acetate via inhalation. A probe inserted into the nasopharyngeal region sampled both 13C1,13C2 vinyl acetate and the major metabolite 13C1,13C2 acetaldehyde during rest and light exercise. Nasopharyngeal air concentrations were analyzed in real time by ion trap mass spectrometry (MS/MS). Experimental concentrations of both vinyl acetate and acetaldehyde were then compared to predicted concentrations calculated from the previously published human model. Model predictions of vinyl acetate nasal extraction compared favorably with measured values of vinyl acetate, as did predictions of nasopharyngeal acetaldehyde when compared to measured acetaldehyde. The results showed that the current PBPK model structure and parameterization are appropriate for vinyl acetate. These analyses were conducted from 1 to 10 ppm vinyl acetate, a range relevant to workplace exposure standards but which would not be expected to saturate vinyl acetate metabolism. Risk assessment based on this model further concluded that 24 h per day exposures up to 1 ppm do not present concern regarding cancer or non-cancer toxicity. Validation of the vinyl acetate human PBPK model provides support for these conclusions.

  9. Maintenance modeling and optimization integrating human and material resources

    Energy Technology Data Exchange (ETDEWEB)

    Martorell, S., E-mail: smartore@iqn.upv.e [Dpto. Ingenieria Quimica y Nuclear, Universidad Politecnica Valencia (Spain); Villamizar, M.; Carlos, S. [Dpto. Ingenieria Quimica y Nuclear, Universidad Politecnica Valencia (Spain); Sanchez, A. [Dpto. Estadistica e Investigacion Operativa Aplicadas y Calidad, Universidad Politecnica Valencia (Spain)

    2010-12-15

    Maintenance planning is a subject of concern to many industrial sectors as plant safety and business depend on it. Traditionally, the maintenance planning is formulated in terms of a multi-objective optimization (MOP) problem where reliability, availability, maintainability and cost (RAM+C) act as decision criteria and maintenance strategies (i.e. maintenance tasks intervals) act as the only decision variables. However the appropriate development of each maintenance strategy depends not only on the maintenance intervals but also on the resources (human and material) available to implement such strategies. Thus, the effect of the necessary resources on RAM+C needs to be modeled and accounted for in formulating the MOP affecting the set of objectives and constraints. In this paper RAM+C models to explicitly address the effect of human resources and material resources (spare parts) on RAM+C criteria are proposed. This extended model allows accounting for explicitly how the above decision criteria depends on the basic model parameters representing the type of strategies, maintenance intervals, durations, human resources and material resources. Finally, an application case is performed to optimize the maintenance plan of a motor-driven pump equipment considering as decision variables maintenance and test intervals and human and material resources.

  10. A Competency-Based Model for Developing Human Resource Professionals

    Science.gov (United States)

    McEvoy, Glenn M.; Hayton, James C.; Warnick, Alan P.; Mumford, Troy V.; Hanks, Steven H.; Blahna, Mary Jo

    2005-01-01

    This article describes a framework for the design and implementation of a competency-based curriculum for graduate management education. The article also outlines how this model has been implemented at one university in the context of a graduate degree in human resource management. Among the significant challenges discussed are the identification…

  11. The Teacher/Writer: Model, Learner, Human Being.

    Science.gov (United States)

    Susi, Geraldine Lee

    1984-01-01

    Describes observations of classrooms in which the teachers participated with the students in writing exercises. Discusses the three teacher/writer roles that emerged during the class--teacher/writer as model, teacher/writer as learner, and teacher/writer as human being--and the bond of understanding that developed as the teachers as students…

  12. Corner Detection Based on Human Visual System Model

    Institute of Scientific and Technical Information of China (English)

    LU Xiaoguang; ZHOU Jie

    2001-01-01

    Corners are useful features in computer vision tasks.In this paper,we present an algorithm for corner detection based on a human visual system model.Experimental results proved that it ismore effective than conventional corner detector under uneven illumination conditions.

  13. Being human: The role of pluripotent stem cells in regenerative medicine and humanizing Alzheimer's disease models.

    Science.gov (United States)

    Sproul, Andrew A

    2015-01-01

    Human pluripotent stem cells (PSCs) have the capacity to revolutionize medicine by allowing the generation of functional cell types such as neurons for cell replacement therapy. However, the more immediate impact of PSCs on treatment of Alzheimer's disease (AD) will be through improved human AD model systems for mechanistic studies and therapeutic screening. This review will first briefly discuss different types of PSCs and genome-editing techniques that can be used to modify PSCs for disease modeling or for personalized medicine. This will be followed by a more in depth analysis of current AD iPSC models and a discussion of the need for more complex multicellular models, including cell types such as microglia. It will finish with a discussion on current clinical trials using PSC-derived cells and the long-term potential of such strategies for treating AD. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Workforce scheduling: A new model incorporating human factors

    Directory of Open Access Journals (Sweden)

    Mohammed Othman

    2012-12-01

    Full Text Available Purpose: The majority of a company’s improvement comes when the right workers with the right skills, behaviors and capacities are deployed appropriately throughout a company. This paper considers a workforce scheduling model including human aspects such as skills, training, workers’ personalities, workers’ breaks and workers’ fatigue and recovery levels. This model helps to minimize the hiring, firing, training and overtime costs, minimize the number of fired workers with high performance, minimize the break time and minimize the average worker’s fatigue level.Design/methodology/approach: To achieve this objective, a multi objective mixed integer programming model is developed to determine the amount of hiring, firing, training and overtime for each worker type.Findings: The results indicate that the worker differences should be considered in workforce scheduling to generate realistic plans with minimum costs. This paper also investigates the effects of human fatigue and recovery on the performance of the production systems.Research limitations/implications: In this research, there are some assumptions that might affect the accuracy of the model such as the assumption of certainty of the demand in each period, and the linearity function of Fatigue accumulation and recovery curves. These assumptions can be relaxed in future work.Originality/value: In this research, a new model for integrating workers’ differences with workforce scheduling is proposed. To the authors' knowledge, it is the first time to study the effects of different important human factors such as human personality, skills and fatigue and recovery in the workforce scheduling process. This research shows that considering both technical and human factors together can reduce the costs in manufacturing systems and ensure the safety of the workers.

  15. A Circuit Model of Real Time Human Body Hydration.

    Science.gov (United States)

    Asogwa, Clement Ogugua; Teshome, Assefa K; Collins, Stephen F; Lai, Daniel T H

    2016-06-01

    Changes in human body hydration leading to excess fluid losses or overload affects the body fluid's ability to provide the necessary support for healthy living. We propose a time-dependent circuit model of real-time human body hydration, which models the human body tissue as a signal transmission medium. The circuit model predicts the attenuation of a propagating electrical signal. Hydration rates are modeled by a time constant τ, which characterizes the individual specific metabolic function of the body part measured. We define a surrogate human body anthropometric parameter θ by the muscle-fat ratio and comparing it with the body mass index (BMI), we find theoretically, the rate of hydration varying from 1.73 dB/min, for high θ and low τ to 0.05 dB/min for low θ and high τ. We compare these theoretical values with empirical measurements and show that real-time changes in human body hydration can be observed by measuring signal attenuation. We took empirical measurements using a vector network analyzer and obtained different hydration rates for various BMI, ranging from 0.6 dB/min for 22.7 [Formula: see text] down to 0.04 dB/min for 41.2 [Formula: see text]. We conclude that the galvanic coupling circuit model can predict changes in the volume of the body fluid, which are essential in diagnosing and monitoring treatment of body fluid disorder. Individuals with high BMI would have higher time-dependent biological characteristic, lower metabolic rate, and lower rate of hydration.

  16. Reduced-order models for vertical human-structure interaction

    Science.gov (United States)

    Van Nimmen, Katrien; Lombaert, Geert; De Roeck, Guido; Van den Broeck, Peter

    2016-09-01

    For slender and lightweight structures, the vibration serviceability under crowd- induced loading is often critical in design. Currently, designers rely on equivalent load models, upscaled from single-person force measurements. Furthermore, it is important to consider the mechanical interaction with the human body as this can significantly reduce the structural response. To account for these interaction effects, the contact force between the pedestrian and the structure can be modelled as the superposition of the force induced by the pedestrian on a rigid floor and the force resulting from the mechanical interaction between the structure and the human body. For the case of large crowds, however, this approach leads to models with a very high system order. In the present contribution, two equivalent reduced-order models are proposed to approximate the dynamic behaviour of the full-order coupled crowd-structure system. A numerical study is performed to evaluate the impact of the modelling assumptions on the structural response to pedestrian excitation. The results show that the full-order moving crowd model can be well approximated by a reduced-order model whereby the interaction with the pedestrians in the crowd is modelled using a single (equivalent) SDOF system.

  17. Age and gender specific biokinetic model for strontium in humans

    Energy Technology Data Exchange (ETDEWEB)

    Shagina, N. B.; Tolstykh, E. I.; Degteva, M. O.; Anspaugh, L. R.; Napier, Bruce A.

    2015-03-01

    A biokinetic model for strontium in humans is necessary for quantification of internal doses due to strontium radioisotopes. The ICRP-recommended biokinetic model for strontium has limitation for use in a population study, because it is not gender specific and does not cover all age ranges. The extensive Techa River data set on 90Sr in humans (tens of thousands of measurements) is a unique source of data on long-term strontium retention for men and women of all ages at intake. These, as well as published data, were used for evaluation of age- and gender-specific parameters for a new compartment biokinetic model for strontium (Sr-AGe model). The Sr-AGe model has similar structure as the ICRP model for the alkaline earth elements. The following parameters were mainly reevaluated: gastro-intestinal absorption and parameters related to the processes of bone formation and resorption defining calcium and strontium transfers in skeletal compartments. The Sr-AGe model satisfactorily describes available data sets on strontium retention for different kinds of intake (dietary and intravenous) at different ages (0–80 years old) and demonstrates good agreement with data sets for different ethnic groups. The Sr-AGe model can be used for dose assessment in epidemiological studies of general population exposed to ingested strontium radioisotopes.

  18. Three-dimensional cell culture models for investigating human viruses.

    Science.gov (United States)

    He, Bing; Chen, Guomin; Zeng, Yi

    2016-10-01

    Three-dimensional (3D) culture models are physiologically relevant, as they provide reproducible results, experimental flexibility and can be adapted for high-throughput experiments. Moreover, these models bridge the gap between traditional two-dimensional (2D) monolayer cultures and animal models. 3D culture systems have significantly advanced basic cell science and tissue engineering, especially in the fields of cell biology and physiology, stem cell research, regenerative medicine, cancer research, drug discovery, and gene and protein expression studies. In addition, 3D models can provide unique insight into bacteriology, virology, parasitology and host-pathogen interactions. This review summarizes and analyzes recent progress in human virological research with 3D cell culture models. We discuss viral growth, replication, proliferation, infection, virus-host interactions and antiviral drugs in 3D culture models.

  19. Computational model of soft tissues in the human upper airway.

    Science.gov (United States)

    Pelteret, J-P V; Reddy, B D

    2012-01-01

    This paper presents a three-dimensional finite element model of the tongue and surrounding soft tissues with potential application to the study of sleep apnoea and of linguistics and speech therapy. The anatomical data was obtained from the Visible Human Project, and the underlying histological data was also extracted and incorporated into the model. Hyperelastic constitutive models were used to describe the material behaviour, and material incompressibility was accounted for. An active Hill three-element muscle model was used to represent the muscular tissue of the tongue. The neural stimulus for each muscle group was determined through the use of a genetic algorithm-based neural control model. The fundamental behaviour of the tongue under gravitational and breathing-induced loading is investigated. It is demonstrated that, when a time-dependent loading is applied to the tongue, the neural model is able to control the position of the tongue and produce a physiologically realistic response for the genioglossus.

  20. Genome editing of human pluripotent stem cells to generate human cellular disease models

    Directory of Open Access Journals (Sweden)

    Kiran Musunuru

    2013-07-01

    Full Text Available Disease modeling with human pluripotent stem cells has come into the public spotlight with the awarding of the Nobel Prize in Physiology or Medicine for 2012 to Drs John Gurdon and Shinya Yamanaka for the discovery that mature cells can be reprogrammed to become pluripotent. This discovery has opened the door for the generation of pluripotent stem cells from individuals with disease and the differentiation of these cells into somatic cell types for the study of disease pathophysiology. The emergence of genome-editing technology over the past few years has made it feasible to generate and investigate human cellular disease models with even greater speed and efficiency. Here, recent technological advances in genome editing, and its utility in human biology and disease studies, are reviewed.

  1. Genome editing of human pluripotent stem cells to generate human cellular disease models.

    Science.gov (United States)

    Musunuru, Kiran

    2013-07-01

    Disease modeling with human pluripotent stem cells has come into the public spotlight with the awarding of the Nobel Prize in Physiology or Medicine for 2012 to Drs John Gurdon and Shinya Yamanaka for the discovery that mature cells can be reprogrammed to become pluripotent. This discovery has opened the door for the generation of pluripotent stem cells from individuals with disease and the differentiation of these cells into somatic cell types for the study of disease pathophysiology. The emergence of genome-editing technology over the past few years has made it feasible to generate and investigate human cellular disease models with even greater speed and efficiency. Here, recent technological advances in genome editing, and its utility in human biology and disease studies, are reviewed.

  2. Analyzing, Modeling, and Simulation for Human Dynamics in Social Network

    Directory of Open Access Journals (Sweden)

    Yunpeng Xiao

    2012-01-01

    Full Text Available This paper studies the human behavior in the top-one social network system in China (Sina Microblog system. By analyzing real-life data at a large scale, we find that the message releasing interval (intermessage time obeys power law distribution both at individual level and at group level. Statistical analysis also reveals that human behavior in social network is mainly driven by four basic elements: social pressure, social identity, social participation, and social relation between individuals. Empirical results present the four elements' impact on the human behavior and the relation between these elements. To further understand the mechanism of such dynamic phenomena, a hybrid human dynamic model which combines “interest” of individual and “interaction” among people is introduced, incorporating the four elements simultaneously. To provide a solid evaluation, we simulate both two-agent and multiagent interactions with real-life social network topology. We achieve the consistent results between empirical studies and the simulations. The model can provide a good understanding of human dynamics in social network.

  3. An Integrated Simulation Tool for Modeling the Human Circulatory System

    Science.gov (United States)

    Asami, Ken'ichi; Kitamura, Tadashi

    This paper presents an integrated simulation of the circulatory system in physiological movement. The large circulatory system model includes principal organs and functional units in modules in which comprehensive physiological changes such as nerve reflexes, temperature regulation, acid/base balance, O2/CO2 balance, and exercise are simulated. A beat-by-beat heart model, in which the corresponding electrical circuit problems are solved by a numerical analytic method, enables calculation of pulsatile blood flow to the major organs. The integration of different perspectives on physiological changes makes this simulation model applicable for the microscopic evaluation of blood flow under various conditions in the human body.

  4. A mouse model of human repetitive mild traumatic brain injury

    OpenAIRE

    Kane, Michael J; Pérez, Mariana Angoa; Briggs, Denise I.; Viano, David C.; Kreipke, Christian W.; Kuhn, Donald M.

    2011-01-01

    A novel method for the study of repetitive mild traumatic brain injury (rmTBI) that models the most common form of head injury in humans is presented. Existing animal models of TBI impart focal, severe damage unlike that seen in repeated and mild concussive injuries, and few are configured for repetitive application. Our model is a modification of the Marmarou weight drop method and allows repeated head impacts to lightly anesthetized mice. A key facet of this method is the delivery of an imp...

  5. Retention modeling of refractory ceramic fibers (RCF) in humans.

    Science.gov (United States)

    Yu, C P; Ding, Y J; Zhang, L; Oberdörster, G; Mast, R W; Maxim, L D; Utell, M J

    1997-02-01

    A mathematical retention model has been developed to predict the lung burden and size distribution of kaolin refractory ceramic fibers (RCF) in the pulmonary region of the human lung during exposure. Fiber dissolution, breakage, and differential clearance are considered in this model; rates for these processes are obtained by extrapolation from available data on laboratory rats. The lung burden predicted by this model is in general agreement with fiber counts from three factory workers. An important prediction from this study is that clearance of RCF is not significantly impaired at a fiber concentration beneath 10 f/cm3 during occupational exposure.

  6. Agent-based cognitive model for human resources competence management.

    Science.gov (United States)

    Oliveira, Stefan; Gluz, João Carlos

    2010-01-01

    This chapter presents an agent-based cognitive model aimed to represent human competency concepts and competence management processes of psychological nature. This model is implemented by a multiagent system application intended to help managers of software development projects to select, based on the competence management model, the right professionals to integrate a development team. There are several software engineering methodologies that can be used to design and develop multiagent systems. However, due to the necessity to handle human competency concepts of cognitive nature, like aptitudes, interests, abilities and knowledge, we were driven to choose methodologies that can handle these concepts since the inception of the system. To do so, we integrated the TROPOS methodology, and a set of software engineering methods derived from intelligent tutoring systems research to successfully analyze and design the proposed system. At the end of the paper we present a study case, showing how the proposed system should be applied to the domain of website development.

  7. New paradigms for metabolic modeling of human cells

    DEFF Research Database (Denmark)

    Mardinoglu, Adil; Nielsen, Jens

    2015-01-01

    Abnormalities in cellular functions are associated with the progression of human diseases, often resulting in metabolic reprogramming. GEnome-scale metabolic Models (GEMs) have enabled studying global metabolic reprogramming in connection with disease development in a systematic manner. Here we......, challenges in integration of cell/tissue models for simulation of whole body functions as well as integration of GEMs with other biological networks for generating complete cell/tissue models are presented....... review recent work on reconstruction of GEMs for human cell/tissue types and cancer, and the use of GEMs for identification of metabolic changes occurring in response to disease development. We further discuss how GEMs can be used for the development of efficient therapeutic strategies. Finally...

  8. Multifractal heart rate dynamics in human cardiovascular model

    Science.gov (United States)

    Kotani, Kiyoshi; Takamasu, Kiyoshi; Safonov, Leonid; Yamamoto, Yoshiharu

    2003-05-01

    Human cardiovascular and/or cardio-respiratory systems are shown to exhibit both multifractal and synchronous dynamics, and we recently developed a nonlinear, physiologically plausible model for the synchronization between heartbeat and respiration (Kotani, et al. Phys. Rev. E 65: 051923, 2002). By using the same model, we now show the multifractality in the heart rate dynamics. We find that beat-to-beat monofractal noise (fractional Brownian motion) added to the brain stem cardiovascular areas results in significantly broader singularity spectra for heart rate through interactions between sympathetic and parasympathetic nervous systems. We conclude that the model proposed here would be useful in studying the complex cardiovascular and/or cardio- respiratory dynamics in humans.

  9. A Culture-Behavior-Brain Loop Model of Human Development.

    Science.gov (United States)

    Han, Shihui; Ma, Yina

    2015-11-01

    Increasing evidence suggests that cultural influences on brain activity are associated with multiple cognitive and affective processes. These findings prompt an integrative framework to account for dynamic interactions between culture, behavior, and the brain. We put forward a culture-behavior-brain (CBB) loop model of human development that proposes that culture shapes the brain by contextualizing behavior, and the brain fits and modifies culture via behavioral influences. Genes provide a fundamental basis for, and interact with, the CBB loop at both individual and population levels. The CBB loop model advances our understanding of the dynamic relationships between culture, behavior, and the brain, which are crucial for human phylogeny and ontogeny. Future brain changes due to cultural influences are discussed based on the CBB loop model.

  10. Transgenic rabbits as therapeutic protein bioreactors and human disease models.

    Science.gov (United States)

    Fan, Jianglin; Watanabe, Teruo

    2003-09-01

    Genetically modified laboratory animals provide a powerful approach for studying gene expression and regulation and allow one to directly examine structure-function and cause-and-effect relationships in pathophysiological processes. Today, transgenic mice are available as a research tool in almost every research institution. On the other hand, the development of a relatively large mammalian transgenic model, transgenic rabbits, has provided unprecedented opportunities for investigators to study the mechanisms of human diseases and has also provided an alternative way to produce therapeutic proteins to treat human diseases. Transgenic rabbits expressing human genes have been used as a model for cardiovascular disease, AIDS, and cancer research. The recombinant proteins can be produced from the milk of transgenic rabbits not only at lower cost but also on a relatively large scale. One of the most promising and attractive recombinant proteins derived from transgenic rabbit milk, human alpha-glucosidase, has been successfully used to treat the patients who are genetically deficient in this enzyme. Although the pronuclear microinjection is still the major and most popular method for the creation of transgenic rabbits, recent progress in gene targeting and animal cloning has opened new avenues that should make it possible to produce transgenic rabbits by somatic cell nuclear transfer in the future. Based on a computer-assisted search of the studies of transgenic rabbits published in the English literature here, we introduce to the reader the achievements made thus far with transgenic rabbits, with emphasis on the application of these rabbits as human disease models and live bioreactors for producing human therapeutic proteins and on the recent progress in cloned rabbits.

  11. A microphysiological model of the human placental barrier.

    Science.gov (United States)

    Blundell, Cassidy; Tess, Emily R; Schanzer, Ariana S R; Coutifaris, Christos; Su, Emily J; Parry, Samuel; Huh, Dongeun

    2016-08-02

    During human pregnancy, the fetal circulation is separated from maternal blood in the placenta by two cell layers - the fetal capillary endothelium and placental trophoblast. This placental barrier plays an essential role in fetal development and health by tightly regulating the exchange of endogenous and exogenous materials between the mother and the fetus. Here we present a microengineered device that provides a novel platform to mimic the structural and functional complexity of this specialized tissue in vitro. Our model is created in a multilayered microfluidic system that enables co-culture of human trophoblast cells and human fetal endothelial cells in a physiologically relevant spatial arrangement to replicate the characteristic architecture of the human placental barrier. We have engineered this co-culture model to induce progressive fusion of trophoblast cells and to form a syncytialized epithelium that resembles the syncytiotrophoblast in vivo. Our system also allows the cultured trophoblasts to form dense microvilli under dynamic flow conditions and to reconstitute expression and physiological localization of membrane transport proteins, such as glucose transporters (GLUTs), critical to the barrier function of the placenta. To provide a proof-of-principle for using this microdevice to recapitulate native function of the placental barrier, we demonstrated physiological transport of glucose across the microengineered maternal-fetal interface. Importantly, the rate of maternal-to-fetal glucose transfer in this system closely approximated that measured in ex vivo perfused human placentas. Our "placenta-on-a-chip" platform represents an important advance in the development of new technologies to model and study the physiological complexity of the human placenta for a wide variety of applications.

  12. Modeling the human invader in the United States

    Science.gov (United States)

    Stohlgren, Thomas J.; Jarnevich, Catherine S.; Giri, Chandra P.

    2010-02-01

    Modern biogeographers recognize that humans are seen as constituents of ecosystems, drivers of significant change, and perhaps, the most invasive species on earth. We found it instructive to model humans as invasive organisms with the same environmental factors. We present a preliminary model of the spread of modern humans in the conterminous United States between 1992 and 2001 based on a subset of National Land Cover Data (NLCD), a time series LANDSAT product. We relied on the commonly used Maxent model, a species-environmental matching model, to map urbanization. Results: Urban areas represented 5.1% of the lower 48 states in 2001, an increase of 7.5% (18,112 km2) in the nine year period. At this rate, an area the size of Massachusetts is converted to urban land use every ten years. We used accepted models commonly used for mapping plant and animal distributions and found that climatic and environmental factors can strongly predict our spread (i.e., the conversion of forests, shrub/grass, and wetland areas into urban areas), with a 92.5% success rate (Area Under the Curve). Adding a roads layer in the model improved predictions to a 95.5% success rate. 8.8% of the 1-km2 cells in the conterminous U.S. now have a major road in them. In 2001, 0.8% of 1-km2 cells in the U.S. had an urbanness value of > 800, (>89% of a 1-km2 cell is urban), while we predict that 24.5% of 1-km2 cells in the conterminous U.S. will be > 800 eventually. Main conclusion: Humans have a highly predictable pattern of urbanization based on climatic and topographic variables. Conservation strategies may benefit from that predictability.

  13. Culture models of human mammary epithelial cell transformation

    Energy Technology Data Exchange (ETDEWEB)

    Stampfer, Martha R.; Yaswen, Paul

    2000-11-10

    Human pre-malignant breast diseases, particularly ductal carcinoma in situ (DCIS)3 already display several of the aberrant phenotypes found in primary breast cancers, including chromosomal abnormalities, telomerase activity, inactivation of the p53 gene and overexpression of some oncogenes. Efforts to model early breast carcinogenesis in human cell cultures have largely involved studies in vitro transformation of normal finite lifespan human mammary epithelial cells (HMEC) to immortality and malignancy. We present a model of HMEC immortal transformation consistent with the know in vivo data. This model includes a recently described, presumably epigenetic process, termed conversion, which occurs in cells that have overcome stringent replicative senescence and are thus able to maintain proliferation with critically short telomeres. The conversion process involves reactivation of telomerase activity, and acquisition of good uniform growth in the absence and presence of TFGB. We propose th at overcoming the proliferative constraints set by senescence, and undergoing conversion, represent key rate-limiting steps in human breast carcinogenesis, and occur during early stage breast cancer progression.

  14. Modeling and Visualization of Human Activities for Multicamera Networks

    Directory of Open Access Journals (Sweden)

    Aswin C. Sankaranarayanan

    2009-01-01

    Full Text Available Multicamera networks are becoming complex involving larger sensing areas in order to capture activities and behavior that evolve over long spatial and temporal windows. This necessitates novel methods to process the information sensed by the network and visualize it for an end user. In this paper, we describe a system for modeling and on-demand visualization of activities of groups of humans. Using the prior knowledge of the 3D structure of the scene as well as camera calibration, the system localizes humans as they navigate the scene. Activities of interest are detected by matching models of these activities learnt a priori against the multiview observations. The trajectories and the activity index for each individual summarize the dynamic content of the scene. These are used to render the scene with virtual 3D human models that mimic the observed activities of real humans. In particular, the rendering framework is designed to handle large displays with a cluster of GPUs as well as reduce the cognitive dissonance by rendering realistic weather effects and illumination. We envision use of this system for immersive visualization as well as summarization of videos that capture group behavior.

  15. Multivariate Models for Prediction of Human Skin Sensitization ...

    Science.gov (United States)

    One of the lnteragency Coordinating Committee on the Validation of Alternative Method's (ICCVAM) top priorities is the development and evaluation of non-animal approaches to identify potential skin sensitizers. The complexity of biological events necessary to produce skin sensitization suggests that no single alternative method will replace the currently accepted animal tests. ICCVAM is evaluating an integrated approach to testing and assessment based on the adverse outcome pathway for skin sensitization that uses machine learning approaches to predict human skin sensitization hazard. We combined data from three in chemico or in vitro assays - the direct peptide reactivity assay (DPRA), human cell line activation test (h-CLAT) and KeratinoSens TM assay - six physicochemical properties and an in silico read-across prediction of skin sensitization hazard into 12 variable groups. The variable groups were evaluated using two machine learning approaches , logistic regression and support vector machine, to predict human skin sensitization hazard. Models were trained on 72 substances and tested on an external set of 24 substances. The six models (three logistic regression and three support vector machine) with the highest accuracy (92%) used: (1) DPRA, h-CLAT and read-across; (2) DPRA, h-CLAT, read-across and KeratinoSens; or (3) DPRA, h-CLAT, read-across, KeratinoSens and log P. The models performed better at predicting human skin sensitization hazard than the murine

  16. Personalized medicine for cystic fibrosis: establishing human model systems.

    Science.gov (United States)

    Mou, Hongmei; Brazauskas, Karissa; Rajagopal, Jayaraj

    2015-10-01

    With over 1,500 identifiable mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that result in distinct functional and phenotypical abnormalities, it is virtually impossible to perform randomized clinical trials to identify the best therapeutics for all patients. Therefore, a personalized medicine approach is essential. The only way to realistically accomplish this is through the development of improved in vitro human model systems. The lack of a readily available and infinite supply of human CFTR-expressing airway epithelial cells is a key bottleneck. We propose that a concerted two-pronged approach is necessary for patient-specific cystic fibrosis research to continue to prosper and realize its potential: (1) more effective culture and differentiation conditions for growing primary human airway and nasal epithelial cells and (2) the development of collective protocols for efficiently differentiating disease- and patient-specific induced pluripotent stem cells (iPSC) into pure populations of adult epithelial cells. Ultimately, we need a personalized human model system for cystic fibrosis with the capacity for uncomplicated bankability, widespread availability, and universal applicability for patient-specific disease modeling, novel pharmacotherapy investigation and screening, and readily executable genetic modification. © 2015 Wiley Periodicals, Inc.

  17. MORPHIN: a web tool for human disease research by projecting model organism biology onto a human integrated gene network.

    Science.gov (United States)

    Hwang, Sohyun; Kim, Eiru; Yang, Sunmo; Marcotte, Edward M; Lee, Insuk

    2014-07-01

    Despite recent advances in human genetics, model organisms are indispensable for human disease research. Most human disease pathways are evolutionally conserved among other species, where they may phenocopy the human condition or be associated with seemingly unrelated phenotypes. Much of the known gene-to-phenotype association information is distributed across diverse databases, growing rapidly due to new experimental techniques. Accessible bioinformatics tools will therefore facilitate translation of discoveries from model organisms into human disease biology. Here, we present a web-based discovery tool for human disease studies, MORPHIN (model organisms projected on a human integrated gene network), which prioritizes the most relevant human diseases for a given set of model organism genes, potentially highlighting new model systems for human diseases and providing context to model organism studies. Conceptually, MORPHIN investigates human diseases by an orthology-based projection of a set of model organism genes onto a genome-scale human gene network. MORPHIN then prioritizes human diseases by relevance to the projected model organism genes using two distinct methods: a conventional overlap-based gene set enrichment analysis and a network-based measure of closeness between the query and disease gene sets capable of detecting associations undetectable by the conventional overlap-based methods. MORPHIN is freely accessible at http://www.inetbio.org/morphin.

  18. Pedigree models for complex human traits involving the mitochrondrial genome

    Energy Technology Data Exchange (ETDEWEB)

    Schork, N.J.; Guo, S.W. (Univ. of Michigan, Ann Arbor, MI (United States))

    1993-12-01

    Recent biochemical and molecular-genetic discoveries concerning variations in human mtDNA have suggested a role for mtDNA mutations in a number of human traits and disorders. Although the importance of these discoveries cannot be emphasized enough, the complex natures of mitochondrial biogenesis, mutant mtDNA phenotype expression, and the maternal inheritance pattern exhibited by mtDNA transmission make it difficult to develop models that can be used routinely in pedigree analyses to quantify and test hypotheses about the role of mtDNA in the expression of a trait. In the present paper, the authors describe complexities inherent in mitochondrial biogenesis and genetic transmission and show how these complexities can be incorporated into appropriate mathematical models. The authors offer a variety of likelihood-based models which account for the complexities discussed. The derivation of the models is meant to stimulate the construction of statistical tests for putative mtDNA contribution to a trait. Results of simulation studies which make use of the proposed models are described. The results of the simulation studies suggest that, although pedigree models of mtDNA effects can be reliable, success in mapping chromosomal determinants of a trait does not preclude the possibility that mtDNA determinants exist for the trait as well. Shortcomings inherent in the proposed models are described in an effort to expose areas in need of additional research. 58 refs., 5 figs., 2 tabs.

  19. Social interactions model and adaptability of human behavior

    Directory of Open Access Journals (Sweden)

    Kun eZhao

    2011-12-01

    Full Text Available Human social networks evolve on the fast timescale of face-to face interactions and of interactions mediated by technology such as a telephone calls or video conferences. The resulting networks have a strong dynamical component that changes significantly the properties of dynamical processes. In this paper we study a general model of pairwise human social interaction intended to model both face-to face interactions and mobile phone communication. We study the distribution of durations of social interactions in whitin the model. This distribution in one limit is a power law, for other values of the parameters of the model this distribution is given by a Weibull function. Therefore the model can be used to model both face-to-face interactions data, where the distribution of duration has been shown to be fat-tailed, and mobile phone communication data where the distribution of duration is given by a Weibull distribution.The highly adaptable social interaction model propose in this paper has a very simple algorithmic implementation and can be used to simulate dynamical processes occurring in dynamical social interaction networks.

  20. What Can Human Geography Offer Climate Change Modelling?

    DEFF Research Database (Denmark)

    Grindsted, Thomas Skou

    2014-01-01

    The discipline of Geography may be one of the most prominent and oldest disciplines in the conceptualization of human–environment interactions that integrates elements from both natural and social sciences. Yet, much research on society–environment interactions on climate change reduces human...... conceptual modelling of climate change adaption and mitigation. In other words, geographical representations do matter. In the following we will first reflect upon what I shall call spatio-temporal tides and waves of the human environment theme to examine the methodological grounds on which climate change...

  1. Cognition and procedure representational requirements for predictive human performance models

    Science.gov (United States)

    Corker, K.

    1992-01-01

    Models and modeling environments for human performance are becoming significant contributors to early system design and analysis procedures. Issues of levels of automation, physical environment, informational environment, and manning requirements are being addressed by such man/machine analysis systems. The research reported here investigates the close interaction between models of human cognition and models that described procedural performance. We describe a methodology for the decomposition of aircrew procedures that supports interaction with models of cognition on the basis of procedures observed; that serves to identify cockpit/avionics information sources and crew information requirements; and that provides the structure to support methods for function allocation among crew and aiding systems. Our approach is to develop an object-oriented, modular, executable software representation of the aircrew, the aircraft, and the procedures necessary to satisfy flight-phase goals. We then encode in a time-based language, taxonomies of the conceptual, relational, and procedural constraints among the cockpit avionics and control system and the aircrew. We have designed and implemented a goals/procedures hierarchic representation sufficient to describe procedural flow in the cockpit. We then execute the procedural representation in simulation software and calculate the values of the flight instruments, aircraft state variables and crew resources using the constraints available from the relationship taxonomies. The system provides a flexible, extensible, manipulative and executable representation of aircrew and procedures that is generally applicable to crew/procedure task-analysis. The representation supports developed methods of intent inference, and is extensible to include issues of information requirements and functional allocation. We are attempting to link the procedural representation to models of cognitive functions to establish several intent inference methods

  2. Surface-bounded growth modeling applied to human mandibles

    DEFF Research Database (Denmark)

    Andresen, Per Rønsholt

    1999-01-01

    This thesis presents mathematical and computational techniques for three dimensional growth modeling applied to human mandibles. The longitudinal shape changes make the mandible a complex bone. The teeth erupt and the condylar processes change direction, from pointing predominantly backward...... to yield a spatially dense field. Different methods for constructing the sparse field are compared. Adaptive Gaussian smoothing is the preferred method since it is parameter free and yields good results in practice. A new method, geometry-constrained diffusion, is used to simplify The most successful...... growth model is linear and based on results from shape analysis and principal component analysis. The growth model is tested in a cross validation study with good results. The worst case mean modeling error in the cross validation study is 3.7 mm. It occurs when modeling the shape and size of a 12 years...

  3. A computational model of the human hand 93-ERI-053

    Energy Technology Data Exchange (ETDEWEB)

    Hollerbach, K.; Axelrod, T.

    1996-03-01

    The objectives of the Computational Hand Modeling project were to prove the feasibility of the Laboratory`s NIKE3D finite element code to orthopaedic problems. Because of the great complexity of anatomical structures and the nonlinearity of their behavior, we have focused on a subset of joints of the hand and lower extremity and have developed algorithms to model their behavior. The algorithms developed here solve fundamental problems in computational biomechanics and can be expanded to describe any other joints of the human body. This kind of computational modeling has never successfully been attempted before, due in part to a lack of biomaterials data and a lack of computational resources. With the computational resources available at the National Laboratories and the collaborative relationships we have established with experimental and other modeling laboratories, we have been in a position to pursue our innovative approach to biomechanical and orthopedic modeling.

  4. A control theory model for human decision making

    Science.gov (United States)

    Levison, W. H.

    1972-01-01

    The optimal control model for pilot-vehicle systems has been extended to handle certain types of human decision tasks. The model for decision making incorporates the observation noise, optimal estimation, and prediction concepts that form the basis of the model for control behavior. Experiments are described for the following task situations: (1) single decision tasks; (2) two decision tasks; and (3) simultaneous manual control and decision tasks. Using fixed values for model parameters, single-task and two-task decision performance scores to within an accuracy of 10 percent can be predicted. The experiment on simultaneous control and decision indicates the presence of task interference in this situation, but the results are not adequate to allow a conclusive test of the predictive capability of the model.

  5. A comprehensive model for the humoral coagulation network in humans.

    Science.gov (United States)

    Wajima, T; Isbister, G K; Duffull, S B

    2009-09-01

    Coagulation is an important process in hemostasis and comprises a complicated interaction of multiple enzymes and proteins. We have developed a mechanistic quantitative model of the coagulation network. The model accurately describes the time courses of coagulation factors following in vivo activation as well as in vitro blood coagulation tests of prothrombin time (PT, often reported as international normalized ratio (INR)) and activated partial thromboplastin time (aPTT). The model predicts the concentration-time and time-effect profiles of warfarin, heparins, and vitamin K in humans. The model can be applied to predict the time courses of coagulation kinetics in clinical situations (e.g., hemophilia) and for biomarker identification during drug development. The model developed in this study is the first quantitative description of the comprehensive coagulation network.

  6. MuscleBuilder:A Modeling Tool for Human Anatomy

    Institute of Scientific and Technical Information of China (English)

    Amaury Aubel; Daniel Thalmann

    2004-01-01

    A traditional multi-layered approach is adopted to human body modeling and deformation. The model is split into three general anatomical structures: the skeleton, musculature and skin. It is shown that each of these layers is modeled and deformed by using fast, procedural, ad-hoc methods that can painlessly be reimplemented. The modeling approach is generic enough to handle muscles of varying shape, size and characteristics and does not break in extreme skeleton poses. It is also described that the integrated MuscleBuilder system whose main features are: i) easy and quick creation of muscle deformation models; ii) automatic deformation of an overlying skin. It is shown that visually realistic results can be obtained at interactive frame rates with very little input from the designer.

  7. Human supervisory approach to modeling industrial scenes using geometric primitives

    Energy Technology Data Exchange (ETDEWEB)

    Luck, J.P.; Little, C.Q.; Roberts, R.S.

    1997-11-19

    A three-dimensional world model is crucial for many robotic tasks. Modeling techniques tend to be either fully manual or autonomous. Manual methods are extremely time consuming but also highly accurate and flexible. Autonomous techniques are fast but inflexible and, with real-world data, often inaccurate. The method presented in this paper combines the two, yielding a highly efficient, flexible, and accurate mapping tool. The segmentation and modeling algorithms that compose the method are specifically designed for industrial environments, and are described in detail. A mapping system based on these algorithms has been designed. It enables a human supervisor to quickly construct a fully defined world model from unfiltered and unsegmented real-world range imagery. Examples of how industrial scenes are modeled with the mapping system are provided.

  8. Proteomics in farm animals models of human diseases.

    Science.gov (United States)

    Ceciliani, Fabrizio; Restelli, Laura; Lecchi, Cristina

    2014-10-01

    The need to provide in vivo complex environments to understand human diseases strongly relies on the use of animal models, which traditionally include small rodents and rabbits. It is becoming increasingly evident that the few species utilised to date cannot be regarded as universal. There is a great need for new animal species that are naturally endowed with specific features relevant to human diseases. Farm animals, including pigs, cows, sheep and horses, represent a valid alternative to commonly utilised rodent models. There is an ample scope for the application of proteomic techniques in farm animals, and the establishment of several proteomic maps of plasma and tissue has clearly demonstrated that farm animals provide a disease environment that closely resembles that of human diseases. The present review offers a snapshot of how proteomic techniques have been applied to farm animals to improve their use as biomedical models. Focus will be on specific topics of biomedical research in which farm animal models have been characterised through the application of proteomic techniques.

  9. Modelling large scale human activity in San Francisco

    Science.gov (United States)

    Gonzalez, Marta

    2010-03-01

    Diverse group of people with a wide variety of schedules, activities and travel needs compose our cities nowadays. This represents a big challenge for modeling travel behaviors in urban environments; those models are of crucial interest for a wide variety of applications such as traffic forecasting, spreading of viruses, or measuring human exposure to air pollutants. The traditional means to obtain knowledge about travel behavior is limited to surveys on travel journeys. The obtained information is based in questionnaires that are usually costly to implement and with intrinsic limitations to cover large number of individuals and some problems of reliability. Using mobile phone data, we explore the basic characteristics of a model of human travel: The distribution of agents is proportional to the population density of a given region, and each agent has a characteristic trajectory size contain information on frequency of visits to different locations. Additionally we use a complementary data set given by smart subway fare cards offering us information about the exact time of each passenger getting in or getting out of the subway station and the coordinates of it. This allows us to uncover the temporal aspects of the mobility. Since we have the actual time and place of individual's origin and destination we can understand the temporal patterns in each visited location with further details. Integrating two described data set we provide a dynamical model of human travels that incorporates different aspects observed empirically.

  10. Patient-Specific Computational Modeling of Human Phonation

    Science.gov (United States)

    Xue, Qian; Zheng, Xudong; University of Maine Team

    2013-11-01

    Phonation is a common biological process resulted from the complex nonlinear coupling between glottal aerodynamics and vocal fold vibrations. In the past, the simplified symmetric straight geometric models were commonly employed for experimental and computational studies. The shape of larynx lumen and vocal folds are highly three-dimensional indeed and the complex realistic geometry produces profound impacts on both glottal flow and vocal fold vibrations. To elucidate the effect of geometric complexity on voice production and improve the fundamental understanding of human phonation, a full flow-structure interaction simulation is carried out on a patient-specific larynx model. To the best of our knowledge, this is the first patient-specific flow-structure interaction study of human phonation. The simulation results are well compared to the established human data. The effects of realistic geometry on glottal flow and vocal fold dynamics are investigated. It is found that both glottal flow and vocal fold dynamics present a high level of difference from the previous simplified model. This study also paved the important step toward the development of computer model for voice disease diagnosis and surgical planning. The project described was supported by Grant Number ROlDC007125 from the National Institute on Deafness and Other Communication Disorders (NIDCD).

  11. Hologram QSAR model for the prediction of human oral bioavailability.

    Science.gov (United States)

    Moda, Tiago L; Montanari, Carlos A; Andricopulo, Adriano D

    2007-12-15

    A drug intended for use in humans should have an ideal balance of pharmacokinetics and safety, as well as potency and selectivity. Unfavorable pharmacokinetics can negatively affect the clinical development of many otherwise promising drug candidates. A variety of in silico ADME (absorption, distribution, metabolism, and excretion) models are receiving increased attention due to a better appreciation that pharmacokinetic properties should be considered in early phases of the drug discovery process. Human oral bioavailability is an important pharmacokinetic property, which is directly related to the amount of drug available in the systemic circulation to exert pharmacological and therapeutic effects. In the present work, hologram quantitative structure-activity relationships (HQSAR) were performed on a training set of 250 structurally diverse molecules with known human oral bioavailability. The most significant HQSAR model (q(2)=0.70, r(2)=0.93) was obtained using atoms, bond, connection, and chirality as fragment distinction. The predictive ability of the model was evaluated by an external test set containing 52 molecules not included in the training set, and the predicted values were in good agreement with the experimental values. The HQSAR model should be useful for the design of new drug candidates having increased bioavailability as well as in the process of chemical library design, virtual screening, and high-throughput screening.

  12. Modeling Humans as Reinforcement Learners: How to Predict Human Behavior in Multi-Stage Games

    Science.gov (United States)

    Lee, Ritchie; Wolpert, David H.; Backhaus, Scott; Bent, Russell; Bono, James; Tracey, Brendan

    2011-01-01

    This paper introduces a novel framework for modeling interacting humans in a multi-stage game environment by combining concepts from game theory and reinforcement learning. The proposed model has the following desirable characteristics: (1) Bounded rational players, (2) strategic (i.e., players account for one anothers reward functions), and (3) is computationally feasible even on moderately large real-world systems. To do this we extend level-K reasoning to policy space to, for the first time, be able to handle multiple time steps. This allows us to decompose the problem into a series of smaller ones where we can apply standard reinforcement learning algorithms. We investigate these ideas in a cyber-battle scenario over a smart power grid and discuss the relationship between the behavior predicted by our model and what one might expect of real human defenders and attackers.

  13. A dengue model incorporating saturation incidence and human migration

    Science.gov (United States)

    Gakkhar, S.; Mishra, A.

    2015-03-01

    In this paper, a non-linear model has been proposed to investigate the effects of human migration on dengue dynamics. Human migration has been considered between two patches having different dengue strains. Due to migration secondary infection is possible. Further, the secondary infection is considered in patch-2 only as strain-2 in patch-2 is considered to be more severe than that of strain-1 in patch-1. The saturation incidence rate has been considered to incorporate the behavioral changes towards epidemic in human population. The basic reproduction number has been computed. Four Equilibrium states have been found and analyzed. Increasing saturation rate decreases the threshold thereby enhancing the stability of disease-free state in both the patches. Control on migration may lead to change in infection level of patches.

  14. Modelling human mobility patterns using photographic data shared online.

    Science.gov (United States)

    Barchiesi, Daniele; Preis, Tobias; Bishop, Steven; Moat, Helen Susannah

    2015-08-01

    Humans are inherently mobile creatures. The way we move around our environment has consequences for a wide range of problems, including the design of efficient transportation systems and the planning of urban areas. Here, we gather data about the position in space and time of about 16 000 individuals who uploaded geo-tagged images from locations within the UK to the Flickr photo-sharing website. Inspired by the theory of Lévy flights, which has previously been used to describe the statistical properties of human mobility, we design a machine learning algorithm to infer the probability of finding people in geographical locations and the probability of movement between pairs of locations. Our findings are in general agreement with official figures in the UK and on travel flows between pairs of major cities, suggesting that online data sources may be used to quantify and model large-scale human mobility patterns.

  15. Malarial birds: modeling infectious human disease in animals.

    Science.gov (United States)

    Slater, Leo B

    2005-01-01

    Through the examination of avian malarias as models of infectious human disease, this paper reveals the kinds of claims that scientists and physicians made on the basis of animal models-biological systems in the laboratory and the field-and what characteristics made for congruence between these models and human malaria. The focus is on the period between 1895 and 1945, and on the genesis and trajectory of certain animal models of malaria within specific locations, such as the Johns Hopkins School of Hygiene and Public Health in Baltimore and Bayer (I. G. Farben) in Elberfeld. These exemplars illustrate a diversity of approaches to malaria-as-disease, and the difficulties of framing aspects of this disease complex within an animal or laboratory system. The diversity and nearness to wild types of the birds, protozoan parasites, and mosquitoes that made up these malaria models contributed a great deal to the complexity of the models. Avian malarias, adopted with enthusiasm, were essential to the success of the U.S. antimalarial program during World War II.

  16. Development and implication of a human-volcano system model

    Science.gov (United States)

    Bachri, Syamsul; Stötter, Johann; Monreal, Matthias; Sartohadi, Junun

    2014-05-01

    In an attempt to understand the complexity of human-environment systems, models help to define, quantify, describe, or simulate complex interactions. With regards to the human-volcano system, we develop a conceptual model in order to assist analysis of its two basic elements, the physical and the social environment. A field survey of the human environment interaction of two of the most active volcanic areas in Indonesia (Mt. Merapi and Mt. Bromo) and a corresponding literature review from other case studies was carried out. A differentiated understanding of human interaction with hazard potential elements within the human-volcano system is the main focus of the model development. We classified volcanic processes and effects as three pairs of dichotomies: positive or negative impacts, on society or environment in an indirect or direct way. Each volcanically induced process or effect characterized accordingly leads to eight distinct process/effect classes. They are positive direct effects on society (PDS); positive direct effects on natural resources (PDN); positive indirect effects on society (PIS); positive indirect effects on natural resources (PIN); negative direct effects on society (NDS); negative direct effects on natural resources (NDN); negative indirect effects on society (NIS) and lastly negative indirect effects on natural resources (NIN). Such differentiated view of volcanic process/effects bears several advantages. First, whereas volcanic processes have hitherto been viewed as hazards only, it becomes possible now to describe a particular process/effect in a particular context as negative or positive. Secondly, such a categorization makes it possible to account for processes of the human-volcano system that do not have a direct physical expression but are of socio-cultural relevance. Thirdly, the greater degree of differentiation that is made possible when evaluating volcanic processes has significant repercussions on the way volcanic risk must be

  17. Immunoarchitectural characterization of a human skin model reconstructed in vitro

    Directory of Open Access Journals (Sweden)

    Luís Ricardo Martinhão Souto

    Full Text Available CONTEXT AND OBJECTIVE: Over the last few years, different models for human skin equivalent reconstructed in vitro (HSERIV have been reported for clinical usage and applications in research for the pharmaceutical industry. Before release for routine use as human skin replacements, HSERIV models need to be tested regarding their similarity with in vivo skin, using morphological (architectural and immunohistochemical (functional analyses. A model for HSERIV has been developed in our hospital, and our aim here was to further characterize its immunoarchitectural features by comparing them with human skin, before it can be tested for clinical use, e.g. for severe burns or wounds, whenever ancillary methods are not indicated. DESIGN AND SETTING: Experimental laboratory study, in the Skin Cell Culture Laboratory, School of Medical Sciences, Universidade Estadual de Campinas. METHODS: Histological sections were stained with hematoxylin-eosin, Masson's trichrome for collagen fibers, periodic acid-Schiff reagent for basement membrane and glycogen, Weigert-Van Gieson for elastic fibers and Fontana-Masson for melanocytes. Immunohistochemistry was used to localize cytokeratins (broad spectrum of molecular weight, AE1/AE3, high molecular weight cytokeratins (34βE12, low molecular weight cytokeratins (35βH11, cytokeratins 7 and 20, vimentin, S-100 protein (for melanocytic and dendritic cells, CD68 (KP1, histiocytes and CD34 (QBend, endothelium. RESULTS: Histology revealed satisfactory similarity between HSERIV and in vivo skin. Immunohistochemical analysis on HSERIV demonstrated that the marker pattern was similar to what is generally present in human skin in vivo. CONCLUSION: HSERIV is morphologically and functionally compatible with human skin observed in vivo.

  18. Disability and General Recommendations of UN Human Rights Committees: An asymmetric relationship between invisibility, medical model and human rights model

    Directory of Open Access Journals (Sweden)

    Leonor Lidón Heras

    2013-07-01

    Full Text Available The purpose of this article is to determine the level of inclusion of Disability in the UN Committees General Comments, and if this is done from a human rights perspective. The methodology used focuses on a critical and emancipatory analysis. In particular investigated the different approached used (mainstreaming or specific treatment, discrimination definition, disability model used and it also compares with other excluded groups. The analysis allows to show different level of commitment with disability, the asymmetric treatment, the lacks in understanding disability as a human rights issue. The main finding is the need of a compulsory expansion of the Convention of the rights of persons with disabilities.

  19. Velocity profiles in idealized model of human respiratory tract

    Directory of Open Access Journals (Sweden)

    Jicha M.

    2013-04-01

    Full Text Available This article deals with numerical simulation focused on velocity profiles in idealized model of human upper airways during steady inspiration. Three r gimes of breathing were investigated: Resting condition, Deep breathing and Light activity which correspond to most common regimes used for experiments and simulations. Calculation was validated with experimental data given by Phase Doppler Anemometry performed on the model with same geometry. This comparison was made in multiple points which form one cross-section in trachea near first bifurcation of bronchial tree. Development of velocity profile in trachea during steady inspiration was discussed with respect for common phenomenon formed in trachea and for future research of transport of aerosol particles in human respiratory tract.

  20. Modelling human problem solving with data from an online game.

    Science.gov (United States)

    Rach, Tim; Kirsch, Alexandra

    2016-11-01

    Since the beginning of cognitive science, researchers have tried to understand human strategies in order to develop efficient and adequate computational methods. In the domain of problem solving, the travelling salesperson problem has been used for the investigation and modelling of human solutions. We propose to extend this effort with an online game, in which instances of the travelling salesperson problem have to be solved in the context of a game experience. We report on our effort to design and run such a game, present the data contained in the resulting openly available data set and provide an outlook on the use of games in general for cognitive science research. In addition, we present three geometrical models mapping the starting point preferences in the problems presented in the game as the result of an evaluation of the data set.

  1. Time-varying priority queuing models for human dynamics.

    Science.gov (United States)

    Jo, Hang-Hyun; Pan, Raj Kumar; Kaski, Kimmo

    2012-06-01

    Queuing models provide insight into the temporal inhomogeneity of human dynamics, characterized by the broad distribution of waiting times of individuals performing tasks. We theoretically study the queuing model of an agent trying to execute a task of interest, the priority of which may vary with time due to the agent's "state of mind." However, its execution is disrupted by other tasks of random priorities. By considering the priority of the task of interest either decreasing or increasing algebraically in time, we analytically obtain and numerically confirm the bimodal and unimodal waiting time distributions with power-law decaying tails, respectively. These results are also compared to the updating time distribution of papers in arXiv.org and the processing time distribution of papers in Physical Review journals. Our analysis helps to understand human task execution in a more realistic scenario.

  2. Drosophila as a genetic model for studying pathogenic human viruses.

    Science.gov (United States)

    Hughes, Tamara T; Allen, Amanda L; Bardin, Joseph E; Christian, Megan N; Daimon, Kansei; Dozier, Kelsey D; Hansen, Caom L; Holcomb, Lisa M; Ahlander, Joseph

    2012-02-05

    Viruses are infectious particles whose viability is dependent on the cells of living organisms, such as bacteria, plants, and animals. It is of great interest to discover how viruses function inside host cells in order to develop therapies to treat virally infected organisms. The fruit fly Drosophila melanogaster is an excellent model system for studying the molecular mechanisms of replication, amplification, and cellular consequences of human viruses. In this review, we describe the advantages of using Drosophila as a model system to study human viruses, and highlight how Drosophila has been used to provide unique insight into the gene function of several pathogenic viruses. We also propose possible directions for future research in this area.

  3. Exploring host-microbiota interactions in animal models and humans.

    Science.gov (United States)

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

    2013-04-01

    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.

  4. Optimality principles for model-based prediction of human gait.

    Science.gov (United States)

    Ackermann, Marko; van den Bogert, Antonie J

    2010-04-19

    Although humans have a large repertoire of potential movements, gait patterns tend to be stereotypical and appear to be selected according to optimality principles such as minimal energy. When applied to dynamic musculoskeletal models such optimality principles might be used to predict how a patient's gait adapts to mechanical interventions such as prosthetic devices or surgery. In this paper we study the effects of different performance criteria on predicted gait patterns using a 2D musculoskeletal model. The associated optimal control problem for a family of different cost functions was solved utilizing the direct collocation method. It was found that fatigue-like cost functions produced realistic gait, with stance phase knee flexion, as opposed to energy-related cost functions which avoided knee flexion during the stance phase. We conclude that fatigue minimization may be one of the primary optimality principles governing human gait.

  5. Time-Varying Priority Queuing Models for Human Dynamics

    CERN Document Server

    Jo, Hang-Hyun; Kaski, Kimmo

    2011-01-01

    Queuing models provide insight into the temporal inhomogeneity of human dynamics, characterized by the broad distribution of waiting times of individuals performing tasks. We study the queuing model of an agent trying to execute a task of interest, the priority of which may vary with time due to the agent's "state of mind." However, its execution can be disrupted by other tasks of random priorities. By considering the priority of the task of interest either decreasing or increasing algebraically in time, we analytically obtain and numerically confirm the bimodal and unimodal waiting time distributions with power-law decaying tails, respectively. These results are also compared to the updating time distribution of papers in the arXiv and the processing time distribution of papers in Physical Review journals. Our analysis helps to understand the human task execution behavior in a more realistic scenario.

  6. Modeling of electromagnetic stimulation of the human brain.

    Science.gov (United States)

    Lazutkin, Dmitry; Husar, Peter

    2010-01-01

    The World Health Organization estimates depression as a serious threat to the health of millions of people worldwide. The purpose of this paper is to introduce the ongoing research devoted to the investigation of a possibility to use low-field electromagnetic stimulation of the human brain in the treatment of depressive disorder. In the course of the work the 3D models of transcranial magnetic stimulation and low-field magnetic stimulation based upon the use of a layered sphere head model have been developed. An initial approach towards the realistic human head reconstruction has been made. The revealed order of the stimulating electromagnetic field suitable for operation makes it possible to draft a technical specification for the stimulation device.

  7. A topological multilayer model of the human body.

    Science.gov (United States)

    Barbeito, Antonio; Painho, Marco; Cabral, Pedro; O'Neill, João

    2015-11-04

    Geographical information systems deal with spatial databases in which topological models are described with alphanumeric information. Its graphical interfaces implement the multilayer concept and provide powerful interaction tools. In this study, we apply these concepts to the human body creating a representation that would allow an interactive, precise, and detailed anatomical study. A vector surface component of the human body is built using a three-dimensional (3-D) reconstruction methodology. This multilayer concept is implemented by associating raster components with the corresponding vector surfaces, which include neighbourhood topology enabling spatial analysis. A root mean square error of 0.18 mm validated the three-dimensional reconstruction technique of internal anatomical structures. The expansion of the identification and the development of a neighbourhood analysis function are the new tools provided in this model.

  8. A family of hyperelastic models for human brain tissue

    Science.gov (United States)

    Mihai, L. Angela; Budday, Silvia; Holzapfel, Gerhard A.; Kuhl, Ellen; Goriely, Alain

    2017-09-01

    Experiments on brain samples under multiaxial loading have shown that human brain tissue is both extremely soft when compared to other biological tissues and characterized by a peculiar elastic response under combined shear and compression/tension: there is a significant increase in shear stress with increasing axial compression compared to a moderate increase with increasing axial tension. Recent studies have revealed that many widely used constitutive models for soft biological tissues fail to capture this characteristic response. Here, guided by experiments of human brain tissue, we develop a family of modeling approaches that capture the elasticity of brain tissue under varying simple shear superposed on varying axial stretch by exploiting key observations about the behavior of the nonlinear shear modulus, which can be obtained directly from the experimental data.

  9. Modeling of human movement monitoring using Bluetooth Low Energy technology.

    Science.gov (United States)

    Mokhtari, G; Zhang, Q; Karunanithi, M

    2015-01-01

    Bluetooth Low Energy (BLE) is a wireless communication technology which can be used to monitor human movements. In this monitoring system, a BLE signal scanner scans signal strength of BLE tags carried by people, to thus infer human movement patterns within its monitoring zone. However to the extent of our knowledge one main aspect of this monitoring system which has not yet been thoroughly investigated in literature is how to build a sound theoretical model, based on tunable BLE communication parameters such as scanning time interval and advertising time interval, to enable the study and design of effective and efficient movement monitoring systems. In this paper, we proposed and developed a statistical model based on Monte-Carlo simulation, which can be utilized to assess impacts of BLE technology parameters in terms of latency and efficiency, on a movement monitoring system, and can thus benefit a more efficient system design.

  10. Tissue-engineered microenvironment systems for modeling human vasculature.

    Science.gov (United States)

    Tourovskaia, Anna; Fauver, Mark; Kramer, Gregory; Simonson, Sara; Neumann, Thomas

    2014-09-01

    The high attrition rate of drug candidates late in the development process has led to an increasing demand for test assays that predict clinical outcome better than conventional 2D cell culture systems and animal models. Government agencies, the military, and the pharmaceutical industry have started initiatives for the development of novel in-vitro systems that recapitulate functional units of human tissues and organs. There is growing evidence that 3D cell arrangement, co-culture of different cell types, and physico-chemical cues lead to improved predictive power. A key element of all tissue microenvironments is the vasculature. Beyond transporting blood the microvasculature assumes important organ-specific functions. It is also involved in pathologic conditions, such as inflammation, tumor growth, metastasis, and degenerative diseases. To provide a tool for modeling this important feature of human tissue microenvironments, we developed a microfluidic chip for creating tissue-engineered microenvironment systems (TEMS) composed of tubular cell structures. Our chip design encompasses a small chamber that is filled with an extracellular matrix (ECM) surrounding one or more tubular channels. Endothelial cells (ECs) seeded into the channels adhere to the ECM walls and grow into perfusable tubular tissue structures that are fluidically connected to upstream and downstream fluid channels in the chip. Using these chips we created models of angiogenesis, the blood-brain barrier (BBB), and tumor-cell extravasation. Our angiogenesis model recapitulates true angiogenesis, in which sprouting occurs from a "parent" vessel in response to a gradient of growth factors. Our BBB model is composed of a microvessel generated from brain-specific ECs within an ECM populated with astrocytes and pericytes. Our tumor-cell extravasation model can be utilized to visualize and measure tumor-cell migration through vessel walls into the surrounding matrix. The described technology can be used

  11. Holistic Modeling for Human-Autonomous System Interaction

    Science.gov (United States)

    2015-01-01

    Dekker  and  Woods,  1999;   Hollnagel,  2003;   Klein ,  2000;   Klein ,  et  al.,  1989;  Lewis  and  Wharton,  1997...complexities  of  human  perception,  cognition,   emotions ,   and  decision-­‐making.  Second,  the  CHAS  model  requires

  12. A novel model of human skin pressure ulcers in mice.

    Directory of Open Access Journals (Sweden)

    Andrés A Maldonado

    Full Text Available INTRODUCTION: Pressure ulcers are a prevalent health problem in today's society. The shortage of suitable animal models limits our understanding and our ability to develop new therapies. This study aims to report on the development of a novel and reproducible human skin pressure ulcer model in mice. MATERIAL AND METHODS: Male non-obese, diabetic, severe combined immunodeficiency mice (n = 22 were engrafted with human skin. A full-thickness skin graft was placed onto 4×3 cm wounds created on the dorsal skin of the mice. Two groups with permanent grafts were studied after 60 days. The control group (n = 6 was focused on the process of engraftment. Evaluations were conducted with photographic assessment, histological analysis and fluorescence in situ hybridization (FISH techniques. The pressure ulcer group (n = 12 was created using a compression device. A pressure of 150 mmHg for 8 h, with a total of three cycles of compression-release was exerted. Evaluations were conducted with photographic assessment and histological analysis. RESULTS: Skin grafts in the control group took successfully, as shown by visual assessment, FISH techniques and histological analysis. Pressure ulcers in the second group showed full-thickness skin loss with damage and necrosis of all the epidermal and dermal layers (ulcer stage III in all cases. Complete repair occurred after 40 days. CONCLUSIONS: An inexpensive, reproducible human skin pressure ulcer model has been developed. This novel model will facilitate the development of new clinically relevant therapeutic strategies that can be tested directly on human skin.

  13. A Revised Model for Dosimetry in the Human Small Intestine

    Energy Technology Data Exchange (ETDEWEB)

    John Poston; Nasir U. Bhuiyan; R. Alex Redd; Neil Parham; Jennifer Watson

    2005-02-28

    A new model for an adult human gastrointestinal tract (GIT) has been developed for use in internal dose estimations to the wall of the GIT and to the other organs and tissues of the body from radionuclides deposited in the lumenal contents of the five sections of the GIT. These sections were the esophasgus, stomach, small intestine, upper large intestine, and the lower large intestine. The wall of each section was separated from its lumenal contents.

  14. Mechanisms and genes in human strial presbycusis from animal models.

    Science.gov (United States)

    Ohlemiller, Kevin K

    2009-06-24

    Schuknecht proposed a discrete form of presbycusis in which hearing loss results principally from degeneration of cochlear stria vascularis and decline of the endocochlear potential (EP). This form was asserted to be genetically linked, and to arise independently from age-related pathology of either the organ of Corti or cochlear neurons. Although extensive strial degeneration in humans coincides with hearing loss, EPs have never been measured in humans, and age-related EP reduction has never been verified. No human genes that promote strial presbycusis have been identified, nor is its pathophysiology well understood. Effective application of animal models to this issue requires models demonstrating EP decline, and preferably, genetically distinct strains that vary in patterns of EP decline and its cellular correlates. Until recently, only two models, Mongolian gerbils and Tyrp1(B-lt) mice, were known to undergo age-associated EP reduction. Detailed studies of seven inbred mouse strains have now revealed three strains (C57BL/6J, B6.CAST-Cdh23(CAST), CBA/J) showing essentially no EP decline with age, and four strains ranging from modest to severe EP reduction (C57BL/6-Tyr(c-2J), BALB/cJ, CBA/CaJ, NOD.NON-H2(nbl)/LtJ). Collectively, animal models support five basic principles regarding a strial form of presbycusis: 1) Progressive EP decline from initially normal levels as a defining characteristic; 2) Non-universality, not all age-associated hearing loss involves EP decline; 3) A clear genetic basis; 4) Modulation by environment or stochastic events; and 5) Independent strial, organ of Corti, and neural pathology. Shared features between human strial presbycusis, gerbils, and BALB/cJ and C57BL/6-Tyr(c-2J) mice further suggest this condition frequently begins with strial marginal cell dysfunction and loss. By contrast, NOD.NON-H2(nbl) mice may model a sequence more closely associated with strial microvascular disease. Additional studies of these and other inbred mouse

  15. A Simulink model for the human circulatory system.

    Science.gov (United States)

    Wabel, P; Leonhardt, S

    1998-01-01

    This paper presents the mathematical simulation of the human circulatory system. The model is based on the former work of Coleman and co-workers and has been redesigned for simulation with the Matlab toolbox "Simulink". It includes the heart and the peripheral circulation, the respiratory system, the kidneys and the major neural and hormonal control mechanisms, which are necessary for maintaining homeostasis. The model contains more than 30 blocks with over 200 physiological variables, which can be accessed and plotted during the simulation.

  16. Human growth and body weight dynamics: an integrative systems model.

    Science.gov (United States)

    Rahmandad, Hazhir

    2014-01-01

    Quantifying human weight and height dynamics due to growth, aging, and energy balance can inform clinical practice and policy analysis. This paper presents the first mechanism-based model spanning full individual life and capturing changes in body weight, composition and height. Integrating previous empirical and modeling findings and validated against several additional empirical studies, the model replicates key trends in human growth including A) Changes in energy requirements from birth to old ages. B) Short and long-term dynamics of body weight and composition. C) Stunted growth with chronic malnutrition and potential for catch up growth. From obesity policy analysis to treating malnutrition and tracking growth trajectories, the model can address diverse policy questions. For example I find that even without further rise in obesity, the gap between healthy and actual Body Mass Indexes (BMIs) has embedded, for different population groups, a surplus of 14%-24% in energy intake which will be a source of significant inertia in obesity trends. In another analysis, energy deficit percentage needed to reduce BMI by one unit is found to be relatively constant across ages. Accompanying documented and freely available simulation model facilitates diverse applications customized to different sub-populations.

  17. Modelling familial dysautonomia in human induced pluripotent stem cells.

    Science.gov (United States)

    Lee, Gabsang; Studer, Lorenz

    2011-08-12

    Induced pluripotent stem (iPS) cells have considerable promise as a novel tool for modelling human disease and for drug discovery. While the generation of disease-specific iPS cells has become routine, realizing the potential of iPS cells in disease modelling poses challenges at multiple fronts. Such challenges include selecting a suitable disease target, directing the fate of iPS cells into symptom-relevant cell populations, identifying disease-related phenotypes and showing reversibility of such phenotypes using genetic or pharmacological approaches. Finally, the system needs to be scalable for use in modern drug discovery. Here, we will discuss these points in the context of modelling familial dysautonomia (FD, Riley-Day syndrome, hereditary sensory and autonomic neuropathy III (HSAN-III)), a rare genetic disorder in the peripheral nervous system. We have demonstrated three disease-specific phenotypes in FD-iPS-derived cells that can be partially rescued by treating cells with the plant hormone kinetin. Here, we will discuss how to use FD-iPS cells further in high throughput drug discovery assays, in modelling disease severity and in performing mechanistic studies aimed at understanding disease pathogenesis. FD is a rare disease but represents an important testing ground for exploring the potential of iPS cell technology in modelling and treating human disease.

  18. Building a Shared Definitional Model of Long Duration Human Spaceflight

    Science.gov (United States)

    Orr, M.; Whitmire, A.; Sandoval, L.; Leveton, L.; Arias, D.

    2011-01-01

    In 1956, on the eve of human space travel Strughold first proposed a simple classification of the present and future stages of manned flight that identified key factors, risks and developmental stages for the evolutionary journey ahead. As we look to optimize the potential of the ISS as a gateway to new destinations, we need a current shared working definitional model of long duration human space flight to help guide our path. Initial search of formal and grey literature augmented by liaison with subject matter experts. Search strategy focused on both the use of term long duration mission and long duration spaceflight, and also broader related current and historical definitions and classification models of spaceflight. The related sea and air travel literature was also subsequently explored with a view to identifying analogous models or classification systems. There are multiple different definitions and classification systems for spaceflight including phase and type of mission, craft and payload and related risk management models. However the frequently used concepts of long duration mission and long duration spaceflight are infrequently operationally defined by authors, and no commonly referenced classical or gold standard definition or model of these terms emerged from the search. The categorization (Cat) system for sailing was found to be of potential analogous utility, with its focus on understanding the need for crew and craft autonomy at various levels of potential adversity and inability to gain outside support or return to a safe location, due to factors of time, distance and location.

  19. Modeling and percept of transcorneal electrical stimulation in humans.

    Science.gov (United States)

    Xie, John; Wang, Gene-Jack; Yow, Lindy; J Cela, Carlos; Humayun, Mark S; Weiland, James D; Lazzi, Gianluca; Jadvar, Hossein

    2011-07-01

    Retinal activation via transcorneal electrical stimulation (TcES) in normal humans was investigated by comparing subject perception, model predictions, and brain activation patterns. The preferential location of retinal stimulation was predicted from 3-D admittance modeling. Visual cortex activation was measured using positron emission tomography (PET) and (18)F-fluorodeoxyglucose (FDG). Two different corneal electrodes were investigated: DTL-Plus and ERG-Jet. Modeling results predicted preferential stimulation of the peripheral, inferior, nasal retina during right eye TcES using DTL-Plus, but more extensive activation of peripheral, nasal hemiretina using ERG-Jet. The results from human FDG PET study using both corneal electrodes showed areas of visual cortex activation that consistently corresponded with the reported phosphene percept and modeling predictions. ERG-Jet was able to generate brighter phosphene percept than DTL-Plus and elicited retinotopically mapped primary visual cortex activation. This study demonstrates that admittance modeling and PET imaging consistently predict the perceived location of electrically elicited phosphenes produced during TcES.

  20. Towards a Fast Dynamic Model of the Human Circulatory System

    Science.gov (United States)

    Kaplan, Carolyn; Green, Melissa; Boris, Jay; Oran, Elaine

    2011-11-01

    We describe a model for systems-level transport in the human circulatory system that is based on a set of equations for a one-dimensional unsteady elastic pipe flow circuit. The system is collapsed from three spatial dimensions and time to one spatial dimension and time by assuming axisymmetric vessel geometry and a parabolic velocity profile across the cylindrical vessels. To drive the fluid, the contractions of a beating heart are modeled as periodic area changes of the elastic vessels. Two different models are compared, both including and neglecting fluid acceleration. Time-resolved distributions of pressure, velocity and area compare reasonably well with reference data. Increasing the rigidity of the vasculature is found to increase peak arterial pressures on the order of ten percent, and including a distributed vascular contraction to model distributed skeletal muscle contractions monotonically increases time-averaged blood flow in the veins, consistent with human physiological response. The circulatory system model presented here simulates the circulatory system on the order of one hundred times faster than real-time; that is, we can compute thousands of heartbeats per minute of CPU time.

  1. Customized Finite Element Modelling of the Human Cornea.

    Directory of Open Access Journals (Sweden)

    Irene Simonini

    Full Text Available To construct patient-specific solid models of human cornea from ocular topographer data, to increase the accuracy of the biomechanical and optical estimate of the changes in refractive power and stress caused by photorefractive keratectomy (PRK.Corneal elevation maps of five human eyes were taken with a rotating Scheimpflug camera combined with a Placido disk before and after refractive surgery. Patient-specific solid models were created and discretized in finite elements to estimate the corneal strain and stress fields in preoperative and postoperative configurations and derive the refractive parameters of the cornea.Patient-specific geometrical models of the cornea allow for the creation of personalized refractive maps at different levels of IOP. Thinned postoperative corneas show a higher stress gradient across the thickness and higher sensitivity of all geometrical and refractive parameters to the fluctuation of the IOP.Patient-specific numerical models of the cornea can provide accurate quantitative information on the refractive properties of the cornea under different levels of IOP and describe the change of the stress state of the cornea due to refractive surgery (PRK. Patient-specific models can be used as indicators of feasibility before performing the surgery.

  2. Validation of a finite element model of the human metacarpal.

    Science.gov (United States)

    Barker, D S; Netherway, D J; Krishnan, J; Hearn, T C

    2005-03-01

    Implant loosening and mechanical failure of components are frequently reported following metacarpophalangeal (MCP) joint replacement. Studies of the mechanical environment of the MCP implant-bone construct are rare. The objective of this study was to evaluate the predictive ability of a finite element model of the intact second human metacarpal to provide a validated baseline for further mechanical studies. A right index human metacarpal was subjected to torsion and combined axial/bending loading using strain gauge (SG) and 3D finite element (FE) analysis. Four different representations of bone material properties were considered. Regression analyses were performed comparing maximum and minimum principal surface strains taken from the SG and FE models. Regression slopes close to unity and high correlation coefficients were found when the diaphyseal cortical shell was modelled as anisotropic and cancellous bone properties were derived from quantitative computed tomography. The inclusion of anisotropy for cortical bone was strongly influential in producing high model validity whereas variation in methods of assigning stiffness to cancellous bone had only a minor influence. The validated FE model provides a tool for future investigations of current and novel MCP joint prostheses.

  3. Modelling of Human Glottis in VLSI for Low Power Architectures

    CERN Document Server

    Raj, Nikhil

    2010-01-01

    The Glottal Source is an important component of voice as it can be considered as the excitation signal to the voice apparatus. Nowadays, new techniques of speech processing such as speech recognition and speech synthesis use the glottal closure and opening instants. Current models of the glottal waves derive their shape from approximate information rather than from exactly measured data. General method concentrate on assessment of the glottis opening using optical, acoustical methods, or on visualization of the larynx position using ultrasound, computer tomography or magnetic resonance imaging techniques. In this work, circuit model of Human Glottis using MOS is designed by exploiting fluid volume velocity to current, fluid pressure to voltage, and linear and nonlinear mechanical impedances to linear and nonlinear electrical impedances. The glottis modeled as current source includes linear, non-linear impedances to represent laminar and turbulent flow respectively, in vocal tract. The MOS modelling and simula...

  4. Computational modeling of hypertensive growth in the human carotid artery

    Science.gov (United States)

    Sáez, Pablo; Peña, Estefania; Martínez, Miguel Angel; Kuhl, Ellen

    2014-06-01

    Arterial hypertension is a chronic medical condition associated with an elevated blood pressure. Chronic arterial hypertension initiates a series of events, which are known to collectively initiate arterial wall thickening. However, the correlation between macrostructural mechanical loading, microstructural cellular changes, and macrostructural adaptation remains unclear. Here, we present a microstructurally motivated computational model for chronic arterial hypertension through smooth muscle cell growth. To model growth, we adopt a classical concept based on the multiplicative decomposition of the deformation gradient into an elastic part and a growth part. Motivated by clinical observations, we assume that the driving force for growth is the stretch sensed by the smooth muscle cells. We embed our model into a finite element framework, where growth is stored locally as an internal variable. First, to demonstrate the features of our model, we investigate the effects of hypertensive growth in a real human carotid artery. Our results agree nicely with experimental data reported in the literature both qualitatively and quantitatively.

  5. Internodal pathways in the human atria: a model study.

    Science.gov (United States)

    Kafer, C J

    1991-12-01

    An electrophysical/anatomical computer model of human atrial excitation was used to investigate the controversy over specialized internodal pathways. The only atrial pathways that have been thoroughly described in the literature are those that connect the sinoatrial (SA) and atrioventricular (AV) nodes, and the right and left atria. By incorporating pathways of rapid propagation representing the internodal and interatrial tracts, anisotropy was introduced into an otherwise isotropic atrial model. Simulated epicardial isochrone maps, heart vector loops, and electrograms were calculated for both the isotropic and anisotropic atrial models, and the simulations were compared with observed normal data. Although the simulations using the anisotropic model compare more favorably with real data, the results suggest that there are more pathways of rapid propagation in the atria than those described and that a global anisotropy based on morphology and fiber direction is a more likely explanation than rapid propagation confined to a few specialized pathways.

  6. Objective models for steroid binding sites of human globulins

    Science.gov (United States)

    Schnitker, Jurgen; Gopalaswamy, Ramesh; Crippen, Gordon M.

    1997-01-01

    We report the application of a recently developed alignment-free 3D QSAR method [Crippen,G.M., J. Comput. Chem., 16 (1995) 486] to a benchmark-type problem. The test systeminvolves the binding of 31 steroid compounds to two kinds of human carrier protein. Themethod used not only allows for arbitrary binding modes, but also avoids the problems oftraditional least-squares techniques with regard to the implicit neglect of informative outlyingdata points. It is seen that models of considerable predictive power can be obtained even witha very vague binding site description. Underlining a systematic, but usually ignored, problemof the QSAR approach, there is not one unique type of model but, rather, an entire manifoldof distinctly different models that are all compatible with the experimental information. Fora given model, there is also a considerable variation in the found binding modes, illustratingthe problems that are inherent in the need for 'correct` molecular alignment in conventional3D QSAR methods.

  7. Estimation of the Human Absorption Cross Section Via Reverberation Models

    DEFF Research Database (Denmark)

    Steinböck, Gerhard; Pedersen, Troels; Fleury, Bernard Henri;

    2016-01-01

    Since the presence of persons affects the reverberation time observed for in-room channels, the absorption cross section of a person can be estimated from measurements via Sabine's and Eyring's models for the reverberation time. We propose an estimator relying on the more accurate model by Eyring...... and compare the obtained results to those of Sabine's model. We find that the absorption by persons is large enough to be measured with a wideband channel sounder and that estimates of the human absorption cross section differ for the two models. The obtained values are comparable to values reported...... in the literature. We also suggest the use of controlled environments with low average absorption coefficients to obtain more reliable estimates. The obtained values can be used to predict the change of reverberation time with persons in the propagation environment. This allows prediction of channel characteristics...

  8. Modelling Neurodegenerative Diseases Using Human Pluripotent Stem Cells

    DEFF Research Database (Denmark)

    Hall, Vanessa J.

    2016-01-01

    Neurodegenerative diseases are being modelled in-vitro using human patient-specific, induced pluripotent stem cells and transgenic embryonic stem cells to determine more about disease mechanisms, as well as to discover new treatments for patients. Current research in modelling Alzheimer’s disease......, frontotemporal dementia and Parkinson’s disease using pluripotent stem cells is described, along with the advent of gene-editing, which has been the complimentary tool for the field. Current methods used to model these diseases are predominantly dependent on 2D cell culture methods. Outcomes reveal that only...... that includes studying more complex 3D cell cultures, as well as accelerating aging of the neurons, may help to yield stronger phenotypes in the cultured cells. Thus, the use and application of pluripotent stem cells for modelling disease have already shown to be a powerful approach for discovering more about...

  9. A novel in vitro human microglia model: characterization of human monocyte-derived microglia.

    Science.gov (United States)

    Etemad, Samar; Zamin, Rasheeda Mohd; Ruitenberg, Marc J; Filgueira, Luis

    2012-07-30

    Microglia are the innate immune cells of the central nervous system. They help maintaining physiological homeostasis and contribute significantly to inflammatory responses in the course of infection, injury and degenerative processes. To date, there is no standardized simple model available to investigate the biology of human microglia. The aim of this study was to establish a new human microglia model. For that purpose, human peripheral blood monocytes were cultured in serum free medium in the presence of M-CSF, GM-CSF, NGF and CCL2 to generate monocyte-derived microglia (M-MG). M-MG were clearly different in morphology, phenotype and function from freshly isolated monocytes, cultured monocytes in the absence of the cytokines and monocyte-derived dendritic cells (M-DC) cultured in the presence of GM-CSF and IL-4. M-MG acquired a ramified morphology with primary and secondary processes. M-MG displayed a comparable phenotype to the human microglia cell line HMC3, expressing very low levels of CD45, CD14 and HLA-DR, CD11b and CD11c; and undetectable levels of CD40, CD80 and CD83, and a distinct pattern of chemokine receptors (positive for CCR1, CCR2, CCR4, CCR5, CXCR1, CXCR3, CX3CR1; negative for CCR6 and CCR7). In comparison with M-DC, M-MG displayed lower T-lymphocyte stimulatory capacity, as well as lower phagocytosis activity. The described protocol for the generation of human monocyte-derived microglia is feasible, well standardized and reliable, as it uses well defined culture medium and recombinant cytokines, but no serum or conditioned medium. This protocol will certainly be very helpful for future studies investigating the biology and pathology of human microglia.

  10. Incorporating the gut microbiota into models of human and non-human primate ecology and evolution.

    Science.gov (United States)

    Amato, Katherine R

    2016-01-01

    The mammalian gut is home to a diverse community of microbes. Advances in technology over the past two decades have allowed us to examine this community, the gut microbiota, in more detail, revealing a wide range of influences on host nutrition, health, and behavior. These host-gut microbe interactions appear to shape host plasticity and fitness in a variety of contexts, and therefore represent a key factor missing from existing models of human and non-human primate ecology and evolution. However, current studies of the gut microbiota tend to include limited contextual data or are clinical, making it difficult to directly test broad anthropological hypotheses. Here, I review what is known about the animal gut microbiota and provide examples of how gut microbiota research can be integrated into the study of human and non-human primate ecology and evolution with targeted data collection. Specifically, I examine how the gut microbiota may impact primate diet, energetics, disease resistance, and cognition. While gut microbiota research is proliferating rapidly, especially in the context of humans, there remain important gaps in our understanding of host-gut microbe interactions that will require an anthropological perspective to fill. Likewise, gut microbiota research will be an important tool for filling remaining gaps in anthropological research.

  11. Extracting Three Dimensional Surface Model of Human Kidney from the Visible Human Data Set using Free Software

    CERN Document Server

    P, Kirana Kumara

    2013-01-01

    Three dimensional digital model of a representative human kidney is needed for a surgical simulator that is capable of simulating a laparoscopic surgery involving kidney. Buying a three dimensional computer model of a representative human kidney, or reconstructing a human kidney from an image sequence using commercial software, both involve (sometimes significant amount of) money. In this paper, author has shown that one can obtain a three dimensional surface model of human kidney by making use of images from the Visible Human Data Set and a few free software packages (ImageJ, ITK-SNAP, and MeshLab in particular). Images from the Visible Human Data Set, and the software packages used here, both do not cost anything. Hence, the practice of extracting the geometry of a representative human kidney for free, as illustrated in the present work, could be a free alternative to the use of expensive commercial software or to the purchase of a digital model.

  12. Theory analysis of the Dental Hygiene Human Needs Conceptual Model.

    Science.gov (United States)

    MacDonald, L; Bowen, D M

    2016-11-09

    Theories provide a structural knowing about concept relationships, practice intricacies, and intuitions and thus shape the distinct body of the profession. Capturing ways of knowing and being is essential to any professions' practice, education and research. This process defines the phenomenon of the profession - its existence or experience. Theory evaluation is a systematic criterion-based assessment of a specific theory. This study presents a theory analysis of the Dental Hygiene Human Needs Conceptual Model (DH HNCM). Using the Walker and Avant Theory Analysis, a seven-step process, the DH HNCM, was analysed and evaluated for its meaningfulness and contribution to dental hygiene. The steps include the following: (i) investigate the origins; (ii) examine relationships of the theory's concepts; (iii) assess the logic of the theory's structure; (iv) consider the usefulness to practice; (v) judge the generalizability; (vi) evaluate the parsimony; and (vii) appraise the testability of the theory. Human needs theory in nursing and Maslow's Hierarchy of Need Theory prompted this theory's development. The DH HNCM depicts four concepts based on the paradigm concepts of the profession: client, health/oral health, environment and dental hygiene actions, and includes validated eleven human needs that evolved overtime to eight. It is logical, simplistic, allows scientific predictions and testing, and provides a unique lens for the dental hygiene practitioner. With this model, dental hygienists have entered practice, knowing they enable clients to meet their human needs. For the DH HNCM, theory analysis affirmed that the model is reasonable and insightful and adds to the dental hygiene professions' epistemology and ontology. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Modeling cognitive loads for evolving shared mental models in human-agent collaboration.

    Science.gov (United States)

    Fan, Xiaocong; Yen, John

    2011-04-01

    Recent research on human-centered teamwork highly demands the design of cognitive agents that can model and exploit human partners' cognitive load to enhance team performance. In this paper, we focus on teams composed of human-agent pairs and develop a system called Shared Mental Models for all--SMMall. SMMall implements a hidden Markov model (HMM)-based cognitive load model for an agent to predict its human partner's instantaneous cognitive load status. It also implements a user interface (UI) concept called shared belief map, which offers a synergic representation of team members' information space and allows them to share beliefs. An experiment was conducted to evaluate the HMM-based load models. The results indicate that the HMM-based load models are effective in helping team members develop a shared mental model (SMM), and the benefit of load-based information sharing becomes more significant as communication capacity increases. It also suggests that multiparty communication plays an important role in forming/evolving team SMMs, and when a group of agents can be partitioned into subteams, splitting messages by their load status can be more effective for developing subteam SMMs.

  14. Modelling Adaptive Learning Behaviours for Consensus Formation in Human Societies

    Science.gov (United States)

    Yu, Chao; Tan, Guozhen; Lv, Hongtao; Wang, Zhen; Meng, Jun; Hao, Jianye; Ren, Fenghui

    2016-06-01

    Learning is an important capability of humans and plays a vital role in human society for forming beliefs and opinions. In this paper, we investigate how learning affects the dynamics of opinion formation in social networks. A novel learning model is proposed, in which agents can dynamically adapt their learning behaviours in order to facilitate the formation of consensus among them, and thus establish a consistent social norm in the whole population more efficiently. In the model, agents adapt their opinions through trail-and-error interactions with others. By exploiting historical interaction experience, a guiding opinion, which is considered to be the most successful opinion in the neighbourhood, can be generated based on the principle of evolutionary game theory. Then, depending on the consistency between its own opinion and the guiding opinion, a focal agent can realize whether its opinion complies with the social norm (i.e., the majority opinion that has been adopted) in the population, and adapt its behaviours accordingly. The highlight of the model lies in that it captures the essential features of people’s adaptive learning behaviours during the evolution and formation of opinions. Experimental results show that the proposed model can facilitate the formation of consensus among agents, and some critical factors such as size of opinion space and network topology can have significant influences on opinion dynamics.

  15. A model of human cooperation in social dilemmas.

    Directory of Open Access Journals (Sweden)

    Valerio Capraro

    Full Text Available Social dilemmas are situations in which collective interests are at odds with private interests: pollution, depletion of natural resources, and intergroup conflicts, are at their core social dilemmas. Because of their multidisciplinarity and their importance, social dilemmas have been studied by economists, biologists, psychologists, sociologists, and political scientists. These studies typically explain tendency to cooperation by dividing people in proself and prosocial types, or appealing to forms of external control or, in iterated social dilemmas, to long-term strategies. But recent experiments have shown that cooperation is possible even in one-shot social dilemmas without forms of external control and the rate of cooperation typically depends on the payoffs. This makes impossible a predictive division between proself and prosocial people and proves that people have attitude to cooperation by nature. The key innovation of this article is in fact to postulate that humans have attitude to cooperation by nature and consequently they do not act a priori as single agents, as assumed by standard economic models, but they forecast how a social dilemma would evolve if they formed coalitions and then they act according to their most optimistic forecast. Formalizing this idea we propose the first predictive model of human cooperation able to organize a number of different experimental findings that are not explained by the standard model. We show also that the model makes satisfactorily accurate quantitative predictions of population average behavior in one-shot social dilemmas.

  16. Weblog patterns and modeling human dynamics with decaying interest

    CERN Document Server

    Guo, Jin-Li

    2010-01-01

    Web log is the fourth network exchange way following Email, BBS and MSN. Most bloggers began to write blogs with great interest, over time their interest gradually achieves a balance. In order to describe the phenomenon that people's interest in something gradually decays and achieves the balance, we first propose a model and give a rigorous analysis on it. This model describes interested in attenuation, and it reflects that people's interest in something is getting more stable after a long period of time. Our analysis indicates that the arrival-time interval distribution of the model is a mixed distribution with exponential and power-law feature. Secondly, we collect blogs in ScienceNet.cn and present an empirical study of blog arrival-time interval distribution. These empirical results verify the model, providing evidence for a new class of phenomena in human dynamics. The empirical results agree with the analytical result well, obeying an approximately mixed form. In human dynamics there are other distribu...

  17. The Northwestern Abdominoplasty Scar Model: A Novel Human Model for Scar Research and Therapeutics.

    Science.gov (United States)

    Lanier, Steven T; Liu, Jing; Chavez-Munoz, Claudia; Mustoe, Thomas A; Galiano, Robert D

    2016-09-01

    There is a growing interest in the development and evaluation of therapeutic agents that improve the cosmetic appearance of scars. Existing nonhuman animal models to study scarring, while valuable, have well-acknowledged limitations, as it is accepted that the biology of human scarring differs significantly from scarring in other species. Moreover, human clinical trials of scarring require large numbers of subjects to achieve statistical power and are plagued by inherent intersubject variability because of the complex nature of wound healing in human beings. As a better alternative, we have developed the Northwestern Abdominoplasty Scar Model-a novel human clinical model that permits analysis of up to 20 cutaneous scars in a single subject and allows for not only visual scar comparison, but also histologic and molecular analyses of factors involved in scarring and wound healing. We have utilized this model in 5 early phase clinical trials designed to test the safety and efficacy of a variety of scar therapeutics without any complications to date. The model not only is applicable to scar therapeutics, but also can be utilized for other applications, such as the testing of implantable biomaterials, injectable products, therapies such as lasers, or even for in vivo study of wound healing processes in humans.

  18. Obesity: from animal models to human genetics to practical applications.

    Science.gov (United States)

    Warden, Craig H; Fisler, Janis S

    2010-01-01

    Although many animal models are used in genetic studies, the mouse is most common. Analysis of single-gene mutations, linkage analysis in crossbred strains, and gene targeting are the primary techniques used to associate obesity phenotypes with specific genes or alleles. The orthologous human gene can then be tested, either in linkage studies in families or in genome-wide association studies (GWAS), for effect on the phenotype. Frequent lack of concordance between mouse and human obesity genes may be due to the difference in phenotypes measured in humans (body mass index) versus mouse (fat mass or % body fat), lack of intermediate phenotypes, and the fact that identified genes account for only a small percentage of the heritability of common obesity, suggesting that many genes remain unknown. New technology allows analysis of individual genomes at a reasonable cost, making large-scale obesity genome projects in humans feasible. Such projects could identify common allelic variants that contribute to obesity and to variable individual response to obesity therapy. Currently, family history may be more predictive than genetics for risk of obesity, but individual testing could ultimately guide therapy and, in the aggregate, guide public health policy. The primary limitation to development of genotype-based diets is that successful randomized diet trials of widely ranging macronutrient content, adequately powered for finding rare Mendelian mutations, have not been performed. Copyright © 2010 Elsevier Inc. All rights reserved.

  19. Carbon-climate-human interactions in an integrated human-Earth system model

    Science.gov (United States)

    Calvin, K. V.; Bond-Lamberty, B. P.; Jones, A. D.; Shi, X.

    2016-12-01

    The C4MIP and CMIP5 results highlighted large uncertainties in climate projections, driven to a large extent by limited understanding of the interactions between terrestrial carbon-cycle and climate feedbacks, and their associated uncertainties. These feedbacks are dominated by uncertainties in soil processes, disturbance dynamics, ecosystem response to climate change, and agricultural productivity, and land-use change. This research addresses three questions: (1) how do terrestrial feedbacks vary across different levels of climate change, (2) what is the relative contribution of CO2 fertilization and climate change, and (3) how robust are the results across different models and methods? We used a coupled modeling framework that integrates an Integrated Assessment Model (modeling economic and energy activity) with an Earth System Model (modeling the natural earth system) to examine how business-as-usual (RCP 8.5) climate change will affect ecosystem productivity, cropland extent, and other aspects of the human-Earth system. We find that higher levels of radiative forcing result in higher productivity growth, that increases in CO2 concentrations are the dominant contributors to that growth, and that our productivity increases fall in the middle of the range when compared to other CMIP5 models and the AgMIP models. These results emphasize the importance of examining both the anthropogenic and natural components of the earth system, and their long-term interactive feedbacks.

  20. Sustainable three-dimensional tissue model of human adipose tissue.

    Science.gov (United States)

    Bellas, Evangelia; Marra, Kacey G; Kaplan, David L

    2013-10-01

    The need for physiologically relevant sustainable human adipose tissue models is crucial for understanding tissue development, disease progression, in vitro drug development and soft tissue regeneration. The coculture of adipocytes differentiated from human adipose-derived stem cells, with endothelial cells, on porous silk protein matrices for at least 6 months is reported, while maintaining adipose-like outcomes. Cultures were assessed for structure and morphology (Oil Red O content and CD31 expression), metabolic functions (leptin, glycerol production, gene expression for GLUT4, and PPARγ) and cell replication (DNA content). The cocultures maintained size and shape over this extended period in static cultures, while increasing in diameter by 12.5% in spinner flask culture. Spinner flask cultures yielded improved adipose tissue outcomes overall, based on structure and function, when compared to the static cultures. This work establishes a tissue model system that can be applied to the development of chronic metabolic dysfunction systems associated with human adipose tissue, such as obesity and diabetes, due to the long term sustainable functions demonstrated here.

  1. Experimental Models in Syrian Golden Hamster Replicate Human Acute Pancreatitis.

    Science.gov (United States)

    Wang, Yunan; Kayoumu, Abudurexiti; Lu, Guotao; Xu, Pengfei; Qiu, Xu; Chen, Liye; Qi, Rong; Huang, Shouxiong; Li, Weiqin; Wang, Yuhui; Liu, George

    2016-06-15

    The hamster has been shown to share a variety of metabolic similarities with humans. To replicate human acute pancreatitis with hamsters, we comparatively studied the efficacy of common methods, such as the peritoneal injections of caerulein, L-arginine, the retrograde infusion of sodium taurocholate, and another novel model with concomitant administration of ethanol and fatty acid. The severity of pancreatitis was evaluated by serum amylase activity, pathological scores, myeloperoxidase activity, and the expression of inflammation factors in pancreas. The results support that the severity of pathological injury is consistent with the pancreatitis induced in mice and rat using the same methods. Specifically, caerulein induced mild edematous pancreatitis accompanied by minimal lung injury, while L-arginine induced extremely severe pancreatic injury including necrosis and neutrophil infiltration. Infusion of Na-taurocholate into the pancreatic duct induced necrotizing pancreatitis in the head of pancreas and lighter inflammation in the distal region. The severity of acute pancreatitis induced by combination of ethanol and fatty acids was between the extent of caerulein and L-arginine induction, with obvious inflammatory cells infiltration. In view of the advantages in lipid metabolism features, hamster models are ideally suited for the studies of pancreatitis associated with altered metabolism in humans.

  2. A Non-Human Primate Model of Severe Pneumococcal Pneumonia

    Science.gov (United States)

    Reyes, Luis F.; Restrepo, Marcos I.; Hinojosa, Cecilia A.; Soni, Nilam J.; Shenoy, Anukul T.; Gilley, Ryan P.; Gonzalez-Juarbe, Norberto; Noda, Julio R.; Winter, Vicki T.; de la Garza, Melissa A.; Shade, Robert E.; Coalson, Jacqueline J.; Giavedoni, Luis D.; Anzueto, Antonio; Orihuela, Carlos J.

    2016-01-01

    Rationale Streptococcus pneumoniae is the leading cause of community-acquired pneumonia and infectious death in adults worldwide. A non-human primate model is needed to study the molecular mechanisms that underlie the development of severe pneumonia, identify diagnostic tools, explore potential therapeutic targets, and test clinical interventions during pneumococcal pneumonia. Objective To develop a non-human primate model of pneumococcal pneumonia. Methods Seven adult baboons (Papio cynocephalus) were surgically tethered to a continuous monitoring system that recorded heart rate, temperature, and electrocardiography. Animals were inoculated with 109 colony-forming units of S. pneumoniae using bronchoscopy. Three baboons were rescued with intravenous ampicillin therapy. Pneumonia was diagnosed using lung ultrasonography and ex vivo confirmation by histopathology and immunodetection of pneumococcal capsule. Organ failure, using serum biomarkers and quantification of bacteremia, was assessed daily. Results Challenged animals developed signs and symptoms of pneumonia 4 days after infection. Infection was characterized by the presence of cough, tachypnea, dyspnea, tachycardia and fever. All animals developed leukocytosis and bacteremia 24 hours after infection. A severe inflammatory reaction was detected by elevation of serum cytokines, including Interleukin (IL)1Ra, IL-6, and IL-8, after infection. Lung ultrasonography precisely detected the lobes with pneumonia that were later confirmed by pathological analysis. Lung pathology positively correlated with disease severity. Antimicrobial therapy rapidly reversed symptomology and reduced serum cytokines. Conclusions We have developed a novel animal model for severe pneumococcal pneumonia that mimics the clinical presentation, inflammatory response, and infection kinetics seen in humans. This is a novel model to test vaccines and treatments, measure biomarkers to diagnose pneumonia, and predict outcomes. PMID:27855182

  3. Bayesian Safety Risk Modeling of Human-Flightdeck Automation Interaction

    Science.gov (United States)

    Ancel, Ersin; Shih, Ann T.

    2015-01-01

    Usage of automatic systems in airliners has increased fuel efficiency, added extra capabilities, enhanced safety and reliability, as well as provide improved passenger comfort since its introduction in the late 80's. However, original automation benefits, including reduced flight crew workload, human errors or training requirements, were not achieved as originally expected. Instead, automation introduced new failure modes, redistributed, and sometimes increased workload, brought in new cognitive and attention demands, and increased training requirements. Modern airliners have numerous flight modes, providing more flexibility (and inherently more complexity) to the flight crew. However, the price to pay for the increased flexibility is the need for increased mode awareness, as well as the need to supervise, understand, and predict automated system behavior. Also, over-reliance on automation is linked to manual flight skill degradation and complacency in commercial pilots. As a result, recent accidents involving human errors are often caused by the interactions between humans and the automated systems (e.g., the breakdown in man-machine coordination), deteriorated manual flying skills, and/or loss of situational awareness due to heavy dependence on automated systems. This paper describes the development of the increased complexity and reliance on automation baseline model, named FLAP for FLightdeck Automation Problems. The model development process starts with a comprehensive literature review followed by the construction of a framework comprised of high-level causal factors leading to an automation-related flight anomaly. The framework was then converted into a Bayesian Belief Network (BBN) using the Hugin Software v7.8. The effects of automation on flight crew are incorporated into the model, including flight skill degradation, increased cognitive demand and training requirements along with their interactions. Besides flight crew deficiencies, automation system

  4. A Big Bang model of human colorectal tumor growth.

    Science.gov (United States)

    Sottoriva, Andrea; Kang, Haeyoun; Ma, Zhicheng; Graham, Trevor A; Salomon, Matthew P; Zhao, Junsong; Marjoram, Paul; Siegmund, Kimberly; Press, Michael F; Shibata, Darryl; Curtis, Christina

    2015-03-01

    What happens in early, still undetectable human malignancies is unknown because direct observations are impractical. Here we present and validate a 'Big Bang' model, whereby tumors grow predominantly as a single expansion producing numerous intermixed subclones that are not subject to stringent selection and where both public (clonal) and most detectable private (subclonal) alterations arise early during growth. Genomic profiling of 349 individual glands from 15 colorectal tumors showed an absence of selective sweeps, uniformly high intratumoral heterogeneity (ITH) and subclone mixing in distant regions, as postulated by our model. We also verified the prediction that most detectable ITH originates from early private alterations and not from later clonal expansions, thus exposing the profile of the primordial tumor. Moreover, some tumors appear 'born to be bad', with subclone mixing indicative of early malignant potential. This new model provides a quantitative framework to interpret tumor growth dynamics and the origins of ITH, with important clinical implications.

  5. Modeling human behavior in economics and social science.

    Science.gov (United States)

    Dolfin, M; Leonida, L; Outada, N

    2017-06-29

    The complex interactions between human behaviors and social economic sciences is critically analyzed in this paper in view of possible applications of mathematical modeling as an attainable interdisciplinary approach to understand and simulate the aforementioned dynamics. The quest is developed along three steps: Firstly an overall analysis of social and economic sciences indicates the main requirements that a contribution of mathematical modeling should bring to these sciences; subsequently the focus moves to an overview of mathematical tools and to the selection of those which appear, according to the authors bias, appropriate to the modeling; finally, a survey of applications is presented looking ahead to research perspectives. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Antisense Oligonucleotides: Translation from Mouse Models to Human Neurodegenerative Diseases.

    Science.gov (United States)

    Schoch, Kathleen M; Miller, Timothy M

    2017-06-21

    Multiple neurodegenerative diseases are characterized by single-protein dysfunction and aggregation. Treatment strategies for these diseases have often targeted downstream pathways to ameliorate consequences of protein dysfunction; however, targeting the source of that dysfunction, the affected protein itself, seems most judicious to achieve a highly effective therapeutic outcome. Antisense oligonucleotides (ASOs) are small sequences of DNA able to target RNA transcripts, resulting in reduced or modified protein expression. ASOs are ideal candidates for the treatment of neurodegenerative diseases, given numerous advancements made to their chemical modifications and delivery methods. Successes achieved in both animal models and human clinical trials have proven ASOs both safe and effective. With proper considerations in mind regarding the human applicability of ASOs, we anticipate ongoing in vivo research and clinical trial development of ASOs for the treatment of neurodegenerative diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. The Human-Computer Domain Relation in UX Models

    DEFF Research Database (Denmark)

    Clemmensen, Torkil

    This paper argues that the conceptualization of the human, the computer and the domain of use in competing lines of UX research have problematic similarities and superficial differences. The paper qualitatively analyses concepts and models in five research papers that together represent two...... influential lines of UX research: aesthetics and temporal UX, and two use situations: using a website and starting to use a smartphone. The results suggest that the two lines of UX research share a focus on users’ evaluative judgments of technology, both focuses on product qualities rather than activity...... domains, give little details about users, and treat human-computer interaction as perception. The conclusion gives similarities and differences between the approaches to UX. The implications for theory building are indicated....

  8. Use of rodents as models of human diseases

    Directory of Open Access Journals (Sweden)

    Thierry F Vandamme

    2014-01-01

    Full Text Available Advances in molecular biology have significantly increased the understanding of the biology of different diseases. However, these discoveries have not yet been fully translated into improved treatments for patients with diseases such as cancers. One of the factors limiting the translation of knowledge from preclinical studies to the clinic has been the limitations of in vivo diseases models. In this brief review, we will discuss the advantages and disadvantages of rodent models that have been developed to simulate human pathologies, focusing in models that employ xenografts and genetic modification. Within the framework of genetically engineered mouse (GEM models, we will review some of the current genetic strategies for modeling diseases in the mouse and the preclinical studies that have already been undertaken. We will also discuss how recent improvements in imaging technologies may increase the information derived from using these GEMs during early assessments of potential therapeutic pathways. Furthermore, it is interesting to note that one of the values of using a mouse model is the very rapid turnover rate of the animal, going through the process of birth to death in a very short timeframe relative to that of larger mammalian species.

  9. Computational Human Performance Modeling For Alarm System Design

    Energy Technology Data Exchange (ETDEWEB)

    Jacques Hugo

    2012-07-01

    The introduction of new technologies like adaptive automation systems and advanced alarms processing and presentation techniques in nuclear power plants is already having an impact on the safety and effectiveness of plant operations and also the role of the control room operator. This impact is expected to escalate dramatically as more and more nuclear power utilities embark on upgrade projects in order to extend the lifetime of their plants. One of the most visible impacts in control rooms will be the need to replace aging alarm systems. Because most of these alarm systems use obsolete technologies, the methods, techniques and tools that were used to design the previous generation of alarm system designs are no longer effective and need to be updated. The same applies to the need to analyze and redefine operators’ alarm handling tasks. In the past, methods for analyzing human tasks and workload have relied on crude, paper-based methods that often lacked traceability. New approaches are needed to allow analysts to model and represent the new concepts of alarm operation and human-system interaction. State-of-the-art task simulation tools are now available that offer a cost-effective and efficient method for examining the effect of operator performance in different conditions and operational scenarios. A discrete event simulation system was used by human factors researchers at the Idaho National Laboratory to develop a generic alarm handling model to examine the effect of operator performance with simulated modern alarm system. It allowed analysts to evaluate alarm generation patterns as well as critical task times and human workload predicted by the system.

  10. Protein buffering in model systems and in whole human saliva.

    Directory of Open Access Journals (Sweden)

    Andreas Lamanda

    Full Text Available The aim of this study was to quantify the buffer attributes (value, power, range and optimum of two model systems for whole human resting saliva, the purified proteins from whole human resting saliva and single proteins. Two model systems, the first containing amyloglucosidase and lysozyme, and the second containing amyloglucosidase and alpha-amylase, were shown to provide, in combination with hydrogencarbonate and di-hydrogenphosphate, almost identical buffer attributes as whole human resting saliva. It was further demonstrated that changes in the protein concentration as small as 0.1% may change the buffer value of a buffer solution up to 15 times. Additionally, it was shown that there was a protein concentration change in the same range (0.16% between saliva samples collected at the time periods of 13:00 and others collected at 9:00 am and 17:00. The mode of the protein expression changed between these samples corresponded to the change in basic buffer power and the change of the buffer value at pH 6.7. Finally, SDS Page and Ruthenium II tris (bathophenantroline disulfonate staining unveiled a constant protein expression in all samples except for one 50 kDa protein band. As the change in the expression pattern of that 50 kDa protein band corresponded to the change in basic buffer power and the buffer value at pH 6.7, it was reasonable to conclude that this 50 kDa protein band may contain the protein(s belonging to the protein buffer system of human saliva.

  11. A Dynamic Approach to Modeling Dependence Between Human Failure Events

    Energy Technology Data Exchange (ETDEWEB)

    Boring, Ronald Laurids [Idaho National Laboratory

    2015-09-01

    In practice, most HRA methods use direct dependence from THERP—the notion that error be- gets error, and one human failure event (HFE) may increase the likelihood of subsequent HFEs. In this paper, we approach dependence from a simulation perspective in which the effects of human errors are dynamically modeled. There are three key concepts that play into this modeling: (1) Errors are driven by performance shaping factors (PSFs). In this context, the error propagation is not a result of the presence of an HFE yielding overall increases in subsequent HFEs. Rather, it is shared PSFs that cause dependence. (2) PSFs have qualities of lag and latency. These two qualities are not currently considered in HRA methods that use PSFs. Yet, to model the effects of PSFs, it is not simply a matter of identifying the discrete effects of a particular PSF on performance. The effects of PSFs must be considered temporally, as the PSFs will have a range of effects across the event sequence. (3) Finally, there is the concept of error spilling. When PSFs are activated, they not only have temporal effects but also lateral effects on other PSFs, leading to emergent errors. This paper presents the framework for tying together these dynamic dependence concepts.

  12. In vivo models of human airway epithelium repair and regeneration

    Directory of Open Access Journals (Sweden)

    C. Coraux

    2005-12-01

    Full Text Available Despite an efficient defence system, the airway surface epithelium, in permanent contact with the external milieu, is frequently injured by inhaled pollutants, microorganisms and viruses. The response of the airway surface epithelium to an acute injury includes a succession of cellular events varying from the loss of the surface epithelium integrity to partial shedding of the epithelium or even to complete denudation of the basement membrane. The epithelium has then to repair and regenerate to restore its functions. The in vivo study of epithelial regeneration in animal models has shown that airway epithelial cells are able to dedifferentiate, spread, migrate over the denuded basement membrane and progressively redifferentiate to reconstitute a functional respiratory epithelium after several weeks. Humanised tracheal xenograft models have been developed in immunodeficient nude and severe combined immunodeficient (SCID mice in order to mimic the natural regeneration process of the human airway epithelium and to analyse the cellular and molecular events involved during the different steps of airway epithelial reconstitution. These models represent very powerful tools for analysing the modulation of the biological functions of the epithelium during its regeneration. They are also very useful for identifying stem/progenitor cells of the human airway epithelium. A better knowledge of the mechanisms involved in airway epithelium regeneration, as well as the characterisation of the epithelial stem and progenitor cells, may pave the way to regenerative therapeutics, allowing the reconstitution of a functional airway epithelium in numerous respiratory diseases, such as asthma, chronic obstructive pulmonary diseases, cystic fibrosis and bronchiolitis.

  13. A Novel Parametric Model For The Human Respiratory System

    Directory of Open Access Journals (Sweden)

    Clara Mihaela IONESCU

    2003-12-01

    Full Text Available The purpose of this work is to present some recent results in an ongoing research project between Ghent University and Chess Medical Technology Company Belgium. The overall aim of the project is to provide a fast method for identification of the human respiratory system in order to allow for an instantaneously diagnosis of the patient by the medical staff. A novel parametric model of the human respiratory system as well as the obtained experimental results is presented in this paper. A prototype apparatus developed by the company, based on the forced oscillation technique is used to record experimental data from 4 patients in this paper. Signal processing is based on spectral analysis and is followed by the parametric identification of a non-linear mechanistic model. The parametric model is equivalent to the structure of a simple electrical RLC-circuit, containing a non-linear capacitor. These parameters have a useful and easy-to-interpret physical meaning for the medical staff members.

  14. Workshop on Human Activity at Scale in Earth System Models

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Melissa R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Aziz, H. M. Abdul [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Coletti, Mark A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kennedy, Joseph H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nair, Sujithkumar S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Omitaomu, Olufemi A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-01-26

    Changing human activity within a geographical location may have significant influence on the global climate, but that activity must be parameterized in such a way as to allow these high-resolution sub-grid processes to affect global climate within that modeling framework. Additionally, we must have tools that provide decision support and inform local and regional policies regarding mitigation of and adaptation to climate change. The development of next-generation earth system models, that can produce actionable results with minimum uncertainties, depends on understanding global climate change and human activity interactions at policy implementation scales. Unfortunately, at best we currently have only limited schemes for relating high-resolution sectoral emissions to real-time weather, ultimately to become part of larger regions and well-mixed atmosphere. Moreover, even our understanding of meteorological processes at these scales is imperfect. This workshop addresses these shortcomings by providing a forum for discussion of what we know about these processes, what we can model, where we have gaps in these areas and how we can rise to the challenge to fill these gaps.

  15. Permeability of the reconstructed human epidermis model Episkin in comparison to various human skin preparations.

    Science.gov (United States)

    Netzlaff, Frank; Kaca, Monika; Bock, Udo; Haltner-Ukomadu, Eleonore; Meiers, Peter; Lehr, Claus-Michael; Schaefer, Ulrich F

    2007-04-01

    The objective of this work was to compare the barrier function of the small diameter reconstructed human epidermis model Episkin (d=12 mm) to human skin in vitro. For that purpose a modification for the Franz diffusion cell (d=15mm) had to be developed so as to allow direct comparison with the following human skin preparations: Full thickness skin (FTS), split thickness skin (STS), heat-separated epidermis (HSE), and trypsin isolated stratum corneum (TISC). Among the tested preparations, HSE appeared to be the most preferable due to its clear morphological structure and ease of preparation. The lipid profile of HSE and Episkin was analyzed and showed significant differences in terms of cholesterol, ceramides and triglycerides contents, whereas cholesterol esters and fatty acids were not different. Permeation data with HSE and Episkin were then gathered using caffeine and testosterone. Both test compounds permeated much faster through Episkin than through HSE. Moreover, opposed to Episkin, HSE differentiated between the two test compounds. In spite of the remarkable progress in developing RHEs in the past years at this time Episkin can obviously not yet fully replace human skin for in vitro permeability experiments.

  16. Modeling physiological and pathological human neurogenesis in the dish

    Directory of Open Access Journals (Sweden)

    Vania eBroccoli

    2014-07-01

    Full Text Available New advances in directing the neuronal differentiation of human embryonic and induced pluripotent stem cells (hPSCs, abbreviation intended to convey both categories of pluripotent stem cells have promoted the development of culture systems capable of modeling early neurogenesis and neural specification at some of their critical milestones. The hPSC-derived neural rosette can be considered the in vitro counterpart of the developing neural tube, since both structures share a virtually equivalent architecture and related functional properties. Epigenetic stimulation methods can modulate the identity of the rosette neural progenitors in order to generate authentic neuronal subtypes, as well as a full spectrum of neural crest derivatives. The intrinsic capacity of induced pluripotent cell-derived neural tissue to self-organize has become fully apparent with the emergence of innovative in vitro systems that are able to shape the neuronal differentiation of hPSCs into organized tissues that develop in three dimensions. However, significant hurdles remain that must be completely solved in order to facilitate the use of hPSCs in modeling (e.g., late-onset disorders or in building therapeutic strategies for cell replacement. In this direction, new procedures have been established to promote the maturation and functionality of hPSC-derived neurons. Meanwhile, new methods to accelerate the aging of in vitro differentiating cells are still in development. hPSC-based technology has matured enough to offer a significant and reliable model system for early and late neurogenesis that could be extremely informative for the study of the physiological and pathological events that occur during this process. Thus, full exploitation of this cellular system can provide a better understanding of the physiological events that shape human brain structures, as well as a solid platform to investigate the pathological mechanisms at the root of human diseases.

  17. Computational model of sustained acceleration effects on human cognitive performance.

    Science.gov (United States)

    McKinlly, Richard A; Gallimore, Jennie J

    2013-08-01

    Extreme acceleration maneuvers encountered in modern agile fighter aircraft can wreak havoc on human physiology, thereby significantly influencing cognitive task performance. As oxygen content declines under acceleration stress, the activity of high order cortical tissue reduces to ensure sufficient metabolic resources are available for critical life-sustaining autonomic functions. Consequently, cognitive abilities reliant on these affected areas suffer significant performance degradations. The goal was to develop and validate a model capable of predicting human cognitive performance under acceleration stress. Development began with creation of a proportional control cardiovascular model that produced predictions of several hemodynamic parameters, including eye-level blood pressure and regional cerebral oxygen saturation (rSo2). An algorithm was derived to relate changes in rSo2 within specific brain structures to performance on cognitive tasks that require engagement of different brain areas. Data from the "precision timing" experiment were then used to validate the model predicting cognitive performance as a function of G(z) profile. The following are value ranges. Results showed high agreement between the measured and predicted values for the rSo2 (correlation coefficient: 0.7483-0.8687; linear best-fit slope: 0.5760-0.9484; mean percent error: 0.75-3.33) and cognitive performance models (motion inference task--correlation coefficient: 0.7103-0.9451; linear best-fit slope: 0.7416-0.9144; mean percent error: 6.35-38.21; precision timing task--correlation coefficient: 0.6856-0.9726; linear best-fit slope: 0.5795-1.027; mean percent error: 6.30-17.28). The evidence suggests that the model is capable of accurately predicting cognitive performance of simplistic tasks under high acceleration stress.

  18. Immunodeficient mouse model for human hematopoietic stem cell engraftment and immune system development.

    Science.gov (United States)

    Aryee, Ken-Edwin; Shultz, Leonard D; Brehm, Michael A

    2014-01-01

    Immunodeficient mice engrafted with human immune systems provide an exciting model to study human immunobiology in an in vivo setting without placing patients at risk. The essential parameter for creation of these "humanized models" is engraftment of human hematopoietic stem cells (HSC) that will allow for optimal development of human immune systems. However, there are a number of strategies to generate humanized mice and specific protocols can vary significantly among different laboratories. Here we describe a protocol for the co-implantation of human HSC with autologous fetal liver and thymic tissues into immunodeficient mice to create a humanized model with optimal human T cell development. This model, often referred to as the Thy/Liv or BLT (bone marrow, liver, thymus) mouse, develops a functional human immune system, including HLA-restricted human T cells, B cells, and innate immune cells.

  19. A novel model for evaluating therapies targeting human tumor vasculature and human cancer stem-like cells.

    Science.gov (United States)

    Burgos-Ojeda, Daniela; McLean, Karen; Bai, Shoumei; Pulaski, Heather; Gong, Yusong; Silva, Ines; Skorecki, Karl; Tzukerman, Maty; Buckanovich, Ronald J

    2013-06-15

    Human tumor vessels express tumor vascular markers (TVM), proteins that are not expressed in normal blood vessels. Antibodies targeting TVMs could act as potent therapeutics. Unfortunately, preclinical in vivo studies testing anti-human TVM therapies have been difficult to do due to a lack of in vivo models with confirmed expression of human TVMs. We therefore evaluated TVM expression in a human embryonic stem cell-derived teratoma (hESCT) tumor model previously shown to have human vessels. We now report that in the presence of tumor cells, hESCT tumor vessels express human TVMs. The addition of mouse embryonic fibroblasts and human tumor endothelial cells significantly increases the number of human tumor vessels. TVM induction is mostly tumor-type-specific with ovarian cancer cells inducing primarily ovarian TVMs, whereas breast cancer cells induce breast cancer specific TVMs. We show the use of this model to test an anti-human specific TVM immunotherapeutics; anti-human Thy1 TVM immunotherapy results in central tumor necrosis and a three-fold reduction in human tumor vascular density. Finally, we tested the ability of the hESCT model, with human tumor vascular niche, to enhance the engraftment rate of primary human ovarian cancer stem-like cells (CSC). ALDH(+) CSC from patients (n = 6) engrafted in hESCT within 4 to 12 weeks whereas none engrafted in the flank. ALDH(-) ovarian cancer cells showed no engraftment in the hESCT or flank (n = 3). Thus, this model represents a useful tool to test anti-human TVM therapy and evaluate in vivo human CSC tumor biology.

  20. JPEG2000 COMPRESSION CODING USING HUMAN VISUAL SYSTEM MODEL

    Institute of Scientific and Technical Information of China (English)

    Xiao Jiang; Wu Chengke

    2005-01-01

    In order to apply the Human Visual System (HVS) model to JPEG2000 standard,several implementation alternatives are discussed and a new scheme of visual optimization isintroduced with modifying the slope of rate-distortion. The novelty is that the method of visual weighting is not lifting the coefficients in wavelet domain, but is complemented by code stream organization. It remains all the features of Embedded Block Coding with Optimized Truncation (EBCOT) such as resolution progressive, good robust for error bit spread and compatibility of lossless compression. Well performed than other methods, it keeps the shortest standard codestream and decompression time and owns the ability of VIsual Progressive (VIP) coding.

  1. Simplified Human-Robot Interaction: Modeling and Evaluation

    Directory of Open Access Journals (Sweden)

    Balazs Daniel

    2013-10-01

    Full Text Available In this paper a novel concept of human-robot interaction (HRI modeling is proposed. Including factors like trust in automation, situational awareness, expertise and expectations a new user experience framework is formed for industrial robots. Service Oriented Robot Operation, proposed in a previous paper, creates an abstract level in HRI and it is also included in the framework. This concept is evaluated with exhaustive tests. Results prove that significant improvement in task execution may be achieved and the new system is more usable for operators with less experience with robotics; personnel specific for small and medium enterprises (SMEs.

  2. Modelling Human Cortical Network in Real Brain Space

    Institute of Scientific and Technical Information of China (English)

    ZHAO Qing-Bai; FENG Hong-Bo; TANG Yi-Yuan

    2007-01-01

    Highly specific structural organization is of great significance in the topology of cortical networks.We introduce a human cortical network model.taking the specific cortical structure into account,in which nodes are brain sites placed in the actual positions of cerebral cortex and the establishment of edges depends on the spatial path length rather than the linear distance.The resulting network exhibits the essential features of cortical connectivity,properties of small-world networks and multiple clusters structure.Additionally.assortative mixing is also found in this roodel.All of these findings may be attributed to the spedtic cortical architecture.

  3. Galleria mellonella as a model host for human pathogens

    Science.gov (United States)

    Junqueira, Juliana Campos

    2012-01-01

    The number of studies using G. mellonella as a model host for human pathogens has increased significantly in the last few years. Important studies were published from different countries for evaluating the pathogenesis of bacterial and fungal infections and for exploring the host defenses against pathogens. Therefore, standardized conditions for the use of G. melonella larvae need to be established. Recent research showed that the deprivation of G. mellonella larvae of food during the experiment caused a reduction in immune responses and an increased susceptibility to infection, suggesting that incubating of larvae in the presence or absence of nutrition may affect the results and comparisons among different laboratories. PMID:23211681

  4. The stability of the three transmembrane and the four transmembrane human vitamin K epoxide reductase models

    Science.gov (United States)

    Wu, Sangwook

    2016-04-01

    The three transmembrane and the four transmembrane helix models are suggested for human vitamin K epoxide reductase (VKOR). In this study, we investigate the stability of the human three transmembrane/four transmembrane VKOR models by employing a coarse-grained normal mode analysis and molecular dynamics simulation. Based on the analysis of the mobility of each transmembrane domain, we suggest that the three transmembrane human VKOR model is more stable than the four transmembrane human VKOR model.

  5. Beyond the zebrafish: diverse fish species for modeling human disease

    Directory of Open Access Journals (Sweden)

    Manfred Schartl

    2014-02-01

    Full Text Available In recent years, zebrafish, and to a lesser extent medaka, have become widely used small animal models for human diseases. These organisms have convincingly demonstrated the usefulness of fish for improving our understanding of the molecular and cellular mechanisms leading to pathological conditions, and for the development of new diagnostic and therapeutic tools. Despite the usefulness of zebrafish and medaka in the investigation of a wide spectrum of traits, there is evidence to suggest that other fish species could be better suited for more targeted questions. With the emergence of new, improved sequencing technologies that enable genomic resources to be generated with increasing efficiency and speed, the potential of non-mainstream fish species as disease models can now be explored. A key feature of these fish species is that the pathological condition that they model is often related to specific evolutionary adaptations. By exploring these adaptations, new disease-causing and disease-modifier genes might be identified; thus, diverse fish species could be exploited to better understand the complexity of disease processes. In addition, non-mainstream fish models could allow us to study the impact of environmental factors, as well as genetic variation, on complex disease phenotypes. This Review will discuss the opportunities that such fish models offer for current and future biomedical research.

  6. A biologically plausible model of human shape symmetry perception.

    Science.gov (United States)

    Poirier, Frédéric J A M; Wilson, Hugh R

    2010-01-19

    Symmetry is usually computationally expensive to encode reliably, and yet it is relatively effortless to perceive. Here, we extend F. J. A. M. Poirier and H. R. Wilson's (2006) model for shape perception to account for H. R. Wilson and F. Wilkinson's (2002) data on shape symmetry. Because the model already accounts for shape perception, only minimal neural circuitry is required to enable it to encode shape symmetry as well. The model is composed of three main parts: (1) recovery of object position using large-scale non-Fourier V4-like concentric units that respond at the center of concentric contour segments across orientations, (2) around that recovered object center, curvature mechanisms combine multiplicatively the responses of oriented filters to encode object-centric local shape information, with a preference for convexities, and (3) object-centric symmetry mechanisms. Model and human performances are comparable for symmetry perception of shapes. Moreover, with some improvement of edge recovery, the model can encode symmetry axes in natural images such as faces.

  7. Screening and analysis of breast cancer genes regulated by the human mammary microenvironment in a humanized mouse model

    Science.gov (United States)

    Zheng, Mingjie; Wang, Jue; Ling, Lijun; Xue, Dandan; Wang, Shui; Zhao, Yi

    2016-01-01

    Tumor microenvironments play critical regulatory roles in tumor growth. Although mouse cancer models have contributed to the understanding of human tumor biology, the effectiveness of mouse cancer models is limited by the inability of the models to accurately present humanized tumor microenvironments. Previously, a humanized breast cancer model in severe combined immunodeficiency mice was established, in which human breast cancer tissue was implanted subcutaneously, followed by injection of human breast cancer cells. It was demonstrated that breast cancer cells showed improved growth in the human mammary microenvironment compared with a conventional subcutaneous mouse model. In the present study, the novel mouse model and microarray technology was used to analyze changes in the expression of genes in breast cancer cells that are regulated by the human mammary microenvironment. Humanized breast and conventional subcutaneous mouse models were established, and orthotopic tumor cells were obtained from orthotopic tumor masses by primary culture. An expression microarray using Illumina HumanHT-12 v4 Expression BeadChip and database analyses were performed to investigate changes in gene expression between tumors from each microenvironment. A total of 94 genes were differentially expressed between the primary cells cultured from the humanized and conventional mouse models. Significant upregulation of genes that promote cell proliferation and metastasis or inhibit apoptosis, such as SH3-domain binding protein 5 (BTK-associated), sodium/chloride cotransporter 3 and periostin, osteoblast specific factor, and genes that promote angiogenesis, such as KIAA1618, was also noted. Other genes that restrain cell proliferation and accelerate cell apoptosis, including tripartite motif containing TRIM36 and NES1, were downregulated. The present results revealed differences in various aspects of tumor growth and metabolism between the two model groups and indicated the functional

  8. Abnormal absorption and scattering effect of human ear model for electromagnetic waves

    Institute of Scientific and Technical Information of China (English)

    NIE Min; PEI Changxing; LI Jiandong; MA Chen; YANG Zhen

    2005-01-01

    @@ To explore the effect of human ear outline structure for electromagnetic waves, two human ear's models, a big one (model 1) and a small one (model 2), were made in proportion as real human ears (Fig. 1). The installation picture is shown in Fig. 2, and its geometry structure and size are shown in Figs. 3 and 4, respectively.

  9. Spider Silk as Guiding Biomaterial for Human Model Neurons

    Directory of Open Access Journals (Sweden)

    Frank Roloff

    2014-01-01

    Full Text Available Over the last years, a number of therapeutic strategies have emerged to promote axonal regeneration. An attractive strategy is the implantation of biodegradable and nonimmunogenic artificial scaffolds into injured peripheral nerves. In previous studies, transplantation of decellularized veins filled with spider silk for bridging critical size nerve defects resulted in axonal regeneration and remyelination by invading endogenous Schwann cells. Detailed interaction of elongating neurons and the spider silk as guidance material is unknown. To visualize direct cellular interactions between spider silk and neurons in vitro, we developed an in vitro crossed silk fiber array. Here, we describe in detail for the first time that human (NT2 model neurons attach to silk scaffolds. Extending neurites can bridge gaps between single silk fibers and elongate afterwards on the neighboring fiber. Culturing human neurons on the silk arrays led to an increasing migration and adhesion of neuronal cell bodies to the spider silk fibers. Within three to four weeks, clustered somata and extending neurites formed ganglion-like cell structures. Microscopic imaging of human neurons on the crossed fiber arrays in vitro will allow for a more efficient development of methods to maximize cell adhesion and neurite growth on spider silk prior to transplantation studies.

  10. Labor of love. A model for planning human resource needs.

    Science.gov (United States)

    Brady, F J

    1989-01-01

    Typically, the annual budgeting process is the hospital's only attempt to forecast human resource requirements. In times of rapid change, this traditional ad hoc approach is incapable of satisfying either the Catholic hospital's ethical obligations as an employer or its responsibilities to provide healthcare to the poor and suffering. Assumptions about future activity, including volume projections on admissions, patient days, and other services, influence the budgeting process to a large degree. Because the amount of work to be done and the number of employees required to do it are related, changes in demand for service immediately and directly affect staffing requirements. A hospital cannot achieve ethical human resource management or provide high-quality healthcare if inadequate planning forces management into a cycle of crisis-coping--reacting to this year's nursing shortage with a major recruiting effort and next year's financial crunch with a traumatic reduction in force. The human resource planning approach outlined here helps the hospital meet legitimate business needs while satisfying its ethical obligations. The model has four phases and covers a charge to the planning committee; committee appointments; announcements; the establishment of ground rules, focus, and task forces; and the work of each task force.

  11. Spider silk as guiding biomaterial for human model neurons.

    Science.gov (United States)

    Roloff, Frank; Strauß, Sarah; Vogt, Peter M; Bicker, Gerd; Radtke, Christine

    2014-01-01

    Over the last years, a number of therapeutic strategies have emerged to promote axonal regeneration. An attractive strategy is the implantation of biodegradable and nonimmunogenic artificial scaffolds into injured peripheral nerves. In previous studies, transplantation of decellularized veins filled with spider silk for bridging critical size nerve defects resulted in axonal regeneration and remyelination by invading endogenous Schwann cells. Detailed interaction of elongating neurons and the spider silk as guidance material is unknown. To visualize direct cellular interactions between spider silk and neurons in vitro, we developed an in vitro crossed silk fiber array. Here, we describe in detail for the first time that human (NT2) model neurons attach to silk scaffolds. Extending neurites can bridge gaps between single silk fibers and elongate afterwards on the neighboring fiber. Culturing human neurons on the silk arrays led to an increasing migration and adhesion of neuronal cell bodies to the spider silk fibers. Within three to four weeks, clustered somata and extending neurites formed ganglion-like cell structures. Microscopic imaging of human neurons on the crossed fiber arrays in vitro will allow for a more efficient development of methods to maximize cell adhesion and neurite growth on spider silk prior to transplantation studies.

  12. ADVANCED DEVELOPMENT MODEL OF TERRITORIAL HUMAN RESOURCES POTENTIAL

    Directory of Open Access Journals (Sweden)

    Alexander G. Моkronosov

    2015-03-01

    Full Text Available The aim of the study is to substantiate the need for eliminating the excessive spatial polarization of territorial socio-economic development as a necessary condition for advanced development of human resources potential. The authors explore the basic problems and contradictions of modern regional and local labor markets in Russia. Based on generalization and systematization of foreign and domestic research outcomes, the paper reveals the main condition for eliminating the territorial polarization threats, which implies formation of a new institutional environment in order to provide co-operation of participants in the territorial interest zone in personnel training and new jobs creating.The research findings demonstrate the increased disproportions between the workforce and labor markets of municipal formations in Sverdlovsk region, and emphasize the need for territorial industrial educational clusters maximizing the network co-operation of the involved parties.The scientific novelty combines adaptation of theoretical concepts of the “new economic geography” applied to reorganization processes in the Russian economy; and elaboration of the cluster model of advanced development of territorial human resources potential by means of territorial centers coordinating the interests of administration, business society, and households.Practical significance of the research results is related to facilitating the administrative efficiency of regional and municipal formations, employers, territorial employment centers, and thereby the advanced development of human resources potential.

  13. ADVANCED DEVELOPMENT MODEL OF TERRITORIAL HUMAN RESOURCES POTENTIAL

    Directory of Open Access Journals (Sweden)

    Alexander G. Моkronosov

    2014-01-01

    Full Text Available The aim of the study is to substantiate the need for eliminating the excessive spatial polarization of territorial socio-economic development as a necessary condition for advanced development of human resources potential. The authors explore the basic problems and contradictions of modern regional and local labor markets in Russia. Based on generalization and systematization of foreign and domestic research outcomes, the paper reveals the main condition for eliminating the territorial polarization threats, which implies formation of a new institutional environment in order to provide co-operation of participants in the territorial interest zone in personnel training and new jobs creating.The research findings demonstrate the increased disproportions between the workforce and labor markets of municipal formations in Sverdlovsk region, and emphasize the need for territorial industrial educational clusters maximizing the network co-operation of the involved parties.The scientific novelty combines adaptation of theoretical concepts of the “new economic geography” applied to reorganization processes in the Russian economy; and elaboration of the cluster model of advanced development of territorial human resources potential by means of territorial centers coordinating the interests of administration, business society, and households.Practical significance of the research results is related to facilitating the administrative efficiency of regional and municipal formations, employers, territorial employment centers, and thereby the advanced development of human resources potential.

  14. Acrylamide induces accelerated endothelial aging in a human cell model.

    Science.gov (United States)

    Sellier, Cyril; Boulanger, Eric; Maladry, François; Tessier, Frédéric J; Lorenzi, Rodrigo; Nevière, Rémi; Desreumaux, Pierre; Beuscart, Jean-Baptiste; Puisieux, François; Grossin, Nicolas

    2015-09-01

    Acrylamide (AAM) has been recently discovered in food as a Maillard reaction product. AAM and glycidamide (GA), its metabolite, have been described as probably carcinogenic to humans. It is widely established that senescence and carcinogenicity are closely related. In vitro, endothelial aging is characterized by replicative senescence in which primary cells in culture lose their ability to divide. Our objective was to assess the effects of AAM and GA on human endothelial cell senescence. Human umbilical vein endothelial cells (HUVECs) cultured in vitro were used as model. HUVECs were cultured over 3 months with AAM or GA (1, 10 or 100 μM) until growth arrest. To analyze senescence, β-galactosidase activity and telomere length of HUVECs were measured by cytometry and semi-quantitative PCR, respectively. At all tested concentrations, AAM or GA reduced cell population doubling compared to the control condition (p < 0.001). β-galactosidase activity in endothelial cells was increased when exposed to AAM (≥10 μM) or GA (≥1 μM) (p < 0.05). AAM (≥10 μM) or GA (100 μM) accelerated telomere shortening in HUVECs (p < 0.05). In conclusion, in vitro chronic exposure to AAM or GA at low concentrations induces accelerated senescence. This result suggests that an exposure to AAM might contribute to endothelial aging.

  15. Modeling the amplification dynamics of human Alu retrotransposons.

    Directory of Open Access Journals (Sweden)

    Dale J Hedges

    2005-09-01

    Full Text Available Retrotransposons have had a considerable impact on the overall architecture of the human genome. Currently, there are three lineages of retrotransposons (Alu, L1, and SVA that are believed to be actively replicating in humans. While estimates of their copy number, sequence diversity, and levels of insertion polymorphism can readily be obtained from existing genomic sequence data and population sampling, a detailed understanding of the temporal pattern of retrotransposon amplification remains elusive. Here we pose the question of whether, using genomic sequence and population frequency data from extant taxa, one can adequately reconstruct historical amplification patterns. To this end, we developed a computer simulation that incorporates several known aspects of primate Alu retrotransposon biology and accommodates sampling effects resulting from the methods by which mobile elements are typically discovered and characterized. By modeling a number of amplification scenarios and comparing simulation-generated expectations to empirical data gathered from existing Alu subfamilies, we were able to statistically reject a number of amplification scenarios for individual subfamilies, including that of a rapid expansion or explosion of Alu amplification at the time of human-chimpanzee divergence.

  16. ras activation in human tumors and in animal model systems

    Energy Technology Data Exchange (ETDEWEB)

    Corominas, M.; Sloan, S.R.; Leon, J.; Kamino, Hideko; Newcomb, E.W.; Pellicer, A. (New York Univ. Medical Center, New York (United States))

    1991-06-01

    Environmental agents such as radiation and chemicals are known to cause genetic damage. Alterations in a limited set of cellular genes called proto-oncogenes lead to unregulated proliferation and differentiation. The authors have studied the role of the ras gene family in carcinogenesis using two different animal models. In one case, thymic lymphomas were induced in mice by either gamma or neutron radiation, and in the other, keratoacanthomas were induced in rabbit skin with dimethylbenzanthracene. Human keratoacanthomas similar to the ones induced in rabbits were also analyzed. They found that different types of radiation such as gamma rays and neutrons, induced different point mutations in ras genes. A novel K-ras mutation in codon 146 has been found in thymic lymphomas induced by neutrons. Keratoacanthomas induced in rabbit skin by dimethylbenzanthracene show a high frequency of H-ras-activated genes carrying a mutation in codon 61. The same is observed in human keratoacanthomas, although mutations are in both the 12th and the 61st codons of the H-ras gene. H-ras activation is less frequent in human squamous cell carcinomas than in keratoacanthomas, suggesting that ras genes could play a role in vivo in differentiation as well as in proliferation.

  17. Developing a computational model of human hand kinetics using AVS

    Energy Technology Data Exchange (ETDEWEB)

    Abramowitz, Mark S. [State Univ. of New York, Binghamton, NY (United States)

    1996-05-01

    As part of an ongoing effort to develop a finite element model of the human hand at the Institute for Scientific Computing Research (ISCR), this project extended existing computational tools for analyzing and visualizing hand kinetics. These tools employ a commercial, scientific visualization package called AVS. FORTRAN and C code, originally written by David Giurintano of the Gillis W. Long Hansen`s Disease Center, was ported to a different computing platform, debugged, and documented. Usability features were added and the code was made more modular and readable. When the code is used to visualize bone movement and tendon paths for the thumb, graphical output is consistent with expected results. However, numerical values for forces and moments at the thumb joints do not yet appear to be accurate enough to be included in ISCR`s finite element model. Future work includes debugging the parts of the code that calculate forces and moments and verifying the correctness of these values.

  18. A model for automatic identification of human pulse signals

    Institute of Scientific and Technical Information of China (English)

    Hui-yan WANG; Pei-yong ZHANG

    2008-01-01

    This paper presents a quantitative method for automatic identification of human pulse signals. The idea is to start with the extraction of characteristic parameters and then to construct the recognition model based on Bayesian networks. To identify depth, frequency and rhythm, several parameters are proposed. To distinguish the strength and shape, which cannot be represented by one or several parameters and are hard to recognize, the main time-domain feature parameters are computed based on the feature points of the pulse signal. Then the extracted parameters are taken as the input and five models for automatic pulse signal identification are constructed based on Bayesian networks. Experimental results demonstrate that the method is feasible and effective in recognizing depth, frequency, rhythm, strength and shape of pulse signals, which can be expected to facilitate the modernization of pulse diagnosis.

  19. Modelling the Role of Human Resource Management in Continuous Improvement

    DEFF Research Database (Denmark)

    Jørgensen, Frances; Hyland, Paul; Kofoed, Lise B.

    2006-01-01

    Although it is widely acknowledged that both Human Resource Management (HRM) and Continuous Improvement have the potential to positively influencing organizational performance, very little attention has been given to how certain HRM practices may support CI, and consequently, a company...... developed by de Leede and Looise (2005) serve as the framework for examining how specific bundles of HRM practices utilized during different phases of the CI implementation process may contribute to sustained organizational performance and enhanced operational performance. The primary contribution...... of the paper is theoretical in nature, as the model developed provides a greater understanding of how HRM can contribute to CI; however, the model also has practical value in that it suggests important relationships between various HRM practices and the behaviors necessary for successful CI. The paper...

  20. Laboratory animals as surrogate models of human obesity

    Institute of Scientific and Technical Information of China (English)

    Cecilia NILSSON; Kirsten RAUN; Fei-fei YAN; Marianne O LARSEN; Mads TANG-CHRISTENSEN

    2012-01-01

    Obesity and obesity-related metabolic diseases represent a growing socioeconomic problem throughout the world.Great emphasis has been put on establishing treatments for this condition,including pharmacological intervention.However,there are many obstacles and pitfalls in the development process from pre-clinical research to the pharmacy counter,and there is no certainty that what has been observed pre-clinically will translate into an improvement in human health.Hence,it is important to test potential new drugs in a valid translational model early in their development.In the current mini-review,a number of monogenetic and polygenic models of obesity will be discussed in view of their translational character.

  1. Perinatal Cerebellar Injury in Human and Animal Models

    Directory of Open Access Journals (Sweden)

    Valerie Biran

    2012-01-01

    Full Text Available Cerebellar injury is increasingly recognized through advanced neonatal brain imaging as a complication of premature birth. Survivors of preterm birth demonstrate a constellation of long-term neurodevelopmental deficits, many of which are potentially referable to cerebellar injury, including impaired motor functions such as fine motor incoordination, impaired motor sequencing and also cognitive, behavioral dysfunction among older patients. This paper reviews the morphogenesis and histogenesis of the human and rodent developing cerebellum, and its more frequent injuries in preterm. Most cerebellar lesions are cerebellar hemorrhage and infarction usually leading to cerebellar abnormalities and/or atrophy, but the exact pathogenesis of lesions of the cerebellum is unknown. The different mechanisms involved have been investigated with animal models and are primarily hypoxia, ischemia, infection, and inflammation Exposure to drugs and undernutrition can also induce cerebellar abnormalities. Different models are detailed to analyze these various disturbances of cerebellar development around birth.

  2. Treatment model of dengue hemorrhagic fever infection in human body

    Science.gov (United States)

    Handayani, D.; Nuraini, N.; Primasari, N.; Wijaya, K. P.

    2014-03-01

    The treatment model of DHF presented in this paper involves the dynamic of five time-dependent compartments, i.e. susceptible, infected, free virus particle, immune cell, and haematocrit level. The treatment model is investigated based on normalization of haematocrit level, which is expressed as intravenous fluid infusion control. We analyze the stability of the disease free equilibrium and the endemic equilibrium. The numerical simulations will explain the dynamic of each compartment in human body. These results show particularly that infected compartment and free virus particle compartment are tend to be vanished in two weeks after the onset of dengue virus. However, these simulation results also show that without the treatment, the haematocrit level will decrease even though not up to the normal level. Therefore the effective haematocrit normalization should be done with the treatment control.

  3. On the dynamics of a human body model.

    Science.gov (United States)

    Huston, R. L.; Passerello, C. E.

    1971-01-01

    Equations of motion for a model of the human body are developed. Basically, the model consists of an elliptical cylinder representing the torso, together with a system of frustrums of elliptical cones representing the limbs. They are connected to the main body and each other by hinges and ball and socket joints. Vector, tensor, and matrix methods provide a systematic organization of the geometry. The equations of motion are developed from the principles of classical mechanics. The solution of these equations then provide the displacement and rotation of the main body when the external forces and relative limb motions are specified. Three simple example motions are studied to illustrate the method. The first is an analysis and comparison of simple lifting on the earth and the moon. The second is an elementary approach to underwater swimming, including both viscous and inertia effects. The third is an analysis of kicking motion and its effect upon a vertically suspended man such as a parachutist.

  4. Using Task Analytic Models and Phenotypes of Erroneous Human Behavior to Discover System Failures Using Model Checking.

    Science.gov (United States)

    Bolton, Matthew L; Bass, Ellen J

    2010-09-01

    Breakdowns in complex systems often occur as a result of system elements interacting in ways unanticipated by analysts or designers. In systems with human operators, human-automation interaction associated with both normative and erroneous human behavior can contribute to such failures. This paper presents a method for automatically generating task analytic models encompassing both erroneous and normative human behavior from normative task models. The resulting model can be integrated into a formal system model so that system safety properties can be formally verified with a model checker. This allows analysts to prove that a human automation-interactive system (as represented by the model) will or will not satisfy safety properties with both normative and generated erroneous human behavior. This method is illustrated with a case study: the operation of a radiation therapy machine. In this example, a problem resulting from a generated erroneous human action is discovered. Future extensions of our method are discussed.

  5. Illustrating a Model-Game-Model Paradigm for Using Human Wargames in Analysis

    Science.gov (United States)

    2017-02-01

    Working Paper Illustrating a Model-Game-Model Paradigm for Using Human Wargames in Analysis Paul K. Davis RAND National Security Research...limitations. The project that the paper draws on was sponsored by the Korea Institute for Defense Analysis (KIDA). The methods discussed are being...the Unified Combatant Commands, the Navy, the Marine Corps, the defense agencies, and the defense Intelligence Community. For more information on

  6. Human embryonic stem cells as models for aneuploid chromosomal syndromes.

    Science.gov (United States)

    Biancotti, Juan-Carlos; Narwani, Kavita; Buehler, Nicole; Mandefro, Berhan; Golan-Lev, Tamar; Yanuka, Ofra; Clark, Amander; Hill, David; Benvenisty, Nissim; Lavon, Neta

    2010-09-01

    Syndromes caused by chromosomal aneuploidies are widely recognized genetic disorders in humans and often lead to spontaneous miscarriage. Preimplantation genetic screening is used to detect chromosomal aneuploidies in early embryos. Our aim was to derive aneuploid human embryonic stem cell (hESC) lines that may serve as models for human syndromes caused by aneuploidies. We have established 25 hESC lines from blastocysts diagnosed as aneuploid on day 3 of their in vitro development. The hESC lines exhibited morphology and expressed markers typical of hESCs. They demonstrated long-term proliferation capacity and pluripotent differentiation. Karyotype analysis revealed that two-third of the cell lines carry a normal euploid karyotype, while one-third remained aneuploid throughout the derivation, resulting in eight hESC lines carrying either trisomy 13 (Patau syndrome), 16, 17, 21 (Down syndrome), X (Triple X syndrome), or monosomy X (Turner syndrome). On the basis of the level of single nucleotide polymorphism heterozygosity in the aneuploid chromosomes, we determined whether the aneuploidy originated from meiotic or mitotic chromosomal nondisjunction. Gene expression profiles of the trisomic cell lines suggested that all three chromosomes are actively transcribed. Our analysis allowed us to determine which tissues are most affected by the presence of a third copy of either chromosome 13, 16, 17 or 21 and highlighted the effects of trisomies on embryonic development. The results presented here suggest that aneuploid embryos can serve as an alternative source for either normal euploid or aneuploid hESC lines, which represent an invaluable tool to study developmental aspects of chromosomal abnormalities in humans.

  7. Modelling and monitoring of passive control structures in human movement

    Science.gov (United States)

    Hemami, Hooshang; Hemami, Mahmoud

    2014-09-01

    Passive tissues, ligaments and cartilage are vital to human movement. Their contribution to stability, joint function and joint integrity is essential. The articulation of their functions and quantitative assessment of what they do in a healthy or injured state are important in athletics, orthopaedics, medicine and health. In this paper, the role of cartilage and ligaments in stability of natural contacts, connections and joints is articulated by including them in two very simple skeletal systems: one- and three-link rigid body systems. Based on the Newton-Euler equations, a state space presentation of the dynamics is discussed that allows inclusion of ligament and cartilage structures in the model, and allows for Lyapunov stability studies for the original and reduced systems. The connection constraints may be holonomic and non-holonomic depending on the structure of the passive elements. The development is pertinent to the eventual design of a computational framework for the study of human movement that involves computer models of all the relevant skeletal, neural and physiological elements of the central nervous system (CNS). Such a structure also permits testing of different hypotheses about the functional neuroanatomy of the CNS, and the study of the effects and dynamics of disease, deterioration, aging and injuries. The formulation here is applied to one- and three-link systems. Digital computer simulations of a two rigid body system are presented to demonstrate the feasibility and effectiveness of the approach and the methods.

  8. A prototypic mathematical model of the human hair cycle.

    Science.gov (United States)

    Al-Nuaimi, Yusur; Goodfellow, Marc; Paus, Ralf; Baier, Gerold

    2012-10-07

    The human hair cycle is a complex, dynamic organ-transformation process during which the hair follicle repetitively progresses from a growth phase (anagen) to a rapid apoptosis-driven involution (catagen) and finally a relative quiescent phase (telogen) before returning to anagen. At present no theory satisfactorily explains the origin of the hair cycle rhythm. Based on experimental evidence we propose a prototypic model that focuses on the dynamics of hair matrix keratinocytes. We argue that a plausible feedback-control structure between two key compartments (matrix keratinocytes and dermal papilla) leads to dynamic instabilities in the population dynamics resulting in rhythmic hair growth. The underlying oscillation consists of an autonomous switching between two quasi-steady states. Additional features of the model, namely bistability and excitability, lead to new hypotheses about the impact of interventions on hair growth. We show how in silico testing may facilitate testing of candidate hair growth modulatory agents in human HF organ culture or in clinical trials. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. An In Vivo Mouse Model for Human Prostate Cancer Metastasis

    Directory of Open Access Journals (Sweden)

    Aaron M. Havens

    2008-04-01

    Full Text Available We developed a sensitive real-time polymerase chain reaction (QPCR assay that allows us to track early lodging/homing events in vivo. We used this technology to develop a metastasis assay of human prostate cancer (PCa growth in severe combined immunodeficient mice. For this purpose, marked human PCa cell lines were implanted subcutaneously or in the prostate (orthotopically of severe combined immunodeficient mice as models of primary tumors. Mice were then sacrificed at various time points, and distant tissues were investigated for the presence of metastatic cells. At 3 weeks, a number of tissues were recovered and evaluated by QPCR for the presence of metastatic cells. The data demonstrate that several PCa cell lines are able to spread from the primary lesion and take up residence in distant sites. If the primary tumors were resected at 3 weeks, in several cases, metastastic lesions were identified over the course of 9 months. We propose that this new model may be particularly useful in exploring the molecular events in early metastasis, identifying the metastatic niche, and studying issues pertaining to dormancy.

  10. Immunology of membranous nephropathy: from animal models to humans.

    Science.gov (United States)

    Sinico, R A; Mezzina, N; Trezzi, B; Ghiggeri, G M; Radice, A

    2016-02-01

    Membranous nephropathy (MN), the leading cause of nephrotic syndrome in adults, is characterized by the deposition of subepithelial immune deposits that consist mainly of immunoglobulin (Ig)G and complement. Most of the cases are primary or idiopathic (iMN), while only approximately 25% of the cases are secondary to some known disease such as systemic lupus erythematosus, hepatitis B, drugs and malignancies. Most of our knowledge on the pathogenesis of iMN has relied upon old experimental models (i.e. Heymann nephritis) that have shown that immune deposits are formed in situ by the reaction of autoantibodies against the respective podocyte antigen. Recent findings indicate that podocyte proteins also act as an autoantigen in human iMN. The M-type phospholipase A2 receptor (PLA2R) has been identified as the main target antigen, as it can be found in approximately 70% of iMN patients but only rarely in other glomerulonephritides. Podocytes damage in the experimental model of Heymann nephritis is complement-mediated. In humans, the presence of complement within the subepithelial deposits is well established, but IgG4, which does not activate complement by classical or alternative pathways, represents the predominant subclass of IgG anti-PLA2R. Some evidence suggests that IgG4 anti-PLA2R autoantibodies can bind mannan-binding lectin (MBL) and activate the lectin complement pathway. A genetic background for iMN has been demonstrated by genome-wide association studies that have shown highly significant associations of the PLA2R1 and the human leucocyte antigen (HLA)-DQA1 loci with iMN. In addition to their diagnostic value, anti-PLA2R antibodies may be useful to monitor disease activity and predict response to treatment.

  11. Integrated modeling of natural and human systems - problems and initiatives

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    Kessler, H.; Giles, J.; Gunnink, J.; Hughes, A.; Moore, R. V.; Peach, D.

    2009-12-01

    Governments and their executive agencies across the world are facing increasing pressure to make decisions about the management of resources in light of population growth and environmental change. In the UK and the Netherlands, for example, groundwater is becoming a scarce resource for large parts of its most densely populated areas. At the same time river and groundwater flooding resulting from high rainfall events are increasing in scale and frequency and sea level rise is threatening the defences of coastal cities. There is also a need for affordable housing, improved transport infrastructure and waste disposal as well as sources of renewable energy and sustainable food production. These challenges can only be resolved if solutions are based on sound scientific evidence. Although we have knowledge and understanding of many individual processes in the natural sciences it is clear that a single science discipline is unable to answer the questions and their inter-relationships. Modern science increasingly employs computer models to simulate the natural, economic and human system. Management and planning requires scenario modelling, forecasts and “predictions”. Although the outputs are often impressive in terms of apparent accuracy and visualisation, they are inherently not suited to simulate the response to feedbacks from other models of the earth system, such as the impact of human actions. Geological Survey Organisations (GSO) are increasingly employing advances in Information Technology to visualise and improve their understanding of geological systems. Instead of 2 dimensional paper maps and reports many GSOs now produce 3 dimensional geological framework models and groundwater flow models as their standard output. Additionally the British Geological Survey and the Geological Survey of the Netherlands have developed standard routines to link geological data to groundwater models, but these models are only aimed at solving one specific part of the earth

  12. The Virtual Physiological Human - a European initiative for in silico human modelling -.

    Science.gov (United States)

    Viceconti, Marco; Clapworthy, Gordon; Van Sint Jan, Serge

    2008-12-01

    The Virtual Physiological Human (VPH) is an initiative, strongly supported by the European Commission (EC), that seeks to develop an integrated model of human physiology at multiple scales from the whole body through the organ, tissue, cell and molecular levels to the genomic level. VPH had its beginnings in 2005 with informal discussions amongst like-minded scientists which led to the STEP project, a Coordination Action funded by the EC that began in early 2006. The STEP project greatly accelerated the progress of the VPH and proved to be a catalyst for wide-ranging discussions within Europe and for outreach activities designed to develop a broad international approach to the huge scientific and technological challenges involved in this area. This paper provides an overview of the VPH and the developments it has engendered in the rapidly expanding worldwide activities associated with the physiome. It then uses one particular project, the Living Human Project, to illustrate the type of advances that are taking place to further the aims of the VPH and similar initiatives worldwide.

  13. A reproducible brain tumour model established from human glioblastoma biopsies

    Directory of Open Access Journals (Sweden)

    Li Xingang

    2009-12-01

    Full Text Available Abstract Background Establishing clinically relevant animal models of glioblastoma multiforme (GBM remains a challenge, and many commonly used cell line-based models do not recapitulate the invasive growth patterns of patient GBMs. Previously, we have reported the formation of highly invasive tumour xenografts in nude rats from human GBMs. However, implementing tumour models based on primary tissue requires that these models can be sufficiently standardised with consistently high take rates. Methods In this work, we collected data on growth kinetics from a material of 29 biopsies xenografted in nude rats, and characterised this model with an emphasis on neuropathological and radiological features. Results The tumour take rate for xenografted GBM biopsies were 96% and remained close to 100% at subsequent passages in vivo, whereas only one of four lower grade tumours engrafted. Average time from transplantation to the onset of symptoms was 125 days ± 11.5 SEM. Histologically, the primary xenografts recapitulated the invasive features of the parent tumours while endothelial cell proliferations and necrosis were mostly absent. After 4-5 in vivo passages, the tumours became more vascular with necrotic areas, but also appeared more circumscribed. MRI typically revealed changes related to tumour growth, several months prior to the onset of symptoms. Conclusions In vivo passaging of patient GBM biopsies produced tumours representative of the patient tumours, with high take rates and a reproducible disease course. The model provides combinations of angiogenic and invasive phenotypes and represents a good alternative to in vitro propagated cell lines for dissecting mechanisms of brain tumour progression.

  14. Modeling human mortality using mixtures of bathtub shaped failure distributions.

    Science.gov (United States)

    Bebbington, Mark; Lai, Chin-Diew; Zitikis, Ricardas

    2007-04-07

    Aging and mortality is usually modeled by the Gompertz-Makeham distribution, where the mortality rate accelerates with age in adult humans. The resulting parameters are interpreted as the frailty and decrease in vitality with age. This fits well to life data from 'westernized' societies, where the data are accurate, of high resolution, and show the effects of high quality post-natal care. We show, however, that when the data are of lower resolution, and contain considerable structure in the infant mortality, the fit can be poor. Moreover, the Gompertz-Makeham distribution is consistent with neither the force of natural selection, nor the recently identified 'late life mortality deceleration'. Although actuarial models such as the Heligman-Pollard distribution can, in theory, achieve an improved fit, the lack of a closed form for the survival function makes fitting extremely arduous, and the biological interpretation can be lacking. We show, that a mixture, assigning mortality to exogenous or endogenous causes, using the reduced additive and flexible Weibull distributions, models well human mortality over the entire life span. The components of the mixture are asymptotically consistent with the reliability and biological theories of aging. The relative simplicity of the mixture distribution makes feasible a technique where the curvature functions of the corresponding survival and hazard rate functions are used to identify the beginning and the end of various life phases, such as infant mortality, the end of the force of natural selection, and late life mortality deceleration. We illustrate our results with a comparative analysis of Canadian and Indonesian mortality data.

  15. An Optimised Human Cell Culture Model for Alveolar Epithelial Transport

    Science.gov (United States)

    Birch, Nigel P.; Suresh, Vinod

    2016-01-01

    Robust and reproducible in vitro models are required for investigating the pathways involved in fluid homeostasis in the human alveolar epithelium. We performed functional and phenotypic characterisation of ion transport in the human pulmonary epithelial cell lines NCI-H441 and A549 to determine their similarity to primary human alveolar type II cells. NCI-H441 cells exhibited high expression of junctional proteins ZO-1, and E-cadherin, seal-forming claudin-3, -4, -5 and Na+-K+-ATPase while A549 cells exhibited high expression of pore-forming claudin-2. Consistent with this phenotype NCI-H441, but not A549, cells formed a functional barrier with active ion transport characterised by higher electrical resistance (529 ± 178 Ω cm2 vs 28 ± 4 Ω cm2), lower paracellular permeability ((176 ± 42) ×10−8 cm/s vs (738 ± 190) ×10−8 cm/s) and higher transepithelial potential difference (11.9 ± 4 mV vs 0 mV). Phenotypic and functional properties of NCI-H441 cells were tuned by varying cell seeding density and supplement concentrations. The cells formed a polarised monolayer typical of in vivo epithelium at seeding densities of 100,000 cells per 12-well insert while higher densities resulted in multiple cell layers. Dexamethasone and insulin-transferrin-selenium supplements were required for the development of high levels of electrical resistance, potential difference and expression of claudin-3 and Na+-K+-ATPase. Treatment of NCI-H441 cells with inhibitors and agonists of sodium and chloride channels indicated sodium absorption through ENaC under baseline and forskolin-stimulated conditions. Chloride transport was not sensitive to inhibitors of the cystic fibrosis transmembrane conductance regulator (CFTR) under either condition. Channels inhibited by 5-nitro-1-(3-phenylpropylamino) benzoic acid (NPPB) contributed to chloride secretion following forskolin stimulation, but not at baseline. These data precisely define experimental conditions for the application of NCI

  16. Mathematical modelling of the growth of human fetus anatomical structures.

    Science.gov (United States)

    Dudek, Krzysztof; Kędzia, Wojciech; Kędzia, Emilia; Kędzia, Alicja; Derkowski, Wojciech

    2016-07-08

    The goal of this study was to present a procedure that would enable mathematical analysis of the increase of linear sizes of human anatomical structures, estimate mathematical model parameters and evaluate their adequacy. Section material consisted of 67 foetuses-rectus abdominis muscle and 75 foetuses- biceps femoris muscle. The following methods were incorporated to the study: preparation and anthropologic methods, image digital acquisition, Image J computer system measurements and statistical analysis method. We used an anthropologic method based on age determination with the use of crown-rump length-CRL (V-TUB) by Scammon and Calkins. The choice of mathematical function should be based on a real course of the curve presenting growth of anatomical structure linear size Ύ in subsequent weeks t of pregnancy. Size changes can be described with a segmental-linear model or one-function model with accuracy adequate enough for clinical purposes. The interdependence of size-age is described with many functions. However, the following functions are most often considered: linear, polynomial, spline, logarithmic, power, exponential, power-exponential, log-logistic I and II, Gompertz's I and II and von Bertalanffy's function. With the use of the procedures described above, mathematical models parameters were assessed for V-PL (the total length of body) and CRL body length increases, rectus abdominis total length h, its segments hI, hII, hIII, hIV, as well as biceps femoris length and width of long head (LHL and LHW) and of short head (SHL and SHW). The best adjustments to measurement results were observed in the exponential and Gompertz's models.

  17. Agent Based Modeling of Human Gut Microbiome Interactions and Perturbations.

    Directory of Open Access Journals (Sweden)

    Tatiana Shashkova

    Full Text Available Intestinal microbiota plays an important role in the human health. It is involved in the digestion and protects the host against external pathogens. Examination of the intestinal microbiome interactions is required for understanding of the community influence on host health. Studies of the microbiome can provide insight on methods of improving health, including specific clinical procedures for individual microbial community composition modification and microbiota correction by colonizing with new bacterial species or dietary changes.In this work we report an agent-based model of interactions between two bacterial species and between species and the gut. The model is based on reactions describing bacterial fermentation of polysaccharides to acetate and propionate and fermentation of acetate to butyrate. Antibiotic treatment was chosen as disturbance factor and used to investigate stability of the system. System recovery after antibiotic treatment was analyzed as dependence on quantity of feedback interactions inside the community, therapy duration and amount of antibiotics. Bacterial species are known to mutate and acquire resistance to the antibiotics. The ability to mutate was considered to be a stochastic process, under this suggestion ratio of sensitive to resistant bacteria was calculated during antibiotic therapy and recovery.The model confirms a hypothesis of feedbacks mechanisms necessity for providing functionality and stability of the system after disturbance. High fraction of bacterial community was shown to mutate during antibiotic treatment, though sensitive strains could become dominating after recovery. The recovery of sensitive strains is explained by fitness cost of the resistance. The model demonstrates not only quantitative dynamics of bacterial species, but also gives an ability to observe the emergent spatial structure and its alteration, depending on various feedback mechanisms. Visual version of the model shows that spatial

  18. Human Internal Mammary Artery (IMA) Transplantation and Stenting: A Human Model to Study the Development of In-Stent Restenosis

    Science.gov (United States)

    Hua, Xiaoqin; Deuse, Tobias; Michelakis, Evangelos D.; Haromy, Alois; Tsao, Phil S.; Maegdefessel, Lars; Erben, Reinhold G.; Bergow, Claudia; Behnisch, Boris B.; Reichenspurner, Hermann; Robbins, Robert C.; Schrepfer, Sonja

    2012-01-01

    Preclinical in vivo research models to investigate pathobiological and pathophysiological processes in the development of intimal hyperplasia after vessel stenting are crucial for translational approaches1,2. The commonly used animal models include mice, rats, rabbits, and pigs3-5. However, the translation of these models into clinical settings remains difficult, since those biological processes are already studied in animal vessels but never performed before in human research models6,7. In this video we demonstrate a new humanized model to overcome this translational gap. The shown procedure is reproducible, easy, and fast to perform and is suitable to study the development of intimal hyperplasia and the applicability of diverse stents. This video shows how to perform the stent technique in human vessels followed by transplantation into immunodeficient rats, and identifies the origin of proliferating cells as human. PMID:22617624

  19. Folded Sheet Versus Transparent Sheet Models for Human Symmetry Judgments

    Directory of Open Access Journals (Sweden)

    Jacques Ninio

    2011-07-01

    Full Text Available As a contribution to the mysteries of human symmetry perception, reaction time data were collected on the detection of symmetry or repetition violations, in the context of short term visual memory studies. The histograms for reaction time distributions are rather narrow in the case of symmetry judgments. Their analysis was performed in terms of a simple kinetic model of a mental process in two steps, a slow one for the construction of the representation of the images to be compared, and a fast one, in the 50 ms range, for the decision. There was no need for an additional ‘mental rotation’ step. Symmetry seems to facilitate the construction step. I also present here original stimuli showing a color equalization effect across a symmetry axis, and its counterpart in periodic patterns. According to a “folded sheet model”, when a shape is perceived, the brain automatically constructs a mirror-image representation of the shape. Based in part on the reaction time analysis, I present here an alternative “transparent sheet” model in which the brain constructs a single representation, which can be accessed from two sides, thus generating simultaneously a pattern and its mirror-symmetric partner. Filtering processes, implied by current models of symmetry perception could intervene at an early stage, by nucleating the propagation of similar perceptual groupings in the two symmetric images.

  20. Bioengineered models of solid human tumors for cancer research

    Science.gov (United States)

    Marturano-Kruik, Alessandro; Villasante, Aranzazu; Vunjak-Novakovic, Gordana

    2016-01-01

    Summary The lack of controllable in vitro models that can recapitulate the features of solid tumors such as Ewing’s sarcoma limits our understanding of the tumor initiation and progression and impedes the development of new therapies. Cancer research still relies of the use of simple cell culture, tumor spheroids, and small animals. Tissue-engineered tumor models are now being grown in vitro to mimic the actual tumors in patients. Recently, we have established a new protocol for bioengineering the Ewing’s sarcoma, by infusing tumor cell aggregates into the human bone engineered from the patient’s mesenchymal stem cells. The bone niche allows crosstalk between the tumor cells, osteoblasts and supporting cells of the bone, extracellular matrix and the tissue microenvironment. The bioreactor platform used in these experiments also allows the implementation of physiologically relevant mechanical signals. Here, we describe a method to build an in vitro model of Ewing’s sarcoma that mimics the key properties of the native tumor and provides the tissue context and physical regulatory signals. PMID:27115504

  1. Predictive models of procedural human supervisory control behavior

    Science.gov (United States)

    Boussemart, Yves

    Human supervisory control systems are characterized by the computer-mediated nature of the interactions between one or more operators and a given task. Nuclear power plants, air traffic management and unmanned vehicles operations are examples of such systems. In this context, the role of the operators is typically highly proceduralized due to the time and mission-critical nature of the tasks. Therefore, the ability to continuously monitor operator behavior so as to detect and predict anomalous situations is a critical safeguard for proper system operation. In particular, such models can help support the decision J]l8king process of a supervisor of a team of operators by providing alerts when likely anomalous behaviors are detected By exploiting the operator behavioral patterns which are typically reinforced through standard operating procedures, this thesis proposes a methodology that uses statistical learning techniques in order to detect and predict anomalous operator conditions. More specifically, the proposed methodology relies on hidden Markov models (HMMs) and hidden semi-Markov models (HSMMs) to generate predictive models of unmanned vehicle systems operators. Through the exploration of the resulting HMMs in two distinct single operator scenarios, the methodology presented in this thesis is validated and shown to provide models capable of reliably predicting operator behavior. In addition, the use of HSMMs on the same data scenarios provides the temporal component of the predictions missing from the HMMs. The final step of this work is to examine how the proposed methodology scales to more complex scenarios involving teams of operators. Adopting a holistic team modeling approach, both HMMs and HSMMs are learned based on two team-based data sets. The results show that the HSMMs can provide valuable timing information in the single operator case, whereas HMMs tend to be more robust to increased team complexity. In addition, this thesis discusses the

  2. A paradigm for human body finite element model integration from a set of regional models.

    Science.gov (United States)

    Thompson, A B; Gayzik, F S; Moreno, D P; Rhyne, A C; Vavalle, N A; Stitzel, J D

    2012-01-01

    Computational modeling offers versatility, scalability, and cost advantages to researchers in the trauma and injury biomechanics communities. The Global Human Body Models Consortium (GHBMC) is a group of government, industry, and academic researchers developing human body models (HBMs) that aim to become the standard tool to meet this growing research need. The objective of this study is to present the methods used to develop the average seated male occupant model (M50, weight = 78 kg, height = 175 cm) from five separately validated body region models (BRMs). BRMs include the head, neck, thorax, abdomen, and a combined pelvis and lower extremity model. Modeling domains were split at the atlanto-occipital joint, C7-T1 boundary, diaphragm, abdominal cavity (peritoneum/retroperitoneum), and the acetabulum respectively. BRM meshes are based on a custom CAD model of the seated male built from a multi-modality imaging protocol of a volunteer subject found in literature.[1] Various meshing techniques were used to integrate the full body model (FBM) including 1-D beam and discrete element connections (e.g. ligamentous structures), 2D shell nodal connections (e.g. inferior vena cava to right atrium), 3D hexahedral nodal connections (e.g. soft tissue envelope connections between regions), and contact definitions varying from tied (muscle insertions) to sliding (liver and diaphragm contact). The model was developed in a general-purpose finite element code, LS-Dyna (LTSC, Livermore, CA) R4.2.1., and consists of 1.95 million elements and 1.3 million nodes. The element breakdown by type is 41% hexahedral, 33.7% tetrahedral, 19.5% quad shells and 5% tria shell. The integration methodology presented highlights the viability of using a collaborative development paradigm for the construction of HBMs, and will be used as template for expanding the suite of GHBMC models.

  3. Caffeine prevents protection in two human models of ischemic preconditioning.

    Science.gov (United States)

    Riksen, Niels P; Zhou, Zhigang; Oyen, Wim J G; Jaspers, Rogier; Ramakers, Bart P; Brouwer, Rene M H J; Boerman, Otto C; Steinmetz, Neil; Smits, Paul; Rongen, Gerard A

    2006-08-15

    We studied whether caffeine impairs protection by ischemic preconditioning (IP) in humans. Ischemic preconditioning is critically dependent on adenosine receptor stimulation. We hypothesize that the adenosine receptor antagonist caffeine blocks the protective effect of IP. In vivo ischemia-reperfusion injury was assessed in the thenar muscle by 99mTc-annexin A5 scintigraphy. Forty-two healthy volunteers performed forearm ischemic exercise. In 24 subjects, this was preceded by a stimulus for IP. In a randomized double-blinded design, the subjects received caffeine (4 mg/kg) or saline intravenously before the experiment. At reperfusion, 99mTc-annexin A5 was administered intravenously. Targeting of annexin was quantified by region-of-interest analysis, and expressed as percentage difference between experimental and contralateral hand. In vitro, we assessed recovery of contractile function of human atrial trabeculae, harvested during heart surgery, as functional end point of ischemia-reperfusion injury. Field-stimulated contraction was quantified at baseline and after simulated ischemia-reperfusion, in a paired approach with and without 5 min of IP, in the presence (n=13) or absence (n = 17) of caffeine (10 mg/l). Ischemic preconditioning reduced annexin targeting in the absence of caffeine (from 13 +/- 3% to 7 +/- 1% at 1 h, and from 19 +/- 2% to 9 +/- 3% at 4 h after reperfusion, p = 0.006), but not after caffeine administration (targeting 11 +/- 2% and 16 +/- 3% at 1 and 4 h). In vitro, IP improved post-ischemic functional recovery in the control group, but not in the caffeine group (8 +/- 3% vs. -8 +/- 5%, p=0.003). Caffeine abolishes IP in 2 human models at a dose equivalent to the drinking of 2 to 4 cups of coffee. (The Effect of Caffeine on Ischemic Preconditioning; http://clinicaltrials.gov/ct/show/NCT00184912?order=1; NCT00184912).

  4. Cat Mammary Tumors: Genetic Models for the Human Counterpart

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    Filomena Adega

    2016-08-01

    Full Text Available The records are not clear, but Man has been sheltering the cat inside his home for over 12,000 years. The close proximity of this companion animal, however, goes beyond sharing the same roof; it extends to the great similarity found at the cellular and molecular levels. Researchers have found a striking resemblance between subtypes of feline mammary tumors and their human counterparts that goes from the genes to the pathways involved in cancer initiation and progression. Spontaneous cat mammary pre-invasive intraepithelial lesions (hyperplasias and neoplasias and malignant lesions seem to share a wide repertoire of molecular features with their human counterparts. In the present review, we tried to compile all the genetics aspects published (i.e., chromosomal alterations, critical cancer genes and their expression regarding cat mammary tumors, which support the cat as a valuable alternative in vitro cell and animal model (i.e., cat mammary cell lines and the spontaneous tumors, respectively, but also to present a critical point of view of some of the issues that really need to be investigated in future research.

  5. A non-human primate model for gluten sensitivity.

    Directory of Open Access Journals (Sweden)

    Michael T Bethune

    Full Text Available BACKGROUND AND AIMS: Gluten sensitivity is widespread among humans. For example, in celiac disease patients, an inflammatory response to dietary gluten leads to enteropathy, malabsorption, circulating antibodies against gluten and transglutaminase 2, and clinical symptoms such as diarrhea. There is a growing need in fundamental and translational research for animal models that exhibit aspects of human gluten sensitivity. METHODS: Using ELISA-based antibody assays, we screened a population of captive rhesus macaques with chronic diarrhea of non-infectious origin to estimate the incidence of gluten sensitivity. A selected animal with elevated anti-gliadin antibodies and a matched control were extensively studied through alternating periods of gluten-free diet and gluten challenge. Blinded clinical and histological evaluations were conducted to seek evidence for gluten sensitivity. RESULTS: When fed with a gluten-containing diet, gluten-sensitive macaques showed signs and symptoms of celiac disease including chronic diarrhea, malabsorptive steatorrhea, intestinal lesions and anti-gliadin antibodies. A gluten-free diet reversed these clinical, histological and serological features, while reintroduction of dietary gluten caused rapid relapse. CONCLUSIONS: Gluten-sensitive rhesus macaques may be an attractive resource for investigating both the pathogenesis and the treatment of celiac disease.

  6. Fetal developmental programing: insights from human studies and experimental models.

    Science.gov (United States)

    Lopes, Gisele Aparecida Dionísio; Ribeiro, Vinícius Luís Bertotti; Barbisan, Luís Fernando; Marchesan Rodrigues, Maria Aparecida

    2017-03-01

    Environmental factors, particularly nutrition during pregnancy and early life can influence the risk of chronic diseases in later life. The underlying mechanism, termed "programing", postulates that an environmental stimulus during a critical window of time, early in life, has a permanent effect on subsequent structure and function of the organism. In this study we review the concept of fetal programing on chronic diseases and the proposed hypotheses for the association between early development and later disease, including epigenetic variation. We concentrate on specific aspects of maternal nutrition, particularly under-nutrition and over-nutrition, in humans and animal models. An adequate maternal nutrition during pregnancy is crucial for the health outcome of the offspring at adulthood.

  7. A theoretical model of phase transitions in the human brain.

    Science.gov (United States)

    Jirsa, V K; Friedrich, R; Haken, H; Kelso, J A

    1994-01-01

    An experiment using a multisensor SQUID (superconducting quantum interference device) array was performed by Kelso and colleagues (1992) which combined information from three different sources: perception, motor response, and brain signals. When an acoustic stimulus frequency is changed systematically, a spontaneous transition in coordination occurs at a critical frequency in both motor behavior and brain signals. Qualitatively analogous transitions are known for physical and biological systems such as changes in the coordination of human hand movements (Kelso 1981, 1984). In this paper we develop a theoretical model based on methods from the interdisciplinary field of synergetics (Haken 1983, 1987) and nonlinear oscillator theory that reproduces the main experimental features very well and suggests a formulation of a fundamental biophysical coupling.

  8. Recapitulating Human Gastric Cancer Pathogenesis: Experimental Models of Gastric Cancer

    Science.gov (United States)

    Ding, Lin; El Zaatari, Mohamad

    2017-01-01

    Overview Gastric cancer has been traditionally defined by the Correa paradigm as a progression of sequential pathological events that begins with chronic inflammation [1]. Infection with Helicobacter pylori (H. pylori) is the typical explanation for why the stomach becomes chronically inflamed. Acute gastric inflammation then leads to chronic gastritis, atrophy particularly of acid-secreting parietal cells, metaplasia due to mucous neck cell expansion from trans-differentiation of zymogenic cells to dysplasia and eventually carcinoma [2]. The chapter contains an overview of gastric anatomy and physiology to set the stage for signaling pathways that play a role in gastric tumorigenesis. Finally, the major known mouse models of gastric transformation are critiqued in terms of the rationale behind their generation and contribution to our understanding of human cancer subtypes. PMID:27573785

  9. Interactive 3D computer model of the human corneolimbal region

    DEFF Research Database (Denmark)

    Molvaer, Rikke Kongshaug; Andreasen, Arne; Heegaard, Steffen;

    2013-01-01

    in the superior limbal region and one LEC, six LCs and 12 FSPs in the inferior limbal region. Only few LECs, LCs and FSPs were localized nasally and temporally. CONCLUSION: Interactive 3D models are a powerful tool that may help to shed more light on the existence and spatial localization of the different stem......PURPOSE: This study aims to clarify the existence of and to map the localization of different proposed stem cell niches in the corneal limbal region. MATERIALS AND METHODS: One human eye was cut into 2200 consecutive sections. Every other section was stained with haematoxylin and eosin, digitized...... in the limbal region: limbal epithelial crypts (LECs), limbal crypts (LCs) and focal stromal projections (FSPs). In all, eight LECs, 25 LCs and 105 FSPs were identified in the limbal region. The LECs, LCs and FSPs were predominantly located in the superior limbal region with seven LECs, 19 LCs and 93 FSPs...

  10. Generation of human/rat xenograft animal model for the study of human donor stem cell behaviors in vivo

    Institute of Scientific and Technical Information of China (English)

    Yan Sun; Dong Xiao; Xing-Hua Pan; Ruo-Shuang Zhang; Guang-Hui Cui; Xi-Gu Chen

    2007-01-01

    AIM: To accurately and realistically elucidate human stem cell behaviors In vivo and the fundamental mechanisms controlling human stem cell fates in vivo, which is urgently required in regenerative medicine and treatments for some human diseases, a surrogate human-rat chimera model was developed.METHODS: Human-rat chimeras were achieved by in utero transplanting low-density mononuclear cells from human umbilical cord blood into the fetal rats at 9-11 d of gestation, and subsequently, a variety of methods, including flow cytometry, PCR as well as immunohistochemical assay, were used to test the human donor contribution in the recipients.RESULTS: Of 29 live-born recipients, 19 had the presence of human CD45+ cells in peripheral blood (PB) detected by flow cytometry, while PCR analysis on genomic DNA from 11 different adult tissues showed that 14 selected from flow cytometry-positive 19 animals possessed of donor-derived human cell engraftment in multiple tissues (i.e. liver, spleen, thymus, heart, kidney, blood, lung, muscle, gut and skin) examined at the time of tissue collection, as confirmed by detecting human β2-microglobulin expression using immunohistochemistry.In this xenogeneic system, the engrafted donor-derived human cells persisted in multiple tissues for at least 6 mo after birth. Moreover, transplanted human donor cells underwent site-specific differentiation into CK18-positive human cells in chimeric liver and CD45-positive human cells in chimeric spleen and thymus of recipients.CONCLUSION: Taken together, these findings suggest that we successfully developed human-rat chimeras, in which xenogeneic human cells exist up to 6 mo later. This humanized small animal model, which offers an in vivo environment more closely resembling to the situations in human, provides an invaluable and effective approach for in vivo investigating human stem cell behaviors, and further in vivo examining fundamental mechanisms controlling human stem cell fates in the future

  11. Comparative digital cartilage histology for human and common osteoarthritis models

    Directory of Open Access Journals (Sweden)

    Pedersen DR

    2013-02-01

    Full Text Available Douglas R Pedersen, Jessica E Goetz, Gail L Kurriger, James A MartinDepartment of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA, USAPurpose: This study addresses the species-specific and site-specific details of weight-bearing articular cartilage zone depths and chondrocyte distributions among humans and common osteoarthritis (OA animal models using contemporary digital imaging tools. Histological analysis is the gold-standard research tool for evaluating cartilage health, OA severity, and treatment efficacy. Historically, evaluations were made by expert analysts. However, state-of-the-art tools have been developed that allow for digitization of entire histological sections for computer-aided analysis. Large volumes of common digital cartilage metrics directly complement elucidation of trends in OA inducement and concomitant potential treatments.Materials and methods: Sixteen fresh human knees, 26 adult New Zealand rabbit stifles, and 104 bovine lateral plateaus were measured for four cartilage zones and the cell densities within each zone. Each knee was divided into four weight-bearing sites: the medial and lateral plateaus and femoral condyles.Results: One-way analysis of variance followed by pairwise multiple comparisons (Holm–Sidak method at a significance of 0.05 clearly confirmed the variability between cartilage depths at each site, between sites in the same species, and between weight-bearing articular cartilage definitions in different species.Conclusion: The present study clearly demonstrates multisite, multispecies differences in normal weight-bearing articular cartilage, which can be objectively quantified by a common digital histology imaging technique. The clear site-specific differences in normal cartilage must be taken into consideration when characterizing the pathoetiology of OA models. Together, these provide a path to consistently analyze the volume and variety of histologic slides necessarily generated

  12. Human sperm chromatin stabilization: a proposed model including zinc bridges.

    Science.gov (United States)

    Björndahl, Lars; Kvist, Ulrik

    2010-01-01

    The primary focus of this review is to challenge the current concepts on sperm chromatin stability. The observations (i) that zinc depletion at ejaculation allows a rapid and total sperm chromatin decondensation without the addition of exogenous disulfide cleaving agents and (ii) that the human sperm chromatin contains one zinc for every protamine for every turn of the DNA helix suggest an alternative model for sperm chromatin structure may be plausible. An alternative model is therefore proposed, that the human spermatozoon could at ejaculation have a rapidly reversible zinc dependent chromatin stability: Zn(2+) stabilizes the structure and prevents the formation of excess disulfide bridges by a single mechanism, the formation of zinc bridges with protamine thiols of cysteine and potentially imidazole groups of histidine. Extraction of zinc enables two biologically totally different outcomes: immediate decondensation if chromatin fibers are concomitantly induced to repel (e.g. by phosphorylation in the ooplasm); otherwise freed thiols become committed into disulfide bridges creating a superstabilized chromatin. Spermatozoa in the zinc rich prostatic fluid (normally the first expelled ejaculate fraction) represent the physiological situation. Extraction of chromatin zinc can be accomplished by the seminal vesicular fluid. Collection of the ejaculate in one single container causes abnormal contact between spermatozoa and seminal vesicular fluid affecting the sperm chromatin stability. There are men in infertile couples with low content of sperm chromatin zinc due to loss of zinc during ejaculation and liquefaction. Tests for sperm DNA integrity may give false negative results due to decreased access for the assay to the DNA in superstabilized chromatin.

  13. New Safety Model for the Commercial Human Spaceflight Industry

    Science.gov (United States)

    Quinn, A.; Bond, S.; Maropoulos, P.

    2012-01-01

    The aviation and space domains have safety guidelines and recommended practices for Design Organisations (DOs) and Operators alike. In terms of Aerospace DOs there are certification criteria to meet and to demonstrate compliance there are Advisory Circulars or Acceptable Means of Compliance to follow. Additionally there are guidelines such as Aerospace Recommended Practices (ARP), Military Standards (MIL-STD 882 series) and System Safety Handbooks to follow in order to identify and manage failure conditions. In terms of Operators there are FAA guidelines and a useful ARP that details many tools and techniques in understanding Operator Safety Risks. However there is currently no methodology for linking the DO and Operator safety efforts. In the space domain NASA have provided safety standards and guidelines to follow and also within Europe there are European Co-operation of Space Standardization (ECSS) to follow. Within the emerging Commercial Human Spaceflight Industry, the FAA's Office of Commercial Space Transportation has provided hazard analysis guidelines. However all of these space domain safety documents are based on the existing aerospace methodology and once again, there is no link between the DO and Operator's safety effort. This paper addresses the problematic issue and presents a coherent methodology of joining up the System Safety effort of the DOs to the Operator Safety Risk Management such that a 'Total System' approach is adopted. Part of the rationale is that the correct mitigation (control) can be applied within the correct place in the accident sequence. Also this contiguous approach ensures that the Operator is fully aware of the safety risks (at the accident level) and therefore has an appreciation of the Total System Risk. The authors of this paper contend that it is better practice to have a fully integrated safety model as opposed to disparate requirements or guidelines. Our methodology is firstly to review 'best practice' approaches from

  14. A Simplified Model of Human Alcohol Metabolism That Integrates Biotechnology and Human Health into a Mass Balance Team Project

    Science.gov (United States)

    Yang, Allen H. J.; Dimiduk, Kathryn; Daniel, Susan

    2011-01-01

    We present a simplified human alcohol metabolism model for a mass balance team project. Students explore aspects of engineering in biotechnology: designing/modeling biological systems, testing the design/model, evaluating new conditions, and exploring cutting-edge "lab-on-a-chip" research. This project highlights chemical engineering's impact on…

  15. A Simplified Model of Human Alcohol Metabolism That Integrates Biotechnology and Human Health into a Mass Balance Team Project

    Science.gov (United States)

    Yang, Allen H. J.; Dimiduk, Kathryn; Daniel, Susan

    2011-01-01

    We present a simplified human alcohol metabolism model for a mass balance team project. Students explore aspects of engineering in biotechnology: designing/modeling biological systems, testing the design/model, evaluating new conditions, and exploring cutting-edge "lab-on-a-chip" research. This project highlights chemical engineering's impact on…

  16. Teaching Qualitative Research for Human Services Students: A Three-Phase Model

    Science.gov (United States)

    Goussinsky, Ruhama; Reshef, Arie; Yanay-Ventura, Galit; Yassour-Borochowitz, Dalit

    2011-01-01

    Qualitative research is an inherent part of the human services profession, since it emphasizes the great and multifaceted complexity characterizing human experience and the sociocultural context in which humans act. In the department of human services at Emek Yezreel College, Israel, we have developed a three-phase model to ensure a relatively…

  17. Modelling soft tissue for kinematic analysis of multi-segment human body models.

    Science.gov (United States)

    Benham, M P; Wright, D K; Bibb, R

    2001-01-01

    Traditionally biomechanical models represent the musculoskeletal system by a series of rigid links connected by rigidly defined rotational joints. More recently though the mechanics of joints and the action of soft tissues has come under closer scrutiny: biomechanical models might now include a full range of physiological structures. However, soft tissue representation, within multi-segment human body models, presents significant problems; not least in computational speed. We present a method for representing soft tissue physiology which provides for soft tissue wrapping around multiple bony objects; while showing forces at the insertion points, as well as normal reactions due to contact between the soft and bony tissues. These soft tissue representations may therefore be used to constrain the joint, as ligaments would, or to generate motion, like a muscle, so that joints may be modelled which more accurately simulate musculoskeletal motion in all degrees of freedom--rotational and translational. This method produces soft tissues that do not need to be tied to a certain path or route between the bony structures, but may move with the motion of the model; demonstrating a more realistic analysis of soft tissue activity in the musculoskeletal system. The combination of solid geometry models of the skeletal structure, and these novel soft tissue representations, may also provide a useful approach to synthesised human motion.

  18. A Simple Model for Human and Nature Interaction

    Science.gov (United States)

    Motesharrei, S.; Rivas, J.; Kalnay, E.

    2012-12-01

    There are widespread concerns that current trends in population and resource-use are unsustainable, but the possibilities of an overshoot and collapse remain unclear and controversial. Collapses of civilizations have occurred many times in the past 5000 years, often followed by centuries of economic, intellectual, and population decline. Many different natural and social phenomena have been invoked to explain specific collapses, but a general explanation remains elusive. Two important features seem to appear across societies that have collapsed: Ecological Strain and Economic Stratification. Our new model (Human And Nature DYnamics, HANDY) has just four equations that describe the evolution of Elites, Commoners, Nature, and Wealth. Mechanisms leading to collapse are discussed and the measure "Carrying Capacity" is developed and defined. The model shows that societal collapse can happen due to either one of two independent factors: (1) over-consumption of natural resources, and/or (2) deep inequity between Elites and Commoners. The model also portrays two distinct types of collapse: (i) collapse followed by recovery of nature, and (ii) full collapse. The model suggests that the estimation of Carrying Capacity is a practical means for early detection of a collapse. Collapse can be avoided, and population can reach a sustainable equilibrium, if the rate of depletion of nature is reduced to a sustainable level, and if resources are distributed in a reasonably equitable fashion.; A type-ii (full) collapse is shown in this figure. With high inequality and high depletion, societies are doomed to collapse. Wealth starts to decrease when population rises above the carrying capacity. The large gap between carrying capacity and its maximum is a result of depletion factor being much larger than the sustainable limit. ; It is possible to overshoot, oscillate, and eventually converge to an equilibrium, even in an inequitable society. However, it requires policies that control

  19. Computational modeling and analysis of the hydrodynamics of human swimming

    Science.gov (United States)

    von Loebbecke, Alfred

    Computational modeling and simulations are used to investigate the hydrodynamics of competitive human swimming. The simulations employ an immersed boundary (IB) solver that allows us to simulate viscous, incompressible, unsteady flow past complex, moving/deforming three-dimensional bodies on stationary Cartesian grids. This study focuses on the hydrodynamics of the "dolphin kick". Three female and two male Olympic level swimmers are used to develop kinematically accurate models of this stroke for the simulations. A simulation of a dolphin undergoing its natural swimming motion is also presented for comparison. CFD enables the calculation of flow variables throughout the domain and over the swimmer's body surface during the entire kick cycle. The feet are responsible for all thrust generation in the dolphin kick. Moreover, it is found that the down-kick (ventral position) produces more thrust than the up-kick. A quantity of interest to the swimming community is the drag of a swimmer in motion (active drag). Accurate estimates of this quantity have been difficult to obtain in experiments but are easily calculated with CFD simulations. Propulsive efficiencies of the human swimmers are found to be in the range of 11% to 30%. The dolphin simulation case has a much higher efficiency of 55%. Investigation of vortex structures in the wake indicate that the down-kick can produce a vortex ring with a jet of accelerated fluid flowing through its center. This vortex ring and the accompanying jet are the primary thrust generating mechanisms in the human dolphin kick. In an attempt to understand the propulsive mechanisms of surface strokes, we have also conducted a computational analysis of two different styles of arm-pulls in the backstroke and the front crawl. These simulations involve only the arm and no air-water interface is included. Two of the four strokes are specifically designed to take advantage of lift-based propulsion by undergoing lateral motions of the hand

  20. Mitigating Insider Threat Using Human Behavior Influence Models

    Science.gov (United States)

    2006-06-01

    Change in Score Versus Time for Both Employees (over 3 years).......................94 45. Distribution of Sensitivity Tests Performed ...Human Behavior Human Behavior is defined as a “collection of activities performed by human beings and influenced by culture, attitudes, emotions...values, ethics, authority, rapport, hypnosis , persuasion, and/or coercion.” [6] The theory behind human behavior is humans react to “definite objective