WorldWideScience

Sample records for brain integrating models

  1. Efficient multilevel brain tumor segmentation with integrated bayesian model classification.

    Science.gov (United States)

    Corso, J J; Sharon, E; Dube, S; El-Saden, S; Sinha, U; Yuille, A

    2008-05-01

    We present a new method for automatic segmentation of heterogeneous image data that takes a step toward bridging the gap between bottom-up affinity-based segmentation methods and top-down generative model based approaches. The main contribution of the paper is a Bayesian formulation for incorporating soft model assignments into the calculation of affinities, which are conventionally model free. We integrate the resulting model-aware affinities into the multilevel segmentation by weighted aggregation algorithm, and apply the technique to the task of detecting and segmenting brain tumor and edema in multichannel magnetic resonance (MR) volumes. The computationally efficient method runs orders of magnitude faster than current state-of-the-art techniques giving comparable or improved results. Our quantitative results indicate the benefit of incorporating model-aware affinities into the segmentation process for the difficult case of glioblastoma multiforme brain tumor. PMID:18450536

  2. Allostasis and the Human Brain: Integrating Models of Stress from the Social and Life Sciences

    Science.gov (United States)

    Ganzel, Barbara L.; Morris, Pamela A.; Wethington, Elaine

    2010-01-01

    We draw on the theory of allostasis to develop an integrative model of the current stress process that highlights the brain as a dynamically adapting interface between the changing environment and the biological self. We review evidence that the core emotional regions of the brain constitute the primary mediator of the well-established association…

  3. Neurocomputational approaches to modelling multisensory integration in the brain: a review.

    Science.gov (United States)

    Ursino, Mauro; Cuppini, Cristiano; Magosso, Elisa

    2014-12-01

    The Brain's ability to integrate information from different modalities (multisensory integration) is fundamental for accurate sensory experience and efficient interaction with the environment: it enhances detection of external stimuli, disambiguates conflict situations, speeds up responsiveness, facilitates processes of memory retrieval and object recognition. Multisensory integration operates at several brain levels: in subcortical structures (especially the Superior Colliculus), in higher-level associative cortices (e.g., posterior parietal regions), and even in early cortical areas (such as primary cortices) traditionally considered to be purely unisensory. Because of complex non-linear mechanisms of brain integrative phenomena, a key tool for their understanding is represented by neurocomputational models. This review examines different modelling principles and architectures, distinguishing the models on the basis of their aims: (i) Bayesian models based on probabilities and realizing optimal estimator of external cues; (ii) biologically inspired models of multisensory integration in the Superior Colliculus and in the Cortex, both at level of single neuron and network of neurons, with emphasis on physiological mechanisms and architectural schemes; among the latter, some models exhibit synaptic plasticity and reproduce development of integrative capabilities via Hebbian-learning rules or self-organizing maps; (iii) models of semantic memory that implement object meaning as a fusion between sensory-motor features (embodied cognition). This overview paves the way to future challenges, such as reconciling neurophysiological and Bayesian models into a unifying theory, and stimulates upcoming research in both theoretical and applicative domains. PMID:25218929

  4. Integration of Multidisciplinary Sensory Data:: A Pilot Model of the Human Brain Project Approach

    OpenAIRE

    Miller, Perry L.; Nadkarni, Prakash; Singer, Michael; Marenco, Luis; Hines, Michael; Shepherd, Gordon

    2001-01-01

    The paper provides an overview of neuroinformatics research at Yale University being performed as part of the national Human Brain Project. This research is exploring the integration of multidisciplinary sensory data, using the olfactory system as a model domain. The neuroinformatics activities fall into three main areas: 1) building databases and related tools that support experimental olfactory research at Yale and can also serve as resources for the field as a whole, 2) using computer mode...

  5. Integrated modeling of PET and DTI information based on conformal brain mapping

    Science.gov (United States)

    Zou, Guangyu; Xi, Yongjian; Heckenburg, Greg; Duan, Ye; Hua, Jing; Gu, Xiangfeng

    2006-03-01

    Recent advances in imaging technologies, such as Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET) and Diffusion Tensor Imaging (DTI) have accelerated brain research in many aspects. In order to better understand the synergy of the many processes involved in normal brain function, integrated modeling and analysis of MRI, PET, and DTI is highly desirable. Unfortunately, the current state-of-art computational tools fall short in offering a comprehensive computational framework that is accurate and mathematically rigorous. In this paper we present a framework which is based on conformal parameterization of a brain from high-resolution structural MRI data to a canonical spherical domain. This model allows natural integration of information from co-registered PET as well as DTI data and lays the foundation for a quantitative analysis of the relationship between diverse data sets. Consequently, the system can be designed to provide a software environment able to facilitate statistical detection of abnormal functional brain patterns in patients with a large number of neurological disorders.

  6. An integrative dynamic model of brain energy metabolism using in vivo neurochemical measurements.

    Science.gov (United States)

    Cloutier, Mathieu; Bolger, Fiachra B; Lowry, John P; Wellstead, Peter

    2009-12-01

    An integrative, systems approach to the modelling of brain energy metabolism is presented. Mechanisms such as glutamate cycling between neurons and astrocytes and glycogen storage in astrocytes have been implemented. A unique feature of the model is its calibration using in vivo data of brain glucose and lactate from freely moving rats under various stimuli. The model has been used to perform simulated perturbation experiments that show that glycogen breakdown in astrocytes is significantly activated during sensory (tail pinch) stimulation. This mechanism provides an additional input of energy substrate during high consumption phases. By way of validation, data from the perfusion of 50 microM propranolol in the rat brain was compared with the model outputs. Propranolol affects the glucose dynamics during stimulation, and this was accurately reproduced in the model by a reduction in the glycogen breakdown in astrocytes. The model's predictive capacity was verified by using data from a sensory stimulation (restraint) that was not used for model calibration. Finally, a sensitivity analysis was conducted on the model parameters, this showed that the control of energy metabolism and transport processes are critical in the metabolic behaviour of cerebral tissue. PMID:19396534

  7. Modeling community integration in workers with delayed recovery from mild traumatic brain injury

    OpenAIRE

    Mollayeva, Tatyana; Shapiro, Colin M; Mollayeva, Shirin; Cassidy, J David; Colantonio, Angela

    2015-01-01

    Background Delayed recovery in persons after mild traumatic brain injury (mTBI) is poorly understood. Community integration (CI) is endorsed by persons with neurological disorders as an important outcome. We aimed to describe CI and its associated factors in insured Ontario workers with delayed recovery following mTBI. Methods A cross-sectional study of insured workers in the chronic phase following mTBI was performed at a rehabilitation hospital in Ontario, Canada. Sociodemographic, occupati...

  8. Markers for blood-brain barrier integrity

    DEFF Research Database (Denmark)

    Saunders, Norman R; Dziegielewska, Katarzyna M; Møllgård, Kjeld;

    2015-01-01

    In recent years there has been a resurgence of interest in brain barriers and various roles their intrinsic mechanisms may play in neurological disorders. Such studies require suitable models and markers to demonstrate integrity and functional changes at the interfaces between blood, brain, and...... cerebrospinal fluid. Studies of brain barrier mechanisms and measurements of plasma volume using dyes have a long-standing history, dating back to the late nineteenth-century. Their use in blood-brain barrier studies continues in spite of their known serious limitations in in vivo applications. These were well...... known when first introduced, but seem to have been forgotten since. Understanding these limitations is important because Evans blue is still the most commonly used marker of brain barrier integrity and those using it seem oblivious to problems arising from its in vivo application. The introduction of...

  9. Bayesian Models of Brain and Behaviour

    OpenAIRE

    Penny, William

    2012-01-01

    This paper presents a review of Bayesian models of brain and behaviour. We first review the basic principles of Bayesian inference. This is followed by descriptions of sampling and variational methods for approximate inference, and forward and backward recursions in time for inference in dynamical models. The review of behavioural models covers work in visual processing, sensory integration, sensorimotor integration, and collective decision making. The review of brain models covers a range of...

  10. Modeling community integration in workers with delayed recovery from mild traumatic brain injury

    DEFF Research Database (Denmark)

    Mollayeva, T.; Shapiro, C. M.; Mollayeva, S.;

    2015-01-01

    clinical variables. In the multivariable regression analysis, several covariates accounted for 36.4 % of the CIQ variance in the final fully adjusted model. Discussion: This study evaluated CI in workers with mTBI, and analyzed its associated variables. Analysis revealed insomnia, head or neck pain, being...... married or in a relationship, time since injury, and a diagnosis of possible/probable malingering were independently associated with limited CI. Conclusions: Workers with delayed recovery from mTBI experience difficulty with CI. Insomnia is a particularly relevant covariate, explaining the greater part of...

  11. Brain Network Modelling

    DEFF Research Database (Denmark)

    Andersen, Kasper Winther

    Three main topics are presented in this thesis. The first and largest topic concerns network modelling of functional Magnetic Resonance Imaging (fMRI) and Diffusion Weighted Imaging (DWI). In particular nonparametric Bayesian methods are used to model brain networks derived from resting state f...... for their ability to reproduce node clustering and predict unseen data. Comparing the models on whole brain networks, BCD and IRM showed better reproducibility and predictability than IDM, suggesting that resting state networks exhibit community structure. This also points to the importance of using models, which...... allow for complex interactions between all pairs of clusters. In addition, it is demonstrated how the IRM can be used for segmenting brain structures into functionally coherent clusters. A new nonparametric Bayesian network model is presented. The model builds upon the IRM and can be used to infer...

  12. Integration of jugular venous return and circle of Willis in a theoretical human model of selective brain cooling.

    Science.gov (United States)

    Neimark, Matthew A; Konstas, Angelos-Aristeidis; Laine, Andrew F; Pile-Spellman, John

    2007-11-01

    A three-dimensional mathematical model was developed to examine the induction of selective brain cooling (SBC) in the human brain by intracarotid cold (2.8 degrees C) saline infusion (ICSI) at 30 ml/min. The Pennes bioheat equation was used to propagate brain temperature. The effect of cooled jugular venous return was investigated, along with the effect of the circle of Willis (CoW) on the intracerebral temperature distribution. The complete CoW, missing A1 variant (mA1), and fetal P1 variant (fP1) were simulated. ICSI induced moderate hypothermia (defined as 32-34 degrees C) in the internal carotid artery (ICA) territory within 5 min. Incorporation of the complete CoW resulted in a similar level of hypothermia in the ICA territory. In addition, the anterior communicating artery and ipsilateral posterior communicating artery distributed cool blood to the contralateral anterior and ipsilateral posterior territories, respectively, imparting mild hypothermia (35 and 35.5 degrees C respectively). The mA1 and fP1 variants allowed for sufficient cooling of the middle cerebral territory (30-32 degrees C). The simulations suggest that ICSI is feasible and may be the fastest method of inducing hypothermia. Moreover, the effect of convective heat transfer via the complete CoW and its variants underlies the important role of CoW anatomy in intracerebral temperature distributions during SBC. PMID:17761787

  13. Integrating Retinoic Acid Signaling with Brain Function

    Science.gov (United States)

    Luo, Tuanlian; Wagner, Elisabeth; Drager, Ursula C.

    2009-01-01

    The vitamin A derivative retinoic acid (RA) regulates the transcription of about a 6th of the human genome. Compelling evidence indicates a role of RA in cognitive activities, but its integration with the molecular mechanisms of higher brain functions is not known. Here we describe the properties of RA signaling in the mouse, which point to…

  14. The modular and integrative functional architecture of the human brain.

    Science.gov (United States)

    Bertolero, Maxwell A; Yeo, B T Thomas; D'Esposito, Mark

    2015-12-01

    Network-based analyses of brain imaging data consistently reveal distinct modules and connector nodes with diverse global connectivity across the modules. How discrete the functions of modules are, how dependent the computational load of each module is to the other modules' processing, and what the precise role of connector nodes is for between-module communication remains underspecified. Here, we use a network model of the brain derived from resting-state functional MRI (rs-fMRI) data and investigate the modular functional architecture of the human brain by analyzing activity at different types of nodes in the network across 9,208 experiments of 77 cognitive tasks in the BrainMap database. Using an author-topic model of cognitive functions, we find a strong spatial correspondence between the cognitive functions and the network's modules, suggesting that each module performs a discrete cognitive function. Crucially, activity at local nodes within the modules does not increase in tasks that require more cognitive functions, demonstrating the autonomy of modules' functions. However, connector nodes do exhibit increased activity when more cognitive functions are engaged in a task. Moreover, connector nodes are located where brain activity is associated with many different cognitive functions. Connector nodes potentially play a role in between-module communication that maintains the modular function of the brain. Together, these findings provide a network account of the brain's modular yet integrated implementation of cognitive functions. PMID:26598686

  15. Apolipoprotein E Regulates the Integrity of Tight Junctions in an Isoform-dependent Manner in an in Vitro Blood-Brain Barrier Model*

    OpenAIRE

    Nishitsuji, Kazuchika; Hosono, Takashi; Nakamura, Toshiyuki; Bu, Guojun; Michikawa, Makoto

    2011-01-01

    Apolipoprotein E (apoE) is a major apolipoprotein in the brain. The ϵ4 allele of apoE is a major risk factor for Alzheimer disease, and apoE deficiency in mice leads to blood-brain barrier (BBB) leakage. However, the effect of apoE isoforms on BBB properties are as yet unknown. Here, using an in vitro BBB model consisting of brain endothelial cells and pericytes prepared from wild-type (WT) mice, and primary astrocytes prepared from human apoE3- and apoE4-knock-in mice, we show that the barri...

  16. Cyberinfrastructure for the digital brain: spatial standards for integrating rodent brain atlases

    Directory of Open Access Journals (Sweden)

    Ilya eZaslavsky

    2014-09-01

    Full Text Available Biomedical research entails capture and analysis of massive data volumes and new discoveries arise from data-integration and mining. This is only possible if data can be mapped onto a common framework such as the genome for genomic data. In neuroscience, the framework is intrinsically spatial and based on a number of paper atlases. This cannot meet today’s data-intensive analysis and integration challenges. A scalable and extensible software infrastructure that is standards based but open for novel data and resources, is required for integrating information such as signal distributions, gene-expression, neuronal connectivity, electrophysiology, anatomy, and developmental processes. Therefore, the International Neuroinformatics Coordinating Facility (INCF initiated the development of a spatial framework for neuroscience data integration with an associated Digital Atlasing Infrastructure (DAI. A prototype implementation of this infrastructure for the rodent brain is reported here. The infrastructure is based on a collection of reference spaces to which data is mapped at the required resolution, such as the Waxholm Space (WHS, a 3D reconstruction of the brain generated using high-resolution, multi-channel microMRI. The core standards of the digital atlasing service-oriented infrastructure include Waxholm Markup Language (WaxML: XML schema expressing a uniform information model for key elements such as coordinate systems, transformations, points of interest (POIs, labels, and annotations; and Atlas Web Services: interfaces for querying and updating atlas data. The services return WaxML-encoded documents with information about capabilities, spatial reference systems and structures, and execute coordinate transformations and POI-based requests. Key elements of INCF-DAI cyberinfrastructure have been prototyped for both mouse and rat brain atlas sources, including the Allen Mouse Brain Atlas, UCSD Cell-Centered Database, and Edinburgh Mouse Atlas

  17. Integrable Bogoliubov Transform and Integrable Model

    Institute of Scientific and Technical Information of China (English)

    王宁

    2003-01-01

    By defining Bogoliubov transform as a function of parameters, the integrability of the Bogoliubov transform in parameter space is investigated. It is shown that integrable Bogoliubov transform is closely related to the known integrable model. The relation between the integrable Bogoliubov transform and geometric phase of vacuum induced by the Bogoliubov transform is also discussed.

  18. Work-up times in an integrated brain cancer pathway

    DEFF Research Database (Denmark)

    Lund Laursen, Emilie; Rasmussen, Birthe Krogh

    2012-01-01

    The integrated brain cancer pathway (IBCP) aims to ensure fast-track diagnostics and treatment for brain cancers in Denmark. This paper focuses on the referral pattern and the time frame of key pathway elements during the first two years following implementation of the IBCP in a regional neurolog...

  19. Integrated Modeling of Telescopes

    CERN Document Server

    Andersen, Torben

    2011-01-01

    With increasingly complex and costly opto-mechanical systems, there is a growing need for reliable computer modeling and simulation. The field of integrated modeling, combining optics, mechanics, control engineering, and other disciplines, is the subject of this book. Although the book primarily focuses on ground-based optical telescopes, the techniques introduced are applicable also to other wavelengths and to other opto-mechanical applications on the ground or in space. Basic tools of integrated modeling are introduced together with concepts of ground-based telescopes. Modeling of optical systems, structures, wavefront control systems with emphasis on segmented mirror control, and active and adaptive optics are described together with a variety of noise sources; many examples are included in this book. Integrated Modeling of Telescopes is a text for physicists and engineers working in the field of opto-mechanical design and wavefront control, but it will also be valuable as a textbook for PhD students.

  20. Searching for the one and many emotional brains. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

    Science.gov (United States)

    Armony, Jorge L.

    2015-06-01

    Over the past hundred years or so, several neurally-based, or at least neurally-inspired, models of emotion have been proposed, with varying degrees of acceptance and success. Early ones were mostly based on data obtained from experiments conducted in non-human animals using classical conditioning paradigms, thus focusing on defensive (threat) and appetitive (reward) behaviors. Some features of the models were sometimes confirmed as being also applicable to humans, usually in experiments with patients suffering from focal brain lesions - although inconsistent, or even contradictory findings were often reported.

  1. Hierarchical models in the brain.

    Directory of Open Access Journals (Sweden)

    Karl Friston

    2008-11-01

    Full Text Available This paper describes a general model that subsumes many parametric models for continuous data. The model comprises hidden layers of state-space or dynamic causal models, arranged so that the output of one provides input to another. The ensuing hierarchy furnishes a model for many types of data, of arbitrary complexity. Special cases range from the general linear model for static data to generalised convolution models, with system noise, for nonlinear time-series analysis. Crucially, all of these models can be inverted using exactly the same scheme, namely, dynamic expectation maximization. This means that a single model and optimisation scheme can be used to invert a wide range of models. We present the model and a brief review of its inversion to disclose the relationships among, apparently, diverse generative models of empirical data. We then show that this inversion can be formulated as a simple neural network and may provide a useful metaphor for inference and learning in the brain.

  2. INTEGRATED CORPORATE STRATEGY MODEL

    Directory of Open Access Journals (Sweden)

    CATALINA SORIANA SITNIKOV

    2014-02-01

    Full Text Available Corporations are at present operating in demanding and highly unsure periods, facing a mixture of increased macroeconomic need, competitive and capital market dangers, and in many cases, the prospect for significant technical and regulative gap. Throughout these demanding and highly unsure times, the corporations must pay particular attention to corporate strategy. In present times, corporate strategy must be perceived and used as a function of various fields, covers, and characters as well as a highly interactive system. For the corporation's strategy to become a competitive advantage is necessary to understand and also to integrate it in a holistic model to ensure sustainable progress of corporation activities under the optimum conditions of profitability. The model proposed in this paper is aimed at integrating the two strategic models, Hoshin Kanri and Integrated Strategy Model, as well as their consolidation with the principles of sound corporate governance set out by the OECD.

  3. An Embodied Brain Model of the Human Foetus

    OpenAIRE

    Yasunori Yamada; Hoshinori Kanazawa; Sho Iwasaki; Yuki Tsukahara; Osuke Iwata; Shigehito Yamada; Yasuo Kuniyoshi

    2016-01-01

    Cortical learning via sensorimotor experiences evoked by bodily movements begins as early as the foetal period. However, the learning mechanisms by which sensorimotor experiences guide cortical learning remain unknown owing to technical and ethical difficulties. To bridge this gap, we present an embodied brain model of a human foetus as a coupled brain-body-environment system by integrating anatomical/physiological data. Using this model, we show how intrauterine sensorimotor experiences rela...

  4. Q-ball imaging models: comparison between high and low angular resolution diffusion-weighted MRI protocols for investigation of brain white matter integrity

    Energy Technology Data Exchange (ETDEWEB)

    Caiazzo, Giuseppina; Trojsi, Francesca; Cirillo, Mario; Tedeschi, Gioacchino [MRI Research Center SUN-FISM-Neurological Institute for Diagnosis and Care ' ' Hermitage Capodimonte' ' , Naples (Italy); Second University of Naples, Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, Naples (Italy); Esposito, Fabrizio [University of Salerno, Department of Medicine and Surgery, Baronissi (Salerno) (Italy); Maastricht University, Department of Cognitive Neuroscience, Maastricht (Netherlands)

    2016-02-15

    Q-ball imaging (QBI) is one of the typical data models for quantifying white matter (WM) anisotropy in diffusion-weighted MRI (DwMRI) studies. Brain and spinal investigation by high angular resolution DwMRI (high angular resolution imaging (HARDI)) protocols exhibits higher angular resolution in diffusion imaging compared to low angular resolution models, although with longer acquisition times. We aimed to assess the difference between QBI-derived anisotropy values from high and low angular resolution DwMRI protocols and their potential advantages or shortcomings in neuroradiology. Brain DwMRI data sets were acquired in seven healthy volunteers using both HARDI (b = 3000 s/mm{sup 2}, 54 gradient directions) and low angular resolution (b = 1000 s/mm{sup 2}, 32 gradient directions) acquisition schemes. For both sequences, tract of interest tractography and generalized fractional anisotropy (GFA) measures were extracted by using QBI model and were compared between the two data sets. QBI tractography and voxel-wise analyses showed that some WM tracts, such as corpus callosum, inferior longitudinal, and uncinate fasciculi, were reconstructed as one-dominant-direction fiber bundles with both acquisition schemes. In these WM tracts, mean percent different difference in GFA between the two data sets was less than 5 %. Contrariwise, multidirectional fiber bundles, such as corticospinal tract and superior longitudinal fasciculus, were more accurately depicted by HARDI acquisition scheme. Our results suggest that the design of optimal DwMRI acquisition protocols for clinical investigation of WM anisotropy by QBI models should consider the specific brain target regions to be explored, inducing researchers to a trade-off choice between angular resolution and acquisition time. (orig.)

  5. Q-ball imaging models: comparison between high and low angular resolution diffusion-weighted MRI protocols for investigation of brain white matter integrity

    International Nuclear Information System (INIS)

    Q-ball imaging (QBI) is one of the typical data models for quantifying white matter (WM) anisotropy in diffusion-weighted MRI (DwMRI) studies. Brain and spinal investigation by high angular resolution DwMRI (high angular resolution imaging (HARDI)) protocols exhibits higher angular resolution in diffusion imaging compared to low angular resolution models, although with longer acquisition times. We aimed to assess the difference between QBI-derived anisotropy values from high and low angular resolution DwMRI protocols and their potential advantages or shortcomings in neuroradiology. Brain DwMRI data sets were acquired in seven healthy volunteers using both HARDI (b = 3000 s/mm2, 54 gradient directions) and low angular resolution (b = 1000 s/mm2, 32 gradient directions) acquisition schemes. For both sequences, tract of interest tractography and generalized fractional anisotropy (GFA) measures were extracted by using QBI model and were compared between the two data sets. QBI tractography and voxel-wise analyses showed that some WM tracts, such as corpus callosum, inferior longitudinal, and uncinate fasciculi, were reconstructed as one-dominant-direction fiber bundles with both acquisition schemes. In these WM tracts, mean percent different difference in GFA between the two data sets was less than 5 %. Contrariwise, multidirectional fiber bundles, such as corticospinal tract and superior longitudinal fasciculus, were more accurately depicted by HARDI acquisition scheme. Our results suggest that the design of optimal DwMRI acquisition protocols for clinical investigation of WM anisotropy by QBI models should consider the specific brain target regions to be explored, inducing researchers to a trade-off choice between angular resolution and acquisition time. (orig.)

  6. What Brain Sciences Reveal about Integrating Theory and Practice

    Science.gov (United States)

    Patton, Michael Quinn

    2014-01-01

    Theory and practice are integrated in the human brain. Situation recognition and response are key to this integration. Scholars of decision making and expertise have found that people with great expertise are more adept at situational recognition and intentional about their decision-making processes. Several interdisciplinary fields of inquiry…

  7. New Ideas for Brain Modelling

    Directory of Open Access Journals (Sweden)

    Kieran Greer

    2016-01-01

    Full Text Available This paper describes some biologically-inspired processes that could be used to build the sort of networks that we associate with the human brain. New to this paper, a ‘refined’ neuron will be proposed. This is a group of neurons that by joining together can produce a more analogue system, but with the same level of control and reliability that a binary neuron would have. With this new structure, it will be possible to think of an essentially binary system in terms of a more variable set of values. The paper also shows how recent research can be combined with established theories, to produce a more complete picture.The propositions are largely in line with conventional thinking, but possibly with one or two more radical suggestions. An earlier cognitive model can be filled in with more specific details, based on the new research results, where the components appear to fit together almost seamlessly. The intention of the research has been to describe plausible ‘mechanical’ processes that can produce the appropriate brain structures and mechanisms, but that could be used without the magical ‘intelligence’ part that is still not fully understood.There are also some important updates from an earlier version of this paper.Keywords: neuron, neural network, cognitive model, self-organise, analogue, resonance.

  8. Neurocomputational models of brain disorders

    NARCIS (Netherlands)

    Cutsuridis, Vassilis; Heida, Tjitske; Duch, Wlodek; Doya, Kenji

    2011-01-01

    Recent decades have witnessed dramatic accumulation of knowledge about the genetic, molecular, pharmacological, neurophysiological, anatomical, imaging and psychological characteristics of brain disorders. Despite these advances, however, experimental brain science has offered very little insight in

  9. Bayesian network models in brain functional connectivity analysis

    OpenAIRE

    Ide, Jaime S.; Zhang, Sheng; Chiang-shan R. Li

    2013-01-01

    Much effort has been made to better understand the complex integration of distinct parts of the human brain using functional magnetic resonance imaging (fMRI). Altered functional connectivity between brain regions is associated with many neurological and mental illnesses, such as Alzheimer and Parkinson diseases, addiction, and depression. In computational science, Bayesian networks (BN) have been used in a broad range of studies to model complex data set in the presence of uncertainty and wh...

  10. Integrated Assessment Model Evaluation

    Science.gov (United States)

    Smith, S. J.; Clarke, L.; Edmonds, J. A.; Weyant, J. P.

    2012-12-01

    Integrated assessment models of climate change (IAMs) are widely used to provide insights into the dynamics of the coupled human and socio-economic system, including emission mitigation analysis and the generation of future emission scenarios. Similar to the climate modeling community, the integrated assessment community has a two decade history of model inter-comparison, which has served as one of the primary venues for model evaluation and confirmation. While analysis of historical trends in the socio-economic system has long played a key role in diagnostics of future scenarios from IAMs, formal hindcast experiments are just now being contemplated as evaluation exercises. Some initial thoughts on setting up such IAM evaluation experiments are discussed. Socio-economic systems do not follow strict physical laws, which means that evaluation needs to take place in a context, unlike that of physical system models, in which there are few fixed, unchanging relationships. Of course strict validation of even earth system models is not possible (Oreskes etal 2004), a fact borne out by the inability of models to constrain the climate sensitivity. Energy-system models have also been grappling with some of the same questions over the last quarter century. For example, one of "the many questions in the energy field that are waiting for answers in the next 20 years" identified by Hans Landsberg in 1985 was "Will the price of oil resume its upward movement?" Of course we are still asking this question today. While, arguably, even fewer constraints apply to socio-economic systems, numerous historical trends and patterns have been identified, although often only in broad terms, that are used to guide the development of model components, parameter ranges, and scenario assumptions. IAM evaluation exercises are expected to provide useful information for interpreting model results and improving model behavior. A key step is the recognition of model boundaries, that is, what is inside

  11. Integrated Assessment Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Edmonds, James A.; Calvin, Katherine V.; Clarke, Leon E.; Janetos, Anthony C.; Kim, Son H.; Wise, Marshall A.; McJeon, Haewon C.

    2012-10-31

    This paper discusses the role of Integrated Assessment models (IAMs) in climate change research. IAMs are an interdisciplinary research platform, which constitutes a consistent scientific framework in which the large-scale interactions between human and natural Earth systems can be examined. In so doing, IAMs provide insights that would otherwise be unavailable from traditional single-discipline research. By providing a broader view of the issue, IAMs constitute an important tool for decision support. IAMs are also a home of human Earth system research and provide natural Earth system scientists information about the nature of human intervention in global biogeophysical and geochemical processes.

  12. Integrated Environmental Assessment Modelling

    Energy Technology Data Exchange (ETDEWEB)

    Guardanz, R.; Gimeno, B. S.; Bermejo, V.; Elvira, S.; Martin, F.; Palacios, M.; Rodriguez, E.; Donaire, I. [Ciemat, Madrid (Spain)

    2000-07-01

    This report describes the results of the Spanish participation in the project Coupling CORINAIR data to cost-effect emission reduction strategies based on critical threshold. (EU/LIFE97/ENV/FIN/336). The subproject has focused on three tasks. Develop tools to improve knowledge on the spatial and temporal details of emissions of air pollutants in Spain. Exploit existing experimental information on plant response to air pollutants in temperate ecosystem and Integrate these findings in a modelling framework that can asses with more accuracy the impact of air pollutants to temperate ecosystems. The results obtained during the execution of this project have significantly improved the models of the impact of alternative emission control strategies on ecosystems and crops in the Iberian Peninsula. (Author) 375 refs.

  13. Computational modeling of brain tumors: discrete, continuum or hybrid?

    Science.gov (United States)

    Wang, Zhihui; Deisboeck, Thomas S.

    In spite of all efforts, patients diagnosed with highly malignant brain tumors (gliomas), continue to face a grim prognosis. Achieving significant therapeutic advances will also require a more detailed quantitative understanding of the dynamic interactions among tumor cells, and between these cells and their biological microenvironment. Data-driven computational brain tumor models have the potential to provide experimental tumor biologists with such quantitative and cost-efficient tools to generate and test hypotheses on tumor progression, and to infer fundamental operating principles governing bidirectional signal propagation in multicellular cancer systems. This review highlights the modeling objectives of and challenges with developing such in silico brain tumor models by outlining two distinct computational approaches: discrete and continuum, each with representative examples. Future directions of this integrative computational neuro-oncology field, such as hybrid multiscale multiresolution modeling are discussed.

  14. Development of a permeability-limited model of the human brain and cerebrospinal fluid (CSF) to integrate known physiological and biological knowledge: Estimating time varying CSF drug concentrations and their variability using in vitro data.

    Science.gov (United States)

    Gaohua, Lu; Neuhoff, Sibylle; Johnson, Trevor N; Rostami-Hodjegan, Amin; Jamei, Masoud

    2016-06-01

    A 4-compartment permeability-limited brain (4Brain) model consisting of brain blood, brain mass, cranial and spinal cerebrospinal fluid (CSF) compartments has been developed and incorporated into a whole body physiologically-based pharmacokinetic (PBPK) model within the Simcyp Simulator. The model assumptions, structure, governing equations and system parameters are described. The model in particular considers the anatomy and physiology of the brain and CSF, including CSF secretion, circulation and absorption, as well as the function of various efflux and uptake transporters existing on the blood-brain barrier (BBB) and blood-CSF barrier (BCSFB), together with the known parameter variability. The model performance was verified using in vitro data and clinical observations for paracetamol and phenytoin. The simulated paracetamol spinal CSF concentration is comparable with clinical lumbar CSF data for both intravenous and oral doses. Phenytoin CSF concentration-time profiles in epileptic patients were simulated after accounting for disease-induced over-expression of efflux transporters within the BBB. Various 'what-if' scenarios, involving variation of specific drug and system parameters of the model, demonstrated that the 4Brain model is able to simulate the possible impact of transporter-mediated drug-drug interactions, the lumbar puncture process and the age-dependent change in the CSF turnover rate on the local PK within the brain. PMID:27236639

  15. Modeling premature brain injury and recovery

    OpenAIRE

    Scafidi, Joey; Fagel, Devon M.; Ment, Laura R.; Vaccarino, Flora M.

    2009-01-01

    Premature birth is a growing and significant public health problem because of the large number of infants that survive with neurodevelopmental sequelae from brain injury. Recent advances in neuroimaging have shown that although some neuroanatomical structures are altered, others improve over time. This review outlines recent insights into brain structure and function in these preterm infants at school age and relevant animal models. These animal models have provided scientists with an opportu...

  16. Joint Modelling of Structural and Functional Brain Networks

    DEFF Research Database (Denmark)

    Andersen, Kasper Winther; Herlau, Tue; Mørup, Morten;

    -parametric Bayesian network model which allows for joint modelling and integration of multiple networks. We demonstrate the model’s ability to detect vertices that share structure across networks jointly in functional MRI (fMRI) and diffusion MRI (dMRI) data. Using two fMRI and dMRI scans per subject, we establish...... significant structures that are consistently shared across subjects and data splits. This provides an unsupervised approach for modeling of structure-function relations in the brain and provides a general framework for multimodal integration....

  17. Business and technology integrated model

    OpenAIRE

    Noce, Irapuan; Carvalho, João Álvaro

    2011-01-01

    There is a growing interest in business modeling and architecture in the areas of management and information systems. One of the issues in the area is the lack of integration between the modeling techniques that are employed to support business development and those used for technology modeling. This paper proposes a modeling approach that is capable of integrating the modeling of the business and of the technology. By depicting the business model, the organization structure and the technolog...

  18. Melanoma Brain Metastasis: Mechanisms, Models, and Medicine.

    Science.gov (United States)

    Kircher, David A; Silvis, Mark R; Cho, Joseph H; Holmen, Sheri L

    2016-01-01

    The development of brain metastases in patients with advanced stage melanoma is common, but the molecular mechanisms responsible for their development are poorly understood. Melanoma brain metastases cause significant morbidity and mortality and confer a poor prognosis; traditional therapies including whole brain radiation, stereotactic radiotherapy, or chemotherapy yield only modest increases in overall survival (OS) for these patients. While recently approved therapies have significantly improved OS in melanoma patients, only a small number of studies have investigated their efficacy in patients with brain metastases. Preliminary data suggest that some responses have been observed in intracranial lesions, which has sparked new clinical trials designed to evaluate the efficacy in melanoma patients with brain metastases. Simultaneously, recent advances in our understanding of the mechanisms of melanoma cell dissemination to the brain have revealed novel and potentially therapeutic targets. In this review, we provide an overview of newly discovered mechanisms of melanoma spread to the brain, discuss preclinical models that are being used to further our understanding of this deadly disease and provide an update of the current clinical trials for melanoma patients with brain metastases. PMID:27598148

  19. Whole Brain Radiotherapy With Hippocampal Avoidance and Simultaneously Integrated Brain Metastases Boost: A Planning Study

    International Nuclear Information System (INIS)

    Purpose: To evaluate the feasibility of using tomotherapy to deliver whole brain radiotherapy with hippocampal avoidance, hypothesized to reduce the risk of memory function decline, and simultaneously integrated boost to brain metastases to improve intracranial tumor control. Methods and Materials: Ten patients treated with radiosurgery and whole brain radiotherapy underwent repeat planning using tomotherapy with the original computed tomography scans and magnetic resonance imaging-computed tomography fusion-defined target and normal structure contours. The individually contoured hippocampus was used as a dose-limiting structure (2 and 5.8 ± 1.9 Gy2 for 2.5- and 1.0-cm FW, respectively. The mean treatment delivery time for the 2.5- and 1.0-cm FW plans was 10.2 ± 1.0 and 21.8 ± 1.8 min, respectively. Conclusion: Composite tomotherapy plans achieved three objectives: homogeneous whole brain dose distribution equivalent to conventional whole brain radiotherapy; conformal hippocampal avoidance; and radiosurgically equivalent dose distributions to individual metastases

  20. Human emotion in the brain and the body: Why language matters. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

    Science.gov (United States)

    Herbert, Cornelia

    2015-06-01

    What is an Emotion? This question has fascinated scientific research since William James. Despite the fact that a consensus has been reached about the biological origin of emotions, uniquely human aspects of emotions are still poorly understood. One of these blind spots concerns the relationship between emotion and human language. Historically, many theories imply a duality between emotions on the one hand and cognitive functions such as language on the other hand. Especially for symbolic forms of written language and word processing, it has been assumed that semantic information would bear no relation to bodily, affective, or sensorimotor processing (for an overview see Ref. [1]). The Quartet Theory proposed by Koelsch and colleagues [2] could provide a solution to this problem. It offers a novel, integrative neurofunctional model of human emotions which considers language and emotion as closely related. Crucially, language - be it spoken or written - is assumed to "regulate, modulate, and partly initiate" activity in core affective brain systems in accord with physical needs and individual concerns [cf. page 34, line 995]. In this regard, the Quartet Theory combines assumptions from earlier bioinformational theories of emotions [3], contemporary theories of embodied cognition [4], and appraisal theories such as the Component Process Model [5] into one framework, thereby providing a holistic model for the neuroscientific investigation of human emotion processing at the interface of emotion and cognition, mind and body.

  1. Whole brain helical Tomotherapy with integrated boost for brain metastases in patients with malignant melanoma–a randomized trial

    International Nuclear Information System (INIS)

    Patients with malignant melanoma may develop brain metastases during the course of the disease, requiring radiotherapeutic treatment. In patients with 1–3 brain metastases, radiosurgery has been established as a treatment option besides surgery. For patients with 4 or more brain metastases, whole brain radiotherapy is considered the standard treatment. In certain patients with brain metastases, radiation treatment using whole brain helical Tomotherapy with integrated boost and hippocampal-sparing may improve prognosis of these patients. The present prospective, randomized two-armed trial aims to exploratory investigate the treatment response to conventional whole brain radiotherapy applying 30 Gy in 10 fractions versus whole brain helical Tomotherapy applying 30 Gy in 10 fractions with an integrated boost of 50 Gy to the brain metastases as well as hippocampal-sparing in patients with brain metastases from malignant melanoma. The main inclusion criteria include magnetic resonance imaging confirmed brain metastases from a histopathologically confirmed malignant melanoma in patients with a minimum age of 18 years. The main exclusion criteria include a previous radiotherapy of the brain and not having recovered from acute high-grade toxicities of prior therapies. The primary endpoint is treatment-related toxicity. Secondary endpoints include imaging response, local and loco-regional progression-free survival, overall survival and quality of life

  2. Integrability of the Rabi Model

    International Nuclear Information System (INIS)

    The Rabi model is a paradigm for interacting quantum systems. It couples a bosonic mode to the smallest possible quantum model, a two-level system. I present the analytical solution which allows us to consider the question of integrability for quantum systems that do not possess a classical limit. A criterion for quantum integrability is proposed which shows that the Rabi model is integrable due to the presence of a discrete symmetry. Moreover, I introduce a generalization with no symmetries; the generalized Rabi model is the first example of a nonintegrable but exactly solvable system.

  3. Nano-Modeling and Computation in Bio and Brain Dynamics

    Directory of Open Access Journals (Sweden)

    Paolo Di Sia

    2016-04-01

    Full Text Available The study of brain dynamics currently utilizes the new features of nanobiotechnology and bioengineering. New geometric and analytical approaches appear very promising in all scientific areas, particularly in the study of brain processes. Efforts to engage in deep comprehension lead to a change in the inner brain parameters, in order to mimic the external transformation by the proper use of sensors and effectors. This paper highlights some crossing research areas of natural computing, nanotechnology, and brain modeling and considers two interesting theoretical approaches related to brain dynamics: (a the memory in neural network, not as a passive element for storing information, but integrated in the neural parameters as synaptic conductances; and (b a new transport model based on analytical expressions of the most important transport parameters, which works from sub-pico-level to macro-level, able both to understand existing data and to give new predictions. Complex biological systems are highly dependent on the context, which suggests a “more nature-oriented” computational philosophy.

  4. IMMIGRANTS’ INTEGRATION MODELS

    Directory of Open Access Journals (Sweden)

    CARMEN UZLĂU

    2012-05-01

    Full Text Available In the context of the European population aging trend, and while the birth rate is still at a low level, the immigrants may contribute to the support of the EU economy and to finance the national social protection systems. But this would be possible only if they have been fully integrated in the host countries, the integration policies being a task of the national governments. The European Union may still offer support and stimulation through financing, policies coordination and good practices exchange facilitation. The new measures should encourage local level actions, including cooperation between local authorities, employers, migrants’ organizations, service providers and local population. Within the EU, there live 20.1 million immigrants (approximately 4% of the entire population coming from outside European area. An important element of the common EU policy on immigration is the one regarding the development of a policy on immigrants’ integration, which should provide a fair treatment within the member states, and guarantee rights and obligations comparable with the ones of the Union citizens.

  5. Integrated materials–structural models

    DEFF Research Database (Denmark)

    Stang, Henrik; Geiker, Mette Rica

    2008-01-01

    structural modelling and materials concepts will both operational in both identifying important research issues and in answering the ‘real’ needs of society. Integrated materials-structural models will allow synergy to develop between materials and structural research. On one side the structural modelling...... should define a framework in which materials research results eventually should fit in and on the other side the materials research should define needs and capabilities in structural modelling. Integrated materials-structural models of a general nature are almost non-existent in the field of cement based...

  6. The brain and somatic integration: insights into the standard biological rationale for equating "brain death" with death.

    Science.gov (United States)

    Shewmon, A D

    2001-10-01

    The mainstream rationale for equating "brain death" (BD) with death is that the brain confers integrative unity upon the body, transforming it from a mere collection of organs and tissues to an "organism as a whole." In support of this conclusion, the impressive list of the brain's myriad integrative functions is often cited. Upon closer examination, and after operational definition of terms, however, one discovers that most integrative functions of the brain are actually not somatically integrating, and, conversely, most integrative functions of the body are not brain-mediated. With respect to organism-level vitality, the brain's role is more modulatory than constitutive, enhancing the quality and survival potential of a presupposedly living organism. Integrative unity of a complex organism is an inherently nonlocalizable, holistic feature involving the mutual interaction among all the parts, not a top-down coordination imposed by one part upon a passive multiplicity of other parts. Loss of somatic integrative unity is not a physiologically tenable rationale for equating BD with death of the organism as a whole. PMID:11588655

  7. Brain functional integration decreases during propofol-induced loss of consciousness.

    OpenAIRE

    Schrouff, Jessica; Perlbarg, Vincent; Boly, Mélanie; Marrelec, Guillaume; Boveroux, Pierre; Vanhaudenhuyse, Audrey; Bruno, Marie-Aurélie; Laureys, Steven; Phillips, Christophe; Pélégrini-Issac, Mélanie; Maquet, Pierre; Benali, Habib

    2011-01-01

    Consciousness has been related to the amount of integrated information that the brain is able to generate. In this paper, we tested the hypothesis that the loss of consciousness caused by propofol anesthesia is associated with a significant reduction in the capacity of the brain to integrate information. To assess the functional structure of the whole brain, functional integration and partial correlations were computed from fMRI data acquired from 18 healthy volunteers during resting wakefuln...

  8. Modulation of semantic integration as a function of syntactic expectations: event-related brain potential evidence.

    Science.gov (United States)

    Isel, Frédéric; Shen, Weilin

    2011-03-30

    This study investigated syntax-semantics interactions during spoken sentence comprehension. We showed that expectations of phrase-structure incongruencies, which were induced by the experimental instructions, although not actually present in the sentences, were able to block the process of semantic integration. Although this process is usually associated with an N400 event-related brain potential component, here we found a P600, that is, an event-related brain potential component that is thought to reflect syntactic revision. This finding lends support to neurophysiological models of sentence interpretation, which postulates that the lexical-semantic integration of a given word can take place only when syntactic analysis has been successfully completed. PMID:21358555

  9. Integrated Debugging of Modelica Models

    Directory of Open Access Journals (Sweden)

    Adrian Pop

    2014-04-01

    Full Text Available The high abstraction level of equation-based object-oriented (EOO languages such as Modelica has the drawback that programming and modeling errors are often hard to find. In this paper we present integrated static and dynamic debugging methods for Modelica models and a debugger prototype that addresses several of those problems. The goal is an integrated debugging framework that combines classical debugging techniques with special techniques for equation-based languages partly based on graph visualization and interaction. To our knowledge, this is the first Modelica debugger that supports both equation-based transformational and algorithmic code debugging in an integrated fashion.

  10. Dyslipidemia and Blood-Brain Barrier Integrity in Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Gene L. Bowman

    2012-01-01

    Full Text Available Background. Blood-brain barrier (BBB dysfunction may have a significant role in the pathogenesis of Alzheimer's disease (AD. Modifiable factors associated with BBB function may have therapeutic implication. This study tested the hypothesis that dyslipidemia is associated with BBB impairment in mild-to-moderate AD. Methods. Thirty-six subjects with AD were followed for 1 year. Fasting CSF and plasma were collected with clinical assessments at baseline and 12 months. BBB impairment was defined as CSF albumin index ≥9. Independent t-tests and linear regression assessed the relationship between plasma lipoproteins and BBB integrity. Results. Dyslipidemia was prevalent in 47% of the population, and in 75% of those with BBB impairment. Subjects with BBB impairment had significantly higher mean plasma triglyceride and lower HDL cholesterol (TG, P=0.007; HDL, P=0.043. Plasma triglycerides explained 22% of the variance in BBB integrity and remained significant after controlling for age, gender, ApoE-4 genotype, blood pressure, and statin use. Conclusion. Dyslipidemia is more prevalent in AD subjects with BBB impairment. Plasma triglyceride and HDL cholesterol may have a role in maintaining BBB integrity in mild-to-moderate Alzheimer's disease.

  11. Brain-inspired Stochastic Models and Implementations

    KAUST Repository

    Al-Shedivat, Maruan

    2015-05-12

    One of the approaches to building artificial intelligence (AI) is to decipher the princi- ples of the brain function and to employ similar mechanisms for solving cognitive tasks, such as visual perception or natural language understanding, using machines. The recent breakthrough, named deep learning, demonstrated that large multi-layer networks of arti- ficial neural-like computing units attain remarkable performance on some of these tasks. Nevertheless, such artificial networks remain to be very loosely inspired by the brain, which rich structures and mechanisms may further suggest new algorithms or even new paradigms of computation. In this thesis, we explore brain-inspired probabilistic mechanisms, such as neural and synaptic stochasticity, in the context of generative models. The two questions we ask here are: (i) what kind of models can describe a neural learning system built of stochastic components? and (ii) how can we implement such systems e ̆ciently? To give specific answers, we consider two well known models and the corresponding neural architectures: the Naive Bayes model implemented with a winner-take-all spiking neural network and the Boltzmann machine implemented in a spiking or non-spiking fashion. We propose and analyze an e ̆cient neuromorphic implementation of the stochastic neu- ral firing mechanism and study the e ̄ects of synaptic unreliability on learning generative energy-based models implemented with neural networks.

  12. Research on Perfusion CT in Rabbit Brain Tumor Model

    International Nuclear Information System (INIS)

    We investigated the vascular characteristics of tumors and normal tissue using perfusion CT in the rabbit brain tumor model. The VX2 carcinoma concentration of 1 x 107 cells/ml(0.1 ml) was implanted in the brain of nine New Zealand white rabbits (weight: 2.4 kg-3.0 kg, mean: 2.6 kg). The perfusion CT was scanned when the tumors were grown up to 5 mm. The tumor volume and perfusion value were quantitatively analyzed by using commercial workstation (advantage windows workstation, AW, version 4.2, GE, USA). The mean volume of implanted tumors was 316±181 mm3, and the biggest and smallest volumes of tumor were 497 mm3 and 195 mm3, respectively. All the implanted tumors in rabbits are single-nodular tumors, and intracranial metastasis was not observed. In the perfusion CT, cerebral blood volume (CBV) were 74.40±9.63, 16.8±0.64, 15.24±3.23 ml/100g in the tumor core, ipsilateral normal brain, and contralateral normal brain, respectively (p≤0.05). In the cerebral blood flow (CBF), there were significant differences between the tumor core and both normal brains (p≤0.05), but no significant differences between ipsilateral and contralateral normal brains (962.91±75.96 vs. 357.82±12.82 vs. 323.19±83.24 ml/100g/min). In the mean transit time (MTT), there were significant differences between the tumor core and both normal brains (p≤0.05), but no significant differences between ipsilateral and contralateral normal brains (4.37±0.19 vs. 3.02±0.41 vs. 2.86±0.22 sec). In the permeability surface (PS), there were significant differences among the tumor core, ipsilateral and contralateral normal brains (47.23±25.44 vs. 14.54±1.60 vs. 6.81±4.20 ml/100g/min)(p≤0.05). In the time to peak (TTP) were no significant differences among the tumor core, ipsilateral and contralateral normal brains. In the positive enhancement integral (PEI), there were significant differences among the tumor core, ipsilateral and contralateral brains (61.56±16.07 vs. 12.58±2.61 vs. 8.26±5

  13. Research on Perfusion CT in Rabbit Brain Tumor Model

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Bon Chul; Kwak, Byung Kook; Jung, Ji Sung [Dept. of Diagnostic Radiology, Chung Ang University Hospital, Seoul (Korea, Republic of); Lim, Cheong Hwan; Jung, Hong Ryang [Dept. of Radiological Science, Hanseo University, Seosan (Korea, Republic of)

    2012-06-15

    We investigated the vascular characteristics of tumors and normal tissue using perfusion CT in the rabbit brain tumor model. The VX2 carcinoma concentration of 1 x 10{sup 7} cells/ml(0.1 ml) was implanted in the brain of nine New Zealand white rabbits (weight: 2.4 kg-3.0 kg, mean: 2.6 kg). The perfusion CT was scanned when the tumors were grown up to 5 mm. The tumor volume and perfusion value were quantitatively analyzed by using commercial workstation (advantage windows workstation, AW, version 4.2, GE, USA). The mean volume of implanted tumors was 316{+-}181 mm{sup 3}, and the biggest and smallest volumes of tumor were 497 mm{sup 3} and 195 mm{sup 3}, respectively. All the implanted tumors in rabbits are single-nodular tumors, and intracranial metastasis was not observed. In the perfusion CT, cerebral blood volume (CBV) were 74.40{+-}9.63, 16.8{+-}0.64, 15.24{+-}3.23 ml/100g in the tumor core, ipsilateral normal brain, and contralateral normal brain, respectively (p{<=}0.05). In the cerebral blood flow (CBF), there were significant differences between the tumor core and both normal brains (p{<=}0.05), but no significant differences between ipsilateral and contralateral normal brains (962.91{+-}75.96 vs. 357.82{+-}12.82 vs. 323.19{+-}83.24 ml/100g/min). In the mean transit time (MTT), there were significant differences between the tumor core and both normal brains (p{<=}0.05), but no significant differences between ipsilateral and contralateral normal brains (4.37{+-}0.19 vs. 3.02{+-}0.41 vs. 2.86{+-}0.22 sec). In the permeability surface (PS), there were significant differences among the tumor core, ipsilateral and contralateral normal brains (47.23{+-}25.44 vs. 14.54{+-}1.60 vs. 6.81{+-}4.20 ml/100g/min)(p{<=}0.05). In the time to peak (TTP) were no significant differences among the tumor core, ipsilateral and contralateral normal brains. In the positive enhancement integral (PEI), there were significant differences among the tumor core, ipsilateral and

  14. Multiscale modeling of brain blow flow

    Science.gov (United States)

    Karniadakis, George

    2014-11-01

    Cardiovascular pathologies, such as brain aneurysms, are affected by the global blood circulation as well as by the local microrheology. Hence, developing computational models for such cases requires the coupling of disparate spatial and temporal scales often governed by diverse mathematical descriptions, e.g., by partial differential equations (continuum, 3D or 1D) and ordinary differential equations for discrete particles (atomistic). However, interfacing atomistic-based with continuum-based domain discretizations is a challenging problem that requires both mathematical and computational advances. We will present a physical model of the brain vasculature consisting at the macro level of all major arteries (about 200 down to 0.5 mm), at the mesoscale the fractal arteriolar tree (more than 10 millions down to 20 nm) and at the microscale the capillary bed. Correspondingly, we employ three different methods to model the total brain vasculature by developing proper interface conditions at each level. We will present examples from aneurysms and other hematological diseases, where red blood cell rheology is modeled explicitly.

  15. Melatonin Preserves Blood-Brain Barrier Integrity and Permeability via Matrix Metalloproteinase-9 Inhibition

    Science.gov (United States)

    Alluri, Himakarnika; Wilson, Rickesha L.; Anasooya Shaji, Chinchusha; Wiggins-Dohlvik, Katie; Patel, Savan; Liu, Yang; Peng, Xu; Beeram, Madhava R.; Davis, Matthew L.; Huang, Jason H.; Tharakan, Binu

    2016-01-01

    Microvascular hyperpermeability that occurs at the level of the blood-brain barrier (BBB) often leads to vasogenic brain edema and elevated intracranial pressure following traumatic brain injury (TBI). At a cellular level, tight junction proteins (TJPs) between neighboring endothelial cells maintain the integrity of the BBB via TJ associated proteins particularly, zonula occludens-1 (ZO-1) that binds to the transmembrane TJPs and actin cytoskeleton intracellularly. The pro-inflammatory cytokine, interleukin-1β (IL-1β) as well as the proteolytic enzymes, matrix metalloproteinase-9 (MMP-9) are key mediators of trauma-associated brain edema. Recent studies indicate that melatonin a pineal hormone directly binds to MMP-9 and also might act as its endogenous inhibitor. We hypothesized that melatonin treatment will provide protection against TBI-induced BBB hyperpermeability via MMP-9 inhibition. Rat brain microvascular endothelial cells grown as monolayers were used as an in vitro model of the BBB and a mouse model of TBI using a controlled cortical impactor was used for all in vivo studies. IL-1β (10 ng/mL; 2 hours)-induced endothelial monolayer hyperpermeability was significantly attenuated by melatonin (10 μg/mL; 1 hour), GM6001 (broad spectrum MMP inhibitor; 10 μM; 1 hour), MMP-9 inhibitor-1 (MMP-9 specific inhibitor; 5 nM; 1 hour) or MMP-9 siRNA transfection (48 hours) in vitro. Melatonin and MMP-9 inhibitor-1 pretreatment attenuated IL-1β-induced MMP-9 activity, loss of ZO-1 junctional integrity and f-actin stress fiber formation. IL-1β treatment neither affected ZO-1 protein or mRNA expression or cell viability. Acute melatonin treatment attenuated BBB hyperpermeability in a mouse controlled cortical impact model of TBI in vivo. In conclusion, one of the protective effects of melatonin against BBB hyperpermeability occurs due to enhanced BBB integrity via MMP-9 inhibition. In addition, acute melatonin treatment provides protection against BBB

  16. Blood-Brain Barrier Integrity and Breast Cancer Metastasis to the Brain

    OpenAIRE

    Hava Karsenty Avraham; Shalom Avraham; Christopher Sy; Lili Wang; Farheen Arshad

    2011-01-01

    Brain metastasis, an important cause of cancer morbidity and mortality, occurs in at least 30% of patients with breast cancer. A key event of brain metastasis is the migration of cancer cells through the blood-brain barrier (BBB). Although preventing brain metastasis is immensely important for survival, very little is known about the early stage of transmigration and the molecular mechanisms of breast tumor cells penetrating the BBB. The brain endothelium plays an important role in brain meta...

  17. Developing Integrated Care: Towards a development model for integrated care

    OpenAIRE

    Minkman, Mirella M.N

    2012-01-01

    textabstractThe thesis adresses the phenomenon of integrated care. The implementation of integrated care for patients with a stroke or dementia is studied. Because a generic quality management model for integrated care is lacking, the study works towards building a development model for integrated care. Based on a systematic approach in which a literature study, a delphi study, a concept mapping study and questionnaire research are combined, a development model for integrated care is created....

  18. Developing Integrated Care: Towards a development model for integrated care

    NARCIS (Netherlands)

    M.M.N. Minkman (Mirella)

    2012-01-01

    textabstractThe thesis adresses the phenomenon of integrated care. The implementation of integrated care for patients with a stroke or dementia is studied. Because a generic quality management model for integrated care is lacking, the study works towards building a development model for integrated c

  19. Modelling Brain Tissue using Magnetic Resonance Imaging

    OpenAIRE

    Dyrby, Tim Bjørn; Hansen, Lars Kai

    2008-01-01

    Diffusion MRI, or diffusion weighted imaging (DWI), is a technique that measures the restricted diffusion of water molecules within brain tissue. Different reconstruction methods quantify water-diffusion anisotropy in the intra- and extra-cellular spaces of the neural environment. Fibre tracking models then use the directions of greatest diffusion as estimates of white matter fibre orientation. Several fibre tracking algorithms have emerged in the last few years that provide reproducible visu...

  20. Mouse Genetic Models of Human Brain Disorders

    OpenAIRE

    Celeste eLeung; Zhengping eJia

    2016-01-01

    Over the past three decades, genetic manipulations in mice have been used in neuroscience as a major approach to investigate the in vivo function of genes and their alterations. In particular, gene targeting techniques using embryonic stem cells have revolutionized the field of mammalian genetics and have been at the forefront in the generation of numerous mouse models of human brain disorders. In this review, we will first examine childhood developmental disorders such as autism, intellectua...

  1. Model human heart or brain signals

    OpenAIRE

    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 a...

  2. The BRAIN Initiative Provides a Unifying Context for Integrating Core STEM Competencies into a Neurobiology Course

    OpenAIRE

    Schaefer, Jennifer E.

    2016-01-01

    The Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative introduced by the Obama Administration in 2013 presents a context for integrating many STEM competencies into undergraduate neuroscience coursework. The BRAIN Initiative core principles overlap with core STEM competencies identified by the AAAS Vision and Change report and other entities. This neurobiology course utilizes the BRAIN Initiative to serve as the unifying theme that facilitates a primary emphasis ...

  3. Integrated materials–structural models

    DEFF Research Database (Denmark)

    Stang, Henrik; Geiker, Mette Rica

    2008-01-01

    , repair works and strengthening methods for structures. A very significant part of the infrastructure consists of reinforced concrete structures. Even though reinforced concrete structures typically are very competitive, certain concrete structures suffer from various types of degradation. A framework of...... structural modelling and materials concepts will both operational in both identifying important research issues and in answering the ‘real’ needs of society. Integrated materials-structural models will allow synergy to develop between materials and structural research. On one side the structural modelling...... should define a framework in which materials research results eventually should fit in and on the other side the materials research should define needs and capabilities in structural modelling. Integrated materials-structural models of a general nature are almost non-existent in the field of cement based...

  4. Virtual Heterogeneous Model Integration Layer

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Memon

    2016-05-01

    Full Text Available The classic way of building a software today sim-plistically consists in connecting a piece of code calling a method with the piece of code implementing that method. We consider these piece of code (software systems not calling anything, behaving in a non deterministic way and providing complex sets of services in different domains. In software engineering reusability is the holly grail, and specially the reusability of code from autonomus tools requires powerful compostion/integration mechanisms. These systems are developed by different developers and being modified inceremently. Integrating these autonomous tools generate various conflicts. To deal with these conflicts, current integration mechanisms defines specific set of rules to resolve these conflicts and accompalish integration. Indeed still there is a big chance that changes made by other developers, or they update their changes in order to make them compliant with other developers cancel the updates done by others. The approach presented here claims three contributions in the field of Hetrogeneous Software Integration. First, this approach eliminate the need of conflicts resolving mechanism. Secondly, it provides the mechanism to work in the presence of conflicts without resolving them. Finally, contribution is that the integration mechanism does not affect if either of the system evolves. We do this by introducing an intermediate virtual layer between two systems that introduce a delta models which consist of three parts; viability that share required elements, hiding that hide conflicting elements and aliasing that aliases same concepts in both systems.

  5. Automatic integration of confidence in the brain valuation signal.

    Science.gov (United States)

    Lebreton, Maël; Abitbol, Raphaëlle; Daunizeau, Jean; Pessiglione, Mathias

    2015-08-01

    A key process in decision-making is estimating the value of possible outcomes. Growing evidence suggests that different types of values are automatically encoded in the ventromedial prefrontal cortex (VMPFC). Here we extend this idea by suggesting that any overt judgment is accompanied by a second-order valuation (a confidence estimate), which is also automatically incorporated in VMPFC activity. In accordance with the predictions of our normative model of rating tasks, two behavioral experiments showed that confidence levels were quadratically related to first-order judgments (age, value or probability ratings). The analysis of three functional magnetic resonance imaging data sets using similar rating tasks confirmed that the quadratic extension of first-order ratings (our proxy for confidence) was encoded in VMPFC activity, even if no confidence judgment was required of the participants. Such an automatic aggregation of value and confidence in a same brain region might provide insight into many distortions of judgment and choice. PMID:26192748

  6. Modelling the anesthetized brain with ensembles of neuronal and astrocytic oscillators

    Science.gov (United States)

    Hansard, T.; Hale, A. C.; Stefanovska, A.

    2013-01-01

    We propose a minimalistic model of the anesthetized brain in order to study the generation of rhythms observed in electroencephalograms (EEGs) recorded from anesthetized humans. We propose that non-neuronal brain cells-astrocytes-play an important role in brain dynamics and that oscillation-based models may provide a simple way to study such dynamics. The model is capable of replicating the main features (i.e. slow and alpha oscillations) observed in EEGs. In addition, this model suggests that astrocytes are integral to the generation of slow EEG (˜0.7 Hz) rhythms. By including astrocytes in the model we take a first step towards investigating the interaction of the brain and cardiovasular system which are primarily connected via astrocytes. The model also illustrates that rich nonlinear dynamics can arise from basic oscillatory "building blocks" and therefore complex systems may be modelled in an uncomplicated way.

  7. The Center for Integrated Molecular Brain Imaging (Cimbi) database.

    Science.gov (United States)

    Knudsen, Gitte M; Jensen, Peter S; Erritzoe, David; Baaré, William F C; Ettrup, Anders; Fisher, Patrick M; Gillings, Nic; Hansen, Hanne D; Hansen, Lars Kai; Hasselbalch, Steen G; Henningsson, Susanne; Herth, Matthias M; Holst, Klaus K; Iversen, Pernille; Kessing, Lars V; Macoveanu, Julian; Madsen, Kathrine Skak; Mortensen, Erik L; Nielsen, Finn Årup; Paulson, Olaf B; Siebner, Hartwig R; Stenbæk, Dea S; Svarer, Claus; Jernigan, Terry L; Strother, Stephen C; Frokjaer, Vibe G

    2016-01-01

    We here describe a multimodality neuroimaging containing data from healthy volunteers and patients, acquired within the Lundbeck Foundation Center for Integrated Molecular Brain Imaging (Cimbi) in Copenhagen, Denmark. The data is of particular relevance for neurobiological research questions related to the serotonergic transmitter system with its normative data on the serotonergic subtype receptors 5-HT1A, 5-HT1B, 5-HT2A, and 5-HT4 and the 5-HT transporter (5-HTT), but can easily serve other purposes. The Cimbi database and Cimbi biobank were formally established in 2008 with the purpose to store the wealth of Cimbi-acquired data in a highly structured and standardized manner in accordance with the regulations issued by the Danish Data Protection Agency as well as to provide a quality-controlled resource for future hypothesis-generating and hypothesis-driven studies. The Cimbi database currently comprises a total of 1100 PET and 1000 structural and functional MRI scans and it holds a multitude of additional data, such as genetic and biochemical data, and scores from 17 self-reported questionnaires and from 11 neuropsychological paper/computer tests. The database associated Cimbi biobank currently contains blood and in some instances saliva samples from about 500 healthy volunteers and 300 patients with e.g., major depression, dementia, substance abuse, obesity, and impulsive aggression. Data continue to be added to the Cimbi database and biobank. PMID:25891375

  8. The digital bee brain: integrating and managing neurons in a common 3D reference system

    Directory of Open Access Journals (Sweden)

    Jürgen Rybak

    2010-07-01

    Full Text Available The honeybee standard brain (HSB serves as an interactive tool for relating morphologies of bee brain neurons and provides a reference system for functional and bibliographical properties (http://www.neurobiologie.fu-berlin.de/beebrain/. The ultimate goal is to document not only the morphological network properties of neurons collected from separate brains, but also to establish a graphical user interface for a neuron-related data base. Here, we review the current methods and protocols used to incorporate neuronal reconstructions into the HSB. Our registration protocol consists of two separate steps applied to imaging data from two-channel confocal microscopy scans: (1 The reconstruction of the neuron, facilitated by an automatic extraction of the neuron’s skeleton based on threshold segmentation, and (2 the semi-automatic 3D segmentation of the neuropils and their registration with the HSB. The integration of neurons in the HSB is performed by applying the transformation computed in step (2 to the reconstructed neurons of step (1. The most critical issue of this protocol in terms of user interaction time – the segmentation process – is drastically improved by the use of a model-based segmentation process. Furthermore, the underlying statistical shape models (SSM allow the visualization and analysis of characteristic variations in large sets of bee brain data. The anatomy of neural networks composed of multiple neurons that are registered into the HSB are visualized by depicting the 3D reconstructions together with semantic information with the objective to integrate data from multiple sources (electrophysiology, imaging, immunocytochemistry, molecular biology. Ultimately, this will allow the user to specify cell types and retrieve their morphologies along with physiological characterizations.

  9. Impaired Visual Integration in Children with Traumatic Brain Injury: An Observational Study.

    Directory of Open Access Journals (Sweden)

    Marsh Königs

    Full Text Available Axonal injury after traumatic brain injury (TBI may cause impaired sensory integration. We aim to determine the effects of childhood TBI on visual integration in relation to general neurocognitive functioning.We compared children aged 6-13 diagnosed with TBI (n = 103; M = 1.7 years post-injury to children with traumatic control (TC injury (n = 44. Three TBI severity groups were distinguished: mild TBI without risk factors for complicated TBI (mildRF- TBI, n = 22, mild TBI with ≥1 risk factor (mildRF+ TBI, n = 46 or moderate/severe TBI (n = 35. An experimental paradigm measured speed and accuracy of goal-directed behavior depending on: (1 visual identification; (2 visual localization; or (3 both, measuring visual integration. Group-differences on reaction time (RT or accuracy were tracked down to task strategy, visual processing efficiency and extra-decisional processes (e.g. response execution using diffusion model analysis. General neurocognitive functioning was measured by a Wechsler Intelligence Scale short form.The TBI group had poorer accuracy of visual identification and visual integration than the TC group (Ps ≤ .03; ds ≤ -0.40. Analyses differentiating TBI severity revealed that visual identification accuracy was impaired in the moderate/severe TBI group (P = .05, d = -0.50 and that visual integration accuracy was impaired in the mildRF+ TBI group and moderate/severe TBI group (Ps < .02, ds ≤ -0.56. Diffusion model analyses tracked impaired visual integration accuracy down to lower visual integration efficiency in the mildRF+ TBI group and moderate/severe TBI group (Ps < .001, ds ≤ -0.73. Importantly, intelligence impairments observed in the TBI group (P = .009, d = -0.48 were statistically explained by visual integration efficiency (P = .002.Children with mildRF+ TBI or moderate/severe TBI have impaired visual integration efficiency, which may contribute to poorer general neurocognitive functioning.

  10. Phenotypic integration of brain size and head morphology in Lake Tanganyika Cichlids

    OpenAIRE

    Tsuboi, Masahito; González-Voyer, Alejandro; Kolm, N.

    2014-01-01

    Abstract Background Phenotypic integration among different anatomical parts of the head is a common phenomenon across vertebrates. Interestingly, despite centuries of research into the factors that contribute to the existing variation in brain size among vertebrates, little is known about the role of phenotypic integration in brain size diversification. Here we used geometric morphometrics on the morphologically diverse Tanganyikan cichlids to investigate phenotypic integration across key mor...

  11. Integrated modeling: a look back

    Science.gov (United States)

    Briggs, Clark

    2015-09-01

    This paper discusses applications and implementation approaches used for integrated modeling of structural systems with optics over the past 30 years. While much of the development work focused on control system design, significant contributions were made in system modeling and computer-aided design (CAD) environments. Early work appended handmade line-of-sight models to traditional finite element models, such as the optical spacecraft concept from the ACOSS program. The IDEAS2 computational environment built in support of Space Station collected a wider variety of existing tools around a parametric database. Later, IMOS supported interferometer and large telescope mission studies at JPL with MATLAB modeling of structural dynamics, thermal analysis, and geometric optics. IMOS's predecessor was a simple FORTRAN command line interpreter for LQG controller design with additional functions that built state-space finite element models. Specialized language systems such as CAESY were formulated and prototyped to provide more complex object-oriented functions suited to control-structure interaction. A more recent example of optical modeling directly in mechanical CAD is used to illustrate possible future directions. While the value of directly posing the optical metric in system dynamics terms is well understood today, the potential payoff is illustrated briefly via project-based examples. It is quite likely that integrated structure thermal optical performance (STOP) modeling could be accomplished in a commercial off-the-shelf (COTS) tool set. The work flow could be adopted, for example, by a team developing a small high-performance optical or radio frequency (RF) instrument.

  12. Highlighting the structure-function relationship of the brain with the Ising model and graph theory.

    Science.gov (United States)

    Das, T K; Abeyasinghe, P M; Crone, J S; Sosnowski, A; Laureys, S; Owen, A M; Soddu, A

    2014-01-01

    With the advent of neuroimaging techniques, it becomes feasible to explore the structure-function relationships in the brain. When the brain is not involved in any cognitive task or stimulated by any external output, it preserves important activities which follow well-defined spatial distribution patterns. Understanding the self-organization of the brain from its anatomical structure, it has been recently suggested to model the observed functional pattern from the structure of white matter fiber bundles. Different models which study synchronization (e.g., the Kuramoto model) or global dynamics (e.g., the Ising model) have shown success in capturing fundamental properties of the brain. In particular, these models can explain the competition between modularity and specialization and the need for integration in the brain. Graphing the functional and structural brain organization supports the model and can also highlight the strategy used to process and organize large amount of information traveling between the different modules. How the flow of information can be prevented or partially destroyed in pathological states, like in severe brain injured patients with disorders of consciousness or by pharmacological induction like in anaesthesia, will also help us to better understand how global or integrated behavior can emerge from local and modular interactions. PMID:25276772

  13. Highlighting the Structure-Function Relationship of the Brain with the Ising Model and Graph Theory

    Directory of Open Access Journals (Sweden)

    T. K. Das

    2014-01-01

    Full Text Available With the advent of neuroimaging techniques, it becomes feasible to explore the structure-function relationships in the brain. When the brain is not involved in any cognitive task or stimulated by any external output, it preserves important activities which follow well-defined spatial distribution patterns. Understanding the self-organization of the brain from its anatomical structure, it has been recently suggested to model the observed functional pattern from the structure of white matter fiber bundles. Different models which study synchronization (e.g., the Kuramoto model or global dynamics (e.g., the Ising model have shown success in capturing fundamental properties of the brain. In particular, these models can explain the competition between modularity and specialization and the need for integration in the brain. Graphing the functional and structural brain organization supports the model and can also highlight the strategy used to process and organize large amount of information traveling between the different modules. How the flow of information can be prevented or partially destroyed in pathological states, like in severe brain injured patients with disorders of consciousness or by pharmacological induction like in anaesthesia, will also help us to better understand how global or integrated behavior can emerge from local and modular interactions.

  14. 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.

  15. On a Quantum Model of Brain Activities

    Science.gov (United States)

    Fichtner, K.-H.; Fichtner, L.; Freudenberg, W.; Ohya, M.

    2010-01-01

    One of the main activities of the brain is the recognition of signals. A first attempt to explain the process of recognition in terms of quantum statistics was given in [6]. Subsequently, details of the mathematical model were presented in a (still incomplete) series of papers (cf. [7, 2, 5, 10]). In the present note we want to give a general view of the principal ideas of this approach. We will introduce the basic spaces and justify the choice of spaces and operations. Further, we bring the model face to face with basic postulates any statistical model of the recognition process should fulfill. These postulates are in accordance with the opinion widely accepted in psychology and neurology.

  16. An integrative view on sex differences in brain tumors

    OpenAIRE

    Sun, Tao; Plutynski, Anya; Ward, Stacey; Rubin, Joshua B.

    2015-01-01

    Sex differences in human health and disease can range from undetectable to profound. Differences in brain tumor rates and outcome are evident in males and females throughout the world and regardless of age. These observations indicate that fundamental aspects of sex determination can impact the biology of brain tumors. It is likely that optimal personalized approaches to the treatment of male and female brain tumor patients will require recognizing and understanding the ways in which the biol...

  17. The integrated environmental control model

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, E.S.; Berkenpas, M.B.; Kalagnanam, J.R. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    1995-11-01

    The capability to estimate the performance and cost of emission control systems is critical to a variety of planning and analysis requirements faced by utilities, regulators, researchers and analysts in the public and private sectors. The computer model described in this paper has been developed for DOe to provide an up-to-date capability for analyzing a variety of pre-combustion, combustion, and post-combustion options in an integrated framework. A unique capability allows performance and costs to be modeled probabilistically, which allows explicit characterization of uncertainties and risks.

  18. Inferring brain-computational mechanisms with models of activity measurements

    OpenAIRE

    Kriegeskorte, Nikolaus; Diedrichsen, Jörn

    2016-01-01

    High-resolution functional imaging is providing increasingly rich measurements of brain activity in animals and humans. A major challenge is to leverage such data to gain insight into the brain's computational mechanisms. The first step is to define candidate brain-computational models (BCMs) that can perform the behavioural task in question. We would then like to infer, which of the candidate BCMs best accounts for measured brain-activity data. Here we describe a method that complements each...

  19. Multiscale modeling and simulation of brain blood flow

    Science.gov (United States)

    Perdikaris, Paris; Grinberg, Leopold; Karniadakis, George Em

    2016-02-01

    The aim of this work is to present an overview of recent advances in multi-scale modeling of brain blood flow. In particular, we present some approaches that enable the in silico study of multi-scale and multi-physics phenomena in the cerebral vasculature. We discuss the formulation of continuum and atomistic modeling approaches, present a consistent framework for their concurrent coupling, and list some of the challenges that one needs to overcome in achieving a seamless and scalable integration of heterogeneous numerical solvers. The effectiveness of the proposed framework is demonstrated in a realistic case involving modeling the thrombus formation process taking place on the wall of a patient-specific cerebral aneurysm. This highlights the ability of multi-scale algorithms to resolve important biophysical processes that span several spatial and temporal scales, potentially yielding new insight into the key aspects of brain blood flow in health and disease. Finally, we discuss open questions in multi-scale modeling and emerging topics of future research.

  20. Multiscale modeling and simulation of brain blood flow

    International Nuclear Information System (INIS)

    The aim of this work is to present an overview of recent advances in multi-scale modeling of brain blood flow. In particular, we present some approaches that enable the in silico study of multi-scale and multi-physics phenomena in the cerebral vasculature. We discuss the formulation of continuum and atomistic modeling approaches, present a consistent framework for their concurrent coupling, and list some of the challenges that one needs to overcome in achieving a seamless and scalable integration of heterogeneous numerical solvers. The effectiveness of the proposed framework is demonstrated in a realistic case involving modeling the thrombus formation process taking place on the wall of a patient-specific cerebral aneurysm. This highlights the ability of multi-scale algorithms to resolve important biophysical processes that span several spatial and temporal scales, potentially yielding new insight into the key aspects of brain blood flow in health and disease. Finally, we discuss open questions in multi-scale modeling and emerging topics of future research

  1. Multiscale modeling and simulation of brain blood flow

    Energy Technology Data Exchange (ETDEWEB)

    Perdikaris, Paris, E-mail: parisp@mit.edu [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Grinberg, Leopold, E-mail: leopoldgrinberg@us.ibm.com [IBM T.J Watson Research Center, 1 Rogers St, Cambridge, Massachusetts 02142 (United States); Karniadakis, George Em, E-mail: george-karniadakis@brown.edu [Division of Applied Mathematics, Brown University, Providence, Rhode Island 02912 (United States)

    2016-02-15

    The aim of this work is to present an overview of recent advances in multi-scale modeling of brain blood flow. In particular, we present some approaches that enable the in silico study of multi-scale and multi-physics phenomena in the cerebral vasculature. We discuss the formulation of continuum and atomistic modeling approaches, present a consistent framework for their concurrent coupling, and list some of the challenges that one needs to overcome in achieving a seamless and scalable integration of heterogeneous numerical solvers. The effectiveness of the proposed framework is demonstrated in a realistic case involving modeling the thrombus formation process taking place on the wall of a patient-specific cerebral aneurysm. This highlights the ability of multi-scale algorithms to resolve important biophysical processes that span several spatial and temporal scales, potentially yielding new insight into the key aspects of brain blood flow in health and disease. Finally, we discuss open questions in multi-scale modeling and emerging topics of future research.

  2. Similarity on neural stem cells and brain tumor stem cells in transgenic brain tumor mouse models

    OpenAIRE

    Qiao, Guanqun; Li, Qingquan; Peng, Gang; Ma, Jun; Fan, Hongwei; Li, Yingbin

    2013-01-01

    Although it is believed that glioma is derived from brain tumor stem cells, the source and molecular signal pathways of these cells are still unclear. In this study, we used stable doxycycline-inducible transgenic mouse brain tumor models (c-myc+/SV40Tag+/Tet-on+) to explore the malignant trans-formation potential of neural stem cells by observing the differences of neural stem cells and brain tumor stem cells in the tumor models. Results showed that chromosome instability occurred in brain t...

  3. The systems integration modeling system

    International Nuclear Information System (INIS)

    This paper discusses the systems integration modeling system (SIMS), an analysis tool for the detailed evaluation of the structure and related performance of the Federal Waste Management System (FWMS) and its interface with waste generators. It's use for evaluations in support of system-level decisions as to FWMS configurations, the allocation, sizing, balancing and integration of functions among elements, and the establishment of system-preferred waste selection and sequencing methods and other operating strategies is presented. SIMS includes major analysis submodels which quantify the detailed characteristics of individual waste items, loaded casks and waste packages, simulate the detailed logistics of handling and processing discrete waste items and packages, and perform detailed cost evaluations

  4. Integral canonical models for Spin Shimura varieties

    OpenAIRE

    Pera, Keerthi Madapusi

    2012-01-01

    We construct regular integral canonical models for Shimura varieties attached to Spin groups at (possibly ramified) odd primes. We exhibit these models as schemes of 'relative PEL type' over integral canonical models of larger Spin Shimura varieties with good reduction. Work of Vasiu-Zink then shows that the classical Kuga-Satake construction extends over the integral model and that the integral models we construct are canonical in a very precise sense. We also construct good compactification...

  5. Bryostatin-1 Restores Blood Brain Barrier Integrity following Blast-Induced Traumatic Brain Injury.

    Science.gov (United States)

    Lucke-Wold, Brandon P; Logsdon, Aric F; Smith, Kelly E; Turner, Ryan C; Alkon, Daniel L; Tan, Zhenjun; Naser, Zachary J; Knotts, Chelsea M; Huber, Jason D; Rosen, Charles L

    2015-12-01

    Recent wars in Iraq and Afghanistan have accounted for an estimated 270,000 blast exposures among military personnel. Blast traumatic brain injury (TBI) is the 'signature injury' of modern warfare. Blood brain barrier (BBB) disruption following blast TBI can lead to long-term and diffuse neuroinflammation. In this study, we investigate for the first time the role of bryostatin-1, a specific protein kinase C (PKC) modulator, in ameliorating BBB breakdown. Thirty seven Sprague-Dawley rats were used for this study. We utilized a clinically relevant and validated blast model to expose animals to moderate blast exposure. Groups included: control, single blast exposure, and single blast exposure + bryostatin-1. Bryostatin-1 was administered i.p. 2.5 mg/kg after blast exposure. Evan's blue, immunohistochemistry, and western blot analysis were performed to assess injury. Evan's blue binds to albumin and is a marker for BBB disruption. The single blast exposure caused an increase in permeability compared to control (t = 4.808, p < 0.05), and a reduction back toward control levels when bryostatin-1 was administered (t = 5.113, p < 0.01). Three important PKC isozymes, PKCα, PKCδ, and PKCε, were co-localized primarily with endothelial cells but not astrocytes. Bryostatin-1 administration reduced toxic PKCα levels back toward control levels (t = 4.559, p < 0.01) and increased the neuroprotective isozyme PKCε (t = 6.102, p < 0.01). Bryostatin-1 caused a significant increase in the tight junction proteins VE-cadherin, ZO-1, and occludin through modulation of PKC activity. Bryostatin-1 ultimately decreased BBB breakdown potentially due to modulation of PKC isozymes. Future work will examine the role of bryostatin-1 in preventing chronic neurodegeneration following repetitive neurotrauma. PMID:25301233

  6. DIRECT INTEGRATION METHODS WITH INTEGRAL MODEL FOR DYNAMIC SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    吕和祥; 于洪洁; 裘春航

    2001-01-01

    A new approach which is a direct integration method with integral model ( DIM IM) to solve dynamic governing equations is presented. The governing equations are integrated into the integral equations. An algorithm with explicit and predict-correct and selfstarting and fourth-order accuracy to integrate the integral equations is given.Theoretical analysis and numerical examples show that DIM-IM discribed in this paper suitable for strong nonlinear and non-conservative system have higher accuracy than central difference, Houbolt , Newmark and Wilson- Theta methods.

  7. Brain systems for probabilistic and dynamic prediction: computational specificity and integration.

    Directory of Open Access Journals (Sweden)

    Jill X O'Reilly

    2013-09-01

    Full Text Available A computational approach to functional specialization suggests that brain systems can be characterized in terms of the types of computations they perform, rather than their sensory or behavioral domains. We contrasted the neural systems associated with two computationally distinct forms of predictive model: a reinforcement-learning model of the environment obtained through experience with discrete events, and continuous dynamic forward modeling. By manipulating the precision with which each type of prediction could be used, we caused participants to shift computational strategies within a single spatial prediction task. Hence (using fMRI we showed that activity in two brain systems (typically associated with reward learning and motor control could be dissociated in terms of the forms of computations that were performed there, even when both systems were used to make parallel predictions of the same event. A region in parietal cortex, which was sensitive to the divergence between the predictions of the models and anatomically connected to both computational networks, is proposed to mediate integration of the two predictive modes to produce a single behavioral output.

  8. AN INTEGRABLE HIERARCHY AND ITS EXPANDING LAX INTEGRABLE MODEL

    Institute of Scientific and Technical Information of China (English)

    张玉峰; 闫庆友; 许曰才

    2004-01-01

    In general, Liouville integrable hierarchies of evolution equations were obtained by choosing proper U in zero curvature frame Ut - Vx + [U, V] = 0 first. But in the present paper, a new Liouville integrable hierarchy possessing bi-Hamiltonian structure is obtained by choosing V with derivatives in x and spectral potentials. Then integrable coupling, i.e. expanding Lax integrable model of the hierarchy obtained is presented by constructing a subalgebra of loop algebra A2.

  9. 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...

  10. Brain functional integration decreases during propofol-induced loss of consciousness.

    Science.gov (United States)

    Schrouff, Jessica; Perlbarg, Vincent; Boly, Mélanie; Marrelec, Guillaume; Boveroux, Pierre; Vanhaudenhuyse, Audrey; Bruno, Marie-Aurélie; Laureys, Steven; Phillips, Christophe; Pélégrini-Issac, Mélanie; Maquet, Pierre; Benali, Habib

    2011-07-01

    Consciousness has been related to the amount of integrated information that the brain is able to generate. In this paper, we tested the hypothesis that the loss of consciousness caused by propofol anesthesia is associated with a significant reduction in the capacity of the brain to integrate information. To assess the functional structure of the whole brain, functional integration and partial correlations were computed from fMRI data acquired from 18 healthy volunteers during resting wakefulness and propofol-induced deep sedation. Total integration was significantly reduced from wakefulness to deep sedation in the whole brain as well as within and between its constituent networks (or systems). Integration was systematically reduced within each system (i.e., brain or networks), as well as between networks. However, the ventral attentional network maintained interactions with most other networks during deep sedation. Partial correlations further suggested that functional connectivity was particularly affected between parietal areas and frontal or temporal regions during deep sedation. Our findings suggest that the breakdown in brain integration is the neural correlate of the loss of consciousness induced by propofol. They stress the important role played by parietal and frontal areas in the generation of consciousness. PMID:21524704

  11. Integrated Resource Planning Model (IRPM)

    Energy Technology Data Exchange (ETDEWEB)

    Graham, T. B.

    2010-04-01

    The Integrated Resource Planning Model (IRPM) is a decision-support software product for resource-and-capacity planning. Users can evaluate changing constraints on schedule performance, projected cost, and resource use. IRPM is a unique software tool that can analyze complex business situations from a basic supply chain to an integrated production facility to a distributed manufacturing complex. IRPM can be efficiently configured through a user-friendly graphical interface to rapidly provide charts, graphs, tables, and/or written results to summarize postulated business scenarios. There is not a similar integrated resource planning software package presently available. Many different businesses (from government to large corporations as well as medium-to-small manufacturing concerns) could save thousands of dollars and hundreds of labor hours in resource and schedule planning costs. Those businesses also could avoid millions of dollars of revenue lost from fear of overcommitting or from penalties and lost future business for failing to meet promised delivery by using IRPM to perform what-if business-case evaluations. Tough production planning questions that previously were left unanswered can now be answered with a high degree of certainty. Businesses can anticipate production problems and have solutions in hand to deal with those problems. IRPM allows companies to make better plans, decisions, and investments.

  12. A STUDY ON FORMAL MODEL INTEGRATION

    Institute of Scientific and Technical Information of China (English)

    Wang Jiayang; Chen Songqiao; Luo An

    2006-01-01

    Model integration is an important section of the model management research area. The paper puts forward a formalization representation of model, and presents some concepts, such as the compound model relation, the composite model and so on. Additionally, the existence of model integration is also analyzed in detail and several sufficient conditions are proved.

  13. Modeling brain resonance phenomena using a neural mass model.

    Directory of Open Access Journals (Sweden)

    Andreas Spiegler

    2011-12-01

    Full Text Available Stimulation with rhythmic light flicker (photic driving plays an important role in the diagnosis of schizophrenia, mood disorder, migraine, and epilepsy. In particular, the adjustment of spontaneous brain rhythms to the stimulus frequency (entrainment is used to assess the functional flexibility of the brain. We aim to gain deeper understanding of the mechanisms underlying this technique and to predict the effects of stimulus frequency and intensity. For this purpose, a modified Jansen and Rit neural mass model (NMM of a cortical circuit is used. This mean field model has been designed to strike a balance between mathematical simplicity and biological plausibility. We reproduced the entrainment phenomenon observed in EEG during a photic driving experiment. More generally, we demonstrate that such a single area model can already yield very complex dynamics, including chaos, for biologically plausible parameter ranges. We chart the entire parameter space by means of characteristic Lyapunov spectra and Kaplan-Yorke dimension as well as time series and power spectra. Rhythmic and chaotic brain states were found virtually next to each other, such that small parameter changes can give rise to switching from one to another. Strikingly, this characteristic pattern of unpredictability generated by the model was matched to the experimental data with reasonable accuracy. These findings confirm that the NMM is a useful model of brain dynamics during photic driving. In this context, it can be used to study the mechanisms of, for example, perception and epileptic seizure generation. In particular, it enabled us to make predictions regarding the stimulus amplitude in further experiments for improving the entrainment effect.

  14. Associations between insulin action and integrity of brain microstructure differ with familial longevity and with age

    Directory of Open Access Journals (Sweden)

    Abimbola A. Akintola

    2015-05-01

    Full Text Available Impaired glucose metabolism and type 2 diabetes have been associated with cognitive decline, dementia, and with structural and functional brain features. However, it is unclear whether these associations differ in individuals that differ in familial longevity or age. Here, we investigated the association between parameters of glucose metabolism and microstructural brain integrity in offspring of long-lived families (offspring and controls; and age categories thereof. From the Leiden Longevity Study, 132 participants underwent oral glucose tolerance test to assess glycemia (fasted glucose and glucose area-under-the-curve (AUC, insulin resistance (fasted insulin, AUCinsulin, and homeostatic model assessment of insulin resistance (HOMA-IR, and pancreatic Beta cell secretory capacity (insulinogenic index. 3Tesla MRI and Magnetization Transfer (MT imaging MT-ratio peak-height was used to quantify differences in microstructural brain parenchymal tissue homogeneity that remain invisible on conventional MRI. Analyses were performed in offspring and age-matched controls, with and without stratification for age.In the full offspring group only, reduced peak-height in grey and white matter was inversely associated with AUCinsulin, fasted insulin, HOMA-IR and insulinogenic-index (all p65 years: in younger controls, significantly stronger inverse associations were observed between peak-height and fasted glucose, AUCglucose, fasted insulin, AUCinsulin and HOMA-IR in grey matter; and for AUCglucose, fasted insulin and HOMA-IR in white matter (all P-interaction<0.05. Although the strength of the associations tended to attenuate with age in the offspring group, the difference between age groups was not statistically significant. Thus, associations between impaired insulin action and reduced microstructural brain parenchymal tissue homogeneity were stronger in offspring compared to controls, and seemed to diminish with age.

  15. Is functional integration of resting state brain networks an unspecific biomarker for working memory performance?

    Science.gov (United States)

    Alavash, Mohsen; Doebler, Philipp; Holling, Heinz; Thiel, Christiane M; Gießing, Carsten

    2015-03-01

    Is there one optimal topology of functional brain networks at rest from which our cognitive performance would profit? Previous studies suggest that functional integration of resting state brain networks is an important biomarker for cognitive performance. However, it is still unknown whether higher network integration is an unspecific predictor for good cognitive performance or, alternatively, whether specific network organization during rest predicts only specific cognitive abilities. Here, we investigated the relationship between network integration at rest and cognitive performance using two tasks that measured different aspects of working memory; one task assessed visual-spatial and the other numerical working memory. Network clustering, modularity and efficiency were computed to capture network integration on different levels of network organization, and to statistically compare their correlations with the performance in each working memory test. The results revealed that each working memory aspect profits from a different resting state topology, and the tests showed significantly different correlations with each of the measures of network integration. While higher global network integration and modularity predicted significantly better performance in visual-spatial working memory, both measures showed no significant correlation with numerical working memory performance. In contrast, numerical working memory was superior in subjects with highly clustered brain networks, predominantly in the intraparietal sulcus, a core brain region of the working memory network. Our findings suggest that a specific balance between local and global functional integration of resting state brain networks facilitates special aspects of cognitive performance. In the context of working memory, while visual-spatial performance is facilitated by globally integrated functional resting state brain networks, numerical working memory profits from increased capacities for local processing

  16. Modeling the brain-pituitary-gonad axis in salmon

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jonghan; Hayton, William L.; Schultz, Irv R.

    2006-08-24

    To better understand the complexity of the brain-pituitary-gonad axis (BPG) in fish, we developed a biologically based pharmacodynamic model capable of accurately predicting the normal functioning of the BPG axis in salmon. This first-generation model consisted of a set of 13 equations whose formulation was guided by published values for plasma concentrations of pituitary- (FSH, LH) and ovary- (estradiol, 17a,20b-dihydroxy-4-pregnene-3-one) derived hormones measured in Coho salmon over an annual spawning period. In addition, the model incorporated pertinent features of previously published mammalian models and indirect response pharmacodynamic models. Model-based equations include a description of gonadotropin releasing hormone (GnRH) synthesis and release from the hypothalamus, which is controlled by environmental variables such as photoperiod and water temperature. GnRH stimulated the biosynthesis of mRNA for FSH and LH, which were also influenced by estradiol concentration in plasma. The level of estradiol in the plasma was regulated by the oocytes, which moved along a maturation progression. Estradiol was synthesized at a basal rate and as oocytes matured, stimulation of its biosynthesis occurred. The BPG model can be integrated with toxico-genomic, -proteomic data, allowing linkage between molecular based biomarkers and reproduction in fish.

  17. Mathematical modelling of blood-brain barrier failure and edema

    Science.gov (United States)

    Waters, Sarah; Lang, Georgina; Vella, Dominic; Goriely, Alain

    2015-11-01

    Injuries such as traumatic brain injury and stroke can result in increased blood-brain barrier permeability. This increase may lead to water accumulation in the brain tissue resulting in vasogenic edema. Although the initial injury may be localised, the resulting edema causes mechanical damage and compression of the vasculature beyond the original injury site. We employ a biphasic mixture model to investigate the consequences of blood-brain barrier permeability changes within a region of brain tissue and the onset of vasogenic edema. We find that such localised changes can indeed result in brain tissue swelling and that the type of damage that results (stress damage or strain damage) depends on the ability of the brain to clear edema fluid.

  18. 21B. A Horizontal Integration Business Model for Integrative Medicine: Sustainability through Integration

    OpenAIRE

    Cotton, Sian; Stevenson, Stefanie; Luberto, Christina

    2013-01-01

    Focus Area: Sustainable Business Models In 2012, with solely institutional support, the University of Cincinnati officially launched its Center for Integrative Health and Wellness, focused on developing integrative medicine clinical, research, and education initiatives horizontally across the academic health center. Given that Integrative Medicine (IM) is intrinsically interdisciplinary, the UC Center purposively functions according to a horizontal integration business and clinical model, rat...

  19. PLATO: data-oriented approach to collaborative large-scale brain system modeling.

    Science.gov (United States)

    Kannon, Takayuki; Inagaki, Keiichiro; Kamiji, Nilton L; Makimura, Kouji; Usui, Shiro

    2011-11-01

    The brain is a complex information processing system, which can be divided into sub-systems, such as the sensory organs, functional areas in the cortex, and motor control systems. In this sense, most of the mathematical models developed in the field of neuroscience have mainly targeted a specific sub-system. In order to understand the details of the brain as a whole, such sub-system models need to be integrated toward the development of a neurophysiologically plausible large-scale system model. In the present work, we propose a model integration library where models can be connected by means of a common data format. Here, the common data format should be portable so that models written in any programming language, computer architecture, and operating system can be connected. Moreover, the library should be simple so that models can be adapted to use the common data format without requiring any detailed knowledge on its use. Using this library, we have successfully connected existing models reproducing certain features of the visual system, toward the development of a large-scale visual system model. This library will enable users to reuse and integrate existing and newly developed models toward the development and simulation of a large-scale brain system model. The resulting model can also be executed on high performance computers using Message Passing Interface (MPI). PMID:21767932

  20. Integration of Neuropsychology in Educational Planning Following Traumatic Brain Injury

    Science.gov (United States)

    Stavinoha, Peter L.

    2005-01-01

    Traumatic brain injuries (TBIs) have the potential to significantly disrupt a student's cognitive, academic, social, emotional, behavioral, and physical functioning. It is important for educators to appreciate the array of difficulties students with TBI may experience in order to appropriately assess needs and create an educational plan that…

  1. Brain Wave Biofeedback: Benefits of Integrating Neurofeedback in Counseling

    Science.gov (United States)

    Myers, Jane E.; Young, J. Scott

    2012-01-01

    Consistent with the "2009 Standards" of the Council for Accreditation of Counseling and Related Educational Programs, counselors must understand neurobiological behavior in individuals of all developmental levels. This requires understanding the brain and strategies for applying neurobiological concepts in counseling practice, training, and…

  2. An integrated model of learning.

    Science.gov (United States)

    Trigg, A M; Cordova, F D

    1987-01-01

    Worldwide, most educational systems are based on three levels of education that utilize the pedagogical approaches to learning. In the 1960s, scholars formulated another approach to education that has become known as andragogy and has been applied to adult education. Several innovative scholars have seen how andragogy can be applied to teaching children. As a result, both andragogy and pedagogy are viewed as the opposite ends of the educational spectrum. Both of these approaches have a place and function within the modern educational framework. If one assumes that the goal of education is for the acquisition and application of knowledge, then both of these approaches can be used effectively for the attainment of that goal. In order to utilize these approaches effectively, an integrated model of learning has been developed that consists of initial teaching and exploratory learning phases. This model has both the directive and flexible qualities found in the theories of pedagogy and andragogy. With careful consideration and analysis this educational model can be utilized effectively within most educational systems. PMID:3588888

  3. Action and Language Mechanisms in the Brain: Data, Models and Neuroinformatics

    OpenAIRE

    Arbib, Michael A.; Bonaiuto, James J.; Bornkessel-Schlesewsky, Ina; Kemmerer, David; MacWhinney, Brian; Nielsen, Finn Årup; Oztop, Erhan

    2014-01-01

    We assess the challenges of studying action and language mechanisms in the brain, both singly and in relation to each other to provide a novel perspective on neuroinformatics, integrating the development of databases for encoding – separately or together – neurocomputational models and empirical data that serve systems and cognitive neuroscience.

  4. Action and Language Mechanisms in the Brain: Data, Models and Neuroinformatics

    DEFF Research Database (Denmark)

    Arbib, Michael A.; Bonaiuto, James J.; Bornkessel-Schlesewsky, Ina;

    2014-01-01

    We assess the challenges of studying action and language mechanisms in the brain, both singly and in relation to each other to provide a novel perspective on neuroinformatics, integrating the development of databases for encoding - separately or together - neurocomputational models and empirical...

  5. Action and language mechanisms in the brain: data, models and neuroinformatics.

    Science.gov (United States)

    Arbib, Michael A; Bonaiuto, James J; Bornkessel-Schlesewsky, Ina; Kemmerer, David; MacWhinney, Brian; Nielsen, Finn Årup; Oztop, Erhan

    2014-01-01

    We assess the challenges of studying action and language mechanisms in the brain, both singly and in relation to each other to provide a novel perspective on neuroinformatics, integrating the development of databases for encoding – separately or together – neurocomputational models and empirical data that serve systems and cognitive neuroscience. PMID:24234916

  6. A Neurocomputational Model of an Imitation Deficit following Brain Lesion

    OpenAIRE

    Petreska, B.; Billard, A.

    2006-01-01

    This paper investigates the neural mechanisms of visuo-motor imitation in humans through convergent evidence from neuroscience. In particular, we consider a deficit in imitation following callosal brain lesion, based on the rational that looking at how imitation is impaired can unveil its underlying neural principles. We ground the functional architecture and information flow of our model in brain imaging studies and use findings from monkey brain neurophysiological studies to drive the choic...

  7. The connected brain: Causality, models and intrinsic dynamics

    OpenAIRE

    A razi; Friston, K.

    2016-01-01

    Recently, there have been several concerted international efforts - the BRAIN initiative, European Human Brain Project and the Human Connectome Project, to name a few - that hope to revolutionize our understanding of the connected brain. Over the past two decades, functional neuroimaging has emerged as the predominant technique in systems neuroscience. This is foreshadowed by an ever increasing number of publications on functional connectivity, causal modeling, connectomics, and multivariate ...

  8. Similarity on neural stem cells and brain tumor stem cells in transgenic brain tumor mouse models

    Institute of Scientific and Technical Information of China (English)

    Guanqun Qiao; Qingquan Li; Gang Peng; Jun Ma; Hongwei Fan; Yingbin Li

    2013-01-01

    Although it is believed that glioma is derived from brain tumor stem cells, the source and molecular signal pathways of these cells are stil unclear. In this study, we used stable doxycycline-inducible transgenic mouse brain tumor models (c-myc+/SV40Tag+/Tet-on+) to explore the malignant trans-formation potential of neural stem cells by observing the differences of neural stem cel s and brain tumor stem cells in the tumor models. Results showed that chromosome instability occurred in brain tumor stem cells. The numbers of cytolysosomes and autophagosomes in brain tumor stem cells and induced neural stem cel s were lower and the proliferative activity was obviously stronger than that in normal neural stem cells. Normal neural stem cells could differentiate into glial fibril ary acidic protein-positive and microtubule associated protein-2-positive cells, which were also negative for nestin. However, glial fibril ary acidic protein/nestin, microtubule associated protein-2/nestin, and glial fibril ary acidic protein/microtubule associated protein-2 double-positive cells were found in induced neural stem cells and brain tumor stem cel s. Results indicate that induced neural stem cells are similar to brain tumor stem cells, and are possibly the source of brain tumor stem cells.

  9. An Adaptive Complex Network Model for Brain Functional Networks

    OpenAIRE

    Gomez Portillo, Ignacio J.; Gleiser, Pablo M.

    2009-01-01

    Brain functional networks are graph representations of activity in the brain, where the vertices represent anatomical regions and the edges their functional connectivity. These networks present a robust small world topological structure, characterized by highly integrated modules connected sparsely by long range links. Recent studies showed that other topological properties such as the degree distribution and the presence (or absence) of a hierarchical structure are not robust, and show diffe...

  10. Modeling Brain Circuitry over a Wide Range of Scales

    Directory of Open Access Journals (Sweden)

    Pascal eFua

    2015-04-01

    Full Text Available If we are ever to unravel the mysteries of brain function at its most fundamental level, we will need a precise understanding of how its component neurons connect to each other. Electron Microscopes (EM can now provide the nanometer resolution that is needed to image synapses, and therefore connections, while Light Microscopes (LM see at the micrometer resolution required to model the 3D structure of the dendritic network. Since both the topology and the connection strength are integral parts of the brain's wiring diagram, being able to combine these two modalities is critically important.In fact, these microscopes now routinely produce high-resolution imagery in such large quantities that the bottleneck becomes automated processing and interpretation, which is needed for such data to be exploited to its full potential. In this paper, we briefly review the Computer Vision techniques we have developed at EPFL to address this need. They include delineating dendritic arbors from LM imagery, segmenting organelles from EM, and combining the two into a consistent representation.

  11. LinkRbrain: Multi-scale data integrator of the brain

    OpenAIRE

    Mesmoudi, Salma; Rodic, Mathieu; Cioli, Claudia; Cointet, Jean-Philippe; Yarkoni, Tal; Burnod, Yves

    2015-01-01

    International audience BackgroundLinkRbrain is an open-access web platform for multi-scale data integration and visualization of human brain data. This platform integrates anatomical, functional, and genetic knowledge produced by the scientific community.New methodThe linkRbrain platform has two major components: (1) a data aggregation component that integrates multiple open databases into a single platform with a unified representation; and (2) a website that provides fast multi-scale int...

  12. Brain

    Science.gov (United States)

    ... will return after updating. Resources Archived Modules Updates Brain Cerebrum The cerebrum is the part of the ... the outside of the brain and spinal cord. Brain Stem The brain stem is the part of ...

  13. Ontogenetic ritualization of primate gesture as a case study in dyadic brain modeling.

    Science.gov (United States)

    Gasser, Brad; Cartmill, Erica A; Arbib, Michael A

    2014-01-01

    This paper introduces dyadic brain modeling - the simultaneous, computational modeling of the brains of two interacting agents - to explore ways in which our understanding of macaque brain circuitry can ground new models of brain mechanisms involved in ape interaction. Specifically, we assess a range of data on gestural communication of great apes as the basis for developing an account of the interactions of two primates engaged in ontogenetic ritualization, a proposed learning mechanism through which a functional action may become a communicative gesture over repeated interactions between two individuals (the 'dyad'). The integration of behavioral, neural, and computational data in dyadic (or, more generally, social) brain modeling has broad application to comparative and evolutionary questions, particularly for the evolutionary origins of cognition and language in the human lineage. We relate this work to the neuroinformatics challenges of integrating and sharing data to support collaboration between primatologists, neuroscientists and modelers that will help speed the emergence of what may be called comparative neuro-primatology. PMID:23608958

  14. Integrating some mind and brain views of transference: the phenomena.

    Science.gov (United States)

    Levin, F M

    1997-01-01

    Because understanding the underpinnings of transferential learning allows the analyst to more effectively exploit transference in the clinical situation, as well as to advance psychoanalytic theory, the functions and mechanisms of transference phenomena in learning are subjected to an interdisciplinary analysis. Through transference the brain creates hierarchical databases that make emotional sense of the world, especially the world of human relationships. Transference plays a role in defense and resistance clinically; less explored but equally important is the adaptive potential of transference and its effect on an individual's readiness for structural change through the activation of working memory. Most investigators within psychoanalysis have not considered the importance of similarity judgments and memory priming, especially as these help to explain why transference and its proper handling are effective in treatment. Yet there are complex relationships among transference, similarity judgment, and memory priming that tie together psychoanalysis, cognitive psychology, and neurophysiology. Evidence increasingly suggests a relationship between transference and the transfer of knowledge between various content domains (databases) of mind and brain, which is essential to cognitive and emotional learning. There are indications as well that transference decisively facilitates learning readiness ("windows") in general by means of two of its components: free association and spontaneous (self-initiated) activity. The important question of which mind/brain mechanisms motivate transference is not yet understood comprehensively. However, Vygotsky's work on the zone of proximal development (ZPD), M.Stern's teleonomic theory, schema theory, and neural network theory offer further insights into what motivates transference. PMID:9474574

  15. Animal models of brain dysfunction in phenylketonuria

    NARCIS (Netherlands)

    Martynyuk, A. E.; van Spronsen, F. J.; Van der Zee, E. A.

    2010-01-01

    Phenylketonuria (PKU) is a metabolic disorder that results in significant brain dysfunction if untreated. Although phenylalanine restricted diets instituted at birth have clearly improved PKU outcomes, neuropsychological deficits and neurological changes still represent substantial problems. The spe

  16. The History and Evolution of Experimental Traumatic Brain Injury Models.

    Science.gov (United States)

    Povlishock, John

    2016-01-01

    This narrative provides a brief history of experimental animal model development for the study of traumatic brain injury. It draws upon a relatively rich history of early animal modeling that employed higher order animals to assess concussive brain injury while exploring the importance of head movement versus stabilization in evaluating the animal's response to injury. These themes are extended to the development of angular/rotational acceleration/deceleration models that also exploited brain movement to generate both the morbidity and pathology typically associated with human traumatic brain injury. Despite the significance of these early model systems, their limitations and overall practicality are discussed. Consideration is given to more contemporary rodent animal models that replicate individual/specific features of human injury, while via various transgenic technologies permitting the evaluation of injury-mediated pathways. The narrative closes on a reconsideration of higher order, porcine animal models of injury and their implication for preclinical/translational research. PMID:27604709

  17. Modeling human brain development with cerebral organoids

    OpenAIRE

    Muzio, Luca; Consalez, G. Giacomo

    2013-01-01

    The recent discovery of a new three-dimensional culture system for the derivation of cerebral organoids from human induced pluripotent stem cells provides developmental neurobiologists with the first example of a three-dimensional framework for the study of human brain development. This innovative approach permits the in vitro assembly of a human embryonic brain rudiment that recapitulates the developing human cerebrum. Organoids contain progenitor populations that develop to yield mature cor...

  18. Brain white matter integrity and cortisol in older men:the Lothian Birth Cohort 1936

    OpenAIRE

    Cox, Simon R.; Bastin, Mark E; Ferguson, Karen J.; Munoz-Maniega, Susana; MacPherson, Sarah E.; Deary, Ian J; Wardlaw, Joanna M.; MacLullich, Alasdair M. J.

    2015-01-01

    Elevated glucocorticoid (GC) levels are hypothesized to be deleterious to some brain regions, including white matter (WM). Older age is accompanied by increased between-participant variation in GC levels, yet relationships between WM integrity and cortisol levels in older humans are underexplored. Moreover, it is unclear whether GC-WM associations might be general or pathway specific. We analyzed relationships between salivary cortisol (diurnal and reactive) and general measures of brain WM h...

  19. NF-κB and epigenetic mechanisms as integrative regulators of brain resilience to anoxic stress.

    Science.gov (United States)

    Sarnico, Ilenia; Branca, Caterina; Lanzillotta, Annamaria; Porrini, Vanessa; Benarese, Marina; Spano, Pier Franco; Pizzi, Marina

    2012-10-01

    Brain cells display an amazing ability to respond to several different types of environmental stimuli and integrate this response physiologically. Some of these responses can outlive the original stimulus by days, weeks or even longer. Long-lasting changes in both physiological and pathological conditions occurring in response to external stimuli are almost always mediated by changes in gene expression. To effect these changes, cells have developed an impressive repertoire of signaling systems designed to modulate the activity of numerous transcription factors and epigenetic mechanisms affecting the chromatin structure. Since its initial characterization in the nervous system, NF-κB has shown to respond to multiple signals and elicit pleiotropic activities suggesting that it may play a pivotal role in integration of different types of information within the brain. Ample evidence demonstrates that NF-κB factors are engaged in and necessary for neuronal development and synaptic plasticity, but they also regulate brain response to environmental noxae. By focusing on the complexity of NF-κB transcriptional activity in neuronal cell death, it emerged that the composition of NF-κB active dimers finely tunes the neuronal vulnerability to brain ischemia. Even though we are only beginning to understand the contribution of distinct NF-κB family members to the regulation of gene transcription in the brain, an additional level of regulation of NF-κB activity has emerged as operated by the epigenetic mechanisms modulating histone acetylation. We will discuss NF-κB and epigenetic mechanisms as integrative regulators of brain resilience to anoxic stress and useful drug targets for restoration of brain function. This article is part of a Special Issue entitled: Brain Integration. PMID:22575713

  20. Animal models of traumatic brain injury : a critical evaluation

    OpenAIRE

    O'Connor, William; Smyth, Aoife; Gilchrist, M. D.

    2011-01-01

    Animal models are necessary to elucidate changes occurring after brain injury and to establish new therapeutic strategies towards a stage where drug efficacy in brain injured patients (against all classes of symptoms) can be predicted. In this review, six established animal models of head trauma, namely fluid percussion, rigid indentation, inertial acceleration, impact acceleration, weight-drop and dynamic cortical deformation are evaluated. While no single animal model is entirely successful...

  1. Performance modeling of a wearable brain PET (BET) camera

    Science.gov (United States)

    Schmidtlein, C. R.; Turner, J. N.; Thompson, M. O.; Mandal, K. C.; Häggström, I.; Zhang, J.; Humm, J. L.; Feiglin, D. H.; Krol, A.

    2016-03-01

    Purpose: To explore, by means of analytical and Monte Carlo modeling, performance of a novel lightweight and low-cost wearable helmet-shaped Brain PET (BET) camera based on thin-film digital Geiger Avalanche Photo Diode (dGAPD) with LSO and LaBr3 scintillators for imaging in vivo human brain processes for freely moving and acting subjects responding to various stimuli in any environment. Methods: We performed analytical and Monte Carlo modeling PET performance of a spherical cap BET device and cylindrical brain PET (CYL) device, both with 25 cm diameter and the same total mass of LSO scintillator. Total mass of LSO in both the BET and CYL systems is about 32 kg for a 25 mm thick scintillator, and 13 kg for 10 mm thick scintillator (assuming an LSO density of 7.3 g/ml). We also investigated a similar system using an LaBr3 scintillator corresponding to 22 kg and 9 kg for the 25 mm and 10 mm thick systems (assuming an LaBr3 density of 5.08 g/ml). In addition, we considered a clinical whole body (WB) LSO PET/CT scanner with 82 cm ring diameter and 15.8 cm axial length to represent a reference system. BET consisted of distributed Autonomous Detector Arrays (ADAs) integrated into Intelligent Autonomous Detector Blocks (IADBs). The ADA comprised of an array of small LYSO scintillator volumes (voxels with base a×a: 1.0 energy resolution was 10.8% and 3.3% for LSO and LaBr3 respectively and the coincidence window was set at 2 ns. The brain was simulated as a sphere of uniform F-18 activity with diameter of 10 cm embedded in a center of water sphere with diameter of 10 cm. Results: Analytical and Monte Carlo models showed similar results for lower energy window values (458 keV versus 445 keV for LSO, and 492 keV versus 485 keV for LaBr3), and for the relative performance of system sensitivity. Monte Carlo results further showed that the BET geometry had >50% better noise equivalent count (NEC) performance relative to the CYL geometry, and >1100% better performance than a WB

  2. Integral dynamical models singularities, signals and control

    CERN Document Server

    Sidorov, Denis

    2014-01-01

    This volume provides a broad introduction to nonlinear integral dynamical models and new classes of evolutionary integral equations. It may be used as an advanced textbook by postgraduate students to study integral dynamical models and their applications in machine learning, electrical and electronic engineering, operations research and image analysis. Contents:Introduction and OverviewVolterra Models of Evolving Dynamical Systems:Volterra Equations of the First Kind with Piecewise Continuous KernelsVolterra Matrix Equation of th

  3. Controlling ferrofluid permeability across the blood–brain barrier model

    International Nuclear Information System (INIS)

    In the present study, an in vitro blood–brain barrier model was developed using murine brain endothelioma cells (b.End3 cells). Confirmation of the blood–brain barrier model was completed by examining the permeability of FITC-Dextran at increasing exposure times up to 96 h in serum-free medium and comparing such values with values from the literature. After such confirmation, the permeability of five novel ferrofluid (FF) nanoparticle samples, GGB (ferrofluids synthesized using glycine, glutamic acid and BSA), GGC (glycine, glutamic acid and collagen), GGP (glycine, glutamic acid and PVA), BPC (BSA, PEG and collagen) and CPB (collagen, PVA and BSA), was determined using this blood–brain barrier model. All of the five FF samples were characterized by zeta potential to determine their charge as well as TEM and dynamic light scattering for determining their hydrodynamic diameter. Results showed that FF coated with collagen passed more easily through the blood–brain barrier than FF coated with glycine and glutamic acid based on an increase of 4.5% in permeability. Through such experiments, diverse magnetic nanomaterials (such as FF) were identified for: (1) MRI use since they were less permeable to penetrate the blood–brain barrier to avoid neural tissue toxicity (e.g. GGB) or (2) brain drug delivery since they were more permeable to the blood–brain barrier (e.g. CPB). (paper)

  4. Controlling ferrofluid permeability across the blood–brain barrier model.

    Science.gov (United States)

    Shi, Di; Sun, Linlin; Mi, Gujie; Sheikh, Lubna; Bhattacharya, Soumya; Nayar, Suprabha; Webster, Thomas J

    2014-02-21

    In the present study, an in vitro blood–brain barrier model was developed using murine brain endothelioma cells (b.End3 cells). Confirmation of the blood–brain barrier model was completed by examining the permeability of FITCDextran at increasing exposure times up to 96 h in serum-free medium and comparing such values with values from the literature. After such confirmation, the permeability of five novel ferrofluid (FF) nanoparticle samples, GGB (ferrofluids synthesized using glycine, glutamic acid and BSA), GGC (glycine, glutamic acid and collagen), GGP (glycine, glutamic acid and PVA), BPC (BSA, PEG and collagen) and CPB (collagen, PVA and BSA), was determined using this blood–brain barrier model. All of the five FF samples were characterized by zeta potential to determine their charge as well as TEM and dynamic light scattering for determining their hydrodynamic diameter. Results showed that FF coated with collagen passed more easily through the blood–brain barrier than FF coated with glycine and glutamic acid based on an increase of 4.5% in permeability. Through such experiments, diverse magnetic nanomaterials (such as FF) were identified for: (1) MRI use since they were less permeable to penetrate the blood–brain barrier to avoid neural tissue toxicity (e.g. GGB) or (2) brain drug delivery since they were more permeable to the blood–brain barrier (e.g. CPB). PMID:24457539

  5. Optically enhanced blood-brain-barrier crossing of plasmonic-active nanoparticles in preclinical brain tumor animal models

    Science.gov (United States)

    Yuan, Hsiangkuo; Wilson, Christy M.; Li, Shuqin; Fales, Andrew M.; Liu, Yang; Grant, Gerald; Vo-Dinh, Tuan

    2014-02-01

    Nanotechnology provides tremendous biomedical opportunities for cancer diagnosis, imaging, and therapy. In contrast to conventional chemotherapeutic agents where their actual target delivery cannot be easily imaged, integrating imaging and therapeutic properties into one platform facilitates the understanding of pharmacokinetic profiles, and enables monitoring of the therapeutic process in each individual. Such a concept dubbed "theranostics" potentiates translational research and improves precision medicine. One particular challenging application of theranostics involves imaging and controlled delivery of nanoplatforms across blood-brain-barrier (BBB) into brain tissues. Typically, the BBB hinders paracellular flux of drug molecules into brain parenchyma. BBB disrupting agents (e.g. mannitol, focused ultrasound), however, suffer from poor spatial confinement. It has been a challenge to design a nanoplatform not only acts as a contrast agent but also improves the BBB permeation. In this study, we demonstrated the feasibility of plasmonic gold nanoparticles as both high-resolution optical contrast agent and focalized tumor BBB permeation-inducing agent. We specifically examined the microscopic distribution of nanoparticles in tumor brain animal models. We observed that most nanoparticles accumulated at the tumor periphery or perivascular spaces. Nanoparticles were present in both endothelial cells and interstitial matrices. This study also demonstrated a novel photothermal-induced BBB permeation. Fine-tuning the irradiating energy induced gentle disruption of the vascular integrity, causing short-term extravasation of nanomaterials but without hemorrhage. We conclude that our gold nanoparticles are a powerful biocompatible contrast agent capable of inducing focal BBB permeation, and therefore envision a strong potential of plasmonic gold nanoparticle in future brain tumor imaging and therapy.

  6. Architectural view model for an integration platform

    Directory of Open Access Journals (Sweden)

    Tomasz Górski

    2012-03-01

    Full Text Available The most common architectural view model is "4+1" by Philipe Kruchten. This model presents the views required for a full description of computer system architecture. By contrast, this model seems to be insufficient to describe architecture of integration platform. Definitely lacks the view of integrated business processes. In the serviceoriented approach, one of the basic elements is a contract. It should also be included in the description of the architecture. Moreover, very important are integration mechanisms and mediation flows that should be presented in the description of architecture. Hence the need for integrated services view, and manner of their integration on the enterprise service bus. Use case view should also be extended by stereotypes required for presenting functionality exposed for other computer systems. It is therefore proposed architectural view model “1+5” for an integration platform. This model has following architectural views: Integrated processes, Use Cases, Logical, Integrated Services, Contracts, Deployment. Furthermore, in article was presented new UML profile "UML Profile for Integration Flows". In the profile were placed stereotypes corresponding to integration patterns and mediation mechanisms. It is important, that UML activity diagram was extended and its special form was obtained to model mediation flows on integration platform. Thus was proposed a new UML diagram: mediation flows diagram.

  7. Integrated Brain Circuits: Astrocytic Networks Modulate Neuronal Activity and Behavior

    Science.gov (United States)

    Halassa, Michael M.; Haydon, Philip G.

    2011-01-01

    The past decade has seen an explosion of research on roles of neuron-astrocyte interactions in the control of brain function. We highlight recent studies performed on the tripartite synapse, the structure consisting of pre- and postsynaptic elements of the synapse and an associated astrocytic process. Astrocytes respond to neuronal activity and neuro-transmitters, through the activation of metabotropic receptors, and can release the gliotransmitters ATP, D-serine, and glutamate, which act on neurons. Astrocyte-derived ATP modulates synaptic transmission, either directly or through its metabolic product adenosine. D-serine modulates NMDA receptor function, whereas glia-derived glutamate can play important roles in relapse following withdrawal from drugs of abuse. Cell type–specific molecular genetics has allowed a new level of examination of the function of astrocytes in brain function and has revealed an important role of these glial cells that is mediated by adenosine accumulation in the control of sleep and in cognitive impairments that follow sleep deprivation. PMID:20148679

  8. Modelling the current distribution across the depth electrode-brain interface in deep brain stimulation

    OpenAIRE

    Yousif, Nada; Liu, Xuguang

    2007-01-01

    The mismatch between the extensive clinical use of deep brain stimulation (DBS), which is being used to treat an increasing number of neurological disorders, and the lack of understanding of the underlying mechanisms, is confounded by the difficulty of measuring the spread of electric current in the brain in vivo. Here we present a brief review of the recent computational models which simulate the electric current and field distribution in the three-dimensional space, and consequently make es...

  9. Mesenchymal Stem Cells Regulate Blood Brain Barrier Integrity in Traumatic Brain Injury Through Production of the Soluble Factor TIMP3

    Science.gov (United States)

    Menge, Tyler; Zhao, Yuhai; Zhao, Jing; Wataha, Kathryn; Geber, Michael; Zhang, Jianhu; Letourneau, Phillip; Redell, John; Shen, Li; Wang, Jing; Peng, Zhalong; Xue, Hasen; Kozar, Rosemary; Cox, Charles S.; Khakoo, Aarif Y.; Holcomb, John B.; Dash, Pramod K.; Pati, Shibani

    2013-01-01

    Mesenchymal stem cells (MCSs) have been shown to have therapeutic potential in multiple disease states associated with vascular instability including traumatic brain injury (TBI). In the present study, Tissue Inhibitor of Matrix Metalloproteinase-3 (TIMP3) is identified as the soluble factor produced by MSCs that can recapitulate the beneficial effects of MSCs on endothelial function and blood brain barrier (BBB) compromise in TBI. Attenuation of TIMP3 expression in MSCs completely abrogates the effect of MSCs on BBB permeability and stability, while intravenous administration of rTIMP3 alone can inhibit BBB permeability in TBI. Our results demonstrate that MSCs increase circulating levels of soluble TIMP3, which inhibits VEGF-A induced breakdown of endothelial AJs in vitro and in vivo. These findings elucidate a clear molecular mechanism for the effects of MSCs on the BBB in TBI, and directly demonstrate a role for TIMP3 in regulation of BBB integrity. PMID:23175708

  10. Integrated spatial sampling modeling of geospatial data

    Institute of Scientific and Technical Information of China (English)

    LI; Lianfa; WANG; Jinfeng

    2004-01-01

    Spatial sampling is a necessary and important method for extracting geospatial data and its methodology directly affects the geo-analysis results. Counter to the deficiency of separate models of spatial sampling, this article analyzes three crucial elements of spatial sampling (frame, correlation and decision diagram) and induces its general integrated model. The program of Spatial Sampling Integration (SSI) has been developed with Component Object Model (COM) to realize the general integrated model. In two practical applications, i.e. design of the monitoring network of natural disasters and sampling survey of the areas of non-cultivated land, SSI has produced accurate results at less cost, better realizing the cost-effective goal of sampling toward the geo-objects with spatial correlation. The two cases exemplify expanded application and convenient implementation of the general integrated model with inset components in an integrated environment, which can also be extended to other modeling of spatial analysis.

  11. Comparing Bayesian models for multisensory cue combination without mandatory integration

    OpenAIRE

    Beierholm, Ulrik R.; Shams, Ladan; Kording, Konrad P; Ma, Wei Ji

    2009-01-01

    Bayesian models of multisensory perception traditionally address the problem of estimating an underlying variable that is assumed to be the cause of the two sensory signals. The brain, however, has to solve a more general problem: it also has to establish which signals come from the same source and should be integrated, and which ones do not and should be segregated. In the last couple of years, a few models have been proposed to solve this problem in a Bayesian fashion. One of these ha...

  12. An architecture for integration of multidisciplinary models

    DEFF Research Database (Denmark)

    Belete, Getachew F.; Voinov, Alexey; Holst, Niels

    2014-01-01

    Integrating multidisciplinary models requires linking models: that may operate at different temporal and spatial scales; developed using different methodologies, tools and techniques; different levels of complexity; calibrated for different ranges of inputs and outputs, etc. On the other hand, in...

  13. Finite element modeling of human brain response to football helmet impacts.

    Science.gov (United States)

    Darling, T; Muthuswamy, J; Rajan, S D

    2016-10-01

    The football helmet is used to help mitigate the occurrence of impact-related traumatic (TBI) and minor traumatic brain injuries (mTBI) in the game of American football. While the current helmet design methodology may be adequate for reducing linear acceleration of the head and minimizing TBI, it however has had less effect in minimizing mTBI. The objectives of this study are (a) to develop and validate a coupled finite element (FE) model of a football helmet and the human body, and (b) to assess responses of different regions of the brain to two different impact conditions - frontal oblique and crown impact conditions. The FE helmet model was validated using experimental results of drop tests. Subsequently, the integrated helmet-human body FE model was used to assess the responses of different regions of the brain to impact loads. Strain-rate, strain, and stress measures in the corpus callosum, midbrain, and brain stem were assessed. Results show that maximum strain-rates of 27 and 19 s(-1) are observed in the brain-stem and mid-brain, respectively. This could potentially lead to axonal injuries and neuronal cell death during crown impact conditions. The developed experimental-numerical framework can be used in the study of other helmet-related impact conditions. PMID:26867124

  14. Learning Computational Models of Video Memorability from fMRI Brain Imaging.

    Science.gov (United States)

    Han, Junwei; Chen, Changyuan; Shao, Ling; Hu, Xintao; Han, Jungong; Liu, Tianming

    2015-08-01

    Generally, various visual media are unequally memorable by the human brain. This paper looks into a new direction of modeling the memorability of video clips and automatically predicting how memorable they are by learning from brain functional magnetic resonance imaging (fMRI). We propose a novel computational framework by integrating the power of low-level audiovisual features and brain activity decoding via fMRI. Initially, a user study experiment is performed to create a ground truth database for measuring video memorability and a set of effective low-level audiovisual features is examined in this database. Then, human subjects' brain fMRI data are obtained when they are watching the video clips. The fMRI-derived features that convey the brain activity of memorizing videos are extracted using a universal brain reference system. Finally, due to the fact that fMRI scanning is expensive and time-consuming, a computational model is learned on our benchmark dataset with the objective of maximizing the correlation between the low-level audiovisual features and the fMRI-derived features using joint subspace learning. The learned model can then automatically predict the memorability of videos without fMRI scans. Evaluations on publically available image and video databases demonstrate the effectiveness of the proposed framework. PMID:25314715

  15. GABA regulates synaptic integration of newly generated neurons in the adult brain

    Science.gov (United States)

    Ge, Shaoyu; Goh, Eyleen L. K.; Sailor, Kurt A.; Kitabatake, Yasuji; Ming, Guo-Li; Song, Hongjun

    2006-02-01

    Adult neurogenesis, the birth and integration of new neurons from adult neural stem cells, is a striking form of structural plasticity and highlights the regenerative capacity of the adult mammalian brain. Accumulating evidence suggests that neuronal activity regulates adult neurogenesis and that new neurons contribute to specific brain functions. The mechanism that regulates the integration of newly generated neurons into the pre-existing functional circuitry in the adult brain is unknown. Here we show that newborn granule cells in the dentate gyrus of the adult hippocampus are tonically activated by ambient GABA (γ-aminobutyric acid) before being sequentially innervated by GABA- and glutamate-mediated synaptic inputs. GABA, the major inhibitory neurotransmitter in the adult brain, initially exerts an excitatory action on newborn neurons owing to their high cytoplasmic chloride ion content. Conversion of GABA-induced depolarization (excitation) into hyperpolarization (inhibition) in newborn neurons leads to marked defects in their synapse formation and dendritic development in vivo. Our study identifies an essential role for GABA in the synaptic integration of newly generated neurons in the adult brain, and suggests an unexpected mechanism for activity-dependent regulation of adult neurogenesis, in which newborn neurons may sense neuronal network activity through tonic and phasic GABA activation.

  16. Brain activity related to integrative processes in visual object recognition

    DEFF Research Database (Denmark)

    Gerlach, Christian; Aaside, C T; Humphreys, G W;

    2002-01-01

    involvement of re-entrant activation from stored structural knowledge. Evidence in favor of this interpretation comes from the additional finding that activation of the anterior part of the left fusiform gyrus and a more anterior part of the right inferior temporal gyrus, areas previously associated with......We report evidence from a PET activation study that the inferior occipital gyri (likely to include area V2) and the posterior parts of the fusiform and inferior temporal gyri are involved in the integration of visual elements into perceptual wholes (single objects). Of these areas, the fusiform and...... perceptual and memorial processes can be dissociated on both functional and anatomical grounds. No evidence was obtained for the involvement of the parietal lobes in the integration of single objects....

  17. Establishment of rat model of opening blood-brain barrier with conventional whole-brain irradiation

    International Nuclear Information System (INIS)

    Objective: To establish a rat model of opening blood-brain barrier with conventional whole-brain irradiation. Methods: According to different dosage of irradiation, a hundred Sprague-Dowley rats were randomly assigned into five groups, the control group (no irradiation), and four irradiated groups at 10 grays, 20 grays, 30 grays and 40 grays. The rats were administered to conventional fraction irradiation (2 Gy/day and 5 days a week) with routine 60Co gamma-rays. The intake of feed and autonomic activities were observed every day. Changes in skin and hair in the irradiated field, body weight, and center nervous system symptoms and signs were examined and recorded every week during irradiation. The neurological status was ranked on a scale based on the Mickley's Scale. Ultrastructure changes of blood-brain barrier at 16 hours after the last irradiation were examined with electron microscope using lanthanum trace labeling. Results: Neither abnormal nervous sign, nor change of feed intake, skin and hair was observed in all the rats. No statistically significant difference of body weight was observed among the five groups (P>0.05). The effect that radiation can directly damage the function and structure of blood-brain barrier was proportional to irradiation doses. Conclusion: This rat model is a suitable for study on blood-brain barrier pathophysiology and molecular biology after conventional whole-brain irradiation. (authors)

  18. Effects of Yishendaluo decoction on blood-brain barrier integrity in mice with experimental autoimmune encephalomyelitis

    Institute of Scientific and Technical Information of China (English)

    Yanqing Wu; Ying Gao; Lingqun Zhu; Yonghong Gao; Dongmei Zhang; Lixia Lou; Yanfang Yan

    2011-01-01

    This study investigated the effects of Yishendaluo decoction on the loss of blood-brain barrier integrity in mice exhibiting experimental autoimmune encephalomyelitis.To this end,we used real-time fluorescent quantitative PCR to measure the levels of mRNAs specific to the T cell markers CD4 and CD8,and the monocyte marker CD11b.In addition,we used Evans blue dye extravasation in the spinal cord and brain tissues to assess blood-brain barrier permeability.The results indicated that an increase in blood-brain barrier permeability was associated with an increase in CD4,CD8 and CD11b mRNA expression in experimental autoimmune encephalomyelitis mice.Yishendaluo decoction administration significantly reversed inflammatory cell accumulation in cerebral tissues of experimental autoimmune encephalomyelitis mice.

  19. A Bayesian model of category-specific emotional brain responses.

    Science.gov (United States)

    Wager, Tor D; Kang, Jian; Johnson, Timothy D; Nichols, Thomas E; Satpute, Ajay B; Barrett, Lisa Feldman

    2015-04-01

    Understanding emotion is critical for a science of healthy and disordered brain function, but the neurophysiological basis of emotional experience is still poorly understood. We analyzed human brain activity patterns from 148 studies of emotion categories (2159 total participants) using a novel hierarchical Bayesian model. The model allowed us to classify which of five categories--fear, anger, disgust, sadness, or happiness--is engaged by a study with 66% accuracy (43-86% across categories). Analyses of the activity patterns encoded in the model revealed that each emotion category is associated with unique, prototypical patterns of activity across multiple brain systems including the cortex, thalamus, amygdala, and other structures. The results indicate that emotion categories are not contained within any one region or system, but are represented as configurations across multiple brain networks. The model provides a precise summary of the prototypical patterns for each emotion category, and demonstrates that a sufficient characterization of emotion categories relies on (a) differential patterns of involvement in neocortical systems that differ between humans and other species, and (b) distinctive patterns of cortical-subcortical interactions. Thus, these findings are incompatible with several contemporary theories of emotion, including those that emphasize emotion-dedicated brain systems and those that propose emotion is localized primarily in subcortical activity. They are consistent with componential and constructionist views, which propose that emotions are differentiated by a combination of perceptual, mnemonic, prospective, and motivational elements. Such brain-based models of emotion provide a foundation for new translational and clinical approaches. PMID:25853490

  20. Brain/MINDS: brain-mapping project in Japan

    OpenAIRE

    Okano, Hideyuki; Miyawaki, Atsushi; Kasai, Kiyoto

    2015-01-01

    There is an emerging interest in brain-mapping projects in countries across the world, including the USA, Europe, Australia and China. In 2014, Japan started a brain-mapping project called Brain Mapping by Integrated Neurotechnologies for Disease Studies (Brain/MINDS). Brain/MINDS aims to map the structure and function of neuronal circuits to ultimately understand the vast complexity of the human brain, and takes advantage of a unique non-human primate animal model, the common marmoset (Calli...

  1. Development of a Model for Whole Brain Learning of Physiology

    Science.gov (United States)

    Eagleton, Saramarie; Muller, Anton

    2011-01-01

    In this report, a model was developed for whole brain learning based on Curry's onion model. Curry described the effect of personality traits as the inner layer of learning, information-processing styles as the middle layer of learning, and environmental and instructional preferences as the outer layer of learning. The model that was developed…

  2. MODELING DATA INTEGRITY UNDER STOCHASTIC LINEAR CONSTRAINTS

    Directory of Open Access Journals (Sweden)

    Lee-Pin Shing

    2015-06-01

    Full Text Available The most commonly used data integrity models today are Bibba, Wilson-Clark and Chinese models. These models are designed for both data integrity protection and confidentiality. Many optimization problems are related to linear programming. In practice, these variables involved are probabilistic. This paper proposes a data integrity model based on data anomalies assuming data are under stochastic linear constraints. An algorithm is constructed using the simplex method to find confidence intervals for the problem solutions. In the end the results from Monte Carlo simulation are compared with those from simplex method.

  3. Unitary Integrals and Related Matrix Models

    CERN Document Server

    Morozov, A

    2009-01-01

    Concise review of the basic properties of unitary matrix integrals. They are studied with the help of the three matrix models: the ordinary unitary model, Brezin-Gross-Witten model and the Harish-Charndra-Itzykson-Zuber model. Especial attention is paid to the tricky sides of the story, from De Wit-t'Hooft anomaly in unitary integrals to the problem of correlators with Itzykson-Zuber measure. Of technical tools emphasized is the method of character expansions. The subject of unitary integrals remains highly under-investigated and a lot of new results are expected in this field when it attracts sufficient attention.

  4. Integral models for buoyant plume calculations

    International Nuclear Information System (INIS)

    Integral models have been proven to be successful and inexpensive tools for the solution of a variety of jet-type environmental flow problems. In the Sonderforschungsbereich 80, a family of integral models has been developed for several applications as, e.g., the mixing of waste water and cooling water plumes discharged into lakes and coastal waters for the dispersion of pollutants and heat emitted by chimneys, cooling towers and urban heat islands into the atmosphere. The common features of these integral models are discussed. Finally, the quality of model results is demonstrated by comparing predictions with experimental data. (orig.)

  5. The INTEGRAL/IBIS telescope modelling

    OpenAIRE

    P. Laurent(CEA/DSM/IRFU, Centre de Saclay); Limousin, O.; Malaguti, G.; Caroli, E.; De Cesare, G.; Bird, A.J.; Grygorczuk, J.; Torrejon, J. M.

    2001-01-01

    The main objective of the IBIS modeling activities is the generation of the IBIS spectral response matrix. This generation will be done step by step by firstly constructing "calibrated model" of each IBIS sub-systems. A "calibrated model" is defined as a GEANT Monte-Carlo model, further checked by intensive corresponding calibration. These calibrated models will be in a second step integrated in the whole IBIS Mass Model. This Mass Model will be checked and refined using the data obtained dur...

  6. Alteration of blood-brain barrier integrity by retroviral infection.

    Directory of Open Access Journals (Sweden)

    Philippe V Afonso

    2008-11-01

    Full Text Available The blood-brain barrier (BBB, which forms the interface between the blood and the cerebral parenchyma, has been shown to be disrupted during retroviral-associated neuromyelopathies. Human T Lymphotropic Virus (HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP is a slowly progressive neurodegenerative disease associated with BBB breakdown. The BBB is composed of three cell types: endothelial cells, pericytes and astrocytes. Although astrocytes have been shown to be infected by HTLV-1, until now, little was known about the susceptibility of BBB endothelial cells to HTLV-1 infection and the impact of such an infection on BBB function. We first demonstrated that human cerebral endothelial cells express the receptors for HTLV-1 (GLUT-1, Neuropilin-1 and heparan sulfate proteoglycans, both in vitro, in a human cerebral endothelial cell line, and ex vivo, on spinal cord autopsy sections from HAM/TSP and non-infected control cases. In situ hybridization revealed HTLV-1 transcripts associated with the vasculature in HAM/TSP. We were able to confirm that the endothelial cells could be productively infected in vitro by HTLV-1 and that blocking of either HSPGs, Neuropilin 1 or Glut1 inhibits this process. The expression of the tight-junction proteins within the HTLV-1 infected endothelial cells was altered. These cells were no longer able to form a functional barrier, since BBB permeability and lymphocyte passage through the monolayer of endothelial cells were increased. This work constitutes the first report of susceptibility of human cerebral endothelial cells to HTLV-1 infection, with implications for HTLV-1 passage through the BBB and subsequent deregulation of the central nervous system homeostasis. We propose that the susceptibility of cerebral endothelial cells to retroviral infection and subsequent BBB dysfunction is an important aspect of HAM/TSP pathogenesis and should be considered in the design of future therapeutics strategies.

  7. Early Shifts of Brain Metabolism by Caloric Restriction Preserve White Matter Integrity and Long-Term Memory in Aging Mice

    OpenAIRE

    Janet eGuo; Vikas eBakshi; Ai-Ling eLin

    2015-01-01

    Preservation of brain integrity with age is highly associated with lifespan determination. Caloric restriction (CR) has been shown to increase longevity and healthspan in various species; however, its effects on preserving living brain functions in aging remain largely unexplored. In the study, we used multimodal, non-invasive neuroimaging (PET/MRI/MRS) to determine in vivo brain glucose metabolism, energy metabolites, and white matter structural integrity in young and old mice fed with eithe...

  8. MOS integrated circuit fault modeling

    Science.gov (United States)

    Sievers, M.

    1985-01-01

    Three digital simulation techniques for MOS integrated circuit faults were examined. These techniques embody a hierarchy of complexity bracketing the range of simulation levels. The digital approaches are: transistor-level, connector-switch-attenuator level, and gate level. The advantages and disadvantages are discussed. Failure characteristics are also described.

  9. Mobile Technology Integrated Pedagogical Model

    Science.gov (United States)

    Khan, Arshia

    2014-01-01

    Integrated curricula and experiential learning are the main ingredients to the recipe to improve student learning in higher education. In the academic computer science world it is mostly assumed that this experiential learning takes place at a business as an internship experience. The intent of this paper is to schism the traditional understanding…

  10. Large-scale in silico modeling of metabolic interactions between cell types in the human brain.

    Science.gov (United States)

    Lewis, Nathan E; Schramm, Gunnar; Bordbar, Aarash; Schellenberger, Jan; Andersen, Michael P; Cheng, Jeffrey K; Patel, Nilam; Yee, Alex; Lewis, Randall A; Eils, Roland; König, Rainer; Palsson, Bernhard Ø

    2010-12-01

    Metabolic interactions between multiple cell types are difficult to model using existing approaches. Here we present a workflow that integrates gene expression data, proteomics data and literature-based manual curation to model human metabolism within and between different types of cells. Transport reactions are used to account for the transfer of metabolites between models of different cell types via the interstitial fluid. We apply the method to create models of brain energy metabolism that recapitulate metabolic interactions between astrocytes and various neuron types relevant to Alzheimer's disease. Analysis of the models identifies genes and pathways that may explain observed experimental phenomena, including the differential effects of the disease on cell types and regions of the brain. Constraint-based modeling can thus contribute to the study and analysis of multicellular metabolic processes in the human tissue microenvironment and provide detailed mechanistic insight into high-throughput data analysis. PMID:21102456

  11. In vivo modeling and molecular characterization: a path towards targeted therapy of melanoma brain metastasis

    Directory of Open Access Journals (Sweden)

    AvitalGaziel-Sovran

    2013-05-01

    Full Text Available Brain metastasis from melanoma remains mostly incurable and the main cause of death from the disease. Early stage clinical trials and case studies show some promise for targeted therapies in the treatment of melanoma brain metastasis. However, the progression-free survival for currently available therapies, although significantly improved, is still very short. The development of new potent agents to eradicate melanoma brain metastasis relies on the elucidation of the molecular mechanisms that drive melanoma cells to reach and colonize the brain. The discovery of such mechanisms depends heavily on pre-clinical models that enable the testing of candidate factors and therapeutic agents in vivo. In this review we summarize the effects of available targeted therapies on melanoma brain metastasis in the clinic. We provide an overview of existing pre-clinical models to study the disease and discuss specific molecules and mechanisms reported to modulate different aspects of melanoma brain metastasis and finally, by integrating both clinical and basic data, we summarize both opportunities and challenges currently presented to researchers in the field.

  12. Using computational models to relate structural and functional brain connectivity

    Czech Academy of Sciences Publication Activity Database

    Hlinka, Jaroslav; Coombes, S.

    2012-01-01

    Roč. 36, č. 2 (2012), s. 2137-2145. ISSN 0953-816X R&D Projects: GA MŠk 7E08027 EU Projects: European Commission(XE) 200728 - BRAIN SYNC Institutional research plan: CEZ:AV0Z10300504 Keywords : brain disease * computational modelling * functional connectivity * graph theory * structural connectivity Subject RIV: FH - Neurology Impact factor: 3.753, year: 2012

  13. The Application of Integrated Knowledge-based Systems for the Biomedical Risk Assessment Intelligent Network (BRAIN)

    Science.gov (United States)

    Loftin, Karin C.; Ly, Bebe; Webster, Laurie; Verlander, James; Taylor, Gerald R.; Riley, Gary; Culbert, Chris; Holden, Tina; Rudisill, Marianne

    1993-01-01

    One of NASA's goals for long duration space flight is to maintain acceptable levels of crew health, safety, and performance. One way of meeting this goal is through the Biomedical Risk Assessment Intelligent Network (BRAIN), an integrated network of both human and computer elements. The BRAIN will function as an advisor to flight surgeons by assessing the risk of in-flight biomedical problems and recommending appropriate countermeasures. This paper describes the joint effort among various NASA elements to develop BRAIN and an Infectious Disease Risk Assessment (IDRA) prototype. The implementation of this effort addresses the technological aspects of the following: (1) knowledge acquisition; (2) integration of IDRA components; (3) use of expert systems to automate the biomedical prediction process; (4) development of a user-friendly interface; and (5) integration of the IDRA prototype and Exercise Countermeasures Intelligent System (ExerCISys). Because the C Language, CLIPS (the C Language Integrated Production System), and the X-Window System were portable and easily integrated, they were chosen as the tools for the initial IDRA prototype. The feasibility was tested by developing an IDRA prototype that predicts the individual risk of influenza. The application of knowledge-based systems to risk assessment is of great market value to the medical technology industry.

  14. Integrative Model of Drosophila Flight

    OpenAIRE

    Dickson, William B.; Andrew D Straw; Dickinson, Michael H

    2008-01-01

    This paper presents a framework for simulating the flight dynamics and control strategies of the fruit fly Drosophila melanogaster. The framework consists of five main components: an articulated rigid-body simulation, a model of the aerodynamic forces and moments, a sensory systems model, a control model, and an environment model. In the rigid-body simulation the fly is represented by a system of three rigid bodies connected by a pair of actuated ball joints. At each instant of th...

  15. New Experimental Model of Brain Tumors in Brains of Adult Immunocompetent Rats

    OpenAIRE

    Baklaushev, Vladimir P.; Kavsan, Vadym M.; Balynska, Olena V; Yusubalieva, Gaukhar M.; Abakumov, Maxim A.; Chekhonin, Vladimir P.

    2012-01-01

    Aims: Xenograft models, namely heterotransplantation of human cancer cells or tumor biopsies into immunodeficient rodents are the major preclinical approach for the development of novel cancer therapeutics. However, in these models the animals must be used only after the severe systemic immune suppression in order to ensure graft survival. Thus, additional new human brain tumor models without immune suppression of the recipient rodent may be required. Place and Duration of Study: Laboratory o...

  16. Drosophila melanogaster as a Model Organism of Brain Diseases

    OpenAIRE

    Werner Paulus; Astrid Jeibmann

    2009-01-01

    Drosophila melanogaster has been utilized to model human brain diseases. In most of these invertebrate transgenic models, some aspects of human disease are reproduced. Although investigation of rodent models has been of significant impact, invertebrate models offer a wide variety of experimental tools that can potentially address some of the outstanding questions underlying neurological disease. This review considers what has been gleaned from invertebrate models of neurodegenerative diseases...

  17. Social Outcomes in Childhood Brain Disorder: A Heuristic Integration of Social Neuroscience and Developmental Psychology

    Science.gov (United States)

    Yeates, Keith Owen; Bigler, Erin D.; Dennis, Maureen; Gerhardt, Cynthia A.; Rubin, Kenneth H.; Stancin, Terry; Taylor, H. Gerry; Vannatta, Kathryn

    2007-01-01

    The authors propose a heuristic model of the social outcomes of childhood brain disorder that draws on models and methods from both the emerging field of social cognitive neuroscience and the study of social competence in developmental psychology/psychopathology. The heuristic model characterizes the relationships between social adjustment, peer…

  18. Integrated climate and hydrology modelling

    DEFF Research Database (Denmark)

    Larsen, Morten Andreas Dahl

    global warming and increased frequency of extreme events. The skill in developing projections of both the present and future climate depends essentially on the ability to numerically simulate the processes of atmospheric circulation, hydrology, energy and ecology. Previous modelling efforts of climate...... existing climate and hydrology models to more directly include the interaction between the atmosphere and the land surface. The present PhD study is motivated by an ambition of developing and applying a modelling tool capable of including the interaction and feedback mechanisms between the atmosphere and...... the land surface. The modelling tool consists of a fully dynamic two-way coupling of the HIRHAM regional climate model and the MIKE SHE hydrological model. The expected gain is twofold. Firstly, HIRHAM utilizes the land surface component of the combined MIKE SHE/SWET hydrology and land surface model...

  19. Measurement of human blood brain barrier integrity using 11C-inulin and positron emission tomography

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) using 11C-inulin was demonstrated to be applicable to the clinical measurement of blood brain barrier permeability and cerebral interstitial fluid volume. Kinetic data were analyzed by application of a two compartment model, in which blood plasma and interstitial fluid spaces constitute the compartments. The blood activity contribution was subtracted from the PET count with the aid of the 11CO inhalation technique. The values we estimated in a human brain were in agreement with the reported values obtained for animal brains by the use of 14C-inulin. (orig.)

  20. Synthesis and deposition of basement membrane proteins by primary brain capillary endothelial cells in a murine model of the blood-brain barrier

    DEFF Research Database (Denmark)

    Thomsen, Maj Schneider; Birkelund, Svend; Burkhart, Annette;

    2016-01-01

    The brain vascular basement membrane is important for both blood-brain barrier (BBB) development, stability, and barrier integrity and the contribution hereto from brain capillary endothelial cells (BCECs), pericytes, and astrocytes of the BBB is probably significant. The aim of the present study......-culture, in co-culture with pericytes or mixed glial cells, or as a triple-culture with both pericytes and mixed glial cells. The integrity of the BBB models was validated by measures of transendothelial electrical resistance (TEER) and passive permeability to mannitol. The expression of basement membrane...... proteins was analysed using RT-qPCR, mass spectrometry, and immunocytochemistry. Co-culturing mBCECs with pericytes, mixed glial cells, or both significantly increased the TEER compared to the mono-culture, and a low passive permeability was correlated with high TEER. The mBCECs expressed all major...

  1. Social Ecological Model Analysis for ICT Integration

    Science.gov (United States)

    Zagami, Jason

    2013-01-01

    ICT integration of teacher preparation programmes was undertaken by the Australian Teaching Teachers for the Future (TTF) project in all 39 Australian teacher education institutions and highlighted the need for guidelines to inform systemic ICT integration approaches. A Social Ecological Model (SEM) was used to positively inform integration…

  2. Model Identification of Integrated ARMA Processes

    Science.gov (United States)

    Stadnytska, Tetiana; Braun, Simone; Werner, Joachim

    2008-01-01

    This article evaluates the Smallest Canonical Correlation Method (SCAN) and the Extended Sample Autocorrelation Function (ESACF), automated methods for the Autoregressive Integrated Moving-Average (ARIMA) model selection commonly available in current versions of SAS for Windows, as identification tools for integrated processes. SCAN and ESACF can…

  3. Calcium-activated potassium channels mediated blood-brain tumor barrier opening in a rat metastatic brain tumor model

    OpenAIRE

    2007-01-01

    Background The blood-brain tumor barrier (BTB) impedes the delivery of therapeutic agents to brain tumors. While adequate delivery of drugs occurs in systemic tumors, the BTB limits delivery of anti-tumor agents into brain metastases. Results In this study, we examined the function and regulation of calcium-activated potassium (KCa) channels in a rat metastatic brain tumor model. We showed that intravenous infusion of NS1619, a KCa channel agonist, and bradykinin selectively enhanced BTB perm...

  4. Data assimilation in integrated hydrological modelling

    DEFF Research Database (Denmark)

    Rasmussen, Jørn

    Integrated hydrological models are useful tools for water resource management and research, and advances in computational power and the advent of new observation types has resulted in the models generally becoming more complex and distributed. However, the models are often characterized by a high...... degree of parameterization which results in significant model uncertainty which cannot be reduced much due to observations often being scarce and often taking the form of point measurements. Data assimilation shows great promise for use in integrated hydrological models , as it allows for observations to...

  5. Creating physical 3D stereolithograph models of brain and skull.

    Directory of Open Access Journals (Sweden)

    Daniel J Kelley

    Full Text Available The human brain and skull are three dimensional (3D anatomical structures with complex surfaces. However, medical images are often two dimensional (2D and provide incomplete visualization of structural morphology. To overcome this loss in dimension, we developed and validated a freely available, semi-automated pathway to build 3D virtual reality (VR and hand-held, stereolithograph models. To evaluate whether surface visualization in 3D was more informative than in 2D, undergraduate students (n = 50 used the Gillespie scale to rate 3D VR and physical models of both a living patient-volunteer's brain and the skull of Phineas Gage, a historically famous railroad worker whose misfortune with a projectile tamping iron provided the first evidence of a structure-function relationship in brain. Using our processing pathway, we successfully fabricated human brain and skull replicas and validated that the stereolithograph model preserved the scale of the VR model. Based on the Gillespie ratings, students indicated that the biological utility and quality of visual information at the surface of VR and stereolithograph models were greater than the 2D images from which they were derived. The method we developed is useful to create VR and stereolithograph 3D models from medical images and can be used to model hard or soft tissue in living or preserved specimens. Compared to 2D images, VR and stereolithograph models provide an extra dimension that enhances both the quality of visual information and utility of surface visualization in neuroscience and medicine.

  6. Classical Wave Model of Quantum-Like Processing in Brain

    Science.gov (United States)

    Khrennikov, A.

    2011-01-01

    We discuss the conjecture on quantum-like (QL) processing of information in the brain. It is not based on the physical quantum brain (e.g., Penrose) - quantum physical carriers of information. In our approach the brain created the QL representation (QLR) of information in Hilbert space. It uses quantum information rules in decision making. The existence of such QLR was (at least preliminary) confirmed by experimental data from cognitive psychology. The violation of the law of total probability in these experiments is an important sign of nonclassicality of data. In so called "constructive wave function approach" such data can be represented by complex amplitudes. We presented 1,2 the QL model of decision making. In this paper we speculate on a possible physical realization of QLR in the brain: a classical wave model producing QLR . It is based on variety of time scales in the brain. Each pair of scales (fine - the background fluctuations of electromagnetic field and rough - the cognitive image scale) induces the QL representation. The background field plays the crucial role in creation of "superstrong QL correlations" in the brain.

  7. Generalized Cauchy's Models and Generalized Integrals

    OpenAIRE

    Sabra Ramadan

    2007-01-01

    The space of generalized complex numbers C* has been constructed. The Cachy's model in the space of new generalized functions is well defined. The generalized integral of new generalized function over the compact K has been defined.

  8. Generalized Cauchy's Models and Generalized Integrals

    Directory of Open Access Journals (Sweden)

    Sabra Ramadan

    2007-01-01

    Full Text Available The space of generalized complex numbers C* has been constructed. The Cachy's model in the space of new generalized functions is well defined. The generalized integral of new generalized function over the compact K has been defined.

  9. Integrated modelling in materials and process technology

    DEFF Research Database (Denmark)

    Hattel, Jesper Henri

    2008-01-01

    Integrated modelling of entire process sequences and the subsequent in-service conditions, and multiphysics modelling of the single process steps are areas that increasingly support optimisation of manufactured parts. In the present paper, three different examples of modelling manufacturing proce...

  10. Formulating multicellular models of metabolism in tissues: application to energy metabolism in the human brain

    OpenAIRE

    Lewis, Nathan E.; Schramm, Gunnar; Bordbar, Aarash; Schellenberger, Jan; Andersen, Michael Paul; Cheng, Jeffrey K.; Patel, Nilam; Yee, Alex; Lewis, Randall A.; Eils, Roland; König, Rainer; Palsson, Bernhard Ø.

    2010-01-01

    A workflow is presented that integrates gene expression data, proteomic data, and literature-based manual curation to construct multicellular, tissue-specific models of human brain energy metabolism that recapitulate metabolic interactions between astrocytes and various neuron types. Three analyses are applied for gene identification, analysis of omics data, and analysis of physiological states. First, we identify glutamate decarboxylase as a target that may contribute to cell-type and region...

  11. Evaluation of cat brain infarction model using microPET

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Jin; Lee, Dong Soo; Kim, Yun Hui; Hwang, Do Won; Kim, Jin Su; Chung, June Key; Lee, Myung Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of); Lim, Sang Moo [Korea Institite of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2004-12-01

    PET has some disadvantage in the imaging of small animal due to poor resolution. With the advent of microPET scanner, it is possible to image small animals. However, the image quality was not good enough as human image. Due to larger brain, cat brain imaging was superior to mouse or rat. In this study, we established the cat brain infarction model and evaluate it and its temporal change using microPET scanner. Two adult male cats were used. Anesthesia was done with xylazine and ketamine HCI. A burr hole was made at 1 cm right lateral to the bregma. Collagenase type IV 10 {mu}l was injected using 30 G needle for 5 minutes to establish the infarction model. {sup 18}F-FDG microPET (Concorde Microsystems Inc., Knoxville, TN) scans were performed 1, 11 and 32 days after the infarction. In addition, {sup 18}F-FDG PET scans were performed using human PET scanner (Gemini, Philips medical systems, CA, USA) 13 and 47 days after the infarction. Two cat brain infarction models were established. The glucose metabolism of an infarction lesion improved with time. An infarction lesion was also distinguishable in the human PET scan. We successfully established the cat brain infarction model and evaluated the infarcted lesion and its temporal change using {sup 18}F-FDG microPET scanner.

  12. Evaluation of cat brain infarction model using microPET

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. J.; Lee, D. S.; Kim, J. H.; Hwang, D. W.; Jung, J. G.; Lee, M. C [College of Medicine, Seoul National University, Seoul (Korea, Republic of); Lim, S. M [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2004-07-01

    PET has some disadvantage in the imaging of small animal due to poor resolution. With the advance of microPET scanner, it is possible to image small animals. However, the image quality was not so much satisfactory as human image. As cats have relatively large sized brain, cat brain imaging was superior to mice or rat. In this study, we established the cat brain infarction model and evaluate it and its temporal change using microPET scanner. Two adult male cats were used. Anesthesia was done with xylazine and ketamine HCl. A burr hole was made at 1cm right lateral to the bregma. Collagenase type IV 10 ul was injected using 30G needle for 5 minutes to establish the infarction model. F-18 FDG microPET (Concorde Microsystems Inc., Knoxville. TN) scans were performed 1. 11 and 32 days after the infarction. In addition. 18F-FDG PET scans were performed using Gemini PET scanner (Philips medical systems. CA, USA) 13 and 47 days after the infarction. Two cat brain infarction models were established. The glucose metabolism of an infraction lesion improved with time. An infarction lesion was also distinguishable in the Gemini PET scan. We successfully established the cat brain infarction model and evaluated the infarcted lesion and its temporal change using F-18 FDG microPET scanner.

  13. Evaluation of cat brain infarction model using microPET

    International Nuclear Information System (INIS)

    PET has some disadvantage in the imaging of small animal due to poor resolution. With the advent of microPET scanner, it is possible to image small animals. However, the image quality was not good enough as human image. Due to larger brain, cat brain imaging was superior to mouse or rat. In this study, we established the cat brain infarction model and evaluate it and its temporal change using microPET scanner. Two adult male cats were used. Anesthesia was done with xylazine and ketamine HCI. A burr hole was made at 1 cm right lateral to the bregma. Collagenase type IV 10 μl was injected using 30 G needle for 5 minutes to establish the infarction model. 18F-FDG microPET (Concorde Microsystems Inc., Knoxville, TN) scans were performed 1, 11 and 32 days after the infarction. In addition, 18F-FDG PET scans were performed using human PET scanner (Gemini, Philips medical systems, CA, USA) 13 and 47 days after the infarction. Two cat brain infarction models were established. The glucose metabolism of an infarction lesion improved with time. An infarction lesion was also distinguishable in the human PET scan. We successfully established the cat brain infarction model and evaluated the infarcted lesion and its temporal change using 18F-FDG microPET scanner

  14. A Measure for Brain Complexity: Relating Functional Segregation and Integration in the Nervous System

    Science.gov (United States)

    Tononi, Giulio; Sporns, Olaf; Edelman, Gerald M.

    1994-05-01

    In brains of higher vertebrates, the functional segregation of local areas that differ in their anatomy and physiology contrasts sharply with their global integration during perception and behavior. In this paper, we introduce a measure, called neural complexity (C_N), that captures the interplay between these two fundamental aspects of brain organization. We express functional segregation within a neural system in terms of the relative statistical independence of small subsets of the system and functional integration in terms of significant deviations from independence of large subsets. C_N is then obtained from estimates of the average deviation from statistical independence for subsets of increasing size. C_N is shown to be high when functional segregation coexists with integration and to be low when the components of a system are either completely independent (segregated) or completely dependent (integrated). We apply this complexity measure in computer simulations of cortical areas to examine how some basic principles of neuroanatomical organization constrain brain dynamics. We show that the connectivity patterns of the cerebral cortex, such as a high density of connections, strong local connectivity organizing cells into neuronal groups, patchiness in the connectivity among neuronal groups, and prevalent reciprocal connections, are associated with high values of C_N. The approach outlined here may prove useful in analyzing complexity in other biological domains such as gene regulation and embryogenesis.

  15. Integrable lattice models and quantum groups

    International Nuclear Information System (INIS)

    These lectures aim at introducing some basic algebraic concepts on lattice integrable models, in particular quantum groups, and to discuss some connections with knot theory and conformal field theories. The list of contents is: Vertex models and Yang-Baxter equation; Quantum sl(2) algebra and the Yang-Baxter equation; Uq sl(2) as a symmetry of statistical mechanical models; Face models; Face models attached to graphs; Yang-Baxter equation, braid group and link polynomials

  16. Modelling Brain Tissue using Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Dyrby, Tim Bjørn

    2008-01-01

    an ongoing chemical reaction due to the fixative used. Short-term instabilities within the first 15 hours of DWI scanning were observed and found likely to be caused by the preparation of the postmortem tissue prior to MR scanning. This artefact can be avoided e.g. by simply excluding DW......Diffusion MRI, or diffusion weighted imaging (DWI), is a technique that measures the restricted diffusion of water molecules within brain tissue. Different reconstruction methods quantify water-diffusion anisotropy in the intra- and extra-cellular spaces of the neural environment. Fibre tracking...... environment differs from that of in vivo both due to a lowered environmental temperature and due to the fixation process itself. We argue that the perfusion fixation procedure employed in this thesis ensures that the postmortem tissue is as close to that of in vivo as possible. Different fibre reconstruction...

  17. Data-driven forward model inference for EEG brain imaging

    DEFF Research Database (Denmark)

    Hansen, Sofie Therese; Hauberg, Søren; Hansen, Lars Kai

    2016-01-01

    Electroencephalography (EEG) is a flexible and accessible tool with excellent temporal resolution but with a spatial resolution hampered by volume conduction. Reconstruction of the cortical sources of measured EEG activity partly alleviates this problem and effectively turns EEG into a brain......-of-concept study, we show that, even when anatomical knowledge is unavailable, a suitable forward model can be estimated directly from the EEG. We propose a data-driven approach that provides a low-dimensional parametrization of head geometry and compartment conductivities, built using a corpus of forward models....... Combined with only a recorded EEG signal, we are able to estimate both the brain sources and a person-specific forward model by optimizing this parametrization. We thus not only solve an inverse problem, but also optimize over its specification. Our work demonstrates that personalized EEG brain imaging...

  18. The Gold Coast Integrated Care Model

    OpenAIRE

    Connor, Martin; Cooper, Helen; McMurray, Anne

    2016-01-01

    This article outlines the development of the Australian Gold Coast Integrated Care Model based on the elements identified in contemporary research literature as essential for successful integration of care between primary care, and acute hospital services. The objectives of the model are to proactively manage high risk patients with complex and chronic conditions in collaboration with General Practitioners to ultimately reduce presentations to the health service emergency department, improve ...

  19. Resolving structural variability in network models and the brain.

    Directory of Open Access Journals (Sweden)

    Florian Klimm

    2014-03-01

    Full Text Available Large-scale white matter pathways crisscrossing the cortex create a complex pattern of connectivity that underlies human cognitive function. Generative mechanisms for this architecture have been difficult to identify in part because little is known in general about mechanistic drivers of structured networks. Here we contrast network properties derived from diffusion spectrum imaging data of the human brain with 13 synthetic network models chosen to probe the roles of physical network embedding and temporal network growth. We characterize both the empirical and synthetic networks using familiar graph metrics, but presented here in a more complete statistical form, as scatter plots and distributions, to reveal the full range of variability of each measure across scales in the network. We focus specifically on the degree distribution, degree assortativity, hierarchy, topological Rentian scaling, and topological fractal scaling--in addition to several summary statistics, including the mean clustering coefficient, the shortest path-length, and the network diameter. The models are investigated in a progressive, branching sequence, aimed at capturing different elements thought to be important in the brain, and range from simple random and regular networks, to models that incorporate specific growth rules and constraints. We find that synthetic models that constrain the network nodes to be physically embedded in anatomical brain regions tend to produce distributions that are most similar to the corresponding measurements for the brain. We also find that network models hardcoded to display one network property (e.g., assortativity do not in general simultaneously display a second (e.g., hierarchy. This relative independence of network properties suggests that multiple neurobiological mechanisms might be at play in the development of human brain network architecture. Together, the network models that we develop and employ provide a potentially useful

  20. Efficient numerical integrators for stochastic models

    CERN Document Server

    De Fabritiis, G; Español, P; Coveney, P V

    2006-01-01

    The efficient simulation of models defined in terms of stochastic differential equations (SDEs) depends critically on an efficient integration scheme. In this article, we investigate under which conditions the integration schemes for general SDEs can be derived using the Trotter expansion. It follows that, in the stochastic case, some care is required in splitting the stochastic generator. We test the Trotter integrators on an energy-conserving Brownian model and derive a new numerical scheme for dissipative particle dynamics. We find that the stochastic Trotter scheme provides a mathematically correct and easy-to-use method which should find wide applicability.

  1. Causation model of autism: Audiovisual brain specialization in infancy competes with social brain networks.

    Science.gov (United States)

    Heffler, Karen Frankel; Oestreicher, Leonard M

    2016-06-01

    Earliest identifiable findings in autism indicate that the autistic brain develops differently from the typical brain in the first year of life, after a period of typical development. Twin studies suggest that autism has an environmental component contributing to causation. Increased availability of audiovisual (AV) materials and viewing practices of infants parallel the time frame of the rise in prevalence of autism spectrum disorder (ASD). Studies have shown an association between ASD and increased TV/cable screen exposure in infancy, suggesting AV exposure in infancy as a possible contributing cause of ASD. Infants are attracted to the saliency of AV materials, yet do not have the experience to recognize these stimuli as socially relevant. The authors present a developmental model of autism in which exposure to screen-based AV input in genetically susceptible infants stimulates specialization of non-social sensory processing in the brain. Through a process of neuroplasticity, the autistic infant develops the skills that are driven by the AV viewing. The AV developed neuronal pathways compete with preference for social processing, negatively affecting development of social brain pathways and causing global developmental delay. This model explains atypical face and speech processing, as well as preference for AV synchrony over biological motion in ASD. Neural hyper-connectivity, enlarged brain size and special abilities in visual, auditory and motion processing in ASD are also explained by the model. Positive effects of early intervention are predicted by the model. Researchers studying causation of autism have largely overlooked AV exposure in infancy as a potential contributing factor. The authors call for increased public awareness of the association between early screen viewing and ASD, and a concerted research effort to determine the extent of causal relationship. PMID:26146132

  2. Misconceptions and Misattributions About Traumatic Brain Injury: An Integrated Conceptual Framework.

    Science.gov (United States)

    Block, Cady K; West, Sarah E; Goldin, Yelena

    2016-01-01

    The objective of the present narrative review was to provide a conceptual framework to address common misconceptions in the field of traumatic brain injury (TBI) and enhance clinical and research practices. This framework is based on review of the literature on TBI knowledge and beliefs. The comprehensive search of the literature included seminal and current texts as well as relevant articles on TBI knowledge and education, misconceptions, and misattributions. Reviewed materials ranged from 1970 to 2013 and were obtained from PubMed and PubMed Central online research databases. Research findings from the reviewed literature were integrated with existing social and cognitive psychological concepts to develop a framework that includes: (1) the identification antecedents of TBI-related misconceptions and misattribution; (2) understanding of how inaccurate beliefs form and persist as the result of pre- and postinjury cognitive operations such as informational cascades and attribution biases; and (3) a discussion of ways in which these beliefs can result in consequences in all domains of a survivor's life, including physical and mental health, stigma, and discrimination. This framework is intended to serve as a first stage of development of a model that will improve treatment endeavors and service delivery to individuals with TBI and their families. PMID:26054960

  3. Ontology modeling in physical asset integrity management

    CERN Document Server

    Yacout, Soumaya

    2015-01-01

    This book presents cutting-edge applications of, and up-to-date research on, ontology engineering techniques in the physical asset integrity domain. Though a survey of state-of-the-art theory and methods on ontology engineering, the authors emphasize essential topics including data integration modeling, knowledge representation, and semantic interpretation. The book also reflects novel topics dealing with the advanced problems of physical asset integrity applications such as heterogeneity, data inconsistency, and interoperability existing in design and utilization. With a distinctive focus on applications relevant in heavy industry, Ontology Modeling in Physical Asset Integrity Management is ideal for practicing industrial and mechanical engineers working in the field, as well as researchers and graduate concerned with ontology engineering in physical systems life cycles. This book also: Introduces practicing engineers, research scientists, and graduate students to ontology engineering as a modeling techniqu...

  4. Inferring brain-computational mechanisms with models of activity measurements.

    Science.gov (United States)

    Kriegeskorte, Nikolaus; Diedrichsen, Jörn

    2016-10-01

    High-resolution functional imaging is providing increasingly rich measurements of brain activity in animals and humans. A major challenge is to leverage such data to gain insight into the brain's computational mechanisms. The first step is to define candidate brain-computational models (BCMs) that can perform the behavioural task in question. We would then like to infer which of the candidate BCMs best accounts for measured brain-activity data. Here we describe a method that complements each BCM by a measurement model (MM), which simulates the way the brain-activity measurements reflect neuronal activity (e.g. local averaging in functional magnetic resonance imaging (fMRI) voxels or sparse sampling in array recordings). The resulting generative model (BCM-MM) produces simulated measurements. To avoid having to fit the MM to predict each individual measurement channel of the brain-activity data, we compare the measured and predicted data at the level of summary statistics. We describe a novel particular implementation of this approach, called probabilistic representational similarity analysis (pRSA) with MMs, which uses representational dissimilarity matrices (RDMs) as the summary statistics. We validate this method by simulations of fMRI measurements (locally averaging voxels) based on a deep convolutional neural network for visual object recognition. Results indicate that the way the measurements sample the activity patterns strongly affects the apparent representational dissimilarities. However, modelling of the measurement process can account for these effects, and different BCMs remain distinguishable even under substantial noise. The pRSA method enables us to perform Bayesian inference on the set of BCMs and to recognize the data-generating model in each case.This article is part of the themed issue 'Interpreting BOLD: a dialogue between cognitive and cellular neuroscience'. PMID:27574316

  5. Animal models of brain maldevelopment induced by cycad plant genotoxins.

    Science.gov (United States)

    Kisby, Glen E; Moore, Holly; Spencer, Peter S

    2013-12-01

    Cycads are long-lived tropical and subtropical plants that contain azoxyglycosides (e.g., cycasin, macrozamin) and neurotoxic amino acids (notably β-N-methylamino-l-alanine l-BMAA), toxins that have been implicated in the etiology of a disappearing neurodegenerative disease, amyotrophic lateral sclerosis and parkinsonism-dementia complex that has been present in high incidence among three genetically distinct populations in the western Pacific. The neuropathology of amyotrophic lateral sclerosis/parkinsonism-dementia complex includes features suggestive of brain maldevelopment, an experimentally proven property of cycasin attributable to the genotoxic action of its aglycone methylazoxymethanol (MAM). This property of MAM has been exploited by neurobiologists as a tool to study perturbations of brain development. Depending on the neurodevelopmental stage, MAM can induce features in laboratory animals that model certain characteristics of epilepsy, schizophrenia, or ataxia. Studies in DNA repair-deficient mice show that MAM perturbs brain development through a DNA damage-mediated mechanism. The brain DNA lesions produced by systemic MAM appear to modulate the expression of genes that regulate neurodevelopment and contribute to neurodegeneration. Epigenetic changes (histone lysine methylation) have also been detected in the underdeveloped brain after MAM administration. The DNA damage and epigenetic changes produced by MAM and, perhaps by chemically related substances (e.g., nitrosamines, nitrosoureas, hydrazines), might be an important mechanism by which early-life exposure to genotoxicants can induce long-term brain dysfunction. PMID:24339036

  6. Dynamic description logic model for data integration

    Institute of Scientific and Technical Information of China (English)

    Guoshun HAO; Shilong MA; Yuefei SUI; Jianghua LV

    2008-01-01

    Data integration is the issue of retrieving and combining data residing at distributed and heterogeneous sources,and of providing users with transparent access without being aware of the details of the sources.Data integration is a very important issue because it deals with data infrastructure issues of coordinated computing systems.Despite its importance,the following key challenges make data integration one of the longest standing problems around:1) how to solve the system heterogeneity;2) how to build a global model;3) how to process queries automatically and correctly;and 4) how to solve semantic heterogeneity. This paper presents an extended dynamic description logic language to describe systems with dynamic actions.By this language,a-universal and unified model for relational database systems and a model for data integration are presented.This paper presents a universal and unified description logic model for relational databases.The model is universal because any relational database system can be automatically transformed to the model;it is unified because it integrates three essential components of relational databases together:description logic knowledge bases modeling the relational data,atomic modalities modeling the atomic relational operations,and combined modalities modeling the combined relational operations-queries. Furthermore,a description logic model for data integration is proposed which contains four layers of ontologies.Based on the model,a solution for each key challenge is proposed:a universal model eliminates system heterogeneity;a novel global model including three ontologies is proposed with some important benefits;a query process mechanism is provided by which user queries can be decomposed to queries over the sources;and for solving the semantic heterogeneity,this paper provides a framework under which semantic relations can be expressed and inferred. In summary,this paper presents a dynamic knowledge base framework by an extended

  7. Integrated modeling of European migration

    OpenAIRE

    Raymer, James; Wiśniowski, Arkadiusz; Forster, Jonathan J.; Smith, Peter W F; BIJAK, Jakub

    2013-01-01

    International migration data in Europe are collected by individual countries with separate collection systems and designs. As a result, reported data are inconsistent in availability, definition and quality. In this paper, we propose a Bayesian model to overcome the limitations of the various data sources. The focus is on estimating recent international migration flows amongst 31 countries in the European Union and European Free Trade Association from 2002 to 2008, using data collated by Euro...

  8. Integrated Semiconductor Optical Sensors for Chronic, Minimally-Invasive Imaging of Brain Function

    OpenAIRE

    Lee, Thomas T.; Levi, Ofer; Cang, Jianhua; Kaneko, Megumi; Stryker, Michael P.; Smith, Stephen J; Shenoy, Krishna V.; Harris, James S.

    2006-01-01

    Intrinsic Optical Signal (IOS) imaging is a widely accepted technique for imaging brain activity. We propose an integrated device consisting of interleaved arrays of gallium arsenide (GaAs) based semiconductor light sources and detectors operating at telecommunications wavelengths in the near-infrared. Such a device will allow for long-term, minimally invasive monitoring of neural activity in freely behaving subjects, and will enable the use of structured illumination patterns to improve syst...

  9. Penn State -Cornell Integrated Assessment Model

    OpenAIRE

    Barron, Eric; Chapman, Duane; Khanna, Neha; Adam Z. Rose; Schultz, Peter A.; Kasting, James F.

    1996-01-01

    In the past decade dynamic geoeconomic climate modelling has been successful in integrating basic relations in macroeconomic growth and climatology. Now physical scientists and economists at The Penn State University and Cornell University propose to link transient annual climate modelling with the greenhouse gas emissions resulting from a macroeconomic-energy model. In climatological terminology, this is a 3-dimensional General Circulation Model with detailed time and geographic data at the ...

  10. A porcine model of haematogenous brain infectionwith staphylococcus aureus

    DEFF Research Database (Denmark)

    Astrup, Lærke Boye; Agerholm, Jørgen Steen; Nielsen, Ole Lerberg;

    2012-01-01

    A PORCINE MODEL OF HAEMATOGENOUS BRAIN INFECTION WITH STAPHYLOCOCCUS AUREUS Astrup Lærke1, Agerholm Jørgen1, Nielsen Ole1, Jensen Henrik1, Leifsson Páll1, Iburg Tine2. 1: Faculty of Health and Medical Sciences, University of Copenhagen, Denmark boye@life.ku.dk 2: National Veterinary Institute......, Uppsala, Sweden Introduction Staphylococcus aureus (S.aureus) is a common cause of sepsis and brain abscesses in man and a frequent cause of porcine pyaemia. Here we present a porcine model of haematogenous S. aureus-induced brain infection. Materials and Methods Four pigs had two intravenous catheters...... inserted surgically, one in a. carotis communis and one in v. jugularis externa. All pigs received 106 CFU/kg body weight S. aureus through the arterial catheter. Bacteria were either suspended in isotonic saline infused at constant flow for 60 minutes (two pigs) or given as a bolus injection of autologoue...

  11. Research on an Integrated Enterprise Workflow Model

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    An integrated enterprise workflow model called PPROCE is presented firstly. Then, an enterprise's ontology established by TOVE and Process Specification Language (PSL) is studied. Combined with TOVE's partition idea, PSL is extended and new PSL Extensions is created to define the ontology of process, organization, resource and product in the PPROCE model. As a result, PPROCE model can be defined by a set of corresponding formal language. It facilitates the future work not only in the model verification, model optimization and model simulation, but also in the model translation.

  12. Scaffold and stem cell based modeling of brain disease

    OpenAIRE

    Karpiak, Jerome V.

    2016-01-01

    Cellular models of brain disease involve genetic modulation, geometric patterning, neurophysiologic monitoring and analyses of both primary and immortalized cell lines. Additionally, recent neurological disease models often necessitate in vitro directed differentiation and maturation of human stem cell lines. To advance human stem cell based neural disease models within this evolving field, adaptive approaches of progressive complexity are essential. First, I invented an adaptable 3D laminar ...

  13. Animal models of focal brain ischemia

    OpenAIRE

    Sicard Kenneth M; Fisher Marc

    2009-01-01

    Abstract Stroke is a leading cause of disability and death in many countries. Understanding the pathophysiology of ischemic injury and developing therapies is an important endeavor that requires much additional research. Animal stroke models provide an important mechanism for these activities. A large number of stroke models have been developed and are currently used in laboratories around the world. These models are overviewed as are approaches for measuring infarct size and functional outcome.

  14. Postnatal experiences influence how the brain integrates information from different senses

    Directory of Open Access Journals (Sweden)

    Benjamin A Rowland

    2009-09-01

    Full Text Available Sensory Processing Disorder (SPD is characterized by anomalous reactions to, and integration of, sensory cues. Although the underlying etiology of SPD is unknown, one brain region likely to reflect these sensory and behavioral anomalies is the Superior Colliculus (SC; a structure involved in the synthesis of information from multiple sensory modalities and the control of overt orientation responses. In this review we describe normal functional properties of this structure, the manner in which its individual neurons integrate cues from different senses, and the overt SC-mediated behaviors that are believed to manifest this “multisensory integration.” Of particular interest here is how SC neurons develop their capacity to engage in multisensory integration during early postnatal life as a consequence of early sensory experience, and that it is the intimate communication between cortex and the midbrain makes this developmental process possible.

  15. Identification of Differentially Expressed Genes through Integrated Study of Alzheimer’s Disease Affected Brain Regions

    Science.gov (United States)

    Berretta, Regina; Moscato, Pablo

    2016-01-01

    Background Alzheimer’s disease (AD) is the most common form of dementia in older adults that damages the brain and results in impaired memory, thinking and behaviour. The identification of differentially expressed genes and related pathways among affected brain regions can provide more information on the mechanisms of AD. In the past decade, several studies have reported many genes that are associated with AD. This wealth of information has become difficult to follow and interpret as most of the results are conflicting. In that case, it is worth doing an integrated study of multiple datasets that helps to increase the total number of samples and the statistical power in detecting biomarkers. In this study, we present an integrated analysis of five different brain region datasets and introduce new genes that warrant further investigation. Methods The aim of our study is to apply a novel combinatorial optimisation based meta-analysis approach to identify differentially expressed genes that are associated to AD across brain regions. In this study, microarray gene expression data from 161 samples (74 non-demented controls, 87 AD) from the Entorhinal Cortex (EC), Hippocampus (HIP), Middle temporal gyrus (MTG), Posterior cingulate cortex (PC), Superior frontal gyrus (SFG) and visual cortex (VCX) brain regions were integrated and analysed using our method. The results are then compared to two popular meta-analysis methods, RankProd and GeneMeta, and to what can be obtained by analysing the individual datasets. Results We find genes related with AD that are consistent with existing studies, and new candidate genes not previously related with AD. Our study confirms the up-regualtion of INFAR2 and PTMA along with the down regulation of GPHN, RAB2A, PSMD14 and FGF. Novel genes PSMB2, WNK1, RPL15, SEMA4C, RWDD2A and LARGE are found to be differentially expressed across all brain regions. Further investigation on these genes may provide new insights into the development of AD

  16. Brain network analysis: separating cost from topology using cost-integration.

    Directory of Open Access Journals (Sweden)

    Cedric E Ginestet

    Full Text Available A statistically principled way of conducting brain network analysis is still lacking. Comparison of different populations of brain networks is hard because topology is inherently dependent on wiring cost, where cost is defined as the number of edges in an unweighted graph. In this paper, we evaluate the benefits and limitations associated with using cost-integrated topological metrics. Our focus is on comparing populations of weighted undirected graphs that differ in mean association weight, using global efficiency. Our key result shows that integrating over cost is equivalent to controlling for any monotonic transformation of the weight set of a weighted graph. That is, when integrating over cost, we eliminate the differences in topology that may be due to a monotonic transformation of the weight set. Our result holds for any unweighted topological measure, and for any choice of distribution over cost levels. Cost-integration is therefore helpful in disentangling differences in cost from differences in topology. By contrast, we show that the use of the weighted version of a topological metric is generally not a valid approach to this problem. Indeed, we prove that, under weak conditions, the use of the weighted version of global efficiency is equivalent to simply comparing weighted costs. Thus, we recommend the reporting of (i differences in weighted costs and (ii differences in cost-integrated topological measures with respect to different distributions over the cost domain. We demonstrate the application of these techniques in a re-analysis of an fMRI working memory task. We also provide a Monte Carlo method for approximating cost-integrated topological measures. Finally, we discuss the limitations of integrating topology over cost, which may pose problems when some weights are zero, when multiplicities exist in the ranks of the weights, and when one expects subtle cost-dependent topological differences, which could be masked by cost-integration.

  17. Modeling energy-economy interactions using integrated models

    International Nuclear Information System (INIS)

    Integrated models are defined as economic energy models that consist of several submodels, either coupled by an interface module, or embedded in one large model. These models can be used for energy policy analysis. Using integrated models yields the following benefits. They provide a framework in which energy-economy interactions can be better analyzed than in stand-alone models. Integrated models can represent both energy sector technological details, as well as the behaviour of the market and the role of prices. Furthermore, the combination of modeling methodologies in one model can compensate weaknesses of one approach with strengths of another. These advantages motivated this survey of the class of integrated models. The purpose of this literature survey therefore was to collect and to present information on integrated models. To carry out this task, several goals were identified. The first goal was to give an overview of what is reported on these models in general. The second one was to find and describe examples of such models. Other goals were to find out what kinds of models were used as component models, and to examine the linkage methodology. Solution methods and their convergence properties were also a subject of interest. The report has the following structure. In chapter 2, a 'conceptual framework' is given. In chapter 3 a number of integrated models is described. In a table, a complete overview is presented of all described models. Finally, in chapter 4, the report is summarized, and conclusions are drawn regarding the advantages and drawbacks of integrated models. 8 figs., 29 refs

  18. Modeling "Soft" Errors in Bipolar Integrated Circuits

    Science.gov (United States)

    Zoutendyk, J.; Benumof, R.; Vonroos, O.

    1985-01-01

    Mathematical models represent single-event upset in bipolar memory chips. Physics of single-event upset in integrated circuits discussed in theoretical paper. Pair of companion reports present mathematical models to predict critical charges for producing single-event upset in bipolar randomaccess memory (RAM) chips.

  19. Read My Lips: Brain Dynamics Associated with Audiovisual Integration and Deviance Detection.

    Science.gov (United States)

    Tse, Chun-Yu; Gratton, Gabriele; Garnsey, Susan M; Novak, Michael A; Fabiani, Monica

    2015-09-01

    Information from different modalities is initially processed in different brain areas, yet real-world perception often requires the integration of multisensory signals into a single percept. An example is the McGurk effect, in which people viewing a speaker whose lip movements do not match the utterance perceive the spoken sounds incorrectly, hearing them as more similar to those signaled by the visual rather than the auditory input. This indicates that audiovisual integration is important for generating the phoneme percept. Here we asked when and where the audiovisual integration process occurs, providing spatial and temporal boundaries for the processes generating phoneme perception. Specifically, we wanted to separate audiovisual integration from other processes, such as simple deviance detection. Building on previous work employing ERPs, we used an oddball paradigm in which task-irrelevant audiovisually deviant stimuli were embedded in strings of non-deviant stimuli. We also recorded the event-related optical signal, an imaging method combining spatial and temporal resolution, to investigate the time course and neuroanatomical substrate of audiovisual integration. We found that audiovisual deviants elicit a short duration response in the middle/superior temporal gyrus, whereas audiovisual integration elicits a more extended response involving also inferior frontal and occipital regions. Interactions between audiovisual integration and deviance detection processes were observed in the posterior/superior temporal gyrus. These data suggest that dynamic interactions between inferior frontal cortex and sensory regions play a significant role in multimodal integration. PMID:25848682

  20. An introduction to Space Weather Integrated Modeling

    Science.gov (United States)

    Zhong, D.; Feng, X.

    2012-12-01

    The need for a software toolkit that integrates space weather models and data is one of many challenges we are facing with when applying the models to space weather forecasting. To meet this challenge, we have developed Space Weather Integrated Modeling (SWIM) that is capable of analysis and visualizations of the results from a diverse set of space weather models. SWIM has a modular design and is written in Python, by using NumPy, matplotlib, and the Visualization ToolKit (VTK). SWIM provides data management module to read a variety of spacecraft data products and a specific data format of Solar-Interplanetary Conservation Element/Solution Element MHD model (SIP-CESE MHD model) for the study of solar-terrestrial phenomena. Data analysis, visualization and graphic user interface modules are also presented in a user-friendly way to run the integrated models and visualize the 2-D and 3-D data sets interactively. With these tools we can locally or remotely analysis the model result rapidly, such as extraction of data on specific location in time-sequence data sets, plotting interplanetary magnetic field lines, multi-slicing of solar wind speed, volume rendering of solar wind density, animation of time-sequence data sets, comparing between model result and observational data. To speed-up the analysis, an in-situ visualization interface is used to support visualizing the data 'on-the-fly'. We also modified some critical time-consuming analysis and visualization methods with the aid of GPU and multi-core CPU. We have used this tool to visualize the data of SIP-CESE MHD model in real time, and integrated the Database Model of shock arrival, Shock Propagation Model, Dst forecasting model and SIP-CESE MHD model developed by SIGMA Weather Group at State Key Laboratory of Space Weather/CAS.

  1. Modeling altered functional connectivity in brain disease states

    Czech Academy of Sciences Publication Activity Database

    Hlinka, Jaroslav

    Lorentz Center, 2011. [Computational Neuroscience and the Dynamics of Disease States. 08.08.2012-12.08.2012, Leiden] Institutional research plan: CEZ:AV0Z10300504 Keywords : synchronization * brain disease * computational modelling * functional connectivity * graph theory * structural connectivity Subject RIV: FH - Neurology http://www.lorentzcenter.nl/lc/web/2011/457/abstracts.php3?wsid=457&type=presentations

  2. Virtual model of the human brain for neurosurgical simulation.

    Science.gov (United States)

    De Paolis, Lucio T; De Mauro, Alessandro; Raczkowsky, Joerg; Aloisio, Giovanni

    2009-01-01

    The aim of this work is to develop a realistic virtual model of the human brain that could be used in a neurosurgical simulation for both educational and preoperative planning purposes. The goal of such a system would be to enhance the practice of surgery students, avoiding the use of animals, cadavers and plastic phantoms. A surgeon, before carrying out the real procedure, will, with this system, be able to rehearse by using a surgical simulator based on detailed virtual reality models of the human brain, reconstructed with real patient's medical images. In order to obtain a realistic and useful simulation we focused our research on the physical modelling of the brain as a deformable body and on the interactions with surgical instruments. The developed prototype is based on the mass-spring-damper model and, in order to obtain deformations similar to the real ones, a three tiered structure has been built. In this way, we have obtained local and realistic deformations using an ad-hoc point distribution in the volume where the contact between the brain surface and a surgical instrument takes place. PMID:19745425

  3. Stochastic model of Tsc1 lesions in mouse brain.

    Directory of Open Access Journals (Sweden)

    Shilpa Prabhakar

    Full Text Available Tuberous sclerosis complex (TSC is an autosomal dominant disorder due to mutations in either TSC1 or TSC2 that affects many organs with hamartomas and tumors. TSC-associated brain lesions include subependymal nodules, subependymal giant cell astrocytomas and tubers. Neurologic manifestations in TSC comprise a high frequency of mental retardation and developmental disorders including autism, as well as epilepsy. Here, we describe a new mouse model of TSC brain lesions in which complete loss of Tsc1 is achieved in multiple brain cell types in a stochastic pattern. Injection of an adeno-associated virus vector encoding Cre recombinase into the cerebral ventricles of mice homozygous for a Tsc1 conditional allele on the day of birth led to reduced survival, and pathologic findings of enlarged neurons, cortical heterotopias, subependymal nodules, and hydrocephalus. The severity of clinical and pathologic findings as well as survival was shown to be dependent upon the dose and serotype of Cre virus injected. Although several other models of TSC brain disease exist, this model is unique in that the pathology reflects a variety of TSC-associated lesions involving different numbers and types of cells. This model provides a valuable and unique addition for therapeutic assessment.

  4. Directions for Mind, Brain, and Education: Methods, Models, and Morality

    Science.gov (United States)

    Stein, Zachary; Fischer, Kurt W.

    2011-01-01

    In this article we frame a set of important issues in the emerging field of Mind, Brain, and Education in terms of three broad headings: methods, models, and morality. Under the heading of methods we suggest that the need for synthesis across scientific and practical disciplines entails the pursuit of usable knowledge via a catalytic symbiosis…

  5. Disruption of White Matter Integrity in Adult Survivors of Childhood Brain Tumors: Correlates with Long-Term Intellectual Outcomes

    OpenAIRE

    King, Tricia Z.; Liya Wang; Hui Mao

    2015-01-01

    Background Although chemotherapy and radiation treatment have contributed to increased survivorship, treatment-induced brain injury has been a concern when examining long-term intellectual outcomes of survivors. Specifically, disruption of brain white matter integrity and its relationship to intellectual outcomes in adult survivors of childhood brain tumors needs to be better understood. Methods Fifty-four participants underwent diffusion tensor imaging in addition to structural MRI and an in...

  6. Typological and Integrative Models of Sexual Abuse

    OpenAIRE

    Demidova L.Y.,; Dvorjanchikov N.V.,

    2014-01-01

    We discuss the basic typological and integrative theoretical models that explain the occurrence of child sexual abuse and the differences detected among the perpetrators of crimes against sexual integrity of minors. A comprehensive review of the theoretical concepts of sexual abuse in our country, in fact has not been carried out, and in this paper for the first time we made such an attempt. It is shown that the existing notions of sexual abuse largely overlap each other, but each of the mode...

  7. Numerical time integration for air pollution models

    OpenAIRE

    Verwer, Jan; Hundsdorfer, Willem; Blom, Joke

    1998-01-01

    Due to the large number of chemical species and the three space dimensions, off-the-shelf stiff ODE integrators are not feasible for the numerical time integration of stiff systems of advection-diffusion-reaction equations [ fracpar{c{t + nabla cdot left( vu{u c right) = nabla cdot left( K ,nabla, c right) + R left( c right), c=c(vu{x,t), c in IR^m, vu{x in Omega subset IR^3 ] from the field of air pollution modelling. This has led to the use of special time integration techniques. This paper...

  8. MODELS OF TECHNOLOGY ADOPTION: AN INTEGRATIVE APPROACH

    OpenAIRE

    Andrei OGREZEANU

    2015-01-01

    The interdisciplinary study of information technology adoption has developed rapidly over the last 30 years. Various theoretical models have been developed and applied such as: the Technology Acceptance Model (TAM), Innovation Diffusion Theory (IDT), Theory of Planned Behavior (TPB), etc. The result of these many years of research is thousands of contributions to the field, which, however, remain highly fragmented. This paper develops a theoretical model of technology adoption by integrating ...

  9. Integrated modelling of the Belgian coastal zone

    OpenAIRE

    Delhez, E. J. M.; Carabin, G.

    2001-01-01

    The management of the water resources in coastal or delta plains asks for an integrated modelling of the water system at a regional scale. In the SALMON project, detailed descriptions of the groundwater, river and marine domains are provided by coupling appropriate numerical models of these different sub-systems.The application of this three-fold model to the Scheldt and Belgian Coastal Zone reveals a marked river plume extending along the Belgian Coast with strong offshore gradients. This pl...

  10. Integrated assessment modeling: Modules for cooperation

    OpenAIRE

    Jaeger, Carlo C.; Leimbach, Marian; Carraro, Carlo; HASSELMANN, KLAUS; Hourcade, Jean-Charles

    2002-01-01

    An integrated assessment (IA) model combines knowledge from very different disciplines in view of a practical problem. Most models developed so far are rather monolithic in the sense that it is difficult to combine components from different models for purposes of new assessments. We propose to develop a modular approach to IA based on advances in knowledge management as well as in object oriented software engineering. The incentive structure of modular IA is based on turning the knowledge pro...

  11. Integrated Modelling - the next steps (Invited)

    Science.gov (United States)

    Moore, R. V.

    2010-12-01

    Integrated modelling (IM) has made considerable advances over the past decade but it has not yet been taken up as an operational tool in the way that its proponents had hoped. The reasons why will be discussed in Session U17. This talk will propose topics for a research and development programme and suggest an institutional structure which, together, could overcome the present obstacles. Their combined aim would be first to make IM into an operational tool useable by competent public authorities and commercial companies and, in time, to see it evolve into the modelling equivalent of Google Maps, something accessible and useable by anyone with a PC or an iphone and an internet connection. In a recent study, a number of government agencies, water authorities and utilities applied integrated modelling to operational problems. While the project demonstrated that IM could be used in an operational setting and had benefit, it also highlighted the advances that would be required for its widespread uptake. These were: greatly improving the ease with which models could be a) made linkable, b) linked and c) run; developing a methodology for applying integrated modelling; developing practical options for calibrating and validating linked models; addressing the science issues that arise when models are linked; extending the range of modelling concepts that can be linked; enabling interface standards to pass uncertainty information; making the interface standards platform independent; extending the range of platforms to include those for high performance computing; developing the concept of modelling components as web services; separating simulation code from the model’s GUI, so that all the results from the linked models can be viewed through a single GUI; developing scenario management systems so that that there is an audit trail of the version of each model and dataset used in each linked model run. In addition to the above, there is a need to build a set of integrated

  12. Lateral (Parasagittal) Fluid Percussion Model of Traumatic Brain Injury.

    Science.gov (United States)

    Van, Ken C; Lyeth, Bruce G

    2016-01-01

    Fluid percussion was first conceptualized in the 1940s and has evolved into one of the leading laboratory methods for studying experimental traumatic brain injury (TBI). Over the decades, fluid percussion has been used in numerous species and today is predominantly applied to the rat. The fluid percussion technique rapidly injects a small volume of fluid, such as isotonic saline, through a circular craniotomy onto the intact dura overlying the brain cortex. In brief, the methods involve surgical production of a circular craniotomy, attachment of a fluid-filled conduit between the dura overlying the cortex and the outlet port of the fluid percussion device. A fluid pulse is then generated by the free-fall of a pendulum striking a piston on the fluid-filled cylinder of the device. The fluid enters the cranium, producing a compression and displacement of the brain parenchyma resulting in a sharp, high magnitude elevation of intracranial pressure that is propagated diffusely through the brain. This results in an immediate and transient period of traumatic unconsciousness as well as a combination of focal and diffuse damage to the brain, which is evident upon histological and behavioral analysis. Numerous studies have demonstrated that the rat fluid percussion model reproduces a wide range of pathological features associated with human TBI. PMID:27604722

  13. Modelling Brain Temperature and Perfusion for Cerebral Cooling

    Science.gov (United States)

    Blowers, Stephen; Valluri, Prashant; Marshall, Ian; Andrews, Peter; Harris, Bridget; Thrippleton, Michael

    2015-11-01

    Brain temperature relies heavily on two aspects: i) blood perfusion and porous heat transport through tissue and ii) blood flow and heat transfer through embedded arterial and venous vasculature. Moreover brain temperature cannot be measured directly unless highly invasive surgical procedures are used. A 3D two-phase fluid-porous model for mapping flow and temperature in brain is presented with arterial and venous vessels extracted from MRI scans. Heat generation through metabolism is also included. The model is robust and reveals flow and temperature maps in unprecedented 3D detail. However, the Karmen-Kozeny parameters of the porous (tissue) phase need to be optimised for expected perfusion profiles. In order to optimise the K-K parameters a reduced order two-phase model is developed where 1D vessels are created with a tree generation algorithm embedded inside a 3D porous domain. Results reveal that blood perfusion is a strong function of the porosity distribution in the tissue. We present a qualitative comparison between the simulated perfusion maps and those obtained clinically. We also present results studying the effect of scalp cooling on core brain temperature and preliminary results agree with those observed clinically.

  14. Separate Brain Circuits Support Integrative and Semantic Priming in the Human Language System.

    Science.gov (United States)

    Feng, Gangyi; Chen, Qi; Zhu, Zude; Wang, Suiping

    2016-07-01

    Semantic priming is a crucial phenomenon to study the organization of semantic memory. A novel type of priming effect, integrative priming, has been identified behaviorally, whereby a prime word facilitates recognition of a target word when the 2 concepts can be combined to form a unitary representation. We used both functional and anatomical imaging approaches to investigate the neural substrates supporting such integrative priming, and compare them with those in semantic priming. Similar behavioral priming effects for both semantic (Bread-Cake) and integrative conditions (Cherry-Cake) were observed when compared with an unrelated condition. However, a clearly dissociated brain response was observed between these 2 types of priming. The semantic-priming effect was localized to the posterior superior temporal and middle temporal gyrus. In contrast, the integrative-priming effect localized to the left anterior inferior frontal gyrus and left anterior temporal cortices. Furthermore, fiber tractography showed that the integrative-priming regions were connected via uncinate fasciculus fiber bundle forming an integrative circuit, whereas the semantic-priming regions connected to the posterior frontal cortex via separated pathways. The results point to dissociable neural pathways underlying the 2 distinct types of priming, illuminating the neural circuitry organization of semantic representation and integration. PMID:26209843

  15. Self-Organized Criticality model for Brain Plasticity

    OpenAIRE

    De Arcangelis, Lucilla; Perrone-Capano, Carla; Herrmann, Hans J.

    2006-01-01

    Networks of living neurons exhibit an avalanche mode of activity, experimentally found in organotypic cultures. Here we present a model based on self-organized criticality and taking into account brain plasticity, which is able to reproduce the spectrum of electroencephalograms (EEG). The model consists in an electrical network with threshold firing and activity-dependent synapse strenghts. The system exhibits an avalanche activity power law distributed. The analysis of the power spectra of t...

  16. Dosha brain-types: A neural model of individual differences

    Directory of Open Access Journals (Sweden)

    Frederick T Travis

    2015-01-01

    Full Text Available This paper explores brain patterns associated with the three categories of regulatory principles of the body, mind, and behavior in Ayurveda, called Vata, Pitta, and Kapha dosha. A growing body of research has reported patterns of blood chemistry, genetic expression, physiological states, and chronic diseases associated with each dosha type. Since metabolic and growth factors are controlled by the nervous system, each dosha type should be associated with patterns of functioning of six major areas of the nervous system: The prefrontal cortex, the reticular activating system, the autonomic nervous system, the enteric nervous system, the limbic system, and the hypothalamus. For instance, the prefrontal cortex, which includes the anterior cingulate, ventral medial, and the dorsal lateral cortices, would exhibit a high range of functioning in the Vata brain-type leading to the possibility of being easily overstimulated. The Vata brain-type performs activity quickly. Learns quickly and forgets quickly. Their fast mind gives them an edge in creative problem solving. The Pitta brain-type reacts strongly to all challenges leading to purposeful and resolute actions. They never give up and are very dynamic and goal oriented. The Kapha brain-type is slow and steady leading to methodical thinking and action. They prefer routine and needs stimulation to get going. A model of dosha brain-types could provide a physiological foundation to understand individual differences. This model could help individualize treatment modalities to address different mental and physical dysfunctions. It also could explain differences in behavior seen in clinical as well as in normal populations.

  17. General solutions to poroviscoelastic model of hydrocephalic human brain tissue.

    Science.gov (United States)

    Mehrabian, Amin; Abousleiman, Younane

    2011-12-21

    Hydrocephalus is a well-known disorder of brain fluidic system. It is commonly associated with complexities in cerebrospinal fluid (CSF) circulation in brain. In this paper, hydrocephalus and shunting surgery which is used in its treatment are modeled. Brain tissues are considered to follow a poroviscoelastic constitutive model in order to address the effects of time dependence of mechanical properties of soft tissues and fluid flow hydraulics. Our solution draws from Biot's theory of poroelasticity, generalized to account for viscoelastic effects through the correspondence principle. Geometrically, the brain is conceived to be spherically symmetric, where the ventricles are assumed to be a hollow concentric space filled with cerebrospinal fluid. A generalized Kelvin model is considered for the rheological properties of brain tissues. The solution presented is useful in the analysis of the disorder of hydrocephalus as well as the treatment associated with it, namely, ventriclostomy surgery. The sensitivity of the solution to various factors such as aqueduct blockage level and trabeculae stiffness is thoroughly analyzed using numerical examples. Results indicate that partial aqueduct stenosis may be a cause of hydrocephalus. However, only severe occlusion of the aqueduct can cause a significant increase in the ventricle and brain's extracellular fluid pressure. Ventriculostomy shunts are commonly used as a remedy to hydrocephalus. They serve to reduce the ventricular pressure to the normal level. However, sensitivity analysis on the shunt's fluid deliverability parameter has shown that inappropriate design or selection of design shunt may cause under-drainage or over-drainage of the ventricles. Excessive drainage of CSF may increase the normal tensile stress on trabeculae. It can cause rupture of superior cerebral veins or damage to trabeculae or even brain tissues which in turn may lead to subdural hematoma, a common side-effect of the surgery. These Post

  18. Corticonic models of brain mechanisms underlying cognition and intelligence

    Science.gov (United States)

    Farhat, Nabil H.

    The concern of this review is brain theory or more specifically, in its first part, a model of the cerebral cortex and the way it: (a) interacts with subcortical regions like the thalamus and the hippocampus to provide higher-level-brain functions that underlie cognition and intelligence, (b) handles and represents dynamical sensory patterns imposed by a constantly changing environment, (c) copes with the enormous number of such patterns encountered in a lifetime by means of dynamic memory that offers an immense number of stimulus-specific attractors for input patterns (stimuli) to select from, (d) selects an attractor through a process of “conjugation” of the input pattern with the dynamics of the thalamo-cortical loop, (e) distinguishes between redundant (structured) and non-redundant (random) inputs that are void of information, (f) can do categorical perception when there is access to vast associative memory laid out in the association cortex with the help of the hippocampus, and (g) makes use of “computation” at the edge of chaos and information driven annealing to achieve all this. Other features and implications of the concepts presented for the design of computational algorithms and machines with brain-like intelligence are also discussed. The material and results presented suggest, that a Parametrically Coupled Logistic Map network (PCLMN) is a minimal model of the thalamo-cortical complex and that marrying such a network to a suitable associative memory with re-entry or feedback forms a useful, albeit, abstract model of a cortical module of the brain that could facilitate building a simple artificial brain. In the second part of the review, the results of numerical simulations and drawn conclusions in the first part are linked to the most directly relevant works and views of other workers. What emerges is a picture of brain dynamics on the mesoscopic and macroscopic scales that gives a glimpse of the nature of the long sought after brain code

  19. Integrated facilities modeling using QUEST and IGRIP

    International Nuclear Information System (INIS)

    A QUEST model and associated detailed IGRIP models were developed and used to simulate several workcells in a proposed Plutonium Storage Facility (PSF). The models are being used by team members assigned to the program to improve communication and to assist in evaluating concepts and in performing trade-off studies which will result in recommendations and a final design. The model was designed so that it could be changed easily. The added flexibility techniques used to make changes easily are described in this paper in addition to techniques for integrating the QUEST and IGRIP products. Many of these techniques are generic in nature and can be applied to any modeling endeavor

  20. Strings, Integrable Systems, Geometry and Statistical Models

    CERN Document Server

    Marshakov, A

    2004-01-01

    The role of integrable systems in string theory is discussed. We remind old examples of the correspondence between stringy partition functions or effective actions and integrable equations, based on effective application of the matrix model technique. Then we turn to a new example, coming from the Nekrasov deformation of the Seiberg-Witten prepotential. In the last case the deformed theory is described by a different statistical model, which becomes equivalent to a partition function of a topological string. The full partition function of string theory arises therefore always as a certain "quantization" of its quasiclassical geometry.

  1. A Mixed Approach for Modeling Blood Flow in Brain Microcirculation

    Science.gov (United States)

    Lorthois, Sylvie; Peyrounette, Myriam; Davit, Yohan; Quintard, Michel; Groupe d'Etude sur les Milieux Poreux Team

    2015-11-01

    Consistent with its distribution and exchange functions, the vascular system of the human brain cortex is a superposition of two components. At small-scale, a homogeneous and space-filling mesh-like capillary network. At large scale, quasi-fractal branched veins and arteries. From a modeling perspective, this is the superposition of: (a) a continuum model resulting from the homogenization of slow transport in the small-scale capillary network; and (b) a discrete network approach describing fast transport in the arteries and veins, which cannot be homogenized because of their fractal nature. This problematic is analogous to fast conducting wells embedded in a reservoir rock in petroleum engineering. An efficient method to reduce the computational cost is to use relatively large grid blocks for the continuum model. This makes it difficult to accurately couple both components. We solve this issue by adapting the ``well model'' concept used in petroleum engineering to brain specific 3D situations. We obtain a unique linear system describing the discrete network, the continuum and the well model. Results are presented for realistic arterial and venous geometries. The mixed approach is compared with full network models including various idealized capillary networks of known permeability. ERC BrainMicroFlow GA615102.

  2. Integrated modelling of two xenobiotic organic compounds

    DEFF Research Database (Denmark)

    Lindblom, Erik Ulfson; Gernaey, K.V.; Henze, Mogens;

    2006-01-01

    This paper presents a dynamic mathematical model that describes the fate and transport of two selected xenobiotic organic compounds (XOCs) in a simplified representation. of an integrated urban wastewater system. A simulation study, where the xenobiotics bisphenol A and pyrene are used as reference...... compounds, is carried out. Sorption and specific biological degradation processes are integrated with standardised water process models to model the fate of both compounds. Simulated mass flows of the two compounds during one dry weather day and one wet weather day are compared for realistic influent flow...... rate and concentration profiles. The wet weather day induces resuspension of stored sediments, which increases the pollutant load on the downstream system. The potential of the model to elucidate important phenomena related to origin and fate of the model compounds is demonstrated....

  3. Adaptive integration of local region information to detect fine-scale brain activity patterns

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    With the rapid development of functional magnetic resonance imaging (fMRI) technology, the spatial resolution of fMRI data is continuously growing. This pro- vides us the possibility to detect the fine-scale patterns of brain activities. The es- tablished univariate and multivariate methods to analyze fMRI data mostly focus on detecting the activation blobs without considering the distributed fine-scale pat- terns within the blobs. To improve the sensitivity of the activation detection, in this paper, multivariate statistical method and univariate statistical method are com- bined to discover the fine-grained activity patterns. For one voxel in the brain, a local homogenous region is constructed. Then, time courses from the local ho- mogenous region are integrated with multivariate statistical method. Univariate statistical method is finally used to construct the interests of statistic for that voxel. The approach has explicitly taken into account the structures of both activity pat- terns and existing noise of local brain regions. Therefore, it could highlight the fine-scale activity patterns of the local regions. Experiments with simulated and real fMRI data demonstrate that the proposed method dramatically increases the sensitivity of detection of fine-scale brain activity patterns which contain the subtle information about experimental conditions.

  4. Comparative Evaluation for Brain Structural Connectivity Approaches: Towards Integrative Neuroinformatics Tool for Epilepsy Clinical Research.

    Science.gov (United States)

    Yang, Sheng; Tatsuoka, Curtis; Ghosh, Kaushik; Lacuey-Lecumberri, Nuria; Lhatoo, Samden D; Sahoo, Satya S

    2016-01-01

    Recent advances in brain fiber tractography algorithms and diffusion Magnetic Resonance Imaging (MRI) data collection techniques are providing new approaches to study brain white matter connectivity, which play an important role in complex neurological disorders such as epilepsy. Epilepsy affects approximately 50 million persons worldwide and it is often described as a disorder of the cortical network organization. There is growing recognition of the need to better understand the role of brain structural networks in the onset and propagation of seizures in epilepsy using high resolution non-invasive imaging technologies. In this paper, we perform a comparative evaluation of two techniques to compute structural connectivity, namely probabilistic fiber tractography and statistics derived from fractional anisotropy (FA), using diffusion MRI data from a patient with rare case of medically intractable insular epilepsy. The results of our evaluation demonstrate that probabilistic fiber tractography provides a more accurate map of structural connectivity and may help address inherent complexities of neural fiber layout in the brain, such as fiber crossings. This work provides an initial result towards building an integrative informatics tool for neuroscience that can be used to accurately characterize the role of fiber tract connectivity in neurological disorders such as epilepsy. PMID:27570685

  5. Neuroteratology and Animal Modeling of Brain Disorders.

    Science.gov (United States)

    Archer, Trevor; Kostrzewa, Richard M

    2016-01-01

    Over the past 60 years, a large number of selective neurotoxins were discovered and developed, making it possible to animal-model a broad range of human neuropsychiatric and neurodevelopmental disorders. In this paper, we highlight those neurotoxins that are most commonly used as neuroteratologic agents, to either produce lifelong destruction of neurons of a particular phenotype, or a group of neurons linked by a specific class of transporter proteins (i.e., dopamine transporter) or body of receptors for a specific neurotransmitter (i.e., NMDA class of glutamate receptors). Actions of a range of neurotoxins are described: 6-hydroxydopamine (6-OHDA), 6-hydroxydopa, DSP-4, MPTP, methamphetamine, IgG-saporin, domoate, NMDA receptor antagonists, and valproate. Their neuroteratologic features are outlined, as well as those of nerve growth factor, epidermal growth factor, and that of stress. The value of each of these neurotoxins in animal modeling of human neurologic, neurodegenerative, and neuropsychiatric disorders is discussed in terms of the respective value as well as limitations of the derived animal model. Neuroteratologic agents have proven to be of immense importance for understanding how associated neural systems in human neural disorders may be better targeted by new therapeutic agents. PMID:26857462

  6. The cumulative effect of genetic polymorphisms on depression and brain structural integrity.

    Science.gov (United States)

    Kostic, Milutin; Canu, Elisa; Agosta, Federica; Munjiza, Ana; Novakovic, Ivana; Dobricic, Valerija; Maria Ferraro, Pilar; Miler Jerkovic, Vera; Pekmezovic, Tatjana; Lecic Tosevski, Dusica; Filippi, Massimo

    2016-06-01

    In major depressive disorder (MDD), the need to study multiple-gene effect on brain structure is emerging. Our aim was to assess the effect of accumulation of specific SERT, BDNF and COMT gene functional polymorphisms on brain structure in MDD patients. Seventy-seven MDD patients and 66 controls underwent a clinical assessment, genetic testing and MRI scan. Compared with controls, patients were more BDNF-Val homozygotes, COMT-Met carriers and SERT-L' carriers. Thus, subjects were split into three groups: 1. High-frequency susceptibility polymorphism group (hfSP, subjects with all three SPs); 2. Intermediate-frequency SP group (ifSP, two SPs); and 3. Low-frequency SP group (lfSP, one/none SP). Cortical thickness, volumetry of hippocampus, amygdala and subcortical structures, and white matter (WM) tract integrity were assessed. Compared to controls, hfSP patients showed thinning of the middle frontal cortex bilaterally, left frontal pole, and right lateral occipital cortex, and smaller hippocampal volume bilaterally; and both hfSP and lfSP patient groups showed thinning of the left inferior parietal cortex and reduced WM integrity of the corpus callosum. Compared to patients, hfSP controls showed greater integrity of the fronto-occipital cortices and corpus callosum. We showed that cortical prefrontal and occipital damage of MDD patients is modulated by the SP accumulation, while damage to the parietal cortex and corpus callosum seem to be independent of genetic accumulation. HfSP controls may experience protective mechanisms leading to a preserved integrity of critical cortical and WM regions. Investigating the effect of multiple genes is promising to understand the pathological mechanisms underlying MDD. Hum Brain Mapp 37:2173-2184, 2016. © 2016 Wiley Periodicals, Inc. PMID:26956059

  7. A prospective study to evaluate a new residential community reintegration programme for severe chronic brain injury: the Brain Integration Programme.

    NARCIS (Netherlands)

    Geurtsen, G.J.; Martina, J.D.; Heugten, C.M. van; Geurts, A.C.H.

    2008-01-01

    PURPOSE: To assess the effectiveness of a residential community reintegration programme for participants with chronic sequelae of severe acquired brain injury that hamper community functioning. DESIGN: Prospective cohort study. SUBJECTS: Twenty-four participants with acquired brain injury (traumatic

  8. CTBT integrated verification system evaluation model supplement

    Energy Technology Data Exchange (ETDEWEB)

    EDENBURN,MICHAEL W.; BUNTING,MARCUS; PAYNE JR.,ARTHUR C.; TROST,LAWRENCE C.

    2000-03-02

    Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia's Monitoring Systems and Technology Center and has been funded by the U.S. Department of Energy's Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, ''top-level,'' modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM's unique features is that it integrates results from the various CTBT sensor technologies (seismic, in sound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection), location accuracy, and identification capability of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system's performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. The original IVSEM report, CTBT Integrated Verification System Evaluation Model, SAND97-25 18, described version 1.2 of IVSEM. This report describes the changes made to IVSEM version 1.2 and the addition of identification capability estimates that have been incorporated into IVSEM version 2.0.

  9. CTBT integrated verification system evaluation model supplement

    International Nuclear Information System (INIS)

    Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia's Monitoring Systems and Technology Center and has been funded by the U.S. Department of Energy's Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, ''top-level,'' modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM's unique features is that it integrates results from the various CTBT sensor technologies (seismic, in sound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection), location accuracy, and identification capability of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system's performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. The original IVSEM report, CTBT Integrated Verification System Evaluation Model, SAND97-25 18, described version 1.2 of IVSEM. This report describes the changes made to IVSEM version 1.2 and the addition of identification capability estimates that have been incorporated into IVSEM version 2.0

  10. Do Different Models of Integration Affect Actual Integration? The Cases of France and Great Britain Revisited

    OpenAIRE

    Haque, Md. Asirul

    2008-01-01

    Britain and France adapted two different integration models, namely assimilationist and multiculturalism to integrate their immigrants. These two big models of integration have distinctive characteristics to integrate immigrants. There is a general claim that multiculturalism model is the best for integrating immigrants in terms of actual integration, however, some argue the opposite, that French assimilationist model is ‘better off.’ This study examines these controversial claims by looking ...

  11. Data and Model Integration Promoting Interdisciplinarity

    Science.gov (United States)

    Koike, T.

    2014-12-01

    It is very difficult to reflect accumulated subsystem knowledge into holistic knowledge. Knowledge about a whole system can rarely be introduced into a targeted subsystem. In many cases, knowledge in one discipline is inapplicable to other disciplines. We are far from resolving cross-disciplinary issues. It is critically important to establish interdisciplinarity so that scientific knowledge can transcend disciplines. We need to share information and develop knowledge interlinkages by building models and exchanging tools. We need to tackle a large increase in the volume and diversity of data from observing the Earth. The volume of data stored has exponentially increased. Previously, almost all of the large-volume data came from satellites, but model outputs occupy the largest volume in general. To address the large diversity of data, we should develop an ontology system for technical and geographical terms in coupling with a metadata design according to international standards. In collaboration between Earth environment scientists and IT group, we should accelerate data archiving by including data loading, quality checking and metadata registration, and enrich data-searching capability. DIAS also enables us to perform integrated research and realize interdisciplinarity. For example, climate change should be addressed in collaboration between the climate models, integrated assessment models including energy, economy, agriculture, health, and the models of adaptation, vulnerability, and human settlement and infrastructure. These models identify water as central to these systems. If a water expert can develop an interrelated system including each component, the integrated crisis can be addressed by collaboration with various disciplines. To realize this purpose, we are developing a water-related data- and model-integration system called a water cycle integrator (WCI).

  12. Renewed mer model of integral management

    Directory of Open Access Journals (Sweden)

    Janko Belak

    2015-12-01

    Full Text Available Background: The research work on entrepreneurship, enterprise's policy and management, which started in 1992, successfully continued in the following years. Between 1992 and 2011, more than 400 academics and other researchers have participated in research work (MER research program whose main orientation has been the creation of their own model of integral management. Results: In past years, academics (researchers and authors of published papers from Austria, Belgium, Bosnia and Herzegovina, Bulgaria, Byelorussia, Canada, the Czech Republic, Croatia, Estonia, France, Germany, Hungary, Italy, Poland, Romania, Russia, the Slovak Republic, Slovenia, Switzerland, Ukraine, and the US have cooperated in MER programs, coming from more than fifty institutions. Thus, scientific doctrines of different universities influenced the development of the MER model which is based on both horizontal and vertical integration of the enterprises' governance and management processes, instruments and institutions into a consistently operating unit. Conclusions: The presented MER model is based on the multi-layer integration of governance and management with an enterprise and its environment, considering the fundamental desires for the enterprises' existence and, thus, their quantitative as well as qualitative changes. The process, instrumental, and institutional integrity of the governance and management is also the initial condition for the implementation of all other integration factors.

  13. Verbal Neuropsychological Functions in Aphasia: An Integrative Model.

    Science.gov (United States)

    Vigliecca, Nora Silvana; Báez, Sandra

    2015-12-01

    A theoretical framework which considers the verbal functions of the brain under a multivariate and comprehensive cognitive model was statistically analyzed. A confirmatory factor analysis was performed to verify whether some recognized aphasia constructs can be hierarchically integrated as latent factors from a homogenously verbal test. The Brief Aphasia Evaluation was used. A sample of 65 patients with left cerebral lesions, and two supplementary samples comprising 35 patients with right cerebral lesions and 30 healthy participants were studied. A model encompassing an all inclusive verbal organizer and two successive organizers was validated. The two last organizers were: three factors of comprehension, expression and a "complementary" verbal factor which included praxia, attention, and memory; followed by the individual (and correlated) factors of auditory comprehension, repetition, naming, speech, reading, writing, and the "complementary" factor. By following this approach all the patients fall inside the classification system; consequently, theoretical improvement is guaranteed. PMID:25168953

  14. Self-Organized Criticality Model for Brain Plasticity

    Science.gov (United States)

    de Arcangelis, Lucilla; Perrone-Capano, Carla; Herrmann, Hans J.

    2006-01-01

    Networks of living neurons exhibit an avalanche mode of activity, experimentally found in organotypic cultures. Here we present a model that is based on self-organized criticality and takes into account brain plasticity, which is able to reproduce the spectrum of electroencephalograms (EEG). The model consists of an electrical network with threshold firing and activity-dependent synapse strengths. The system exhibits an avalanche activity in a power-law distribution. The analysis of the power spectra of the electrical signal reproduces very robustly the power-law behavior with the exponent 0.8, experimentally measured in EEG spectra. The same value of the exponent is found on small-world lattices and for leaky neurons, indicating that universality holds for a wide class of brain models.

  15. Lateral fluid percussion: model of traumatic brain injury in mice.

    Science.gov (United States)

    Alder, Janet; Fujioka, Wendy; Lifshitz, Jonathan; Crockett, David P; Thakker-Varia, Smita

    2011-01-01

    Traumatic brain injury (TBI) research has attained renewed momentum due to the increasing awareness of head injuries, which result in morbidity and mortality. Based on the nature of primary injury following TBI, complex and heterogeneous secondary consequences result, which are followed by regenerative processes (1,2). Primary injury can be induced by a direct contusion to the brain from skull fracture or from shearing and stretching of tissue causing displacement of brain due to movement (3,4). The resulting hematomas and lacerations cause a vascular response (3,5), and the morphological and functional damage of the white matter leads to diffuse axonal injury (6-8). Additional secondary changes commonly seen in the brain are edema and increased intracranial pressure (9). Following TBI there are microscopic alterations in biochemical and physiological pathways involving the release of excitotoxic neurotransmitters, immune mediators and oxygen radicals (10-12), which ultimately result in long-term neurological disabilities (13,14). Thus choosing appropriate animal models of TBI that present similar cellular and molecular events in human and rodent TBI is critical for studying the mechanisms underlying injury and repair. Various experimental models of TBI have been developed to reproduce aspects of TBI observed in humans, among them three specific models are widely adapted for rodents: fluid percussion, cortical impact and weight drop/impact acceleration (1). The fluid percussion device produces an injury through a craniectomy by applying a brief fluid pressure pulse on to the intact dura. The pulse is created by a pendulum striking the piston of a reservoir of fluid. The percussion produces brief displacement and deformation of neural tissue (1,15). Conversely, cortical impact injury delivers mechanical energy to the intact dura via a rigid impactor under pneumatic pressure (16,17). The weight drop/impact model is characterized by the fall of a rod with a specific

  16. Rethinking School Bullying: Towards an Integrated Model

    Science.gov (United States)

    Dixon, Roz; Smith, Peter K.

    2011-01-01

    What would make anti-bullying initiatives more successful? This book offers a new approach to the problem of school bullying. The question of what constitutes a useful theory of bullying is considered and suggestions are made as to how priorities for future research might be identified. The integrated, systemic model of school bullying introduced…

  17. Integrating MOOCs in the conventional education models

    OpenAIRE

    AMBROSCH EKATERINA А.; NETAEVA MARIA А.

    2014-01-01

    The objective of this paper is to analyze the latest trend in education that has the potential to disrupt and revolutionize the conventional education model, namely massive open online courses. The focus is to find out how this innovative concept can be approached and applied in the context of the Russian higher education. The viable model adaptable for the Russian reality implies integration of open online education into the traditional educational system in the form of blended education. Ad...

  18. Modeling the impact of COPD on the brain

    Directory of Open Access Journals (Sweden)

    Soo Borson

    2008-10-01

    Full Text Available Soo Borson1, James Scanlan1, Seth Friedman2, Elizabeth Zuhr1, Julie Fields3, Elizabeth Aylward1,2, Rodney Mahurin2, Todd Richards2, Yoshimi Anzai2, Michi Yukawa4, Shingshing Yeh51Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA; 2Radiology Department, University of Washington, Seattle, Washington, USA; 3Department of Psychology (Neuropsychology, University of Texas Southwestern Medical Center, Texas, USA; 4Department of Medicine (Geriatrics, University of Washington, Seattle, WA, USA; 5Department of Medicine (Geriatrics, Veterans Affairs Medical Center, Northport, New York, USAAbstract: Previous studies have shown that COPD adversely affects distant organs and body systems, including the brain. This pilot study aims to model the relationships between respiratory insufficiency and domains related to brain function, including low mood, subtly impaired cognition, systemic inflammation, and brain structural and neurochemical abnormalities. Nine healthy controls were compared with 18 age- and education-matched medically stable COPD patients, half of whom were oxygen-dependent. Measures included depression, anxiety, cognition, health status, spirometry, oximetry at rest and during 6-minute walk, and resting plasma cytokines and soluble receptors, brain MRI, and MR spectroscopy in regions relevant to mood and cognition. ANOVA was used to compare controls with patients and with COPD subgroups (oxygen users [n = 9] and nonusers [n = 9], and only variables showing group differences at p ≤ 0.05 were included in multiple regressions controlling for age, gender, and education to develop the final model. Controls and COPD patients differed significantly in global cognition and memory, mood, and soluble TNFR1 levels but not brain structural or neurochemical measures. Multiple regressions identified pathways linking disease severity with impaired performance on sensitive cognitive processing measures, mediated

  19. Organization, maturation and plasticity of multisensory integration: Insights from computational modelling studies

    Directory of Open Access Journals (Sweden)

    CristianoCuppini

    2011-05-01

    Full Text Available In this paper, we present two neural network models - devoted to two specific and widely investigated aspects of multisensory integration - in order to evidence the potentialities of computational models to gain insight into the neural mechanisms underlying organization, development and plasticity of multisensory integration in the brain. The first model considers visual-auditory interaction in a midbrain structure named Superior Colliculus (SC. The model is able to reproduce and explain the main physiological features of multisensory integration in SC neurons and to describe how SC integrative capability – not present at birth - develops gradually during postnatal life depending on sensory experience with cross-modal stimuli. The second model tackles the problem of how tactile stimuli on a body part and visual (or auditory stimuli close to the same body part are integrated in multimodal parietal neurons to form the perception of peripersonal (i.e., near space. The model investigates how the extension of peripersonal space - where multimodal integration occurs - may be modified by experience such as use of a tool to interact with the far space. The utility of the modelling approach relies on several aspects: i The two models, although devoted to different problems and simulating different brain regions, share some common mechanisms (lateral inhibition and excitation, non-linear neuron characteristics, recurrent connections, competition, Hebbian rules of potentiation and depression that may govern more generally the fusion of senses in the brain, and the learning and plasticity of multisensory integration. ii The models may help interpretation of behavioural and psychophysical responses in terms of neural activity and synaptic connections. iii The models can make testable predictions that can help guiding future experiments in order to validate, reject, or modify the main assumptions.

  20. Associations between brain white matter integrity and disease severity in obstructive sleep apnea.

    Science.gov (United States)

    Tummala, Sudhakar; Roy, Bhaswati; Park, Bumhee; Kang, Daniel W; Woo, Mary A; Harper, Ronald M; Kumar, Rajesh

    2016-10-01

    Obstructive sleep apnea (OSA) is characterized by recurrent upper airway blockage, with continued diaphragmatic efforts to breathe during sleep. Brain structural changes in OSA appear in various regions, including white matter sites that mediate autonomic, mood, cognitive, and respiratory control. However, the relationships between brain white matter changes and disease severity in OSA are unclear. This study examines associations between an index of tissue integrity, magnetization transfer (MT) ratio values (which show MT between free and proton pools associated with tissue membranes and macromolecules), and disease severity (apnea-hypopnea index [AHI]) in OSA subjects. We collected whole-brain MT imaging data from 19 newly diagnosed, treatment-naïve OSA subjects (50.4 ± 8.6 years of age, 13 males, AHI 39.7 ± 24.3 events/hr], using a 3.0-Tesla MRI scanner. With these data, whole-brain MT ratio maps were calculated, normalized to common space, smoothed, and correlated with AHI scores by using partial correlation analyses (covariates, age and gender; P brain sites in OSA subjects, including superior and inferior frontal regions, ventral medial prefrontal cortex and nearby white matter, midfrontal white matter, insula, cingulate and cingulum bundle, internal and external capsules, caudate nuclei and putamen, basal forebrain, hypothalamus, corpus callosum, and temporal regions, showed principally lateralized negative correlations (P < 0.005). These regions showed significant correlations even with correction for multiple comparisons (cluster-level, family-wise error, P < 0.05), except for a few superior frontal areas. Predominantly negative correlations emerged between local MT values and OSA disease severity, indicating potential usefulness of MT imaging for examining the OSA condition. These findings indicate that OSA severity plays a significant role in white matter injury. © 2016 Wiley Periodicals, Inc. PMID:27315771

  1. Toward "optimal" integration of terrestrial biosphere models

    Science.gov (United States)

    Schwalm, Christopher R.; Huntzinger, Deborah N.; Fisher, Joshua B.; Michalak, Anna M.; Bowman, Kevin; Ciais, Philippe; Cook, Robert; El-Masri, Bassil; Hayes, Daniel; Huang, Maoyi; Ito, Akihiko; Jain, Atul; King, Anthony W.; Lei, Huimin; Liu, Junjie; Lu, Chaoqun; Mao, Jiafu; Peng, Shushi; Poulter, Benjamin; Ricciuto, Daniel; Schaefer, Kevin; Shi, Xiaoying; Tao, Bo; Tian, Hanqin; Wang, Weile; Wei, Yaxing; Yang, Jia; Zeng, Ning

    2015-06-01

    Multimodel ensembles (MME) are commonplace in Earth system modeling. Here we perform MME integration using a 10-member ensemble of terrestrial biosphere models (TBMs) from the Multiscale synthesis and Terrestrial Model Intercomparison Project (MsTMIP). We contrast optimal (skill based for present-day carbon cycling) versus naïve ("one model-one vote") integration. MsTMIP optimal and naïve mean land sink strength estimates (-1.16 versus -1.15 Pg C per annum respectively) are statistically indistinguishable. This holds also for grid cell values and extends to gross uptake, biomass, and net ecosystem productivity. TBM skill is similarly indistinguishable. The added complexity of skill-based integration does not materially change MME values. This suggests that carbon metabolism has predictability limits and/or that all models and references are misspecified. Resolving this issue requires addressing specific uncertainty types (initial conditions, structure, and references) and a change in model development paradigms currently dominant in the TBM community.

  2. Avoiding Boltzmann Brain domination in holographic dark energy models

    Directory of Open Access Journals (Sweden)

    R. Horvat

    2015-11-01

    Full Text Available In a spatially infinite and eternal universe approaching ultimately a de Sitter (or quasi-de Sitter regime, structure can form by thermal fluctuations as such a space is thermal. The models of Dark Energy invoking holographic principle fit naturally into such a category, and spontaneous formation of isolated brains in otherwise empty space seems the most perplexing, creating the paradox of Boltzmann Brains (BB. It is thus appropriate to ask if such models can be made free from domination by Boltzmann Brains. Here we consider only the simplest model, but adopt both the local and the global viewpoint in the description of the Universe. In the former case, we find that if a dimensionless model parameter c, which modulates the Dark Energy density, lies outside the exponentially narrow strip around the most natural c=1 line, the theory is rendered BB-safe. In the latter case, the bound on c is exponentially stronger, and seemingly at odds with those bounds on c obtained from various observational tests.

  3. [Integrated model system for environmental policy analysis].

    Science.gov (United States)

    Jiang, Lin

    2006-05-01

    An integrated model system for environmental policy analysis is built up with a Computable General Equilibrium (CGE) model as a core model, which is linked with an environmental model, air dispersion model, and health effect model (exposure-response functions) in an explicit way, therefore the model system is capable of evaluating the effects of policies on environment, health and economy and their interactions comprehensively. This method is used to analyze the effects of Beijing presumptive (energy) taxes on air quality, health, welfare and economic growth, and the conclusion is that sole presumptive taxes may slow down the economic growth, but the presumptive taxes with green tax reform can promote Beijing sustainable development. PMID:16850855

  4. Neuronal regeneration in a zebrafish model of adult brain injury

    Directory of Open Access Journals (Sweden)

    Norihito Kishimoto

    2012-03-01

    Neural stem cells in the subventricular zone (SVZ of the adult mammalian forebrain are a potential source of neurons for neural tissue repair after brain insults such as ischemic stroke and traumatic brain injury (TBI. Recent studies show that neurogenesis in the ventricular zone (VZ of the adult zebrafish telencephalon has features in common with neurogenesis in the adult mammalian SVZ. Here, we established a zebrafish model to study injury-induced neurogenesis in the adult brain. We show that the adult zebrafish brain possesses a remarkable capacity for neuronal regeneration. Telencephalon injury prompted the proliferation of neuronal precursor cells (NPCs in the VZ of the injured hemisphere, compared with in the contralateral hemisphere. The distribution of NPCs, viewed by BrdU labeling and ngn1-promoter-driven GFP, suggested that they migrated laterally and reached the injury site via the subpallium and pallium. The number of NPCs reaching the injury site significantly decreased when the fish were treated with an inhibitor of γ-secretase, a component of the Notch signaling pathway, suggesting that injury-induced neurogenesis mechanisms are at least partly conserved between fish and mammals. The injury-induced NPCs differentiated into mature neurons in the regions surrounding the injury site within a week after the injury. Most of these cells expressed T-box brain protein (Tbr1, suggesting they had adopted the normal neuronal fate in this region. These results suggest that the telencephalic VZ contributes to neural tissue recovery following telencephalic injury in the adult zebrafish, and that the adult zebrafish is a useful model for regenerative medicine.

  5. Theoretical Compartment Modeling of DCE-MRI Data Based on the Transport across Physiological Barriers in the Brain

    Directory of Open Access Journals (Sweden)

    Laura Fanea

    2012-01-01

    Full Text Available Neurological disorders represent major causes of lost years of healthy life and mortality worldwide. Development of their quantitative interdisciplinary in vivo evaluation is required. Compartment modeling (CM of brain data acquired in vivo using magnetic resonance imaging techniques with clinically available contrast agents can be performed to quantitatively assess brain perfusion. Transport of 1H spins in water molecules across physiological compartmental brain barriers in three different pools was mathematically modeled and theoretically evaluated in this paper and the corresponding theoretical compartment modeling of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI data was analyzed. The pools considered were blood, tissue, and cerebrospinal fluid (CSF. The blood and CSF data were mathematically modeled assuming continuous flow of the 1H spins in these pools. Tissue data was modeled using three CMs. Results in this paper show that transport across physiological brain barriers such as the blood to brain barrier, the extracellular space to the intracellular space barrier, or the blood to CSF barrier can be evaluated quantitatively. Statistical evaluations of this quantitative information may be performed to assess tissue perfusion, barriers' integrity, and CSF flow in vivo in the normal or disease-affected brain or to assess response to therapy.

  6. Neurocomputational models of the remote effects of focal brain damage.

    Science.gov (United States)

    Reggia, James A

    2004-11-01

    Sudden localized brain damage, such as occurs in stroke, produces neurological deficits directly attributable to the damaged site. In addition, other clinical deficits occur due to secondary "remote" effects that functionally impair the remaining intact brain regions (e.g., due to their sudden disconnection from the damaged area), a phenomenon known as diaschisis. The underlying mechanisms of these remote effects, particularly those involving interactions between the left and right cerebral hemispheres, have proven somewhat difficult to understand in the context of current theories of hemispheric specialization. This article describes some recent neurocomputational models done in the author's research group that try to explain diaschisis qualitatively. These studies show that both specialization and diaschisis can be accounted for with a single model of hemispheric interactions. Further, the results suggest that left-right subcortical influences may be much more important in influencing hemispheric specialization than is generally recognized. PMID:15564108

  7. Self-organization in a simple brain model

    Energy Technology Data Exchange (ETDEWEB)

    Stassinopoulos, D.; Bak, P. [Brookhaven National Lab., Upton, NY (United States). Dept. of Physics; Alstroem, P. [Niels Bohr Inst., Copenhagen (Denmark). Dept. of Physics

    1994-03-10

    Simulations on a simple model of the brain are presented. The model consists of a set of randomly connected neurons. Inputs and outputs are also connected randomly to a subset of neurons. For each input there is a set of output neurons which must fire in order to achieve success. A signal giving information as to whether or not the action was successful is fed back to the brain from the environment. The connections between firing neurons are strengthened or weakened according to whether or not the action was successful. The system learns, through a self-organization process, to react intelligently to input signals, i.e. it learns to quickly select the correct output for each input. If part of the network is damaged, the system relearns the correct response after a training period.

  8. Developing better and more valid animal models of brain disorders.

    Science.gov (United States)

    Stewart, Adam Michael; Kalueff, Allan V

    2015-01-01

    Valid sensitive animal models are crucial for understanding the pathobiology of complex human disorders, such as anxiety, autism, depression and schizophrenia, which all have the 'spectrum' nature. Discussing new important strategic directions of research in this field, here we focus i) on cross-species validation of animal models, ii) ensuring their population (external) validity, and iii) the need to target the interplay between multiple disordered domains. We note that optimal animal models of brain disorders should target evolutionary conserved 'core' traits/domains and specifically mimic the clinically relevant inter-relationships between these domains. PMID:24384129

  9. Paradox of integration -- a computational model

    CERN Document Server

    Krawczyk, Malgorzata J

    2016-01-01

    The paradoxical aspect of integration of a social group has been highlighted by Peter Blau (Exchange and Power in Social Life, Wiley and Sons, 1964). During the integration process, the group members simultaneously compete for social status and play the role of the audience. Here we show that when the competition prevails over the desire of approval, a sharp transition breaks all friendly relations. However, as was described by Blau, people with high status are inclined to bother more with acceptance of others; this is achieved by praising others and revealing her/his own weak points. In our model, this action smooths the transition and improves interpersonal relations.

  10. Brain Arteriovenous Malformation Modeling, Pathogenesis and Novel Therapeutic Targets

    OpenAIRE

    Chen, Wanqiu; Choi, Eun-Jung; McDougall, Cameron M.; Su, Hua

    2014-01-01

    Patients harboring brain arteriovenous malformation (bAVM) are at life-threatening risk of rupture and intracranial hemorrhage (ICH). The pathogenesis of bAVM has not been completely understood. Current treatment options are invasive and ≈ 20% of patients are not offered interventional therapy because of excessive treatment risk. There are no specific medical therapies to treat bAVMs. The lack of validated animal models has been an obstacle for testing hypotheses of bAVM pathogenesis and test...

  11. Globalization and Migration: A “Unified Brain Drain” Model

    OpenAIRE

    Elise S. Brezis; Soueri, Ariel

    2012-01-01

    Globalization has led to a vast flow of migration of workers but also of students. The purpose of this paper is to analyze the migration of individuals encompassing decisions already at the level of education. We develop a unified brain drain model that incorporates the decisions of an individual vis - à - vis both education and migration. In the empirical part, this paper addresses international flows of migration within the EU and presents strong evidence of concentration of students in cou...

  12. Novel Hybrid Model: Integrating Scrum and XP

    Directory of Open Access Journals (Sweden)

    Zaigham Mushtaq

    2012-06-01

    Full Text Available Scrum does not provide any direction about how to engineer a software product. The project team has to adopt suitable agile process model for the engineering of software. XP process model is mainly focused on engineering practices rather than management practices. The design of XP process makes it suitable for simple and small size projects and not appropriate for medium and large projects. A fine integration of management and engineering practices is desperately required to build quality product to make it valuable for customers. In this research a novel framework hybrid model is proposed to achieve this integration. The proposed hybrid model is actually an express version of Scrum model. It possesses features of engineering practices that are necessary to develop quality software as per customer requirements and company objectives. A case study is conducted to validate the proposal of hybrid model. The results of the case study reveal that proposed model is an improved version of XP and Scrum model.

  13. Avoiding Boltzmann Brain domination in holographic dark energy models

    CERN Document Server

    Horvat, R

    2015-01-01

    In a spatially infinite and eternal universe approaching ultimately a de Sitter (or quasi-de Sitter) regime, structure can form by thermal fluctuations as such a space is thermal. The models of Dark Energy invoking holographic principle fit naturally into such a category, and spontaneous formation of isolated brains in otherwise empty space seems the most perplexing, creating the paradox of Boltzmann Brains (BB). It is thus appropriate to ask if such models can be made free from domination by Boltzmann Brains. Here we consider only the simplest model, but adopt both the local and the global viewpoint in the description of the Universe. In the former case, we find that if a parameter $c$, which modulates the Dark Energy density, lies outside the exponentially narrow strip around the most natural $c = 1$ line, the theory is rendered BB-safe. In the later case, the bound on $c$ is exponentially stronger, and seemingly at odds with those bounds on $c$ obtained from various observational tests.

  14. Integrated Model of Bioenergy and Agriculture System

    DEFF Research Database (Denmark)

    Sigurjonsson, Hafthor Ægir; Elmegaard, Brian; Clausen, Lasse Røngaard

    2015-01-01

    approach that builds on Life Cycle Inventory and carries out Life Cycle Impact Assessment for a con- sequential Life Cycle Assessment on integrated bioenergy and agriculture systems. The model framework is built in Python which connects various freely available soft- ware that handle different aspects of...... the overall model. C- TOOL and Yasso07 are used in the carbon balance of agri- culture, Dynamic Network Analysis is used for the energy simulation and Brightway2 is used to build a Life Cycle Inventory compatible database and processes it for vari- ous impacts assessment methods. The model is success...

  15. Integrated Modeling for Flood Hazard Mapping Using Watershed Modeling System

    OpenAIRE

    Seyedeh S. Sadrolashrafi; Thamer A. Mohamed; Ahmad R.B. Mahmud; Majid K. Kholghi; Amir Samadi

    2008-01-01

    In this stduy, a new framework which integrates the Geographic Information System (GIS) with the Watershed Modeling System (WMS) for flood modeling is developed. It also interconnects the terrain models and the GIS software, with commercial standard hydrological and hydraulic models, including HEC-1, HEC-RAS, etc. The Dez River Basin (about 16213 km2) in Khuzestan province, IRAN, is domain of study because of occuring frequent severe flash flooding. As a case of study, a major flood in autumn...

  16. Androgen modulation of social decision making mechanisms in the brain: an integrative and embodied perspective

    Directory of Open Access Journals (Sweden)

    Rui F Oliveira

    2014-07-01

    Full Text Available Apart from their role in reproduction androgens also respond to social challenges and this response has been seen as a way to regulate the expression of behaviour according to the perceived social environment (Challenge hypothesis, Wingfield et al. 1990. This hypothesis implies that social decision-making mechanisms localized in the central nervous system (CNS are open to the influence of peripheral hormones that ultimately are under the control of the CNS through the hypothalamic-pituitary-gonadal axis. Therefore, two puzzling questions emerge at two different levels of biological analysis: (1 Why does the brain, which perceives the social environment and regulates androgen production in the gonad, need feedback information from the gonad to adjust its social decision-making processes? (2 How does the brain regulate gonadal androgen responses to social challenges and how do these feedback into the brain? In this paper, we will address these two questions using the integrative approach proposed by Niko Tinbergen, who proposed that a full understanding of behaviour requires its analysis at both proximate (physiology, ontogeny and ultimate (ecology, evolution levels.

  17. CTBT Integrated Verification System Evaluation Model

    Energy Technology Data Exchange (ETDEWEB)

    Edenburn, M.W.; Bunting, M.L.; Payne, A.C. Jr.

    1997-10-01

    Sandia National Laboratories has developed a computer based model called IVSEM (Integrated Verification System Evaluation Model) to estimate the performance of a nuclear detonation monitoring system. The IVSEM project was initiated in June 1994, by Sandia`s Monitoring Systems and Technology Center and has been funded by the US Department of Energy`s Office of Nonproliferation and National Security (DOE/NN). IVSEM is a simple, top-level, modeling tool which estimates the performance of a Comprehensive Nuclear Test Ban Treaty (CTBT) monitoring system and can help explore the impact of various sensor system concepts and technology advancements on CTBT monitoring. One of IVSEM`s unique features is that it integrates results from the various CTBT sensor technologies (seismic, infrasound, radionuclide, and hydroacoustic) and allows the user to investigate synergy among the technologies. Specifically, IVSEM estimates the detection effectiveness (probability of detection) and location accuracy of the integrated system and of each technology subsystem individually. The model attempts to accurately estimate the monitoring system`s performance at medium interfaces (air-land, air-water) and for some evasive testing methods such as seismic decoupling. This report describes version 1.2 of IVSEM.

  18. Predictive models for pressure-driven fluid infusions into brain parenchyma

    OpenAIRE

    Raghavan, Raghu; Brady, Martin

    2011-01-01

    Direct infusions into brain parenchyma of biological therapeutics for serious brain diseases have been, and are being, considered. However, individual brains, as well as distinct cytoarchitectural regions within brains, vary in their response to fluid flow and pressure. Further, the tissue responds dynamically to these stimuli, requiring a nonlinear treatment of equations that would describe fluid flow and drug transport in brain. We here report in detail on an individual–specific model and a...

  19. A Delphi Study on Brain-based Instructional Model in Science

    OpenAIRE

    Duangkamon Charnsirirattana; Prasart Nuangchalerm

    2010-01-01

    Development of science instructional model for brain-based learning by using knowledge of the brain to be the tool designed of learning process is now interesting. This study aimed to develop science instructional model for brain-based learning. Delphi method was employed with 18 panel members. The findings can be showed that science instructional model for brain-based learning consisted of five steps of learning organization (PRADA- Preparation, Relaxation, Action, Discussion, and Applicatio...

  20. Statistical shape model-based segmentation of brain MRI images.

    Science.gov (United States)

    Bailleul, Jonathan; Ruan, Su; Constans, Jean-Marc

    2007-01-01

    We propose a segmentation method that automatically delineates structures contours from 3D brain MRI images using a statistical shape model. We automatically build this 3D Point Distribution Model (PDM) in applying a Minimum Description Length (MDL) annotation to a training set of shapes, obtained by registration of a 3D anatomical atlas over a set of patients brain MRIs. Delineation of any structure from a new MRI image is first initialized by such registration. Then, delineation is achieved in iterating two consecutive steps until the 3D contour reaches idempotence. The first step consists in applying an intensity model to the latest shape position so as to formulate a closer guess: our model requires far less priors than standard model in aiming at direct interpretation rather than compliance to learned contexts. The second step consists in enforcing shape constraints onto previous guess so as to remove all bias induced by artifacts or low contrast on current MRI. For this, we infer the closest shape instance from the PDM shape space using a new estimation method which accuracy is significantly improved by a huge increase in the model resolution and by a depth-search in the parameter space. The delineation results we obtained are very encouraging and show the interest of the proposed framework. PMID:18003193

  1. Functional gradients through the cortex, multisensory integration and scaling laws in brain dynamics

    OpenAIRE

    Gonzalo-Fonrodona, Isabel

    2008-01-01

    In the context of the increasing number of works on multisensory and cross-modal effects in cerebral processing, a review is made on the functional model of human brain proposed by Justo Gonzalo (1910-1986), in relation to what he called central syndrome (caused by unilateral lesion in the parieto-occipital cortex, equidistant from the visual, tactile and auditory projection areas). The syndrome is featured by a bilateral, symmetric and multisensory involvement, and by a functional depression...

  2. Integrating Biosystem Models Using Waveform Relaxation

    Directory of Open Access Journals (Sweden)

    Seymour RobertM

    2008-01-01

    Full Text Available Modelling in systems biology often involves the integration of component models into larger composite models. How to do this systematically and efficiently is a significant challenge: coupling of components can be unidirectional or bidirectional, and of variable strengths. We adapt the waveform relaxation (WR method for parallel computation of ODEs as a general methodology for computing systems of linked submodels. Four test cases are presented: (i a cascade of unidirectionally and bidirectionally coupled harmonic oscillators, (ii deterministic and stochastic simulations of calcium oscillations, (iii single cell calcium oscillations showing complex behaviour such as periodic and chaotic bursting, and (iv a multicellular calcium model for a cell plate of hepatocytes. We conclude that WR provides a flexible means to deal with multitime-scale computation and model heterogeneity. Global solutions over time can be captured independently of the solution techniques for the individual components, which may be distributed in different computing environments.

  3. Integrating Biosystem Models Using Waveform Relaxation

    Directory of Open Access Journals (Sweden)

    Stephen Baigent

    2008-12-01

    Full Text Available Modelling in systems biology often involves the integration of component models into larger composite models. How to do this systematically and efficiently is a significant challenge: coupling of components can be unidirectional or bidirectional, and of variable strengths. We adapt the waveform relaxation (WR method for parallel computation of ODEs as a general methodology for computing systems of linked submodels. Four test cases are presented: (i a cascade of unidirectionally and bidirectionally coupled harmonic oscillators, (ii deterministic and stochastic simulations of calcium oscillations, (iii single cell calcium oscillations showing complex behaviour such as periodic and chaotic bursting, and (iv a multicellular calcium model for a cell plate of hepatocytes. We conclude that WR provides a flexible means to deal with multitime-scale computation and model heterogeneity. Global solutions over time can be captured independently of the solution techniques for the individual components, which may be distributed in different computing environments.

  4. Oligodendrocyte precursor cells support blood-brain barrier integrity via TGF-β signaling.

    Directory of Open Access Journals (Sweden)

    Ji Hae Seo

    Full Text Available Trophic coupling between cerebral endothelium and their neighboring cells is required for the development and maintenance of blood-brain barrier (BBB function. Here we report that oligodendrocyte precursor cells (OPCs secrete soluble factor TGF-β1 to support BBB integrity. Firstly, we prepared conditioned media from OPC cultures and added them to cerebral endothelial cultures. Our pharmacological experiments showed that OPC-conditioned media increased expressions of tight-junction proteins and decreased in vitro BBB permeability by activating TGB-β-receptor-MEK/ERK signaling pathway. Secondly, our immuno-electron microscopic observation revealed that in neonatal mouse brains, OPCs attach to cerebral endothelial cells via basal lamina. And finally, we developed a novel transgenic mouse line that TGF-β1 is knocked down specifically in OPCs. Neonates of these OPC-specific TGF-β1 deficient mice (OPC-specific TGF-β1 partial KO mice: PdgfraCre/Tgfb1flox/wt mice or OPC-specific TGF-β1 total KO mice: PdgfraCre/Tgfb1flox/flox mice exhibited cerebral hemorrhage and loss of BBB function. Taken together, our current study demonstrates that OPCs increase BBB tightness by upregulating tight junction proteins via TGF-β signaling. Although astrocytes and pericytes are well-known regulators of BBB maturation and maintenance, these findings indicate that OPCs also play a pivotal role in promoting BBB integrity.

  5. Integrating Data-Mining Support into a Brain-Image Database Using Open-Source Components

    International Nuclear Information System (INIS)

    Purpose: Previously, we described our implementation of a brain-image database (braid), based on the proprietary object-relational database-management system (ORDBMS). In conjunction with our collaborators, we have used this database to manage and analyze image and clinical data from what we call image-based clinical trials (IBCTs). Herein we describe the results of redesigning braid using open-source components, and integrating support for mining image and clinical data from braids user interface. Material and Methods: We re-designed and re-implemented BRAID using open-source components, including PostgreSQL, gcc, and PHP. We integrated data-mining algorithms into braid, based on PL/R, a PostgreSQL package to support efficient communication between R and PostgreSQL. Results: We present a sample clinical study to demonstrate how clinicians can perform queries for visualization, statistical analysis, and data mining, using a web-based interface. Conclusion: We have developed a database system with data-mining capabilities for managing, querying, analyzing and visualizing brain-MR images. We implemented this system using open-source components, with the express goal of wide dissemination throughout the neuroimaging research community. (authors)

  6. Pedagogic process modeling: Humanistic-integrative approach

    Directory of Open Access Journals (Sweden)

    Boritko Nikolaj M.

    2007-01-01

    Full Text Available The paper deals with some current problems of modeling the dynamics of the subject-features development of the individual. The term "process" is considered in the context of the humanistic-integrative approach, in which the principles of self education are regarded as criteria for efficient pedagogic activity. Four basic characteristics of the pedagogic process are pointed out: intentionality reflects logicality and regularity of the development of the process; discreteness (stageability in dicates qualitative stages through which the pedagogic phenomenon passes; nonlinearity explains the crisis character of pedagogic processes and reveals inner factors of self-development; situationality requires a selection of pedagogic conditions in accordance with the inner factors, which would enable steering the pedagogic process. Offered are two steps for singling out a particular stage and the algorithm for developing an integrative model for it. The suggested conclusions might be of use for further theoretic research, analyses of educational practices and for realistic predicting of pedagogical phenomena. .

  7. Modeling the dynamical effects of anesthesia on brain circuits.

    Science.gov (United States)

    Ching, Shinung; Brown, Emery N

    2014-04-01

    General anesthesia is a neurophysiological state that consists of unconsciousness, amnesia, analgesia, and immobility along with maintenance of physiological stability. General anesthesia has been used in the United States for more than 167 years. Now, using systems neuroscience paradigms how anesthetics act in the brain and central nervous system to create the states of general anesthesia is being understood. Propofol is one of the most widely used and the most widely studied anesthetics. When administered for general anesthesia or sedation, the electroencephalogram (EEG) under propofol shows highly structured, rhythmic activity that is strongly associated with changes in the patient's level of arousal. These highly structured oscillations lend themselves readily to mathematical descriptions using dynamical systems models. We review recent model descriptions of the commonly observed EEG patterns associated with propofol: paradoxical excitation, strong frontal alpha oscillations, anteriorization and burst suppression. Our analysis suggests that propofol's actions at GABAergic networks in the cortex, thalamus and brainstem induce profound brain dynamics that are one of the likely mechanisms through which this anesthetic induces altered arousal states from sedation to unconsciousness. Because these dynamical effects are readily observed in the EEG, the mathematical descriptions of how propofol's EEG signatures relate to its mechanisms of action in neural circuits provide anesthesiologists with a neurophysiologically based approach to monitoring the brain states of patients receiving anesthesia care. PMID:24457211

  8. Ontological Modeling for Integrated Spacecraft Analysis

    Science.gov (United States)

    Wicks, Erica

    2011-01-01

    Current spacecraft work as a cooperative group of a number of subsystems. Each of these requiresmodeling software for development, testing, and prediction. It is the goal of my team to create anoverarching software architecture called the Integrated Spacecraft Analysis (ISCA) to aid in deploying the discrete subsystems' models. Such a plan has been attempted in the past, and has failed due to the excessive scope of the project. Our goal in this version of ISCA is to use new resources to reduce the scope of the project, including using ontological models to help link the internal interfaces of subsystems' models with the ISCA architecture.I have created an ontology of functions specific to the modeling system of the navigation system of a spacecraft. The resulting ontology not only links, at an architectural level, language specificinstantiations of the modeling system's code, but also is web-viewable and can act as a documentation standard. This ontology is proof of the concept that ontological modeling can aid in the integration necessary for ISCA to work, and can act as the prototype for future ISCA ontologies.

  9. Site descriptive modelling - strategy for integrated evaluation

    International Nuclear Information System (INIS)

    The current document establishes the strategy to be used for achieving sufficient integration between disciplines in producing Site Descriptive Models during the Site Investigation stage. The Site Descriptive Model should be a multidisciplinary interpretation of geology, rock mechanics, thermal properties, hydrogeology, hydrogeochemistry, transport properties and ecosystems using site investigation data from deep bore holes and from the surface as input. The modelling comprise the following iterative steps, evaluation of primary data, descriptive and quantitative modelling (in 3D), overall confidence evaluation. Data are first evaluated within each discipline and then the evaluations are checked between the disciplines. Three-dimensional modelling (i.e. estimating the distribution of parameter values in space and its uncertainty) is made in a sequence, where the geometrical framework is taken from the geological model and in turn used by the rock mechanics, thermal and hydrogeological modelling etc. The three-dimensional description should present the parameters with their spatial variability over a relevant and specified scale, with the uncertainty included in this description. Different alternative descriptions may be required. After the individual discipline modelling and uncertainty assessment a phase of overall confidence evaluation follows. Relevant parts of the different modelling teams assess the suggested uncertainties and evaluate the feedback. These discussions should assess overall confidence by, checking that all relevant data are used, checking that information in past model versions is considered, checking that the different kinds of uncertainty are addressed, checking if suggested alternatives make sense and if there is potential for additional alternatives, and by discussing, if appropriate, how additional measurements (i.e. more data) would affect confidence. The findings as well as the modelling results are to be documented in a Site Description

  10. INTEGRATING CORPORATE SOCIAL RESPONSIBILITY IN BUSINESS MODELS

    OpenAIRE

    N. A. DENTCHEV

    2005-01-01

    The literature on strategic integration of corporate social responsibility (CSR) in business models is still underdeveloped. We therefore borrow from the theory on strategic management to organize this contribution according to the process of strategic management. After a review of the few strategic CSR approaches, an explorative case-study methodology is adopted to study the management of a CSR proxy, viz. Health Safety and Environment (HSE), in a multinational company in the petrochemicals....

  11. KNET: Integrating Hypermedia and Bayesian Modeling

    OpenAIRE

    Chavez, R. Martin; Cooper, Gregory F.

    2013-01-01

    KNET is a general-purpose shell for constructing expert systems based on belief networks and decision networks. Such networks serve as graphical representations for decision models, in which the knowledge engineer must define clearly the alternatives, states, preferences, and relationships that constitute a decision basis. KNET contains a knowledge-engineering core written in Object Pascal and an interface that tightly integrates HyperCard, a hypertext authoring tool for the Apple Macintosh c...

  12. Model sparsity and brain pattern interpretation of classification models in neuroimaging

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup; Madsen, Kristoffer Hougaard; Churchill, Nathan W; Hansen, Lars Kai; Strother, Stephen C

    2012-01-01

    Interest is increasing in applying discriminative multivariate analysis techniques to the analysis of functional neuroimaging data. Model interpretation is of great importance in the neuroimaging context, and is conventionally based on a ‘brain map’ derived from the classification model. In this...... study we focus on the relative influence of model regularization parameter choices on both the model generalization, the reliability of the spatial patterns extracted from the classification model, and the ability of the resulting model to identify relevant brain networks defining the underlying neural...... for both ℓ2 and ℓ1 regularization. Importantly, we illustrate a trade-off between model spatial reproducibility and prediction accuracy. We show that known parts of brain networks can be overlooked in pursuing maximization of classification accuracy alone with either ℓ2 and/or ℓ1 regularization. This...

  13. Integrated modeling of advanced optical systems

    Science.gov (United States)

    Briggs, Hugh C.; Needels, Laura; Levine, B. Martin

    1993-02-01

    This poster session paper describes an integrated modeling and analysis capability being developed at JPL under funding provided by the JPL Director's Discretionary Fund and the JPL Control/Structure Interaction Program (CSI). The posters briefly summarize the program capabilities and illustrate them with an example problem. The computer programs developed under this effort will provide an unprecedented capability for integrated modeling and design of high performance optical spacecraft. The engineering disciplines supported include structural dynamics, controls, optics and thermodynamics. Such tools are needed in order to evaluate the end-to-end system performance of spacecraft such as OSI, POINTS, and SMMM. This paper illustrates the proof-of-concept tools that have been developed to establish the technology requirements and demonstrate the new features of integrated modeling and design. The current program also includes implementation of a prototype tool based upon the CAESY environment being developed under the NASA Guidance and Control Research and Technology Computational Controls Program. This prototype will be available late in FY-92. The development plan proposes a major software production effort to fabricate, deliver, support and maintain a national-class tool from FY-93 through FY-95.

  14. Drosophila melanogaster as a Model Organism of Brain Diseases

    Directory of Open Access Journals (Sweden)

    Werner Paulus

    2009-02-01

    Full Text Available Drosophila melanogaster has been utilized to model human brain diseases. In most of these invertebrate transgenic models, some aspects of human disease are reproduced. Although investigation of rodent models has been of significant impact, invertebrate models offer a wide variety of experimental tools that can potentially address some of the outstanding questions underlying neurological disease. This review considers what has been gleaned from invertebrate models of neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, metabolic diseases such as Leigh disease, Niemann-Pick disease and ceroid lipofuscinoses, tumor syndromes such as neurofibromatosis and tuberous sclerosis, epilepsy as well as CNS injury. It is to be expected that genetic tools in Drosophila will reveal new pathways and interactions, which hopefully will result in molecular based therapy approaches.

  15. Blast-Associated Shock Waves Result in Increased Brain Vascular Leakage and Elevated ROS Levels in a Rat Model of Traumatic Brain Injury.

    Science.gov (United States)

    Kabu, Shushi; Jaffer, Hayder; Petro, Marianne; Dudzinski, Dave; Stewart, Desiree; Courtney, Amy; Courtney, Michael; Labhasetwar, Vinod

    2015-01-01

    Blast-associated shock wave-induced traumatic brain injury (bTBI) remains a persistent risk for armed forces worldwide, yet its detailed pathophysiology remains to be fully investigated. In this study, we have designed and characterized a laboratory-scale shock tube to develop a rodent model of bTBI. Our blast tube, driven by a mixture of oxygen and acetylene, effectively generates blast overpressures of 20-130 psi, with pressure-time profiles similar to those of free-field blast waves. We tested our shock tube for brain injury response to various blast wave conditions in rats. The results show that blast waves cause diffuse vascular brain damage, as determined using a sensitive optical imaging method based on the fluorescence signal of Evans Blue dye extravasation developed in our laboratory. Vascular leakage increased with increasing blast overpressures and mapping of the brain slices for optical signal intensity indicated nonhomogeneous damage to the cerebral vasculature. We confirmed vascular leakage due to disruption in the blood-brain barrier (BBB) integrity following blast exposure. Reactive oxygen species (ROS) levels in the brain also increased with increasing blast pressures and with time post-blast wave exposure. Immunohistochemical analysis of the brain sections analyzed at different time points post blast exposure demonstrated astrocytosis and cell apoptosis, confirming sustained neuronal injury response. The main advantages of our shock-tube design are minimal jet effect and no requirement for specialized equipment or facilities, and effectively generate blast-associated shock waves that are relevant to battle-field conditions. Overall data suggest that increased oxidative stress and BBB disruption could be the crucial factors in the propagation and spread of neuronal degeneration following blast injury. Further studies are required to determine the interplay between increased ROS activity and BBB disruption to develop effective therapeutic strategies

  16. The integrated Regional Earth System Model

    Science.gov (United States)

    Kraucunas, I.; Clarke, L.; Dirks, J.; Hejazi, M. I.; Hibbard, K. A.; Huang, M.; Janetos, A. C.; Kintner-Meyer, M.; Kleese van Dam, K.; Leung, L.; Moss, R. H.; Rice, J.; Scott, M. J.; Thomson, A. M.; West, T. O.; Whitney, P.; Yang, Z.

    2012-12-01

    The integrated Regional Earth System Model (iRESM) is a unique modeling framework being developed at Pacific Northwest National Laboratory (PNNL) to simulate the interactions among natural and human systems at scales relevant to regional decision making. The framework unites high-resolution models of regional climate, hydrology, agriculture, socioeconomics, and energy systems using a flexible software architecture. The framework is portable and can be customized to inform a variety of complex questions and decisions, including (but not limited to) planning, implementation, and evaluation of mitigation and adaptation options across a range of sectors. iRESM also incorporates extensive stakeholder interactions and analysis to inform model development, coupling strategies, and characterization of uncertainties. Ongoing numerical experiments are yielding new insights into the interactions among human and natural systems on regional scales, with an initial focus on the energy-land-water nexus and the penetration of renewable energy technologies in the upper U.S. Midwest. The iRESM framework also is being extended and applied to the U.S. Gulf Coast, with a particular emphasis on how changes in extreme events will affect both coastal in inland energy infrastructure in the region. This talk will focus on iRESM's development and capabilities, initial results from numerical experiments, and the challenges and opportunities associated with integrated regional modeling.

  17. Systematic Review of Traumatic Brain Injury Animal Models.

    Science.gov (United States)

    Phipps, Helen W

    2016-01-01

    The goals of this chapter are to provide an introduction into the variety of animal models available for studying traumatic brain injury (TBI) and to provide a concise systematic review of the general materials and methods involved in each model. Materials and methods were obtained from a literature search of relevant peer-reviewed articles. Strengths and weaknesses of each animal choice were presented to include relative cost, anatomical and physiological features, and mechanism of injury desired. Further, a variety of homologous, isomorphic/induced, and predictive animal models were defined, described, and compared with respect to their relative ease of use, characteristics, range, adjustability (e.g., amplitude, duration, mass/size, velocity, and pressure), and rough order of magnitude cost. Just as the primary mechanism of action of TBI is limitless, so are the animal models available to study TBI. With such a wide variety of available animals, types of injury models, along with the research needs, there exists no single "gold standard" model of TBI rendering cross-comparison of data extremely difficult. Therefore, this chapter reflects a representative sampling of the TBI animal models available and is not an exhaustive comparison of every possible model and associated parameters. Throughout this chapter, special considerations for animal choice and TBI animal model classification are discussed. Criteria central to choosing appropriate animal models of TBI include ethics, funding, complexity (ease of use, safety, and controlled access requirements), type of model, model characteristics, and range of control (scope). PMID:27604713

  18. Hierarchical linear modeling (HLM) of longitudinal brain structural and cognitive changes in alcohol-dependent individuals during sobriety

    DEFF Research Database (Denmark)

    Yeh, P.H.; Gazdzinski, S.; Durazzo, T.C.; Sjöstrand, Karl; Meyerhoff, D.J.

    )-derived brain volume changes and cognitive changes in abstinent alcohol-dependent individuals as a function of smoking status, smoking severity, and drinking quantities. Methods: Twenty non-smoking recovering alcoholics (nsALC) and 30 age-matched smoking recovering alcoholics (sALC) underwent quantitative MRI...... and cognitive assessments at 1 week, 1 month, and 7 months of sobriety. Eight non-smoking light drinking controls were studied at baseline and 7 months later. Brain and ventricle volumes at each time point were quantified using MRI masks, while the boundary shift integral method measured volume...... changes between time points. Using HLM, we modeled volumetric and cognitive outcome measures as a function of cigarette and alcohol use variables. Results: Different hierarchical linear models with unique model structures are presented and discussed. The results show that smaller brain volumes at baseline...

  19. Multiscale modeling of brain dynamics: from single neurons and networks to mathematical tools.

    Science.gov (United States)

    Siettos, Constantinos; Starke, Jens

    2016-09-01

    The extreme complexity of the brain naturally requires mathematical modeling approaches on a large variety of scales; the spectrum ranges from single neuron dynamics over the behavior of groups of neurons to neuronal network activity. Thus, the connection between the microscopic scale (single neuron activity) to macroscopic behavior (emergent behavior of the collective dynamics) and vice versa is a key to understand the brain in its complexity. In this work, we attempt a review of a wide range of approaches, ranging from the modeling of single neuron dynamics to machine learning. The models include biophysical as well as data-driven phenomenological models. The discussed models include Hodgkin-Huxley, FitzHugh-Nagumo, coupled oscillators (Kuramoto oscillators, Rössler oscillators, and the Hindmarsh-Rose neuron), Integrate and Fire, networks of neurons, and neural field equations. In addition to the mathematical models, important mathematical methods in multiscale modeling and reconstruction of the causal connectivity are sketched. The methods include linear and nonlinear tools from statistics, data analysis, and time series analysis up to differential equations, dynamical systems, and bifurcation theory, including Granger causal connectivity analysis, phase synchronization connectivity analysis, principal component analysis (PCA), independent component analysis (ICA), and manifold learning algorithms such as ISOMAP, and diffusion maps and equation-free techniques. WIREs Syst Biol Med 2016, 8:438-458. doi: 10.1002/wsbm.1348 For further resources related to this article, please visit the WIREs website. PMID:27340949

  20. BrainSignals Revisited: Simplifying a Computational Model of Cerebral Physiology.

    Directory of Open Access Journals (Sweden)

    Matthew Caldwell

    Full Text Available Multimodal monitoring of brain state is important both for the investigation of healthy cerebral physiology and to inform clinical decision making in conditions of injury and disease. Near-infrared spectroscopy is an instrument modality that allows non-invasive measurement of several physiological variables of clinical interest, notably haemoglobin oxygenation and the redox state of the metabolic enzyme cytochrome c oxidase. Interpreting such measurements requires the integration of multiple signals from different sources to try to understand the physiological states giving rise to them. We have previously published several computational models to assist with such interpretation. Like many models in the realm of Systems Biology, these are complex and dependent on many parameters that can be difficult or impossible to measure precisely. Taking one such model, BrainSignals, as a starting point, we have developed several variant models in which specific regions of complexity are substituted with much simpler linear approximations. We demonstrate that model behaviour can be maintained whilst achieving a significant reduction in complexity, provided that the linearity assumptions hold. The simplified models have been tested for applicability with simulated data and experimental data from healthy adults undergoing a hypercapnia challenge, but relevance to different physiological and pathophysiological conditions will require specific testing. In conditions where the simplified models are applicable, their greater efficiency has potential to allow their use at the bedside to help interpret clinical data in near real-time.

  1. Integrated Model for E-Learning Acceptance

    Science.gov (United States)

    Ramadiani; Rodziah, A.; Hasan, S. M.; Rusli, A.; Noraini, C.

    2016-01-01

    E-learning is not going to work if the system is not used in accordance with user needs. User Interface is very important to encourage using the application. Many theories had discuss about user interface usability evaluation and technology acceptance separately, actually why we do not make it correlation between interface usability evaluation and user acceptance to enhance e-learning process. Therefore, the evaluation model for e-learning interface acceptance is considered important to investigate. The aim of this study is to propose the integrated e-learning user interface acceptance evaluation model. This model was combined some theories of e-learning interface measurement such as, user learning style, usability evaluation, and the user benefit. We formulated in constructive questionnaires which were shared at 125 English Language School (ELS) students. This research statistics used Structural Equation Model using LISREL v8.80 and MANOVA analysis.

  2. Completely integrable models of nonlinear optics

    Indian Academy of Sciences (India)

    Andrey I Maimistov

    2001-11-01

    The models of the nonlinear optics in which solitons appeared are considered. These models are of paramount importance in studies of nonlinear wave phenomena. The classical examples of phenomena of this kind are the self-focusing, self-induced transparency and parametric interaction of three waves. At present there are a number of theories based on completely integrable systems of equations, which are, both, generations of the original known models and new ones. The modified Korteweg-de Vries equation, the nonlinear Schrödinger equation, the derivative nonlinear Schrödinger equation, Sine–Gordon equation, the reduced Maxwell–Bloch equation, Hirota equation, the principal chiral field equations, and the equations of massive Thirring model are some soliton equations, which are usually to be found in nonlinear optics theory.

  3. Cyclosporin safety in a simplified rat brain tumor implantation model

    Directory of Open Access Journals (Sweden)

    Francisco H. C. Felix

    2012-01-01

    Full Text Available Brain cancer is the second neurological cause of death. A simplified animal brain tumor model using W256 (carcinoma 256, Walker cell line was developed to permit the testing of novel treatment modalities. Wistar rats had a cell tumor solution inoculated stereotactically in the basal ganglia (right subfrontal caudate. This model yielded tumor growth in 95% of the animals, and showed absence of extracranial metastasis and systemic infection. Survival median was 10 days. Estimated tumor volume was 17.08±6.7 mm³ on the 7th day and 67.25±19.8 mm³ on 9th day post-inoculation. Doubling time was 24.25 h. Tumor growth induced cachexia, but no hematological or biochemical alterations. This model behaved as an undifferentiated tumor and can be promising for studying tumor cell migration in the central nervous system. Dexamethasone 3.0 mg/kg/day diminished significantly survival in this model. Cyclosporine 10 mg/kg/day administration was safely tolerated.

  4. Integration of Simulink Models with Component-based Software Models

    DEFF Research Database (Denmark)

    Marian, Nicolae; Top, Søren

    2008-01-01

    abstract system descriptions. Usually, in mechatronics systems, design proceeds by iterating model construction, model analysis, and model transformation. Constructing a MATLAB/Simulink model, a plant and controller behavior is simulated using graphical blocks to represent mathematical and logical...... analyzed. One way of doing that is to integrate in wrapper files the model back into Simulink S-functions, and use its extensive simulation features, thus allowing an early exploration of the possible design choices over multiple disciplines. The paper describes a safe translation of a restricted set of...

  5. Typological and Integrative Models of Sexual Abuse

    Directory of Open Access Journals (Sweden)

    Demidova L.Y.,

    2014-11-01

    Full Text Available We discuss the basic typological and integrative theoretical models that explain the occurrence of child sexual abuse and the differences detected among the perpetrators of crimes against sexual integrity of minors. A comprehensive review of the theoretical concepts of sexual abuse in our country, in fact has not been carried out, and in this paper for the first time we made such an attempt. It is shown that the existing notions of sexual abuse largely overlap each other, but each of the models somehow takes into account the factors not explicitly addressed in other concepts. Systematic consideration of the theoretical models of sexual abuse can generalize and systematize the available data on the mechanisms of pedophile behavior. This review provides an opportunity to develop a new benchmark in the study of sexual abuse, get closer to building the most accurate and comprehensive model. In turn, this may contribute to solving the questions about the factors, dynamics, and the prevention of criminal sexual conduct against children

  6. Automatic segmentation of meningioma from non-contrasted brain MRI integrating fuzzy clustering and region growing

    Directory of Open Access Journals (Sweden)

    Liao Chun-Chih

    2011-08-01

    Full Text Available Abstract Background In recent years, magnetic resonance imaging (MRI has become important in brain tumor diagnosis. Using this modality, physicians can locate specific pathologies by analyzing differences in tissue character presented in different types of MR images. This paper uses an algorithm integrating fuzzy-c-mean (FCM and region growing techniques for automated tumor image segmentation from patients with menigioma. Only non-contrasted T1 and T2 -weighted MR images are included in the analysis. The study's aims are to correctly locate tumors in the images, and to detect those situated in the midline position of the brain. Methods The study used non-contrasted T1- and T2-weighted MR images from 29 patients with menigioma. After FCM clustering, 32 groups of images from each patient group were put through the region-growing procedure for pixels aggregation. Later, using knowledge-based information, the system selected tumor-containing images from these groups and merged them into one tumor image. An alternative semi-supervised method was added at this stage for comparison with the automatic method. Finally, the tumor image was optimized by a morphology operator. Results from automatic segmentation were compared to the "ground truth" (GT on a pixel level. Overall data were then evaluated using a quantified system. Results The quantified parameters, including the "percent match" (PM and "correlation ratio" (CR, suggested a high match between GT and the present study's system, as well as a fair level of correspondence. The results were compatible with those from other related studies. The system successfully detected all of the tumors situated at the midline of brain. Six cases failed in the automatic group. One also failed in the semi-supervised alternative. The remaining five cases presented noticeable edema inside the brain. In the 23 successful cases, the PM and CR values in the two groups were highly related. Conclusions Results indicated

  7. Global Environmental Change: An integrated modelling approach

    International Nuclear Information System (INIS)

    Two major global environmental problems are dealt with: climate change and stratospheric ozone depletion (and their mutual interactions), briefly surveyed in part 1. In Part 2 a brief description of the integrated modelling framework IMAGE 1.6 is given. Some specific parts of the model are described in more detail in other Chapters, e.g. the carbon cycle model, the atmospheric chemistry model, the halocarbon model, and the UV-B impact model. In Part 3 an uncertainty analysis of climate change and stratospheric ozone depletion is presented (Chapter 4). Chapter 5 briefly reviews the social and economic uncertainties implied by future greenhouse gas emissions. Chapters 6 and 7 describe a model and sensitivity analysis pertaining to the scientific uncertainties and/or lacunae in the sources and sinks of methane and carbon dioxide, and their biogeochemical feedback processes. Chapter 8 presents an uncertainty and sensitivity analysis of the carbon cycle model, the halocarbon model, and the IMAGE model 1.6 as a whole. Part 4 presents the risk assessment methodology as applied to the problems of climate change and stratospheric ozone depletion more specifically. In Chapter 10, this methodology is used as a means with which to asses current ozone policy and a wide range of halocarbon policies. Chapter 11 presents and evaluates the simulated globally-averaged temperature and sea level rise (indicators) for the IPCC-1990 and 1992 scenarios, concluding with a Low Risk scenario, which would meet the climate targets. Chapter 12 discusses the impact of sea level rise on the frequency of the Dutch coastal defence system (indicator) for the IPCC-1990 scenarios. Chapter 13 presents projections of mortality rates due to stratospheric ozone depletion based on model simulations employing the UV-B chain model for a number of halocarbon policies. Chapter 14 presents an approach for allocating future emissions of CO2 among regions. (Abstract Truncated)

  8. A watershed model to integrate EO data

    Science.gov (United States)

    Jauch, Eduardo; Chambel-Leitao, Pedro; Carina, Almeida; Brito, David; Cherif, Ines; Alexandridis, Thomas; Neves, Ramiro

    2013-04-01

    MOHID LAND is a open source watershed model developed by MARETEC and is part of the MOHID Framework. It integrates four mediums (or compartments): porous media, surface, rivers and atmosphere. The movement of water between these mediums are based on mass and momentum balance equations. The atmosphere medium is not explicity simulated. Instead, it's used as boundary condition to the model through meteorological properties: precipitation, solar radiation, wind speed/direction, relative humidity and air temperature. The surface medium includes the overland runoff and vegetation growth processes and is simulated using a 2D grid. The porous media includes both the unsaturated (soil) and saturated zones (aquifer) and is simulated using a 3D grid. The river flow is simulated through a 1D drainage network. All these mediums are linked through evapotranspiration and flow exchanges (infiltration, river-soil growndwater flow, surface-river overland flow). Besides the water movement, it is also possible to simulate water quality processes and solute/sediment transport. Model setup include the definition of the geometry and the properties of each one of its compartments. After the setup of the model, the only continuous input data that MOHID LAND requires are the atmosphere properties (boundary conditions) that can be provided as timeseries or spacial data. MOHID LAND has been adapted the last 4 years under FP7 and ESA projects to integrate Earth Observation (EO) data, both variable in time and in space. EO data can be used to calibrate/validate or as input/assimilation data to the model. The currently EO data used include LULC (Land Use Land Cover) maps, LAI (Leaf Area Index) maps, EVTP (Evapotranspiration) maps and SWC (Soil Water Content) maps. Model results are improved by the EO data, but the advantage of this integration is that the model can still run without the EO data. This means that model do not stop due to unavailability of EO data and can run on a forecast mode

  9. Spatiotemporal Modeling of Brain Dynamics Using Resting-State Functional Magnetic Resonance Imaging with Gaussian Hidden Markov Model.

    Science.gov (United States)

    Chen, Shiyang; Langley, Jason; Chen, Xiangchuan; Hu, Xiaoping

    2016-05-01

    Analyzing functional magnetic resonance imaging (fMRI) time courses with dynamic approaches has generated a great deal of interest because of the additional temporal features that can be extracted. In this work, to systemically model spatiotemporal patterns of the brain, a Gaussian hidden Markov model (GHMM) was adopted to model the brain state switching process. We assumed that the brain switches among a number of different brain states as a Markov process and used multivariate Gaussian distributions to represent the spontaneous activity patterns of brain states. This model was applied to resting-state fMRI data from 100 subjects in the Human Connectome Project and detected nine highly reproducible brain states and their temporal and transition characteristics. Our results indicate that the GHMM can unveil brain dynamics that may provide additional insights regarding the brain at resting state. PMID:27008543

  10. 3D segmented model of head for modelling electrical activity of brain

    Directory of Open Access Journals (Sweden)

    Egill A. Friðgeirsson

    2012-03-01

    Full Text Available Computer simulation and modelling of the human body and its behaviour are very useful tools in situations where it is either too risky to perform an invasive procedure or too costly for in vivo experiments or simply impossible for ethical reasons. In this paper we describe a method to model the electrical behaviour of human brain from segmented MR images. The aim of the work is to use these models to predict the electrical activity of human brain under normal and pathological conditions. The image processing software package MIMICS is used for 3D volume segmentation of MR images. These models have detailed 3D representation of major tissue surfaces within the head, with over 12 different tissues segmented. In addition, computational tools in Matlab were developed for calculating normal vectors on the brain surface and for associating this information to the equivalent electrical dipole sources as an input into the model.

  11. Model of the Brain Tumor–Pumilio translation repressor complex

    OpenAIRE

    Edwards, Thomas A.; Wilkinson, Brian D.; Wharton, Robin P.; Aggarwal, Aneel K.

    2003-01-01

    The Brain Tumor (Brat) protein is recruited to the 3′ untranslated region (UTR) of hunchback mRNA to regulate its translation. Recruitment is mediated by interactions between the Pumilio RNA-binding Puf repeats and the NHL domain of Brat, a conserved structural motif present in a large family of growth regulators. In this report, we describe the crystal structure of the Brat NHL domain and present a model of the Pumilio–Brat complex derived from in silico docking experiments and supported by ...

  12. 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.

  13. Functional brain networks contributing to the Parieto-Frontal Integration Theory of Intelligence.

    Science.gov (United States)

    Vakhtin, Andrei A; Ryman, Sephira G; Flores, Ranee A; Jung, Rex E

    2014-12-01

    The refinement of localization of intelligence in the human brain is converging onto a distributed network that broadly conforms to the Parieto-Frontal Integration Theory (P-FIT). While this theory has received support in the neuroimaging literature, no functional magnetic resonance imaging study to date has conducted a whole-brain network-wise examination of the changes during engagement in tasks that are reliable measures of general intelligence (e.g., Raven's Progressive Matrices Test; RPM). Seventy-nine healthy subjects were scanned while solving RPM problems and during rest. Functional networks were extracted from the RPM and resting state data using Independent Component Analysis. Twenty-nine networks were identified, 26 of which were detected in both conditions. Fourteen networks were significantly correlated with the RPM task. The networks' spatial maps and functional connectivity measures at 3 frequency levels (low, medium, & high) were compared between the RPM and rest conditions. The regions involved in the networks that were found to be task related were consistent with the P-FIT, localizing to the bilateral medial frontal and parietal regions, right superior frontal lobule, and the right cingulate gyrus. Functional connectivity in multiple component pairs was differentially affected across all frequency levels during the RPM task. Our findings demonstrate that functional brain networks are more stable than previously thought, and maintain their general features across resting state and engagement in a complex cognitive task. The described spatial and functional connectivity alterations that such components undergo during fluid reasoning provide a network-wise framework of the P-FIT that can be valuable for further, network based, neuroimaging inquiries regarding the neural underpinnings of intelligence. PMID:25284305

  14. Selectionist models of perceptual and motor systems and implications for functionalist theories of brain function

    Science.gov (United States)

    Reeke, George N.; Sporns, Olaf

    1990-06-01

    Functionalism is at present widely accepted as a working basis for cognitive science and artificial intelligence. This view holds that psychological phenomena can be adequately described in terms of functional processes carried out in the brain, and that these processes can be understood independently of the detailed structure and mode of development of the brain. In the functionalist view, the brain is analogous to a computer; both can properly be described at the level of symbolic representations and algorithms. However, an analysis of the structure, development, and evolution of the brain makes it highly unlikely that it could be a Turing machine or that brain algorithms could be either acquired by experience in the world or transmitted between generations. An alternative view is that the brain is a selective system in which two different domains of stochastic variation, the world and neural repertoires, become mapped onto each other in an individual, historical manner. Neural systems capable of such mapping can generalize and can deal with novelty in an open-ended environment. Several models have been constructed to test these ideas, including automata of a new kind that can recognize and associate patterns of sensory input by selective mechanisms. In an approach called synthetic neural modelling, the environment, the phenotype, and the nervous system of such an automaton are integrated into a single computer model. One example is Darwin III, a sessile “creature” with an eye and a multi-jointed arm having a sense of touch; its environment consists of simple shapes moving on a featureless background; its nervous system consists of some 50 000 cells of 50 different kinds connected by about 620 000 synaptic junctions. Darwin III can be trained to track moving objects with its eye, to reach out and touch objects with its arm, to categorize objects according to combinations of visual and tactile cues, and to respond in a positive or negative way to such objects

  15. Assessment of traumatic brain injury degree in animal model

    Institute of Scientific and Technical Information of China (English)

    Jian-Qiang Chen; Cheng-Cheng Zhang; Hong Lu; Wei Wang

    2014-01-01

    Objective:To establish stable and controllable brain injury with accurate degree and good repeatability in rat model.Methods:Controlled cortical impact(CCI) device was used to prepare for the rat brain injury model by the impact head of different model(GroupANo.4,GroupBNo.5, GroupCNo.6) and the impact depth(GroupA:1.5-2.0 mm,GroupB:2.5-3.0 mm,GroupC:3.5-4.0 mm) with impact time of0.1 s and impact velocity of2.5 m/s.Twelve rats with three months of age were used in each group(the impact depth of every two rats was added1 mm respectively).After modeling for1 h, magnetic resonance imaging(MRI) was received and brain histopathology was observed to assess degree of injury by model parameters of three groups.Results:After modeling ofGroupA,MRI showed that the cortex structure was damaged with a small amount of bleeding in center and mild edema around, and the total volume of injury was(28.69±4.94) mm3.Pathology revealed the injury was confined to the superficial cortical with mild edema of nerve cell, which was assessed as mild cerebral contusion.While after modeling,MRI ofGroupB showed that the structure of cortex and medulla were damaged simultaneously and extended to cerebral nuclei zone, with4 cases of hematoma in the center and larger edema range around, and the total volume of injury was(78.38±9.28) mm3.Pathology revealed the injury range was reached nuclei zone, with swell of nerve cell and mitochondria, which was assessed to moderate cerebral contusion. After modeling ofGroupC,MRI showed that extensive tissue injury was appeared in cortex and medulla and deep nuclei, with9 cases of hematoma and large edema signal of surrounding tissue T2WI, while in5 cases, lateral nucleus of injury signal was increased, and the total volume of injury was(135.89±24.80) mm3.Pathology revealed the deep cerebral nuclei was damaged, with the disappearance of neuronal structure and vacuolization of mitochondria, which was assessed as severe cerebral contusion.MRI changes were

  16. The Simulation and Correction to the Brain Deformation Based on the Linear Elastic Model in IGS

    Institute of Scientific and Technical Information of China (English)

    MU Xiao-lan; SONG Zhi-jian

    2004-01-01

    @@ The brain deformation is a vital factor affecting the precision of the IGS and it becomes a hotspot to simulate and correct the brain deformation recently.The research organizations, which firstly resolved the brain deformation with the physical models, have the Image Processing and Analysis department of Yale University, Biomedical Modeling Lab of Vanderbilt University and so on. The former uses the linear elastic model; the latter uses the consolidation model.The linear elastic model only needs to drive the model using the surface displacement of exposed brain cortex,which is more convenient to be measured in the clinic.

  17. Differential and Integral Models of TOKAMAK

    Directory of Open Access Journals (Sweden)

    Ivo Dolezel

    2004-01-01

    Full Text Available Modeling of 3D electromagnetic phenomena in TOKAMAK with typically distributed main and additional coils is not an easy business. Evaluated must be not only distribution of the magnetic field, but also forces acting in particular coils. Use of differential methods (such as FDM or FEM for this purpose may be complicated because of geometrical incommensurability of particular subregions in the investigated area or problems with the boundary conditions. That is why integral formulation of the problem may sometimes be an advantages. The theoretical analysis is illustrated on an example processed by both methods, whose results are compared and discussed.

  18. Brain Death and Human Organismal Integration: A Symposium on the Definition of Death.

    Science.gov (United States)

    Moschella, Melissa

    2016-06-01

    Does the ability of some brain dead bodies to maintain homeostasis with the help of artificial life support actually imply that those bodies are living human organisms? Or might it be possible that a brain dead body on life support is a mere collection of still-living cells, organs and tissues which can coordinate with one another, but which lack the genuine integration that is the hallmark of a unified human organism as a whole? To foster further study of these difficult and timely questions, a Symposium on the Definition of Death was held at The Catholic University of America in June 2014. The Symposium brought together scholars from a variety of disciplines-law, medicine, biology, philosophy and theology-who all share a commitment to the dead donor rule and to a biological definition of death, but who have differing opinions regarding the validity of neurological criteria for human death. The papers found in this special issue are among the fruits of this Symposium. PMID:27107428

  19. Sixty minutes of what? A developing brain perspective for activating children with an integrative exercise approach.

    Science.gov (United States)

    Myer, Gregory D; Faigenbaum, Avery D; Edwards, Nicholas M; Clark, Joseph F; Best, Thomas M; Sallis, Robert E

    2015-12-01

    Current recommendations for physical activity in children overlook the critical importance of motor skill acquisition early in life. Instead, they focus on the quantitative aspects of physical activity (eg, accumulate 60 min of daily moderate to vigorous physical activity) and selected health-related components of physical fitness (eg, aerobic fitness, muscular strength, muscular endurance, flexibility and body composition). This focus on exercise quantity in youth may limit considerations of qualitative aspects of programme design which include (1) skill development, (2) socialisation and (3) enjoyment of exercise. The timing of brain development and associated neuroplasticity for motor skill learning makes the preadolescence period a critical time to develop and reinforce fundamental movement skills in boys and girls. Children who do not participate regularly in structured motor skill-enriched activities during physical education classes or diverse youth sports programmes may never reach their genetic potential for motor skill control which underlies sustainable physical fitness later in life. The goals of this review are twofold: (1) challenge current dogma that is currently focused on the quantitative rather than qualitative aspects of physical activity recommendations for youth and (2) synthesise the latest evidence regarding the brain and motor control that will provide the foundation for integrative exercise programming that provide a framework sustainable activity for life. PMID:25617423

  20. A Fuzzy Integral Ensemble Method in Visual P300 Brain-Computer Interface

    Science.gov (United States)

    Cavrini, Francesco; Quitadamo, Lucia Rita; Saggio, Giovanni

    2016-01-01

    We evaluate the possibility of application of combination of classifiers using fuzzy measures and integrals to Brain-Computer Interface (BCI) based on electroencephalography. In particular, we present an ensemble method that can be applied to a variety of systems and evaluate it in the context of a visual P300-based BCI. Offline analysis of data relative to 5 subjects lets us argue that the proposed classification strategy is suitable for BCI. Indeed, the achieved performance is significantly greater than the average of the base classifiers and, broadly speaking, similar to that of the best one. Thus the proposed methodology allows realizing systems that can be used by different subjects without the need for a preliminary configuration phase in which the best classifier for each user has to be identified. Moreover, the ensemble is often capable of detecting uncertain situations and turning them from misclassifications into abstentions, thereby improving the level of safety in BCI for environmental or device control. PMID:26819595

  1. Diffusion tensor imaging reveals adolescent binge ethanol-induced brain structural integrity alterations in adult rats that correlate with behavioral dysfunction.

    Science.gov (United States)

    Vetreno, Ryan P; Yaxley, Richard; Paniagua, Beatriz; Crews, Fulton T

    2016-07-01

    Adolescence is characterized by considerable brain maturation that coincides with the development of adult behavior. Binge drinking is common during adolescence and can have deleterious effects on brain maturation because of the heightened neuroplasticity of the adolescent brain. Using an animal model of adolescent intermittent ethanol [AIE; 5.0 g/kg, intragastric, 20 percent EtOH w/v; 2 days on/2 days off from postnatal day (P)25 to P55], we assessed the adult brain structural volumes and integrity on P80 and P220 using diffusion tensor imaging (DTI). While we did not observe a long-term effect of AIE on structural volumes, AIE did reduce axial diffusivity (AD) in the cerebellum, hippocampus and neocortex. Radial diffusivity (RD) was reduced in the hippocampus and neocortex of AIE-treated animals. Prior AIE treatment did not affect fractional anisotropy (FA), but did lead to long-term reductions of mean diffusivity (MD) in both the cerebellum and corpus callosum. AIE resulted in increased anxiety-like behavior and diminished object recognition memory, the latter of which was positively correlated with DTI measures. Across aging, whole brain volumes increased, as did volumes of the corpus callosum and neocortex. This was accompanied by age-associated AD reductions in the cerebellum and neocortex as well as RD and MD reductions in the cerebellum. Further, we found that FA increased in both the cerebellum and corpus callosum as rats aged from P80 to P220. Thus, both age and AIE treatment caused long-term changes to brain structural integrity that could contribute to cognitive dysfunction. PMID:25678360

  2. The Simulation and Correction to the Brain Deformation Based on the Linear Elastic Model in IGS

    Institute of Scientific and Technical Information of China (English)

    MUXiao-lan; SONGZhi-jian

    2004-01-01

    The brain deformation is a vital factor affecting the precision of the IGS and it becomes a hotspot to simulate and correct the brain deformation recently.The research organizations, which firstly resolved the brain deformation with the physical models, have the Image Processing and Analysis department of Yale University, Biomedical Modeling Lab of Vanderbilt University and so on. The former uses the linear elastic model; the latter uses the consolidation model.

  3. Developing Metrics in Systems Integration (ISS Program COTS Integration Model)

    Science.gov (United States)

    Lueders, Kathryn

    2007-01-01

    This viewgraph presentation reviews some of the complications in developing metrics for systems integration. Specifically it reviews a case study of how two programs within NASA try to develop and measure performance while meeting the encompassing organizational goals.

  4. Foundational model of neuroanatomy: implications for the Human Brain Project.

    OpenAIRE

    Martin, R F; Mejino, J. L.; Bowden, D. M.; Brinkley, J. F.; Rosse, C.

    2001-01-01

    In order to meet the need for a controlled terminology in neuroinformatics, we have integrated the extensive terminology of NeuroNames into the Foundational Model of anatomy. We illustrate the application of foundational principles for the establishment of an inheritance hierarchy, which accommodates anatomical attributes of neuroanatomical concepts and provides the foundation to which other information may be linked.

  5. Cluster imaging of multi-brain networks (CIMBN: a general framework for hyperscanning and modeling a group of interacting brains

    Directory of Open Access Journals (Sweden)

    Lian eDuan

    2015-07-01

    Full Text Available Studying the neural basis of human social interactions is a key topic in the field of social neuroscience. Brain imaging studies in this field usually focus on the neural correlates of the social interactions between two participants. However, as the participant number further increases, even by a small amount, great difficulties raise. One challenge is how to concurrently scan all the interacting brains with high ecological validity, especially for a large number of participants. The other challenge is how to effectively model the complex group interaction behaviors emerging from the intricate neural information exchange among a group of socially organized people. Confronting these challenges, we propose a new approach called Cluster Imaging of Multi-brain Networks (CIMBN. CIMBN consists of two parts. The first part is a cluster imaging technique with high ecological validity based on multiple functional near-infrared spectroscopy (fNIRS systems. Using this technique, we can easily extend the simultaneous imaging capacity of social neuroscience studies up to dozens of participants. The second part of CIMBN is a multi-brain network (MBN modeling method based on graph theory. By taking each brain as a network node and the relationship between any two brains as a network edge, one can construct a network model for a group of interacting brains. The emergent group social behaviors can then be studied using the network’s properties, such as its topological structure and information exchange efficiency. Although there is still much work to do, as a general framework for hyperscanning and modeling a group of interacting brains, CIMBN can provide new insights into the neural correlates of group social interactions, and advance social neuroscience and social psychology.

  6. Cluster imaging of multi-brain networks (CIMBN): a general framework for hyperscanning and modeling a group of interacting brains.

    Science.gov (United States)

    Duan, Lian; Dai, Rui-Na; Xiao, Xiang; Sun, Pei-Pei; Li, Zheng; Zhu, Chao-Zhe

    2015-01-01

    Studying the neural basis of human social interactions is a key topic in the field of social neuroscience. Brain imaging studies in this field usually focus on the neural correlates of the social interactions between two participants. However, as the participant number further increases, even by a small amount, great difficulties raise. One challenge is how to concurrently scan all the interacting brains with high ecological validity, especially for a large number of participants. The other challenge is how to effectively model the complex group interaction behaviors emerging from the intricate neural information exchange among a group of socially organized people. Confronting these challenges, we propose a new approach called "Cluster Imaging of Multi-brain Networks" (CIMBN). CIMBN consists of two parts. The first part is a cluster imaging technique with high ecological validity based on multiple functional near-infrared spectroscopy (fNIRS) systems. Using this technique, we can easily extend the simultaneous imaging capacity of social neuroscience studies up to dozens of participants. The second part of CIMBN is a multi-brain network (MBN) modeling method based on graph theory. By taking each brain as a network node and the relationship between any two brains as a network edge, one can construct a network model for a group of interacting brains. The emergent group social behaviors can then be studied using the network's properties, such as its topological structure and information exchange efficiency. Although there is still much work to do, as a general framework for hyperscanning and modeling a group of interacting brains, CIMBN can provide new insights into the neural correlates of group social interactions, and advance social neuroscience and social psychology. PMID:26283906

  7. Air pollution model and neural network: an integrated modelling system

    International Nuclear Information System (INIS)

    It is well known that neural networks can work as universal approximators of non-linear functions and they have become a useful tool either where any precise phenomenological model is available or when uncertainty complicates the application of deterministic modelling as, for example, in environmental systems. Usually, N N models are using as regression tool. We have developed an integrated modelling system coupling an air dispersion model with a neural network method both to simulate the influence of important parameters on air pollution models and to minimize the input neural net variables. In our approach, an optimised 3-Layer Perception is used to filter the air pollution concentrations evaluated by means of the non-Gaussian analytical model ADMD. We applied this methodology to the well known Indianapolis urban data set which deals with a release of pollutants from an elevated emission source.

  8. Performance of an integrated network model

    Science.gov (United States)

    Lehmann, François; Dunn, David; Beaulieu, Marie-Dominique; Brophy, James

    2016-01-01

    Objective To evaluate the changes in accessibility, patients’ care experiences, and quality-of-care indicators following a clinic’s transformation into a fully integrated network clinic. Design Mixed-methods study. Setting Verdun, Que. Participants Data on all patient visits were used, in addition to 2 distinct patient cohorts: 134 patients with chronic illness (ie, diabetes, arteriosclerotic heart disease, or both); and 450 women between the ages of 20 and 70 years. Main outcome measures Accessibility was measured by the number of walk-in visits, scheduled visits, and new patient enrolments. With the first cohort, patients’ care experiences were measured using validated serial questionnaires; and quality-of-care indicators were measured using biologic data. With the second cohort, quality of preventive care was measured using the number of Papanicolaou tests performed as a surrogate marker. Results Despite a negligible increase in the number of physicians, there was an increase in accessibility after the clinic’s transition to an integrated network model. During the first 4 years of operation, the number of scheduled visits more than doubled, nonscheduled visits (walk-in visits) increased by 29%, and enrolment of vulnerable patients (those with chronic illnesses) at the clinic remained high. Patient satisfaction with doctors was rated very highly at all points of time that were evaluated. While the number of Pap tests done did not increase with time, the proportion of patients meeting hemoglobin A1c and low-density lipoprotein guideline target levels increased, as did the number of patients tested for microalbuminuria. Conclusion Transformation to an integrated network model of care led to increased efficiency and enhanced accessibility with no negative effects on the doctor-patient relationship. Improvements in biologic data also suggested better quality of care. PMID:27521410

  9. Describing Ecosystem Complexity through Integrated Catchment Modeling

    Science.gov (United States)

    Shope, C. L.; Tenhunen, J. D.; Peiffer, S.

    2011-12-01

    Land use and climate change have been implicated in reduced ecosystem services (ie: high quality water yield, biodiversity, and agricultural yield. The prediction of ecosystem services expected under future land use decisions and changing climate conditions has become increasingly important. Complex policy and management decisions require the integration of physical, economic, and social data over several scales to assess effects on water resources and ecology. Field-based meteorology, hydrology, soil physics, plant production, solute and sediment transport, economic, and social behavior data were measured in a South Korean catchment. A variety of models are being used to simulate plot and field scale experiments within the catchment. Results from each of the local-scale models provide identification of sensitive, local-scale parameters which are then used as inputs into a large-scale watershed model. We used the spatially distributed SWAT model to synthesize the experimental field data throughout the catchment. The approach of our study was that the range in local-scale model parameter results can be used to define the sensitivity and uncertainty in the large-scale watershed model. Further, this example shows how research can be structured for scientific results describing complex ecosystems and landscapes where cross-disciplinary linkages benefit the end result. The field-based and modeling framework described is being used to develop scenarios to examine spatial and temporal changes in land use practices and climatic effects on water quantity, water quality, and sediment transport. Development of accurate modeling scenarios requires understanding the social relationship between individual and policy driven land management practices and the value of sustainable resources to all shareholders.

  10. Integrated modelling of ITER scenarios with ECCD

    International Nuclear Information System (INIS)

    Full text: The main application of EC waves in ITER will be the control of NTM by means of the top launchers. However, virtually every ITER scenario would profit from appropriate use of ECCD by means of the equatorial launcher. In particular, hybrid and steady-state scenarios require off-axis current drive in order to either keep the safety factor above 1 or produce negative shear in a large part of the plasma cross-section. In this type of applications, alignment of the current sources and self-consistency of current and temperature profiles are critical issues, which can only be addressed by integrated modelling. To this end, the CRONOS suite of codes has been applied to the simulation of these scenarios. CRONOS integrates, in a modular structure, general 2-D magnetic equilibria, radiation and particle losses, several heat, particle and impurities transport models, as well as heat, particle and momentum source modules, associated, e.g., with neutral beams, radio-frequency waves, pellet ablation, etc. The ECCD module includes toroidal ray-tracing and linear computation of the driven current, which is generally adequate for ITER parameters. This presentation will give a short description of the CRONOS suite of codes, followed by results of simulations of ITER hybrid scenarios assisted by ECCD. Use of ECCD in steady-state scenarios will also be addressed. (author)

  11. High-Dimensional Schwarzian Derivatives and Painleve Integrable Models

    Institute of Scientific and Technical Information of China (English)

    ZHANGShun-Li; LOUSen-Yue; 等

    2002-01-01

    Because all the known integrable models possess Schwarzian forms with Moebious transformation invariance,it may be one of the best ways to find new integrable models stating from some suitable Moebious transformation invariant equations.In this paper,we study the Painleve integrability of some special(3+1)-dimensional Schwarzian models.

  12. Resuscitation speed affects brain injury in a large animal model of traumatic brain injury and shock

    DEFF Research Database (Denmark)

    Sillesen, Martin; Jin, Guang; Johansson, Pär I;

    2014-01-01

    infusion speed increment NS (n¿=¿7). Hemodynamic variables over a 6-hour observation phase were recorded. Following euthanasia, brains were harvested and lesion size as well as brain swelling was measured.ResultsBolus FFP resuscitation resulted in greater brain swelling (22.36¿±¿1.03% vs. 15.58¿±¿2.52%, p...

  13. Integrating the EFQM Model with EADS-CASA Business Model

    International Nuclear Information System (INIS)

    Business Models can be used to assess and to evaluate the management system of an organization. In this paper, it will be described the EADS-CASA experience of integrating the EFQM Model with the organization business model, how areas for improvement have been identified and managed from 1994 up to now. It will also be described the implementation process of selected improvement actions, describing among others, how Environment Health and Safety Management of facilities and employees and how Safety and Reliability Management of our products is implemented within the organization

  14. Advances in NLTE Modeling for Integrated Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Scott, H A; Hansen, S B

    2009-07-08

    The last few years have seen significant progress in constructing the atomic models required for non-local thermodynamic equilibrium (NLTE) simulations. Along with this has come an increased understanding of the requirements for accurately modeling the ionization balance, energy content and radiative properties of different elements for a wide range of densities and temperatures. Much of this progress is the result of a series of workshops dedicated to comparing the results from different codes and computational approaches applied to a series of test problems. The results of these workshops emphasized the importance of atomic model completeness, especially in doubly excited states and autoionization transitions, to calculating ionization balance, and the importance of accurate, detailed atomic data to producing reliable spectra. We describe a simple screened-hydrogenic model that calculates NLTE ionization balance with surprising accuracy, at a low enough computational cost for routine use in radiation-hydrodynamics codes. The model incorporates term splitting, {Delta}n = 0 transitions, and approximate UTA widths for spectral calculations, with results comparable to those of much more detailed codes. Simulations done with this model have been increasingly successful at matching experimental data for laser-driven systems and hohlraums. Accurate and efficient atomic models are just one requirement for integrated NLTE simulations. Coupling the atomic kinetics to hydrodynamics and radiation transport constrains both discretizations and algorithms to retain energy conservation, accuracy and stability. In particular, the strong coupling between radiation and populations can require either very short timesteps or significantly modified radiation transport algorithms to account for NLTE material response. Considerations such as these continue to provide challenges for NLTE simulations.

  15. Multistability in Large Scale Models of Brain Activity.

    Directory of Open Access Journals (Sweden)

    Mathieu Golos

    2015-12-01

    Full Text Available Noise driven exploration of a brain network's dynamic repertoire has been hypothesized to be causally involved in cognitive function, aging and neurodegeneration. The dynamic repertoire crucially depends on the network's capacity to store patterns, as well as their stability. Here we systematically explore the capacity of networks derived from human connectomes to store attractor states, as well as various network mechanisms to control the brain's dynamic repertoire. Using a deterministic graded response Hopfield model with connectome-based interactions, we reconstruct the system's attractor space through a uniform sampling of the initial conditions. Large fixed-point attractor sets are obtained in the low temperature condition, with a bigger number of attractors than ever reported so far. Different variants of the initial model, including (i a uniform activation threshold or (ii a global negative feedback, produce a similarly robust multistability in a limited parameter range. A numerical analysis of the distribution of the attractors identifies spatially-segregated components, with a centro-medial core and several well-delineated regional patches. Those different modes share similarity with the fMRI independent components observed in the "resting state" condition. We demonstrate non-stationary behavior in noise-driven generalizations of the models, with different meta-stable attractors visited along the same time course. Only the model with a global dynamic density control is found to display robust and long-lasting non-stationarity with no tendency toward either overactivity or extinction. The best fit with empirical signals is observed at the edge of multistability, a parameter region that also corresponds to the highest entropy of the attractors.

  16. Three-dimensional visualization of functional brain tissue and functional magnetic resonance imaging-integrated neuronavigation in the resection of brain tumor adjacent to motor cortex

    International Nuclear Information System (INIS)

    Objective: To assess the value of three -dimensional visualization of functional brain tissue and the functional magnetic resonance imaging (fMRI)-integrated neuronavigation in the resection of brain tumor adjacent to motor cortex. Method: Sixty patients with tumor located in the central sulcus were enrolled. Thirty patients were randomly assigned to function group and 30 to control group. Patients in function group underwent fMRI to localize the functional brain tissues. Then the function information was transferred to the neurosurgical navigator. The patients in control group underwent surgery with navigation without function information. The therapeutic effect, excision rate. improvement of motor function, and survival quality during follow-up were analyzed. Result: All patients in function group were accomplished visualization of functional brain tissues and fMRI-integrated neuronavigation. The locations of tumors, central sulcus and motor cortex were marked during the operation. The fMRI -integrated information played a great role in both pre- and post-operation. Pre-operation: designing the location of the skin flap and window bone, determining the relationship between the tumor and motor cortex, and designing the pathway for the resection. Post- operation: real-time navigation of relationship between the tumor and motor cortex, assisting to localize the motor cortex using interoperation ultra-sound for correcting the displacement by the CSF outflow and collapsing tumor. The patients in the function group had better results than the patients in the control group in therapeutic effect (u=2.646, P=0.008), excision rate (χ=7.200, P<0.01), improvement of motor function (u=2.231, P=0.026), and survival quality (KPS uc= 2.664, P=0.008; Zubrod -ECOG -WHO uc=2.135, P=0.033). Conclusions: Using preoperative three -dimensional visualization of cerebral function tissue and the fMRI-integrated neuronavigation technology, combining intraoperative accurate positioning

  17. Language Model Applications to Spelling with Brain-Computer Interfaces

    Directory of Open Access Journals (Sweden)

    Anderson Mora-Cortes

    2014-03-01

    Full Text Available Within the Ambient Assisted Living (AAL community, Brain-Computer Interfaces (BCIs have raised great hopes as they provide alternative communication means for persons with disabilities bypassing the need for speech and other motor activities. Although significant advancements have been realized in the last decade, applications of language models (e.g., word prediction, completion have only recently started to appear in BCI systems. The main goal of this article is to review the language model applications that supplement non-invasive BCI-based communication systems by discussing their potential and limitations, and to discern future trends. First, a brief overview of the most prominent BCI spelling systems is given, followed by an in-depth discussion of the language models applied to them. These language models are classified according to their functionality in the context of BCI-based spelling: the static/dynamic nature of the user interface, the use of error correction and predictive spelling, and the potential to improve their classification performance by using language models. To conclude, the review offers an overview of the advantages and challenges when implementing language models in BCI-based communication systems when implemented in conjunction with other AAL technologies.

  18. The Bee as a Model to Investigate Brain and Behavioural Asymmetries

    Directory of Open Access Journals (Sweden)

    Elisa Frasnelli

    2014-01-01

    Full Text Available The honeybee Apis mellifera, with a brain of only 960,000 neurons and the ability to perform sophisticated cognitive tasks, has become an excellent model in life sciences and in particular in cognitive neurosciences. It has been used in our laboratories to investigate brain and behavioural asymmetries, i.e., the different functional specializations of the right and the left sides of the brain. It is well known that bees can learn to associate an odour stimulus with a sugar reward, as demonstrated by extension of the proboscis when presented with the trained odour in the so-called Proboscis Extension Reflex (PER paradigm. Bees recall this association better when trained using their right antenna than they do when using their left antenna. They also retrieve short-term memory of this task better when using the right antenna. On the other hand, when tested for long-term memory recall, bees respond better when using their left antenna. Here we review a series of behavioural studies investigating bees’ lateralization, integrated with electrophysiological measurements to study asymmetries of olfactory sensitivity, and discuss the possible evolutionary origins of these asymmetries. We also present morphological data obtained by scanning electron microscopy and two-photon microscopy. Finally, a behavioural study conducted in a social context is summarised, showing that honeybees control context-appropriate social interactions using their right antenna, rather than the left, thus suggesting that lateral biases in behaviour might be associated with requirements of social life.

  19. Integrated Safety Culture Model and Application

    Institute of Scientific and Technical Information of China (English)

    汪磊; 孙瑞山; 刘汉辉

    2009-01-01

    A new safety culture model is constructed and is applied to analyze the correlations between safety culture and SMS. On the basis of previous typical definitions, models and theories of safety culture, an in-depth analysis on safety culture's structure, composing elements and their correlations was conducted. A new definition of safety culture was proposed from the perspective of sub-cuhure. 7 types of safety sub-culture, which are safety priority culture, standardizing culture, flexible culture, learning culture, teamwork culture, reporting culture and justice culture were defined later. Then integrated safety culture model (ISCM) was put forward based on the definition. The model divided safety culture into intrinsic latency level and extrinsic indication level and explained the potential relationship between safety sub-culture and all safety culture dimensions. Finally in the analyzing of safety culture and SMS, it concluded that positive safety culture is the basis of im-plementing SMS effectively and an advanced SMS will improve safety culture from all around.

  20. A Study on Integrated Model of Decision Support Systems

    Institute of Scientific and Technical Information of China (English)

    MO Zan; FENG Shan; TANG Chao

    2002-01-01

    This paper discusses two kinds of systems integrated models available to DSS: Multi-AgentBased Model and Application-Framework-Oriented Model. Both of them are application-oriented integration so it is possible to combine them at the level of application. Based on this theory, this paper presents a new model, MAAFUM, which combines two models and applies them synthetically in DSS.

  1. Hearing facial identities: brain correlates of face--voice integration in person identification.

    Science.gov (United States)

    Schweinberger, Stefan R; Kloth, Nadine; Robertson, David M C

    2011-10-01

    Audiovisual integration (AVI) is a well-known aspect of speech perception, but integration of facial and vocal information is also important for speaker recognition. We recently demonstrated AVI in the recognition of familiar (but not unfamiliar) speakers. Specifically, systematic behavioural benefits and costs in recognizing a familiar voice occur when the voice is combined with a time-synchronised articulating face of corresponding or noncorresponding speaker identity, respectively (Schweinberger et al., 2007; Robertson and Schweinberger, 2010). Here we report an experiment assessing event-related brain potentials (ERPs) in this novel paradigm, while participants recognized familiar speakers presented in (1) Voice only, (2) voice with identity-corresponding and (3) noncorresponding time-synchronised speaking faces, as well as (4) Face only conditions. Audiovisual speaker identity correspondence influenced only later ERPs around 250-600 msec, with increased negativity for noncorresponding identities at central electrodes. Strikingly, when compared with the ERPs from both unimodal conditions, both audiovisual conditions led to a much earlier onset of frontocentral negativity, with maximal differences around 50-80 msec. Moreover, audiovisual stimuli elicited larger N170 responses than Face only stimuli. These findings suggest that the perception of a voice and a time-synchronised articulating face triggers remarkably early and mandatory mechanisms of audiovisual processing, although the correspondence or discrepancy in audiovisual speaker identity may only be computed ∼200msec later. PMID:21208611

  2. How Anatomy Shapes Dynamics: A Semi-Analytical Study of the Brain at Rest by a Simple Spin Model

    OpenAIRE

    Gustavo eDeco; Mario eSenden; Viktor eJirsa

    2012-01-01

    Resting state networks (RSNs) show a surprisingly coherent and robust spatiotemporal organization. Previous theoretical studies demonstrated that these patterns can be understood as emergent on the basis of the underlying neuroanatomical connectivity skeleton. Integrating the biologically realistic DTI/DSI-(Diffusion Tensor Imaging/Diffusion Spectrum Imaging)based neuroanatomical connectivity into a brain model of Ising spin dynamics, we found a system with multiple attractors,...

  3. Peculiarities of integral brain activity under compromised thyroid gland function of children and adolescent from radionuclide contaminated territories of Belarus

    International Nuclear Information System (INIS)

    80 children with thyroid gland hypertrophy (50 girls + 30 boys, 10 - 17 years old) from Luninets town, the Brest region, were investigated for integral brain activity. Quantitative determination of thyrotropic hormone level in blood serum was made by using enzyme immunodetection. Mentation, attention and memory were tested by questionnaire design. Results of experiments are given

  4. Integrated core-edge-divertor modeling studies

    International Nuclear Information System (INIS)

    An integrated calculation model for simulating the interaction of physics phenomena taking place in the plasma core, in the plasma edge and in the SOL and divertor of tokamaks has been developed and applied to study such interactions. The model synthesises a combination of numerical calculations (1) the power and particle balances for the core plasma, using empirical confinement scaling laws and taking into account radiation losses (2), the particle, momentum and power balances in the SOL and divertor, taking into account the effects of radiation and recycling neutrals, (3) the transport of feeling and recycling neutrals, explicitly representing divertor and pumping geometry, and (4) edge pedestal gradient scale lengths and widths, evaluation of theoretical predictions (5) confinement degradation due to thermal instabilities in the edge pedestals, (6) detachment and divertor MARFE onset, (7) core MARFE onsets leading to a H-L transition, and (8) radiative collapse leading to a disruption and evaluation of empirical fits (9) power thresholds for the L-H and H-L transitions and (10) the width of the edge pedestals. The various components of the calculation model are coupled and must be iterated to a self-consistent convergence. The model was developed over several years for the purpose of interpreting various edge phenomena observed in DIII-D experiments and thereby, to some extent, has been benchmarked against experiment. Because the model treats the interactions of various phenomena in the core, edge and divertor, yet is computationally efficient, it lends itself to the investigation of the effects of different choices of various edge plasma operating conditions on overall divertor and core plasma performance. Studies of the effect of feeling location and rate, divertor geometry, plasma shape, pumping and over 'edge parameters' on core plasma properties (line average density, confinement, density limit, etc.) have been performed for DIII-D model problems. A

  5. Disruption of White Matter Integrity in Adult Survivors of Childhood Brain Tumors: Correlates with Long-Term Intellectual Outcomes.

    Directory of Open Access Journals (Sweden)

    Tricia Z King

    Full Text Available Although chemotherapy and radiation treatment have contributed to increased survivorship, treatment-induced brain injury has been a concern when examining long-term intellectual outcomes of survivors. Specifically, disruption of brain white matter integrity and its relationship to intellectual outcomes in adult survivors of childhood brain tumors needs to be better understood.Fifty-four participants underwent diffusion tensor imaging in addition to structural MRI and an intelligence test (IQ. Voxel-wise group comparisons of fractional anisotropy calculated from DTI data were performed using Tract Based Spatial Statistics (TBSS on 27 survivors (14 treated with radiation with and without chemotherapy and 13 treated without radiation treatment on average over 13 years since diagnosis and 27 healthy comparison participants. Whole brain white matter fractional anisotropy (FA differences were explored between each group. The relationships between IQ and FA in the regions where statistically lower FA values were found in survivors were examined, as well as the role of cumulative neurological factors.The group of survivors treated with radiation with and without chemotherapy had lower IQ relative to the group of survivors without radiation treatment and the healthy comparison group. TBSS identified white matter regions with significantly different mean fractional anisotropy between the three different groups. A lower level of white matter integrity was found in the radiation with or without chemotherapy treated group compared to the group without radiation treatment and also the healthy control group. The group without radiation treatment had a lower mean FA relative to healthy controls. The white matter disruption of the radiation with or without chemotherapy treated survivors was positively correlated with IQ and cumulative neurological factors.Lower long-term intellectual outcomes of childhood brain tumor survivors are associated with lower white

  6. Modeling of a segmented electrode for desynchronizing deep brain stimulation

    Directory of Open Access Journals (Sweden)

    Julia eBuhlmann

    2011-12-01

    Full Text Available Deep brain stimulation (DBS is an effective therapy for medically refrac- tory movement disorders like Parkinson’s disease. The electrodes, implanted in the target area within the human brain, generate an electric field which activates nerve fibers and cell bodies in the proximate vicinity. Even though the different target nuclei display considerable differences in their anatomical structure, only few types of electrodes are currently commercially available. It is desirable to adjust the electric field and in particular the volume of tissue activated around the electrode with respect to the corresponding target nucleus in a such way that side effects can be reduced. Furthermore, a more selective and partial activation of the target structure is desirable for an optimal application of novel stimulation strate- gies, e.g. coordinated reset neuromodulation. Hence we designed a DBS electrode with a segmented design allowing a more selective activation of the target struc- ture. We created a finite element model (FEM of the electrode and analyzed the volume of tissue activated for this electrode design. The segmented electrode ac- tivated an area in a targeted manner, of which the dimension and position relative to the electrode could be controlled by adjusting the stimulation parameters for each contact. According to our computational analysis, this directed stimulation might be superior with respect to the occurrence of side effects and it enables the application of coordinated reset neuromodulation under optimal conditions.

  7. On the appropriateness of modelling brain parenchyma as a biphasic continuum.

    Science.gov (United States)

    Tavner, A C R; Roy, T Dutta; Hor, K W W; Majimbi, M; Joldes, G R; Wittek, A; Bunt, S; Miller, K

    2016-08-01

    Computational methods originally developed for analysis in engineering have been applied to the analysis of biological materials for many years. One particular application of these engineering tools is the brain, allowing researchers to predict the behaviour of brain tissue in various traumatic, surgical and medical scenarios. Typically two different approaches have been used to model deformation of brain tissue: single-phase models which treat the brain as a viscoelastic material, and biphasic models which treat the brain as a porous deformable medium through which liquid can move. In order to model the brain as a biphasic continuum, the hydraulic conductivity of the solid phase is required; there are many theoretical values for this conductivity in the literature, with variations of up to three orders of magnitude. We carried out a series of simple experiments using lamb and sheep brain tissue to establish the rate at which cerebrospinal fluid moves through the brain parenchyma. Mindful of possible variations in hydraulic conductivity with tissue deformation, our intention was to carry out our experiments on brain tissue subjected to minimal deformation. This has enabled us to compare the rate of flow with values predicted by some of the theoretical values of hydraulic conductivity from the literature. Our results indicate that the hydraulic conductivity of the brain parenchyma is consistent with the lowest theoretical published values. These extremely low hydraulic conductivities lead to such low rates of CSF flow through the brain tissue that in effect the material behaves as a single-phase deformable solid. PMID:27136087

  8. Modelling Spark Integration in Science Classroom

    Directory of Open Access Journals (Sweden)

    Marie Paz E. Morales

    2014-02-01

    Full Text Available The study critically explored how a PASCO-designed technology (SPARK ScienceLearning System is meaningfully integrated into the teaching of selected topics in Earth and Environmental Science. It highlights on modelling the effectiveness of using the SPARK Learning System as a primary tool in learning science that leads to learning and achievement of the students. Data and observation gathered and correlation of the ability of the technology to develop high intrinsic motivation to student achievement were used to design framework on how to meaningfully integrate SPARK ScienceLearning System in teaching Earth and Environmental Science. Research instruments used in this study were adopted from standardized questionnaires available from literature. Achievement test and evaluation form were developed and validated for the purpose of deducing data needed for the study. Interviews were done to delve into the deeper thoughts and emotions of the respondents. Data from the interviews served to validate all numerical data culled from this study. Cross-case analysis of the data was done to reveal some recurring themes, problems and benefits derived by the students in using the SPARK Science Learning System to further establish its effectiveness in the curriculum as a forerunner to the shift towards the 21st Century Learning.

  9. A model for traumatic brain injury using laser induced shockwaves

    Science.gov (United States)

    Selfridge, A.; Preece, D.; Gomez, V.; Shi, L. Z.; Berns, M. W.

    2015-08-01

    Traumatic brain injury (TBI) represents a major treatment challenge in both civilian and military medicine; on the cellular level, its mechanisms are poorly understood. As a method to study the dysfunctional repair mechanisms following injury, laser induced shock waves (LIS) are a useful way to create highly precise, well characterized mechanical forces. We present a simple model for TBI using laser induced shock waves as a model for damage. Our objective is to develop an understanding of the processes responsible for neuronal death, the ways in which we can manipulate these processes to improve cell survival and repair, and the importance of these processes at different levels of biological organization. The physics of shock wave creation has been modeled and can be used to calculate forces acting on individual neurons. By ensuring that the impulse is in the same regime as that occurring in practical TBI, the LIS model can ensure that in vitro conditions and damage are similar to those experienced in TBI. This model will allow for the study of the biochemical response of neurons to mechanical stresses, and can be combined with microfluidic systems for cell growth in order to better isolate areas of damage.

  10. Classification of integrable discrete Klein-Gordon models

    Science.gov (United States)

    Habibullin, Ismagil T.; Gudkova, Elena V.

    2011-04-01

    The Lie algebraic integrability test is applied to the problem of classification of integrable Klein-Gordon-type equations on quad graphs. The list of equations passing the test is presented, containing several well-known integrable models. A new integrable example is found; its higher symmetry is presented.

  11. Classification of integrable discrete Klein-Gordon models

    International Nuclear Information System (INIS)

    The Lie algebraic integrability test is applied to the problem of classification of integrable Klein-Gordon-type equations on quad graphs. The list of equations passing the test is presented, containing several well-known integrable models. A new integrable example is found; its higher symmetry is presented.

  12. Chapter 3 animal models of traumatic brain injury: is there an optimal model that parallels human brain injury?

    Science.gov (United States)

    Briones, Teresita L

    2015-01-01

    Traumatic brain injury (TBI) is the leading cause of mortality and morbidity in the younger population worldwide. Survivors of TBI often experience long-term disability in the form of cognitive, sensorimotor, and affective impairments. Despite the high prevalence in, and cost of TBI to, both individuals and society, some of its underlying pathophysiology is not completely understood. Animal models have been developed over the past few decades to closely replicate the different facets of TBI in humans to better understand the underlying pathophysiology and behavioral impairments and assess potential therapies that can promote neuroprotection. However, no effective treatment for TBI has been established to date in the clinical setting, despite promising results generated in preclinical studies in the use of neuroprotective strategies. The failure to translate results from preclinical studies to the clinical setting underscores a compelling need to revisit the current state of knowledge in the use of animal models in TBI. PMID:25946383

  13. Employment Enhancing Integrative Graduate Education Model

    Directory of Open Access Journals (Sweden)

    Ismail H. Genc

    2014-06-01

    Full Text Available There is a strong call to look for approaches to integrate business and engineering education across disciplines to provide a more coherent system for students with the job market. As graduates fail to find satisfying employment, the value of college education is questioned. The unemployment of the highly educated has economic, social and political ramifications. Worst is when the highly educated unemployed takes up lower status jobs, ever reducing the quality of the job market with future consequences. In this study, we concentrate on ways to enhance students’ competitiveness in the post-graduate environment by proposing a curriculum to yield viable business proposals. Our model is for business or engineering students willing to pursue a master’s degree without PhD. We go beyond the compartmentalization of the current educational system to increase employability, particularly self-employment. Rise in productivity is a side benefit since there is a strong correlation between productivity and welfare

  14. Integrated Semantic Similarity Model Based on Ontology

    Institute of Scientific and Technical Information of China (English)

    LIU Ya-Jun; ZHAO Yun

    2004-01-01

    To solve the problem of the inadequacy of semantic processing in the intelligent question answering system, an integrated semantic similarity model which calculates the semantic similarity using the geometric distance and information content is presented in this paper.With the help of interrelationship between concepts, the information content of concepts and the strength of the edges in the ontology network, we can calculate the semantic similarity between two concepts and provide information for the further calculation of the semantic similarity between user's question and answers in knowlegdge base.The results of the experiments on the prototype have shown that the semantic problem in natural language processing can also be solved with the help of the knowledge and the abundant semantic information in ontology.More than 90% accuracy with less than 50 ms average searching time in the intelligent question answering prototype system based on ontology has been reached.The result is very satisfied.

  15. Towards an Integrative Model of Knowledge Transfer

    DEFF Research Database (Denmark)

    Turcan, Romeo V.; Heslop, Ben

    This paper aims to contribute towards the advancement of an efficient architecture of a single market for knowledge through the development of an integrative model of knowledge transfer. Within this aim, several points of departure can be singled out. One, the article builds on the call of the...... European Commission to improve the European market for KT between research institutions and industry. Two, various barriers exist that hinder efficient KT in Europe, especially in transition economies that recently joined the EU where the issues of restructuring higher education, building trust between...... business and academia, and implementing the respective legislature are enduring. The research objectives were to explore (i) the process of knowledge transfer in universities, including the nature of tensions, obstacles and incentives, (ii) the relationships between key stakeholders in the KT market and...

  16. Modeling DNA Dynamics by Path Integrals

    CERN Document Server

    Zoli, Marco

    2013-01-01

    Complementary strands in DNA double helix show temporary fluctuational openings which are essential to biological functions such as transcription and replication of the genetic information. Such large amplitude fluctuations, known as the breathing of DNA, are generally localized and, microscopically, are due to the breaking of the hydrogen bonds linking the base pairs (\\emph{bps}). I apply imaginary time path integral techniques to a mesoscopic Hamiltonian which accounts for the helicoidal geometry of a short circular DNA molecule. The \\emph{bps} displacements with respect to the ground state are interpreted as time dependent paths whose amplitudes are consistent with the model potential for the hydrogen bonds. The portion of the paths configuration space contributing to the partition function is determined by selecting the ensemble of paths which fulfill the second law of thermodynamics. Computations of the thermodynamics in the denaturation range show the energetic advantage for the equilibrium helicoidal g...

  17. Phase lagging model of brain response to external stimuli - modeling of single action potential

    CERN Document Server

    Seetharaman, Karthik; Kulish, Vladimir V

    2012-01-01

    In this paper we detail a phase lagging model of brain response to external stimuli. The model is derived using the basic laws of physics like conservation of energy law. This model eliminates the paradox of instantaneous propagation of the action potential in the brain. The solution of this model is then presented. The model is further applied in the case of a single neuron and is verified by simulating a single action potential. The results of this modeling are useful not only for the fundamental understanding of single action potential generation, but also they can be applied in case of neuronal interactions where the results can be verified against the real EEG signal.

  18. Full feature data model for spatial information network integration

    Institute of Scientific and Technical Information of China (English)

    DENG Ji-qiu; BAO Guang-shu

    2006-01-01

    In allusion to the difficulty of integrating data with different models in integrating spatial information,the characteristics of raster structure, vector structure and mixed model were analyzed, and a hierarchical vectorraster integrative full feature model was put forward by integrating the advantage of vector and raster model and using the object-oriented method. The data structures of the four basic features, i.e. point, line, surface and solid,were described. An application was analyzed and described, and the characteristics of this model were described. In this model, all objects in the real world are divided into and described as features with hierarchy, and all the data are organized in vector. This model can describe data based on feature, field, network and other models, and avoid the disadvantage of inability to integrate data based on different models and perform spatial analysis on them in spatial information integration.

  19. HERMES: towards an integrated toolbox to characterize functional and effective brain connectivity.

    Science.gov (United States)

    Niso, Guiomar; Bruña, Ricardo; Pereda, Ernesto; Gutiérrez, Ricardo; Bajo, Ricardo; Maestú, Fernando; del-Pozo, Francisco

    2013-10-01

    The analysis of the interdependence between time series has become an important field of research in the last years, mainly as a result of advances in the characterization of dynamical systems from the signals they produce, the introduction of concepts such as generalized and phase synchronization and the application of information theory to time series analysis. In neurophysiology, different analytical tools stemming from these concepts have added to the 'traditional' set of linear methods, which includes the cross-correlation and the coherency function in the time and frequency domain, respectively, or more elaborated tools such as Granger Causality.This increase in the number of approaches to tackle the existence of functional (FC) or effective connectivity (EC) between two (or among many) neural networks, along with the mathematical complexity of the corresponding time series analysis tools, makes it desirable to arrange them into a unified-easy-to-use software package. The goal is to allow neuroscientists, neurophysiologists and researchers from related fields to easily access and make use of these analysis methods from a single integrated toolbox.Here we present HERMES ( http://hermes.ctb.upm.es ), a toolbox for the Matlab® environment (The Mathworks, Inc), which is designed to study functional and effective brain connectivity from neurophysiological data such as multivariate EEG and/or MEG records. It includes also visualization tools and statistical methods to address the problem of multiple comparisons. We believe that this toolbox will be very helpful to all the researchers working in the emerging field of brain connectivity analysis. PMID:23812847

  20. Integration of ultra-high field MRI and histology for connectome based research of brain disorders

    Directory of Open Access Journals (Sweden)

    Shan eYang

    2013-09-01

    Full Text Available Ultra-high field magnetic resonance imaging (MRI became increasingly relevant for in vivo neuroscientific research because of improved spatial resolutions. However, this is still the unchallenged domain of histological studies, which long played an important role in the investigation of neuropsychiatric disorders. While the field of biological psychiatry strongly advanced on macroscopic levels, current developments are rediscovering the richness of immunohistological information when attempting a multi-level systematic approach to brain function and dysfunction. For most studies, histology sections lost information on three-dimensional reconstructions. Translating histological sections to 3D-volumes would thus not only allow for multi-stain and multi-subject alignment in post mortem data, but also provide a crucial step in big data initiatives involving the network analyses currently performed with in vivo MRI. We therefore investigated potential pitfalls during integration of MR and histological information where no additional blockface information is available. We demonstrated that strengths and requirements from both methods seem to be ideally merged at a spatial resolution of 200 μm. However, the success of this approach is heavily dependent on choices of hardware, sequence and reconstruction. We provide a fully automated pipeline that optimizes histological 3D reconstructions, providing a potentially powerful solution not only for primary human post mortem research institutions in neuropsychiatric research, but also to help alleviate the massive workloads in neuroanatomical atlas initiatives. We further demonstrate (for the first time the feasibility and quality of ultra-high spatial resolution (150 µm isotopic imaging of the entire human brain MRI at 7T, offering new opportunities for analyses on MR-derived information.

  1. Integrating histology and MRI in the first digital brain of common squirrel monkey, Saimiri sciureus

    Science.gov (United States)

    Sun, Peizhen; Parvathaneni, Prasanna; Schilling, Kurt G.; Gao, Yurui; Janve, Vaibhav; Anderson, Adam; Landman, Bennett A.

    2015-03-01

    This effort is a continuation of development of a digital brain atlas of the common squirrel monkey, Saimiri sciureus, a New World monkey with functional and microstructural organization of central nervous system similar to that of humans. Here, we present the integration of histology with multi-modal magnetic resonance imaging (MRI) atlas constructed from the brain of an adult female squirrel monkey. The central concept of this work is to use block face photography to establish an intermediate common space in coordinate system which preserves the high resolution in-plane resolution of histology while enabling 3-D correspondence with MRI. In vivo MRI acquisitions include high resolution T2 structural imaging (300 μm isotropic) and low resolution diffusion tensor imaging (600 um isotropic). Ex vivo MRI acquisitions include high resolution T2 structural imaging and high resolution diffusion tensor imaging (both 300 μm isotropic). Cortical regions were manually annotated on the co-registered volumes based on published histological sections in-plane. We describe mapping of histology and MRI based data of the common squirrel monkey and construction of a viewing tool that enable online viewing of these datasets. The previously descried atlas MRI is used for its deformation to provide accurate conformation to the MRI, thus adding information at the histological level to the MRI volume. This paper presents the mapping of single 2D image slice in block face as a proof of concept and this can be extended to map the atlas space in 3D coordinate system as part of the future work and can be loaded to an XNAT system for further use.

  2. Using an Integrated -Omics Approach to Identify Key Cellular Processes That Are Disturbed in the Kidney After Brain Death.

    Science.gov (United States)

    Akhtar, M Z; Huang, H; Kaisar, M; Lo Faro, M L; Rebolledo, R; Morten, K; Heather, L C; Dona, A; Leuvenink, H G; Fuggle, S V; Kessler, B M; Pugh, C W; Ploeg, R J

    2016-05-01

    In an era where we are becoming more reliant on vulnerable kidneys for transplantation from older donors, there is an urgent need to understand how brain death leads to kidney dysfunction and, hence, how this can be prevented. Using a rodent model of hemorrhagic stroke and next-generation proteomic and metabolomic technologies, we aimed to delineate which key cellular processes are perturbed in the kidney after brain death. Pathway analysis of the proteomic signature of kidneys from brain-dead donors revealed large-scale changes in mitochondrial proteins that were associated with altered mitochondrial activity and morphological evidence of mitochondrial injury. We identified an increase in a number of glycolytic proteins and lactate production, suggesting a shift toward anaerobic metabolism. Higher amounts of succinate were found in the brain death group, in conjunction with increased markers of oxidative stress. We characterized the responsiveness of hypoxia inducible factors and found this correlated with post-brain death mean arterial pressures. Brain death leads to metabolic disturbances in the kidney and alterations in mitochondrial function and reactive oxygen species generation. This metabolic disturbance and alteration in mitochondrial function may lead to further cellular injury. Conditioning the brain-dead organ donor by altering metabolism could be a novel approach to ameliorate this brain death-induced kidney injury. PMID:26602379

  3. Mapping Metabolic Brain Activity in Three Models of Hepatic Encephalopathy

    Directory of Open Access Journals (Sweden)

    Natalia Arias

    2013-01-01

    Full Text Available Cirrhosis is a common disease in Western countries. Liver failure, hyperammonemia, and portal hypertension are the main factors that contribute to human cirrhosis that frequently leads to a neuropsychiatric disorder known as hepatic encephalopathy (HE. In this study, we examined the differential contribution of these leading factors to the oxidative metabolism of diverse brain limbic system regions frequently involved in memory process by histochemical labelling of cytochrome oxidase (COx. We have analyzed cortical structures such as the infralimbic and prelimbic cotices, subcortical structures such as hippocampus and ventral striatum, at thalamic level like the anterodorsal, anteroventral, and mediodorsal thalamus, and, finally, the hypothalamus, where the mammillary nuclei (medial and lateral were measured. The severest alteration is found in the model that mimics intoxication by ammonia, followed by the thioacetamide-treated group and the portal hypertension group. No changes were found at the mammillary bodies for any of the experimental groups.

  4. Discovering transnosological molecular basis of human brain diseases using biclustering analysis of integrated gene expression data

    OpenAIRE

    Cha, Kihoon; Hwang, Taeho; Oh, Kimin; Yi, Gwan-Su

    2015-01-01

    Background It has been reported that several brain diseases can be treated as transnosological manner implicating possible common molecular basis under those diseases. However, molecular level commonality among those brain diseases has been largely unexplored. Gene expression analyses of human brain have been used to find genes associated with brain diseases but most of those studies were restricted either to an individual disease or to a couple of diseases. In addition, identifying significa...

  5. Modeling the dynamics of human brain activity with recurrent neural networks

    OpenAIRE

    Güçlü, Umut; Marcel A J van Gerven

    2016-01-01

    Encoding models are used for predicting brain activity in response to sensory stimuli with the objective of elucidating how sensory information is represented in the brain. Encoding models typically comprise a nonlinear transformation of stimuli to features (feature model) and a linear transformation of features to responses (response model). While there has been extensive work on developing better feature models, the work on developing better response models has been rather limited. Here, we...

  6. Stroke and Drug Delivery—In Vitro Models of the Ischemic Blood-Brain Barrier

    DEFF Research Database (Denmark)

    Tornabene, Erica; Brodin, Birger

    2016-01-01

    Stroke is a major cause of death and disability worldwide. Both cerebral hypoperfusion and focal cerebral infarcts are caused by a reduction of blood flow to the brain, leading to stroke and subsequent brain damage. At present, only few medical treatments of stroke are available, with the Food and...... permeation pathways across the barrier in ischemic and postischemic brain endothelium is important for development of new medical treatments. The blood-brain barrier, that is, the endothelial monolayer lining the brain capillaries, changes properties during an ischemic event. In vitro models of the blood...

  7. Characterization of a novel brain barrier ex vivo insect-based P-glycoprotein screening model

    DEFF Research Database (Denmark)

    Andersson, O.; Badisco, L.; Hansen, A. H.;

    2014-01-01

    In earlier studies insects were proposed as suitable models for vertebrate blood–brain barrier (BBB) permeability prediction and useful in early drug discovery. Here we provide transcriptome and functional data demonstrating the presence of a P-glycoprotein (Pgp) efflux transporter in the brain...... vertebrates, the locust brain–barrier function is morphologically confined to one specific cell layer and by using a whole-brain ex vivo drug exposure technique our locust model may retain the major cues that maintain and modulate the physiological function of the brain barrier. We show that the locust model...

  8. Integrated Modeling for Flood Hazard Mapping Using Watershed Modeling System

    Directory of Open Access Journals (Sweden)

    Seyedeh S. Sadrolashrafi

    2008-01-01

    Full Text Available In this stduy, a new framework which integrates the Geographic Information System (GIS with the Watershed Modeling System (WMS for flood modeling is developed. It also interconnects the terrain models and the GIS software, with commercial standard hydrological and hydraulic models, including HEC-1, HEC-RAS, etc. The Dez River Basin (about 16213 km2 in Khuzestan province, IRAN, is domain of study because of occuring frequent severe flash flooding. As a case of study, a major flood in autumn of 2001 is chosen to examine the modeling framework. The model consists of a rainfall-runoff model (HEC-1 that converts excess precipitation to overland flow and channel runoff and a hydraulic model (HEC-RAS that simulates steady state flow through the river channel network based on the HEC-1, peak hydrographs. In addition, it delineates the maps of potential flood zonation for the Dez River Basin. These are achieved based on the state of the art GIS with using WMS software. Watershed parameters are calibrated manually to perform a good simulation of discharge at three sub-basins. With the calibrated discharge, WMS is capable of producing flood hazard map. The modeling framework presented in this study demonstrates the accuracy and usefulness of the WMS software for flash flooding control. The results of this research will benefit future modeling efforts by providing validate hydrological software to forecast flooding on a regional scale. This model designed for the Dez River Basin, while this regional scale model may be used as a prototype for model applications in other areas.

  9. World Integrated Nuclear Evaluation System: Model documentation

    International Nuclear Information System (INIS)

    The World Integrated Nuclear Evaluation System (WINES) is an aggregate demand-based partial equilibrium model used by the Energy Information Administration (EIA) to project long-term domestic and international nuclear energy requirements. WINES follows a top-down approach in which economic growth rates, delivered energy demand growth rates, and electricity demand are projected successively to ultimately forecast total nuclear generation and nuclear capacity. WINES could be potentially used to produce forecasts for any country or region in the world. Presently, WINES is being used to generate long-term forecasts for the United States, and for all countries with commercial nuclear programs in the world, excluding countries located in centrally planned economic areas. Projections for the United States are developed for the period from 2010 through 2030, and for other countries for the period starting in 2000 or 2005 (depending on the country) through 2010. EIA uses a pipeline approach to project nuclear capacity for the period between 1990 and the starting year for which the WINES model is used. This approach involves a detailed accounting of existing nuclear generating units and units under construction, their capacities, their actual or estimated time of completion, and the estimated date of retirements. Further detail on this approach can be found in Appendix B of Commercial Nuclear Power 1991: Prospects for the United States and the World

  10. Developing engineering processes through integrated modelling of product and process

    OpenAIRE

    Nielsen, Jeppe Bjerrum; Hvam, Lars

    2012-01-01

    This article aims at developing an operational tool for integrated modelling of product assortments and engineering processes in companies making customer specific products. Integrating a product model in the design of engineering processes will provide a deeper understanding of the engineering activities as well as insight into how product features affect the engineering processes. The article suggests possible ways of integrating models of products with models of engineering processes. The ...

  11. INTEGRATED CORPORATE STRUCTURE LIFE CYCLE MANAGEMENT MODELING AND ORGANIZATION

    OpenAIRE

    Naumenko, M.; Morozova, L.

    2011-01-01

    Integrated business structure presented as complementary pool of its participants skills. The methodical approach to integrated business structure life cycle modeling proposed. Recommendations of enterprises life cycles stages correlate are submitted.

  12. 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.

  13. Model-integrating software components engineering flexible software systems

    CERN Document Server

    Derakhshanmanesh, Mahdi

    2015-01-01

    In his study, Mahdi Derakhshanmanesh builds on the state of the art in modeling by proposing to integrate models into running software on the component-level without translating them to code. Such so-called model-integrating software exploits all advantages of models: models implicitly support a good separation of concerns, they are self-documenting and thus improve understandability and maintainability and in contrast to model-driven approaches there is no synchronization problem anymore between the models and the code generated from them. Using model-integrating components, software will be

  14. Traumatic brain injury–Modeling neuropsychiatric symptoms in rodents

    Directory of Open Access Journals (Sweden)

    Oz eMalkesman

    2013-10-01

    Full Text Available Each year in the United States, approximately 1.5 million people sustain a traumatic brain injury (TBI. Victims of TBI can suffer from chronic post-TBI symptoms, such as sensory and motor deficits, cognitive impairments including problems with memory, learning, and attention, and neuropsychiatric symptoms such as depression, anxiety, irritability, aggression, and suicidal rumination. Although partially associated with the site and severity of injury, the biological mechanisms associated with many of these symptoms—and why some patients experience differing assortments of persistent maladies—are largely unknown. The use of animal models is a promising strategy for elucidation of the mechanisms of impairment and treatment, and learning, memory, sensory and motor tests have widespread utility in rodent models of TBI and psychopharmacology. Comparatively, behavioral tests for the evaluation of neuropsychiatric symptomatology are rarely employed in animal models of TBI and, as determined in this review, the results have been inconsistent. Animal behavioral studies contribute to the understanding of the biological mechanisms by which TBI is associated with neurobehavioral symptoms and offer a powerful means for pre-clinical treatment validation. Therefore, further exploration of the utility of animal behavioral tests for the study of injury mechanisms and therapeutic strategies for the alleviation of emotional symptoms are relevant and essential.

  15. Integrated Free Energy Model (IFEM) for microemulsions.

    Science.gov (United States)

    Boza Troncoso, Américo; Acosta, Edgar

    2016-03-15

    The Integrated Free Energy Model (IFEM) is a platform used to predict the solubilization of nonpolar oils in nonionic alkyl-polyethylene oxide (C(X)EO(Y)) micelles starting from a free energy balance of costs and gains when surfactants from empty micelles and oil from a continuous oil phase assemble to form an oil-swollen micelle. IFEM considers lipophilic interactions between surfactant tails and oil solubilized in the core of micelles, and the interaction between surfactant tails and the oil solubilized in the surfactant tail domain, as well as oil-oil and surfactant-surfactant tail interactions. Expressions to calculate these lipophilic interactions from van der Waals (VDW) interaction potential were introduced in a previous publication. In this article, two new surfactant-water interactions are considered, surfactant headgroup dehydration during solubilization, and surfactant tail group dehydration. These six interaction terms, in addition to two entropy of mixing contributions (in the lipophilic and in the hydrophilic domains) make up the eight terms of the IFEM platform. Of these terms, only the headgroup dehydration requires a calibrated parameter. After calibrating this parameter, the model is capable of predicting experimental solubilization data, and the experimental trends reflected by a semi-empirical model, the Hydrophilic-Lipophilic-Difference+Net-Average-Curvature (HLD-NAC). Although there are numerous approaches to predict the surfactant-oil-water (SOW) phase behavior, the IFEM platform is the only one, to the knowledge of the authors that produces an explicit connection between molecular interactions and experimental data for real SOW systems. The IFEM platform can be programmed in a personal computer using relatively inexpensive software and its explicit nature opens the possibility to introduce additional interaction terms for more complex SOW systems. PMID:26759991

  16. Modelling of the human brain with detailed anatomy for numerical simulation of surgical interventions

    International Nuclear Information System (INIS)

    During the design and simulation process of MEMS medical devices used in neurosurgery, there is a need to build a brain model with detailed anatomy and physical properties incorporated as a platform to conduct numerical analysis. This paper presents a study on constructing a brain model for simulation of medical device interventions during neurosurgery. A brain atlas was utilized to develop a detailed model consisting of multiple structures. Two types of atlas model were generated employing different mesh types and biomechanical properties suited for various applications. The developed model was able to capture the detailed anatomy of the brain and reflect the application-dependant biomechanical behaviour based on material modelling of brain tissue under surgical intervention

  17. "Neuro-semeiotics" and "free-energy minimization" suggest a unified perspective for integrative brain actions: focus on receptor heteromers and Roamer type of volume transmission.

    Science.gov (United States)

    Agnati, Luigi F; Guidolin, Diego; Marcoli, Manuela; Genedani, Susanna; Borroto-Escuela, Dasiel; Maura, Guido; Fuxe, Kjell

    2014-01-01

    Two far-reaching theoretical approaches, namely "Neuro-semeiotics" (NS) and "Free-energy Minimization" (FEM), have been recently proposed as frames within which to put forward heuristic hypotheses on integrative brain actions. In the present paper these two theoretical approaches are briefly discussed in the perspective of a recent model of brain architecture and information handling based on what we suggest calling Jacob's tinkering principle, whereby "to create is to recombine!". The NS and FEM theoretical approaches will be discussed from the perspective both of the Roamer-Type Volume Transmission (especially exosome-mediated) of intercellular communication and of the impact of receptor oligomers and Receptor-Receptor Interactions (RRIs) on signal recognition/decoding processes. In particular, the Bio-semeiotics concept of "adaptor" will be used to analyze RRIs as an important feature of NS. Furthermore, the concept of phenotypic plasticity of cells will be introduced in view of the demonstration of the possible transfer of receptors (i.e., adaptors) into a computational network via exosomes (see also Appendix). Thus, Jacob's tinkering principle will be proposed as a theoretical basis for some learning processes both at the network level (Turing-like type of machine) and at the molecular level as a consequence of both the plastic changes in the adaptors caused by the allosteric interactions in the receptor oligomers and the intercellular transfer of receptors. Finally, on the basis of NS and FEM theories, a unified perspective for integrative brain actions will be proposed. PMID:25175453

  18. Assessment of Cognitive Function in the Water Maze Task: Maximizing Data Collection and Analysis in Animal Models of Brain Injury.

    Science.gov (United States)

    Whiting, Mark D; Kokiko-Cochran, Olga N

    2016-01-01

    Animal models play a critical role in understanding the biomechanical, pathophysiological, and behavioral consequences of traumatic brain injury (TBI). In preclinical studies, cognitive impairment induced by TBI is often assessed using the Morris water maze (MWM). Frequently described as a hippocampally dependent spatial navigation task, the MWM is a highly integrative behavioral task that requires intact functioning in numerous brain regions and involves an interdependent set of mnemonic and non-mnemonic processes. In this chapter, we review the special considerations involved in using the MWM in animal models of TBI, with an emphasis on maximizing the degree of information extracted from performance data. We include a theoretical framework for examining deficits in discrete stages of cognitive function and offer suggestions for how to make inferences regarding the specific nature of TBI-induced cognitive impairment. The ultimate goal is more precise modeling of the animal equivalents of the cognitive deficits seen in human TBI. PMID:27604738

  19. A Pilot Project of Early Integrated Traumatic Brain Injury Rehabilitation in Singapore

    Directory of Open Access Journals (Sweden)

    Siew Kwaon Lui

    2014-01-01

    Full Text Available Objective. Document acute neurosurgical and rehabilitation parameters of patients of all traumatic brain injury (TBI severities and determine whether early screening along with very early integrated TBI rehabilitation changes functional outcomes. Methods. Prospective study involving all patients with TBI admitted to a neurosurgical department of a tertiary hospital. They were assessed within 72 hours of admission by the rehabilitation team and received twice weekly rehabilitation reviews. Patients with further rehabilitation needs were then transferred to the attached acute inpatient TBI rehabilitation unit (TREATS and their functional outcomes were compared against a historical group of patients. Demographic variables, acute neurosurgical characteristics, medical complications, and rehabilitation outcomes were recorded. Results. There were 298 patients screened with an average age of 61.8±19.1 years. The most common etiology was falls (77.5%. Most patients were discharged home directly (67.4% and 22.8% of patients were in TREATS. The TREATS group functionally improved (P<0.001. Regression analysis showed by the intervention of TREATS, that there was a statistically significant FIM functional gain of 18.445 points (95% CI −30.388 to −0.6502, P=0.03. Conclusion. Our study demonstrated important epidemiological data on an unselected cohort of patients with TBI in Singapore and functional improvement in patients who further received inpatient rehabilitation.

  20. A Fuzzy Integral Ensemble Method in Visual P300 Brain-Computer Interface

    Directory of Open Access Journals (Sweden)

    Francesco Cavrini

    2016-01-01

    Full Text Available We evaluate the possibility of application of combination of classifiers using fuzzy measures and integrals to Brain-Computer Interface (BCI based on electroencephalography. In particular, we present an ensemble method that can be applied to a variety of systems and evaluate it in the context of a visual P300-based BCI. Offline analysis of data relative to 5 subjects lets us argue that the proposed classification strategy is suitable for BCI. Indeed, the achieved performance is significantly greater than the average of the base classifiers and, broadly speaking, similar to that of the best one. Thus the proposed methodology allows realizing systems that can be used by different subjects without the need for a preliminary configuration phase in which the best classifier for each user has to be identified. Moreover, the ensemble is often capable of detecting uncertain situations and turning them from misclassifications into abstentions, thereby improving the level of safety in BCI for environmental or device control.

  1. Loss of Microstructural Integrity in the Limbic-Subcortical Networks for Acute Symptomatic Traumatic Brain Injury

    Directory of Open Access Journals (Sweden)

    Yanan Zhu

    2014-01-01

    Full Text Available Previous studies reported discrepant white matter diffusivity in mild traumatic brain injury (mTBI on the base of Glasgow Coma Scale, which are unreliable for some TBI severity indicators and the frequency of missing documentation in the medical record. In the present study, we adopted the Mayo classification system for TBI severity. In this system, the mTBI is also divided into two groups as “probable and symptomatic” TBI. We aimed to investigate altered microstructural integrity in symptomatic acute TBI (<1 week by using tract-based spatial statics (TBSS approach. A total of 12 patients and 13 healthy volunteers were involved and underwent MRI scans including conventional scan, and SWI and DTI. All the patients had no visible lesions by using conventional and SWI neuroimaging techniques, while showing widespread declines in the fractional anisotropy (FA of gray matter and white matter throughout the TBSS skeleton, particularly in the limbic-subcortical structures. By contrast, symptomatic TBI patients showed no significant enhanced changes in FA compared to the healthy controls. A better understanding of the acute changes occurring following symptomatic TBI may increase our understanding of neuroplasticity and continuing degenerative change, which, in turn, may facilitate advances in management and intervention.

  2. Nano-Modeling and Computation in Bio and Brain Dynamics

    OpenAIRE

    Paolo Di Sia; Ignazio Licata

    2016-01-01

    The study of brain dynamics currently utilizes the new features of nanobiotechnology and bioengineering. New geometric and analytical approaches appear very promising in all scientific areas, particularly in the study of brain processes. Efforts to engage in deep comprehension lead to a change in the inner brain parameters, in order to mimic the external transformation by the proper use of sensors and effectors. This paper highlights some crossing research areas of natural computing, nanotech...

  3. An integrated network model of psychotic symptoms

    NARCIS (Netherlands)

    Looijestijn, Jasper; Blom, Jan Dirk; Aleman, Andre; Hoek, Hans W.; Goekoop, Rutger

    2015-01-01

    The full body of research on the nature of psychosis and its determinants indicates that a considerable number of factors are relevant to the development of hallucinations, delusions, and other positive symptoms, ranging from neurodevelopmental parameters and altered connectivity of brain regions to

  4. Effects of tetrahydroxystilbene - glucoside on Animal Models of Dementia or Brain Aging

    Institute of Scientific and Technical Information of China (English)

    LinLi; JinChu; LiLiu; LingZhao; LanZhang

    2004-01-01

    Aim: To investigate the effects of 2, 3, 5, 4'-tetrahydroxystilbene-2-O-β-D-glucoside(TSG) from a Chinese Medicinal Herb polygonum multiflorum on dementia or brain aging. Methods. The brain aging model of mice was developed by s. c. injection of D-galactose (50mg/kg/day) for 60 days. The Alzheimer disease (AD) model of mice

  5. 77 FR 34363 - Disability and Rehabilitation Research Projects and Centers Program; Traumatic Brain Injury Model...

    Science.gov (United States)

    2012-06-11

    ... Disability and Rehabilitation Research Projects and Centers Program; Traumatic Brain Injury Model Systems... Program--Disability Rehabilitation Research Project (DRRP)-- Traumatic Brain Injury Model Systems Centers... Plan, which was published in the Federal Register on February 15, 2006 (71 FR 8165), can be accessed...

  6. Melatonin promotes blood-brain barrier integrity in methamphetamine-induced inflammation in primary rat brain microvascular endothelial cells.

    Science.gov (United States)

    Jumnongprakhon, Pichaya; Govitrapong, Piyarat; Tocharus, Chainarong; Tocharus, Jiraporn

    2016-09-01

    Melatonin is a neurohormone and has high potent of antioxidant that is widely reported to be active against methamphetamine (METH)-induced toxicity to neuron, glial cells, and brain endothelial cells. However, the role of melatonin on the inflammatory responses which are mostly caused by blood-brain barrier (BBB) impairment by METH administration has not been investigated. This study used the primary rat brain microvascular endothelial cells (BMVECs) to determine the protective mechanism of melatonin on METH-induced inflammatory responses in the BBB via nuclear factor-ĸB (NF-κB) and nuclear factor erythroid 2-related factor-2 (Nrf2) signaling. Herein, we demonstrated that melatonin reduced the level of the inflammatory mediators, including intercellular adhesion molecules (ICAM)-1, vascular cell adhesion molecules (VCAM)-1, matrix metallopeptidase (MMP)-9, inducible nitric oxide synthase (iNOS), and nitric oxide (NO) caused by METH. These responses were related to the decrease of the expression and translocation of the NF-κB p65 subunit and the activity of NADPH oxidase (NOX)-2. In addition, melatonin promoted the antioxidant processes, modulated the expression and translocation of Nrf2, and also increased the level of heme oxygenase (HO)-1, NAD (P) H: quinone oxidoreductase (NQO)-1, γ-glutamylcysteine synthase (γ-GCLC), and the activity of superoxide dismutase (SOD) through NOX2 mechanism. In addition, we found that the protective role of melatonin in METH-induced inflammatory responses in the BBB was mediated through melatonin receptors (MT1/2). We concluded that the interaction of melatonin with its receptor prevented METH-induced inflammatory responses by suppressing the NF-κB signaling and promoting the Nrf2 signaling before BBB impairment. PMID:27268413

  7. Atomic data for integrated tokamak modelling

    International Nuclear Information System (INIS)

    The Integrated Tokamak Modeling Task Force (ITM-TF) was set up in 2004. The main target is to coordinate the European fusion modeling effort and providing a complete European modeling structure for International Thermonuclear Experimental Reactor (ITER), with the highest degree of flexibility. For the accurate simulation of the processes in the active fusion reactor in the ITM-TF, numerous atomic, molecular, nuclear and surface related data are required. In this work we present total-, single- and multiple-ionization and charge exchange cross sections in close connection to the ITM-TF. Interpretation of these cross sections in multi-electron ion-atom collisions is a challenging task for theories. The main difficulty is caused by the many-body feature of the collision, involving the projectile, projectile electron(s), target nucleus, and target electron(s). The classical trajectory Monte Carlo (CTMC) method has been quite successful in dealing with the atomic processes in ion-atom collisions. One of the advantages of the CTMC method is that many-body interactions are exactly taken into account related CTMC simulations for a various collision systems are presented. To highlight the efficiency of the method we present electron emission cross sections in collision between dressed Alq+ ions with He target. The theory delivers separate spectra for electrons emitted from the target and the projectile. By summing these two components in the rest frame of the target we may make a comparison with available experimental data. For the collision system in question, a significant contribution from Fermi-shuttle ionization has to be expected in the spectra at energies higher than E=0.5 me (nV)2, where me is the mass of the electron, V the projectile velocity and n an integer greater than 1. We found enhanced electron yields compared to first order theory in this region of CTMC spectra, which can be directly attributed to the contribution of Fermi-shuttle type multiple scattering

  8. Modeling DNA Dynamics by Path Integrals

    International Nuclear Information System (INIS)

    Complementary strands in DNA double helix show temporary fluctuational openings which are essential to biological functions such as transcription and replication of the genetic information. Such large amplitude fluctuations, known as the breathing of DNA, are generally localized and, microscopically, are due to the breaking of the hydrogen bonds linking the base pairs (bps). I apply imaginary time path integral techniques to a mesoscopic Hamiltonian which accounts for the helicoidal geometry of a short circular DNA molecule. The bps displacements with respect to the ground state are interpreted as time dependent paths whose amplitudes are consistent with the model potential for the hydrogen bonds. The portion of the paths configuration space contributing to the partition function is determined by selecting the ensemble of paths which fulfill the second law of thermodynamics. Computations of the thermodynamics in the denaturation range show the energetic advantage for the equilibrium helicoidal geometry peculiar of B-DNA. I discuss the interplay between twisting of the double helix and anharmonic stacking along the molecule backbone suggesting an interesting relation between intrinsic nonlinear character of the microscopic interactions and molecular topology.

  9. Fractional Diffusion Based Modelling and Prediction of Human Brain Response to External Stimuli

    Directory of Open Access Journals (Sweden)

    Hamidreza Namazi

    2015-01-01

    Full Text Available Human brain response is the result of the overall ability of the brain in analyzing different internal and external stimuli and thus making the proper decisions. During the last decades scientists have discovered more 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 were fewer efforts which have been done on the mathematical modeling of the human brain response to external stimuli. This research is devoted to the modeling and prediction of the human EEG signal, as an alert state of overall human brain activity monitoring, upon receiving external stimuli, based on fractional diffusion equations. The results of this modeling show very good agreement with the real human EEG signal and thus this model can be used for many types of applications such as prediction of seizure onset in patient with epilepsy.

  10. Model of the Brain Tumor–Pumilio translation repressor complex

    Science.gov (United States)

    Edwards, Thomas A.; Wilkinson, Brian D.; Wharton, Robin P.; Aggarwal, Aneel K.

    2003-01-01

    The Brain Tumor (Brat) protein is recruited to the 3′ untranslated region (UTR) of hunchback mRNA to regulate its translation. Recruitment is mediated by interactions between the Pumilio RNA-binding Puf repeats and the NHL domain of Brat, a conserved structural motif present in a large family of growth regulators. In this report, we describe the crystal structure of the Brat NHL domain and present a model of the Pumilio–Brat complex derived from in silico docking experiments and supported by mutational analysis of the protein–protein interface. A key feature of the model is recognition of the outer, convex surface of the Pumilio Puf domain by the top, electropositive face of the six-bladed Brat β-propeller. In particular, an extended loop in Puf repeat 8 fits in the entrance to the central channel of the Brat β-propeller. Together, these interactions are likely to be prototypic of the recruitment strategies of other NHL-containing proteins in development. PMID:14561773

  11. Local Model of Arteriovenous Malformation of the Human Brain

    Science.gov (United States)

    Nadezhda Telegina, Ms; Aleksandr Chupakhin, Mr; Aleksandr Cherevko, Mr

    2013-02-01

    Vascular diseases of the human brain are one of the reasons of deaths and people's incapacitation not only in Russia, but also in the world. The danger of an arteriovenous malformation (AVM) is in premature rupture of pathological vessels of an AVM which may cause haemorrhage. Long-term prognosis without surgical treatment is unfavorable. The reduced impact method of AVM treatment is embolization of a malformation which often results in complete obliteration of an AVM. Pre-surgical mathematical modeling of an arteriovenous malformation can help surgeons with an optimal sequence of the operation. During investigations, the simple mathematical model of arteriovenous malformation is developed and calculated, and stationary and non-stationary processes of its embolization are considered. Various sequences of embolization of a malformation are also considered. Calculations were done with approximate steady flow on the basis of balanced equations derived from conservation laws. Depending on pressure difference, a fistula-type AVM should be embolized at first, and then small racemose AVMs are embolized. Obtained results are in good correspondence with neurosurgical AVM practice.

  12. Local Model of Arteriovenous Malformation of the Human Brain

    International Nuclear Information System (INIS)

    Vascular diseases of the human brain are one of the reasons of deaths and people's incapacitation not only in Russia, but also in the world. The danger of an arteriovenous malformation (AVM) is in premature rupture of pathological vessels of an AVM which may cause haemorrhage. Long-term prognosis without surgical treatment is unfavorable. The reduced impact method of AVM treatment is embolization of a malformation which often results in complete obliteration of an AVM. Pre-surgical mathematical modeling of an arteriovenous malformation can help surgeons with an optimal sequence of the operation. During investigations, the simple mathematical model of arteriovenous malformation is developed and calculated, and stationary and non-stationary processes of its embolization are considered. Various sequences of embolization of a malformation are also considered. Calculations were done with approximate steady flow on the basis of balanced equations derived from conservation laws. Depending on pressure difference, a fistula-type AVM should be embolized at first, and then small racemose AVMs are embolized. Obtained results are in good correspondence with neurosurgical AVM practice.

  13. Radiolysis Model Formulation for Integration with the Mixed Potential Model

    Energy Technology Data Exchange (ETDEWEB)

    Buck, Edgar C.; Wittman, Richard S.

    2014-07-10

    The U.S. Department of Energy Office of Nuclear Energy (DOE-NE), Office of Fuel Cycle Technology has established the Used Fuel Disposition Campaign (UFDC) to conduct the research and development activities related to storage, transportation, and disposal of used nuclear fuel (UNF) and high-level radioactive waste. Within the UFDC, the components for a general system model of the degradation and subsequent transport of UNF is being developed to analyze the performance of disposal options [Sassani et al., 2012]. Two model components of the near-field part of the problem are the ANL Mixed Potential Model and the PNNL Radiolysis Model. This report is in response to the desire to integrate the two models as outlined in [Buck, E.C, J.L. Jerden, W.L. Ebert, R.S. Wittman, (2013) “Coupling the Mixed Potential and Radiolysis Models for Used Fuel Degradation,” FCRD-UFD-2013-000290, M3FT-PN0806058

  14. Integral Canonical Models for Automorphic Vector Bundles of Abelian Type

    OpenAIRE

    Lovering, Tom

    2016-01-01

    We define and construct integral canonical models for automorphic vector bundles over Shimura varieties of abelian type. More precisely, we first build on Kisin's work to construct integral canonical models over rings of integers of number fields with finitely many primes inverted for Shimura varieties of abelian type with hyperspecial level at all primes we do not invert, compatible with Kisin's construction. We then define a notion of an integral canonical model for the standard principal b...

  15. Neurodegeneration from mitochondrial insufficiency: nutrients, stem cells, growth factors, and prospects for brain rebuilding using integrative management.

    Science.gov (United States)

    Kidd, Parris M

    2005-12-01

    Degenerative brain disorders (neurodegeneration) can be frustrating for both conventional and alternative practitioners. A more comprehensive, integrative approach is urgently needed. One emerging focus for intervention is brain energetics. Specifically, mitochondrial insufficiency contributes to the etiopathology of many such disorders. Electron leakages inherent to mitochondrial energetics generate reactive oxygen free radical species that may place the ultimate limit on lifespan. Exogenous toxins, such as mercury and other environmental contaminants, exacerbate mitochondrial electron leakage, hastening their demise and that of their host cells. Studies of the brain in Alzheimer's and other dementias, Down syndrome, stroke, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis, Huntington's disease, Friedreich's ataxia, aging, and constitutive disorders demonstrate impairments of the mitochondrial citric acid cycle and oxidative phosphorylation (OXPHOS) enzymes. Imaging or metabolic assays frequently reveal energetic insufficiency and depleted energy reserve in brain tissue in situ. Orthomolecular nutrients involved in mitochondrial metabolism provide clinical benefit. Among these are the essential minerals and the B vitamin group; vitamins E and K; and the antioxidant and energetic cofactors alpha-lipoic acid (ALA), ubiquinone (coenzyme Q10; CoQ10), and nicotinamide adenine dinucleotide, reduced (NADH). Recent advances in the area of stem cells and growth factors encourage optimism regarding brain regeneration. The trophic nutrients acetyl L-carnitine (ALCAR), glycerophosphocholine (GPC), and phosphatidylserine (PS) provide mitochondrial support and conserve growth factor receptors; all three improved cognition in double-blind trials. The omega-3 fatty acid docosahexaenoic acid (DHA) is enzymatically combined with GPC and PS to form membrane phospholipids for nerve cell expansion. Practical recommendations are presented for integrating these

  16. Executive control of language in the bilingual brain: integrating the evidence from neuroimaging to neuropsychology.

    OpenAIRE

    AlexisGeorgesHervais-Adelman; BarbaraMoser-Mercer

    2011-01-01

    In this review we will focus on delineating the neural substrates of the executive control of language in the bilingual brain, based on the existing neuroimaging, intracranial, transcranial magnetic stimulation, and neuropsychological evidence. We will also offer insights from ongoing brain-imaging studies into the development of expertise in multilingual language control. We will concentrate specifically on evidence regarding how the brain selects and controls languages for comprehension and...

  17. Brain Structural Integrity and Intrinsic Functional Connectivity Forecast 6 Year Longitudinal Growth in Children's Numerical Abilities

    OpenAIRE

    Evans, Tanya M.; Kochalka, John; Ngoon, Tricia J.; Wu, Sarah S.; Qin, Shaozheng; Battista, Christian; Menon, Vinod

    2015-01-01

    Early numerical proficiency lays the foundation for acquiring quantitative skills essential in today's technological society. Identification of cognitive and brain markers associated with long-term growth of children's basic numerical computation abilities is therefore of utmost importance. Previous attempts to relate brain structure and function to numerical competency have focused on behavioral measures from a single time point. Thus, little is known about the brain predictors of individual...

  18. Integrated modelling requires mass collaboration (Invited)

    Science.gov (United States)

    Moore, R. V.

    2009-12-01

    add, “and are the plans sustainable?” To return to the present, although, it is now possible to ask the first question and obtain an answer through linked modelling; we are still at a very early stage and the associated uncertainties are large. The process of linking and running linked systems is not yet the simple, reliable process needed for widespread uptake. At this point, it is useful to look back over the development process which has taken us from paper maps to GIS and Google Maps; it was the result of tens of thousands of PhD and MSc projects over forty years. During the development of the OpenMI, it was quickly appreciated that to transform integrated modelling from something possible in a research lab to something that had the ease of use and reliability of Google Maps would require a similar process but on a far greater scale; one far larger than any single organisation or state could support. A dramatic change to the research and development process would be needed. Using the OpenMI Association’s strategy as an example, the presentation will describe how through openness, sharing and mass collaboration made possible by inexpensive communications and computing power and adoption of a minimum set of standards, the innovation and enterprise of thousands of individuals across the world can be brought to bear upon the problems.

  19. Effects of exogenous ganglioside-1 on learning and memory in a neonatal rat model of hypoxia-ischemia brain injury

    Institute of Scientific and Technical Information of China (English)

    Shizhi Li; Nong Xiao; Xiaoping Zhang; Ling Liu; Liyun Lin; Siyuan Chen; Yuxia Chen; Bei Xu

    2008-01-01

    greater in the hippocampal CA3 region compared to the model group I week after surgery (P < 0.05). In all three groups, brain weight of the right hemisphere was significantly less than the left hemisphere, in particular in the model group (P < 0.05). In the GMI group, the weight difference between two hemispheres, as well as the extent of damage in the right hemisphere, was less than the model group (P < 0.01). In the sham operation group, brain tissue consisted of integrated structures and ordered cells. In the model group, the cerebral cortex layers of the right hemisphere were not defined, neurons were damaged, and neurons were disarranged in the hippocampal area. In the GMI group, neurons were dense in the right cerebral cortex and hippocampal area, with no significant change in glial prolitferation. (2) The average time of escape latency in the GM1 group was shortened 4 weeks after surgery, and significantly less than the model group (P < 0.05), In addition, the frequency platform passing in the GM1 group was significantly greater than the model group (P < 0.01). CONCLUSION: Exogenous GMI may reduce brain injury and improve learning and memory in hypoxia-ischemia-induced brain damage rats. This protection may be associated with increased growth-associated protein-43 expression, which is involved in neuronal remodeling processes.

  20. Intracerebroventricular transplantation of ex vivo expanded endothelial colony-forming cells restores blood-brain barrier integrity and promotes angiogenesis of mice with traumatic brain injury.

    Science.gov (United States)

    Huang, Xin-Tao; Zhang, Yong-Qiang; Li, Sheng-Jie; Li, Sheng-Hui; Tang, Qing; Wang, Zhi-Tao; Dong, Jing-Fei; Zhang, Jian-Ning

    2013-12-15

    Endothelial progenitor cells (EPCs) play a key role in tissue repair and regeneration. Previous studies have shown a positive correlation between the number of circulating EPCs and clinical outcomes of patients with traumatic brain injury (TBI). A recent study has further shown that intravenous infusion of human umbilical cord blood-derived endothelial colony-forming cells (ECFCs) improves outcomes of mice subjected to experimental TBI. This follow-up study was designed to determine whether intracerebroventricular (i.c.v.) infusion of ECFCs, which may reduce systemic effects of these cells, could repair the blood-brain barrier (BBB) and promote angiogenesis of mice with TBI. Adult nude mice were exposed to fluid percussion injury and transplanted i.c.v. with ECFCs on day 1 post-TBI. These ECFCs were detected at the TBI zone 3 days after transplantation by SP-DiIC18(3) and fluorescence in situ hybridization. Mice with ECFCs transplant had reduced Evans blue extravasation and brain water content, increased expression of ZO-1 and claudin-5, and showed a higher expression of angiopoietin 1. Consistent with the previous report, mice with ECFCs transplant had also increased microvascular density. Modified neurological severity score and Morris water maze test indicated significant improvements in motor ability, spatial acquisition and reference memory in mice receiving ECFCs, compared to those receiving saline. These data demonstrate the beneficial effects of ECFC transplant on BBB integrity and angiogenesis in mice with TBI. PMID:23957220

  1. Integrated Enterprise Modeling Method Based on Workflow Model and Multiviews%Integrated Enterprise Modeling Method Based on Workflow Model and Multiviews

    Institute of Scientific and Technical Information of China (English)

    林慧苹; 范玉顺; 吴澄

    2001-01-01

    Many enterprise modeling methods are proposed to model thebusiness process of enterprises and to implement CIM systems. But difficulties are still encountered when these methods are applied to the CIM system design and implementation. This paper proposes a new integrated enterprise modeling methodology based on the workflow model. The system architecture and the integrated modeling environment are described with a new simulation strategy. The modeling process and the relationship between the workflow model and the views are discussed.

  2. Current preclinical studies on neuroinflammation and changes in blood-brain barrier integrity by MDMA and methamphetamine.

    Science.gov (United States)

    O'Shea, Esther; Urrutia, Andrés; Green, A Richard; Colado, M Isabel

    2014-12-01

    The blood-brain barrier (BBB) is essential in the maintenance of brain homeostasis both by preserving normal brain functioning and also by protecting the brain from exposure to a range of potentially harmful substances. This review presents some of the evidence of BBB disruption following exposure to the substituted amphetamines 3,4-methylenedioxymethamphetamine (MDMA, 'ecstasy') and methamphetamine (METH), two drugs of abuse which are widely consumed recreationally by younger sectors of the population. Both MDMA and METH have been shown to produce disruption of the BBB as reflected by IgG extravasation and Evans Blue leakage. In particular, METH decreases the expression of basal lamina proteins associated with an increase in matrix metalloproteinase activity. These changes in BBB integrity appear to be related to MDMA-induced activation of the mitogen-activated protein kinase (MAPK) JNK1/2. The consequences of the disruption in the BBB by these two drugs remain to be established, but there is evidence in the literature that, at least in the case of METH, increased matrix metalloproteinase (MMP) activity may be related to increased behavioural sensitization and reward perhaps because of the modification of the passage of the drug into the CNS. In addition, the high incidence of AIDS-related neurologic disease in METH users may also be related to increased entry into the brain of virally derived neurotoxic products. This article is part of the Special Issue entitled 'CNS Stimulants'. PMID:24594477

  3. Brain Emotional Learning-Based Prediction Model (For Long-Term Chaotic Prediction Applications)

    OpenAIRE

    Parsapoor, Mahboobeh

    2016-01-01

    This study suggests a new prediction model for chaotic time series inspired by the brain emotional learning of mammals. We describe the structure and function of this model, which is referred to as BELPM (Brain Emotional Learning-Based Prediction Model). Structurally, the model mimics the connection between the regions of the limbic system, and functionally it uses weighted k nearest neighbors to imitate the roles of those regions. The learning algorithm of BELPM is defined using steepest des...

  4. Physiologically based pharmacokinetic modeling to investigate regional brain distribution kinetics in rats.

    Science.gov (United States)

    Westerhout, Joost; Ploeger, Bart; Smeets, Jean; Danhof, Meindert; de Lange, Elizabeth C M

    2012-09-01

    One of the major challenges in the development of central nervous system (CNS)-targeted drugs is predicting CNS exposure in human from preclinical data. In this study, we present a methodology to investigate brain disposition in rats using a physiologically based modeling approach aiming at improving the prediction of human brain exposure. We specifically focused on quantifying regional diffusion and fluid flow processes within the brain. Acetaminophen was used as a test compound as it is not subjected to active transport processes. Microdialysis probes were implanted in striatum, for sampling brain extracellular fluid (ECF) concentrations, and in lateral ventricle (LV) and cisterna magna (CM), for sampling cerebrospinal fluid (CSF) concentrations. Serial blood samples were taken in parallel. These data, in addition to physiological parameters from literature, were used to develop a physiologically based model to describe the regional brain pharmacokinetics of acetaminophen. The concentration-time profiles of brain ECF, CSF(LV), and CSF(CM) indicate a rapid equilibrium with plasma. However, brain ECF concentrations are on average fourfold higher than CSF concentrations, with average brain-to-plasma AUC(0-240) ratios of 121%, 28%, and 35% for brain ECF, CSF(LV), and CSF(CM), respectively. It is concluded that for acetaminophen, a model compound for passive transport into, within, and out of the brain, differences exist between the brain ECF and the CSF pharmacokinetics. The physiologically based pharmacokinetic modeling approach is important, as it allowed the prediction of human brain ECF exposure on the basis of human CSF concentrations. PMID:22588644

  5. Low propensity to return: A model of permanent Italian brain drain

    OpenAIRE

    Alessio Emanuele Biondo; Simona Monteleone

    2010-01-01

    The paper analyzes permanent aspects of brain drain phenomenon referred to Italian highly skilled workers. The analysis regards a sample of post-doctoral graduates, medical specialists, and academic researchers. Results suggest that brain drain in Italy is not temporary, as demonstrated by Dustmann-Weiss (2007) for UK case. A modified version of their model allows us to explain why Italy performs a peculiar characterization of brain drain with no return. Reasons for this diversity are shown t...

  6. Generative models of rich clubs in Hebbian neuronal networks and large-scale human brain networks

    OpenAIRE

    Vértes, Petra E.; Alexander-Bloch, Aaron; Bullmore, Edward T

    2014-01-01

    Rich clubs arise when nodes that are ‘rich’ in connections also form an elite, densely connected ‘club’. In brain networks, rich clubs incur high physical connection costs but also appear to be especially valuable to brain function. However, little is known about the selection pressures that drive their formation. Here, we take two complementary approaches to this question: firstly we show, using generative modelling, that the emergence of rich clubs in large-scale human brain networks can be...

  7. Integrating Structure to Protein-Protein Interaction Networks That Drive Metastasis to Brain and Lung in Breast Cancer

    OpenAIRE

    H Billur Engin; Emre Guney; Ozlem Keskin; Baldo Oliva; Attila Gursoy

    2013-01-01

    Integrating Structure to Protein-Protein Interaction Networks That Drive Metastasis to Brain and Lung in Breast Cancer H. Billur Engin1, Emre Guney2, Ozlem Keskin1, Baldo Oliva2, Attila Gursoy1* 1 Center for Computational Biology and Bioinformatics and College of Engineering, Koc University, Istanbul, Turkey, 2 Structural Bioinformatics Group (GRIB), Universitat Pompeu Fabra Abstract Blocking specific protein interactions can lead to human diseases. Accordingly, protein i...

  8. Brain Radiation Information Data Exchange (BRIDE): integration of experimental data from low-dose ionising radiation research for pathway discovery

    OpenAIRE

    Karapiperis, Christos; Kempf, Stefan J.; Quintens, Roel; Azimzadeh, Omid; Vidal, Victoria Linares; Pazzaglia, Simonetta; Bazyka, Dimitry; Mastroberardino, Pier G.; Scouras, Zacharias G.; Tapio, Soile; BENOTMANE, MOHAMMED ABDERRAFI; Ouzounis, Christos A

    2016-01-01

    Background The underlying molecular processes representing stress responses to low-dose ionising radiation (LDIR) in mammals are just beginning to be understood. In particular, LDIR effects on the brain and their possible association with neurodegenerative disease are currently being explored using omics technologies. Results We describe a light-weight approach for the storage, analysis and distribution of relevant LDIR omics datasets. The data integration platform, called BRIDE, contains inf...

  9. White matter integrity in veterans with mild traumatic brain injury: Associations with executive function and loss of consciousness

    OpenAIRE

    Sorg, SF; DELANO-WOOD, L.; Luc, N; Schiehser, DM; Hanson, KL; Nation, DA; Lanni, E; Jak, AJ; Lu, K.; Meloy, MJ; Frank, LR; Lohr, JB; Bondi, MW

    2014-01-01

    OBJECTIVE: We investigated using diffusion tensor imaging (DTI) and the association between white matter integrity and executive function (EF) performance in postacute mild traumatic brain injury (mTBI). In addition, we examined whether injury severity, as measured by loss of consciousness (LOC) versus alterations in consciousness (AOC), is related to white matter microstructural alterations and neuropsychological outcome. PARTICIPANTS: Thirty Iraq and Afghanistan War era veterans with a hist...

  10. Integrating structure to protein-protein interaction networks that drive metastasis to brain and lung in breast cancer

    OpenAIRE

    Engin, H Billur; G??ney, Emre, 1983-; Keskin, Ozlem; Oliva Miguel, Baldomero; Gursoy, Attila

    2013-01-01

    Integrating Structure to Protein-Protein Interaction Networks That Drive Metastasis to Brain and Lung in Breast Cancer H. Billur Engin1, Emre Guney2, Ozlem Keskin1, Baldo Oliva2, Attila Gursoy1* 1 Center for Computational Biology and Bioinformatics and College of Engineering, Koc University, Istanbul, Turkey, 2 Structural Bioinformatics Group (GRIB), Universitat Pompeu Fabra Abstract Blocking specific protein interactions can lead to human diseases. Accordingly, protein i...

  11. 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

  12. Bridging animal and human models of exercise-induced brain plasticity

    OpenAIRE

    Voss, Michelle W.; Vivar, Carmen; Arthur F Kramer; Van Praag, Henriette

    2013-01-01

    Significant progress has been made in understanding the neurobiological mechanisms through which exercise protects and restores the brain. In this feature review, we integrate animal and human research, examining physical activity effects across multiple levels of description (neurons up to inter-regional pathways). We evaluate the influence of exercise on hippocampal structure and function, addressing common themes such as spatial memory and pattern separation, brain structure and plasticity...

  13. 脑控:基于脑-机接口的人机融合控制%Brain Control: Human-computer Integration Control Based on Brain-computer Interface

    Institute of Scientific and Technical Information of China (English)

    王行愚; 金晶; 张宇; 王蓓

    2013-01-01

    近年来,一类被称之为脑控的新型控制系统发展迅速,这是一种基于脑-机接口(Brain-computer interface,BCI)的人机融合控制系统,也是一种基于人的意念和思维的控制系统.脑控系统己被成功应用于残疾人的生活辅助、中风病人和损伤肢体的康复训练、操作员状态的实时监控、游戏娱乐和智能家居等广泛的领域.本文在简要介绍了脑控的研究背景、基本原理、系统结构和发展概况的基础上,着重对脑电信号(Electroencephalogram,EEG)模式、控制信号转换算法和应用系统研究等主要问题的研究现状,进行了较为详细的论述和分析,并探讨了进一步研究的方向和思路.最后对脑控的未来发展方向和应用前景进行了分析和展望.%Recently, a new system called brain control system has been developed rapidly. Brain control system is a human-computer integration control system based on brain-computer interface (BCI), which relies on human's ideas and thinking. Brain control system has been successfully applied in wide fields, assisting disabled patients daily life, training patients with stroke or limb injury, monitoring the status of human operator, as well as entertainment and smart house etc. In this paper, the background, basic principle, system structure and developments are firstly introduced briefly. The current research status focusing on the problems of electroencephalogram (EEG) signal pattern, control signal transfer algorithm and system application is summarized and analyzed in detail. The further research direction and thoughts are discussed. Finally, the future development of brain control is analyzed and prospects are given.

  14. Modeling localized delivery of Doxorubicin to the brain following focused ultrasound enhanced blood-brain barrier permeability

    International Nuclear Information System (INIS)

    Doxorubicin (Dox) is a well-established chemotherapeutic agent, however it has limited efficacy in treating brain malignancies due to the presence of the blood-brain barrier (BBB). Recent preclinical studies have demonstrated that focused ultrasound induced BBB disruption (BBBD) enables efficient delivery of Dox to the brain. For future treatment planning of BBBD-based drug delivery, it is crucial to establish a mathematical framework to predict the effect of transient BBB permeability enhancement on the spatiotemporal distribution of Dox at the targeted area. The constructed model considers Dox concentrations within three compartments (plasma, extracellular, intracellular) that are governed by various transport processes (e.g. diffusion in interstitial space, exchange across vessel wall, clearance by cerebral spinal fluid, uptake by brain cells). By examining several clinical treatment aspects (e.g. sonication scheme, permeability enhancement, injection mode), our simulation results support the experimental findings of optimal interval delay between two consecutive sonications and therapeutically-sufficient intracellular concentration with respect to transfer constant Ktrans range of 0.01–0.03 min−1. Finally, the model suggests that infusion over a short duration (20–60 min) should be employed along with single-sonication or multiple-sonication at 10 min interval to ensure maximum delivery to the intracellular compartment while attaining minimal cardiotoxicity via suppressing peak plasma concentration. (paper)

  15. Modeling the effects of noninvasive transcranial brain stimulation at the biophysical, network, and cognitive Level

    DEFF Research Database (Denmark)

    Hartwigsen, Gesa; Bergmann, Til Ole; Herz, Damian Marc;

    2015-01-01

    Noninvasive transcranial brain stimulation (NTBS) is widely used to elucidate the contribution of different brain regions to various cognitive functions. Here we present three modeling approaches that are informed by functional or structural brain mapping or behavior profiling and discuss how the...... emerge in the context of rapid automatic responses or in the context of slow deliberate responses. We argue that these complementary modeling approaches facilitate the use of NTBS as a means of dissecting the causal architecture of cognitive systems of the human brain.......Noninvasive transcranial brain stimulation (NTBS) is widely used to elucidate the contribution of different brain regions to various cognitive functions. Here we present three modeling approaches that are informed by functional or structural brain mapping or behavior profiling and discuss how these...... approaches advance the scientific potential of NTBS as an interventional tool in cognitive neuroscience. (i) Leveraging the anatomical information provided by structural imaging, the electric field distribution in the brain can be modeled and simulated. Biophysical modeling approaches generate testable...

  16. Quantitative profiling of brain lipid raft proteome in a mouse model of fragile X syndrome.

    Directory of Open Access Journals (Sweden)

    Magdalena Kalinowska

    Full Text Available Fragile X Syndrome, a leading cause of inherited intellectual disability and autism, arises from transcriptional silencing of the FMR1 gene encoding an RNA-binding protein, Fragile X Mental Retardation Protein (FMRP. FMRP can regulate the expression of approximately 4% of brain transcripts through its role in regulation of mRNA transport, stability and translation, thus providing a molecular rationale for its potential pleiotropic effects on neuronal and brain circuitry function. Several intracellular signaling pathways are dysregulated in the absence of FMRP suggesting that cellular deficits may be broad and could result in homeostatic changes. Lipid rafts are specialized regions of the plasma membrane, enriched in cholesterol and glycosphingolipids, involved in regulation of intracellular signaling. Among transcripts targeted by FMRP, a subset encodes proteins involved in lipid biosynthesis and homeostasis, dysregulation of which could affect the integrity and function of lipid rafts. Using a quantitative mass spectrometry-based approach we analyzed the lipid raft proteome of Fmr1 knockout mice, an animal model of Fragile X syndrome, and identified candidate proteins that are differentially represented in Fmr1 knockout mice lipid rafts. Furthermore, network analysis of these candidate proteins reveals connectivity between them and predicts functional connectivity with genes encoding components of myelin sheath, axonal processes and growth cones. Our findings provide insight to aid identification of molecular and cellular dysfunctions arising from Fmr1 silencing and for uncovering shared pathologies between Fragile X syndrome and other autism spectrum disorders.

  17. The establishment of brain radiation injury experimental model of SD rats with whole brain irradiation in wakefulness

    International Nuclear Information System (INIS)

    Objective: To establish the brain radiation injury experimental model of Sprague-Dawley (SD) rat being irradiated in wakefulness so that the side effects from the anesthetics can be eliminated. Methods: Experiment animals were divided into 4 groups randomly according to the difference of radiation dose. Each group involved 25 rats. 'Thermoplastic material fixing cage' was used to keep rats in wakefulness during irradiation. The whole brains of SD rats were irradiated by 4 MeV electron beam at a single dose of 0 Gy, 2 Gy, 15 Gy and 30 Gy, which was measured by therapy beam analyser and dosimeter. The scores of gross neurological symptoms and changes in body weight were sequentially evaluated twice every week after irradiation. The examination of the head skin inside the field was performed as well. The changes of the nerve cell in the hippocampus region of rats with the Hematoxylin-eosin (HE) staining were observed at the time of 6 hours, 1 day, 1 week and 1 month after irradiation. Results: The peak dosage depth of 4 MeV electron beam was 14.3 mm, and the dosimetry homogeneity of the radiation field was within 5%. The dose attenuation rate was less than 2.57% because of the thermoplastic material fixing cage. Intra-portal alopecia was observed in all the rats exposed to radiation at the dose of 30 Gy and in some of the rats exposed to radiation at the dose of 15 Gy. There was no significant difference in increasing trend of body weight and the score changes of the gross neurological symptoms in all groups. The obvious lesion was observed in the hippocampus region of rats after 30 Gy irradiated. Conclusion: The brain radiation injury experimental model of SD rat in wakefulness with whole brain radiation eliminates the side effects from the anesthetic. It appears to be an excellent model for studying on the brain radiation injury in the early stage

  18. Integrating Functional Brain Neuroimaging and Developmental Cognitive Neuroscience in Child Psychiatry Research

    Science.gov (United States)

    Pavuluri, Mani N.; Sweeney, John A.

    2008-01-01

    The use of cognitive neuroscience and functional brain neuroimaging to understand brain dysfunction in pediatric psychiatric disorders is discussed. Results show that bipolar youths demonstrate impairment in affective and cognitive neural systems and in these two circuits' interface. Implications for the diagnosis and treatment of psychiatric…

  19. Integration of chemotherapy into current treatment strategies for brain metastases from solid tumors

    International Nuclear Information System (INIS)

    Patients with brain metastases represent a heterogeneous group where selection of the most appropriate treatment depends on many patient- and disease-related factors. Eventually, a considerable proportion of patients are treated with palliative approaches such as whole-brain radiotherapy. Whole-brain radiotherapy in combination with chemotherapy has recently gained increasing attention and is hoped to augment the palliative effect of whole-brain radiotherapy alone and to extend survival in certain subsets of patients with controlled extracranial disease and good performance status. The randomized trials of whole-brain radiotherapy vs. whole-brain radiotherapy plus chemotherapy suggest that this concept deserves further study, although they failed to improve survival. However, survival might not be the most relevant endpoint in a condition, where most patients die from extracranial progression. Sometimes, the question arises whether patients with newly detected brain metastases and the indication for systemic treatment of extracranial disease can undergo standard systemic chemotherapy with the option of deferred rather than immediate radiotherapy to the brain. The literature contains numerous small reports on this issue, mainly in malignant melanoma, breast cancer, lung cancer and ovarian cancer, but very few sufficiently powered randomized trials. With chemotherapy alone, response rates were mostly in the order of 20–40%. The choice of chemotherapy regimen is often complicated by previous systemic treatment and takes into account the activity of the drugs in extracranial metastatic disease. Because the blood-brain barrier is partially disrupted in most macroscopic metastases, systemically administered agents can gain access to such tumor sites. Our systematic literature review suggests that both chemotherapy and radiochemotherapy for newly diagnosed brain metastases need further critical evaluation before standard clinical implementation. A potential chemotherapy

  20. Integration of chemotherapy into current treatment strategies for brain metastases from solid tumors

    Directory of Open Access Journals (Sweden)

    Thamm Reinhard

    2006-06-01

    Full Text Available Abstract Patients with brain metastases represent a heterogeneous group where selection of the most appropriate treatment depends on many patient- and disease-related factors. Eventually, a considerable proportion of patients are treated with palliative approaches such as whole-brain radiotherapy. Whole-brain radiotherapy in combination with chemotherapy has recently gained increasing attention and is hoped to augment the palliative effect of whole-brain radiotherapy alone and to extend survival in certain subsets of patients with controlled extracranial disease and good performance status. The randomized trials of whole-brain radiotherapy vs. whole-brain radiotherapy plus chemotherapy suggest that this concept deserves further study, although they failed to improve survival. However, survival might not be the most relevant endpoint in a condition, where most patients die from extracranial progression. Sometimes, the question arises whether patients with newly detected brain metastases and the indication for systemic treatment of extracranial disease can undergo standard systemic chemotherapy with the option of deferred rather than immediate radiotherapy to the brain. The literature contains numerous small reports on this issue, mainly in malignant melanoma, breast cancer, lung cancer and ovarian cancer, but very few sufficiently powered randomized trials. With chemotherapy alone, response rates were mostly in the order of 20–40%. The choice of chemotherapy regimen is often complicated by previous systemic treatment and takes into account the activity of the drugs in extracranial metastatic disease. Because the blood-brain barrier is partially disrupted in most macroscopic metastases, systemically administered agents can gain access to such tumor sites. Our systematic literature review suggests that both chemotherapy and radiochemotherapy for newly diagnosed brain metastases need further critical evaluation before standard clinical

  1. Integrating Seasonal Oscillations into Basel II Behavioural Scoring Models

    Directory of Open Access Journals (Sweden)

    Goran Klepac

    2007-09-01

    Full Text Available The article introduces a new methodology of temporal influence measurement (seasonal oscillations, temporal patterns for behavioural scoring development purposes. The paper shows how significant temporal variables can be recognised and then integrated into the behavioural scoring models in order to improve model performance. Behavioural scoring models are integral parts of the Basel II standard on Internal Ratings-Based Approaches (IRB. The IRB approach much more precisely reflects individual risk bank profile.A solution of the problem of how to analyze and integrate macroeconomic and microeconomic factors represented in time series into behavioural scorecard models will be shown in the paper by using the REF II model.

  2. Developing engineering processes through integrated modelling of product and process

    DEFF Research Database (Denmark)

    Nielsen, Jeppe Bjerrum; Hvam, Lars

    2012-01-01

    This article aims at developing an operational tool for integrated modelling of product assortments and engineering processes in companies making customer specific products. Integrating a product model in the design of engineering processes will provide a deeper understanding of the engineering...... activities as well as insight into how product features affect the engineering processes. The article suggests possible ways of integrating models of products with models of engineering processes. The models have been tested and further developed in an action research study carried out in collaboration with...... a major international engineering company....

  3. Revisiting hydrocephalus as a model to study brain resilience.

    Directory of Open Access Journals (Sweden)

    Matheus Fernandes De Oliveira

    2012-01-01

    Full Text Available Hydrocephalus is an entity which embraces a variety of diseases whose final result is the enlarged size of cerebral ventricular system, partially or completely. The physiopathology of hydrocephalus lies in the dynamics of circulation of cerebrospinal fluid (CSF. The consequent CSF stasis in hydrocephalus interferes with cerebral and ventricular system development. Children and adults who sustain congenital or acquired brain injury typically experience a diffuse insult that impacts many areas of the brain. Development and recovery after such injuries reflects both restoration and reorganization of cognitive functions. Classic examples were already reported in literature. This suggests the presence of biological mechanisms associated with resilient adaptation of brain networks. We will settle a link between the notable modifications to neurophysiology secondary to hydrocephalus and the ability of neuronal tissue to reassume and reorganize its functions.Key words: hydrocephalus; resilience; brain; neural networks; plasticity.

  4. Brain networks engaged in audiovisual integration during speech perception revealed by persistent homology-based network filtration.

    Science.gov (United States)

    Kim, Heejung; Hahm, Jarang; Lee, Hyekyoung; Kang, Eunjoo; Kang, Hyejin; Lee, Dong Soo

    2015-05-01

    The human brain naturally integrates audiovisual information to improve speech perception. However, in noisy environments, understanding speech is difficult and may require much effort. Although the brain network is supposed to be engaged in speech perception, it is unclear how speech-related brain regions are connected during natural bimodal audiovisual or unimodal speech perception with counterpart irrelevant noise. To investigate the topological changes of speech-related brain networks at all possible thresholds, we used a persistent homological framework through hierarchical clustering, such as single linkage distance, to analyze the connected component of the functional network during speech perception using functional magnetic resonance imaging. For speech perception, bimodal (audio-visual speech cue) or unimodal speech cues with counterpart irrelevant noise (auditory white-noise or visual gum-chewing) were delivered to 15 subjects. In terms of positive relationship, similar connected components were observed in bimodal and unimodal speech conditions during filtration. However, during speech perception by congruent audiovisual stimuli, the tighter couplings of left anterior temporal gyrus-anterior insula component and right premotor-visual components were observed than auditory or visual speech cue conditions, respectively. Interestingly, visual speech is perceived under white noise by tight negative coupling in the left inferior frontal region-right anterior cingulate, left anterior insula, and bilateral visual regions, including right middle temporal gyrus, right fusiform components. In conclusion, the speech brain network is tightly positively or negatively connected, and can reflect efficient or effortful processes during natural audiovisual integration or lip-reading, respectively, in speech perception. PMID:25495216

  5. Using Structural Equation Modeling to Assess Functional Connectivity in the Brain: Power and Sample Size Considerations

    Science.gov (United States)

    Sideridis, Georgios; Simos, Panagiotis; Papanicolaou, Andrew; Fletcher, Jack

    2014-01-01

    The present study assessed the impact of sample size on the power and fit of structural equation modeling applied to functional brain connectivity hypotheses. The data consisted of time-constrained minimum norm estimates of regional brain activity during performance of a reading task obtained with magnetoencephalography. Power analysis was first…

  6. Integrated Space Asset Management Database and Modeling

    Science.gov (United States)

    Gagliano, L.; MacLeod, T.; Mason, S.; Percy, T.; Prescott, J.

    The Space Asset Management Database (SAM-D) was implemented in order to effectively track known objects in space by ingesting information from a variety of databases and performing calculations to determine the expected position of the object at a specified time. While SAM-D performs this task very well, it is limited by technology and is not available outside of the local user base. Modeling and simulation can be powerful tools to exploit the information contained in SAM-D. However, the current system does not allow proper integration options for combining the data with both legacy and new M&S tools. A more capable data management infrastructure would extend SAM-D to support the larger data sets to be generated by the COI. A service-oriented architecture model will allow it to easily expand to incorporate new capabilities, including advanced analytics, M&S tools, fusion techniques and user interface for visualizations. Based on a web-centric approach, the entire COI will be able to access the data and related analytics. In addition, tight control of information sharing policy will increase confidence in the system, which would encourage industry partners to provide commercial data. SIMON is a Government off the Shelf information sharing platform in use throughout DoD and DHS information sharing and situation awareness communities. SIMON providing fine grained control to data owners allowing them to determine exactly how and when their data is shared. SIMON supports a micro-service approach to system development, meaning M&S and analytic services can be easily built or adapted. It is uniquely positioned to fill this need as an information-sharing platform with a proven track record of successful situational awareness system deployments. Combined with the integration of new and legacy M&S tools, a SIMON-based architecture will provide a robust SA environment for the NASA SA COI that can be extended and expanded indefinitely. First Results of Coherent Uplink from a

  7. Authentic Integration: a model for integrating mathematics and science in the classroom

    Science.gov (United States)

    Treacy, Páraic; O'Donoghue, John

    2014-07-01

    Attempts at integrating mathematics and science have been made previously but no definitive, widely adopted teaching model has been developed to date. Research suggests that hands-on, practical, student-centred tasks should form a central element when designing an effective model for the integration of mathematics and science. Aided by this research, the author created a new model entitled 'Authentic Integration' which caters for the specific needs of integration of mathematics and science. This model requires that each lesson be based around a rich task which relates to the real world and ensures that hands-on group work, inquiry, and discussion are central to the lesson. It was found that Authentic Integration, when applied in four Irish post-primary schools, positively affected pupil understanding. The teachers who completed the intervention displayed a very positive attitude towards the approach, intimating that they would continue to implement the practice in their classrooms.

  8. Mathematical Models of Visual Information Processing in the Human Brain and Applications to Image Processing

    OpenAIRE

    Arai, Hitoshi

    2013-01-01

    In this lecture I give a survey of joint works of Hitoshi Arai and Shinobu Arai. The main purpose of our study is to construct mathematical models of visual information processing in the brain, and to give applications to image processing. On the past few decades, several studies have been made on mathematical models of visual information processing in the human brain. Our new models are constructed by using simple pinwheel framelets ([4]) and pinwheel framelets ([6]), which are a new class o...

  9. Microwave and magnetic (M2 proteomics of a mouse model of mild traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Teresa M. Evans

    2014-06-01

    Full Text Available Short-term increases in oxidative stress and decreases in motor function, including debilitating effects on balance and motor control, can occur following primary mild traumatic brain injuries (mTBI. However, the long-term effects on motor unit impairment and integrity as well as the molecular mechanisms underlying secondary injuries are poorly understood. We hypothesized that changes in central nervous system-specific protein (CSP expression might correlate to these long-term effects. To test our hypothesis, we longitudinally assessed a closed-skull mTBI mouse model, vs. sham control, at 1, 7, 30, and 120 days post-injury. Motor impairment was determined by rotarod and grip strength performance measures, while motor unit integrity was determined using electromyography. Relative protein expression was determined by microwave and magnetic (M2 proteomics of ipsilateral brain tissue, as previously described. Isoprostane measurements were performed to confirm a primary oxidative stress response. Decoding the relative expression of 476 ± 56 top-ranked proteins for each specimen revealed statistically significant changes in the expression of two well-known CSPs at 1, 7 and 30 days post-injury: P < 0.001 for myelin basic protein (MBP and p < 0.05 for myelin associated glycoprotein (MAG. This was confirmed by Western blot. Moreover, MAG, αII-spectrin (SPNA2 and neurofilament light (NEFL expression at 30 days post-injury were directly related to grip strength (p < 0.05. While higher-powered studies of larger cohorts merit further investigation, this study supports the proof-of-concept that M2 proteomics is a rapid method to quantify putative protein biomarkers and therapeutic targets of mTBI and suggests the feasibility of CSP expression correlations to long-term effects on motor impairment.

  10. Integrated modelling of near field and engineered barrier system processes

    International Nuclear Information System (INIS)

    The Yucca Mountain Integrating Model (YMIM) is an integrated model of the Engineered Barrier System. It has been developed to assist project managers at LLNL in identifying areas where research emphasis should be placed. The model was designed to be highly modular so that a model of an individual process could be easily modified or replaced without interfering with the models of other processes. The modules modelling container failure and the dissolution of nuclides include particularly detailed, temperature dependent models of their corresponding processes

  11. Comparison of Integrated Analysis Methods for Two Model Scenarios

    Science.gov (United States)

    Amundsen, Ruth M.

    1999-01-01

    Integrated analysis methods have the potential to substantially decrease the time required for analysis modeling. Integration with computer aided design (CAD) software can also allow a model to be more accurate by facilitating import of exact design geometry. However, the integrated method utilized must sometimes be tailored to the specific modeling situation, in order to make the process most efficient. Two cases are presented here that illustrate different processes used for thermal analysis on two different models. These examples are used to illustrate how the requirements, available input, expected output, and tools available all affect the process selected by the analyst for the most efficient and effective analysis.

  12. A Graph Based Framework to Model Virus Integration Sites.

    Science.gov (United States)

    Fronza, Raffaele; Vasciaveo, Alessandro; Benso, Alfredo; Schmidt, Manfred

    2016-01-01

    With next generation sequencing thousands of virus and viral vector integration genome targets are now under investigation to uncover specific integration preferences and to define clusters of integration, termed common integration sites (CIS), that may allow to assess gene therapy safety or to detect disease related genomic features such as oncogenes. Here, we addressed the challenge to: 1) define the notion of CIS on graph models, 2) demonstrate that the structure of CIS enters in the category of scale-free networks and 3) show that our network approach analyzes CIS dynamically in an integrated systems biology framework using the Retroviral Transposon Tagged Cancer Gene Database (RTCGD) as a testing dataset. PMID:27257470

  13. Toward an Integrative Model of Global Business Strategy

    DEFF Research Database (Denmark)

    Li, Xin

    fragmentation-integration-fragmentation-integration upward spiral. In response to the call for integrative approach to strategic management research, we propose an integrative model of global business strategy that aims at integrating not only strategy and IB but also the different paradigms within the strategy......In this paper, we first review the development of the strategy field by introducing Hoskisson et al.’s (1999) notion of ‘swings of a pendulum’. With problematization of this notion, we then offer an alternative interpretation of the advancement of strategy knowledge, namely, a recursive...

  14. Development of Multisensory Integration Approach Model

    Science.gov (United States)

    Kumar, S. Prasanna; Nathan, B. Sami

    2016-01-01

    Every teacher expects optimum level of processing in mind of them students. The level of processing is mainly depends upon memory process. Most of the students have retrieval difficulties on past learning. Memory difficulties directly related to sensory integration. In these circumstances the investigator made an attempt to construct Multisensory…

  15. The Kurzweil integral in financial market modeling

    Czech Academy of Sciences Publication Activity Database

    Krejčí, Pavel; Lamba, H.; Monteiro, Giselle Antunes; Rachinskii, D.

    2016-01-01

    Roč. 141, č. 2 (2016), s. 261-286. ISSN 0862-7959 R&D Projects: GA ČR(CZ) GA15-12227S Institutional support: RVO:67985840 Keywords : hysteresis * Prandtl-Ishlinskii operator * Kurzweil integral Subject RIV: BA - General Mathematics http://hdl.handle.net/10338.dmlcz/145715

  16. The implementation of integrated care: the empirical validation of the Development Model for Integrated Care

    OpenAIRE

    Ahaus Kees TB; Vermeulen Robbert P; Minkman Mirella MN; Huijsman Robbert

    2011-01-01

    Abstract Background Integrated care is considered as a strategy to improve the delivery, efficiency, client outcomes and satisfaction rates of health care. To integrate the care from multiple providers into a coherent client-focused service, a large number of activities and agreements have to be implemented like streamlining information flows and patient transfers. The Development Model for Integrated care (DMIC) describes nine clusters containing in total 89 elements that contribute to the i...

  17. Brain Based Teaching Model as Transformation of Learning Paradigm in Higher Education

    Directory of Open Access Journals (Sweden)

    Zulfani Sesmiarni

    2015-12-01

    Full Text Available Brain -based teaching model is a new paradigm that can facilitate students in optimizing student learning by the functioning the brain as a whole. Lessons are held today assume that all students equally so that learning provide the same services to each student in the class. With this model, the students are given different stimulation according to their abilities and needs. Base on brain learning theory -based teaching, the learning should pay attention to the five needs of the brain in general. The fifth factor is the need for a sense of comfort, the need for interaction, the need for knowledge, the need for the activity and the need for self-reflection. All these needs will be connected if the lecturers able to present emotional learning, social learning, cognitive learning, physical learning and teaching reflection. Key Word : Instrucetional, Brain Based teaching, Learning.Copyright © 2015 by Al-Ta'lim All right reserved

  18. Integrable Marginal Points in the N-Cosine Model

    CERN Document Server

    Gerganov, B E

    2000-01-01

    The integrability of the N-cosine model, a N-field generalization of the sine-Gordon model, is investigated. We establish to first order in conformal perturbation theory that, for arbitrary N, the model possesses a quantum conserved current of Lorentz spin 3 on a submanifold of the parameter space where the interaction becomes marginal. The integrability of the model on this submanifold is further studied using renormalization techniques. It is shown that for N = 2, 3, and 4 there exist special points on the marginal manifold at which the N-cosine model is equivalent to models of Gross-Neveu type and therefore is integrable. In the 2-field case we further argue that the points mentioned above exhaust all integrable cases on the marginal submanifold.

  19. P-glycoprotein Mediated Efflux Limits Substrate and Drug Uptake in a Preclinical Brain Metastases of Breast Cancer Model

    Directory of Open Access Journals (Sweden)

    Chris E Adkins

    2013-11-01

    Full Text Available The blood-brain barrier (BBB is a specialized vascular interface that restricts the entry of many compounds into brain. This is accomplished through the sealing of vascular endothelial cells together with tight junction proteins to prevent paracellular diffusion. In addition, the BBB has a high degree of expression of numerous efflux transporters which actively extrude compounds back into blood. However, when a metastatic lesion develops in brain the vasculature is typically compromised with increases in passive permeability (blood-tumor barrier; BTB. What is not well documented is to what degree active efflux retains function at the BTB despite the changes observed in passive permeability. In addition, there have been previous reports documenting both increased and decreased expression of P-gp in lesion vasculature. Herein, we simultaneously administer a passive diffusion marker (14C-AIB and a tracer subject to P-gp efflux (rhodamine 123 into a murine preclinical model of brain metastases of breast cancer. We observed that the metastatic lesions had similar expression (p>0.05; n=756-1214 vessels evaluated at the BBB and the BTB. Moreover, tissue distribution of R123 was not significantly (p>0.05 different between normal brain and the metastatic lesion. It is possible that the similar expression of P-gp on the BBB and the BTB contribute to this phenomenon. Additionally we observed P-gp expression at the metastatic cancer cells adjacent to the vasculature which may also contribute to reduced R123 uptake into the lesion. The data suggest that despite the disrupted integrity of the BTB, efflux mechanisms appear to be intact, and may be functionally comparable to the normal BBB. The BTB is a significant hurdle to delivering drugs to brain metastasis.

  20. Multiplicative integrable models from Poisson-Nijenhuis structures

    CERN Document Server

    Bonechi, Francesco

    2015-01-01

    We discuss the role of Poisson-Nijenhuis geometry in the definition of multiplicative integrable models on symplectic groupoids. These are integrable models that are compatible with the groupoid structure in such a way that the set of contour levels of the hamiltonians in involution inherits a topological groupoid structure. We show that every maximal rank PN structure defines such a model. We consider the examples defined on compact hermitian symmetric spaces and studied in [arXiv:1503.07339].

  1. On the Integrability of the Bukhvostov-Lipatov Model

    CERN Document Server

    Ameduri, M; Gerganov, B E; Ameduri, Marco; Efthimiou, Costas J.; Gerganov, Bogomil

    1999-01-01

    The integrability of the Bukhvostov-Lipatov four-fermion model is investigated. It is shown that the classical model possesses a current of Lorentz spin 3, conserved both in the bulk and on the half-line for specific types of boundary actions. It is then established that the conservation law is spoiled at the quantum level -- a fact that might indicate that the quantum Bukhvostov-Lipatov model is not integrable, contrary to what was previously believed.

  2. Academic Support through Information System : Srinivas Integrated Model

    OpenAIRE

    Aithal, Sreeramana; Kumar, Suresh

    2016-01-01

    As part of imparting quality higher education for undergraduate and postgraduate students, Srinivas Institute of Management Studies (SIMS) developed an education service model for integrated academic support known as Srinivas Integrated Model. Backed by the presumption that knowledge is power and information is fundamental to knowledge building and knowledge sharing, this model is aimed to provide information support to students for improved academic performance. Information on the college...

  3. Ozone depletion and skin cancer incidence: an integrated modelling approach

    OpenAIRE

    Slaper H; den Elzen MGJ; de Woerd HJ; Greef J de

    1992-01-01

    A decrease in stratospheric ozone, probably caused by chlorofluorocarbon (CFC) emissions, has been observed over large parts of the globe. The incidence of skin cancer is expected to increase due to ozone depletion. An integrated source-risk model is developed and applied to evaluate the increased skin cancer incidence related to various CFC emission scenarios. The source-risk model is an independent submodule within the framework of IMAGE, an integrated source-effect-model for climate change...

  4. Bethe vectors in GL(3)-based quantum integrable models

    CERN Document Server

    Pakuliak, S; Slavnov, N A

    2015-01-01

    We consider a composite generalized quantum integrable model solvable by the nested algebraic Bethe ansatz. Using explicit formulas of the action of the monodromy matrix elements onto Bethe vectors in the GL(3)-based quantum integrable models we prove a formula for the Bethe vectors of composite model. We show that this representation is a particular case of general coproduct property of the weight functions (Bethe vectors) found in the theory of the deformed Knizhnik--Zamolodchokov equation.

  5. A Model for Information Integration Using Service Oriented Architectur

    Directory of Open Access Journals (Sweden)

    C. Punitha Devi

    2014-06-01

    Full Text Available Business agility remains to be the keyword that drives the business into different directions and enabling a 360 degree shift in the business process. To achieve agility the organization should work on real time information and data. The need to have instant access to information appears to be ever shine requirement of all organizations or enterprise. Access to information does not come directly with a single query but a complex process termed Information integration. Information integration has been in existence for the past two decades and has been progressive up to now. The challenges and issues keep on persisting as information integration problem evolves by itself. This paper addresses the issues in the approaches, techniques and models pertaining to information integration and identifies the problem for a need for a complete model. As SOA is the architectural style that is changing the business patterns today, this paper proposes a service oriented model for information integration. The model mainly focuses on giving a complete structure for information integration that is adaptable to any environment and open in nature. Here information is converted into service and then the information services are integrated through service oriented integration to provide the integrated information also as service.

  6. QMU in Integrated Spacecraft System Models Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ACTA and Sandia National Laboratories propose to quantify and propagate substructure modeling uncertainty for reduced-order substructure models to higher levels of...

  7. A model based system for the interpretation of MR human brain scans

    International Nuclear Information System (INIS)

    This paper describes a prototype system for identifying and characterizing Multiple Scleroris (MS) lesions in the brain from magnetic resonance (MR) images. The system is designed to obtain an initial segmentation of each cross-sectional image with low level vision methods, and then derive successive refinements of image subregions through a model-driven approach that correlates relevant information from T1 and T2 images and 3-D information from complementary cross-sections when necessary. The system uses a b-spline surface model of the brain that matches the characteristics of the individual's brain. The normal internal structures of the brain are then scaled proportionately before carrying out the successive refinement operations for the detection of the MS lesions. The low level vision and the solid modeling components of the system have been successfully tested on several hundred images from a number of MR patient studies. The first steps of model fitting have been implemented and show promising results

  8. Integration models: multicultural and liberal approaches confronted

    Science.gov (United States)

    Janicki, Wojciech

    2012-01-01

    European societies have been shaped by their Christian past, upsurge of international migration, democratic rule and liberal tradition rooted in religious tolerance. Boosting globalization processes impose new challenges on European societies, striving to protect their diversity. This struggle is especially clearly visible in case of minorities trying to resist melting into mainstream culture. European countries' legal systems and cultural policies respond to these efforts in many ways. Respecting identity politics-driven group rights seems to be the most common approach, resulting in creation of a multicultural society. However, the outcome of respecting group rights may be remarkably contradictory to both individual rights growing out from liberal tradition, and to reinforced concept of integration of immigrants into host societies. The hereby paper discusses identity politics upturn in the context of both individual rights and integration of European societies.

  9. Pharmacokinetic modeling of subcutaneous heroin and its metabolites in blood and brain of mice.

    Science.gov (United States)

    Boix, Fernando; Andersen, Jannike M; Mørland, Jørg

    2013-01-01

    High blood-brain permeability and effective delivery of morphine to the brain have been considered as explanations for the high potency of heroin. Results from Andersen et al. indicate that 6-monoacetylmorphine (6-MAM), and not morphine, is the active metabolite responsible for the acute effects observed for heroin. Here, we use pharmacokinetic modeling on data from the aforementioned study to calculate parameters of the distribution of heroin, 6-MAM and morphine in blood and brain tissue after subcutaneous heroin administration in mice. The estimated pharmacokinetic parameters imply that the very low heroin and the high 6-MAM levels observed both in blood and brain in the original experiment are likely to be caused by a very high metabolic rate of heroin in blood. The estimated metabolic rate of heroin in brain was much lower and cannot account for the low heroin and high 6-MAM levels in the brain, which would primarily reflect the concentrations of these compounds in blood. The very different metabolic rates for heroin in blood and brain calculated by the model were confirmed by in vitro experiments. These results show that heroin's fast metabolism in blood renders high concentrations of 6-MAM which, due to its relatively good blood-brain permeability, results in high levels of this metabolite in the brain. Thus, it is the high blood metabolism rate of heroin and the blood-brain permeability to 6-MAM, and not to heroin, which could account for the highly efficient delivery of active metabolites to the brain after heroin administration. PMID:21481103

  10. Manipulation of Dysfunctional Spinal Joints Affects Sensorimotor Integration in the Prefrontal Cortex: A Brain Source Localization Study.

    Science.gov (United States)

    Lelic, Dina; Niazi, Imran Khan; Holt, Kelly; Jochumsen, Mads; Dremstrup, Kim; Yielder, Paul; Murphy, Bernadette; Drewes, Asbjørn Mohr; Haavik, Heidi

    2016-01-01

    Objectives. Studies have shown decreases in N30 somatosensory evoked potential (SEP) peak amplitudes following spinal manipulation (SM) of dysfunctional segments in subclinical pain (SCP) populations. This study sought to verify these findings and to investigate underlying brain sources that may be responsible for such changes. Methods. Nineteen SCP volunteers attended two experimental sessions, SM and control in random order. SEPs from 62-channel EEG cap were recorded following median nerve stimulation (1000 stimuli at 2.3 Hz) before and after either intervention. Peak-to-peak amplitude and latency analysis was completed for different SEPs peak. Dipolar models of underlying brain sources were built by using the brain electrical source analysis. Two-way repeated measures ANOVA was used to assessed differences in N30 amplitudes, dipole locations, and dipole strengths. Results. SM decreased the N30 amplitude by 16.9 ± 31.3% (P = 0.02), while no differences were seen following the control intervention (P = 0.4). Brain source modeling revealed a 4-source model but only the prefrontal source showed reduced activity by 20.2 ± 12.2% (P = 0.03) following SM. Conclusion. A single session of spinal manipulation of dysfunctional segments in subclinical pain patients alters somatosensory processing at the cortical level, particularly within the prefrontal cortex. PMID:27047694

  11. Manipulation of Dysfunctional Spinal Joints Affects Sensorimotor Integration in the Prefrontal Cortex: A Brain Source Localization Study

    Directory of Open Access Journals (Sweden)

    Dina Lelic

    2016-01-01

    Full Text Available Objectives. Studies have shown decreases in N30 somatosensory evoked potential (SEP peak amplitudes following spinal manipulation (SM of dysfunctional segments in subclinical pain (SCP populations. This study sought to verify these findings and to investigate underlying brain sources that may be responsible for such changes. Methods. Nineteen SCP volunteers attended two experimental sessions, SM and control in random order. SEPs from 62-channel EEG cap were recorded following median nerve stimulation (1000 stimuli at 2.3 Hz before and after either intervention. Peak-to-peak amplitude and latency analysis was completed for different SEPs peak. Dipolar models of underlying brain sources were built by using the brain electrical source analysis. Two-way repeated measures ANOVA was used to assessed differences in N30 amplitudes, dipole locations, and dipole strengths. Results. SM decreased the N30 amplitude by 16.9±31.3% (P=0.02, while no differences were seen following the control intervention (P=0.4. Brain source modeling revealed a 4-source model but only the prefrontal source showed reduced activity by 20.2±12.2% (P=0.03 following SM. Conclusion. A single session of spinal manipulation of dysfunctional segments in subclinical pain patients alters somatosensory processing at the cortical level, particularly within the prefrontal cortex.

  12. Manipulation of Dysfunctional Spinal Joints Affects Sensorimotor Integration in the Prefrontal Cortex: A Brain Source Localization Study

    Science.gov (United States)

    Lelic, Dina; Niazi, Imran Khan; Holt, Kelly; Jochumsen, Mads; Dremstrup, Kim; Yielder, Paul; Murphy, Bernadette; Drewes, Asbjørn Mohr; Haavik, Heidi

    2016-01-01

    Objectives. Studies have shown decreases in N30 somatosensory evoked potential (SEP) peak amplitudes following spinal manipulation (SM) of dysfunctional segments in subclinical pain (SCP) populations. This study sought to verify these findings and to investigate underlying brain sources that may be responsible for such changes. Methods. Nineteen SCP volunteers attended two experimental sessions, SM and control in random order. SEPs from 62-channel EEG cap were recorded following median nerve stimulation (1000 stimuli at 2.3 Hz) before and after either intervention. Peak-to-peak amplitude and latency analysis was completed for different SEPs peak. Dipolar models of underlying brain sources were built by using the brain electrical source analysis. Two-way repeated measures ANOVA was used to assessed differences in N30 amplitudes, dipole locations, and dipole strengths. Results. SM decreased the N30 amplitude by 16.9 ± 31.3% (P = 0.02), while no differences were seen following the control intervention (P = 0.4). Brain source modeling revealed a 4-source model but only the prefrontal source showed reduced activity by 20.2 ± 12.2% (P = 0.03) following SM. Conclusion. A single session of spinal manipulation of dysfunctional segments in subclinical pain patients alters somatosensory processing at the cortical level, particularly within the prefrontal cortex. PMID:27047694

  13. Integral model of pulsed electrodynamic launcher

    Czech Academy of Sciences Publication Activity Database

    Karban, P.; Ulrych, B.; Doležel, Ivo

    Graz: Technical University of Graz, 2006, s. 295-300. ISBN 3-902465-56-5. [International Symposium on Numerical Field Calculation in Electrical Engineering - IGTE /12./. Graz (AT), 18.09.2006-20.09.2006] R&D Projects: GA ČR(CZ) GA102/04/0095 Institutional research plan: CEZ:AV0Z20570509 Keywords : electrodynamic launching * integral approach * numerical simulation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  14. Employment Enhancing Integrative Graduate Education Model

    OpenAIRE

    Ismail H. Genc; Mustafa Copoglu

    2014-01-01

    There is a strong call to look for approaches to integrate business and engineering education across disciplines to provide a more coherent system for students with the job market. As graduates fail to find satisfying employment, the value of college education is questioned. The unemployment of the highly educated has economic, social and political ramifications. Worst is when the highly educated unemployed takes up lower status jobs, ever reducing the quality of the job market with future co...

  15. Material and physical model for evaluation of deep brain activity contribution to EEG recordings

    Science.gov (United States)

    Ye, Yan; Li, Xiaoping; Wu, Tiecheng; Li, Zhe; Xie, Wenwen

    2015-12-01

    Deep brain activity is conventionally recorded with surgical implantation of electrodes. During the neurosurgery, brain tissue damage and the consequent side effects to patients are inevitably incurred. In order to eliminate undesired risks, we propose that deep brain activity should be measured using the noninvasive scalp electroencephalography (EEG) technique. However, the deeper the neuronal activity is located, the noisier the corresponding scalp EEG signals are. Thus, the present study aims to evaluate whether deep brain activity could be observed from EEG recordings. In the experiment, a three-layer cylindrical head model was constructed to mimic a human head. A single dipole source (sine wave, 10 Hz, altering amplitudes) was embedded inside the model to simulate neuronal activity. When the dipole source was activated, surface potential was measured via electrodes attached on the top surface of the model and raw data were recorded for signal analysis. Results show that the dipole source activity positioned at 66 mm depth in the model, equivalent to the depth of deep brain structures, is clearly observed from surface potential recordings. Therefore, it is highly possible that deep brain activity could be observed from EEG recordings and deep brain activity could be measured using the noninvasive scalp EEG technique.

  16. Investigation of Brain Arterial Circle Malformations Using Electrical Modelling and Simulation

    Directory of Open Access Journals (Sweden)

    Klara Capova

    2006-01-01

    Full Text Available The paper deals with the cerebral arterial system investigation by means of electrical modelling and simulations. The main attention is paid to the brain arterial circle malformations (stenoses and aneurysms and their determination and evaluation by computer-aided methods as tools of a non-invasive diagnostics. The compensation possibilities of brain arterial circle in case of presence of concrete arterial malformations are modelled and simulated. The simulation results of brain arteries blood pressures and volume flow velocities time dependences are presented and discussed under various health conditions.

  17. Non-integrable quantum field theories as perturbations of certain integrable models

    International Nuclear Information System (INIS)

    We approach the study of non-integrable models of two-dimensional quantum field theory as perturbations of the integrable ones. By exploiting the knowledge of the exact S-matrix and Form Factors of the integrable field theories we obtain the first order corrections to the mass ratios, the vacuum energy density and the S-matrix of the non-integrable theories. As interesting applications of the formalism, we study the scaling region of the Ising model in an external magnetic field at T ∼ Tc and the scaling region around the minimal model M2,τ. For these models, a remarkable agreement is observed between the theoretical predictions and the data extracted by a numerical diagonalization of their Hamiltonian. (author). 41 refs, 9 figs, 1 tab

  18. Integrated Mechanical and Hydrodynamic Modeling of Offshore Floating Wind Turbines

    OpenAIRE

    Pedersen, Morten Dinhoff

    2009-01-01

    This thesis presents the development of a nonlinear mechanical and hydrodynamical model for floating offshore wind turbines. The model employs results from robotics to model the equations of motion. A simple rigid-body turbine model has been implemented. Hydrodynamic forces are modeled in part with the generalized Morison equation, in part with direct integration of the Froude-Krylov pressures. Buoyancy forces are modeled via a non-linear buoyancy scheme that considers variations in water-pla...

  19. Localized dose delivering by ion beam irradiation for experimental trial of establishing brain necrosis model.

    Science.gov (United States)

    Takata, Takushi; Kondo, Natsuko; Sakurai, Yoshinori; Tanaka, Hiroki; Hasegawa, Takashi; Kume, Kyo; Suzuki, Minoru

    2015-11-01

    Localized dose delivery techniques to establish a brain radiation necrosis model are described. An irradiation field was designed by using accelerated protons or helium ions with a spread-out Bragg peak. Measurement of the designed field confirmed that a high dose can be confined to a local volume of an animal brain. The irradiation techniques described here are very useful for establishing a necrosis model without existence of extraneous complications. PMID:26454176

  20. A statistical model describing combined irreversible electroporation and electroporation-induced blood-brain barrier disruption

    Directory of Open Access Journals (Sweden)

    Sharabi Shirley

    2016-03-01

    Full Text Available Electroporation-based therapies such as electrochemotherapy (ECT and irreversible electroporation (IRE are emerging as promising tools for treatment of tumors. When applied to the brain, electroporation can also induce transient blood-brain-barrier (BBB disruption in volumes extending beyond IRE, thus enabling efficient drug penetration. The main objective of this study was to develop a statistical model predicting cell death and BBB disruption induced by electroporation. This model can be used for individual treatment planning.

  1. Model-Based Integration and Interpretation of Data

    DEFF Research Database (Denmark)

    Petersen, Johannes

    2004-01-01

    Data integration and interpretation plays a crucial role in supervisory control. The paper defines a set of generic inference steps for the data integration and interpretation process based on a three-layer model of system representations. The three-layer model is used to clarify the combination...... of constraint and object-centered representations of the work domain throwing new light on the basic principles underlying the data integration and interpretation process of Rasmussen's abstraction hierarchy as well as other model-based approaches combining constraint and object-centered representations. Based...

  2. Dynamic integration of context model constraints in web service processes

    OpenAIRE

    Bandara, Kosala Yapa; Wang, Ming Xue; Pahl, Claus

    2009-01-01

    Autonomic Web service composition has been a challenging topic for some years. The context in which composition takes places determines essential aspects. A context model can provide meaningful composition information for services process composition. An ontology-based approach for context information integration is the basis of a constraint approach to dynamically integrate context validation into service processes. The dynamic integration of context constraints into an orchestrated service ...

  3. 13A. Integrative Cancer Care: The Life Over Cancer Model

    OpenAIRE

    Block, Keith; Block, Penny; Gyllenhaal, Charlotte; Shoham, Jacob

    2013-01-01

    Focus Areas: Integrative Algorithms of Care Integrative cancer treatment fully blends conventional cancer treatment with integrative therapies such as diet, supplements, exercise and biobehavioral approaches. The Life Over Cancer model comprises three spheres of intervention: improving lifestyle, improving biochemical environment (terrain), and improving tolerance of conventional treatment. These levels are applied within the context of a life-affirming approach to cancer patients and treatme...

  4. Housekeeping while brain's storming Validation of normalizing factors for gene expression studies in a murine model of traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Escriou Virginie

    2008-07-01

    Full Text Available Abstract Background Traumatic brain injury models are widely studied, especially through gene expression, either to further understand implied biological mechanisms or to assess the efficiency of potential therapies. A large number of biological pathways are affected in brain trauma models, whose elucidation might greatly benefit from transcriptomic studies. However the suitability of reference genes needed for quantitative RT-PCR experiments is missing for these models. Results We have compared five potential reference genes as well as total cDNA level monitored using Oligreen reagent in order to determine the best normalizing factors for quantitative RT-PCR expression studies in the early phase (0–48 h post-trauma (PT of a murine model of diffuse brain injury. The levels of 18S rRNA, and of transcripts of β-actin, glyceraldehyde-3P-dehydrogenase (GAPDH, β-microtubulin and S100β were determined in the injured brain region of traumatized mice sacrificed at 30 min, 3 h, 6 h, 12 h, 24 h and 48 h post-trauma. The stability of the reference genes candidates and of total cDNA was evaluated by three different methods, leading to the following rankings as normalization factors, from the most suitable to the less: by using geNorm VBA applet, we obtained the following sequence: cDNA(Oligreen; GAPDH > 18S rRNA > S100β > β-microtubulin > β-actin; by using NormFinder Excel Spreadsheet, we obtained the following sequence: GAPDH > cDNA(Oligreen > S100β > 18S rRNA > β-actin > β-microtubulin; by using a Confidence-Interval calculation, we obtained the following sequence: cDNA(Oligreen > 18S rRNA; GAPDH > S100β > β-microtubulin > β-actin. Conclusion This work suggests that Oligreen cDNA measurements, 18S rRNA and GAPDH or a combination of them may be used to efficiently normalize qRT-PCR gene expression in mouse brain trauma injury, and that β-actin and β-microtubulin should be avoided. The potential of total cDNA as measured by Oligreen as a

  5. Whole brain diffeomorphic metric mapping via integration of sulcal and gyral curves, cortical surfaces, and images.

    Science.gov (United States)

    Du, Jia; Younes, Laurent; Qiu, Anqi

    2011-05-01

    This paper introduces a novel large deformation diffeomorphic metric mapping algorithm for whole brain registration where sulcal and gyral curves, cortical surfaces, and intensity images are simultaneously carried from one subject to another through a flow of diffeomorphisms. To the best of our knowledge, this is the first time that the diffeomorphic metric from one brain to another is derived in a shape space of intensity images and point sets (such as curves and surfaces) in a unified manner. We describe the Euler-Lagrange equation associated with this algorithm with respect to momentum, a linear transformation of the velocity vector field of the diffeomorphic flow. The numerical implementation for solving this variational problem, which involves large-scale kernel convolution in an irregular grid, is made feasible by introducing a class of computationally friendly kernels. We apply this algorithm to align magnetic resonance brain data. Our whole brain mapping results show that our algorithm outperforms the image-based LDDMM algorithm in terms of the mapping accuracy of gyral/sulcal curves, sulcal regions, and cortical and subcortical segmentation. Moreover, our algorithm provides better whole brain alignment than combined volumetric and surface registration (Postelnicu et al., 2009) and hierarchical attribute matching mechanism for elastic registration (HAMMER) (Shen and Davatzikos, 2002) in terms of cortical and subcortical volume segmentation. PMID:21281722

  6. T helper 17 cells may drive neuroprogression in major depressive disorder: Proposal of an integrative model.

    Science.gov (United States)

    Slyepchenko, Anastasiya; Maes, Michael; Köhler, Cristiano A; Anderson, George; Quevedo, João; Alves, Gilberto S; Berk, Michael; Fernandes, Brisa S; Carvalho, André F

    2016-05-01

    The exact pathophysiology of major depressive disorder (MDD) remains elusive. The monoamine theory, which hypothesizes that MDD emerges as a result of dysfunctional serotonergic, dopaminergic and noradrenergic pathways, has guided the therapy of this illness for several decades. More recently, the involvement of activated immune, oxidative and nitrosative stress pathways and of decreased levels of neurotrophic factors has provided emerging insights regarding the pathophysiology of MDD, leading to integrated theories emphasizing the complex interplay of these mechanisms that could lead to neuroprogression. In this review, we propose an integrative model suggesting that T helper 17 (Th17) cells play a pivotal role in the pathophysiology of MDD through (i) microglial activation, (ii) interactions with oxidative and nitrosative stress, (iii) increases of autoantibody production and the propensity for autoimmunity, (iv) disruption of the blood-brain barrier, and (v) dysregulation of the gut mucosa and microbiota. The clinical and research implications of this model are discussed. PMID:26898639

  7. Upregulated expression of brain enzymatic markers of arachidonic and docosahexaenoic acid metabolism in a rat model of the metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Taha Ameer Y

    2012-10-01

    Full Text Available Abstract Background In animal models, the metabolic syndrome elicits a cerebral response characterized by altered phospholipid and unesterified fatty acid concentrations and increases in pro-apoptotic inflammatory mediators that may cause synaptic loss and cognitive impairment. We hypothesized that these changes are associated with phospholipase (PLA2 enzymes that regulate arachidonic (AA, 20:4n-6 and docosahexaenoic (DHA, 22:6n-6 acid metabolism, major polyunsaturated fatty acids in brain. Male Wistar rats were fed a control or high-sucrose diet for 8 weeks. Brains were assayed for markers of AA metabolism (calcium-dependent cytosolic cPLA2 IVA and cyclooxygenases, DHA metabolism (calcium-independent iPLA2 VIA and lipoxygenases, brain-derived neurotrophic factor (BDNF, and synaptic integrity (drebrin and synaptophysin. Lipid concentrations were measured in brains subjected to high-energy microwave fixation. Results The high-sucrose compared with control diet induced insulin resistance, and increased phosphorylated-cPLA2 protein, cPLA2 and iPLA2 activity and 12-lipoxygenase mRNA, but decreased BDNF mRNA and protein, and drebrin mRNA. The concentration of several n-6 fatty acids in ethanolamine glycerophospholipids and lysophosphatidylcholine was increased, as was unesterified AA concentration. Eicosanoid concentrations (prostaglandin E2, thromboxane B2 and leukotriene B4 did not change. Conclusion These findings show upregulated brain AA and DHA metabolism and reduced BDNF and drebrin, but no changes in eicosanoids, in an animal model of the metabolic syndrome. These changes might contribute to altered synaptic plasticity and cognitive impairment in rats and humans with the metabolic syndrome.

  8. MODELS OF TECHNOLOGY ADOPTION: AN INTEGRATIVE APPROACH

    OpenAIRE

    Andrei OGREZEANU

    2015-01-01

    The interdisciplinary study of information technology adoption has developed rapidly over the last 30 years. Various theoretical models have been developed and applied such as: the Technology Acceptance Model (TAM), Innovation Diffusion Theory (IDT), Theory of Planned Behavior (TPB), etc. The result of these many years of research is thousands of contributions to the field, which, however, remain highly fragmented. This paper develops a theoretical model of technology adoption by in...

  9. Hippocampus-Sparing Whole-Brain Radiotherapy and Simultaneous Integrated Boost for Multiple Brain Metastases From Lung Adenocarcinoma: Early Response and Dosimetric Evaluation.

    Science.gov (United States)

    Kim, Kyung Hwan; Cho, Byoung Chul; Lee, Chang Geol; Kim, Hye Ryun; Suh, Yang Gun; Kim, Jun Won; Choi, Chihwan; Baek, Jong Geal; Cho, Jaeho

    2016-02-01

    In this study, the volume response and treatment outcome after hippocampus-sparing whole-brain radiotherapy (HS-WBRT) with simultaneous integrated boost (SIB) using tomotherapy were evaluated. Patients with primary lung adenocarcinoma and multiple brain metastases who had a Karnofsky performance status ≥ 70 and exhibited well-controlled extracranial disease were treated. The prescribed dose was administered in 10 to 14 fractions as 25 to 28 Gy to whole-brain parenchyma, as 40 to 48 Gy to the gross metastatic lesion, and as 30 to 42 Gy to a 5-mm margin to the metastatic lesion. Double-dose gadolinium contrast-enhanced magnetic resonance imaging at 1-mm slice thickness was performed before treatment and at 1, 4, and 7 months post-treatment. The tumor volume reduction ratio was calculated for each follow-up. Between July 2011 and September 2012, 11 patients with 70 lesions were included in this analysis. The median number of lesions per patient was 4 (range, 2-15). The median initial tumor volume was 0.235 cm(3) (range, 0.020-10.140 cm(3)). The treatment plans were evaluated regarding conformation number (CN), target coverage (TC), and homogeneity index (HI). The median follow-up duration was 14 months (range, 3-25 months) and the 1-year intracranial control rate was 67%. The tumor volume reduction was most prominent during the first month with a median reduction rate of 0.717 (range, -0.190 to 1.000). Complete remission was seen in 22 (33%) lesions, and 45 (64%) lesions showed more than 65% reduction in tumor volume. The CN, TC, and HI values were comparable to that of previous studies, and the mean hippocampal dose was 13.65 Gy. No treatment breaks or ≥ G3 acute toxicities were observed during or after treatment. The HS-WBRT with SIB in patients with multiple brain metastases was effective and feasible for volume reduction and showed excellent intracranial control. PMID:25601853

  10. Buried Waste Integrated Demonstration stakeholder involvement model

    International Nuclear Information System (INIS)

    The Buried Waste Integrated Demonstration (BWID) is a program funded by the US Department of Energy (DOE) Office of Technology Development. BWID supports the applied research, development, demonstration, and evaluation of a suite of advanced technologies that together form a comprehensive remediation system for the effective and efficient remediation of buried waste. Stakeholder participation in the DOE Environmental Management decision-making process is critical to remediation efforts. Appropriate mechanisms for communication with the public, private sector, regulators, elected officials, and others are being aggressively pursued by BWID to permit informed participation. This document summarizes public outreach efforts during FY-93 and presents a strategy for expanded stakeholder involvement during FY-94

  11. Integration of Management Systems: A Process Based Model

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The paper discusses the barriers of integration of management systems (IMS). A model based on process is explored. It is indicated that integrating management systems should not ignore the characteristics of the management systems, especially scope issues. IMS needs to take into the continuous improvement.

  12. PT-symmetry in quasi-integrable models

    CERN Document Server

    Assis, P E G

    2015-01-01

    We reinforce the observations of almost stable scattering in nonintegrable models and show that $\\mathcal{PT}$-symmetry can be used as a guiding principle to select relevant systems also when it comes to integrability properties. We show that the presence of unbroken $\\mathcal{PT}$-symmetry in classical field theories produces quasi-integrable excitations with asymptotically conserved charges.

  13. MR-guided transcranial brain HIFU in small animal models

    Energy Technology Data Exchange (ETDEWEB)

    Larrat, B; Pernot, M; Aubry, J-F; Sinkus, R; Fink, M; Tanter, M [Institut Langevin, ESPCI ParisTech, CNRS UMR 7587, INSERM U979, Universite Paris VII, Laboratoire Ondes et Acoustique, 10 rue Vauquelin, 75 231 Paris Cedex 05 (France); Dervishi, E; Boch, A-L [Hopital de la Pitie-Salpetriere-INSERM, U495, 47 Boulevard de l' Hopital, 75651 Paris Cedex 13 (France); Seilhean, D [Hopital de la Pitie-Salpetriere-Neuropathology Department, 47 Boulevard de l' Hopital, 75651 Paris Cedex 13 (France); Marie, Y [Hopital de la Pitie-Salpetriere-Neurosurgery Department, 47 Boulevard de l' Hopital, 75651 Paris Cedex 13 (France)], E-mail: benoit.larrat@espci.fr

    2010-01-21

    Recent studies have demonstrated the feasibility of transcranial high-intensity focused ultrasound (HIFU) therapy in the brain using adaptive focusing techniques. However, the complexity of the procedures imposes provision of accurate targeting, monitoring and control of this emerging therapeutic modality in order to ensure the safety of the treatment and avoid potential damaging effects of ultrasound on healthy tissues. For these purposes, a complete workflow and setup for HIFU treatment under magnetic resonance (MR) guidance is proposed and implemented in rats. For the first time, tissue displacements induced by the acoustic radiation force are detected in vivo in brain tissues and measured quantitatively using motion-sensitive MR sequences. Such a valuable target control prior to treatment assesses the quality of the focusing pattern in situ and enables us to estimate the acoustic intensity at focus. This MR-acoustic radiation force imaging is then correlated with conventional MR-thermometry sequences which are used to follow the temperature changes during the HIFU therapeutic session. Last, pre- and post-treatment magnetic resonance elastography (MRE) datasets are acquired and evaluated as a new potential way to non-invasively control the stiffness changes due to the presence of thermal necrosis. As a proof of concept, MR-guided HIFU is performed in vitro in turkey breast samples and in vivo in transcranial rat brain experiments. The experiments are conducted using a dedicated MR-compatible HIFU setup in a high-field MRI scanner (7 T). Results obtained on rats confirmed that both the MR localization of the US focal point and the pre- and post-HIFU measurement of the tissue stiffness, together with temperature control during HIFU are feasible and valuable techniques for efficient monitoring of HIFU in the brain. Brain elasticity appears to be more sensitive to the presence of oedema than to tissue necrosis.

  14. MR-guided transcranial brain HIFU in small animal models

    International Nuclear Information System (INIS)

    Recent studies have demonstrated the feasibility of transcranial high-intensity focused ultrasound (HIFU) therapy in the brain using adaptive focusing techniques. However, the complexity of the procedures imposes provision of accurate targeting, monitoring and control of this emerging therapeutic modality in order to ensure the safety of the treatment and avoid potential damaging effects of ultrasound on healthy tissues. For these purposes, a complete workflow and setup for HIFU treatment under magnetic resonance (MR) guidance is proposed and implemented in rats. For the first time, tissue displacements induced by the acoustic radiation force are detected in vivo in brain tissues and measured quantitatively using motion-sensitive MR sequences. Such a valuable target control prior to treatment assesses the quality of the focusing pattern in situ and enables us to estimate the acoustic intensity at focus. This MR-acoustic radiation force imaging is then correlated with conventional MR-thermometry sequences which are used to follow the temperature changes during the HIFU therapeutic session. Last, pre- and post-treatment magnetic resonance elastography (MRE) datasets are acquired and evaluated as a new potential way to non-invasively control the stiffness changes due to the presence of thermal necrosis. As a proof of concept, MR-guided HIFU is performed in vitro in turkey breast samples and in vivo in transcranial rat brain experiments. The experiments are conducted using a dedicated MR-compatible HIFU setup in a high-field MRI scanner (7 T). Results obtained on rats confirmed that both the MR localization of the US focal point and the pre- and post-HIFU measurement of the tissue stiffness, together with temperature control during HIFU are feasible and valuable techniques for efficient monitoring of HIFU in the brain. Brain elasticity appears to be more sensitive to the presence of oedema than to tissue necrosis.

  15. Integrating Behaviour in Software Models: An Event Coordination Notation

    DEFF Research Database (Denmark)

    Kindler, Ekkart

    One of the main problems in model-based software engineering is modelling behaviour in such a way that the behaviour models can be easily integrated with each other, with the structural software models and with pre-existing software. In this paper, we propose an event coordination notation (ECNO......) that deals with this problem. We present the main concepts and rationales behind this notation and discuss a prototype and run-time environment that executes these models, and provides an API so that other parts of the software can be easily integrated. The core concepts of the ECNO seem to be...

  16. A Role for Astrocytes in Sensing the Brain Microenvironment and Neuro-Metabolic Integration.

    Science.gov (United States)

    Teschemacher, A G; Gourine, A V; Kasparov, S

    2015-12-01

    Astrocytes occupy a strategic position in the brain where they can act as an interface between neurones and blood vessels, and neurones and the cerebro-spinal fluid. This location is ideal for functioning as interoceptors, as they may sense changes in brain microenvironment and contribute to the adaptive homeostatic responses coordinated by neuronal networks. Here we briefly review some of the recent evidence, which implicates the involvement of astrocytes in the central nervous control of breathing, sympathetic tone and blood glucose levels. L-lactate appears a potentially crucial signaling molecule in the communication between astrocytes and neurones. Based on the available evidence, we conclude that astrocytes contribute to the homeostasis by playing a significant role in the brain's interoceptive mechanisms. PMID:25837670

  17. Executive control of language in the bilingual brain: Integrating the evidence from neuroimaging to neuropsychology

    Directory of Open Access Journals (Sweden)

    AlexisGeorgesHervais-Adelman

    2011-09-01

    Full Text Available In this review we will focus on delineating the neural substrates of the executive control of language in the bilingual brain, based on the existing neuroimaging, intracranial, transcranial magnetic stimulation and neuropsychological evidence. We will also offer insights from ongoing brain imaging studies into the development of expertise in multilingual language control. We will concentrate specifically on evidence regarding how the brain selects and controls languages for comprehension and production. This question has been addressed in a number of ways and using various tasks, including language switching during production or perception, translation and interpretation. We will attempt to synthesise existing evidence in order to bring to light the neural substrates that are crucial to executive control of language.

  18. Multimodal investigations of trans-endothelial cell trafficking under condition of disrupted blood-brain barrier integrity

    Directory of Open Access Journals (Sweden)

    Masaryk Thomas

    2010-03-01

    Full Text Available Abstract Background Stem cells or immune cells targeting the central nervous system (CNS bear significant promises for patients affected by CNS disorders. Brain or spinal cord delivery of therapeutic cells is limited by the blood-brain barrier (BBB which remains one of the recognized rate-limiting steps. Osmotic BBB disruption (BBBD has been shown to improve small molecule chemotherapy for brain tumors, but successful delivery of cells in conjunction with BBBD has never been reported. We have used a clinically relevant model (pig of BBBD to attempt brain delivery of TALL-104, a human leukemic T cell line. TALL-104 cells are potent tumor killers and have demonstrated potential for systemic tumor therapy. The pig model used is analogous to the clinical BBBD procedure. Cells were injected in the carotid artery after labeling with the MRI T1 contrast agent GdHPDO3A. Contrast CT scans were used to quantify BBBD and MRI was used to detect Gd++-loaded cells in the brain. Transcranial Doppler was used to monitor cerebral blood flow. EEG recordings were used to detect seizures. Immunocytochemical detection (Cresyl Violet, anti-human CD8 for TALL-104, Evans Blue for BBB damage, GFAP and NEUN was performed. Results At the concentration used TALL-104 cells were tolerated. Incomplete BBBD did not allow cell entry into the brain. MRI scans at 24 and 48 hours post-injection allowed visualization of topographically segregated cells in the hemisphere that underwent successful BBBD. Perivascular location of TALL-104 was confirmed in the BBBD hemisphere by Cresyl violet and CD8 immunocytochemistry. No significant alteration in CBF or EEG activity was recorded during cell injections. Conclusions Our data show that targeted CNS cell therapy requires blood-brain barrier disruption. MRI-detectable cytotoxic anti-neoplastic cells can be forced to transverse the BBB and accumulate in the perivascular space. The virtual absence of toxicity, the high anti-tumor activity

  19. Development of the Integrated Communication Model

    Science.gov (United States)

    Ho, Hua-Kuo

    2008-01-01

    Human communication is a critical issue in personal life. It also should be the indispensable core element of general education curriculum in universities and colleges. Based on literature analysis and the author's clinical observation, the importance of human communication, functions of model, and often seen human communication models were…

  20. In vivo whole brain, cellular and molecular imaging in nonhuman primate models of neuropathology.

    Science.gov (United States)

    Huang, Lieven; Merson, Tobias D; Bourne, James A

    2016-07-01

    Rodents have been the principal model to study brain anatomy and function due to their well-mapped brain architecture, rapid reproduction and amenability to genetic modification. However, there are clear limitations, for example their simpler neocortex, necessitating the need to adopt a model that is closer to humans in order to understand human cognition and brain conditions. Nonhuman primates (NHPs) are ideally suited as they are our closest relatives in the animal kingdom but in vivo imaging technologies to study brain structure and function in these species can be challenging. With the surge in NHP research in recent years, scientists have begun adapting imaging technologies, such as two-photon microscopy, for these species. Here we review the various NHP models that exist as well as their use in advanced microscopic and mesoscopic studies. We discuss the challenges in the field and investigate the opportunities that lie ahead. PMID:27151822

  1. Integrated Krill Model WG-SAM-14/20

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The integrated modeling framework for Antarctic krill (Euphausia superba) has been extended to include estimates of krill growth consistent with survey data and to...

  2. An Integrated Approach to Flexible Modelling and Animated Simulation

    Institute of Scientific and Technical Information of China (English)

    Li Shuliang; Wu Zhenye

    1994-01-01

    Based on the software support of SIMAN/CINEMA, this paper presents an integrated approach to flexible modelling and simulation with animation. The methodology provides a structured way of integrating mathematical and logical model, statistical experinentation, and statistical analysis with computer animation. Within this methodology, an animated simulation study is separated into six different activities: simulation objectives identification , system model development, simulation experiment specification, animation layout construction, real-time simulation and animation run, and output data analysis. These six activities are objectives driven, relatively independent, and integrate through software organization and simulation files. The key ideas behind this methodology are objectives orientation, modelling flexibility,simulation and animation integration, and application tailorability. Though the methodology is closely related to SIMAN/CINEMA, it can be extended to other software environments.

  3. On the Behavioral Modeling of Integrated Circuit Output Buffers

    OpenAIRE

    Canavero, Flavio; Stievano, Igor Simone; Maio, Ivano Adolfo

    2003-01-01

    The properties of common behavioral macromodels for single ended CMOS integrated circuits output buffers are discussed with the aim of providing criteria for an effective use of possible modeling options

  4. Integrated Visualization Environment for Science Mission Modeling Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA is emphasizing the use of larger, more integrated models in conjunction with systems engineering tools and decision support systems. These tools place a...

  5. Integrated Main Propulsion System Performance Reconstruction Process/Models

    Science.gov (United States)

    Lopez, Eduardo; Elliott, Katie; Snell, Steven; Evans, Michael

    2013-01-01

    The Integrated Main Propulsion System (MPS) Performance Reconstruction process provides the MPS post-flight data files needed for postflight reporting to the project integration management and key customers to verify flight performance. This process/model was used as the baseline for the currently ongoing Space Launch System (SLS) work. The process utilizes several methodologies, including multiple software programs, to model integrated propulsion system performance through space shuttle ascent. It is used to evaluate integrated propulsion systems, including propellant tanks, feed systems, rocket engine, and pressurization systems performance throughout ascent based on flight pressure and temperature data. The latest revision incorporates new methods based on main engine power balance model updates to model higher mixture ratio operation at lower engine power levels.

  6. Computer models as social learning tools in participatory integrated assessment

    OpenAIRE

    De Kraker, Joop; Kroeze, Carolien; Kirschner, Paul A.

    2011-01-01

    De Kraker, J., Kroeze, C., & Kirschner, P. A. (2011). Computer models as social learning tools in participatory integrated assessment. International Journal of Agricultural Sustainability, 9, 297-309. doi:10.1080/14735903.2011.582356

  7. Integrability and Quantum Phase Transitions in Interacting Boson Models

    CERN Document Server

    Dukelsky, J; García-Ramos, J E; Pittel, S

    2003-01-01

    The exact solution of the boson pairing hamiltonian given by Richardson in the sixties is used to study the phenomena of level crossings and quantum phase transitions in the integrable regions of the sd and sdg interacting boson models.

  8. On the integrability of pure Skyrme models in two dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Leznov, A.N. [Institute for High Energy Physics, Protvino (Russia); Piette, B.; Zakrzewski, W.J. [Department of Mathematical Sciences, University of Durham, Durham DH1 3LE (United Kingdom)

    1997-06-01

    We point out that some recently studied pure skyrme models in (2+0) dimensions are completely integrable. We discuss some implications of this fact. {copyright} {ital 1997 American Institute of Physics.}

  9. Integration of Design and Control Through Model Analysis

    DEFF Research Database (Denmark)

    Russel, Boris Mariboe; Henriksen, Jens Peter; Jørgensen, Sten Bay;

    2000-01-01

    phenomena models representing the process model identify the relationships between the important process and design variables, which help to understand, define and address some of the issues related to integration of design and control issues. The model analysis is highlighted through examples involving...... processes with mass and/or energy recycle. (C) 2000 Elsevier Science Ltd. All rights reserved....

  10. EnergyPlus Air Source Integrated Heat Pump Model

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Energy and Transportation Science Division; Adams, Mark B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Energy and Transportation Science Division; New, Joshua Ryan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Energy and Transportation Science Division

    2016-03-30

    This report summarizes the development of the EnergyPlus air-source integrated heat pump model. It introduces its physics, sub-models, working modes, and control logic. In addition, inputs and outputs of the new model are described, and input data file (IDF) examples are given.

  11. An Integrated Model of Information Literacy, Based upon Domain Learning

    Science.gov (United States)

    Thompson, Gary B.; Lathey, Johnathan W.

    2013-01-01

    Introduction. Grounded in Alexander's model of domain learning, this study presents an integrated micro-model of information literacy. It is predicated upon the central importance of domain learning for the development of the requisite research skills by students. Method. The authors reviewed previous models of information literacy and…

  12. Computer Integrated Manufacturing: Physical Modelling Systems Design. A Personal View.

    Science.gov (United States)

    Baker, Richard

    A computer-integrated manufacturing (CIM) Physical Modeling Systems Design project was undertaken in a time of rapid change in the industrial, business, technological, training, and educational areas in Australia. A specification of a manufacturing physical modeling system was drawn up. Physical modeling provides a flexibility and configurability…

  13. Modeling of Amperometric Immunosensor for CMOS Integration

    Institute of Scientific and Technical Information of China (English)

    Ce Li; Haigang Yang; Shanhong Xia; Chao Bian

    2006-01-01

    A circuit model of the Amperometric immunosensor for use in the biosensor system-on-chip simulation is proposed in this paper. The model parameters are extracted with several methods and verified by MATLAB and SPICE simulation. A CMOS potentiostat circuit required for conditioning the Amperometric immunosensor is also included in the circuit model. The mean square error norm of the simulated curve against the measured one is 8.65 × 10-17. The whole circuit has been fabricated in a 0.35am CMOS process.

  14. Comment on "Integrability of the Rabi model"

    CERN Document Server

    Moroz, Alexander

    2012-01-01

    In his recent letter, Braak suggested that a regular spectrum of the Rabi model was given by the zeroes of a transcendental function $G_\\pm(x)$ (cf Eqs. (3)-(5) of Ref. [1]) and highlighted the role of the discrete $\\mathbb{Z}_2$-symmetry, or parity, in determining $G_\\pm(x)$. We show here to the contrary that one can define a transcendental function $F_0(x)$ and obtain the regular spectrum of the Rabi model as the zeroes of $F_0(x)$ (see Fig. 1) without ever making use of the underlying $\\mathbb{Z}_2$-symmetry of the model.

  15. MRI as a tool to study brain structure from mouse models for mental retardation

    Science.gov (United States)

    Verhoye, Marleen; Sijbers, Jan; Kooy, R. F.; Reyniers, E.; Fransen, E.; Oostra, B. A.; Willems, Peter; Van der Linden, Anne-Marie

    1998-07-01

    Nowadays, transgenic mice are a common tool to study brain abnormalities in neurological disorders. These studies usually rely on neuropathological examinations, which have a number of drawbacks, including the risk of artefacts introduced by fixation and dehydration procedures. Here we present 3D Fast Spin Echo Magnetic Resonance Imaging (MRI) in combination with 2D and 3D segmentation techniques as a powerful tool to study brain anatomy. We set up MRI of the brain in mouse models for the fragile X syndrome (FMR1 knockout) and Corpus callosum hypoplasia, mental Retardation, Adducted thumbs, Spastic paraplegia and Hydrocephalus (CRASH) syndrome (L1CAM knockout). Our major goal was to determine qualitative and quantitative differences in specific brain structures. MRI of the brain of fragile X and CRASH patients has revealed alterations in the size of specific brain structures, including the cerebellar vermis and the ventricular system. In the present MRI study of the brain from fragile X knockout mice, we have measured the size of the brain, cerebellum and 4th ventricle, which were reported as abnormal in human fragile X patients, but found no evidence for altered brain regions in the mouse model. In CRASH syndrome, the most specific brain abnormalities are vermis hypoplasia and abnormalities of the ventricular system with some degree of hydrocephalus. With the MRI study of L1CAM knockout mice we found vermis hypoplasia, abnormalities of the ventricular system including dilatation of the lateral and the 4th ventricles. These subtle abnormalities were not detected upon standard neuropathological examination. Here we proved that this sensitive MRI technique allows to measure small differences which can not always be detected by means of pathology.

  16. SU-E-T-549: Modeling Relative Biological Effectiveness of Protons for Radiation Induced Brain Necrosis

    International Nuclear Information System (INIS)

    Purpose: To develop a model of the relative biological effectiveness (RBE) of protons as a function of dose and linear energy transfer (LET) for induction of brain necrosis using clinical data. Methods: In this study, treatment planning information was exported from a clinical treatment planning system (TPS) and used to construct a detailed Monte Carlo model of the patient and the beam delivery system. The physical proton dose and LET were computed in each voxel of the patient volume using Monte Carlo particle transport. A follow-up magnetic resonance imaging (MRI) study registered to the treatment planning CT was used to determine the region of the necrosis in the brain volume. Both, the whole brain and the necrosis volumes were segmented from the computed tomography (CT) dataset using the contours drawn by a physician and the corresponding voxels were binned with respect to dose and LET. The brain necrosis probability was computed as a function of dose and LET by dividing the total volume of all necrosis voxels with a given dose and LET with the corresponding total brain volume resulting in a set of NTCP-like curves (probability as a function of dose parameterized by LET). Results: The resulting model shows dependence on both dose and LET indicating the weakness of the constant RBE model for describing the brain toxicity. To the best of our knowledge the constant RBE model is currently used in all clinical applications which may Result in increased rate of brain toxicities in patients treated with protons. Conclusion: Further studies are needed to develop more accurate brain toxicity models for patients treated with protons and other heavy ions

  17. A model for semantic integration of business components

    CERN Document Server

    Kzaz, Larbi; Sekkaki, Abderrahim; 10.1016/S0550-3213(01)00405-9

    2010-01-01

    Today, reusable components are available in several repositories. These last are certainly conceived for the reusing However, this re-use is not immediate; it requires, in the fact, to pass through some essential conceptual operations, among them in particular, research, integration, adaptation, and composition. We are interested in the present work to the problem of semantic integration of heterogeneous Business Components. This problem is often put in syntactical terms, while the real stake is of semantic order. Our contribution concerns a model proposal for Business components integration as well as resolution method of semantic naming conflicts, met during the integration of Business Components.

  18. Translation model, translation analysis, translation strategy: an integrated methodology

    OpenAIRE

    VOLKOVA TATIANA A.

    2014-01-01

    The paper revisits the concepts of translation model, translation analysis, and translation strategy from an integrated perspective: a translation strategy naturally follows translation analysis performed on a given set of textual, discursive and communicative parameters that form a valid translation model. Translation modeling is reconsidered in terms of a paradigm shift and a distinction between a process-oriented (descriptive) model and an action-oriented (prescriptive) model. Following th...

  19. On conceptual differentiation and integration of strategy and business model

    OpenAIRE

    Ivan Stefanovic; Dragan Milosevic

    2012-01-01

    The objective of this paper is to develop the conceptual integration of strategy and business model. Theoretical method is used in order to achieve this objective. The theory building leads to the construction of conceptual model of strategy and business model, and provides its underlying logic. The main finding is that strategy is a pattern within which a business model changes. Only one strategy may exist for a firm in a concrete time frame, while there may be countless business models in t...

  20. Exploring Factors Causing Low Brain Penetration of the Opioid Peptide DAMGO through Experimental Methods and Modeling.

    Science.gov (United States)

    Lindqvist, Annika; Jönsson, Siv; Hammarlund-Udenaes, Margareta

    2016-04-01

    To advance the development of peptide analogues for improved treatment of pain, we need to learn more about the blood-brain barrier transport of these substances. A low penetration into the brain, with an unbound brain to blood ratio, Kp,uu, of 0.08, is an important reason for the lack of effect of the enkephalin analogue DAMGO (H-Tyr-d-Ala-Gly-MePhe-Gly-ol) according to earlier findings. The aim of this study was to investigate the role of efflux transporters, metabolism in the brain, and/or elimination through interstitial fluid bulk flow for the brain exposure of DAMGO. The in vivo brain distribution of DAMGO was evaluated using microdialysis in the rat. Data were analyzed with population modeling which resulted in a clearance into the brain of 1.1 and an efflux clearance 14 μL/min/g_brain. The efflux clearance was thus much higher than the bulk flow known from the literature. Coadministration with the efflux transporter inhibitors cyclosporin A and elacridar in vivo did not affect Kp,uu. The permeability of DAMGO in the Caco-2 assay was very low, of the same size as mannitol. The efflux ratio was Pgp and Bcrp are not responsible for the higher efflux of DAMGO, which opens up for an important role of other transporters at the BBB. PMID:26898546

  1. Exploring RNA structure by integrative molecular modelling

    DEFF Research Database (Denmark)

    Masquida, Benoît; Beckert, Bertrand; Jossinet, Fabrice

    2010-01-01

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

  2. Integrated modeling of software cost and quality

    International Nuclear Information System (INIS)

    In modeling the cost and quality of software systems, the relationship between cost and quality must be considered. This explicit relationship is dictated by the criticality of the software being developed. The balance between cost and quality is a viable software engineering trade-off throughout the life cycle. Therefore, the ability to accurately estimate the cost and quality of software systems is essential to providing reliable software on time and within budget. Software cost models relate the product error rate to the percent of the project labor that is required for independent verification and validation. The criticality of the software determines which cost model is used to estimate the labor required to develop the software. Software quality models yield an expected error discovery rate based on the software size, criticality, software development environment, and the level of competence of the project and the developers with respect to the processes being employed

  3. Integrated thermodynamic model for ignition target performance

    Directory of Open Access Journals (Sweden)

    Springer P.T.

    2013-11-01

    Full Text Available We have derived a 3-dimensional synthetic model for NIF implosion conditions, by predicting and optimizing fits to a broad set of x-ray and nuclear diagnostics obtained on each shot. By matching x-ray images, burn width, neutron time-of-flight ion temperature, yield, and fuel ρr, we obtain nearly unique constraints on conditions in the hotspot and fuel in a model that is entirely consistent with the observables. This model allows us to determine hotspot density, pressure, areal density (ρr, total energy, and other ignition-relevant parameters not available from any single diagnostic. This article describes the model and its application to National Ignition Facility (NIF tritium–hydrogen–deuterium (THD and DT implosion data, and provides an explanation for the large yield and ρr degradation compared to numerical code predictions.

  4. An integral representation of functions in gas-kinetic models

    Science.gov (United States)

    Perepelitsa, Misha

    2016-08-01

    Motivated by the theory of kinetic models in gas dynamics, we obtain an integral representation of lower semicontinuous functions on {{{R}}^d,} {d≥1}. We use the representation to study the problem of compactness of a family of the solutions of the discrete time BGK model for the compressible Euler equations. We determine sufficient conditions for strong compactness of moments of kinetic densities, in terms of the measures from their integral representations.

  5. An integrated model for the study of teacher motivation

    OpenAIRE

    Jesus, Saul Neves de; Lens, Willy

    2005-01-01

    Recent studies show that teachers suffer more than other professional groups from the occupational lack of motivation. A global understanding of teacher motivation requires an adequate framework for its study. The main goal of the current research was to propose and test a model of teacher motivation that integrates constructs from several cognitive-motivational theories. This integrative model starts from the perspectives of Expectancy-Value and Learned Helplessness but ove...

  6. An Integrative Model of Internationalization Strategies

    DEFF Research Database (Denmark)

    Li, Xin; Gammelgaard, Jens

    2014-01-01

    – The OLI and the UIP models fail to include corporate entrepreneurship and managerial psychology in their analyses. We suggest that regulatory focus theory unifies the managerial strategic choice between position logic and opportunity logic. In addition, host country institutions affect this managerial...... choice with regard to internationalization. Practical implications – Regulatory focus theory originates from managerial psychology. The model is, therefore, relevant for managers, and it shows how the outcomes and processes of corporate entrepreneurial activity should manifest themselves in managerial...

  7. Child, Adolescent, and Young Adult Community Integration after a Traumatic Brain Injury

    Science.gov (United States)

    Barton, Barbara; Brouwers, Lynn; Ruoff, Janis; Trudel, Tina M.; Valnes, Betsy; Elias, Eileen; Pines, Hayley

    2010-01-01

    "Rehabilitation," as a term in and of itself, implies a goal of bringing something back to its original state of being. However, for many people living with traumatic brain injury (TBI), rehabilitation means learning to live all over again. Through means of education and employment, this article explores the quest for inclusive community…

  8. Mathematical modeling for evolution of heterogeneous modules in the brain.

    Science.gov (United States)

    Yamaguti, Yutaka; Tsuda, Ichiro

    2015-02-01

    Modular architecture has been found in most cortical areas of mammalian brains, but little is known about its evolutionary origin. It has been proposed by several researchers that maximizing information transmission among subsystems can be used as a principle for understanding the development of complex brain networks. In this paper, we study how heterogeneous modules develop in coupled-map networks via a genetic algorithm, where selection is based on maximizing bidirectional information transmission. Two functionally differentiated modules evolved from two homogeneous systems with random couplings, which are associated with symmetry breaking of intrasystem and intersystem couplings. By exploring the parameter space of the network around the optimal parameter values, it was found that the optimum network exists near transition points, at which the incoherent state loses its stability and an extremely slow oscillatory motion emerges. PMID:25124068

  9. Integrating robotic action with biologic perception: A brain-machine symbiosis theory

    Science.gov (United States)

    Mahmoudi, Babak

    In patients with motor disability the natural cyclic flow of information between the brain and external environment is disrupted by their limb impairment. Brain-Machine Interfaces (BMIs) aim to provide new communication channels between the brain and environment by direct translation of brain's internal states into actions. For enabling the user in a wide range of daily life activities, the challenge is designing neural decoders that autonomously adapt to different tasks, environments, and to changes in the pattern of neural activity. In this dissertation, a novel decoding framework for BMIs is developed in which a computational agent autonomously learns how to translate neural states into action based on maximization of a measure of shared goal between user and the agent. Since the agent and brain share the same goal, a symbiotic relationship between them will evolve therefore this decoding paradigm is called a Brain-Machine Symbiosis (BMS) framework. A decoding agent was implemented within the BMS framework based on the Actor-Critic method of Reinforcement Learning. The rule of the Actor as a neural decoder was to find mapping between the neural representation of motor states in the primary motor cortex (MI) and robot actions in order to solve reaching tasks. The Actor learned the optimal control policy using an evaluative feedback that was estimated by the Critic directly from the user's neural activity of the Nucleus Accumbens (NAcc). Through a series of computational neuroscience studies in a cohort of rats it was demonstrated that NAcc could provide a useful evaluative feedback by predicting the increase or decrease in the probability of earning reward based on the environmental conditions. Using a closed-loop BMI simulator it was demonstrated the Actor-Critic decoding architecture was able to adapt to different tasks as well as changes in the pattern of neural activity. The custom design of a dual micro-wire array enabled simultaneous implantation of MI and

  10. Modeling the dynamical effects of anesthesia on brain circuits

    OpenAIRE

    Ching, ShiNung; Brown, Emery N

    2014-01-01

    General anesthesia is a neurophysiological state that consists of unconsciousness, amnesia, analgesia, and immobility along with maintenance of physiological stability. General anesthesia has been used in the United States for more than 167 years. Now, using systems neuroscience paradigms how anesthetics act in the brain and central nervous system to create the states of general anesthesia is being understood. Propofol is one of the most widely used and the most widely studied anesthetics. Wh...

  11. The Substitute Brain and the Potential of the Gel Model

    OpenAIRE

    Pomfret, Roland; Miranpuri, Gurwattan; Sillay, Karl

    2013-01-01

    This purpose of this paper is to review the recent history of the use of agarose gels. Although originally confined to electrophoresis work, agarose gels have proven themselves useful to a number of disciplines in the modern world, which includes brain infusion studies for research involving the treatment of various neurological conditions, such as Parkinson’s Disease. In reviewing the relevant research leading up to the modern day, this paper attempts to track agarose gels through their stag...

  12. On integrable directed polymer models on the square lattice

    International Nuclear Information System (INIS)

    In a recent work Povolotsky (2013 J. Phys. A: Math. Theor. 46 465205) provided a three-parameter family of stochastic particle systems with zero-range interactions in one-dimension which are integrable by coordinate Bethe ansatz. Using these results we obtain the corresponding condition for integrability of a class of directed polymer models with random weights on the square lattice. Analyzing the solutions we find, besides known cases, a new two-parameter family of integrable DP model, which we call the Inverse-Beta polymer, and provide its Bethe ansatz solution. (paper)

  13. Achieving Integrated FEA Model and Loads Management

    Science.gov (United States)

    Lauzon, Dominick; Huf, Brian; Hagstrom, Dustin

    2012-07-01

    Recent developments in enterprise level simulation tools now enable CAE engineers and managers to keep up with today’s accelerating rate in the number and complexity of simulation models. All simulation related activities including Finite Element Models (FEM) variants and their respective results datasets can now be captured and managed. This provides valuable model pedigree from the source geometry referenced in the PDM system, spacecraft design and FEM configurations, external loads, simulation results and internal loads down to key results with the final critical design review and test correlation reports. The process presented in this paper demonstrates how simulation data capture and relationships can be achieved. Moreover, process management from conceptual design to spacecraft final proto-flight tests can now be achieved systematically and efficiently while performing and ensuring model quality, all the way from assembly level down to component level. MSC Software’s SimXpert and SimManager, two commercial off-the-shelf software codes, are used to highlight the benefits of this approach. In addition, an automation process that performs model validation per aerospace engineering best practice standards is also presented.

  14. Development of an Integrated Global Energy Model

    International Nuclear Information System (INIS)

    The primary objective of this research was to develop a forefront analysis tool for application to enhance understanding of long-term, global, nuclear-energy and nuclear-material futures. To this end, an existing economics-energy-environmental (E3) model was adopted, modified, and elaborated to examine this problem in a multi-regional (13), long-term (approximately2,100) context. The E3 model so developed was applied to create a Los Alamos presence in this E3 area through ''niche analyses'' that provide input to the formulation of policies dealing with and shaping of nuclear-energy and nuclear-materials futures. Results from analyses using the E3 model have been presented at a variety of national and international conferences and workshops. Through use of the E3 model Los Alamos was afforded the opportunity to participate in a multi-national E3 study team that is examining a range of global, long-term nuclear issues under the auspices of the IAEA during the 1998-99 period . Finally, the E3 model developed under this LDRD project is being used as an important component in more recent Nuclear Material Management Systems (NMMS) project

  15. Multiscale modeling of integrated CCS systems

    Science.gov (United States)

    Alhajaj, Ahmed; Shah, Nilay

    2015-01-01

    The world will continue consuming fossil fuel within the coming decades to meet its growing energy demand; however, this source must be cleaner through implementation of carbon capture, transport and storage (CCTS). This process is complex and involves multiple phases, owned by different operational companies and stakeholders with different business models and regulatory framework. The objective of this work is to develop a multiscale modeling approach to link process models, post-combustion capture plant model and network design models under an optimization framework in order to design and analyse the cost optimal CO2 infrastructure that match CO2 sources and sinks in capacity and time. The network comprises a number of CO2 sources at fixed locations and a number of potential CO2 storage sites. The decisions to be determined include from which sources it is appropriate to capture CO2 and the cost-optimal degree-of-capture (DOC) for a given source and the infrastructural layout of the CO2 transmission network.

  16. A putative model of overeating and obesity based on brain-derived neurotrophic factor: direct and indirect effects.

    Science.gov (United States)

    Ooi, Cara L; Kennedy, James L; Levitan, Robert D

    2012-08-01

    Increased food intake is a major contributor to the obesity epidemic in all age groups. Elucidating brain systems that drive overeating and that might serve as targets for novel prevention and treatment interventions is thus a high priority for obesity research. The authors consider 2 major pathways by which decreased activity of brain-derived neurotrophic factor (BDNF) may confer vulnerability to overeating and weight gain in an obesogenic environment. The first "direct" pathway focuses on the specific role of BDNF as a mediator of food intake control at brain areas rich in BDNF receptors, including the hypothalamus and hindbrain. It is proposed that low BDNF activity limited to this direct pathway may best explain overeating and obesity outside the context of major neuropsychiatric disturbance. A second "indirect" pathway considers the broad neurotrophic effects of BDNF on key monoamine systems that mediate mood dysregulation, impulsivity, and executive dysfunction as well as feeding behavior per se. Disruption in this pathway may best explain overeating and obesity in the context of various neuropsychiatric disturbances including mood disorders, attention-deficit disorder, and/or binge eating disorders. An integrative model that considers these potential roles of BDNF in promoting obesity is presented. The implications of this model for the early prevention and treatment of obesity are also considered. PMID:22687148

  17. Multi-study integration of brain cancer transcriptomes reveals organ-level molecular signatures.

    Directory of Open Access Journals (Sweden)

    Jaeyun Sung

    Full Text Available We utilized abundant transcriptomic data for the primary classes of brain cancers to study the feasibility of separating all of these diseases simultaneously based on molecular data alone. These signatures were based on a new method reported herein--Identification of Structured Signatures and Classifiers (ISSAC--that resulted in a brain cancer marker panel of 44 unique genes. Many of these genes have established relevance to the brain cancers examined herein, with others having known roles in cancer biology. Analyses on large-scale data from multiple sources must deal with significant challenges associated with heterogeneity between different published studies, for it was observed that the variation among individual studies often had a larger effect on the transcriptome than did phenotype differences, as is typical. For this reason, we restricted ourselves to studying only cases where we had at least two independent studies performed for each phenotype, and also reprocessed all the raw data from the studies using a unified pre-processing pipeline. We found that learning signatures across multiple datasets greatly enhanced reproducibility and accuracy in predictive performance on truly independent validation sets, even when keeping the size of the training set the same. This was most likely due to the meta-signature encompassing more of the heterogeneity across different sources and conditions, while amplifying signal from the repeated global characteristics of the phenotype. When molecular signatures of brain cancers were constructed from all currently available microarray data, 90% phenotype prediction accuracy, or the accuracy of identifying a particular brain cancer from the background of all phenotypes, was found. Looking forward, we discuss our approach in the context of the eventual development of organ-specific molecular signatures from peripheral fluids such as the blood.

  18. Neurochemostat: A Neural Interface SoC With Integrated Chemometrics for Closed-Loop Regulation of Brain Dopamine.

    Science.gov (United States)

    Bozorgzadeh, Bardia; Schuweiler, Douglas R; Bobak, Martin J; Garris, Paul A; Mohseni, Pedram

    2016-06-01

    This paper presents a 3.3×3.2 mm(2) system-on-chip (SoC) fabricated in AMS 0.35 μm 2P/4M CMOS for closed-loop regulation of brain dopamine. The SoC uniquely integrates neurochemical sensing, on-the-fly chemometrics, and feedback-controlled electrical stimulation to realize a "neurochemostat" by maintaining brain levels of electrically evoked dopamine between two user-set thresholds. The SoC incorporates a 90 μW, custom-designed, digital signal processing (DSP) unit for real-time processing of neurochemical data obtained by 400 V/s fast-scan cyclic voltammetry (FSCV) with a carbon-fiber microelectrode (CFM). Specifically, the DSP unit executes a chemometrics algorithm based upon principal component regression (PCR) to resolve in real time electrically evoked brain dopamine levels from pH change and CFM background-current drift, two common interferents encountered using FSCV with a CFM in vivo. Further, the DSP unit directly links the chemically resolved dopamine levels to the activation of the electrical microstimulator in on-off-keying (OOK) fashion. Measured results from benchtop testing, flow injection analysis (FIA), and biological experiments with an anesthetized rat are presented. PMID:26390501

  19. Models for efficient integration of solar energy

    DEFF Research Database (Denmark)

    Bacher, Peder

    the available flexibility in the system. In the present thesis methods related to operation of solar energy systems and for optimal energy use in buildings are presented. Two approaches for forecasting of solar power based on numerical weather predictions (NWPs) are presented, they are applied to forecast...... the power output from PV and solar thermal collector systems. The first approach is based on a developed statistical clear-sky model, which is used for estimating the clear-sky output solely based on observations of the output. This enables local effects such as shading from trees to be taken into account....... The second approach to solar power forecasting is based on conditional parametric modelling. It is well suited for forecasting of solar thermal power, since is it can be make non-linear in the inputs. The approach is also extended to a probabilistic solar power forecasting model. The statistical clear...

  20. Integrability in three dimensions: Algebraic Bethe ansatz for anyonic models

    Science.gov (United States)

    Khachatryan, Sh.; Ferraz, A.; Klümper, A.; Sedrakyan, A.

    2015-10-01

    We extend basic properties of two dimensional integrable models within the Algebraic Bethe Ansatz approach to 2 + 1 dimensions and formulate the sufficient conditions for the commutativity of transfer matrices of different spectral parameters, in analogy with Yang-Baxter or tetrahedron equations. The basic ingredient of our models is the R-matrix, which describes the scattering of a pair of particles over another pair of particles, the quark-anti-quark (meson) scattering on another quark-anti-quark state. We show that the Kitaev model belongs to this class of models and its R-matrix fulfills well-defined equations for integrability.