Sample records for active intrinsically unstructured

  1. Rational design of p53, an intrinsically unstructured protein, for the fabrication of novel molecular sensors.

    PubMed

    Geddie, Melissa L; O'Loughlin, Taryn L; Woods, Kristen K; Matsumura, Ichiro

    2005-10-21

    The dominant paradigm of protein engineering is structure-based site-directed mutagenesis. This rational approach is generally more effective for the engineering of local properties, such as substrate specificity, than global ones such as allostery. Previous workers have modified normally unregulated reporter enzymes, including beta-galactosidase, alkaline phosphatase, and beta-lactamase, so that the engineered versions are activated (up to 4-fold) by monoclonal antibodies. A reporter that could easily be "reprogrammed" for the facile detection of novel effectors (binding or modifying activities) would be useful in high throughput screens for directed evolution or drug discovery. Here we describe a straightforward and general solution to this potentially difficult design problem. The transcription factor p53 is normally regulated by a variety of post-translational modifications. The insertion of peptides into intrinsically unstructured domains of p53 generated variants that were activated up to 100-fold by novel effectors (proteases or antibodies). An engineered p53 was incorporated into an existing high throughput screen for the detection of human immunodeficiency virus protease, an arbitrarily chosen novel effector. These results suggest that the molecular recognition properties of intrinsically unstructured proteins are relatively easy to engineer and that the absence of crystal structures should not deter the rational engineering of this class of proteins.

  2. Protein-Water and Protein-Buffer Interactions in the Aqueous Solution of an Intrinsically Unstructured Plant Dehydrin: NMR Intensity and DSC Aspects

    PubMed Central

    Tompa, P.; Bánki, P.; Bokor, M.; Kamasa, P.; Kovács, D.; Lasanda, G.; Tompa, K.

    2006-01-01

    Proton NMR intensity and differential scanning calorimetry measurements were carried out on an intrinsically unstructured late embryogenesis abundant protein, ERD10, the globular BSA, and various buffer solutions to characterize water and ion binding of proteins by this novel combination of experimental approaches. By quantifying the number of hydration water molecules, the results demonstrate the interaction between the protein and NaCl and between buffer and NaCl on a microscopic level. The findings overall provide direct evidence that the intrinsically unstructured ERD10 not only has a high hydration capacity but can also bind a large amount of charged solute ions. In accord, the dehydration stress function of this protein probably results from its simultaneous action of retaining water in the drying cells and preventing an adverse increase in ionic strength, thus countering deleterious effects such as protein denaturation. PMID:16798808

  3. Playground Exploration: An Opportunity for Incidental Learning of Mechanical Principles

    ERIC Educational Resources Information Center

    Lyons, Brian

    2005-01-01

    Play involves unstructured activity that is freely entered into and intrinsically rewarding. When children engage in play there is little intentional learning. There are no lesson plans. There are no daily objectives or specific learning outcomes. Incidental learning can cause relatively permanent changes in the way one thinks; accidental learning…

  4. Single-Molecule FRET Spectroscopy and the Polymer Physics of Unfolded and Intrinsically Disordered Proteins.

    PubMed

    Schuler, Benjamin; Soranno, Andrea; Hofmann, Hagen; Nettels, Daniel

    2016-07-05

    The properties of unfolded proteins have long been of interest because of their importance to the protein folding process. Recently, the surprising prevalence of unstructured regions or entirely disordered proteins under physiological conditions has led to the realization that such intrinsically disordered proteins can be functional even in the absence of a folded structure. However, owing to their broad conformational distributions, many of the properties of unstructured proteins are difficult to describe with the established concepts of structural biology. We have thus seen a reemergence of polymer physics as a versatile framework for understanding their structure and dynamics. An important driving force for these developments has been single-molecule spectroscopy, as it allows structural heterogeneity, intramolecular distance distributions, and dynamics to be quantified over a wide range of timescales and solution conditions. Polymer concepts provide an important basis for relating the physical properties of unstructured proteins to folding and function.

  5. Cryptochrome 1 regulates the circadian clock through dynamic interactions with the BMAL1 C-terminus

    PubMed Central

    Sammons, Patrick J.; Khan, Sanjoy K.; Parsley, Nicole C.; Ramanathan, Chidambaram; Lee, Hsiau-Wei; Liu, Andrew C.; Partch, Carrie L.

    2015-01-01

    The molecular circadian clock in mammals is generated from transcriptional activation by the bHLH-PAS transcription factor CLOCK–BMAL1 and subsequent repression by PERIOD and CRYPTOCHROME (CRY). The mechanism by which CRYs repress CLOCK–BMAL1 to close the negative feedback loop and generate 24-hour timing is not known. Here we show that CRY1 competes for binding with coactivators to the intrinsically unstructured C-terminal transactivation domain (TAD) of BMAL1 to establish a functional switch between activation and repression of CLOCK–BMAL1. Mutations within the TAD that alter affinities for coregulators change the balance of repression and activation to consequently change intrinsic circadian period or eliminate cycling altogether. Our results suggest that CRY1 fulfills its role as an essential circadian repressor by sequestering the TAD from coactivators and highlight regulation of the BMAL1 TAD as a critical mechanism for establishing circadian timing. PMID:25961797

  6. NMR relaxation studies on the hydrate layer of intrinsically unstructured proteins.

    PubMed

    Bokor, Mónika; Csizmók, Veronika; Kovács, Dénes; Bánki, Péter; Friedrich, Peter; Tompa, Peter; Tompa, Kálmán

    2005-03-01

    Intrinsically unstructured/disordered proteins (IUPs) exist in a disordered and largely solvent-exposed, still functional, structural state under physiological conditions. As their function is often directly linked with structural disorder, understanding their structure-function relationship in detail is a great challenge to structural biology. In particular, their hydration and residual structure, both closely linked with their mechanism of action, require close attention. Here we demonstrate that the hydration of IUPs can be adequately approached by a technique so far unexplored with respect to IUPs, solid-state NMR relaxation measurements. This technique provides quantitative information on various features of hydrate water bound to these proteins. By freezing nonhydrate (bulk) water out, we have been able to measure free induction decays pertaining to protons of bound water from which the amount of hydrate water, its activation energy, and correlation times could be calculated. Thus, for three IUPs, the first inhibitory domain of calpastatin, microtubule-associated protein 2c, and plant dehydrin early responsive to dehydration 10, we demonstrate that they bind a significantly larger amount of water than globular proteins, whereas their suboptimal hydration and relaxation parameters are correlated with their differing modes of function. The theoretical treatment and experimental approach presented in this article may have general utility in characterizing proteins that belong to this novel structural class.

  7. RNA-protein interactions in an unstructured context.

    PubMed

    Zagrovic, Bojan; Bartonek, Lukas; Polyansky, Anton A

    2018-05-31

    Despite their importance, our understanding of noncovalent RNA-protein interactions is incomplete. This especially concerns the binding between RNA and unstructured protein regions, a widespread class of such interactions. Here, we review the recent experimental and computational work on RNA-protein interactions in an unstructured context with a particular focus on how such interactions may be shaped by the intrinsic interaction affinities between individual nucleobases and protein side chains. Specifically, we articulate the claim that the universal genetic code reflects the binding specificity between nucleobases and protein side chains and that, in turn, the code may be seen as the Rosetta stone for understanding RNA-protein interactions in general. © 2018 The Authors. FEBS Letters published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

  8. Organized Sports and Unstructured Active Play as Physical Activity Sources in Children From Low-Income, Chicago Households.

    PubMed

    Appelhans, Bradley M; Li, Hong

    2016-08-01

    This study tested associations of organized sports participation and unstructured active play with overall moderate and vigorous physical activity (MVPA) in low-income children and examined factors associated with participation frequency. Research staff visited 88 low-income Chicago households with children ages 6-13 years. MVPA was assessed through 7-day accelerometry. Researchers documented the home availability of physical activity equipment. Caregivers reported on child participation in organized sports and unstructured active play, family support for physical activity, perceived neighborhood safety, and access to neighborhood physical activity venues. Despite similar participation in organized sports and unstructured active play, boys accumulated more MVPA than girls. MVPA was predicted by an interaction between gender and unstructured active play. Boys accumulated 23-45 additional minutes of weekday MVPA and 53-62 additional minutes of weekend MVPA through unstructured active play, with no such associations in girls. Higher reported neighborhood safety and family support for physical activity were associated with engagement in unstructured active play for both genders, and with participation in organized sports for girls. Physical activity interventions for low-income, urban children should emphasize unstructured active play, particularly in boys. Fostering family support for physical activity and safe play environments may be critical intervention components.

  9. Structured and Unstructured Binding of an Intrinsically Disordered Protein as Revealed by Atomistic Simulations.

    PubMed

    Ithuralde, Raúl Esteban; Roitberg, Adrián Enrique; Turjanski, Adrián Gustavo

    2016-07-20

    Intrinsically disordered proteins (IDPs) are a set of proteins that lack a definite secondary structure in solution. IDPs can acquire tertiary structure when bound to their partners; therefore, the recognition process must also involve protein folding. The nature of the transition state (TS), structured or unstructured, determines the binding mechanism. The characterization of the TS has become a major challenge for experimental techniques and molecular simulations approaches since diffusion, recognition, and binding is coupled to folding. In this work we present atomistic molecular dynamics (MD) simulations that sample the free energy surface of the coupled folding and binding of the transcription factor c-myb to the cotranscription factor CREB binding protein (CBP). This process has been recently studied and became a model to study IDPs. Despite the plethora of available information, we still do not know how c-myb binds to CBP. We performed a set of atomistic biased MD simulations running a total of 15.6 μs. Our results show that c-myb folds very fast upon binding to CBP with no unique pathway for binding. The process can proceed through both structured or unstructured TS's with similar probabilities. This finding reconciles previous seemingly different experimental results. We also performed Go-type coarse-grained MD of several structured and unstructured models that indicate that coupled folding and binding follows a native contact mechanism. To the best of our knowledge, this is the first atomistic MD simulation that samples the free energy surface of the coupled folding and binding processes of IDPs.

  10. Robot soccer anywhere: achieving persistent autonomous navigation, mapping, and object vision tracking in dynamic environments

    NASA Astrophysics Data System (ADS)

    Dragone, Mauro; O'Donoghue, Ruadhan; Leonard, John J.; O'Hare, Gregory; Duffy, Brian; Patrikalakis, Andrew; Leederkerken, Jacques

    2005-06-01

    The paper describes an ongoing effort to enable autonomous mobile robots to play soccer in unstructured, everyday environments. Unlike conventional robot soccer competitions that are usually held on purpose-built robot soccer "fields", in our work we seek to develop the capability for robots to demonstrate aspects of soccer-playing in more diverse environments, such as schools, hospitals, or shopping malls, with static obstacles (furniture) and dynamic natural obstacles (people). This problem of "Soccer Anywhere" presents numerous research challenges including: (1) Simultaneous Localization and Mapping (SLAM) in dynamic, unstructured environments, (2) software control architectures for decentralized, distributed control of mobile agents, (3) integration of vision-based object tracking with dynamic control, and (4) social interaction with human participants. In addition to the intrinsic research merit of these topics, we believe that this capability would prove useful for outreach activities, in demonstrating robotics technology to primary and secondary school students, to motivate them to pursue careers in science and engineering.

  11. Intrinsically disordered proteins--relation to general model expressing the active role of the water environment.

    PubMed

    Kalinowska, Barbara; Banach, Mateusz; Konieczny, Leszek; Marchewka, Damian; Roterman, Irena

    2014-01-01

    This work discusses the role of unstructured polypeptide chain fragments in shaping the protein's hydrophobic core. Based on the "fuzzy oil drop" model, which assumes an idealized distribution of hydrophobicity density described by the 3D Gaussian, we can determine which fragments make up the core and pinpoint residues whose location conflicts with theoretical predictions. We show that the structural influence of the water environment determines the positions of disordered fragments, leading to the formation of a hydrophobic core overlaid by a hydrophilic mantle. This phenomenon is further described by studying selected proteins which are known to be unstable and contain intrinsically disordered fragments. Their properties are established quantitatively, explaining the causative relation between the protein's structure and function and facilitating further comparative analyses of various structural models. © 2014 Elsevier Inc. All rights reserved.

  12. Rapid Proteasomal Degradation of Posttranscriptional Regulators of the TIS11/Tristetraprolin Family Is Induced by an Intrinsically Unstructured Region Independently of Ubiquitination

    PubMed Central

    Ngoc, Long Vo; Wauquier, Corinne; Soin, Romuald; Bousbata, Sabrina; Twyffels, Laure; Kruys, Véronique

    2014-01-01

    The TIS11/tristetraprolin (TTP) CCCH tandem zinc finger proteins are major effectors in the destabilization of mRNAs bearing AU-rich elements (ARE) in their 3′ untranslated regions. In this report, we demonstrate that the Drosophila melanogaster dTIS11 protein is short-lived due to its rapid ubiquitin-independent degradation by the proteasome. Our data indicate that this mechanism is tightly associated with the intrinsically unstructured, disordered N- and C-terminal domains of the protein. Furthermore, we show that TTP, the mammalian TIS11/TTP protein prototype, shares the same three-dimensional characteristics and is degraded by the same proteolytic pathway as dTIS11, thereby indicating that this mechanism has been conserved across evolution. Finally, we observed a phosphorylation-dependent inhibition of dTIS11 and TTP degradation by the proteasome in vitro, raising the possibility that such modifications directly affect proteasomal recognition for these proteins. As a group, RNA-binding proteins (RNA-BPs) have been described as enriched in intrinsically disordered regions, thus raising the possibility that the mechanism that we uncovered for TIS11/TTP turnover is widespread among other RNA-BPs. PMID:25246635

  13. A dihydropyridine receptor alpha1s loop region critical for skeletal muscle contraction is intrinsically unstructured and binds to a SPRY domain of the type 1 ryanodine receptor.

    PubMed

    Cui, Yanfang; Tae, Han-Shen; Norris, Nicole C; Karunasekara, Yamuna; Pouliquin, Pierre; Board, Philip G; Dulhunty, Angela F; Casarotto, Marco G

    2009-03-01

    The II-III loop of the dihydropyridine receptor (DHPR) alpha(1s) subunit is a modulator of the ryanodine receptor (RyR1) Ca(2+) release channel in vitro and is essential for skeletal muscle contraction in vivo. Despite its importance, the structure of this loop has not been reported. We have investigated its structure using a suite of NMR techniques which revealed that the DHPR II-III loop is an intrinsically unstructured protein (IUP) and as such belongs to a burgeoning structural class of functionally important proteins. The loop does not possess a stable tertiary fold: it is highly flexible, with a strong N-terminal helix followed by nascent helical/turn elements and unstructured segments. Its residual structure is loosely globular with the N and C termini in close proximity. The unstructured nature of the II-III loop may allow it to easily modify its interaction with RyR1 following a surface action potential and thus initiate rapid Ca(2+) release and contraction. The in vitro binding partner for the II-III was investigated. The II-III loop interacts with the second of three structurally distinct SPRY domains in RyR1, whose function is unknown. This interaction occurs through two preformed N-terminal alpha-helical regions and a C-terminal hydrophobic element. The A peptide corresponding to the helical N-terminal region is a common probe of RyR function and binds to the same SPRY domain as the full II-III loop. Thus the second SPRY domain is an in vitro binding site for the II-III loop. The possible in vivo role of this region is discussed.

  14. Intrinsically disordered proteins aggregate at fungal cell-to-cell channels and regulate intercellular connectivity.

    PubMed

    Lai, Julian; Koh, Chuan Hock; Tjota, Monika; Pieuchot, Laurent; Raman, Vignesh; Chandrababu, Karthik Balakrishna; Yang, Daiwen; Wong, Limsoon; Jedd, Gregory

    2012-09-25

    Like animals and plants, multicellular fungi possess cell-to-cell channels (septal pores) that allow intercellular communication and transport. Here, using a combination of MS of Woronin body-associated proteins and a bioinformatics approach that identifies related proteins based on composition and character, we identify 17 septal pore-associated (SPA) proteins that localize to the septal pore in rings and pore-centered foci. SPA proteins are not homologous at the primary sequence level but share overall physical properties with intrinsically disordered proteins. Some SPA proteins form aggregates at the septal pore, and in vitro assembly assays suggest aggregation through a nonamyloidal mechanism involving mainly α-helical and disordered structures. SPA loss-of-function phenotypes include excessive septation, septal pore degeneration, and uncontrolled Woronin body activation. Together, our data identify the septal pore as a complex subcellular compartment and focal point for the assembly of unstructured proteins controlling diverse aspects of intercellular connectivity.

  15. Peptide affinity analysis of proteins that bind to an unstructured NH2-terminal region of the osmoprotective transcription factor NFAT5

    PubMed Central

    DuMond, Jenna F.; Ramkissoon, Kevin; Zhang, Xue; Izumi, Yuichiro; Wang, Xujing; Eguchi, Koji; Gao, Shouguo; Mukoyama, Masashi; Ferraris, Joan D.

    2016-01-01

    NFAT5 is an osmoregulated transcription factor that particularly increases expression of genes involved in protection against hypertonicity. Transcription factors often contain unstructured regions that bind co-regulatory proteins that are crucial for their function. The NH2-terminal region of NFAT5 contains regions predicted to be intrinsically disordered. We used peptide aptamer-based affinity chromatography coupled with mass spectrometry to identify protein preys pulled down by one or more overlapping 20 amino acid peptide baits within a predicted NH2-terminal unstructured region of NFAT5. We identify a total of 467 unique protein preys that associate with at least one NH2-terminal peptide bait from NFAT5 in either cytoplasmic or nuclear extracts from HEK293 cells treated with elevated, normal, or reduced NaCl concentrations. Different sets of proteins are pulled down from nuclear vs. cytoplasmic extracts. We used GeneCards to ascertain known functions of the protein preys. The protein preys include many that were previously known, but also many novel ones. Consideration of the novel ones suggests many aspects of NFAT5 regulation, interaction and function that were not previously appreciated, for example, hypertonicity inhibits NFAT5 by sumoylating it and the NFAT5 protein preys include components of the CHTOP complex that desumoylate proteins, an action that should contribute to activation of NFAT5. PMID:26757802

  16. Isolation and Compositional Analysis of a CP12-Associated Complex of Calvin Cycle Enzymes from Nicotiana tabacum

    USDA-ARS?s Scientific Manuscript database

    CP12 is a small intrinsically unstructured protein that forms a multiprotein complex with two Calvin Cycle enzymes, phosphoribulokinase (PRK) and NAD(P)-dependent glyceraldehyde-3-phosphate dehydrogenase (GAPDH). The complex can be reconstituted in vitro from recombinant proteins under conditions t...

  17. Organized and Unstructured Activity Participation among Adolescents Involved with Child Protective Services in the United States

    ERIC Educational Resources Information Center

    Kwak, Yoonyoung; Lu, Ting; Christ, Sharon L.

    2017-01-01

    Background: Many adolescents are referred to Child Protective Services for possible maltreatment every year, but not much is known about their organized and unstructured activity participation. Objective: The purposes of this study are to provide a description of organized and unstructured activity participation for adolescents who were possible…

  18. The α-Helical Structure of Prodomains Promotes Translocation of Intrinsically Disordered Neuropeptide Hormones into the Endoplasmic Reticulum*

    PubMed Central

    Dirndorfer, Daniela; Seidel, Ralf P.; Nimrod, Guy; Miesbauer, Margit; Ben-Tal, Nir; Engelhard, Martin; Zimmermann, Richard; Winklhofer, Konstanze F.; Tatzelt, Jörg

    2013-01-01

    Different neuropeptide hormones, which are either too small to adopt a stable conformation or are predicted to be intrinsically disordered, are synthesized as larger precursors containing a prodomain in addition to an N-terminal signal peptide. We analyzed the biogenesis of three unstructured neuropeptide hormones and observed that translocation of these precursors into the lumen of the endoplasmic reticulum (ER) is critically dependent on the presence of the prodomain. The hormone domains could be deleted from the precursors without interfering with ER import and secretion, whereas constructs lacking the prodomain remained in the cytosol. Domain-swapping experiments revealed that the activity of the prodomains to promote productive ER import resides in their ability to adopt an α-helical structure. Removal of the prodomain from the precursor did not interfere with co-translational targeting of the nascent chain to the Sec61 translocon but with its subsequent productive translocation into the ER lumen. Our study reveals a novel function of prodomains to enable import of small or intrinsically disordered secretory proteins into the ER based on their ability to adopt an α-helical conformation. PMID:23532840

  19. The α-helical structure of prodomains promotes translocation of intrinsically disordered neuropeptide hormones into the endoplasmic reticulum.

    PubMed

    Dirndorfer, Daniela; Seidel, Ralf P; Nimrod, Guy; Miesbauer, Margit; Ben-Tal, Nir; Engelhard, Martin; Zimmermann, Richard; Winklhofer, Konstanze F; Tatzelt, Jörg

    2013-05-17

    Different neuropeptide hormones, which are either too small to adopt a stable conformation or are predicted to be intrinsically disordered, are synthesized as larger precursors containing a prodomain in addition to an N-terminal signal peptide. We analyzed the biogenesis of three unstructured neuropeptide hormones and observed that translocation of these precursors into the lumen of the endoplasmic reticulum (ER) is critically dependent on the presence of the prodomain. The hormone domains could be deleted from the precursors without interfering with ER import and secretion, whereas constructs lacking the prodomain remained in the cytosol. Domain-swapping experiments revealed that the activity of the prodomains to promote productive ER import resides in their ability to adopt an α-helical structure. Removal of the prodomain from the precursor did not interfere with co-translational targeting of the nascent chain to the Sec61 translocon but with its subsequent productive translocation into the ER lumen. Our study reveals a novel function of prodomains to enable import of small or intrinsically disordered secretory proteins into the ER based on their ability to adopt an α-helical conformation.

  20. Intrinsically disordered proteins aggregate at fungal cell-to-cell channels and regulate intercellular connectivity

    PubMed Central

    Lai, Julian; Koh, Chuan Hock; Tjota, Monika; Pieuchot, Laurent; Raman, Vignesh; Chandrababu, Karthik Balakrishna; Yang, Daiwen; Wong, Limsoon; Jedd, Gregory

    2012-01-01

    Like animals and plants, multicellular fungi possess cell-to-cell channels (septal pores) that allow intercellular communication and transport. Here, using a combination of MS of Woronin body-associated proteins and a bioinformatics approach that identifies related proteins based on composition and character, we identify 17 septal pore-associated (SPA) proteins that localize to the septal pore in rings and pore-centered foci. SPA proteins are not homologous at the primary sequence level but share overall physical properties with intrinsically disordered proteins. Some SPA proteins form aggregates at the septal pore, and in vitro assembly assays suggest aggregation through a nonamyloidal mechanism involving mainly α-helical and disordered structures. SPA loss-of-function phenotypes include excessive septation, septal pore degeneration, and uncontrolled Woronin body activation. Together, our data identify the septal pore as a complex subcellular compartment and focal point for the assembly of unstructured proteins controlling diverse aspects of intercellular connectivity. PMID:22955885

  1. Surveying Unstructured Time of Adults with Mental Retardation Living in Two Community Settings: A Search for Normalization.

    ERIC Educational Resources Information Center

    Pierce, Thomas B., Jr.; And Others

    1990-01-01

    A survey assessed time spent in the community and/or on unstructured activities by randomly selected individuals in Intermediate Care Facilities for the Mentally Retarded (ICF/MR) (N=20) or minigroup home settings (N=20). Individuals in ICF/MR homes spent more time in the community with staff and made fewer choices of unstructured activities.…

  2. Abundance of intrinsic structural disorder in the histone H1 subtypes.

    PubMed

    Kowalski, Andrzej

    2015-12-01

    The intrinsically disordered proteins consist of partially structured regions linked to the unstructured stretches, which consequently form the transient and dynamic conformational ensembles. They undergo disorder to order transition upon binding their partners. Intrinsic disorder is attributed to histones H1, perceived as assemblers of chromatin structure and the regulators of DNA and proteins activity. In this work, the comparison of intrinsic disorder abundance in the histone H1 subtypes was performed both by the analysis of their amino acid composition and by the prediction of disordered stretches, as well as by identifying molecular recognition features (MoRFs) and ANCHOR protein binding regions (APBR) that are responsible for recognition and binding. Both human and model organisms-animals, plants, fungi and protists-have H1 histone subtypes with the properties typical of disordered state. They possess a significantly higher content of hydrophilic and charged amino acid residues, arranged in the long regions, covering over half of the whole amino acid residues in chain. Almost complete disorder corresponds to histone H1 terminal domains, including MoRFs and ANCHOR. Those motifs were also identified in a more ordered histone H1 globular domain. Compared to the control (globular and fibrous) proteins, H1 histones demonstrate the increased folding rate and a higher proportion of low-complexity segments. The results of this work indicate that intrinsic disorder is an inherent structural property of histone H1 subtypes and it is essential for establishing a protein conformation which defines functional outcomes affecting on DNA- and/or partner protein-dependent cell processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Self-Assembly of Spider Silk-Fusion Proteins Comprising Enzymatic and Fluorescence Activity.

    PubMed

    Humenik, Martin; Mohrand, Madeleine; Scheibel, Thomas

    2018-04-18

    The recombinant spider silk protein eADF4(C16) was genetically fused either with esterase 2 (EST2) or green fluorescent protein (GFP). The fusions EST-eADF4(C16) and GFP-eADF4(C16) were spectroscopically investigated and showed native structures of EST and GFP. The structural integrity was confirmed by the enzymatic activity of EST and the fluorescence of GFP. The spider silk moiety retained its intrinsically unstructured conformation in solution and the self-assembly into either nanofibrils or nanoparticles could be controlled by the concentration of phosphate. Particles, however, showed significantly lower activity of the EST and GFP domains likely caused by a steric hindrance. However, upon self-assembly of EST-eADF4(C16) and GFP-eADF4(C16) into fibrils the protein activities were retained. In general, the fusion of globular enzymes with the spider silk domain allows the generation of fibrous biomaterials with catalytic or light emitting properties.

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

    Dai, Jin; He, Jianfeng, E-mail: Antti.Niemi@physics.uu.se, E-mail: hjf@bit.edu.cn; Niemi, Antti J., E-mail: Antti.Niemi@physics.uu.se, E-mail: hjf@bit.edu.cn

    The Landau-Ginzburg-Wilson paradigm is proposed as a framework, to investigate the conformational landscape of intrinsically unstructured proteins. A universal Cα-trace Landau free energy is deduced from general symmetry considerations, with the ensuing all-atom structure modeled using publicly available reconstruction programs Pulchra and Scwrl. As an example, the conformational stability of an amyloid precursor protein intra-cellular domain (AICD) is inspected; the reference conformation is the crystallographic structure with code 3DXC in Protein Data Bank (PDB) that describes a heterodimer of AICD and a nuclear multi-domain adaptor protein Fe65. Those conformations of AICD that correspond to local or near-local minima of themore » Landau free energy are identified. For this, the response of the original 3DXC conformation to variations in the ambient temperature is investigated, using the Glauber algorithm. The conclusion is that in isolation the AICD conformation in 3DXC must be unstable. A family of degenerate conformations that minimise the Landau free energy is identified, and it is proposed that the native state of an isolated AICD is a superposition of these conformations. The results are fully in line with the presumed intrinsically unstructured character of isolated AICD and should provide a basis for a systematic analysis of AICD structure in future NMR experiments.« less

  5. Conformational landscape of an amyloid intra-cellular domain and Landau-Ginzburg-Wilson paradigm in protein dynamics

    NASA Astrophysics Data System (ADS)

    Dai, Jin; Niemi, Antti J.; He, Jianfeng

    2016-07-01

    The Landau-Ginzburg-Wilson paradigm is proposed as a framework, to investigate the conformational landscape of intrinsically unstructured proteins. A universal Cα-trace Landau free energy is deduced from general symmetry considerations, with the ensuing all-atom structure modeled using publicly available reconstruction programs Pulchra and Scwrl. As an example, the conformational stability of an amyloid precursor protein intra-cellular domain (AICD) is inspected; the reference conformation is the crystallographic structure with code 3DXC in Protein Data Bank (PDB) that describes a heterodimer of AICD and a nuclear multi-domain adaptor protein Fe65. Those conformations of AICD that correspond to local or near-local minima of the Landau free energy are identified. For this, the response of the original 3DXC conformation to variations in the ambient temperature is investigated, using the Glauber algorithm. The conclusion is that in isolation the AICD conformation in 3DXC must be unstable. A family of degenerate conformations that minimise the Landau free energy is identified, and it is proposed that the native state of an isolated AICD is a superposition of these conformations. The results are fully in line with the presumed intrinsically unstructured character of isolated AICD and should provide a basis for a systematic analysis of AICD structure in future NMR experiments.

  6. Contractile and chiral activities codetermine the helicity of swimming droplet trajectories

    NASA Astrophysics Data System (ADS)

    Tjhung, Elsen; Cates, Michael E.; Marenduzzo, Davide

    2017-05-01

    Active fluids are a class of nonequilibrium systems where energy is injected into the system continuously by the constituent particles themselves. Many examples, such as bacterial suspensions and actomyosin networks, are intrinsically chiral at a local scale, so that their activity involves torque dipoles alongside the force dipoles usually considered. Although many aspects of active fluids have been studied, the effects of chirality on them are much less known. Here, we study by computer simulation the dynamics of an unstructured droplet of chiral active fluid in three dimensions. Our model considers only the simplest possible combination of chiral and achiral active stresses, yet this leads to an unprecedented range of complex motilities, including oscillatory swimming, helical swimming, and run-and-tumble motion. Strikingly, whereas the chirality of helical swimming is the same as the microscopic chirality of torque dipoles in one regime, the two are opposite in another. Some of the features of these motility modes resemble those of some single-celled protozoa, suggesting that underlying mechanisms may be shared by some biological systems and synthetic active droplets.

  7. Sequence repeats and protein structure

    NASA Astrophysics Data System (ADS)

    Hoang, Trinh X.; Trovato, Antonio; Seno, Flavio; Banavar, Jayanth R.; Maritan, Amos

    2012-11-01

    Repeats are frequently found in known protein sequences. The level of sequence conservation in tandem repeats correlates with their propensities to be intrinsically disordered. We employ a coarse-grained model of a protein with a two-letter amino acid alphabet, hydrophobic (H) and polar (P), to examine the sequence-structure relationship in the realm of repeated sequences. A fraction of repeated sequences comprises a distinct class of bad folders, whose folding temperatures are much lower than those of random sequences. Imperfection in sequence repetition improves the folding properties of the bad folders while deteriorating those of the good folders. Our results may explain why nature has utilized repeated sequences for their versatility and especially to design functional proteins that are intrinsically unstructured at physiological temperatures.

  8. Unstructured Grid Generation Techniques and Software

    NASA Technical Reports Server (NTRS)

    Posenau, Mary-Anne K. (Editor)

    1993-01-01

    The Workshop on Unstructured Grid Generation Techniques and Software was conducted for NASA to assess its unstructured grid activities, improve the coordination among NASA centers, and promote technology transfer to industry. The proceedings represent contributions from Ames, Langley, and Lewis Research Centers, and the Johnson and Marshall Space Flight Centers. This report is a compilation of the presentations made at the workshop.

  9. NMR binding and crystal structure reveal that intrinsically-unstructured regulatory domain auto-inhibits PAK4 by a mechanism different from that of PAK1.

    PubMed

    Wang, Wei; Lim, Liangzhong; Baskaran, Yohendran; Manser, Ed; Song, Jianxing

    2013-08-16

    Six human PAK members are classified into groups I (PAKs 1-3) and II (PAK4-6). Previously, only group I PAKs were thought to be auto-inhibited but very recently PAK4, the prototype of group II PAKs, has also been shown to be auto-inhibited by its N-terminal regulatory domain. However, the complete auto-inhibitory domain (AID) sequence remains undefined and the mechanism underlying its auto-inhibition is largely elusive. Here, the N-terminal regulatory domain of PAK4 sufficient for auto-inhibiting and binding Cdc42/Rac was characterized to be intrinsically unstructured, but nevertheless we identified the entire AID sequence by NMR. Strikingly, an AID peptide was derived by deleting the binding-unnecessary residues, which has a Kd of 320 nM to the PAK4 catalytic domain. Consequently, the PAK4 crystal structure complexed with the entire AID has been determined, which reveals that the complete kinase cleft is occupied by 20 AID residuescomposed of an N-terminal α-helix and a previously-identified pseudosubstrate motif, thus achieving auto-inhibition. Our study reveals that PAK4 is auto-inhibited by a novel mechanism which is completely different from that for PAK1, thus bearing critical implications for design of inhibitors specific for group II PAKs. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Neural correlates of processing sentences and compound words in Chinese

    PubMed Central

    Hung, Yi-Hui; Tzeng, Ovid; Wu, Denise H.

    2017-01-01

    Sentence reading involves multiple linguistic operations including processing of lexical and compositional semantics, and determining structural and grammatical relationships among words. Previous studies on Indo-European languages have associated left anterior temporal lobe (aTL) and left interior frontal gyrus (IFG) with reading sentences compared to reading unstructured word lists. To examine whether these brain regions are also involved in reading a typologically distinct language with limited morphosyntax and lack of agreement between sentential arguments, an FMRI study was conducted to compare passive reading of Chinese sentences, unstructured word lists and disconnected character lists that are created by only changing the order of an identical set of characters. Similar to previous findings from other languages, stronger activation was found in mainly left-lateralized anterior temporal regions (including aTL) for reading sentences compared to unstructured word and character lists. On the other hand, stronger activation was identified in left posterior temporal sulcus for reading unstructured words compared to unstructured characters. Furthermore, reading unstructured word lists compared to sentences evoked stronger activation in left IFG and left inferior parietal lobule. Consistent with the literature on Indo-European languages, the present results suggest that left anterior temporal regions subserve sentence-level integration, while left IFG supports restoration of sentence structure. In addition, left posterior temporal sulcus is associated with morphological compounding. Taken together, reading Chinese sentences engages a common network as reading other languages, with particular reliance on integration of semantic constituents. PMID:29194453

  11. Protein conformational disorder and enzyme catalysis.

    PubMed

    Schulenburg, Cindy; Hilvert, Donald

    2013-01-01

    Though lacking a well-defined three-dimensional structure, intrinsically unstructured proteins are ubiquitous in nature. These molecules play crucial roles in many cellular processes, especially signaling and regulation. Surprisingly, even enzyme catalysis can tolerate substantial disorder. This observation contravenes conventional wisdom but is relevant to an understanding of how protein dynamics modulates enzyme function. This chapter reviews properties and characteristics of disordered proteins, emphasizing examples of enzymes that lack defined structures, and considers implications of structural disorder for catalytic efficiency and evolution.

  12. Indoor and Outdoor Context-Specific Contributions to Early Adolescent Moderate to Vigorous Physical Activity as Measured by Combined Diary, Accelerometer, and GPS.

    PubMed

    Pearce, Matthew; Saunders, David H; Allison, Peter; Turner, Anthony P

    2018-01-01

    The distribution of adolescent moderate to vigorous physical activity (MVPA) across multiple contexts is unclear. This study examined indoor and outdoor leisure time in terms of being structured or unstructured and explored relationships with total daily MVPA. Between September 2012 and January 2014, 70 participants (aged 11-13 y) from 4 schools in Edinburgh wore an accelerometer and global positioning system receiver over 7 days, reporting structured physical activity using a diary. Time spent and MVPA were summarized according to indoor/outdoor location and whether activity was structured/unstructured. Independent associations between context-specific time spent and total daily MVPA were examined using a multivariate linear regression model. Very little time or MVPA was recorded in structured contexts. Unstructured outdoor leisure time was associated with an increase in total daily MVPA almost twice that of unstructured indoor leisure time [b value (95% confidence interval), 8.45 (1.71 to 14.48) vs 4.38 (0.20 to 8.22) minute increase per hour spent]. The association was stronger for time spent in structured outdoor leisure time [35.81 (20.60 to 52.27)]. Research and interventions should focus on strategies to facilitate time outdoors during unstructured leisure time and maximize MVPA once youth are outdoors. Increasing the proportion of youth engaging in structured activity may be beneficial given that, although time spent was limited, association with MVPA was strongest.

  13. Molecular Dynamics of "Fuzzy" Transcriptional Activator-Coactivator Interactions

    PubMed Central

    Scholes, Natalie S.; Weinzierl, Robert O. J.

    2016-01-01

    Transcriptional activation domains (ADs) are generally thought to be intrinsically unstructured, but capable of adopting limited secondary structure upon interaction with a coactivator surface. The indeterminate nature of this interface made it hitherto difficult to study structure/function relationships of such contacts. Here we used atomistic accelerated molecular dynamics (aMD) simulations to study the conformational changes of the GCN4 AD and variants thereof, either free in solution, or bound to the GAL11 coactivator surface. We show that the AD-coactivator interactions are highly dynamic while obeying distinct rules. The data provide insights into the constant and variable aspects of orientation of ADs relative to the coactivator, changes in secondary structure and energetic contributions stabilizing the various conformers at different time points. We also demonstrate that a prediction of α-helical propensity correlates directly with the experimentally measured transactivation potential of a large set of mutagenized ADs. The link between α-helical propensity and the stimulatory activity of ADs has fundamental practical and theoretical implications concerning the recruitment of ADs to coactivators. PMID:27175900

  14. Structural properties of the promiscuous VP16 activation domain.

    PubMed

    Jonker, Hendrik R A; Wechselberger, Rainer W; Boelens, Rolf; Folkers, Gert E; Kaptein, Rob

    2005-01-25

    Herpes simplex virion protein 16 (VP16) contains two strong activation regions that can independently and cooperatively activate transcription in vivo. We have identified the regions and residues involved in the interaction with the human transcriptional coactivator positive cofactor 4 (PC4) and the general transcription factor TFIIB. NMR and biochemical experiments revealed that both VP16 activation regions are required for the interaction and undergo a conformational transition from random coil to alpha-helix upon binding to its target PC4. The interaction is strongly electrostatically driven and the binding to PC4 is enhanced by the presence of its amino-terminal domain. We propose models for binding of VP16 to the core domains of PC4 and TFIIB that are based on two independent docking approaches using NMR chemical shift changes observed in titration experiments. The models are consistent with results from site-directed mutagenesis and provide an explanation for the contribution of both acidic and hydrophobic residues for transcriptional activation by VP16. Both intrinsically unstructured activation domains are attracted to their interaction partner by electrostatic interactions, and adopt an alpha-helical conformation around the important hydrophobic residues. The models showed multiple distinct binding surfaces upon interaction with various partners, providing an explanation for the promiscuous properties, cooperativity, and the high activity of this activation domain.

  15. Direct Ubiquitin Independent Recognition and Degradation of a Folded Protein by the Eukaryotic Proteasomes-Origin of Intrinsic Degradation Signals

    PubMed Central

    Singh Gautam, Amit Kumar; Balakrishnan, Satish; Venkatraman, Prasanna

    2012-01-01

    Eukaryotic 26S proteasomes are structurally organized to recognize, unfold and degrade globular proteins. However, all existing model substrates of the 26S proteasome in addition to ubiquitin or adaptor proteins require unstructured regions in the form of fusion tags for efficient degradation. We report for the first time that purified 26S proteasome can directly recognize and degrade apomyoglobin, a globular protein, in the absence of ubiquitin, extrinsic degradation tags or adaptor proteins. Despite a high affinity interaction, absence of a ligand and presence of only helices/loops that follow the degradation signal, apomyoglobin is degraded slowly by the proteasome. A short floppy F-helix exposed upon ligand removal and in conformational equilibrium with a disordered structure is mandatory for recognition and initiation of degradation. Holomyoglobin, in which the helix is buried, is neither recognized nor degraded. Exposure of the floppy F-helix seems to sensitize the proteasome and primes the substrate for degradation. Using peptide panning and competition experiments we speculate that initial encounters through the floppy helix and additional strong interactions with N-terminal helices anchors apomyoglobin to the proteasome. Stabilizing helical structure in the floppy F-helix slows down degradation. Destabilization of adjacent helices accelerates degradation. Unfolding seems to follow the mechanism of helix unraveling rather than global unfolding. Our findings while confirming the requirement for unstructured regions in degradation offers the following new insights: a) origin and identification of an intrinsic degradation signal in the substrate, b) identification of sequences in the native substrate that are likely to be responsible for direct interactions with the proteasome, and c) identification of critical rate limiting steps like exposure of the intrinsic degron and destabilization of an unfolding intermediate that are presumably catalyzed by the ATPases. Apomyoglobin emerges as a new model substrate to further explore the role of ATPases and protein structure in proteasomal degradation PMID:22506054

  16. Community health workers' experiences and perspectives on mass drug administration for schistosomiasis control in western Kenya: the SCORE Project.

    PubMed

    Omedo, Martin O; Matey, Elizabeth J; Awiti, Alphonce; Ogutu, Michael; Alaii, Jane; Karanja, Diana M S; Montgomery, Susan P; Secor, W Evan; Mwinzi, Pauline N M

    2012-12-01

    Abstract. The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) includes communitywide treatment in areas with ≥ 25% prevalence of schistosomiasis along the shores of Lake Victoria using community health workers (CHWs). The CHWs are key drivers in community-owned mass drug administration (MDA) intervention programs. We explored their experiences and perceptions after initial MDA participation. Unstructured open-ended group discussions were conducted after completion of MDA activities. Narratives were obtained from CHWs using a digital audio recorder during the group discussion, transcribed verbatim and translated into English where applicable. Thematic decomposition of data was done using ATLAS.t.i. software. From the perspective of the CHWs, factors influencing MDA compliance included drug side effects, food supply stability, and conspiracy theories about the "real" purpose of treatment. The interest of CHWs to serve as community drug distributors stemmed from both intrinsic and extrinsic factors. Feedback from CHWs can promote more effective MDA in rural Kenyan communities.

  17. Development of a self-healing soft pneumatic actuator: a first concept.

    PubMed

    Terryn, Seppe; Mathijssen, Glenn; Brancart, Joost; Lefeber, Dirk; Assche, Guy Van; Vanderborght, Bram

    2015-07-07

    Inspired by the intrinsic softness and the corresponding embodied intelligence principles, soft pneumatic actuators (SPA) have been developed, which ensure safe interaction in unstructured, unknown environments. Due to their intrinsic softness, these actuators have the ability to resist large mechanical impacts. However, the soft materials used in these structures are in general susceptible to damage caused by sharp objects found in the unstructured environments. This paper proposes to integrate a self-healing (SH-) mechanism in SPAs, such that cuts, tears and perforations in the actuator can be self-healed. Diels-Alder (DA-) polymers, covalent polymer network systems based on the thermoreversible DA-reaction, were selected and their mechanical, as well as SH-properties, are described. To evaluate the feasibility of developing an SPA constructed out of SH-material, a single cell prototype, a SH-soft pneumatic cell (SH-SPC), was constructed entirely out of DA-polymers. Exploiting the SH-property of the DA-polymers, a completely new shaping process is presented in this paper, referred to as 'shaping through folding and self-healing'. 3D polygon structures, like the cubic SH-SPC, can be constructed by folding SH-polymer sheet. The sides of the structures can be sealed and made airtight using a SH-procedure at relatively low temperatures (<90 °C). Both the (thermo) mechanical and SH-properties of the SH-SPC prototype were experimentally validated and showed excellent performances. Macroscopic incisions in the prototype were completely healed using a SH-procedure (<70 °C). Starting from this single-cell prototype, it is straight-forward to develop a multi-cell prototype, the first SPA ever built completely out of SH-polymers.

  18. Extracurricular activities and the development of social skills in children with intellectual and specific learning disabilities.

    PubMed

    Brooks, B A; Floyd, F; Robins, D L; Chan, W Y

    2015-07-01

    Children with intellectual disability and specific learning disabilities often lack age-appropriate social skills, which disrupts their social functioning. Because of the limited effectiveness of classroom mainstreaming and social skills training for these children, it is important to explore alternative opportunities for social skill acquisition. Participation in social activities is positively related to children's social adjustment, but little is known about the benefits of activity participation for children with intellectual and specific learning disabilities. This study investigated the association between frequency and type of social activity participation and the social competence of 8-11-year-old children with intellectual disability (n = 40) and specific learning disabilities (n = 53), in comparison with typically developing peers (n = 24). More time involved in unstructured activities, but not structured activities, was associated with higher levels of social competence for all children. This association was strongest for children with intellectual disability, suggesting that participation in unstructured social activities was most beneficial for these children. Future research on the quality of involvement is necessary to further understand specific aspects of unstructured activities that might facilitate social development. © 2014 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

  19. Simulation of Unsteady Flows Using an Unstructured Navier-Stokes Solver on Moving and Stationary Grids

    NASA Technical Reports Server (NTRS)

    Biedron, Robert T.; Vatsa, Veer N.; Atkins, Harold L.

    2005-01-01

    We apply an unsteady Reynolds-averaged Navier-Stokes (URANS) solver for unstructured grids to unsteady flows on moving and stationary grids. Example problems considered are relevant to active flow control and stability and control. Computational results are presented using the Spalart-Allmaras turbulence model and are compared to experimental data. The effect of grid and time-step refinement are examined.

  20. Gossip-Based Broadcast

    NASA Astrophysics Data System (ADS)

    Leitão, João; Pereira, José; Rodrigues, Luís

    Gossip, or epidemic, protocols have emerged as a powerful strategy to implement highly scalable and resilient reliable broadcast primitives on large scale peer-to-peer networks. Epidemic protocols are scalable because they distribute the load among all nodes in the system and resilient because they have an intrinsic level of redundancy that masks node and network failures. This chapter provides an introduction to gossip-based broadcast on large-scale unstructured peer-to-peer overlay networks: it surveys the main results in the field, discusses techniques to build and maintain the overlays that support efficient dissemination strategies, and provides an in-depth discussion and experimental evaluation of two concrete protocols, named HyParView and Plumtree.

  1. Bioinformatic Analysis Reveals Conservation of Intrinsic Disorder in the Linker Sequences of Prokaryotic Dual-family Immunophilin Chaperones.

    PubMed

    Barik, Sailen

    2018-01-01

    The two classical immunophilin families, found essentially in all living cells, are: cyclophilin (CYN) and FK506-binding protein (FKBP). We previously reported a novel class of immunophilins that are natural chimera of these two, which we named dual-family immunophilin (DFI). The DFIs were found in either of two conformations: CYN-linker-FKBP (CFBP) or FKBP-3TPR-CYN (FCBP). While the 3TPR domain can serve as a flexible linker between the FKBP and CYN modules in the FCBP-type DFI, the linker sequences in the CFBP-type DFIs are relatively short, diverse in sequence, and contain no discernible motif or signature. Here, I present several lines of computational evidence that, regardless of their primary structure, these CFBP linkers are intrinsically disordered. This report provides the first molecular foundation for the model that the CFBP linker acts as an unstructured, flexible loop, allowing the two flanking chaperone modules function independently while linked in cis , likely to assist in the folding of multisubunit client complexes.

  2. Free energy surface of an intrinsically disordered protein: comparison between temperature replica exchange molecular dynamics and bias-exchange metadynamics.

    PubMed

    Zerze, Gül H; Miller, Cayla M; Granata, Daniele; Mittal, Jeetain

    2015-06-09

    Intrinsically disordered proteins (IDPs), which are expected to be largely unstructured under physiological conditions, make up a large fraction of eukaryotic proteins. Molecular dynamics simulations have been utilized to probe structural characteristics of these proteins, which are not always easily accessible to experiments. However, exploration of the conformational space by brute force molecular dynamics simulations is often limited by short time scales. Present literature provides a number of enhanced sampling methods to explore protein conformational space in molecular simulations more efficiently. In this work, we present a comparison of two enhanced sampling methods: temperature replica exchange molecular dynamics and bias exchange metadynamics. By investigating both the free energy landscape as a function of pertinent order parameters and the per-residue secondary structures of an IDP, namely, human islet amyloid polypeptide, we found that the two methods yield similar results as expected. We also highlight the practical difference between the two methods by describing the path that we followed to obtain both sets of data.

  3. Cellular abundance of Mps1 and the role of its carboxyl terminal tail in substrate recruitment.

    PubMed

    Sun, Tingting; Yang, Xiaomei; Wang, Wei; Zhang, Xiaojuan; Xu, Quanbin; Zhu, Songcheng; Kuchta, Robert; Chen, Guanjun; Liu, Xuedong

    2010-12-03

    Mps1 is a protein kinase that regulates normal mitotic progression and the spindle checkpoint in response to spindle damage. The levels of Mps1 are relatively low in cells during interphase but elevated in mitosis or upon activation of the spindle checkpoint, although the dynamic range of Mps1 expression and the Mps1 catalytic mechanism have not been carefully characterized. Our recent structural studies of the Mps1 kinase domain revealed that the carboxyl-terminal tail region of Mps1 is unstructured, raising the question of whether this region has any functional role in Mps1 catalysis. Here we first determined the cellular abundance of Mps1 during cell cycle progression and found that Mps1 levels vary between 60,000 per cell in early G(1) and 110,000 per cell during mitosis. We studied phosphorylation of a number of Mps1 substrates in vitro and in culture cells. Unexpectedly, we found that the unstructured carboxyl-terminal region of Mps1 plays an essential role in substrate recruitment. Kinetics studies using the purified recombinant wild type and mutant kinases indicate that the carboxyl-terminal tail is largely dispensable for autophosphorylation of Mps1 but critical for trans-phosphorylation of substrates in vitro and in cultured cells. Mps1 mutant without the unstructured tail region is defective in mediating spindle assembly checkpoint activation. Our results underscore the importance of the unstructured tail region of Mps1 in kinase activation.

  4. Intrinsic disorder in Viral Proteins Genome-Linked: experimental and predictive analyses

    PubMed Central

    Hébrard, Eugénie; Bessin, Yannick; Michon, Thierry; Longhi, Sonia; Uversky, Vladimir N; Delalande, François; Van Dorsselaer, Alain; Romero, Pedro; Walter, Jocelyne; Declerk, Nathalie; Fargette, Denis

    2009-01-01

    Background VPgs are viral proteins linked to the 5' end of some viral genomes. Interactions between several VPgs and eukaryotic translation initiation factors eIF4Es are critical for plant infection. However, VPgs are not restricted to phytoviruses, being also involved in genome replication and protein translation of several animal viruses. To date, structural data are still limited to small picornaviral VPgs. Recently three phytoviral VPgs were shown to be natively unfolded proteins. Results In this paper, we report the bacterial expression, purification and biochemical characterization of two phytoviral VPgs, namely the VPgs of Rice yellow mottle virus (RYMV, genus Sobemovirus) and Lettuce mosaic virus (LMV, genus Potyvirus). Using far-UV circular dichroism and size exclusion chromatography, we show that RYMV and LMV VPgs are predominantly or partly unstructured in solution, respectively. Using several disorder predictors, we show that both proteins are predicted to possess disordered regions. We next extend theses results to 14 VPgs representative of the viral diversity. Disordered regions were predicted in all VPg sequences whatever the genus and the family. Conclusion Based on these results, we propose that intrinsic disorder is a common feature of VPgs. The functional role of intrinsic disorder is discussed in light of the biological roles of VPgs. PMID:19220875

  5. Non-Cooperative Group Decision Support Systems: Problems and Some Solutions.

    DTIC Science & Technology

    1986-09-01

    appears that in these situations the 46 content of the problem and the structure of the problem is " fuzzy ." It requires an active cooperation between the...some unstructured parts will remain. This partial ’unstructurability’ is due to uncertainty, fuzziness , ignorance, and an inability to...according to the Analytic Hierarchy Process ( AHP ) technique (Gui, 1985). The AHP algorithm consists of the following steps; (i) Perform a pairwise comparison

  6. Discrete Molecular Dynamics Approach to the Study of Disordered and Aggregating Proteins.

    PubMed

    Emperador, Agustí; Orozco, Modesto

    2017-03-14

    We present a refinement of the Coarse Grained PACSAB force field for Discrete Molecular Dynamics (DMD) simulations of proteins in aqueous conditions. As the original version, the refined method provides good representation of the structure and dynamics of folded proteins but provides much better representations of a variety of unfolded proteins, including some very large, impossible to analyze by atomistic simulation methods. The PACSAB/DMD method also reproduces accurately aggregation properties, providing good pictures of the structural ensembles of proteins showing a folded core and an intrinsically disordered region. The combination of accuracy and speed makes the method presented here a good alternative for the exploration of unstructured protein systems.

  7. Relationships between discretionary time activities, emotional experiences, delinquency and depressive symptoms among urban African American adolescents.

    PubMed

    Bohnert, Amy M; Richards, Maryse; Kohl, Krista; Randall, Edin

    2009-04-01

    Using the Experience Sampling Method (ESM), this cross-sectional study examined mediated and moderated associations between different types of discretionary time activities and depressive symptoms and delinquency among a sample of 246 (107 boys, 139 girls) fifth through eighth grade urban African American adolescents. More time spent in passive unstructured activities was associated with higher levels of depressive symptoms only for adolescents residing in less dangerous neighborhoods, whereas more time spent in active unstructured activities was associated with higher levels of delinquency only if adolescents resided in more dangerous neighborhoods. Alienation was positively associated with depressive symptoms and delinquency, but neither alienation nor positive affect mediated the relationship between activities and adjustment. These findings suggest the importance of considering neighborhood environment issues when determining what types of discretionary time activities are most beneficial for urban African American young adolescents.

  8. Toddlers: Learning by Playing

    MedlinePlus

    ... months old, current National Association for Sports and Physical Education (NASPE) guidelines recommend this much daily activity: at least 30 minutes of structured physical activity (adult-led) at least 60 minutes unstructured ...

  9. Leisure-time physical activity behavior: structured and unstructured choices according to sex, age, and level of physical activity.

    PubMed

    Mota, Jorge; Esculcas, Carlos

    2002-01-01

    The main goals of this cross-sectional survey were (a) to describe the associations between sex, age, and physical activity behavior and (b) to describe the age and sex-related associations with the choice of structured (formal) and unstructured (nonformal) physical activity programs. At baseline, data were selected randomly from 1,013 students, from the 7th to the 12th grades. A response rate of 73% (n = 739) was obtained. Accordingly, the sample of this study consisted of 594 adolescents (304 females and 290 males) with mean age of 15.9 years (range 13-20). Physical activity was assessed by means of a questionnaire. A questionnaire about leisure activities was applied to the sample to define the nominal variable "nature of physical activity." The data showed that significantly more girls than boys (p < or = .001) belonged to the sedentary group (80.7% girls) and low activity group (64.5% girls). Boys more frequently belonged to the more active groups (92.1%; p < or = .001). The older participants were more engaged in formal physical activities, whereas the younger mostly chose informal ones whatever their level of physical activity. There were more significant differences in girls' physical activity groups (chi 2 = 20.663, p < or = .001) than in boys' (chi 2 = 7.662, p < or = .05). Furthermore, active girls chose more structured physical activities than their sedentary counterparts (18.8% vs. 83.3%). However, boys preferred unstructured activities regardless of physical activity group (83.7% vs. 58.5%; p < or = .05). It can be concluded that as age increased, organized sports activities became a relatively more important component of total weekly activity for both male and female participants.

  10. A comparison of a child’s fundamental frequencies in structured elicited vocalizations versus unstructured natural vocalizations: A case study

    PubMed Central

    Hunter, Eric J.

    2009-01-01

    Objectives Building on the concept that task type may influence fundamental frequency (F0) values, the purpose of this case study was to investigate the difference in a child’s F0 during structured, elicited tasks and long-term, unstructured activities. It also explores the possibility that the distribution in children’s F0 may make the standard statistical measures of mean and standard deviation less than ideal metrics. Methods A healthy male child (5 years, 7 months) was evaluated. The child completed four voice tasks used in a previous study of the influence of task type on F0 values: (1) sustaining the vowel /a/; (2) sustaining the vowel, /a/, embedded in a word at the end of a phrase; (3) repeating a sentence; and (4) counting from 1 to 10. The child also wore a National Center for Voice and Speech voice dosimeter, a device that collects voice data over the course of an entire day, during all activities for 34 hours over 4 days. Results Throughout the structured vocal tasks within the clinical environment, the child’s F0, as measured by both the dosimeter and acoustic analysis of microphone data, was similar for all four tasks, with the counting task the most dissimilar. The mean F0 (~257 Hz) matched very closely to the average task results in the literature given for the child’s age group. However, the child’s mean fundamental frequency during the unstructured activities was significantly higher (~376 Hz). Finally, the mode and median of the structured vocal tasks were respectively 260 Hz and 259 Hz (both near the mean), while the unstructured mode and median were respectively 290 Hz and 355 Hz. Conclusions The results of this study suggest that children may produce a notably different voice pattern during clinical observations compared to routine daily activities. In addition, the child’s long-term F0 distribution is not normal. If this distribution is consistent in long-term, unstructured natural vocalization patterns of children, statistical mean would not be a valid measure. Mode and median are suggested as two parameters which convey more accurate information about typical F0 usage. Finally, future research avenues, including further exploration of how children may adapt their F0 to various environments, conversation partners, and activity, are suggested. PMID:19185926

  11. Incorporating Unstructured Socializing Into the Study of Secondary Exposure to Community Violence: Etiological and Empirical Implications.

    PubMed

    Zimmerman, Gregory M; Messner, Steven F; Rees, Carter

    2014-07-01

    Secondary exposure to community violence, defined as witnessing or hearing violence in the community, has the potential to profoundly impact long-term development, health, happiness, and security. While research has explored pathways to community violence exposure at the individual, family, and neighborhood levels, prior work has largely neglected situational factors conducive to secondary violence exposure. The present study evaluates "unstructured socializing with peers in the absence of authority figures" as a situational process that has implications for secondary exposure to violence. Results indicate that a measure of unstructured socializing was significantly associated with exposure to violence, net of an array of theoretically relevant covariates of violence exposure. Moreover, the relationships between exposure to violence and three of the most well-established correlates of violence exposure in the literature-age, male, and prior violence-were mediated to varying degrees by unstructured socializing. The results suggest a more nuanced approach to the study of secondary violence exposure that expands the focus of attention beyond individual and neighborhood background factors to include situational opportunities presented by patterns of everyday activities. © The Author(s) 2013.

  12. A glycosylated form of the human cardiac hormone pro B-type natriuretic peptide is an intrinsically unstructured monomeric protein.

    PubMed

    Crimmins, Dan L; Kao, Jeffrey L-F

    2008-07-01

    The N-terminal fragment of pro B-type natriuretic peptide (NT-proBNP) and proBNP are used as gold standard clinical markers of myocardial dysfunction such as cardiac hypertrophy and left ventricle heart failure. The actual circulating molecular forms of these peptides have been the subject of intense investigation particularly since these analytes are measured in clinical assays. Conflicting data has been reported and no firm consensus on the exact nature of the molecular species exists. Because these clinical assays are immunoassay-based, specific epitopes are detected. It is conceivable then that certain epitopes may be masked and therefore unavailable for antibody binding, thus the importance of determining the nature of the circulating molecular forms of these analytes. This situation is an unavoidable Achilles' heel of immunoassays in general. A recombinant O-linked glycosylated form of proBNP has been show to mimic some of the properties of extracted plasma from a heart failure patient. In particular the recombinant and native material co-migrated as diffuse Western-immunostained bands on SDS-PAGE and each band collapsed to an apparent homogeneous band following deglycosylation. Thus, glycosylated-proBNP may be one such circulating form. Here we provide extensive physiochemical characterization for this O-linked protein and compare these results to other described circulating species, non-glycosylated-proBNP and NT-proBNP. It will be shown that glycosylation has no influence on the secondary and quaternary structure of proBNP. In fact, at moderate concentration in benign physiological neutral pH buffer, all three likely circulating species are essentially devoid of major secondary structure, i.e., are intrinsically unstructured proteins (IUPs). Furthermore, all three proteins exist as monomers in solution. These results may have important implications in the design of NT-proBNP/BNP immunoassays.

  13. Go! Including Movement during Routines and Transitions

    ERIC Educational Resources Information Center

    Orlowski, Marietta A.; Hart, Aaron

    2010-01-01

    Good schools for children ages 5 to 8 provide multiple opportunities for physical activity throughout the school day. Ideally, physical education, recess, extracurricular activities, and classroom activities together help ensure that children meet the recommended 60 minutes a day of structured activity and 60 of unstructured. Additionally, brief…

  14. Hybrid Grid Techniques for Propulsion Applications

    NASA Technical Reports Server (NTRS)

    Koomullil, Roy P.; Soni, Bharat K.; Thornburg, Hugh J.

    1996-01-01

    During the past decade, computational simulation of fluid flow for propulsion activities has progressed significantly, and many notable successes have been reported in the literature. However, the generation of a high quality mesh for such problems has often been reported as a pacing item. Hence, much effort has been expended to speed this portion of the simulation process. Several approaches have evolved for grid generation. Two of the most common are structured multi-block, and unstructured based procedures. Structured grids tend to be computationally efficient, and have high aspect ratio cells necessary for efficently resolving viscous layers. Structured multi-block grids may or may not exhibit grid line continuity across the block interface. This relaxation of the continuity constraint at the interface is intended to ease the grid generation process, which is still time consuming. Flow solvers supporting non-contiguous interfaces require specialized interpolation procedures which may not ensure conservation at the interface. Unstructured or generalized indexing data structures offer greater flexibility, but require explicit connectivity information and are not easy to generate for three dimensional configurations. In addition, unstructured mesh based schemes tend to be less efficient and it is difficult to resolve viscous layers. Recently hybrid or generalized element solution and grid generation techniques have been developed with the objective of combining the attractive features of both structured and unstructured techniques. In the present work, recently developed procedures for hybrid grid generation and flow simulation are critically evaluated, and compared to existing structured and unstructured procedures in terms of accuracy and computational requirements.

  15. Syndrome specificity and mother-child interactions: Examining positive and negative parenting across contexts and time

    PubMed Central

    Blacher, Jan; Baker, Bruce L.; Kaladjian, Araksia

    2012-01-01

    This study examined the extent to which child syndromes and observation context related to mothers’ parenting behaviors. Longitudinal observations were conducted of parenting behavior across ages 3, 4, and 5 years during structured and unstructured activities. The 183 participants included mothers of children with autism spectrum disorders, cerebral palsy, Down syndrome, undifferentiated developmental delay, or typical cognitive development. Negative parenting behaviors were higher in structured activities and higher in mothers of children in all developmentally delayed groups. Positive parenting was higher in unstructured activities and especially high for mothers of children with Down syndrome. Despite differences found through direct observation of parenting children in different diagnostic groups, they are not as strong as syndrome-group differences found through more commonly used self-report questionnaires assessing domains like parenting stress. PMID:22829243

  16. An Evaluation of Photographic Activity Schedules to Increase Independent Playground Skills in Young Children with Autism

    ERIC Educational Resources Information Center

    Akers, Jessica S.; Higbee, Thomas S.; Pollard, Joy S.; Pellegrino, Azure J.; Gerencser, Kristina R.

    2016-01-01

    We used photographic activity schedules to increase the number of play activities completed by children with autism during unstructured time on the playground. All 3 participants engaged in more playground activities during and after training, and they continued to complete activities when novel photographs were introduced.

  17. Prospects and expectations for unstructured methods

    NASA Technical Reports Server (NTRS)

    Baker, Timothy J.

    1995-01-01

    The last decade has witnessed a vigorous and sustained research effort on unstructured methods for computational fluid dynamics. Unstructured mesh generators and flow solvers have evolved to the point where they are now in use for design purposes throughout the aerospace industry. In this paper we survey the various mesh types, structured as well as unstructured, and examine their relative strengths and weaknesses. We argue that unstructured methodology does offer the best prospect for the next generation of computational fluid dynamics algorithms.

  18. Generation of unstructured grids and Euler solutions for complex geometries

    NASA Technical Reports Server (NTRS)

    Loehner, Rainald; Parikh, Paresh; Salas, Manuel D.

    1989-01-01

    Algorithms are described for the generation and adaptation of unstructured grids in two and three dimensions, as well as Euler solvers for unstructured grids. The main purpose is to demonstrate how unstructured grids may be employed advantageously for the economic simulation of both geometrically as well as physically complex flow fields.

  19. Conformational transition of κ-casein in micellar environment: Insight from the tryptophan fluorescence

    NASA Astrophysics Data System (ADS)

    Mishra, Smruti; Meher, Geetanjali; Chakraborty, Hirak

    2017-11-01

    Intrinsically disordered proteins (IDPs) are under intense analysis due to their structural flexibility and importance in biological functions. Minuscule modulation in the microenvironment induces significant conformational changes in IDPs, and these non-native conformations of the IDPs often induce aggregation and cause cell death. Changes in the membrane composition often change the microenvironment, which promote conformational change and aggregation of IDPs. κ-Casein, an important milk protein, belongs to the class of IDPs containing net negative charges. In this present work, we have studied the interaction of κ-casein with cetyltrimethyl ammonium bromide (CTAB), a positively charged surfactant, utilizing various steady state fluorescence, time-resolved fluorescence and circular dichroism spectroscopy. Our results clearly indicate that κ-casein undergoes at least two conformational transitions in presence of various concentrations of CTAB. The intrinsically disordered κ-casein assumes a partially folded conformation at lower concentration of CTAB, which adopts an unstructured conformation at higher concentration of CTAB. The partially folded conformation of κ-casein at a lower CTAB concentration might be induced by the favorable electrostatic interaction between the positively charged surfactant headgroup and net negative charges of the protein, whereas surfactant nature of CTAB is being pronounced at higher concentration of CTAB.

  20. Free-energy landscape of intrinsically disordered proteins investigated by all-atom multicanonical molecular dynamics.

    PubMed

    Higo, Junichi; Umezawa, Koji

    2014-01-01

    We introduce computational studies on intrinsically disordered proteins (IDPs). Especially, we present our multicanonical molecular dynamics (McMD) simulations of two IDP-partner systems: NRSF-mSin3 and pKID-KIX. McMD is one of enhanced conformational sampling methods useful for conformational sampling of biomolecular systems. IDP adopts a specific tertiary structure upon binding to its partner molecule, although it is unstructured in the unbound state (i.e. the free state). This IDP-specific property is called "coupled folding and binding". The McMD simulation treats the biomolecules with an all-atom model immersed in an explicit solvent. In the initial configuration of simulation, IDP and its partner molecules are set to be distant from each other, and the IDP conformation is disordered. The computationally obtained free-energy landscape for coupled folding and binding has shown that native- and non-native-complex clusters distribute complicatedly in the conformational space. The all-atom simulation suggests that both of induced-folding and population-selection are coupled complicatedly in the coupled folding and binding. Further analyses have exemplified that the conformational fluctuations (dynamical flexibility) in the bound and unbound states are essentially important to characterize IDP functioning.

  1. Uncovering the role of the flexible C-terminal tail: A model study with Strep-tagged GFP.

    PubMed

    Lassalle, Michael W; Kondou, Shinobu

    2016-06-01

    Recently, it has been recognized that, much like an electric current in an electric circuit, dynamic disruptions from flexible, unstructured regions distal to the active region are transferred through the contact network to the active site and influence protein stability and/or function. As transmembrane proteins frequently possess the β-barrel structure, studies of proteins with this topology are required. The unstructured lid segments of the β-barrel GFP protein are conserved and could play a role in the backbone stabilization required for chromophore function. A study of the disordered C-terminus and the function within the lid is necessary. In this study, we entirely truncated the flexible C-terminal tail and investigated the N-terminal Strep-tagged GFP by fluorescence spectroscopy, and the temperature- and GdnHCl-induced unfolding by circular dichroism. The introduction of the unstructured Strep-tag itself changed the unfolding pathway. Truncating the entire flexible tail did not decrease the fluorescence intensity to a large extent; however, the protein stability changed dramatically. The temperature for half-denaturation T 1/2 changed significantly from 79 °C for the wild-type to 72.8 °C for the mutant. Unfolding kinetics at different temperatures have been induced by 4 M GdnHCl, and the apparent Arrhenius activation energy decreased by 40% as compared to the wild-type.

  2. Using nature and outdoor activity to improve children's health.

    PubMed

    McCurdy, Leyla E; Winterbottom, Kate E; Mehta, Suril S; Roberts, James R

    2010-05-01

    Childhood obesity affects 17% or 12.5 million of America's children, contributing to the rise in children's health disparities. Type 2 diabetes, asthma, vitamin D deficiency, and attention-deficit/hyperactivity disorder have also increased over the past few decades. A shift toward a sedentary lifestyle is a major contributor to the decline in children's health. Children spend more time indoors using electronic media and less time engaged in outdoor unstructured play. This article reviews the current evidence of the mental and physical health benefits associated with unstructured, outdoor activities and time spent in a natural environment such as a park or other recreational area. Pediatric health care providers should recommend outdoor activities for children and refer families to safe and easily accessible outdoor areas. Pediatric health care providers can incorporate this simple, lifestyle-based intervention into anticipatory guidance. Copyright 2010 Mosby, Inc. All rights reserved.

  3. Using Perseverative Interests to Improve Interactions Between Adolescents with Autism and their Typical Peers in School Settings

    PubMed Central

    Koegel, Robert; Fredeen, Rosy; Kim, Sunny; Danial, John; Rubinstein, Derek; Koegel, Lynn

    2013-01-01

    The literature suggests that adolescents with ASD typically are not socially engaged during unstructured school activities and do not initiate social activities with typically developing peers. This study assessed whether implementing socialization opportunities in the form of lunch clubs based around aspects of the adolescents with ASD’s perseverative interests would promote positive direct and generalized social interaction between the target adolescent and their typically developing peers. A repeated measures multiple baseline experimental design (with two reversals) was implemented across participants. During baseline measures, the participants did not show social engagement or initiations. During intervention, results showed large increases in both social engagement and initiations. Generalization measures also showed that the target adolescents improved their social engagements and initiations with typically developing peers throughout unstructured lunchtime activities. These results have implications for understanding variables related to social development in autism. PMID:24163577

  4. Self-Concept and Participation in School Activities Reanalyzed.

    ERIC Educational Resources Information Center

    Winne, Philip H.; Walsh, John

    1980-01-01

    Yarworth and Gauthier (EJ 189 606) examined whether self-concept variables enhanced predictions about students' participation in school activities, using unstructured stepwise regression techniques. A reanalysis of their data using hierarchial regression models tested their hypothesis more appropriately, and uncovered multicollinearity and…

  5. A comparison of two group-delivered social skills programs for young children with autism.

    PubMed

    Kroeger, K A; Schultz, Janet R; Newsom, Crighton

    2007-05-01

    A social skills group intervention was developed and evaluated for young children with autism. Twenty-five 4- to 6-year-old (diagnosed) children were assigned to one of two kinds of social skills groups: the direct teaching group or the play activities group. The direct teaching group used a video-modeling format to teach play and social skills over the course of the intervention, while the play activities group engaged in unstructured play during the sessions. Groups met for 5 weeks, three times per week, 1 h each time. Data were derived and coded from videotapes of pre- and post-treatment unstructured play sessions. Findings indicated that while members of both groups increased prosocial behaviors, the direct teaching group made more gains in social skills.

  6. Identifying the neural substrates of intrinsic motivation during task performance.

    PubMed

    Lee, Woogul; Reeve, Johnmarshall

    2017-10-01

    Intrinsic motivation is the inherent tendency to seek out novelty and challenge, to explore and investigate, and to stretch and extend one's capacities. When people imagine performing intrinsically motivating tasks, they show heightened anterior insular cortex (AIC) activity. To fully explain the neural system of intrinsic motivation, however, requires assessing neural activity while people actually perform intrinsically motivating tasks (i.e., while answering curiosity-inducing questions or solving competence-enabling anagrams). Using event-related functional magnetic resonance imaging, we found that the neural system of intrinsic motivation involves not only AIC activity, but also striatum activity and, further, AIC-striatum functional interactions. These findings suggest that subjective feelings of intrinsic satisfaction (associated with AIC activations), reward processing (associated with striatum activations), and their interactions underlie the actual experience of intrinsic motivation. These neural findings are consistent with the conceptualization of intrinsic motivation as the pursuit and satisfaction of subjective feelings (interest and enjoyment) as intrinsic rewards.

  7. Influence on Transfer of selected synthetic pyrethroids from treated Formica® to Foods

    EPA Science Inventory

    Children’s unstructured eating habits and activities may lead to excess dietary exposures not traditionally taken into consideration. Influence of these activities on transfer of pesticides from treated Formica® to foods was studied. The objective was to perform simulation expe...

  8. Implicit schemes and parallel computing in unstructured grid CFD

    NASA Technical Reports Server (NTRS)

    Venkatakrishnam, V.

    1995-01-01

    The development of implicit schemes for obtaining steady state solutions to the Euler and Navier-Stokes equations on unstructured grids is outlined. Applications are presented that compare the convergence characteristics of various implicit methods. Next, the development of explicit and implicit schemes to compute unsteady flows on unstructured grids is discussed. Next, the issues involved in parallelizing finite volume schemes on unstructured meshes in an MIMD (multiple instruction/multiple data stream) fashion are outlined. Techniques for partitioning unstructured grids among processors and for extracting parallelism in explicit and implicit solvers are discussed. Finally, some dynamic load balancing ideas, which are useful in adaptive transient computations, are presented.

  9. Celecoxib Encapsulation in β-Casein Micelles: Structure, Interactions, and Conformation.

    PubMed

    Turovsky, Tanya; Khalfin, Rafail; Kababya, Shifi; Schmidt, Asher; Barenholz, Yechezkel; Danino, Dganit

    2015-07-07

    β-Casein is a 24 kDa natural protein that has an open conformation and almost no folded or secondary structure, and thus is classified as an intrinsically unstructured protein. At neutral pH, β-casein has an amphiphilic character. Therefore, in contrast to most unstructured proteins that remain monomeric in solution, β-casein self-assembles into well-defined core-shell micelles. We recently developed these micelles as potential carriers for oral administration of poorly water-soluble pharmaceuticals, using celecoxib as a model drug. Herein we present deep and precise insight into the physicochemical characteristics of the protein-drug formulation, both in bulk solution and in dry form, emphasizing drug conformation, packing properties and aggregation state. In addition, the formulation is extensively studied in terms of structure and morphology, protein/drug interactions and physical stability. Particularly, NMR measurements indicated strong drug-protein interactions and noncrystalline drug conformation, which is expected to improve drug solubility and bioavailability. Small-angle X-ray scattering (SAXS) and cryogenic transmission electron microscopy (cryo-TEM) were combined for nanostructural characterization, proving that drug-protein interactions lead to well-defined spheroidal micelles that become puffier and denser upon drug loading. Dynamice light scattering (DLS), turbidity measurements, and visual observations complemented the analysis for determining formulation structure, interactions, and stability. Additionally, it was shown that the loaded micelles retain their properties through freeze-drying and rehydration, providing long-term physical and chemical stability. Altogether, the formulation seems greatly promising for oral drug delivery.

  10. A robust and contact resolving Riemann solver on unstructured mesh, Part I, Euler method

    NASA Astrophysics Data System (ADS)

    Shen, Zhijun; Yan, Wei; Yuan, Guangwei

    2014-07-01

    This article presents a new cell-centered numerical method for compressible flows on arbitrary unstructured meshes. A multi-dimensional Riemann solver based on the HLLC method (denoted by HLLC-2D solver) is established. The work is an extension from the cell-centered Lagrangian scheme of Maire et al. [27] to the Eulerian framework. Similarly to the work in [27], a two-dimensional contact velocity defined on a grid node is introduced, and the motivation is to keep an edge flux consistency with the node velocity connected to the edge intrinsically. The main new feature of the algorithm is to relax the condition that the contact pressures must be same in the traditional HLLC solver. The discontinuous fluxes are constructed across each wave sampling direction rather than only along the contact wave direction. The two-dimensional contact velocity of the grid node is determined via enforcing conservation of mass, momentum and total energy, and thus the new method satisfies these conservation properties at nodes rather than on grid edges. Other good properties of the HLLC-2d solver, such as the positivity and the contact preserving, are described, and the two-dimensional high-order extension is constructed employing MUSCL type reconstruction procedure. Numerical results based on both quadrilateral and triangular grids are presented to demonstrate the robustness and the accuracy of this new solver, which shows it has better performance than the existing HLLC method.

  11. Leisure Activities and Adolescent Psychological Well-Being

    ERIC Educational Resources Information Center

    Trainor, Sarah; Delfabbro, Paul; Anderson, Sarah; Winefield, Anthony

    2010-01-01

    We examined the validity of the reported link between well-being and leisure participation in adolescents. Nine hundred and forty-seven, Year 10 students from 19 schools in Adelaide, South Australia, were recruited. Participants completed a questionnaire concerning participation in social, non-social and unstructured leisure activities as well as…

  12. Be BOLD: Encouraging Girls to Include Unstructured Bouts of Physical Activity into Daily Routines

    ERIC Educational Resources Information Center

    Hill, Kory; Williams, Gwynne M.

    2014-01-01

    Adolescent girls are less active than their male counterparts and physical activity levels tend to decline as one ages. One of the goals of concerned physical educators is to promote a physically active lifestyle and to teach skills and promote behaviors that will allow students to be active both in and out of school. This article presents a…

  13. The DNA repair endonuclease XPG interacts directly and functionally with the WRN helicase defective in Werner syndrome

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

    Trego, Kelly S.; Chernikova, Sophia B.; Davalos, Albert R.

    XPG is a structure-specific endonuclease required for nucleotide excision repair (NER). XPG incision defects result in the cancer-prone syndrome xeroderma pigmentosum, whereas truncating mutations of XPG cause the severe postnatal progeroid developmental disorder Cockayne syndrome. We show that XPG interacts directly with WRN protein, which is defective in the premature aging disorder Werner syndrome, and that the two proteins undergo similar sub-nuclear redistribution in S-phase and co-localize in nuclear foci. The co-localization was observed in mid- to late-S-phase, when WRN moves from nucleoli to nuclear foci that have been shown to contain protein markers of both stalled replication forks andmore » telomeric proteins. We mapped the interaction between XPG and WRN to the C-terminal domains of each and show that interaction with the C-terminal domain of XPG strongly stimulates WRN helicase activity. WRN also possesses a competing DNA single-strand annealing activity that, combined with unwinding, has been shown to coordinate regression of model replication forks to form Holliday junction/chicken foot intermediate structures. We tested whether XPG stimulated WRN annealing activity and found that XPG itself has intrinsic strand annealing activity that requires the unstructured R- and C-terminal domains, but not the conserved catalytic core or endonuclease activity. Annealing by XPG is cooperative, rather than additive, with WRN annealing. Taken together, our results suggest a novel function for XPG in S-phase that is at least in part carried out coordinately with WRN, and which may contribute to the severity of the phenotypes that occur upon loss of XPG.« less

  14. Physical Activity Intensity, Lesson Context, and Teacher Interactions during an Unstructured Afterschool Physical Activity Program

    ERIC Educational Resources Information Center

    Behrens, Timothy K.; Miller, Daniel J.; Schuna, John M.; Liebert, Mina L.

    2015-01-01

    Background: Afterschool programs are promising arenas to improve youth physical activity (PA) levels. During the school year for 2012-2013, 5 elementary schools from a low-socioeconomic status (SES) school district in southern Colorado participated in evaluation of the afterschool program entitled Keep It Moving! (KIM). Methods: In this…

  15. Feasibility and Effects of Short Activity Breaks for Increasing Preschool-Age Children's Physical Activity Levels

    ERIC Educational Resources Information Center

    Alhassan, Sofiya; Nwaokelemeh, Ogechi; Mendoza, Albert; Shitole, Sanyog; Puleo, Elaine; Pfeiffer, Karin A.; Whitt-Glover, Melicia C.

    2016-01-01

    Background: We examined the effects of short bouts of structured physical activity (SBS-PA) implemented within the classroom setting as part of designated gross-motor playtime on preschoolers PA. Methods: Preschools were randomized to SBS-PA (centers, N = 5; participants, N = 141) or unstructured free playtime (UPA) (centers, N = 5; participants,…

  16. Implications of Out-of-School Activities for School Engagement in African American Adolescents

    ERIC Educational Resources Information Center

    Dotterer, Aryn M.; McHale, Susan M.; Crouter, Ann C.

    2007-01-01

    The connection between out-of-school activities and school engagement was examined in 140, 6th through 9th grade African American adolescents. Youth's out-of-school activities were measured with a series of 7 nightly phone calls and focused on time in structured (homework, academically-oriented, extracurricular/sports) and unstructured (watching…

  17. The Feasibility of Adaptive Unstructured Computations On Petaflops Systems

    NASA Technical Reports Server (NTRS)

    Biswas, Rupak; Oliker, Leonid; Heber, Gerd; Gao, Guang; Saini, Subhash (Technical Monitor)

    1999-01-01

    This viewgraph presentation covers the advantages of mesh adaptation, unstructured grids, and dynamic load balancing. It illustrates parallel adaptive communications, and explains PLUM (Parallel dynamic load balancing for adaptive unstructured meshes), and PSAW (Proper Self Avoiding Walks).

  18. Best Practices for Unstructured Grid Shock-Fitting

    NASA Technical Reports Server (NTRS)

    McCoud, Peter L.

    2017-01-01

    Unstructured grid solvers have well-known issues predicting surface heat fluxes when strong shocks are present. Various efforts have been made to address the underlying numerical issues that cause the erroneous predictions. The present work addresses some of the shortcomings of unstructured grid solvers, not by addressing the numerics, but by applying structured grid best practices to unstructured grids. A methodology for robust shock detection and shock-fitting is outlined and applied to production-relevant cases. Results

  19. Adaption of unstructured meshes using node movement

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

    Carpenter, J.G.; McRae, V.D.S.

    1996-12-31

    The adaption algorithm of Benson and McRae is modified for application to unstructured grids. The weight function generation was modified for application to unstructured grids and movement was limited to prevent cross over. A NACA 0012 airfoil is used as a test case to evaluate the modified algorithm when applied to unstructured grids and compared to results obtained by Warren. An adaptive mesh solution for the Sudhoo and Hall four element airfoil is included as a demonstration case.

  20. Structural Dissection of Crotalicidin, a Rattlesnake Venom Cathelicidin, Retrieves a Fragment with Antimicrobial and Antitumor Activity.

    PubMed

    Falcao, Claudio Borges; Pérez-Peinado, Clara; de la Torre, Beatriz G; Mayol, Xavier; Zamora-Carreras, Héctor; Jiménez, M Ángeles; Rádis-Baptista, Gandhi; Andreu, David

    2015-11-12

    In silico dissection of crotalicidin (Ctn), a cathelicidin from a South American pit viper, yielded fragments Ctn[1-14] and Ctn[15-34], which were tested to ascertain to what extent they reproduced the structure and activity of the parent peptide. NMR data showing Ctn to be α-helical at the N-terminus and unstructured at the C-terminus were matched by similar data from the fragments. The peptides were tested against Gram-positive and -negative bacteria and for toxicity against both tumor and healthy cells. Despite its amphipathic α-helical structure, Ctn[1-14] was totally inert toward bacteria or eukaryotic cells. In contrast, unstructured Ctn[15-34] replicated the activity of parent Ctn against Gram-negative bacteria and tumor cells while being significantly less toxic toward eukaryotic cells. This selectivity for bacteria and tumor cells, plus a stability to serum well above that of Ctn, portrays Ctn[15-34] as an appealing candidate for further development as an anti-infective or antitumor lead.

  1. Identification of HYPK-Interacting Proteins Reveals Involvement of HYPK in Regulating Cell Growth, Cell Cycle, Unfolded Protein Response and Cell Death

    PubMed Central

    Choudhury, Kamalika Roy; Raychaudhuri, Swasti; Bhattacharyya, Nitai P.

    2012-01-01

    Huntingtin Yeast Two-Hybrid Protein K (HYPK) is an intrinsically unstructured huntingtin (HTT)-interacting protein with chaperone-like activity. To obtain more information about the function(s) of the protein, we identified 27 novel interacting partners of HYPK by pull-down assay coupled with mass spectrometry and, further, 9 proteins were identified by co-localization and co-immunoprecipitation (co-IP) assays. In neuronal cells, (EEF1A1 and HSPA1A), (HTT and LMNB2) and (TP53 and RELA) were identified in complex with HYPK in different experiments. Various Gene Ontology (GO) terms for biological processes, like protein folding (GO: 0006457), response to unfolded protein (GO: 0006986), cell cycle arrest (GO: 0007050), anti-apoptosis (GO: 0006916) and regulation of transcription (GO: 0006355) were significantly enriched with the HYPK-interacting proteins. Cell growth and the ability to refold heat-denatured reporter luciferase were decreased, but cytotoxicity was increased in neuronal cells where HYPK was knocked-down using HYPK antisense DNA construct. The proportion of cells in different phases of cell cycle was also altered in cells with reduced levels of HYPK. These results show that HYPK is involved in several biological processes, possibly through interaction with its partners. PMID:23272104

  2. CHILDREN'S DIETARY EXPOSURES TO CHEMICAL CONTAMINANTS

    EPA Science Inventory

    The Food Quality Protection Act of 1996 requires EPA to more accurately assess children's aggregate exposures to environmental contaminants. Children have unstructured eating behaviors which cause excess exposures as a result of their activities. Determining total dietary intak...

  3. The Effect of Play on the Creativity of Young Children during Subsequent Activity.

    ERIC Educational Resources Information Center

    Howard-Jones, Paul A.; Taylor, Jayne R.; Sutton, Lesley

    2002-01-01

    Investigated whether experiencing 25 minutes of unstructured play in a preceding task influenced the creativity of 6- and 7-year-olds in a subsequent activity. Found that there was a positive effect of a preceding salt-dough play activity upon the creativity and range of colors used in creating a collage with a controlled range of materials.…

  4. Where to Next for School Playground Interventions to Encourage Active Play? An Exploration of Structured and Unstructured School Playground Strategies

    ERIC Educational Resources Information Center

    Hyndman, Brendon

    2015-01-01

    An emerging public health priority is to enhance children's opportunities for active play. Children spend a large proportion of weekdays in schools, making schools an influential and suitable setting to promote children's active play. Rather than continually increasing the burdens placed upon busy teaching staff, the use of school playground…

  5. Overcoming the Challenges of Unstructured Data in Multisite, Electronic Medical Record-based Abstraction.

    PubMed

    Polnaszek, Brock; Gilmore-Bykovskyi, Andrea; Hovanes, Melissa; Roiland, Rachel; Ferguson, Patrick; Brown, Roger; Kind, Amy J H

    2016-10-01

    Unstructured data encountered during retrospective electronic medical record (EMR) abstraction has routinely been identified as challenging to reliably abstract, as these data are often recorded as free text, without limitations to format or structure. There is increased interest in reliably abstracting this type of data given its prominent role in care coordination and communication, yet limited methodological guidance exists. As standard abstraction approaches resulted in substandard data reliability for unstructured data elements collected as part of a multisite, retrospective EMR study of hospital discharge communication quality, our goal was to develop, apply and examine the utility of a phase-based approach to reliably abstract unstructured data. This approach is examined using the specific example of discharge communication for warfarin management. We adopted a "fit-for-use" framework to guide the development and evaluation of abstraction methods using a 4-step, phase-based approach including (1) team building; (2) identification of challenges; (3) adaptation of abstraction methods; and (4) systematic data quality monitoring. Unstructured data elements were the focus of this study, including elements communicating steps in warfarin management (eg, warfarin initiation) and medical follow-up (eg, timeframe for follow-up). After implementation of the phase-based approach, interrater reliability for all unstructured data elements demonstrated κ's of ≥0.89-an average increase of +0.25 for each unstructured data element. As compared with standard abstraction methodologies, this phase-based approach was more time intensive, but did markedly increase abstraction reliability for unstructured data elements within multisite EMR documentation.

  6. Sensation Seeking and Adolescent Alcohol Use: Exploring the Mediating Role of Unstructured Socializing With Peers.

    PubMed

    Sznitman, Sharon; Engel-Yeger, Batya

    2017-05-01

    Researchers have theorized that adolescents high in sensation seeking are particularly sensitive to positive reinforcement and the rewarding outcomes of alcohol use, and thus that the personality vulnerability is a direct causal risk factor for alcohol use. In contrast, the routine activity perspective theorizes that part of the effect of sensation seeking on alcohol use goes through the propensity that sensation seekers have towards unstructured socializing with peers. The study tests a model with indirect and direct paths from sensation seeking and participation in unstructured peer socialization to adolescent alcohol use. Cross-sectional data were collected from 360 students in a state-secular Jewish high school (10th to 12th grade) in the center region of Israel. The sample was equally divided between boys (51.9%) and girls (48.1%), respondents' age ranged from 15 to 17 years (mean = 16.02 ± 0.85). Structural equation modeling was used to test the direct and indirect paths. While sensation seeking had a significant direct path to adolescent alcohol use, part of the association was mediated by unstructured socializing with peers. The mediated paths were similar for boys and girls alike. Sensation seeking is primarily biologically determined and prevention efforts are unlikely to modify this personality vulnerability. The results of this study suggest that a promising prevention avenue is to modify extracurricular participation patterns of vulnerable adolescents. © The Author 2017. Medical Council on Alcohol and Oxford University Press. All rights reserved.

  7. Unstructured play for anxiety in pediatric inpatient care.

    PubMed

    Al-Yateem, Nabeel; Rossiter, Rachel C

    2017-01-01

    The purpose of this study was to examine the effects of unstructured play activities on the anxiety levels of hospitalized children. A nonequivalent control group pretest posttest design was employed for this study. The sample included children (N = 165) ages 4-7 years admitted to a large pediatric referral center in the United Arab Emirates. The control group (n = 84) received usual care, while the experimental group (n = 81) engaged in age-appropriate unstructured play activities using disposable games and toys. Parents and siblings, if present, were encouraged to participate. Research assistants conducted the play activities twice a day, with 30-min morning and evening sessions. Anxiety was measured at baseline and at the end of days 2 and 3 with a translated form of the Short-State-Trait Anxiety Inventory for Children. Anxiety scores in both groups were similar at baseline and decreased significantly over the 3 days. Compared with the control group, anxiety scores in the intervention group were significantly lower on day 2 (12.7 ± 2.3 vs. 10.7 ± 2.5, p = .003) and day 3 (10.6 ± 2.2 vs. 9.47 ± 2.4, p < .001). The greatest decrease occurred in the percentage of children in the experimental group with medium-level anxiety scores: baseline (n = 61, 75%), day 2 (n = 24, 30%), and day 3 (n = 0, 0%). This simple, low-cost play intervention implemented by nurses resulted in statistically and clinically significant decreases in the anxiety levels of children in an acute inpatient setting. © 2016, Wiley Periodicals, Inc.

  8. Comparison of structured and unstructured physical activity training on predicted VO2max and heart rate variability in adolescents - a randomized control trial.

    PubMed

    Sharma, Vivek Kumar; Subramanian, Senthil Kumar; Radhakrishnan, Krishnakumar; Rajendran, Rajathi; Ravindran, Balasubramanian Sulur; Arunachalam, Vinayathan

    2017-05-01

    Physical inactivity contributes to many health issues. The WHO-recommended physical activity for adolescents encompasses aerobic, resistance, and bone strengthening exercises aimed at achieving health-related physical fitness. Heart rate variability (HRV) and maximal aerobic capacity (VO2max) are considered as noninvasive measures of cardiovascular health. The objective of this study is to compare the effect of structured and unstructured physical training on maximal aerobic capacity and HRV among adolescents. We designed a single blinded, parallel, randomized active-controlled trial (Registration No. CTRI/2013/08/003897) to compare the physiological effects of 6 months of globally recommended structured physical activity (SPA), with that of unstructured physical activity (USPA) in healthy school-going adolescents. We recruited 439 healthy student volunteers (boys: 250, girls: 189) in the age group of 12-17 years. Randomization across the groups was done using age and gender stratified randomization method, and the participants were divided into two groups: SPA (n=219, boys: 117, girls: 102) and USPA (n=220, boys: 119, girls: 101). Depending on their training status and gender the participants in both SPA and USPA groups were further subdivided into the following four sub-groups: SPA athlete boys (n=22) and girls (n=17), SPA nonathlete boys (n=95) and girls (n=85), USPA athlete boys (n=23) and girls (n=17), and USPA nonathlete boys (n=96) and girls (n=84). We recorded HRV, body fat%, and VO2 max using Rockport Walk Fitness test before and after the intervention. Maximum aerobic capacity and heart rate variability increased significantly while heart rate, systolic blood pressure, diastolic blood pressure, and body fat percentage decreased significantly after both SPA and USPA intervention. However, the improvement was more in SPA as compared to USPA. SPA is more beneficial for improving cardiorespiratory fitness, HRV, and reducing body fat percentage in terms of magnitude than USPA in adolescent individuals irrespective of their gender and sports activities.

  9. Best Practices for Unstructured Grid Shock Fitting

    NASA Technical Reports Server (NTRS)

    McCloud, Peter L.

    2017-01-01

    Unstructured grid solvers have well-known issues predicting surface heat fluxes when strong shocks are present. Various efforts have been made to address the underlying numerical issues that cause the erroneous predictions. The present work addresses some of the shortcomings of unstructured grid solvers, not by addressing the numerics, but by applying structured grid best practices to unstructured grids. A methodology for robust shock detection and shock fitting is outlined and applied to production relevant cases. Results achieved by using the Loci-CHEM Computational Fluid Dynamics solver are provided.

  10. Aspects of Unstructured Grids and Finite-Volume Solvers for the Euler and Navier-Stokes Equations

    NASA Technical Reports Server (NTRS)

    Barth, Timothy J.

    1992-01-01

    One of the major achievements in engineering science has been the development of computer algorithms for solving nonlinear differential equations such as the Navier-Stokes equations. In the past, limited computer resources have motivated the development of efficient numerical schemes in computational fluid dynamics (CFD) utilizing structured meshes. The use of structured meshes greatly simplifies the implementation of CFD algorithms on conventional computers. Unstructured grids on the other hand offer an alternative to modeling complex geometries. Unstructured meshes have irregular connectivity and usually contain combinations of triangles, quadrilaterals, tetrahedra, and hexahedra. The generation and use of unstructured grids poses new challenges in CFD. The purpose of this note is to present recent developments in the unstructured grid generation and flow solution technology.

  11. Development of a Regional Structured and Unstructured Grid Methodology for Chemically Reactive Turbulent Flows

    NASA Astrophysics Data System (ADS)

    Stefanski, Douglas Lawrence

    A finite volume method for solving the Reynolds Averaged Navier-Stokes (RANS) equations on unstructured hybrid grids is presented. Capabilities for handling arbitrary mixtures of reactive gas species within the unstructured framework are developed. The modeling of turbulent effects is carried out via the 1998 Wilcox k -- o model. This unstructured solver is incorporated within VULCAN -- a multi-block structured grid code -- as part of a novel patching procedure in which non-matching interfaces between structured blocks are replaced by transitional unstructured grids. This approach provides a fully-conservative alternative to VULCAN's non-conservative patching methods for handling such interfaces. In addition, the further development of the standalone unstructured solver toward large-eddy simulation (LES) applications is also carried out. Dual time-stepping using a Crank-Nicholson formulation is added to recover time-accuracy, and modeling of sub-grid scale effects is incorporated to provide higher fidelity LES solutions for turbulent flows. A switch based on the work of Ducros, et al., is implemented to transition from a monotonicity-preserving flux scheme near shocks to a central-difference method in vorticity-dominated regions in order to better resolve small-scale turbulent structures. The updated unstructured solver is used to carry out large-eddy simulations of a supersonic constrained mixing layer.

  12. EVALUATING EXCESS DIETARY EXPOSURE OF YOUNG CHILDREN EATING IN CONTAMINATED ENVIRONMENTS

    EPA Science Inventory

    The United States' Food Quality Protection Act of 1996 requires more accurate assessment of children's aggregate exposures to environmental contaminants. Since children have unstructured eating behaviors, their excess exposures, caused by eating activities, becomes an importan...

  13. Adaptive Neural Networks Decentralized FTC Design for Nonstrict-Feedback Nonlinear Interconnected Large-Scale Systems Against Actuator Faults.

    PubMed

    Li, Yongming; Tong, Shaocheng

    The problem of active fault-tolerant control (FTC) is investigated for the large-scale nonlinear systems in nonstrict-feedback form. The nonstrict-feedback nonlinear systems considered in this paper consist of unstructured uncertainties, unmeasured states, unknown interconnected terms, and actuator faults (e.g., bias fault and gain fault). A state observer is designed to solve the unmeasurable state problem. Neural networks (NNs) are used to identify the unknown lumped nonlinear functions so that the problems of unstructured uncertainties and unknown interconnected terms can be solved. By combining the adaptive backstepping design principle with the combination Nussbaum gain function property, a novel NN adaptive output-feedback FTC approach is developed. The proposed FTC controller can guarantee that all signals in all subsystems are bounded, and the tracking errors for each subsystem converge to a small neighborhood of zero. Finally, numerical results of practical examples are presented to further demonstrate the effectiveness of the proposed control strategy.The problem of active fault-tolerant control (FTC) is investigated for the large-scale nonlinear systems in nonstrict-feedback form. The nonstrict-feedback nonlinear systems considered in this paper consist of unstructured uncertainties, unmeasured states, unknown interconnected terms, and actuator faults (e.g., bias fault and gain fault). A state observer is designed to solve the unmeasurable state problem. Neural networks (NNs) are used to identify the unknown lumped nonlinear functions so that the problems of unstructured uncertainties and unknown interconnected terms can be solved. By combining the adaptive backstepping design principle with the combination Nussbaum gain function property, a novel NN adaptive output-feedback FTC approach is developed. The proposed FTC controller can guarantee that all signals in all subsystems are bounded, and the tracking errors for each subsystem converge to a small neighborhood of zero. Finally, numerical results of practical examples are presented to further demonstrate the effectiveness of the proposed control strategy.

  14. Extreme disorder in an ultrahigh-affinity protein complex

    NASA Astrophysics Data System (ADS)

    Borgia, Alessandro; Borgia, Madeleine B.; Bugge, Katrine; Kissling, Vera M.; Heidarsson, Pétur O.; Fernandes, Catarina B.; Sottini, Andrea; Soranno, Andrea; Buholzer, Karin J.; Nettels, Daniel; Kragelund, Birthe B.; Best, Robert B.; Schuler, Benjamin

    2018-03-01

    Molecular communication in biology is mediated by protein interactions. According to the current paradigm, the specificity and affinity required for these interactions are encoded in the precise complementarity of binding interfaces. Even proteins that are disordered under physiological conditions or that contain large unstructured regions commonly interact with well-structured binding sites on other biomolecules. Here we demonstrate the existence of an unexpected interaction mechanism: the two intrinsically disordered human proteins histone H1 and its nuclear chaperone prothymosin-α associate in a complex with picomolar affinity, but fully retain their structural disorder, long-range flexibility and highly dynamic character. On the basis of closely integrated experiments and molecular simulations, we show that the interaction can be explained by the large opposite net charge of the two proteins, without requiring defined binding sites or interactions between specific individual residues. Proteome-wide sequence analysis suggests that this interaction mechanism may be abundant in eukaryotes.

  15. Estimation of the left ventricular shape and motion with a limited number of slices

    NASA Astrophysics Data System (ADS)

    Robert, Anne; Schmitt, Francis J. M.; Mousseaux, Elie

    1996-04-01

    In this paper, we describe a method for the reconstruction of the surface of the left ventricle from a set of lacunary data (that is an incomplete, unevenly sampled and unstructured data set). Global models, because they compress the properties of a surface into a small set of parameters, have a strong regularizing power and are therefore very well suited to lacunary data. Globally deformable superquadrics are particularly attractive, because of their simplicity. This model can be fitted to the data using the Levenberg-Marquardt algorithm for non-linear optimization. However, the difficulties we experienced to get temporally consistent solutions as well as the intrinsic 4D character of the data led us to generalize the classical 3D superquadric model to 4D. We present results on a 4D sequence from the Dynamic Spatial Reconstructor of the Mayo Clinic, and on a 4D IRM sequence.

  16. Enhanced Wang Landau sampling of adsorbed protein conformations.

    PubMed

    Radhakrishna, Mithun; Sharma, Sumit; Kumar, Sanat K

    2012-03-21

    Using computer simulations to model the folding of proteins into their native states is computationally expensive due to the extraordinarily low degeneracy of the ground state. In this paper, we develop an efficient way to sample these folded conformations using Wang Landau sampling coupled with the configurational bias method (which uses an unphysical "temperature" that lies between the collapse and folding transition temperatures of the protein). This method speeds up the folding process by roughly an order of magnitude over existing algorithms for the sequences studied. We apply this method to study the adsorption of intrinsically disordered hydrophobic polar protein fragments on a hydrophobic surface. We find that these fragments, which are unstructured in the bulk, acquire secondary structure upon adsorption onto a strong hydrophobic surface. Apparently, the presence of a hydrophobic surface allows these random coil fragments to fold by providing hydrophobic contacts that were lost in protein fragmentation. © 2012 American Institute of Physics

  17. Digital Pharmacovigilance and Disease Surveillance: Combining Traditional and Big-Data Systems for Better Public Health

    PubMed Central

    Salathé, Marcel

    2016-01-01

    The digital revolution has contributed to very large data sets (ie, big data) relevant for public health. The two major data sources are electronic health records from traditional health systems and patient-generated data. As the two data sources have complementary strengths—high veracity in the data from traditional sources and high velocity and variety in patient-generated data—they can be combined to build more-robust public health systems. However, they also have unique challenges. Patient-generated data in particular are often completely unstructured and highly context dependent, posing essentially a machine-learning challenge. Some recent examples from infectious disease surveillance and adverse drug event monitoring demonstrate that the technical challenges can be solved. Despite these advances, the problem of verification remains, and unless traditional and digital epidemiologic approaches are combined, these data sources will be constrained by their intrinsic limits. PMID:28830106

  18. Overcoming the Challenges of Unstructured Data in Multi-site, Electronic Medical Record-based Abstraction

    PubMed Central

    Polnaszek, Brock; Gilmore-Bykovskyi, Andrea; Hovanes, Melissa; Roiland, Rachel; Ferguson, Patrick; Brown, Roger; Kind, Amy JH

    2014-01-01

    Background Unstructured data encountered during retrospective electronic medical record (EMR) abstraction has routinely been identified as challenging to reliably abstract, as this data is often recorded as free text, without limitations to format or structure. There is increased interest in reliably abstracting this type of data given its prominent role in care coordination and communication, yet limited methodological guidance exists. Objective As standard abstraction approaches resulted in sub-standard data reliability for unstructured data elements collected as part of a multi-site, retrospective EMR study of hospital discharge communication quality, our goal was to develop, apply and examine the utility of a phase-based approach to reliably abstract unstructured data. This approach is examined using the specific example of discharge communication for warfarin management. Research Design We adopted a “fit-for-use” framework to guide the development and evaluation of abstraction methods using a four step, phase-based approach including (1) team building, (2) identification of challenges, (3) adaptation of abstraction methods, and (4) systematic data quality monitoring. Measures Unstructured data elements were the focus of this study, including elements communicating steps in warfarin management (e.g., warfarin initiation) and medical follow-up (e.g., timeframe for follow-up). Results After implementation of the phase-based approach, inter-rater reliability for all unstructured data elements demonstrated kappas of ≥ 0.89 -- an average increase of + 0.25 for each unstructured data element. Conclusions As compared to standard abstraction methodologies, this phase-based approach was more time intensive, but did markedly increase abstraction reliability for unstructured data elements within multi-site EMR documentation. PMID:27624585

  19. Effects of a Bug-in-the-Ear Intervention to Increase Physical Activity Prompting and Level during Preschool Recess

    ERIC Educational Resources Information Center

    Kahan, David; Nicaise, Virginie; Reuben, Karen

    2016-01-01

    Teacher prompting is a means to increase preschool children's physical activity. Twelve 4- and 5-year-olds at one preschool in the southwest U.S. participated in an ABA prompting intervention that utilized a bug-in-the-ear device to signal teachers to prompt sedentary children to increase physical activity level during unstructured recess.…

  20. Advanced ensemble modelling of flexible macromolecules using X-ray solution scattering.

    PubMed

    Tria, Giancarlo; Mertens, Haydyn D T; Kachala, Michael; Svergun, Dmitri I

    2015-03-01

    Dynamic ensembles of macromolecules mediate essential processes in biology. Understanding the mechanisms driving the function and molecular interactions of 'unstructured' and flexible molecules requires alternative approaches to those traditionally employed in structural biology. Small-angle X-ray scattering (SAXS) is an established method for structural characterization of biological macromolecules in solution, and is directly applicable to the study of flexible systems such as intrinsically disordered proteins and multi-domain proteins with unstructured regions. The Ensemble Optimization Method (EOM) [Bernadó et al. (2007 ▶). J. Am. Chem. Soc. 129, 5656-5664] was the first approach introducing the concept of ensemble fitting of the SAXS data from flexible systems. In this approach, a large pool of macromolecules covering the available conformational space is generated and a sub-ensemble of conformers coexisting in solution is selected guided by the fit to the experimental SAXS data. This paper presents a series of new developments and advancements to the method, including significantly enhanced functionality and also quantitative metrics for the characterization of the results. Building on the original concept of ensemble optimization, the algorithms for pool generation have been redesigned to allow for the construction of partially or completely symmetric oligomeric models, and the selection procedure was improved to refine the size of the ensemble. Quantitative measures of the flexibility of the system studied, based on the characteristic integral parameters of the selected ensemble, are introduced. These improvements are implemented in the new EOM version 2.0, and the capabilities as well as inherent limitations of the ensemble approach in SAXS, and of EOM 2.0 in particular, are discussed.

  1. An assessment of unstructured grid technology for timely CFD analysis

    NASA Technical Reports Server (NTRS)

    Kinard, Tom A.; Schabowski, Deanne M.

    1995-01-01

    An assessment of two unstructured methods is presented in this paper. A tetrahedral unstructured method USM3D, developed at NASA Langley Research Center is compared to a Cartesian unstructured method, SPLITFLOW, developed at Lockheed Fort Worth Company. USM3D is an upwind finite volume solver that accepts grids generated primarily from the Vgrid grid generator. SPLITFLOW combines an unstructured grid generator with an implicit flow solver in one package. Both methods are exercised on three test cases, a wing, and a wing body, and a fully expanded nozzle. The results for the first two runs are included here and compared to the structured grid method TEAM and to available test data. On each test case, the set up procedure are described, including any difficulties that were encountered. Detailed descriptions of the solvers are not included in this paper.

  2. Comparison of Environmental Interactions and Motor Activity of Visually Handicapped and Sighted Children.

    ERIC Educational Resources Information Center

    Schneekloth, Lynda H.; Day, Diane

    The study compared the motor activities and environmental interactions of 36 sighted, partially sighted, and blind children (7 to 13 years old) during unstructured play. Objectives were to assess motor proficiency level; to establish frequency and kind of gross motor, manipulative self stimulation, and social/play behaviors; and to assess use of…

  3. Links between Older and Younger Adolescent Siblings' Adjustment: The Moderating Role of Shared Activities

    ERIC Educational Resources Information Center

    Tucker, Corinna Jenkins; McHale, Susan M.; Crouter, Ann C.

    2008-01-01

    Siblings' constructive and unstructured shared activities were examined as moderators of the links between first- and second-born siblings' adjustment across a two-year period in adolescence. Siblings (N = 189 dyads) reported on their depression, peer competency, self worth during home interviews, and their time together in constructive (e.g.,…

  4. Comparative Reliability of Structured Versus Unstructured Interviews in the Admission Process of a Residency Program

    PubMed Central

    Blouin, Danielle; Day, Andrew G.; Pavlov, Andrey

    2011-01-01

    Background Although never directly compared, structured interviews are reported as being more reliable than unstructured interviews. This study compared the reliability of both types of interview when applied to a common pool of applicants for positions in an emergency medicine residency program. Methods In 2008, one structured interview was added to the two unstructured interviews traditionally used in our resident selection process. A formal job analysis using the critical incident technique guided the development of the structured interview tool. This tool consisted of 7 scenarios assessing 4 of the domains deemed essential for success as a resident in this program. The traditional interview tool assessed 5 general criteria. In addition to these criteria, the unstructured panel members were asked to rate each candidate on the same 4 essential domains rated by the structured panel members. All 3 panels interviewed all candidates. Main outcomes were the overall, interitem, and interrater reliabilities, the correlations between interview panels, and the dimensionality of each interview tool. Results Thirty candidates were interviewed. The overall reliability reached 0.43 for the structured interview, and 0.81 and 0.71 for the unstructured interviews. Analyses of the variance components showed a high interrater, low interitem reliability for the structured interview, and a high interrater, high interitem reliability for the unstructured interviews. The summary measures from the 2 unstructured interviews were significantly correlated, but neither was correlated with the structured interview. Only the structured interview was multidimensional. Conclusions A structured interview did not yield a higher overall reliability than both unstructured interviews. The lower reliability is explained by a lower interitem reliability, which in turn is due to the multidimensionality of the interview tool. Both unstructured panels consistently rated a single dimension, even when prompted to assess the 4 specific domains established as essential to succeed in this residency program. PMID:23205201

  5. Comparative reliability of structured versus unstructured interviews in the admission process of a residency program.

    PubMed

    Blouin, Danielle; Day, Andrew G; Pavlov, Andrey

    2011-12-01

    Although never directly compared, structured interviews are reported as being more reliable than unstructured interviews. This study compared the reliability of both types of interview when applied to a common pool of applicants for positions in an emergency medicine residency program. In 2008, one structured interview was added to the two unstructured interviews traditionally used in our resident selection process. A formal job analysis using the critical incident technique guided the development of the structured interview tool. This tool consisted of 7 scenarios assessing 4 of the domains deemed essential for success as a resident in this program. The traditional interview tool assessed 5 general criteria. In addition to these criteria, the unstructured panel members were asked to rate each candidate on the same 4 essential domains rated by the structured panel members. All 3 panels interviewed all candidates. Main outcomes were the overall, interitem, and interrater reliabilities, the correlations between interview panels, and the dimensionality of each interview tool. Thirty candidates were interviewed. The overall reliability reached 0.43 for the structured interview, and 0.81 and 0.71 for the unstructured interviews. Analyses of the variance components showed a high interrater, low interitem reliability for the structured interview, and a high interrater, high interitem reliability for the unstructured interviews. The summary measures from the 2 unstructured interviews were significantly correlated, but neither was correlated with the structured interview. Only the structured interview was multidimensional. A structured interview did not yield a higher overall reliability than both unstructured interviews. The lower reliability is explained by a lower interitem reliability, which in turn is due to the multidimensionality of the interview tool. Both unstructured panels consistently rated a single dimension, even when prompted to assess the 4 specific domains established as essential to succeed in this residency program.

  6. Young Children's Mathematics References during Free Play in Family Childcare Settings

    ERIC Educational Resources Information Center

    Hendershot, Shawnee M.; Berghout Austin, Ann M.; Blevins-Knabe, Belinda; Ota, Carrie

    2016-01-01

    Very little is known about children's discussion of mathematics topics during unstructured play. Ginsburg, Lin, Ness, and Seo [2003. Young American and Chinese children's everyday mathematical activity. Mathematical Thinking and Learning, 5(4), 235-258. Retrieved from…

  7. Multigrid techniques for unstructured meshes

    NASA Technical Reports Server (NTRS)

    Mavriplis, D. J.

    1995-01-01

    An overview of current multigrid techniques for unstructured meshes is given. The basic principles of the multigrid approach are first outlined. Application of these principles to unstructured mesh problems is then described, illustrating various different approaches, and giving examples of practical applications. Advanced multigrid topics, such as the use of algebraic multigrid methods, and the combination of multigrid techniques with adaptive meshing strategies are dealt with in subsequent sections. These represent current areas of research, and the unresolved issues are discussed. The presentation is organized in an educational manner, for readers familiar with computational fluid dynamics, wishing to learn more about current unstructured mesh techniques.

  8. Unstructured Euler flow solutions using hexahedral cell refinement

    NASA Technical Reports Server (NTRS)

    Melton, John E.; Cappuccio, Gelsomina; Thomas, Scott D.

    1991-01-01

    An attempt is made to extend grid refinement into three dimensions by using unstructured hexahedral grids. The flow solver is developed using the TIGER (topologically Independent Grid, Euler Refinement) as the starting point. The program uses an unstructured hexahedral mesh and a modified version of the Jameson four-stage, finite-volume Runge-Kutta algorithm for integration of the Euler equations. The unstructured mesh allows for local refinement appropriate for each freestream condition, thereby concentrating mesh cells in the regions of greatest interest. This increases the computational efficiency because the refinement is not required to extend throughout the entire flow field.

  9. The intrinsically disordered C-terminal domain of the measles virus nucleoprotein interacts with the C-terminal domain of the phosphoprotein via two distinct sites and remains predominantly unfolded

    PubMed Central

    Bourhis, Jean-Marie; Receveur-Bréchot, Véronique; Oglesbee, Michael; Zhang, Xinsheng; Buccellato, Matthew; Darbon, Hervé; Canard, Bruno; Finet, Stéphanie; Longhi, Sonia

    2005-01-01

    Measles virus is a negative-sense, single-stranded RNA virus within theMononegavirales order,which includes several human pathogens, including rabies, Ebola, Nipah, and Hendra viruses. Themeasles virus nucleoprotein consists of a structured N-terminal domain, and of an intrinsically disordered C-terminal domain, NTAIL (aa 401–525), which undergoes induced folding in the presence of the C-terminal domain (XD, aa 459–507) of the viral phosphoprotein. With in NTAIL, an α-helical molecular recognition element (α-MoRE, aa 488–499) involved in binding to P and in induced folding was identified and then observed in the crystal structure of XD. Using small-angle X-ray scattering, we have derived a low-resolution structural model of the complex between XD and NTAIL, which shows that most of NTAIL remains disordered in the complex despite P-induced folding within the α-MoRE. The model consists of an extended shape accommodating the multiple conformations adopted by the disordered N-terminal region of NTAIL, and of a bulky globular region, corresponding to XD and to the C terminus of NTAIL (aa 486–525). Using surface plasmon resonance, circular dichroism, fluorescence spectroscopy, and heteronuclear magnetic resonance, we show that NTAIL has an additional site (aa 517–525) involved in binding to XD but not in the unstructured-to-structured transition. This work provides evidence that intrinsically disordered domains can establish complex interactions with their partners, and can contact them through multiple sites that do not all necessarily gain regular secondary structure. PMID:16046624

  10. Design and baseline characteristics of the Short bouTs of Exercise for Preschoolers (STEP) study.

    PubMed

    Alhassan, Sofiya; Nwaokelemeh, Ogechi; Mendoza, Albert; Shitole, Sanyog; Whitt-Glover, Melicia C; Yancey, Antronette K

    2012-08-01

    Most preschool centers provide two 30-min sessions of gross-motor/outdoor playtime per preschool day. Within this time frame, children accumulate most of their activity within the first 10 min. This paper describes the design and baseline participant characteristics of the Short bouTs of Exercise for Preschoolers (STEP) study. The STEP study is a cluster randomized controlled study designed to examine the effects of short bouts of structured physical activity (SBS-PA) implemented within the classroom setting as part of designated gross-motor playtime on during-school physical activity (PA) in preschoolers. Ten preschool centers serving low-income families were randomized into SBS-PA versus unstructured PA (UPA). SBS-PA schools were asked to implement age-appropriate 10 min structured PA routines within the classroom setting, twice daily, followed by 20 min of usual unstructured playtime. UPA intervention consisted of 30 min of supervised unstructured free playtime twice daily. Interventions were implemented during the morning and afternoon designated gross-motor playtime for 30 min/session, five days/week for six months. Outcome measures were between group difference in during-preschool PA (accelerometers and direct observation) over six-months. Ten preschool centers, representing 34 classrooms and 315 children, enrolled in the study. The average age and BMI percentile for the participants was 4.1 ± 0.8 years and 69th percentile, respectively. Participants spent 74% and 6% of their preschool day engaged in sedentary and MVPA, respectively. Results from the STEP intervention could provide evidence that a PA policy that exposes preschoolers to shorter bouts of structured PA throughout the preschool day could potentially increase preschoolers' PA levels.

  11. Design and baseline characteristics of the Short bouTs of Exercise for Preschoolers (STEP) study

    PubMed Central

    2012-01-01

    Background Most preschool centers provide two 30-min sessions of gross-motor/outdoor playtime per preschool day. Within this time frame, children accumulate most of their activity within the first 10 min. This paper describes the design and baseline participant characteristics of the Short bouTs of Exercise for Preschoolers (STEP) study. The STEP study is a cluster randomized controlled study designed to examine the effects of short bouts of structured physical activity (SBS-PA) implemented within the classroom setting as part of designated gross-motor playtime on during-school physical activity (PA) in preschoolers. Methods/Design Ten preschool centers serving low-income families were randomized into SBS-PA versus unstructured PA (UPA). SBS-PA schools were asked to implement age-appropriate 10 min structured PA routines within the classroom setting, twice daily, followed by 20 min of usual unstructured playtime. UPA intervention consisted of 30 min of supervised unstructured free playtime twice daily. Interventions were implemented during the morning and afternoon designated gross-motor playtime for 30 min/session, five days/week for six months. Outcome measures were between group difference in during-preschool PA (accelerometers and direct observation) over six-months. Ten preschool centers, representing 34 classrooms and 315 children, enrolled in the study. The average age and BMI percentile for the participants was 4.1 ± 0.8 years and 69th percentile, respectively. Participants spent 74% and 6% of their preschool day engaged in sedentary and MVPA, respectively. Discussion Results from the STEP intervention could provide evidence that a PA policy that exposes preschoolers to shorter bouts of structured PA throughout the preschool day could potentially increase preschoolers’ PA levels. Trial registration Clinicaltrials.gov, NCT01588392 PMID:22853642

  12. War Termination: Dreaming of the End and the Ultimate Triumph

    DTIC Science & Technology

    2004-05-17

    and unstructured, art and science . To realize national strategic objectives and develop a triumphant peace, operational commanders must shun the...itself, war termination is both political and military, structured and unstructured, art and science . To realize national strategic objectives and...termination is political and military, structured and unstructured, art and science . By applying elements of operational art to war termination and

  13. Should Students Have a Gap Year? Motivation and Performance Factors Relevant to Time Out after Completing School

    ERIC Educational Resources Information Center

    Martin, Andrew J.

    2010-01-01

    Increasingly, school leavers are taking time out from study or formal work after completing high school--often referred to as a "gap year" (involving structured activities such as "volunteer tourism" and unstructured activities such as leisure). Although much opinion exists about the merits--or otherwise--of taking time out after completing…

  14. Park design and children’s active play a micro-scale spatial analysis of intensity of play in Olmsted’s Delaware Park

    USDA-ARS?s Scientific Manuscript database

    This paper offers a micro-scale exploration of the role of park design on intensity of physical activity among youth. The actual, unstructured use of a park - specifically, Delaware Park, an Olmsted-designed park in Buffalo, New York - by 94 children was objectively observed and analyzed using Geog...

  15. Can organized leisure-time activities buffer the negative outcomes of unstructured activities for adolescents' health?

    PubMed

    Badura, Petr; Madarasova Geckova, Andrea; Sigmundova, Dagmar; Sigmund, Erik; van Dijk, Jitse P; Reijneveld, Sijmen A

    2018-06-02

    We aimed to assess the associations of involvement in selected unstructured activities (UA) with health-risk behaviours and academic achievement and the degree to which the participation in organized leisure-time activities (OLTA) changes these associations. Using a sample of 6935 Czech adolescents aged 13 and 15 years, we investigated adolescents' weekly involvement in hanging out, visiting shopping malls for fun and meeting friends after 8 p.m., OLTA and engagement in three health-risk behaviours and academic achievement. Weekly involvement in the selected UA was associated with higher odds for regular smoking, being drunk, having early sexual intercourse and low academic achievement. Concurrent participation in OLTA did not buffer these negative outcomes, except for sexual experience. However, those highly engaged only in UA were more likely to participate in the health-risk behaviours and report worse academic achievement than those participating in any OLTA concurrently. The selected UA are strongly associated with an increased occurrence of adolescents' health-risk behaviours and low academic achievement. Concurrent participation in OLTA does not buffer these negative outcomes significantly, but adolescents engaged only in UA consistently report the least favourable outcomes.

  16. Sports participation and juvenile delinquency: the role of the peer context among adolescent boys and girls with varied histories of problem behavior.

    PubMed

    Gardner, Margo; Roth, Jodie; Brooks-Gunn, Jeanne

    2009-03-01

    In a study of 1,344 urban adolescents, the authors examined the relation between participation in organized sports and juvenile delinquency. They compared youth who participated in sports to those who only participated in nonathletic activities and to those who did not participate in any organized activities. They also examined the indirect relations between sports and delinquency via 2 peer-related constructs-deviant peer affiliations and unstructured socializing. Finally, they examined the extent to which gender and prior externalizing problems moderated the direct and indirect relations between sports participation and delinquency. The authors found that the odds of nonviolent delinquency were higher among boys who participated in sports when compared to boys who participated only in nonathletic activities but not when compared to boys who did not participate in any organized activities. Deviant peer affiliations and unstructured socializing mediated the relation between sports participation and boys' nonviolent delinquency. Moreover, prior externalizing problems moderated the mediated path through peer deviance. The authors did not, however, find direct, mediated, or moderated relations between sports and boys' violent delinquency nor between sports and girls' violent or nonviolent delinquency.

  17. Io's Plasma Environment During the Galileo Flyby: Global Three-Dimensional MHD Modeling with Adaptive Mesh Refinement

    NASA Technical Reports Server (NTRS)

    Combi, M. R.; Kabin, K.; Gombosi, T. I.; DeZeeuw, D. L.; Powell, K. G.

    1998-01-01

    The first results for applying a three-dimensional multimedia ideal MHD model for the mass-loaded flow of Jupiter's corotating magnetospheric plasma past Io are presented. The model is able to consider simultaneously physically realistic conditions for ion mass loading, ion-neutral drag, and intrinsic magnetic field in a full global calculation without imposing artificial dissipation. Io is modeled with an extended neutral atmosphere which loads the corotating plasma torus flow with mass, momentum, and energy. The governing equations are solved using adaptive mesh refinement on an unstructured Cartesian grid using an upwind scheme for AHMED. For the work described in this paper we explored a range of models without an intrinsic magnetic field for Io. We compare our results with particle and field measurements made during the December 7, 1995, flyby of to, as published by the Galileo Orbiter experiment teams. For two extreme cases of lower boundary conditions at Io, our model can quantitatively explain the variation of density along the spacecraft trajectory and can reproduce the general appearance of the variations of magnetic field and ion pressure and temperature. The net fresh ion mass-loading rates are in the range of approximately 300-650 kg/s, and equivalent charge exchange mass-loading rates are in the range approximately 540-1150 kg/s in the vicinity of Io.

  18. Protein domain definition should allow for conditional disorder

    PubMed Central

    Yegambaram, Kavestri; Bulloch, Esther MM; Kingston, Richard L

    2013-01-01

    Abstract: Proteins are often classified in a binary fashion as either structured or disordered. However this approach has several deficits. Firstly, protein folding is always conditional on the physiochemical environment. A protein which is structured in some circumstances will be disordered in others. Secondly, it hides a fundamental asymmetry in behavior. While all structured proteins can be unfolded through a change in environment, not all disordered proteins have the capacity for folding. Failure to accommodate these complexities confuses the definition of both protein structural domains and intrinsically disordered regions. We illustrate these points with an experimental study of a family of small binding domains, drawn from the RNA polymerase of mumps virus and its closest relatives. Assessed at face value the domains fall on a structural continuum, with folded, partially folded, and near unstructured members. Yet the disorder present in the family is conditional, and these closely related polypeptides can access the same folded state under appropriate conditions. Any heuristic definition of the protein domain emphasizing conformational stability divides this domain family in two, in a way that makes no biological sense. Structural domains would be better defined by their ability to adopt a specific tertiary structure: a structure that may or may not be realized, dependent on the circumstances. This explicitly allows for the conditional nature of protein folding, and more clearly demarcates structural domains from intrinsically disordered regions that may function without folding. PMID:23963781

  19. Conformational Dynamics of Titin PEVK Explored with FRET Spectroscopy

    PubMed Central

    Huber, Tamás; Grama, László; Hetényi, Csaba; Schay, Gusztáv; Fülöp, Lívia; Penke, Botond; Kellermayer, Miklós S.Z.

    2012-01-01

    The proline-, glutamate-, valine-, and lysine-rich (PEVK) domain of the giant muscle protein titin is thought to be an intrinsically unstructured random-coil segment. Various observations suggest, however, that the domain may not be completely devoid of internal interactions and structural features. To test the validity of random polymer models for PEVK, we determined the mean end-to-end distances of an 11- and a 21-residue synthetic PEVK peptide, calculated from the efficiency of the fluorescence resonance energy transfer (FRET) between an N-terminal intrinsic tryptophan donor and a synthetically added C-terminal IAEDANS acceptor obtained in steady-state and time-resolved experiments. We find that the contour-length scaling of mean end-to-end distance deviates from predictions of a purely statistical polymer chain. Furthermore, the addition of guanidine hydrochloride decreased, whereas the addition of salt increased the FRET efficiency, pointing at the disruption of structure-stabilizing interactions. Increasing temperature between 10 and 50°C increased the normalized FRET efficiency in both peptides but with different trajectories, indicating that their elasticity and conformational stability are different. Simulations suggest that whereas the short PEVK peptide displays an overall random structure, the long PEVK peptide retains residual, loose helical configurations. Transitions in the local structure and dynamics of the PEVK domain may play a role in the modulation of passive muscle mechanics. PMID:23062340

  20. Self-generated strategic behavior in an ecological shopping task.

    PubMed

    Bottari, Carolina; Wai Shun, Priscilla Lam; Dorze, Guylaine Le; Gosselin, Nadia; Dawson, Deirdre

    2014-01-01

    OBJECTIVES. The use of cognitive strategies optimizes performance in complex everyday tasks such as shopping. This exploratory study examined the cognitive strategies people with traumatic brain injury (TBI) effectively use in an unstructured, real-world situation. METHOD. A behavioral analysis of the self-generated strategic behaviors of 5 people with severe TBI using videotaped sessions of an ecological shopping task (Instrumental Activities of Daily Living Profile) was performed. RESULTS. All participants used some form of cognitive strategy in an unstructured real-world shopping task, although the number, type, and degree of effectiveness of the strategies in leading to goal attainment varied. The most independent person used the largest number and a broader repertoire of self-generated strategies. CONCLUSION. These results provide initial evidence that occupational therapists should examine the use of self-generated cognitive strategies in real-world contexts as a potential means of guiding therapy aimed at improving independence in everyday activities for people with TBI. Copyright © 2014 by the American Occupational Therapy Association, Inc.

  1. Effects of Weaning and Spatial Enrichment on Behavior of Turkish Saanen Goat Kids.

    PubMed

    Tölü, Cemil; Göktürk, Semra; Sava, Türker

    2016-06-01

    As is in all economic activities, the highest yield per unit area is the main goal in animal production, while addressing the temperamental needs of animals often is ignored. Animal welfare is not only an ethical fact; it also has an economic value. Spatial environmental enrichment contributes positively to animal welfare by addressing their behavioral and mental requirements. The present study was conducted to determine the effects of weaning and spatial environmental arrangements on behaviors of goat-kids. Experimental groups were arranged in structured and unstructured spatial environments. Roughage feeder, semi-automatic concentrate feeder, bunk, bridge, and wood block were placed in the structured environment. No equipment was placed in the unstructured environment and paddock sides were enclosed with an iron sheet to prevent bipedal stance and to provide environmental isolation. In the study 10 male and 10 female Turkish Saanen goat kids were used in each group. Spatial environmental arrangements did not have significant impacts on the growth performance of kids (p>0.05). All objects in the structured group were accepted by the kids. Average use ratios of roughage feeder, semi-automatic concentrate feeder, bunk, bridge and wood block were observed as 19.3%, 14.0%, 12.6%, 3.8%, and 0.7%, respectively. There were significant differences between before- and after-weaning in use of all objects except for underneath bridge (p≤0.05). Concentrate feed consumption, locomotion, and resting behaviors in kids showed significant differences by structural group and growth period. Roughage consumption was similar between groups, while it differed by growth period (p≤0.05). Interaction frequency was significantly higher in structured group (p = 0.0023). Playing behavior significantly differentiated based on the growth period rather than on groups (p≤0.05). Playing behavior significantly decreased after weaning. Abnormal oral activity was significantly higher in the structured group before weaning (p≤0.05). Despite there being no installations facilitating climbing and bipedal stance, the kids of the unstructured group were able to exhibit 1/3 as much bipedal stance behavior as the kids of the structured group through leaning over slippery paddock wall or over their groupmates. Bipedal stance behavior of unstructured group was similar before and after weaning, while bipedal stance behavior before weaning was about 2 times that of after weaning in structured group. It was concluded that unstructured environmental arrangement limited the behavior repertoire of the goat kids.

  2. Effects of Weaning and Spatial Enrichment on Behavior of Turkish Saanen Goat Kids

    PubMed Central

    Tölü, Cemil; Göktürk, Semra; Sava, Türker

    2016-01-01

    As is in all economic activities, the highest yield per unit area is the main goal in animal production, while addressing the temperamental needs of animals often is ignored. Animal welfare is not only an ethical fact; it also has an economic value. Spatial environmental enrichment contributes positively to animal welfare by addressing their behavioral and mental requirements. The present study was conducted to determine the effects of weaning and spatial environmental arrangements on behaviors of goat-kids. Experimental groups were arranged in structured and unstructured spatial environments. Roughage feeder, semi-automatic concentrate feeder, bunk, bridge, and wood block were placed in the structured environment. No equipment was placed in the unstructured environment and paddock sides were enclosed with an iron sheet to prevent bipedal stance and to provide environmental isolation. In the study 10 male and 10 female Turkish Saanen goat kids were used in each group. Spatial environmental arrangements did not have significant impacts on the growth performance of kids (p>0.05). All objects in the structured group were accepted by the kids. Average use ratios of roughage feeder, semi-automatic concentrate feeder, bunk, bridge and wood block were observed as 19.3%, 14.0%, 12.6%, 3.8%, and 0.7%, respectively. There were significant differences between before- and after-weaning in use of all objects except for underneath bridge (p≤0.05). Concentrate feed consumption, locomotion, and resting behaviors in kids showed significant differences by structural group and growth period. Roughage consumption was similar between groups, while it differed by growth period (p≤0.05). Interaction frequency was significantly higher in structured group (p = 0.0023). Playing behavior significantly differentiated based on the growth period rather than on groups (p≤0.05). Playing behavior significantly decreased after weaning. Abnormal oral activity was significantly higher in the structured group before weaning (p≤0.05). Despite there being no installations facilitating climbing and bipedal stance, the kids of the unstructured group were able to exhibit 1/3 as much bipedal stance behavior as the kids of the structured group through leaning over slippery paddock wall or over their groupmates. Bipedal stance behavior of unstructured group was similar before and after weaning, while bipedal stance behavior before weaning was about 2 times that of after weaning in structured group. It was concluded that unstructured environmental arrangement limited the behavior repertoire of the goat kids. PMID:26954169

  3. Hanging Out with Which Friends? Friendship-Level Predictors of Unstructured and Unsupervised Socializing in Adolescence

    PubMed Central

    Siennick, Sonja E.; Osgood, D. Wayne

    2012-01-01

    Companions are central to explanations of the risky nature of unstructured and unsupervised socializing, yet we know little about whom adolescents are with when hanging out. We examine predictors of how often friendship dyads hang out via multilevel analyses of longitudinal friendship-level data on over 5,000 middle schoolers. Adolescents hang out most with their most available friends and their most generally similar friends, not with their most at-risk or similarly at-risk friends. These findings vary little by gender and wave. Together, the findings suggest that the risks of hanging out stem from the nature of hanging out as an activity, not the nature of adolescents’ companions, and that hanging out is a context for friends’ mutual reinforcement of pre-existing characteristics. PMID:23204811

  4. Hanging Out with Which Friends? Friendship-Level Predictors of Unstructured and Unsupervised Socializing in Adolescence.

    PubMed

    Siennick, Sonja E; Osgood, D Wayne

    2012-12-01

    Companions are central to explanations of the risky nature of unstructured and unsupervised socializing, yet we know little about whom adolescents are with when hanging out. We examine predictors of how often friendship dyads hang out via multilevel analyses of longitudinal friendship-level data on over 5,000 middle schoolers. Adolescents hang out most with their most available friends and their most generally similar friends, not with their most at-risk or similarly at-risk friends. These findings vary little by gender and wave. Together, the findings suggest that the risks of hanging out stem from the nature of hanging out as an activity, not the nature of adolescents' companions, and that hanging out is a context for friends' mutual reinforcement of pre-existing characteristics.

  5. The Importance of Outdoor Activity and Place Attachment to Adolescent Development in Coös County, New Hampshire. Paper 208. New Hampshire and New England Issue Brief No. 37

    ERIC Educational Resources Information Center

    Seaman, Jayson; McLaughlin, Sean

    2013-01-01

    This brief discusses the rates of participation in structured and unstructured outdoor activities as Coös County youth age, along with the relationship between outdoor activity involvement and indicators of place attachment throughout this period. The analysis is based on data collected between 2008 and 2013 as part of the Carsey Institute's Panel…

  6. VisualUrText: A Text Analytics Tool for Unstructured Textual Data

    NASA Astrophysics Data System (ADS)

    Zainol, Zuraini; Jaymes, Mohd T. H.; Nohuddin, Puteri N. E.

    2018-05-01

    The growing amount of unstructured text over Internet is tremendous. Text repositories come from Web 2.0, business intelligence and social networking applications. It is also believed that 80-90% of future growth data is available in the form of unstructured text databases that may potentially contain interesting patterns and trends. Text Mining is well known technique for discovering interesting patterns and trends which are non-trivial knowledge from massive unstructured text data. Text Mining covers multidisciplinary fields involving information retrieval (IR), text analysis, natural language processing (NLP), data mining, machine learning statistics and computational linguistics. This paper discusses the development of text analytics tool that is proficient in extracting, processing, analyzing the unstructured text data and visualizing cleaned text data into multiple forms such as Document Term Matrix (DTM), Frequency Graph, Network Analysis Graph, Word Cloud and Dendogram. This tool, VisualUrText, is developed to assist students and researchers for extracting interesting patterns and trends in document analyses.

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

    Burke, Timothy P.; Martz, Roger L.; Kiedrowski, Brian C.

    New unstructured mesh capabilities in MCNP6 (developmental version during summer 2012) show potential for conducting multi-physics analyses by coupling MCNP to a finite element solver such as Abaqus/CAE[2]. Before these new capabilities can be utilized, the ability of MCNP to accurately estimate eigenvalues and pin powers using an unstructured mesh must first be verified. Previous work to verify the unstructured mesh capabilities in MCNP was accomplished using the Godiva sphere [1], and this work attempts to build on that. To accomplish this, a criticality benchmark and a fuel assembly benchmark were used for calculations in MCNP using both the Constructivemore » Solid Geometry (CSG) native to MCNP and the unstructured mesh geometry generated using Abaqus/CAE. The Big Ten criticality benchmark [3] was modeled due to its geometry being similar to that of a reactor fuel pin. The C5G7 3-D Mixed Oxide (MOX) Fuel Assembly Benchmark [4] was modeled to test the unstructured mesh capabilities on a reactor-type problem.« less

  8. Revealing the functional neuroanatomy of intrinsic alertness using fMRI: methodological peculiarities.

    PubMed

    Clemens, Benjamin; Zvyagintsev, Mikhail; Sack, Alexander T; Sack, Alexander; Heinecke, Armin; Willmes, Klaus; Sturm, Walter

    2011-01-01

    Clinical observations and neuroimaging data revealed a right-hemisphere fronto-parietal-thalamic-brainstem network for intrinsic alertness, and additional left fronto-parietal activity during phasic alertness. The primary objective of this fMRI study was to map the functional neuroanatomy of intrinsic alertness as precisely as possible in healthy participants, using a novel assessment paradigm already employed in clinical settings. Both the paradigm and the experimental design were optimized to specifically assess intrinsic alertness, while at the same time controlling for sensory-motor processing. The present results suggest that the processing of intrinsic alertness is accompanied by increased activity within the brainstem, thalamus, anterior cingulate gyrus, right insula, and right parietal cortex. Additionally, we found increased activation in the left hemisphere around the middle frontal gyrus (BA 9), the insula, the supplementary motor area, and the cerebellum. Our results further suggest that rather minute aspects of the experimental design may induce aspects of phasic alertness, which in turn might lead to additional brain activation in left-frontal areas not normally involved in intrinsic alertness. Accordingly, left BA 9 activation may be related to co-activation of the phasic alertness network due to the switch between rest and task conditions functioning as an external warning cue triggering the phasic alertness network. Furthermore, activation of the intrinsic alertness network during fixation blocks due to enhanced expectancy shortly before the switch to the task block might, when subtracted from the task block, lead to diminished activation in the typical right hemisphere intrinsic alertness network. Thus, we cautiously suggest that--as a methodological artifact--left frontal activations might show up due to phasic alertness involvement and intrinsic alertness activations might be weakened due to contrasting with fixation blocks, when assessing the functional neuroanatomy of intrinsic alertness with a block design in fMRI studies.

  9. Revealing the Functional Neuroanatomy of Intrinsic Alertness Using fMRI: Methodological Peculiarities

    PubMed Central

    Clemens, Benjamin; Zvyagintsev, Mikhail; Sack, Alexander; Heinecke, Armin; Willmes, Klaus; Sturm, Walter

    2011-01-01

    Clinical observations and neuroimaging data revealed a right-hemisphere fronto-parietal-thalamic-brainstem network for intrinsic alertness, and additional left fronto-parietal activity during phasic alertness. The primary objective of this fMRI study was to map the functional neuroanatomy of intrinsic alertness as precisely as possible in healthy participants, using a novel assessment paradigm already employed in clinical settings. Both the paradigm and the experimental design were optimized to specifically assess intrinsic alertness, while at the same time controlling for sensory-motor processing. The present results suggest that the processing of intrinsic alertness is accompanied by increased activity within the brainstem, thalamus, anterior cingulate gyrus, right insula, and right parietal cortex. Additionally, we found increased activation in the left hemisphere around the middle frontal gyrus (BA 9), the insula, the supplementary motor area, and the cerebellum. Our results further suggest that rather minute aspects of the experimental design may induce aspects of phasic alertness, which in turn might lead to additional brain activation in left-frontal areas not normally involved in intrinsic alertness. Accordingly, left BA 9 activation may be related to co-activation of the phasic alertness network due to the switch between rest and task conditions functioning as an external warning cue triggering the phasic alertness network. Furthermore, activation of the intrinsic alertness network during fixation blocks due to enhanced expectancy shortly before the switch to the task block might, when subtracted from the task block, lead to diminished activation in the typical right hemisphere intrinsic alertness network. Thus, we cautiously suggest that – as a methodological artifact – left frontal activations might show up due to phasic alertness involvement and intrinsic alertness activations might be weakened due to contrasting with fixation blocks, when assessing the functional neuroanatomy of intrinsic alertness with a block design in fMRI studies. PMID:21984928

  10. Hybrid Solution-Adaptive Unstructured Cartesian Method for Large-Eddy Simulation of Detonation in Multi-Phase Turbulent Reactive Mixtures

    DTIC Science & Technology

    2012-03-27

    pulse- detonation engines ( PDE ), stage separation, supersonic cav- ity oscillations, hypersonic aerodynamics, detonation induced structural...ADAPTIVE UNSTRUCTURED CARTESIAN METHOD FOR LARGE-EDDY SIMULATION OF DETONATION IN MULTI-PHASE TURBULENT REACTIVE MIXTURES 5b. GRANT NUMBER FA9550...CCL Report TR-2012-03-03 Hybrid Solution-Adaptive Unstructured Cartesian Method for Large-Eddy Simulation of Detonation in Multi-Phase Turbulent

  11. Efficacy of the World Health Organization-recommended handwashing technique and a modified washing technique to remove Clostridium difficile from hands.

    PubMed

    Deschênes, Philippe; Chano, Frédéric; Dionne, Léa-Laurence; Pittet, Didier; Longtin, Yves

    2017-08-01

    The efficacy of the World Health Organization (WHO)-recommended handwashing technique against Clostridium difficile is uncertain, and whether it could be improved remains unknown. Also, the benefit of using a structured technique instead of an unstructured technique remains unclear. This study was a prospective comparison of 3 techniques (unstructured, WHO, and a novel technique dubbed WHO shortened repeated [WHO-SR] technique) to remove C difficile. Ten participants were enrolled and performed each technique. Hands were contaminated with 3 × 10 6 colony forming units (CFU) of a nontoxigenic strain containing 90% spores. Efficacy was assessed using the whole-hand method. The relative efficacy of each technique and of a structured (either WHO or WHO-SR) vs an unstructured technique were assessed by Mann-Whitney U test and Wilcoxon signed-rank test. The median effectiveness of the unstructured, WHO, and WHO-SR techniques in log 10 CFU reduction was 1.30 (interquartile range [IQR], 1.27-1.43), 1.71 (IQR, 1.34-1.91), and 1.70 (IQR, 1.54-2.42), respectively. The WHO-SR technique was significantly more efficacious than the unstructured technique (P = .01). Washing hands with a structured technique was more effective than washing with an unstructured technique (median, 1.70 vs 1.30 log 10 CFU reduction, respectively; P = .007). A structured washing technique is more effective than an unstructured technique against C difficile. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  12. Assessing Individual-Level Factors Supporting Student Intrinsic Motivation in Online Discussions: A Qualitative Study

    ERIC Educational Resources Information Center

    Shroff, Ronnie H.; Vogel, Douglas R.; Coombes, John

    2008-01-01

    Research has established that intrinsic motivation has a positive effect on learning and academic achievement. However, little is known about the impact of different technology-supported learning activities on student intrinsic motivation or whether such learning activities significantly enhance student intrinsic motivation compared to traditional…

  13. Acute Effects of a Therapeutic Mobility Device on Physical Activity and Heart Rate in Children with Down Syndrome

    ERIC Educational Resources Information Center

    Hauck, Janet L.; Ulrich, Dale A.

    2015-01-01

    Purpose: The purpose of this feasibility study was to provide an opportunity to increase physical activity (PA) and heart rate (HR) for children with Down syndrome (DS) during unstructured group exercise utilizing a riding device called the Power Pumper®. Method: Twenty-four children aged 5 to 7 years old participated in this case-control study,…

  14. Faculty motivations to use active learning among pharmacy educators.

    PubMed

    Rockich-Winston, Nicole; Train, Brian C; Rudolph, Michael J; Gillette, Chris

    2018-03-01

    Faculty motivations to use active learning have been limited to surveys evaluating faculty perceptions within active learning studies. Our objective in this study was to evaluate the relationship between faculty intrinsic motivation, extrinsic motivation, and demographic variables and the extent of active learning use in the classroom. An online survey was administered to individual faculty members at 137 colleges and schools of pharmacy across the United States. The survey assessed intrinsic and extrinsic motivations, active learning strategies, classroom time dedicated to active learning, and faculty development resources. Bivariate associations and multivariable stepwise linear regression were used to analyze the results. In total, 979 faculty members completed the questionnaire (23.6% response rate). All motivation variables were significantly correlated with percent active learning use (p < 0.001). Intrinsic motivation demonstrated the highest correlation (r = 0.447) followed by current extrinsic motivations (r = 0.245) and ideal extrinsic motivations (r = 0.291). Variables associated with higher intrinsic motivation included the number of resources used (r = 0.233, p < 0.001) and the number of active learning methods used in the last year (r = 0.259, p < 0.001). Years of teaching experience was negatively associated with intrinsic motivation (r = -0.177, p < 0.001). Regression analyses confirmed the importance of intrinsic and extrinsic motivations in predicting active learning use. Our results suggest that faculty members who are intrinsically motivated to use active learning are more likely to dedicate additional class time to active learning. Furthermore, intrinsic motivation may be positively associated with encouraging faculty members to attend active learning workshops and supporting faculty to use various active learning strategies in the classroom. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Intrinsic Brain Activity of Cognitively Normal Older Persons Resembles More That of Patients Both with and at Risk for Alzheimer's Disease Than That of Healthy Younger Persons

    PubMed Central

    Pasquini, Lorenzo; Tonch, Annika; Plant, Claudia; Zherdin, Andrew; Ortner, Marion; Kurz, Alexander; Förstl, Hans; Zimmer, Claus; Grimmer, Timo; Wohlschäger, Afra; Riedl, Valentin

    2014-01-01

    Abstract In Alzheimer's disease (AD), recent findings suggest that amyloid-β (Aβ)-pathology might start 20–30 years before first cognitive symptoms arise. To account for age as most relevant risk factor for sporadic AD, it has been hypothesized that lifespan intrinsic (i.e., ongoing) activity of hetero-modal brain areas with highest levels of functional connectivity triggers Aβ-pathology. This model induces the simple question whether in older persons without any cognitive symptoms intrinsic activity of hetero-modal areas is more similar to that of symptomatic patients with AD or to that of younger healthy persons. We hypothesize that due to advanced age and therefore potential impact of pre-clinical AD, intrinsic activity of older persons resembles more that of patients than that of younger controls. We tested this hypothesis in younger (ca. 25 years) and older healthy persons (ca. 70 years) and patients with mild cognitive impairment and AD-dementia (ca. 70 years) by the use of resting-state functional magnetic resonance imaging, distinct measures of intrinsic brain activity, and different hierarchical clustering approaches. Independently of applied methods and involved areas, healthy older persons' intrinsic brain activity was consistently more alike that of patients than that of younger controls. Our result provides evidence for larger similarity in intrinsic brain activity between healthy older persons and patients with or at-risk for AD than between older and younger ones, suggesting a significant proportion of pre-clinical AD cases in the group of cognitively normal older people. The observed link of aging and AD with intrinsic brain activity supports the view that lifespan intrinsic activity may contribute critically to the pathogenesis of AD. PMID:24689864

  16. High and Low Activity Rats: Elevated intrinsic physical activity drives resistance to diet induced obesity in non-bred rats

    PubMed Central

    Perez-Leighton, Claudio E.; Boland, Kelsey; Billington, Charles; Kotz, Catherine M.

    2012-01-01

    Humans and rodents show large variability in their individual sensitivity to diet-induced obesity, which has been associated with differences in intrinsic spontaneous physical activity (SPA). Evidence from genetic and out-bred rat obesity models shows that higher activity of the orexin peptides results in higher intrinsic SPA and protection against diet-induced obesity. Based on this, we hypothesized that naturally occurring variation in SPA and orexin signaling activity is sufficient to drive differences in sensitivity to diet-induced obesity. We analyzed orexin activity and sensitivity to diet-induced obesity in non-manipulated male Sprague Dawley rats selected for high and low intrinsic SPA. Our results defined a new model of differential DIO sensitivity, the high-activity and low activity-rats, and suggest that naturally occurring variations in intrinsic SPA cause differences in energy expenditure that are mediated by orexin signaling and alter DIO sensitivity. PMID:23404834

  17. SKILLED BIMANUAL TRAINING DRIVES MOTOR CORTEX PLASTICITY IN CHILDREN WITH UNILATERAL CEREBRAL PALSY

    PubMed Central

    Friel, Kathleen M.; Kuo, Hsing-Ching; Fuller, Jason; Ferre, Claudio L.; Brandão, Marina; Carmel, Jason B.; Bleyenheuft, Yannick; Gowatsky, Jaimie L.; Stanford, Arielle D.; Rowny, Stefan B.; Luber, Bruce; Bassi, Bruce; Murphy, David LK; Lisanby, Sarah H.; Gordon, Andrew M.

    2015-01-01

    Background Intensive bimanual therapy can improve hand function in children with unilateral spastic cerebral palsy (USCP). We compared the effects of structured bimanual skill training vs. unstructured bimanual practice on motor outcomes and motor map plasticity in children with USCP. Objective We hypothesized that structured skill training would produce greater motor map plasticity than unstructured practice. Methods Twenty children with USCP (average age 9,5; 12 males) received therapy in a day-camp-setting, 6 h/day, 5 days/week, for 3 weeks. In structured skill training (n=10), children performed progressively more difficult movements and practiced functional goals. In unstructured practice (n=10), children engaged in bimanual activities but did not practice skillful movements or functional goals. We used the Assisting Hand Assessment (AHA), Jebsen-Taylor test of Hand Function (JTTHF) and Canadian Occupational Performance Measure (COPM) to measure hand function. We used single-pulse transcranial magnetic stimulation (TMS) to map the representation of first dorsal interosseous (FDI) and flexor carpi radialis (FCR) muscles bilaterally. Results Both groups showed significant improvements in bimanual hand use (AHA; p<0.05) and hand dexterity (JTTHF; p<0.001). However, only the structured skill group showed increases in the size of the affected hand motor map and amplitudes of motor evoked potentials (p<0.01). Most children who showed the most functional improvements (COPM) had the largest changes in map size. Conclusions These findings uncover a dichotomy of plasticity: the unstructured practice group improved hand function but did not show changes in motor maps. Skill training is important for driving motor cortex plasticity in children with USCP. PMID:26867559

  18. Do people differentiate between intrinsic and extrinsic goals for physical activity?

    PubMed

    McLachlan, Sarah; Hagger, Martin S

    2011-04-01

    The distinction between intrinsic and extrinsic goals, and between goal pursuit for intrinsically and extrinsically motivated reasons, is a central premise of self-determination theory. Proponents of the theory have proposed that the pursuit of intrinsic goals and intrinsically motivated goal striving each predict adaptive psychological and behavioral outcomes relative to the pursuit of extrinsic goals and extrinsically motivated goal striving. Despite evidence to support these predictions, research has not explored whether individuals naturally differentiate between intrinsic and extrinsic goals. Two studies tested whether people make this differentiation when recalling goals for leisure-time physical activity. Using memory-recall methods, participants in Study 1 were asked to freely generate physical activity goals. A subsample (N = 43) was asked to code their freely generated goals as intrinsic or extrinsic. In Study 2, participants were asked to recall intrinsic and extrinsic goals after making a decision regarding their future physical activity. Results of these studies revealed that individuals' goal generation and recall exhibited significant clustering by goal type. Participants encountered some difficulties when explicitly coding goals. Findings support self-determination theory and indicate that individuals discriminate between intrinsic and extrinsic goals.

  19. A hybrid structured-unstructured grid method for unsteady turbomachinery flow computations

    NASA Technical Reports Server (NTRS)

    Mathur, Sanjay R.; Madavan, Nateri K.; Rajagopalan, R. G.

    1993-01-01

    A hybrid grid technique for the solution of 2D, unsteady flows is developed. This technique is capable of handling complex, multiple component geometries in relative motion, such as those encountered in turbomachinery. The numerical approach utilizes a mixed structured-unstructured zonal grid topology along with modeling equations and solution methods that are most appropriate in the individual domains, therefore combining the advantages of both structured and unstructured grid techniques.

  20. Exploring Hypersonic, Unstructured-Grid Issues through Structured Grids

    NASA Technical Reports Server (NTRS)

    Mazaheri, Ali R.; Kleb, Bill

    2007-01-01

    Pure-tetrahedral unstructured grids have been shown to produce asymmetric heat transfer rates for symmetric problems. Meanwhile, two-dimensional structured grids produce symmetric solutions and as documented here, introducing a spanwise degree of freedom to these structured grids also yields symmetric solutions. The effects of grid skewness and other perturbations of structured-grids are investigated to uncover possible mechanisms behind the unstructured-grid solution asymmetries. By using controlled experiments around a known, good solution, the effects of particular grid pathologies are uncovered. These structured-grid experiments reveal that similar solution degradation occurs as for unstructured grids, especially for heat transfer rates. Non-smooth grids within the boundary layer is also shown to produce large local errors in heat flux but do not affect surface pressures.

  1. An Innovative Whole Child Approach to Learning: The LiiNK Project®

    ERIC Educational Resources Information Center

    Rhea, Deborah; Bauml, Michellle

    2018-01-01

    Others' success can be a powerful motivation to innovate, which sometimes means finding new ways to return to beneficial activities. Finland's academic success has prompted many to explore that country's policies and practices, particularly regarding providing opportunities for children to enjoy more unstructured play.

  2. Ongoing Activities to Facilitate Access to Supplementary Materials for Cartographic Education.

    ERIC Educational Resources Information Center

    Anderson, Paul S.

    A wealth of unpublished or unstructured educational materials for all aspects of cartographic instruction are widely dispersed and unnecessarily difficult to obtain. The Cartography Assistance Brochures Project of the Cartography Specialty Group of the Association of American Geographers (AAG), the North American Cartographic Information Society,…

  3. Effects of Temperature, Salinity and Seed Age on Induction of Zostera japonica Germination in North America, USA

    EPA Science Inventory

    Seagrasses can colonize unstructured mudflats either through clonal growth or seed germination and survival. Zostera japonica is an introduced seagrass in North America that has rapidly colonized mudflats along the Pacific Coast, leading to active management of the species. Gro...

  4. Intrinsic Motivation.

    ERIC Educational Resources Information Center

    Deci, Edward L.

    The paper draws together a wide variety of research which relates to the topic of intrinsic motivation; intrinsically motivated activities are defined as those which a person does for no apparent reward except the activity itself or the feelings which result from the activity. Most of this research was not originally reported within the framework…

  5. Unstructured mesh generation and adaptivity

    NASA Technical Reports Server (NTRS)

    Mavriplis, D. J.

    1995-01-01

    An overview of current unstructured mesh generation and adaptivity techniques is given. Basic building blocks taken from the field of computational geometry are first described. Various practical mesh generation techniques based on these algorithms are then constructed and illustrated with examples. Issues of adaptive meshing and stretched mesh generation for anisotropic problems are treated in subsequent sections. The presentation is organized in an education manner, for readers familiar with computational fluid dynamics, wishing to learn more about current unstructured mesh techniques.

  6. Galerkin finite difference Laplacian operators on isolated unstructured triangular meshes by linear combinations

    NASA Technical Reports Server (NTRS)

    Baumeister, Kenneth J.

    1990-01-01

    The Galerkin weighted residual technique using linear triangular weight functions is employed to develop finite difference formulae in Cartesian coordinates for the Laplacian operator on isolated unstructured triangular grids. The weighted residual coefficients associated with the weak formulation of the Laplacian operator along with linear combinations of the residual equations are used to develop the algorithm. The algorithm was tested for a wide variety of unstructured meshes and found to give satisfactory results.

  7. Improving Urban Minority Girls' Health Via Community Summer Programming.

    PubMed

    Bohnert, Amy M; Bates, Carolyn R; Heard, Amy M; Burdette, Kimberly A; Ward, Amanda K; Silton, Rebecca L; Dugas, Lara R

    2017-12-01

    Summertime has emerged as a high-risk period for weight gain among low-income minority youth who often experience a lack of resources when not attending school. Structured programming may be an effective means of reducing risk for obesity by improving obesogenic behaviors among these youth. The current multi-method study examined sedentary time, physical activity, and dietary intake among low-income urban minority girls in two contexts: an unstructured summertime setting and in the context of a structured 4-week community-based summer day camp program promoting physical activity. Data were analyzed using paired-sample t tests and repeated-measure analyses of variance with significance at the p < .05 level. Results evidenced no significant differences in total calories and fat consumed between the unstructured and structured settings. Participants exhibited significant increases in fruit consumption and physical activity and significant decreases in sedentary time of over 2 h/day and dairy consumption when engaged in structured summer programming. All improvements were independent of weight status and age, and African-American participants evidenced greater changes in physical activity during programming. The study concludes that structured, community-based summertime programming may be associated with fewer obesogenic behaviors in low-income urban youth and may be a powerful tool to address disparities in weight gain and obesity among high-risk samples.

  8. Hydration and conformational mechanics of single, end-tethered elastin-like polypeptides.

    PubMed

    Valiaev, Alexei; Lim, Dong Woo; Schmidler, Scott; Clark, Robert L; Chilkoti, Ashutosh; Zauscher, Stefan

    2008-08-20

    We investigated the effect of temperature, ionic strength, solvent polarity, and type of guest residue on the force-extension behavior of single, end-tethered elastin-like polypeptides (ELPs), using single molecule force spectroscopy (SMFS). ELPs are stimulus-responsive polypeptides that contain repeats of the five amino acids Val-Pro-Gly-Xaa-Gly (VPGXG), where Xaa is a guest residue that can be any amino acid with the exception of proline. We fitted the force-extension data with a freely jointed chain (FJC) model which allowed us to resolve small differences in the effective Kuhn segment length distributions that largely arise from differences in the hydrophobic hydration behavior of ELP. Our results agree qualitatively with predictions from recent molecular dynamics simulations and demonstrate that hydrophobic hydration modulates the molecular elasticity for ELPs. Furthermore, our results show that SMFS, when combined with our approach for data analysis, can be used to study the subtleties of polypeptide-water interactions and thus provides a basis for the study of hydrophobic hydration in intrinsically unstructured biomacromolecules.

  9. Structural Landscape of the Proline-Rich Domain of Sos1 Nucleotide Exchange Factor

    PubMed Central

    McDonald, Caleb B.; Bhat, Vikas; Kurouski, Dmitry; Mikles, David C.; Deegan, Brian J.; Seldeen, Kenneth L.; Lednev, Igor K.; Farooq, Amjad

    2013-01-01

    Despite its key role in mediating a plethora of cellular signaling cascades pertinent to health and disease, little is known about the structural landscape of the proline-rich (PR) domain of Sos1 guanine nucleotide exchange factor. Herein, using a battery of biophysical tools, we provide evidence that the PR domain of Sos1 is structurally disordered and adopts an extended random coil-like conformation in solution. Of particular interest is the observation that while chemical denaturation of PR domain results in the formation of a significant amount of polyproline II (PPII) helices, it has little or negligible effect on its overall size as measured by its hydrodynamic radius. Our data also show that the PR domain displays a highly dynamic conformational basin in agreement with the knowledge that the intrinsically unstructured proteins rapidly interconvert between an ensemble of conformations. Collectively, our study provides new insights into the conformational equilibrium of a key signaling molecule with important consequences on its physiological function. PMID:23528987

  10. Binding-induced Folding of Prokaryotic Ubiquitin-like Protein on the Mycobacterium Proteasomal ATPase Targets Substrates for Degradation

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

    T Wang; K Heran Darwin; H Li

    2011-12-31

    Mycobacterium tuberculosis uses a proteasome system that is analogous to the eukaryotic ubiquitin-proteasome pathway and is required for pathogenesis. However, the bacterial analog of ubiquitin, prokaryotic ubiquitin-like protein (Pup), is an intrinsically disordered protein that bears little sequence or structural resemblance to the highly structured ubiquitin. Thus, it was unknown how pupylated proteins were recruited to the proteasome. Here, we show that the Mycobacterium proteasomal ATPase (Mpa) has three pairs of tentacle-like coiled coils that recognize Pup. Mpa bound unstructured Pup through hydrophobic interactions and a network of hydrogen bonds, leading to the formation of an {alpha}-helix in Pup. Ourmore » work describes a binding-induced folding recognition mechanism in the Pup-proteasome system that differs mechanistically from substrate recognition in the ubiquitin-proteasome system. This key difference between the prokaryotic and eukaryotic systems could be exploited for the development of a small molecule-based treatment for tuberculosis.« less

  11. Binding-induced folding of prokaryotic ubiquitin-like protein on the mycobacterium proteasomal ATPase targets substrates for degradation

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

    Wang, T.; Li, H.; Darwin, K. H.

    2010-11-01

    Mycobacterium tuberculosis uses a proteasome system that is analogous to the eukaryotic ubiquitin-proteasome pathway and is required for pathogenesis. However, the bacterial analog of ubiquitin, prokaryotic ubiquitin-like protein (Pup), is an intrinsically disordered protein that bears little sequence or structural resemblance to the highly structured ubiquitin. Thus, it was unknown how pupylated proteins were recruited to the proteasome. Here, we show that the Mycobacterium proteasomal ATPase (Mpa) has three pairs of tentacle-like coiled coils that recognize Pup. Mpa bound unstructured Pup through hydrophobic interactions and a network of hydrogen bonds, leading to the formation of an {alpha}-helix in Pup. Ourmore » work describes a binding-induced folding recognition mechanism in the Pup-proteasome system that differs mechanistically from substrate recognition in the ubiquitin-proteasome system. This key difference between the prokaryotic and eukaryotic systems could be exploited for the development of a small molecule-based treatment for tuberculosis.« less

  12. Synthesis of Intrinsically Disordered Fluorinated Peptides for Modular Design of High-Signal 19 F MRI Agents.

    PubMed

    Kirberger, Steven E; Maltseva, Sofia D; Manulik, Joseph C; Einstein, Samuel A; Weegman, Bradley P; Garwood, Michael; Pomerantz, William C K

    2017-06-01

    19 F MRI is valuable for in vivo imaging due to the only trace amounts of fluorine in biological systems. Because of the low sensitivity of MRI however, designing new fluorochemicals remains a significant challenge for achieving sufficient 19 F signal. Here, we describe a new class of high-signal, water-soluble fluorochemicals as 19 F MRI imaging agents. A polyamide backbone is used for tuning the proteolytic stability to avoid retention within the body, which is a limitation of current state-of-the-art perfluorochemicals. We show that unstructured peptides containing alternating N-ϵ-trifluoroacetyllysine and lysine provide a degenerate 19 F NMR signal. 19 F MRI phantom images provide sufficient contrast at micromolar concentrations, showing promise for eventual clinical applications. Finally, the degenerate high signal characteristics were retained when conjugated to a large protein, indicating potential for in vivo targeting applications, including molecular imaging and cell tracking. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Digital Pharmacovigilance and Disease Surveillance: Combining Traditional and Big-Data Systems for Better Public Health.

    PubMed

    Salathé, Marcel

    2016-12-01

    The digital revolution has contributed to very large data sets (ie, big data) relevant for public health. The two major data sources are electronic health records from traditional health systems and patient-generated data. As the two data sources have complementary strengths-high veracity in the data from traditional sources and high velocity and variety in patient-generated data-they can be combined to build more-robust public health systems. However, they also have unique challenges. Patient-generated data in particular are often completely unstructured and highly context dependent, posing essentially a machine-learning challenge. Some recent examples from infectious disease surveillance and adverse drug event monitoring demonstrate that the technical challenges can be solved. Despite these advances, the problem of verification remains, and unless traditional and digital epidemiologic approaches are combined, these data sources will be constrained by their intrinsic limits. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America.

  14. The LC Domain of hnRNPA2 Adopts Similar Conformations in Hydrogel Polymers, Liquid-like Droplets and Nuclei

    PubMed Central

    Xiang, Siheng; Kato, Masato; Wu, Leeju; Lin, Yi; Ding, Ming; Zhang, Yajie; Yu, Yonghao; McKnight, Steven L.

    2016-01-01

    SUMMARY Many DNA and RNA regulatory proteins contain polypeptide domains that are unstructured when analyzed in cell lysates. These domains are typified by an over-representation of a limited number of amino acids and have been termed prion-like, intrinsically disordered or low complexity (LC) domains. When incubated at high concentration, certain of these LC domains polymerize into labile, amyloid-like fibers. Here we report methods allowing the generation of a molecular footprint of the polymeric state of the LC domain of hnRNPA2. By deploying this footprinting technique to probe the structure of the native hnRNPA2 protein present in isolated nuclei, we offer evidence that its LC domain exists in a similar conformation as that described for recombinant polymers of the protein. These observations favor biologic utility to the polymerization of LC domains in the pathway of information transfer from gene to message to protein. PMID:26544936

  15. The Contribution of the Division of Radiophysics Murraybank Field Station to International Radio Astronomy

    NASA Astrophysics Data System (ADS)

    Wendt, Harry; Orchiston, Wayne; Slee, Bruce

    During the 1950s Australia was one of the world's foremost astronomical nations owing primarily to the work of the dynamic radio astronomy group within the Commonwealth Scientific and Industrial Research Organisation's Division of Radiophysics. Most of the observations were made at the network of field stations maintained by the Division in or near Sydney, and one of these field stations was Murraybank in the north-western suburbs of Sydney. GVaucouleursDe1954The Magellanic Clouds and the GalaxyThe Observatory7423311954Obs....74...23DDe Vaucouleurs, G., 1954a. The Magellanic Clouds and the Galaxy. The Observatory, 74, 23-31. GVaucouleursDe1954The Magellanic Clouds and the Galaxy, IIThe Observatory741581641954Obs....74..158DDe Vaucouleurs, G., 1954b. The Magellanic Clouds and the Galaxy, II. The Observatory, 74, 158-164. GVaucouleursDe1961Classification and radial velocities of bright southern galaxiesMemoirs of the Royal Astronomical Society6869871961MmRAS..68...69DDe Vaucouleurs, G., 1961. Classification and radial velocities of bright southern galaxies. Memoirs of the Royal Astronomical Society, 68, 69-87. JDeane2006Vacuum Tube SupercomputerSydneyScience Foundation for Physics and the Australian Computer Museum SocietyDeane, J., 2006. Vacuum Tube Supercomputer. Sydney, Science Foundation for Physics and the Australian Computer Museum Society. NHDeiter1965Neutral hydrogen near the galactic polesAstErickson, W.C., Helfer, H.L., and Tatel, H.E., 1959. A survey of neutral hydrogen at high galactic latitudes. In Bracewell, 390-397. MWFeastADThackerayAJWesselink1957Radial velocities of southern B stars determined at the Radcliffe Observatory (Paper II) (summary)Monthly Notices of the Royal Astronomical Society1175791957MNRAS.117..579FFeast, M.W., Thackeray, A.D., and Wesselink, A.J., 1957. Radial velocities of southern B stars determined at the Radcliffe Observatory (Paper II) (summary). Monthly Notices of the Royal Astronomical Society, 117, 579. KCFreeman1970On the disks of spiral and SO galaxiesAstrophysical Journal1608118301970ApJ...160..811F10.1086/150474Freeman, K.C., 1970. On the disks of spiral and SO galaxies. Astrophysical Journal, 160, 811-830. Getmanzev, G.G., Tankevitch, K.S., and Troitzky, V.S., 1957. Detection of the spectral line of deuterium from the centre of the Galaxy on the wave-length of 91.6 cm. In van de Hulst, 90-91. HCGoldwireMGoss1967Microwave radiation of singly charged helium 3 from HII regionsAstrophysical Journal14915221967ApJ...149...15G10.1086/149225Goldwire, H.C., and Goss, M., 1967. Microwave radiation of singly charged helium 3 from HII regions. Astrophysical Journal, 149, 15-22. JLGreenstein1937The effect of absorbing clouds on the general absorption coefficientAnnals of the Astronomical Observatory of Harvard College105359369Greenstein, J.L., 1937. The effect of absorbing clouds on the general absorption coefficient. Annals of the Astronomical Observatory of Harvard College, 105, 359-369. CSGum1956The extent and excitation of the large H II region in Vela-PuppisThe Observatory761501531956Obs....76..150GGum, C.S., 1956. The extent and excitation of the large H II region in Vela-Puppis. The Observatory, 76, 150-153. KGHenize1956Catalogues of Hα-emission stars and nebulae in the Magellanic CloudsAstrophysical Journal Supplement23153441956ApJS....2..315H10.1086/190025Henize, K.G., 1956. Catalogues of Hα-emission stars and nebulae in the Magellanic Clouds. Astrophysical Journal Supplement, 2, 315-344. JVHindman1967A high resolution study of the distribution and motions of neutral hydrogen in the Small Cloud of MagellanAustralian Journal of Physics201471711967AuJPh..20..147H10.1071/PH670147Hindman, J.V., 1967. A high resolution study of the distribution and motions of neutral hydrogen in the Small Cloud of Magellan. Australian Journal of Physics, 20, 147-171. Hindman, J.V., Kerr, F.J., and McGee, R.X., 1963a. A low resolution hydrogen-line survey of the Magellanic system. II. Interpretation of results. Australian Journal of Physics, 16, 570-583. Hindman, J.V., McGee, R.X., Carter, A.W.L., Holmes, E.C.J., and Beard, M., 1963b. A low resolution hydrogen-line survey of the Magellanic system. I. Observations and digital reduction procedures. Australian Journal of Physics, 16, 552-569. Hodge, P.W., 1960. Studies of the Large Magellanic Cloud. I. The red globular clusters. Astrophysical Journal, 131, 351-357. Hodge, P.W., 1961. Studies of the Large Magellanic Cloud. V. The young populous clusters. Astrophysical Journal, 133, 413-419. WEHowardDGWentzelRXMcGee1963On a correlation between the radial velocities of optical and radio interstellar linesAstrophysical Journal13898810011963ApJ...138..988H10.1086/147700Howard, W.E., Wentzel, D.G., and McGee, R.X., 1963. On a correlation between the radial velocities of optical and radio interstellar lines. Astrophysical Journal, 138, 988-1001. HMJohnson1961The structure of the Small Magellanic CloudProceedings of the Astronomical Society of the Pacific7320281961PASP...73...20J10.1086/127613Johnson, H.M., 1961. The structure of the Small Magellanic Cloud. Proceedings of the Astronomical Society of the Pacific, 73, 20-28. KIKellermanWOrchistonBSlee2005Gordon James Stanley and the early development of radio astronomy in Australia and the United StatesPublications of the Astronomical Society of Australia2213232005PASA...22...13K10.1071/AS04008Kellerman, K.I., Orchiston, W., and Slee, B., 2005. Gordon James Stanley and the early development of radio astronomy in Australia and the United States. Publications of the Astronomical Society of Australia, 22, 13-23. Kerr, F.J., 1953. Minutes of the Hydrogen-Line Planning Committee Meeting dated 12 November. National Archives of Australia, Sydney, 972420 - C3830 - A1/3/17 Part 1. Kerr, F.J., 1954. Minutes of the Hydrogen Line Planning Committee Meeting dated 9 June. National Archives of Australia, Sydney, 972420 - C3830 - A1/3/17 Part 2. FJKerr1962Galactic velocity models and the interpretation of 21-cm surveysMonthly Notices of the Royal Astronomical Society1233273451962MNRAS.123..327KKerr, F.J., 1962. Galactic velocity models and the interpretation of 21-cm surveys. Monthly Notices of the Royal Astronomical Society, 123, 327-345. FJKerrJVHindmanBJRobinson1954Observations of the 21 cm line from the Magellanic CloudsAustralian Journal of Physics72973141954AuJPh...7..297K10.1071/PH540297Kerr, F.J., Hindman, J.V., and Robinson, B J., 1954. Observations of the 21 cm line from the Magellanic Clouds. Australian Journal of Physics, 7, 297-314. JVKuilenburg1972A systematic search for high-velocity hydrogen outside the Galactic Plane IIAstronomy and Astrophysics162761972A&A....16..276VKuilenburg, J.V., 1972. A systematic search for high-velocity hydrogen outside the Galactic Plane II. Astronomy and Astrophysics, 16, 276. KKKweeCAMullerGWesterhout1954The rotation of the inner parts of the galactic systemBulletin of the Astronomical Institutes of the Netherlands122112221954BAN....12..211KKwee, K.K., Muller, C.A., and Westerhout, G., 1954. The rotation of the inner parts of the galactic system. Bulletin of the Astronomical Institutes of the Netherlands, 12, 211-222. EMLindsay1958The cluster system of the Small Magellanic CloudMonthly Notices of the Royal Astronomical Society1181721821958MNRAS.118..172LLindsay, E.M., 1958. The cluster system of the Small Magellanic Cloud. Monthly Notices of the Royal Astronomical Society, 118, 172-182. EMLindsay1961A new catalogue of emission-line stars and planetary nebulae in the SmaDSMathewsonMNClearyJDMurray1974The Magellanic StreamAstrophysical Journal1902912961974ApJ...190..291M10.1086/152875Mathewson, D.S., Cleary, M.N., and Murray, J.D., 1974. The Magellanic Stream. Astrophysical Journal, 190, 291-296. Mathewson, D.S., Healey, J.R., and Rome, J.M., 1962. A radio survey of the southern Milky Way at a frequency of 1440 Mc/s. II. The continuum emission from the Galactic disk. Australian Journal of Physics, 15, 369-377. DSMathewsonSRWayteVLFordKRuan1987The `high velocity cloud' origin of the Magellanic systemProceedings of the Astronomical Society of Australia719251987PASAu...7...19MMathewson, D.S., Wayte, S.R., Ford, V.L., and Ruan, K., 1987. The `high velocity cloud' origin of the Magellanic system. Proceedings of the Astronomical Society of Australia, 7, 19-25. NMMcClure-GriffithsLStaveley-SmithFJLockmanMRCalabrettaHAFordPMWKalberlaTMurphyHNakanishiDJPisano2008An interaction of a Magellanic leading arm high-velocity cloud with the Milky Way diskAstrophysical Journal673L143L1462008ApJ...673L.143M10.1086/528683McClure-Griffiths, N.M., Staveley-Smith, L., Lockman, F.J., Calabretta, M.R., Ford, H.A., Kalberla, P.M. W., Murphy, T., Nakanishi, H., and Pisano, D.J., 2008. An interaction of a Magellanic leading arm high-velocity cloud with the Milky Way disk. Astrophysical Journal, 673, L143-L146. McCready, L.L., 1954. Letter to J.L. Pawsey, dated 19 August. National Archives of Australia, Sydney, 974347 - C3830 - F1/4/PAW/1. McCready, L.L., 1957. Letter to J.L. Pawsey, dated 28 October. National Archives of Australia, Sydney, 974347 - C3830 - F1/4/PAW/1. RXMcGee1964Large HI clouds in the GalaxyFJKerrThe Galaxy and the Magellanic Clouds. Proceedings of the International Astronomical Union Symposium No. 20 Held in Canberra March 18-28, 1963Australian Academy of Science. PpCanberra126130McGee, R.X., 1964. Large HI clouds in the Galaxy. In Kerr, F.J. (ed.). The Galaxy and the Magellanic Clouds. Proceedings of the International Astronomical Union Symposium No. 20 Held in Canberra March 18-28, 1963. Canberra, Australian Academy of Science. Pp. 126-130. McGee, R.X., and Milton, J.A., 1964. A sky survey of neutral hydrogen at λ 21 cm. III. Gas at higher radial velocities. Australian Journal of Physics, 17, 128-157. RXMcGeeJDMurray1961McGee, R.X., and Murray, J.D., 1961b. A sky survey of neutral hydrogen at λ 21 cm I. The general distribution and motions of the local gas. Australian Journal of Physics, 14, 260-278. McGee, R.X., Murray, J.D., and Milton, J.A., 1963. A sky survey of neutral hydrogen at λ 21 cm. II. The detailed distribution of low velocity gas. Australian Journal of Physics, 16, 136-170. RXMcGeeJDMurrayJLPawsey1961Streaming of interstellar hydrogen in the vicinity of the SunNature1899579591961Natur.189..957M10.1038/189957a0McGee, R.X., Murray, J.D., and Pawsey, J.L., 1961. Streaming of interstellar hydrogen in the vicinity of the Sun. Nature, 189, 957-959. KMMentenMJReidJForbrichABrunthaler2007The distance to the Orion NebulaAstronomy and Astrophysics4745155202007A&A...474..515M10.1051/0004-6361:20078247Menten, K.M., Reid, M.J., Forbrich, J., and Brunthaler, A., 2007. The distance to the Orion Nebula. Astronomy and Astrophysics, 474, 515-520. CAMullerGWesterhout1957A catalogue of 21-cm line profilesBulletin of the Astronomical Institutes of the Netherlands131511951957BAN....13..151MMuller, C.A., and Westerhout, G., 1957. A catalogue of 21-cm line profiles. Bulletin of the Astronomical Institutes of the Netherlands, 13, 151-195. JDMurrayRXMcGee1958A new hydrogen cloud in Pyxis-HydraThe Observatory782422441958Obs....78..242MMurray, J.D., and McGee, R.X., 1958. A new hydrogen cloud in Pyxis-Hydra. The Observatory, 78, 242-244. JDMurrayRXMcGee1959Neutral hydrogen gas in the Taurus-Orion region observed with a multichannel 21 cm line receiverAustralian Journal of Physics121271331959AuJPh..12..127M10.1071/PH590127Murray, J.D., and McGee, R.X., 1959. Neutral hydrogen gas in the Taurus-Orion region observed with a multichannel 21 cm line receiver. Australian Journal of Physics, 12, 127-133. JDMurrayRXMcGee1963A multi-channel hydrogen line (21 cm) receiverProceedings of the Institute of Radio Engineers Australia24191196Murray, J.D., and McGee, R.X., 1963. A multi-channel hydrogen line (21 cm) receiver. Proceedings of the Institute of Radio Engineers Australia, 24, 191-196. AOllongrenHCHulstvan de1957Corrections of 21-cm line profilesBulletin of the Astronomical Institutes of the Netherlands131962001957BAN....13..196OOllongren, A., and van de Hulst, H.C., 1957. Corrections of 21-cm line profiles. Bulletin of the Astronomical Institutes of the Netherlands, 13, 196-200. WOrchiston1993New Zealand's role in the identification of the first "radio stars"Southern Stars3546521993SouSt..35...46OOrchiston, W., 1993. New Zealand's role in the identification of the first "radio stars." Southern Stars, 35, 46-52. WOrchiston1994John Bolton, discrete sources, and the New Zealand field-trip of 1948Australian Journal of Physics475415471994AuJPh..47..541OOrchiston, W., 1994. John Bolton, discrete sources, and the New Zealand field-trip of 1948. Australian Journal of Physics, 47, 541-547 Orchiston, W., 2004. The rise and fall of the Chris Cross: a pioneering Australian radio telescope. In Orchiston, W., Stephenson, R., Debarbat, S., and Nha, I.-S. (eds.). Astronomical Instruments and Archives from the Asia-Pacific Region. Seoul, IAU Commission 41. Pp. 157-162. WOrchistonDMathewson2009Chris Christiansen and the Chris CrossJournal of Astronomical History and Heritage1211322009JAHH...12...11OOrchiston, W., and Mathewson, D., 2009. Chris Christiansen and the Chris Cross. Journal of Astronomical History and Heritage, 12, 11-32. WOrchistonBSlee2002Ingenuity and initiative in Australian radio astronomy: the Dover Heights `hole-in-the-ground' antennaJournal of Astronomical History and Heritage521342002JAHH....5...21OOrchiston, W., and Slee, B., 2002. Ingenuity and initiative in Australian radio astronomy: the Dover Heights `hole-in-the-ground' antenna. Journal of Astronomical History and Heritage, 5, 21-34. WOrchistonBSlee2005The Radiophysics field stations and the early development of radio astronomyWOrchistonThe New Astronomy: Opening the Electromagnetic Window and Expanding our View of Planet EarthSpringer. PpDordrecht11916810.1007/1-4020-3724-4_8Orchiston, W., and Slee, B., 2005. The Radiophysics field stations and the early development of radio astronomy. In Orchiston, W. (ed.). The New Astronomy: Opening the Electromagnetic Window and Expanding our View of Planet Earth. Dordrecht, Springer. Pp. 119-168. WOrchistonTNakamuraRStrom2011Highlighting the History of Astronomy in the Asia-Pacific RegionNew YorkSpringerOrchiston, W., Nakamura, T., and Strom, R. (eds.), 2011. Highlighting the History of Astronomy in the Asia-Pacific Region. New York, Springer. AEERodgersKADudevoirJCCarterBJFanousEKratzenberg2005Deuterium abundance in the interstellar gas of the Galactic Anticentre from the 327 MHz LineAstrophysical Journal630L41L442005ApJ...630L..41R10.1086/466524Rodgers, A.E.E., Dudevoir, K.A., Carter, J.C., Fanous, B.J., and Kratzenberg, E., 2005. Deuterium abundance in the interstellar gas of the Galactic Anticentre from the 327 MHz Line. Astrophysical Journal, 630, L41-L44. VCRubinWKFord1970Rotation of the Andromeda Nebula from a spectroscopic survey of emission regionsAstrophysical Journal1593794031970ApJ...159..379R10.1086/150317Rubin, V.C., and Ford, W.K., 1970. Rotation of the Andromeda Nebula from a spectroscopic survey of emission regions. Astrophysical Journal, 159, 379-403. MSchmidt1957Spiral structure in the inner parts of the galactic system derived from the hydrogen emission at 21-cm wavelengthBulletin of the Astronomical Institutes of the Netherlands132472681957BAN....13..247SSchmidt, M., 1957. Spiral structure in the inner parts of the galactic system derived from the hydrogen emission at 21-cm wavelength. Bulletin of the Astronomical Institutes of the Netherlands, 13, 247-268. GAShain1957The inclination to the Galactic Equator of the general magnetic field of LSSparkeJSGallagher2000Galaxies in the Universe: An IntroductionCambridge University PressCambridgeSparke, L.S., and Gallagher, J.S., 2000. Galaxies in the Universe: An Introduction, Cambridge, Cambridge University Press. SStanimirovicLStaveley-SmithJMDickeyRJSaultSLSnowden1999The large-scale HI structure of the Small Magellanic CloudMonthly Notices of the Royal Astronomical Society3024174361999MNRAS.302..417S10.1046/j.1365-8711.1999.02013.xStanimirovic, S., Staveley-Smith, L., Dickey, J.M., Sault, R.J., and Snowden, S.L., 1999. The large-scale HI structure of the Small Magellanic Cloud. Monthly Notices of the Royal Astronomical Society, 302, 417-436. GJStanleyRPrice1956An investigation of monochromatic radio emission of deuterium from the GalaxyNature177122112221956Natur.177.1221S10.1038/1771221a0Stanley, G.J., and Price, R., 1956. An investigation of monochromatic radio emission of deuterium from the Galaxy. Nature, 177, 1221-1222. Stanley, G.J., 1994. Recollections of John G. Bolton at Dover Heights and Caltech. Australian Journal of Physics, 47, 507-516. WTSullivan2009Cosmic Noise. A History of Early Radio AstronomyCambridge University PressCambridgeSullivan, W.T., 2009. Cosmic Noise. A History of Early Radio Astronomy. Cambridge, Cambridge University Press. Townes, C.H., 1957. Microwave and radio-frequency resonance lines of interest to radio astronomy. In van de Hulst, 92-103. HCHulstvan de1957Radio Astronomy, Proceedings from 4th IAU Symposium. International Astronomical UnionCambridgeCambridge University Pressvan de Hulst, H.C. (ed.), 1957. Radio Astronomy, Proceedings from 4th IAU Symposium. International Astronomical Union. Cambridge, Cambridge University Press. HCHulstvan de1958Density and velocity distribution of the interstellar gasReviews of Modern Physics309139231958RvMP...30..913V10.1103/RevModPhys.30.913van de Hulst, H.C., 1958. Density and velocity distribution of the interstellar gas. Reviews of Modern Physics, 30, 913-923. HCHulstvan deCAMullerJHOort1954The spiral structure of the outer part of the galactic system derived from the hydrogen emission at 21 cm wavelengthBulletin of the Astronomical Institutes of the Netherlands121171491954BAN....12..117Vvan de Hulst, H.C., Muller, C.A., and Oort, J.H., 1954. The spiral structure of the outer part of the galactic system derived from the hydrogen emission at 21 cm wavelength. Bulletin of the Astronomical Institutes of the Netherlands, 12, 117-149. HWoerdenvanRStrom2006The beginnings of radio astronomy in the NetherlandsJournal of Astronomical History and Heritage93202006JAHH....9....3Vvan Woerden, H., and Strom, R., 2006. The beginnings of radio astronomy in the Netherlands. Journal of Astronomical History and Heritage, 9, 3-20. PWannierGTWrixon1972An unusual high-velocity hydrogen featureAstrophysical Journal1731191231972ApJ...173L.119W10.1086/180930Wannier, P., and Wrixon, G.T., 1972. An unusual high-velocity hydrogen feature. Astrophysical Journal, 173, 119-123. Wendt, H.W., 2008. The Contribution of the CSIRO Division of Radiophysics Potts Hill and Murraybank Field Stations to International Radio Astronomy. Ph.D. Thesis, Centre for Astronomy, James Cook University, Townsville, Australia. Wendt, H., Orchiston, W., and Slee, B., 2008. W.N. Christiansen and the initial Australian investigation of the 21cm hydrogen line. Journal of Astronomical History and Heritage, 11, 185-193. Wendt, H.W., Orchiston, W., and Slee, W., 2011a. The contribution of the Division of Radiophysics Potts Hill field station to international radio astronomy. In Orchiston et al., 379-431. Wendt, H., Orchiston, W., and Slee, B., 2011b. The contribution of W.N. Christiansen to radio astronomy: 1948-1960. In Orchiston et al., 547-587. GWesterhout1957The distribution of atomic hydrogen in the outer parts of the galactic systemBulletin of the Astronomical Institutes of the Netherlands132012461957BAN....13..201WWesterhout, G., 1957. The distribution of atomic hydrogen in the outer parts of the galactic system. Bulletin of the Astronomical Institutes of the Netherlands, 13, 201-246. GWesterhout1958A survey of the continuous radiation from the galactic system at a frequency of 1390 Mc/sBulletin of the Astronomical Institutes of the Netherlands142152601958BAN....14..215WWesterhout, G., 1958. A survey of the continuous radiation from the galactic system at a frequency of 1390 Mc/s. Bulletin of the Astronomical Institutes of the Netherlands, 14, 215-260. JPWild1952The radio-frequency line spectrum of atomic hydrogen and its applications in astronomyAstrophysical Journal1152062211952ApJ...115..206W10.1086/145533Wild, J.P., 1952. The radio-frequency line spectrum of atomic hydrogen and its applications in astronomy. Astrophysical Journal, 115, 206-221.

  16. Unstructured mesh algorithms for aerodynamic calculations

    NASA Technical Reports Server (NTRS)

    Mavriplis, D. J.

    1992-01-01

    The use of unstructured mesh techniques for solving complex aerodynamic flows is discussed. The principle advantages of unstructured mesh strategies, as they relate to complex geometries, adaptive meshing capabilities, and parallel processing are emphasized. The various aspects required for the efficient and accurate solution of aerodynamic flows are addressed. These include mesh generation, mesh adaptivity, solution algorithms, convergence acceleration, and turbulence modeling. Computations of viscous turbulent two-dimensional flows and inviscid three-dimensional flows about complex configurations are demonstrated. Remaining obstacles and directions for future research are also outlined.

  17. Multigrid solution of internal flows using unstructured solution adaptive meshes

    NASA Technical Reports Server (NTRS)

    Smith, Wayne A.; Blake, Kenneth R.

    1992-01-01

    This is the final report of the NASA Lewis SBIR Phase 2 Contract Number NAS3-25785, Multigrid Solution of Internal Flows Using Unstructured Solution Adaptive Meshes. The objective of this project, as described in the Statement of Work, is to develop and deliver to NASA a general three-dimensional Navier-Stokes code using unstructured solution-adaptive meshes for accuracy and multigrid techniques for convergence acceleration. The code will primarily be applied, but not necessarily limited, to high speed internal flows in turbomachinery.

  18. Perceptions about exercise and intrinsic motivation of students attending a health-related physical education program.

    PubMed

    Papacharisis, Vassilios; Goudas, Marios

    2003-12-01

    The present study examined effects of sex, attitude towards physical activity, perceived barriers for participation in physical activity, and students' perception of their parents' participation in physical activity on the intrinsic motivation of students participating in a health related program in physical education. 643 students (303 boys and 340 girls) responded to questionnaires measuring intrinsic motivation, attitudes towards physical activity, perceived barriers to exercise and perceived parents' participation in physical activity. Mean age was 12.9 yr. (SD=1.2, range 11-14 years). Analysis indicated that students' intrinsic motivation towards the program was influenced by perceived barriers to exercise. Sex, attitudes towards physical activity, and perceived parents' participation in physical activity seem to be less important.

  19. Quantum Cosmology

    NASA Astrophysics Data System (ADS)

    Bojowald, Martin

    The universe, ultimately, is to be described by quantum theory. Quantum aspects of all there is, including space and time, may not be significant for many purposes, but are crucial for some. And so a quantum description of cosmology is required for a complete and consistent worldview. At any rate, even if we were not directly interested in regimes where quantum cosmology plays a role, a complete physical description could not stop at a stage before the whole universe is reached. Quantum theory is essential in the microphysics of particles, atoms, molecules, solids, white dwarfs and neutron stars. Why should one expect this ladder of scales to end at a certain size? 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Gen.3212316685761999JPhA...32..123G0919.4706110.1088/0305-4470/32/1/013arXiv:1011.3022Gazeau, J.P., Klauder, J.: J. Phys. A: Math. Gen. 32, 123 (1999) 4.M.NovelloS.E.P.Bergliaffa2008Phys. Rep.46312724370502008PhR...463..127N10.1016/j.physrep.2008.04.006Novello, M., Bergliaffa, S.E.P.: Phys. Rep. 463, 127 (2008) 5.M.Bojowald2010Canonical Gravity and Applications: Cosmology, Black Holes, and Quantum GravityCambridge University PressCambridge10.1017/CBO9780511921759Bojowald, M.: Canonical Gravity and Applications: Cosmology, Black Holes, and Quantum Gravity. Cambridge University Press, Cambridge (2010) 6.A.Ashtekar1987Phys. Rev. D36615879096671987PhRvD..36.1587A10.1103/PhysRevD.36.1587Ashtekar, A.: Phys. Rev. D 36(6), 1587 (1987) 7.Barbero G.J.F., (1995) Phys. Rev. D 51(10): 5507 8.G.Immirzi1997Class. Quantum Grav.14L 17714765391997CQGra..14L.177I10.1088/0264-9381/14/10/002Immirzi, G.: Class. Quantum Grav. 14, L 177 (1997) 9.J.LewandowskiE.T.NewmanC.Rovelli1993J. Math. Phys.34464612359631993JMP....34.4646L0790.5305710.1063/1.530362Lewandowski, J., Newman, E.T., Rovelli, C.: J. Math. Phys. 34, 4646 (1993) 10.C.RovelliL.Smolin1990Nucl. Phys. B3318010444931990NuPhB.331...80R10.1016/0550-3213(90)90019-ARovelli, C., Smolin, L.: Nucl. Phys. B 331, 80 (1990) 11.A.CorichiK.Krasnov1998Mod. Phys. Lett. A13133916358811998MPLA...13.1339C10.1142/S0217732398001406hep-th/9703177Corichi, A., Krasnov, K.: Mod. Phys. Lett. A 13, 1339 (1998). hep-th/9703177 12.A.AshtekarJ.LewandowskiD.MarolfJ.Mour aoT.Thiemann1995J. Math. Phys.3611645613559161995JMP....36.6456A0856.5800610.1063/1.531252gr-qc/9504018Ashtekar, A., Lewandowski, J., Marolf, D., Mour ao, J., Thiemann, T.: J. Math. Phys. 36(11), 6456 (1995). gr-qc/9504018 13.A.AshtekarJ.Lewandowski1995J. Math. Phys.365217013292511995JMP....36.2170A0844.5800910.1063/1.531037Ashtekar, A., Lewandowski, J.: J. Math. Phys. 36(5), 2170 (1995) 14.C.RovelliL.Smolin1995Phys. Rev. D5210574313604271995PhRvD..52.5743R10.1103/PhysRevD.52.5743Rovelli, C., Smolin, L.: Phys. Rev. D 52(10), 5743 (1995) 15.C.RovelliL.Smolin1995Nucl. Phys. B44259313327051995NuPhB.442..593R0925.8301310.1016/0550-3213(95)00150-Qgr-qc/9411005, Erratum: Nucl. Phys. B 456 (1995) 753Rovelli, C., Smolin, L.: Nucl. Phys. B 442, 593 (1995). gr-qc/9411005 16.A.AshtekarJ.Lewandowski1997Class Quantum Grav.14A 5516918871997CQGra..14A..55Agr-qc/9602046Ashtekar, A., Lewandowski, J.: Class Quantum Grav. 14, A 55 (1997). gr-qc/9602046 17.A.AshtekarJ.Lewandowski1998Adv. Theor. Math. Phys.13881605640gr-qc/9711031Ashtekar, A., Lewandowski, J.: Adv. Theor. Math. Phys. 1, 388 (1998). gr-qc/9711031 18.R.De PietriC.Rovelli1996Phys. Rev. D544266414069701996PhRvD..54.2664D10.1103/PhysRevD.54.2664De Pietri, R., Rovelli, C.: Phys. Rev. D 54(4), 2664 (1996) 19.J.BrunnemannT.Thiemann2006Class Quantum Grav.23128922054852006CQGra..23.1289B1089.8301310.1088/0264-9381/23/4/014gr-qc/0405060Brunnemann, J., Thiemann, T.: Class Quantum Grav. 23, 1289 (2006). gr-qc/0405060 20.J..BrunnemannD.Rideout2008Class. Quant. Grav.2506500123987022008CQGra..25f5001B10.1088/0264-9381/25/6/065001arXiv:0706.0469Brunnemann, J.., Rideout, D.: Class. Quant. Grav. 25, 065001 (2008). arXiv:0706.0469 21.J.BrunnemannD.Rideout2008Class. Quant. Grav.2506500223987032008CQGra..25f5002B10.1088/0264-9381/25/6/065002arXiv:0706.0382Brunnemann, J., Rideout, D.: Class. Quant. Grav. 25, 065002 (2008). arXiv:0706.0382 22.M.Bojowald2008Living Rev. Relativity1142008LRR....11....4B10.12942/lrr-2008-4gr-qc/0601085, http://www.livingreviews.org/lrr-2008-4Bojowald, M.: Living Rev. Relativity 11, 4 (2008). gr-qc/0601085 23.M.Bojowald2000Class. Quantum Grav.17148917526492000CQGra..17.1489B0969.8303510.1088/0264-9381/17/6/312gr-qc/9910103Bojowald, M.: Class. Quantum Grav. 17, 1489 (2000). gr-qc/9910103 24.M.Bojowald2002Class. Quantum Grav.19271719081252002CQGra..19.2717B1008.8303710.1088/0264-9381/19/10/313gr-qc/0202077Bojowald, M.: Class. Quantum Grav. 19, 2717 (2002). gr-qc/0202077 25.C.FewsterH.Sahlmann2008Class Quantum Grav2522501524533882008CQGra..25v5015F10.1088/0264-9381/25/22/225015arXiv:0804.2541Fewster, C., Sahlmann, H.: Class Quantum Grav 25, 225015 (2008). arXiv:0804.2541 26.J.M.Velhinho2007Class. Quantum Grav.24374523394202007CQGra..24.3745V1129.8332410.1088/0264-9381/24/14/013arXiv:0704.2397.Velhinho, J.M.: Class. Quantum Grav. 24, 3745 (2007). arXiv:0704.2397. 27.TThiemann1998Class Quantum Grav1583916202091998CQGra..15..839T0956.8301310.1088/0264-9381/15/4/011gr-qc/9606089Thiemann, T.: Class Quantum Grav 15, 839 (1998). gr-qc/9606089 28.T.Thiemann1998Class. Quantum Grav.15128116230751998CQGra..15.1281T0945.8301610.1088/0264-9381/15/5/012gr-qc/9705019Thiemann, T.: Class. Quantum Grav. 15, 1281 (1998). gr-qc/9705019 29.M.Bojowald2001Phys. Rev. D6408401818587272001PhRvD..64h4018B10.1103/PhysRevD.64.084018gr-qc/0105067Bojowald, M.: Phys. Rev. D 64, 084018 (2001). gr-qc/0105067 30.J.BrunnemannT.Thiemann2006Class. Quantum Grav.23139522046892006CQGra..23.1395B1097.8301310.1088/0264-9381/23/5/001gr-qc/0505032Brunnemann, J., Thiemann, T.: Class. Quantum Grav. 23, 1395 (2006). gr-qc/0505032 31.M.Bojowald2006Class. Quantum Grav.2398722029402006CQGra..23..987B1087.8302710.1088/0264-9381/23/3/023gr-qc/0508118Bojowald, M.: Class. Quantum Grav. 23, 987 (2006). gr-qc/0508118 32.J.BrunnemannT.Thiemann2006Class. Quantum Grav.23142922046902006CQGra..23.1429B1089.8301410.1088/0264-9381/23/5/002gr-qc/0505033Brunnemann, J., Thiemann, T.: Class. Quantum Grav. 23, 1429 (2006). gr-qc/0505033 1.W.Unruh1997Time, Gravity, and Quantum MechanicsCambridge University PressCambridge2394Unruh, W.: Time, Gravity, and Quantum Mechanics pp. 23-94. 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Lett. 72, 446 (1994). gr-qc/9308002 6.K.GieselT.Thiemann2007Class Quantum Grav.24246523194272007CQGra..24.2465G1117.8304510.1088/0264-9381/24/10/003gr-qc/0607099Giesel, K., Thiemann, T.: Class Quantum Grav. 24, 2465 (2007). gr-qc/0607099 7.T.Thiemann1998Class Quantum Grav.1583916202091998CQGra..15..839T0956.8301310.1088/0264-9381/15/4/011gr-qc/9606089Thiemann, T.: Class Quantum Grav. 15, 839 (1998). gr-qc/9606089 8.T.Thiemann1998Class Quantum Grav.15128116230751998CQGra..15.1281T0945.8301610.1088/0264-9381/15/5/012gr-qc/9705019Thiemann, T.: Class Quantum Grav. 15, 1281 (1998). gr-qc/9705019 9.T.Thiemann1998Class Quantum Grav.1587516202131998CQGra..15..875T10.1088/0264-9381/15/4/012gr-qc/9606090Thiemann, T.: Class Quantum Grav. 15, 875 (1998). gr-qc/9606090 10.T.Thiemann1996Phys. Lett. B38025713983881996PhLB..380..257T0945.8301310.1016/0370-2693(96)00532-1gr-qc/9606088Thiemann, T.: Phys. Lett. B 380, 257 (1996). gr-qc/9606088 11.J.LewandowskiD.Marolf1998Int. J. Mod. Phys. D729916357561998IJMPD...7..299L0936.8302210.1142/S0218271898000231gr-qc/9710016Lewandowski, J., Marolf, D.: Int. J Mod. Phys. D 7, 299 (1998). gr-qc/9710016 12.R.GambiniJ.LewandowskiD.MarolfJ.Pullin1998Int. J Mod. Phys. D79716250591998IJMPD...7...97G0936.8302110.1142/S0218271898000103gr-qc/9710018Gambini, R., Lewandowski, J., Marolf, D., Pullin, J.: Int. J Mod. Phys. D 7, 97 (1998).gr-qc/9710018 13.A.AshtekarJ.LewandowskiH.Sahlmann2003Class Quantum Grav.20L1119557752003CQGra..20L..11A1025.8350110.1088/0264-9381/20/1/103gr-qc/0211012Ashtekar, A., Lewandowski, J., Sahlmann, H.: Class Quantum Grav. 20, L11 (2003). gr-qc/0211012 14.H.SahlmannT.Thiemann2006Class Quantum Grav.2386722029362006CQGra..23..867S1098.8301410.1088/0264-9381/23/3/019gr-qc/0207030Sahlmann, H., Thiemann, T.: Class Quantum Grav. 23, 867 (2006). gr-qc/0207030 15.M.Bojowald2009

  20. Design of Open Content Social Learning Based on the Activities of Learner and Similar Learners

    ERIC Educational Resources Information Center

    John, Benneaser; Jayakumar, J.; Thavavel, V.; Arumugam, Muthukumar; Poornaselvan, K. J.

    2017-01-01

    Teaching and learning are increasingly taking advantage of the rapid growth in Internet resources, open content, mobile technologies and social media platforms. However, due to the generally unstructured nature and overwhelming quantity of learning content, effective learning remains challenging. In an effort to close this gap, the authors…

  1. Applying a Framework for Student Modeling in Exploratory Learning Environments: Comparing Data Representation Granularity to Handle Environment Complexity

    ERIC Educational Resources Information Center

    Fratamico, Lauren; Conati, Cristina; Kardan, Samad; Roll, Ido

    2017-01-01

    Interactive simulations can facilitate inquiry learning. However, similarly to other Exploratory Learning Environments, students may not always learn effectively in these unstructured environments. Thus, providing adaptive support has great potential to help improve student learning with these rich activities. Providing adaptive support requires a…

  2. Exploring a Paperless Business Administrative System (BAS) Implementation in a K-12 School

    ERIC Educational Resources Information Center

    Issa, Marwan M.

    2011-01-01

    The primary purpose of this qualitative study was to investigate how a paperless BAS can affect the overall performance of a school's administrative activities. The research included direct observation, survey questionnaires, document review, and both structured and unstructured interviews. The selected school, a K-12 charter school, was an ideal…

  3. Syndrome Specificity and Mother-Child Interactions: Examining Positive and Negative Parenting across Contexts and Time

    ERIC Educational Resources Information Center

    Blacher, Jan; Baker, Bruce L.; Kaladjian, Araksia

    2013-01-01

    This study examined the extent to which child syndromes and observation context related to mothers' parenting behaviors. Longitudinal observations were conducted of parenting behavior across ages 3, 4, and 5 years during structured and unstructured activities. The 183 participants included mothers of children with autism spectrum disorders,…

  4. Balancing Online Teaching Activities: Strategies for Optimizing Efficiency and Effectiveness

    ERIC Educational Resources Information Center

    Raffo, Deana M.; Brinthaupt, Thomas M.; Gardner, Justin G.; Fisher, Lawanna S.

    2015-01-01

    Increased demands in professional expectations have required online faculty to learn how to balance multiple roles in an open-ended, changing, and relatively unstructured job. In this paper, we argue that being strategic about one's balance of the various facets of online teaching will improve one's teaching efficiency and effectiveness. We…

  5. Pupil Participation and Playground Design: Listening and Responding to Children's Views

    ERIC Educational Resources Information Center

    Pearson, Rebecca; Howe, Julia

    2017-01-01

    This article outlines a small-scale research project that attempted to involve primary aged pupils actively in the redesign of their school playground. The project stemmed from concerns raised by school staff regarding the frequency of problematic behaviours during unstructured times, particularly lunchtimes, and the decision to redesign the…

  6. Correlates of moderate-to-vigorous physical activity among preschoolers during unstructured outdoor play periods.

    PubMed

    Nicaise, Virginie; Kahan, David; Sallis, James F

    2011-10-01

    Quantify moderate-to-vigorous physical activity (MVPA) and its correlates in preschool children during outdoor unstructured play periods using direct observation. Cross-sectional data consisting of 204 observation periods collected from 51 four- and five-year-old children using the Observation System for Recording Physical Activity in Children - Preschool (OSRAC-P) at a preschool in southern California, autumn and spring 2009-2010. Gender and BMI classification and OSRAC-P environmental codes were related to observed MVPA in multiple logistic regression models. Less than 21% of intervals were spent in MVPA overall. Boys and normal weight children engaged in higher intensity levels than their respective counterparts. More MVPA was associated with normal weight (OR=2.49-3.25, R(2)=3%), location (grass, playground, looping cycle path; OR=3.21-4.90, R(2)=4-12%), play context (ball/objects, wheel, open space; OR=2.78-8.51, R(2)=9%), and group composition (solitary, one-on-one; OR=1.34-2.08, R(2)=1%). Open spaces located in playgrounds and grass fields, and activity-genic portable equipment, manipulative objects, and riding vehicles are some design and equipment features that appear to foster MVPA. Lowering play space density and engaging children through teacher prompts and teacher-arranged activities may further increase MVPA on playgrounds. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Protein intrinsic disorder in plants.

    PubMed

    Pazos, Florencio; Pietrosemoli, Natalia; García-Martín, Juan A; Solano, Roberto

    2013-09-12

    To some extent contradicting the classical paradigm of the relationship between protein 3D structure and function, now it is clear that large portions of the proteomes, especially in higher organisms, lack a fixed structure and still perform very important functions. Proteins completely or partially unstructured in their native (functional) form are involved in key cellular processes underlain by complex networks of protein interactions. The intrinsic conformational flexibility of these disordered proteins allows them to bind multiple partners in transient interactions of high specificity and low affinity. In concordance, in plants this type of proteins has been found in processes requiring these complex and versatile interaction networks. These include transcription factor networks, where disordered proteins act as integrators of different signals or link different transcription factor subnetworks due to their ability to interact (in many cases simultaneously) with different partners. Similarly, they also serve as signal integrators in signaling cascades, such as those related to response to external stimuli. Disordered proteins have also been found in plants in many stress-response processes, acting as protein chaperones or protecting other cellular components and structures. In plants, it is especially important to have complex and versatile networks able to quickly and efficiently respond to changing environmental conditions since these organisms cannot escape and have no other choice than adapting to them. Consequently, protein disorder can play an especially important role in plants, providing them with a fast mechanism to obtain complex, interconnected and versatile molecular networks.

  8. Protein intrinsic disorder in plants

    PubMed Central

    Pazos, Florencio; Pietrosemoli, Natalia; García-Martín, Juan A.; Solano, Roberto

    2013-01-01

    To some extent contradicting the classical paradigm of the relationship between protein 3D structure and function, now it is clear that large portions of the proteomes, especially in higher organisms, lack a fixed structure and still perform very important functions. Proteins completely or partially unstructured in their native (functional) form are involved in key cellular processes underlain by complex networks of protein interactions. The intrinsic conformational flexibility of these disordered proteins allows them to bind multiple partners in transient interactions of high specificity and low affinity. In concordance, in plants this type of proteins has been found in processes requiring these complex and versatile interaction networks. These include transcription factor networks, where disordered proteins act as integrators of different signals or link different transcription factor subnetworks due to their ability to interact (in many cases simultaneously) with different partners. Similarly, they also serve as signal integrators in signaling cascades, such as those related to response to external stimuli. Disordered proteins have also been found in plants in many stress-response processes, acting as protein chaperones or protecting other cellular components and structures. In plants, it is especially important to have complex and versatile networks able to quickly and efficiently respond to changing environmental conditions since these organisms cannot escape and have no other choice than adapting to them. Consequently, protein disorder can play an especially important role in plants, providing them with a fast mechanism to obtain complex, interconnected and versatile molecular networks. PMID:24062761

  9. Quantum search of a real unstructured database

    NASA Astrophysics Data System (ADS)

    Broda, Bogusław

    2016-02-01

    A simple circuit implementation of the oracle for Grover's quantum search of a real unstructured classical database is proposed. The oracle contains a kind of quantumly accessible classical memory, which stores the database.

  10. Parallel deterministic transport sweeps of structured and unstructured meshes with overloaded mesh decompositions

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

    Pautz, Shawn D.; Bailey, Teresa S.

    Here, the efficiency of discrete ordinates transport sweeps depends on the scheduling algorithm, the domain decomposition, the problem to be solved, and the computational platform. Sweep scheduling algorithms may be categorized by their approach to several issues. In this paper we examine the strategy of domain overloading for mesh partitioning as one of the components of such algorithms. In particular, we extend the domain overloading strategy, previously defined and analyzed for structured meshes, to the general case of unstructured meshes. We also present computational results for both the structured and unstructured domain overloading cases. We find that an appropriate amountmore » of domain overloading can greatly improve the efficiency of parallel sweeps for both structured and unstructured partitionings of the test problems examined on up to 10 5 processor cores.« less

  11. Parallel deterministic transport sweeps of structured and unstructured meshes with overloaded mesh decompositions

    DOE PAGES

    Pautz, Shawn D.; Bailey, Teresa S.

    2016-11-29

    Here, the efficiency of discrete ordinates transport sweeps depends on the scheduling algorithm, the domain decomposition, the problem to be solved, and the computational platform. Sweep scheduling algorithms may be categorized by their approach to several issues. In this paper we examine the strategy of domain overloading for mesh partitioning as one of the components of such algorithms. In particular, we extend the domain overloading strategy, previously defined and analyzed for structured meshes, to the general case of unstructured meshes. We also present computational results for both the structured and unstructured domain overloading cases. We find that an appropriate amountmore » of domain overloading can greatly improve the efficiency of parallel sweeps for both structured and unstructured partitionings of the test problems examined on up to 10 5 processor cores.« less

  12. A nonlinear model predictive control formulation for obstacle avoidance in high-speed autonomous ground vehicles in unstructured environments

    NASA Astrophysics Data System (ADS)

    Liu, Jiechao; Jayakumar, Paramsothy; Stein, Jeffrey L.; Ersal, Tulga

    2018-06-01

    This paper presents a nonlinear model predictive control (MPC) formulation for obstacle avoidance in high-speed, large-size autono-mous ground vehicles (AGVs) with high centre of gravity (CoG) that operate in unstructured environments, such as military vehicles. The term 'unstructured' in this context denotes that there are no lanes or traffic rules to follow. Existing MPC formulations for passenger vehicles in structured environments do not readily apply to this context. Thus, a new nonlinear MPC formulation is developed to navigate an AGV from its initial position to a target position at high-speed safely. First, a new cost function formulation is used that aims to find the shortest path to the target position, since no reference trajectory exists in unstructured environments. Second, a region partitioning approach is used in conjunction with a multi-phase optimal control formulation to accommodate the complicated forms the obstacle-free region can assume due to the presence of multiple obstacles in the prediction horizon in an unstructured environment. Third, the no-wheel-lift-off condition, which is the major dynamical safety concern for high-speed, high-CoG AGVs, is ensured by limiting the steering angle within a range obtained offline using a 14 degrees-of-freedom vehicle dynamics model. Thus, a safe, high-speed navigation is enabled in an unstructured environment. Simulations of an AGV approaching multiple obstacles are provided to demonstrate the effectiveness of the algorithm.

  13. Factors Influencing Intrinsic Motivation towards Physical Activity.

    ERIC Educational Resources Information Center

    Rutherford, William J.; And Others

    1992-01-01

    Study examined factors that influenced intrinsic motivation toward physical activity in 60 adult males who completed questionnaires and physical fitness tests. Results showed that performance information given immediately after task performance increased perceived competence and intrinsic motivation levels toward exercise of individuals with…

  14. Four-Week Unstructured Break Improved Athletic Performance in Collegiate Rugby Players.

    PubMed

    Jensen, Courtney D; Gleason, Derrick; VanNess, Mark

    2018-06-01

    Jensen, CD, Gleason, D, and VanNess, JM. Four-week unstructured break improved athletic performance in collegiate rugby players. J Strength Cond Res 32(6): 1671-1677, 2018-This study analyzed the changes in athletic performance and anthropometric characteristics in collegiate male club rugby athletes (n = 14) after a 4-week winter break. All measurements were collected before and after the break. Body composition was assessed by body mass index and hydrostatic weighing. Performance measurements were as follows: V[Combining Dot Above]O2max, vertical jump, 10-yard sprint, squat max, and bench press max. Before testing, each subject was acclimated to the protocols to reduce learning effects. During the 4-week break, no workouts were provided for the athletes; it was unsupervised and unstructured. Participants were required to maintain and submit self-reported nutritional and activity logs during this period. After the break, the athletes demonstrated a 5.0% improvement in V[Combining Dot Above]O2max (absolute increase of 2.25 ml·kg·min), 6.8% improvement in vertical jump (1.50 inches), and a 14.3% increase in squat max (38.64 lb). Although increases in body mass (1.0%) were not significant, the body fat percentage exhibited a relative increase of 19.3% (absolute change from 13.35 to 15.93%). A significant discriminate function analysis indicated statistical differences between groups based on these variables. Self-reported behavior logs confirmed participation in >3 days of moderate to intense physical activity per week but somewhat poor dietary habits. These results indicate that collegiate rugby athletes may not need prescribed exercise routines during seasonal breaks in the athletic schedule. However, it may be beneficial to provide structured nutritional advice during unsupervised periods.

  15. Warehousing Structured and Unstructured Data for Data Mining.

    ERIC Educational Resources Information Center

    Miller, L. L.; Honavar, Vasant; Barta, Tom

    1997-01-01

    Describes an extensible object-oriented view system that supports the integration of both structured and unstructured data sources in either the multidatabase or data warehouse environment. Discusses related work and data mining issues. (AEF)

  16. Domain decomposition by the advancing-partition method for parallel unstructured grid generation

    NASA Technical Reports Server (NTRS)

    Banihashemi, legal representative, Soheila (Inventor); Pirzadeh, Shahyar Z. (Inventor)

    2012-01-01

    In a method for domain decomposition for generating unstructured grids, a surface mesh is generated for a spatial domain. A location of a partition plane dividing the domain into two sections is determined. Triangular faces on the surface mesh that intersect the partition plane are identified. A partition grid of tetrahedral cells, dividing the domain into two sub-domains, is generated using a marching process in which a front comprises only faces of new cells which intersect the partition plane. The partition grid is generated until no active faces remain on the front. Triangular faces on each side of the partition plane are collected into two separate subsets. Each subset of triangular faces is renumbered locally and a local/global mapping is created for each sub-domain. A volume grid is generated for each sub-domain. The partition grid and volume grids are then merged using the local-global mapping.

  17. Changes in At-Risk Boys' Intrinsic Motivation toward Physical Activity: A Three-Year Longitudinal Study

    ERIC Educational Resources Information Center

    Liu, Jiling; Xiang, Ping; McBride, Ron E.; Su, Xiaoxia; Juzaily, Nasnoor

    2015-01-01

    Intrinsic motivation (IM) is an important predictor of children's physical activity participation. The present 3-year longitudinal study examined changes in IM toward physical activity among a group of at-risk boys (N = 92) at a summer sports camp. Results showed the boys were intrinsically motivated in their first camp year, but their IM levels…

  18. Tuned grid generation with ICEM CFD

    NASA Technical Reports Server (NTRS)

    Wulf, Armin; Akdag, Vedat

    1995-01-01

    ICEM CFD is a CAD based grid generation package that supports multiblock structured, unstructured tetrahedral and unstructured hexahedral grids. Major development efforts have been spent to extend ICEM CFD's multiblock structured and hexahedral unstructured grid generation capabilities. The modules added are: a parametric grid generation module and a semi-automatic hexahedral grid generation module. A fully automatic version of the hexahedral grid generation module for around a set of predefined objects in rectilinear enclosures has been developed. These modules will be presented and the procedures used will be described, and examples will be discussed.

  19. A three-dimensional structured/unstructured hybrid Navier-Stokes method for turbine blade rows

    NASA Technical Reports Server (NTRS)

    Tsung, F.-L.; Loellbach, J.; Kwon, O.; Hah, C.

    1994-01-01

    A three-dimensional viscous structured/unstructured hybrid scheme has been developed for numerical computation of high Reynolds number turbomachinery flows. The procedure allows an efficient structured solver to be employed in the densely clustered, high aspect-ratio grid around the viscous regions near solid surfaces, while employing an unstructured solver elsewhere in the flow domain to add flexibility in mesh generation. Test results for an inviscid flow over an external transonic wing and a Navier-Stokes flow for an internal annular cascade are presented.

  20. Application of an unstructured grid flow solver to planes, trains and automobiles

    NASA Technical Reports Server (NTRS)

    Spragle, Gregory S.; Smith, Wayne A.; Yadlin, Yoram

    1993-01-01

    Rampant, an unstructured flow solver developed at Fluent Inc., is used to compute three-dimensional, viscous, turbulent, compressible flow fields within complex solution domains. Rampant is an explicit, finite-volume flow solver capable of computing flow fields using either triangular (2d) or tetrahedral (3d) unstructured grids. Local time stepping, implicit residual smoothing, and multigrid techniques are used to accelerate the convergence of the explicit scheme. The paper describes the Rampant flow solver and presents flow field solutions about a plane, train, and automobile.

  1. Unstructured grids on SIMD torus machines

    NASA Technical Reports Server (NTRS)

    Bjorstad, Petter E.; Schreiber, Robert

    1994-01-01

    Unstructured grids lead to unstructured communication on distributed memory parallel computers, a problem that has been considered difficult. Here, we consider adaptive, offline communication routing for a SIMD processor grid. Our approach is empirical. We use large data sets drawn from supercomputing applications instead of an analytic model of communication load. The chief contribution of this paper is an experimental demonstration of the effectiveness of certain routing heuristics. Our routing algorithm is adaptive, nonminimal, and is generally designed to exploit locality. We have a parallel implementation of the router, and we report on its performance.

  2. Neuron’s eye view: Inferring features of complex stimuli from neural responses

    PubMed Central

    Chen, Xin; Beck, Jeffrey M.

    2017-01-01

    Experiments that study neural encoding of stimuli at the level of individual neurons typically choose a small set of features present in the world—contrast and luminance for vision, pitch and intensity for sound—and assemble a stimulus set that systematically varies along these dimensions. Subsequent analysis of neural responses to these stimuli typically focuses on regression models, with experimenter-controlled features as predictors and spike counts or firing rates as responses. Unfortunately, this approach requires knowledge in advance about the relevant features coded by a given population of neurons. For domains as complex as social interaction or natural movement, however, the relevant feature space is poorly understood, and an arbitrary a priori choice of features may give rise to confirmation bias. Here, we present a Bayesian model for exploratory data analysis that is capable of automatically identifying the features present in unstructured stimuli based solely on neuronal responses. Our approach is unique within the class of latent state space models of neural activity in that it assumes that firing rates of neurons are sensitive to multiple discrete time-varying features tied to the stimulus, each of which has Markov (or semi-Markov) dynamics. That is, we are modeling neural activity as driven by multiple simultaneous stimulus features rather than intrinsic neural dynamics. We derive a fast variational Bayesian inference algorithm and show that it correctly recovers hidden features in synthetic data, as well as ground-truth stimulus features in a prototypical neural dataset. To demonstrate the utility of the algorithm, we also apply it to cluster neural responses and demonstrate successful recovery of features corresponding to monkeys and faces in the image set. PMID:28827790

  3. An Efficient Algorithm for Mapping Imaging Data to 3D Unstructured Grids in Computational Biomechanics

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

    Einstein, Daniel R.; Kuprat, Andrew P.; Jiao, Xiangmin

    2013-01-01

    Geometries for organ scale and multiscale simulations of organ function are now routinely derived from imaging data. However, medical images may also contain spatially heterogeneous information other than geometry that are relevant to such simulations either as initial conditions or in the form of model parameters. In this manuscript, we present an algorithm for the efficient and robust mapping of such data to imaging based unstructured polyhedral grids in parallel. We then illustrate the application of our mapping algorithm to three different mapping problems: 1) the mapping of MRI diffusion tensor data to an unstuctured ventricular grid; 2) the mappingmore » of serial cyro-section histology data to an unstructured mouse brain grid; and 3) the mapping of CT-derived volumetric strain data to an unstructured multiscale lung grid. Execution times and parallel performance are reported for each case.« less

  4. Large-scale Parallel Unstructured Mesh Computations for 3D High-lift Analysis

    NASA Technical Reports Server (NTRS)

    Mavriplis, Dimitri J.; Pirzadeh, S.

    1999-01-01

    A complete "geometry to drag-polar" analysis capability for the three-dimensional high-lift configurations is described. The approach is based on the use of unstructured meshes in order to enable rapid turnaround for complicated geometries that arise in high-lift configurations. Special attention is devoted to creating a capability for enabling analyses on highly resolved grids. Unstructured meshes of several million vertices are initially generated on a work-station, and subsequently refined on a supercomputer. The flow is solved on these refined meshes on large parallel computers using an unstructured agglomeration multigrid algorithm. Good prediction of lift and drag throughout the range of incidences is demonstrated on a transport take-off configuration using up to 24.7 million grid points. The feasibility of using this approach in a production environment on existing parallel machines is demonstrated, as well as the scalability of the solver on machines using up to 1450 processors.

  5. On Adding Structure to Unstructured Overlay Networks

    NASA Astrophysics Data System (ADS)

    Leitão, João; Carvalho, Nuno A.; Pereira, José; Oliveira, Rui; Rodrigues, Luís

    Unstructured peer-to-peer overlay networks are very resilient to churn and topology changes, while requiring little maintenance cost. Therefore, they are an infrastructure to build highly scalable large-scale services in dynamic networks. Typically, the overlay topology is defined by a peer sampling service that aims at maintaining, in each process, a random partial view of peers in the system. The resulting random unstructured topology is suboptimal when a specific performance metric is considered. On the other hand, structured approaches (for instance, a spanning tree) may optimize a given target performance metric but are highly fragile. In fact, the cost for maintaining structures with strong constraints may easily become prohibitive in highly dynamic networks. This chapter discusses different techniques that aim at combining the advantages of unstructured and structured networks. Namely we focus on two distinct approaches, one based on optimizing the overlay and another based on optimizing the gossip mechanism itself.

  6. An unstructured grid, three-dimensional model based on the shallow water equations

    USGS Publications Warehouse

    Casulli, V.; Walters, R.A.

    2000-01-01

    A semi-implicit finite difference model based on the three-dimensional shallow water equations is modified to use unstructured grids. There are obvious advantages in using unstructured grids in problems with a complicated geometry. In this development, the concept of unstructured orthogonal grids is introduced and applied to this model. The governing differential equations are discretized by means of a semi-implicit algorithm that is robust, stable and very efficient. The resulting model is relatively simple, conserves mass, can fit complicated boundaries and yet is sufficiently flexible to permit local mesh refinements in areas of interest. Moreover, the simulation of the flooding and drying is included in a natural and straightforward manner. These features are illustrated by a test case for studies of convergence rates and by examples of flooding on a river plain and flow in a shallow estuary. Copyright ?? 2000 John Wiley & Sons, Ltd.

  7. Parallel performance optimizations on unstructured mesh-based simulations

    DOE PAGES

    Sarje, Abhinav; Song, Sukhyun; Jacobsen, Douglas; ...

    2015-06-01

    This paper addresses two key parallelization challenges the unstructured mesh-based ocean modeling code, MPAS-Ocean, which uses a mesh based on Voronoi tessellations: (1) load imbalance across processes, and (2) unstructured data access patterns, that inhibit intra- and inter-node performance. Our work analyzes the load imbalance due to naive partitioning of the mesh, and develops methods to generate mesh partitioning with better load balance and reduced communication. Furthermore, we present methods that minimize both inter- and intranode data movement and maximize data reuse. Our techniques include predictive ordering of data elements for higher cache efficiency, as well as communication reduction approaches.more » We present detailed performance data when running on thousands of cores using the Cray XC30 supercomputer and show that our optimization strategies can exceed the original performance by over 2×. Additionally, many of these solutions can be broadly applied to a wide variety of unstructured grid-based computations.« less

  8. Three-Dimensional High-Lift Analysis Using a Parallel Unstructured Multigrid Solver

    NASA Technical Reports Server (NTRS)

    Mavriplis, Dimitri J.

    1998-01-01

    A directional implicit unstructured agglomeration multigrid solver is ported to shared and distributed memory massively parallel machines using the explicit domain-decomposition and message-passing approach. Because the algorithm operates on local implicit lines in the unstructured mesh, special care is required in partitioning the problem for parallel computing. A weighted partitioning strategy is described which avoids breaking the implicit lines across processor boundaries, while incurring minimal additional communication overhead. Good scalability is demonstrated on a 128 processor SGI Origin 2000 machine and on a 512 processor CRAY T3E machine for reasonably fine grids. The feasibility of performing large-scale unstructured grid calculations with the parallel multigrid algorithm is demonstrated by computing the flow over a partial-span flap wing high-lift geometry on a highly resolved grid of 13.5 million points in approximately 4 hours of wall clock time on the CRAY T3E.

  9. Computing Axisymmetric Jet Screech Tones Using Unstructured Grids

    NASA Technical Reports Server (NTRS)

    Jorgenson, Philip C. E.; Loh, Ching Y.

    2002-01-01

    The space-time conservation element and solution element (CE/SE) method is used to solve the conservation law form of the compressible axisymmetric Navier-Stokes equations. The equations are time marched to predict the unsteady flow and the near-field screech tone noise issuing from an underexpanded circular jet. The CE/SE method uses an unstructured grid based data structure. The unstructured grids for these calculations are generated based on the method of Delaunay triangulation. The purpose of this paper is to show that an acoustics solution with a feedback loop can be obtained using truly unstructured grid technology. Numerical results are presented for two different nozzle geometries. The first is considered to have a thin nozzle lip and the second has a thick nozzle lip. Comparisons with available experimental data are shown for flows corresponding to several different jet Mach numbers. Generally good agreement is obtained in terms of flow physics, screech tone frequency, and sound pressure level.

  10. Quality factors and local adaption (with applications in Eulerian hydrodynamics)

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

    Crowley, W.P.

    1992-06-17

    Adapting the mesh to suit the solution is a technique commonly used for solving both ode`s and pde`s. For Lagrangian hydrodynamics, ALE and Free-Lagrange are examples of structured and unstructured adaptive methods. For Eulerian hydrodynamics the two basic approaches are the macro-unstructuring technique pioneered by Oliger and Berger and the micro-structuring technique due to Lohner and others. Here we will describe a new micro-unstructuring technique, LAM, (for Local Adaptive Mesh) as applied to Eulerian hydrodynamics. The LAM technique consists of two independent parts: (1) the time advance scheme is a variation on the artificial viscosity method; (2) the adaption schememore » uses a micro-unstructured mesh with quadrilateral mesh elements. The adaption scheme makes use of quality factors and the relation between these and truncation errors is discussed. The time advance scheme; the adaption strategy; and the effect of different adaption parameters on numerical solutions are described.« less

  11. Quality factors and local adaption (with applications in Eulerian hydrodynamics)

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

    Crowley, W.P.

    1992-06-17

    Adapting the mesh to suit the solution is a technique commonly used for solving both ode's and pde's. For Lagrangian hydrodynamics, ALE and Free-Lagrange are examples of structured and unstructured adaptive methods. For Eulerian hydrodynamics the two basic approaches are the macro-unstructuring technique pioneered by Oliger and Berger and the micro-structuring technique due to Lohner and others. Here we will describe a new micro-unstructuring technique, LAM, (for Local Adaptive Mesh) as applied to Eulerian hydrodynamics. The LAM technique consists of two independent parts: (1) the time advance scheme is a variation on the artificial viscosity method; (2) the adaption schememore » uses a micro-unstructured mesh with quadrilateral mesh elements. The adaption scheme makes use of quality factors and the relation between these and truncation errors is discussed. The time advance scheme; the adaption strategy; and the effect of different adaption parameters on numerical solutions are described.« less

  12. Effects of GABA, Neural Regulation, and Intrinsic Cardiac Factors on Heart Rate Variability in Zebrafish Larvae.

    PubMed

    Vargas, Rafael Antonio

    2017-04-01

    Heart rate (HR) is a periodic activity that is variable over time due to intrinsic cardiac factors and extrinsic neural control, largely by the autonomic nervous system. Heart rate variability (HRV) is analyzed by measuring consecutive beat-to-beat intervals. This variability can contain information about the factors regulating cardiac activity under normal and pathological conditions, but the information obtained from such analyses is not yet fully understood. In this article, HRV in zebrafish larvae was evaluated under normal conditions and under the effect of substances that modify intrinsic cardiac activity and cardiac activity modulated by the nervous system. We found that the factors affecting intrinsic activity have negative chronotropic and arrhythmogenic effects at this stage of development, whereas neural modulatory factors have a lesser impact. The results suggest that cardiac activity largely depends on the intrinsic properties of the heart tissue in the early stages of development and, to a lesser extent, in the maturing nervous system. We also report, for the first time, the influence of the neurotransmitter gamma amino butyric acid on HRV. The results demonstrate the larval zebrafish model as a useful tool in the study of intrinsic cardiac activity and its role in heart diseases.

  13. Transcription Regulation of HYPK by Heat Shock Factor 1

    PubMed Central

    Das, Srijit; Bhattacharyya, Nitai Pada

    2014-01-01

    HYPK (Huntingtin Yeast Partner K) was originally identified by yeast two-hybrid assay as an interactor of Huntingtin, the protein mutated in Huntington's disease. HYPK was characterized earlier as an intrinsically unstructured protein having chaperone-like activity in vitro and in vivo. HYPK has the ability of reducing rate of aggregate formation and subsequent toxicity caused by mutant Huntingtin. Further investigation revealed that HYPK is involved in diverse cellular processes and required for normal functioning of cells. In this study we observed that hyperthermia increases HYPK expression in human and mouse cells in culture. Expression of exogenous Heat Shock Factor 1 (HSF1), upon heat treatment could induce HYPK expression, whereas HSF1 knockdown reduced endogenous as well as heat-induced HYPK expression. Putative HSF1-binding site present in the promoter of human HYPK gene was identified and validated by reporter assay. Chromatin immunoprecipitation revealed in vivo interaction of HSF1 and RNA polymerase II with HYPK promoter sequence. Additionally, acetylation of histone H4, a known epigenetic marker of inducible HSF1 binding, was observed in response to heat shock in HYPK gene promoter. Overexpression of HYPK inhibited cells from lethal heat-induced death whereas knockdown of HYPK made the cells susceptible to lethal heat shock-induced death. Apart from elevated temperature, HYPK was also upregulated by hypoxia and proteasome inhibition, two other forms of cellular stress. We concluded that chaperone-like protein HYPK is induced by cellular stress and under transcriptional regulation of HSF1. PMID:24465598

  14. Intrinsic resting-state activity predicts working memory brain activation and behavioral performance.

    PubMed

    Zou, Qihong; Ross, Thomas J; Gu, Hong; Geng, Xiujuan; Zuo, Xi-Nian; Hong, L Elliot; Gao, Jia-Hong; Stein, Elliot A; Zang, Yu-Feng; Yang, Yihong

    2013-12-01

    Although resting-state brain activity has been demonstrated to correspond with task-evoked brain activation, the relationship between intrinsic and evoked brain activity has not been fully characterized. For example, it is unclear whether intrinsic activity can also predict task-evoked deactivation and whether the rest-task relationship is dependent on task load. In this study, we addressed these issues on 40 healthy control subjects using resting-state and task-driven [N-back working memory (WM) task] functional magnetic resonance imaging data collected in the same session. Using amplitude of low-frequency fluctuation (ALFF) as an index of intrinsic resting-state activity, we found that ALFF in the middle frontal gyrus and inferior/superior parietal lobules was positively correlated with WM task-evoked activation, while ALFF in the medial prefrontal cortex, posterior cingulate cortex, superior frontal gyrus, superior temporal gyrus, and fusiform gyrus was negatively correlated with WM task-evoked deactivation. Further, the relationship between the intrinsic resting-state activity and task-evoked activation in lateral/superior frontal gyri, inferior/superior parietal lobules, superior temporal gyrus, and midline regions was stronger at higher WM task loads. In addition, both resting-state activity and the task-evoked activation in the superior parietal lobule/precuneus were significantly correlated with the WM task behavioral performance, explaining similar portions of intersubject performance variance. Together, these findings suggest that intrinsic resting-state activity facilitates or is permissive of specific brain circuit engagement to perform a cognitive task, and that resting activity can predict subsequent task-evoked brain responses and behavioral performance. Copyright © 2012 Wiley Periodicals, Inc.

  15. High Structure Active Learning Pedagogy for the Teaching of Organic Chemistry: Assessing the Impact on Academic Outcomes

    ERIC Educational Resources Information Center

    Crimmins, Michael T.; Midkiff, Brooke

    2017-01-01

    Organic Chemistry is a required course for programs in chemistry, biology, and many health science careers. It has historically been considered a highly challenging course with significant failure rates. As with many science disciplines, the teaching of Organic Chemistry has traditionally focused on unstructured exposition-centered delivery of…

  16. Effectiveness of a Classroom Mindfulness Coloring Activity for Test Anxiety in Children

    ERIC Educational Resources Information Center

    Carsley, Dana; Heath, Nancy L.; Fajnerova, Sophia

    2015-01-01

    To evaluate the effectiveness of mindfulness-based structured versus unstructured coloring on test anxiety, 52 participants (53.8% female; M[subscript age] = 10.92 years, SD = 0.82) were randomly assigned to either a structured mandala (n = 26) or free coloring condition (n = 26), and completed a standardized anxiety measure to assess anxiety…

  17. Growing Literacy. Eighteenth Yearbook of the College Reading Association.

    ERIC Educational Resources Information Center

    Sturtevant, Elizabeth G., Ed.; Linek, Wayne M., Ed.

    Focusing on the theme of what literacy is and how it grows, this book presents 25 essays and studies that explore literacy growth in young children, teens, college students, and adults. Essays and studies in the book are (1) "Kindergarten Children's Uses of Oral Language and Social Interaction in Literacy Activities during Unstructured Play" (J.K.…

  18. Distinct neural control of intrinsic and extrinsic muscles of the hand during single finger pressing.

    PubMed

    Dupan, Sigrid S G; Stegeman, Dick F; Maas, Huub

    2018-06-01

    Single finger force tasks lead to unintended activation of the non-instructed fingers, commonly referred to as enslaving. Both neural and mechanical factors have been associated with this absence of finger individuality. This study investigates the amplitude modulation of both intrinsic and extrinsic finger muscles during single finger isometric force tasks. Twelve participants performed single finger flexion presses at 20% of maximum voluntary contraction, while simultaneously the electromyographic activity of several intrinsic and extrinsic muscles associated with all four fingers was recorded using 8 electrode pairs in the hand and two 30-electrode grids on the lower arm. The forces exerted by each of the fingers, in both flexion and extension direction, were recorded with individual force sensors. This study shows distinct activation patterns in intrinsic and extrinsic hand muscles. Intrinsic muscles exhibited individuation, where the agonistic and antagonistic muscles associated with the instructed fingers showed the highest activation. This activation in both agonistic and antagonistic muscles appears to facilitate finger stabilisation during the isometric force task. Extrinsic muscles show an activation independent from instructed finger in both agonistic and antagonistic muscles, which appears to be associated with stabilisation of the wrist, with an additional finger-dependent modulation only present in the agonistic extrinsic muscles. These results indicate distinct muscle patterns in intrinsic and extrinsic hand muscles during single finger isometric force pressing. We conclude that the finger specific activation of intrinsic muscles is not sufficient to fully counteract enslaving caused by the broad activation of the extrinsic muscles. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Changes in Intrinsic Motivation as a Function of Negative Feedback and Threats.

    ERIC Educational Resources Information Center

    Deci, Edward L.; Cascio, Wayne F.

    Recent studies have demonstrated that external rewards can affect intrinsic motivation to perform an activity. Money tends to decrease intrinsic motivation, whereas positive verbal reinforcements tend to increase intrinsic motivation. This paper presents evidence that negative feedback and threats of punishment also decrease intrinsic motivation.…

  20. Interplay between Chaperones and Protein Disorder Promotes the Evolution of Protein Networks

    PubMed Central

    Pechmann, Sebastian; Frydman, Judith

    2014-01-01

    Evolution is driven by mutations, which lead to new protein functions but come at a cost to protein stability. Non-conservative substitutions are of interest in this regard because they may most profoundly affect both function and stability. Accordingly, organisms must balance the benefit of accepting advantageous substitutions with the possible cost of deleterious effects on protein folding and stability. We here examine factors that systematically promote non-conservative mutations at the proteome level. Intrinsically disordered regions in proteins play pivotal roles in protein interactions, but many questions regarding their evolution remain unanswered. Similarly, whether and how molecular chaperones, which have been shown to buffer destabilizing mutations in individual proteins, generally provide robustness during proteome evolution remains unclear. To this end, we introduce an evolutionary parameter λ that directly estimates the rate of non-conservative substitutions. Our analysis of λ in Escherichia coli, Saccharomyces cerevisiae, and Homo sapiens sequences reveals how co- and post-translationally acting chaperones differentially promote non-conservative substitutions in their substrates, likely through buffering of their destabilizing effects. We further find that λ serves well to quantify the evolution of intrinsically disordered proteins even though the unstructured, thus generally variable regions in proteins are often flanked by very conserved sequences. Crucially, we show that both intrinsically disordered proteins and highly re-wired proteins in protein interaction networks, which have evolved new interactions and functions, exhibit a higher λ at the expense of enhanced chaperone assistance. Our findings thus highlight an intricate interplay of molecular chaperones and protein disorder in the evolvability of protein networks. Our results illuminate the role of chaperones in enabling protein evolution, and underline the importance of the cellular context and integrated approaches for understanding proteome evolution. We feel that the development of λ may be a valuable addition to the toolbox applied to understand the molecular basis of evolution. PMID:24968255

  1. The National Grid Project: A system overview

    NASA Technical Reports Server (NTRS)

    Gaither, Adam; Gaither, Kelly; Jean, Brian; Remotigue, Michael; Whitmire, John; Soni, Bharat; Thompson, Joe; Dannenhoffer,, John; Weatherill, Nigel

    1995-01-01

    The National Grid Project (NGP) is a comprehensive numerical grid generation software system that is being developed at the National Science Foundation (NSF) Engineering Research Center (ERC) for Computational Field Simulation (CFS) at Mississippi State University (MSU). NGP is supported by a coalition of U.S. industries and federal laboratories. The objective of the NGP is to significantly decrease the amount of time it takes to generate a numerical grid for complex geometries and to increase the quality of these grids to enable computational field simulations for applications in industry. A geometric configuration can be discretized into grids (or meshes) that have two fundamental forms: structured and unstructured. Structured grids are formed by intersecting curvilinear coordinate lines and are composed of quadrilateral (2D) and hexahedral (3D) logically rectangular cells. The connectivity of a structured grid provides for trivial identification of neighboring points by incrementing coordinate indices. Unstructured grids are composed of cells of any shape (commonly triangles, quadrilaterals, tetrahedra and hexahedra), but do not have trivial identification of neighbors by incrementing an index. For unstructured grids, a set of points and an associated connectivity table is generated to define unstructured cell shapes and neighboring points. Hybrid grids are a combination of structured grids and unstructured grids. Chimera (overset) grids are intersecting or overlapping structured grids. The NGP system currently provides a user interface that integrates both 2D and 3D structured and unstructured grid generation, a solid modeling topology data management system, an internal Computer Aided Design (CAD) system based on Non-Uniform Rational B-Splines (NURBS), a journaling language, and a grid/solution visualization system.

  2. Using structured and unstructured data to identify patients' need for services that address the social determinants of health.

    PubMed

    Vest, Joshua R; Grannis, Shaun J; Haut, Dawn P; Halverson, Paul K; Menachemi, Nir

    2017-11-01

    Increasingly, health care providers are adopting population health management approaches that address the social determinants of health (SDH). However, effectively identifying patients needing services that address a SDH in primary care settings is challenging. The purpose of the current study is to explore how various data sources can identify adult primary care patients that are in need of services that address SDH. A cross-sectional study described patients in need of SDH services offered by a safety-net hospital's federally qualified health center clinics. SDH services of social work, behavioral health, nutrition counseling, respiratory therapy, financial planning, medical-legal partnership assistance, patient navigation, and pharmacist consultation were offered on a co-located basis and were identified using structured billing and scheduling data, and unstructured electronic health record data. We report the prevalence of the eight different SDH service needs and the patient characteristics associated with service need. Moreover, characteristics of patients with SDH services need documented in structured data sources were compared with those documented by unstructured data sources. More than half (53%) of patients needed SDH services. Those in need of such services tended to be female, older, more medically complex, and higher utilizers of services. Structured and unstructured data sources exhibited poor agreement on patient SDH services need. Patients with SDH services need documented by unstructured data tended to be more complex. The need for SDH services among a safety-net population is high. Identifying patients in need of such services requires multiple data sources with structured and unstructured data. Copyright © 2017. Published by Elsevier B.V.

  3. Getting the Most from Working with Higher Education: A Review of Methods Used within a Participatory Design Activity Involving KS3 Special School Pupils and Undergraduate and Post-Graduate Industrial Design Students

    ERIC Educational Resources Information Center

    Torrens, George Edward; Newton, Helen

    2013-01-01

    This paper provides education-based researchers and practitioners with the preferred research and design methods used by Higher Education Institute (HEI) students and Key Stage 3 (KS3) pupils applied within a participatory approach to a design activity. The outcomes were that both pupils and students found informal (unstructured) interview to be…

  4. Physical Activity Intensity, Lesson Context, and Teacher Interactions During an Unstructured Afterschool Physical Activity Program.

    PubMed

    Behrens, Timothy K; Miller, Daniel J; Schuna, John M; Liebert, Mina L

    2015-12-01

    Afterschool programs are promising arenas to improve youth physical activity (PA) levels. During the school year for 2012-2013, 5 elementary schools from a low-socioeconomic status (SES) school district in southern Colorado participated in evaluation of the afterschool program entitled Keep It Moving! (KIM). In this cross-sectional analysis we sought to evaluate the relationships among participant PA, teacher interaction, and lesson context during an unstructured afterschool PA program. Participants were third-fifth grade students enrolled in the KIM program at the 5 participating elementary schools and were assessed utilizing accelerometers and direct observation with the System for Observing Fitness Instruction Time (SOFIT). Program participants wore the accelerometer 37.1 ± 5.4 min session(-1). Approximately half of the time was spent in light PA (LPA) and 15.7 ± 5.3 min session(-1) in moderate to vigorous PA (MVPA). Game play was positively associated with LPA and negatively associated with MVPA. When teachers did not promote PA with students there was a positive association with sedentary activity (SA) and a negative association with MVPA. Lesson context and teacher interactions may be important factors associated with PA intensity of afterschool PA programming. Future research should address whether structured PA curricula may improve quality of afterschool PA programming. © 2015, American School Health Association.

  5. Perceptions of the activity, the social climate, and the self during group exercise classes regulate intrinsic satisfaction

    PubMed Central

    Maher, Jaclyn P.; Gottschall, Jinger S.; Conroy, David E.

    2015-01-01

    Engaging in regular physical activity is a challenging task for many adults. Intrinsic satisfaction with exercise classes is thought to promote adherence to physical activity. This study examined the characteristics of exercise classes that impact within-person changes in intrinsic satisfaction over the course of an extended group exercise program. A 30-week physical activity trial was conducted with assessments at the end of each class. Community-living adults (n = 29) were instructed to complete at least six group exercise classes each week and, following each exercise class, complete a questionnaire asking about the characteristics of the class and the participant’s evaluation of the class. Intrinsic satisfaction was high, on average, but varied as much within-person from class-to-class as it did between exercisers. Participants reported the greatest intrinsic satisfaction when classes placed greater emphasis on exercisers’ involvement with the group task, feelings of competence, and encouragement from the instructor. For the most part, exercise classes that were more intense than usual were perceived by exercisers as less intrinsically satisfying. Some overall characteristics of the exercise classes were also associated with intrinsic satisfaction. The social and motivational characteristics of group exercise classes contribute to exercisers’ intrinsic satisfaction with classes and attention to those dynamics, as well as the intensity of the exercise, may improve adherence for exercise regimens. PMID:26347696

  6. Perceptions of the activity, the social climate, and the self during group exercise classes regulate intrinsic satisfaction.

    PubMed

    Maher, Jaclyn P; Gottschall, Jinger S; Conroy, David E

    2015-01-01

    Engaging in regular physical activity is a challenging task for many adults. Intrinsic satisfaction with exercise classes is thought to promote adherence to physical activity. This study examined the characteristics of exercise classes that impact within-person changes in intrinsic satisfaction over the course of an extended group exercise program. A 30-week physical activity trial was conducted with assessments at the end of each class. Community-living adults (n = 29) were instructed to complete at least six group exercise classes each week and, following each exercise class, complete a questionnaire asking about the characteristics of the class and the participant's evaluation of the class. Intrinsic satisfaction was high, on average, but varied as much within-person from class-to-class as it did between exercisers. Participants reported the greatest intrinsic satisfaction when classes placed greater emphasis on exercisers' involvement with the group task, feelings of competence, and encouragement from the instructor. For the most part, exercise classes that were more intense than usual were perceived by exercisers as less intrinsically satisfying. Some overall characteristics of the exercise classes were also associated with intrinsic satisfaction. The social and motivational characteristics of group exercise classes contribute to exercisers' intrinsic satisfaction with classes and attention to those dynamics, as well as the intensity of the exercise, may improve adherence for exercise regimens.

  7. EMPHASIS™/Nevada UTDEM User Guide Version 2.1.2

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

    Turner, C. David; Pasik, Michael F.; Seidel, David B.

    The Unstructured Time-Domain ElectroMagnetics (UTDEM) portion of the EMPHASIS suite solves Maxwell’s equations using finite-element techniques on unstructured meshes. This document provides user-specific information to facilitate the use of the code for applications of interest.

  8. On Convergence Acceleration Techniques for Unstructured Meshes

    NASA Technical Reports Server (NTRS)

    Mavriplis, Dimitri J.

    1998-01-01

    A discussion of convergence acceleration techniques as they relate to computational fluid dynamics problems on unstructured meshes is given. Rather than providing a detailed description of particular methods, the various different building blocks of current solution techniques are discussed and examples of solution strategies using one or several of these ideas are given. Issues relating to unstructured grid CFD problems are given additional consideration, including suitability of algorithms to current hardware trends, memory and cpu tradeoffs, treatment of non-linearities, and the development of efficient strategies for handling anisotropy-induced stiffness. The outlook for future potential improvements is also discussed.

  9. Wind-US Unstructured Flow Solutions for a Transonic Diffuser

    NASA Technical Reports Server (NTRS)

    Mohler, Stanley R., Jr.

    2005-01-01

    The Wind-US Computational Fluid Dynamics flow solver computed flow solutions for a transonic diffusing duct. The calculations used an unstructured (hexahedral) grid. The Spalart-Allmaras turbulence model was used. Static pressures along the upper and lower wall agreed well with experiment, as did velocity profiles. The effect of the smoothing input parameters on convergence and solution accuracy was investigated. The meaning and proper use of these parameters are discussed for the benefit of Wind-US users. Finally, the unstructured solver is compared to the structured solver in terms of run times and solution accuracy.

  10. Being Eager to Prove Oneself: U-Shaped Relationship between Competence Frustration and Intrinsic Motivation in Another Activity.

    PubMed

    Fang, Hui; He, Bin; Fu, Huijian; Meng, Liang

    2017-01-01

    Competence frustration has been consistently found to undermine one's intrinsic motivation in the same activity. However, the relationship between competence frustration in a preceding activity and one's intrinsic motivation in a subsequent one remains unclear. In order to explore this relationship, self-reported data were collected from 617 undergraduate students of a large comprehensive university in southern China, who took varied courses immediately before taking a less-demanding one. Results suggested a U-shaped relationship between students' competence frustration in a preceding course and intrinsic motivation in a subsequent one. To be specific, for students whose competence frustration reached the inflection point, a restoration process would be activated if the current course would help restore their competence. Importantly, these students' competence frustration in a preceding course was found to positively predict their intrinsic motivation level in a subsequent course. As far as we are concerned, this is the first study to reveal a potential positive effect of need frustration outside of its primary thwarting context, which complements and extends existing literatures on the dynamics between need frustration and intrinsic motivation.

  11. Impaired prefrontal activity to regulate the intrinsic motivation-action link in schizophrenia.

    PubMed

    Takeda, Kazuyoshi; Matsumoto, Madoka; Ogata, Yousuke; Maida, Keiko; Murakami, Hiroki; Murayama, Kou; Shimoji, Keigo; Hanakawa, Takashi; Matsumoto, Kenji; Nakagome, Kazuyuki

    2017-01-01

    A core feature of schizophrenia (SCZ) is impairment in intrinsic motivation. Although intrinsic motivation plays an important role in enhancing improvement of the social functioning, its neural mechanisms of impairment have yet to be clarified. We hypothesized that abnormal function of the frontostriatal loop consisting of the striatum and lateral prefrontal cortex (LPFC) may be related to impaired intrinsic motivation in SCZ. We tested this by comparing the brain activity measured by functional magnetic resonance imaging and behavioral parameters associated with movement, motivation, and cognitive control between 18 stable SCZ patients and 17 healthy control (HC) participants during a task that elicits intrinsic motivation. We also compared the functional connectivity during resting-state and the fractional anisotropy using diffusion tensor imaging analysis between the two groups. We adopted an enjoyable timing task to stop a stopwatch at an exact time, which in our previous study has demonstrated to elicit intrinsic motivation. Although the performance level in general was not different between groups, the SCZ group performed worse than the HC group in trials following "overshoot" errors (i.e., the response was too late). SCZ participants showed lower intrinsic motivation to the task than the HC group in an inventory report. The striatal activity during the prediction at the task cue period was consistently lower in SCZ participants than in HC. The LPFC activity at the task cue period positively correlated with intrinsic motivation and also with the rate of success following overshoot errors in the HC group, but not in the SCZ group. The LPFC activity at the task cue period was also positively correlated with the striatal activity in both groups. The striatal activity during the feedback period was not significantly different between groups. These results suggest that, unlike HC, the neural activity in the LPFC fails to mediate between prediction of hedonic events and cognitive control of action plans in SCZ, whereas the hedonic response is retained.

  12. Cholinesterase inhibitors modify the activity of intrinsic cardiac neurons.

    PubMed

    Darvesh, Sultan; Arora, Rakesh C; Martin, Earl; Magee, David; Hopkins, David A; Armour, J Andrew

    2004-08-01

    Cholinesterase inhibitors used to treat the symptoms of Alzheimer's disease (AD) inhibit both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), albeit to different degrees. Because central and peripheral neurons, including intrinsic cardiac neurons located on the surface of the mammalian heart, express both BuChE and AChE, we studied spontaneously active intrinsic cardiac neurons in the pig as a model to assess the effects of inhibition of AChE compared to BuChE. Neuroanatomical experiments showed that some porcine intrinsic cardiac neurons expressed AChE and/or BuChE. Enzyme kinetic experiments with cholinesterase inhibitors, namely, donepezil, galantamine, (+/-) huperzine A, metrifonate, rivastigmine, and tetrahydroaminoacridine, demonstrated that these compounds differentially inhibited porcine AChE and BuChE. Donepezil and (+/-) huperzine A were better reversible inhibitors of AChE, and galantamine equally inhibited both the enzymes. Tetrahydroaminoacridine was a better reversible inhibitor of BuChE. Rivastigmine caused more rapid inactivation of BuChE as compared to AChE. Neurophysiological studies showed that acetylcholine and butyrylcholine increase or decrease the spontaneous activity of the intrinsic cardiac neurons. Donepezil, galantamine, (+/-) huperzine A, and tetrahydroaminoacridine changed spontaneous neuronal activity by about 30-35 impulses per minute, while rivastigmine changed it by approximately 100 impulses per minute. It is concluded that (i) inhibition of AChE and BuChE directly affects the porcine intrinsic cardiac nervous system, (ii) the intrinsic cardiac nervous system represents a suitable model for examining the effects of cholinesterase inhibitors on mammalian neurons in vivo, and (iii) the activity of intrinsic cardiac neurons may be affected by pharmacological agents that inhibit cholinesterases.

  13. Structured and Unstructured Learning.

    ERIC Educational Resources Information Center

    1996

    This document contains four papers presented at a sympoisum on structured and unstructured learning moderated by Catherine Sleezer at the 1996 conference of the Academy of Human Resource Development (AHRD). "Designing Experiential Learning into Organizational Work Life: Proposing a Framework for Theory and Research" (Cheri Maben-Crouch)…

  14. Security Aspects of Computer Supported Collaborative Work

    DTIC Science & Technology

    1993-09-01

    unstructured tasks at one end 11 and prescriptive tasks at the other. Unstructured tasks are those requiring creative input from a number of users and...collaborative technology begun to mature, it has begun to outstrip prevailing management attitudes. One barrier to telecommuting is the perception that

  15. Parallel Performance Optimizations on Unstructured Mesh-based Simulations

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

    Sarje, Abhinav; Song, Sukhyun; Jacobsen, Douglas

    2015-01-01

    © The Authors. Published by Elsevier B.V. This paper addresses two key parallelization challenges the unstructured mesh-based ocean modeling code, MPAS-Ocean, which uses a mesh based on Voronoi tessellations: (1) load imbalance across processes, and (2) unstructured data access patterns, that inhibit intra- and inter-node performance. Our work analyzes the load imbalance due to naive partitioning of the mesh, and develops methods to generate mesh partitioning with better load balance and reduced communication. Furthermore, we present methods that minimize both inter- and intranode data movement and maximize data reuse. Our techniques include predictive ordering of data elements for higher cachemore » efficiency, as well as communication reduction approaches. We present detailed performance data when running on thousands of cores using the Cray XC30 supercomputer and show that our optimization strategies can exceed the original performance by over 2×. Additionally, many of these solutions can be broadly applied to a wide variety of unstructured grid-based computations.« less

  16. Application of an Unstructured Grid Navier-Stokes Solver to a Generic Helicopter Boby: Comparison of Unstructured Grid Results with Structured Grid Results and Experimental Results

    NASA Technical Reports Server (NTRS)

    Mineck, Raymond E.

    1999-01-01

    An unstructured-grid Navier-Stokes solver was used to predict the surface pressure distribution, the off-body flow field, the surface flow pattern, and integrated lift and drag coefficients on the ROBIN configuration (a generic helicopter) without a rotor at four angles of attack. The results are compared to those predicted by two structured- grid Navier-Stokes solvers and to experimental surface pressure distributions. The surface pressure distributions from the unstructured-grid Navier-Stokes solver are in good agreement with the results from the structured-grid Navier-Stokes solvers. Agreement with the experimental pressure coefficients is good over the forward portion of the body. However, agreement is poor on the lower portion of the mid-section of the body. Comparison of the predicted surface flow patterns showed similar regions of separated flow. Predicted lift and drag coefficients were in fair agreement with each other.

  17. Computing Flows Using Chimera and Unstructured Grids

    NASA Technical Reports Server (NTRS)

    Liou, Meng-Sing; Zheng, Yao

    2006-01-01

    DRAGONFLOW is a computer program that solves the Navier-Stokes equations of flows in complexly shaped three-dimensional regions discretized by use of a direct replacement of arbitrary grid overlapping by nonstructured (DRAGON) grid. A DRAGON grid (see figure) is a combination of a chimera grid (a composite of structured subgrids) and a collection of unstructured subgrids. DRAGONFLOW incorporates modified versions of two prior Navier-Stokes-equation-solving programs: OVERFLOW, which is designed to solve on chimera grids; and USM3D, which is used to solve on unstructured grids. A master module controls the invocation of individual modules in the libraries. At each time step of a simulated flow, DRAGONFLOW is invoked on the chimera portion of the DRAGON grid in alternation with USM3D, which is invoked on the unstructured subgrids of the DRAGON grid. The USM3D and OVERFLOW modules then immediately exchange their solutions and other data. As a result, USM3D and OVERFLOW are coupled seamlessly.

  18. The design and implementation of a parallel unstructured Euler solver using software primitives

    NASA Technical Reports Server (NTRS)

    Das, R.; Mavriplis, D. J.; Saltz, J.; Gupta, S.; Ponnusamy, R.

    1992-01-01

    This paper is concerned with the implementation of a three-dimensional unstructured grid Euler-solver on massively parallel distributed-memory computer architectures. The goal is to minimize solution time by achieving high computational rates with a numerically efficient algorithm. An unstructured multigrid algorithm with an edge-based data structure has been adopted, and a number of optimizations have been devised and implemented in order to accelerate the parallel communication rates. The implementation is carried out by creating a set of software tools, which provide an interface between the parallelization issues and the sequential code, while providing a basis for future automatic run-time compilation support. Large practical unstructured grid problems are solved on the Intel iPSC/860 hypercube and Intel Touchstone Delta machine. The quantitative effect of the various optimizations are demonstrated, and we show that the combined effect of these optimizations leads to roughly a factor of three performance improvement. The overall solution efficiency is compared with that obtained on the CRAY-YMP vector supercomputer.

  19. It's about time: Earlier rewards increase intrinsic motivation.

    PubMed

    Woolley, Kaitlin; Fishbach, Ayelet

    2018-06-01

    Can immediate (vs. delayed) rewards increase intrinsic motivation? Prior research compared the presence versus absence of rewards. By contrast, this research compared immediate versus delayed rewards, predicting that more immediate rewards increase intrinsic motivation by creating a perceptual fusion between the activity and its goal (i.e., the reward). In support of the hypothesis, framing a reward from watching a news program as more immediate (vs. delayed) increased intrinsic motivation to watch the program (Study 1), and receiving more immediate bonus (vs. delayed, Study 2; and vs. delayed and no bonus, Study 3) increased intrinsic motivation in an experimental task. The effect of reward timing was mediated by the strength of the association between an activity and a reward, and was specific to intrinsic (vs. extrinsic) motivation-immediacy influenced the positive experience of an activity, but not perceived outcome importance (Study 4). In addition, the effect of the timing of rewards was independent of the effect of the magnitude of the rewards (Study 5). (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  20. A Study of Extrinsic vs. Intrinsic Motivation in College Students.

    ERIC Educational Resources Information Center

    Elbel, Jacquelyn; Horton, Irene P.

    Attribution theorists have argued that if an intrinsically motivated activity is extrinsically reinforced, the activity will be devalued and extinguished when the reward is removed. Hypothesizing that activities performed for their instrumental outcome are valued less than activities not so externally oriented, and that activities performed for…

  1. Museums, Adventures, Discovery Activities: Gifted Curriculum Intrinsically Differentiated.

    ERIC Educational Resources Information Center

    Haensly, Patricia A.

    This paper discusses how museums, adventure programs, and discovery activities can become an intrinsically differentiated gifted curriculum for gifted learners. Museums and adventure programs are a forum for meaningful learning activities. The contextual characteristics of effectively designed settings for learning activities can, if the…

  2. Intrinsically active and pacemaker neurons in pluripotent stem cell-derived neuronal populations.

    PubMed

    Illes, Sebastian; Jakab, Martin; Beyer, Felix; Gelfert, Renate; Couillard-Despres, Sébastien; Schnitzler, Alfons; Ritter, Markus; Aigner, Ludwig

    2014-03-11

    Neurons generated from pluripotent stem cells (PSCs) self-organize into functional neuronal assemblies in vitro, generating synchronous network activities. Intriguingly, PSC-derived neuronal assemblies develop spontaneous activities that are independent of external stimulation, suggesting the presence of thus far undetected intrinsically active neurons (IANs). Here, by using mouse embryonic stem cells, we provide evidence for the existence of IANs in PSC-neuronal networks based on extracellular multielectrode array and intracellular patch-clamp recordings. IANs remain active after pharmacological inhibition of fast synaptic communication and possess intrinsic mechanisms required for autonomous neuronal activity. PSC-derived IANs are functionally integrated in PSC-neuronal populations, contribute to synchronous network bursting, and exhibit pacemaker properties. The intrinsic activity and pacemaker properties of the neuronal subpopulation identified herein may be particularly relevant for interventions involving transplantation of neural tissues. IANs may be a key element in the regulation of the functional activity of grafted as well as preexisting host neuronal networks.

  3. Intrinsically Active and Pacemaker Neurons in Pluripotent Stem Cell-Derived Neuronal Populations

    PubMed Central

    Illes, Sebastian; Jakab, Martin; Beyer, Felix; Gelfert, Renate; Couillard-Despres, Sébastien; Schnitzler, Alfons; Ritter, Markus; Aigner, Ludwig

    2014-01-01

    Summary Neurons generated from pluripotent stem cells (PSCs) self-organize into functional neuronal assemblies in vitro, generating synchronous network activities. Intriguingly, PSC-derived neuronal assemblies develop spontaneous activities that are independent of external stimulation, suggesting the presence of thus far undetected intrinsically active neurons (IANs). Here, by using mouse embryonic stem cells, we provide evidence for the existence of IANs in PSC-neuronal networks based on extracellular multielectrode array and intracellular patch-clamp recordings. IANs remain active after pharmacological inhibition of fast synaptic communication and possess intrinsic mechanisms required for autonomous neuronal activity. PSC-derived IANs are functionally integrated in PSC-neuronal populations, contribute to synchronous network bursting, and exhibit pacemaker properties. The intrinsic activity and pacemaker properties of the neuronal subpopulation identified herein may be particularly relevant for interventions involving transplantation of neural tissues. IANs may be a key element in the regulation of the functional activity of grafted as well as preexisting host neuronal networks. PMID:24672755

  4. Impaired helix 12 dynamics due to proline 892 substitutions in the androgen receptor are associated with complete androgen insensitivity.

    PubMed

    Elhaji, Youssef A; Stoica, Ileana; Dennis, Sheldon; Purisima, Enrico O; Lumbroso, Rose; Beitel, Lenore K; Trifiro, Mark A

    2006-03-15

    Structural studies of the ligand-binding domain (LBD) of several steroid receptors have revealed that the dynamic properties of the C-terminal helix 12 (H12) are the major determinant of the activation mode of these receptors. H12 exhibits high mobility and different conformations in the absence of ligand. Upon ligand binding, H12 is stabilized in a precise position to seal the ligand-binding pocket and finalize the assembly of the activation function (AF-2) domain. In this study, we investigated the role of the conserved proline 892 of the androgen receptor (AR) in directing the dynamic location and orientation of the AR-H12. We used a combined approach including kinetic and biochemical assays with molecular dynamic simulations to analyze two substitutions (P892A and P892L) identified in individuals with complete androgen insensitivity syndrome. Our analyses revealed distinct mechanisms by which these substitutions impair H12 function resulting in severely defective receptors. The AR-P892A receptor exhibited reduced ligand binding and transactivational potential because of an increased flexibility in H12. The AR-P892L substitution renders the receptor inactive due to a distorted, unstructured and misplaced H12. To confirm the mutants' inability to stabilize H12 in an active position, we have developed a novel in vivo assay to evaluate the accessibility of the H12-docking site on the AR-LBD surface. An extrinsic AR-H12 peptide was able to interact with wild-type and mutant LBDs in the absence of ligand. Ligand-induced proper positioning of the intrinsic H12 of wild-type AR prevented these interactions, whereas the misplacement of the mutants' H12 did not. Proline at this position may be critical for H12 dynamics not only in the AR, but also in other nuclear receptors where this proline is conserved.

  5. Structural differences between bovine A(1) and A(2) β-casein alter micelle self-assembly and influence molecular chaperone activity.

    PubMed

    Raynes, J K; Day, L; Augustin, M A; Carver, J A

    2015-04-01

    Within each milk protein there are many individual protein variants and marked alterations to milk functionality can occur depending on the genetic variants of each protein present. Bovine A(1) and A(2) β-casein (β-CN) are 2 variants that contribute to differences in the gelation performance of milk. The A(1) and A(2) β-CN variants differ by a single AA, the substitution of histidine for proline at position 67. β-Casein not only participates in formation of the casein micelle but also forms an oligomeric micelle itself and functions as a molecular chaperone to prevent the aggregation of a wide range of proteins, including the other caseins. Micelle assembly of A(1) and A(2) β-CN was investigated using dynamic light scattering and small-angle X-ray scattering, whereas protein functionality was assessed using fluorescence techniques and molecular chaperone assays. The A(2) β-CN variant formed smaller micelles than A(1) β-CN, with the monomer-micelle equilibrium of A(2) β-CN being shifted toward the monomer. This shift most likely arose from structural differences between the 2 β-CN variants associated with the adoption of greater polyproline-II helix in A(2) β-CN and most likely led to enhanced chaperone activity of A(2) β-CN compared with A(1) β-CN. The difference in micelle assembly, and hence chaperone activity, may provide explain differences in the functionality of homozygous A(1) and A(2) milk. The results of this study highlight that substitution of even a single AA can significantly alter the properties of an intrinsically unstructured protein such as β-CN and, in this case, may have an effect on the functionality of milk. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  6. Bracketing as a skill in conducting unstructured qualitative interviews.

    PubMed

    Sorsa, Minna Anneli; Kiikkala, Irma; Åstedt-Kurki, Päivi

    2015-03-01

    To provide an overview of bracketing as a skill in unstructured qualitative research interviews. Researchers affect the qualitative research process. Bracketing in descriptive phenomenology entails researchers setting aside their pre-understanding and acting non-judgementally. In interpretative phenomenology, previous knowledge is used intentionally to create new understanding. A literature search of bracketing in phenomenology and qualitative research. This is a methodology paper examining the researchers' impact in creating data in creating data in qualitative research. Self-knowledge, sensitivity and reflexivity of the researcher enable bracketing. Skilled and experienced researchers are needed to use bracketing in unstructured qualitative research interviews. Bracketing adds scientific rigour and validity to any qualitative study.

  7. A Solution Adaptive Structured/Unstructured Overset Grid Flow Solver with Applications to Helicopter Rotor Flows

    NASA Technical Reports Server (NTRS)

    Duque, Earl P. N.; Biswas, Rupak; Strawn, Roger C.

    1995-01-01

    This paper summarizes a method that solves both the three dimensional thin-layer Navier-Stokes equations and the Euler equations using overset structured and solution adaptive unstructured grids with applications to helicopter rotor flowfields. The overset structured grids use an implicit finite-difference method to solve the thin-layer Navier-Stokes/Euler equations while the unstructured grid uses an explicit finite-volume method to solve the Euler equations. Solutions on a helicopter rotor in hover show the ability to accurately convect the rotor wake. However, isotropic subdivision of the tetrahedral mesh rapidly increases the overall problem size.

  8. Intrinsic disorder as a generalizable strategy for the rational design of highly responsive, allosterically cooperative receptors.

    PubMed

    Simon, Anna J; Vallée-Bélisle, Alexis; Ricci, Francesco; Plaxco, Kevin W

    2014-10-21

    Control over the sensitivity with which biomolecular receptors respond to small changes in the concentration of their target ligand is critical for the proper function of many cellular processes. Such control could likewise be of utility in artificial biotechnologies, such as biosensors, genetic logic gates, and "smart" materials, in which highly responsive behavior is of value. In nature, the control of molecular responsiveness is often achieved using "Hill-type" cooperativity, a mechanism in which sequential binding events on a multivalent receptor are coupled such that the first enhances the affinity of the next, producing a steep, higher-order dependence on target concentration. Here, we use an intrinsic-disorder-based mechanism that can be implemented without requiring detailed structural knowledge to rationally introduce this potentially useful property into several normally noncooperative biomolecules. To do so, we fabricate a tandem repeat of the receptor that is destabilized (unfolded) via the introduction of a long, unstructured loop. The first binding event requires the energetically unfavorable closing of this loop, reducing its affinity relative to that of the second binding event, which, in contrast occurs at a preformed site. Using this approach, we have rationally introduced cooperativity into three unrelated DNA aptamers, achieving in the best of these a Hill coefficient experimentally indistinguishable from the theoretically expected maximum. The extent of cooperativity and thus the steepness of the binding transition are, moreover, well modeled as simple functions of the energetic cost of binding-induced folding, speaking to the quantitative nature of this design strategy.

  9. Modeling dam-break flows using finite volume method on unstructured grid

    USDA-ARS?s Scientific Manuscript database

    Two-dimensional shallow water models based on unstructured finite volume method and approximate Riemann solvers for computing the intercell fluxes have drawn growing attention because of their robustness, high adaptivity to complicated geometry and ability to simulate flows with mixed regimes and di...

  10. The 3-D unstructured mesh generation using local transformations

    NASA Technical Reports Server (NTRS)

    Barth, Timothy J.

    1993-01-01

    The topics are presented in viewgraph form and include the following: 3D combinatorial edge swapping; 3D incremental triangulation via local transformations; a new approach to multigrid for unstructured meshes; surface mesh generation using local transforms; volume triangulations; viscous mesh generation; and future directions.

  11. 36 CFR 1236.24 - What are the additional requirements for managing unstructured electronic records?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... requirements for managing unstructured electronic records? 1236.24 Section 1236.24 Parks, Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION RECORDS MANAGEMENT ELECTRONIC RECORDS MANAGEMENT Additional Requirements for Electronic Records § 1236.24 What are the additional requirements for managing...

  12. 36 CFR 1236.24 - What are the additional requirements for managing unstructured electronic records?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... requirements for managing unstructured electronic records? 1236.24 Section 1236.24 Parks, Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION RECORDS MANAGEMENT ELECTRONIC RECORDS MANAGEMENT Additional Requirements for Electronic Records § 1236.24 What are the additional requirements for managing...

  13. 36 CFR 1236.24 - What are the additional requirements for managing unstructured electronic records?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... requirements for managing unstructured electronic records? 1236.24 Section 1236.24 Parks, Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION RECORDS MANAGEMENT ELECTRONIC RECORDS MANAGEMENT Additional Requirements for Electronic Records § 1236.24 What are the additional requirements for managing...

  14. 36 CFR 1236.24 - What are the additional requirements for managing unstructured electronic records?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... requirements for managing unstructured electronic records? 1236.24 Section 1236.24 Parks, Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION RECORDS MANAGEMENT ELECTRONIC RECORDS MANAGEMENT Additional Requirements for Electronic Records § 1236.24 What are the additional requirements for managing...

  15. Dopamine modulates an intrinsic mGluR5-mediated depolarization underlying prefrontal persistent activity

    PubMed Central

    Sidiropoulou, Kyriaki; Lu, Fang-Min; Fowler, Melissa A.; Xiao, Rui; Phillips, Christopher; Ozkan, Emin D.; Zhu, Michael X.; White, Francis J.; Cooper, Donald C.

    2009-01-01

    Intrinsic properties of neurons that enable them to maintain depolarized, persistently activated states in the absence of sustained input are poorly understood. In short-term memory tasks, individual prefrontal cortical (PFC) neurons are capable of maintaining persistent action potential output during delay periods between informative cues and behavioral responses. Dopamine and drugs of abuse alter PFC function and working memory possibly by modulating intrinsic neuronal properties. Here we use patch-clamp recording of layer 5 PFC pyramidal neurons to identify an action potential burst-evoked intrinsic mGluR5-mediated postsynaptic depolarization that initiates an activated state. Depolarization occurs in the absence of recurrent synaptic activity and is reduced by a postsynaptic dopamine D1/5 receptor pathway. The depolarization is substantially diminished following behavioral sensitization to cocaine; moreover the D1/5 receptor modulation is lost. We propose the burst-evoked intrinsic depolarization to be a novel form of short-term cellular memory that is modulated by dopamine and cocaine experience. PMID:19169252

  16. Conversion of Natively Unstructured α-Synuclein to Its α-Helical Conformation Significantly Attenuates Production of Reactive Oxygen Species

    PubMed Central

    Zhou, Binbin; Hao, Yuanqiang; Wang, Chengshan; Li, Ding; Liu, You-Nian; Zhou, Feimeng

    2012-01-01

    The intracellular α-synuclein (α-syn) protein, whose conformational change and aggregation have been closely linked to the pathology of Parkingson’s disease (PD), is highly populated at the presynaptic termini and remains there in the α-helical conformation. In this study, circular dichroism confirmed that natively unstructured α-syn in aqueous solution was transformed to its α-helical conformation upon addition of trifluoroethanol (TFE). Electrochemical and UV–visible spectroscopic experiments reveal that both Cu(I) and Cu(II) are stabilized, with the former being stabilized by about two orders of magnitude. Compared to unstructured α-syn (Binolfi et al., J. Am. Chem. Soc. 133 (2011) 194–196), α-helical α-syn stabilizes Cu(I) by more than three orders of magnitude. Through the measurements of H2O2 and hydroxyl radicals (OH•) in solutions containing different forms of Cu(II) (free and complexed by unstructured or α-helical α-syn), we demonstrate that the significantly enhanced Cu(I) binding affinity helps inhibit the production of highly toxic reactive oxygen species, especially the hydroxyl radicals. Our study provides strong evidence that, as a possible means to prevent neuronal cell damage, conversion of the natively unstructured α-syn to its α-helical conformation in vivo could significantly attenuate the copper-modulated ROS production. PMID:23123341

  17. A multidimensional unified gas-kinetic scheme for radiative transfer equations on unstructured mesh

    NASA Astrophysics Data System (ADS)

    Sun, Wenjun; Jiang, Song; Xu, Kun

    2017-12-01

    In order to extend the unified gas kinetic scheme (UGKS) to solve radiative transfer equations in a complex geometry, a multidimensional asymptotic preserving implicit method on unstructured mesh is constructed in this paper. With an implicit formulation, the CFL condition for the determination of the time step in UGKS can be much relaxed, and a large time step is used in simulations. Differently from previous direction-by-direction UGKS on orthogonal structured mesh, on unstructured mesh the interface flux transport takes into account multi-dimensional effect, where gradients of radiation intensity and material temperature in both normal and tangential directions of a cell interface are included in the flux evaluation. The multiple scale nature makes the UGKS be able to capture the solutions in both optically thin and thick regions seamlessly. In the optically thick region the condition of cell size being less than photon's mean free path is fully removed, and the UGKS recovers a solver for diffusion equation in such a limit on unstructured mesh. For a distorted quadrilateral mesh, the UGKS goes to a nine-point scheme for the diffusion equation, and it naturally reduces to the standard five-point scheme for a orthogonal quadrilateral mesh. Numerical computations covering a wide range of transport regimes on unstructured and distorted quadrilateral meshes will be presented to validate the current approach.

  18. Out-of-Core Streamline Visualization on Large Unstructured Meshes

    NASA Technical Reports Server (NTRS)

    Ueng, Shyh-Kuang; Sikorski, K.; Ma, Kwan-Liu

    1997-01-01

    It's advantageous for computational scientists to have the capability to perform interactive visualization on their desktop workstations. For data on large unstructured meshes, this capability is not generally available. In particular, particle tracing on unstructured grids can result in a high percentage of non-contiguous memory accesses and therefore may perform very poorly with virtual memory paging schemes. The alternative of visualizing a lower resolution of the data degrades the original high-resolution calculations. This paper presents an out-of-core approach for interactive streamline construction on large unstructured tetrahedral meshes containing millions of elements. The out-of-core algorithm uses an octree to partition and restructure the raw data into subsets stored into disk files for fast data retrieval. A memory management policy tailored to the streamline calculations is used such that during the streamline construction only a very small amount of data are brought into the main memory on demand. By carefully scheduling computation and data fetching, the overhead of reading data from the disk is significantly reduced and good memory performance results. This out-of-core algorithm makes possible interactive streamline visualization of large unstructured-grid data sets on a single mid-range workstation with relatively low main-memory capacity: 5-20 megabytes. Our test results also show that this approach is much more efficient than relying on virtual memory and operating system's paging algorithms.

  19. JIGSAW-GEO (1.0): Locally Orthogonal Staggered Unstructured Grid Generation for General Circulation Modelling on the Sphere

    NASA Technical Reports Server (NTRS)

    Engwirda, Darren

    2017-01-01

    An algorithm for the generation of non-uniform, locally orthogonal staggered unstructured spheroidal grids is described. This technique is designed to generate very high-quality staggered VoronoiDelaunay meshes appropriate for general circulation modelling on the sphere, including applications to atmospheric simulation, ocean-modelling and numerical weather prediction. Using a recently developed Frontal-Delaunay refinement technique, a method for the construction of high-quality unstructured spheroidal Delaunay triangulations is introduced. A locally orthogonal polygonal grid, derived from the associated Voronoi diagram, is computed as the staggered dual. It is shown that use of the Frontal-Delaunay refinement technique allows for the generation of very high-quality unstructured triangulations, satisfying a priori bounds on element size and shape. Grid quality is further improved through the application of hill-climbing-type optimisation techniques. Overall, the algorithm is shown to produce grids with very high element quality and smooth grading characteristics, while imposing relatively low computational expense. A selection of uniform and non-uniform spheroidal grids appropriate for high-resolution, multi-scale general circulation modelling are presented. These grids are shown to satisfy the geometric constraints associated with contemporary unstructured C-grid-type finite-volume models, including the Model for Prediction Across Scales (MPAS-O). The use of user-defined mesh-spacing functions to generate smoothly graded, non-uniform grids for multi-resolution-type studies is discussed in detail.

  20. JIGSAW-GEO (1.0): locally orthogonal staggered unstructured grid generation for general circulation modelling on the sphere

    NASA Astrophysics Data System (ADS)

    Engwirda, Darren

    2017-06-01

    An algorithm for the generation of non-uniform, locally orthogonal staggered unstructured spheroidal grids is described. This technique is designed to generate very high-quality staggered Voronoi-Delaunay meshes appropriate for general circulation modelling on the sphere, including applications to atmospheric simulation, ocean-modelling and numerical weather prediction. Using a recently developed Frontal-Delaunay refinement technique, a method for the construction of high-quality unstructured spheroidal Delaunay triangulations is introduced. A locally orthogonal polygonal grid, derived from the associated Voronoi diagram, is computed as the staggered dual. It is shown that use of the Frontal-Delaunay refinement technique allows for the generation of very high-quality unstructured triangulations, satisfying a priori bounds on element size and shape. Grid quality is further improved through the application of hill-climbing-type optimisation techniques. Overall, the algorithm is shown to produce grids with very high element quality and smooth grading characteristics, while imposing relatively low computational expense. A selection of uniform and non-uniform spheroidal grids appropriate for high-resolution, multi-scale general circulation modelling are presented. These grids are shown to satisfy the geometric constraints associated with contemporary unstructured C-grid-type finite-volume models, including the Model for Prediction Across Scales (MPAS-O). The use of user-defined mesh-spacing functions to generate smoothly graded, non-uniform grids for multi-resolution-type studies is discussed in detail.

  1. Unstructured mesh adaptivity for urban flooding modelling

    NASA Astrophysics Data System (ADS)

    Hu, R.; Fang, F.; Salinas, P.; Pain, C. C.

    2018-05-01

    Over the past few decades, urban floods have been gaining more attention due to their increase in frequency. To provide reliable flooding predictions in urban areas, various numerical models have been developed to perform high-resolution flood simulations. However, the use of high-resolution meshes across the whole computational domain causes a high computational burden. In this paper, a 2D control-volume and finite-element flood model using adaptive unstructured mesh technology has been developed. This adaptive unstructured mesh technique enables meshes to be adapted optimally in time and space in response to the evolving flow features, thus providing sufficient mesh resolution where and when it is required. It has the advantage of capturing the details of local flows and wetting and drying front while reducing the computational cost. Complex topographic features are represented accurately during the flooding process. For example, the high-resolution meshes around the buildings and steep regions are placed when the flooding water reaches these regions. In this work a flooding event that happened in 2002 in Glasgow, Scotland, United Kingdom has been simulated to demonstrate the capability of the adaptive unstructured mesh flooding model. The simulations have been performed using both fixed and adaptive unstructured meshes, and then results have been compared with those published 2D and 3D results. The presented method shows that the 2D adaptive mesh model provides accurate results while having a low computational cost.

  2. Intention to Be Physically Active after School Graduation and Its Relationship to Three Types of Intrinsic Motivation

    ERIC Educational Resources Information Center

    Hein, Vello; Muur, Maret; Koka, Andre

    2004-01-01

    In this article the relationships between three different types of intrinsic motivation and students' intention to be physically active after school graduation were examined. The participants were 400 school children aged 14-18 years. The modified version of SMS was used to measure the three different types of intrinsic motivation. The intention…

  3. Being Eager to Prove Oneself: U-Shaped Relationship between Competence Frustration and Intrinsic Motivation in Another Activity

    PubMed Central

    Fang, Hui; He, Bin; Fu, Huijian; Meng, Liang

    2017-01-01

    Competence frustration has been consistently found to undermine one’s intrinsic motivation in the same activity. However, the relationship between competence frustration in a preceding activity and one’s intrinsic motivation in a subsequent one remains unclear. In order to explore this relationship, self-reported data were collected from 617 undergraduate students of a large comprehensive university in southern China, who took varied courses immediately before taking a less-demanding one. Results suggested a U-shaped relationship between students’ competence frustration in a preceding course and intrinsic motivation in a subsequent one. To be specific, for students whose competence frustration reached the inflection point, a restoration process would be activated if the current course would help restore their competence. Importantly, these students’ competence frustration in a preceding course was found to positively predict their intrinsic motivation level in a subsequent course. As far as we are concerned, this is the first study to reveal a potential positive effect of need frustration outside of its primary thwarting context, which complements and extends existing literatures on the dynamics between need frustration and intrinsic motivation. PMID:29312025

  4. The intrinsic resistome of bacterial pathogens

    PubMed Central

    Olivares, Jorge; Bernardini, Alejandra; Garcia-Leon, Guillermo; Corona, Fernando; B. Sanchez, Maria; Martinez, Jose L.

    2013-01-01

    Intrinsically resistant bacteria have emerged as a relevant health problem in the last years. Those bacterial species, several of them with an environmental origin, present naturally low-level susceptibility to several drugs. It has been proposed that intrinsic resistance is mainly the consequence of the impermeability of cellular envelopes, the activity of multidrug efflux pumps or the lack of appropriate targets for a given family of drugs. However, recently published articles indicate that the characteristic phenotype of susceptibility to antibiotics of a given bacterial species depends on the concerted activity of several elements, what has been named as intrinsic resistome. These determinants comprise not just classical resistance genes. Other elements, several of them involved in basic bacterial metabolic processes, are of relevance for the intrinsic resistance of bacterial pathogens. In the present review we analyze recent publications on the intrinsic resistomes of Escherichia coli and Pseudomonas aeruginosa. We present as well information on the role that global regulators of bacterial metabolism, as Crc from P. aeruginosa, may have on modulating bacterial susceptibility to antibiotics. Finally, we discuss the possibility of searching inhibitors of the intrinsic resistome in the aim of improving the activity of drugs currently in use for clinical practice. PMID:23641241

  5. The intrinsic resistome of bacterial pathogens.

    PubMed

    Olivares, Jorge; Bernardini, Alejandra; Garcia-Leon, Guillermo; Corona, Fernando; B Sanchez, Maria; Martinez, Jose L

    2013-01-01

    Intrinsically resistant bacteria have emerged as a relevant health problem in the last years. Those bacterial species, several of them with an environmental origin, present naturally low-level susceptibility to several drugs. It has been proposed that intrinsic resistance is mainly the consequence of the impermeability of cellular envelopes, the activity of multidrug efflux pumps or the lack of appropriate targets for a given family of drugs. However, recently published articles indicate that the characteristic phenotype of susceptibility to antibiotics of a given bacterial species depends on the concerted activity of several elements, what has been named as intrinsic resistome. These determinants comprise not just classical resistance genes. Other elements, several of them involved in basic bacterial metabolic processes, are of relevance for the intrinsic resistance of bacterial pathogens. In the present review we analyze recent publications on the intrinsic resistomes of Escherichia coli and Pseudomonas aeruginosa. We present as well information on the role that global regulators of bacterial metabolism, as Crc from P. aeruginosa, may have on modulating bacterial susceptibility to antibiotics. Finally, we discuss the possibility of searching inhibitors of the intrinsic resistome in the aim of improving the activity of drugs currently in use for clinical practice.

  6. Structural landscape of the proline-rich domain of Sos1 nucleotide exchange factor.

    PubMed

    McDonald, Caleb B; Bhat, Vikas; Kurouski, Dmitry; Mikles, David C; Deegan, Brian J; Seldeen, Kenneth L; Lednev, Igor K; Farooq, Amjad

    2013-01-01

    Despite its key role in mediating a plethora of cellular signaling cascades pertinent to health and disease, little is known about the structural landscape of the proline-rich (PR) domain of Sos1 guanine nucleotide exchange factor. Herein, using a battery of biophysical tools, we provide evidence that the PR domain of Sos1 is structurally disordered and adopts an extended random coil-like conformation in solution. Of particular interest is the observation that while chemical denaturation of PR domain results in the formation of a significant amount of polyproline II (PPII) helices, it has little or negligible effect on its overall size as measured by its hydrodynamic radius. Our data also show that the PR domain displays a highly dynamic conformational basin in agreement with the knowledge that the intrinsically unstructured proteins rapidly interconvert between an ensemble of conformations. Collectively, our study provides new insights into the conformational equilibrium of a key signaling molecule with important consequences on its physiological function. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Analytic Steering: Inserting Context into the Information Dialog

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

    Bohn, Shawn J.; Calapristi, Augustin J.; Brown, Shyretha D.

    2011-10-23

    An analyst’s intrinsic domain knowledge is a primary asset in almost any analysis task. Unstructured text analysis systems that apply un-supervised content analysis approaches can be more effective if they can leverage this domain knowledge in a manner that augments the information discovery process without obfuscating new or unexpected content. Current unsupervised approaches rely upon the prowess of the analyst to submit the right queries or observe generalized document and term relationships from ranked or visual results. We propose a new approach which allows the user to control or steer the analytic view within the unsupervised space. This process ismore » controlled through the data characterization process via user supplied context in the form of a collection of key terms. We show that steering with an appropriate choice of key terms can provide better relevance to the analytic domain and still enable the analyst to uncover un-expected relationships; this paper discusses cases where various analytic steering approaches can provide enhanced analysis results and cases where analytic steering can have a negative impact on the analysis process.« less

  8. The Social Stigma Experience in Patients With Hepatitis B Infection: A Qualitative Study.

    PubMed

    Valizadeh, Leila; Zamanzadeh, Vahid; Bayani, Masomeh; Zabihi, Ali

    The social stigma in patients with hepatitis B virus infection has caused several complications for both the patients and the associated medical system. This study aimed at demonstrating the social stigma experienced by these patients in Iran. This is a qualitative study using a content analysis approach with references to primary and secondary sources. The data were collected through 15 unstructured and in-depth interviews conducted in 2014. By analyzing the data, two main themes were noted: extrinsic concepts of social stigma (causing reprehension, embarrassment, and discrimination) and intrinsic concepts of social stigma (sense of rejection, isolation, and frustration). The analysis of participants' experiences showed that social stigma is a simple lack of knowledge among the patients and society and it is more intense in the first days after the diagnosis. Stigma is prevalent among patients with hepatitis B virus, causes them to hide the disease, and provokes various complications for them as well as society. This study emphasizes the necessity of implementing health education programs about hepatitis B and its associated stigma, especially considering the potential impact of a mass media campaign.

  9. Observed Free-Play Patterns of Children with ADHD and Their Real-Life Friends.

    PubMed

    Normand, Sébastien; Soucisse, Marie Michèle; Melançon, Marie Pier Vézina; Schneider, Barry H; Lee, Matthew D; Maisonneuve, Marie-France

    2018-04-26

    Previous observational studies conducted in highly structured, analog situations indicate that children with Attention-Deficit/Hyperactivity Disorder (ADHD) mismanage their relationships with same-age peers and friends. Such structured situations may not, however, fully represent the true nature of children's play, which is typically characterized by free choice, intrinsic motivation, and spontaneity. The unique objective of the current observational study was to describe how 87 children with ADHD and 46 comparison (76% boys) aged 7-13 years behave when interacting with their real-life dyadic friends during an unstructured, free-play situation. Results indicate that dyads comprising one referred child with ADHD and an invited friend ("ADHD dyads") engaged in less cooperative play, displayed less companionship, and showed less sensitivity to friends than comparison dyads. ADHD dyads also engaged in more conflict and exhibited significantly more negative affect than comparison dyads. These findings complement and extend, possibly with somewhat enhanced ecological validity, results obtained in previous studies on the friendships of children with ADHD featuring closed-field observations and questionnaire methodology.

  10. The solution structures of the cucumber mosaic virus and tomato aspermy virus coat proteins explored with molecular dynamics simulations.

    PubMed

    Gellért, Akos; Balázs, Ervin

    2010-02-26

    The three-dimensional structures of two cucumovirus coat proteins (CP), namely Cucumber mosaic virus (CMV) and Tomato aspermy virus (TAV), were explored by molecular dynamics (MD) simulations. The N-terminal domain and the C-terminal tail of the CPs proved to be intrinsically unstructured protein regions in aqueous solution. The N-terminal alpha-helix had a partially unrolled conformation. The thermal factor analysis of the CP loop regions demonstrated that the CMV CP had more flexible loop regions than the TAV CP. The principal component analysis (PCA) of the MD trajectories showed that the first three eigenvectors represented the three main conformational motions in the CPs. The first motion components with the highest variance contribution described an opening movement between the hinge and the N-terminal domain of both CPs. The second eigenvector showed a closing motion, while the third eigenvector represented crosswise conformational fluctuations. These new findings, together with previous results, suggest that the hinge region of CPs plays a central role in the recognition and binding of viral RNA. Copyright 2009 Elsevier Inc. All rights reserved.

  11. Unsupervised Ontology Generation from Unstructured Text. CRESST Report 827

    ERIC Educational Resources Information Center

    Mousavi, Hamid; Kerr, Deirdre; Iseli, Markus R.

    2013-01-01

    Ontologies are a vital component of most knowledge acquisition systems, and recently there has been a huge demand for generating ontologies automatically since manual or supervised techniques are not scalable. In this paper, we introduce "OntoMiner", a rule-based, iterative method to extract and populate ontologies from unstructured or…

  12. Marathon Group Therapy with Female Narcotic Addicts.

    ERIC Educational Resources Information Center

    Kilmann, Peter R.

    This study evaluated the impact of structured and unstructured marathon therapy on institutionalized female narcotic addicts. Subjects were randomly assigned to one of five groups: two structured therapy groups, two unstructured therapy groups, and a no-treatment control group. The Personal Orientation Inventory, the Adjective Check List, and a…

  13. Imaging diagnosis--pulmonary metastases in New World camelids.

    PubMed

    Gall, David A; Zekas, Lisa J; Van Metre, David; Holt, Timothy

    2006-01-01

    The radiographic appearance of pulmonary metastatic disease from carcinoma is described in a llama and an alpaca. In one, a diffuse miliary pattern was seen. In the other, a more atypical unstructured interstitial pattern was recognized. Metastatic pulmonary neoplasia in camelids may assume a generalized miliary or unstructured pattern.

  14. Prediction of sport adherence through the influence of autonomy-supportive coaching among spanish adolescent athletes.

    PubMed

    Almagro, Bartolomé J; Sáenz-López, Pedro; Moreno, Juan A

    2010-01-01

    The purpose of this study was to test a motivational model of the coach-athlete relationship, based on self-determination theory and on the hierarchical model of intrinsic and extrinsic motivation. The sample comprised of 608 athletes (ages of 12-17 years) completed the following measures: interest in athlete's input, praise for autonomous behavior, perceived autonomy, intrinsic motivation, and the intention to be physically active. Structural equation modeling results demonstrated that interest in athletes' input and praise for autonomous behavior predicted perceived autonomy, and perceived autonomy positively predicted intrinsic motivation. Finally, intrinsic motivation predicted the intention to be physically active in the future. The results are discussed in relation to the importance of the climate of autonomy support created by the coach on intrinsic motivation and adherence to sport by adolescent athletes. Further, the results provide information related to the possible objectives of future interventions for the education of coaches, with the goal of providing them with tools and strategies to favor the development of intrinsic motivation among their athletes. In conclusion, the climate of autonomy support created by the coach can predict the autonomy perceived by the athletes which predicts the intrinsic motivation experienced by the athletes, and therefore, their adherence to athletic practice. Key pointsImportance of the climate of autonomy support created by the coach on intrinsic motivation and adherence to sport by adolescent athletes.Interest in athletes' input and praise for autonomous behavior predicted perceived autonomy, and perceived autonomy positively predicted intrinsic motivation.Intrinsic motivation predicted the intention to be physically active in the future.

  15. Prediction of Sport Adherence Through the Influence of Autonomy-Supportive Coaching Among Spanish Adolescent Athletes

    PubMed Central

    Almagro, Bartolomé J.; Sáenz-López, Pedro; Moreno, Juan A.

    2010-01-01

    The purpose of this study was to test a motivational model of the coach-athlete relationship, based on self-determination theory and on the hierarchical model of intrinsic and extrinsic motivation. The sample comprised of 608 athletes (ages of 12-17 years) completed the following measures: interest in athlete's input, praise for autonomous behavior, perceived autonomy, intrinsic motivation, and the intention to be physically active. Structural equation modeling results demonstrated that interest in athletes' input and praise for autonomous behavior predicted perceived autonomy, and perceived autonomy positively predicted intrinsic motivation. Finally, intrinsic motivation predicted the intention to be physically active in the future. The results are discussed in relation to the importance of the climate of autonomy support created by the coach on intrinsic motivation and adherence to sport by adolescent athletes. Further, the results provide information related to the possible objectives of future interventions for the education of coaches, with the goal of providing them with tools and strategies to favor the development of intrinsic motivation among their athletes. In conclusion, the climate of autonomy support created by the coach can predict the autonomy perceived by the athletes which predicts the intrinsic motivation experienced by the athletes, and therefore, their adherence to athletic practice. Key points Importance of the climate of autonomy support created by the coach on intrinsic motivation and adherence to sport by adolescent athletes. Interest in athletes' input and praise for autonomous behavior predicted perceived autonomy, and perceived autonomy positively predicted intrinsic motivation. Intrinsic motivation predicted the intention to be physically active in the future. PMID:24149380

  16. Neural differences between intrinsic reasons for doing versus extrinsic reasons for doing: an fMRI study.

    PubMed

    Lee, Woogul; Reeve, Johnmarshall; Xue, Yiqun; Xiong, Jinhu

    2012-05-01

    The contemporary neural understanding of motivation is based almost exclusively on the neural mechanisms of incentive motivation. Recognizing this as a limitation, we used event-related functional magnetic resonance imaging (fMRI) to pursue the viability of expanding the neural understanding of motivation by initiating a pioneering study of intrinsic motivation by scanning participants' neural activity when they decided to act for intrinsic reasons versus when they decided to act for extrinsic reasons. As expected, intrinsic reasons for acting more recruited insular cortex activity while extrinsic reasons for acting more recruited posterior cingulate cortex (PCC) activity. The results demonstrate that engagement decisions based on intrinsic motivation are more determined by weighing the presence of spontaneous self-satisfactions such as interest and enjoyment while engagement decisions based on extrinsic motivation are more determined by weighing socially-acquired stored values as to whether the environmental incentive is attractive enough to warrant action.

  17. Psychological determinants of adolescent exercise adherence.

    PubMed

    Douthitt, V L

    1994-01-01

    The purpose of this study was to identify some psychological determinants of exercise adherence on which public school physical education programs may have an impact. Data were collected twice, once representing a structured physical education classroom setting (N = 132), and later representing an unstructured summer vacation exercise setting (N = 110). Male and female physical education students at a large suburban high school completed five questionnaires which represented four psychological variables (self-motivation, perceived control, personality/sport congruence, and perceived self-competency), and one physical activity variable (exercise adherence) in both of the two data-collection periods. The results indicated that Perceived Romantic Appeal was predictive of male exercise adherence while Perceived Athletic Competency, Perceived Global Self-Worth, and Perceived Physical Appearance were predictive of female exercise adherence. None of the psychological predictor variables was significant for competitive subjects in either exercise setting, yet Perceived Romantic Appeal and Personality/Sport Congruence were predictive of noncompetitive subjects' exercise adherence in the structured and unstructured settings, respectively.

  18. Comparison of effect of regular unstructured physical training and athletic level training on body composition and cardio respiratory fitness in adolescents.

    PubMed

    Subramanian, Senthil Kumar; Sharma, Vivek Kumar; A, Vinayathan

    2013-09-01

    Childhood obesity and hypertension are global problems that are on the rise in India. Improving physical activity is an accepted main line of strategy for overcoming poor body composition, hypertension and reduced cardio respiratory fitness (CRF) all of which are considered as independent risk factors for the development of future cardiovascular complications. Present study was conducted to evaluate the effect of regular unstructured physical training and athletic level training on anthropometric measures, body composition, blood pressure and cardio respiratory fitness in adolescents. This is a collaborative study between the Department of physiology, Jawaharlal Institute of Postgraduate Medical Education and Research and Residential school, Jawahar Navodhya Vidyalaya, Puducherry, India. Student volunteers in the age group of 12-17 years were classified into athletes (group 1) and physically active non-athletes (group 2). Parameters measured and calculated were weight, height, body mass index, waist and hip circumference, body fat percentage (BF%), fat free mass (FFM), Systolic (SBP) & Diastolic blood pressure (DBP), Mean arterial pressure (MAP), Rate pressure product (RPP) and Predicted VO2 max. Mean difference between the groups was analysed using unpaired Student's t-test. All statistical analysis was carried out for two-tailed significance at the 5 % level using SPSS version 19 (SPSSInc, USA). Anthropometric measures, body composition measures and blood pressure values of both the group students were within the normal limits. There was no significant difference in anthropometric and body composition parameters between the group 1 and group 2 students. DBP, MAP and RPP were significantly lower in group 1 students when compared to group 2 students. VO2 max values were more in group 1 girls as compared to group 2 girls while the values of boys were comparable between the two groups. Regular unstructured physical activity for 60 minutes daily for the duration of one year can help the students to maintain their anthropometric parameters, body composition measures and CRF at par with the athletes of the same age and gender. However, athletic level training further reduces the cardiovascular load of the adolescent students.

  19. Progress Toward Overset-Grid Moving Body Capability for USM3D Unstructured Flow Solver

    NASA Technical Reports Server (NTRS)

    Pandyna, Mohagna J.; Frink, Neal T.; Noack, Ralph W.

    2005-01-01

    A static and dynamic Chimera overset-grid capability is added to an established NASA tetrahedral unstructured parallel Navier-Stokes flow solver, USM3D. Modifications to the solver primarily consist of a few strategic calls to the Donor interpolation Receptor Transaction library (DiRTlib) to facilitate communication of solution information between various grids. The assembly of multiple overlapping grids into a single-zone composite grid is performed by the Structured, Unstructured and Generalized Grid AssembleR (SUGGAR) code. Several test cases are presented to verify the implementation, assess overset-grid solution accuracy and convergence relative to single-grid solutions, and demonstrate the prescribed relative grid motion capability.

  20. Intrinsic Foot Muscle Activation During Specific Exercises: A T2 Time Magnetic Resonance Imaging Study.

    PubMed

    Gooding, Thomas M; Feger, Mark A; Hart, Joseph M; Hertel, Jay

    2016-08-01

    The intrinsic foot muscles maintain the medial longitudinal arch and aid in force distribution and postural control during gait. Impaired intrinsic foot-muscle function has been linked to various foot conditions. Several rehabilitative exercises have been proposed to improve it; however, literature that identifies which individual muscles are activated during specific intrinsic foot-muscle exercises is lacking. To describe changes in activation of the intrinsic plantar foot muscles after 4 exercises as measured with T2 magnetic resonance imaging (MRI). Descriptive laboratory study. Research laboratory. Eight healthy National Collegiate Athletic Association Division I collegiate cross-country and track athletes (5 men and 3 women: age = 20 ± 0.93 years, height = 180.98 ± 10.84 cm, mass = 70.91 ± 7.82 kg). Participants underwent T2 MRI before and after each exercise. They completed 1 set of 40 repetitions of each exercise (short-foot exercise, toes spread out, first-toe extension, second- to fifth-toes extension). Percentage increases in muscle activation of the abductor hallucis, flexor digitorum brevis, abductor digiti minimi, quadratus plantae, flexor digiti minimi, adductor hallucis oblique, flexor hallucis brevis, and interossei and lumbricals (analyzed together) after each exercise were assessed using T2 MRI. All muscles showed increased activation after all exercises. The mean percentage increase in activation ranged from 16.7% to 34.9% for the short-foot exercise, 17.3% to 35.2% for toes spread out, 13.1% to 18.1% for first-toe extension, and 8.9% to 22.5% for second- to fifth-toes extension. All increases in activation had associated 95% confidence intervals that did not cross zero. Each of the 4 exercises was associated with increased activation in all of the plantar intrinsic foot muscles evaluated. These results may have clinical implications for the prescription of specific exercises to target individual intrinsic foot muscles.

  1. Effect of intrinsic motivation on affective responses during and after exercise: latent curve model analysis.

    PubMed

    Shin, Myoungjin; Kim, Inwoo; Kwon, Sungho

    2014-12-01

    Understanding the relationship between affect and exercise is helpful in predicting human behavior with respect to exercise participation. The goals of the present study were to investigate individual differences in affective response during and after exercise and to identify the role of intrinsic motivation in affective changes. 30 active male college students (M age = 21.4 yr.) who regularly participated in sports activities volunteered to answer a questionnaire measuring intrinsic motivation toward running activities and performed a 20-min. straight running protocol at heavy intensity (about 70% of VO2max). Participants' affective responses were measured every 5 min. from the beginning of the run to 10 min. after completing the run. Latent curve model analysis indicated that individuals experienced different changes in affective state during exercise, moderated by intrinsic motivation. Higher intrinsic motivation was associated with more positive affect during exercise. There were no significant individual differences in the positive tendency of the participants' affective responses after exercise over time. Intrinsic motivation seems to facilitate positive feelings during exercise and encourages participation in exercise.

  2. 36 CFR § 1236.24 - What are the additional requirements for managing unstructured electronic records?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... requirements for managing unstructured electronic records? § 1236.24 Section § 1236.24 Parks, Forests, and Public Property NATIONAL ARCHIVES AND RECORDS ADMINISTRATION RECORDS MANAGEMENT ELECTRONIC RECORDS MANAGEMENT Additional Requirements for Electronic Records § 1236.24 What are the additional requirements for...

  3. Teaching Social Media Analytics: An Assessment Based on Natural Disaster Postings

    ERIC Educational Resources Information Center

    Goh, Tiong T.; Sun, Pei-Chen

    2015-01-01

    Unstructured data in social media is as part of the "big data" spectrum. Unstructured data in Social media can provide useful insights into social phenomena and citizen opinions, both of which are critical to government policy and businesses decisions. Teachers of business intelligence and analytics commonly use quantitative data from…

  4. Numerical aspects and implementation of a two-layer zonal wall model for LES of compressible turbulent flows on unstructured meshes

    NASA Astrophysics Data System (ADS)

    Park, George Ilhwan; Moin, Parviz

    2016-01-01

    This paper focuses on numerical and practical aspects associated with a parallel implementation of a two-layer zonal wall model for large-eddy simulation (LES) of compressible wall-bounded turbulent flows on unstructured meshes. A zonal wall model based on the solution of unsteady three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations on a separate near-wall grid is implemented in an unstructured, cell-centered finite-volume LES solver. The main challenge in its implementation is to couple two parallel, unstructured flow solvers for efficient boundary data communication and simultaneous time integrations. A coupling strategy with good load balancing and low processors underutilization is identified. Face mapping and interpolation procedures at the coupling interface are explained in detail. The method of manufactured solution is used for verifying the correct implementation of solver coupling, and parallel performance of the combined wall-modeled LES (WMLES) solver is investigated. The method has successfully been applied to several attached and separated flows, including a transitional flow over a flat plate and a separated flow over an airfoil at an angle of attack.

  5. A solution-adaptive hybrid-grid method for the unsteady analysis of turbomachinery

    NASA Technical Reports Server (NTRS)

    Mathur, Sanjay R.; Madavan, Nateri K.; Rajagopalan, R. G.

    1993-01-01

    A solution-adaptive method for the time-accurate analysis of two-dimensional flows in turbomachinery is described. The method employs a hybrid structured-unstructured zonal grid topology in conjunction with appropriate modeling equations and solution techniques in each zone. The viscous flow region in the immediate vicinity of the airfoils is resolved on structured O-type grids while the rest of the domain is discretized using an unstructured mesh of triangular cells. Implicit, third-order accurate, upwind solutions of the Navier-Stokes equations are obtained in the inner regions. In the outer regions, the Euler equations are solved using an explicit upwind scheme that incorporates a second-order reconstruction procedure. An efficient and robust grid adaptation strategy, including both grid refinement and coarsening capabilities, is developed for the unstructured grid regions. Grid adaptation is also employed to facilitate information transfer at the interfaces between unstructured grids in relative motion. Results for grid adaptation to various features pertinent to turbomachinery flows are presented. Good comparisons between the present results and experimental measurements and earlier structured-grid results are obtained.

  6. Investigation of advancing front method for generating unstructured grid

    NASA Technical Reports Server (NTRS)

    Thomas, A. M.; Tiwari, S. N.

    1992-01-01

    The advancing front technique is used to generate an unstructured grid about simple aerodynamic geometries. Unstructured grids are generated using VGRID2D and VGRID3D software. Specific problems considered are a NACA 0012 airfoil, a bi-plane consisting of two NACA 0012 airfoil, a four element airfoil in its landing configuration, and an ONERA M6 wing. Inviscid time dependent solutions are computed on these geometries using USM3D and the results are compared with standard test results obtained by other investigators. A grid convergence study is conducted for the NACA 0012 airfoil and compared with a structured grid. A structured grid is generated using GRIDGEN software and inviscid solutions computed using CFL3D flow solver. The results obtained by unstructured grid for NACA 0012 airfoil showed an asymmetric distribution of flow quantities, and a fine distribution of grid was required to remove this asymmetry. On the other hand, the structured grid predicted a very symmetric distribution, but when the total number of points were compared to obtain the same results it was seen that structured grid required more grid points.

  7. Modeling and simulation of xylitol production in bioreactor by Debaryomyces nepalensis NCYC 3413 using unstructured and artificial neural network models.

    PubMed

    Pappu, J Sharon Mano; Gummadi, Sathyanarayana N

    2016-11-01

    This study examines the use of unstructured kinetic model and artificial neural networks as predictive tools for xylitol production by Debaryomyces nepalensis NCYC 3413 in bioreactor. An unstructured kinetic model was proposed in order to assess the influence of pH (4, 5 and 6), temperature (25°C, 30°C and 35°C) and volumetric oxygen transfer coefficient kLa (0.14h(-1), 0.28h(-1) and 0.56h(-1)) on growth and xylitol production. A feed-forward back-propagation artificial neural network (ANN) has been developed to investigate the effect of process condition on xylitol production. ANN configuration of 6-10-3 layers was selected and trained with 339 experimental data points from bioreactor studies. Results showed that simulation and prediction accuracy of ANN was apparently higher when compared to unstructured mechanistic model under varying operational conditions. ANN was found to be an efficient data-driven tool to predict the optimal harvest time in xylitol production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Development of an unstructured solution adaptive method for the quasi-three-dimensional Euler and Navier-Stokes equations

    NASA Technical Reports Server (NTRS)

    Jiang, Yi-Tsann

    1993-01-01

    A general solution adaptive scheme-based on a remeshing technique is developed for solving the two-dimensional and quasi-three-dimensional Euler and Favre-averaged Navier-Stokes equations. The numerical scheme is formulated on an unstructured triangular mesh utilizing an edge-based pointer system which defines the edge connectivity of the mesh structure. Jameson's four-stage hybrid Runge-Kutta scheme is used to march the solution in time. The convergence rate is enhanced through the use of local time stepping and implicit residual averaging. As the solution evolves, the mesh is regenerated adaptively using flow field information. Mesh adaptation parameters are evaluated such that an estimated local numerical error is equally distributed over the whole domain. For inviscid flows, the present approach generates a complete unstructured triangular mesh using the advancing front method. For turbulent flows, the approach combines a local highly stretched structured triangular mesh in the boundary layer region with an unstructured mesh in the remaining regions to efficiently resolve the important flow features. One-equation and two-equation turbulence models are incorporated into the present unstructured approach. Results are presented for a wide range of flow problems including two-dimensional multi-element airfoils, two-dimensional cascades, and quasi-three-dimensional cascades. This approach is shown to gain flow resolution in the refined regions while achieving a great reduction in the computational effort and storage requirements since solution points are not wasted in regions where they are not required.

  9. Description of the F-16XL Geometry and Computational Grids Used in CAWAPI

    NASA Technical Reports Server (NTRS)

    Boelens, O. J.; Badcock, K. J.; Gortz, S.; Morton, S.; Fritz, W.; Karman, S. L., Jr.; Michal, T.; Lamar, J. E.

    2009-01-01

    The objective of the Cranked-Arrow Wing Aerodynamics Project International (CAWAPI) was to allow a comprehensive validation of Computational Fluid Dynamics methods against the CAWAP flight database. A major part of this work involved the generation of high-quality computational grids. Prior to the grid generation an IGES file containing the air-tight geometry of the F-16XL aircraft was generated by a cooperation of the CAWAPI partners. Based on this geometry description both structured and unstructured grids have been generated. The baseline structured (multi-block) grid (and a family of derived grids) has been generated by the National Aerospace Laboratory NLR. Although the algorithms used by NLR had become available just before CAWAPI and thus only a limited experience with their application to such a complex configuration had been gained, a grid of good quality was generated well within four weeks. This time compared favourably with that required to produce the unstructured grids in CAWAPI. The baseline all-tetrahedral and hybrid unstructured grids has been generated at NASA Langley Research Center and the USAFA, respectively. To provide more geometrical resolution, trimmed unstructured grids have been generated at EADS-MAS, the UTSimCenter, Boeing Phantom Works and KTH/FOI. All grids generated within the framework of CAWAPI will be discussed in the article. Both results obtained on the structured grids and the unstructured grids showed a significant improvement in agreement with flight test data in comparison with those obtained on the structured multi-block grid used during CAWAP.

  10. Development of an unstructured solution adaptive method for the quasi-three-dimensional Euler and Navier-Stokes equations

    NASA Technical Reports Server (NTRS)

    Jiang, Yi-Tsann; Usab, William J., Jr.

    1993-01-01

    A general solution adaptive scheme based on a remeshing technique is developed for solving the two-dimensional and quasi-three-dimensional Euler and Favre-averaged Navier-Stokes equations. The numerical scheme is formulated on an unstructured triangular mesh utilizing an edge-based pointer system which defines the edge connectivity of the mesh structure. Jameson's four-stage hybrid Runge-Kutta scheme is used to march the solution in time. The convergence rate is enhanced through the use of local time stepping and implicit residual averaging. As the solution evolves, the mesh is regenerated adaptively using flow field information. Mesh adaptation parameters are evaluated such that an estimated local numerical error is equally distributed over the whole domain. For inviscid flows, the present approach generates a complete unstructured triangular mesh using the advancing front method. For turbulent flows, the approach combines a local highly stretched structured triangular mesh in the boundary layer region with an unstructured mesh in the remaining regions to efficiently resolve the important flow features. One-equation and two-equation turbulence models are incorporated into the present unstructured approach. Results are presented for a wide range of flow problems including two-dimensional multi-element airfoils, two-dimensional cascades, and quasi-three-dimensional cascades. This approach is shown to gain flow resolution in the refined regions while achieving a great reduction in the computational effort and storage requirements since solution points are not wasted in regions where they are not required.

  11. Unsteady flow simulations around complex geometries using stationary or rotating unstructured grids

    NASA Astrophysics Data System (ADS)

    Sezer-Uzol, Nilay

    In this research, the computational analysis of three-dimensional, unsteady, separated, vortical flows around complex geometries is studied by using stationary or moving unstructured grids. Two main engineering problems are investigated. The first problem is the unsteady simulation of a ship airwake, where helicopter operations become even more challenging, by using stationary unstructured grids. The second problem is the unsteady simulation of wind turbine rotor flow fields by using moving unstructured grids which are rotating with the whole three-dimensional rigid rotor geometry. The three dimensional, unsteady, parallel, unstructured, finite volume flow solver, PUMA2, is used for the computational fluid dynamics (CFD) simulations considered in this research. The code is modified to have a moving grid capability to perform three-dimensional, time-dependent rotor simulations. An instantaneous log-law wall model for Large Eddy Simulations is also implemented in PUMA2 to investigate the very large Reynolds number flow fields of rotating blades. To verify the code modifications, several sample test cases are also considered. In addition, interdisciplinary studies, which are aiming to provide new tools and insights to the aerospace and wind energy scientific communities, are done during this research by focusing on the coupling of ship airwake CFD simulations with the helicopter flight dynamics and control analysis, the coupling of wind turbine rotor CFD simulations with the aeroacoustic analysis, and the analysis of these time-dependent and large-scale CFD simulations with the help of a computational monitoring, steering and visualization tool, POSSE.

  12. Motivation and Barriers for Leisure-Time Physical Activity in Socioeconomically Disadvantaged Women.

    PubMed

    Santos, Inês; Ball, Kylie; Crawford, David; Teixeira, Pedro J

    2016-01-01

    The aim of this study was to examine cross-sectional and longitudinal associations between motivation and barriers for physical activity, and physical activity behavior in women living in socioeconomic disadvantage. This study also examined whether weight control intentions moderate those associations. Data from 1664 women aged 18-46 years was collected at baseline and three-year follow-up as part of the Resilience for Eating and Activity Despite Inequality study. In mail-based surveys, women reported sociodemographic and neighborhood environmental characteristics, intrinsic motivation, goals and perceived family barriers to be active, weight control intentions and leisure-time physical activity (assessed through the IPAQ-L). Linear regression models assessed the association of intrinsic motivation, goals and barriers with physical activity at baseline and follow-up, adjusting for environmental characteristics and also physical activity at baseline (for longitudinal analyses), and the moderating effects of weight control intentions were examined. Intrinsic motivation and, to a lesser extent, appearance and relaxation goals for being physically active were consistently associated with leisure-time physical activity at baseline and follow-up. Perceived family barriers, health, fitness, weight and stress relief goals were associated with leisure-time physical activity only at baseline. Moderated regression analyses revealed that weight control intentions significantly moderated the association between weight goals and leisure-time physical activity at baseline (β = 0.538, 99% CI = 0.057, 0.990) and between intrinsic motivation and leisure-time physical activity at follow-up (β = 0.666, 99% CI = 0.188, 1.145). For women actively trying to control their weight, intrinsic motivation was significantly associated with leisure-time physical activity at follow-up (β = 0.184, 99% CI = 0.097, 0.313). Results suggest that, especially in women trying to control their weight, intrinsic motivation plays an important role in sustaining physical activity participation over time. Also, weight goals for being physically active seem to play a role regarding short-term physical activity participation in this particular population. Addressing these motivational features may be important when promoting physical activity participation in women living in socioeconomically disadvantaged neighborhoods.

  13. Motivation and Barriers for Leisure-Time Physical Activity in Socioeconomically Disadvantaged Women

    PubMed Central

    Santos, Inês; Ball, Kylie; Crawford, David; Teixeira, Pedro J.

    2016-01-01

    Introduction The aim of this study was to examine cross-sectional and longitudinal associations between motivation and barriers for physical activity, and physical activity behavior in women living in socioeconomic disadvantage. This study also examined whether weight control intentions moderate those associations. Methods Data from 1664 women aged 18–46 years was collected at baseline and three-year follow-up as part of the Resilience for Eating and Activity Despite Inequality study. In mail-based surveys, women reported sociodemographic and neighborhood environmental characteristics, intrinsic motivation, goals and perceived family barriers to be active, weight control intentions and leisure-time physical activity (assessed through the IPAQ-L). Linear regression models assessed the association of intrinsic motivation, goals and barriers with physical activity at baseline and follow-up, adjusting for environmental characteristics and also physical activity at baseline (for longitudinal analyses), and the moderating effects of weight control intentions were examined. Results Intrinsic motivation and, to a lesser extent, appearance and relaxation goals for being physically active were consistently associated with leisure-time physical activity at baseline and follow-up. Perceived family barriers, health, fitness, weight and stress relief goals were associated with leisure-time physical activity only at baseline. Moderated regression analyses revealed that weight control intentions significantly moderated the association between weight goals and leisure-time physical activity at baseline (β = 0.538, 99% CI = 0.057, 0.990) and between intrinsic motivation and leisure-time physical activity at follow-up (β = 0.666, 99% CI = 0.188, 1.145). For women actively trying to control their weight, intrinsic motivation was significantly associated with leisure-time physical activity at follow-up (β = 0.184, 99% CI = 0.097, 0.313). Conclusions Results suggest that, especially in women trying to control their weight, intrinsic motivation plays an important role in sustaining physical activity participation over time. Also, weight goals for being physically active seem to play a role regarding short-term physical activity participation in this particular population. Addressing these motivational features may be important when promoting physical activity participation in women living in socioeconomically disadvantaged neighborhoods. PMID:26808440

  14. Genetically increased cell-intrinsic excitability enhances neuronal integration into adult brain circuits

    PubMed Central

    Lin, Chia-Wei; Sim, Shuyin; Ainsworth, Alice; Okada, Masayoshi; Kelsch, Wolfgang; Lois, Carlos

    2009-01-01

    New neurons are added to the adult brain throughout life, but only half ultimately integrate into existing circuits. Sensory experience is an important regulator of the selection of new neurons but it remains unknown whether experience provides specific patterns of synaptic input, or simply a minimum level of overall membrane depolarization critical for integration. To investigate this issue, we genetically modified intrinsic electrical properties of adult-generated neurons in the mammalian olfactory bulb. First, we observed that suppressing levels of cell-intrinsic neuronal activity via expression of ESKir2.1 potassium channels decreases, whereas enhancing activity via expression of NaChBac sodium channels increases survival of new neurons. Neither of these modulations affects synaptic formation. Furthermore, even when neurons are induced to fire dramatically altered patterns of action potentials, increased levels of cell-intrinsic activity completely blocks cell death triggered by NMDA receptor deletion. These findings demonstrate that overall levels of cell-intrinsic activity govern survival of new neurons and precise firing patterns are not essential for neuronal integration into existing brain circuits. PMID:20152111

  15. Biphasic Somatic A-Type K+ Channel Downregulation Mediates Intrinsic Plasticity in Hippocampal CA1 Pyramidal Neurons

    PubMed Central

    Jung, Sung-Cherl; Hoffman, Dax A.

    2009-01-01

    Since its original description, the induction of synaptic long-term potentiation (LTP) has been known to be accompanied by a lasting increase in the intrinsic excitability (intrinsic plasticity) of hippocampal neurons. Recent evidence shows that dendritic excitability can be enhanced by an activity-dependent decrease in the activity of A-type K+ channels. In the present manuscript, we examined the role of A-type K+ channels in regulating intrinsic excitability of CA1 pyramidal neurons of the hippocampus after synapse-specific LTP induction. In electrophysiological recordings we found that LTP induced a potentiation of excitability which was accompanied by a two-phased change in A-type K+ channel activity recorded in nucleated patches from organotypic slices of rat hippocampus. Induction of LTP resulted in an immediate but short lasting hyperpolarization of the voltage-dependence of steady-state A-type K+ channel inactivation along with a progressive, long-lasting decrease in peak A-current density. Blocking clathrin-mediated endocytosis prevented the A-current decrease and most measures of intrinsic plasticity. These results suggest that two temporally distinct but overlapping mechanisms of A-channel downregulation together contribute to the plasticity of intrinsic excitability. Finally we show that intrinsic plasticity resulted in a global enhancement of EPSP-spike coupling. PMID:19662093

  16. Rotor Airloads Prediction Using Unstructured Meshes and Loose CFD/CSD Coupling

    NASA Technical Reports Server (NTRS)

    Biedron, Robert T.; Lee-Rausch, Elizabeth M.

    2008-01-01

    The FUN3D unsteady Reynolds-averaged Navier-Stokes solver for unstructured grids has been modified to allow prediction of trimmed rotorcraft airloads. The trim of the rotorcraft and the aeroelastic deformation of the rotor blades are accounted for via loose coupling with the CAMRAD II rotorcraft computational structural dynamics code. The set of codes is used to analyze the HART-II Baseline, Minimum Noise and Minimum Vibration test conditions. The loose coupling approach is found to be stable and convergent for the cases considered. Comparison of the resulting airloads and structural deformations with experimentally measured data is presented. The effect of grid resolution and temporal accuracy is examined. Rotorcraft airloads prediction presents a very substantial challenge for Computational Fluid Dynamics (CFD). Not only must the unsteady nature of the flow be accurately modeled, but since most rotorcraft blades are not structurally stiff, an accurate simulation must account for the blade structural dynamics. In addition, trim of the rotorcraft to desired thrust and moment targets depends on both aerodynamic loads and structural deformation, and vice versa. Further, interaction of the fuselage with the rotor flow field can be important, so that relative motion between the blades and the fuselage must be accommodated. Thus a complete simulation requires coupled aerodynamics, structures and trim, with the ability to model geometrically complex configurations. NASA has recently initiated a Subsonic Rotary Wing (SRW) Project under the overall Fundamental Aeronautics Program. Within the context of SRW are efforts aimed at furthering the state of the art of high-fidelity rotorcraft flow simulations, using both structured and unstructured meshes. Structured-mesh solvers have an advantage in computation speed, but even though remarkably complex configurations may be accommodated using the overset grid approach, generation of complex structured-mesh systems can require months to set up. As a result, many rotorcraft simulations using structured-grid CFD neglect the fuselage. On the other hand, unstructured-mesh solvers are easily able to handle complex geometries, but suffer from slower execution speed. However, advances in both computer hardware and CFD algorithms have made previously state-of-the-art computations routine for unstructured-mesh solvers, so that rotorcraft simulations using unstructured grids are now viable. The aim of the present work is to develop a first principles rotorcraft simulation tool based on an unstructured CFD solver.

  17. Unstructured medical image query using big data - An epilepsy case study.

    PubMed

    Istephan, Sarmad; Siadat, Mohammad-Reza

    2016-02-01

    Big data technologies are critical to the medical field which requires new frameworks to leverage them. Such frameworks would benefit medical experts to test hypotheses by querying huge volumes of unstructured medical data to provide better patient care. The objective of this work is to implement and examine the feasibility of having such a framework to provide efficient querying of unstructured data in unlimited ways. The feasibility study was conducted specifically in the epilepsy field. The proposed framework evaluates a query in two phases. In phase 1, structured data is used to filter the clinical data warehouse. In phase 2, feature extraction modules are executed on the unstructured data in a distributed manner via Hadoop to complete the query. Three modules have been created, volume comparer, surface to volume conversion and average intensity. The framework allows for user-defined modules to be imported to provide unlimited ways to process the unstructured data hence potentially extending the application of this framework beyond epilepsy field. Two types of criteria were used to validate the feasibility of the proposed framework - the ability/accuracy of fulfilling an advanced medical query and the efficiency that Hadoop provides. For the first criterion, the framework executed an advanced medical query that spanned both structured and unstructured data with accurate results. For the second criterion, different architectures were explored to evaluate the performance of various Hadoop configurations and were compared to a traditional Single Server Architecture (SSA). The surface to volume conversion module performed up to 40 times faster than the SSA (using a 20 node Hadoop cluster) and the average intensity module performed up to 85 times faster than the SSA (using a 40 node Hadoop cluster). Furthermore, the 40 node Hadoop cluster executed the average intensity module on 10,000 models in 3h which was not even practical for the SSA. The current study is limited to epilepsy field and further research and more feature extraction modules are required to show its applicability in other medical domains. The proposed framework advances data-driven medicine by unleashing the content of unstructured medical data in an efficient and unlimited way to be harnessed by medical experts. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Investigating motivational regulations and physical activity over 25 weeks.

    PubMed

    Sweet, Shane N; Fortier, Michelle S; Blanchard, Chris M

    2014-07-01

    Because motivation has been deemed a key barrier to physical activity, it is imperative that we know how motivational levels change over time and how that change relates to physical activity. Based in Self-Determination Theory, this study investigated fluctuations in physical activity and motivational regulations over 25 weeks and tested the relationship between these 2 variables. Data from the Physical Activity Counseling trial were examined. Inactive adults recruited from a primary care center (N = 120) answered motivation and physical activity questionnaires during the intervention and postintervention phases. Hierarchical linear modeling was used to test the hypotheses. Quadratic changes were found for external regulation (γ20= 0.02, P < .05) and physical activity (γ20 = -2.64, P < .001), while identified (γ10= 0.04, P = .03) and intrinsic (γ10= 0.04, P = .01) regulations increased linearly over the course of the 25 weeks. Only identified regulation (γ30= 3.15, P = .01) and intrinsic motivation (γ30= 4.68, P < .001) were significantly and positively related with physical activity. Physical activity, external and identified regulations and intrinsic motivation changed over the 25 weeks. Intervention should aim at fostering identified regulation and intrinsic motivation as greater levels of these regulations were related with physical activity.

  19. Intrinsic Patterns of Human Activity

    NASA Astrophysics Data System (ADS)

    Hu, Kun; Ivanov, Plamen Ch.; Chen, Zhi; Hilton, Michael; Stanley, H. Eugene; Shea, Steven

    2003-03-01

    Activity is one of the defining features of life. Control of human activity is complex, being influenced by many factors both extrinsic and intrinsic to the body. The most obvious extrinsic factors that affect activity are the daily schedule of planned events, such as work and recreation, as well as reactions to unforeseen or random events. These extrinsic factors may account for the apparently random fluctuations in human motion observed over short time scales. The most obvious intrinsic factors are the body clocks including the circadian pacemaker that influences our sleep/wake cycle and ultradian oscillators with shorter time scales [2, 3]. These intrinsic rhythms may account for the underlying regularity in average activity level over longer periods of up to 24 h. Here we ask if the known extrinsic and intrinsic factors fully account for all complex features observed in recordings of human activity. To this end, we measure activity over two weeks from forearm motion in subjects undergoing their regular daily routine. Utilizing concepts from statistical physics, we demonstrate that during wakefulness human activity possesses previously unrecognized complex dynamic patterns. These patterns of activity are characterized by robust fractal and nonlinear dynamics including a universal probability distribution and long-range power-law correlations that are stable over a wide range of time scales (from minutes to hours). Surprisingly, we find that these dynamic patterns are unaffected by changes in the average activity level that occur within individual subjects throughout the day and on different days of the week, and between subjects. Moreover, we find that these patterns persist when the same subjects undergo time-isolation laboratory experiments designed to account for the phase of the circadian pacemaker, and control the known extrinsic factors by restricting behaviors and manipulating scheduled events including the sleep/wake cycle. We attribute these newly discovered patterns to a robust intrinsic multi-scale dynamic regulation of human activity that is independent of known extrinsic factors, and independent from the circadian and ultradian rhythms.

  20. Relations of perception of responsibility to intrinsic motivation and physical activity among Korean middle school students.

    PubMed

    Lee, Okseon; Kim, Younhee; Kim, Oung Jun

    2012-12-01

    To validate the Personal and Social Responsibility Questionnaire, the relations between perceived responsibility and intrinsic motivation were examined among Korean middle school students. The relations of change in stages of physical activity and students' perceived responsibility were also examined. Participants were 357 middle school students (160 boys, 197 girls) from three schools in the Seoul metropolitan area. Exploratory factor analysis supported a three-factor structure with effort and self-direction merged into one factor and the responsibilities of respect and caring for others constituted separate factors. Pearson correlations among factors showed perceptions of personal responsibility were associated with more intrinsic motivation toward physical education and a higher stage of physical activity. A moderate or low association between perceived social responsibility and intrinsic motivation implied a need to develop strategies for Korean students to use social responsibility for promoting physical activity.

  1. Child, family and environmental correlates of children's motor skill proficiency.

    PubMed

    Barnett, Lisa; Hinkley, Trina; Okely, Anthony D; Salmon, Jo

    2013-07-01

    To identify factors associated with children's motor skills. Cross-sectional. Australian preschool-aged children were recruited in 2009 as part of a larger study. Parent proxy-report of child factors (age, sex, parent perception of child skill, participation in unstructured and structured activity), self-report of parent factors (confidence in their own skills to support child's activity, parent-child physical activity interaction, parent physical activity) and perceived environmental factors (play space visits, equipment at home) were collected. Moderate to vigorous physical activity (MVPA) (ActiGraph GT1M accelerometer) and motor skills (Test of Gross Motor Development-2) were also assessed. After age adjustment, variables were checked for association with raw object control and locomotor scores. Variables with associations of p<0.20 were entered into two multiple regression models with locomotor/object control as respective outcome variables. Motor skills were assessed for 76 children (42 female), mean [SD] age=4.1 [0.68]; 71 completed parent proxy-report and 53 had valid MVPA data. Child age, swimming lessons, and home equipment were positively associated explaining 20% of locomotor skill variance, but only age was significant (β=0.36, p=0.002). Child age and sex, unstructured activity participation, MVPA%, parent confidence, home equipment (all positively associated), and dance participation (inversely associated) explained 32% object control variance. But only age (β=0.67, p<0.0001), MVPA% (β=0.37, p=0.038) and no dance (β=-0.34, p=0.028) were significant. Motor skill correlates differ according to skill category and are context specific with child level correlates appearing more important. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  2. Nine centuries waiting: The experiences of Iranians surrogacy commissioning mothers.

    PubMed

    Zandi, Mitra; Vanaki, Zohreh; Shiva, Marziyeh; Mohammadi, Eesa

    2014-05-01

    There are a few studies about commissioning mothers' understanding from the surrogacy during 9 months of waiting for delivery in Iran and other countries. This study was conducted with an aim to explore and explain the nature of concerns (experiences) of commissioning mothers. A qualitative design with a conventional content analysis approach was used to gather and analyze the experiences of commissioning mothers. They were selected from Royan Research Centre and other infertility centers in Iran. After purposive sampling for the selection of the participants, unstructured interviews were held for data collection. Twenty-four unstructured interviews were conducted with 12 commissioning mothers, 2 surrogate mothers, and 2 infertility center social workers who directly and continuously dealt with these mothers. TWO MAIN THEMES EMERGED FROM THE DATA ANALYSIS: 1. cultural dilemma (consisting of three subthemes: Social taboo, concerns about disclosure to others and the child, concerns about altering maternal and child's identity, and 2. uncertain waiting (consisting of three subthemes: Concerns about health of fetus and surrogate, concerns about an unfamiliar surrogate, and concerns about lack of preparation for maternal role). The study reveals the importance of maternal emotional care in this group and introduces a new arena for nurses' activity. These findings help the mothers by nurses' activities in health care clinics and anywhere they deliver nursing care.

  3. Unstructured Adaptive (UA) NAS Parallel Benchmark. Version 1.0

    NASA Technical Reports Server (NTRS)

    Feng, Huiyu; VanderWijngaart, Rob; Biswas, Rupak; Mavriplis, Catherine

    2004-01-01

    We present a complete specification of a new benchmark for measuring the performance of modern computer systems when solving scientific problems featuring irregular, dynamic memory accesses. It complements the existing NAS Parallel Benchmark suite. The benchmark involves the solution of a stylized heat transfer problem in a cubic domain, discretized on an adaptively refined, unstructured mesh.

  4. Young Children's Opportunities for Unstructured Environmental Exploration of Nature: Links to Adults' Experiences in Childhood

    ERIC Educational Resources Information Center

    Laird, Shelby Gull; McFarland-Piazza, Laura; Allen, Sydnye

    2014-01-01

    Outdoor environmental education and provision of unstructured exploration of nature are often forgotten aspects of the early childhood experience. The aim of this study was to understand how adults' early experiences in nature relate to their attitudes and practices in providing such experiences for young children. This study surveyed 33 parents…

  5. 2D Mesh Manipulation

    DTIC Science & Technology

    2011-11-01

    the Poisson form of the equations can also be generated by manipulating the computational space , so forcing functions become superfluous . The...ABSTRACT Unstructured methods for region discretization have become common in computational fluid dynamics (CFD) analysis because of certain benefits...application of Winslow elliptic smoothing equations to unstructured meshes. It has been shown that it is not necessary for the computational space of

  6. Learning to Take an Inquiry Stance in Teacher Research: An Exploration of Unstructured Thought-Partner Spaces

    ERIC Educational Resources Information Center

    Lawton-Sticklor, Nastasia; Bodamer, Scott F.

    2016-01-01

    This article explores a research partnership between a university-based researcher and a middle school science teacher. Our partnership began with project-based inquiry and continued with unstructured thought-partner spaces: meetings with no agenda where we wrestled with problems of practice. Framed as incubation periods, these meetings allowed us…

  7. Implementation of a parallel unstructured Euler solver on shared and distributed memory architectures

    NASA Technical Reports Server (NTRS)

    Mavriplis, D. J.; Das, Raja; Saltz, Joel; Vermeland, R. E.

    1992-01-01

    An efficient three dimensional unstructured Euler solver is parallelized on a Cray Y-MP C90 shared memory computer and on an Intel Touchstone Delta distributed memory computer. This paper relates the experiences gained and describes the software tools and hardware used in this study. Performance comparisons between two differing architectures are made.

  8. Development of a solution adaptive unstructured scheme for quasi-3D inviscid flows through advanced turbomachinery cascades

    NASA Technical Reports Server (NTRS)

    Usab, William J., Jr.; Jiang, Yi-Tsann

    1991-01-01

    The objective of the present research is to develop a general solution adaptive scheme for the accurate prediction of inviscid quasi-three-dimensional flow in advanced compressor and turbine designs. The adaptive solution scheme combines an explicit finite-volume time-marching scheme for unstructured triangular meshes and an advancing front triangular mesh scheme with a remeshing procedure for adapting the mesh as the solution evolves. The unstructured flow solver has been tested on a series of two-dimensional airfoil configurations including a three-element analytic test case presented here. Mesh adapted quasi-three-dimensional Euler solutions are presented for three spanwise stations of the NASA rotor 67 transonic fan. Computed solutions are compared with available experimental data.

  9. NCAR global model topography generation software for unstructured grids

    NASA Astrophysics Data System (ADS)

    Lauritzen, P. H.; Bacmeister, J. T.; Callaghan, P. F.; Taylor, M. A.

    2015-06-01

    It is the purpose of this paper to document the NCAR global model topography generation software for unstructured grids. Given a model grid, the software computes the fraction of the grid box covered by land, the gridbox mean elevation, and associated sub-grid scale variances commonly used for gravity wave and turbulent mountain stress parameterizations. The software supports regular latitude-longitude grids as well as unstructured grids; e.g. icosahedral, Voronoi, cubed-sphere and variable resolution grids. As an example application and in the spirit of documenting model development, exploratory simulations illustrating the impacts of topographic smoothing with the NCAR-DOE CESM (Community Earth System Model) CAM5.2-SE (Community Atmosphere Model version 5.2 - Spectral Elements dynamical core) are shown.

  10. RIACS

    NASA Technical Reports Server (NTRS)

    Oliger, Joseph

    1997-01-01

    Topics considered include: high-performance computing; cognitive and perceptual prostheses (computational aids designed to leverage human abilities); autonomous systems. Also included: development of a 3D unstructured grid code based on a finite volume formulation and applied to the Navier-stokes equations; Cartesian grid methods for complex geometry; multigrid methods for solving elliptic problems on unstructured grids; algebraic non-overlapping domain decomposition methods for compressible fluid flow problems on unstructured meshes; numerical methods for the compressible navier-stokes equations with application to aerodynamic flows; research in aerodynamic shape optimization; S-HARP: a parallel dynamic spectral partitioner; numerical schemes for the Hamilton-Jacobi and level set equations on triangulated domains; application of high-order shock capturing schemes to direct simulation of turbulence; multicast technology; network testbeds; supercomputer consolidation project.

  11. Laminar and turbulent flow computations of Type 4 shock-shock interference aerothermal loads using unstructured grids

    NASA Technical Reports Server (NTRS)

    Vemaganti, Gururaja R.

    1994-01-01

    This report presents computations for the Type 4 shock-shock interference flow under laminar and turbulent conditions using unstructured grids. Mesh adaptation was accomplished by remeshing, refinement, and mesh movement. Two two-equation turbulence models were used to analyze turbulent flows. The mean flow governing equations and the turbulence governing equations are solved in a coupled manner. The solution algorithm and the details pertaining to its implementation on unstructured grids are described. Computations were performed at two different freestream Reynolds numbers at a freestream Mach number of 11. Effects of the variation in the impinging shock location are studied. The comparison of the results in terms of wall heat flux and wall pressure distributions is presented.

  12. A note on implementation of decaying product correlation structures for quasi-least squares.

    PubMed

    Shults, Justine; Guerra, Matthew W

    2014-08-30

    This note implements an unstructured decaying product matrix via the quasi-least squares approach for estimation of the correlation parameters in the framework of generalized estimating equations. The structure we consider is fairly general without requiring the large number of parameters that are involved in a fully unstructured matrix. It is straightforward to show that the quasi-least squares estimators of the correlation parameters yield feasible values for the unstructured decaying product structure. Furthermore, subject to conditions that are easily checked, the quasi-least squares estimators are valid for longitudinal Bernoulli data. We demonstrate implementation of the structure in a longitudinal clinical trial with both a continuous and binary outcome variable. Copyright © 2014 John Wiley & Sons, Ltd.

  13. Extended bounds limiter for high-order finite-volume schemes on unstructured meshes

    NASA Astrophysics Data System (ADS)

    Tsoutsanis, Panagiotis

    2018-06-01

    This paper explores the impact of the definition of the bounds of the limiter proposed by Michalak and Ollivier-Gooch in [56] (2009), for higher-order Monotone-Upstream Central Scheme for Conservation Laws (MUSCL) numerical schemes on unstructured meshes in the finite-volume (FV) framework. A new modification of the limiter is proposed where the bounds are redefined by utilising all the spatial information provided by all the elements in the reconstruction stencil. Numerical results obtained on smooth and discontinuous test problems of the Euler equations on unstructured meshes, highlight that the newly proposed extended bounds limiter exhibits superior performance in terms of accuracy and mesh sensitivity compared to the cell-based or vertex-based bounds implementations.

  14. Context Oriented Information Integration

    NASA Astrophysics Data System (ADS)

    Mohania, Mukesh; Bhide, Manish; Roy, Prasan; Chakaravarthy, Venkatesan T.; Gupta, Himanshu

    Faced with growing knowledge management needs, enterprises are increasingly realizing the importance of seamlessly integrating critical business information distributed across both structured and unstructured data sources. Academicians have focused on this problem but there still remain a lot of obstacles for its widespread use in practice. One of the key problems is the absence of schema in unstructured text. In this paper we present a new paradigm for integrating information which overcomes this problem - that of Context Oriented Information Integration. The goal is to integrate unstructured data with the structured data present in the enterprise and use the extracted information to generate actionable insights for the enterprise. We present two techniques which enable context oriented information integration and show how they can be used for solving real world problems.

  15. Coordination of intrinsic and extrinsic hand muscle activity as a function of wrist joint angle during two-digit grasping.

    PubMed

    Johnston, Jamie A; Bobich, Lisa R; Santello, Marco

    2010-04-26

    Fingertip forces result from the activation of muscles that cross the wrist and muscles whose origins and insertions reside within the hand (extrinsic and intrinsic hand muscles, respectively). Thus, tasks that involve changes in wrist angle affect the moment arm and length, hence the force-producing capabilities, of extrinsic muscles only. If a grasping task requires the exertion of constant fingertip forces, the Central Nervous System (CNS) may respond to changes in wrist angle by modulating the neural drive to extrinsic or intrinsic muscles only or by co-activating both sets of muscles. To distinguish between these scenarios, we recorded electromyographic (EMG) activity of intrinsic and extrinsic muscles of the thumb and index finger as a function of wrist angle during a two-digit object hold task. We hypothesized that changes in wrist angle would elicit EMG amplitude modulation of the extrinsic and intrinsic hand muscles. In one experimental condition we asked subjects to exert the same digit forces at each wrist angle, whereas in a second condition subjects could choose digit forces for holding the object. EMG activity was significantly modulated in both extrinsic and intrinsic muscles as a function of wrist angle (both p<0.05) but only for the constant force condition. Furthermore, EMG modulation resulted from uniform scaling of EMG amplitude across all muscles. We conclude that the CNS controlled both extrinsic and intrinsic muscles as a muscle synergy. These findings are discussed within the theoretical frameworks of synergies and common neural input across motor nuclei of hand muscles. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  16. Neural differences between intrinsic reasons for doing versus extrinsic reasons for doing: an fMRI study

    PubMed Central

    Lee, Woogul; Reeve, Johnmarshall; Xue, Yiqun; Xiong, Jinhu

    2012-01-01

    The contemporary neural understanding of motivation is based almost exclusively on the neural mechanisms of incentive motivation. Recognizing this as a limitation, we used event-related functional magnetic resonance imaging (fMRI) to pursue the viability of expanding the neural understanding of motivation by initiating a pioneering study of intrinsic motivation by scanning participants’ neural activity when they decided to act for intrinsic reasons versus when they decided to act for extrinsic reasons. As expected, intrinsic reasons for acting more recruited insular cortex activity while extrinsic reasons for acting more recruited posterior cingulate cortex (PCC) activity. The results demonstrate that engagement decisions based on intrinsic motivation are more determined by weighing the presence of spontaneous self-satisfactions such as interest and enjoyment while engagement decisions based on extrinsic motivation are more determined by weighing socially-acquired stored values as to whether the environmental incentive is attractive enough to warrant action. PMID:23565014

  17. Intrinsic motivation towards sports in Singaporean students: the role of sport ability beliefs.

    PubMed

    Wang, C K John; Biddle, Stuart J H

    2003-09-01

    This study investigated determinants of active lifestyles in Singaporean university students. Using confirmatory factor analysis, a measure of lay beliefs concerning athletic ability was confirmed. Other results confirmed hypotheses that beliefs reflecting that athletic ability can be developed over time (incremental beliefs) predict an achievement task (self-referenced) orientation, while beliefs reflecting that athletic ability is relatively stable (entity beliefs) predict an ego (other-person, comparative) orientation. Goal orientations directly affect perceived competence which, in turn, influence intrinsic motivation to be physically active. A task orientation had a direct link to intrinsic motivation. Results suggest that intrinsic motivation towards sport and physical activity might be enhanced through interventions that focus on self-referenced and self-improvement notions of ability as well as perceived competence.

  18. The brain correlates of the effects of monetary and verbal rewards on intrinsic motivation.

    PubMed

    Albrecht, Konstanze; Abeler, Johannes; Weber, Bernd; Falk, Armin

    2014-01-01

    Apart from everyday duties, such as doing the laundry or cleaning the house, there are tasks we do for pleasure and enjoyment. We do such tasks, like solving crossword puzzles or reading novels, without any external pressure or force; instead, we are intrinsically motivated: we do the tasks because we enjoy doing them. Previous studies suggest that external rewards, i.e., rewards from the outside, affect the intrinsic motivation to engage in a task: while performance-based monetary rewards are perceived as controlling and induce a business-contract framing, verbal rewards praising one's competence can enhance the perceived self-determination. Accordingly, the former have been shown to decrease intrinsic motivation, whereas the latter have been shown to increase intrinsic motivation. The present study investigated the neural processes underlying the effects of monetary and verbal rewards on intrinsic motivation in a group of 64 subjects applying functional magnetic resonance imaging (fMRI). We found that, when participants received positive performance feedback, activation in the anterior striatum and midbrain was affected by the nature of the reward; compared to a non-rewarded control group, activation was higher while monetary rewards were administered. However, we did not find a decrease in activation after reward withdrawal. In contrast, we found an increase in activation for verbal rewards: after verbal rewards had been withdrawn, participants showed a higher activation in the aforementioned brain areas when they received success compared to failure feedback. We further found that, while participants worked on the task, activation in the lateral prefrontal cortex was enhanced after the verbal rewards were administered and withdrawn.

  19. The brain correlates of the effects of monetary and verbal rewards on intrinsic motivation

    PubMed Central

    Albrecht, Konstanze; Abeler, Johannes; Weber, Bernd; Falk, Armin

    2014-01-01

    Apart from everyday duties, such as doing the laundry or cleaning the house, there are tasks we do for pleasure and enjoyment. We do such tasks, like solving crossword puzzles or reading novels, without any external pressure or force; instead, we are intrinsically motivated: we do the tasks because we enjoy doing them. Previous studies suggest that external rewards, i.e., rewards from the outside, affect the intrinsic motivation to engage in a task: while performance-based monetary rewards are perceived as controlling and induce a business-contract framing, verbal rewards praising one's competence can enhance the perceived self-determination. Accordingly, the former have been shown to decrease intrinsic motivation, whereas the latter have been shown to increase intrinsic motivation. The present study investigated the neural processes underlying the effects of monetary and verbal rewards on intrinsic motivation in a group of 64 subjects applying functional magnetic resonance imaging (fMRI). We found that, when participants received positive performance feedback, activation in the anterior striatum and midbrain was affected by the nature of the reward; compared to a non-rewarded control group, activation was higher while monetary rewards were administered. However, we did not find a decrease in activation after reward withdrawal. In contrast, we found an increase in activation for verbal rewards: after verbal rewards had been withdrawn, participants showed a higher activation in the aforementioned brain areas when they received success compared to failure feedback. We further found that, while participants worked on the task, activation in the lateral prefrontal cortex was enhanced after the verbal rewards were administered and withdrawn. PMID:25278834

  20. Rapid activity-dependent modulation of the intrinsic excitability through up-regulation of KCNQ/Kv7 channel function in neonatal spinal motoneurons.

    PubMed

    Lombardo, Joseph; Sun, Jianli; Harrington, Melissa A

    2018-01-01

    Activity-dependent changes in the properties of the motor system underlie the necessary adjustments in its responsiveness on the basis of the environmental and developmental demands of the organism. Although plastic changes in the properties of the spinal cord have historically been neglected because of the archaic belief that the spinal cord is constituted by a hardwired network that simply relays information to muscles, plenty of evidence has been accumulated showing that synapses impinging on spinal motoneurons undergo short- and long-term plasticity. In the brain, brief changes in the activity level of the network have been shown to be paralleled by changes in the intrinsic excitability of the neurons and are suggested to either reinforce or stabilize the changes at the synaptic level. However, rapid activity-dependent changes in the intrinsic properties of spinal motoneurons have never been reported. In this study, we show that in neonatal mice the intrinsic excitability of spinal motoneurons is depressed after relatively brief but sustained changes in the spinal cord network activity. Using electrophysiological techniques together with specific pharmacological blockers of KCNQ/Kv7 channels, we demonstrate their involvement in the reduction of the intrinsic excitability of spinal motoneurons. This action results from an increased M-current, the product of the activation of KCNQ/Kv7 channels, which leads to a hyperpolarization of the resting membrane potential and a decrease in the input resistance of spinal motoneurons. Computer simulations showed that specific up-regulations in KCNQ/Kv7 channels functions lead to a modulation of the intrinsic excitability of spinal motoneurons as observed experimentally. These results indicate that KCNQ/Kv7 channels play a fundamental role in the activity-dependent modulation of the excitability of spinal motoneurons.

  1. Exploitation of molecular mobilities for advanced organic optoelectronic and photonic nano-materials

    NASA Astrophysics Data System (ADS)

    Gray, Tomoko O.

    Electro-optically active organic materials have shown great potential in advanced technologies such as ultrafast electro-optical switches for broadband communication, light-emitting diodes, and photovoltaic cells. Currently, the maturity of chemical synthesis enables a sophisticated integration of the active elements into complex macromolecules. Also, the structure-property relationships of the isolated single electrically/optically active elements are well established. Unfortunately, such correlations involving single molecule are not applicable to complex unstructured condensed systems, in which unique mesoscale properties and complex dynamics of super-/supra-molecular structures are present. Our current challenge arises, in particular, from a deficiency of appropriate characterization tools that close the gap between phenomenological measurements and theoretical models. This work addresses submolecular mobilities relevant for opto-electronic functionalities of photoluminescent polymers and non-linear optical (NLO) materials. Thereby, I will introduce novel nanoscale thermomechanical characterization tools that are based on scanning force microscopy. From nanoscale thermomechanical measurements sub-/super-molecular mobilities of novel optoelectronic materials can be inferred and to some degree controlled. For instance, we have explored interfacial constraints as a engineering tool to control molecular mobility. This will be illustrated with electroluminescent polymers, which are prone to undesired pi-pi aggregation due to the rod-like structure---intrinsic to all conjugated polymers. The nanoscale confinement is used to reduced chain mobility, and thus, hinders undesired aggregation, and consequently, yields superior spectral stability. From the nanomaterial design perspective, I will also address mobility control with targeted molecular designs. This involves two classes of novel NLO materials, side-chain dendronized polymers and self-assembling molecular glasses. The side-chain dendronized polymers are, due to the structural complexity, self-constrained systems. Our thermomechanical investigations identified that a local relaxation mode associated to the NLO side-chain is the critical design parameter in yielding high mobility to the active element. Relaxation processes of the self-assembling molecular glasses are discussed from a thermodynamic perspective involving both enthalpic and entropic contributions, considering the very special nature of interactions for the NLO molecular glasses, i.e., the formation and dissociation of phenyl/perfluorophenyl quadrupol pairs.

  2. Autonomy supportive environments and mastery as basic factors to motivate physical activity in children: a controlled laboratory study

    USDA-ARS?s Scientific Manuscript database

    Background Choice promotes the experience of autonomy, which enhances intrinsic motivation. Providing a greater choice of traditional active toys may increase children’s activity time. Mastery also increases intrinsic motivation and is designed into exergames, which may increase play time of a singl...

  3. Assessment of Hybrid RANS/LES Turbulence Models for Aeroacoustics Applications

    NASA Technical Reports Server (NTRS)

    Vatsa, Veer N.; Lockard, David P.

    2010-01-01

    Predicting the noise from aircraft with exposed landing gear remains a challenging problem for the aeroacoustics community. Although computational fluid dynamics (CFD) has shown promise as a technique that could produce high-fidelity flow solutions, generating grids that can resolve the pertinent physics around complex configurations can be very challenging. Structured grids are often impractical for such configurations. Unstructured grids offer a path forward for simulating complex configurations. However, few unstructured grid codes have been thoroughly tested for unsteady flow problems in the manner needed for aeroacoustic prediction. A widely used unstructured grid code, FUN3D, is examined for resolving the near field in unsteady flow problems. Although the ultimate goal is to compute the flow around complex geometries such as the landing gear, simpler problems that include some of the relevant physics, and are easily amenable to the structured grid approaches are used for testing the unstructured grid approach. The test cases chosen for this study correspond to the experimental work on single and tandem cylinders conducted in the Basic Aerodynamic Research Tunnel (BART) and the Quiet Flow Facility (QFF) at NASA Langley Research Center. These configurations offer an excellent opportunity to assess the performance of hybrid RANS/LES turbulence models that transition from RANS in unresolved regions near solid bodies to LES in the outer flow field. Several of these models have been implemented and tested in both structured and unstructured grid codes to evaluate their dependence on the solver and mesh type. Comparison of FUN3D solutions with experimental data and numerical solutions from a structured grid flow solver are found to be encouraging.

  4. Integrating Structured and Unstructured EHR Data Using an FHIR-based Type System: A Case Study with Medication Data.

    PubMed

    Hong, Na; Wen, Andrew; Shen, Feichen; Sohn, Sunghwan; Liu, Sijia; Liu, Hongfang; Jiang, Guoqian

    2018-01-01

    Standards-based modeling of electronic health records (EHR) data holds great significance for data interoperability and large-scale usage. Integration of unstructured data into a standard data model, however, poses unique challenges partially due to heterogeneous type systems used in existing clinical NLP systems. We introduce a scalable and standards-based framework for integrating structured and unstructured EHR data leveraging the HL7 Fast Healthcare Interoperability Resources (FHIR) specification. We implemented a clinical NLP pipeline enhanced with an FHIR-based type system and performed a case study using medication data from Mayo Clinic's EHR. Two UIMA-based NLP tools known as MedXN and MedTime were integrated in the pipeline to extract FHIR MedicationStatement resources and related attributes from unstructured medication lists. We developed a rule-based approach for assigning the NLP output types to the FHIR elements represented in the type system, whereas we investigated the FHIR elements belonging to the source of the structured EMR data. We used the FHIR resource "MedicationStatement" as an example to illustrate our integration framework and methods. For evaluation, we manually annotated FHIR elements in 166 medication statements from 14 clinical notes generated by Mayo Clinic in the course of patient care, and used standard performance measures (precision, recall and f-measure). The F-scores achieved ranged from 0.73 to 0.99 for the various FHIR element representations. The results demonstrated that our framework based on the FHIR type system is feasible for normalizing and integrating both structured and unstructured EHR data.

  5. Effects of domain-specific exercise load on speed and accuracy of a domain-specific perceptual-cognitive task.

    PubMed

    Schapschröer, M; Baker, J; Schorer, J

    2016-08-01

    In the context of perceptual-cognitive expertise it is important to know whether physiological loads influence perceptual-cognitive performance. This study examined whether a handball specific physical exercise load influenced participants' speed and accuracy in a flicker task. At rest and during a specific interval exercise of 86.5-90% HRmax, 35 participants (experts: n=8, advanced: n=13, novices, n=14) performed a handball specific flicker task with two types of patterns (structured and unstructured). For reaction time, results revealed moderate effect sizes for group, with experts reacting faster than advanced and advanced reacting faster than novices, and for structure, with structured videos being performed faster than unstructured ones. A significant interaction for structure×group was also found, with experts and advanced players faster for structured videos, and novices faster for unstructured videos. For accuracy, significant main effects were found for structure with structured videos solved more accurately. A significant interaction for structure×group was revealed, with experts and advanced more accurate for structured scenes and novices more accurate for unstructured scenes. A significant interaction was also found for condition×structure; at rest, unstructured and structured scenes were performed with the same accuracy while under physical exercise, structured scenes were solved more accurately. No other interactions were found. These results were somewhat surprising given previous work in this area, although the impact of a specific physical exercise on a specific perceptual-cognitive task may be different from those tested generally. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Expanding the proteome: disordered and alternatively-folded proteins

    PubMed Central

    Dyson, H. Jane

    2011-01-01

    Proteins provide much of the scaffolding for life, as well as undertaking a variety of essential catalytic reactions. These characteristic functions have led us to presuppose that proteins are in general functional only when well-structured and correctly folded. As we begin to explore the repertoire of possible protein sequences inherent in the human and other genomes, two stark facts that belie this supposition become clear: firstly, the number of apparent open reading frames in the human genome is significantly smaller than appears to be necessary to code for all of the diverse proteins in higher organisms, and secondly that a significant proportion of the protein sequences that would be coded by the genome would not be expected to form stable three-dimensional structures. Clearly the genome must include coding for a multitude of alternative forms of proteins, some of which may be partly or fully disordered or incompletely structured in their functional states. At the same time as this likelihood was recognized, experimental studies also began to uncover examples of important protein molecules and domains that were incompletely structured or completely disordered in solution, yet remained perfectly functional. In the ensuing years, we have seen an explosion of experimental and genome-annotation studies that have mapped the extent of the intrinsic disorder phenomenon and explored the possible biological rationales for its widespread occurrence. Answers to the question “why would a particular domain need to be unstructured?” are as varied as the systems where such domains are found. This review provides a survey of recent new directions in this field, and includes an evaluation of the role not only of intrinsically disordered proteins but of partially structured and highly dynamic members of the disorder-order continuum. PMID:21729349

  7. Computer Science Students' Attitudes towards the Use of Structured and Unstructured Discussion Forums in Fully Online Courses

    ERIC Educational Resources Information Center

    Tibi, Moanes H.

    2018-01-01

    This study aims to investigate and analyze the attitudes and opinions of computer science students at two academic colleges of education with regards to the use of structured and unstructured discussion forums in computer science courses conducted entirely online. Fifty-two students participated in two online courses. The students in each course…

  8. A mesh regeneration method using quadrilateral and triangular elements for compressible flows

    NASA Technical Reports Server (NTRS)

    Vemaganti, G. R.; Thornton, E. A.

    1989-01-01

    An adaptive remeshing method using both triangular and quadrilateral elements suitable for high-speed viscous flows is presented. For inviscid flows, the method generates completely unstructured meshes. For viscous flows, structured meshes are generated for boundary layers, and unstructured meshes are generated for inviscid flow regions. Examples of inviscid and viscous adaptations for high-speed flows are presented.

  9. Center for Efficient Exascale Discretizations Software Suite

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

    Kolev, Tzanio; Dobrev, Veselin; Tomov, Vladimir

    The CEED Software suite is a collection of generally applicable software tools focusing on the following computational motives: PDE discretizations on unstructured meshes, high-order finite element and spectral element methods and unstructured adaptive mesh refinement. All of this software is being developed as part of CEED, a co-design Center for Efficient Exascale Discretizations, within DOE's Exascale Computing Project (ECP) program.

  10. Hanging out with Which Friends? Friendship-Level Predictors of Unstructured and Unsupervised Socializing in Adolescence

    ERIC Educational Resources Information Center

    Siennick, Sonja E.; Osgood, D. Wayne

    2012-01-01

    Companions are central to explanations of the risky nature of unstructured and unsupervised socializing, yet we know little about whom adolescents are with when hanging out. We examine predictors of how often friendship dyads hang out via multilevel analyses of longitudinal friendship-level data on over 5,000 middle schoolers. Adolescents hang out…

  11. Impact of Machine-Translated Text on Entity and Relationship Extraction

    DTIC Science & Technology

    2014-12-01

    20 1 1. Introduction Using social network analysis tools is an important asset in...semantic modeling software to automatically build detailed network models from unstructured text. Contour imports unstructured text and then maps the text...onto an existing ontology of frames at the sentence level, using FrameNet, a structured language model, and through Semantic Role Labeling ( SRL

  12. On unstructured grids and solvers

    NASA Technical Reports Server (NTRS)

    Barth, T. J.

    1990-01-01

    The fundamentals and the state-of-the-art technology for unstructured grids and solvers are highlighted. Algorithms and techniques pertinent to mesh generation are discussed. It is shown that grid generation and grid manipulation schemes rely on fast multidimensional searching. Flow solution techniques for the Euler equations, which can be derived from the integral form of the equations are discussed. Sample calculations are also provided.

  13. Consequences of the Allee effect and intraspecific competition on population persistence under adverse environmental conditions.

    PubMed

    Petrovskii, Sergei; Blackshaw, Rod; Li, Bai-Lian

    2008-02-01

    The impact of intraspecific interactions on ecological stability and population persistence in terms of steady state(s) existence is considered theoretically based on a general competition model. We compare persistence of a structured population consisting of a few interacting (competitive) subpopulations, or groups, to persistence of the corresponding unstructured population. For a general case, we show that if the intra-group competition is stronger than the inter-group competition, then the structured population is less prone to extinction, i.e. it can persist in a parameter range where the unstructured population goes extinct. For a more specific case of a population with hierarchical competition, we show that relative viability of structured and unstructured populations depend on the type of density dependence in the population growth. Namely, while in the case of logistic growth, structured and unstructured populations exhibit equivalent persistence; in the case of Allee dynamics, the persistence of a hierarchically structured population is shown to be higher. We then apply these results to the case of behaviourally structured populations and demonstrate that an extreme form of individual aggression can be beneficial at the population level and enhance population persistence.

  14. Finding geospatial pattern of unstructured data by clustering routes

    NASA Astrophysics Data System (ADS)

    Boustani, M.; Mattmann, C. A.; Ramirez, P.; Burke, W.

    2016-12-01

    Today the majority of data generated has a geospatial context to it. Either in attribute form as a latitude or longitude, or name of location or cross referenceable using other means such as an external gazetteer or location service. Our research is interested in exploiting geospatial location and context in unstructured data such as that found on the web in HTML pages, images, videos, documents, and other areas, and in structured information repositories found on intranets, in scientific environments, and otherwise. We are working together on the DARPA MEMEX project to exploit open source software tools such as the Lucene Geo Gazetteer, Apache Tika, Apache Lucene, and Apache OpenNLP, to automatically extract, and make meaning out of geospatial information. In particular, we are interested in unstructured descriptors e.g., a phone number, or a named entity, and the ability to automatically learn geospatial paths related to these descriptors. For example, a particular phone number may represent an entity that travels on a monthly basis, according to easily identifiable and somes more difficult to track patterns. We will present a set of automatic techniques to extract descriptors, and then to geospatially infer their paths across unstructured data.

  15. Unstructured Socializing with Peers and Delinquent Behavior: A Genetically Informed Analysis.

    PubMed

    Meldrum, Ryan C; Barnes, J C

    2017-09-01

    A large body of research finds that unstructured socializing with peers is positively associated with delinquency during adolescence. Yet, existing research has not ruled out the potential for confounding due to genetic factors and factors that can be traced to environments shared between siblings. To fill this void, the current study examines whether the association between unstructured socializing with peers and delinquent behavior remains when accounting for genetic factors, shared environmental influences, and a variety of non-shared environmental covariates. We do so by using data from the twin subsample of the National Longitudinal Study of Adolescent to Adult Health (n = 1200 at wave 1 and 1103 at wave 2; 51% male; mean age at wave 1 = 15.63). Results from both cross-sectional and lagged models indicate the association between unstructured socializing with peers and delinquent behavior remains when controlling for both genetic and environmental influences. Supplementary analyses examining the association under different specifications offer additional, albeit qualified, evidence supportive of this finding. The study concludes with a discussion highlighting the importance of limiting free time with friends in the absence of authority figures as a strategy for reducing delinquency during adolescence.

  16. Collaborative human-machine analysis to disambiguate entities in unstructured text and structured datasets

    NASA Astrophysics Data System (ADS)

    Davenport, Jack H.

    2016-05-01

    Intelligence analysts demand rapid information fusion capabilities to develop and maintain accurate situational awareness and understanding of dynamic enemy threats in asymmetric military operations. The ability to extract relationships between people, groups, and locations from a variety of text datasets is critical to proactive decision making. The derived network of entities must be automatically created and presented to analysts to assist in decision making. DECISIVE ANALYTICS Corporation (DAC) provides capabilities to automatically extract entities, relationships between entities, semantic concepts about entities, and network models of entities from text and multi-source datasets. DAC's Natural Language Processing (NLP) Entity Analytics model entities as complex systems of attributes and interrelationships which are extracted from unstructured text via NLP algorithms. The extracted entities are automatically disambiguated via machine learning algorithms, and resolution recommendations are presented to the analyst for validation; the analyst's expertise is leveraged in this hybrid human/computer collaborative model. Military capability is enhanced by these NLP Entity Analytics because analysts can now create/update an entity profile with intelligence automatically extracted from unstructured text, thereby fusing entity knowledge from structured and unstructured data sources. Operational and sustainment costs are reduced since analysts do not have to manually tag and resolve entities.

  17. An Introduction to Natural Language Processing: How You Can Get More From Those Electronic Notes You Are Generating.

    PubMed

    Kimia, Amir A; Savova, Guergana; Landschaft, Assaf; Harper, Marvin B

    2015-07-01

    Electronically stored clinical documents may contain both structured data and unstructured data. The use of structured clinical data varies by facility, but clinicians are familiar with coded data such as International Classification of Diseases, Ninth Revision, Systematized Nomenclature of Medicine-Clinical Terms codes, and commonly other data including patient chief complaints or laboratory results. Most electronic health records have much more clinical information stored as unstructured data, for example, clinical narrative such as history of present illness, procedure notes, and clinical decision making are stored as unstructured data. Despite the importance of this information, electronic capture or retrieval of unstructured clinical data has been challenging. The field of natural language processing (NLP) is undergoing rapid development, and existing tools can be successfully used for quality improvement, research, healthcare coding, and even billing compliance. In this brief review, we provide examples of successful uses of NLP using emergency medicine physician visit notes for various projects and the challenges of retrieving specific data and finally present practical methods that can run on a standard personal computer as well as high-end state-of-the-art funded processes run by leading NLP informatics researchers.

  18. Queries over Unstructured Data: Probabilistic Methods to the Rescue

    NASA Astrophysics Data System (ADS)

    Sarawagi, Sunita

    Unstructured data like emails, addresses, invoices, call transcripts, reviews, and press releases are now an integral part of any large enterprise. A challenge of modern business intelligence applications is analyzing and querying data seamlessly across structured and unstructured sources. This requires the development of automated techniques for extracting structured records from text sources and resolving entity mentions in data from various sources. The success of any automated method for extraction and integration depends on how effectively it unifies diverse clues in the unstructured source and in existing structured databases. We argue that statistical learning techniques like Conditional Random Fields (CRFs) provide a accurate, elegant and principled framework for tackling these tasks. Given the inherent noise in real-world sources, it is important to capture the uncertainty of the above operations via imprecise data models. CRFs provide a sound probability distribution over extractions but are not easy to represent and query in a relational framework. We present methods of approximating this distribution to query-friendly row and column uncertainty models. Finally, we present models for representing the uncertainty of de-duplication and algorithms for various Top-K count queries on imprecise duplicates.

  19. Activation and reactivation of the RNA polymerase II trigger loop for intrinsic RNA cleavage and catalysis

    PubMed Central

    Čabart, Pavel; Jin, Huiyan; Li, Liangtao; Kaplan, Craig D

    2014-01-01

    In addition to RNA synthesis, multisubunit RNA polymerases (msRNAPs) support enzymatic reactions such as intrinsic transcript cleavage. msRNAP active sites from different species appear to exhibit differential intrinsic transcript cleavage efficiency and have likely evolved to allow fine-tuning of the transcription process. Here we show that a single amino-acid substitution in the trigger loop (TL) of Saccharomyces RNAP II, Rpb1 H1085Y, engenders a gain of intrinsic cleavage activity where the substituted tyrosine appears to participate in acid-base chemistry at alkaline pH for both intrinsic cleavage and nucleotidyl transfer. We extensively characterize this TL substitution for each of these reactions by examining the responses RNAP II enzymes to catalytic metals, altered pH, and factor inputs. We demonstrate that TFIIF stimulation of the first phosphodiester bond formation by RNAP II requires wild type TL function and that H1085Y substitution within the TL compromises or alters RNAP II responsiveness to both TFIIB and TFIIF. Finally, Mn2+ stimulation of H1085Y RNAP II reveals possible allosteric effects of TFIIB on the active center and cooperation between TFIIB and TFIIF. PMID:25764335

  20. Exploring the Role of Intrinsic Nodal Activation on the Spread of Influence in Complex Networks

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

    Visweswara Sathanur, Arun; Halappanavar, Mahantesh; Shi, Yi

    In many complex networked systems such as online social networks, at any given time, activity originates at certain nodes and subsequently spreads on the network through influence. To model the spread of influence in such a scenario, we consider the problem of identification of influential entities in a complex network when nodal activation can happen through two different mechanisms. The first mode of activation is due mechanisms intrinsic to the node. The second mechanism is through the influence of connected neighbors. In this work, we present a simple probabilistic formulation that models such self-evolving systems where information diffusion occurs primarilymore » because of the intrinsic activity of users and the spread of activity occurs due to influence. We provide an algorithm to mine for the influential seeds in such a scenario by modifying the well-known influence maximization framework with the independent cascade diffusion model. We provide small motivating examples to provide an intuitive understanding of the effect of including the intrinsic activation mechanism. We sketch a proof of the submodularity of the influence function under the new formulation and demonstrate the same with larger graphs. We then show by means of additional experiments on a real-world twitter dataset how the formulation can be applied to real-world social media datasets. Finally we derive a computationally efficient centrality metric that takes into account, both the mechanisms of activation and provides for an accurate as well as computationally efficient alternative approach to the problem of identifying influencers under intrinsic activation.« less

  1. Focal activation of primary visual cortex following supra-choroidal electrical stimulation of the retina: Intrinsic signal imaging and linear model analysis.

    PubMed

    Cloherty, Shaun L; Hietanen, Markus A; Suaning, Gregg J; Ibbotson, Michael R

    2010-01-01

    We performed optical intrinsic signal imaging of cat primary visual cortex (Area 17 and 18) while delivering bipolar electrical stimulation to the retina by way of a supra-choroidal electrode array. Using a general linear model (GLM) analysis we identified statistically significant (p < 0.01) activation in a localized region of cortex following supra-threshold electrical stimulation at a single retinal locus. (1) demonstrate that intrinsic signal imaging combined with linear model analysis provides a powerful tool for assessing cortical responses to prosthetic stimulation, and (2) confirm that supra-choroidal electrical stimulation can achieve localized activation of the cortex consistent with focal activation of the retina.

  2. Robust and efficient overset grid assembly for partitioned unstructured meshes

    NASA Astrophysics Data System (ADS)

    Roget, Beatrice; Sitaraman, Jayanarayanan

    2014-03-01

    This paper presents a method to perform efficient and automated Overset Grid Assembly (OGA) on a system of overlapping unstructured meshes in a parallel computing environment where all meshes are partitioned into multiple mesh-blocks and processed on multiple cores. The main task of the overset grid assembler is to identify, in parallel, among all points in the overlapping mesh system, at which points the flow solution should be computed (field points), interpolated (receptor points), or ignored (hole points). Point containment search or donor search, an algorithm to efficiently determine the cell that contains a given point, is the core procedure necessary for accomplishing this task. Donor search is particularly challenging for partitioned unstructured meshes because of the complex irregular boundaries that are often created during partitioning.

  3. Boundary-Layer Stability Analysis of the Mean Flows Obtained Using Unstructured Grids

    NASA Technical Reports Server (NTRS)

    Liao, Wei; Malik, Mujeeb R.; Lee-Rausch, Elizabeth M.; Li, Fei; Nielsen, Eric J.; Buning, Pieter G.; Chang, Chau-Lyan; Choudhari, Meelan M.

    2012-01-01

    Boundary-layer stability analyses of mean flows extracted from unstructured-grid Navier- Stokes solutions have been performed. A procedure has been developed to extract mean flow profiles from the FUN3D unstructured-grid solutions. Extensive code-to-code validations have been performed by comparing the extracted mean ows as well as the corresponding stability characteristics to the predictions based on structured-grid solutions. Comparisons are made on a range of problems from a simple at plate to a full aircraft configuration-a modified Gulfstream-III with a natural laminar flow glove. The future aim of the project is to extend the adjoint-based design capability in FUN3D to include natural laminar flow and laminar flow control by integrating it with boundary-layer stability analysis codes, such as LASTRAC.

  4. Mixed Element Type Unstructured Grid Generation for Viscous Flow Applications

    NASA Technical Reports Server (NTRS)

    Marcum, David L.; Gaither, J. Adam

    2000-01-01

    A procedure is presented for efficient generation of high-quality unstructured grids suitable for CFD simulation of high Reynolds number viscous flow fields. Layers of anisotropic elements are generated by advancing along prescribed normals from solid boundaries. The points are generated such that either pentahedral or tetrahedral elements with an implied connectivity can be be directly recovered. As points are generated they are temporarily attached to a volume triangulation of the boundary points. This triangulation allows efficient local search algorithms to be used when checking merging layers, The existing advancing-front/local-reconnection procedure is used to generate isotropic elements outside of the anisotropic region. Results are presented for a variety of applications. The results demonstrate that high-quality anisotropic unstructured grids can be efficiently and consistently generated for complex configurations.

  5. Motivation and Behavioral Regulation of Physical Activity in Middle-School Students

    PubMed Central

    Dishman, Rod K.; McIver, Kerry L; Dowda, Marsha; Saunders, Ruth P.; Pate, Russell R.

    2015-01-01

    Purpose To examine whether intrinsic motivation and behavioral self-regulation are related to physical activity during middle school. Method Structural equation modeling was applied in cross-sectional and longitudinal tests of self-determination theory. Results Consistent with theory, hypothesized relationships among variables were supported. Integrated regulation and intrinsic motivation were most strongly correlated with moderate-to-vigorous physical activity measured by an accelerometer. Results were independent of a measure of biological maturity. Construct validity and equivalence of measures was confirmed longitudinally between 6th and 7th grades and between boys and girls, non-Hispanic black and white children and overweight and normal weight students. Conclusions Measures of autonomous motivation (identified, integrated, and intrinsic) were more strongly related to physical activity in the 7th grade than measures of controlled motivation (external and introjected), implying that physical activity became more intrinsically motivating for some girls and boys as they moved through middle school. Nonetheless, introjected regulation was related to physical activity in 7th grade, suggesting that internalized social pressures, which can be detrimental to sustained activity and well-being, also became motivating. These results encourage longer prospective studies during childhood and adolescence to clarify how controlled and autonomous motivations for physical activity develop and whether they respond to interventions designed to increase physical activity. PMID:25628178

  6. Motivation and Behavioral Regulation of Physical Activity in Middle School Students.

    PubMed

    Dishman, Rod K; McIver, Kerry L; Dowda, Marsha; Saunders, Ruth P; Pate, Russell R

    2015-09-01

    This study aimed to examine whether intrinsic motivation and behavioral self-regulation are related to physical activity during middle school. Structural equation modeling was applied in cross-sectional and longitudinal tests of self-determination theory. Consistent with theory, hypothesized relations among variables were supported. Integrated regulation and intrinsic motivation were most strongly correlated with moderate-to-vigorous physical activity measured by an accelerometer. Results were independent of a measure of biological maturity. Construct validity and equivalence of measures were confirmed longitudinally between the sixth and seventh grades and between boys and girls, non-Hispanic Black and White children and overweight and normal-weight students. Measures of autonomous motivation (identified, integrated, and intrinsic) were more strongly related to physical activity in the seventh grade than measures of controlled motivation (external and introjected), implying that physical activity became more intrinsically motivating for some girls and boys as they moved through middle school. Nonetheless, change in introjected regulation was related to change in physical activity in the seventh grade, suggesting that internalized social pressures, which can be detrimental to sustained activity and well-being, also became motivating. These results encourage longer prospective studies during childhood and adolescence to clarify how controlled and autonomous motivations for physical activity develop and whether they respond to interventions designed to increase physical activity.

  7. Generating unstructured nuclear reactor core meshes in parallel

    DOE PAGES

    Jain, Rajeev; Tautges, Timothy J.

    2014-10-24

    Recent advances in supercomputers and parallel solver techniques have enabled users to run large simulations problems using millions of processors. Techniques for multiphysics nuclear reactor core simulations are under active development in several countries. Most of these techniques require large unstructured meshes that can be hard to generate in a standalone desktop computers because of high memory requirements, limited processing power, and other complexities. We have previously reported on a hierarchical lattice-based approach for generating reactor core meshes. Here, we describe efforts to exploit coarse-grained parallelism during reactor assembly and reactor core mesh generation processes. We highlight several reactor coremore » examples including a very high temperature reactor, a full-core model of the Korean MONJU reactor, a ¼ pressurized water reactor core, the fast reactor Experimental Breeder Reactor-II core with a XX09 assembly, and an advanced breeder test reactor core. The times required to generate large mesh models, along with speedups obtained from running these problems in parallel, are reported. A graphical user interface to the tools described here has also been developed.« less

  8. Divergence-free MHD on unstructured meshes using high order finite volume schemes based on multidimensional Riemann solvers

    NASA Astrophysics Data System (ADS)

    Balsara, Dinshaw S.; Dumbser, Michael

    2015-10-01

    Several advances have been reported in the recent literature on divergence-free finite volume schemes for Magnetohydrodynamics (MHD). Almost all of these advances are restricted to structured meshes. To retain full geometric versatility, however, it is also very important to make analogous advances in divergence-free schemes for MHD on unstructured meshes. Such schemes utilize a staggered Yee-type mesh, where all hydrodynamic quantities (mass, momentum and energy density) are cell-centered, while the magnetic fields are face-centered and the electric fields, which are so useful for the time update of the magnetic field, are centered at the edges. Three important advances are brought together in this paper in order to make it possible to have high order accurate finite volume schemes for the MHD equations on unstructured meshes. First, it is shown that a divergence-free WENO reconstruction of the magnetic field can be developed for unstructured meshes in two and three space dimensions using a classical cell-centered WENO algorithm, without the need to do a WENO reconstruction for the magnetic field on the faces. This is achieved via a novel constrained L2-projection operator that is used in each time step as a postprocessor of the cell-centered WENO reconstruction so that the magnetic field becomes locally and globally divergence free. Second, it is shown that recently-developed genuinely multidimensional Riemann solvers (called MuSIC Riemann solvers) can be used on unstructured meshes to obtain a multidimensionally upwinded representation of the electric field at each edge. Third, the above two innovations work well together with a high order accurate one-step ADER time stepping strategy, which requires the divergence-free nonlinear WENO reconstruction procedure to be carried out only once per time step. The resulting divergence-free ADER-WENO schemes with MuSIC Riemann solvers give us an efficient and easily-implemented strategy for divergence-free MHD on unstructured meshes. Several stringent two- and three-dimensional problems are shown to work well with the methods presented here.

  9. Modulating the Intrinsic Disorder in the Cytoplasmic Domain Alters the Biological Activity of the N-Methyl-d-aspartate-sensitive Glutamate Receptor*

    PubMed Central

    Choi, Ucheor B.; Kazi, Rashek; Stenzoski, Natalie; Wollmuth, Lonnie P.; Uversky, Vladimir N.; Bowen, Mark E.

    2013-01-01

    The NMDA-sensitive glutamate receptor is a ligand-gated ion channel that mediates excitatory synaptic transmission in the nervous system. Extracellular zinc allosterically regulates the NMDA receptor by binding to the extracellular N-terminal domain, which inhibits channel gating. Phosphorylation of the intrinsically disordered intracellular C-terminal domain alleviates inhibition by extracellular zinc. The mechanism for this functional effect is largely unknown. Proline is a hallmark of intrinsic disorder, so we used proline mutagenesis to modulate disorder in the cytoplasmic domain. Proline depletion selectively uncoupled zinc inhibition with little effect on receptor biogenesis, surface trafficking, or ligand-activated gating. Proline depletion also reduced the affinity for a PDZ domain involved in synaptic trafficking and affected small molecule binding. To understand the origin of these phenomena, we used single molecule fluorescence and ensemble biophysical methods to characterize the structural effects of proline mutagenesis. Proline depletion did not eliminate intrinsic disorder, but the underlying conformational dynamics were changed. Thus, we altered the form of intrinsic disorder, which appears sufficient to affect the biological activity. These findings suggest that conformational dynamics within the intrinsically disordered cytoplasmic domain are important for the allosteric regulation of NMDA receptor gating. PMID:23782697

  10. Intrinsic and Extrinsic Neuromodulation of Olfactory Processing.

    PubMed

    Lizbinski, Kristyn M; Dacks, Andrew M

    2017-01-01

    Neuromodulation is a ubiquitous feature of neural systems, allowing flexible, context specific control over network dynamics. Neuromodulation was first described in invertebrate motor systems and early work established a basic dichotomy for neuromodulation as having either an intrinsic origin (i.e., neurons that participate in network coding) or an extrinsic origin (i.e., neurons from independent networks). In this conceptual dichotomy, intrinsic sources of neuromodulation provide a "memory" by adjusting network dynamics based upon previous and ongoing activation of the network itself, while extrinsic neuromodulators provide the context of ongoing activity of other neural networks. Although this dichotomy has been thoroughly considered in motor systems, it has received far less attention in sensory systems. In this review, we discuss intrinsic and extrinsic modulation in the context of olfactory processing in invertebrate and vertebrate model systems. We begin by discussing presynaptic modulation of olfactory sensory neurons by local interneurons (LNs) as a mechanism for gain control based on ongoing network activation. We then discuss the cell-class specific effects of serotonergic centrifugal neurons on olfactory processing. Finally, we briefly discuss the integration of intrinsic and extrinsic neuromodulation (metamodulation) as an effective mechanism for exerting global control over olfactory network dynamics. The heterogeneous nature of neuromodulation is a recurring theme throughout this review as the effects of both intrinsic and extrinsic modulation are generally non-uniform.

  11. An Adaptable Spectrin/Ankyrin-Based Mechanism for Long-Range Organization of Plasma Membranes in Vertebrate Tissues.

    PubMed

    Bennett, Vann; Lorenzo, Damaris N

    2016-01-01

    Ankyrins are membrane-associated proteins that together with their spectrin partners are responsible for micron-scale organization of vertebrate plasma membranes, including those of erythrocytes, excitable membranes of neurons and heart, lateral membrane domains of columnar epithelial cells, and striated muscle. Ankyrins coordinate functionally related membrane transporters and cell adhesion proteins (15 protein families identified so far) within plasma membrane compartments through independently evolved interactions of intrinsically disordered sequences with a highly conserved peptide-binding groove formed by the ANK repeat solenoid. Ankyrins are coupled to spectrins, which are elongated organelle-sized proteins that form mechanically resilient arrays through cross-linking by specialized actin filaments. In addition to protein interactions, cellular targeting and assembly of spectrin/ankyrin domains also critically depend on palmitoylation of ankyrin-G by aspartate-histidine-histidine-cysteine 5/8 palmitoyltransferases, as well as interaction of beta-2 spectrin with phosphoinositide lipids. These lipid-dependent spectrin/ankyrin domains are not static but are locally dynamic and determine membrane identity through opposing endocytosis of bulk lipids as well as specific proteins. A partnership between spectrin, ankyrin, and cell adhesion molecules first emerged in bilaterians over 500 million years ago. Ankyrin and spectrin may have been recruited to plasma membranes from more ancient roles in organelle transport. The basic bilaterian spectrin-ankyrin toolkit markedly expanded in vertebrates through gene duplications combined with variation in unstructured intramolecular regulatory sequences as well as independent evolution of ankyrin-binding activity by ion transporters involved in action potentials and calcium homeostasis. In addition, giant vertebrate ankyrins with specialized roles in axons acquired new coding sequences by exon shuffling. We speculate that early axon initial segments and epithelial lateral membranes initially were based on spectrin-ankyrin-cell adhesion molecule assemblies and subsequently served as "incubators," where ion transporters independently acquired ankyrin-binding activity through positive selection. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Intrinsic feature-based pose measurement for imaging motion compensation

    DOEpatents

    Baba, Justin S.; Goddard, Jr., James Samuel

    2014-08-19

    Systems and methods for generating motion corrected tomographic images are provided. A method includes obtaining first images of a region of interest (ROI) to be imaged and associated with a first time, where the first images are associated with different positions and orientations with respect to the ROI. The method also includes defining an active region in the each of the first images and selecting intrinsic features in each of the first images based on the active region. Second, identifying a portion of the intrinsic features temporally and spatially matching intrinsic features in corresponding ones of second images of the ROI associated with a second time prior to the first time and computing three-dimensional (3D) coordinates for the portion of the intrinsic features. Finally, the method includes computing a relative pose for the first images based on the 3D coordinates.

  13. Psychological need satisfaction, intrinsic motivation and affective response to exercise in adolescents

    PubMed Central

    Schneider, Margaret L.; Kwan, Bethany M.

    2013-01-01

    Objectives To further understanding of the factors influencing adolescents’ motivations for physical activity, the relationship of variables derived from Self-Determination Theory to adolescents’ affective response to exercise was examined. Design Correlational. Method Adolescents (N = 182) self-reported psychological needs satisfaction (perceived competence, relatedness, and autonomy) and intrinsic motivation related to exercise. In two clinic visits, adolescents reported their affect before, during, and after a moderate-intensity and a hard-intensity exercise task. Results Affective response to exercise and psychological needs satisfaction independently contributed to the prediction of intrinsic motivation in hierarchical linear regression models. The association between affective response to exercise and intrinsic motivation was partially mediated by psychological needs satisfaction. Conclusions Intrinsic motivation for exercise among adolescents may be enhanced when the environment supports perceived competence, relatedness, and autonomy, and when adolescents participate in activities that they find enjoyable. PMID:24015110

  14. Quantifying the density and utilization of active sites in non-precious metal oxygen electroreduction catalysts

    PubMed Central

    Sahraie, Nastaran Ranjbar; Kramm, Ulrike I.; Steinberg, Julian; Zhang, Yuanjian; Thomas, Arne; Reier, Tobias; Paraknowitsch, Jens-Peter; Strasser, Peter

    2015-01-01

    Carbon materials doped with transition metal and nitrogen are highly active, non-precious metal catalysts for the electrochemical conversion of molecular oxygen in fuel cells, metal air batteries, and electrolytic processes. However, accurate measurement of their intrinsic turn-over frequency and active-site density based on metal centres in bulk and surface has remained difficult to date, which has hampered a more rational catalyst design. Here we report a successful quantification of bulk and surface-based active-site density and associated turn-over frequency values of mono- and bimetallic Fe/N-doped carbons using a combination of chemisorption, desorption and 57Fe Mössbauer spectroscopy techniques. Our general approach yields an experimental descriptor for the intrinsic activity and the active-site utilization, aiding in the catalyst development process and enabling a previously unachieved level of understanding of reactivity trends owing to a deconvolution of site density and intrinsic activity. PMID:26486465

  15. The UGRID Reader - A ParaView Plugin for the Visualization of Unstructured Climate Model Data in NetCDF Format

    NASA Astrophysics Data System (ADS)

    Brisc, Felicia; Vater, Stefan; Behrens, Joern

    2016-04-01

    We present the UGRID Reader, a visualization software component that implements the UGRID Conventions into Paraview. It currently supports the reading and visualization of 2D unstructured triangular, quadrilateral and mixed triangle/quadrilateral meshes, while the data can be defined per cell or per vertex. The Climate and Forecast Metadata Conventions (CF Conventions) have been set for many years as the standard framework for climate data written in NetCDF format. While they allow storing unstructured data simply as data defined at a series of points, they do not currently address the topology of the underlying unstructured mesh. However, it is often necessary to have additional mesh topology information, i.e. is it a one dimensional network, a 2D triangular mesh or a flexible mixed triangle/quadrilateral mesh, a 2D mesh with vertical layers, or a fully unstructured 3D mesh. The UGRID Conventions proposed by the UGRID Interoperability group are attempting to fill in this void by extending the CF Conventions with topology specifications. As the UGRID Conventions are increasingly popular with an important subset of the CF community, they warrant the development of a customized tool for the visualization and exploration of UGRID-conforming data. The implementation of the UGRID Reader has been designed corresponding to the ParaView plugin architecture. This approach allowed us to tap into the powerful reading and rendering capabilities of ParaView, while the reader is easy to install. We aim at parallelism to be able to process large data sets. Furthermore, our current application of the reader is the visualization of higher order simulation output which demands for a special representation of the data within a cell.

  16. The unfoldomics decade: an update on intrinsically disordered proteins.

    PubMed

    Dunker, A Keith; Oldfield, Christopher J; Meng, Jingwei; Romero, Pedro; Yang, Jack Y; Chen, Jessica Walton; Vacic, Vladimir; Obradovic, Zoran; Uversky, Vladimir N

    2008-09-16

    Our first predictor of protein disorder was published just over a decade ago in the Proceedings of the IEEE International Conference on Neural Networks (Romero P, Obradovic Z, Kissinger C, Villafranca JE, Dunker AK (1997) Identifying disordered regions in proteins from amino acid sequence. Proceedings of the IEEE International Conference on Neural Networks, 1: 90-95). By now more than twenty other laboratory groups have joined the efforts to improve the prediction of protein disorder. While the various prediction methodologies used for protein intrinsic disorder resemble those methodologies used for secondary structure prediction, the two types of structures are entirely different. For example, the two structural classes have very different dynamic properties, with the irregular secondary structure class being much less mobile than the disorder class. The prediction of secondary structure has been useful. On the other hand, the prediction of intrinsic disorder has been revolutionary, leading to major modifications of the more than 100 year-old views relating protein structure and function. Experimentalists have been providing evidence over many decades that some proteins lack fixed structure or are disordered (or unfolded) under physiological conditions. In addition, experimentalists are also showing that, for many proteins, their functions depend on the unstructured rather than structured state; such results are in marked contrast to the greater than hundred year old views such as the lock and key hypothesis. Despite extensive data on many important examples, including disease-associated proteins, the importance of disorder for protein function has been largely ignored. Indeed, to our knowledge, current biochemistry books don't present even one acknowledged example of a disorder-dependent function, even though some reports of disorder-dependent functions are more than 50 years old. The results from genome-wide predictions of intrinsic disorder and the results from other bioinformatics studies of intrinsic disorder are demanding attention for these proteins. Disorder prediction has been important for showing that the relatively few experimentally characterized examples are members of a very large collection of related disordered proteins that are wide-spread over all three domains of life. Many significant biological functions are now known to depend directly on, or are importantly associated with, the unfolded or partially folded state. Here our goal is to review the key discoveries and to weave these discoveries together to support novel approaches for understanding sequence-function relationships. Intrinsically disordered protein is common across the three domains of life, but especially common among the eukaryotic proteomes. Signaling sequences and sites of posttranslational modifications are frequently, or very likely most often, located within regions of intrinsic disorder. Disorder-to-order transitions are coupled with the adoption of different structures with different partners. Also, the flexibility of intrinsic disorder helps different disordered regions to bind to a common binding site on a common partner. Such capacity for binding diversity plays important roles in both protein-protein interaction networks and likely also in gene regulation networks. Such disorder-based signaling is further modulated in multicellular eukaryotes by alternative splicing, for which such splicing events map to regions of disorder much more often than to regions of structure. Associating alternative splicing with disorder rather than structure alleviates theoretical and experimentally observed problems associated with the folding of different length, isomeric amino acid sequences. The combination of disorder and alternative splicing is proposed to provide a mechanism for easily "trying out" different signaling pathways, thereby providing the mechanism for generating signaling diversity and enabling the evolution of cell differentiation and multicellularity. Finally, several recent small molecules of interest as potential drugs have been shown to act by blocking protein-protein interactions based on intrinsic disorder of one of the partners. Study of these examples has led to a new approach for drug discovery, and bioinformatics analysis of the human proteome suggests that various disease-associated proteins are very rich in such disorder-based drug discovery targets.

  17. The unstructured linker arms of Mlh1-Pms1 are important for interactions with DNA during mismatch repair

    PubMed Central

    Plys, Aaron J.; Rogacheva, Maria V.; Greene, Eric C.; Alani, Eric

    2012-01-01

    DNA mismatch repair (MMR) models have proposed that MSH proteins identify DNA polymerase errors while interacting with the DNA replication fork. MLH proteins (primarily Mlh1-Pms1 in baker’s yeast) then survey the genome for lesion-bound MSH proteins. The resulting MSH-MLH complex formed at a DNA lesion initiates downstream steps in repair. MLH proteins act as dimers and contain long (20 – 30 nanometers) unstructured arms that connect two terminal globular domains. These arms can vary between 100 to 300 amino acids in length, are highly divergent between organisms, and are resistant to amino acid substitutions. To test the roles of the linker arms in MMR, we engineered a protease cleavage site into the Mlh1 linker arm domain of baker’s yeast Mlh1-Pms1. Cleavage of the Mlh1 linker arm in vitro resulted in a defect in Mlh1-Pms1 DNA binding activity, and in vivo proteolytic cleavage resulted in a complete defect in MMR. We then generated a series of truncation mutants bearing Mlh1 and Pms1 linker arms of varying lengths. This work revealed that MMR is greatly compromised when portions of the Mlh1 linker are removed, whereas repair is less sensitive to truncation of the Pms1 linker arm. Purified complexes containing truncations in Mlh1 and Pms1 linker arms were analyzed and found to have differential defects in DNA binding that also correlated with the ability to form a ternary complex with Msh2-Msh6 and mismatch DNA. These observations are consistent with the unstructured linker domains of MLH proteins providing distinct interactions with DNA during MMR. PMID:22659005

  18. Comparison of Effect of Regular Unstructured Physical Training and Athletic Level Training on Body Composition and Cardio Respiratory Fitness in Adolescents

    PubMed Central

    Subramanian, Senthil Kumar; Sharma, Vivek Kumar; A, Vinayathan

    2013-01-01

    Background: Childhood obesity and hypertension are global problems that are on the rise in India. Improving physical activity is an accepted main line of strategy for overcoming poor body composition, hypertension and reduced cardio respiratory fitness (CRF) all of which are considered as independent risk factors for the development of future cardiovascular complications. Aim: Present study was conducted to evaluate the effect of regular unstructured physical training and athletic level training on anthropometric measures, body composition, blood pressure and cardio respiratory fitness in adolescents. Settings and Design: This is a collaborative study between the Department of physiology, Jawaharlal Institute of Postgraduate Medical Education and Research and Residential school, Jawahar Navodhya Vidyalaya, Puducherry, India. Method and Material: Student volunteers in the age group of 12–17 years were classified into athletes (group 1) and physically active non-athletes (group 2). Parameters measured and calculated were weight, height, body mass index, waist and hip circumference, body fat percentage (BF%), fat free mass (FFM), Systolic (SBP) & Diastolic blood pressure (DBP), Mean arterial pressure (MAP), Rate pressure product (RPP) and Predicted VO2 max. Statistical Analysis used: Mean difference between the groups was analysed using unpaired Student’s t–test. All statistical analysis was carried out for two-tailed significance at the 5 % level using SPSS version 19 (SPSSInc, USA). Results: Anthropometric measures, body composition measures and blood pressure values of both the group students were within the normal limits. There was no significant difference in anthropometric and body composition parameters between the group 1 and group 2 students. DBP, MAP and RPP were significantly lower in group 1 students when compared to group 2 students. VO2 max values were more in group 1 girls as compared to group 2 girls while the values of boys were comparable between the two groups. Conclusion: Regular unstructured physical activity for 60 minutes daily for the duration of one year can help the students to maintain their anthropometric parameters, body composition measures and CRF at par with the athletes of the same age and gender. However, athletic level training further reduces the cardiovascular load of the adolescent students. PMID:24179887

  19. Prefrontal Cortex HCN1 Channels Enable Intrinsic Persistent Neural Firing and Executive Memory Function

    PubMed Central

    Thuault, Sébastien J.; Malleret, Gaël; Constantinople, Christine M.; Nicholls, Russell; Chen, Irene; Zhu, Judy; Panteleyev, Andrey; Vronskaya, Svetlana; Nolan, Matthew F.; Bruno, Randy

    2013-01-01

    In many cortical neurons, HCN1 channels are the major contributors to Ih, the hyperpolarization-activated current, which regulates the intrinsic properties of neurons and shapes their integration of synaptic inputs, paces rhythmic activity, and regulates synaptic plasticity. Here, we examine the physiological role of Ih in deep layer pyramidal neurons in mouse prefrontal cortex (PFC), focusing on persistent activity, a form of sustained firing thought to be important for the behavioral function of the PFC during working memory tasks. We find that HCN1 contributes to the intrinsic persistent firing that is induced by a brief depolarizing current stimulus in the presence of muscarinic agonists. Deletion of HCN1 or acute pharmacological blockade of Ih decreases the fraction of neurons capable of generating persistent firing. The reduction in persistent firing is caused by the membrane hyperpolarization that results from the deletion of HCN1 or Ih blockade, rather than a specific role of the hyperpolarization-activated current in generating persistent activity. In vivo recordings show that deletion of HCN1 has no effect on up states, periods of enhanced synaptic network activity. Parallel behavioral studies demonstrate that HCN1 contributes to the PFC-dependent resolution of proactive interference during working memory. These results thus provide genetic evidence demonstrating the importance of HCN1 to intrinsic persistent firing and the behavioral output of the PFC. The causal role of intrinsic persistent firing in PFC-mediated behavior remains an open question. PMID:23966682

  20. β-Catenin is required for intrinsic but not extrinsic BCR-ABL1 kinase-independent resistance to tyrosine kinase inhibitors in chronic myeloid leukemia.

    PubMed

    Eiring, A M; Khorashad, J S; Anderson, D J; Yu, F; Redwine, H M; Mason, C C; Reynolds, K R; Clair, P M; Gantz, K C; Zhang, T Y; Pomicter, A D; Kraft, I L; Bowler, A D; Johnson, K; Partlin, M Mac; O'Hare, T; Deininger, M W

    2015-12-01

    Activation of nuclear β-catenin and expression of its transcriptional targets promotes chronic myeloid leukemia (CML) progression, tyrosine kinase inhibitor (TKI) resistance, and leukemic stem cell self-renewal. We report that nuclear β-catenin has a role in leukemia cell-intrinsic but not -extrinsic BCR-ABL1 kinase-independent TKI resistance. Upon imatinib inhibition of BCR-ABL1 kinase activity, β-catenin expression was maintained in intrinsically resistant cells grown in suspension culture and sensitive cells cultured in direct contact (DC) with bone marrow (BM) stromal cells. Thus, TKI resistance uncouples β-catenin expression from BCR-ABL1 kinase activity. In β-catenin reporter assays, intrinsically resistant cells showed increased transcriptional activity versus parental TKI-sensitive controls, and this was associated with restored expression of β-catenin target genes. In contrast, DC with BM stromal cells promoted TKI resistance, but had little effects on Lef/Tcf reporter activity and no consistent effects on cytoplasmic β-catenin levels, arguing against a role for β-catenin in extrinsic TKI resistance. N-cadherin or H-cadherin blocking antibodies abrogated DC-based resistance despite increasing Lef/Tcf reporter activity, suggesting that factors other than β-catenin contribute to extrinsic, BM-derived TKI resistance. Our data indicate that, while nuclear β-catenin enhances survival of intrinsically TKI-resistant CML progenitors, it is not required for extrinsic resistance mediated by the BM microenvironment.

  1. Ontology for Semantic Data Integration in the Domain of IT Benchmarking.

    PubMed

    Pfaff, Matthias; Neubig, Stefan; Krcmar, Helmut

    2018-01-01

    A domain-specific ontology for IT benchmarking has been developed to bridge the gap between a systematic characterization of IT services and their data-based valuation. Since information is generally collected during a benchmark exercise using questionnaires on a broad range of topics, such as employee costs, software licensing costs, and quantities of hardware, it is commonly stored as natural language text; thus, this information is stored in an intrinsically unstructured form. Although these data form the basis for identifying potentials for IT cost reductions, neither a uniform description of any measured parameters nor the relationship between such parameters exists. Hence, this work proposes an ontology for the domain of IT benchmarking, available at https://w3id.org/bmontology. The design of this ontology is based on requirements mainly elicited from a domain analysis, which considers analyzing documents and interviews with representatives from Small- and Medium-Sized Enterprises and Information and Communications Technology companies over the last eight years. The development of the ontology and its main concepts is described in detail (i.e., the conceptualization of benchmarking events, questionnaires, IT services, indicators and their values) together with its alignment with the DOLCE-UltraLite foundational ontology.

  2. Amyloidogenic Regions and Interaction Surfaces Overlap in Globular Proteins Related to Conformational Diseases

    PubMed Central

    Castillo, Virginia; Ventura, Salvador

    2009-01-01

    Protein aggregation underlies a wide range of human disorders. The polypeptides involved in these pathologies might be intrinsically unstructured or display a defined 3D-structure. Little is known about how globular proteins aggregate into toxic assemblies under physiological conditions, where they display an initially folded conformation. Protein aggregation is, however, always initiated by the establishment of anomalous protein-protein interactions. Therefore, in the present work, we have explored the extent to which protein interaction surfaces and aggregation-prone regions overlap in globular proteins associated with conformational diseases. Computational analysis of the native complexes formed by these proteins shows that aggregation-prone regions do frequently overlap with protein interfaces. The spatial coincidence of interaction sites and aggregating regions suggests that the formation of functional complexes and the aggregation of their individual subunits might compete in the cell. Accordingly, single mutations affecting complex interface or stability usually result in the formation of toxic aggregates. It is suggested that the stabilization of existing interfaces in multimeric proteins or the formation of new complexes in monomeric polypeptides might become effective strategies to prevent disease-linked aggregation of globular proteins. PMID:19696882

  3. Transient α-helices in the disordered RPEL motifs of the serum response factor coactivator MKL1

    NASA Astrophysics Data System (ADS)

    Mizuguchi, Mineyuki; Fuju, Takahiro; Obita, Takayuki; Ishikawa, Mitsuru; Tsuda, Masaaki; Tabuchi, Akiko

    2014-06-01

    The megakaryoblastic leukemia 1 (MKL1) protein functions as a transcriptional coactivator of the serum response factor. MKL1 has three RPEL motifs (RPEL1, RPEL2, and RPEL3) in its N-terminal region. MKL1 binds to monomeric G-actin through RPEL motifs, and the dissociation of MKL1 from G-actin promotes the translocation of MKL1 to the nucleus. Although structural data are available for RPEL motifs of MKL1 in complex with G-actin, the structural characteristics of RPEL motifs in the free state have been poorly defined. Here we characterized the structures of free RPEL motifs using NMR and CD spectroscopy. NMR and CD measurements showed that free RPEL motifs are largely unstructured in solution. However, NMR analysis identified transient α-helices in the regions where helices α1 and α2 are induced upon binding to G-actin. Proline mutagenesis showed that the transient α-helices are locally formed without helix-helix interactions. The helix content is higher in the order of RPEL1, RPEL2, and RPEL3. The amount of preformed structure may correlate with the binding affinity between the intrinsically disordered protein and its target molecule.

  4. Studies of Inviscid Flux Schemes for Acoustics and Turbulence Problems

    NASA Technical Reports Server (NTRS)

    Morris, C. I.

    2013-01-01

    The last two decades have witnessed tremendous growth in computational power, the development of computational fluid dynamics (CFD) codes which scale well over thousands of processors, and the refinement of unstructured grid-generation tools which facilitate rapid surface and volume gridding of complex geometries. Thus, engineering calculations of 10(exp 7) - 10(exp 8) finite-volume cells have become routine for some types of problems. Although the Reynolds Averaged Navier Stokes (RANS) approach to modeling turbulence is still in extensive and wide use, increasingly large-eddy simulation (LES) and hybrid RANS-LES approaches are being applied to resolve the largest scales of turbulence in many engineering problems. However, it has also become evident that LES places different requirements on the numerical approaches for both the spatial and temporal discretization of the Navier Stokes equations than does RANS. In particular, LES requires high time accuracy and minimal intrinsic numerical dispersion and dissipation over a wide spectral range. In this paper, the performance of both central-difference and upwind-biased spatial discretizations is examined for a one-dimensional acoustic standing wave problem, the Taylor-Green vortex problem, and the turbulent channel fl ow problem.

  5. Studies of Inviscid Flux Schemes for Acoustics and Turbulence Problems

    NASA Technical Reports Server (NTRS)

    Morris, Christopher I.

    2013-01-01

    The last two decades have witnessed tremendous growth in computational power, the development of computational fluid dynamics (CFD) codes which scale well over thousands of processors, and the refinement of unstructured grid-generation tools which facilitate rapid surface and volume gridding of complex geometries. Thus, engineering calculations of 10(exp 7) - 10(exp 8) finite-volume cells have become routine for some types of problems. Although the Reynolds Averaged Navier Stokes (RANS) approach to modeling turbulence is still in extensive and wide use, increasingly large-eddy simulation (LES) and hybrid RANS-LES approaches are being applied to resolve the largest scales of turbulence in many engineering problems. However, it has also become evident that LES places different requirements on the numerical approaches for both the spatial and temporal discretization of the Navier Stokes equations than does RANS. In particular, LES requires high time accuracy and minimal intrinsic numerical dispersion and dissipation over a wide spectral range. In this paper, the performance of both central-difference and upwind-biased spatial discretizations is examined for a one-dimensional acoustic standing wave problem, the Taylor-Green vortex problem, and the turbulent channel ow problem.

  6. From protein interaction profile to functional assignment: the human protein Ki-1/57 is associated with pre-mRNA splicing events.

    PubMed

    Bressan, Gustavo Costa; Kobarg, Jörg

    2010-01-01

    The mapping of protein-protein interactions of a determined organism is considered fundamental to assign protein function in the post-genomic era. As part of this effort, screenings for pairwise interactions by yeast two-hybrid system have been used popularly to reveal protein interaction networks in different biological systems. Through the identification of protein interaction partners we have successfully obtained interesting functional clues for Ki-1/57, a human protein with no previous functional annotation, in the context of RNA metabolism. We briefly discuss the way we approached protein-protein interaction data to conduct and interpret further molecular biological and cellular studies as well as structural analyses on this protein. Our data suggest that Ki-1/57 belongs to the family of intrinsically unstructured proteins and that the structural flexibility may be crucial for its capacity to interact with many different proteins. A large fraction of these proteins are involved in pre-mRNA splicing control. Finally, Ki-1/57 is localized to several subnuclear domains, all of which have been described to splicing and other RNA processing events.

  7. A new multiscale air quality transport model (Fluidity, 4.1.9) using fully unstructured anisotropic adaptive mesh technology

    NASA Astrophysics Data System (ADS)

    Zheng, J.; Zhu, J.; Wang, Z.; Fang, F.; Pain, C. C.; Xiang, J.

    2015-06-01

    A new anisotropic hr-adaptive mesh technique has been applied to modelling of multiscale transport phenomena, which is based on a discontinuous Galerkin/control volume discretization on unstructured meshes. Over existing air quality models typically based on static-structured grids using a locally nesting technique, the advantage of the anisotropic hr-adaptive model has the ability to adapt the mesh according to the evolving pollutant distribution and flow features. That is, the mesh resolution can be adjusted dynamically to simulate the pollutant transport process accurately and effectively. To illustrate the capability of the anisotropic adaptive unstructured mesh model, three benchmark numerical experiments have been setup for two-dimensional (2-D) transport phenomena. Comparisons have been made between the results obtained using uniform resolution meshes and anisotropic adaptive resolution meshes.

  8. MECHANISM OF ALPHA-SYNUCLEIN OLIGOMERIZATION AND MEMBRANE INTERACTION: THEORETICAL APPROACH TO UNSTRUCTURED PROTEINS STUDIES

    PubMed Central

    Tsigelny, Igor F.; Sharikov, Yuriy; Miller, Mark A.; Masliah, Eliezer

    2008-01-01

    Misfolding and oligomerization of unstructured proteins is involved in the pathogenesis of Parkinson’s (PD), Alzheimer’s (AD), Huntington’s, and other neurodegenerative disorders. Elucidation of possible conformations of these proteins and their interactions with the membrane is necessary to understand the molecular mechanisms of neurodegeneration. We developed a strategy that makes it possible to elucidate the molecular mechanisms of of alpha-synuclein aggregation- a key molecular event in the pathogenesis of PD. This strategy can be also useful for the study of other unstructured proteins involved in neurodegeneration. The results of these theoretical studies have been confirmed with biochemical and electrophysiological studies. Our studies provide insights into the molecular mechanism for PD initiation and progression, and provide a useful paradigm for identifying possible therapeutic interventions through computational modeling. PMID:18640077

  9. Discrete Adjoint-Based Design Optimization of Unsteady Turbulent Flows on Dynamic Unstructured Grids

    NASA Technical Reports Server (NTRS)

    Nielsen, Eric J.; Diskin, Boris; Yamaleev, Nail K.

    2009-01-01

    An adjoint-based methodology for design optimization of unsteady turbulent flows on dynamic unstructured grids is described. The implementation relies on an existing unsteady three-dimensional unstructured grid solver capable of dynamic mesh simulations and discrete adjoint capabilities previously developed for steady flows. The discrete equations for the primal and adjoint systems are presented for the backward-difference family of time-integration schemes on both static and dynamic grids. The consistency of sensitivity derivatives is established via comparisons with complex-variable computations. The current work is believed to be the first verified implementation of an adjoint-based optimization methodology for the true time-dependent formulation of the Navier-Stokes equations in a practical computational code. Large-scale shape optimizations are demonstrated for turbulent flows over a tiltrotor geometry and a simulated aeroelastic motion of a fighter jet.

  10. Visualizing unstructured patient data for assessing diagnostic and therapeutic history.

    PubMed

    Deng, Yihan; Denecke, Kerstin

    2014-01-01

    Having access to relevant patient data is crucial for clinical decision making. The data is often documented in unstructured texts and collected in the electronic health record. In this paper, we evaluate an approach to visualize information extracted from clinical documents by means of tag cloud. Tag clouds will be generated using a bag of word approach and by exploiting part of speech tags. For a real word data set comprising radiological reports, pathological reports and surgical operation reports, tag clouds are generated and a questionnaire-based study is conducted as evaluation. Feedback from the physicians shows that the tag cloud visualization is an effective and rapid approach to represent relevant parts of unstructured patient data. To handle the different medical narratives, we have summarized several possible improvements according to the user feedback and evaluation results.

  11. The computation of three-dimensional flows using unstructured grids

    NASA Technical Reports Server (NTRS)

    Morgan, K.; Peraire, J.; Peiro, J.; Hassan, O.

    1991-01-01

    A general method is described for automatically discretizing, into unstructured assemblies of tetrahedra, the three-dimensional solution domains of complex shape which are of interest in practical computational aerodynamics. An algorithm for the solution of the compressible Euler equations which can be implemented on such general unstructured tetrahedral grids is described. This is an explicit cell-vertex scheme which follows a general Taylor-Galerkin philosophy. The approach is employed to compute a transonic inviscid flow over a standard wing and the results are shown to compare favorably with experimental observations. As a more practical demonstration, the method is then applied to the analysis of inviscid flow over a complete modern fighter configuration. The effect of using mesh adaptivity is illustrated when the method is applied to the solution of high speed flow in an engine inlet.

  12. Studies of Plasma Instabilities using Unstructured Discontinuous Galerkin Method with the Two-Fluid Plasma Model

    NASA Astrophysics Data System (ADS)

    Song, Yang; Srinivasan, Bhuvana

    2017-10-01

    The discontinuous Galerkin (DG) method has the advantage of resolving shocks and sharp gradients that occur in neutral fluids and plasmas. An unstructured DG code has been developed in this work to study plasma instabilities using the two-fluid plasma model. Unstructured meshes are known to produce small and randomized grid errors compared to traditional structured meshes. Computational tests for Rayleigh-Taylor instabilities in radially-converging flows are performed using the MHD model. Choice of grid geometry is not obvious for simulations of instabilities in these circular configurations. Comparisons of the effects for different grids are made. A 2D magnetic nozzle simulation using the two-fluid plasma model is also performed. A vacuum boundary condition technique is applied to accurately solve the Riemann problem on the edge of the plume.

  13. Learning Long-Range Vision for an Offroad Robot

    DTIC Science & Technology

    2008-09-01

    robot to perceive and navigate in an unstructured natural world is a difficult task. Without learning, navigation systems are short-range and extremely...unsupervised or weakly supervised learning methods are necessary for training general feature representations for natural scenes. The process was...the world looked dark, and Legos when I was weary. iii ABSTRACT Teaching a robot to perceive and navigate in an unstructured natural world is a

  14. WENO schemes on arbitrary mixed-element unstructured meshes in three space dimensions

    NASA Astrophysics Data System (ADS)

    Tsoutsanis, P.; Titarev, V. A.; Drikakis, D.

    2011-02-01

    The paper extends weighted essentially non-oscillatory (WENO) methods to three dimensional mixed-element unstructured meshes, comprising tetrahedral, hexahedral, prismatic and pyramidal elements. Numerical results illustrate the convergence rates and non-oscillatory properties of the schemes for various smooth and discontinuous solutions test cases and the compressible Euler equations on various types of grids. Schemes of up to fifth order of spatial accuracy are considered.

  15. Thermal Protection System Cavity Heating for Simplified and Actual Geometries Using Computational Fluid Dynamics Simulations with Unstructured Grids

    NASA Technical Reports Server (NTRS)

    McCloud, Peter L.

    2010-01-01

    Thermal Protection System (TPS) Cavity Heating is predicted using Computational Fluid Dynamics (CFD) on unstructured grids for both simplified cavities and actual cavity geometries. Validation was performed using comparisons to wind tunnel experimental results and CFD predictions using structured grids. Full-scale predictions were made for simplified and actual geometry configurations on the Space Shuttle Orbiter in a mission support timeframe.

  16. Implementation of a parallel unstructured Euler solver on the CM-5

    NASA Technical Reports Server (NTRS)

    Morano, Eric; Mavriplis, D. J.

    1995-01-01

    An efficient unstructured 3D Euler solver is parallelized on a Thinking Machine Corporation Connection Machine 5, distributed memory computer with vectoring capability. In this paper, the single instruction multiple data (SIMD) strategy is employed through the use of the CM Fortran language and the CMSSL scientific library. The performance of the CMSSL mesh partitioner is evaluated and the overall efficiency of the parallel flow solver is discussed.

  17. Unstructured grids for sonic-boom analysis

    NASA Technical Reports Server (NTRS)

    Fouladi, Kamran

    1993-01-01

    A fast and efficient unstructured grid scheme is evaluated for sonic-boom applications. The scheme is used to predict the near-field pressure signatures of a body of revolution at several body lengths below the configuration, and those results are compared with experimental data. The introduction of the 'sonic-boom grid topology' to this scheme make it well suited for sonic-boom applications, thus providing an alternative to conventional multiblock structured grid schemes.

  18. A perspective on unstructured grid flow solvers

    NASA Technical Reports Server (NTRS)

    Venkatakrishnan, V.

    1995-01-01

    This survey paper assesses the status of compressible Euler and Navier-Stokes solvers on unstructured grids. Different spatial and temporal discretization options for steady and unsteady flows are discussed. The integration of these components into an overall framework to solve practical problems is addressed. Issues such as grid adaptation, higher order methods, hybrid discretizations and parallel computing are briefly discussed. Finally, some outstanding issues and future research directions are presented.

  19. EMPHASIS/Nevada UTDEM user guide. Version 2.0.

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

    Turner, C. David; Seidel, David Bruce; Pasik, Michael Francis

    The Unstructured Time-Domain ElectroMagnetics (UTDEM) portion of the EMPHASIS suite solves Maxwell's equations using finite-element techniques on unstructured meshes. This document provides user-specific information to facilitate the use of the code for applications of interest. UTDEM is a general-purpose code for solving Maxwell's equations on arbitrary, unstructured tetrahedral meshes. The geometries and the meshes thereof are limited only by the patience of the user in meshing and by the available computing resources for the solution. UTDEM solves Maxwell's equations using finite-element method (FEM) techniques on tetrahedral elements using vector, edge-conforming basis functions. EMPHASIS/Nevada Unstructured Time-Domain ElectroMagnetic Particle-In-Cell (UTDEM PIC) ismore » a superset of the capabilities found in UTDEM. It adds the capability to simulate systems in which the effects of free charge are important and need to be treated in a self-consistent manner. This is done by integrating the equations of motion for macroparticles (a macroparticle is an object that represents a large number of real physical particles, all with the same position and momentum) being accelerated by the electromagnetic forces upon the particle (Lorentz force). The motion of these particles results in a current, which is a source for the fields in Maxwell's equations.« less

  20. Active Control of Generalized Complex Modal Structures in a Stochastic Environment

    DTIC Science & Technology

    1992-05-15

    began with the design of a baseline controller. The system of interest was a MIMO, heavily damped structure with complex modes, and the control objective...feed-through term in our system that was due to the use of accelerometers as sensors. This provided an acceptable baseline solution to our I problem...to which we could compare our ideas for improvement. One area in which the baseline design was deficient was robust stability to unstructured

  1. Numerical Examination of Flux Correction for Solving the Navier-Stokes Equations on Unstructured Meshes

    DTIC Science & Technology

    2014-08-29

    lends itself to parallelization due to it’s discontinuous nature [27]. It has well-established stability properties and is actively being researched...from considering Conservation of Mass , Conservation of Momentum, and Conservation of Energy. This well-known result, known as the Navier-Stokes...internal plus kinetic) per unit mass and h = e+ Pρ as the enthalpy. qj is the jth component of the heat flux vector. This can be related to temperature

  2. Nine centuries waiting: The experiences of Iranians surrogacy commissioning mothers

    PubMed Central

    Zandi, Mitra; Vanaki, Zohreh; Shiva, Marziyeh; Mohammadi, Eesa

    2014-01-01

    Background: There are a few studies about commissioning mothers’ understanding from the surrogacy during 9 months of waiting for delivery in Iran and other countries. This study was conducted with an aim to explore and explain the nature of concerns (experiences) of commissioning mothers. Materials and Methods: A qualitative design with a conventional content analysis approach was used to gather and analyze the experiences of commissioning mothers. They were selected from Royan Research Centre and other infertility centers in Iran. After purposive sampling for the selection of the participants, unstructured interviews were held for data collection. Twenty-four unstructured interviews were conducted with 12 commissioning mothers, 2 surrogate mothers, and 2 infertility center social workers who directly and continuously dealt with these mothers. Results: Two main themes emerged from the data analysis: 1. cultural dilemma (consisting of three subthemes: Social taboo, concerns about disclosure to others and the child, concerns about altering maternal and child's identity, and 2. uncertain waiting (consisting of three subthemes: Concerns about health of fetus and surrogate, concerns about an unfamiliar surrogate, and concerns about lack of preparation for maternal role). Conclusions: The study reveals the importance of maternal emotional care in this group and introduces a new arena for nurses’ activity. These findings help the mothers by nurses’ activities in health care clinics and anywhere they deliver nursing care. PMID:24949058

  3. Diversification of intrinsic motoneuron electrical properties during normal development and botulinum toxin-induced muscle paralysis in early postnatal mice.

    PubMed

    Nakanishi, S T; Whelan, P J

    2010-05-01

    During early postnatal development, between birth and postnatal days 8-11, mice start to achieve weight-bearing locomotion. In association with the progression of weight-bearing locomotion there are presumed developmental changes in the intrinsic electrical properties of spinal -motoneurons. However, these developmental changes in the properties of -motoneuron properties have not been systematically explored in mice. Here, data are presented documenting the developmental changes of selected intrinsic motoneuron electrical properties, including statistically significant changes in action potential half-width, intrinsic excitability and diversity (quantified as coefficient of variation) of rheobase current, afterhyperpolarization half-decay time, and input resistance. In various adult mammalian preparations, the maintenance of intrinsic motoneuron electrical properties is dependent on activity and/or transmission-sensitive motoneuron-muscle interactions. In this study, we show that botulinum toxin-induced muscle paralysis led to statistically significant changes in the normal development of intrinsic motoneuron electrical properties in the postnatal mouse. This suggests that muscle activity during early neonatal life contributes to the development of normal motoneuron electrical properties.

  4. Probing the Role of Nascent Helicity in p27 Function as a Cell Cycle Regulator

    PubMed Central

    Otieno, Steve; Kriwacki, Richard

    2012-01-01

    p27 regulates the activity of Cdk complexes which are the principal governors of phase transitions during cell division. Members of the p27 family of proteins, which also includes p21 and p57, are called the Cip/Kip cyclin-dependent kinase regulators (CKRs). Interestingly, the Cip/Kip CKRs play critical roles in cell cycle regulation by being intrinsically unstructured, a characteristic contrary to the classical structure-function paradigm. They exhibit nascent helicity which has been localized to a segment referred to as sub-domain LH. The nascent helicity of this sub-domain is conserved and we hypothesize that it is an important determinant of their functional properties. To test this hypothesis, we successfully designed and prepared p27 variants in which domain LH was either more or less helical with respect to the wild-type protein. Thermal denaturation experiments showed that the ternary complexes of the p27 variants bound to Cdk2/Cyclin A were less stable compared to the wild-type complex. Isothermal titration calorimetry experiments showed a decrease in the enthalpy of binding for all the mutants with respect to p27. The free energies of binding varied within a much narrower range. In vitro Cdk2 inhibition assays showed that the p27 variants exhibited disparate inhibitory potencies. Furthermore, when over-expressed in NIH 3T3 mouse fibroblast cells, the less helical p27 variants were less effective in causing cell cycle arrest relative to the wild-type p27. Our results indicate that the nascent helicity of sub-domain LH plays a key role mediating the biological function of p27. PMID:23071750

  5. The role of ω-subunit of Escherichia coli RNA polymerase in stress response.

    PubMed

    Bhardwaj, Neerupma; Syal, Kirtimaan; Chatterji, Dipankar

    2018-05-01

    ppGpp, an alarmone for stringent response, plays an important role in the reprogramming of the transcription complex at the time of stress. In Escherichia coli, ppGpp mediates its action by binding to at least two different sites on RNA polymerase (RNAP). One of the sites to which ppGpp binds to RNAP is at the β'-ω interface; however, the underlying molecular mechanism and the physiological relevance of ppGpp binding to this site remain unclear. In this study, we have performed UV cross-linking experiments using 32 P azido-labeled ppGpp to probe its association with RNAP in the absence and presence of ω, and observed weaker binding of ppGpp to the RNAP without ω. Furthermore, we followed the binding kinetics of ppGpp to RNAP with and without ω by isothermal titration calorimetry and found it to be concurrent with the cross-linking results. Native ω is intrinsically disordered, and we have used a previously characterized structured mutant of ω, which affects the plasticity of the active site of RNAP. Results show that the flexibility conferred by the unstructured ω is a prerequisite for ppGpp binding to RNAP. We have analyzed the stress-associated phenotypes in an E. coli strain devoid of ω (∆rpoZ). ppGpp levels in ∆rpoZ strain were found to be similar to that of the wild-type strain. Interestingly, when the ∆rpoZ strain of E. coli was transferred after nutritional stress to an enriched media, the recovery of growth was compromised. We have identified a new phenotype of ∆rpoZ strain corresponding to defect in biofilm formation in minimal media. © 2018 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

  6. Bidirectional Modulation of Intrinsic Excitability in Rat Prelimbic Cortex Neuronal Ensembles and Non-Ensembles after Operant Learning.

    PubMed

    Whitaker, Leslie R; Warren, Brandon L; Venniro, Marco; Harte, Tyler C; McPherson, Kylie B; Beidel, Jennifer; Bossert, Jennifer M; Shaham, Yavin; Bonci, Antonello; Hope, Bruce T

    2017-09-06

    Learned associations between environmental stimuli and rewards drive goal-directed learning and motivated behavior. These memories are thought to be encoded by alterations within specific patterns of sparsely distributed neurons called neuronal ensembles that are activated selectively by reward-predictive stimuli. Here, we use the Fos promoter to identify strongly activated neuronal ensembles in rat prelimbic cortex (PLC) and assess altered intrinsic excitability after 10 d of operant food self-administration training (1 h/d). First, we used the Daun02 inactivation procedure in male FosLacZ-transgenic rats to ablate selectively Fos-expressing PLC neurons that were active during operant food self-administration. Selective ablation of these neurons decreased food seeking. We then used male FosGFP-transgenic rats to assess selective alterations of intrinsic excitability in Fos-expressing neuronal ensembles (FosGFP + ) that were activated during food self-administration and compared these with alterations in less activated non-ensemble neurons (FosGFP - ). Using whole-cell recordings of layer V pyramidal neurons in an ex vivo brain slice preparation, we found that operant self-administration increased excitability of FosGFP + neurons and decreased excitability of FosGFP - neurons. Increased excitability of FosGFP + neurons was driven by increased steady-state input resistance. Decreased excitability of FosGFP - neurons was driven by increased contribution of small-conductance calcium-activated potassium (SK) channels. Injections of the specific SK channel antagonist apamin into PLC increased Fos expression but had no effect on food seeking. Overall, operant learning increased intrinsic excitability of PLC Fos-expressing neuronal ensembles that play a role in food seeking but decreased intrinsic excitability of Fos - non-ensembles. SIGNIFICANCE STATEMENT Prefrontal cortex activity plays a critical role in operant learning, but the underlying cellular mechanisms are unknown. Using the chemogenetic Daun02 inactivation procedure, we found that a small number of strongly activated Fos-expressing neuronal ensembles in rat PLC play an important role in learned operant food seeking. Using GFP expression to identify Fos-expressing layer V pyramidal neurons in prelimbic cortex (PLC) of FosGFP-transgenic rats, we found that operant food self-administration led to increased intrinsic excitability in the behaviorally relevant Fos-expressing neuronal ensembles, but decreased intrinsic excitability in Fos - neurons using distinct cellular mechanisms. Copyright © 2017 the authors 0270-6474/17/378845-12$15.00/0.

  7. Expanded RNA-binding activities of mammalian Argonaute 2

    PubMed Central

    Tan, Grace S.; Garchow, Barry G.; Liu, Xuhang; Yeung, Jennifer; Morris, John P.; Cuellar, Trinna L.; McManus, Michael T.; Kiriakidou, Marianthi

    2009-01-01

    Mammalian Argonaute 2 (Ago2) protein associates with microRNAs (miRNAs) or small interfering RNAs (siRNAs) forming RNA-induced silencing complexes (RISCs/miRNPs). In the present work, we characterize the RNA-binding and nucleolytic activity of recombinant mouse Ago2. Our studies show that recombinant mouse Ago2 binds efficiently to miRNAs forming active RISC. Surprisingly, we find that recombinant mouse Ago2 forms active RISC using pre-miRNAs or long unstructured single stranded RNAs as guides. Furthermore, we demonstrate that, in vivo, endogenous human Ago2 binds directly to pre-miRNAs independently of Dicer, and that Ago2:pre-miRNA complexes are found both in the cytoplasm and in the nucleus of human cells. PMID:19808937

  8. Autonomy Support and Intrinsic Goal Progress Expectancy and Its Links to Longitudinal Study Effort and Subjective Wellbeing: The Differential Mediating Effect of Intrinsic and Identified Regulations and the Moderator Effects of Effort and Intrinsic Goals

    ERIC Educational Resources Information Center

    Waaler, Rune; Halvari, Halgeir; Skjesol, Knut; Bagoien, Tor Egil

    2013-01-01

    The authors tested a self-determination theory (Deci & Ryan, 2000) process model of subjective wellbeing among students at Norwegian Folk High Schools. In this model the authors hypothesized that students' intrinsic goal progress expectancy in the chosen study activity and perceived autonomy support from teachers would be positively associated…

  9. Intrinsic atopic dermatitis shows similar TH2 and higher TH17 immune activation compared with extrinsic atopic dermatitis.

    PubMed

    Suárez-Fariñas, Mayte; Dhingra, Nikhil; Gittler, Julia; Shemer, Avner; Cardinale, Irma; de Guzman Strong, Cristina; Krueger, James G; Guttman-Yassky, Emma

    2013-08-01

    Atopic dermatitis (AD) is classified as extrinsic and intrinsic, representing approximately 80% and 20% of patients with the disease, respectively. Although sharing a similar clinical phenotype, only extrinsic AD is characterized by high serum IgE levels. Because most patients with AD exhibit high IgE levels, an "allergic"/IgE-mediated disease pathogenesis was hypothesized. However, current models associate AD with T-cell activation, particularly TH2/TH22 polarization, and epidermal barrier defects. We sought to define whether both variants share a common pathogenesis. We stratified 51 patients with severe AD into extrinsic AD (n = 42) and intrinsic AD (n = 9) groups (with similar mean disease activity/SCORAD scores) and analyzed the molecular and cellular skin pathology of lesional and nonlesional intrinsic AD and extrinsic AD by using gene expression (real-time PCR) and immunohistochemistry. A significant correlation between IgE levels and SCORAD scores (r = 0.76, P < 10(-5)) was found only in patients with extrinsic AD. Marked infiltrates of T cells and dendritic cells and corresponding epidermal alterations (keratin 16, Mki67, and S100A7/A8/A9) defined lesional skin of patients with both variants. However, higher activation of all inflammatory axes (including TH2) was detected in patients with intrinsic AD, particularly TH17 and TH22 cytokines. Positive correlations between TH17-related molecules and SCORAD scores were only found in patients with intrinsic AD, whereas only patients with extrinsic AD showed positive correlations between SCORAD scores and TH2 cytokine (IL-4 and IL-5) levels and negative correlations with differentiation products (loricrin and periplakin). Although differences in TH17 and TH22 activation exist between patients with intrinsic AD and those with extrinsic AD, we identified common disease-defining features of T-cell activation, production of polarized cytokines, and keratinocyte responses to immune products. Our data indicate that a TH2 bias is not the sole cause of high IgE levels in patients with extrinsic AD, with important implications for similar therapeutic interventions. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  10. Intrinsic and Extrinsic Neuromodulation of Olfactory Processing

    PubMed Central

    Lizbinski, Kristyn M.; Dacks, Andrew M.

    2018-01-01

    Neuromodulation is a ubiquitous feature of neural systems, allowing flexible, context specific control over network dynamics. Neuromodulation was first described in invertebrate motor systems and early work established a basic dichotomy for neuromodulation as having either an intrinsic origin (i.e., neurons that participate in network coding) or an extrinsic origin (i.e., neurons from independent networks). In this conceptual dichotomy, intrinsic sources of neuromodulation provide a “memory” by adjusting network dynamics based upon previous and ongoing activation of the network itself, while extrinsic neuromodulators provide the context of ongoing activity of other neural networks. Although this dichotomy has been thoroughly considered in motor systems, it has received far less attention in sensory systems. In this review, we discuss intrinsic and extrinsic modulation in the context of olfactory processing in invertebrate and vertebrate model systems. We begin by discussing presynaptic modulation of olfactory sensory neurons by local interneurons (LNs) as a mechanism for gain control based on ongoing network activation. We then discuss the cell-class specific effects of serotonergic centrifugal neurons on olfactory processing. Finally, we briefly discuss the integration of intrinsic and extrinsic neuromodulation (metamodulation) as an effective mechanism for exerting global control over olfactory network dynamics. The heterogeneous nature of neuromodulation is a recurring theme throughout this review as the effects of both intrinsic and extrinsic modulation are generally non-uniform. PMID:29375314

  11. Induction of the Intrinsic Apoptotic Pathway by 3-Deazaadenosine Is Mediated by BAX Activation in HL-60 Cells

    PubMed Central

    Lee, Sun-Young; Ko, Kyoung-Won; Kang, Won-Kyung; Choe, Yun-Jeong; Kim, Yoon-Hyoung; Kim, In-Kyung; Kim, Jin

    2010-01-01

    3-Deazaadenosine (DZA), a potent inhibitor of S-adenosylhomocysteine hydrolase, was previously proposed to induce intrinsic apoptosis in human leukemic cells. In the present study, we analyzed the mechanism underlying the DZA-induced intrinsic apoptotic pathway. DZA activated typical caspase-dependent apoptosis in HL-60 cells, as demonstrated by an accumulation of hypo-diploidic cells, the processing of multiple procaspases and an inhibitory effect of z-VAD-Fmk on this cell death. During DZA-induced apoptosis, cytochrome c (cyt c) was released into the cytosol. This was neither prevented by z-VAD-Fmk and nor was it associated with the dissipation of mitochondrial membrane potential (ΔΨm). Prior to the release of cyt c, BAX was translocated from the cytosol to mitochondria and underwent oligomerization. Finally, the overexpression of BCL-XL protected HL-60 cells from apoptosis by blocking both the cyt c release and BAX oligomerization. Collectively, these findings suggest that DZA may activate intrinsic apoptosis by stimulating BAX activation and thereby the release of cyt c. PMID:21311682

  12. High temperature sensitivity is intrinsic to voltage-gated potassium channels

    PubMed Central

    Yang, Fan; Zheng, Jie

    2014-01-01

    Temperature-sensitive transient receptor potential (TRP) ion channels are members of the large tetrameric cation channels superfamily but are considered to be uniquely sensitive to heat, which has been presumed to be due to the existence of an unidentified temperature-sensing domain. Here we report that the homologous voltage-gated potassium (Kv) channels also exhibit high temperature sensitivity comparable to that of TRPV1, which is detectable under specific conditions when the voltage sensor is functionally decoupled from the activation gate through either intrinsic mechanisms or mutations. Interestingly, mutations could tune Shaker channel to be either heat-activated or heat-deactivated. Therefore, high temperature sensitivity is intrinsic to both TRP and Kv channels. Our findings suggest important physiological roles of heat-induced variation in Kv channel activities. Mechanistically our findings indicate that temperature-sensing TRP channels may not contain a specialized heat-sensor domain; instead, non-obligatory allosteric gating permits the intrinsic heat sensitivity to drive channel activation, allowing temperature-sensitive TRP channels to function as polymodal nociceptors. DOI: http://dx.doi.org/10.7554/eLife.03255.001 PMID:25030910

  13. A 3D Unstructured Mesh Euler Solver Based on the Fourth-Order CESE Method

    DTIC Science & Technology

    2013-06-01

    Form 298 (Rev. 8-98) Prescribed by ANSI Std. 239.18 A 3D Unstructured Mesh Euler Solver Based on the Fourth-Order CESE Method David L. Bilyeu ∗1,2...Similarly, the fluxes, f x,y,z i , and their derivatives inside a SE are also discretized by the Taylor series expansion: ∂ Cfx ,y,zi ∂xI∂yJ∂zK∂tL = A

  14. A 3-D CE/SE Navier-Stokes Solver With Unstructured Hexahedral Grid for Computation of Near Field Jet Screech Noise

    NASA Technical Reports Server (NTRS)

    Loh, Ching Y.; Himansu, Ananda; Hultgren, Lennart S.

    2003-01-01

    A 3-D space-time CE/SE Navier-Stokes solver using an unstructured hexahedral grid is described and applied to a circular jet screech noise computation. The present numerical results for an underexpanded jet, corresponding to a fully expanded Mach number of 1.42, capture the dominant and nonaxisymmetric 'B' screech mode and are generally in good agreement with existing experiments.

  15. A New Approach to Parallel Dynamic Partitioning for Adaptive Unstructured Meshes

    NASA Technical Reports Server (NTRS)

    Heber, Gerd; Biswas, Rupak; Gao, Guang R.

    1999-01-01

    Classical mesh partitioning algorithms were designed for rather static situations, and their straightforward application in a dynamical framework may lead to unsatisfactory results, e.g., excessive data migration among processors. Furthermore, special attention should be paid to their amenability to parallelization. In this paper, a novel parallel method for the dynamic partitioning of adaptive unstructured meshes is described. It is based on a linear representation of the mesh using self-avoiding walks.

  16. Three-dimensional unstructured grid refinement and optimization using edge-swapping

    NASA Technical Reports Server (NTRS)

    Gandhi, Amar; Barth, Timothy

    1993-01-01

    This paper presents a three-dimensional (3-D) 'edge-swapping method based on local transformations. This method extends Lawson's edge-swapping algorithm into 3-D. The 3-D edge-swapping algorithm is employed for the purpose of refining and optimizing unstructured meshes according to arbitrary mesh-quality measures. Several criteria including Delaunay triangulations are examined. Extensions from two to three dimensions of several known properties of Delaunay triangulations are also discussed.

  17. PLUM: Parallel Load Balancing for Unstructured Adaptive Meshes. Degree awarded by Colorado Univ.

    NASA Technical Reports Server (NTRS)

    Oliker, Leonid

    1998-01-01

    Dynamic mesh adaption on unstructured grids is a powerful tool for computing large-scale problems that require grid modifications to efficiently resolve solution features. By locally refining and coarsening the mesh to capture physical phenomena of interest, such procedures make standard computational methods more cost effective. Unfortunately, an efficient parallel implementation of these adaptive methods is rather difficult to achieve, primarily due to the load imbalance created by the dynamically-changing nonuniform grid. This requires significant communication at runtime, leading to idle processors and adversely affecting the total execution time. Nonetheless, it is generally thought that unstructured adaptive- grid techniques will constitute a significant fraction of future high-performance supercomputing. Various dynamic load balancing methods have been reported to date; however, most of them either lack a global view of loads across processors or do not apply their techniques to realistic large-scale applications.

  18. An Exact Dual Adjoint Solution Method for Turbulent Flows on Unstructured Grids

    NASA Technical Reports Server (NTRS)

    Nielsen, Eric J.; Lu, James; Park, Michael A.; Darmofal, David L.

    2003-01-01

    An algorithm for solving the discrete adjoint system based on an unstructured-grid discretization of the Navier-Stokes equations is presented. The method is constructed such that an adjoint solution exactly dual to a direct differentiation approach is recovered at each time step, yielding a convergence rate which is asymptotically equivalent to that of the primal system. The new approach is implemented within a three-dimensional unstructured-grid framework and results are presented for inviscid, laminar, and turbulent flows. Improvements to the baseline solution algorithm, such as line-implicit relaxation and a tight coupling of the turbulence model, are also presented. By storing nearest-neighbor terms in the residual computation, the dual scheme is computationally efficient, while requiring twice the memory of the flow solution. The scheme is expected to have a broad impact on computational problems related to design optimization as well as error estimation and grid adaptation efforts.

  19. Domain Decomposition By the Advancing-Partition Method for Parallel Unstructured Grid Generation

    NASA Technical Reports Server (NTRS)

    Pirzadeh, Shahyar Z.; Zagaris, George

    2009-01-01

    A new method of domain decomposition has been developed for generating unstructured grids in subdomains either sequentially or using multiple computers in parallel. Domain decomposition is a crucial and challenging step for parallel grid generation. Prior methods are generally based on auxiliary, complex, and computationally intensive operations for defining partition interfaces and usually produce grids of lower quality than those generated in single domains. The new technique, referred to as "Advancing Partition," is based on the Advancing-Front method, which partitions a domain as part of the volume mesh generation in a consistent and "natural" way. The benefits of this approach are: 1) the process of domain decomposition is highly automated, 2) partitioning of domain does not compromise the quality of the generated grids, and 3) the computational overhead for domain decomposition is minimal. The new method has been implemented in NASA's unstructured grid generation code VGRID.

  20. Unstructured viscous grid generation by advancing-front method

    NASA Technical Reports Server (NTRS)

    Pirzadeh, Shahyar

    1993-01-01

    A new method of generating unstructured triangular/tetrahedral grids with high-aspect-ratio cells is proposed. The method is based on new grid-marching strategy referred to as 'advancing-layers' for construction of highly stretched cells in the boundary layer and the conventional advancing-front technique for generation of regular, equilateral cells in the inviscid-flow region. Unlike the existing semi-structured viscous grid generation techniques, the new procedure relies on a totally unstructured advancing-front grid strategy resulting in a substantially enhanced grid flexibility and efficiency. The method is conceptually simple but powerful, capable of producing high quality viscous grids for complex configurations with ease. A number of two-dimensional, triangular grids are presented to demonstrate the methodology. The basic elements of the method, however, have been primarily designed with three-dimensional problems in mind, making it extendible for tetrahedral, viscous grid generation.

  1. A Robust and Scalable Software Library for Parallel Adaptive Refinement on Unstructured Meshes

    NASA Technical Reports Server (NTRS)

    Lou, John Z.; Norton, Charles D.; Cwik, Thomas A.

    1999-01-01

    The design and implementation of Pyramid, a software library for performing parallel adaptive mesh refinement (PAMR) on unstructured meshes, is described. This software library can be easily used in a variety of unstructured parallel computational applications, including parallel finite element, parallel finite volume, and parallel visualization applications using triangular or tetrahedral meshes. The library contains a suite of well-designed and efficiently implemented modules that perform operations in a typical PAMR process. Among these are mesh quality control during successive parallel adaptive refinement (typically guided by a local-error estimator), parallel load-balancing, and parallel mesh partitioning using the ParMeTiS partitioner. The Pyramid library is implemented in Fortran 90 with an interface to the Message-Passing Interface (MPI) library, supporting code efficiency, modularity, and portability. An EM waveguide filter application, adaptively refined using the Pyramid library, is illustrated.

  2. Discrete Adjoint-Based Design for Unsteady Turbulent Flows On Dynamic Overset Unstructured Grids

    NASA Technical Reports Server (NTRS)

    Nielsen, Eric J.; Diskin, Boris

    2012-01-01

    A discrete adjoint-based design methodology for unsteady turbulent flows on three-dimensional dynamic overset unstructured grids is formulated, implemented, and verified. The methodology supports both compressible and incompressible flows and is amenable to massively parallel computing environments. The approach provides a general framework for performing highly efficient and discretely consistent sensitivity analysis for problems involving arbitrary combinations of overset unstructured grids which may be static, undergoing rigid or deforming motions, or any combination thereof. General parent-child motions are also accommodated, and the accuracy of the implementation is established using an independent verification based on a complex-variable approach. The methodology is used to demonstrate aerodynamic optimizations of a wind turbine geometry, a biologically-inspired flapping wing, and a complex helicopter configuration subject to trimming constraints. The objective function for each problem is successfully reduced and all specified constraints are satisfied.

  3. Parallel volume ray-casting for unstructured-grid data on distributed-memory architectures

    NASA Technical Reports Server (NTRS)

    Ma, Kwan-Liu

    1995-01-01

    As computing technology continues to advance, computational modeling of scientific and engineering problems produces data of increasing complexity: large in size and unstructured in shape. Volume visualization of such data is a challenging problem. This paper proposes a distributed parallel solution that makes ray-casting volume rendering of unstructured-grid data practical. Both the data and the rendering process are distributed among processors. At each processor, ray-casting of local data is performed independent of the other processors. The global image composing processes, which require inter-processor communication, are overlapped with the local ray-casting processes to achieve maximum parallel efficiency. This algorithm differs from previous ones in four ways: it is completely distributed, less view-dependent, reasonably scalable, and flexible. Without using dynamic load balancing, test results on the Intel Paragon using from two to 128 processors show, on average, about 60% parallel efficiency.

  4. Population-level mating patterns and fluctuating asymmetry in swordtail hybrids

    NASA Astrophysics Data System (ADS)

    Culumber, Zachary W.; Rosenthal, Gil G.

    2013-08-01

    Morphological symmetry is a correlate of fitness-related traits or even a direct target of mate choice in a variety of taxa. In these taxa, when females discriminate among potential mates, increased selection on males should reduce fluctuating asymmetry (FA). Hybrid populations of the swordtails Xiphophorus birchmanni and Xiphophorus malinche vary from panmictic (unstructured) to highly structured, in which reproductive isolation is maintained among hybrids and parental species. We predicted that FA in flanking vertical bars used in sexual signalling should be lower in structured populations, where non-random mating patterns are observed. FA in vertical bars was markedly lower in structured populations than in parental and unstructured hybrid populations. There was no difference in FA between parentals and hybrids, suggesting that hybridisation does not directly affect FA. Rather, variation in FA likely results from contrasting mating patterns in unstructured and structured populations.

  5. An effective lattice Boltzmann flux solver on arbitrarily unstructured meshes

    NASA Astrophysics Data System (ADS)

    Wu, Qi-Feng; Shu, Chang; Wang, Yan; Yang, Li-Ming

    2018-05-01

    The recently proposed lattice Boltzmann flux solver (LBFS) is a new approach for the simulation of incompressible flow problems. It applies the finite volume method (FVM) to discretize the governing equations, and the flux at the cell interface is evaluated by local reconstruction of lattice Boltzmann solution from macroscopic flow variables at cell centers. In the previous application of the LBFS, the structured meshes have been commonly employed, which may cause inconvenience for problems with complex geometries. In this paper, the LBFS is extended to arbitrarily unstructured meshes for effective simulation of incompressible flows. Two test cases, the lid-driven flow in a triangular cavity and flow around a circular cylinder, are carried out for validation. The obtained results are compared with the data available in the literature. Good agreement has been achieved, which demonstrates the effectiveness and reliability of the LBFS in simulating flows on arbitrarily unstructured meshes.

  6. Workspace Safe Operation of a Force- or Impedance-Controlled Robot

    NASA Technical Reports Server (NTRS)

    Abdallah, Muhammad E. (Inventor); Hargrave, Brian (Inventor); Strawser, Philip A. (Inventor); Yamokoski, John D. (Inventor)

    2013-01-01

    A method of controlling a robotic manipulator of a force- or impedance-controlled robot within an unstructured workspace includes imposing a saturation limit on a static force applied by the manipulator to its surrounding environment, and may include determining a contact force between the manipulator and an object in the unstructured workspace, and executing a dynamic reflex when the contact force exceeds a threshold to thereby alleviate an inertial impulse not addressed by the saturation limited static force. The method may include calculating a required reflex torque to be imparted by a joint actuator to a robotic joint. A robotic system includes a robotic manipulator having an unstructured workspace and a controller that is electrically connected to the manipulator, and which controls the manipulator using force- or impedance-based commands. The controller, which is also disclosed herein, automatically imposes the saturation limit and may execute the dynamic reflex noted above.

  7. Numerical approach for unstructured quantum key distribution

    PubMed Central

    Coles, Patrick J.; Metodiev, Eric M.; Lütkenhaus, Norbert

    2016-01-01

    Quantum key distribution (QKD) allows for communication with security guaranteed by quantum theory. The main theoretical problem in QKD is to calculate the secret key rate for a given protocol. Analytical formulas are known for protocols with symmetries, since symmetry simplifies the analysis. However, experimental imperfections break symmetries, hence the effect of imperfections on key rates is difficult to estimate. Furthermore, it is an interesting question whether (intentionally) asymmetric protocols could outperform symmetric ones. Here we develop a robust numerical approach for calculating the key rate for arbitrary discrete-variable QKD protocols. Ultimately this will allow researchers to study ‘unstructured' protocols, that is, those that lack symmetry. Our approach relies on transforming the key rate calculation to the dual optimization problem, which markedly reduces the number of parameters and hence the calculation time. We illustrate our method by investigating some unstructured protocols for which the key rate was previously unknown. PMID:27198739

  8. Multi-Resolution Unstructured Grid-Generation for Geophysical Applications on the Sphere

    NASA Technical Reports Server (NTRS)

    Engwirda, Darren

    2015-01-01

    An algorithm for the generation of non-uniform unstructured grids on ellipsoidal geometries is described. This technique is designed to generate high quality triangular and polygonal meshes appropriate for general circulation modelling on the sphere, including applications to atmospheric and ocean simulation, and numerical weather predication. Using a recently developed Frontal-Delaunay-refinement technique, a method for the construction of high-quality unstructured ellipsoidal Delaunay triangulations is introduced. A dual polygonal grid, derived from the associated Voronoi diagram, is also optionally generated as a by-product. Compared to existing techniques, it is shown that the Frontal-Delaunay approach typically produces grids with near-optimal element quality and smooth grading characteristics, while imposing relatively low computational expense. Initial results are presented for a selection of uniform and non-uniform ellipsoidal grids appropriate for large-scale geophysical applications. The use of user-defined mesh-sizing functions to generate smoothly graded, non-uniform grids is discussed.

  9. Assessment of the Unstructured Grid Software TetrUSS for Drag Prediction of the DLR-F4 Configuration

    NASA Technical Reports Server (NTRS)

    Pirzadeh, Shahyar Z.; Frink, Neal T.

    2002-01-01

    An application of the NASA unstructured grid software system TetrUSS is presented for the prediction of aerodynamic drag on a transport configuration. The paper briefly describes the underlying methodology and summarizes the results obtained on the DLR-F4 transport configuration recently presented in the first AIAA computational fluid dynamics (CFD) Drag Prediction Workshop. TetrUSS is a suite of loosely coupled unstructured grid CFD codes developed at the NASA Langley Research Center. The meshing approach is based on the advancing-front and the advancing-layers procedures. The flow solver employs a cell-centered, finite volume scheme for solving the Reynolds Averaged Navier-Stokes equations on tetrahedral grids. For the present computations, flow in the viscous sublayer has been modeled with an analytical wall function. The emphasis of the paper is placed on the practicality of the methodology for accurately predicting aerodynamic drag data.

  10. A matrix-free implicit unstructured multigrid finite volume method for simulating structural dynamics and fluid structure interaction

    NASA Astrophysics Data System (ADS)

    Lv, X.; Zhao, Y.; Huang, X. Y.; Xia, G. H.; Su, X. H.

    2007-07-01

    A new three-dimensional (3D) matrix-free implicit unstructured multigrid finite volume (FV) solver for structural dynamics is presented in this paper. The solver is first validated using classical 2D and 3D cantilever problems. It is shown that very accurate predictions of the fundamental natural frequencies of the problems can be obtained by the solver with fast convergence rates. This method has been integrated into our existing FV compressible solver [X. Lv, Y. Zhao, et al., An efficient parallel/unstructured-multigrid preconditioned implicit method for simulating 3d unsteady compressible flows with moving objects, Journal of Computational Physics 215(2) (2006) 661-690] based on the immersed membrane method (IMM) [X. Lv, Y. Zhao, et al., as mentioned above]. Results for the interaction between the fluid and an immersed fixed-free cantilever are also presented to demonstrate the potential of this integrated fluid-structure interaction approach.

  11. Intrinsic Connectivity Provides the Baseline Framework for Variability in Motor Performance: A Multivariate Fusion Analysis of Low- and High-Frequency Resting-State Oscillations and Antisaccade Performance.

    PubMed

    Jamadar, Sharna D; Egan, Gary F; Calhoun, Vince D; Johnson, Beth; Fielding, Joanne

    2016-07-01

    Intrinsic brain activity provides the functional framework for the brain's full repertoire of behavioral responses; that is, a common mechanism underlies intrinsic and extrinsic neural activity, with extrinsic activity building upon the underlying baseline intrinsic activity. The generation of a motor movement in response to sensory stimulation is one of the most fundamental functions of the central nervous system. Since saccadic eye movements are among our most stereotyped motor responses, we hypothesized that individual variability in the ability to inhibit a prepotent saccade and make a voluntary antisaccade would be related to individual variability in intrinsic connectivity. Twenty-three individuals completed the antisaccade task and resting-state functional magnetic resonance imaging (fMRI). A multivariate analysis of covariance identified relationships between fMRI oscillations (0.01-0.2 Hz) of resting-state networks determined using high-dimensional independent component analysis and antisaccade performance (latency, error rate). Significant multivariate relationships between antisaccade latency and directional error rate were obtained in independent components across the entire brain. Some of the relationships were obtained in components that overlapped substantially with the task; however, many were obtained in components that showed little overlap with the task. The current results demonstrate that even in the absence of a task, spectral power in regions showing little overlap with task activity predicts an individual's performance on a saccade task.

  12. Motivation towards extracurricular activities and motivation at school: A test of the generalization effect hypothesis.

    PubMed

    Denault, Anne-Sophie; Guay, Frédéric

    2017-01-01

    Participation in extracurricular activities is a promising avenue for enhancing students' school motivation. Using self-determination theory (Deci & Ryan, 2000), the goal of this study was to test a serial multiple mediator model. In this model, students' perceptions of autonomy support from their extracurricular activity leader predicted their activity-based intrinsic and identified regulations. In turn, these regulations predicted their school-based intrinsic and identified regulations during the same school year. Finally, these regulations predicted their school-based intrinsic and identified regulations one year later. A total of 276 youths (54% girls) from disadvantaged neighborhoods were surveyed over two waves of data collection. The proposed mediation model was supported for both types of regulation. These results highlight the generalization effects of motivation from the extracurricular activity context to the school context. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  13. Asymmetric Volcano Trend in Oxygen Reduction Activity of Pt and Non-Pt Catalysts: In Situ Identification of the Site-Blocking Effect.

    PubMed

    Li, Jingkun; Alsudairi, Amell; Ma, Zi-Feng; Mukerjee, Sanjeev; Jia, Qingying

    2017-02-01

    Proper understanding of the major limitations of current catalysts for oxygen reduction reaction (ORR) is essential for further advancement. Herein by studying representative Pt and non-Pt ORR catalysts with a wide range of redox potential (E redox ) via combined electrochemical, theoretical, and in situ spectroscopic methods, we demonstrate that the role of the site-blocking effect in limiting the ORR varies drastically depending on the E redox of active sites; and the intrinsic activity of active sites with low E redox have been markedly underestimated owing to the overlook of this effect. Accordingly, we establish a general asymmetric volcano trend in the ORR activity: the ORR of the catalysts on the overly high E redox side of the volcano is limited by the intrinsic activity; whereas the ORR of the catalysts on the low E redox side is limited by either the site-blocking effect and/or intrinsic activity depending on the E redox .

  14. Hierarchy of Information Processing in the Brain: A Novel 'Intrinsic Ignition' Framework.

    PubMed

    Deco, Gustavo; Kringelbach, Morten L

    2017-06-07

    A general theory of brain function has to be able to explain local and non-local network computations over space and time. We propose a new framework to capture the key principles of how local activity influences global computation, i.e., describing the propagation of information and thus the broadness of communication driven by local activity. More specifically, we consider the diversity in space (nodes or brain regions) over time using the concept of intrinsic ignition, which are naturally occurring intrinsic perturbations reflecting the capability of a given brain area to propagate neuronal activity to other regions in a given brain state. Characterizing the profile of intrinsic ignition for a given brain state provides insight into the precise nature of hierarchical information processing. Combining this data-driven method with a causal whole-brain computational model can provide novel insights into the imbalance of brain states found in neuropsychiatric disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Toward a More Human Way of Working in America. A Report on the National Conference of the American Quality of Work Life Association Convoked by the American Center for the Quality of Work Life (1st, Washington, D.C., May 20-22, 1977).

    ERIC Educational Resources Information Center

    Zwerdling, Daniel

    Beginning an an informal, unstructured information interchange among 100 union, worker, and management representatives from seventeen public and private sector organizations operationally involved in quality of work life activities, a 1977 conference evolved into the first annual meeting of the American Quality of Work Life Association.…

  16. Research in Computational Aeroscience Applications Implemented on Advanced Parallel Computing Systems

    NASA Technical Reports Server (NTRS)

    Wigton, Larry

    1996-01-01

    Improving the numerical linear algebra routines for use in new Navier-Stokes codes, specifically Tim Barth's unstructured grid code, with spin-offs to TRANAIR is reported. A fast distance calculation routine for Navier-Stokes codes using the new one-equation turbulence models is written. The primary focus of this work was devoted to improving matrix-iterative methods. New algorithms have been developed which activate the full potential of classical Cray-class computers as well as distributed-memory parallel computers.

  17. The Emerging Neuroscience of Intrinsic Motivation: A New Frontier in Self-Determination Research

    PubMed Central

    Di Domenico, Stefano I.; Ryan, Richard M.

    2017-01-01

    Intrinsic motivation refers to people’s spontaneous tendencies to be curious and interested, to seek out challenges and to exercise and develop their skills and knowledge, even in the absence of operationally separable rewards. Over the past four decades, experimental and field research guided by self-determination theory (SDT; Ryan and Deci, 2017) has found intrinsic motivation to predict enhanced learning, performance, creativity, optimal development and psychological wellness. Only recently, however, have studies begun to examine the neurobiological substrates of intrinsic motivation. In the present article, we trace the history of intrinsic motivation research, compare and contrast intrinsic motivation to closely related topics (flow, curiosity, trait plasticity), link intrinsic motivation to key findings in the comparative affective neurosciences, and review burgeoning neuroscience research on intrinsic motivation. We review converging evidence suggesting that intrinsically motivated exploratory and mastery behaviors are phylogenetically ancient tendencies that are subserved by dopaminergic systems. Studies also suggest that intrinsic motivation is associated with patterns of activity across large-scale neural networks, namely, those that support salience detection, attentional control and self-referential cognition. We suggest novel research directions and offer recommendations for the application of neuroscience methods in the study of intrinsic motivation. PMID:28392765

  18. The Emerging Neuroscience of Intrinsic Motivation: A New Frontier in Self-Determination Research.

    PubMed

    Di Domenico, Stefano I; Ryan, Richard M

    2017-01-01

    Intrinsic motivation refers to people's spontaneous tendencies to be curious and interested, to seek out challenges and to exercise and develop their skills and knowledge, even in the absence of operationally separable rewards. Over the past four decades, experimental and field research guided by self-determination theory (SDT; Ryan and Deci, 2017) has found intrinsic motivation to predict enhanced learning, performance, creativity, optimal development and psychological wellness. Only recently, however, have studies begun to examine the neurobiological substrates of intrinsic motivation. In the present article, we trace the history of intrinsic motivation research, compare and contrast intrinsic motivation to closely related topics (flow, curiosity, trait plasticity), link intrinsic motivation to key findings in the comparative affective neurosciences, and review burgeoning neuroscience research on intrinsic motivation. We review converging evidence suggesting that intrinsically motivated exploratory and mastery behaviors are phylogenetically ancient tendencies that are subserved by dopaminergic systems. Studies also suggest that intrinsic motivation is associated with patterns of activity across large-scale neural networks, namely, those that support salience detection, attentional control and self-referential cognition. We suggest novel research directions and offer recommendations for the application of neuroscience methods in the study of intrinsic motivation.

  19. Towards active capsular endoscopy: preliminary results on a legged platform.

    PubMed

    Menciassi, Arianna; Stefanini, Cesare; Orlandi, Giovanni; Quirini, Marco; Dario, Paolo

    2006-01-01

    This paper illustrates the problem of active locomotion in the gastrointestinal tract for endoscopic capsules. Authors analyze the problem of locomotion in unstructured, flexible and tubular environments and explain the reasons leading to the selection of a legged system. They present a theoretical simulation of legged capsule locomotion, which is used to define the optimal parameters for capsule design and gait selection. Finally, a legged capsule--about 3 cm3 in volume--is presented; it consists of 4 back legs whose actuation is achieved thanks to a miniaturized DC brushless motor. In vitro tests demonstrate good performance in terms of achievable speed (92 mm/min).

  20. Achievement-Based Rewards and Intrinsic Motivation: A Test of Cognitive Mediators

    ERIC Educational Resources Information Center

    Cameron, Judy; Pierce, W. David; Banko, Katherine M.; Gear, Amber

    2005-01-01

    This study assessed how rewards impacted intrinsic motivation when students were rewarded for achievement while learning an activity, for performing at a specific level on a test, or for both. Undergraduate university students engaged in a problem-solving activity. The design was a 2 * 2 factorial with 2 levels of reward in a learning phase…

  1. Motives Emanating from Personality Associated with Achievement in a Finnish Senior High School: Physical Activity, Curiosity, and Family Motives

    ERIC Educational Resources Information Center

    Froiland, John Mark; Mayor, Päivi; Herlevi, Marjaana

    2015-01-01

    Numerous studies indicate that intrinsic motivation predicts academic achievement. However, relatively few have examined various subtypes of intrinsic motivation that predict overall achievement, such as motivation for exercise and physical activity. Based upon the 16 basic desires theory of personality, the current study examined the motives of…

  2. Third-order accurate conservative method on unstructured meshes for gasdynamic simulations

    NASA Astrophysics Data System (ADS)

    Shirobokov, D. A.

    2017-04-01

    A third-order accurate finite-volume method on unstructured meshes is proposed for solving viscous gasdynamic problems. The method is described as applied to the advection equation. The accuracy of the method is verified by computing the evolution of a vortex on meshes of various degrees of detail with variously shaped cells. Additionally, unsteady flows around a cylinder and a symmetric airfoil are computed. The numerical results are presented in the form of plots and tables.

  3. EMPHASIS(TM)/Nevada UTDEM User Guide Version 2.1.1.

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

    Turner, C. David; Pasik, Michael F.; Pointon, Timothy D.

    The Unstructured Time - Domain ElectroMagnetics (UTDEM) portion of the EMPHASIS suite solves Maxwell's equations using finite - element techniques on unstructured meshes. This document provides user - specific information to facilitate the use of the code for ap plications of interest. Acknowledgement The authors would like to thank all of those individuals who have helped to bring EMPHASIS/Nevada to the point it is today, including Bill Bohnhoff, Rich Drake, and all of the NEVADA code team.

  4. Unstructured Polyhedral Mesh Thermal Radiation Diffusion

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

    Palmer, T.S.; Zika, M.R.; Madsen, N.K.

    2000-07-27

    Unstructured mesh particle transport and diffusion methods are gaining wider acceptance as mesh generation, scientific visualization and linear solvers improve. This paper describes an algorithm that is currently being used in the KULL code at Lawrence Livermore National Laboratory to solve the radiative transfer equations. The algorithm employs a point-centered diffusion discretization on arbitrary polyhedral meshes in 3D. We present the results of a few test problems to illustrate the capabilities of the radiation diffusion module.

  5. Unstructured 3D Delaunay mesh generation applied to planes, trains and automobiles

    NASA Technical Reports Server (NTRS)

    Blake, Kenneth R.; Spragle, Gregory S.

    1993-01-01

    Technical issues associated with domain-tessellation production, including initial boundary node triangulation and volume mesh refinement, are presented for the 'TGrid' 3D Delaunay unstructured grid generation program. The approach employed is noted to be capable of preserving predefined triangular surface facets in the final tessellation. The capabilities of the approach are demonstrated by generating grids about an entire fighter aircraft configuration, a train, and a wind tunnel model of an automobile.

  6. Solution algorithms for the two-dimensional Euler equations on unstructured meshes

    NASA Technical Reports Server (NTRS)

    Whitaker, D. L.; Slack, David C.; Walters, Robert W.

    1990-01-01

    The objective of the study was to analyze implicit techniques employed in structured grid algorithms for solving two-dimensional Euler equations and extend them to unstructured solvers in order to accelerate convergence rates. A comparison is made between nine different algorithms for both first-order and second-order accurate solutions. Higher-order accuracy is achieved by using multidimensional monotone linear reconstruction procedures. The discussion is illustrated by results for flow over a transonic circular arc.

  7. elsA-Hybrid: an all-in-one structured/unstructured solver for the simulation of internal and external flows. Application to turbomachinery

    NASA Astrophysics Data System (ADS)

    de la Llave Plata, M.; Couaillier, V.; Le Pape, M.-C.; Marmignon, C.; Gazaix, M.

    2013-03-01

    This paper reports recent work on the extension of the multiblock structured solver elsA to deal with hybrid grids. The new hybrid-grid solver is called elsA-H (elsA-Hybrid), is based on the investigation of a new unstructured-grid module has been built within the original elsA CFD (computational fluid dynamics) system. The implementation benefits from the flexibility of the object-oriented design. The aim of elsA-H is to take advantage of the full potential of structured solvers and unstructured mesh generation by allowing any type of grid to be used within the same simulation process. The main challenge lies in the numerical treatment of the hybrid-grid interfaces where blocks of different type meet. In particular, one must pay attention to the transfer of information across these boundaries, so that the accuracy of the numerical scheme is preserved and flux conservation is guaranteed. In this paper, the numerical approach allowing to achieve this is presented. A comparison between the hybrid and the structured-grid methods is also carried out by considering a fully hexahedral multiblock mesh for which a few blocks have been transformed into unstructured. The performance of elsA-H for the simulation of internal flows will be demonstrated on a number of turbomachinery configurations.

  8. Coronary artery disease risk assessment from unstructured electronic health records using text mining.

    PubMed

    Jonnagaddala, Jitendra; Liaw, Siaw-Teng; Ray, Pradeep; Kumar, Manish; Chang, Nai-Wen; Dai, Hong-Jie

    2015-12-01

    Coronary artery disease (CAD) often leads to myocardial infarction, which may be fatal. Risk factors can be used to predict CAD, which may subsequently lead to prevention or early intervention. Patient data such as co-morbidities, medication history, social history and family history are required to determine the risk factors for a disease. However, risk factor data are usually embedded in unstructured clinical narratives if the data is not collected specifically for risk assessment purposes. Clinical text mining can be used to extract data related to risk factors from unstructured clinical notes. This study presents methods to extract Framingham risk factors from unstructured electronic health records using clinical text mining and to calculate 10-year coronary artery disease risk scores in a cohort of diabetic patients. We developed a rule-based system to extract risk factors: age, gender, total cholesterol, HDL-C, blood pressure, diabetes history and smoking history. The results showed that the output from the text mining system was reliable, but there was a significant amount of missing data to calculate the Framingham risk score. A systematic approach for understanding missing data was followed by implementation of imputation strategies. An analysis of the 10-year Framingham risk scores for coronary artery disease in this cohort has shown that the majority of the diabetic patients are at moderate risk of CAD. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Simulating hydrodynamics and ice cover in Lake Erie using an unstructured grid model

    NASA Astrophysics Data System (ADS)

    Fujisaki-Manome, A.; Wang, J.

    2016-02-01

    An unstructured grid Finite-Volume Coastal Ocean Model (FVCOM) is applied to Lake Erie to simulate seasonal ice cover. The model is coupled with an unstructured-grid, finite-volume version of the Los Alamos Sea Ice Model (UG-CICE). We replaced the original 2-time-step Euler forward scheme in time integration by the central difference (i.e., leapfrog) scheme to assure a neutrally inertial stability. The modified version of FVCOM coupled with the ice model is applied to the shallow freshwater lake in this study using unstructured grids to represent the complicated coastline in the Laurentian Great Lakes and refining the spatial resolution locally. We conducted multi-year simulations in Lake Erie from 2002 to 2013. The results were compared with the observed ice extent, water surface temperature, ice thickness, currents, and water temperature profiles. Seasonal and interannual variation of ice extent and water temperature was captured reasonably, while the modeled thermocline was somewhat diffusive. The modeled ice thickness tends to be systematically thinner than the observed values. The modeled lake currents compared well with measurements obtained from an Acoustic Doppler Current Profiler located in the deep part of the lake, whereas the simulated currents deviated from measurements near the surface, possibly due to the model's inability to reproduce the sharp thermocline during the summer and the lack of detailed representation of offshore wind fields in the interpolated meteorological forcing.

  10. Advanced Computational Aeroacoustics Methods for Fan Noise Prediction

    NASA Technical Reports Server (NTRS)

    Envia, Edmane (Technical Monitor); Tam, Christopher

    2003-01-01

    Direct computation of fan noise is presently not possible. One of the major difficulties is the geometrical complexity of the problem. In the case of fan noise, the blade geometry is critical to the loading on the blade and hence the intensity of the radiated noise. The precise geometry must be incorporated into the computation. In computational fluid dynamics (CFD), there are two general ways to handle problems with complex geometry. One way is to use unstructured grids. The other is to use body fitted overset grids. In the overset grid method, accurate data transfer is of utmost importance. For acoustic computation, it is not clear that the currently used data transfer methods are sufficiently accurate as not to contaminate the very small amplitude acoustic disturbances. In CFD, low order schemes are, invariably, used in conjunction with unstructured grids. However, low order schemes are known to be numerically dispersive and dissipative. dissipative errors are extremely undesirable for acoustic wave problems. The objective of this project is to develop a high order unstructured grid Dispersion-Relation-Preserving (DRP) scheme. would minimize numerical dispersion and dissipation errors. contains the results of the funded portion of the project. scheme on an unstructured grid has been developed. constructed in the wave number space. The characteristics of the scheme can be improved by the inclusion of additional constraints. Stability of the scheme has been investigated. Stability can be improved by adopting the upwinding strategy.

  11. Transonic Drag Prediction Using an Unstructured Multigrid Solver

    NASA Technical Reports Server (NTRS)

    Mavriplis, D. J.; Levy, David W.

    2001-01-01

    This paper summarizes the results obtained with the NSU-3D unstructured multigrid solver for the AIAA Drag Prediction Workshop held in Anaheim, CA, June 2001. The test case for the workshop consists of a wing-body configuration at transonic flow conditions. Flow analyses for a complete test matrix of lift coefficient values and Mach numbers at a constant Reynolds number are performed, thus producing a set of drag polars and drag rise curves which are compared with experimental data. Results were obtained independently by both authors using an identical baseline grid and different refined grids. Most cases were run in parallel on commodity cluster-type machines while the largest cases were run on an SGI Origin machine using 128 processors. The objective of this paper is to study the accuracy of the subject unstructured grid solver for predicting drag in the transonic cruise regime, to assess the efficiency of the method in terms of convergence, cpu time, and memory, and to determine the effects of grid resolution on this predictive ability and its computational efficiency. A good predictive ability is demonstrated over a wide range of conditions, although accuracy was found to degrade for cases at higher Mach numbers and lift values where increasing amounts of flow separation occur. The ability to rapidly compute large numbers of cases at varying flow conditions using an unstructured solver on inexpensive clusters of commodity computers is also demonstrated.

  12. The Tera Multithreaded Architecture and Unstructured Meshes

    NASA Technical Reports Server (NTRS)

    Bokhari, Shahid H.; Mavriplis, Dimitri J.

    1998-01-01

    The Tera Multithreaded Architecture (MTA) is a new parallel supercomputer currently being installed at San Diego Supercomputing Center (SDSC). This machine has an architecture quite different from contemporary parallel machines. The computational processor is a custom design and the machine uses hardware to support very fine grained multithreading. The main memory is shared, hardware randomized and flat. These features make the machine highly suited to the execution of unstructured mesh problems, which are difficult to parallelize on other architectures. We report the results of a study carried out during July-August 1998 to evaluate the execution of EUL3D, a code that solves the Euler equations on an unstructured mesh, on the 2 processor Tera MTA at SDSC. Our investigation shows that parallelization of an unstructured code is extremely easy on the Tera. We were able to get an existing parallel code (designed for a shared memory machine), running on the Tera by changing only the compiler directives. Furthermore, a serial version of this code was compiled to run in parallel on the Tera by judicious use of directives to invoke the "full/empty" tag bits of the machine to obtain synchronization. This version achieves 212 and 406 Mflop/s on one and two processors respectively, and requires no attention to partitioning or placement of data issues that would be of paramount importance in other parallel architectures.

  13. COMPENSATION FOR VARIABLE INTRINSIC NEURONAL EXCITABILITY BY CIRCUIT-SYNAPTIC INTERACTIONS

    PubMed Central

    Grashow, Rachel; Brookings, Ted; Marder, Eve

    2010-01-01

    Recent theoretical and experimental work indicates that neurons tune themselves to maintain target levels of excitation by modulating ion channel expression and synaptic strengths. As a result, functionally equivalent circuits can produce similar activity despite disparate underlying network and cellular properties. To experimentally test the extent to which synaptic and intrinsic conductances can produce target activity in the presence of variability in neuronal intrinsic properties, we used the dynamic clamp to create hybrid two-cell circuits built from four types of stomatogastric (STG) neurons coupled to the same model Morris-Lecar neuron by reciprocal inhibition. We measured six intrinsic properties (input resistance, minimum membrane potential, firing rate in response to +1nA of injected current, slope of the FI curve, spike height and spike voltage threshold) of Dorsal Gastric (DG), Gastric Mill (GM), Lateral Pyloric (LP) and Pyloric Dilator (PD) neurons from male crabs, Cancer borealis. The intrinsic properties varied two to seven-fold in each cell type. We coupled each biological neuron to the Morris-Lecar model with seven different values of inhibitory synaptic conductance, and also used the dynamic clamp to add seven different values of an artificial h-conductance, thus creating 49 different circuits for each biological neuron. Despite the variability in intrinsic excitability, networks formed from each neuron produced similar circuit performance at some values of synaptic and h-conductances. This work experimentally confirms results from previous modeling studies; tuning synaptic and intrinsic conductances can yield similar circuit output from neurons with variable intrinsic excitability. PMID:20610748

  14. Intrinsic Motivation and Flow Condition on the Music Teacher's Performance

    ERIC Educational Resources Information Center

    Torres Delgado, Gabriela

    2017-01-01

    The aim of these research is to identify if music teachers and teachers from other areas are intrinsically or extrinsically motivated, to identify the dimensions of the flow state, and to identify if there is a relationship between intrinsic motivation and flow state in these teachers. The sample was made up of 738 active teachers. The presence of…

  15. Personal motivation, exercise, and smoking behaviors among young adults.

    PubMed

    Scioli, Erica Rose; Biller, Henry; Rossi, Joseph; Riebe, Deborah

    2009-01-01

    This study explored the motivational factors that influence individuals across the stages of change for exercise. The authors compared physically active nonsmokers with physically active smokers in a college student population. Half of regular exercisers identified themselves as smokers. Compared with their nonsmoking peers, young smokers have higher rates of physical and emotional distress. Those participants who exercise and do not smoke are more likely to exhibit intrinsic factors for exercise. Undergraduate psychology students (N = 614) completed an Internet survey on exercise and smoking behavior as well as motivational factors for exercise. Multivariate analyses of variance revealed that intrinsic motivational factors for exercise were significantly higher for the active nonsmokers than for the active smokers. Interventions promoting consistent exercise and smoking abstinence should continue to be directed toward young adults, focusing on fostering intrinsic motivational factors for exercise.

  16. Genetics Home Reference: prekallikrein deficiency

    MedlinePlus

    ... a role in a process called the intrinsic coagulation pathway (also called the contact activation pathway). This ... functional plasma kallikrein, which likely impairs the intrinsic coagulation pathway. Researchers suggest that this lack (deficiency) of ...

  17. Functional interdependence of neurons in a single canine intrinsic cardiac ganglionated plexus

    PubMed Central

    Thompson, G W; Collier, K; Ardell, J L; Kember, G; Armour, J A

    2000-01-01

    To determine the activity characteristics displayed by different subpopulations of neurons in a single intrinsic cardiac ganglionated plexus, the behaviour and co-ordination of activity generated by neurons in two loci of the right atrial ganglionated plexus (RAGP) were evaluated in 16 anaesthetized dogs during basal states as well as in response to increasing inputs from ventricular sensory neurites. These sub-populations of right atrial neurons received afferent inputs from sensory neurites in both ventricles that were responsive to local mechanical stimuli and the nitric oxide donor nitroprusside. Neurons in at least one RAGP locus were activated by epicardial application of veratridine, bradykinin, the β1-adrenoceptor agonist prenaterol or glutamate. Epicardial application of angiotensin II, the selective β2-adrenoceptor agonist terbutaline and selective α-adrenoceptor agonists elicited inconsistent neuronal responses. The activity generated by both populations of atrial neurons studied over 5 min periods during basal states displayed periodic coupled behaviour (cross-correlation coefficients of activities that reached, on average, 0·88 ± 0·03; range 0·71–1) for 15–30 s periods of time. These periods of coupled activity occurred every 30–50 s during basal states, as well as when neuronal activity was enhanced by chemical activation of their ventricular sensory inputs. These results indicate that neurons throughout one intrinsic cardiac ganglionated plexus receive inputs from mechano- and chemosensory neurites located in both ventricles. That such neurons respond to multiple chemical stimuli, including those liberated from adjacent adrenergic efferent nerve terminals, indicates the complexity of the integrative processing of information that occurs within the intrinsic cardiac nervous system. It is proposed that the interdependent activity displayed by populations of neurons in different regions of one intrinsic cardiac ganglionated plexus, responding as they do to multiple cardiac sensory inputs, forms the basis for integrated regional cardiac control. PMID:11060132

  18. Television Viewing Does Not Have to Be Sedentary: Motivation to Participate in a TV Exercise Program

    PubMed Central

    Meis, Jessie J. M.; Kremers, Stef P. J.; Bouman, Martine P. A.

    2012-01-01

    The present study explored which underlying motivations induced people to participate in a television exercise program called “The Netherlands on the Move!-television” (NOM-tv). A cross-sectional study was carried out among 1,349 viewers of NOM-tv. The respondents completed the intrinsic motivation inventory (IMI), assessing their levels of intrinsic motivation towards participating in the NOM-tv exercises. The results showed that higher levels of intrinsic motivation (i.e. enjoying the NOM-tv exercises, feeling competent to perform this activity, and willingness to put effort into the exercises) were the most important predictive factors of more frequent participation in the NOM-tv exercises. Future screen-based interventions to reduce sedentary behavior should aim especially at encouraging people's intrinsic orientations towards physical activity in an autonomy-supportive way. PMID:22187637

  19. Neural evidence for the intrinsic value of action as motivation for behavior.

    PubMed

    Miura, Naoki; Tanabe, Hiroki C; Sasaki, Akihiro T; Harada, Tokiko; Sadato, Norihiro

    2017-06-03

    The intrinsic value of an action refers to the inherent sense that experiencing a behavior is enjoyable even if it has no explicit outcome. Previous research has suggested that a common valuation mechanism within the reward network may be responsible for processing the intrinsic value of achieving both the outcome and external rewards. However, how the intrinsic value of action is neurally represented remains unknown. We hypothesized that the intrinsic value of action is determined by an action-outcome contingency indicating the behavior is controllable and that the outcome of the action can be evaluated by this feedback. Consequently, the reward network should be activated, reflecting the generation of the intrinsic value of action. To test this hypothesis, we conducted a functional magnetic resonance imaging (fMRI) investigation of a stopwatch game in which the action-outcome contingency was manipulated. This experiment involved 36 healthy volunteers and four versions of a stopwatch game that manipulated controllability (the feeling that participants were controlling the stopwatch themselves) and outcome (a signal allowing participants to see the result of their action). A free-choice experiment was administered after the fMRI to explore preference levels for each game. The results showed that the stopwatch game with the action-outcome contingency evoked a greater degree of enjoyment because the participants chose this condition over those that lacked such a contingency. The ventral striatum and midbrain were activated only when action-outcome contingency was present. Thus, the intrinsic value of action was represented by an increase in ventral striatal and midbrain activation. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. Novel Intrinsic Ignition Method Measuring Local-Global Integration Characterizes Wakefulness and Deep Sleep

    PubMed Central

    Tagliazucchi, Enzo; Sanjuán, Ana

    2017-01-01

    Abstract A precise definition of a brain state has proven elusive. Here, we introduce the novel local-global concept of intrinsic ignition characterizing the dynamical complexity of different brain states. Naturally occurring intrinsic ignition events reflect the capability of a given brain area to propagate neuronal activity to other regions, giving rise to different levels of integration. The ignitory capability of brain regions is computed by the elicited level of integration for each intrinsic ignition event in each brain region, averaged over all events. This intrinsic ignition method is shown to clearly distinguish human neuroimaging data of two fundamental brain states (wakefulness and deep sleep). Importantly, whole-brain computational modelling of this data shows that at the optimal working point is found where there is maximal variability of the intrinsic ignition across brain regions. Thus, combining whole brain models with intrinsic ignition can provide novel insights into underlying mechanisms of brain states. PMID:28966977

  1. Novel Intrinsic Ignition Method Measuring Local-Global Integration Characterizes Wakefulness and Deep Sleep.

    PubMed

    Deco, Gustavo; Tagliazucchi, Enzo; Laufs, Helmut; Sanjuán, Ana; Kringelbach, Morten L

    2017-01-01

    A precise definition of a brain state has proven elusive. Here, we introduce the novel local-global concept of intrinsic ignition characterizing the dynamical complexity of different brain states. Naturally occurring intrinsic ignition events reflect the capability of a given brain area to propagate neuronal activity to other regions, giving rise to different levels of integration. The ignitory capability of brain regions is computed by the elicited level of integration for each intrinsic ignition event in each brain region, averaged over all events. This intrinsic ignition method is shown to clearly distinguish human neuroimaging data of two fundamental brain states (wakefulness and deep sleep). Importantly, whole-brain computational modelling of this data shows that at the optimal working point is found where there is maximal variability of the intrinsic ignition across brain regions. Thus, combining whole brain models with intrinsic ignition can provide novel insights into underlying mechanisms of brain states.

  2. Negative regulators in homeostasis of naïve peripheral T cells.

    PubMed

    Modiano, Jaime F; Johnson, Lisa D S; Bellgrau, Donald

    2008-01-01

    It is now apparent that naïve peripheral T cells are a dynamic population where active processes prevent inappropriate activation while supporting survival. The process of thymic education makes naïve peripheral T cells dependent on interactions with self-MHC for survival. However, as these signals can potentially result in inappropriate activation, various non-redundant, intrinsic negative regulatory molecules including Tob, Nfatc2, and Smad3 actively enforce T cell quiescence. Interactions among these pathways are only now coming to light and may include positive or negative crosstalk. In the case of positive crosstalk, self-MHC initiated signals and intrinsic negative regulatory factors may cooperate to dampen T cell activation and sustain peripheral tolerance in a binary fashion (on-off). In the case of negative crosstalk, self-MHC signals may promote survival through partial activation while intrinsic negative regulatory factors act as rheostats to restrain cell cycle entry and prevent T cells from crossing a threshold that would break tolerance.

  3. Phosphorothioate oligonucleotides inhibit the intrinsic tenase complex.

    PubMed

    Sheehan, J P; Lan, H C

    1998-09-01

    Systemic administration of ISIS 2302, a 20-mer antisense phosphorothioate oligonucleotide targeting human intercellular adhesion molecule-1 mRNA, causes prolongation of plasma clotting times in both monkey and human studies. The anticoagulant effects of ISIS 2302 were investigated with both in vitro coagulation assays in human plasma and purified enzyme systems. At high oligonucleotide plasma concentrations (>100 microgram/mL), prolongation of the prothrombin and thrombin times was observed. In a thrombin time assay using purified components, high concentrations of ISIS 2302 inhibited thrombin clotting activity both by stimulating inhibition by heparin cofactor II and directly competing with fibrinogen for binding to anion binding exosite I. In contrast, low concentrations of ISIS 2302 (<100 microgram/mL) showed a selective, linear prolongation of the activated partial thromboplastin time (PTT). The rate limiting effect of 50 microgram/mL ISIS 2302, which prolonged the PTT to 1.5 times control, was identified by sequential modification of the clotting assay. Delaying addition of oligonucleotide until after contact activation failed to correct prolongation of the PTT. The calcium-dependent steps of the intrinsic pathway were individually assessed by adding sufficient activated coagulation factor to correct the PTT in plasma deficient in that specific factor. Addition of factor XIa, IXa, VIIIa, or Va failed to correct the PTT in the presence of ISIS 2302. In contrast, 0.2 nmol/L factor Xa corrected prolongation of the PTT in factor X-deficient plasma with or without oligonucleotide present. ISIS 2302 (50 microgram/mL) did not prolong a modified Russel viper venom time, suggesting no significant inhibition of prothrombinase. Thus, 50 microgram/mL ISIS 2302 prolonged the PTT by selectively inhibiting intrinsic tenase activity. ISIS 2302 showed partial inhibition of intrinsic tenase activity (to approximately 35% of control) at clinically relevant oligonucleotide concentrations in a chromogenic assay. This activity was oligonucleotide sequence-independent but required the phosphorothioate backbone, suggesting that inhibition of intrinsic tenase is a general property of this class of oligonucleotides. These results are relevant to both the therapeutic use of phosphorothioate oligonucleotides and the potential design of inhibitors of the intrinsic tenase complex, a novel target for anticoagulation. Copyright 1998 by The American Society of Hematology.

  4. Flow simulations about steady-complex and unsteady moving configurations using structured-overlapped and unstructured grids

    NASA Technical Reports Server (NTRS)

    Newman, James C., III

    1995-01-01

    The limiting factor in simulating flows past realistic configurations of interest has been the discretization of the physical domain on which the governing equations of fluid flow may be solved. In an attempt to circumvent this problem, many Computational Fluid Dynamic (CFD) methodologies that are based on different grid generation and domain decomposition techniques have been developed. However, due to the costs involved and expertise required, very few comparative studies between these methods have been performed. In the present work, the two CFD methodologies which show the most promise for treating complex three-dimensional configurations as well as unsteady moving boundary problems are evaluated. These are namely the structured-overlapped and the unstructured grid schemes. Both methods use a cell centered, finite volume, upwind approach. The structured-overlapped algorithm uses an approximately factored, alternating direction implicit scheme to perform the time integration, whereas, the unstructured algorithm uses an explicit Runge-Kutta method. To examine the accuracy, efficiency, and limitations of each scheme, they are applied to the same steady complex multicomponent configurations and unsteady moving boundary problems. The steady complex cases consist of computing the subsonic flow about a two-dimensional high-lift multielement airfoil and the transonic flow about a three-dimensional wing/pylon/finned store assembly. The unsteady moving boundary problems are a forced pitching oscillation of an airfoil in a transonic freestream and a two-dimensional, subsonic airfoil/store separation sequence. Accuracy was accessed through the comparison of computed and experimentally measured pressure coefficient data on several of the wing/pylon/finned store assembly's components and at numerous angles-of-attack for the pitching airfoil. From this study, it was found that both the structured-overlapped and the unstructured grid schemes yielded flow solutions of comparable accuracy for these simulations. This study also indicated that, overall, the structured-overlapped scheme was slightly more CPU efficient than the unstructured approach.

  5. MODFLOW–USG version 1: An unstructured grid version of MODFLOW for simulating groundwater flow and tightly coupled processes using a control volume finite-difference formulation

    USGS Publications Warehouse

    Panday, Sorab; Langevin, Christian D.; Niswonger, Richard G.; Ibaraki, Motomu; Hughes, Joseph D.

    2013-01-01

    A new version of MODFLOW, called MODFLOW–USG (for UnStructured Grid), was developed to support a wide variety of structured and unstructured grid types, including nested grids and grids based on prismatic triangles, rectangles, hexagons, and other cell shapes. Flexibility in grid design can be used to focus resolution along rivers and around wells, for example, or to subdiscretize individual layers to better represent hydrostratigraphic units. MODFLOW–USG is based on an underlying control volume finite difference (CVFD) formulation in which a cell can be connected to an arbitrary number of adjacent cells. To improve accuracy of the CVFD formulation for irregular grid-cell geometries or nested grids, a generalized Ghost Node Correction (GNC) Package was developed, which uses interpolated heads in the flow calculation between adjacent connected cells. MODFLOW–USG includes a Groundwater Flow (GWF) Process, based on the GWF Process in MODFLOW–2005, as well as a new Connected Linear Network (CLN) Process to simulate the effects of multi-node wells, karst conduits, and tile drains, for example. The CLN Process is tightly coupled with the GWF Process in that the equations from both processes are formulated into one matrix equation and solved simultaneously. This robustness results from using an unstructured grid with unstructured matrix storage and solution schemes. MODFLOW–USG also contains an optional Newton-Raphson formulation, based on the formulation in MODFLOW–NWT, for improving solution convergence and avoiding problems with the drying and rewetting of cells. Because the existing MODFLOW solvers were developed for structured and symmetric matrices, they were replaced with a new Sparse Matrix Solver (SMS) Package developed specifically for MODFLOW–USG. The SMS Package provides several methods for resolving nonlinearities and multiple symmetric and asymmetric linear solution schemes to solve the matrix arising from the flow equations and the Newton-Raphson formulation, respectively.

  6. Resurrecting free play in young children: looking beyond fitness and fatness to attention, affiliation, and affect.

    PubMed

    Burdette, Hillary L; Whitaker, Robert C

    2005-01-01

    We have observed that the nature and amount of free play in young children has changed. Our purpose in this article is to demonstrate why play, and particularly active, unstructured, outdoor play, needs to be restored in children's lives. We propose that efforts to increase physical activity in young children might be more successful if physical activity is promoted using different language-encouraging play-and if a different set of outcomes are emphasized-aspects of child well-being other than physical health. Because most physical activity in preschoolers is equivalent to gross motor play, we suggest that the term "play" be used to encourage movement in preschoolers. The benefits of play on children's social, emotional, and cognitive development are explored.

  7. Cardiac extrinsic apoptotic pathway is silent in young but activated in elder mice overexpressing bovine GH: interplay with the intrinsic pathway.

    PubMed

    Bogazzi, Fausto; Russo, Dania; Raggi, Francesco; Bohlooly-Y, Mohammad; Tornell, Jan; Sardella, Chiara; Lombardi, Martina; Urbani, Claudio; Manetti, Luca; Brogioni, Sandra; Martino, Enio

    2011-08-01

    Apoptosis may occur through the mitochondrial (intrinsic) pathway and activation of death receptors (extrinsic pathway). Young acromegalic mice have reduced cardiac apoptosis whereas elder animals have increased cardiac apoptosis. Multiple intrinsic apoptotic pathways have been shown to be modulated by GH and other stimuli in the heart of acromegalic mice. However, the role of the extrinsic apoptotic pathways in acromegalic hearts is currently unknown. In young (3-month-old) acromegalic mice, expression of proteins of the extrinsic apoptotic pathway did not differ from that of wild-type animals, suggesting that this mechanism did not participate in the lower cardiac apoptosis levels observed at this age. On the contrary, the extrinsic pathway was active in elder (9-month-old) animals (as shown by increased expression of TRAIL, FADD, TRADD and increased activation of death inducing signaling complex) leading to increased levels of active caspase 8. It is worth noting that changes of some pro-apoptotic proteins were induced by GH, which seemed to have, in this context, pro-apoptotic effects. The extrinsic pathway influenced the intrinsic pathway by modulating t-Bid, the cellular levels of which were reduced in young and increased in elder animals. However, in young animals this effect was due to reduced levels of Bid regulated by the extrinsic pathway, whereas in elder animals the increased levels of t-Bid were due to the increased levels of active caspase 8. In conclusion, the extrinsic pathway participates in the cardiac pro-apoptotic phenotype of elder acromegalic animals either directly, enhancing caspase 8 levels or indirectly, increasing t-Bid levels and conveying death signals to the intrinsic pathway.

  8. Intrinsic resistance to EGFR tyrosine kinase inhibitors in advanced non-small-cell lung cancer with activating EGFR mutations

    PubMed Central

    Wang, Jun; Wang, Baocheng; Chu, Huili; Yao, Yunfeng

    2016-01-01

    Identifying activating EGFR mutations is a useful predictive strategy that helps select a population of advanced non-small-cell lung cancer (NSCLC) patients for treatment with EGFR tyrosine kinase inhibitors (TKIs). Patients with sensitizing EGFR mutations (predominantly an in-frame deletion in exon 19 and an L858R substitution) are highly responsive to first-generation EGFR TKIs, such as gefitinib and erlotinib, and show improved progression-free survival without serious side effects. However, all patients with activating EGFR mutations who are initially responsive to EGFR TKIs eventually develop acquired resistance after a median progression-free survival of 10–16 months, followed by disease progression. Moreover, ~20%–30% of NSCLC patients have no objective tumor regression on initial EGFR TKI treatment, although they harbor an activating EGFR mutation. These patients represent an NSCLC subgroup that is defined as having intrinsic or primary resistance to EGFR TKIs. Different mechanisms of acquired EGFR TKI resistance have been identified, and several novel compounds have been developed to reverse acquired resistance, but little is known about EGFR TKI intrinsic resistance. In this review, we summarize the latest findings involving mechanisms of intrinsic resistance to EGFR TKIs in advanced NSCLC with activating EGFR mutations and present possible therapeutic strategies to overcome this resistance. PMID:27382309

  9. Validation of parent-reported physical activity and sedentary time by accelerometry in young children.

    PubMed

    Sarker, Hrishov; Anderson, Laura N; Borkhoff, Cornelia M; Abreo, Kathleen; Tremblay, Mark S; Lebovic, Gerald; Maguire, Jonathon L; Parkin, Patricia C; Birken, Catherine S

    2015-11-30

    It is unknown if young children's parent-reported physical activity and sedentary time are correlated with direct measures. The study objectives were to compare parent-reported physical and sedentary activity versus directly measured accelerometer data in early childhood. From 2013 to 2014, 117 healthy children less than 6 years of age were recruited to wear Actical accelerometers for 7 days. Accelerometer data and questionnaires were available on 87 children (74%). Average daily physical activity was defined as the sum of activity ≥100 counts per minute, and sedentary time as the sum of activity <100 counts per minute during waking hours. Parents reported daily physical activity (unstructured free play in and out of school, and organized activities) and selected sedentary behaviors (screen time, stroller time, time in motor vehicle). Spearman correlation coefficients and Bland-Altman plots were used to assess the validity of parent-reported measures compared to accelerometer data. Total physical activity was significantly greater when measured by accelerometer than parent-report; the median difference was 131 min/day (p < 0.001). Parent-reported child physical activity was weak to moderately correlated with directly measured total physical activity (r = 0.39, 95% CI 0.19, 0.56). The correlations between types of physical activity (unstructured free play in and outside of school/daycare, and organized structured activity) and accelerometer were r = 0.30 (95% CI 0.09, 0.49); r = 0.42 (95% CI 0.23, 0.58); r = 0.26 (95% CI 0.05, 0.46), respectively. There was no correlation between parent-reported and accelerometer-measured total sedentary time in children (r = 0.10, 95% CI -0.12, 0.33). When the results were stratified by age group (<18, 18-47, and 48-70 months of age) no statistically significant correlations were observed and some inverse associations were observed. The correlation between parent-report of young children's physical activity and accelerometer-measured activity was weak to moderate depending on type of activity and age group. Parent-report of children's sedentary time was not correlated with accelerometer-measured sedentary time. Additional validation studies are needed to determine if parent-reported measures of physical activity and sedentary time are valid among children less than 6 years of age and across these young age groups.

  10. Computation of UH-60A Airloads Using CFD/CSD Coupling on Unstructured Meshes

    NASA Technical Reports Server (NTRS)

    Biedron, Robert T.; Lee-Rausch, Elizabeth M.

    2011-01-01

    An unsteady Reynolds-averaged Navier-Stokes solver for unstructured grids is used to compute the rotor airloads on the UH-60A helicopter at high-speed and high thrust conditions. The flow solver is coupled to a rotorcraft comprehensive code in order to account for trim and aeroelastic deflections. Simulations are performed both with and without the fuselage, and the effects of grid resolution, temporal resolution and turbulence model are examined. Computed airloads are compared to flight data.

  11. Multiple chiral topological states in liquid crystals from unstructured light beams

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

    Loussert, Charles; Brasselet, Etienne, E-mail: e.brasselet@loma.u-bordeaux1.fr

    2014-02-03

    It is shown experimentally that unstructured light beams can generate a wealth of distinct metastable defect structures in thin films of chiral liquid crystals. Various kinds of individual chiral topological states are obtained as well as dimers and trimers, which correspond to the entanglement of several topological unit cells. Self-assembled nested assemblies of several metastable particle-like topological states can also be formed. Finally, we propose and experimentally demonstrate an opto-electrical approach to generate tailor-made architectures.

  12. Exchanging Peers to Establish P2P Networks

    NASA Astrophysics Data System (ADS)

    Akon, Mursalin; Islam, Mohammad Towhidul; Shen, Xuemin(Sherman); Singh, Ajit

    Structure-wise, P2P networks can be divided into two major categories: (1) structured and (2) unstructured. In this chapter, we survey a group of unstructured P2P networks. This group of networks employs a gossip or epidemic protocol to maintain the members of the network and during a gossip, peers exchange a subset of their neighbors with each other. It is reported that this kind of networks are scalable, robust and resilient to severe network failure, at the same time very inexpensive to operate.

  13. Segmentation of Unstructured Datasets

    NASA Technical Reports Server (NTRS)

    Bhat, Smitha

    1996-01-01

    Datasets generated by computer simulations and experiments in Computational Fluid Dynamics tend to be extremely large and complex. It is difficult to visualize these datasets using standard techniques like Volume Rendering and Ray Casting. Object Segmentation provides a technique to extract and quantify regions of interest within these massive datasets. This thesis explores basic algorithms to extract coherent amorphous regions from two-dimensional and three-dimensional scalar unstructured grids. The techniques are applied to datasets from Computational Fluid Dynamics and from Finite Element Analysis.

  14. YAP Version 4.0

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

    Nelson, Eric M.

    2004-05-20

    The YAP software library computes (1) electromagnetic modes, (2) electrostatic fields, (3) magnetostatic fields and (4) particle trajectories in 2d and 3d models. The code employs finite element methods on unstructured grids of tetrahedral, hexahedral, prism and pyramid elements, with linear through cubic element shapes and basis functions to provide high accuracy. The novel particle tracker is robust, accurate and efficient, even on unstructured grids with discontinuous fields. This software library is a component of the MICHELLE 3d finite element gun code.

  15. An unstructured shock-fitting solver for hypersonic plasma flows in chemical non-equilibrium

    NASA Astrophysics Data System (ADS)

    Pepe, R.; Bonfiglioli, A.; D'Angola, A.; Colonna, G.; Paciorri, R.

    2015-11-01

    A CFD solver, using Residual Distribution Schemes on unstructured grids, has been extended to deal with inviscid chemical non-equilibrium flows. The conservative equations have been coupled with a kinetic model for argon plasma which includes the argon metastable state as independent species, taking into account electron-atom and atom-atom processes. Results in the case of an hypersonic flow around an infinite cylinder, obtained by using both shock-capturing and shock-fitting approaches, show higher accuracy of the shock-fitting approach.

  16. CFD in the 1980's from one point of view

    NASA Technical Reports Server (NTRS)

    Lomax, Harvard

    1991-01-01

    The present interpretive treatment of the development history of CFD in the 1980s gives attention to advancements in such algorithmic techniques as flux Jacobian-based upwind differencing, total variation-diminishing and essentially nonoscillatory schemes, multigrid methods, unstructured grids, and nonrectangular structured grids. At the same time, computational turbulence research gave attention to turbulence modeling on the bases of increasingly powerful supercomputers and meticulously constructed databases. The major future developments in CFD will encompass such capabilities as structured and unstructured three-dimensional grids.

  17. Higher Levels of Intrinsic Motivation Are Related to Higher Levels of Class Performance for Male but Not Female Students

    ERIC Educational Resources Information Center

    Cortright, Ronald N.; Lujan, Heidi L.; Blumberg, Amanda J.; Cox, Julie H.; DiCarlo, Stephen E.

    2013-01-01

    Our students are naturally curious, with powerful intrinsic motives to understand their world. Accordingly, we, as teachers, must capitalize on this inherently active and curious nature so that learning becomes a lifelong activity where students take initiative for learning, are skilled in learning, and want to learn new things. Achieving this…

  18. Intrinsic Motivation and Engagement as "Active Ingredients" in Garden-Based Education: Examining Models and Measures Derived from Self-Determination Theory

    ERIC Educational Resources Information Center

    Skinner, Ellen A.; Chi, Una

    2012-01-01

    Building on self-determination theory, this study presents a model of intrinsic motivation and engagement as "active ingredients" in garden-based education. The model was used to create reliable and valid measures of key constructs, and to guide the empirical exploration of motivational processes in garden-based learning. Teacher- and…

  19. Characterization of the intrinsic activity for a novel class of cannabinoid receptor ligands: Indole Quinuclidine analogues

    PubMed Central

    Franks, Lirit N.; Ford, Benjamin M.; Madadi, Nikhil R.; Penthala, Narsimha R.; Crooks, Peter A.; Prather, Paul L.

    2014-01-01

    Our laboratory recently reported that a group of novel indole quinuclidine analogues bind with nanomolar affinity to cannabinoid type-1 and type-2 receptors. This study characterized the intrinsic activity of these compounds by determining whether they exhibit agonist, antagonist, or inverse agonist activity at cannabinoid type-1 and/or type-2 receptors. Cannabinoid receptors activate Gi/Go-proteins that then proceed to inhibit activity of the downstream intracellular effector adenylyl cyclase. Therefore, intrinsic activity was quantified by measuring the ability of compounds to modulate levels of intracellular cAMP in intact cells. Concerning cannabinoid type-1 receptors endogenously expressed in Neuro2A cells, a single analogue exhibited agonist activity, while eight acted as neutral antagonists and two possessed inverse agonist activity. For cannabinoid type-2 receptors stably expressed in CHO cells, all but two analogues acted as agonists; these two exceptions exhibited inverse agonist activity. Confirming specificity at cannabinoid type-1 receptors, modulation of adenylyl cyclase activity by all proposed agonists and inverse agonists was blocked by co-incubation with the neutral cannabinoid type-1 antagonist O-2050. All proposed cannabinoid type-1 receptor antagonists attenuated adenylyl cyclase modulation by cannabinoid agonist CP-55,940. Specificity at cannabinoid type-2 receptors was confirmed by failure of all compounds to modulate adenylyl cyclase activity in CHO cells devoid of cannabinoid type-2 receptors. Further characterization of select analogues demonstrated concentration-dependent modulation of adenylyl cyclase activity with potencies similar to their respective affinities for cannabinoid receptors. Therefore, indole quinuclidines are a novel structural class of compounds exhibiting high affinity and a range of intrinsic activity at cannabinoid type-1 and type-2 receptors. PMID:24858620

  20. Motivation and flow: toward an understanding of the dynamics of the relation in architecture students.

    PubMed

    Mills, Maura J; Fullagar, Clive J

    2008-09-01

    The authors investigated the relation between motivation and flow in a sample of 327 architecture students. Specifically, they investigated the relation between flow and several levels of intrinsic and extrinsic motivation, as well as amotivation. They also assessed the need for autonomy in moderating the relation between intrinsic motivation and engagement. Results indicated a significant relation between flow experiences in academic activities and the more self-determined forms of intrinsic motivation, but not for extrinsic motivation. The need for autonomy moderated the relation between flow and intrinsic motivation. These results are discussed in the context of understanding flow as an intrinsically motivating state and a viable construct for understanding engagement.

  1. Body-related self-conscious emotions relate to physical activity motivation and behavior in men.

    PubMed

    Castonguay, Andree L; Pila, Eva; Wrosch, Carsten; Sabiston, Catherine M

    2015-05-01

    The aim of this study was to examine the associations between the body-related self-conscious emotions of shame, guilt, and pride and physical activity motivation and behavior among adult males. Specifically, motivation regulations (external, introjected, indentified, intrinsic) were examined as possible mediators between each of the body-related self-conscious emotions and physical activity behavior. A cross-sectional study was conducted with adult men (N = 152; Mage = 23.72, SD = 10.92 years). Participants completed a questionnaire assessing body-related shame, guilt, authentic pride, hubristic pride, motivational regulations, and leisure-time physical activity. In separate multiple mediation models, body-related shame was positively associated with external and introjected regulations and negatively correlated with intrinsic regulation. Guilt was positively linked to external, introjected, and identified regulations. Authentic pride was negatively related to external regulation and positively correlated with both identified and intrinsic regulations and directly associated with physical activity behavior. Hubristic pride was positively associated with intrinsic regulation. Overall, there were both direct and indirect effects via motivation regulations between body-related self-conscious emotions and physical activity (R(2) shame = .15, guilt = .16, authentic pride = .18, hubristic pride = .16). These findings highlight the importance of targeting and understanding self-conscious emotions contextualized to the body and links to motivation and positive health behavior among men. © The Author(s) 2014.

  2. Importance and challenges of measuring intrinsic foot muscle strength

    PubMed Central

    2012-01-01

    Background Intrinsic foot muscle weakness has been implicated in a range of foot deformities and disorders. However, to establish a relationship between intrinsic muscle weakness and foot pathology, an objective measure of intrinsic muscle strength is needed. The aim of this review was to provide an overview of the anatomy and role of intrinsic foot muscles, implications of intrinsic weakness and evaluate the different methods used to measure intrinsic foot muscle strength. Method Literature was sourced from database searches of MEDLINE, PubMed, SCOPUS, Cochrane Library, PEDro and CINAHL up to June 2012. Results There is no widely accepted method of measuring intrinsic foot muscle strength. Methods to estimate toe flexor muscle strength include the paper grip test, plantar pressure, toe dynamometry, and the intrinsic positive test. Hand-held dynamometry has excellent interrater and intrarater reliability and limits toe curling, which is an action hypothesised to activate extrinsic toe flexor muscles. However, it is unclear whether any method can actually isolate intrinsic muscle strength. Also most methods measure only toe flexor strength and other actions such as toe extension and abduction have not been adequately assessed. Indirect methods to investigate intrinsic muscle structure and performance include CT, ultrasonography, MRI, EMG, and muscle biopsy. Indirect methods often discriminate between intrinsic and extrinsic muscles, but lack the ability to measure muscle force. Conclusions There are many challenges to accurately measure intrinsic muscle strength in isolation. Most studies have measured toe flexor strength as a surrogate measure of intrinsic muscle strength. Hand-held dynamometry appears to be a promising method of estimating intrinsic muscle strength. However, the contribution of extrinsic muscles cannot be excluded from toe flexor strength measurement. Future research should clarify the relative contribution of intrinsic and extrinsic muscles during intrinsic foot muscle strength testing. PMID:23181771

  3. A Force-Sensing System on Legs for Biomimetic Hexapod Robots Interacting with Unstructured Terrain

    PubMed Central

    Wu, Rui; Li, Changle; Zang, Xizhe; Zhang, Xuehe; Jin, Hongzhe; Zhao, Jie

    2017-01-01

    The tiger beetle can maintain its stability by controlling the interaction force between its legs and an unstructured terrain while it runs. The biomimetic hexapod robot mimics a tiger beetle, and a comprehensive force sensing system combined with certain algorithms can provide force information that can help the robot understand the unstructured terrain that it interacts with. This study introduces a complicated leg force sensing system for a hexapod robot that is the same for all six legs. First, the layout and configuration of sensing system are designed according to the structure and sizes of legs. Second, the joint toque sensors, 3-DOF foot-end force sensor and force information processing module are designed, and the force sensor performance parameters are tested by simulations and experiments. Moreover, a force sensing system is implemented within the robot control architecture. Finally, the experimental evaluation of the leg force sensor system on the hexapod robot is discussed and the performance of the leg force sensor system is verified. PMID:28654003

  4. Formation flight and collision avoidance for multiple UAVs based on modified tentacle algorithm in unstructured environments

    PubMed Central

    2017-01-01

    This paper presents a method for formation flight and collision avoidance of multiple UAVs. Due to the shortcomings such as collision avoidance caused by UAV’s high-speed and unstructured environments, this paper proposes a modified tentacle algorithm to ensure the high performance of collision avoidance. Different from the conventional tentacle algorithm which uses inverse derivation, the modified tentacle algorithm rapidly matches the radius of each tentacle and the steering command, ensuring that the data calculation problem in the conventional tentacle algorithm is solved. Meanwhile, both the speed sets and tentacles in one speed set are reduced and reconstructed so as to be applied to multiple UAVs. Instead of path iterative optimization, the paper selects the best tentacle to obtain the UAV collision avoidance path quickly. The simulation results show that the method presented in the paper effectively enhances the performance of flight formation and collision avoidance for multiple high-speed UAVs in unstructured environments. PMID:28763498

  5. Personalized Guideline-Based Treatment Recommendations Using Natural Language Processing Techniques.

    PubMed

    Becker, Matthias; Böckmann, Britta

    2017-01-01

    Clinical guidelines and clinical pathways are accepted and proven instruments for quality assurance and process optimization. Today, electronic representation of clinical guidelines exists as unstructured text, but is not well-integrated with patient-specific information from electronic health records. Consequently, generic content of the clinical guidelines is accessible, but it is not possible to visualize the position of the patient on the clinical pathway, decision support cannot be provided by personalized guidelines for the next treatment step. The Systematized Nomenclature of Medicine - Clinical Terms (SNOMED CT) provides common reference terminology as well as the semantic link for combining the pathways and the patient-specific information. This paper proposes a model-based approach to support the development of guideline-compliant pathways combined with patient-specific structured and unstructured information using SNOMED CT. To identify SNOMED CT concepts, a software was developed to extract SNOMED CT codes out of structured and unstructured German data to map these with clinical pathways annotated in accordance with the systematized nomenclature.

  6. Efficient Parallelization of a Dynamic Unstructured Application on the Tera MTA

    NASA Technical Reports Server (NTRS)

    Oliker, Leonid; Biswas, Rupak

    1999-01-01

    The success of parallel computing in solving real-life computationally-intensive problems relies on their efficient mapping and execution on large-scale multiprocessor architectures. Many important applications are both unstructured and dynamic in nature, making their efficient parallel implementation a daunting task. This paper presents the parallelization of a dynamic unstructured mesh adaptation algorithm using three popular programming paradigms on three leading supercomputers. We examine an MPI message-passing implementation on the Cray T3E and the SGI Origin2OOO, a shared-memory implementation using cache coherent nonuniform memory access (CC-NUMA) of the Origin2OOO, and a multi-threaded version on the newly-released Tera Multi-threaded Architecture (MTA). We compare several critical factors of this parallel code development, including runtime, scalability, programmability, and memory overhead. Our overall results demonstrate that multi-threaded systems offer tremendous potential for quickly and efficiently solving some of the most challenging real-life problems on parallel computers.

  7. Jali - Unstructured Mesh Infrastructure for Multi-Physics Applications

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

    Garimella, Rao V; Berndt, Markus; Coon, Ethan

    2017-04-13

    Jali is a parallel unstructured mesh infrastructure library designed for use by multi-physics simulations. It supports 2D and 3D arbitrary polyhedral meshes distributed over hundreds to thousands of nodes. Jali can read write Exodus II meshes along with fields and sets on the mesh and support for other formats is partially implemented or is (https://github.com/MeshToolkit/MSTK), an open source general purpose unstructured mesh infrastructure library from Los Alamos National Laboratory. While it has been made to work with other mesh frameworks such as MOAB and STKmesh in the past, support for maintaining the interface to these frameworks has been suspended formore » now. Jali supports distributed as well as on-node parallelism. Support of on-node parallelism is through direct use of the the mesh in multi-threaded constructs or through the use of "tiles" which are submeshes or sub-partitions of a partition destined for a compute node.« less

  8. A package for 3-D unstructured grid generation, finite-element flow solution and flow field visualization

    NASA Technical Reports Server (NTRS)

    Parikh, Paresh; Pirzadeh, Shahyar; Loehner, Rainald

    1990-01-01

    A set of computer programs for 3-D unstructured grid generation, fluid flow calculations, and flow field visualization was developed. The grid generation program, called VGRID3D, generates grids over complex configurations using the advancing front method. In this method, the point and element generation is accomplished simultaneously, VPLOT3D is an interactive, menudriven pre- and post-processor graphics program for interpolation and display of unstructured grid data. The flow solver, VFLOW3D, is an Euler equation solver based on an explicit, two-step, Taylor-Galerkin algorithm which uses the Flux Corrected Transport (FCT) concept for a wriggle-free solution. Using these programs, increasingly complex 3-D configurations of interest to aerospace community were gridded including a complete Space Transportation System comprised of the space-shuttle orbitor, the solid-rocket boosters, and the external tank. Flow solutions were obtained on various configurations in subsonic, transonic, and supersonic flow regimes.

  9. On the application of Chimera/unstructured hybrid grids for conjugate heat transfer

    NASA Technical Reports Server (NTRS)

    Kao, Kai-Hsiung; Liou, Meng-Sing

    1995-01-01

    A hybrid grid system that combines the Chimera overset grid scheme and an unstructured grid method is developed to study fluid flow and heat transfer problems. With the proposed method, the solid structural region, in which only the heat conduction is considered, can be easily represented using an unstructured grid method. As for the fluid flow region external to the solid material, the Chimera overset grid scheme has been shown to be very flexible and efficient in resolving complex configurations. The numerical analyses require the flow field solution and material thermal response to be obtained simultaneously. A continuous transfer of temperature and heat flux is specified at the interface, which connects the solid structure and the fluid flow as an integral system. Numerical results are compared with analytical and experimental data for a flat plate and a C3X cooled turbine cascade. A simplified drum-disk system is also simulated to show the effectiveness of this hybrid grid system.

  10. Revisiting the Least-squares Procedure for Gradient Reconstruction on Unstructured Meshes

    NASA Technical Reports Server (NTRS)

    Mavriplis, Dimitri J.; Thomas, James L. (Technical Monitor)

    2003-01-01

    The accuracy of the least-squares technique for gradient reconstruction on unstructured meshes is examined. While least-squares techniques produce accurate results on arbitrary isotropic unstructured meshes, serious difficulties exist for highly stretched meshes in the presence of surface curvature. In these situations, gradients are typically under-estimated by up to an order of magnitude. For vertex-based discretizations on triangular and quadrilateral meshes, and cell-centered discretizations on quadrilateral meshes, accuracy can be recovered using an inverse distance weighting in the least-squares construction. For cell-centered discretizations on triangles, both the unweighted and weighted least-squares constructions fail to provide suitable gradient estimates for highly stretched curved meshes. Good overall flow solution accuracy can be retained in spite of poor gradient estimates, due to the presence of flow alignment in exactly the same regions where the poor gradient accuracy is observed. However, the use of entropy fixes has the potential for generating large but subtle discretization errors.

  11. Runge-Kutta discontinuous Galerkin method using a new type of WENO limiters on unstructured meshes

    NASA Astrophysics Data System (ADS)

    Zhu, Jun; Zhong, Xinghui; Shu, Chi-Wang; Qiu, Jianxian

    2013-09-01

    In this paper we generalize a new type of limiters based on the weighted essentially non-oscillatory (WENO) finite volume methodology for the Runge-Kutta discontinuous Galerkin (RKDG) methods solving nonlinear hyperbolic conservation laws, which were recently developed in [32] for structured meshes, to two-dimensional unstructured triangular meshes. The key idea of such limiters is to use the entire polynomials of the DG solutions from the troubled cell and its immediate neighboring cells, and then apply the classical WENO procedure to form a convex combination of these polynomials based on smoothness indicators and nonlinear weights, with suitable adjustments to guarantee conservation. The main advantage of this new limiter is its simplicity in implementation, especially for the unstructured meshes considered in this paper, as only information from immediate neighbors is needed and the usage of complicated geometric information of the meshes is largely avoided. Numerical results for both scalar equations and Euler systems of compressible gas dynamics are provided to illustrate the good performance of this procedure.

  12. Unstructured Grids for Sonic Boom Analysis and Design

    NASA Technical Reports Server (NTRS)

    Campbell, Richard L.; Nayani, Sudheer N.

    2015-01-01

    An evaluation of two methods for improving the process for generating unstructured CFD grids for sonic boom analysis and design has been conducted. The process involves two steps: the generation of an inner core grid using a conventional unstructured grid generator such as VGRID, followed by the extrusion of a sheared and stretched collar grid through the outer boundary of the core grid. The first method evaluated, known as COB, automatically creates a cylindrical outer boundary definition for use in VGRID that makes the extrusion process more robust. The second method, BG, generates the collar grid by extrusion in a very efficient manner. Parametric studies have been carried out and new options evaluated for each of these codes with the goal of establishing guidelines for best practices for maintaining boom signature accuracy with as small a grid as possible. In addition, a preliminary investigation examining the use of the CDISC design method for reducing sonic boom utilizing these grids was conducted, with initial results confirming the feasibility of a new remote design approach.

  13. The Unstructured Paramyxovirus Nucleocapsid Protein Tail Domain Modulates Viral Pathogenesis through Regulation of Transcriptase Activity.

    PubMed

    Thakkar, Vidhi D; Cox, Robert M; Sawatsky, Bevan; da Fontoura Budaszewski, Renata; Sourimant, Julien; Wabbel, Katrin; Makhsous, Negar; Greninger, Alexander L; von Messling, Veronika; Plemper, Richard K

    2018-04-15

    The paramyxovirus replication machinery comprises the viral large (L) protein and phosphoprotein (P-protein) in addition to the nucleocapsid (N) protein, which encapsidates the single-stranded RNA genome. Common to paramyxovirus N proteins is a C-terminal tail (Ntail). The mechanistic role and relevance for virus replication of the structurally disordered central Ntail section are unknown. Focusing initially on members of the Morbillivirus genus, a series of measles virus (MeV) and canine distemper virus (CDV) N proteins were generated with internal deletions in the unstructured tail section. N proteins with large tail truncations remained bioactive in mono- and polycistronic minireplicon assays and supported efficient replication of recombinant viruses. Bioactivity of Ntail mutants extended to N proteins derived from highly pathogenic Nipah virus. To probe an effect of Ntail truncations on viral pathogenesis, recombinant CDVs were analyzed in a lethal CDV/ferret model of morbillivirus disease. The recombinant viruses displayed different stages of attenuation ranging from ameliorated clinical symptoms to complete survival of infected animals, depending on the molecular nature of the Ntail truncation. Reinfection of surviving animals with pathogenic CDV revealed robust protection against a lethal challenge. The highly attenuated virus was genetically stable after ex vivo passaging and recovery from infected animals. Mechanistically, gradual viral attenuation coincided with stepwise altered viral transcriptase activity in infected cells. These results identify the central Ntail section as a determinant for viral pathogenesis and establish a novel platform to engineer gradual virus attenuation for next-generation paramyxovirus vaccine design. IMPORTANCE Investigating the role of the paramyxovirus N protein tail domain (Ntail) in virus replication, we demonstrated in this study that the structurally disordered central Ntail region is a determinant for viral pathogenesis. We show that internal deletions in this Ntail region of up to 55 amino acids in length are compatible with efficient replication of recombinant viruses in cell culture but result in gradual viral attenuation in a lethal canine distemper virus (CDV)/ferret model. Mechanistically, we demonstrate a role of the intact Ntail region in the regulation of viral transcriptase activity. Recombinant viruses with Ntail truncations induce protective immunity against lethal challenge of ferrets with pathogenic CDV. This identification of the unstructured central Ntail domain as a nonessential paramyxovirus pathogenesis factor establishes a foundation for harnessing Ntail truncations for vaccine engineering against emerging and reemerging members of the paramyxovirus family. Copyright © 2018 American Society for Microbiology.

  14. Repositioning forelimb superficialis muscles: tendon attachment and muscle activity enable active relocation of functional myofibers.

    PubMed

    Huang, Alice H; Riordan, Timothy J; Wang, Lingyan; Eyal, Shai; Zelzer, Elazar; Brigande, John V; Schweitzer, Ronen

    2013-09-16

    The muscles that govern hand motion are composed of extrinsic muscles that reside within the forearm and intrinsic muscles that reside within the hand. We find that the extrinsic muscles of the flexor digitorum superficialis (FDS) first differentiate as intrinsic muscles within the hand and then relocate as myofibers to their final position in the arm. This remarkable translocation of differentiated myofibers across a joint is dependent on muscle contraction and muscle-tendon attachment. Interestingly, the intrinsic flexor digitorum brevis (FDB) muscles of the foot are identical to the FDS in tendon pattern and delayed developmental timing but undergo limited muscle translocation, providing strong support for evolutionary homology between the FDS and FDB muscles. We propose that the intrinsic FDB pattern represents the original tetrapod limb and that translocation of the muscles to form the FDS is a mammalian evolutionary addition. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Re-positioning forelimb superficialis muscles: tendon attachment and muscle activity enable active relocation of functional myofibers

    PubMed Central

    Huang, Alice H.; Riordan, Timothy J.; Wang, Lingyan; Eyal, Shai; Zelzer, Elazar; Brigande, John V.; Schweitzer, Ronen

    2013-01-01

    Summary The muscles that govern hand motion are composed of extrinsic muscles that reside within the forearm and intrinsic muscles that reside within the hand. We find that the extrinsic muscles of the flexor digitorum superficialis (FDS) first differentiate as intrinsic muscles within the hand and then relocate as myofibers to their final position in the arm. This unique translocation of differentiated myofibers across a joint is dependent on muscle contraction and muscle-tendon attachment. Interestingly, the intrinsic flexor digitorum brevis (FDB) muscles of the foot are identical to the FDS in tendon pattern and delayed developmental timing, but undergo limited muscle translocation, providing strong support for evolutionary homology between the FDS and FDB muscles. We propose that the intrinsic FDB pattern represents the original tetrapod limb and translocation of the muscles to form the FDS is a mammalian evolutionary addition. PMID:24044893

  16. Self-perception of intrinsic and extrinsic motivation: effects on institutionalized mentally retarded adolescents.

    PubMed

    Lee, D Y; Syrnyk, R

    1977-01-01

    Self-perception theory predicts that the introduction of extrinsic rewards for behavior that was intrinsically rewarding may decrease rather than enhance overall motivation. This hypothesis was tested on a group of institutionalized mentally retarded adolescents (34 boys, 10 girls). Intrinsic (high and low task interest) and extrinsic (high- and low-incentive objects) motivation were both manipulated as independent variables, and the dependent variable was task persistence during a free-play period. Results indicated that for a high intrinsically interesting task, the task persistence was greater under the external reward of low- rather than high-incentive value conditions. The opposite trend was revealed for the low intrinsically interesting task. The results provided some evidence that the greater the amount of the reward for an interesting activity, the greater the degree to which the intrinsic interest is undermined.

  17. Older adults' intrinsic and extrinsic motivation toward physical activity.

    PubMed

    Dacey, Marie; Baltzell, Amy; Zaichkowsky, Len

    2008-01-01

    To examine how motives discriminate 3 physical activity levels of inactive, active, and sustained maintainers. Six hundred forty-five adults (M age = 63.8) completed stage-of-change and Exercise Motivations Inventory (EMI-2) scales. Exploratory factor analysis established psychometric properties of the EMI-2 suitable for older adults. Six factors emerged in the EMI-2: health and fitness, social/emotional benefits, weight management, stress management, enjoyment, and appearance. Enjoyment contributed most to differentiating activity levels. Moderators of age and gender were delineated. Intrinsic motivation and self-determined extrinsic motivation distinguish older adults' activity levels.

  18. Sensitivity analysis of discharge patterns of subthalamic nucleus in the model of basal ganglia in Parkinson disease.

    PubMed

    Singh, Jyotsna; Singh, Phool; Malik, Vikas

    2017-01-01

    Parkinson disease alters the information patterns in movement related pathways in brain. Experimental results performed on rats show that the activity patterns changes from single spike activity to mixed burst mode in Parkinson disease. However the cause of this change in activity pattern is not yet completely understood. Subthalamic nucleus is one of the main nuclei involved in the origin of motor dysfunction in Parkinson disease. In this paper, a single compartment conductance based model is considered which focuses on subthalamic nucleus and synaptic input from globus pallidus (external). This model shows highly nonlinear behavior with respect to various intrinsic parameters. Behavior of model has been presented with the help of activity patterns generated in healthy and Parkinson condition. These patterns have been compared by calculating their correlation coefficient for different values of intrinsic parameters. Results display that the activity patterns are very sensitive to various intrinsic parameters and calcium shows some promising results which provide insights into the motor dysfunction.

  19. Scalable hierarchical PDE sampler for generating spatially correlated random fields using nonmatching meshes: Scalable hierarchical PDE sampler using nonmatching meshes

    DOE PAGES

    Osborn, Sarah; Zulian, Patrick; Benson, Thomas; ...

    2018-01-30

    This work describes a domain embedding technique between two nonmatching meshes used for generating realizations of spatially correlated random fields with applications to large-scale sampling-based uncertainty quantification. The goal is to apply the multilevel Monte Carlo (MLMC) method for the quantification of output uncertainties of PDEs with random input coefficients on general and unstructured computational domains. We propose a highly scalable, hierarchical sampling method to generate realizations of a Gaussian random field on a given unstructured mesh by solving a reaction–diffusion PDE with a stochastic right-hand side. The stochastic PDE is discretized using the mixed finite element method on anmore » embedded domain with a structured mesh, and then, the solution is projected onto the unstructured mesh. This work describes implementation details on how to efficiently transfer data from the structured and unstructured meshes at coarse levels, assuming that this can be done efficiently on the finest level. We investigate the efficiency and parallel scalability of the technique for the scalable generation of Gaussian random fields in three dimensions. An application of the MLMC method is presented for quantifying uncertainties of subsurface flow problems. Here, we demonstrate the scalability of the sampling method with nonmatching mesh embedding, coupled with a parallel forward model problem solver, for large-scale 3D MLMC simulations with up to 1.9·109 unknowns.« less

  20. Wave Resource Characterization Using an Unstructured Grid Modeling Approach

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

    Wu, Wei-Cheng; Yang, Zhaoqing; Wang, Taiping

    This paper presents a modeling study conducted on the central Oregon coast for wave resource characterization using the unstructured-grid SWAN model coupled with a nested-grid WWIII model. The flexibility of models of various spatial resolutions and the effects of open- boundary conditions simulated by a nested-grid WWIII model with different physics packages were evaluated. The model results demonstrate the advantage of the unstructured-grid modeling approach for flexible model resolution and good model skills in simulating the six wave resource parameters recommended by the International Electrotechnical Commission in comparison to the observed data in Year 2009 at National Data Buoy Centermore » Buoy 46050. Notably, spectral analysis indicates that the ST4 physics package improves upon the model skill of the ST2 physics package for predicting wave power density for large waves, which is important for wave resource assessment, device load calculation, and risk management. In addition, bivariate distributions show the simulated sea state of maximum occurrence with the ST4 physics package matched the observed data better than that with the ST2 physics package. This study demonstrated that the unstructured-grid wave modeling approach, driven by the nested-grid regional WWIII outputs with the ST4 physics package, can efficiently provide accurate wave hindcasts to support wave resource characterization. Our study also suggests that wind effects need to be considered if the dimension of the model domain is greater than approximately 100 km, or O (10^2 km).« less

  1. Scalable hierarchical PDE sampler for generating spatially correlated random fields using nonmatching meshes: Scalable hierarchical PDE sampler using nonmatching meshes

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

    Osborn, Sarah; Zulian, Patrick; Benson, Thomas

    This work describes a domain embedding technique between two nonmatching meshes used for generating realizations of spatially correlated random fields with applications to large-scale sampling-based uncertainty quantification. The goal is to apply the multilevel Monte Carlo (MLMC) method for the quantification of output uncertainties of PDEs with random input coefficients on general and unstructured computational domains. We propose a highly scalable, hierarchical sampling method to generate realizations of a Gaussian random field on a given unstructured mesh by solving a reaction–diffusion PDE with a stochastic right-hand side. The stochastic PDE is discretized using the mixed finite element method on anmore » embedded domain with a structured mesh, and then, the solution is projected onto the unstructured mesh. This work describes implementation details on how to efficiently transfer data from the structured and unstructured meshes at coarse levels, assuming that this can be done efficiently on the finest level. We investigate the efficiency and parallel scalability of the technique for the scalable generation of Gaussian random fields in three dimensions. An application of the MLMC method is presented for quantifying uncertainties of subsurface flow problems. Here, we demonstrate the scalability of the sampling method with nonmatching mesh embedding, coupled with a parallel forward model problem solver, for large-scale 3D MLMC simulations with up to 1.9·109 unknowns.« less

  2. A Deep Penetration Problem Calculation Using AETIUS:An Easy Modeling Discrete Ordinates Transport Code UsIng Unstructured Tetrahedral Mesh, Shared Memory Parallel

    NASA Astrophysics Data System (ADS)

    KIM, Jong Woon; LEE, Young-Ouk

    2017-09-01

    As computing power gets better and better, computer codes that use a deterministic method seem to be less useful than those using the Monte Carlo method. In addition, users do not like to think about space, angles, and energy discretization for deterministic codes. However, a deterministic method is still powerful in that we can obtain a solution of the flux throughout the problem, particularly as when particles can barely penetrate, such as in a deep penetration problem with small detection volumes. Recently, a new state-of-the-art discrete-ordinates code, ATTILA, was developed and has been widely used in several applications. ATTILA provides the capabilities to solve geometrically complex 3-D transport problems by using an unstructured tetrahedral mesh. Since 2009, we have been developing our own code by benchmarking ATTILA. AETIUS is a discrete ordinates code that uses an unstructured tetrahedral mesh such as ATTILA. For pre- and post- processing, Gmsh is used to generate an unstructured tetrahedral mesh by importing a CAD file (*.step) and visualizing the calculation results of AETIUS. Using a CAD tool, the geometry can be modeled very easily. In this paper, we describe a brief overview of AETIUS and provide numerical results from both AETIUS and a Monte Carlo code, MCNP5, in a deep penetration problem with small detection volumes. The results demonstrate the effectiveness and efficiency of AETIUS for such calculations.

  3. Early Years Education: Are Young Students Intrinsically or Extrinsically Motivated Towards School Activities? A Discussion about the Effects of Rewards on Young Children's Learning

    ERIC Educational Resources Information Center

    Theodotou, Evgenia

    2014-01-01

    Rewards can reinforce and at the same time forestall young children's willingness to learn. However, they are broadly used in the field of education, especially in early years settings, to stimulate children towards learning activities. This paper reviews the theoretical and research literature related to intrinsic and extrinsic motivational…

  4. Aqueous synthesis of porous platinum nanotubes at room temperature and their intrinsic peroxidase-like activity.

    PubMed

    Cai, Kai; Lv, Zhicheng; Chen, Kun; Huang, Liang; Wang, Jing; Shao, Feng; Wang, Yanjun; Han, Heyou

    2013-07-11

    Platinum nanotubes (PtNTs) exhibiting high porosity were constructed by sacrificing the exterior of tellurium nanowires (TeNWs) and disintegrating the inner part spontaneously in aqueous solution at room temperature, in which the Kirkendall effect may play an important role. The present PtNTs exhibited intrinsic peroxidase-like activity in the presence of H2O2.

  5. Neural constraints on learning.

    PubMed

    Sadtler, Patrick T; Quick, Kristin M; Golub, Matthew D; Chase, Steven M; Ryu, Stephen I; Tyler-Kabara, Elizabeth C; Yu, Byron M; Batista, Aaron P

    2014-08-28

    Learning, whether motor, sensory or cognitive, requires networks of neurons to generate new activity patterns. As some behaviours are easier to learn than others, we asked if some neural activity patterns are easier to generate than others. Here we investigate whether an existing network constrains the patterns that a subset of its neurons is capable of exhibiting, and if so, what principles define this constraint. We employed a closed-loop intracortical brain-computer interface learning paradigm in which Rhesus macaques (Macaca mulatta) controlled a computer cursor by modulating neural activity patterns in the primary motor cortex. Using the brain-computer interface paradigm, we could specify and alter how neural activity mapped to cursor velocity. At the start of each session, we observed the characteristic activity patterns of the recorded neural population. The activity of a neural population can be represented in a high-dimensional space (termed the neural space), wherein each dimension corresponds to the activity of one neuron. These characteristic activity patterns comprise a low-dimensional subspace (termed the intrinsic manifold) within the neural space. The intrinsic manifold presumably reflects constraints imposed by the underlying neural circuitry. Here we show that the animals could readily learn to proficiently control the cursor using neural activity patterns that were within the intrinsic manifold. However, animals were less able to learn to proficiently control the cursor using activity patterns that were outside of the intrinsic manifold. These results suggest that the existing structure of a network can shape learning. On a timescale of hours, it seems to be difficult to learn to generate neural activity patterns that are not consistent with the existing network structure. These findings offer a network-level explanation for the observation that we are more readily able to learn new skills when they are related to the skills that we already possess.

  6. Aggregation propensity of critical regions of the protein Tau

    NASA Astrophysics Data System (ADS)

    Muthee, Micaiah; Ahmed, Azka; Larini, Luca

    The Alzheimer's disease is an irreversible, progressive brain disorder that slowly destroys memory and thinking skills, which eventually leads to the ability to not able to carry out the simplest tasks. The Alzheimer's disease is characterized by the formation of protein aggregates both within and outside of the brain's cells, the neurons. Within the neurons, the aggregation of the protein tau leads to the destruction of the microtubules in the axon of the neuron. Tau belongs to a group of proteins referred to as Microtubule-Associated Proteins. It is extremely flexible and is classified as an intrinsically unstructured protein due to its low propensity to form secondary structure. Tau promotes tubulin assembly into microtubules thereby stabilizing the cytoskeleton of the axon of the neurons. The microtubule binding region of tau consists of 4 pseudo-repeats. In this study, we will focus on the aggregation propensity of two fragments. In this study we will focus on the PHF43 fragment that contains the third pseudo-repeat and has been shown experimentally to aggregate readily. Another fragment that contains the second pseudo-repeat will be considered as well. Mutations in this region are associated with various form of dementia and for this reason we will consider the mutant P301L.

  7. Dynamics of partially folded and unfolded proteins investigated with quasielastic neutron spectroscopy

    NASA Astrophysics Data System (ADS)

    Stadler, Andreas M.

    2018-05-01

    Molecular dynamics in proteins animate and play a vital role for biologically relevant processes of these biomacromolecules. Quasielastic incoherent neutron scattering (QENS) is a well-suited experimental method to study protein dynamics from the picosecond to several nanoseconds and in the Ångström length-scale. In QENS experiments of protein solutions hydrogens act as reporters for the motions of methyl groups or amino acids to which they are bound. Neutron Spin-Echo spectroscopy (NSE) offers the highest energy resolution in the field of neutron spectroscopy and allows the study of slow collective motions in proteins up to several hundred nanoseconds and in the nanometer length-scale. In the following manuscript I will review recent studies that stress the relevance of molecular dynamics for protein folding and for conformational transitions of intrinsically disordered proteins (IDPs). During the folding collapse the protein is exploring its accessible conformational space via molecular motions. A large flexibility of partially folded and unfolded proteins, therefore, is mandatory for rapid protein folding. IDPs are a special case as they are largely unstructured under physiological conditions. A large flexibility is a characteristic property of IDPs as it allows, for example, the interaction with various binding partners or the rapid response to different conditions.

  8. The Next Frontier: Quantitative Biochemistry in Living Cells.

    PubMed

    Honigmann, Alf; Nadler, André

    2018-01-09

    Researchers striving to convert biology into an exact science foremost rely on structural biology and biochemical reconstitution approaches to obtain quantitative data. However, cell biological research is moving at an ever-accelerating speed into areas where these approaches lose much of their edge. Intrinsically unstructured proteins and biochemical interaction networks composed of interchangeable, multivalent, and unspecific interactions pose unique challenges to quantitative biology, as do processes that occur in discrete cellular microenvironments. Here we argue that a conceptual change in our way of conducting biochemical experiments is required to take on these new challenges. We propose that reconstitution of cellular processes in vitro should be much more focused on mimicking the cellular environment in vivo, an approach that requires detailed knowledge of the material properties of cellular compartments, essentially requiring a material science of the cell. In a similar vein, we suggest that quantitative biochemical experiments in vitro should be accompanied by corresponding experiments in vivo, as many newly relevant cellular processes are highly context-dependent. In essence, this constitutes a call for chemical biologists to convert their discipline from a proof-of-principle science to an area that could rightfully be called quantitative biochemistry in living cells. In this essay, we discuss novel techniques and experimental strategies with regard to their potential to fulfill such ambitious aims.

  9. Biomimetic Architectures for Peripheral Nerve Repair: A Review of Biofabrication Strategies.

    PubMed

    Wieringa, Paul A; Gonçalves de Pinho, Ana Rita; Micera, Silvestro; van Wezel, Richard J A; Moroni, Lorenzo

    2018-04-01

    Biofabrication techniques have endeavored to improve the regeneration of the peripheral nervous system (PNS), but nothing has surpassed the performance of current clinical practices. However, these current approaches have intrinsic limitations that compromise patient care. The "gold standard" autograft provides the best outcomes but requires suitable donor material, while implantable hollow nerve guide conduits (NGCs) can only repair small nerve defects. This review places emphasis on approaches that create structural cues within a hollow NGC lumen in order to match or exceed the regenerative performance of the autograft. An overview of the PNS and nerve regeneration is provided. This is followed by an assessment of reported devices, divided into three major categories: isotropic hydrogel fillers, acting as unstructured interluminal support for regenerating nerves; fibrous interluminal fillers, presenting neurites with topographical guidance within the lumen; and patterned interluminal scaffolds, providing 3D support for nerve growth via structures that mimic native PNS tissue. Also presented is a critical framework to evaluate the impact of reported outcomes. While a universal and versatile nerve repair strategy remains elusive, outlined here is a roadmap of past, present, and emerging fabrication techniques to inform and motivate new developments in the field of peripheral nerve regeneration. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Is the philosophy of mechanism philosophy enough?

    PubMed

    Moss, Lenny

    2012-03-01

    Recognition of the widespread use of the word 'mechanism' in bio-molecular research has resulted in the concept of 'mechanism' becoming a focal point for a highly visible group of philosophers of biology. Rather, however, than grasping and elucidating the situated aims and practices of biologists themselves, the philosophical investigation of the contemporary meaning of mechanism in biology has been commandeered by the needs of 'hard naturalists' to replace the old deductive-nomological model of the 'received view' with a new normative-explanatory gold-standard. It is argued that rather than an orientation toward an increasingly precise characterization of mechanisms as being an ultimate end in biological research, in actual biological practice 'mechanism' means different things in different contexts, pragmatically draws on our embodied know-how in the use of machines and is not, nor should be, an ultimate end of biological research. Further, it is argued, that classic work on low-level mechanisms became taken up qualitatively as parts of the scaffolding for investigating higher level regulatory processes and that in so doing, and in light of new findings such as that of the regulatory significance of 'pleiomorphic ensembles' and 'intrinsically unstructured proteins' the explanatory limits of the mechanism image have already come into view. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Cotranslocational processing of the protein substrate calmodulin by an AAA+ unfoldase occurs via unfolding and refolding intermediates.

    PubMed

    Augustyniak, Rafal; Kay, Lewis E

    2018-05-22

    Protein remodeling by AAA+ enzymes is central for maintaining proteostasis in a living cell. However, a detailed structural description of how this is accomplished at the level of the substrate molecules that are acted upon is lacking. Here, we combine chemical cross-linking and methyl transverse relaxation-optimized NMR spectroscopy to study, at atomic resolution, the stepwise unfolding and subsequent refolding of the two-domain substrate calmodulin by the VAT AAA+ unfoldase from Thermoplasma acidophilum By engineering intermolecular disulphide bridges between the substrate and VAT we trap the substrate at different stages of translocation, allowing structural studies throughout the translocation process. Our results show that VAT initiates substrate translocation by pulling on intrinsically unstructured N or C termini of substrate molecules without showing specificity for a particular amino acid sequence. Although the B1 domain of protein G is shown to unfold cooperatively, translocation of calmodulin leads to the formation of intermediates, and these differ on an individual domain level in a manner that depends on whether pulling is from the N or C terminus. The approach presented generates an atomic resolution picture of substrate unfolding and subsequent refolding by unfoldases that can be quite different from results obtained via in vitro denaturation experiments.

  12. Relationships between physical education students' motivational profiles, enjoyment, state anxiety, and self-reported physical activity.

    PubMed

    Yli-Piipari, Sami; Watt, Anthony; Jaakkola, Timo; Liukkonen, Jarmo; Nurmi, Jari-Erik

    2009-01-01

    The purpose of this study was to analyze motivational profiles based on the self-determination theory (Deci and Ryan, 2000) and how these profiles are related to physical education students' enjoyment, state anxiety, and physical activity. The participants, 429 sixth grade students (girls = 216; boys = 213) completed SMS, Sport Enjoyment Scale, PESAS, and Physical Activity Scale. Cluster analyses identified two motivational profiles: 1) the "High motivation profile", in which the students had high intrinsic and extrinsic motivation, and low levels of amotivation, and 2) the "Low motivation profile", in which the students had low intrinsic and extrinsic motivation, and low levels of amotivation. The students in the first cluster enjoyed physical education more and were physically more active. The results revealed that students may be motivated towards physical education lessons both intrinsically and extrinsically, and still experience enjoyment in physical education. Key pointsTWO MOTIVATIONAL PROFILES WERE REVEALED: 1) the "High motivation profile", in which the students had high intrinsic and extrinsic motivation, and low levels of amotivation, and 2) the "Low motivation profile", in which the students had low intrinsic and extrinsic motivation, and low levels of amotivation.The students in the first profile enjoyed physical education more and were physically more active than the students in the second profile.Moreover, the representatives of the "High motivation profile "experienced greater anxiety toward physical education than the representatives of the "Low motivation profile"These findings raised an interesting question whether students engaging in physical education benefit more from the presence of both self-determined and non-self-determined forms of motivation, or are the benefits higher if students are primarily self-determined?

  13. Direct measurement of the intrinsic ankle stiffness during standing.

    PubMed

    Vlutters, M; Boonstra, T A; Schouten, A C; van der Kooij, H

    2015-05-01

    Ankle stiffness contributes to standing balance, counteracting the destabilizing effect of gravity. The ankle stiffness together with the compliance between the foot and the support surface make up the ankle-foot stiffness, which is relevant to quiet standing. The contribution of the intrinsic ankle-foot stiffness to balance, and the ankle-foot stiffness amplitude dependency remain a topic of debate in the literature. We therefore developed an experimental protocol to directly measure the bilateral intrinsic ankle-foot stiffness during standing balance, and determine its amplitude dependency. By applying fast (40 ms) ramp-and-hold support surface rotations (0.005-0.08 rad) during standing, reflexive contributions could be excluded, and the amplitude dependency of the intrinsic ankle-foot stiffness was investigated. Results showed that reflexive activity could not have biased the torque used for estimating the intrinsic stiffness. Furthermore, subjects required less recovery action to restore balance after bilateral rotations in opposite directions compared to rotations in the same direction. The intrinsic ankle-foot stiffness appears insufficient to ensure balance, ranging from 0.93±0.09 to 0.44±0.06 (normalized to critical stiffness 'mgh'). This implies that changes in muscle activation are required to maintain balance. The non-linear stiffness decrease with increasing rotation amplitude supports the previous published research. With the proposed method reflexive effects can be ruled out from the measured torque without any model assumptions, allowing direct estimation of intrinsic stiffness during standing. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Perceived influence of intrinsic/extrinsic factors on participation in life activities after spinal cord injury.

    PubMed

    Cobb, John E; Leblond, Jean; Dumont, Frédéric S; Noreau, Luc

    2018-04-03

    Various types of limitations on community participation are experienced by people with spinal cord injury (SCI). To determine: 1) the perceived influence of six intrinsic/extrinsic factors (i.e. physical impairment, emotional condition, thinking skills, environment, lack of assistance, discrimination) on participation in 26 life activities, 2) if this influence varied based on extent of participation, and 3) if personal or environmental characteristics influenced perceptions. Secondary analysis of a cohort (SCI Community Survey, n = 1508) using the SCI Person-Perceived Participation in Daily Activities Questionnaire. Frequency tables, Fisher's exact tests and correspondence analyses. Respectively, 79.6% and 38.5% of respondents perceived that their physical impairment and the natural and/or built environment were the main factors that limited participation across all activities. Considering participation between three groups (no participation; less than wanted; as much as wanted), significant differences (p < 0.001) of perceptions were observed in 65% of the combinations (26 activities x 6 factors). The hypothesis that respondents who did not participate would perceive the highest proportion of limitations was confirmed in 41% of the combinations. Perceived influence of the intrinsic/extrinsic factors on participation was not significantly influenced by other personal or environmental characteristics. A majority of people with SCI perceived that their participation is limited by one or more of intrinsic/extrinsic factors. Perceptions regarding which factors influence participation differ between activities and these perceptions appear related to the extent of participation suggesting that those who actively participate could be the most sensitive to limitations in certain activities. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Relationship between individual neuron and network spontaneous activity in developing mouse cortex.

    PubMed

    Barnett, Heather M; Gjorgjieva, Julijana; Weir, Keiko; Comfort, Cara; Fairhall, Adrienne L; Moody, William J

    2014-12-15

    Spontaneous synchronous activity (SSA) that propagates as electrical waves is found in numerous central nervous system structures and is critical for normal development, but the mechanisms of generation of such activity are not clear. In previous work, we showed that the ventrolateral piriform cortex is uniquely able to initiate SSA in contrast to the dorsal neocortex, which participates in, but does not initiate, SSA (Lischalk JW, Easton CR, Moody WJ. Dev Neurobiol 69: 407-414, 2009). In this study, we used Ca(2+) imaging of cultured embryonic day 18 to postnatal day 2 coronal slices (embryonic day 17 + 1-4 days in culture) of the mouse cortex to investigate the different activity patterns of individual neurons in these regions. In the piriform cortex where SSA is initiated, a higher proportion of neurons was active asynchronously between waves, and a larger number of groups of coactive cells was present compared with the dorsal cortex. When we applied GABA and glutamate synaptic antagonists, asynchronous activity and cellular clusters remained, while synchronous activity was eliminated, indicating that asynchronous activity is a result of cell-intrinsic properties that differ between these regions. To test the hypothesis that higher levels of cell-autonomous activity in the piriform cortex underlie its ability to initiate waves, we constructed a conductance-based network model in which three layers differed only in the proportion of neurons able to intrinsically generate bursting behavior. Simulations using this model demonstrated that a gradient of intrinsic excitability was sufficient to produce directionally propagating waves that replicated key experimental features, indicating that the higher level of cell-intrinsic activity in the piriform cortex may provide a substrate for SSA generation. Copyright © 2014 the American Physiological Society.

  16. Mutation extraction tools can be combined for robust recognition of genetic variants in the literature

    PubMed Central

    Jimeno Yepes, Antonio; Verspoor, Karin

    2014-01-01

    As the cost of genomic sequencing continues to fall, the amount of data being collected and studied for the purpose of understanding the genetic basis of disease is increasing dramatically. Much of the source information relevant to such efforts is available only from unstructured sources such as the scientific literature, and significant resources are expended in manually curating and structuring the information in the literature. As such, there have been a number of systems developed to target automatic extraction of mutations and other genetic variation from the literature using text mining tools. We have performed a broad survey of the existing publicly available tools for extraction of genetic variants from the scientific literature. We consider not just one tool but a number of different tools, individually and in combination, and apply the tools in two scenarios. First, they are compared in an intrinsic evaluation context, where the tools are tested for their ability to identify specific mentions of genetic variants in a corpus of manually annotated papers, the Variome corpus. Second, they are compared in an extrinsic evaluation context based on our previous study of text mining support for curation of the COSMIC and InSiGHT databases. Our results demonstrate that no single tool covers the full range of genetic variants mentioned in the literature. Rather, several tools have complementary coverage and can be used together effectively. In the intrinsic evaluation on the Variome corpus, the combined performance is above 0.95 in F-measure, while in the extrinsic evaluation the combined recall performance is above 0.71 for COSMIC and above 0.62 for InSiGHT, a substantial improvement over the performance of any individual tool. Based on the analysis of these results, we suggest several directions for the improvement of text mining tools for genetic variant extraction from the literature. PMID:25285203

  17. Aggregation and structural changes of α(S1)-, β- and κ-caseins induced by homocysteinylation.

    PubMed

    Stroylova, Yulia Y; Zimny, Jaroslaw; Yousefi, Reza; Chobert, Jean-Marc; Jakubowski, Hieronim; Muronetz, Vladimir I; Haertlé, Thomas

    2011-10-01

    Elevated homocysteine levels are resulting in N-homocysteinylation of lysyl residues in proteins and they correlate with a number of human pathologies. However, the role of homocysteinylation of lysyl residues is still poorly known. In order to study the features of homocysteinylation of intrinsically unstructured proteins (IUP) bovine caseins were used as a model. α(S1)-, β- and κ-caseins, showing different aggregations and micelle formation, were modified with homocysteine-thiolactone and their physico-chemical properties were studied. Efficiency of homocysteine incorporation was estimated to be about 1.5, 2.1 and 1.3 homocysteyl residues per one β-, α(S1)-, and κ-casein molecule, respectively. Use of intrinsic and extrinsic fluorescent markers such as Trp, thioflavin T and ANS, reveal structural changes of casein structures after homocysteinylation reflected by an increase in beta-sheet content, which in some cases may be characteristic of amyloid-like transformations. CD spectra also show an increase in beta-sheet content of homocysteinylated caseins. Casein homocysteinylation leads in all cases to aggregation. The sizes of aggregates and aggregation rates were dependent on homocysteine thiolactone concentration and temperature. DLS and microscopic studies have revealed the formation of large aggregates of about 1-3μm. Homocysteinylation of α(S1)- and β-caseins results in formation of regular spheres. Homocysteinylated κ-casein forms thin unbranched fibrils about 400-800nm long. In case of κ-casein amyloidogenic effect of homocysteinylation was confirmed by Congo red spectra. Taken together, data indicate that N-homocysteinylation provokes significant changes in properties of native caseins. A comparison of amyloidogenic transformation of 3 different casein types, belonging to the IUP protein family, shows that the efficiency of amyloidogenic transformation upon homocysteinylation depends on micellization capacity, additional disulphide bonds and other structural features. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Brain-state dependent astrocytic Ca2+ signals are coupled to both positive and negative BOLD-fMRI signals.

    PubMed

    Wang, Maosen; He, Yi; Sejnowski, Terrence J; Yu, Xin

    2018-02-13

    Astrocytic Ca 2+ -mediated gliovascular interactions regulate the neurovascular network in situ and in vivo. However, it is difficult to measure directly both the astrocytic activity and fMRI to relate the various forms of blood-oxygen-level-dependent (BOLD) signaling to brain states under normal and pathological conditions. In this study, fMRI and GCaMP-mediated Ca 2+ optical fiber recordings revealed distinct evoked astrocytic Ca 2+ signals that were coupled with positive BOLD signals and intrinsic astrocytic Ca 2+ signals that were coupled with negative BOLD signals. Both evoked and intrinsic astrocytic calcium signal could occur concurrently or respectively during stimulation. The intrinsic astrocytic calcium signal can be detected globally in multiple cortical sites in contrast to the evoked astrocytic calcium signal only detected at the activated cortical region. Unlike propagating Ca 2+ waves in spreading depolarization/depression, the intrinsic Ca 2+ spikes occurred simultaneously in both hemispheres and were initiated upon the activation of the central thalamus and midbrain reticular formation. The occurrence of the intrinsic astrocytic calcium signal is strongly coincident with an increased EEG power level of the brain resting-state fluctuation. These results demonstrate highly correlated astrocytic Ca 2+ spikes with bidirectional fMRI signals based on the thalamic regulation of cortical states, depicting a brain-state dependency of both astrocytic Ca 2+ and BOLD fMRI signals.

  19. Intrinsic Kinetics of Dimethyl Ether Synthesis from Plasma Activation of CO2 Hydrogenation over Cu-Fe-Ce/HZSM-5.

    PubMed

    Su, Tongming; Zhou, Xinhui; Qin, Zuzeng; Ji, Hongbing

    2017-02-02

    CO 2 is activated in a plasma reactor followed by hydrogenation over a Cu-Fe-Ce/HZSM-5 catalyst, and the intrinsic kinetics of the plasma catalytic process are studied. Compared with CO 2 hydrogenation using Cu-Fe-Ce/HZSM-5 alone, the CO 2 conversion and the dimethyl ether selectivity for the plasma catalytic process are increased by 16.3 %, and 10.1 %, respectively, indicating that the CO 2 was activated by the plasma to promote hydrogenation. A study of the intrinsic kinetics shows that the activation energies of methanol formation, the reverse water-gas shift reaction, and methanol dehydration to dimethyl ether are 149.34, 75.47, and 73.18 kJ mol -1 , respectively, which are lower than if Cu-Fe-Ce/HZSM-5 is used without plasma, indicating that the activation of CO 2 in the plasma reduces the activation energy of the hydrogenation reaction and improves the yield of dimethyl ether. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Plasma Membrane Intrinsic Proteins from Maize Cluster in Two Sequence Subgroups with Differential Aquaporin Activity1

    PubMed Central

    Chaumont, François; Barrieu, François; Jung, Rudolf; Chrispeels, Maarten J.

    2000-01-01

    The transport of water through membranes is regulated in part by aquaporins or water channel proteins. These proteins are members of the larger family of major intrinsic proteins (MIPs). Plant aquaporins are categorized as either tonoplast intrinsic proteins (TIPs) or plasma membrane intrinsic proteins (PIPs). Sequence analysis shows that PIPs form several subclasses. We report on the characterization of three maize (Zea mays) PIPs belonging to the PIP1 and PIP2 subfamilies (ZmPIP1a, ZmPIP1b, and ZmPIP2a). The ZmPIP2a clone has normal aquaporin activity in Xenopus laevis oocytes. ZmPIP1a and ZmPIP1b have no activity, and a review of the literature shows that most PIP1 proteins identified in other plants have no or very low activity in oocytes. Arabidopsis PIP1 proteins are the only exception. Control experiments show that this lack of activity of maize PIP1 proteins is not caused by their failure to arrive at the plasma membrane of the oocytes. ZmPIP1b also does not appear to facilitate the transport of any of the small solutes tried (glycerol, choline, ethanol, urea, and amino acids). These results are discussed in relationship to the function and regulation of the PIP family of aquaporins. PMID:10759498

  1. Learning from Demonstration for Autonomous Navigation in Complex Unstructured Terrain

    DTIC Science & Technology

    2010-06-24

    unstructured terrain Seraji and Howard, 2002, Huertas et al., 2005, Biesiadecki and Maimone, 2006] The common thread amongst these approaches is that they con...can be gathered either of- fline [ Seraji and Howard, 2002, Howard et al., 2007] or online [Thrun et al., 2006, Sun et al., 2007] by ob- serving where... Fe = F∗ = ~0; foreach P ie do P i∗ = planLossAugPath(start(P i e), goal(P ie), M); foreach x ∈ P ie do Fe + = Fe + Fx; foreach x ∈ P i∗ do F∗ = F∗ + Fx

  2. Quality assessment of two- and three-dimensional unstructured meshes and validation of an upwind Euler flow solver

    NASA Technical Reports Server (NTRS)

    Woodard, Paul R.; Batina, John T.; Yang, Henry T. Y.

    1992-01-01

    Quality assessment procedures are described for two-dimensional unstructured meshes. The procedures include measurement of minimum angles, element aspect ratios, stretching, and element skewness. Meshes about the ONERA M6 wing and the Boeing 747 transport configuration are generated using an advancing front method grid generation package of programs. Solutions of Euler's equations for these meshes are obtained at low angle-of-attack, transonic conditions. Results for these cases, obtained as part of a validation study demonstrate accuracy of an implicit upwind Euler solution algorithm.

  3. Data Storing Proposal from Heterogeneous Systems into a Specialized Repository

    NASA Astrophysics Data System (ADS)

    Václavová, Andrea; Tanuška, Pavol; Jánošík, Ján

    2016-12-01

    The aim of this paper is to analyze and to propose an appropriate system for processing and simultaneously storing a vast volume of structured and unstructured data. The paper consists of three parts. The first part addresses the issue of structured and unstructured data. The second part provides the detailed analysis of data repositories and subsequent evaluation indicating which system would be for the given type and volume of data optimal. The third part focuses on the use of gathered information to transfer data to the proposed repository.

  4. Unstructured-grid methods development: Lessons le arned

    NASA Technical Reports Server (NTRS)

    Batina, John T.

    1991-01-01

    The development is summarized of unstructured grid methods for the solution of the equations of fluid flow and some of the lessons learned are shared. The 3-D Euler equations are solved, including spatial discretizations, temporal discretizations, and boundary conditions. An example calculation with an upwind implicit method using a CFL (Courant Friedricks Lewy) number of infinity is presented for the Boeing 747 aircraft. The results obtained in less than one hour of CPU time on a Cray-2 computer, thus demonstrating the speed and robustness of the present capability.

  5. Parametric robust control and system identification: Unified approach

    NASA Technical Reports Server (NTRS)

    Keel, Leehyun

    1994-01-01

    Despite significant advancement in the area of robust parametric control, the problem of synthesizing such a controller is still a wide open problem. Thus, we attempt to give a solution to this important problem. Our approach captures the parametric uncertainty as an H(sub infinity) unstructured uncertainty so that H(sub infinity) synthesis techniques are applicable. Although the techniques cannot cope with the exact parametric uncertainty, they give a reasonable guideline to model the unstructured uncertainty that contains the parametric uncertainty. An additional loop shaping technique is also introduced to relax its conservatism.

  6. 3D Feature Extraction for Unstructured Grids

    NASA Technical Reports Server (NTRS)

    Silver, Deborah

    1996-01-01

    Visualization techniques provide tools that help scientists identify observed phenomena in scientific simulation. To be useful, these tools must allow the user to extract regions, classify and visualize them, abstract them for simplified representations, and track their evolution. Object Segmentation provides a technique to extract and quantify regions of interest within these massive datasets. This article explores basic algorithms to extract coherent amorphous regions from two-dimensional and three-dimensional scalar unstructured grids. The techniques are applied to datasets from Computational Fluid Dynamics and those from Finite Element Analysis.

  7. Shoes alter the spring-like function of the human foot during running

    PubMed Central

    Kelly, Luke A.; Lichtwark, Glen A.; Farris, Dominic J.; Cresswell, Andrew

    2016-01-01

    The capacity to store and return energy in legs and feet that behave like springs is crucial to human running economy. Recent comparisons of shod and barefoot running have led to suggestions that modern running shoes may actually impede leg and foot-spring function by reducing the contributions from the leg and foot musculature. Here we examined the effect of running shoes on foot longitudinal arch (LA) motion and activation of the intrinsic foot muscles. Participants ran on a force-instrumented treadmill with and without running shoes. We recorded foot kinematics and muscle activation of the intrinsic foot muscles using intramuscular electromyography. In contrast to previous assertions, we observed an increase in both the peak (flexor digitorum brevis +60%) and total stance muscle activation (flexor digitorum brevis +70% and abductor hallucis +53%) of the intrinsic foot muscles when running with shoes. Increased intrinsic muscle activation corresponded with a reduction in LA compression (−25%). We confirm that running shoes do indeed influence the mechanical function of the foot. However, our findings suggest that these mechanical adjustments are likely to have occurred as a result of increased neuromuscular output, rather than impaired control as previously speculated. We propose a theoretical model for foot–shoe interaction to explain these novel findings. PMID:27307512

  8. Shoes alter the spring-like function of the human foot during running.

    PubMed

    Kelly, Luke A; Lichtwark, Glen A; Farris, Dominic J; Cresswell, Andrew

    2016-06-01

    The capacity to store and return energy in legs and feet that behave like springs is crucial to human running economy. Recent comparisons of shod and barefoot running have led to suggestions that modern running shoes may actually impede leg and foot-spring function by reducing the contributions from the leg and foot musculature. Here we examined the effect of running shoes on foot longitudinal arch (LA) motion and activation of the intrinsic foot muscles. Participants ran on a force-instrumented treadmill with and without running shoes. We recorded foot kinematics and muscle activation of the intrinsic foot muscles using intramuscular electromyography. In contrast to previous assertions, we observed an increase in both the peak (flexor digitorum brevis +60%) and total stance muscle activation (flexor digitorum brevis +70% and abductor hallucis +53%) of the intrinsic foot muscles when running with shoes. Increased intrinsic muscle activation corresponded with a reduction in LA compression (-25%). We confirm that running shoes do indeed influence the mechanical function of the foot. However, our findings suggest that these mechanical adjustments are likely to have occurred as a result of increased neuromuscular output, rather than impaired control as previously speculated. We propose a theoretical model for foot-shoe interaction to explain these novel findings. © 2016 The Author(s).

  9. Machine Learning Classification of Cirrhotic Patients with and without Minimal Hepatic Encephalopathy Based on Regional Homogeneity of Intrinsic Brain Activity.

    PubMed

    Chen, Qiu-Feng; Chen, Hua-Jun; Liu, Jun; Sun, Tao; Shen, Qun-Tai

    2016-01-01

    Machine learning-based approaches play an important role in examining functional magnetic resonance imaging (fMRI) data in a multivariate manner and extracting features predictive of group membership. This study was performed to assess the potential for measuring brain intrinsic activity to identify minimal hepatic encephalopathy (MHE) in cirrhotic patients, using the support vector machine (SVM) method. Resting-state fMRI data were acquired in 16 cirrhotic patients with MHE and 19 cirrhotic patients without MHE. The regional homogeneity (ReHo) method was used to investigate the local synchrony of intrinsic brain activity. Psychometric Hepatic Encephalopathy Score (PHES) was used to define MHE condition. SVM-classifier was then applied using leave-one-out cross-validation, to determine the discriminative ReHo-map for MHE. The discrimination map highlights a set of regions, including the prefrontal cortex, anterior cingulate cortex, anterior insular cortex, inferior parietal lobule, precentral and postcentral gyri, superior and medial temporal cortices, and middle and inferior occipital gyri. The optimized discriminative model showed total accuracy of 82.9% and sensitivity of 81.3%. Our results suggested that a combination of the SVM approach and brain intrinsic activity measurement could be helpful for detection of MHE in cirrhotic patients.

  10. From Emotions to Consciousness – A Neuro-Phenomenal and Neuro-Relational Approach

    PubMed Central

    Northoff, Georg

    2012-01-01

    The James–Lange theory considers emotional feelings as perceptions of physiological body changes. This approach has recently resurfaced and modified in both neuroscientific and philosophical concepts of embodiment of emotional feelings. In addition to the body, the role of the environment in emotional feeling needs to be considered. I here claim that the environment has not merely an indirect and instrumental, i.e., modulatory role on emotional feelings via the body and its sensorimotor and vegetative functions. Instead, the environment may have a direct and non-instrumental, i.e., constitutional role in emotional feelings. This implies that the environment itself is constitutive of emotional feeling rather than the bodily representation of the environment. I call this the relational concept of emotional feeling. The present paper discusses recent data from neuroimaging that investigate emotions in relation to interoceptive processing and the brain’s intrinsic activity. These data show the intrinsic linkage of interoceptive stimulus processing to both exteroceptive stimuli and the brain’s intrinsic activity. This is possible only if the differences between intrinsic activity and intero- and exteroceptive stimuli is encoded into neural activity. Such relational coding makes possible the assignment of subjective and affective features to the otherwise objective and non-affective stimulus. I therefore consider emotions to be intrinsically affective and subjective as it is manifest in emotional feelings. The relational approach thus goes together with what may be described as neuro-phenomenal approach. Such neuro-phenomenal approach does not only inform emotions and emotional feeling but is also highly relevant to better understand the neuronal mechanisms underlying consciousness in general. PMID:22969736

  11. Soft Active Materials for Actuation, Sensing, and Electronics

    NASA Astrophysics Data System (ADS)

    Kramer, Rebecca Krone

    Future generations of robots, electronics, and assistive medical devices will include systems that are soft and elastically deformable, allowing them to adapt their morphology in unstructured environments. This will require soft active materials for actuation, circuitry, and sensing of deformation and contact pressure. The emerging field of soft robotics utilizes these soft active materials to mimic the inherent compliance of natural soft-bodied systems. As the elasticity of robot components increases, the challenges for functionality revert to basic questions of fabrication, materials, and design - whereas such aspects are far more developed for traditional rigid-bodied systems. This thesis will highlight preliminary materials and designs that address the need for soft actuators and sensors, as well as emerging fabrication techniques for manufacturing stretchable circuits and devices based on liquid-embedded elastomers.

  12. Maximum entropy models as a tool for building precise neural controls.

    PubMed

    Savin, Cristina; Tkačik, Gašper

    2017-10-01

    Neural responses are highly structured, with population activity restricted to a small subset of the astronomical range of possible activity patterns. Characterizing these statistical regularities is important for understanding circuit computation, but challenging in practice. Here we review recent approaches based on the maximum entropy principle used for quantifying collective behavior in neural activity. We highlight recent models that capture population-level statistics of neural data, yielding insights into the organization of the neural code and its biological substrate. Furthermore, the MaxEnt framework provides a general recipe for constructing surrogate ensembles that preserve aspects of the data, but are otherwise maximally unstructured. This idea can be used to generate a hierarchy of controls against which rigorous statistical tests are possible. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. The underlying mechanism of proinflammatory NF-κB activation by the mTORC2/Akt/IKKα pathway during skin aging

    PubMed Central

    Choi, Yeon Ja; Moon, Kyoung Mi; Chung, Ki Wung; Jeong, Ji Won; Park, Daeui; Kim, Dae Hyun; Yu, Byung Pal; Chung, Hae Young

    2016-01-01

    Mammalian target of rapamycin complex 2 (mTORC2), one of two different enzymatic complexes of mTOR, regulates a diverse set of substrates including Akt. mTOR pathway is one of well-known mediators of aging process, however, its role in skin aging has not been determined. Skin aging can be induced by physical age and ultraviolet (UV) irradiation which are intrinsic and extrinsic factors, respectively. Here, we report increased mTORC2 pathway in intrinsic and photo-induced skin aging, which is implicated in the activation of nuclear factor-κB (NF-κB). UVB-irradiated or aged mice skin revealed that mTORC2 activity and its component, rictor were significantly upregulated which in turn increased Akt activation and Akt-dependent IκB kinase α (IKKα) phosphorylation at Thr23 in vivo. We also confirmed that UVB induced the mTORC2/Akt/IKKα signaling pathway with HaCaT human normal keratinocytes. The increased mTORC2 signaling pathway during skin aging were associated to NF-κB activation. Suppression of mTORC2 activity by the treatment of a mTOR small inhibitor or knockdown of RICTOR partially rescued UVB-induced NF-κB activation through the downregulation of Akt/IKKα activity. Our data demonstrated the upregulation of mTORC2 pathway in intrinsic and photo-induced skin aging and its role in IKKα/NF-κB activation. These data not only expanded the functions of mTOR to skin aging but also revealed the therapeutic potential of inhibiting mTORC2 in ameliorating both intrinsic skin aging and photoaging. PMID:27486771

  14. Cognitive Evaluation Theory: The Effects of External Rewards on Intrinsic Motivation of Gifted Students.

    ERIC Educational Resources Information Center

    Rogers, Brenda T.

    1985-01-01

    E. Deci's cognitive evaluation theory, which suggests that external rewards undermine intrinsic interest in an activity, is applied to the decline of instrinsic motivation in gifted students. Implications for feedback, rewards, and teacher role are noted. (CL)

  15. Explorations in achievement motivation

    NASA Technical Reports Server (NTRS)

    Helmreich, Robert L.

    1982-01-01

    Recent research on the nature of achievement motivation is reviewed. A three-factor model of intrinsic motives is presented and related to various criteria of performance, job satisfaction and leisure activities. The relationships between intrinsic and extrinsic motives are discussed. Needed areas for future research are described.

  16. Unstructured Cartesian refinement with sharp interface immersed boundary method for 3D unsteady incompressible flows

    NASA Astrophysics Data System (ADS)

    Angelidis, Dionysios; Chawdhary, Saurabh; Sotiropoulos, Fotis

    2016-11-01

    A novel numerical method is developed for solving the 3D, unsteady, incompressible Navier-Stokes equations on locally refined fully unstructured Cartesian grids in domains with arbitrarily complex immersed boundaries. Owing to the utilization of the fractional step method on an unstructured Cartesian hybrid staggered/non-staggered grid layout, flux mismatch and pressure discontinuity issues are avoided and the divergence free constraint is inherently satisfied to machine zero. Auxiliary/hanging nodes are used to facilitate the discretization of the governing equations. The second-order accuracy of the solver is ensured by using multi-dimension Lagrange interpolation operators and appropriate differencing schemes at the interface of regions with different levels of refinement. The sharp interface immersed boundary method is augmented with local near-boundary refinement to handle arbitrarily complex boundaries. The discrete momentum equation is solved with the matrix free Newton-Krylov method and the Krylov-subspace method is employed to solve the Poisson equation. The second-order accuracy of the proposed method on unstructured Cartesian grids is demonstrated by solving the Poisson equation with a known analytical solution. A number of three-dimensional laminar flow simulations of increasing complexity illustrate the ability of the method to handle flows across a range of Reynolds numbers and flow regimes. Laminar steady and unsteady flows past a sphere and the oblique vortex shedding from a circular cylinder mounted between two end walls demonstrate the accuracy, the efficiency and the smooth transition of scales and coherent structures across refinement levels. Large-eddy simulation (LES) past a miniature wind turbine rotor, parameterized using the actuator line approach, indicates the ability of the fully unstructured solver to simulate complex turbulent flows. Finally, a geometry resolving LES of turbulent flow past a complete hydrokinetic turbine illustrates the potential of the method to simulate turbulent flows past geometrically complex bodies on locally refined meshes. In all the cases, the results are found to be in very good agreement with published data and savings in computational resources are achieved.

  17. An implicit higher-order spatially accurate scheme for solving time dependent flows on unstructured meshes

    NASA Astrophysics Data System (ADS)

    Tomaro, Robert F.

    1998-07-01

    The present research is aimed at developing a higher-order, spatially accurate scheme for both steady and unsteady flow simulations using unstructured meshes. The resulting scheme must work on a variety of general problems to ensure the creation of a flexible, reliable and accurate aerodynamic analysis tool. To calculate the flow around complex configurations, unstructured grids and the associated flow solvers have been developed. Efficient simulations require the minimum use of computer memory and computational times. Unstructured flow solvers typically require more computer memory than a structured flow solver due to the indirect addressing of the cells. The approach taken in the present research was to modify an existing three-dimensional unstructured flow solver to first decrease the computational time required for a solution and then to increase the spatial accuracy. The terms required to simulate flow involving non-stationary grids were also implemented. First, an implicit solution algorithm was implemented to replace the existing explicit procedure. Several test cases, including internal and external, inviscid and viscous, two-dimensional, three-dimensional and axi-symmetric problems, were simulated for comparison between the explicit and implicit solution procedures. The increased efficiency and robustness of modified code due to the implicit algorithm was demonstrated. Two unsteady test cases, a plunging airfoil and a wing undergoing bending and torsion, were simulated using the implicit algorithm modified to include the terms required for a moving and/or deforming grid. Secondly, a higher than second-order spatially accurate scheme was developed and implemented into the baseline code. Third- and fourth-order spatially accurate schemes were implemented and tested. The original dissipation was modified to include higher-order terms and modified near shock waves to limit pre- and post-shock oscillations. The unsteady cases were repeated using the higher-order spatially accurate code. The new solutions were compared with those obtained using the second-order spatially accurate scheme. Finally, the increased efficiency of using an implicit solution algorithm in a production Computational Fluid Dynamics flow solver was demonstrated for steady and unsteady flows. A third- and fourth-order spatially accurate scheme has been implemented creating a basis for a state-of-the-art aerodynamic analysis tool.

  18. Performance tests of a large volume cerium tribromide (CeBr3) scintillation detector.

    PubMed

    Naqvi, A A; Khiari, F Z; Liadi, F A; Khateeb-Ur-Rehman; Isab, A A

    2016-08-01

    The response of a large cylindrical 76mm×76mm (height×diameter) cerium tribromide (CeBr3) detector was measured for prompt gamma rays. The total intrinsic activity of the CeBr3 detector, which was measured over 0.33-3.33MeV range, was found to be 0.022±0.001 counts/s/cm(3). The partial intrinsic activity ( due to (227)Ac contamination), was measured over a energy range of 1.22-2.20MeV energy, was found to be 0.007±0.001 counts/s/cm(3). Compared to intrinsic activities of LaBr3:Ce and LaCl3:Ce detectors of equivalent volume, the CeBr3 detector has 7-8 times less total intrinsic activity. The detector response for low energy prompt gamma rays was measured over 0.3-0.6MeVgamma energy range using a portable neutron generator-based Prompt Gamma Neutron Activation Analysis (PGNAA) setup. The experimental yield of boron, cadmium and mercury prompt gamma-rays was measured from water samples contaminated with 0.75-2.5wt% mercury, 0.31-2.50wt% boron, and 0.0625-0.500wt% cadmium, respectively. An excellent agreement has been observed between the calculated and experimental yields of the gamma rays. Also minimum detection limit (MDC) of the CeBr3 detector was measured for boron, cadmium and mercury samples. The CeBr3 detector has 23% smaller value of MDCB and 18% larger value of MDCCd than those of a LaBr3:Ce detector of equivalent size. This study has shown that CeBr3 detector has an excellent response for the low energy prompt gamma-rays with almost an order of magnitude low intrinsic activity as compared to LaCl3:Ce and LaBr3:Ce detectors of equivalent volume. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Validation of a Simulation Model of Intrinsic Lutetium-176 Activity in LSO-Based Preclinical PET Systems

    NASA Astrophysics Data System (ADS)

    McIntosh, Bryan

    The LSO scintillator crystal commonly used in PET scanners contains a low level of intrinsic radioactivity due to a small amount of Lu-176. This is not usually a concern in routine scanning but can become an issue in small animal imaging, especially when imaging low tracer activity levels. Previously there had been no systematic validation of simulations of this activity; this thesis discusses the validation of a GATE model of intrinsic Lu-176 against results from a bench-top pair of detectors and a Siemens Inveon preclinical PET system. The simulation results matched those from the bench-top system very well, but did not agree as well with results from the complete Inveon system due to a drop-off in system sensitivity at low energies that was not modelled. With this validation the model can now be used with confidence to predict the effects of Lu-176 activity in future PET systems.

  20. Physiological regulation of magnocellular neurosecretory cell activity: Integration of intrinsic, local and afferent mechanisms

    PubMed Central

    Brown, Colin H.; Bains, Jaideep S.; Ludwig, Mike; Stern, Javier E.

    2013-01-01

    The hypothalamic supraoptic and paraventricular nucleus contain magnocellular neurosecretory cells (MNCs) that project to the posterior pituitary gland where they secrete either oxytocin or vasopressin (the anti-diuretic hormone) into the circulation. Oxytocin is important for delivery at birth and is essential for milk ejection during suckling. Vasopressin primarily promotes water reabsorption in the kidney to maintain body fluid balance, but also increases vasoconstriction. The profile of oxytocin and vasopressin secretion is principally determined by the pattern of action potentials initiated at the cell bodies. While it has long been known that the activity of MNCs depends upon afferent inputs that relay information on reproductive, osmotic and cardiovascular status, it has recently become clear that activity depends critically on local regulation by glial cells, as well as intrinsic regulation by the MNCs themselves. Here, we provide an overview of recent advances in our understanding of how intrinsic and local extrinsic mechanisms integrate with afferent inputs to generate appropriate physiological regulation of oxytocin and vasopressin MNC activity. PMID:23701531

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