Students' Understanding on Newton's Third Law in Identifying the Reaction Force in Gravity Interactions

ERIC Educational Resources Information Center

Zhou, Shaona; Zhang, Chunbin; Xiao, Hua

2015-01-01

In the past three decades, previous researches showed that students had various misconceptions of Newton's Third Law. The present study focused on students' difficulties in identifying the third-law force pair in gravity interaction situations. An instrument involving contexts with gravity and non-gravity associated interactions was designed and…

The Straightforwardness of Advice: Advice-Giving in Interactions Between Swedish District Nurses and Patients.

ERIC Educational Resources Information Center

Leppanen, Vesa

1998-01-01

A study examined advice-giving interactions between Swedish district nurses and patients, comparing these sequences with parallel interactions between British health visitors and first-time mothers in previous research. Analysis focused on how advice-giving is organized in the settings, including how advice is initiated and designed, its…

Automated identification of protein-ligand interaction features using Inductive Logic Programming: a hexose binding case study.

PubMed

A Santos, Jose C; Nassif, Houssam; Page, David; Muggleton, Stephen H; E Sternberg, Michael J

2012-07-11

There is a need for automated methods to learn general features of the interactions of a ligand class with its diverse set of protein receptors. An appropriate machine learning approach is Inductive Logic Programming (ILP), which automatically generates comprehensible rules in addition to prediction. The development of ILP systems which can learn rules of the complexity required for studies on protein structure remains a challenge. In this work we use a new ILP system, ProGolem, and demonstrate its performance on learning features of hexose-protein interactions. The rules induced by ProGolem detect interactions mediated by aromatics and by planar-polar residues, in addition to less common features such as the aromatic sandwich. The rules also reveal a previously unreported dependency for residues cys and leu. They also specify interactions involving aromatic and hydrogen bonding residues. This paper shows that Inductive Logic Programming implemented in ProGolem can derive rules giving structural features of protein/ligand interactions. Several of these rules are consistent with descriptions in the literature. In addition to confirming literature results, ProGolem's model has a 10-fold cross-validated predictive accuracy that is superior, at the 95% confidence level, to another ILP system previously used to study protein/hexose interactions and is comparable with state-of-the-art statistical learners.

Decoding directional genetic dependencies through orthogonal CRISPR/Cas screens | Office of Cancer Genomics

Cancer.gov

Genetic interaction studies are a powerful approach to identify functional interactions between genes. This approach can reveal networks of regulatory hubs and connect uncharacterized genes to well-studied pathways. However, this approach has previously been limited to simple gene inactivation studies. Here, we present an orthogonal CRISPR/Cas-mediated genetic interaction approach that allows the systematic activation of one gene while simultaneously knocking out a second gene in the same cell.

Enhancing Interactive Tutorial Effectiveness through Visual Cueing

ERIC Educational Resources Information Center

Jamet, Eric; Fernandez, Jonathan

2016-01-01

The present study investigated whether learning how to use a web service with an interactive tutorial can be enhanced by cueing. We expected the attentional guidance provided by visual cues to facilitate the selection of information in static screen displays that corresponded to spoken explanations. Unlike most previous studies in this area, we…

The Effects of Website Information Utility on the Outcomes of User-Website Interactions

ERIC Educational Resources Information Center

Hasley, Joseph Paul

2010-01-01

This study investigates the relationships between website information content utility and various outcomes of user interactions with e-tail websites. Although previous research has consistently identified high quality information content as a critical factor of successful e-commerce websites, those studies have not reported how to identify the…

Early Childhood Family Structure and Mother-Child Interactions: Variation by Race and Ethnicity

ERIC Educational Resources Information Center

Gibson-Davis, Christina M.; Gassman-Pines, Anna

2010-01-01

With data from the Early Childhood Longitudinal Study-Birth Cohort (n = 6,449), a nationally representative sample of births in 2001, we used hierarchical linear modeling to analyze differences in observed interactions between married, cohabiting, never-married, and divorced mothers and their children. In contrast to previous studies, we…

Temperament Clusters and Individual Differences in the Elementary Classroom: A Summary.

ERIC Educational Resources Information Center

Barclay, James R.

This study examines the interaction of individual differences in pupils' temperament and ability with variations in educational strategies used in elementary school classrooms. This interaction was analyzed by re-examining the data from 2 previous studies of the effects of various educational strategies on social and academic behavior problems.…

Context Matters: Increasing Understanding with Interactive Clicker Case Studies

ERIC Educational Resources Information Center

Lundeberg, Mary A.; Kang, Hosun; Wolter, Bjorn; delMas, Robert; Armstrong, Norris; Borsari, Bruno; Boury, Nancy; Brickman, Peggy; Hannam, Kristi; Heinz, Cheryl; Horvath, Thomas; Knabb, Maureen; Platt, Terry; Rice, Nancy; Rogers, Bill; Sharp, Joan; Ribbens, Eric; Maier, Kimberly S.; Deschryver, Mike; Hagley, Rodney; Goulet, Tamar; Herreid, Clyde F.

2011-01-01

Although interactive technology is presumed to increase student understanding in large classes, no previous research studies have empirically explored the effects of Clicker Cases on students' performance. A Clicker Case is a story (e.g., a problem someone is facing) that uses clickers (student response systems) to engage students in understanding…

The Human Performance Envelope: Past Research, Present Activities and Future Directions

NASA Technical Reports Server (NTRS)

Edwards, Tamsyn

2017-01-01

Air traffic controllers (ATCOs) must maintain a consistently high level of human performance in order to maintain flight safety and efficiency. In current control environments, performance-influencing factors such as workload, fatigue and situation awareness can co-occur, and interact, to effect performance. However, multifactor influences and the association with performance are under-researched. This study utilized a high fidelity human in the loop enroute air traffic control simulation to investigate the relationship between workload, situation awareness and ATCO performance. The study aimed to replicate and extend Edwards, Sharples, Wilson and Kirwans (2012) previous study and confirm multifactor interactions with a participant sample of ex-controllers. The study also aimed to extend Edwards et als previous research by comparing multifactor relationships across 4 automation conditions. Results suggest that workload and SA may interact to produce a cumulative impact on controller performance, although the effect of the interaction on performance may be dependent on the context and amount of automation present. Findings have implications for human-automation teaming in air traffic control, and the potential prediction and support of ATCO performance.

The protein interaction map of bacteriophage lambda

PubMed Central

2011-01-01

Background Bacteriophage lambda is a model phage for most other dsDNA phages and has been studied for over 60 years. Although it is probably the best-characterized phage there are still about 20 poorly understood open reading frames in its 48-kb genome. For a complete understanding we need to know all interactions among its proteins. We have manually curated the lambda literature and compiled a total of 33 interactions that have been found among lambda proteins. We set out to find out how many protein-protein interactions remain to be found in this phage. Results In order to map lambda's interactions, we have cloned 68 out of 73 lambda open reading frames (the "ORFeome") into Gateway vectors and systematically tested all proteins for interactions using exhaustive array-based yeast two-hybrid screens. These screens identified 97 interactions. We found 16 out of 30 previously published interactions (53%). We have also found at least 18 new plausible interactions among functionally related proteins. All previously found and new interactions are combined into structural and network models of phage lambda. Conclusions Phage lambda serves as a benchmark for future studies of protein interactions among phage, viruses in general, or large protein assemblies. We conclude that we could not find all the known interactions because they require chaperones, post-translational modifications, or multiple proteins for their interactions. The lambda protein network connects 12 proteins of unknown function with well characterized proteins, which should shed light on the functional associations of these uncharacterized proteins. PMID:21943085

The Complexity of School Racial Climate: Reliability and Validity of a New Measure for Secondary Students

ERIC Educational Resources Information Center

Byrd, Christy M.

2017-01-01

Background: The conceptualization of the role of race and culture in students' experience of school has been limited. This study presents a more comprehensive and multidimensional framework than previously conceptualized and includes the two domains of (1) intergroup interactions (frequency of interaction, quality of interaction, equal status, and…

Fires following bark beetles: Factors controlling severity and disturbance interactions in ponderosa pine

Treesearch

Carolyn H. Sieg; Rodman R. Linn; Francois Pimont; Chad M. Hoffman; Joel D. McMillin; Judith Winterkamp; L. Scott Baggett

2017-01-01

Previous studies have suggested that bark beetles and fires can be interacting disturbances, whereby bark beetle-caused tree mortality can alter the risk and severity of subsequent wildland fires. However, there remains considerable uncertainty around the type and magnitude of the interaction between fires following bark beetle attacks, especially in drier forest types...

Oligomerization affects the kinetics and thermodynamics of the interaction of a Bowman-Birk inhibitor with proteases.

PubMed

Brand, G D; Pires, D A T; Furtado, J R; Cooper, A; Freitas, S M; Bloch, C

2017-03-15

The black-eyed pea trypsin/chymotrypsin inhibitor (BTCI) forms concentration dependent homomultimers, as previously demonstrated by Light scattering and Atomic Force Microscopy. Considering that these self-aggregates might influence their binding to cognate enzymes, we investigated the interaction of BTCI at picomolar concentrations using surface immobilized Chymotrypsin (α-CT) and Trypsin (T) by Surface Plasmon Resonance. Our results indicate that BTCI has subnanomolar affinity to both immobilized enzymes, which is approximately two orders of magnitude higher than previously reported. Moreover, we probed the influence of temperature on protein binding equilibria in order to investigate their interaction energetics. While the BTCI/T interaction concurs with the canonical entropy-driven mechanism described for BBI interactions with serine proteinases, the BTCI/α-CT interaction does not. Our measurements indicate that bimolecular BTCI/α-CT complexes form with a negative enthalpy change and a moderate entropic increase. Direct calorimetric evaluation is in accord with the van't Hoff approximation obtained by SPR. We demonstrate that as protein concentrations increase to the micromolar range, secondary endothermic events become prevalent and affect both the kinetics and thermodynamics of protein associations. Our study reinforces that BBI interactions with serine proteinases should be studied in dilute solutions to abridge often neglected secondary interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

Insights into the Nature of Anesthetic-Protein Interactions: An ONIOM Study.

PubMed

Qiu, Ling; Lin, Jianguo; Bertaccini, Edward J

2015-10-08

Anesthetics have been employed widely to relieve surgical suffering, but their mechanism of action is not yet clear. For over a century, the mechanism of anesthesia was previously thought to be via lipid bilayer interactions. In the present work, a rigorous three-layer ONIOM(M06-2X/6-31+G*:PM6:AMBER) method was utilized to investigate the nature of interactions between several anesthetics and actual protein binding sites. According to the calculated structural features, interaction energies, atomic charges, and electrostatic potential surfaces, the amphiphilic nature of anesthetic-protein interactions was demonstrated for both inhalational and injectable anesthetics. The existence of hydrogen and halogen bonding interactions between anesthetics and proteins was clearly identified, and these interactions served to assist ligand recognition and binding by the protein. Within all complexes of inhalational or injectable anesthetics, the polarization effects play a dominant role over the steric effects and induce a significant asymmetry in the otherwise symmetric atomic charge distributions of the free ligands in vacuo. This study provides new insight into the mechanism of action of general anesthetics in a more rigorous way than previously described. Future rational design of safer anesthetics for an aging and more physiologically vulnerable population will be predicated on this greater understanding of such specific interactions.

Hamaker constants of iron oxide nanoparticles.

PubMed

Faure, Bertrand; Salazar-Alvarez, German; Bergström, Lennart

2011-07-19

The Hamaker constants for iron oxide nanoparticles in various media have been calculated using Lifshitz theory. Expressions for the dielectric responses of three iron oxide phases (magnetite, maghemite, and hematite) were derived from recently published optical data. The nonretarded Hamaker constants for the iron oxide nanoparticles interacting across water, A(1w1) = 33 - 39 zJ, correlate relatively well with previous reports, whereas the calculated values in nonpolar solvents (hexane and toluene), A(131) = 9 - 29 zJ, are much lower than the previous estimates, particularly for magnetite. The magnitude of van der Waals interactions varies significantly between the studied phases (magnetite < maghemite < hematite), which highlights the importance of a thorough characterization of the particles. The contribution of magnetic dispersion interactions for particle sizes in the superparamagnetic regime was found to be negligible. Previous conjectures related to colloidal stability and self-assembly have been revisited on the basis of the new Lifshitz values of the Hamaker constants.

Defining the human deubiquitinating enzyme interaction landscape.

PubMed

Sowa, Mathew E; Bennett, Eric J; Gygi, Steven P; Harper, J Wade

2009-07-23

Deubiquitinating enzymes (Dubs) function to remove covalently attached ubiquitin from proteins, thereby controlling substrate activity and/or abundance. For most Dubs, their functions, targets, and regulation are poorly understood. To systematically investigate Dub function, we initiated a global proteomic analysis of Dubs and their associated protein complexes. This was accomplished through the development of a software platform called CompPASS, which uses unbiased metrics to assign confidence measurements to interactions from parallel nonreciprocal proteomic data sets. We identified 774 candidate interacting proteins associated with 75 Dubs. Using Gene Ontology, interactome topology classification, subcellular localization, and functional studies, we link Dubs to diverse processes, including protein turnover, transcription, RNA processing, DNA damage, and endoplasmic reticulum-associated degradation. This work provides the first glimpse into the Dub interaction landscape, places previously unstudied Dubs within putative biological pathways, and identifies previously unknown interactions and protein complexes involved in this increasingly important arm of the ubiquitin-proteasome pathway.

Defining the Human Deubiquitinating Enzyme Interaction Landscape

PubMed Central

Sowa, Mathew E.; Bennett, Eric J.; Gygi, Steven P.; Harper, J. Wade

2009-01-01

Summary Deubiquitinating enzymes (Dubs) function to remove covalently attached ubiquitin from proteins, thereby controlling substrate activity and/or abundance. For most Dubs, their functions, targets, and regulation are poorly understood. To systematically investigate Dub function, we initiated a global proteomic analysis of Dubs and their associated protein complexes. This was accomplished through the development of a software platform, called CompPASS, which uses unbiased metrics to assign confidence measurements to interactions from parallel non-reciprocal proteomic datasets. We identified 774 candidate interacting proteins associated with 75 Dubs. Using Gene Ontology, interactome topology classification, sub-cellular localization and functional studies, we link Dubs to diverse processes, including protein turnover, transcription, RNA processing, DNA damage, and endoplasmic reticulum-associated degradation. This work provides the first glimpse into the Dub interaction landscape, places previously unstudied Dubs within putative biological pathways, and identifies previously unknown interactions and protein complexes involved in this increasingly important arm of the ubiquitin-proteasome pathway. PMID:19615732

Interphyletic relationships in the use of nesting cavities: mutualism, competition and amensalism among hymenopterans and vertebrates

NASA Astrophysics Data System (ADS)

Veiga, José P.; Wamiti, Wanyoike; Polo, Vicente; Muchai, Muchane

2013-09-01

Although competition is usually assumed to be the most common interaction between closely related organisms that share limiting resources, the relationships linking distant taxa that use the same nesting sites are poorly understood. In the present study, we examine the interactions among social hymenopterans (honeybees and wasps) and vertebrates in tropical ecosystems of East Africa. By analysing the preferences of these three groups for nest boxes that were empty or previously occupied by a different taxon, we try to establish whether the relationships among them are commensal, mutualistic, competitive or amensal. Vertebrates and honeybees selected nest boxes that had previously been occupied by the other, which suggests that each obtains some benefit from the other. This relationship can be considered mutualistic, although a mutual preference for each others' nests does not exclude a competitive interaction. Vertebrates and wasps preferred nest boxes not previously occupied by the other, which suggests that they compete for tree cavities. Finally, wasps seemed to completely refuse cavities previously used by honeybees, while the bees occupied cavities regardless of whether they had been previously used by wasps, an apparently amensal relationship. These results indicate that the interdependence between distantly related taxa is stronger and more complex than previously described, which may have important implications for population dynamics and community structure.

Vortex/boundary layer interactions

NASA Technical Reports Server (NTRS)

Cutler, A. D.; Bradshaw, P.

1989-01-01

Detailed and high quality measurements with hot-wires and pressure probes are presented for two different interactions between a vortex pair with common flow down and a turbulent boundary layer. The interactions studied have larger values of the vortex circulation parameter than those studied previously. The results indicate that the boundary layer under the vortex pair is thinned by lateral divergence and that boundary layer fluid is entrained into the vortex. The effect of the interaction on the vortex core (other than the inviscid effect of the image vortices behind the surface) is small.

Network topological analysis reveals the functional cohesiveness for the newly discovered links by Yeast 2 Hybrid approach

NASA Astrophysics Data System (ADS)

Ghiassian, Susan; Pevzner, Sam; Rolland, Thomas; Tassan, Murat; Barabasi, Albert Laszlo; Vidal, Mark; CCNR, Northeastern University Collaboration; Dana Farber Cancer Institute Collaboration

2014-03-01

Protein-protein interaction maps and interactomes are the blueprint of Network Medicine and systems biology and are being experimentally studied by different groups. Despite the wide usage of Literature Curated Interactome (LCI), these sources are biased towards different parameters such as highly studied proteins. Yeast two hybrid method is a high throughput experimental setup which screens proteins in an unbiased fashion. Current knowledge of protein interactions is far from complete. In fact the previous offered data from Y2H method (2005), is estimated to offer only 5% of all potential protein interactions. Currently this coverage has increased to 20% of what is known as reference HI In this work we study the topological properties of Y2H protein-protein interactions network with LCI and show although they both agree on some properties, LCI shows a clear unbiased nature of interaction selections. Most importantly, we assess the properties of PPI as it evolves with increasing the coverage. We show that, the newly discovered interactions tend to connect proteins that have been closer than average in the previous PPI release. reinforcing the modular structure of PPI. Furthermore, we show, some unseen effects on PPI (as opposed to LCI) can be explained by its incompleteness.

Designing algorithm visualization on mobile platform: The proposed guidelines

NASA Astrophysics Data System (ADS)

Supli, A. A.; Shiratuddin, N.

2017-09-01

This paper entails an ongoing study about the design guidelines of algorithm visualization (AV) on mobile platform, helping students learning data structures and algorithm (DSA) subject effectively. Our previous review indicated that design guidelines of AV on mobile platform are still few. Mostly, previous guidelines of AV are developed for AV on desktop and website platform. In fact, mobile learning has been proved to enhance engagement in learning circumstances, and thus effect student's performance. In addition, the researchers highly recommend including UI design and Interactivity in designing effective AV system. However, the discussions of these two aspects in previous AV design guidelines are not comprehensive. The UI design in this paper describes the arrangement of AV features in mobile environment, whereas interactivity is about the active learning strategy features based on learning experiences (how to engage learners). Thus, this study main objective is to propose design guidelines of AV on mobile platform (AVOMP) that entails comprehensively UI design and interactivity aspects. These guidelines are developed through content analysis and comparative analysis from various related studies. These guidelines are useful for AV designers to help them constructing AVOMP for various topics on DSA.

Automated identification of protein-ligand interaction features using Inductive Logic Programming: a hexose binding case study

PubMed Central

2012-01-01

Background There is a need for automated methods to learn general features of the interactions of a ligand class with its diverse set of protein receptors. An appropriate machine learning approach is Inductive Logic Programming (ILP), which automatically generates comprehensible rules in addition to prediction. The development of ILP systems which can learn rules of the complexity required for studies on protein structure remains a challenge. In this work we use a new ILP system, ProGolem, and demonstrate its performance on learning features of hexose-protein interactions. Results The rules induced by ProGolem detect interactions mediated by aromatics and by planar-polar residues, in addition to less common features such as the aromatic sandwich. The rules also reveal a previously unreported dependency for residues cys and leu. They also specify interactions involving aromatic and hydrogen bonding residues. This paper shows that Inductive Logic Programming implemented in ProGolem can derive rules giving structural features of protein/ligand interactions. Several of these rules are consistent with descriptions in the literature. Conclusions In addition to confirming literature results, ProGolem’s model has a 10-fold cross-validated predictive accuracy that is superior, at the 95% confidence level, to another ILP system previously used to study protein/hexose interactions and is comparable with state-of-the-art statistical learners. PMID:22783946

The genetic interacting landscape of 63 candidate genes in Major Depressive Disorder: an explorative study.

PubMed

Lekman, Magnus; Hössjer, Ola; Andrews, Peter; Källberg, Henrik; Uvehag, Daniel; Charney, Dennis; Manji, Husseini; Rush, John A; McMahon, Francis J; Moore, Jason H; Kockum, Ingrid

2014-01-01

Genetic contributions to major depressive disorder (MDD) are thought to result from multiple genes interacting with each other. Different procedures have been proposed to detect such interactions. Which approach is best for explaining the risk of developing disease is unclear. This study sought to elucidate the genetic interaction landscape in candidate genes for MDD by conducting a SNP-SNP interaction analysis using an exhaustive search through 3,704 SNP-markers in 1,732 cases and 1,783 controls provided from the GAIN MDD study. We used three different methods to detect interactions, two logistic regressions models (multiplicative and additive) and one data mining and machine learning (MDR) approach. Although none of the interaction survived correction for multiple comparisons, the results provide important information for future genetic interaction studies in complex disorders. Among the 0.5% most significant observations, none had been reported previously for risk to MDD. Within this group of interactions, less than 0.03% would have been detectable based on main effect approach or an a priori algorithm. We evaluated correlations among the three different models and conclude that all three algorithms detected the same interactions to a low degree. Although the top interactions had a surprisingly large effect size for MDD (e.g. additive dominant model Puncorrected = 9.10E-9 with attributable proportion (AP) value = 0.58 and multiplicative recessive model with Puncorrected = 6.95E-5 with odds ratio (OR estimated from β3) value = 4.99) the area under the curve (AUC) estimates were low (< 0.54). Moreover, the population attributable fraction (PAF) estimates were also low (< 0.15). We conclude that the top interactions on their own did not explain much of the genetic variance of MDD. The different statistical interaction methods we used in the present study did not identify the same pairs of interacting markers. Genetic interaction studies may uncover previously unsuspected effects that could provide novel insights into MDD risk, but much larger sample sizes are needed before this strategy can be powerfully applied.

Ethnic status and engagement with health services: Attitudes toward help-seeking and intercultural willingness to interact among South East Asian students in Australia.

PubMed

Logan, Shanna; Steel, Zachary; Hunt, Caroline

2017-04-01

Previous research has demonstrated the importance of intercultural willingness to interact; however, these investigations have yet to be applied to a health context or to compare an ethnic minority with a majority sample. Consequently, the current study sought to better understand engagement with health services by investigating both attitudes towards seeking psychological help and intercultural willingness to interact within an ethnic minority South East Asian population, relative to an Anglo Australian sample. As predicted, negative attitudes towards seeking psychological help were higher in the South East Asian sample, with this relationship persisting across generations, despite significant differences in acculturation. In contrast, intercultural willingness to interact was not associated with ethnicity status but was associated with higher anxiety, uncertainty, ethnocentrism and help-seeking, consistent with current empirical and theoretical literature. The current study also sought to examine factors associated with help-seeking attitudes and found that ethnocentrism was a significant predictor, when accounting for previous health experience.

How do walkers behave when crossing the way of a mobile robot that replicates human interaction rules?

PubMed

Vassallo, Christian; Olivier, Anne-Hélène; Souères, Philippe; Crétual, Armel; Stasse, Olivier; Pettré, Julien

2018-02-01

Previous studies showed the existence of implicit interaction rules shared by human walkers when crossing each other. Especially, each walker contributes to the collision avoidance task and the crossing order, as set at the beginning, is preserved along the interaction. This order determines the adaptation strategy: the first arrived increases his/her advance by slightly accelerating and changing his/her heading, whereas the second one slows down and moves in the opposite direction. In this study, we analyzed the behavior of human walkers crossing the trajectory of a mobile robot that was programmed to reproduce this human avoidance strategy. In contrast with a previous study, which showed that humans mostly prefer to give the way to a non-reactive robot, we observed similar behaviors between human-human avoidance and human-robot avoidance when the robot replicates the human interaction rules. We discuss this result in relation with the importance of controlling robots in a human-like way in order to ease their cohabitation with humans. Copyright © 2017 Elsevier B.V. All rights reserved.

Framing matters: contextual influences on interracial interaction outcomes.

PubMed

Babbitt, Laura G; Sommers, Samuel R

2011-09-01

Previous studies indicate that interracial interactions frequently have negative outcomes but have typically focused on social contexts. The current studies examined the effect of manipulating interaction context. In Study 1, Black and White participants worked together with instructions that created either a social focus or a task focus. With a task focus, interracial pairs were more consistently synchronized, Black participants showed less executive function depletion, and White participants generally showed reduced implicit bias. Follow-up studies suggested that prejudice concerns help explain these findings: White participants reported fewer concerns about appearing prejudiced when they imagined an interracial interaction with a task focus rather than a social focus (Study 2a), and Black participants reported less vigilance against prejudice in an imagined interracial interaction with a task focus rather than a social focus (Study 2b). Taken together, these studies illustrate the importance of interaction context for the experiences of both Blacks and Whites.

Anxiogenic Patterns in Mother-Child Interactions

ERIC Educational Resources Information Center

Harvison, Kyle W.; Chapman, L. Kevin; Ballash, Natalie G.; Woodruff-Borden, Janet

2008-01-01

The current study examined psychosocial variables associated with the development of anxiety in children. While previous literature has established parental affectionless control as an important contributor to the development of anxiety in children, few have examined this construct within the dynamic context of parent-child interaction. In the…

Gene-by-Socioeconomic Status Interaction on School Readiness

PubMed Central

Rhemtulla, Mijke; Tucker-Drob, Elliot M.

2017-01-01

In previous work with a nationally representative sample of over 1,400 monozygotic and dizygotic twins born in the United States, Tucker-Drob, Rhemtulla, Harden, Turkheimer, and Fask (2011; Psychological Science, 22, 125–133) uncovered a gene × environment interaction on scores on the Bayley Short Form test of mental ability at 2 years of age—higher socioeconomic status (SES) was associated not only with higher mental ability, but also with larger genetic contributions to individual differences in mental ability. The current study examined gene × SES interactions in mathematics skill and reading skill at 4 years of age (preschool age) in the same sample of twins, and further examined whether interactions detected at 4 years could be attributed to the persistence of the interaction previously observed at 2 years. For early mathematics skill but not early reading skill, genetic influences were more pronounced at higher levels of SES. This interaction was not accounted for by the interaction observed at 2 years. These findings indicate that SES moderates the etiological influences on certain cognitive functions at multiple stages of child development. PMID:22350185

The Oncoprotein Tax Binds the SRC-1-Interacting Domain of CBP/p300 To Mediate Transcriptional Activation

PubMed Central

Scoggin, Kirsten E. S.; Ulloa, Aida; Nyborg, Jennifer K.

2001-01-01

Oncogenesis associated with human T-cell leukemia virus (HTLV) infection is directly linked to the virally encoded transcription factor Tax. To activate HTLV-1 transcription Tax interacts with the cellular protein CREB and the pleiotropic coactivators CBP and p300. While extensively studied, the molecular mechanisms of Tax transcription function and coactivator utilization are not fully understood. Previous studies have focused on Tax binding to the KIX domain of CBP, as this was believed to be the key step in recruiting the coactivator to the HTLV-1 promoter. In this study, we identify a carboxy-terminal region of CBP (and p300) that strongly interacts with Tax and mediates Tax transcription function. Through deletion mutagenesis, we identify amino acids 2003 to 2212 of CBP, which we call carboxy-terminal region 2 (CR2), as the minimal region for Tax interaction. Interestingly, this domain corresponds to the steroid receptor coactivator 1 (SRC-1)-interacting domain of CBP. We show that a double point mutant targeted to one of the putative α-helical motifs in this domain significantly compromises the interaction with Tax. We also characterize the region of Tax responsible for interaction with CR2 and show that the previously identified transactivation domain of Tax (amino acids 312 to 319) participates in CR2 binding. This region of Tax corresponds to a consensus amphipathic helix, and single point mutations targeted to amino acids on the face of this helix abolish interaction with CR2 and dramatically reduce Tax transcription function. Finally, we demonstrate that Tax and SRC-1 bind to CR2 in a mutually exclusive fashion. Together, these studies identify a novel Tax-interacting site on CBP/p300 and extend our understanding of the molecular mechanism of Tax transactivation. PMID:11463834

Design, Utility, and History of the Colorado Adoption Project: Examples Involving Adjustment Interactions1

PubMed Central

Rhea, Sally Ann; Bricker, Josh B.; Corley, Robin P.; DeFries, John C.; Wadsworth, Sally J.

2013-01-01

This paper describes the Colorado Adoption Project (CAP), a longitudinal study in behavioral development, and discusses how adoption studies may be used to assess genetic and environmental etiologies of individual differences for important developmental outcomes. Previous CAP research on adjustment outcomes in childhood and adolescence which found significant interactions, including gene-environment interactions, is reviewed. New research suggests mediating effects of menarche and religiosity on age at first sex in this predominantly middle-class, Caucasian sample. PMID:23833552

The Interaction of Child-Parent Shared Reading with an Augmented Reality (AR) Picture Book and Parents' Conceptions of AR Learning

ERIC Educational Resources Information Center

Cheng, Kun-Hung; Tsai, Chin-Chung

2016-01-01

Following a previous study (Cheng & Tsai, 2014. "Computers & Education"), this study aimed to probe the interaction of child-parent shared reading with the augmented reality (AR) picture book in more depth. A series of sequential analyses were thus conducted to infer the behavioral transition diagrams and visualize the continuity…

Factors Mediating the Interactions between Adviser and Advisee during the Master's Thesis Project: A Quantitative Approach

ERIC Educational Resources Information Center

Rodrigues Jr., Jose Florencio; Lehmann, Angela Valeria Levay; Fleith, Denise De Souza

2005-01-01

Building on previous studies centred on the interaction between adviser and advisee in masters thesis projects, in which a qualitative approach was used, the present study uses factor analysis to identify the factors that determine either a successful or unsuccessful outcome for the masters thesis project. There were five factors relating to the…

The ABCA1 domain responsible for interaction with HIV-1 Nef is conformational and not linear

PubMed Central

Jacob, Daria; Hunegnaw, Ruth; Sabyrzyanova, Tatyana A.; Pushkarsky, Tatiana; Chekhov, Vladimir O.; Adzhubei, Alexei A.; Kalebina, Tatyana S.; Bukrinsky, Michael

2014-01-01

HIV-1 Nef is an accessory protein responsible for inactivation of a number of host cell proteins essential for anti-viral immune responses. In most cases, Nef binds to the target protein and directs it to a degradation pathway. Our previous studies demonstrated that Nef impairs activity of the cellular cholesterol transporter, ABCA1, and that Nef interacts with ABCA1. Mutation of the 2226DDDHLK motif in the C-terminal cytoplasmic tail of ABCA1 disrupted interaction with Nef. Here, we tested Nef interaction with the ABCA1 C-terminal cytoplasmic fragment using yeast 2-hybrid system assay and co-immunoprecipitation analysis in human cells. Surprisingly, analysis in a yeast 2-hybrid system did not reveal any interaction between Nef and the C-terminal cytoplasmic fragment of ABCA1. Using coimmunoprecipitation from HEK 293T cells expressing these polypeptides, only a very weak interaction could be detected. The 2226DDDHLK motif in the C-terminal cytoplasmic tail of ABCA1 found previously to be essential for interaction between ABCA1 and Nef is insufficient to bestow strong binding to Nef. Molecular modeling suggested that interaction with Nef may be mediated by a conformational epitope composed of the sequences within the cytoplasmic loop of ABCA1 and the C-terminal cytoplasmic domain. Studies are now underway to characterize this epitope. PMID:24406162

Mental exercising through simple socializing: social interaction promotes general cognitive functioning.

PubMed

Ybarra, Oscar; Burnstein, Eugene; Winkielman, Piotr; Keller, Matthew C; Manis, Melvin; Chan, Emily; Rodriguez, Joel

2008-02-01

Social interaction is a central feature of people's life and engages a variety of cognitive resources. Thus, social interaction should facilitate general cognitive functioning. Previous studies suggest such a link, but they used special populations (e.g., elderly with cognitive impairment), measured social interaction indirectly (e.g., via marital status), and only assessed effects of extended interaction in correlational designs. Here the relation between mental functioning and direct indicators of social interaction was examined in a younger and healthier population. Study 1 using survey methodology found a positive relationship between social interaction, assessed via amount of actual social contact, and cognitive functioning in people from three age groups including younger adults. Study 2 using an experimental design found that a small amount of social interaction (10 min) can facilitate cognitive performance. The findings are discussed in the context of the benefits social relationships have for so many aspects of people's lives.

The Use of Memories in Understanding Interactive Science and Technology Exhibits

ERIC Educational Resources Information Center

Afonso, Ana S.; Gilbert, John K.

2006-01-01

Framed by a "personal constructivist" perspective, this study analyses visitors' use of spontaneous memories in understanding different types of interactive exhibits, the nature and sources of the retrieved memories, and the way that visitors relate an exhibit analogically to memories of previous exhibits. One hundred and thirteen…

Toward an Understanding of How Threads Die in Asynchronous Computer Conferences

ERIC Educational Resources Information Center

Hewitt, Jim

2005-01-01

Previous computer conferencing research has been concerned with the organizational, technical, social, and motivational factors that support and sustain online interaction. This article studies online interaction from a different perspective. Rather than analyze the processes that sustain discourse, the following research examines how and why…

Effects of structure on the interactions between five natural antimicrobial compounds and phospholipids of bacterial cell membrane on model monolayers

USDA-ARS?s Scientific Manuscript database

Monolayers composed of bacterial phospholipids were used as model membranes to study interactions of naturally occurring phenolic compounds 2,5-dihydroxybenzaldehyde, 2-hydroxy-5-methoxybenzaldehyde and the plant essential oil compounds carvacrol, cinnamaldehyde, and geraniol, previously found to be...

Computational study of the interplay between intermolecular interactions and CO2 orientations in type I hydrates.

PubMed

Pérez-Rodríguez, M; Vidal-Vidal, A; Míguez, J M; Blas, F J; Torré, J-P; Piñeiro, M M

2017-01-25

Carbon dioxide (CO 2 ) molecules show a rich orientation landscape when they are enclathrated in type I hydrates. Previous studies have described experimentally their preferential orientations, and some theoretical works have explained, but only partially, these experimental results. In the present paper, we use classical molecular dynamics and electronic density functional theory to advance in the theoretical description of CO 2 orientations within type I hydrates. Our results are fully compatible with those previously reported, both theoretical and experimental, the geometric shape of the cavities in hydrate being, and therefore, the steric constraints, responsible for some (but not all) preferential angles. In addition, our calculations also show that guest-guest interactions in neighbouring cages are a key factor to explain the remaining experimental angles. Besides the implication concerning equation of state hydrate modeling approximations, the conclusion is that these guest-guest interactions should not be neglected, contrary to the usual practice.

Facebook and MySpace: complement or substitute for face-to-face interaction?

PubMed

Kujath, Carlyne L

2011-01-01

Previous studies have claimed that social-networking sites are used as a substitute for face-to-face interaction, resulting in deteriorating relationship quality and decreased intimacy among its users. The present study hypothesized that this type of communication is not a substitute for face-to-face interaction; rather, that it is an extension of communication with face-to-face partners. A survey was administered to examine the use of Facebook and MySpace in this regard among 183 college students. The study confirmed that Facebook and MySpace do act as an extension of face-to-face interaction, but that some users do tend to rely on Facebook and MySpace for interpersonal communication more than face-to-face interaction.

Gene-environment interaction study for BMI reveals interactions between genetic factors and physical activity, alcohol consumption and socioeconomic status

PubMed Central

Karlsson, Torgny; Ek, Weronica E.

2017-01-01

Previous genome-wide association studies (GWAS) have identified hundreds of genetic loci to be associated with body mass index (BMI) and risk of obesity. Genetic effects can differ between individuals depending on lifestyle or environmental factors due to gene-environment interactions. In this study, we examine gene-environment interactions in 362,496 unrelated participants with Caucasian ancestry from the UK Biobank resource. A total of 94 BMI-associated SNPs, selected from a previous GWAS on BMI, were used to construct weighted genetic scores for BMI (GSBMI). Linear regression modeling was used to estimate the effect of gene-environment interactions on BMI for 131 lifestyle factors related to: dietary habits, smoking and alcohol consumption, physical activity, socioeconomic status, mental health, sleeping patterns, as well as female-specific factors such as menopause and childbirth. In total, 15 lifestyle factors were observed to interact with GSBMI, of which alcohol intake frequency, usual walking pace, and Townsend deprivation index, a measure of socioeconomic status, were all highly significant (p = 1.45*10−29, p = 3.83*10−26, p = 4.66*10−11, respectively). Interestingly, the frequency of alcohol consumption, rather than the total weekly amount resulted in a significant interaction. The FTO locus was the strongest single locus interacting with any of the lifestyle factors. However, 13 significant interactions were also observed after omitting the FTO locus from the genetic score. Our analyses indicate that many lifestyle factors modify the genetic effects on BMI with some groups of individuals having more than double the effect of the genetic score. However, the underlying causal mechanisms of gene-environmental interactions are difficult to deduce from cross-sectional data alone and controlled experiments are required to fully characterise the causal factors. PMID:28873402

Gγ recruitment system incorporating a novel signal amplification circuit to screen transient protein-protein interactions.

PubMed

Fukuda, Nobuo; Ishii, Jun; Kondo, Akihiko

2011-09-01

Weak and transient protein-protein interactions are associated with biological processes, but many are still undefined because of the difficulties in their identification. Here, we describe a redesigned method to screen transient protein-protein interactions by using a novel signal amplification circuit, which is incorporated into yeast to artificially magnify the signal responding to the interactions. This refined method is based on the previously established Gγ recruitment system, which utilizes yeast G-protein signaling and mating growth selection to screen interacting protein pairs. In the current study, to test the capability of our method, we chose mutants of the Z-domain derived from Staphylococcus aureus protein A as candidate proteins, and the Fc region of human IgG as the counterpart. By introduction of an artificial signal amplifier into the previous Gγ recruitment system, the signal transduction responding to transient interactions between Z-domain mutants and the Fc region with significantly low affinity (8.0 × 10(3) M(-1)) was successfully amplified in recombinant haploid yeast cells. As a result of zygosis with the opposite mating type of wild-type haploid cells, diploid colonies were vigorously and selectively generated on the screening plates, whereas our previous system rarely produced positive colonies. This new approach will be useful for exploring the numerous transient interactions that remain undefined because of the lack of powerful screening tools for their identification. © 2011 The Authors Journal compilation © 2011 FEBS.

Interaction between ALDH2*1*1 and DRD2/ANKK1 TaqI A1A1 genes may be associated with antisocial personality disorder not co-morbid with alcoholism.

PubMed

Lu, Ru-Band; Lee, Jia-Fu; Huang, San-Yuan; Lee, Sheng-Yu; Chang, Yun-Hsuan; Kuo, Po-Hsiu; Chen, Shiou-Lan; Chen, Shih-Heng; Chu, Chun-Hsien; Lin, Wei-Wen; Wu, Pei-Lin; Ko, Huei-Chen

2012-09-01

Previous studies on acetaldehyde dehydrogenase 2 (ALDH2) focused on drinking behavior or alcoholism because the ALDH2*2 allele protects against the risk of developing alcoholism. The mechanism provides that the ALDH2 gene's protective effect is also involved in dopamine metabolism. The interaction of the ALDH2 gene with neurotransmitters, such as dopamine, is suggested to be related to alcoholism. Because alcoholism is often co-morbid with antisocial personality disorder (ASPD), previous association studies on antisocial alcoholism cannot differentiate whether those genes relate to ASPD with alcoholism or ASPD only. This study examined the influence of the interaction effect of the ALDH2*1*1, *1*2 or *2*2 polymorphisms with the dopamine 2 receptor (DRD2) Taq I polymorphism on ASPD. Our 541 Han Chinese male participants were classified into three groups: antisocial alcoholism (ASPD co-morbid with alcohol dependence, antisocial ALC; n = 133), ASPD without alcoholism (ASPD not co-morbid with alcohol dependence, antisocial non-ALC; n = 164) and community controls (healthy volunteers from the community; n = 244). Compared with healthy controls, individuals with the DRD2 A1/A1 and the ALDH2*1/*1 genotypes were at a 5.39 times greater risk for antisocial non-ALC than were those with other genotypes. Our results suggest that the DRD2/ANKK1 and ALDH2 genes interacted in the antisocial non-ALC group; a connection neglected in previous studies caused by not separating antisocial ALC from ASPD. Our study made this distinction and showed that these two genes may be associated ASPD without co-morbid alcoholism. © 2010 The Authors, Addiction Biology © 2010 Society for the Study of Addiction.

Artifact interactions retard technological improvement: An empirical study

PubMed Central

Magee, Christopher L.

2017-01-01

Empirical research has shown performance improvement of many different technological domains occurs exponentially but with widely varying improvement rates. What causes some technologies to improve faster than others do? Previous quantitative modeling research has identified artifact interactions, where a design change in one component influences others, as an important determinant of improvement rates. The models predict that improvement rate for a domain is proportional to the inverse of the domain’s interaction parameter. However, no empirical research has previously studied and tested the dependence of improvement rates on artifact interactions. A challenge to testing the dependence is that any method for measuring interactions has to be applicable to a wide variety of technologies. Here we propose a novel patent-based method that is both technology domain-agnostic and less costly than alternative methods. We use textual content from patent sets in 27 domains to find the influence of interactions on improvement rates. Qualitative analysis identified six specific keywords that signal artifact interactions. Patent sets from each domain were then examined to determine the total count of these 6 keywords in each domain, giving an estimate of artifact interactions in each domain. It is found that improvement rates are positively correlated with the inverse of the total count of keywords with Pearson correlation coefficient of +0.56 with a p-value of 0.002. The results agree with model predictions, and provide, for the first time, empirical evidence that artifact interactions have a retarding effect on improvement rates of technological domains. PMID:28777798

Posterior insular cortex - a site of vestibular-somatosensory interaction?

PubMed

Baier, Bernhard; Zu Eulenburg, Peter; Best, Christoph; Geber, Christian; Müller-Forell, Wibke; Birklein, Frank; Dieterich, Marianne

2013-09-01

Background In previous imaging studies the insular cortex (IC) has been identified as an essential part of the processing of a wide spectrum of perception and sensorimotor integration. Yet, there are no systematic lesion studies in a sufficient number of patients examining whether processing of vestibular and the interaction of somatosensory and vestibular signals take place in the IC. Methods We investigated acute stroke patients with lesions affecting the IC in order to fill this gap. In detail, we explored signs of a vestibular tone imbalance such as the deviation of the subjective visual vertical (SVV). We applied voxel-lesion behaviour mapping analysis in 27 patients with acute unilateral stroke. Results Our data demonstrate that patients with lesions of the posterior IC have an abnormal tilt of SVV. Furthermore, re-analysing data of 20 patients from a previous study, we found a positive correlation between thermal perception contralateral to the stroke and the severity of the SVV tilt. Conclusions We conclude that the IC is a sensory brain region where different modalities might interact.

Impact of Interactive Aerosol on the African Easterly Jet in the NASA GEOS-5 Global Forecasting System

NASA Technical Reports Server (NTRS)

Reale, O.; Lau, K. M.; da Silva, A.

2010-01-01

The real-time treatment of interactive realistically varying aerosol in a global operational forecasting system, as opposed to prescribed (fixed or climatologically varying) aerosols, is a very difficult challenge that only recently begins to be addressed. Experiment results from a recent version of the NASA GEOS-5 forecasting system, inclusive of interactive aerosol treatment, are presented in this work. Four sets of 30 5-day forecasts are initialized from a high quality set of analyses previously produced and documented to cover the period from 15 August to 16 September 2006, which corresponds to the NASA African Monsoon Multidisciplinary Analysis (NAMMA) observing campaign. The four forecast sets are at two different horizontal resolutions and with and without interactive aerosol treatment. The net impact of aerosol, at times in which there is a strong dust outbreak, is a temperature increase at the dust level and decrease in the near-surface levels, in complete agreement with previous observational and modeling studies. Moreover, forecasts in which interactive aerosols are included depict an African Easterly (AEJ) at slightly higher elevation, and slightly displace northward, with respect to the forecasts in which aerosols are not include. The shift in the AEJ position goes in the direction of observations and agrees with previous results.

Spherical solid model system: Exact evaluation of the van der Waals interaction between a microscopic or submacroscopic spherical solid and a deformable fluid interface

NASA Astrophysics Data System (ADS)

Wang, Y. Z.; Wang, B.; Xiong, X. M.; Zhang, J. X.

2011-03-01

In many previous research work associated with studying the deformation of the fluid interface interacting with a solid, the theoretical calculation of the surface energy density on the deformed fluid interface (or its interaction surface pressure) is often approximately obtained by using the expression for the interaction energy per unit area (or pressure) between two parallel macroscopic plates, e.g. σ(D) = - A / 12 πD2or π(D) = - A / 6 πD3for the van der Waals (vdW) interaction, through invoking the Derjaguin approximation (DA). This approximation however would result in over- or even inaccurate-prediction of the interaction force and the corresponding deformation of the fluid interface due to the invalidation of Derjaguin approximation in cases of microscopic or submacroscopic solids. To circumvent the above limitations existing in the previous DA-based theoretical work, a more accurate and quantitative theoretical model, available for exactly calculating the vdW-induced deformation of a planar fluid interface interacting with a sphere, and the interaction forces taking into account its change, is presented in this paper. The validity and advantage of the new mathematical and physical technique is rigorously verified by comparison with the numerical results on basis of the previous Paraboloid solid (PS) model and the Hamaker's sphere-flat expression (viz. F = - 2 Aa3 / (3 D2( D + 2 a) 2)), as well as its well-known DA-based general form of F / a = - A / 6z p02.

The Structure of Pre-Adolescents' Perceptions of Their Teacher's Interpersonal Behaviours and Their Relation to Pre-Adolescents' Learning Outcomes

ERIC Educational Resources Information Center

Charalampous, Kyriakos; Kokkinos, Constantinos M.

2018-01-01

Previous studies have offered indications that the way pre-adolescents (fifth and sixth graders) structure their perceptions of their teacher's interaction in terms of Agency and Communion differs from adolescents. The purpose of this study was to delineate previous findings by thoroughly examining the structure of pre-adolescents' perceptions of…

Flow field interactions between two tandem cyclists

NASA Astrophysics Data System (ADS)

Barry, Nathan; Burton, David; Sheridan, John; Thompson, Mark; Brown, Nicholas A. T.

2016-12-01

Aerodynamic drag is the primary resistive force acting on cyclists at racing speeds. Many events involve cyclists travelling in very close proximity. Previous studies have shown that interactions result in significant drag reductions for inline cyclists. However, the interaction between cyclist leg position (pedalling) and the vortical flow structures that contribute significantly to the drag on an isolated cyclist has not previously been quantified or described for tandem cyclists of varying separation. To this end, scale model cyclists were constructed for testing in a water channel for inline tandem configurations. Particle image velocimetry was used to capture time-averaged velocity fields around two tandem cyclists. Perhaps surprisingly, the wake of a trailing cyclist maintains strong similarity to the characteristic wake of a single cyclist despite a significant disturbance to the upstream flow. Together with streamwise velocity measurements through the wake and upstream of the trailing cyclist, this work supports previous findings, which showed that the trailing cyclist drag reduction is primarily due to upstream sheltering effects reducing the stagnation pressure on forward-facing surfaces.

Relationship of Gender and Teacher/Student Classroom Interaction. Sex Bias/Sex Stereotyping Project. Year End Report for the Period of July 1, 1987 to June 30, 1988.

ERIC Educational Resources Information Center

Kentucky Univ., Lexington. Div. of Vocational Education.

A project was conducted to identify the pattern of interactions in a sample of 62 vocational classes in 19 representative Kentucky secondary schools and to compare the findings to other studies to ascertain whether these classes displayed the sex bias observed in previous research. Seven observers recorded classroom interactions using the…

Theory of mind in Alzheimer disease: Evidence of authentic impairment during social interaction.

PubMed

Moreau, Noémie; Rauzy, Stéphane; Viallet, François; Champagne-Lavau, Maud

2016-03-01

The present study aimed to investigate theory of mind (the ability to infer others' mental states) deficit in 20 patients with mild Alzheimer's disease and 20 healthy controls, with 2 theory of mind tasks, 1 of them being a real interactive task. Previous results concerning preserved or altered theory of mind abilities in Alzheimer's disease have been inconsistent and relationships with other cognitive dysfunctions (notably episodic memory and executive functions) are still unclear. The first task we used was a false belief paradigm as frequently used in literature whereas the second task, a referential communication task, assessed theory of mind in a real situation of interaction. Participants also underwent neuropsychological evaluation to investigate potential relationships between theory of mind and memory deficits. The results showed that Alzheimer patients presented a genuine and significant theory of mind deficit compared to control participants characterized notably by difficulties to attribute knowledge to an interlocutor in a real social interaction. These results further confirm that theory of mind is altered in early stages of Alzheimer dementia which is consistent with previous works. More specifically, this study is the first to objectivize this impairment in social interaction. (c) 2016 APA, all rights reserved).

Analyzing the Knowledge Construction and Cognitive Patterns of Blog-Based Instructional Activities Using Four Frequent Interactive Strategies (Problem Solving, Peer Assessment, Role Playing and Peer Tutoring): A Preliminary Study

ERIC Educational Resources Information Center

Wang, Shu-Ming; Hou, Huei-Tse; Wu, Sheng-Yi

2017-01-01

Instructional strategies can be helpful in facilitating students' knowledge construction and developing advanced cognitive skills. In the context of collaborative learning, instructional strategies as scripts can guide learners to engage in more meaningful interaction. Previous studies have been investigated the benefits of different instructional…

Exploring an Age Difference in Preschool Children's Competitiveness Following a Competition.

PubMed

Hu, Yu; Zhu, Yi

2018-01-01

Literature suggests that resource acquisition compels competition in young children. However, little is still known about the development of preschool children's competitiveness. In this preliminary study, 166 children (aged 2-4 and 5-6 years) engaged in a dyadic competition which resulted in a winning and a losing group (in a control/non-competition group, participants engaged in a similar task which did not lead to winning/losing outcome), and then experimenters tracked their decisions to compete again with a rival (i.e., an individual they interacted in the previous competition task) and a non-rival competitor (i.e., an anonymous classmate they did not interact in the previous competition task) for a reward, respectively. As expected, results showed an age-related decreasing trend in the percentage of choices to compete with a competitor. However, this age difference was only significant in the control group when participants played with the partner with whom they interacted in the previous game and in the losing group when participants competed with a non-rival competitor. This study contributes to our knowledge of how competitiveness develop in preschool childhood, and calls for further research on the roles of motivation and cognitive control in children's competitiveness.

The influence of exercise identity and social physique anxiety on exercise dependence.

PubMed

Cook, Brian; Karr, Trisha M; Zunker, Christie; Mitchell, James E; Thompson, Ron; Sherman, Roberta; Erickson, Ann; Cao, Li; Crosby, Ross D

2015-09-01

Previous research has identified exercise identity and social physique anxiety as two independent factors that are associated with exercise dependence. The purpose of our study was to investigate the unique and interactive effect of these two known correlates of exercise dependence in a sample of 1,766 female runners. Regression analyses tested the main effects of exercise identity and social physique anxiety on exercise dependence. An interaction term was calculated to examine the potential moderating effect of social physique anxiety on the exercise identity and exercise dependence relationship. Results indicate a main effect for exercise identity and social physique anxiety on exercise dependence; and the interaction of these factors explained exercise dependence scores beyond the independent effects. Thus, social physique anxiety acted as a moderator in the exercise identity and exercise dependence relationship. Our results indicate that individuals who strongly identify themselves as an exerciser and also endorse a high degree of social physique anxiety may be at risk for developing exercise dependence. Our study supports previous research which has examined factors that may contribute to the development of exercise dependence and also suggests a previously unknown moderating relationship for social physique anxiety on exercise dependence.

Degree of Response to Homeopathic Potencies Correlates with Dipole Moment Size in Molecular Detectors: Implications for Understanding the Fundamental Nature of Serially Diluted and Succussed Solutions.

PubMed

Cartwright, Steven J

2018-02-01

 The use of solvatochromic dyes to investigate homeopathic potencies holds out the promise of understanding the nature of serially succussed and diluted solutions at a fundamental physicochemical level. Recent studies have shown that a range of different dyes interact with potencies and, moreover, the nature of the interaction is beginning to allow certain specific characteristics of potencies to be delineated.  The study reported in this article takes previous investigations further and aims to understand more about the nature of the interaction between potencies and solvatochromic dyes. To this end, the UV-visible spectra of a wide range of potential detectors of potencies have been examined using methodologies previously described.  Results presented demonstrate that solvatochromic dyes are a sub-group of a larger class of compounds capable of demonstrating interactions with potencies. In particular, amino acids containing an aromatic bridge also show marked optical changes in the presence of potencies. Several specific features of molecular detectors can now be shown to be necessary for significant interactions with homeopathic potencies. These include systems with a large dipole moment, electron delocalisation, polarizability and molecular rigidity.  Analysis of the optical changes occurring on interaction with potencies suggests that in all cases potencies increase the polarity of molecular detectors to a degree that correlates with the size of the compound's permanent or ground dipole moment. These results can be explained by inferring that potencies themselves have polarity. Possible candidates for the identity of potencies, based on these and previously reported results, are discussed. The Faculty of Homeopathy.

iLOCi: a SNP interaction prioritization technique for detecting epistasis in genome-wide association studies

PubMed Central

2012-01-01

Background Genome-wide association studies (GWAS) do not provide a full account of the heritability of genetic diseases since gene-gene interactions, also known as epistasis are not considered in single locus GWAS. To address this problem, a considerable number of methods have been developed for identifying disease-associated gene-gene interactions. However, these methods typically fail to identify interacting markers explaining more of the disease heritability over single locus GWAS, since many of the interactions significant for disease are obscured by uninformative marker interactions e.g., linkage disequilibrium (LD). Results In this study, we present a novel SNP interaction prioritization algorithm, named iLOCi (Interacting Loci). This algorithm accounts for marker dependencies separately in case and control groups. Disease-associated interactions are then prioritized according to a novel ranking score calculated from the difference in marker dependencies for every possible pair between case and control groups. The analysis of a typical GWAS dataset can be completed in less than a day on a standard workstation with parallel processing capability. The proposed framework was validated using simulated data and applied to real GWAS datasets using the Wellcome Trust Case Control Consortium (WTCCC) data. The results from simulated data showed the ability of iLOCi to identify various types of gene-gene interactions, especially for high-order interaction. From the WTCCC data, we found that among the top ranked interacting SNP pairs, several mapped to genes previously known to be associated with disease, and interestingly, other previously unreported genes with biologically related roles. Conclusion iLOCi is a powerful tool for uncovering true disease interacting markers and thus can provide a more complete understanding of the genetic basis underlying complex disease. The program is available for download at http://www4a.biotec.or.th/GI/tools/iloci. PMID:23281813

Investigation of head group behaviour of lamellar liquid crystals

NASA Astrophysics Data System (ADS)

Delikatny, E. J.; Burnell, E. E.

A mean field equilibrium statistical mechanical model, based on the Samulski inertial frame model, was developed to simulate experimental dipolar and quadrupolar nmr couplings of isotopically substituted potassium palmitates. An isolated four spin system was synthesized (2,2,3,3,-H4-palmitic acid-d27) and in conjunction with data presented in a previous paper on perdeuterated and carbon 13 labelled soaps, the head group behaviour of the molecule was investigated. Two interactions were considered in the modelling procedure: a mean field steric interaction characterized by a constraining cylinder, and a head group interaction characterized by a mass on the end of a rod of variable length. The rod lies along the first C-C bond direction and accounts for the interaction between polar head group and water via its effect on the moment of inertia of the molecule. In potassium palmitate mean field steric repulsive forces remain constant over the entire temperature range studied. In contrast, electrostatic interactions between polar head group and water, approximately constant at higher temperatures, increase dramatically as the phase transition is approached. This evidence supports a previously proposed model of lipidwater interaction.

The Individual, Joint, and Additive Interaction Associations of Aerobic-Based Physical Activity and Muscle Strengthening Activities on Metabolic Syndrome.

PubMed

Dankel, Scott J; Loenneke, Jeremy P; Loprinzi, Paul D

2016-12-01

Previous research has demonstrated that physical activity and muscle strengthening activities are independently and inversely associated with metabolic syndrome. Despite a number of studies examining the individual associations, only a few studies have examined the joint associations, and to our knowledge, no previous studies have examined the potential additive interaction of performing muscle strengthening activities and aerobic-based physical activity and their association with metabolic syndrome. Using data from the 2003 to 2006 National Health and Nutrition Examination Survey (NHANES), we computed three separate multivariable logistic regression models to examine the individual, combined, and additive interaction of meeting guidelines for accelerometer-assessed physical activity and self-reported muscle strengthening activities, and their association with metabolic syndrome. We found that individuals meeting physical activity and muscle strengthening activity guidelines, respectively, were at 61 and 25 % lower odds of having metabolic syndrome. Furthermore, individuals meeting both guidelines had the lowest odds of having metabolic syndrome (70 %), in part due to the additive interaction of performing both modes of exercise. In this national sample, accelerometer-assessed physical activity and muscle strengthening activities were synergistically associated with metabolic syndrome.

A genome-wide analysis of gene–caffeine consumption interaction on basal cell carcinoma

PubMed Central

Li, Xin; Cornelis, Marilyn C.; Liang, Liming; Song, Fengju; De Vivo, Immaculata; Giovannucci, Edward; Tang, Jean Y.; Han, Jiali

2016-01-01

Animal models have suggested that oral or topical administration of caffeine could inhibit ultraviolet-induced carcinogenesis via the ataxia telangiectasia and rad3 (ATR)-related apoptosis. Previous epidemiological studies have demonstrated that increased caffeine consumption is associated with reduced risk of basal cell carcinoma (BCC). To identify common genetic markers that may modify this association, we tested gene–caffeine intake interaction on BCC risk in a genome-wide analysis. We included 3383 BCC cases and 8528 controls of European ancestry from the Nurses’ Health Study and Health Professionals Follow-up Study. Single nucleotide polymorphism (SNP) rs142310826 near the NEIL3 gene showed a genome-wide significant interaction with caffeine consumption (P = 1.78 × 10–8 for interaction) on BCC risk. There was no gender difference for this interaction (P = 0.64 for heterogeneity). NEIL3, a gene belonging to the base excision DNA repair pathway, encodes a DNA glycosylase that recognizes and removes lesions produced by oxidative stress. In addition, we identified several loci with P value for interaction <5 × 10–7 in gender-specific analyses (P for heterogeneity between genders < 0.001) including those mapping to the genes LRRTM4, ATF3 and DCLRE1C in women and POTEA in men. Finally, we tested the associations between caffeine consumption-related SNPs reported by previous genome-wide association studies and risk of BCC, both individually and jointly, but found no significant association. In sum, we identified a DNA repair gene that could be involved in caffeine-mediated skin tumor inhibition. Further studies are warranted to confirm these findings. PMID:27797824

Message Modality and Source Credibility Can Interact to Affect Argument Processing.

ERIC Educational Resources Information Center

Booth-Butterfield, Steve; Gutowski, Christine

1993-01-01

Extends previous modality and source cue studies by manipulating argument quality. Randomly assigned college students by class to an argument quality by source attribute by modality factorial experiment. Finds the print mode produces only argument main effects, and audio and video modes produce argument by cue interactions. Finds data inconsistent…

Bark Beetle-Fungal Symbiosis: Context Dependency in Complex Associations

Treesearch

Kier D. Klepzig; D.L. Six

2004-01-01

Recent thinking in symbiosis research has emphasized a holistic consideration of these complex interactions. Bark beetles and their associated microbes are one group which has previously not been addressed in this manner. We review the study of symbiotic interactions among bark beetles and microbes in light of this thinking. We describe the considerable progress...

Maternal Employment, Nonparental Care, Mother-Child Interactions, and Child Outcomes during Preschool Years

ERIC Educational Resources Information Center

Nomaguchi, Kei M.

2006-01-01

This study examines the relationships between maternal employment, nonparental care, mother-child interactions, and preschoolers' outcomes. Data from the Canadian National Longitudinal Survey of Children and Youth (N = 1,248) show that maternal employment during the previous year, especially full-time employment, was related to care by…

Effectiveness of Abstinence-Based Incentives: Interaction with Intake Stimulant Test Results

ERIC Educational Resources Information Center

Stitzer, Maxine L.; Petry, Nancy; Peirce, Jessica; Kirby, Kimberly; Killeen, Therese; Roll, John; Hamilton, John; Stabile, Patricia Q.; Sterling, Robert; Brown, Chanda; Kolodner, Ken; Li, Rui

2007-01-01

Intake urinalysis test result (drug positive vs. negative) has been previously identified as a strong predictor of drug abuse treatment outcome, but there is little information about how this prognostic factor may interact with the type of treatment delivered. The authors used data from a multisite study of abstinence incentives for stimulant…

Neural Correlates of Audiovisual Integration of Semantic Category Information

ERIC Educational Resources Information Center

Hu, Zhonghua; Zhang, Ruiling; Zhang, Qinglin; Liu, Qiang; Li, Hong

2012-01-01

Previous studies have found a late frontal-central audiovisual interaction during the time period about 150-220 ms post-stimulus. However, it is unclear to which process is this audiovisual interaction related: to processing of acoustical features or to classification of stimuli? To investigate this question, event-related potentials were recorded…

Unraveling Students' Interaction around a Tangible Interface Using Multimodal Learning Analytics

ERIC Educational Resources Information Center

Schneider, Bertrand; Blikstein, Paulo

2015-01-01

In this paper, we describe multimodal learning analytics (MMLA) techniques to analyze data collected around an interactive learning environment. In a previous study (Schneider & Blikstein, submitted), we designed and evaluated a Tangible User Interface (TUI) where dyads of students were asked to learn about the human hearing system by…

Change and Consistency in Social Participation during Early Adulthood.

ERIC Educational Resources Information Center

Reis, Harry T.; And Others

1993-01-01

A total of 113 adults from 26 to 31 years of age who had participated in previous social interaction studies while in college kept detailed records of social activity for 2 weeks. Found that from college to adulthood opposite-sex socializing increased, whereas same-sex, mixed-sex, and group interactions decreased. (MDM)

Is a Partner's Competence Threatening during Dyadic Cooperative Work? It Depends on Resource Interdependence

ERIC Educational Resources Information Center

Buchs, Celine; Butera, Fabrizio

2009-01-01

Previous studies with university students have shown that resource interdependence during cooperative dyadic work on texts produces two different dynamics in student interaction and learning. Working on complementary information produces positive interactions, but a good quality of information transmission is needed to foster student learning.…

Inferring Mechanisms of Compensation from E-MAP and SGA Data Using Local Search Algorithms for Max Cut

NASA Astrophysics Data System (ADS)

Leiserson, Mark D. M.; Tatar, Diana; Cowen, Lenore J.; Hescott, Benjamin J.

A new method based on a mathematically natural local search framework for max cut is developed to uncover functionally coherent module and BPM motifs in high-throughput genetic interaction data. Unlike previous methods which also consider physical protein-protein interaction data, our method utilizes genetic interaction data only; this becomes increasingly important as high-throughput genetic interaction data is becoming available in settings where less is known about physical interaction data. We compare modules and BPMs obtained to previous methods and across different datasets. Despite needing no physical interaction information, the BPMs produced by our method are competitive with previous methods. Biological findings include a suggested global role for the prefoldin complex and a SWR subcomplex in pathway buffering in the budding yeast interactome.

Inferring mechanisms of compensation from E-MAP and SGA data using local search algorithms for max cut.

PubMed

Leiserson, Mark D M; Tatar, Diana; Cowen, Lenore J; Hescott, Benjamin J

2011-11-01

A new method based on a mathematically natural local search framework for max cut is developed to uncover functionally coherent module and BPM motifs in high-throughput genetic interaction data. Unlike previous methods, which also consider physical protein-protein interaction data, our method utilizes genetic interaction data only; this becomes increasingly important as high-throughput genetic interaction data is becoming available in settings where less is known about physical interaction data. We compare modules and BPMs obtained to previous methods and across different datasets. Despite needing no physical interaction information, the BPMs produced by our method are competitive with previous methods. Biological findings include a suggested global role for the prefoldin complex and a SWR subcomplex in pathway buffering in the budding yeast interactome.

Bacterial co-expression of human Tau protein with protein kinase A and 14-3-3 for studies of 14-3-3/phospho-Tau interaction

PubMed Central

Tugaeva, Kristina V.; Tsvetkov, Philipp O.

2017-01-01

Abundant regulatory 14-3-3 proteins have an extremely wide interactome and coordinate multiple cellular events via interaction with specifically phosphorylated partner proteins. Notwithstanding the key role of 14-3-3/phosphotarget interactions in many physiological and pathological processes, they are dramatically underexplored. Here, we focused on the 14-3-3 interaction with human Tau protein associated with the development of several neurodegenerative disorders, including Alzheimer’s and Parkinson’s diseases. Among many known phosphorylation sites within Tau, protein kinase A (PKA) phosphorylates several key residues of Tau and induces its tight interaction with 14-3-3 proteins. However, the stoichiometry and mechanism of 14-3-3 interaction with phosphorylated Tau (pTau) are not clearly elucidated. In this work, we describe a simple bacterial co-expression system aimed to facilitate biochemical and structural studies on the 14-3-3/pTau interaction. We show that dual co-expression of human fetal Tau with PKA in Escherichia coli results in multisite Tau phosphorylation including also naturally occurring sites which were not previously considered in the context of 14-3-3 binding. Tau protein co-expressed with PKA displays tight functional interaction with 14-3-3 isoforms of a different type. Upon triple co-expression with 14-3-3 and PKA, Tau protein could be co-purified with 14-3-3 and demonstrates complex which is similar to that formed in vitro between individual 14-3-3 and pTau obtained from dual co-expression. Although used in this study for the specific case of the previously known 14-3-3/pTau interaction, our co-expression system may be useful to study of other selected 14-3-3/phosphotarget interactions and for validations of 14-3-3 complexes identified by other methods. PMID:28575131

General recognition theory with individual differences: a new method for examining perceptual and decisional interactions with an application to face perception.

PubMed

Soto, Fabian A; Vucovich, Lauren; Musgrave, Robert; Ashby, F Gregory

2015-02-01

A common question in perceptual science is to what extent different stimulus dimensions are processed independently. General recognition theory (GRT) offers a formal framework via which different notions of independence can be defined and tested rigorously, while also dissociating perceptual from decisional factors. This article presents a new GRT model that overcomes several shortcomings with previous approaches, including a clearer separation between perceptual and decisional processes and a more complete description of such processes. The model assumes that different individuals share similar perceptual representations, but vary in their attention to dimensions and in the decisional strategies they use. We apply the model to the analysis of interactions between identity and emotional expression during face recognition. The results of previous research aimed at this problem have been disparate. Participants identified four faces, which resulted from the combination of two identities and two expressions. An analysis using the new GRT model showed a complex pattern of dimensional interactions. The perception of emotional expression was not affected by changes in identity, but the perception of identity was affected by changes in emotional expression. There were violations of decisional separability of expression from identity and of identity from expression, with the former being more consistent across participants than the latter. One explanation for the disparate results in the literature is that decisional strategies may have varied across studies and influenced the results of tests of perceptual interactions, as previous studies lacked the ability to dissociate between perceptual and decisional interactions.

Theoretical study of interactions between cysteine and perfluoropropanoic acid in gas and aqueous phase

NASA Astrophysics Data System (ADS)

Holmes, Tiffani M.; Doskocz, Jacek; Wright, Terrance; Hill, Glake A.

The interaction of perfluoropropanoic acid (PFPA) with the amino acid cysteine was investigated using density functional theory. Previous studies suggest that the peroxisome proliferator chemical, perfluorooctanoic acid, is circulated throughout the body by way of sulfur-containing amino acids. We present conformational analysis of the interactions of PFPA, a small model of perfluorooctanoic acid, with the sulfur-containing amino acid which occur by the process of hydrogen bonding, in which the hydrogen of the sulfhydryl group interacts with the carboxyl oxygen, and the amino nitrogen forms a hydrogen bond with the hydrogen of the bond OH group of the fluorinated alkyl. We also show in our structures a recently characterized weak nonbonded interaction between divalent sulfur and a main chain carboxyl oxygen in proteins. B3LYP calculated free energies and interaction energies predict low-energy, high-interaction conformations for complex systems of perfluorinated fatty acid interactions with cysteine.

Interactional synchrony and the origins of infant-mother attachment: a replication study.

PubMed

Isabella, R A; Belsky, J

1991-04-01

This study sought to replicate previous work in testing the hypothesis that interactions of dyads developing secure attachment relationships would be characterized by disproportionately synchronous and those of dyads developing insecure relationships by disproportionately asynchronous exchanges. Additionally, a priori hypotheses were tested regarding expected differences in the interactional histories of dyads developing insecure-avoidant and insecure-resistant attachments. Results supported the study's predictions in all cases. Dyads developing secure attachments were observed at 3 and 9 months to interact in a disproportionately well-timed, reciprocal, and mutually rewarding manner; dyads developing insecure relationships were disproportionately characterized by interactions in which mothers were minimally involved, unresponsive to infant signals, or intrusive. Within the insecure group, as predicted, 3- and 9-month interactions of avoidant dyads were characterized by maternal intrusiveness and overstimulation; resistant dyads were characterized at both ages by poorly coordinated interactions in which mothers were underinvolved and inconsistent. These findings are discussed as they lend to a growing body of evidence concerning associations between differential interactional histories and attachment quality.

Competition Between Fusarium pseudograminearum and Cochliobolus sativus Observed in Field and Greenhouse Studies.

PubMed

Troth, Erin E Gunnink; Johnston, Jeffrey A; Dyer, Alan T

2018-02-01

Among root pathogens, one of the most documented antagonisms is the suppression of Cochliobolus sativus by Fusarium (roseum) species. Unfortunately, previous studies involved single isolates of each pathogen and thus, provided no indication of the spectrum of responses that occur across the respective species. To investigate the variability in interactions between Cochliobolus sativus and Fusarium pseudograminearum, field and greenhouse trials were conducted that included monitoring of spring wheat plant health and monitoring of pathogen populations via quantitative real-time polymerase chain reaction. The interactions between two isolates of C. sativus and four isolates of F. pseudograminearum were explored in three geographically distinct wheat fields. To complement field trials and to limit potentially confounding environmental variables that are often associated with field studies, greenhouse trials were performed that investigated the interactions among and between three isolates of C. sativus and four isolates of F. pseudograminearum. Across field locations, C. sativus isolate Cs2344 consistently and significantly reduced Fusarium populations by an average of 20.1%. Similarly, F. pseudograminearum isolate Fp2228 consistently and significantly reduced C. sativus field populations by an average of 30.9%. No interaction was detected in the field between pathogen species with regards to disease or crop losses. Greenhouse results confirmed a powerful (>99%), broadly effective suppression of Fusarium populations by isolate Cs2344. Among greenhouse trials, additional isolate-isolate interactions were observed affecting Fusarium populations. Due to lower C. sativus population sizes in greenhouse trials, significant Fusarium suppression of C. sativus was only detected in one isolate-isolate interaction. This study is the first to demonstrate suppression of Fusarium spp. by C. sativus in field and greenhouse settings. These findings also reveal a complex competitive interaction between these two pathogen species that was previously unknown.

T:G mismatch-specific thymine-DNA glycosylase (TDG) as a coregulator of transcription interacts with SRC1 family members through a novel tyrosine repeat motif

PubMed Central

Lucey, Marie J.; Chen, Dongsheng; Lopez-Garcia, Jorge; Hart, Stephen M.; Phoenix, Fladia; Al-Jehani, Rajai; Alao, John P.; White, Roger; Kindle, Karin B.; Losson, Régine; Chambon, Pierre; Parker, Malcolm G.; Schär, Primo; Heery, David M.; Buluwela, Lakjaya; Ali, Simak

2005-01-01

Gene activation involves protein complexes with diverse enzymatic activities, some of which are involved in chromatin modification. We have shown previously that the base excision repair enzyme thymine DNA glycosylase (TDG) acts as a potent coactivator for estrogen receptor-α. To further understand how TDG acts in this context, we studied its interaction with known coactivators of nuclear receptors. We find that TDG interacts in vitro and in vivo with the p160 coactivator SRC1, with the interaction being mediated by a previously undescribed motif encoding four equally spaced tyrosine residues in TDG, each tyrosine being separated by three amino acids. This is found to interact with two motifs in SRC1 also containing tyrosine residues separated by three amino acids. Site-directed mutagenesis shows that the tyrosines encoded in these motifs are critical for the interaction. The related p160 protein TIF2 does not interact with TDG and has the altered sequence, F-X-X-X-Y, at the equivalent positions relative to SRC1. Substitution of the phenylalanines to tyrosines is sufficient to bring about interaction of TIF2 with TDG. These findings highlight a new protein–protein interaction motif based on Y-X-X-X-Y and provide new insight into the interaction of diverse proteins in coactivator complexes. PMID:16282588

Effects of temperature on consumer-resource interactions.

PubMed

Amarasekare, Priyanga

2015-05-01

Understanding how temperature variation influences the negative (e.g. self-limitation) and positive (e.g. saturating functional responses) feedback processes that characterize consumer-resource interactions is an important research priority. Previous work on this topic has yielded conflicting outcomes with some studies predicting that warming should increase consumer-resource oscillations and others predicting that warming should decrease consumer-resource oscillations. Here, I develop a consumer-resource model that both synthesizes previous findings in a common framework and yields novel insights about temperature effects on consumer-resource dynamics. I report three key findings. First, when the resource species' birth rate exhibits a unimodal temperature response, as demonstrated by a large number of empirical studies, the temperature range over which the consumer-resource interaction can persist is determined by the lower and upper temperature limits to the resource species' reproduction. This contrasts with the predictions of previous studies, which assume that the birth rate exhibits a monotonic temperature response, that consumer extinction is determined by temperature effects on consumer species' traits, rather than the resource species' traits. Secondly, the comparative analysis I have conducted shows that whether warming leads to an increase or decrease in consumer-resource oscillations depends on the manner in which temperature affects intraspecific competition. When the strength of self-limitation increases monotonically with temperature, warming causes a decrease in consumer-resource oscillations. However, if self-limitation is strongest at temperatures physiologically optimal for reproduction, a scenario previously unanalysed by theory but amply substantiated by empirical data, warming can cause an increase in consumer-resource oscillations. Thirdly, the model yields testable comparative predictions about consumer-resource dynamics under alternative hypotheses for how temperature affects competitive and resource acquisition traits. Importantly, it does so through empirically quantifiable metrics for predicting temperature effects on consumer viability and consumer-resource oscillations, which obviates the need for parameterizing complex dynamical models. Tests of these metrics with empirical data on a host-parasitoid interaction yield realistic estimates of temperature limits for consumer persistence and the propensity for consumer-resource oscillations, highlighting their utility in predicting temperature effects, particularly warming, on consumer-resource interactions in both natural and agricultural settings. © 2014 The Author. Journal of Animal Ecology © 2014 British Ecological Society.

Inferring Mechanisms of Compensation from E-MAP and SGA Data Using Local Search Algorithms for Max Cut

PubMed Central

Leiserson, Mark D.M.; Tatar, Diana; Cowen, Lenore J.

2011-01-01

Abstract A new method based on a mathematically natural local search framework for max cut is developed to uncover functionally coherent module and BPM motifs in high-throughput genetic interaction data. Unlike previous methods, which also consider physical protein-protein interaction data, our method utilizes genetic interaction data only; this becomes increasingly important as high-throughput genetic interaction data is becoming available in settings where less is known about physical interaction data. We compare modules and BPMs obtained to previous methods and across different datasets. Despite needing no physical interaction information, the BPMs produced by our method are competitive with previous methods. Biological findings include a suggested global role for the prefoldin complex and a SWR subcomplex in pathway buffering in the budding yeast interactome. PMID:21882903

Modulation of Memory Consolidation by the Basolateral Amygdala or Nucleus Accumbens Shell Requires Concurrent Dopamine Receptor Activation in Both Brain Regions

ERIC Educational Resources Information Center

LaLumiere, Ryan T.; Nawar, Erene M.; McGaugh, James L.

2005-01-01

Previous findings indicate that the basolateral amygdala (BLA) and the nucleus accumbens (NAc) interact in influencing memory consolidation. The current study investigated whether this interaction requires concurrent dopamine (DA) receptor activation in both brain regions. Unilateral, right-side cannulae were implanted into the BLA and the…

"Not the Romantic, All Happy, Coochy Coo Experience": A Qualitative Analysis of Interactions on an Irish Parenting Web Site

ERIC Educational Resources Information Center

Brady, Ellen; Guerin, Suzanne

2010-01-01

Support groups in online communities provide an anonymous place to exchange information and advice. Previous research has suggested that these groups offer a safe, nonjudgmental forum for new parents to share experiences and interact anonymously. This study investigated how participants in online parenting groups experience support via the…

The Interaction of Attitudes toward Racial Membership and Learning Ability in School-Age Children

ERIC Educational Resources Information Center

Nowicki, Elizabeth A.

2008-01-01

Although prejudice exists during childhood, it is unclear how attitudes toward peers of lower or higher academic ability and from one's own or a different racial group interact. This study qualifies previous research by showing that prejudice varies according to whether children are asked to evaluate peers based on academic ability, racial…

Utilizing Peer Moderating in Online Discussions: Addressing the Controversy between Teacher Moderation and Nonmoderation

ERIC Educational Resources Information Center

Seo, Kay Kyeongju

2007-01-01

This study focused on the effects of peer moderation on meaningful interactions in online discussions. A meaningful interaction was defined as a message relating to a discussion topic, responding to a previous message, and adding substance to the discussion. A randomized-subject, posttest-only control group design was used to test the first…

Gene by Environment Interactions Influencing Reading Disability and the Inattentive Symptom Dimension of Attention Deficit/Hyperactivity Disorder

ERIC Educational Resources Information Center

Rosenberg, Jenni; Pennington, Bruce F.; Willcutt, Erik G.; Olson, Richard K.

2012-01-01

Background: Reading disability (RD) and attention deficit/hyperactivity disorder (ADHD) are comorbid and genetically correlated, especially the inattentive dimension of ADHD (ADHD-I). However, previous research indicates that RD and ADHD enter into opposite gene by environment (G x E) interactions. Methods: This study used behavioral genetic…

Behaviorally Based Interventions for Teaching Social Interaction Skills to Children with ASD in Inclusive Settings: A Meta-Analysis

ERIC Educational Resources Information Center

Camargo, Síglia Pimentel Höher; Rispoli, Mandy; Ganz, Jennifer; Hong, Ee Rea; Davis, Heather; Mason, Rose

2016-01-01

Behaviorally based interventions have been demonstrated to be effective to teach social interaction skills for children with autism spectrum disorders in general education. However, the overall and moderating effects of these interventions have not been previously investigated in inclusive settings. The goal of this study was to investigate the…

Quantifying long-range correlations and 1/f patterns in a minimal experiment of social interaction

PubMed Central

Bedia, Manuel G.; Aguilera, Miguel; Gómez, Tomás; Larrode, David G.; Seron, Francisco

2014-01-01

In recent years, researchers in social cognition have found the “perceptual crossing paradigm” to be both a theoretical and practical advance toward meeting particular challenges. This paradigm has been used to analyze the type of interactive processes that emerge in minimal interactions and it has allowed progress toward understanding of the principles of social cognition processes. In this paper, we analyze whether some critical aspects of these interactions could not have been observed by previous studies. We consider alternative indicators that could complete, or even lead us to rethink, the current interpretation of the results obtained from both experimental and simulated modeling in the fields of social interactions and minimal perceptual crossing. In particular, we discuss the possibility that previous experiments have been analytically constrained to a short-term dynamic type of player response. Additionally, we propose the possibility of considering these experiments from a more suitable framework based on the use and analysis of long-range correlations and fractal dynamics. We will also reveal evidence supporting the idea that social interactions are deployed along many scales of activity. Specifically, we propose that the fractal structure of the interactions could be a more adequate framework to understand the type of social interaction patterns generated in a social engagement. PMID:25429277

In vivo screening reveals interactions between Drosophila Manf and genes involved in the mitochondria and the ubiquinone synthesis pathway.

PubMed

Lindström, Riitta; Lindholm, Päivi; Palgi, Mari; Saarma, Mart; Heino, Tapio I

2017-06-02

Mesencephalic Astrocyte-derived Neurotrophic Factor (MANF) and Cerebral Dopamine Neurotrophic Factor (CDNF) form an evolutionarily conserved family of neurotrophic factors. Orthologues for MANF/CDNF are the only neurotrophic factors as yet identified in invertebrates with conserved amino acid sequence. Previous studies indicate that mammalian MANF and CDNF support and protect brain dopaminergic system in non-cell-autonomous manner. However, MANF has also been shown to function intracellularly in the endoplasmic reticulum. To date, the knowledge on the interacting partners of MANF/CDNF and signaling pathways they activate is rudimentary. Here, we have employed the Drosophila genetics to screen for potential interaction partners of Drosophila Manf (DmManf) in vivo. We first show that DmManf plays a role in the development of Drosophila wing. We exploited this function by using Drosophila UAS-RNAi lines and discovered novel genetic interactions of DmManf with genes known to function in the mitochondria. We also found evidence of an interaction between DmManf and the Drosophila homologue encoding Ku70, the closest structural homologue of SAP domain of mammalian MANF. In addition to the previously known functions of MANF/CDNF protein family, DmManf also interacts with mitochondria-related genes. Our data supports the functional importance of these evolutionarily significant proteins and provides new insights for the future studies.

Interaction between FTO rs9939609 and the Native American-origin ABCA1 rs9282541 affects BMI in the admixed Mexican population.

PubMed

Villalobos-Comparán, Marisela; Antuna-Puente, Bárbara; Villarreal-Molina, María Teresa; Canizales-Quinteros, Samuel; Velázquez-Cruz, Rafael; León-Mimila, Paola; Villamil-Ramírez, Hugo; González-Barrios, Juan Antonio; Merino-García, José Luis; Thompson-Bonilla, María Rocío; Jarquin, Diego; Sánchez-Hernández, Osvaldo Erik; Rodríguez-Arellano, Martha Eunice; Posadas-Romero, Carlos; Vargas-Alarcón, Gilberto; Campos-Pérez, Francisco; Quiterio, Manuel; Salmerón-Castro, Jorge; Carnevale, Alessandra; Romero-Hidalgo, Sandra

2017-05-02

The aim of this study was to explore whether interactions between FTO rs9939609 and ABCA1 rs9282541 affect BMI and waist circumference (WC), and could explain previously reported population differences in FTO-obesity and FTO-BMI associations in the Mexican and European populations. A total of 3938 adults and 636 school-aged children from Central Mexico were genotyped for both polymorphisms. Subcutaneous and visceral adipose tissue biopsies from 22 class III obesity patients were analyzed for FTO and ABCA1 mRNA expression. Generalized linear models were used to test for associations and gene-gene interactions affecting BMI, WC and FTO expression. FTO and ABCA1 risk alleles were not individually associated with higher BMI or WC. However, in the absence of the ABCA1 risk allele, the FTO risk variant was significantly associated with higher BMI (P = 0.043) and marginally associated with higher WC (P = 0.067), as reported in Europeans. The gene-gene interaction affecting BMI and WC was statistically significant only in adults. FTO mRNA expression in subcutaneous abdominal adipose tissue according to ABCA1 genotype was consistent with these findings. This is the first report showing evidence of FTO and ABCA1 gene variant interactions affecting BMI, which may explain previously reported population differences. Further studies are needed to confirm this interaction.

Tabulation as a high-resolution alternative to coarse-graining protein interactions: Initial application to virus capsid subunits

NASA Astrophysics Data System (ADS)

Spiriti, Justin; Zuckerman, Daniel M.

2015-12-01

Traditional coarse-graining based on a reduced number of interaction sites often entails a significant sacrifice of chemical accuracy. As an alternative, we present a method for simulating large systems composed of interacting macromolecules using an energy tabulation strategy previously devised for small rigid molecules or molecular fragments [S. Lettieri and D. M. Zuckerman, J. Comput. Chem. 33, 268-275 (2012); J. Spiriti and D. M. Zuckerman, J. Chem. Theory Comput. 10, 5161-5177 (2014)]. We treat proteins as rigid and construct distance and orientation-dependent tables of the interaction energy between them. Arbitrarily detailed interactions may be incorporated into the tables, but as a proof-of-principle, we tabulate a simple α-carbon Gō-like model for interactions between dimeric subunits of the hepatitis B viral capsid. This model is significantly more structurally realistic than previous models used in capsid assembly studies. We are able to increase the speed of Monte Carlo simulations by a factor of up to 6700 compared to simulations without tables, with only minimal further loss in accuracy. To obtain further enhancement of sampling, we combine tabulation with the weighted ensemble (WE) method, in which multiple parallel simulations are occasionally replicated or pruned in order to sample targeted regions of a reaction coordinate space. In the initial study reported here, WE is able to yield pathways of the final ˜25% of the assembly process.

Interactive Land-Use Optimization Using Laguerre Voronoi Diagram with Dynamic Generating Point Allocation

NASA Astrophysics Data System (ADS)

Chaidee, S.; Pakawanwong, P.; Suppakitpaisarn, V.; Teerasawat, P.

2017-09-01

In this work, we devise an efficient method for the land-use optimization problem based on Laguerre Voronoi diagram. Previous Voronoi diagram-based methods are more efficient and more suitable for interactive design than discrete optimization-based method, but, in many cases, their outputs do not satisfy area constraints. To cope with the problem, we propose a force-directed graph drawing algorithm, which automatically allocates generating points of Voronoi diagram to appropriate positions. Then, we construct a Laguerre Voronoi diagram based on these generating points, use linear programs to adjust each cell, and reconstruct the diagram based on the adjustment. We adopt the proposed method to the practical case study of Chiang Mai University's allocated land for a mixed-use complex. For this case study, compared to other Voronoi diagram-based method, we decrease the land allocation error by 62.557 %. Although our computation time is larger than the previous Voronoi-diagram-based method, it is still suitable for interactive design.

The continuous prisoner's dilemma and the evolution of cooperation through reciprocal altruism with variable investment.

PubMed

Killingback, Timothy; Doebeli, Michael

2002-10-01

Understanding the evolutionary origin and persistence of cooperative behavior is a fundamental biological problem. The standard "prisoner's dilemma," which is the most widely adopted framework for studying the evolution of cooperation through reciprocal altruism between unrelated individuals, does not allow for varying degrees of cooperation. Here we study the continuous iterated prisoner's dilemma, in which cooperative investments can vary continuously in each round. This game has been previously considered for a class of reactive strategies in which current investments are based on the partner's previous investment. In the standard iterated prisoner's dilemma, such strategies are inferior to strategies that take into account both players' previous moves, as is exemplified by the evolutionary dominance of "Pavlov" over "tit for tat." Consequently, we extend the analysis of the continuous prisoner's dilemma to a class of strategies in which current investments depend on previous payoffs and, hence, on both players' previous investments. We show, both analytically and by simulation, that payoff-based strategies, which embody the intuitively appealing idea that individuals invest more in cooperative interactions when they profit from these interactions, provide a natural explanation for the gradual evolution of cooperation from an initially noncooperative state and for the maintenance of cooperation thereafter.

Wasp-Waist Interactions in the North Sea Ecosystem

PubMed Central

Fauchald, Per; Skov, Henrik; Skern-Mauritzen, Mette; Johns, David; Tveraa, Torkild

2011-01-01

Background In a “wasp-waist” ecosystem, an intermediate trophic level is expected to control the abundance of predators through a bottom-up interaction and the abundance of prey through a top-down interaction. Previous studies suggest that the North Sea is mainly governed by bottom-up interactions driven by climate perturbations. However, few studies have investigated the importance of the intermediate trophic level occupied by small pelagic fishes. Methodology/Principal Findings We investigated the numeric interactions among 10 species of seabirds, two species of pelagic fish and four groups of zooplankton in the North Sea using decadal-scale databases. Linear models were used to relate the time series of zooplankton and seabirds to the time series of pelagic fish. Seabirds were positively related to herring (Clupea harengus), suggesting a bottom-up interaction. Two groups of zooplankton; Calanus helgolandicus and krill were negatively related to sprat (Sprattus sprattus) and herring respectively, suggesting top-down interactions. In addition, we found positive relationships among the zooplankton groups. Para/pseudocalanus was positively related to C. helgolandicus and C. finmarchicus was positively related to krill. Conclusion/Significance Our results indicate that herring was important in regulating the abundance of seabirds through a bottom-up interaction and that herring and sprat were important in regulating zooplankton through top-down interactions. We suggest that the positive relationships among zooplankton groups were due to selective foraging and switching in the two clupeid fishes. Our results suggest that “wasp-waist” interactions might be more important in the North Sea than previously anticipated. Fluctuations in the populations of pelagic fish due to harvesting and depletion of their predators might accordingly have profound consequences for ecosystem dynamics through trophic cascades. PMID:21829494

Surface-supported Ag islands stabilized by a quantum size effect: Their interaction with small molecules relevant to ethylene epoxidation

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

Shao, Dahai

2013-05-15

This dissertation focuses on how QSE-stabilized, surface-supported Ag nanoclusters will interact with ethylene or oxygen. Experiments are performed to determine whether the QSE-mediated Ag islands react differently toward adsorption of ethylene or oxygen, or whether the adsorption of these small molecules will affect the QSE-mediated stability of Ag islands. Studies of the interaction of oxygen with Ag/Si(111)-7×7 were previously reported, but these studies were performed at a low Ag coverage where 3D Ag islands were not formed. So the study of such a system at a higher Ag coverage will be a subject of this work. The interaction of ethylenemore » with Ag/Si(111)-7×7, as well as the interaction of oxygen with Ag/NiAl(110) are also important parts of this study.« less

Gene function prediction with gene interaction networks: a context graph kernel approach.

PubMed

Li, Xin; Chen, Hsinchun; Li, Jiexun; Zhang, Zhu

2010-01-01

Predicting gene functions is a challenge for biologists in the postgenomic era. Interactions among genes and their products compose networks that can be used to infer gene functions. Most previous studies adopt a linkage assumption, i.e., they assume that gene interactions indicate functional similarities between connected genes. In this study, we propose to use a gene's context graph, i.e., the gene interaction network associated with the focal gene, to infer its functions. In a kernel-based machine-learning framework, we design a context graph kernel to capture the information in context graphs. Our experimental study on a testbed of p53-related genes demonstrates the advantage of using indirect gene interactions and shows the empirical superiority of the proposed approach over linkage-assumption-based methods, such as the algorithm to minimize inconsistent connected genes and diffusion kernels.

An artificial network model for estimating the network structure underlying partially observed neuronal signals.

PubMed

Komatsu, Misako; Namikawa, Jun; Chao, Zenas C; Nagasaka, Yasuo; Fujii, Naotaka; Nakamura, Kiyohiko; Tani, Jun

2014-01-01

Many previous studies have proposed methods for quantifying neuronal interactions. However, these methods evaluated the interactions between recorded signals in an isolated network. In this study, we present a novel approach for estimating interactions between observed neuronal signals by theorizing that those signals are observed from only a part of the network that also includes unobserved structures. We propose a variant of the recurrent network model that consists of both observable and unobservable units. The observable units represent recorded neuronal activity, and the unobservable units are introduced to represent activity from unobserved structures in the network. The network structures are characterized by connective weights, i.e., the interaction intensities between individual units, which are estimated from recorded signals. We applied this model to multi-channel brain signals recorded from monkeys, and obtained robust network structures with physiological relevance. Furthermore, the network exhibited common features that portrayed cortical dynamics as inversely correlated interactions between excitatory and inhibitory populations of neurons, which are consistent with the previous view of cortical local circuits. Our results suggest that the novel concept of incorporating an unobserved structure into network estimations has theoretical advantages and could provide insights into brain dynamics beyond what can be directly observed. Copyright © 2014 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Four Forensic Entomology Case Studies: Records and Behavioral Observations on Seldom Reported Cadaver Fauna With Notes on Relevant Previous Occurrences and Ecology.

PubMed

Lindgren, Natalie K; Sisson, Melissa S; Archambeault, Alan D; Rahlwes, Brent C; Willett, James R; Bucheli, Sibyl R

2015-03-01

A yearlong survey of insect taxa associated with human decomposition was conducted at the Southeast Texas Applied Forensic Science (STAFS) facility located in the Center for Biological Field Studies of Sam Houston State University in Huntsville, TX. During this study, four insect-cadaver interactions were observed that represent previously poorly documented yet forensically significant interactions: Syrphidae maggots colonized a corpse in an aquatic situation; Psychodidae adults mated and oviposited on an algal film that was present on a corpse that had been recently removed from water; several Panorpidae were the first insects to feed upon a freshly placed corpse in the autumn; and a noctuid caterpillar was found chewing and ingesting dried human skin. Baseline knowledge of insect-cadaver interactions is the foundation of forensic entomology, and unique observations have the potential to expand our understanding of decomposition ecology. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Posterior insular cortex – a site of vestibular–somatosensory interaction?

PubMed Central

Baier, Bernhard; zu Eulenburg, Peter; Best, Christoph; Geber, Christian; Müller-Forell, Wibke; Birklein, Frank; Dieterich, Marianne

2013-01-01

Background In previous imaging studies the insular cortex (IC) has been identified as an essential part of the processing of a wide spectrum of perception and sensorimotor integration. Yet, there are no systematic lesion studies in a sufficient number of patients examining whether processing of vestibular and the interaction of somatosensory and vestibular signals take place in the IC. Methods We investigated acute stroke patients with lesions affecting the IC in order to fill this gap. In detail, we explored signs of a vestibular tone imbalance such as the deviation of the subjective visual vertical (SVV). We applied voxel-lesion behaviour mapping analysis in 27 patients with acute unilateral stroke. Results Our data demonstrate that patients with lesions of the posterior IC have an abnormal tilt of SVV. Furthermore, re-analysing data of 20 patients from a previous study, we found a positive correlation between thermal perception contralateral to the stroke and the severity of the SVV tilt. Conclusions We conclude that the IC is a sensory brain region where different modalities might interact. PMID:24392273

Femtosecond Time-Resolved Photoelectron Imaging of Excited Doped Helium Nanodroplets

NASA Astrophysics Data System (ADS)

Saladrigas, Catherine; Bacellar, Camila; Leone, Stephen R.; Neumark, Daniel M.; Gessner, Oliver

2017-04-01

Helium nanodroplets are excellent matrices for high resolution spectroscopy and the study of ultracold chemistry. They are optically transparent. In their electronic ground state, interact very weakly with any atomic or molecular dopant. Electronically excited droplets, however, can strongly interact with dopants through a variety of relaxation mechanisms. Previously, these host-dopant interactions were studied in the energy domain, revealing Penning ionization processes enabled by energy transfer between the droplet host and atomic dopants. Using femtosecond time resolved XUV photoelectron imaging, we plan to perform complementary experiments in the time domain to gain deeper insight into the timescales of energy transfer processes and how they compete with internal droplet relaxation. First experiments will be performed using noble gas dopants, such as Kr and Ne, which will be compared to previous energy-domain studies. Femtosecond XUV pulses produced by high harmonic generation will be used to excite the droplets, IR and near-UV light will be used to monitor the relaxation dynamics. Using velocity map imaging, both photoelectron kinetic energies and angular distributions will be recorded as a function of time. Preliminary results and proposed experiments will be presented.

Two complement receptor one alleles have opposing associations with cerebral malaria and interact with α+thalassaemia.

PubMed

Opi, D Herbert; Swann, Olivia; Macharia, Alexander; Uyoga, Sophie; Band, Gavin; Ndila, Carolyne M; Harrison, Ewen M; Thera, Mahamadou A; Kone, Abdoulaye K; Diallo, Dapa A; Doumbo, Ogobara K; Lyke, Kirsten E; Plowe, Christopher V; Moulds, Joann M; Shebbe, Mohammed; Mturi, Neema; Peshu, Norbert; Maitland, Kathryn; Raza, Ahmed; Kwiatkowski, Dominic P; Rockett, Kirk A; Williams, Thomas N; Rowe, J Alexandra

2018-04-25

Malaria has been a major driving force in the evolution of the human genome. In sub-Saharan African populations, two neighbouring polymorphisms in the Complement Receptor One ( CR1 ) gene, named Sl2 and McC b , occur at high frequencies, consistent with selection by malaria. Previous studies have been inconclusive. Using a large case-control study of severe malaria in Kenyan children and statistical models adjusted for confounders, we estimate the relationship between Sl2 and McC b and malaria phenotypes, and find they have opposing associations. The Sl2 polymorphism is associated with markedly reduced odds of cerebral malaria and death, while the McC b polymorphism is associated with increased odds of cerebral malaria. We also identify an apparent interaction between Sl2 and α + thalassaemia, with the protective association of Sl2 greatest in children with normal α-globin. The complex relationship between these three mutations may explain previous conflicting findings, highlighting the importance of considering genetic interactions in disease-association studies. © 2018, Opi et al.

Recorded interactive seminars and follow-up discussions as an effective method for distance learning.

PubMed

Miller, Kenneth T; Hannum, Wallace M; Proffit, William R

2011-03-01

Previous studies have suggested that, although orthodontic residents prefer to be live and interactive in a seminar, they learn almost as much when watching a previously recorded interactive seminar and following up with live discussion. Our objective was to test the effectiveness and acceptability of using previously recorded interactive seminars and different types of live follow-up discussions. Residents at schools participating from a distance completed preseminar readings and at their convenience watched streaming video of some or all recordings of 4 interactive seminar sequences consisting of 6 seminars each. Afterward, distant residents participated in 1 of 4 types of interaction: local follow-up discussion, videoconference, teleconference, and no discussion. The effectiveness of the seminar sequences was tested by pretest and posttest scores. Acceptability was evaluated from ratings of aspects of the seminar and discussion experience. Open-ended questions allowed residents to express what they liked and to suggest changes in their experiences. In each seminar sequence, test scores of schools participating through recordings and follow-up discussions improved more than those participating live and interactive. After viewing, residents preferred local follow-up discussion, which was not statistically different from participating live and interactive both locally and from a distance. Videoconference and teleconference discussions were both more acceptable to residents than no follow-up discussion, which was found to be significantly below all methods tested. When residents are live and interactive in a seminar, there does not appear to be a significant difference between being local vs at a distance. Recorded interactive seminars with follow-up discussions are also an effective and acceptable method of distance learning. Residents preferred local follow-up discussion, but, at a distance, they preferred videoconference to both teleconference and no discussion. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Is racial bias malleable? Whites' lay theories of racial bias predict divergent strategies for interracial interactions.

PubMed

Neel, Rebecca; Shapiro, Jenessa R

2012-07-01

How do Whites approach interracial interactions? We argue that a previously unexamined factor-beliefs about the malleability of racial bias-guides Whites' strategies for difficult interracial interactions. We predicted and found that those who believe racial bias is malleable favor learning-oriented strategies such as taking the other person's perspective and trying to learn why an interaction is challenging, whereas those who believe racial bias is fixed favor performance-oriented strategies such as overcompensating in the interaction and trying to end the interaction as quickly as possible. Four studies support these predictions. Whether measured (Studies 1, 3, and 4) or manipulated (Study 2), beliefs that racial bias is fixed versus malleable yielded these divergent strategies for difficult interracial interactions. Furthermore, beliefs about the malleability of racial bias are distinct from related constructs (e.g., prejudice and motivations to respond without prejudice; Studies 1, 3, and 4) and influence self-reported (Studies 1-3) and actual (Study 4) strategies in imagined (Studies 1-2) and real (Studies 3-4) interracial interactions. Together, these findings demonstrate that beliefs about the malleability of racial bias influence Whites' approaches to and strategies within interracial interactions. PsycINFO Database Record (c) 2012 APA, all rights reserved

Camera traps reveal an apparent mutualism between a common mesocarnivore and an endangered ungulate

USGS Publications Warehouse

Cove, Michael V.; Maurer, Andrew S.; O'Connell, Allan F.

2017-01-01

Camera traps are commonly used to study mammal ecology and they occasionally capture previously undocumented species interactions. The key deer (Odocoileus virginianus clavium) is an endangered endemic subspecies of the Florida Keys, where it exists with few predators. We obtained a camera trap sequence of 80 photos in which a key deer interacted with two northern raccoons (Procyon lotor). One of the raccoons groomed the deer’s face for ∼1 min. This interaction is peculiar and appears mutualistic because the deer was not concerned and willingly remained still throughout the physical contact. Although mutualistic relationships between deer and birds are common, we are unaware of any previously documented mesocarnivore-deer mutualisms. Key deer have evolved in the absence of mammalian predators and we hypothesize that they exhibit reduced vigilance or concern when encountering other species because of predator naivety. Key deer and raccoons are commonly associated with humans and urbanization and an alternative hypothesis is that the interactions are a consequence of heightened deer density, causing a greater probability of sustained interactions with the common mesocarnivores.

Influence of dipolar interactions on the superparamagnetic relaxation time of γ-Fe2O3

NASA Astrophysics Data System (ADS)

Labzour, A.; Housni, A.; Limame, K.; Essahlaoui, A.; Sayouri, S.

2017-03-01

Influence of dipolar interactions on the Néel superparamagnetic relaxation time, τ , of an assembly of ultrafine ferromagnetic particles (γ-Fe2O3 ) with uniaxial anisotropy and of different sizes has been widely studied using Mössbauer technique. These studies, based on different analytical approaches, have shown that τ decreases with increasing interactions between particles. To interpret these results, we propose a model where interaction effects are considered as being due to a constant and external randomly oriented magnetic field B(Ψ, ϕ). The model is based on the resolution of the Fokker-Planck equation (FPE), generalizes previous calculations and gives satisfactory interpretation of the relaxation phenomenon in such systems.

Exploring an Age Difference in Preschool Children’s Competitiveness Following a Competition

PubMed Central

Hu, Yu; Zhu, Yi

2018-01-01

Literature suggests that resource acquisition compels competition in young children. However, little is still known about the development of preschool children’s competitiveness. In this preliminary study, 166 children (aged 2–4 and 5–6 years) engaged in a dyadic competition which resulted in a winning and a losing group (in a control/non-competition group, participants engaged in a similar task which did not lead to winning/losing outcome), and then experimenters tracked their decisions to compete again with a rival (i.e., an individual they interacted in the previous competition task) and a non-rival competitor (i.e., an anonymous classmate they did not interact in the previous competition task) for a reward, respectively. As expected, results showed an age-related decreasing trend in the percentage of choices to compete with a competitor. However, this age difference was only significant in the control group when participants played with the partner with whom they interacted in the previous game and in the losing group when participants competed with a non-rival competitor. This study contributes to our knowledge of how competitiveness develop in preschool childhood, and calls for further research on the roles of motivation and cognitive control in children’s competitiveness. PMID:29593610

The influence of exercise identity and social physique anxiety on exercise dependence

PubMed Central

Cook, Brian; Karr, Trisha M.; Zunker, Christie; Mitchell, James E.; Thompson, Ron; Sherman, Roberta; Erickson, Ann; Cao, Li; Crosby, Ross D.

2015-01-01

Background Previous research has identified exercise identity and social physique anxiety as two independent factors that are associated with exercise dependence. Aims The purpose of our study was to investigate the unique and interactive effect of these two known correlates of exercise dependence in a sample of 1,766 female runners. Methods Regression analyses tested the main effects of exercise identity and social physique anxiety on exercise dependence. An interaction term was calculated to examine the potential moderating effect of social physique anxiety on the exercise identity and exercise dependence relationship. Results Results indicate a main effect for exercise identity and social physique anxiety on exercise dependence; and the interaction of these factors explained exercise dependence scores beyond the independent effects. Thus, social physique anxiety acted as a moderator in the exercise identity and exercise dependence relationship. Discussion Our results indicate that individuals who strongly identify themselves as an exerciser and also endorse a high degree of social physique anxiety may be at risk for developing exercise dependence. Conclusions Our study supports previous research which has examined factors that may contribute to the development of exercise dependence and also suggests a previously unknown moderating relationship for social physique anxiety on exercise dependence. PMID:26551910

Visual adaptation dominates bimodal visual-motor action adaptation

PubMed Central

de la Rosa, Stephan; Ferstl, Ylva; Bülthoff, Heinrich H.

2016-01-01

A long standing debate revolves around the question whether visual action recognition primarily relies on visual or motor action information. Previous studies mainly examined the contribution of either visual or motor information to action recognition. Yet, the interaction of visual and motor action information is particularly important for understanding action recognition in social interactions, where humans often observe and execute actions at the same time. Here, we behaviourally examined the interaction of visual and motor action recognition processes when participants simultaneously observe and execute actions. We took advantage of behavioural action adaptation effects to investigate behavioural correlates of neural action recognition mechanisms. In line with previous results, we find that prolonged visual exposure (visual adaptation) and prolonged execution of the same action with closed eyes (non-visual motor adaptation) influence action recognition. However, when participants simultaneously adapted visually and motorically – akin to simultaneous execution and observation of actions in social interactions - adaptation effects were only modulated by visual but not motor adaptation. Action recognition, therefore, relies primarily on vision-based action recognition mechanisms in situations that require simultaneous action observation and execution, such as social interactions. The results suggest caution when associating social behaviour in social interactions with motor based information. PMID:27029781

A Proteome-wide Fission Yeast Interactome Reveals Network Evolution Principles from Yeasts to Human.

PubMed

Vo, Tommy V; Das, Jishnu; Meyer, Michael J; Cordero, Nicolas A; Akturk, Nurten; Wei, Xiaomu; Fair, Benjamin J; Degatano, Andrew G; Fragoza, Robert; Liu, Lisa G; Matsuyama, Akihisa; Trickey, Michelle; Horibata, Sachi; Grimson, Andrew; Yamano, Hiroyuki; Yoshida, Minoru; Roth, Frederick P; Pleiss, Jeffrey A; Xia, Yu; Yu, Haiyuan

2016-01-14

Here, we present FissionNet, a proteome-wide binary protein interactome for S. pombe, comprising 2,278 high-quality interactions, of which ∼ 50% were previously not reported in any species. FissionNet unravels previously unreported interactions implicated in processes such as gene silencing and pre-mRNA splicing. We developed a rigorous network comparison framework that accounts for assay sensitivity and specificity, revealing extensive species-specific network rewiring between fission yeast, budding yeast, and human. Surprisingly, although genes are better conserved between the yeasts, S. pombe interactions are significantly better conserved in human than in S. cerevisiae. Our framework also reveals that different modes of gene duplication influence the extent to which paralogous proteins are functionally repurposed. Finally, cross-species interactome mapping demonstrates that coevolution of interacting proteins is remarkably prevalent, a result with important implications for studying human disease in model organisms. Overall, FissionNet is a valuable resource for understanding protein functions and their evolution. Copyright © 2016 Elsevier Inc. All rights reserved.

Finite-size scaling with respect to interaction and disorder strength at the many-body localization transition

NASA Astrophysics Data System (ADS)

Kudo, Kazue; Deguchi, Tetsuo

2018-06-01

We present a finite-size scaling for both interaction and disorder strengths in the critical regime of the many-body localization (MBL) transition for a spin-1/2 X X Z spin chain with a random field by studying level statistics. We show how the dynamical transition from the thermal to MBL phase depends on interaction together with disorder by evaluating the ratio of adjacent level spacings, and thus, extend previous studies in which interaction coupling is fixed. We introduce an extra critical exponent in order to describe the nontrivial interaction dependence of the MBL transition. It is characterized by the ratio of the disorder strength to the power of the interaction coupling with respect to the extra critical exponent and not by the simple ratio between them.

Strong electronic interaction and multiple quantum Hall ferromagnetic phases in trilayer graphene

NASA Astrophysics Data System (ADS)

Datta, Biswajit; Dey, Santanu; Samanta, Abhisek; Agarwal, Hitesh; Borah, Abhinandan; Watanabe, Kenji; Taniguchi, Takashi; Sensarma, Rajdeep; Deshmukh, Mandar M.

2017-02-01

Quantum Hall effect provides a simple way to study the competition between single particle physics and electronic interaction. However, electronic interaction becomes important only in very clean graphene samples and so far the trilayer graphene experiments are understood within non-interacting electron picture. Here, we report evidence of strong electronic interactions and quantum Hall ferromagnetism seen in Bernal-stacked trilayer graphene. Due to high mobility ~500,000 cm2 V-1 s-1 in our device compared to previous studies, we find all symmetry broken states and that Landau-level gaps are enhanced by interactions; an aspect explained by our self-consistent Hartree-Fock calculations. Moreover, we observe hysteresis as a function of filling factor and spikes in the longitudinal resistance which, together, signal the formation of quantum Hall ferromagnetic states at low magnetic field.

The Nature of Elementary Science Teachers' Experiences with Synchronous Online, Asynchronous Online and Face-to-Face Coaching

NASA Astrophysics Data System (ADS)

Gilbert, Amanda M.

This study investigated the nature of instructional coaching interactions in three formats: online synchronous, online asynchronous, and face-to-face. Knight's (2007) Seven Partnership Principles of Instructional Coaching were used as a framework to analyze and compare the coaching interactions between coach and teacher to determine whether online coaching may be a viable option to provide support for the teachers unprepared to teach the new science standards. Some previous research has suggested that online communication can result in deeper personal interactions (Walther, 1996), while other studies suggest that interactions are more natural and easier in formats that are more similar to face-to-face interactions (Kock, 2005). The findings of this study support the media naturalness theory (Kock, 2005) and suggest that collaboration may be especially difficult in asynchronous online communication. Although differences were noted in the actual interactions, teacher perception remained fairly consistently positive across the three formats. Research beyond this exploratory study is needed to make findings generalizable.

[The role of genotype in the intergenerational transmission of experiences of childhood adversity].

PubMed

Reichl, Corinna; Kaess, Michael; Resch, Franz; Brunner, Romuald

2014-09-01

The prevalence of childhood abuse and maltreatment is estimated to lie at about 15% in the overall German population. Previous research suggested that about one third of all individuals who had experienced childhood adversity subsequently maltreated their own children or responded insensitively to their children's needs. Empirical studies imply that interindividual differences in the responsiveness to childhood adversity can partially be explained by gene-environment interactions. This article discusses the potential interplay of genes and environment in the context of transmitting maltreating behavior and (in)sensitive parenting against the background of current challenges in genetic research. Selected studies on gene × environment interactions are presented and relevant gene polymorphisms are identified. Overall, previous studies reported interactions between polymorphisms of the serotonergic, dopaminergic, oxytocin-related, and arginine vasopressin-related systems and childhood experiences of care and abuse in the prediction of social behaviors during mother-child interactions. The results indicate a differential susceptibility toward both negative and positive environments which is dependent on genetic characteristics. Future research should thus investigate the effects of children's presumed risk gene variants toward negative as well as positive parenting. This could contribute to a deeper understanding of the underlying mechanisms of the intergenerational transmission of abusive and beneficial parenting behavior and help to avoid false stigmatizations.

The Interplay of Episodic and Semantic Memory in Guiding Repeated Search in Scenes

ERIC Educational Resources Information Center

Vo, Melissa L.-H.; Wolfe, Jeremy M.

2013-01-01

It seems intuitive to think that previous exposure or interaction with an environment should make it easier to search through it and, no doubt, this is true in many real-world situations. However, in a recent study, we demonstrated that previous exposure to a scene does not necessarily speed search within that scene. For instance, when observers…

Maternal condition and previous reproduction interact to affect offspring sex in a wild mammal.

PubMed

Douhard, Mathieu; Festa-Bianchet, Marco; Pelletier, Fanie

2016-08-01

Trivers and Willard proposed that offspring sex ratio should vary with maternal condition when condition, meant as maternal capacity to care, has different fitness consequences for sons and daughters. In polygynous and dimorphic species, mothers in good condition should preferentially produce sons, whereas mothers in poor condition should produce more daughters. Despite its logical appeal, support for this hypothesis has been inconsistent. Sex-ratio variation may be influenced by additional factors, such as environmental conditions and previous reproduction, which are often ignored in empirical studies. We analysed 39 years of data on bighorn sheep (Ovis canadensis) that fit all the assumptions of the Trivers-Willard hypothesis. Production of sons increased with maternal condition only for mothers that weaned a son the previous year. This relationship likely reflects a mother's ability to bear the higher reproductive costs of sons. The interaction between maternal condition and previous weaning success on the probability of producing a son was independent of the positive effect of paternal reproductive success. Maternal and paternal effects accounted for similar proportions of the variance in offspring sex. Maternal reproductive history should be considered in addition to current condition in studies of sex allocation. © 2016 The Author(s).

Teacher Feedback and Interactions in Physical Education: Effects of Student Gender and Physical Activities

ERIC Educational Resources Information Center

Nicaise, Virginie; Cogerino, Genevieve; Fairclough, Stuart; Bois, Julien; Davis, Kathryn

2007-01-01

Previous research conducted in both classroom and physical education (PE) settings has examined the impact of student gender on teacher-student interactions. The purpose of this study was to extend this line of research by analysing the influence of student gender and different types of physical activity on the frequency and nature of teacher…

Training Teaching Staff to Facilitate Spontaneous Communication in Children with Autism: Adult Interactive Style Intervention (AISI)

ERIC Educational Resources Information Center

Kossyvaki, Lila; Jones, Glenys; Guldberg, Karen

2016-01-01

Previous research has demonstrated that the way adults interact with children with autism can have a great impact on their spontaneous communication. However, to date, few studies have focused on modifying adults' behaviour and even fewer have been conducted in school settings which actively involve teaching staff in designing the intervention.…

Symmetry considerations in the scattering of identical composite bodies

NASA Technical Reports Server (NTRS)

Norbury, J. W.; Townsend, L. W.; Deutchman, P. A.

1986-01-01

Previous studies of the interactions between composite particles were extended to the case in which the composites are identical. The form of the total interaction potential matrix elements was obtained, and guidelines for their explicit evaluation were given. For the case of elastic scattering of identical composites, the matrix element approach was shown to be equivalent to the scattering amplitude method.

Social Interaction and Conditional Self-Discrimination under a Paradigm of Avoidance and Positive Reinforcement in Wistar Rats

ERIC Educational Resources Information Center

Penagos-Corzo, Julio C.; Pérez-Acosta, Andrés M.; Hernández, Ingrid

2015-01-01

The experiment reported here uses a conditional self-discrimination task to examine the influence of social interaction on the facilitation of self-discrimination in rats. The study is based on a previous report (Penagos- Corzo et al., 2011) showing positive evidence of such facilitation, but extending the exposition to social interaction…

Brief Report: Diminished Gaze Preference for Dynamic Social Interaction Scenes in Youth with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Shaffer, Rebecca C.; Pedapati, Ernest V.; Shic, Frederick; Gaietto, Kristina; Bowers, Katherine; Wink, Logan K.; Erickson, Craig A.

2017-01-01

In this study, we present an eye-tracking paradigm, adapted from previous work with toddlers, for assessing social-interaction looking preferences in youth ages 5-17 with ASD and typically-developing controls (TDC). Videos of children playing together (Social Scenes, SS) were presented side-by-side with animated geometric shapes (GS). Participants…

"I Was Born Full Deaf." Written Language Outcomes after 1 Year of Strategic and Interactive Writing Instruction

ERIC Educational Resources Information Center

Wolbers, Kimberly A.; Dostal, Hannah M.; Bowers, Lisa M.

2012-01-01

Nonstandard grammatical forms are often present in the writing of deaf students that are rarely, if ever, seen in the writing of hearing students. With the implementation of Strategic and Interactive Writing Instruction (SIWI) in previous studies, students have demonstrated significant gains in high-level writing skills (e.g., text structure) but…

The VIRI (Virtual, Interactive, Real-Time, Instructor-Led) Classroom: The Impact of Blended Synchronous Online Courses on Student Performance, Engagement, and Satisfaction

ERIC Educational Resources Information Center

Francescucci, Anthony; Foster, Mary

2013-01-01

Previous research on blended course offerings focuses on the addition of asynchronous online content to an existing course. While some explore synchronous communication, few control for differences between treatment groups. This study investigates the impact of teaching a blended course, using a virtual, interactive, real-time, instructor-led…

Competing interactions in semiconductor quantum dots

DOE PAGES

van den Berg, R.; Brandino, G. P.; El Araby, O.; ...

2014-10-14

In this study, we introduce an integrability-based method enabling the study of semiconductor quantum dot models incorporating both the full hyperfine interaction as well as a mean-field treatment of dipole-dipole interactions in the nuclear spin bath. By performing free induction decay and spin echo simulations we characterize the combined effect of both types of interactions on the decoherence of the electron spin, for external fields ranging from low to high values. We show that for spin echo simulations the hyperfine interaction is the dominant source of decoherence at short times for low fields, and competes with the dipole-dipole interactions atmore » longer times. On the contrary, at high fields the main source of decay is due to the dipole-dipole interactions. In the latter regime an asymmetry in the echo is observed. Furthermore, the non-decaying fraction previously observed for zero field free induction decay simulations in quantum dots with only hyperfine interactions, is destroyed for longer times by the mean-field treatment of the dipolar interactions.« less

Color surface-flow visualization of fin-generated shock wave boundary-layer interactions

NASA Technical Reports Server (NTRS)

Lu, F. K.; Settles, G. S.

1990-01-01

Kerosene-lampblack mixtures with addition of a ground colored chalk were used in an experiment on visualizing surface flows of swept shock boundary-layer interactions. The results show that contrasting colors intensify the visualization of different regions of the interaction surface, and help the eye in following the fine streaks to locate the upstream influence. The study confirms observations of the separation occurring at shock strength below accepted values. The superiority of the reported technique over the previous monochrome technique is demonstrated.

Color surface-flow visualization of fin-generated shock wave boundary-layer interactions

NASA Astrophysics Data System (ADS)

Lu, F. K.; Settles, G. S.

1990-03-01

Kerosene-lampblack mixtures with addition of a ground colored chalk were used in an experiment on visualizing surface flows of swept shock boundary-layer interactions. The results show that contrasting colors intensify the visualization of different regions of the interaction surface, and help the eye in following the fine streaks to locate the upstream influence. The study confirms observations of the separation occurring at shock strength below accepted values. The superiority of the reported technique over the previous monochrome technique is demonstrated.

Casimir Interaction from Magnetically Coupled Eddy Currents

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

Intravaia, Francesco; Henkel, Carsten

2009-09-25

We study the quantum and thermal fluctuations of eddy (Foucault) currents in thick metallic plates. A Casimir interaction between two plates arises from the coupling via quasistatic magnetic fields. As a function of distance, the relevant eddy current modes cross over from a quantum to a thermal regime. These modes alone reproduce previously discussed thermal anomalies of the electromagnetic Casimir interaction between good conductors. In particular, they provide a physical picture for the Casimir entropy whose nonzero value at zero temperature arises from a correlated, glassy state.

Muon neutrino CCQE at MINERvA

DOE PAGES

Betancourt, M.

2016-12-13

A precise understanding of quasi-elastic interactions is crucial to measure neutrino oscillations. The MINERvA experiment is currently working on different analyses of muon neutrino charged current quasi-elastic interactions. Here, we present updates to the previous quasi-elastic measurement, using a new flux, and we present the status of several analyses in progress; including double differential cross sections, a study of final state interactions using a sample with muon and a proton and the status of the CCQE analysis in the medium energy neutrino beam.

Laser-driven Ion Acceleration using Nanodiamonds

NASA Astrophysics Data System (ADS)

D'Hauthuille, Luc; Nguyen, Tam; Dollar, Franklin

2016-10-01

Interactions of high-intensity lasers with mass-limited nanoparticles enable the generation of extremely high electric fields. These fields accelerate ions, which has applications in nuclear medicine, high brightness radiography, as well as fast ignition for inertial confinement fusion. Previous studies have been performed with ensembles of nanoparticles, but this obscures the physics of the interaction due to the wide array of variables in the interaction. The work presented here looks instead at the interactions of a high intensity short pulse laser with an isolated nanodiamond. Specifically, we studied the effect of nanoparticle size and intensity of the laser on the interaction. A novel target scheme was developed to isolate the nanodiamond. Particle-in-cell simulations were performed using the EPOCH framework to show the sheath fields and resulting energetic ion beams.

A theoretical study of interaction effects on the remanence curves of particulate dispersions

NASA Astrophysics Data System (ADS)

Fearon, M.; Chantrell, R. W.; Wohlfarth, E. P.

1990-05-01

The remanence curves of strongly interacting fine-particle systems are investigated theoretically. It is shown that the Henkel plot of the dc demagnetisation remanence vs. the isothermal remanence is a useful representation of interactions. The form of the plot is found to be a reflection of the magnetic and physical microstructure of the material, which is consistent with experimental data. The relationship between the Henkel plot and the noise of a particulate recording medium, another property dependent on the microstructure, is also considered. The Interaction Field Factor (IFF), a single parameter characterising the non-linearity of the Henkel plot, is also investigated. The results are consistent with a previous experimental study. Finally, the effect of interactions on the Switching Field Distribution are investigated.

A Trio of Brownian Donkeys

NASA Astrophysics Data System (ADS)

van den Broeck, C.; Cleuren, B.; Kawai, R.; Kambon, M.

A previously introduced model (B. Cleuren and C. Van den Broeck, Europhys. Lett. 54, 1 (2001)) is studied numerically. Pure negative mobility is found for the minimum number of three interacting walkers.

Effect of Interpersonal Interaction on Festinating Gait Rehabilitation in Patients with Parkinson’s Disease

PubMed Central

Uchitomi, Hirotaka; Ogawa, Ken-ichiro; Orimo, Satoshi; Wada, Yoshiaki; Miyake, Yoshihiro

2016-01-01

Although human walking gait rhythms are generated by native individual gait dynamics, these gait dynamics change during interactions between humans. A typical phenomenon is synchronization of gait rhythms during cooperative walking. Our previous research revealed that fluctuation characteristics in stride interval of subjects with Parkinson’s disease changed from random to 1/f fluctuation as fractal characteristics during cooperative walking with the gait assist system Walk-Mate, which emulates a human interaction using interactive rhythmic cues. Moreover, gait dynamics were relearned through Walk-Mate gait training. However, the system’s clinical efficacy was unclear because the previous studies did not focus on specific gait rhythm disorder symptoms. Therefore, this study aimed to evaluate the effect of Walk-Mate on festinating gait among subjects with Parkinson’s disease. Three within-subject experimental conditions were used: (1) preinteraction condition, (2) interaction condition, and (3) postinteraction condition. The only difference between conditions was the interactive rhythmic cues generated by Walk-Mate. Because subjects with festinating gait gradually and involuntarily decreased their stride interval, the regression slope of stride interval as an index of severity of preinteraction festinating gait was elevated. The regression slope in the interaction condition was more gradual than during the preinteraction condition, indicating that the interactive rhythmic cues contributed to relieving festinating gait and stabilizing gait dynamics. Moreover, the gradual regression slope was carried over to the postinteraction condition, indicating that subjects with festinating gait have the potential to relearn stable gait dynamics. These results suggest that disordered gait dynamics are clinically restored through interactive rhythmic cues and that Walk-Mate may have the potential to assist therapists in more effective rehabilitation. Trial Registration: UMIN Clinical Trials Registry UMIN000012591 PMID:27253376

Effect of Interpersonal Interaction on Festinating Gait Rehabilitation in Patients with Parkinson's Disease.

PubMed

Uchitomi, Hirotaka; Ogawa, Ken-Ichiro; Orimo, Satoshi; Wada, Yoshiaki; Miyake, Yoshihiro

2016-01-01

Although human walking gait rhythms are generated by native individual gait dynamics, these gait dynamics change during interactions between humans. A typical phenomenon is synchronization of gait rhythms during cooperative walking. Our previous research revealed that fluctuation characteristics in stride interval of subjects with Parkinson's disease changed from random to 1/f fluctuation as fractal characteristics during cooperative walking with the gait assist system Walk-Mate, which emulates a human interaction using interactive rhythmic cues. Moreover, gait dynamics were relearned through Walk-Mate gait training. However, the system's clinical efficacy was unclear because the previous studies did not focus on specific gait rhythm disorder symptoms. Therefore, this study aimed to evaluate the effect of Walk-Mate on festinating gait among subjects with Parkinson's disease. Three within-subject experimental conditions were used: (1) preinteraction condition, (2) interaction condition, and (3) postinteraction condition. The only difference between conditions was the interactive rhythmic cues generated by Walk-Mate. Because subjects with festinating gait gradually and involuntarily decreased their stride interval, the regression slope of stride interval as an index of severity of preinteraction festinating gait was elevated. The regression slope in the interaction condition was more gradual than during the preinteraction condition, indicating that the interactive rhythmic cues contributed to relieving festinating gait and stabilizing gait dynamics. Moreover, the gradual regression slope was carried over to the postinteraction condition, indicating that subjects with festinating gait have the potential to relearn stable gait dynamics. These results suggest that disordered gait dynamics are clinically restored through interactive rhythmic cues and that Walk-Mate may have the potential to assist therapists in more effective rehabilitation. UMIN Clinical Trials Registry UMIN000012591.

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

Farmer, M. T.

The overall objective of the current work is to carry out a scoping analysis to determine the impact of ATF on late phase accident progression; in particular, the molten core-concrete interaction portion of the sequence that occurs after the core debris fails the reactor vessel and relocates into containment. This additional study augments previous work by including kinetic effects that govern chemical reaction rates during core-concrete interaction. The specific ATF considered as part of this study is SiC-clad UO 2.

PPARγ Pro12Ala interacts with fat intake for obesity and weight loss in a behavioural treatment based on the Mediterranean diet

PubMed Central

Garaulet, Marta; Smith, Caren E; Hernández-González, Teresa; Lee, Yu-Chi; Ordovás, Jose M.

2014-01-01

Scope The goal of this study was to examine whether the Pro12Ala polymorphism of peroxisome proliferator-activated receptor γ (PPARγ) is associated with insulin resistance, obesity and weight loss and to analyze potential interactions between fat intake and PPARγ polymorphism in a Spanish overweight/obese population. Materials and methods We recruited 1465 subjects enrolled in a behavioural treatment program for obesity based on a Mediterranean diet, which included the following: dietary treatment, physical activity, nutritional education and behavioral techniques. A significant association was found between PPARγ2 Pro12Ala genotype and plasma insulin concentration and homeostasis model assessment insulin resistance. Subjects with the Ala12 genotype had lower insulin levels than those with the Pro12Pro genotype. We detected a gene–diet interaction between the PPARγ Pro12Ala polymorphism and MUFA for BMI and body fat. Furthermore, we detected an interaction between the PPARγ Pro12Ala polymorphism and fat intake for total weight loss (p<0.001). When total fat intake was high, Ala12-carriers exhibited a significantly lower percentage of total weight loss than major-allele-carriers (p=0.037). Conclusion Data are consistent with previous results showing a protective role for the Ala12 allele against insulin resistance, and replicate an earlier study that detected an interaction between dietary MUFA and PPARγ2 for BMI. Our detection of a gene–diet interaction between PPARγ Pro12Ala and fat intake for weight loss may explain previous discrepancies among different studies. PMID:22102511

Electrostatic Interactions in the Binding Pathway of a Transient Protein Complex Studied by NMR and Isothermal Titration Calorimetry*

PubMed Central

Meneses, Erick; Mittermaier, Anthony

2014-01-01

Much of our knowledge of protein binding pathways is derived from extremely stable complexes that interact very tightly, with lifetimes of hours to days. Much less is known about weaker interactions and transient complexes because these are challenging to characterize experimentally. Nevertheless, these types of interactions are ubiquitous in living systems. The combination of NMR relaxation dispersion Carr–Purcell–Meiboom–Gill (CPMG) experiments and isothermal titration calorimetry allows the quantification of rapid binding kinetics for complexes with submillisecond lifetimes that are difficult to study using conventional techniques. We have used this approach to investigate the binding pathway of the Src homology 3 (SH3) domain from the Fyn tyrosine kinase, which forms complexes with peptide targets whose lifetimes are on the order of about a millisecond. Long range electrostatic interactions have been shown to play a critical role in the binding pathways of tightly binding complexes. The role of electrostatics in the binding pathways of transient complexes is less well understood. Similarly to previously studied tight complexes, we find that SH3 domain association rates are enhanced by long range electrostatics, whereas short range interactions are formed late in the docking process. However, the extent of electrostatic association rate enhancement is several orders of magnitudes less, whereas the electrostatic-free basal association rate is significantly greater. Thus, the SH3 domain is far less reliant on electrostatic enhancement to achieve rapid association kinetics than are previously studied systems. This suggests that there may be overall differences in the role played by electrostatics in the binding pathways of extremely stable versus transient complexes. PMID:25122758

Is there a difference in survival between men and women suffering in-hospital cardiac arrest?

PubMed

Israelsson, Johan; Persson, Carina; Strömberg, Anna; Arestedt, Kristofer

2014-01-01

To describe in-hospital cardiac arrest (CA) events with regard to sex and to investigate if sex is associated with survival. Previous studies exploring differences between sexes are incongruent with regard to clinical outcomes. In order to provide equality and improve care, further investigations into these aspects are warranted. This registry study included 286 CAs. To investigate if sex was associated with survival, logistic regression analyses were performed. The proportion of CA with a resuscitation attempt compared to CA without resuscitation was higher among men. There were no associations between sex and survival when controlling for previously known predictors and interaction effects. Sex does not appear to be a predictor for survival among patients suffering CA where resuscitation is attempted. The difference regarding proportion of resuscitation attempts requires more attention. It is important to consider possible interaction effects when studying the sex perspective. Copyright © 2014 Elsevier Inc. All rights reserved.

Renormalization of Coulomb interactions in a system of two-dimensional tilted Dirac fermions

NASA Astrophysics Data System (ADS)

Lee, Yu-Wen; Lee, Yu-Li

2018-01-01

We investigate the effects of long-ranged Coulomb interactions in a tilted Dirac semimetal in two dimensions by using the perturbative renormalization-group (RG) method. Depending on the magnitude of the tilting parameter, the undoped system can have either Fermi points (type I) or Fermi lines (type II). Previous studies usually performed the renormalization-group transformations by integrating out the modes with large momenta. This is problematic when the Fermi surface is open, like type-II Dirac fermions. In this work we study the effects of Coulomb interactions, following the spirit of Shankar [Rev. Mod. Phys. 66, 129 (1994), 10.1103/RevModPhys.66.129], by introducing a cutoff in the energy scale around the Fermi surface and integrating out the high-energy modes. For type-I Dirac fermions, our result is consistent with that of the previous work. On the other hand, we find that for type-II Dirac fermions, the magnitude of the tilting parameter increases monotonically with lowering energies. This implies the stability of type-II Dirac fermions in the presence of Coulomb interactions, in contrast with previous results. Furthermore, for type-II Dirac fermions, the velocities in different directions acquire different renormalization even if they have the same bare values. By taking into account the renormalization of the tilting parameter and the velocities due to the Coulomb interactions, we show that while the presence of a charged impurity leads only to charge redistribution around the impurity for type-I Dirac fermions, for type-II Dirac fermions, the impurity charge is completely screened, albeit with a very long screening length. The latter indicates that the temperature dependence of physical observables are essentially determined by the RG equations we derived. We illustrate this by calculating the temperature dependence of the compressibility and specific heat of the interacting tilted Dirac fermions.

Microsatellite polymorphisms associated with human behavioural and psychological phenotypes including a gene-environment interaction.

PubMed

Bagshaw, Andrew T M; Horwood, L John; Fergusson, David M; Gemmell, Neil J; Kennedy, Martin A

2017-02-03

The genetic and environmental influences on human personality and behaviour are a complex matter of ongoing debate. Accumulating evidence indicates that short tandem repeats (STRs) in regulatory regions are good candidates to explain heritability not accessed by genome-wide association studies. We tested for associations between the genotypes of four selected repeats and 18 traits relating to personality, behaviour, cognitive ability and mental health in a well-studied longitudinal birth cohort (n = 458-589) using one way analysis of variance. The repeats were a highly conserved poly-AC microsatellite in the upstream promoter region of the T-box brain 1 (TBR1) gene and three previously studied STRs in the activating enhancer-binding protein 2-beta (AP2-β) and androgen receptor (AR) genes. Where significance was found we used multiple regression to assess the influence of confounding factors. Carriers of the shorter, most common, allele of the AR gene's GGN microsatellite polymorphism had fewer anxiety-related symptoms, which was consistent with previous studies, but in our study this was not significant following Bonferroni correction. No associations with two repeats in the AP2-β gene withstood this correction. A novel finding was that carriers of the minor allele of the TBR1 AC microsatellite were at higher risk of conduct problems in childhood at age 7-9 (p = 0.0007, which did pass Bonferroni correction). Including maternal smoking during pregnancy (MSDP) in models controlling for potentially confounding influences showed that an interaction between TBR1 genotype and MSDP was a significant predictor of conduct problems in childhood and adolescence (p < 0.001), and of self-reported criminal behaviour up to age 25 years (p ≤ 0.02). This interaction remained significant after controlling for possible confounders including maternal age at birth, socio-economic status and education, and offspring birth weight. The potential functional importance of the TBR1 gene's promoter microsatellite deserves further investigation. Our results suggest that it participates in a gene-environment interaction with MDSP and antisocial behaviour. However, previous evidence that mothers who smoke during pregnancy carry genes for antisocial behaviour suggests that epistasis may influence the interaction.

Promotion of cooperation by adaptive interaction: The role of heterogeneity in neighborhoods

NASA Astrophysics Data System (ADS)

Han, Xu; Zhao, Xiaowei; Xia, Haoxiang

2018-07-01

Evolution of cooperation in prisoner's dilemma games has been studied extensively in the past decades. Recent studies have investigated the effect of adaptive interaction intensity on spatial prisoner's dilemma, showing that if individuals can adjust their interaction intensity with each opponent at the same extent, cooperation can be promoted in a proper scale. However, the previous studies about adaptive interaction willingness do not consider the heterogeneity of the opponents. In this paper, a simulative model is developed to examine whether and how the interactive diversity influences cooperation in the spatial prisoner's dilemma games, in which individuals consider the corresponding behavior of different opponents. The simulation results show that the proposed mechanism can effectively promote cooperation, and the average payoff of the system can significantly be improved by high interaction intensity between cooperators. In addition, we also show four kinds of different individuals to analyze the evolution progresses. The simulations show that cooperators on the boundary decrease their interaction willingness, which makes the boundary defectors lose their opportunity to participate in the interaction and be invaded by cooperators.

Computational Study of the Structure of a Sepiolite/Thioindigo Mayan Pigment

PubMed Central

Alvarado, Manuel; Chianelli, Russell C.; Arrowood, Roy M.

2012-01-01

The interaction of thioindigo and the phyllosilicate clay sepiolite is investigated using density functional theory (DFT) and molecular orbital theory (MO). The best fit to experimental UV/Vis spectra occurs when a single thioindigo molecule attaches via Van der Waals forces to a tetrahedrally coordinated Al3+ cation with an additional nearby tetrahedrally coordinated Al3+ also present. The thioindigo molecule distorts from its planar structure, a behavior consistent with a color change. Due to the weak interaction between thioindigo and sepiolite we conclude that the thioindigo molecule must be trapped in a channel, an observation consistent with previous experimental studies. Future computational studies will look at the interaction of indigo with sepiolite. PMID:23193386

Intrinsic limits to gene regulation by global crosstalk

PubMed Central

Friedlander, Tamar; Prizak, Roshan; Guet, Călin C.; Barton, Nicholas H.; Tkačik, Gašper

2016-01-01

Gene regulation relies on the specificity of transcription factor (TF)–DNA interactions. Limited specificity may lead to crosstalk: a regulatory state in which a gene is either incorrectly activated due to noncognate TF–DNA interactions or remains erroneously inactive. As each TF can have numerous interactions with noncognate cis-regulatory elements, crosstalk is inherently a global problem, yet has previously not been studied as such. We construct a theoretical framework to analyse the effects of global crosstalk on gene regulation. We find that crosstalk presents a significant challenge for organisms with low-specificity TFs, such as metazoans. Crosstalk is not easily mitigated by known regulatory schemes acting at equilibrium, including variants of cooperativity and combinatorial regulation. Our results suggest that crosstalk imposes a previously unexplored global constraint on the functioning and evolution of regulatory networks, which is qualitatively distinct from the known constraints that act at the level of individual gene regulatory elements. PMID:27489144

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

van den Berg, R.; Brandino, G. P.; El Araby, O.

In this study, we introduce an integrability-based method enabling the study of semiconductor quantum dot models incorporating both the full hyperfine interaction as well as a mean-field treatment of dipole-dipole interactions in the nuclear spin bath. By performing free induction decay and spin echo simulations we characterize the combined effect of both types of interactions on the decoherence of the electron spin, for external fields ranging from low to high values. We show that for spin echo simulations the hyperfine interaction is the dominant source of decoherence at short times for low fields, and competes with the dipole-dipole interactions atmore » longer times. On the contrary, at high fields the main source of decay is due to the dipole-dipole interactions. In the latter regime an asymmetry in the echo is observed. Furthermore, the non-decaying fraction previously observed for zero field free induction decay simulations in quantum dots with only hyperfine interactions, is destroyed for longer times by the mean-field treatment of the dipolar interactions.« less

Communicating with people living with dementia who are nonverbal: The creation of Adaptive Interaction.

PubMed

Ellis, Maggie; Astell, Arlene

2017-01-01

Loss of verbal language production makes people with dementia appear unreachable. We previously presented a case study applying nonverbal communication techniques with a lady with dementia who could no longer speak, which we termed Adaptive Interaction. The current small-n study examines the applicability of Adaptive Interaction as a general tool for uncovering the communication repertoires of non-verbal individuals living with dementia. Communicative responses of 30 interaction sessions were coded and analysed in two conditions: Standard (Baseline) and Adaptive Interaction (Intervention). All participants retained the ability to interact plus a unique communication repertoire comprising a variety of nonverbal components, spanning eye gaze, emotion expression, and movement. In comparison to Baseline sessions, Intervention sessions were characterised by more smiling, looking at ME and imitation behaviour from the people with dementia. These findings allude to the potential of Adaptive Interaction as the basis for interacting with people living with dementia who can no longer speak.

A weakly nonlinear theory for wave-vortex interactions in curved channel flow

NASA Technical Reports Server (NTRS)

Singer, Bart A.; Erlebacher, Gordon; Zang, Thomas A.

1992-01-01

A weakly nonlinear theory is developed to study the interaction of Tollmien-Schlichting (TS) waves and Dean vortices in curved channel flow. The predictions obtained from the theory agree well with results obtained from direct numerical simulations of curved channel flow, especially for low amplitude disturbances. Some discrepancies in the results of a previous theory with direct numerical simulations are resolved.

Mind-mindedness and maternal responsiveness in infant-mother interactions in mothers with severe mental illness.

PubMed

Pawlby, S; Fernyhough, C; Meins, E; Pariante, C M; Seneviratne, G; Bentall, R P

2010-11-01

Previous cross-diagnosis studies of interaction between mothers with severe mental illness and their babies have concluded that mothers with schizophrenia have deficits in interaction, but these studies have not included healthy controls. In-patients on a mother and baby unit, with diagnoses of schizophrenia (n=15), depressive mood disorders with or without psychosis (n=23), or mood disorders where mania was the predominant feature, with or without psychosis (n=12), were observed interacting with their infants on admission and discharge. Mothers' mind-mindedness and other measures of the quality of maternal and infant behaviour were coded. Findings from this sample were compared with those from healthy mothers and their infants (n=49). Compared with healthy controls, on admission depressed mothers were marginally less likely to comment appropriately on their infants' mental states. Both the depressed and mania groups were more likely to touch their babies and engage in attention-seeking behaviours. Interactional behaviours of mothers in the schizophrenia group were not markedly different from healthy controls. On discharge there were fewer differences between the clinical and healthy groups, although the depressed group continued to engage in more attention-seeking and touching behaviour and the mania group continued to touch their infants more. Only mothers in the schizophrenia group showed changes in interactional behaviours between admission and discharge, talking more to their infants. The findings challenge previous conclusions that mothers with schizophrenia have deficits in their interactions with their babies, and demonstrate that mothers with severe mental illness are able to respond appropriately to their infants' cues.

Filamentous fungal-specific septin AspE is phosphorylated in vivo and interacts with actin, tubulin and other septins in the human pathogen Aspergillus fumigatus

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

Juvvadi, Praveen Rao; Belina, Detti; Soderblom, Erik J.

2013-02-15

Highlights: ► In vivo interactions of the novel septin AspE were identified by GFP-Trap® affinity purification. ► Septins AspA, AspB, AspC and AspD interacted with AspE in vivo. ► Actin and tubulin interacted with AspE in vivo. ► AspE is phosphorylated at six serine residues in vivo. -- Abstract: We previously analyzed the differential localization patterns of five septins (AspA–E), including a filamentous fungal-specific septin, AspE, in the human pathogen Aspergillus fumigatus. Here we utilized the A. fumigatus strain expressing an AspE–EGFP fusion protein and show that this novel septin with a tubular localization pattern in hyphae is phosphorylated inmore » vivo and interacts with the other septins, AspA, AspB, AspC and AspD. The other major proteins interacting with AspE included the cytoskeletal proteins, actin and tubulin, which may be involved in the organization and transport of the septins. This is the first report analyzing the phosphorylation of AspE and localizing the sites of phosphorylation, and opens opportunities for further analysis on the role of post-translational modifications in the assembly and organization of A. fumigatus septins. This study also describes the previously unknown interaction of AspE with the actin-microtubule network. Furthermore, the novel GFP-Trap® affinity purification method used here complements widely-used GFP localization studies in fungal systems.« less

Predictors of victim disclosure in child sexual abuse: Additional evidence from a sample of incarcerated adult sex offenders.

PubMed

Leclerc, Benoit; Wortley, Richard

2015-05-01

The under-reporting of child sexual abuse by victims is a serious problem that may prolong the suffering of victims and leave perpetrators free to continue offending. Yet empirical evidence indicates that victim disclosure rates are low. In this study, we perform regression analysis with a sample of 369 adult child sexual offenders to examine potential predictors of victim disclosure. Specifically, we extend the range of previously examined potential predictors of victim disclosure and investigate interaction effects in order to better capture under which circumstances victim disclosure is more likely. The current study differs from previous studies in that it examines the impact of victim and offense variables on victim disclosure from the perspective of the offender. In line with previous studies, we found that disclosure increased with the age of the victim and if penetration had occurred. In addition, we found that disclosure increased when the victim came from a non-dysfunctional family and resisted the abuse. The presence of an interaction effect highlighted the impact of the situation on victim disclosure. This effect indicated that as victims get older, they are more likely to disclose the abuse when they are not living with the offender at the time of abuse, but less likely to do so when they are living with the offender at the time of abuse. These findings are discussed in relation to previous studies and the need to facilitate victim disclosure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Experimental study of three-wave interactions among capillary-gravity surface waves

NASA Astrophysics Data System (ADS)

Haudin, Florence; Cazaubiel, Annette; Deike, Luc; Jamin, Timothée; Falcon, Eric; Berhanu, Michael

2016-04-01

In propagating wave systems, three- or four-wave resonant interactions constitute a classical nonlinear mechanism exchanging energy between the different scales. Here we investigate three-wave interactions for gravity-capillary surface waves in a closed laboratory tank. We generate two crossing wave trains and we study their interaction. Using two optical methods, a local one (laser doppler vibrometry) and a spatiotemporal one (diffusive light photography), a third wave of smaller amplitude is detected, verifying the three-wave resonance conditions in frequency and in wave number. Furthermore, by focusing on the stationary regime and by taking into account viscous dissipation, we directly estimate the growth rate of the resonant mode. The latter is then compared to the predictions of the weakly nonlinear triadic resonance interaction theory. The obtained results confirm qualitatively and extend previous experimental results obtained only for collinear wave trains. Finally, we discuss the relevance of three-wave interaction mechanisms in recent experiments studying gravity-capillary turbulence.

Experimental study of three-wave interactions among capillary-gravity surface waves.

PubMed

Haudin, Florence; Cazaubiel, Annette; Deike, Luc; Jamin, Timothée; Falcon, Eric; Berhanu, Michael

2016-04-01

In propagating wave systems, three- or four-wave resonant interactions constitute a classical nonlinear mechanism exchanging energy between the different scales. Here we investigate three-wave interactions for gravity-capillary surface waves in a closed laboratory tank. We generate two crossing wave trains and we study their interaction. Using two optical methods, a local one (laser doppler vibrometry) and a spatiotemporal one (diffusive light photography), a third wave of smaller amplitude is detected, verifying the three-wave resonance conditions in frequency and in wave number. Furthermore, by focusing on the stationary regime and by taking into account viscous dissipation, we directly estimate the growth rate of the resonant mode. The latter is then compared to the predictions of the weakly nonlinear triadic resonance interaction theory. The obtained results confirm qualitatively and extend previous experimental results obtained only for collinear wave trains. Finally, we discuss the relevance of three-wave interaction mechanisms in recent experiments studying gravity-capillary turbulence.

Antagonistic interactions are sufficient to explain self-assemblage of bacterial communities in a homogeneous environment: a computational modeling approach

PubMed Central

Zapién-Campos, Román; Olmedo-Álvarez, Gabriela; Santillán, Moisés

2015-01-01

Most of the studies in Ecology have been devoted to analyzing the effects the environment has on individuals, populations, and communities, thus neglecting the effects of biotic interactions on the system dynamics. In the present work we study the structure of bacterial communities in the oligotrophic shallow water system of Churince, Cuatro Cienegas, Mexico. Since the physicochemical conditions of this water system are homogeneous and quite stable in time, it is an excellent candidate to study how biotic factors influence the structure of bacterial communities. In a previous study, the binary antagonistic interactions of 78 bacterial strains, isolated from Churince, were experimentally determined. We employ these data to develop a computer algorithm to simulate growth experiments in a cellular grid representing the pond. Remarkably, in our model, the dynamics of all the simulated bacterial populations is determined solely by antagonistic interactions. Our results indicate that all bacterial strains (even those that are antagonized by many other bacteria) survive in the long term, and that the underlying mechanism is the formation of bacterial community patches. Patches corresponding to less antagonistic and highly susceptible strains are consistently isolated from the highly-antagonistic bacterial colonies by patches of neutral strains. These results concur with the observed features of the bacterial community structure previously reported. Finally, we study how our findings depend on factors like initial population size, differential population growth rates, homogeneous population death rates, and enhanced bacterial diffusion. PMID:26052318

Analysis of Timing Control Mechanism of Utterance and Body Motion Using Dialogue between Human and Communication Robot

NASA Astrophysics Data System (ADS)

Takasugi, Shoji; Yamamoto, Tomohito; Muto, Yumiko; Abe, Hiroyuki; Miyake, Yoshihiro

The purpose of this study is to clarify the effects of timing control of utterance and body motion in human-robot interaction. Our previous study has already revealed the correlation of timing of utterance and body motion in human-human communication. Here we proposed a timing control model based on our previous research and estimated its influence to realize human-like communication using a questionnaire method. The results showed that the difference of effectiveness between the communication with the timing control model and that without it was observed. In addition, elderly people evaluated the communication with timing control much higher than younger people. These results show not only the importance of timing control of utterance and body motion in human communication but also its effectiveness for realizing human-like human-robot interaction.

Limitation of degree information for analyzing the interaction evolution in online social networks

NASA Astrophysics Data System (ADS)

Shang, Ke-Ke; Yan, Wei-Sheng; Xu, Xiao-Ke

2014-04-01

Previously many studies on online social networks simply analyze the static topology in which the friend relationship once established, then the links and nodes will not disappear, but this kind of static topology may not accurately reflect temporal interactions on online social services. In this study, we define four types of users and interactions in the interaction (dynamic) network. We found that active, disappeared, new and super nodes (users) have obviously different strength distribution properties and this result also can be revealed by the degree characteristics of the unweighted interaction and friendship (static) networks. However, the active, disappeared, new and super links (interactions) only can be reflected by the strength distribution in the weighted interaction network. This result indicates the limitation of the static topology data on analyzing social network evolutions. In addition, our study uncovers the approximately stable statistics for the dynamic social network in which there are a large variation for users and interaction intensity. Our findings not only verify the correctness of our definitions, but also helped to study the customer churn and evaluate the commercial value of valuable customers in online social networks.

Sex differences in the effect of aging on dry eye disease.

PubMed

Ahn, Jong Ho; Choi, Yoon-Hyeong; Paik, Hae Jung; Kim, Mee Kum; Wee, Won Ryang; Kim, Dong Hyun

2017-01-01

Aging is a major risk factor in dry eye disease (DED), and understanding sexual differences is very important in biomedical research. However, there is little information about sex differences in the effect of aging on DED. We investigated sex differences in the effect of aging and other risk factors for DED. This study included data of 16,824 adults from the Korea National Health and Nutrition Examination Survey (2010-2012), which is a population-based cross-sectional survey. DED was defined as the presence of frequent ocular dryness or a previous diagnosis by an ophthalmologist. Basic sociodemographic factors and previously known risk factors for DED were included in the analyses. Linear regression modeling and multivariate logistic regression modeling were used to compare the sex differences in the effect of risk factors for DED; we additionally performed tests for interactions between sex and other risk factors for DED in logistic regression models. In our linear regression models, the prevalence of DED symptoms in men increased with age ( R =0.311, P =0.012); however, there was no association between aging and DED in women ( P >0.05). Multivariate logistic regression analyses showed that aging in men was not associated with DED (DED symptoms/diagnosis: odds ratio [OR] =1.01/1.04, each P >0.05), while aging in women was protectively associated with DED (DED symptoms/diagnosis: OR =0.94/0.91, P =0.011/0.003). Previous ocular surgery was significantly associated with DED in both men and women (men/women: OR =2.45/1.77 [DED symptoms] and 3.17/2.05 [DED diagnosis], each P <0.001). Tests for interactions of sex revealed significantly different aging × sex and previous ocular surgery × sex interactions ( P for interaction of sex: DED symptoms/diagnosis - 0.044/0.011 [age] and 0.012/0.006 [previous ocular surgery]). There were distinct sex differences in the effect of aging on DED in the Korean population. DED following ocular surgery also showed sexually different patterns. Age matching and sex matching are strongly recommended in further studies about DED, especially DED following ocular surgery.

Physical robustness of canopy temperature models for crop heat stress simulation across environments and production conditions

USDA-ARS?s Scientific Manuscript database

Despite widespread application in studying climate change impacts, most crop models ignore complex interactions among air temperature, crop and soil water status, CO2 concentration and atmospheric conditions that influence crop canopy temperature. The current study extended previous studies by evalu...

Analysis of Learning Tools in the study of Developmental of Interactive Multimedia Based Physic Learning Charged in Problem Solving

NASA Astrophysics Data System (ADS)

Manurung, Sondang; Demonta Pangabean, Deo

2017-05-01

The main purpose of this study is to produce needs analysis, literature review, and learning tools in the study of developmental of interactive multimedia based physic learning charged in problem solving to improve thinking ability of physic prospective student. The first-year result of the study is: result of the draft based on a needs analysis of the facts on the ground, the conditions of existing learning and literature studies. Following the design of devices and instruments performed as well the development of media. Result of the second study is physics learning device -based interactive multimedia charged problem solving in the form of textbooks and scientific publications. Previous learning models tested in a limited sample, then in the evaluation and repair. Besides, the product of research has an economic value on the grounds: (1) a virtual laboratory to offer this research provides a solution purchases physics laboratory equipment is expensive; (2) address the shortage of teachers of physics in remote areas as a learning tool can be accessed offline and online; (3). reducing material or consumables as tutorials can be done online; Targeted research is the first year: i.e story board learning physics that have been scanned in a web form CD (compact disk) and the interactive multimedia of gas Kinetic Theory concept. This draft is based on a needs analysis of the facts on the ground, the existing learning conditions, and literature studies. Previous learning models tested in a limited sample, then in the evaluation and repair.

Who Is Influencing Whom? Latino Parent–Child Request Interactions and Product Purchases in Food Retail Environments

PubMed Central

Castro, Iana A.; Calderon, Joanna; Ayala, Guadalupe X.

2017-01-01

This study examines Latino parent–child interactions about foods and beverages requested in food retail environments in San Diego, CA. It seeks to extend our understanding of parent–child request interactions and purchases by studying how the number of product request interactions and purchases differ based on four factors that have been understudied in previous parent–child interaction research: parent gender, child gender, product healthfulness, and who initiated the request interaction (parent or child). By unobtrusively observing Latino parent–child dyads for the duration of a brief shopping trip, we found that parent and child gender are related to the number of request interactions initiated by parents and children. For gender-specific child-initiated request interactions, sons initiated more request interactions with fathers while daughters initiated more request interactions with mothers. Most request interactions were for products that were categorized as calorie dense, and a higher percentage of these products were purchased as a result of parent-initiated (vs. child-initiated) request interactions. The results provide important considerations for practitioners and researchers working on improving nutrition and reducing obesity. Assumptions about who is influencing whom in food store request interactions are challenged, requiring more research. PMID:29081718

Describing the complexity of systems: multivariable "set complexity" and the information basis of systems biology.

PubMed

Galas, David J; Sakhanenko, Nikita A; Skupin, Alexander; Ignac, Tomasz

2014-02-01

Context dependence is central to the description of complexity. Keying on the pairwise definition of "set complexity," we use an information theory approach to formulate general measures of systems complexity. We examine the properties of multivariable dependency starting with the concept of interaction information. We then present a new measure for unbiased detection of multivariable dependency, "differential interaction information." This quantity for two variables reduces to the pairwise "set complexity" previously proposed as a context-dependent measure of information in biological systems. We generalize it here to an arbitrary number of variables. Critical limiting properties of the "differential interaction information" are key to the generalization. This measure extends previous ideas about biological information and provides a more sophisticated basis for the study of complexity. The properties of "differential interaction information" also suggest new approaches to data analysis. Given a data set of system measurements, differential interaction information can provide a measure of collective dependence, which can be represented in hypergraphs describing complex system interaction patterns. We investigate this kind of analysis using simulated data sets. The conjoining of a generalized set complexity measure, multivariable dependency analysis, and hypergraphs is our central result. While our focus is on complex biological systems, our results are applicable to any complex system.

Alkaloids from psychotria target sirtuins: in silico and in vitro interaction studies.

PubMed

Sacconnay, Lionel; Ryckewaert, Lucie; Dos Santos Passos, Carolina; Guerra, Maria Cristina; Kato, Lucilia; Alves de Oliveira, Cecilia Maria; Henriques, Amélia; Carrupt, Pierre-Alain; Simões-Pires, Claudia; Nurisso, Alessandra

2015-04-01

Epigenetic enzymes such as histone deacetylases play a crucial role in the development of ageing-related diseases. Among the 18 histone deacetylase isoforms found in humans, class III histone deacetylases, also known as sirtuins, seem to be promising targets for treating neurodegenerative conditions. Recently, Psychotria alkaloids, mainly monoterpene indoles, have been reported for their inhibitory properties against central nervous system cholinesterase and monoamine oxidase proteins. Given the multifunctional profile of these alkaloids in the central nervous system, and the fact that the indole scaffold has been previously associated with sirtuin inhibition, we hypothesized that these indole derivatives could also interact with sirtuins. In the present study, alkaloids previously isolated from Psychotria spp. were evaluated for their potential interaction with human sirtuin 1 and sirtuin 2 by molecular docking and molecular dynamics simulation approaches. The in silico results allowed for the selection of five potentially active compounds, namely, prunifoleine, 14-oxoprunifoleine, E-vallesiachotamine, Z-vallesiachotamine, and vallesiachotamine lactone. The sirtuin inhibition of these compounds was confirmed in vitro in a dose-response manner, with preliminary information on their pharmacokinetics properties. Georg Thieme Verlag KG Stuttgart · New York.

Effects of variation in solar conditions and crustal sources' orientation on the Martian magnetic field topology

NASA Astrophysics Data System (ADS)

Ulusen, D.; Luhmann, J. G.; Ma, Y.; Brain, D. A.

2013-12-01

Strong crustal magnetic sources on the surface of Mars directly interact with the solar magnetic field and plasma, resulting a very dynamic environment near the planet. Effects of the orientation of these remnant magnetic sources with respect to the sun and variation of the solar conditions on the Martian plasma interaction have been investigated in a previous paper. In this previous study, magnetic topology maps obtained from ~7 years of Mars Global Surveyor (MGS) directional electron observations (obtained by Dave Brain) were compared with the topology maps obtained from a set of BATS-R-US MHD simulations for Mars. One conclusion from this study was that although the MHD model is consistent with the data and provides insight about the global magnetic field topology variation with changing crustal field orientation and solar parameters, detailed investigation of local effects is difficult due to MGS orbital bias. Moreover, proper comparison of the observations with the model requires more careful data selection rather than using 7 years time averages. In this paper, we readdress the study to tackle the problems of our previous work by performing more detailed data analysis and present the results of the updated model-data comparison.

Facading in transcultural interactions: examples from pediatric cancer care in Sweden.

PubMed

Pergert, Pernilla

2017-07-01

The aims of the study were to generate a grounded theory explaining the latent pattern of behavior in transcultural care interactions in the context of pediatric cancer care and to unify previously performed studies. The basic tenets of classic grounded theory were applied on a theoretical sample of data from previous studies that included 5 focus group interviews with health care professionals (n = 35) and individual interviews with nurses (n = 12) and foreign-born parents (n = 11). Facading emerged as the core category and is the act of showing an outer appearance that will influence other people's interpretations. In transcultural interactions, facading might be misinterpreted related to different obstacles. Examples are given of different facades explored in pediatric cancer care including strength facading. Facading is a strategy aiming to protect oneself and others emotionally in care and includes: emotional facading and facading-sensitive issues. This grounded theory could help make health care professionals aware of different meanings of facading across cultures in health care. Also, awareness is needed of different views on emotional facading and facading-sensitive issues to provide a congruent care. Copyright © 2016 John Wiley & Sons, Ltd.

μ-Opioid and 5-HT1A receptors in the dorsomedial hypothalamus interact for the regulation of panic-related defensive responses.

PubMed

Roncon, Camila Marroni; Yamashita, Paula Shimene de Melo; Frias, Alana Tercino; Audi, Elisabeth Aparecida; Graeff, Frederico Guilherme; Coimbra, Norberto Cysne; Zangrossi, Helio

2017-06-01

The dorsomedial hypothalamus (DMH) and the dorsal periaqueductal gray (DPAG) have been implicated in the genesis and regulation of panic-related defensive behaviors, such as escape. Previous results point to an interaction between serotonergic and opioidergic systems within the DPAG to inhibit escape, involving µ-opioid and 5-HT1A receptors (5-HT1AR). In the present study we explore this interaction in the DMH, using escape elicited by electrical stimulation of this area as a panic attack index. The obtained results show that intra-DMH administration of the non-selective opioid receptor antagonist naloxone (0.5 nmol) prevented the panicolytic-like effect of a local injection of serotonin (20 nmol). Pretreatment with the selective μ-opioid receptor (MOR) antagonist CTOP (1 nmol) blocked the panicolytic-like effect of the 5-HT1AR agonist 8-OHDPAT (8 nmol). Intra-DMH injection of the selective MOR agonist DAMGO (0.3 nmol) also inhibited escape behavior, and a previous injection of the 5-HT1AR antagonist WAY-100635 (0.37 nmol) counteracted this panicolytic-like effect. These results offer the first evidence that serotonergic and opioidergic systems work together within the DMH to inhibit panic-like behavior through an interaction between µ-opioid and 5-HT1A receptors, as previously described in the DPAG.

Relativistic well-tempered Gaussian basis sets for helium through mercury. Breit interaction included

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

Okada, S.; Shinada, M.; Matsuoka, O.

1990-10-01

A systematic calculation of new relativistic Gaussian basis sets is reported. The new basis sets are similar to the previously reported ones (J. Chem. Phys. {bold 91}, 4193 (1989)), but, in the calculation, the Breit interaction has been explicitly included besides the Dirac--Coulomb Hamiltonian. They have been adopted for the calculation of the self-consistent field effect on the Breit interaction energies and are expected to be useful for the studies on higher-order effects such as the electron correlations and other quantum electrodynamical effects.

Gene-Environment Interaction in Parkinson's Disease: Coffee, ADORA2A, and CYP1A2.

PubMed

Chuang, Yu-Hsuan; Lill, Christina M; Lee, Pei-Chen; Hansen, Johnni; Lassen, Christina F; Bertram, Lars; Greene, Naomi; Sinsheimer, Janet S; Ritz, Beate

2016-01-01

Drinking caffeinated coffee has been reported to provide protection against Parkinson's disease (PD). Caffeine is an adenosine A2A receptor (encoded by the gene ADORA2A) antagonist that increases dopaminergic neurotransmission and Cytochrome P450 1A2 (gene: CYP1A2) metabolizes caffeine; thus, gene polymorphisms in ADORA2A and CYP1A2 may influence the effect coffee consumption has on PD risk. In a population-based case-control study (PASIDA) in Denmark (1,556 PD patients and 1,606 birth year- and gender-matched controls), we assessed interactions between lifetime coffee consumption and 3 polymorphisms in ADORA2A and CYP1A2 for all subjects, and incident and prevalent PD cases separately using logistic regression models. We also conducted a meta-analysis combining our results with those from previous studies. We estimated statistically significant interactions for ADORA2A rs5760423 and heavy vs. light coffee consumption in incident (OR interaction = 0.66 [95% CI 0.46-0.94], p = 0.02) but not prevalent PD. We did not observe interactions for CYP1A2 rs762551 and rs2472304 in incident or prevalent PD. In meta-analyses, PD associations with daily coffee consumption were strongest among carriers of variant alleles in both ADORA2A and CYP1A2. We corroborated results from a previous report that described interactions between ADORA2A and CYP1A2 polymorphisms and coffee consumption. Our results also suggest that survivor bias may affect results of studies that enroll prevalent PD cases. © 2017 S. Karger AG, Basel.

Disinfection by-products exposure and intra-uterine growth restriction: Do genetic polymorphisms of CYP2E1or deletion of GSTM1 or GSTT1 modify the association?

PubMed

Levallois, Patrick; Giguère, Yves; Nguile-Makao, Molière; Rodriguez, Manuel; Campagna, Céline; Tardif, Robert; Bureau, Alexandre

2016-01-01

Exposure to disinfection by-products (DBPs) during pregnancy was associated with reduced foetal growth. Genetic susceptibility might play a role, especially for genes encoding for the Cytochrome P450 (CYP2E1) and Glutathione S-Transferase (GST) enzymes, involved in metabolism and activation of DBPs. Few epidemiological studies evaluated these gene-environment interactions and their results were never replicated. This study aims to examine interactions between trihalomethanes (THM) or haloacetic acids (HAA) exposure and genetic polymorphisms on small for gestational age (SGA) neonates by investigating single nucleotide polymorphisms (SNPs) in CYP2E1 gene and GSTM1 and GSTT1 deletions in mothers-children pairs. A population-based case-control study of 1549 mothers and 1455 children was conducted on SGA and THM/HAA exposure. DNA was extracted from blood or saliva cells. Targeted SNPs and deletions were genotyped. Statistical interaction between SNPs/deletions and THMs or HAAs in utero exposure with regard to SGA occurrence was evaluated by unconditional logistic regression with control of potential confounders. Previously reported positive modification of the effect of THM uterine exposure by mothers or newborns CYP2E1 rs3813867 C allele or GSTM1 deletion was not replicated. However interactions with CYP2E1 rs117618383 and rs2515641 were observed but were not statistically significant after correction for multiple testing. Previous positive interactions between THMs exposure and CYP2E1 and GSTM1 were not replicated but interactions with other CYP2E1 polymorphisms are reported. Copyright © 2016 Elsevier Ltd. All rights reserved.

Disinfection by-products exposure and intra-uterine growth restriction: do genetic polymorphisms of CYP2E1or deletion of GSTM1 or GSTT1 modify the association?

PubMed Central

Levallois, Patrick; Giguère, Yves; Nguile-Makao, Molière; Rodriguez, Manuel; Campagna, Céline; Tardif, Robert; Bureau, Alexandre

2016-01-01

Background Exposure to disinfection by-products (DBPs) during pregnancy was associated with reduced fetal growth. Genetic susceptibility might play a role, especially for genes encoding for the Cytochrome P450 (CYP2E1) and Glutathione S-Transferase (GST) enzymes, involved in metabolism and activation of DBPs. Few epidemiological studies evaluated these gene-environment interactions and their results were never replicated. Objective This study aims to examine interactions between trihalomethanes (THM) or haloacetic acids (HAA) exposure and genetic polymorphisms on small for gestational age (SGA) neonates by investigating single nucleotide polymorphisms (SNPs) in CYP2E1 gene and GSTM1 and GSTT1 deletions in mothers-children pairs. Methods A population-based case-control study of 1549 mothers and 1455 children was conducted on SGA and THM/HAA exposure. DNA was extracted from blood or saliva cells. Targeted SNPs and deletions were genotyped. Statistical interaction between SNPs/deletions and THMs or HAAs in utero exposure with regard to SGA occurrence was evaluated by unconditional logistic regression with control of potential confounders. Results Previously reported positive modification of the effect of THM uterine exposure by mothers or newborns CYP2E1 rs3813867 C allele or GSTM1 deletion was not replicated. However interactions with CYP2E1 rs117618383 and rs2515641 were observed but were not statistically significant after correction for multiple testing. Conclusions Previous positive interactions between THMs exposure and CYP2E1 and GSTM1 were not replicated but interactions with other CYP2E1 polymorphisms are reported. PMID:27107227

An adventitious interaction of filamin A with RhoGDI2(Tyr153Glu)

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

Song, Mia; He, Qianjing; Berk, Benjamin-Andreas

2016-01-15

Filamin A (FLNA) is an actin filament crosslinking protein with multiple intracellular binding partners. Mechanical force exposes cryptic FLNA binding sites for some of these ligands. To identify new force-dependent binding interactions, we used a fusion construct composed of two FLNA domains, one of which was previously identified as containing a force-dependent binding site as a bait in a yeast two-hybrid system and identified the Rho dissociation inhibitor 2 (RhoGDI2) as a potential interacting partner. A RhoGDI2 truncate with 81 N-terminal amino acid residues and a phosphomimetic mutant, RhoGDI(Tyr153Glu) interacted with the FLNA construct. However, neither wild-type or full-length RhoGDI2 phosphorylatedmore » at Y153 interacted with FLNA. Our interpretation of these contradictions is that truncation and/or mutation of RhoGDI2 perturbs its conformation to expose a site that adventitiously binds FLNA and is not a bona–fide interaction. Therefore, previous studies reporting that a RhoGDI(Y153E) mutant suppresses the metastasis of human bladder cancer cells must be reinvestigated in light of artificial interaction of this point mutant with FLNA. - Highlights: • RhoGDI2 is identified as a potential filamin A (FLNA)-binding partner. • Phosphomimetic mutant, RhoGDI2(Tyr153Glu) interacts with FLNA. • RhoGDI2 phosphorylated (Tyr153) by src kinase does not interact with FLNA. • Mutation of Tyr-153 to Glu of RhoGDI2 does not mimic phosphorylation. • RhoGDI2(Tyr153Glu) provokes an adventitious interaction with FLNA.« less

Electron electric dipole moment and hyperfine interaction constants for ThO

NASA Astrophysics Data System (ADS)

Fleig, Timo; Nayak, Malaya K.

2014-06-01

A recently implemented relativistic four-component configuration interaction approach to study P- and T-odd interaction constants in atoms and molecules is employed to determine the electron electric dipole moment effective electric field in the Ω=1 first excited state of the ThO molecule. We obtain a value of Eeff=75.2GV/cm with an estimated error bar of 3% and 10% smaller than a previously reported result (Skripnikov et al., 2013). Using the same wavefunction model we obtain an excitation energy of TvΩ=1=5410 (cm), in accord with the experimental value within 2%. In addition, we report the implementation of the magnetic hyperfine interaction constant A|| as an expectation value, resulting in A||=-1339 (MHz) for the Ω=1 state in ThO. The smaller effective electric field increases the previously determined upper bound (Baron et al., 2014) on the electron electric dipole moment to |de|<9.7×10-29e cm and thus mildly mitigates constraints to possible extensions of the Standard Model of particle physics.

Exclusive Meson Electroweak production off Bound Nucleons

NASA Astrophysics Data System (ADS)

Sato, Toru

2018-05-01

The effects of final state interaction in electroweak pion production reactions have been studied. The one loop corrections to the impulse approximation due to the nucleon and the pion rescattering is evaluated using the ANL-Osaka dynamical coupled channel model for the meson production reactions. It is found the final state interaction will affects the ν N cross section extracted in the previous analysis of the ν d data.

When a Body Meets a Body: An Exploration of the Negative Impact of Social Interactions on Museum Experiences of Art

ERIC Educational Resources Information Center

Pelowski, Matthew; Liu, Tao; Palacios, Victor; Akiba, Fuminori

2014-01-01

We consider the phenomenon of social interactions within the art museum, arguing that even the bare possibility of meeting others or intruding into their gaze can have a profoundly detrimental effect on art experience. This is done by tracing a finding from our previous studies in which we considered three museum galleries--each with the same…

Does Parental Divorce Moderate the Heritability of Body Dissatisfaction? An Extension of Previous Gene-Environment Interaction Effects

PubMed Central

O’Connor, Shannon M.; Klump, Kelly L.; VanHuysse, Jessica L.; McGue, Matt; Iacono, William

2015-01-01

Objective Previous research suggests that parental divorce moderates genetic influences on body dissatisfaction. Specifically, the heritability of body dissatisfaction is higher in children of divorced versus intact families, suggesting possible gene-environment interaction effects. However, prior research is limited to a single, self-report measure of body dissatisfaction. The primary aim of the present study was to examine whether these findings extend to a different dimension of body dissatisfaction, body image perceptions. Method Participants were 1,534 female twins from the Minnesota Twin Family Study, ages 16–20 years. The Body Rating Scale (BRS) was used to assess body image perceptions. Results Although BRS scores were heritable in twins from divorced and intact families, the heritability estimates in the divorced group were not significantly greater than estimates in the intact group. However, there were differences in nonshared environmental effects, where the magnitude of these environmental influences was larger in the divorced as compared to the intact families. Discussion Different dimensions of body dissatisfaction (i.e., negative self-evaluation versus body image perceptions) may interact with environmental risk, such as parental divorce, in discrete ways. Future research should examine this possibility and explore differential gene x environment interactions using diverse measures. PMID:26314278

Assessment of temporal state-dependent interactions between auditory fMRI responses to desired and undesired acoustic sources.

PubMed

Olulade, O; Hu, S; Gonzalez-Castillo, J; Tamer, G G; Luh, W-M; Ulmer, J L; Talavage, T M

2011-07-01

A confounding factor in auditory functional magnetic resonance imaging (fMRI) experiments is the presence of the acoustic noise inherently associated with the echo planar imaging acquisition technique. Previous studies have demonstrated that this noise can induce unwanted neuronal responses that can mask stimulus-induced responses. Similarly, activation accumulated over multiple stimuli has been demonstrated to elevate the baseline, thus reducing the dynamic range available for subsequent responses. To best evaluate responses to auditory stimuli, it is necessary to account for the presence of all recent acoustic stimulation, beginning with an understanding of the attenuating effects brought about by interaction between and among induced unwanted neuronal responses, and responses to desired auditory stimuli. This study focuses on the characterization of the duration of this temporal memory and qualitative assessment of the associated response attenuation. Two experimental parameters--inter-stimulus interval (ISI) and repetition time (TR)--were varied during an fMRI experiment in which participants were asked to passively attend to an auditory stimulus. Results present evidence of a state-dependent interaction between induced responses. As expected, attenuating effects of these interactions become less significant as TR and ISI increase and in contrast to previous work, persist up to 18s after a stimulus presentation. Copyright © 2011 Elsevier B.V. All rights reserved.

Does parental divorce moderate the heritability of body dissatisfaction? An extension of previous gene-environment interaction effects.

PubMed

O'Connor, Shannon M; Klump, Kelly L; VanHuysse, Jessica L; McGue, Matt; Iacono, William

2016-02-01

Previous research suggests that parental divorce moderates genetic influences on body dissatisfaction. Specifically, the heritability of body dissatisfaction is higher in children of divorced versus intact families, suggesting possible gene-environment interaction effects. However, prior research is limited to a single, self-reported measure of body dissatisfaction. The primary aim of this study was to examine whether these findings extend to a different dimension of body dissatisfaction: body image perceptions. Participants were 1,534 female twins from the Minnesota Twin Family Study, aged 16-20 years. The Body Rating Scale (BRS) was used to assess body image perceptions. Although BRS scores were heritable in twins from divorced and intact families, the heritability estimates in the divorced group were not significantly greater than estimates in the intact group. However, there were differences in nonshared environmental effects, where the magnitude of these environmental influences was larger in the divorced as compared with the intact families. Different dimensions of body dissatisfaction (i.e., negative self-evaluation versus body image perceptions) may interact with environmental risk, such as parental divorce, in discrete ways. Future research should examine this possibility and explore differential gene-environment interactions using diverse measures. © 2015 Wiley Periodicals, Inc.

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

Rawle, Rachel A.; Hamerly, Timothy; Tripet, Brian P.

Studies of interspecies interactions are inherently difficult due to the complex mechanisms which enable these relationships. A model system for studying interspecies interactions is the marine hyperthermophiles Ignicoccus hospitalis and Nanoarchaeum equitans. Recent independently-conducted ‘omics’ analyses have generated insights into the molecular factors modulating this association. However, significant questions remain about the nature of the interactions between these archaea. We jointly analyzed multiple levels of omics datasets obtained from published, independent transcriptomics, proteomics, and metabolomics analyses. DAVID identified functionally-related groups enriched when I. hospitalis is grown alone or in co-culture with N. equitans. Enriched molecular pathways were subsequently visualized usingmore » interaction maps generated using STRING. Key findings of our multi-level omics analysis indicated that I. hospitalis provides precursors to N. equitans for energy metabolism. Analysis indicated an overall reduction in diversity of metabolic precursors in the I. hospitalis–N. equitans co-culture, which has been connected to the differential use of ribosomal subunits and was previously unnoticed. We also identified differences in precursors linked to amino acid metabolism, NADH metabolism, and carbon fixation, providing new insights into the metabolic adaptions of I. hospitalis enabling the growth of N. equitans. In conclusion, this multi-omics analysis builds upon previously identified cellular patterns while offering new insights into mechanisms that enable the I. hospitalis–N. equitans association. This study applies statistical and visualization techniques to a mixed-source omics dataset to yield a more global insight into a complex system, that was not readily discernable from separate omics studies.« less

The Use of Human Liver Cell Model and Cytochrome P450 Substrate-Inhibitor Panel for Studies of Dasatinib and Warfarin Interactions.

PubMed

Zakharyants, A A; Burmistrova, O A; Poloznikov, A A

2017-02-01

The possibility of interactions between warfarin and dasatinib and their interactions with other drugs metabolized by cytochrome P450 isoform CYP3A4 was demonstrated using a previously created cytochrome P450 substrate-inhibitor panel for preclinical in vitro studies of drug biotransformation on a 3D histotypical microfluidic cell model of human liver (liver-on-a-chip technology). Dasatinib and warfarin are inhibitors of CYP2C19 isoform and hence, can interfere the drugs metabolized by this isoform. Our findings are in line with the data obtained on primary culture of human hepatocytes and suggest that the model can be used in preclinical in vitro studies of drugs.

ISPAN (Interactive Stiffened Panel Analysis): A tool for quick concept evaluation and design trade studies

NASA Technical Reports Server (NTRS)

Hairr, John W.; Dorris, William J.; Ingram, J. Edward; Shah, Bharat M.

1993-01-01

Interactive Stiffened Panel Analysis (ISPAN) modules, written in FORTRAN, were developed to provide an easy to use tool for creating finite element models of composite material stiffened panels. The modules allow the user to interactively construct, solve and post-process finite element models of four general types of structural panel configurations using only the panel dimensions and properties as input data. Linear, buckling and post-buckling solution capability is provided. This interactive input allows rapid model generation and solution by non finite element users. The results of a parametric study of a blade stiffened panel are presented to demonstrate the usefulness of the ISPAN modules. Also, a non-linear analysis of a test panel was conducted and the results compared to measured data and previous correlation analysis.

Rotor/Wing Interactions in Hover

NASA Technical Reports Server (NTRS)

Young, Larry A.; Derby, Michael R.

2002-01-01

Hover predictions of tiltrotor aircraft are hampered by the lack of accurate and computationally efficient models for rotor/wing interactional aerodynamics. This paper summarizes the development of an approximate, potential flow solution for the rotor-on-rotor and wing-on-rotor interactions. This analysis is based on actuator disk and vortex theory and the method of images. The analysis is applicable for out-of-ground-effect predictions. The analysis is particularly suited for aircraft preliminary design studies. Flow field predictions from this simple analytical model are validated against experimental data from previous studies. The paper concludes with an analytical assessment of the influence of rotor-on-rotor and wing-on-rotor interactions. This assessment examines the effect of rotor-to-wing offset distance, wing sweep, wing span, and flaperon incidence angle on tiltrotor inflow and performance.

Does parental expressed emotion moderate genetic effects in ADHD? An exploration using a genome wide association scan.

PubMed

Sonuga-Barke, Edmund J S; Lasky-Su, Jessica; Neale, Benjamin M; Oades, Robert; Chen, Wai; Franke, Barbara; Buitelaar, Jan; Banaschewski, Tobias; Ebstein, Richard; Gill, Michael; Anney, Richard; Miranda, Ana; Mulas, Fernando; Roeyers, Herbert; Rothenberger, Aribert; Sergeant, Joseph; Steinhausen, Hans Christoph; Thompson, Margaret; Asherson, Philip; Faraone, Stephen V

2008-12-05

Studies of gene x environment (G x E) interaction in ADHD have previously focused on known risk genes for ADHD and environmentally mediated biological risk. Here we use G x E analysis in the context of a genome-wide association scan to identify novel genes whose effects on ADHD symptoms and comorbid conduct disorder are moderated by high maternal expressed emotion (EE). SNPs (600,000) were genotyped in 958 ADHD proband-parent trios. After applying data cleaning procedures we examined 429,981 autosomal SNPs in 909 family trios. ADHD symptom severity and comorbid conduct disorder was measured using the Parental Account of Childhood Symptoms interview. Maternal criticism and warmth (i.e., EE) were coded by independent observers on comments made during the interview. No G x E interactions reached genome-wide significance. Nominal effects were found both with and without genetic main effects. For those with genetic main effects 36 uncorrected interaction P-values were <10(-5) implicating both novel genes as well as some previously supported candidates. These were found equally often for all of the interactions being investigated. The observed interactions in SLC1A1 and NRG3 SNPs represent reasonable candidate genes for further investigation given their previous association with several psychiatric illnesses. We find evidence for the role of EE in moderating the effects of genes on ADHD severity and comorbid conduct disorder, implicating both novel and established candidates. These findings need replicating in larger independent samples. Copyright 2008 Wiley-Liss, Inc.

Essential Assembly Factor Rpf2 Forms Novel Interactions within the 5S RNP in Trypanosoma brucei

PubMed Central

Kamina, Anyango D.; Jaremko, Daniel; Christen, Linda

2017-01-01

ABSTRACT Ribosome biogenesis is a highly complex and conserved cellular process that is responsible for making ribosomes. During this process, there are several assembly steps that function as regulators to ensure proper ribosome formation. One of these steps is the assembly of the 5S ribonucleoprotein particle (5S RNP) in the central protuberance of the 60S ribosomal subunit. In eukaryotes, the 5S RNP is composed of 5S rRNA, ribosomal proteins L5 and L11, and assembly factors Rpf2 and Rrs1. Our laboratory previously showed that in Trypanosoma brucei, the 5S RNP is composed of 5S rRNA, L5, and trypanosome-specific RNA binding proteins P34 and P37. In this study, we characterize an additional component of the 5S RNP, the T. brucei homolog of Rpf2. This is the first study to functionally characterize interactions mediated by Rpf2 in an organism other than fungi. T. brucei Rpf2 (TbRpf2) was identified from tandem affinity purification using extracts prepared from protein A-tobacco etch virus (TEV)-protein C (PTP)-tagged L5, P34, and P37 cell lines, followed by mass spectrometry analysis. We characterized the binding interactions between TbRpf2 and the previously characterized members of the T. brucei 5S RNP. Our studies show that TbRpf2 mediates conserved binding interactions with 5S rRNA and L5 and that TbRpf2 also interacts with trypanosome-specific proteins P34 and P37. We performed RNA interference (RNAi) knockdown of TbRpf2 and showed that this protein is essential for the survival of the parasites and is critical for proper ribosome formation. These studies provide new insights into a critical checkpoint in the ribosome biogenesis pathway in T. brucei. IMPORTANCE Trypanosoma brucei is the parasitic protozoan that causes African sleeping sickness. Ribosome assembly is essential for the survival of this parasite through the different host environments it encounters during its life cycle. The assembly of the 5S ribonucleoprotein particle (5S RNP) functions as one of the regulatory checkpoints during ribosome biogenesis. We have previously characterized the 5S RNP in T. brucei and showed that trypanosome-specific proteins P34 and P37 are part of this complex. In this study, we characterize for the first time the interactions of the homolog of the assembly factor Rpf2 with members of the 5S RNP in another organism besides fungi. Our studies show that Rpf2 is essential in T. brucei and that it forms unique interactions within the 5S RNP, particularly with P34 and P37. These studies have identified parasite-specific interactions that can potentially function as new therapeutic targets against sleeping sickness. PMID:29062898

Essential Assembly Factor Rpf2 Forms Novel Interactions within the 5S RNP in Trypanosoma brucei.

PubMed

Kamina, Anyango D; Jaremko, Daniel; Christen, Linda; Williams, Noreen

2017-01-01

Ribosome biogenesis is a highly complex and conserved cellular process that is responsible for making ribosomes. During this process, there are several assembly steps that function as regulators to ensure proper ribosome formation. One of these steps is the assembly of the 5S ribonucleoprotein particle (5S RNP) in the central protuberance of the 60S ribosomal subunit. In eukaryotes, the 5S RNP is composed of 5S rRNA, ribosomal proteins L5 and L11, and assembly factors Rpf2 and Rrs1. Our laboratory previously showed that in Trypanosoma brucei , the 5S RNP is composed of 5S rRNA, L5, and trypanosome-specific RNA binding proteins P34 and P37. In this study, we characterize an additional component of the 5S RNP, the T. brucei homolog of Rpf2. This is the first study to functionally characterize interactions mediated by Rpf2 in an organism other than fungi. T . brucei Rpf2 (TbRpf2) was identified from tandem affinity purification using extracts prepared from protein A-tobacco etch virus (TEV)-protein C (PTP)-tagged L5, P34, and P37 cell lines, followed by mass spectrometry analysis. We characterized the binding interactions between TbRpf2 and the previously characterized members of the T. brucei 5S RNP. Our studies show that TbRpf2 mediates conserved binding interactions with 5S rRNA and L5 and that TbRpf2 also interacts with trypanosome-specific proteins P34 and P37. We performed RNA interference (RNAi) knockdown of TbRpf2 and showed that this protein is essential for the survival of the parasites and is critical for proper ribosome formation. These studies provide new insights into a critical checkpoint in the ribosome biogenesis pathway in T. brucei . IMPORTANCE Trypanosoma brucei is the parasitic protozoan that causes African sleeping sickness. Ribosome assembly is essential for the survival of this parasite through the different host environments it encounters during its life cycle. The assembly of the 5S ribonucleoprotein particle (5S RNP) functions as one of the regulatory checkpoints during ribosome biogenesis. We have previously characterized the 5S RNP in T. brucei and showed that trypanosome-specific proteins P34 and P37 are part of this complex. In this study, we characterize for the first time the interactions of the homolog of the assembly factor Rpf2 with members of the 5S RNP in another organism besides fungi. Our studies show that Rpf2 is essential in T. brucei and that it forms unique interactions within the 5S RNP, particularly with P34 and P37. These studies have identified parasite-specific interactions that can potentially function as new therapeutic targets against sleeping sickness.

The interaction between monoamine oxidase A and punitive discipline in the development of antisocial behavior: Mediation by maladaptive social information processing.

PubMed

Galán, Chardée A; Choe, Daniel Ewon; Forbes, Erika E; Shaw, Daniel S

2017-10-01

Previous studies demonstrate that boys' monoamine oxidase A (MAOA) genotype interacts with adverse rearing environments in early childhood, including punitive discipline, to predict later antisocial behavior. Yet the mechanisms by which MAOA and punitive parenting interact during childhood to amplify risk for antisocial behavior are not well understood. In the present study, hostile attributional bias and aggressive response generation during middle childhood, salient aspects of maladaptive social information processing, were tested as possible mediators of this relation in a sample of 187 low-income men followed prospectively from infancy into early adulthood. Given racial-ethnic variation in MAOA allele frequencies, analyses were conducted separately by race. In both African American and Caucasian men, those with the low-activity MAOA allele who experienced more punitive discipline at age 1.5 generated more aggressive responses to perceived threat at age 10 relative to men with the high-activity variant. In the African American subsample only, formal mediation analyses indicated a marginally significant indirect effect of maternal punitiveness on adult arrest records via aggressive response generation in middle childhood. The findings suggest that maladaptive social information processing may be an important mechanism underlying the association between MAOA × Parenting interactions and antisocial behavior in early adulthood. The present study extends previous work in the field by demonstrating that MAOA and harsh parenting assessed in early childhood interact to not only predict antisocial behavior in early adulthood, but also predict social information processing, a well-established social-cognitive correlate of antisocial behavior.

The morphological interaction between the nasal cavity and maxillary sinuses in living humans.

PubMed

Holton, Nathan; Yokley, Todd; Butaric, Lauren

2013-03-01

To understand how variation in nasal architecture accommodates the need for effective conditioning of respired air, it is necessary to assess the morphological interaction between the nasal cavity and other aspects of the nasofacial skeleton. Previous studies indicate that the maxillary sinuses may play a key role in accommodating climatically induced nasal variation such that a decrease in nasal cavity volume is associated with a concomitant increase in maxillary sinus volume. However, due to conflicting results in previous studies, the precise interaction of the nasal cavity and maxillary sinuses, in humans, is unclear. This is likely due to the prior emphasis on nasal cavity size, whereas arguably, nasal cavity shape is more important with regard to the interaction with the maxillary sinuses. Using computed tomography scans of living human subjects (N=40), the goal of this study is to assess the interaction between nasal cavity form and maxillary sinus volume in European- and African-derived individuals with differences in nasal cavity morphology. First, we assessed whether there is an inverse relationship between nasal cavity and maxillary sinus volumes. Next, we examined the relationship between maxillary sinus volume and nasal cavity shape using multivariate regression. Our results show that there is a positive relationship between nasal cavity and maxillary sinus volume, indicating that the maxillary sinuses do not accommodate variation in nasal cavity size. However, maxillary sinus volume is significantly correlated with variation in relative internal nasal breadth. Thus, the maxillary sinuses appear to be important for accommodating nasal cavity shape rather than size. Copyright © 2013 Wiley Periodicals, Inc.

Coherent microscopic picture for urea-induced denaturation of proteins.

PubMed

Yang, Zaixing; Xiu, Peng; Shi, Biyun; Hua, Lan; Zhou, Ruhong

2012-08-02

In a previous study, we explored the mechanism of urea-induced denaturation of proteins by performing molecular dynamics (MD) simulations of hen lysozyme in 8 M urea and supported the "direct interaction mechanism" whereby urea denatures protein via dispersion interaction (Hua, L.; Zhou, R. H.; Thirumalai, D.; Berne, B. J. Proc. Natl. Acad. Sci. U.S.A. 2008, 105, 16928). Here we perform large scale MD simulations of five representative protein/peptide systems in aqueous urea to investigate if the above mechanism is common to other proteins. In all cases, accumulations of urea around proteins/peptide are observed, suggesting that urea denatures proteins by directly attacking protein backbones and side chains rather than indirectly disrupting water structure as a "water breaker". Consistent with our previous case study of lysozyme, the current energetic analyses with five protein/peptide systems reveal that urea's preferential binding to proteins mainly comes from urea's stronger dispersion interactions with proteins than with bulk solution, whereas the electrostatic (hydrogen-bonded) interactions only play a relatively minor (even negative) role during this denaturation process. Furthermore, the simulations of the peptide system at different urea concentrations (8 and 4.5 M), and with different force fields (CHARMM and OPLSAA) suggest that the above mechanism is robust, independent of the urea concentration and force field used. Last, we emphasize the importance of periodic boundary conditions in pairwise energetic analyses. This article provides a comprehensive study on the physical mechanism of urea-induced protein denaturation and suggests that the "dispersion-interaction-driven" mechanism should be general.

Dynamical mass generation in unquenched QED using the Dyson-Schwinger equations

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

Kızılersü, Ayse; Sizer, Tom; Pennington, Michael R.

We present a comprehensive numerical study of dynamical mass generation for unquenched QED in four dimensions, in the absence of four-fermion interactions, using the Dyson-Schwinger approach. We begin with an overview of previous investigations of criticality in the quenched approximation. To this we add an analysis using a new fermion-antifermion-boson interaction ansatz, the Kizilersu-Pennington (KP) vertex, developed for an unquenched treatment. After surveying criticality in previous unquenched studies, we investigate the performance of the KP vertex in dynamical mass generation using a renormalized fully unquenched system of equations. This we compare with the results for two hybrid vertices incorporating themore » Curtis-Pennington vertex in the fermion equation. We conclude that the KP vertex is as yet incomplete, and its relative gauge-variance is due to its lack of massive transverse components in its design.« less

Inequity aversion and the evolution of cooperation

NASA Astrophysics Data System (ADS)

Ahmed, Asrar; Karlapalem, Kamalakar

2014-02-01

Evolution of cooperation is a widely studied problem in biology, social science, economics, and artificial intelligence. Most of the existing approaches that explain cooperation rely on some notion of direct or indirect reciprocity. These reciprocity based models assume agents recognize their partner and know their previous interactions, which requires advanced cognitive abilities. In this paper we are interested in developing a model that produces cooperation without requiring any explicit memory of previous game plays. Our model is based on the notion of inequity aversion, a concept introduced within behavioral economics, whereby individuals care about payoff equality in outcomes. Here we explore the effect of using income inequality to guide partner selection and interaction. We study our model by considering both the well-mixed and the spatially structured population and present the conditions under which cooperation becomes dominant. Our results support the hypothesis that inequity aversion promotes cooperative relationship among nonkin.

Inequity aversion and the evolution of cooperation.

PubMed

Ahmed, Asrar; Karlapalem, Kamalakar

2014-02-01

Evolution of cooperation is a widely studied problem in biology, social science, economics, and artificial intelligence. Most of the existing approaches that explain cooperation rely on some notion of direct or indirect reciprocity. These reciprocity based models assume agents recognize their partner and know their previous interactions, which requires advanced cognitive abilities. In this paper we are interested in developing a model that produces cooperation without requiring any explicit memory of previous game plays. Our model is based on the notion of inequity aversion, a concept introduced within behavioral economics, whereby individuals care about payoff equality in outcomes. Here we explore the effect of using income inequality to guide partner selection and interaction. We study our model by considering both the well-mixed and the spatially structured population and present the conditions under which cooperation becomes dominant. Our results support the hypothesis that inequity aversion promotes cooperative relationship among nonkin.

Dynamical mass generation in unquenched QED using the Dyson-Schwinger equations

DOE PAGES

Kızılersü, Ayse; Sizer, Tom; Pennington, Michael R.; ...

2015-03-13

We present a comprehensive numerical study of dynamical mass generation for unquenched QED in four dimensions, in the absence of four-fermion interactions, using the Dyson-Schwinger approach. We begin with an overview of previous investigations of criticality in the quenched approximation. To this we add an analysis using a new fermion-antifermion-boson interaction ansatz, the Kizilersu-Pennington (KP) vertex, developed for an unquenched treatment. After surveying criticality in previous unquenched studies, we investigate the performance of the KP vertex in dynamical mass generation using a renormalized fully unquenched system of equations. This we compare with the results for two hybrid vertices incorporating themore » Curtis-Pennington vertex in the fermion equation. We conclude that the KP vertex is as yet incomplete, and its relative gauge-variance is due to its lack of massive transverse components in its design.« less

A pollen-specific calmodulin-binding protein, NPG1, interacts with putative pectate lyases.

PubMed

Shin, Sung-Bong; Golovkin, Maxim; Reddy, Anireddy S N

2014-06-12

Previous genetic studies have revealed that a pollen-specific calmodulin-binding protein, No Pollen Germination 1 (NPG1), is required for pollen germination. However, its mode of action is unknown. Here we report direct interaction of NPG1 with pectate lyase-like proteins (PLLs). A truncated form of AtNPG1 lacking the N-terminal tetratricopeptide repeat 1 (TPR1) failed to interact with PLLs, suggesting that it is essential for NPG1 interaction with PLLs. Localization studies with AtNPG1 fused to a fluorescent reporter driven by its native promoter revealed its presence in the cytosol and cell wall of the pollen grain and the growing pollen tube of plasmolyzed pollen. Together, our data suggest that the function of NPG1 in regulating pollen germination is mediated through its interaction with PLLs, which may modify the pollen cell wall and regulate pollen tube emergence and growth.

Selection of trilateral continuums of life history strategies under food web interactions.

PubMed

Fujiwara, Masami

2018-03-14

The study of life history strategies has a long history in ecology and evolution, but determining the underlying mechanisms driving the evolution of life history variation and its consequences for population regulation remains a major challenge. In this study, a food web model with constant environmental conditions was used to demonstrate how multi-species consumer-resource interactions (food-web interactions) can create variation in the duration of the adult stage, age of maturation, and fecundity among species. The model included three key ecological processes: size-dependent species interactions, energetics, and transition among developmental stages. Resultant patterns of life history variation were consistent with previous empirical observations of the life history strategies of aquatic organisms referred to as periodic, equilibrium, and opportunistic strategies (trilateral continuums of life history strategies). Results from the simulation model suggest that these three life history strategies can emerge from food web interactions even when abiotic environmental conditions are held constant.

Research Techniques Made Simple: Emerging Methods to Elucidate Protein Interactions through Spatial Proximity.

PubMed

Che, Yonglu; Khavari, Paul A

2017-12-01

Interactions between proteins are essential for fundamental cellular processes, and the diversity of such interactions enables the vast variety of functions essential for life. A persistent goal in biological research is to develop assays that can faithfully capture different types of protein interactions to allow their study. A major step forward in this direction came with a family of methods that delineates spatial proximity of proteins as an indirect measure of protein-protein interaction. A variety of enzyme- and DNA ligation-based methods measure protein co-localization in space, capturing novel interactions that were previously too transient or low affinity to be identified. Here we review some of the methods that have been successfully used to measure spatially proximal protein-protein interactions. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

ADCYAP1R1 genotype associates with post-traumatic stress symptoms in highly traumatized African-American females.

PubMed

Almli, Lynn M; Mercer, Kristina B; Kerley, Kimberly; Feng, Hao; Bradley, Bekh; Conneely, Karen N; Ressler, Kerry J

2013-04-01

Pituitary adenylate cyclase-activating polypeptide (PACAP) and its receptor (PAC1) play a critical role in biological processes that mediate stress response and have been implicated in psychological outcome following trauma. Our previous work [Ressler et al. (2011); Nature 470:492-497] demonstrated that a variant, rs2267735, in the gene encoding PAC1 (ADCYAP1R1) is associated with post-traumatic stress disorder (PTSD) in a primarily African-American cohort of highly traumatized females. We sought to extend and replicate our previous finding in a similarly trauma-exposed, replicate sample of 1,160 African-American adult male and female patients. Self-reported psychiatric measures were collected, and DNA was obtained for genetic analysis. Using linear regression models to test for association with PTSD symptom severity under an additive (allelic) model, we found a genotype × trauma interaction in females (P < 0.001), but not males (P > 0.1); however, there was no main effect of genotype as in our previous study. The observed interaction suggests a genetic association that increases with the degree of trauma exposure in females only. This interaction remained significant in females, but not males, after controlling for age (P < 0.001), income (P < 0.01), past substance abuse (P < 0.001), depression severity (P = 0.02), or child abuse (P < 0.0005), and all five combined (P = 0.01). No significant effects of genotype (or interactions) were found when modeling depression severity when controlling for comorbid PTSD symptom severity (P > 0.1), demonstrating the relative specificity of this variant for PTSD symptoms. A meta-analysis with the previously reported African-American samples revealed a strong association between PTSD symptom severity and the interaction between trauma and genotype in females (N = 1424, P < 0.0001). Copyright © 2013 Wiley Periodicals, Inc.

Cross-Linguistic Activation in Bilingual Sentence Processing: The Role of Word Class Meaning

ERIC Educational Resources Information Center

Baten, Kristof; Hofman, Fabrice; Loeys, Tom

2011-01-01

This study investigates how categorial (word class) semantics influences cross-linguistic interactions when reading in L2. Previous homograph studies paid little attention to the possible influence of different word classes in the stimulus material on cross-linguistic activation. The present study examines the word recognition performance of…

Interaction of SO2 with the Surface of a Water Nanodroplet.

PubMed

Zhong, Jie; Zhu, Chongqin; Li, Lei; Richmond, Geraldine L; Francisco, Joseph S; Zeng, Xiao Cheng

2017-11-29

We present a comprehensive computational study of interaction of a SO 2 with water molecules in the gas phase and with the surface of various sized water nanodroplets to investigate the solvation behavior of SO 2 in different atmospheric environments. Born-Oppenheimer molecular dynamics (BOMD) simulation shows that, in the gas phase and at a temperature of 300 K, the dominant interaction between SO 2 and H 2 O is (SO 2 ) S···O (H 2 O) , consistent with previous density-functional theory (DFT) computation at 0 K. However, at the surface of a water nanodroplet, BOMD simulation shows that the hydrogen-bonding interaction of (SO 2 ) O···H (H 2 O) becomes increasingly important with the increase of droplet size, reflecting a marked effect of the water surface on the SO 2 solvation. This conclusion is in good accordance with spectroscopy evidence obtained previously (J. Am. Chem. Soc. 2005, 127, 16806; J. Am. Chem. Soc. 2006, 128, 3256). The prevailing interaction (SO 2 ) O···H (H 2 O) on a large droplet is mainly due to favorable exposure of H atoms of H 2 O at the air-water interface. Indeed, the conversion of the dominant interaction in the gas phase (SO 2 ) S···O (H 2 O) to the dominant interaction on the water nanodroplet (SO 2 ) O···H (H 2 O) may incur effects on the SO 2 chemistry in atmospheric aerosols because the solvation of SO 2 at the water surface can affect the reactive sites and electrophilicity of SO 2 . Hence, the solvation of SO 2 on the aerosol surface may have new implications when studying SO 2 chemistry in the aerosol-containing troposphere.

Parasite Removal, but Not Herbivory, Deters Future Parasite Attachment on Tomato

PubMed Central

Tjiurutue, Muvari Connie; Palmer-Young, Evan C.; Adler, Lynn S.

2016-01-01

Plants face many antagonistic interactions that occur sequentially. Often, plants employ defense strategies in response to the initial damage that are highly specific and can affect interactions with subsequent antagonists. In addition to herbivores and pathogens, plants face attacks by parasitic plants, but we know little about how prior herbivory compared to prior parasite attachment affects subsequent host interactions. If host plants can respond adaptively to these different damage types, we predict that prior parasitism would have a greater deterrent effect on subsequent parasites than would prior herbivory. To test the effects of prior parasitism and prior herbivory on subsequent parasitic dodder (Cuscuta spp.) preference, we conducted two separate greenhouse studies with tomato hosts (Solanum lycopersicum). In the first experiment, we tested the effects of previous dodder attachment on subsequent dodder preference on tomato hosts using three treatments: control plants that had no previous dodder attachment; dodder-removed plants that had an initial dodder seedling attached, removed and left in the same pot to simulate parasite death; and dodder-continuous plants with an initial dodder seedling that remained attached. In the second experiment, we tested the effects of previous caterpillar damage (Spodoptera exigua) and mechanical damage on future dodder attachment on tomato hosts. Dodder attached most slowly to tomato hosts that had dodder plants previously attached and then removed, compared to control plants or plants with continuous dodder attachment. In contrast, herbivory did not affect subsequent dodder attachment rate. These results indicate that dodder preference depended on the identity and the outcome of the initial attack, suggesting that early-season interactions have the potential for profound impacts on subsequent community dynamics. PMID:27529694

The influence of previous subject experience on interactions during peer instruction in an introductory physics course: A mixed methods analysis

NASA Astrophysics Data System (ADS)

Vondruska, Judy A.

Over the past decade, peer instruction and the introduction of student response systems has provided a means of improving student engagement and achievement in large-lecture settings. While the nature of the student discourse occurring during peer instruction is less understood, existing studies have shown student ideas about the subject, extraneous cues, and confidence level appear to matter in the student-student discourse. Using a mixed methods research design, this study examined the influence of previous subject experience on peer instruction in an introductory, one-semester Survey of Physics course. Quantitative results indicated students in discussion pairs where both had previous subject experience were more likely to answer clicker question correctly both before and after peer discussion compared to student groups where neither partner had previous subject experience. Students in mixed discussion pairs were not statistically different in correct response rates from the other pairings. There was no statistically significant difference between the experience pairs on unit exam scores or the Peer Instruction Partner Survey. Although there was a statistically significant difference between the pre-MPEX and post-MPEX scores, there was no difference between the members of the various subject experience peer discussion pairs. The qualitative study, conducted after the quantitative study, helped to inform the quantitative results by exploring the nature of the peer interactions through survey questions and a series of focus groups discussions. While the majority of participants described a benefit to the use of clickers in the lecture, their experience with their discussion partners varied. Students with previous subject experience tended to describe peer instruction more positively than students who did not have previous subject experience, regardless of the experience level of their partner. They were also more likely to report favorable levels of comfort with the peer instruction experience. Students with no previous subject experience were more likely to describe a level of discomfort being assigned a stranger for a discussion partner and were more likely to report communication issues with their partner. Most group members, regardless of previous subject experience, related deeper discussions occurring when partners did not initially have the same answer to the clicker questions.

Ecological interactions are evolutionarily conserved across the entire tree of life.

PubMed

Gómez, José M; Verdú, Miguel; Perfectti, Francisco

2010-06-17

Ecological interactions are crucial to understanding both the ecology and the evolution of organisms. Because the phenotypic traits regulating species interactions are largely a legacy of their ancestors, it is widely assumed that ecological interactions are phylogenetically conserved, with closely related species interacting with similar partners. However, the existing empirical evidence is inadequate to appropriately evaluate the hypothesis of phylogenetic conservatism in ecological interactions, because it is both ecologically and taxonomically biased. In fact, most studies on the evolution of ecological interactions have focused on specialized organisms, such as some parasites or insect herbivores, belonging to a limited subset of the overall tree of life. Here we study the evolution of host use in a large and diverse group of interactions comprising both specialist and generalist acellular, unicellular and multicellular organisms. We show that, as previously found for specialized interactions, generalized interactions can be evolutionarily conserved. Significant phylogenetic conservatism of interaction patterns was equally likely to occur in symbiotic and non-symbiotic interactions, as well as in mutualistic and antagonistic interactions. Host-use differentiation among species was higher in phylogenetically conserved clades, irrespective of their generalization degree and taxonomic position within the tree of life. Our findings strongly suggest a shared pattern in the organization of biological systems through evolutionary time, mediated by marked conservatism of ecological interactions among taxa.

Social interaction anxiety and the discounting of positive interpersonal events.

PubMed

Vassilopoulos, Stephanos P; Banerjee, Robin

2010-10-01

Recent research has indicated that individuals with social interaction anxiety make biased interpretations of positive social interactions, with greater general apprehension in response to such events and more negative predictions about the future. There has also been some preliminary evidence for a second facet of interpretation bias, namely a failure to accept others' positive reactions at face value, but this has so far not been adequately studied. The present study developed a new measure of this "discounting" dimension and utilized a nonclinical sample of undergraduate students to provide an initial analysis of the scale. Results provide early support for the psychometric properties of our scale, and indicate that discounting mediates the relationship between social interaction anxiety and low positive affect, over and above the previously studied aspect of positive event interpretation bias. The implications for treatment interventions and further research are discussed.

First principles calculations for interaction of tyrosine with (ZnO)3 cluster

NASA Astrophysics Data System (ADS)

Singh, Satvinder; Singh, Gurinder; Kaura, Aman; Tripathi, S. K.

2018-04-01

First Principles Calculations have been performed to study interactions of Phenol ring of Tyrosine (C6H5OH) with (ZnO)3 atomic cluster. All the calculations have been performed under the Density Functional Theory (DFT) framework. Structural and electronic properties of (ZnO)3/C6H5OH have been studied. Gaussian basis set approach has been adopted for the calculations. A ring type most stable (ZnO)3 atomic cluster has been modeled, analyzed and used for the calculations. The compatibility of the results with previous studies has been presented here.

Adiabatic quantum computation with neutral atoms via the Rydberg blockade

NASA Astrophysics Data System (ADS)

Goyal, Krittika; Deutsch, Ivan

2011-05-01

We study a trapped-neutral-atom implementation of the adiabatic model of quantum computation whereby the Hamiltonian of a set of interacting qubits is changed adiabatically so that its ground state evolves to the desired output of the algorithm. We employ the ``Rydberg blockade interaction,'' which previously has been used to implement two-qubit entangling gates in the quantum circuit model. Here it is employed via off-resonant virtual dressing of the excited levels, so that atoms always remain in the ground state. The resulting dressed-Rydberg interaction is insensitive to the distance between the atoms within a certain blockade radius, making this process robust to temperature and vibrational fluctuations. Single qubit interactions are implemented with global microwaves and atoms are locally addressed with light shifts. With these ingredients, we study a protocol to implement the two-qubit Quadratic Unconstrained Binary Optimization (QUBO) problem. We model atom trapping, addressing, coherent evolution, and decoherence. We also explore collective control of the many-atom system and generalize the QUBO problem to multiple qubits. We study a trapped-neutral-atom implementation of the adiabatic model of quantum computation whereby the Hamiltonian of a set of interacting qubits is changed adiabatically so that its ground state evolves to the desired output of the algorithm. We employ the ``Rydberg blockade interaction,'' which previously has been used to implement two-qubit entangling gates in the quantum circuit model. Here it is employed via off-resonant virtual dressing of the excited levels, so that atoms always remain in the ground state. The resulting dressed-Rydberg interaction is insensitive to the distance between the atoms within a certain blockade radius, making this process robust to temperature and vibrational fluctuations. Single qubit interactions are implemented with global microwaves and atoms are locally addressed with light shifts. With these ingredients, we study a protocol to implement the two-qubit Quadratic Unconstrained Binary Optimization (QUBO) problem. We model atom trapping, addressing, coherent evolution, and decoherence. We also explore collective control of the many-atom system and generalize the QUBO problem to multiple qubits. We acknowledge funding from the AQUARIUS project, Sandia National Laboratories

Studying Parental Involvement and University Access and Choice: An "Interacting Multiple Capitals" Model

ERIC Educational Resources Information Center

Gao, Fang; Ng, Jacky Chi Kit

2017-01-01

Capital-embedded parental involvement in education is essential in enhancing university enrolment and maximising the educational potentials for equality and excellence. Previous studies in this field have mainly utilised Perna's (2000, 2006) model, which defines parental involvement as social capital and identifies the additive influences of…

Influence of Role-Switching on Phonetic Convergence in Conversation

ERIC Educational Resources Information Center

Pardo, Jennifer S.; Jay, Isabel Cajori; Hoshino, Risa; Hasbun, Sara Maria; Sowemimo-Coker, Chantal; Krauss, Robert M.

2013-01-01

The current study examined phonetic convergence when talkers alternated roles during conversational interaction. The talkers completed a map navigation task in which they alternated instruction Giver and Receiver roles across multiple map pairs. Previous studies found robust effects of the role of a talker on phonetic convergence, and it was…

Using Mixed-Effects Structural Equation Models to Study Student Academic Development.

ERIC Educational Resources Information Center

Pike, Gary R.

1992-01-01

A study at the University of Tennessee Knoxville used mixed-effect structural equation models incorporating latent variables as an alternative to conventional methods of analyzing college students' (n=722) first-year-to-senior academic gains. Results indicate, contrary to previous analysis, that coursework and student characteristics interact to…

Combining Cognitive and Interactive Approaches to Lingua Receptiva

ERIC Educational Resources Information Center

Bahtina, Daria; ten Thije, Jan D.; Wijnen, Frank

2013-01-01

This study takes an experimental approach to "lingua receptiva" (LaRa), a communication mode in which interlocutors each use their own--different--native language. In contrast to previous work on LaRa, this study investigates the phenomenon in genetically unrelated languages. Native speakers of Estonian and Russian were engaged in a…

International Students' Networks: A Case Study in a UK University

ERIC Educational Resources Information Center

Taha, Nashrawan; Cox, Andrew

2016-01-01

The great influx of international students into UK universities has led to internationalisation becoming an important issue. Previous studies have focused on the integration of home and international students, illustrating a lack of intercultural interaction. Yet there has been a lack of research investigating international students' networks and…

A Case Study of International Students' Social Adjustment, Friendship Development, and Physical Activity

ERIC Educational Resources Information Center

Li, Shuang; Zizzi, Sam

2018-01-01

Previous literature has focused on international student's social transition and monocultural and bicultural ties. Little research has explored international students' multicultural friendship development and the role that physical activity plays in their social interaction. The current case study explored a group of international students'…

The Role of Attractiveness and Aggression in High School Popularity

ERIC Educational Resources Information Center

Borch, Casey; Hyde, Allen; Cillessen, Antonius H. N.

2011-01-01

This study examines the effects of physical attractiveness and aggression on popularity among high school students. Previous work has found positive relationships between aggression and popularity and physical attractiveness and popularity. The current study goes beyond this work by examining the interactive effects of physical attractiveness and…

Identifying the Educationally Influential Physician: A Systematic Review of Approaches

ERIC Educational Resources Information Center

Kronberger, Matthew P.; Bakken, Lori L.

2011-01-01

Introduction: Previous studies have indicated that educationally influential physicians' (EIPs) interactions with peers can lead to practice changes and improved patient outcomes. However, multiple approaches have been used to identify and investigate EIPs' informal or formal influence on practice, which creates study outcomes that are difficult…

Extension of the quasistatic far-wing line shape theory to multicomponent anisotropic potentials

NASA Technical Reports Server (NTRS)

Ma, Q.; Tipping, R. H.

1994-01-01

The formalism developed previously for the calculation of the far-wing line shape function and the corresponding absorption coefficient using a single-component anisotropic interaction term and the binary collision and quasistatic approximations is generalized to multicomponent anisotropic potential functions. Explicit expressions are presented for several common cases, including the long-range dipole-dipole plus dipole-quadrupole interaction and a linear molecule interacting with a perturber atom. After determining the multicomponent functional representation for the interaction between the CO2 and Ar from previously published data, we calculate the theoretical line shape function and the corresponding absorption due to the nu(sub 3) band of CO2 in the frequency range 2400-2580 cm(exp -1) and compare our results with previous calculations carried out using a single-component anisotropic interaction, and with the results obtained assuming Lorentzian line shapes. The principal uncertainties in the present results, possible refinements of the theoretical formalism, and the applicability to other systems are discussed briefly.

Modeling the process of interaction of 10 keV electrons with a plane dielectric surface

NASA Astrophysics Data System (ADS)

Vokhmyanina, Kristina; Sotnikova, Valentina; Sotnikov, Alexey; Kaplii, Anna; Nikulicheva, Tatyana; Kubankin, Alexandr; Kishin, Ivan

2018-05-01

The effect of guiding of charged particles by dielectric channels is of noticeable interest at the present time. The phenomenon is widely studied experimentally and theoretically but some points still need to be clarified. A previously developed model of interaction of fast electrons with dielectric surface at grazing incidence is used to study the independence of electron deflection on the value of electron beam current. The calculations were performed assuming a smooth dependence of the surface conductivity on the beam current in the 40-3000 nA range.

Modulation of frontostriatal interaction aligns with reduced primary reward processing under serotonergic drugs.

PubMed

Abler, Birgit; Grön, Georg; Hartmann, Antonie; Metzger, Coraline; Walter, Martin

2012-01-25

Recently, functional interactions between anteroventral prefrontal cortex and nucleus accumbens (NAcc) have been shown to relate to behavior counteracting reward-desiring (Diekhof and Gruber, 2010). Downregulation of the reward system by serotonin has also been suggested as the mode of action accounting for unsatisfactory effects of serotonin reuptake inhibitors (SSRIs) such as insufficient alleviation or even increase of anhedonia, and loss of interest. However, understanding of the in vivo mechanisms of SSRI-related alteration of the human reward system is still incomplete. Using functional magnetic resonance imaging (fMRI) within a double-blind cross-over within-subjects study design and administering the SSRI paroxetine, the dopamine/norepinephrine reuptake inhibitor bupropione, and placebo for 7 d each, we investigated a group of 18 healthy male subjects. Under paroxetine, subjects showed significantly decreased activation of the bilateral NAcc during processing of primary rewards (erotic videos), but not under bupropion. Similar to the previous study, analysis of psychophysiological interactions revealed that this downregulation relied on negative interactions between left and right NAcc fMRI signals and the bilateral anteroventral prefrontal cortex that now were significantly enhanced under paroxetine and reduced under bupropion. Individual drug-dependent modulations of interacting brain regions were significantly associated with individual expressions of impulsivity as a personality trait. Our results corroborate and extend previous insights on interregional crosstalk from secondary to primary rewards and demonstrate parallels between active inhibitory control of and serotonergic effects on the dopaminergic reward system's activity.

Effects of non-adiabatic walls on shock/boundary-layer interaction using direct numerical simulations

NASA Astrophysics Data System (ADS)

Volpiani, Pedro S.; Bernardini, Matteo; Larsson, Johan

2017-11-01

The influence of wall thermal conditions on the properties of an impinging shock wave interacting with a turbulent supersonic boundary layer is a research topic that still remains underexplored. In the present study, direct numerical simulations (DNS) are employed to investigate the flow properties of a shock wave interacting with a turbulent boundary layer at free-stream Mach number M∞ = 2.28 with distinct wall thermal conditions and shock strengths. Instantaneous and mean flow fields, wall quantities and the low-frequency unsteadiness are analyzed. While heating contributes to increase the extent of the interaction zone, wall cooling turns out to be a good candidate for flow control. The distribution of the Stanton number shows a good agreement with prior experimental studies and confirms the strong heat transfer and complex pattern within the interaction region. Numerical results indicate that the changes in the interaction length are mainly linked to the incoming boundary layer as suggested in previous studies (Souverein et al., 2013 and Jaunet et al., 2014). This work was supported by the Air Force Office of Scientific Research, Grant FA95501610385.

Interaction of magnetic resonators studied by the magnetic field enhancement

NASA Astrophysics Data System (ADS)

Hou, Yumin

2013-12-01

It is the first time that the magnetic field enhancement (MFE) is used to study the interaction of magnetic resonators (MRs), which is more sensitive than previous parameters-shift and damping of resonance frequency. To avoid the coherence of lattice and the effect of Bloch wave, the interaction is simulated between two MRs with same primary phase when the distance is changed in the range of several resonance wavelengths, which is also compared with periodic structure. The calculated MFE oscillating and decaying with distance with the period equal to resonance wavelength directly shows the retardation effect. Simulation also shows that the interaction at normal incidence is sensitive to the phase correlation which is related with retardation effect and is ultra-long-distance interaction when the two MRs are strongly localized. When the distance is very short, the amplitude of magnetic resonance is oppressed by the strong interaction and thus the MFE can be much lower than that of single MR. This study provides the design rules of metamaterials for engineering resonant properties of MRs.

Interaction between Wine Phenolic Acids and Salivary Proteins by Saturation-Transfer Difference Nuclear Magnetic Resonance Spectroscopy (STD-NMR) and Molecular Dynamics Simulations.

PubMed

Ferrer-Gallego, Raúl; Hernández-Hierro, José Miguel; Brás, Natércia F; Vale, Nuno; Gomes, Paula; Mateus, Nuno; de Freitas, Victor; Heredia, Francisco J; Escribano-Bailón, María Teresa

2017-08-09

The interaction between phenolic compounds and salivary proteins is highly related to the astringency perception. Recently, it has been proven the existence of synergisms on the perceived astringency when phenolic acids were tested as mixtures in comparison to individual compounds, maintaining constant the total amount of the stimulus. The interactions between wine phenolic acids and the peptide fragment IB7 12 have been studied by saturation-transfer difference (STD) NMR spectroscopy. This technique provided the dissociation constants and the percentage of interaction between both individual and mixtures of hydroxybenzoic and hydroxycinnamic acids and the model peptide. It is noteworthy that hydroxybenzoic acids showed higher affinity for the peptide than hydroxycinnamic acids. To obtain further insights into the mechanisms of interaction, molecular dynamics simulations have been performed. Results obtained not only showed the ability of these compounds to interact with salivary proteins but also may justify the synergistic effect observed in previous sensory studies.

Identification of Protein–Excipient Interaction Hotspots Using Computational Approaches

PubMed Central

Barata, Teresa S.; Zhang, Cheng; Dalby, Paul A.; Brocchini, Steve; Zloh, Mire

2016-01-01

Protein formulation development relies on the selection of excipients that inhibit protein–protein interactions preventing aggregation. Empirical strategies involve screening many excipient and buffer combinations using force degradation studies. Such methods do not readily provide information on intermolecular interactions responsible for the protective effects of excipients. This study describes a molecular docking approach to screen and rank interactions allowing for the identification of protein–excipient hotspots to aid in the selection of excipients to be experimentally screened. Previously published work with Drosophila Su(dx) was used to develop and validate the computational methodology, which was then used to determine the formulation hotspots for Fab A33. Commonly used excipients were examined and compared to the regions in Fab A33 prone to protein–protein interactions that could lead to aggregation. This approach could provide information on a molecular level about the protective interactions of excipients in protein formulations to aid the more rational development of future formulations. PMID:27258262

Exploring Covalent Allosteric Inhibition of Antigen 85C from Mycobacterium tuberculosis by Ebselen Derivatives

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

Goins, Christopher M.; Dajnowicz, Steven; Thanna, Sandeep

Previous studies identified ebselen as a potent in vitro and in vivo inhibitor of the Mycobacterium tuberculosis ( Mtb) antigen 85 (Ag85) complex, comprising three homologous enzymes required for the biosynthesis of the mycobacterial cell wall. In this study, the Mtb Ag85C enzyme was cocrystallized with azido and adamantyl ebselen derivatives, resulting in two crystallographic structures of 2.01 and 1.30 Å resolution, respectively. Both structures displayed the anticipated covalent modification of the solvent accessible, noncatalytic Cys209 residue forming a selenenylsulfide bond. Continuous difference density for both thiol modifiers allowed for the assessment of interactions that influence ebselen binding and inhibitormore » orientation that were unobserved in previous Ag85C ebselen structures. The k inact/ K I values for ebselen, adamantyl ebselen, and azido ebselen support the importance of observed constructive chemical interactions with Arg239 for increased in vitro efficacy toward Ag85C. To better understand the in vitro kinetic properties of these ebselen derivatives, the energetics of specific protein–inhibitor interactions and relative reaction free energies were calculated for ebselen and both derivatives using density functional theory. These studies further support the different in vitro properties of ebselen and two select ebselen derivatives from our previously published ebselen library with respect to kinetics and protein–inhibitor interactions. In both structures, the α9 helix was displaced farther from the enzyme active site than the previous Ag85C ebselen structure, resulting in the restructuring of a connecting loop and imparting a conformational change to residues believed to play a role in substrate binding specific to Ag85C. These notable structural changes directly affect protein stability, reducing the overall melting temperature by up to 14.5 °C, resulting in the unfolding of protein at physiological temperatures. Additionally, this structural rearrangement due to covalent allosteric modification creates a sizable solvent network that encompasses the active site and extends to the modified Cys209 residue. In all, this study outlines factors that influence enzyme inhibition by ebselen and its derivatives while further highlighting the effects of the covalent modification of Cys209 by said inhibitors on the structure and stability of Ag85C. Moreover, the results suggest a strategy for developing new classes of Ag85 inhibitors with increased specificity and potency.« less

Exploring Covalent Allosteric Inhibition of Antigen 85C from Mycobacterium tuberculosis by Ebselen Derivatives.

PubMed

Goins, Christopher M; Dajnowicz, Steven; Thanna, Sandeep; Sucheck, Steven J; Parks, Jerry M; Ronning, Donald R

2017-05-12

Previous studies identified ebselen as a potent in vitro and in vivo inhibitor of the Mycobacterium tuberculosis (Mtb) antigen 85 (Ag85) complex, comprising three homologous enzymes required for the biosynthesis of the mycobacterial cell wall. In this study, the Mtb Ag85C enzyme was cocrystallized with azido and adamantyl ebselen derivatives, resulting in two crystallographic structures of 2.01 and 1.30 Å resolution, respectively. Both structures displayed the anticipated covalent modification of the solvent accessible, noncatalytic Cys209 residue forming a selenenylsulfide bond. Continuous difference density for both thiol modifiers allowed for the assessment of interactions that influence ebselen binding and inhibitor orientation that were unobserved in previous Ag85C ebselen structures. The k inact /K I values for ebselen, adamantyl ebselen, and azido ebselen support the importance of observed constructive chemical interactions with Arg239 for increased in vitro efficacy toward Ag85C. To better understand the in vitro kinetic properties of these ebselen derivatives, the energetics of specific protein-inhibitor interactions and relative reaction free energies were calculated for ebselen and both derivatives using density functional theory. These studies further support the different in vitro properties of ebselen and two select ebselen derivatives from our previously published ebselen library with respect to kinetics and protein-inhibitor interactions. In both structures, the α9 helix was displaced farther from the enzyme active site than the previous Ag85C ebselen structure, resulting in the restructuring of a connecting loop and imparting a conformational change to residues believed to play a role in substrate binding specific to Ag85C. These notable structural changes directly affect protein stability, reducing the overall melting temperature by up to 14.5 °C, resulting in the unfolding of protein at physiological temperatures. Additionally, this structural rearrangement due to covalent allosteric modification creates a sizable solvent network that encompasses the active site and extends to the modified Cys209 residue. In all, this study outlines factors that influence enzyme inhibition by ebselen and its derivatives while further highlighting the effects of the covalent modification of Cys209 by said inhibitors on the structure and stability of Ag85C. Furthermore, the results suggest a strategy for developing new classes of Ag85 inhibitors with increased specificity and potency.

Exploring Covalent Allosteric Inhibition of Antigen 85C from Mycobacterium tuberculosis by Ebselen Derivatives

DOE PAGES

Goins, Christopher M.; Dajnowicz, Steven; Thanna, Sandeep; ...

2017-03-13

Previous studies identified ebselen as a potent in vitro and in vivo inhibitor of the Mycobacterium tuberculosis ( Mtb) antigen 85 (Ag85) complex, comprising three homologous enzymes required for the biosynthesis of the mycobacterial cell wall. In this study, the Mtb Ag85C enzyme was cocrystallized with azido and adamantyl ebselen derivatives, resulting in two crystallographic structures of 2.01 and 1.30 Å resolution, respectively. Both structures displayed the anticipated covalent modification of the solvent accessible, noncatalytic Cys209 residue forming a selenenylsulfide bond. Continuous difference density for both thiol modifiers allowed for the assessment of interactions that influence ebselen binding and inhibitormore » orientation that were unobserved in previous Ag85C ebselen structures. The k inact/ K I values for ebselen, adamantyl ebselen, and azido ebselen support the importance of observed constructive chemical interactions with Arg239 for increased in vitro efficacy toward Ag85C. To better understand the in vitro kinetic properties of these ebselen derivatives, the energetics of specific protein–inhibitor interactions and relative reaction free energies were calculated for ebselen and both derivatives using density functional theory. These studies further support the different in vitro properties of ebselen and two select ebselen derivatives from our previously published ebselen library with respect to kinetics and protein–inhibitor interactions. In both structures, the α9 helix was displaced farther from the enzyme active site than the previous Ag85C ebselen structure, resulting in the restructuring of a connecting loop and imparting a conformational change to residues believed to play a role in substrate binding specific to Ag85C. These notable structural changes directly affect protein stability, reducing the overall melting temperature by up to 14.5 °C, resulting in the unfolding of protein at physiological temperatures. Additionally, this structural rearrangement due to covalent allosteric modification creates a sizable solvent network that encompasses the active site and extends to the modified Cys209 residue. In all, this study outlines factors that influence enzyme inhibition by ebselen and its derivatives while further highlighting the effects of the covalent modification of Cys209 by said inhibitors on the structure and stability of Ag85C. Moreover, the results suggest a strategy for developing new classes of Ag85 inhibitors with increased specificity and potency.« less

An Evolving Genetic Architecture Interacts with Hill–Robertson Interference to Determine the Benefit of Sex

PubMed Central

Whitlock, Alexander O. B.; Peck, Kayla M.; Azevedo, Ricardo B. R.; Burch, Christina L.

2016-01-01

Sex is ubiquitous in the natural world, but the nature of its benefits remains controversial. Previous studies have suggested that a major advantage of sex is its ability to eliminate interference between selection on linked mutations, a phenomenon known as Hill–Robertson interference. However, those studies may have missed both important advantages and important disadvantages of sexual reproduction because they did not allow the distributions of mutational effects and interactions (i.e., the genetic architecture) to evolve. Here we investigate how Hill–Robertson interference interacts with an evolving genetic architecture to affect the evolutionary origin and maintenance of sex by simulating evolution in populations of artificial gene networks. We observed a long-term advantage of sex—equilibrium mean fitness of sexual populations exceeded that of asexual populations—that did not depend on population size. We also observed a short-term advantage of sex—sexual modifier mutations readily invaded asexual populations—that increased with population size, as was observed in previous studies. We show that the long- and short-term advantages of sex were both determined by differences between sexual and asexual populations in the evolutionary dynamics of two properties of the genetic architecture: the deleterious mutation rate (Ud) and recombination load (LR). These differences resulted from a combination of selection to minimize LR, which is experienced only by sexuals, and Hill–Robertson interference experienced primarily by asexuals. In contrast to the previous studies, in which Hill–Robertson interference had only a direct impact on the fitness advantages of sex, the impact of Hill–Robertson interference in our simulations was mediated additionally by an indirect impact on the efficiency with which selection acted to reduce Ud. PMID:27098911

Condition-dependent functional connectivity: syntax networks in bilinguals

PubMed Central

Dodel, Silke; Golestani, Narly; Pallier, Christophe; ElKouby, Vincent; Le Bihan, Denis; Poline, Jean-Baptiste

2005-01-01

This paper introduces a method to study the variation of brain functional connectivity networks with respect to experimental conditions in fMRI data. It is related to the psychophysiological interaction technique introduced by Friston et al. and extends to networks of correlation modulation (CM networks). Extended networks containing several dozens of nodes are determined in which the links correspond to consistent correlation modulation across subjects. In addition, we assess inter-subject variability and determine networks in which the condition-dependent functional interactions can be explained by a subject-dependent variable. We applied the technique to data from a study on syntactical production in bilinguals and analysed functional interactions differentially across tasks (word reading or sentence production) and across languages. We find an extended network of consistent functional interaction modulation across tasks, whereas the network comparing languages shows fewer links. Interestingly, there is evidence for a specific network in which the differences in functional interaction across subjects can be explained by differences in the subjects' syntactical proficiency. Specifically, we find that regions, including ones that have previously been shown to be involved in syntax and in language production, such as the left inferior frontal gyrus, putamen, insula, precentral gyrus, as well as the supplementary motor area, are more functionally linked during sentence production in the second, compared with the first, language in syntactically more proficient bilinguals than in syntactically less proficient ones. Our approach extends conventional activation analyses to the notion of networks, emphasizing functional interactions between regions independently of whether or not they are activated. On the one hand, it gives rise to testable hypotheses and allows an interpretation of the results in terms of the previous literature, and on the other hand, it provides a basis for studying the structure of functional interactions as a whole, and hence represents a further step towards the notion of large-scale networks in functional imaging. PMID:16087437

CACTI: free, open-source software for the sequential coding of behavioral interactions.

PubMed

Glynn, Lisa H; Hallgren, Kevin A; Houck, Jon M; Moyers, Theresa B

2012-01-01

The sequential analysis of client and clinician speech in psychotherapy sessions can help to identify and characterize potential mechanisms of treatment and behavior change. Previous studies required coding systems that were time-consuming, expensive, and error-prone. Existing software can be expensive and inflexible, and furthermore, no single package allows for pre-parsing, sequential coding, and assignment of global ratings. We developed a free, open-source, and adaptable program to meet these needs: The CASAA Application for Coding Treatment Interactions (CACTI). Without transcripts, CACTI facilitates the real-time sequential coding of behavioral interactions using WAV-format audio files. Most elements of the interface are user-modifiable through a simple XML file, and can be further adapted using Java through the terms of the GNU Public License. Coding with this software yields interrater reliabilities comparable to previous methods, but at greatly reduced time and expense. CACTI is a flexible research tool that can simplify psychotherapy process research, and has the potential to contribute to the improvement of treatment content and delivery.

The serotonin-dopamine interaction measured with positron emission tomography (PET) and C-11 raclopride in normal human subjects

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

Smith, G.S.; Dewey, S.L.; Logan, J.

1994-05-01

Our previous studies have shown that the interaction between serotonin and dopamine can be measured with C-11 raclopride and PET in the baboon brain. A series of studies was undertaken to extend dim findings to the normal human brain. PET studies were conducted in male control subjects (n=8) using the CTI 931 tomograph. Two C-11 raclopride scans were performed, prior to and 180 minutes following administration of the selective serotonin releasing agent, fenfluramine (60mg/PO). The neuroendocrine response to fenfluramine challenge is commonly used in psychiatric research as an index of serotonin activity. The C-11 raclopride data were analyzed with themore » distribution volume method. For the group of subjects, an increase was observed in the striatum to cerebellum ratio (specific to non-specific binding ratio), in excess of the test-retest variability of the ligand. Variability in response was observed across subjects. These results are consistent with our previous findings in the baboon that citalopram administration increased C-11 raclopride binding, consistent with a decrease in endogenous dopamine. In vivo microdialysis studies in freely moving rats confirmed that citalopram produces a time-dependent decrease in extracellular dopamine levels, consistent with the PET results. In vivo PET studies of the serotonin-dopamine interaction are relevant to the evaluation of etiologic and therapeutic mechanisms in schizophrenia and affective disorder.« less

Conformational and NBO studies of serotonin as a radical scavenger. Changes induced by the OH group.

PubMed

Lobayan, Rosana M; Schmit, María Celia Pérez

2018-03-01

Serotonin (5-hydroxytryptamine, SER) is a neurotransmitter that affects many different processes within the human body. We studied the conformational space of SER, and explored in depth the significant stereoelectronic features for the structure stabilization and antioxidant activity. Forty-eight equilibrium structures were described at the B3LYP/6-311++G(d,p) level, characterizing four non-previously reported conformers. Electron distributions were analyzed by topological QTAIM (Quantum Theory of atoms in molecules) and natural bond orbital (NBO) studies. The study was supplemented by an exploration of molecular electrostatic potential (MEP). Intramolecular hydrogen interactions were also investigated; N10⋯HC4 or N10⋯HC2 hydrogen bondings were depicted in 5 conformers. The conformer stabilization and the corresponding energy arrangement were explained by hyperconjugation interactions obtained by NBO analysis. The present study is based on the effect of the 5-OH group on geometric and electronic behavior that we have previously reported on the similar structure tryptamine (TRA). Our interest also lies in SER's free radical scavenging capacity as a member of the indole family. The H-atom abstraction and single-electron transfer mechanisms were taken into account. Our results showed that donor-acceptor interactions play a major role in explaining the changes induced by the OH group, and free-radical scavenging capability of the indole compounds. Copyright © 2018 Elsevier Inc. All rights reserved.

Transition-density-fragment interaction combined with transfer integral approach for excitation-energy transfer via charge-transfer states

NASA Astrophysics Data System (ADS)

Fujimoto, Kazuhiro J.

2012-07-01

A transition-density-fragment interaction (TDFI) combined with a transfer integral (TI) method is proposed. The TDFI method was previously developed for describing electronic Coulomb interaction, which was applied to excitation-energy transfer (EET) [K. J. Fujimoto and S. Hayashi, J. Am. Chem. Soc. 131, 14152 (2009)] and exciton-coupled circular dichroism spectra [K. J. Fujimoto, J. Chem. Phys. 133, 124101 (2010)]. In the present study, the TDFI method is extended to the exchange interaction, and hence it is combined with the TI method for applying to the EET via charge-transfer (CT) states. In this scheme, the overlap correction is also taken into account. To check the TDFI-TI accuracy, several test calculations are performed to an ethylene dimer. As a result, the TDFI-TI method gives a much improved description of the electronic coupling, compared with the previous TDFI method. Based on the successful description of the electronic coupling, the decomposition analysis is also performed with the TDFI-TI method. The present analysis clearly shows a large contribution from the Coulomb interaction in most of the cases, and a significant influence of the CT states at the small separation. In addition, the exchange interaction is found to be small in this system. The present approach is useful for analyzing and understanding the mechanism of EET.

Kinesin 1 regulates cilia length through an interaction with the Bardet-Biedl syndrome related protein CCDC28B.

PubMed

Novas, Rossina; Cardenas-Rodriguez, Magdalena; Lepanto, Paola; Fabregat, Matías; Rodao, Magela; Fariello, María Inés; Ramos, Mauricio; Davison, Camila; Casanova, Gabriela; Alfaya, Lucía; Lecumberry, Federico; González-Sapienza, Gualberto; Irigoín, Florencia; Badano, Jose L

2018-02-14

Bardet-Biedl syndrome (BBS) is a ciliopathy characterized by retinal degeneration, obesity, polydactyly, renal disease and mental retardation. CCDC28B is a BBS-associated protein that we have previously shown plays a role in cilia length regulation whereby its depletion results in shortened cilia both in cells and Danio rerio (zebrafish). At least part of that role is achieved by its interaction with the mTORC2 component SIN1, but the mechanistic details of this interaction and/or additional functions that CCDC28B might play in the context of cilia remain poorly understood. Here we uncover a novel interaction between CCDC28B and the kinesin 1 molecular motor that is relevant to cilia. CCDC28B interacts with kinesin light chain 1 (KLC1) and the heavy chain KIF5B. Notably, depletion of these kinesin 1 components results in abnormally elongated cilia. Furthermore, through genetic interaction studies we demonstrate that kinesin 1 regulates ciliogenesis through CCDC28B. We show that kinesin 1 regulates the subcellular distribution of CCDC28B, unexpectedly, inhibiting its nuclear accumulation, and a ccdc28b mutant missing a nuclear localization motif fails to rescue the phenotype in zebrafish morphant embryos. Therefore, we uncover a previously unknown role of kinesin 1 in cilia length regulation that relies on the BBS related protein CCDC28B.

Revealing hidden insect-fungus interactions; moderately specialized, modular and anti-nested detritivore networks.

PubMed

Jacobsen, Rannveig M; Sverdrup-Thygeson, Anne; Kauserud, Håvard; Birkemoe, Tone

2018-04-11

Ecological networks are composed of interacting communities that influence ecosystem structure and function. Fungi are the driving force for ecosystem processes such as decomposition and carbon sequestration in terrestrial habitats, and are strongly influenced by interactions with invertebrates. Yet, interactions in detritivore communities have rarely been considered from a network perspective. In the present study, we analyse the interaction networks between three functional guilds of fungi and insects sampled from dead wood. Using DNA metabarcoding to identify fungi, we reveal a diversity of interactions differing in specificity in the detritivore networks, involving three guilds of fungi. Plant pathogenic fungi were relatively unspecialized in their interactions with insects inhabiting dead wood, while interactions between the insects and wood-decay fungi exhibited the highest degree of specialization, which was similar to estimates for animal-mediated seed dispersal networks in previous studies. The low degree of specialization for insect symbiont fungi was unexpected. In general, the pooled insect-fungus networks were significantly more specialized, more modular and less nested than randomized networks. Thus, the detritivore networks had an unusual anti-nested structure. Future studies might corroborate whether this is a common aspect of networks based on interactions with fungi, possibly owing to their often intense competition for substrate. © 2018 The Author(s).

Mathematical Analysis for Non-reciprocal-interaction-based Model of Collective Behavior

NASA Astrophysics Data System (ADS)

Kano, Takeshi; Osuka, Koichi; Kawakatsu, Toshihiro; Ishiguro, Akio

2017-12-01

In many natural and social systems, collective behaviors emerge as a consequence of non-reciprocal interaction between their constituents. As a first step towards understanding the core principle that underlies these phenomena, we previously proposed a minimal model of collective behavior based on non-reciprocal interactions by drawing inspiration from friendship formation in human society, and demonstrated via simulations that various non-trivial patterns emerge by changing parameters. In this study, a mathematical analysis of the proposed model wherein the system size is small is performed. Through the analysis, the mechanism of the transition between several patterns is elucidated.

Intrinsic limits to gene regulation by global crosstalk

NASA Astrophysics Data System (ADS)

Friedlander, Tamar; Prizak, Roshan; Guet, Calin; Barton, Nicholas H.; Tkacik, Gasper

Gene activity is mediated by the specificity of binding interactions between special proteins, called transcription factors, and short regulatory sequences on the DNA, where different protein species preferentially bind different DNA targets. Limited interaction specificity may lead to crosstalk: a regulatory state in which a gene is either incorrectly activated due to spurious interactions or remains erroneously inactive. Since each protein can potentially interact with numerous DNA targets, crosstalk is inherently a global problem, yet has previously not been studied as such. We construct a theoretical framework to analyze the effects of global crosstalk on gene regulation, using statistical mechanics. We find that crosstalk in regulatory interactions puts fundamental limits on the reliability of gene regulation that are not easily mitigated by tuning proteins concentrations or by complex regulatory schemes proposed in the literature. Our results suggest that crosstalk imposes a previously unexplored global constraint on the functioning and evolution of regulatory networks, which is qualitatively distinct from the known constraints that act at the level of individual gene regulatory elements. The research leading to these results has received funding from the People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme (FP7/2007-2013) under REA Grant agreement Nr. 291734 (T.F.) and ERC Grant Nr. 250152 (N.B.).

Cross-neutralizing human anti-poliovirus antibodies bind the recognition site for cellular receptor

PubMed Central

Chen, Zhaochun; Fischer, Elizabeth R.; Kouiavskaia, Diana; Hansen, Bryan T.; Ludtke, Steven J.; Bidzhieva, Bella; Makiya, Michelle; Agulto, Liane; Purcell, Robert H.; Chumakov, Konstantin

2013-01-01

Most structural information about poliovirus interaction with neutralizing antibodies was obtained in the 1980s in studies of mouse monoclonal antibodies. Recently we have isolated a number of human/chimpanzee anti-poliovirus antibodies and demonstrated that one of them, MAb A12, could neutralize polioviruses of both serotypes 1 and 2. This communication presents data on isolation of an additional cross-neutralizing antibody (F12) and identification of a previously unknown epitope on the surface of poliovirus virions. Epitope mapping was performed by sequencing of antibody-resistant mutants and by cryo-EM of complexes of virions with Fab fragments. The results have demonstrated that both cross-neutralizing antibodies bind the site located at the bottom of the canyon surrounding the fivefold axis of symmetry that was previously shown to interact with cellular poliovirus receptor CD155. However, the same antibody binds to serotypes 1 and 2 through different specific interactions. It was also shown to interact with type 3 poliovirus, albeit with about 10-fold lower affinity, insufficient for effective neutralization. Antibody interaction with the binding site of the cellular receptor may explain its broad reactivity and suggest that further screening or antibody engineering could lead to a universal antibody capable of neutralizing all three serotypes of poliovirus. PMID:24277851

Orientation-dependent interaction between Drosophila insulators is a property of this class of regulatory elements.

PubMed

Kyrchanova, Olga; Chetverina, Darya; Maksimenko, Oksana; Kullyev, Andrey; Georgiev, Pavel

2008-12-01

Insulators are defined as a class of regulatory elements that delimit independent transcriptional domains within eukaryotic genomes. According to previous data, an interaction (pairing) between some Drosophila insulators can support distant activation of a promoter by an enhancer. Here, we have demonstrated that pairs of well-studied insulators such as scs-scs, scs'-scs', 1A2-1A2 and Wari-Wari support distant activation of the white promoter by the yeast GAL4 activator in an orientation-dependent manner. The same is true for the efficiency of the enhancer that stimulates white expression in the eyes. In all insulator pairs tested, stimulation of the white gene was stronger when insulators were inserted between the eye enhancer or GAL4 and the white promoter in opposite orientations relative to each other. As shown previously, Zw5, Su(Hw) and dCTCF proteins are required for the functioning of different insulators that do not interact with each other. Here, strong functional interactions have been revealed between DNA fragments containing binding sites for either Zw5 or Su(Hw) or dCTCF protein but not between heterologous binding sites [Zw5-Su(Hw), dCTCF-Su(Hw), or dCTCF-Zw5]. These results suggest that insulator proteins can support selective interactions between distant regulatory elements.

Applicant Personality and Procedural Justice Perceptions of Group Selection Interviews.

PubMed

Bye, Hege H; Sandal, Gro M

2016-01-01

We investigated how job applicants' personalities influence perceptions of the structural and social procedural justice of group selection interviews (i.e., a group of several applicants being evaluated simultaneously). We especially addressed trait interactions between neuroticism and extraversion (the affective plane) and extraversion and agreeableness (the interpersonal plane). Data on personality (pre-interview) and justice perceptions (post-interview) were collected in a field study among job applicants ( N  = 97) attending group selection interviews for positions as teachers in a Norwegian high school. Interaction effects in hierarchical regression analyses showed that perceptions of social and structural justice increased with levels of extraversion among high scorers on neuroticism. Among emotionally stable applicants, however, being introverted or extraverted did not matter to justice perceptions. Extraversion did not impact on the perception of social justice for applicants low in agreeableness. Agreeable applicants, however, experienced the group interview as more socially fair when they were also extraverted. The impact of applicant personality on justice perceptions may be underestimated if traits interactions are not considered. Procedural fairness ratings for the group selection interview were high, contrary to the negative reactions predicted by other researchers. There was no indication that applicants with desirable traits (i.e., traits predictive of job performance) reacted negatively to this selection tool. Despite the widespread use of interviews in selection, previous studies of applicant personality and fairness reactions have not included interviews. The study demonstrates the importance of previously ignored trait interactions in understanding applicant reactions.

Analysis of Protein Interactions with Picomolar Binding Affinity by Fluorescence-Detected Sedimentation Velocity

PubMed Central

2014-01-01

The study of high-affinity protein interactions with equilibrium dissociation constants (KD) in the picomolar range is of significant interest in many fields, but the characterization of stoichiometry and free energy of such high-affinity binding can be far from trivial. Analytical ultracentrifugation has long been considered a gold standard in the study of protein interactions but is typically applied to systems with micromolar KD. Here we present a new approach for the study of high-affinity interactions using fluorescence detected sedimentation velocity analytical ultracentrifugation (FDS-SV). Taking full advantage of the large data sets in FDS-SV by direct boundary modeling with sedimentation coefficient distributions c(s), we demonstrate detection and hydrodynamic resolution of protein complexes at low picomolar concentrations. We show how this permits the characterization of the antibody–antigen interactions with low picomolar binding constants, 2 orders of magnitude lower than previously achieved. The strongly size-dependent separation and quantitation by concentration, size, and shape of free and complex species in free solution by FDS-SV has significant potential for studying high-affinity multistep and multicomponent protein assemblies. PMID:24552356

Criteria for Public Open Space Enhancement to Achieve Social Interaction: a Review Paper

NASA Astrophysics Data System (ADS)

Salih, S. A.; Ismail, S.

2017-12-01

A This paper presents a various literatures, studies, transcripts and papers aiming to provide an overview of some theories and existing research on the significance of natural environments and green open spaces to achieve social interaction and outdoor recreation. The main objective of the paper is to identify the factors that affecting social interaction in green open spaces, through proving that an appropriate open spaces is important to enhance social interaction and community. This study employs (qualitative) summarizing content analysis method which mainly focused on collect and summarizing of documentation such as transcripts, articles, papers, and books from more than 25 source, regarding the importance of public open spaces for the community. The summarizing content analysis of this paper is the fundament for a qualitative oriented procedure of text interpretation used to analyse the information gathered. Results of this study confirms that sound social interaction need an appropriate physical space including criteria of: design, activities, access and linkage, administration and maintenance, place attachment and users’ characteristics, also previous studies in this area have a health perspective with measures of physical activity of open spaces in general.

Technology Adoption: an Interaction Perspective

NASA Astrophysics Data System (ADS)

Sitorus, Hotna M.; Govindaraju, Rajesri; Wiratmadja, I. I.; Sudirman, Iman

2016-02-01

The success of a new technology depends on how well it is accepted by its intended users. Many technologies face the problem of low adoption rate, despite the benefits. An understanding of what makes people accept or reject a new technology can help speed up the adoption rate. This paper presents a framework for technology adoption based on an interactive perspective, resulting from a literature study on technology adoption. In studying technology adoption, it is necessary to consider the interactions among elements involved in the system, for these interactions may generate new characteristics or new relationships. The interactions among elements in a system adoption have not received sufficient consideration in previous studies of technology adoption. Based on the proposed interaction perspective, technology adoption is elaborated by examining interactions among the individual (i.e. the user or prospective user), the technology, the task and the environment. The framework is formulated by adopting several theories, including Perceived Characteristics of Innovating, Diffusion of Innovation Theory, Technology Acceptance Model, Task-Technology Fit and usability theory. The proposed framework is illustrated in the context of mobile banking adoption. It is aimed to offer a better understanding of determinants of technology adoption in various contexts, including technology in manufacturing systems.

Effects of visual and verbal interaction on unintentional interpersonal coordination.

PubMed

Richardson, Michael J; Marsh, Kerry L; Schmidt, R C

2005-02-01

Previous research has demonstrated that people's movements can become unintentionally coordinated during interpersonal interaction. The current study sought to uncover the degree to which visual and verbal (conversation) interaction constrains and organizes the rhythmic limb movements of coactors. Two experiments were conducted in which pairs of participants completed an interpersonal puzzle task while swinging handheld pendulums with instructions that minimized intentional coordination but facilitated either visual or verbal interaction. Cross-spectral analysis revealed a higher degree of coordination for conditions in which the pairs were visually coupled. In contrast, verbal interaction alone was not found to provide a sufficient medium for unintentional coordination to occur, nor did it enhance the unintentional coordination that emerged during visual interaction. The results raise questions concerning differences between visual and verbal informational linkages during interaction and how these differences may affect interpersonal movement production and its coordination.

Molecular dynamics analysis of the aggregation propensity of polyglutamine segments

PubMed Central

Wen, Jingran; Scoles, Daniel R.

2017-01-01

Protein misfolding and aggregation is a pathogenic feature shared among at least ten polyglutamine (polyQ) neurodegenerative diseases. While solvent-solution interaction is a key factor driving protein folding and aggregation, the solvation properties of expanded polyQ tracts are not well understood. By using GPU-enabled all-atom molecular dynamics simulations of polyQ monomers in an explicit solvent environment, this study shows that solvent-polyQ interaction propensity decreases as the lengths of polyQ tract increases. This study finds a predominance in long-distance interactions between residues far apart in polyQ sequences with longer polyQ segments, that leads to significant conformational differences. This study also indicates that large loops, comprised of parallel β-structures, appear in long polyQ tracts and present new aggregation building blocks with aggregation driven by long-distance intra-polyQ interactions. Finally, consistent with previous observations using coarse-grain simulations, this study demonstrates that there is a gain in the aggregation propensity with increased polyQ length, and that this gain is correlated with decreasing ability of solvent-polyQ interaction. These results suggest the modulation of solvent-polyQ interactions as a possible therapeutic strategy for treating polyQ diseases. PMID:28542401

Boldness by habituation and social interactions: a model.

PubMed

Oosten, Johanneke E; Magnhagen, Carin; Hemelrijk, Charlotte K

2010-04-01

Most studies of animal personality attribute personality to genetic traits. But a recent study by Magnhagen and Staffan (Behav Ecol Sociobiol 57:295-303, 2005) on young perch in small groups showed that boldness, a central personality trait, is also shaped by social interactions and by previous experience. The authors measured boldness by recording the duration that an individual spent near a predator and the speed with which it fed there. They found that duration near the predator increased over time and was higher the higher the average boldness of other group members. In addition, the feeding rate of shy individuals was reduced if other members of the same group were bold. The authors supposed that these behavioral dynamics were caused by genetic differences, social interactions, and habituation to the predator. However, they did not quantify exactly how this could happen. In the present study, we therefore use an agent-based model to investigate whether these three factors may explain the empirical findings. We choose an agent-based model because this type of model is especially suited to study the relation between behavior at an individual level and behavioral dynamics at a group level. In our model, individuals were either hiding in vegetation or feeding near a predator, whereby their behavior was affected by habituation and by two social mechanisms: social facilitation to approach the predator and competition over food. We show that even if we start the model with identical individuals, these three mechanisms were sufficient to reproduce the behavioral dynamics of the empirical study, including the consistent differences among individuals. Moreover, if we start the model with individuals that already differ in boldness, the behavioral dynamics produced remained the same. Our results indicate the importance of previous experience and social interactions when studying animal personality empirically.

Development of an interactive GIS based work zone traffic control tool.

DOT National Transportation Integrated Search

2013-08-01

The purpose of this study was to include consideration for intersections into the previously created GIS traffic control planning tool. Available data for making intersection control calculations were collected and integrated into the design of the t...

A continuum mechanics-based musculo-mechanical model for esophageal transport

NASA Astrophysics Data System (ADS)

Kou, Wenjun; Griffith, Boyce E.; Pandolfino, John E.; Kahrilas, Peter J.; Patankar, Neelesh A.

2017-11-01

In this work, we extend our previous esophageal transport model using an immersed boundary (IB) method with discrete fiber-based structural model, to one using a continuum mechanics-based model that is approximated based on finite elements (IB-FE). To deal with the leakage of flow when the Lagrangian mesh becomes coarser than the fluid mesh, we employ adaptive interaction quadrature points to deal with Lagrangian-Eulerian interaction equations based on a previous work (Griffith and Luo [1]). In particular, we introduce a new anisotropic adaptive interaction quadrature rule. The new rule permits us to vary the interaction quadrature points not only at each time-step and element but also at different orientations per element. This helps to avoid the leakage issue without sacrificing the computational efficiency and accuracy in dealing with the interaction equations. For the material model, we extend our previous fiber-based model to a continuum-based model. We present formulations for general fiber-reinforced material models in the IB-FE framework. The new material model can handle non-linear elasticity and fiber-matrix interactions, and thus permits us to consider more realistic material behavior of biological tissues. To validate our method, we first study a case in which a three-dimensional short tube is dilated. Results on the pressure-displacement relationship and the stress distribution matches very well with those obtained from the implicit FE method. We remark that in our IB-FE case, the three-dimensional tube undergoes a very large deformation and the Lagrangian mesh-size becomes about 6 times of Eulerian mesh-size in the circumferential orientation. To validate the performance of the method in handling fiber-matrix material models, we perform a second study on dilating a long fiber-reinforced tube. Errors are small when we compare numerical solutions with analytical solutions. The technique is then applied to the problem of esophageal transport. We use two fiber-reinforced models for the esophageal tissue: a bi-linear model and an exponential model. We present three cases on esophageal transport that differ in the material model and the muscle fiber architecture. The overall transport features are consistent with those observed from the previous model. We remark that the continuum-based model can handle more realistic and complicated material behavior. This is demonstrated in our third case where a spatially varying fiber architecture is included based on experimental study. We find that this unique muscle fiber architecture could generate a so-called pressure transition zone, which is a luminal pressure pattern that is of clinical interest. This suggests an important role of muscle fiber architecture in esophageal transport.

Look Who’s Talking NOW! Parentese Speech, Social Context, and Language Development Across Time

PubMed Central

Ramírez-Esparza, Nairán; García-Sierra, Adrián; Kuhl, Patricia K.

2017-01-01

In previous studies, we found that the social interactions infants experience in their everyday lives at 11- and 14-months of age affect language ability at 24 months of age. These studies investigated relationships between the speech style (i.e., parentese speech vs. standard speech) and social context [i.e., one-on-one (1:1) vs. group] of language input in infancy and later speech development (i.e., at 24 months of age), controlling for socioeconomic status (SES). Results showed that the amount of exposure to parentese speech-1:1 in infancy was related to productive vocabulary at 24 months. The general goal of the present study was to investigate changes in (1) the pattern of social interactions between caregivers and their children from infancy to childhood and (2) relationships among speech style, social context, and language learning across time. Our study sample consisted of 30 participants from the previously published infant studies, evaluated at 33 months of age. Social interactions were assessed at home using digital first-person perspective recordings of the auditory environment. We found that caregivers use less parentese speech-1:1, and more standard speech-1:1, as their children get older. Furthermore, we found that the effects of parentese speech-1:1 in infancy on later language development at 24 months persist at 33 months of age. Finally, we found that exposure to standard speech-1:1 in childhood was the only social interaction that related to concurrent word production/use. Mediation analyses showed that standard speech-1:1 in childhood fully mediated the effects of parentese speech-1:1 in infancy on language development in childhood, controlling for SES. This study demonstrates that engaging in one-on-one interactions in infancy and later in life has important implications for language development. PMID:28676774

Geographical Variations in the Interaction of Relative Age Effects in Youth and Adult Elite Soccer.

PubMed

Steingröver, Christina; Wattie, Nick; Baker, Joseph; Helsen, Werner F; Schorer, Jörg

2017-01-01

Selection biases based on the use of cut-off dates and the timing of athletes' birthdates have been termed relative age effects. These effects have been shown to differentially affect individuals involved in sport. For example, young male soccer players born early in their age group are overrepresented in elite teams while studies in adult soccer indicated potential carry-over effects from talent development systems. This two-study approach focuses on the processes within multi-year age groups in youth and adult elite soccer and on the role of players' age position within the age band with regard to players' birth year and birth month. Study 1 tests for an interaction of two different types of relative age effects among data from participants in the last five Under-17 FIFA World Cups (2007-2015). Analyses revealed a significant global within-year effect and varying birthdate distributions were found between confederations. Even stronger effects were found for constituent year effects. For the total sample, a multi-way frequency analysis (MFA) revealed an interaction with a pattern of a stronger within-year effect for the younger year group. This study highlights the need to consider interactions between different types of age effects. The main aim of Study 2 was to test for carry-over effects from previously found constituent year effects among players participating in the 2014 soccer World Cup and, therefore, to test for long-term effects of age grouping structures used during earlier stages of talent development. A secondary purpose of this study was to replicate findings on the existence of within-year effects and to test whether effects vary between continental confederations. No significant interaction between constituent year and within-year effects was shown by the MFA among the World Cup sample and previous findings on varying within-year effects were replicated. Results indicate that long-term effects of age grouping structures in earlier high-level talent development structures exist.

Geographical Variations in the Interaction of Relative Age Effects in Youth and Adult Elite Soccer

PubMed Central

Steingröver, Christina; Wattie, Nick; Baker, Joseph; Helsen, Werner F.; Schorer, Jörg

2017-01-01

Selection biases based on the use of cut-off dates and the timing of athletes’ birthdates have been termed relative age effects. These effects have been shown to differentially affect individuals involved in sport. For example, young male soccer players born early in their age group are overrepresented in elite teams while studies in adult soccer indicated potential carry-over effects from talent development systems. This two-study approach focuses on the processes within multi-year age groups in youth and adult elite soccer and on the role of players’ age position within the age band with regard to players’ birth year and birth month. Study 1 tests for an interaction of two different types of relative age effects among data from participants in the last five Under-17 FIFA World Cups (2007–2015). Analyses revealed a significant global within-year effect and varying birthdate distributions were found between confederations. Even stronger effects were found for constituent year effects. For the total sample, a multi-way frequency analysis (MFA) revealed an interaction with a pattern of a stronger within-year effect for the younger year group. This study highlights the need to consider interactions between different types of age effects. The main aim of Study 2 was to test for carry-over effects from previously found constituent year effects among players participating in the 2014 soccer World Cup and, therefore, to test for long-term effects of age grouping structures used during earlier stages of talent development. A secondary purpose of this study was to replicate findings on the existence of within-year effects and to test whether effects vary between continental confederations. No significant interaction between constituent year and within-year effects was shown by the MFA among the World Cup sample and previous findings on varying within-year effects were replicated. Results indicate that long-term effects of age grouping structures in earlier high-level talent development structures exist. PMID:28326044

Identification of structural protein-protein interactions of herpes simplex virus type 1.

PubMed

Lee, Jin H; Vittone, Valerio; Diefenbach, Eve; Cunningham, Anthony L; Diefenbach, Russell J

2008-09-01

In this study we have defined protein-protein interactions between the structural proteins of herpes simplex virus type 1 (HSV-1) using a LexA yeast two-hybrid system. The majority of the capsid, tegument and envelope proteins of HSV-1 were screened in a matrix approach. A total of 40 binary interactions were detected including 9 out of 10 previously identified tegument-tegument interactions (Vittone, V., Diefenbach, E., Triffett, D., Douglas, M.W., Cunningham, A.L., and Diefenbach, R.J., 2005. Determination of interactions between tegument proteins of herpes simplex virus type 1. J. Virol. 79, 9566-9571). A total of 12 interactions involving the capsid protein pUL35 (VP26) and 11 interactions involving the tegument protein pUL46 (VP11/12) were identified. The most significant novel interactions detected in this study, which are likely to play a role in viral assembly, include pUL35-pUL37 (capsid-tegument), pUL46-pUL37 (tegument-tegument) and pUL49 (VP22)-pUS9 (tegument-envelope). This information will provide further insights into the pathways of HSV-1 assembly and the identified interactions are potential targets for new antiviral drugs.

Unsupportive social interactions and affective states: examining associations of two oxytocin-related polymorphisms.

PubMed

McInnis, Opal A; McQuaid, Robyn J; Matheson, Kimberly; Anisman, Hymie

2017-01-01

Two single-nucleotide polymorphisms (SNPs) on oxytocin-related genes, specifically the oxytocin receptor (OXTR) rs53576 and the CD38 rs3796863 variants, have been associated with alterations in prosocial behaviors. A cross-sectional study was conducted among undergraduate students (N = 476) to examine associations between the OXTR and CD38 polymorphisms and unsupportive social interactions and mood states. Results revealed no association between perceived levels of unsupportive social interactions and the OXTR polymorphism. However, A carriers of the CD38 polymorphism, a variant previously associated with elevated oxytocin, reported greater perceived peer unsupportive interactions compared to CC carriers. As expected, perceived unsupportive interactions from peers was associated with greater negative affect, which was moderated by the CD38 polymorphism. Specifically, this relation was stronger among CC carriers of the CD38 polymorphism (a variant thought to be linked to lower oxytocin). When examining whether the OXTR polymorphism moderated the relation between unsupportive social interactions from peers and negative affect there was a trend toward significance, however, this did not withstand multiple testing corrections. These findings are consistent with the perspective that a variant on an oxytocin polymorphism that may be tied to lower oxytocin is related to poor mood outcomes in association with negative social interactions. At the same time, having a genetic constitution presumed to be associated with higher oxytocin was related to increased perceptions of unsupportive social interactions. These seemingly paradoxical findings could be related to previous reports in which variants associated with prosocial behaviors were also tied to relatively more effective coping styles to deal with challenges.

Personality factors and posttraumatic stress: associations in civilians one year after air attacks.

PubMed

Lecic-Tosevski, Dusica; Gavrilovic, Jelena; Knezevic, Goran; Priebe, Stefan

2003-12-01

There is an ongoing debate on which risk factors for developing posttraumatic stress symptoms are more important--personality traits reflecting vulnerability, previous stressful experiences or characteristics of the traumatic event. In this study, posttraumatic stress symptoms and their relationship with personality traits, previous stressful experiences and exposure to stressful events during air attacks in Yugoslavia were investigated. The Millon Clinical Multiaxial Inventory (MCMI; Millon, 1983), Impact of Events Scale (IES; Horowitz, Wilner, & Alvarez, 1979), Life Stressor Checklist Revised (LSCL-R; Wolfe & Kimerling, 1997), and List of Stressors were administered to a homogeneous group of medical students 1 year after the attacks. In multiple regression analyses, compulsive and passive-aggressive personality traits and a higher level of exposure to stressors during air attacks independently predicted the degree of intrusion symptoms. Avoidance symptoms were predicted by avoidant personality traits and a higher exposure to stressors both previously in life and during the attacks. In the next step, we tested in analyses of variance whether personality traits, previous stressful experiences, and stressful events during attacks as independent variables interact in predicting intrusion and avoidance symptoms. For this, students were clustered into three groups depending on their predominant personality traits. In addition to direct predictive effects, there were significant interaction effects in predicting both intrusion and avoidance. The findings suggest that each of the tested factors, i.e., personality traits, previous stressful experiences, and exposure to traumatic events may have an independent and direct influence on developing posttraumatic stress. However, the effect of these factors cannot just be added up. Rather, the factors interact in their impact on posttraumatic stress symptoms. Bigger samples and longitudinal designs will be required to understand precisely how different personality traits influence response to stressful events.

Multi-omics analysis provides insight to the Ignicoccus hospitalis - Nanoarchaeum equitans association

DOE PAGES

Rawle, Rachel A.; Hamerly, Timothy; Tripet, Brian P.; ...

2017-06-04

Studies of interspecies interactions are inherently difficult due to the complex mechanisms which enable these relationships. A model system for studying interspecies interactions is the marine hyperthermophiles Ignicoccus hospitalis and Nanoarchaeum equitans. Recent independently-conducted ‘omics’ analyses have generated insights into the molecular factors modulating this association. However, significant questions remain about the nature of the interactions between these archaea. We jointly analyzed multiple levels of omics datasets obtained from published, independent transcriptomics, proteomics, and metabolomics analyses. DAVID identified functionally-related groups enriched when I. hospitalis is grown alone or in co-culture with N. equitans. Enriched molecular pathways were subsequently visualized usingmore » interaction maps generated using STRING. Key findings of our multi-level omics analysis indicated that I. hospitalis provides precursors to N. equitans for energy metabolism. Analysis indicated an overall reduction in diversity of metabolic precursors in the I. hospitalis–N. equitans co-culture, which has been connected to the differential use of ribosomal subunits and was previously unnoticed. We also identified differences in precursors linked to amino acid metabolism, NADH metabolism, and carbon fixation, providing new insights into the metabolic adaptions of I. hospitalis enabling the growth of N. equitans. In conclusion, this multi-omics analysis builds upon previously identified cellular patterns while offering new insights into mechanisms that enable the I. hospitalis–N. equitans association. This study applies statistical and visualization techniques to a mixed-source omics dataset to yield a more global insight into a complex system, that was not readily discernable from separate omics studies.« less

Multi-omics analysis provides insight to the Ignicoccus hospitalis-Nanoarchaeum equitans association.

PubMed

Rawle, Rachel A; Hamerly, Timothy; Tripet, Brian P; Giannone, Richard J; Wurch, Louie; Hettich, Robert L; Podar, Mircea; Copié, Valerie; Bothner, Brian

2017-09-01

Studies of interspecies interactions are inherently difficult due to the complex mechanisms which enable these relationships. A model system for studying interspecies interactions is the marine hyperthermophiles Ignicoccus hospitalis and Nanoarchaeum equitans. Recent independently-conducted 'omics' analyses have generated insights into the molecular factors modulating this association. However, significant questions remain about the nature of the interactions between these archaea. We jointly analyzed multiple levels of omics datasets obtained from published, independent transcriptomics, proteomics, and metabolomics analyses. DAVID identified functionally-related groups enriched when I. hospitalis is grown alone or in co-culture with N. equitans. Enriched molecular pathways were subsequently visualized using interaction maps generated using STRING. Key findings of our multi-level omics analysis indicated that I. hospitalis provides precursors to N. equitans for energy metabolism. Analysis indicated an overall reduction in diversity of metabolic precursors in the I. hospitalis-N. equitans co-culture, which has been connected to the differential use of ribosomal subunits and was previously unnoticed. We also identified differences in precursors linked to amino acid metabolism, NADH metabolism, and carbon fixation, providing new insights into the metabolic adaptions of I. hospitalis enabling the growth of N. equitans. This multi-omics analysis builds upon previously identified cellular patterns while offering new insights into mechanisms that enable the I. hospitalis-N. equitans association. Our study applies statistical and visualization techniques to a mixed-source omics dataset to yield a more global insight into a complex system, that was not readily discernable from separate omics studies. Copyright © 2017 Elsevier B.V. All rights reserved.

Ets-1 interacts through a similar binding interface with Ku70 and Poly (ADP-Ribose) Polymerase-1.

PubMed

Choul-Li, Souhaila; Legrand, Arnaud J; Vicogne, Dorothée; Villeret, Vincent; Aumercier, Marc

2018-06-18

The Ets-1 transcription factor plays an important role in various physiological and pathological processes. These diverse roles of Ets-1 are likely to depend on its interaction proteins. We have previously showed that Ets-1 interacted with DNA-dependent protein kinase (DNA-PK) complex including its regulatory subunits, Ku70 and Ku86 and with poly (ADP-ribose) polymerase-1 (PARP-1). In this study, the binding domains for the interaction between Ets-1 and these proteins were reported. We demonstrated that the interaction of Ets-1 with DNA-PK was mediated through the Ku70 subunit and was mapped to the C-terminal region of Ets-1 and the C-terminal part of Ku70 including SAP domain. The interactive domains between Ets-1 and PARP-1 have been mapped to the C-terminal region of Ets-1 and the BRCA1 carboxy-terminal (BRCT) domain of PARP-1. The results presented in this study may advance our understanding of the functional link between Ets-1 and its interaction partners, DNA-PK and PARP-1.

Interaction of native and apo-carbonic anhydrase with hydrophobic adsorbents: A comparative structure-function study.

PubMed

Salemi, Zahra; Hosseinkhani, Saman; Ranjbar, Bijan; Nemat-Gorgani, Mohsen

2006-09-30

Our previous studies indicated that native carbonic anhydrase does not interact with hydrophobic adsorbents and that it acquires this ability upon denaturation. In the present study, an apo form of the enzyme was prepared by removal of zinc and a comparative study was performed on some characteristic features of the apo and native forms by far- and near-UV circular dichroism (CD), intrinsic fluorescent spectroscopy, 1-anilino naphthalene-8-sulfonate (ANS) binding, fluorescence quenching by acrylamide, and Tm measurement. Results indicate that protein flexibility is enhanced and the hydrophobic sites become more exposed upon conversion to the apo form. Accordingly, the apo structure showed a greater affinity for interaction with hydrophobic adsorbents as compared with the native structure. As observed for the native enzyme, heat denaturation of the apo form promoted interaction with alkyl residues present on the adsorbents and, by cooling followed by addition of zinc, catalytically-active immobilized preparations were obtained.

Solute atmospheres at dislocations

DOE PAGES

Hirth, John P.; Barnett, David M.; Hoagland, Richard G.

2017-06-01

In this study, a two-dimensional plane strain elastic solution is determined for the Cottrell solute atmosphere around an edge dislocation in an infinitely long cylinder of finite radius (the matrix), in which rows of solutes are represented by cylindrical rods with in-plane hydrostatic misfit (axial misfit is also considered). The periphery of the matrix is traction-free, thus introducing an image solute field which generates a solute-solute interaction energy that has not been considered previously. The relevant energy for the field of any distribution of solutes coexistent with a single edge dislocation along the (matrix) cylinder axis is determined, and coherencymore » effects are discussed and studied. Monte Carlo simulations accounting for all pertinent interactions over a range of temperatures are found to yield solute distributions different from classical results, namely, (1) Fermi-Dirac condensations at low temperatures at the free surface, (2) the majority of the atmosphere lying within an unexpectedly large non-linear interaction region near the dislocation core, and (3) temperature-dependent asymmetrical solute arrangements that promote bending. The solute distributions at intermediate temperatures show a 1/r dependence in agreement with previous linearized approximations. With a standard state of solute corresponding to a mean concentration, c 0, the relevant interaction energy expression presented in this work is valid when extended to large concentrations for which Henry's Law and Vegard's Law do not apply.« less

Solute atmospheres at dislocations

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

Hirth, John P.; Barnett, David M.; Hoagland, Richard G.

In this study, a two-dimensional plane strain elastic solution is determined for the Cottrell solute atmosphere around an edge dislocation in an infinitely long cylinder of finite radius (the matrix), in which rows of solutes are represented by cylindrical rods with in-plane hydrostatic misfit (axial misfit is also considered). The periphery of the matrix is traction-free, thus introducing an image solute field which generates a solute-solute interaction energy that has not been considered previously. The relevant energy for the field of any distribution of solutes coexistent with a single edge dislocation along the (matrix) cylinder axis is determined, and coherencymore » effects are discussed and studied. Monte Carlo simulations accounting for all pertinent interactions over a range of temperatures are found to yield solute distributions different from classical results, namely, (1) Fermi-Dirac condensations at low temperatures at the free surface, (2) the majority of the atmosphere lying within an unexpectedly large non-linear interaction region near the dislocation core, and (3) temperature-dependent asymmetrical solute arrangements that promote bending. The solute distributions at intermediate temperatures show a 1/r dependence in agreement with previous linearized approximations. With a standard state of solute corresponding to a mean concentration, c 0, the relevant interaction energy expression presented in this work is valid when extended to large concentrations for which Henry's Law and Vegard's Law do not apply.« less

Chitin-Like Molecules Associate with Cryptococcus neoformans Glucuronoxylomannan To Form a Glycan Complex with Previously Unknown Properties

PubMed Central

Ramos, Caroline L.; Fonseca, Fernanda L.; Rodrigues, Jessica; Guimarães, Allan J.; Cinelli, Leonardo P.; Miranda, Kildare; Nimrichter, Leonardo; Casadevall, Arturo; Travassos, Luiz R.

2012-01-01

In prior studies, we demonstrated that glucuronoxylomannan (GXM), the major capsular polysaccharide of the fungal pathogen Cryptococcus neoformans, interacts with chitin oligomers at the cell wall-capsule interface. The structural determinants regulating these carbohydrate-carbohydrate interactions, as well as the functions of these structures, have remained unknown. In this study, we demonstrate that glycan complexes composed of chitooligomers and GXM are formed during fungal growth and macrophage infection by C. neoformans. To investigate the required determinants for the assembly of chitin-GXM complexes, we developed a quantitative scanning electron microscopy-based method using different polysaccharide samples as inhibitors of the interaction of chitin with GXM. This assay revealed that chitin-GXM association involves noncovalent bonds and large GXM fibers and depends on the N-acetyl amino group of chitin. Carboxyl and O-acetyl groups of GXM are not required for polysaccharide-polysaccharide interactions. Glycan complex structures composed of cryptococcal GXM and chitin-derived oligomers were tested for their ability to induce pulmonary cytokines in mice. They were significantly more efficient than either GXM or chitin oligomers alone in inducing the production of lung interleukin 10 (IL-10), IL-17, and tumor necrosis factor alpha (TNF-α). These results indicate that association of chitin-derived structures with GXM through their N-acetyl amino groups generates glycan complexes with previously unknown properties. PMID:22562469

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

Bowley, S.; Okumura, N; Lord, S

'A:a' knob-hole interactions and D:D interfacial interactions are important for fibrin polymerization. Previous studies with recombinant ?N308K fibrinogen, a substitution at the D:D interface, showed impaired polymerization. We examined the molecular basis for this loss of function by solving the crystal structure of ?N308K fragment D. In contrast to previous fragment D crystals, the ?N308K crystals belonged to a tetragonal space group with an unusually long unit cell (a = b = 95 Angstroms, c = 448.3 Angstroms). Alignment of the normal and ?N308K structures showed the global structure of the variant was not changed and the knob 'A' peptidemore » GPRP was bound as usual to hole 'a'. The substitution introduced an elongated positively charged patch in the D:D region. The structure showed novel, symmetric D:D crystal contacts between ?N308K molecules, indicating the normal asymmetric D:D interface in fibrin would be unstable in this variant. We examined GPRP binding to ?N308K in solution by plasmin protection assay. The results showed weaker peptide binding, suggesting that 'A:a' interactions were altered. We examined fibrin network structures by scanning electron microscopy and found the variant fibers were thicker and more heterogeneous than normal fibers. Considered together, our structural and biochemical studies indicate both 'A:a' and D:D interactions are weaker. We conclude that stable protofibrils cannot assemble from ?N308K monomers, leading to impaired polymerization.« less

Amorphization of the interaction products in U-Mo/Al dispersion fuel during irradiation

NASA Astrophysics Data System (ADS)

Ryu, Ho Jin; Kim, Yeon Soo; Hofman, G. L.

2009-04-01

The microstructures of the product resulting from interaction between U-Mo fuel particles and the Al matrix in U-Mo/Al dispersion fuel are discussed. We analyzed the available characterization results for the Al matrix dispersion fuels from both the out-of-pile and in-pile tests and examined the difference between these results. The morphology of pores that form in the interaction products during irradiation is similar to the porosity previously observed in irradiation-induced amorphized uranium compounds. The available diffraction studies for the interaction products formed in both the out-of-pile and in-pile tests are analyzed. We have concluded that the interaction products in the U-Mo/Al dispersion fuel are formed as an amorphous state or become amorphous during irradiation, depending on the irradiation conditions.

Autokinase activity of alpha-crystallin inhibits its specific interaction with the DOTIS element in the murine gamma D/E/F-crystallin promoter in vitro.

PubMed

Pietrowski, D; Graw, J

1997-10-01

In a previous report we demonstrated the in vitro interaction of alpha-crystallin with an element downstream of the transcriptional initiation site (DOTIS) of the murine gamma E-crystallin promoter (Pietrowski et al., 1994, Gene 144, 171-178). The aim of the present study was to investigate the influence of phosphorylation on this particular interaction. We could demonstrate that the autophosphorylation of alpha-crystallin leads to a complete loss of interaction with the DOTIS element, however, PKA-dependent phosphorylation of alpha-crystallin is without effect on the interaction. It is hypothesized that the autophosphorylation of alpha-crystallin might be involved in regulatory mechanisms of the murine gamma D/E/F-crystallin gene expression.

Learning and signal copying facilitate communication among bird species

PubMed Central

Wheatcroft, David; Price, Trevor D.

2013-01-01

Signals relevant to different sets of receivers in different contexts create a conflict for signal design. A classic example is vocal alarm signals, often used both during intraspecific and interspecific interactions. How can signals alert individuals from a variety of other species in some contexts, while also maintaining efficient communication among conspecifics? We studied heterospecific responses to avian alarm signals that drive the formation of anti-predator groups but are also used during intraspecific interactions. In three species-rich communities in the western Himalayas, alarm signals vary drastically across species. We show that, independently of differences in their calls, birds respond strongly to the alarm signals of other species with which they co-occur and much more weakly to those of species with which they do not co-occur. These results suggest that previous exposure and learning maintain heterospecific responses in the face of widespread signal divergence. At an area where only two species regularly interact, one species' calls incorporate the call of the other. We demonstrate experimentally that signal copying allows strong responses even without previous exposure and suggest that such hybrid calls may be especially favoured when pairwise interactions between species are strong. PMID:23446529

Identifying cooperative transcriptional regulations using protein–protein interactions

PubMed Central

Nagamine, Nobuyoshi; Kawada, Yuji; Sakakibara, Yasubumi

2005-01-01

Cooperative transcriptional activations among multiple transcription factors (TFs) are important to understand the mechanisms of complex transcriptional regulations in eukaryotes. Previous studies have attempted to find cooperative TFs based on gene expression data with gene expression profiles as a measure of similarity of gene regulations. In this paper, we use protein–protein interaction data to infer synergistic binding of cooperative TFs. Our fundamental idea is based on the assumption that genes contributing to a similar biological process are regulated under the same control mechanism. First, the protein–protein interaction networks are used to calculate the similarity of biological processes among genes. Second, we integrate this similarity and the chromatin immuno-precipitation data to identify cooperative TFs. Our computational experiments in yeast show that predictions made by our method have successfully identified eight pairs of cooperative TFs that have literature evidences but could not be identified by the previous method. Further, 12 new possible pairs have been inferred and we have examined the biological relevances for them. However, since a typical problem using protein–protein interaction data is that many false-positive data are contained, we propose a method combining various biological data to increase the prediction accuracy. PMID:16126847

Assessing the Effectiveness of "Wise Guys": A Mixed-Methods Approach

ERIC Educational Resources Information Center

Herrman, Judith W.; Gordon, Mellissa; Rahmer, Brian; Moore, Christopher C.; Habermann, Barbara; Haigh, Katherine M.

2017-01-01

Previous research raised questions on the validity of survey studies with the teen population. As one response, our team implemented a mixed-methods study to evaluate an evidence-based, interactive curriculum, "Wise Guys," which is designed to promote healthy relationships and sexual behavior in young men ages 4-17. The current study…

Gaze Aversion to Stuttered Speech: A Pilot Study Investigating Differential Visual Attention to Stuttered and Fluent Speech

ERIC Educational Resources Information Center

Bowers, Andrew L.; Crawcour, Stephen C.; Saltuklaroglu, Tim; Kalinowski, Joseph

2010-01-01

Background: People who stutter are often acutely aware that their speech disruptions, halted communication, and aberrant struggle behaviours evoke reactions in communication partners. Considering that eye gaze behaviours have emotional, cognitive, and pragmatic overtones for communicative interactions and that previous studies have indicated…

Formative Assessment of Writing in English as a Foreign Language

ERIC Educational Resources Information Center

Burner, Tony

2016-01-01

Recognizing the importance of formative assessment, this mixed-methods study investigates how four teachers and 100 students respond to the new emphasis on formative assessment in English as a foreign language (EFL) writing classes in Norway. While previous studies have examined formative assessment in oral classroom interactions and focused on…

Social Perception Training: Improving Social Competence by Reducing Cognitive Distortions

ERIC Educational Resources Information Center

Finne, Johannes N.; Svartdal, Frode

2017-01-01

Social Perception Training (SPT) is a program focused on changing the perceptual and cognitive processes involved in suboptimal social interactions. It is administered with whole class of pupils over ten weeks. No previous studies have evaluated its efficacy. The present study investigated the outcome benefit of the program in 18 primary and…

Rape Survivors' Agency within the Legal and Medical Systems

ERIC Educational Resources Information Center

Greeson, Megan R.; Campbell, Rebecca

2011-01-01

Many rape survivors seek help from the legal and medical systems post-assault. Previous studies have examined how social system personnel treat survivors, but less attention has been paid to how survivors attempt to shape their interactions with these systems. The purpose of this qualitative study was to examine rape survivors' agency--the active…

Learner-Learner Interaction during Collaborative Pragmatic Tasks: The Role of Cognitive and Pragmatic Task Demands

ERIC Educational Resources Information Center

Kim, YouJin; Taguchi, Naoko

2016-01-01

Previous task complexity studies have suggested that learners produce more negotiation of meaning opportunities during complex tasks than simple tasks (Robinson, 2011). The present study builds on the existing task complexity literature by examining the impact of task complexity and pragmatic situational demands on the number of learning…

Homophobic Bullying in Schools: The Role of Homophobic Attitudes and Exposure to Homophobic Aggression

ERIC Educational Resources Information Center

Orue, Izaskun; Calvete, Esther

2018-01-01

This study examined the reciprocal longitudinal relations between homophobic attitudes and homophobic bullying at school. Furthermore, the study also assessed the roles of exposure to homophobic bullying at school, homophobic language at home, and previous social interaction with individuals who identify as lesbian, gay, bisexual, or transgender…

The choice of product indicators in latent variable interaction models: post hoc analyses.

PubMed

Foldnes, Njål; Hagtvet, Knut Arne

2014-09-01

The unconstrained product indicator (PI) approach is a simple and popular approach for modeling nonlinear effects among latent variables. This approach leaves the practitioner to choose the PIs to be included in the model, introducing arbitrariness into the modeling. In contrast to previous Monte Carlo studies, we evaluated the PI approach by 3 post hoc analyses applied to a real-world case adopted from a research effort in social psychology. The measurement design applied 3 and 4 indicators for the 2 latent 1st-order variables, leaving the researcher with a choice among more than 4,000 possible PI configurations. Sixty so-called matched-pair configurations that have been recommended in previous literature are of special interest. In the 1st post hoc analysis we estimated the interaction effect for all PI configurations, keeping the real-world sample fixed. The estimated interaction effect was substantially affected by the choice of PIs, also across matched-pair configurations. Subsequently, a post hoc Monte Carlo study was conducted, with varying sample sizes and data distributions. Convergence, bias, Type I error and power of the interaction test were investigated for each matched-pair configuration and the all-pairs configuration. Variation in estimates across matched-pair configurations for a typical sample was substantial. The choice of specific configuration significantly affected convergence and the interaction test's outcome. The all-pairs configuration performed overall better than the matched-pair configurations. A further advantage of the all-pairs over the matched-pairs approach is its unambiguity. The final study evaluates the all-pairs configuration for small sample sizes and compares it to the non-PI approach of latent moderated structural equations. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Effects of heat treatment on U-Mo fuel foils with a zirconium diffusion barrier

NASA Astrophysics Data System (ADS)

Jue, Jan-Fong; Trowbridge, Tammy L.; Breckenridge, Cynthia R.; Moore, Glenn A.; Meyer, Mitchell K.; Keiser, Dennis D.

2015-05-01

A monolith fuel design based on U-Mo alloy has been selected as the fuel type for conversion of the United States' high performance research reactors (HPRRs) from highly enriched uranium (HEU) to low-enriched uranium (LEU). In this fuel design, a thin layer of zirconium is used to eliminate the direct interaction between the U-Mo fuel meat and the aluminum-alloy cladding during irradiation. The co-rolling process used to bond the Zr barrier layer to the U-Mo foil during fabrication alters the microstructure of both the U-10Mo fuel meat and the U-Mo/Zr interface. This work studied the effects of post-rolling annealing treatment on the microstructure of the co-rolled U-Mo fuel meat and the U-Mo/Zr interaction layer. Microscopic characterization shows that the grain size of U-Mo fuel meat increases with the annealing temperature, as expected. The grain sizes were ∼9, ∼13, and ∼20 μm for annealing temperature of 650, 750, and 850 °C, respectively. No abnormal grain growth was observed. The U-Mo/Zr interaction-layer thickness increased with the annealing temperature with an Arrhenius constant for growth of 184 kJ/mole, consistent with a previous diffusion-couple study. The interaction layer thickness was 3.2 ± 0.5 μm, 11.1 ± 2.1 μm, 27.1 ± 0.9 μm for annealing temperature of 650, 750, to 850 °C, respectively. The homogeneity of Mo improves with post rolling annealing temperature and with U-Mo coupon homogenization. The phases in the Zr/U-Mo interaction layer produced by co-rolling, however, differ from those reported in the previous diffusion couple studies.

Effects of heat treatment on U–Mo fuel foils with a zirconium diffusion barrier

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

Jue, Jan-Fong; Trowbridge, Tammy L.; Breckenridge, Cynthia R.

A monolith fuel design based on U–Mo alloy has been selected as the fuel type for conversion of the United States’ high performance research reactors (HPRRs) from highly enriched uranium (HEU) to low-enriched uranium (LEU). In this fuel design, a thin layer of zirconium is used to eliminate the direct interaction between the U–Mo fuel meat and the aluminum-alloy cladding during irradiation. The co-rolling process used to bond the Zr barrier layer to the U–Mo foil during fabrication alters the microstructure of both the U–10Mo fuel meat and the U–Mo/Zr interface. This work studied the effects of post-rolling annealing treatmentmore » on the microstructure of the co-rolled U–Mo fuel meat and the U–Mo/Zr interaction layer. Microscopic characterization shows that the grain size of U–Mo fuel meat increases with the annealing temperature, as expected. The grain sizes were ~9, ~13, and ~20 μm for annealing temperature of 650, 750, and 850 °C, respectively. No abnormal grain growth was observed. The U–Mo/Zr interaction-layer thickness increased with the annealing temperature with an Arrhenius constant for growth of 184 kJ/mole, consistent with a previous diffusion-couple study. The interaction layer thickness was 3.2 ± 0.5 μm, 11.1 ± 2.1 μm, 27.1 ± 0.9 μm for annealing temperature of 650, 750, to 850 °C, respectively. The homogeneity of Mo improves with post rolling annealing temperature and with U–Mo coupon homogenization. The phases in the Zr/U–Mo interaction layer produced by co-rolling, however, differ from those reported in the previous diffusion couple studies.« less

Characteristics of German hospitals adopting health IT systems - results from an empirical study.

PubMed

Liebe, Jan-David; Egbert, Nicole; Frey, Andreas; Hübner, Ursula

2011-01-01

Hospital characteristics that facilitate IT adoption have been described by the literature extensively, however with controversial results. The aim of this study therefore is to draw a set of the most important variables from previous studies and include them in a combined analysis for testing their contribution as single factors and their interactions. Total number of IT systems installed and number of clinical IT systems in the hospital were used as criterion variables. Data from a national survey of German hospitals served as basis. Based on a stepwise multiple regression analysis four variables were identified to significantly explain the degree of IT adoption (60% explained variance): 1) hospital size, 2) IT department, 3) reference customer and 4) ownership (private vs. public). Our results replicate previous findings with regard to hospital size and ownership. In addition our study emphasizes the importance of a reliable internal structure for IT projects (existence of an IT department) and the culture of testing and installing most recent IT products (being a reference customer). None of the interactions between factors was significant.

The dynamics of turbulent premixed flames: Mechanisms and models for turbulence-flame interaction

NASA Astrophysics Data System (ADS)

Steinberg, Adam M.

The use of turbulent premixed combustion in engines has been garnering renewed interest due to its potential to reduce NOx emissions. However there are many aspects of turbulence-flame interaction that must be better understood before such flames can be accurately modeled. The focus of this dissertation is to develop an improved understanding for the manner in which turbulence interacts with a premixed flame in the 'thin flamelet regime'. To do so, two new diagnostics were developed and employed in a turbulent slot Bunsen flame. These diagnostics, Cinema-Stereoscopic Particle Image Velocimetry and Orthogonal-Plane Cinema-Stereoscopic Particle Image Velocimetry, provided temporally resolved velocity and flame surface measurements in two- and three-dimensions with rates of up to 3 kHz and spatial resolutions as low as 280 mum. Using these measurements, the mechanisms with which turbulence generates flame surface area were studied. It was found that the previous concept that flame stretch is characterized by counter-rotating vortex pairs does not accurately describe real turbulence-flame interactions. Analysis of the experimental data showed that the straining of the flame surface is determined by coherent structures of fluid dynamic strain rate, while the wrinkling is caused by vortical structures. Furthermore, it was shown that the canonical vortex pair configuration is not an accurate reflection of the real interaction geometry. Hence, models developed based on this geometry are unlikely to be accurate. Previous models for the strain rate, curvature stretch rate, and turbulent burning velocity were evaluated. It was found that the previous models did not accurately predict the measured data for a variety of reasons: the assumed interaction geometries did not encompass enough possibilities to describe the possible effects of real turbulence, the turbulence was not properly characterized, and the transport of flame surface area was not always considered. New models therefore were developed that accurately reflect real turbulence-flame interactions and agree with the measured data. These can be implemented in Large Eddy Simulations to provide improved modeling of turbulence-flame interaction.

Shape and size variation on the wing of Drosophila mediopunctata: influence of chromosome inversions and genotype-environment interaction.

PubMed

Hatadani, Luciane Mendes; Klaczko, Louis Bernard

2008-07-01

The second chromosome of Drosophila mediopunctata is highly polymorphic for inversions. Previous work reported a significant interaction between these inversions and collecting date on wing size, suggesting the presence of genotype-environment interaction. We performed experiments in the laboratory to test for the joint effects of temperature and chromosome inversions on size and shape of the wing in D. mediopunctata. Size was measured as the centroid size, and shape was analyzed using the generalized least squares Procrustes superimposition followed by discriminant analysis and canonical variates analysis of partial warps and uniform components scores. Our findings show that wing size and shape are influenced by temperature, sex, and karyotype. We also found evidence suggestive of an interaction between the effects of karyotype and temperature on wing shape, indicating the existence of genotype-environment interaction for this trait in D. mediopunctata. In addition, the association between wing size and chromosome inversions is in agreement with previous results indicating that these inversions might be accumulating alleles adapted to different temperatures. However, no significant interaction between temperature and karyotype for size was found--in spite of the significant presence of temperature-genotype (cross) interaction. We suggest that other ecological factors--such as larval crowding--or seasonal variation of genetic content within inversions may explain the previous results.

The influence of emotion regulation on social interactive decision-making.

PubMed

van't Wout, Mascha; Chang, Luke J; Sanfey, Alan G

2010-12-01

Although adequate emotion regulation is considered to be essential in every day life, it is especially important in social interactions. However, the question as to what extent two different regulation strategies are effective in changing decision-making in a consequential socially interactive context remains unanswered. We investigated the effect of expressive suppression and emotional reappraisal on strategic decision-making in a social interactive task, that is, the Ultimatum Game. As hypothesized, participants in the emotional reappraisal condition accepted unfair offers more often than participants in the suppression and no-regulation condition. Additionally, the effect of emotional reappraisal influenced the amount of money participants proposed during a second interaction with partners that had treated them unfairly in a previous interaction. These results support and extend previous findings that emotional reappraisal as compared to expressive suppression, is a powerful regulation strategy that influences and changes how we interact with others even in the face of inequity.

The influence of emotion regulation on social interactive decision-making

PubMed Central

van ’t Wout, Mascha; Chang, Luke J.; Sanfey, Alan G.

2010-01-01

Although adequate emotion regulation is considered to be essential in every day life, it is especially important in social interactions. However, the question as to what extent two different regulation strategies are effective in changing decision-making in a consequential socially interactive context remains unanswered. We investigated the effect of expressive suppression and emotional reappraisal on strategic decision-making in a social interactive task, i.e. the Ultimatum Game. As hypothesized, participants in the emotional reappraisal condition accepted unfair offers more often than participants in the suppression and no-regulation condition. Additionally, the effect of emotional reappraisal influenced the amount of money participants proposed during a second interaction with partners that had treated them unfairly in a previous interaction. These results support and extend previous findings that emotional reappraisal as compared to expressive suppression, is a powerful regulation strategy that influences and changes how we interact with others even in the face of inequity. PMID:21171756

Contribution of Hydrophobic Interactions to Protein Stability

PubMed Central

Pace, C. Nick; Fu, Hailong; Fryar, Katrina Lee; Landua, John; Trevino, Saul R.; Shirley, Bret A.; Hendricks, Marsha McNutt; Iimura, Satoshi; Gajiwala, Ketan; Scholtz, J. Martin; Grimsley, Gerald R.

2011-01-01

Our goal was to gain a better understanding of the contribution of hydrophobic interactions to protein stability. We measured the change in conformational stability, Δ(ΔG), for hydrophobic mutants of four proteins: villin head piece subdomain (VHP) with 36 residues, a surface protein from Borrelia burgdorferi (VlsE) with 341 residues, and two proteins previously studied in our laboratory, ribonucleases Sa and T1. We compare our results with previous studies and reach the following conclusions. 1. Hydrophobic interactions contribute less to the stability of a small protein, VHP (0.6 ± 0.3 kcal/mole per –CH2– group), than to the stability of a large protein, VlsE (1.6 ± 0.3 kcal/mol per –CH2– group). 2. Hydrophobic interactions make the major contribution to the stability of VHP (40 kcal/mol) and the major contributors are (in kcal/mol): Phe 18 (3.9), Met 13 (3.1), Phe 7 (2.9), Phe 11 (2.7), and Leu 21 (2.7). 3. Based on Δ(ΔG) values for 148 hydrophobic mutants in 13 proteins, burying a –CH2– group on folding contributes, on average, 1.1 ± 0.5 kcal/mol to protein stability. 4. The experimental Δ(ΔG) values for aliphatic side chains (Ala, Val, Ile, and Leu) are in good agreement with their ΔGtr values from water to cyclohexane. 5. For 22 proteins with 36 to 534 residues, hydrophobic interactions contribute 60 ± 4% and hydrogen bonds 40 ± 4% to protein stability. 6. Conformational entropy contributes about 2.4 kcal/mol per residue to protein instability. The globular conformation of proteins is stabilized predominately by hydrophobic interactions. PMID:21377472

Characterization of Molecules Binding to the 70K N-terminal Region of Fibronectin by IFAST Purification Coupled with Mass Spectrometry

PubMed Central

Moussavi-Harami, S. Farshid; Annis, Douglas S.; Ma, Wenjiang; Berry, Scott M.; Coughlin, Emma E.; Strotman, Lindsay N.; Maurer, Lisa M.; Westphall, Michael S.; Coon, Joshua J.; Mosher, Deane F.; Beebe, David J.

2013-01-01

Fibronectin (Fn) is a large glycoprotein present in plasma and extracellular matrix and is important for many processes. Within Fn the 70kDa N-terminal region (70k-Fn) is involved in cell-mediated Fn assembly, a process that contributes to embryogenesis, development, and platelet thrombus formation. In addition, major human pathogens including Staphlycoccus aureus and Streptococcus pyogenes, bind the 70k-Fn region by a novel form of protein-protein interaction called β-zipper formation, facilitating bacterial spread and colonization. Knowledge of blood plasma and platelet proteins that interact with 70k-Fn by β-zipper formation is incomplete. In the current study, we aimed to characterize these proteins through affinity purification. For this affinity purification, we used a novel purification technique termed immiscible filtration assisted by surface tension (IFAST). The foundation of this technology is immiscible phase filtration, using a magnet to draw paramagnetic particle (PMP)-bound analyte through an immiscible barrier (oil or organic solvent) that separates an aqueous sample from an aqueous eluting buffer. The immiscible barrier functions to remove unbound proteins via exclusion rather than dilutive washing used in traditional isolation methods. We identified 31 interactors from plasma, of which only seven were previously known to interact with Fn. Furthermore, five proteins were identified to interact with 70k-Fn from platelet lysate, of which one was previously known. These results demonstrate that IFAST offers advantages for proteomic studies of interacting molecules in that the technique requires small sample volumes, can be done with high enough throughput to sample multiple interaction conditions, and is amenable to exploratory mass spectrometric and confirmatory immuno-blotting read-outs. PMID:23750785

Docking and free energy simulations to predict conformational domains involved in hCG-LH receptor interactions using recombinant antibodies.

PubMed

Majumdar, Ritankar; Railkar, Reema; Dighe, Rajan R

2011-11-01

Single chain fragment variables (ScFvs) have been extensively employed in studying the protein-protein interactions. ScFvs derived from phage display libraries have an additional advantage of being generated against a native antigen, circumventing loss of information on conformational epitopes. In the present study, an attempt has been made to elucidate human chorionic gonadotropin (hCG)-luteinizing hormone (LH) receptor interactions by using a neutral and two inhibitory ScFvs against hCG. The objective was to dock a computationally derived model of these ScFvs onto the crystal structure of hCG and understand the differential roles of the mapped epitopes in hCG-LH receptor interactions. An anti-hCG ScFv, whose epitope was mapped previously using biochemical tools, served as the positive control for assessing the quality of docking analysis. To evaluate the role of specific side chains at the hCG-ScFv interface, binding free energy as well as residue interaction energies of complexes in solution were calculated using molecular mechanics Poisson-Boltzmann/surface area method after performing the molecular dynamic simulations on the selected hCG-ScFv models and validated using biochemical and SPR analysis. The robustness of these calculations was demonstrated by comparing the theoretically determined binding energies with the experimentally obtained kinetic parameters for hCG-ScFv complexes. Superimposition of hCG-ScFv model onto a model of hCG complexed with the 51-266 residues of LH receptor revealed importance of the residues previously thought to be unimportant for hormone binding and response. This analysis provides an alternate tool for understanding the structure-function analysis of ligand-receptor interactions. Copyright © 2011 Wiley-Liss, Inc.

Multifactor dimensionality reduction reveals a three-locus epistatic interaction associated with susceptibility to pulmonary tuberculosis.

PubMed

Collins, Ryan L; Hu, Ting; Wejse, Christian; Sirugo, Giorgio; Williams, Scott M; Moore, Jason H

2013-02-18

Identifying high-order genetics associations with non-additive (i.e. epistatic) effects in population-based studies of common human diseases is a computational challenge. Multifactor dimensionality reduction (MDR) is a machine learning method that was designed specifically for this problem. The goal of the present study was to apply MDR to mining high-order epistatic interactions in a population-based genetic study of tuberculosis (TB). The study used a previously published data set consisting of 19 candidate single-nucleotide polymorphisms (SNPs) in 321 pulmonary TB cases and 347 healthy controls from Guniea-Bissau in Africa. The ReliefF algorithm was applied first to generate a smaller set of the five most informative SNPs. MDR with 10-fold cross-validation was then applied to look at all possible combinations of two, three, four and five SNPs. The MDR model with the best testing accuracy (TA) consisted of SNPs rs2305619, rs187084, and rs11465421 (TA = 0.588) in PTX3, TLR9 and DC-Sign, respectively. A general 1000-fold permutation test of the null hypothesis of no association confirmed the statistical significance of the model (p = 0.008). An additional 1000-fold permutation test designed specifically to test the linear null hypothesis that the association effects are only additive confirmed the presence of non-additive (i.e. nonlinear) or epistatic effects (p = 0.013). An independent information-gain measure corroborated these results with a third-order epistatic interaction that was stronger than any lower-order associations. We have identified statistically significant evidence for a three-way epistatic interaction that is associated with susceptibility to TB. This interaction is stronger than any previously described one-way or two-way associations. This study highlights the importance of using machine learning methods that are designed to embrace, rather than ignore, the complexity of common diseases such as TB. We recommend future studies of the genetics of TB take into account the possibility that high-order epistatic interactions might play an important role in disease susceptibility.

A male-specific QTL for social interaction behavior in mice mapped with automated pattern detection by a hidden Markov model incorporated into newly developed freeware.

PubMed

Arakawa, Toshiya; Tanave, Akira; Ikeuchi, Shiho; Takahashi, Aki; Kakihara, Satoshi; Kimura, Shingo; Sugimoto, Hiroki; Asada, Nobuhiko; Shiroishi, Toshihiko; Tomihara, Kazuya; Tsuchiya, Takashi; Koide, Tsuyoshi

2014-08-30

Owing to their complex nature, social interaction tests normally require the observation of video data by a human researcher, and thus are difficult to use in large-scale studies. We previously established a statistical method, a hidden Markov model (HMM), which enables the differentiation of two social states ("interaction" and "indifference"), and three social states ("sniffing", "following", and "indifference"), automatically in silico. Here, we developed freeware called DuoMouse for the rapid evaluation of social interaction behavior. This software incorporates five steps: (1) settings, (2) video recording, (3) tracking from the video data, (4) HMM analysis, and (5) visualization of the results. Using DuoMouse, we mapped a genetic locus related to social interaction. We previously reported that a consomic strain, B6-Chr6C(MSM), with its chromosome 6 substituted for one from MSM/Ms, showed more social interaction than C57BL/6 (B6). We made four subconsomic strains, C3, C5, C6, and C7, each of which has a shorter segment of chromosome 6 derived from B6-Chr6C, and conducted social interaction tests on these strains. DuoMouse indicated that C6, but not C3, C5, and C7, showed higher interaction, sniffing, and following than B6, specifically in males. The data obtained by human observation showed high concordance to those from DuoMouse. The results indicated that the MSM-derived chromosomal region present in C6-but not in C3, C5, and C7-associated with increased social behavior. This method to analyze social interaction will aid primary screening for difference in social behavior in mice. Copyright © 2014 Elsevier B.V. All rights reserved.

High temperature (>350 °C) thermal histories of the long lived (>500 Ma) active margin of Ecuador and Colombia: Apatite, titanite and rutile U-Pb thermochronology

NASA Astrophysics Data System (ADS)

Paul, Andre N.; Spikings, Richard A.; Ulianov, Alexey; Ovtcharova, Maria

2018-05-01

Quantitative reconstruction of thermal histories can be a powerful tool to study numerous natural processes such as tectonic plate interaction, cratonic stability and extra-terrestrial phenomena such as asteroid ejection. A majority of thermochronological studies have focused on temperatures lower than 300 °C. Few previous studies have demonstrated that U-Pb data from apatite and other accessory phases can be used to recover thermal history information at T > 350 °C. We present U-Pb data from apatite, to constrain the thermal histories of Triassic peralluminous anatectites from the Northern Andes between the temperatures of ∼350-550 °C. The accuracy of the thermal history models is assessed by comparisons with previous geological models, and comparisons with pre-existing and newly acquired U/Pb (titanite and rutile), 40Ar/39Ar (muscovite) and low temperature thermochronological data. This study also examines the feasibility of using a large, regionally dispersed apatite U-Pb data set to obtain continuous thermal history paths along a long-lived (>500 Ma) active margin. A second aim of this study is to further test the hypothesis that the dominant mechanism for Pb displacement through apatite is volume diffusion, as opposed to aqueous fluid interaction. The thermal history models derived from the Triassic anatectites exposed in the Andes of Colombia and Ecuador are entirely consistent with lower temperature thermochronological constraints, and previously established geochronological and geochemical constraints. They reveal and quantify trench parallel changes in the amount of Jurassic - Early Cretaceous extension, significantly bolstering and adding to previous tectonic interpretations. Confirmation of the utility of U-Pb thermochronology provides geologists with a powerful tool for investigating the high-temperature thermal evolution of accessory minerals.

Client Engagement Characteristics Associated with Problem Gambling Treatment Outcomes

ERIC Educational Resources Information Center

Dowling, Nicki A.; Cosic, Sanja

2011-01-01

Previous research examining the factors associated with problem gambling treatment outcomes has examined client factors and to date, treatment characteristics, therapist factors, and client-therapist interactions have essentially remained unexplored. This study aimed to investigate how client engagement variables (client-rated therapeutic…

A step towards understanding the mechanisms of running-related injuries.

PubMed

Malisoux, Laurent; Nielsen, Rasmus Oestergaard; Urhausen, Axel; Theisen, Daniel

2015-09-01

To investigate the association between training-related characteristics and running-related injury using a new conceptual model for running-related injury generation, focusing on the synergy between training load and previous injuries, short-term running experience or body mass index (> or < 25 kg m(-2)). Prospective cohort study with a 9-month follow-up. The data of two previous studies using the same methodology were revisited. Recreational runners (n = 517) reported information about running training characteristics (weekly distance, frequency, speed), other sport participation and injuries on a dedicated internet platform. Weekly volume (dichotomized into < 2h and ≥ 2 h) and session frequency (dichotomized into < 2 and ≥ 2) were the main exposures because they were considered necessary causes for running-related injury. Non-training-related characteristics were included in Cox regression analyses as effect-measure modifiers. Hazard ratio was the measure of association. The size of effect-measure modification was calculated as the relative excess risk due to interaction. One hundred sixty-seven runners reported a running-related injury. Crude analyses revealed that weekly volume < 2h (hazard ratio = 3.29; 95% confidence intervals = 2.27; 4.79) and weekly session frequency < 2 (hazard ratio = 2.41; 95% confidence intervals = 1.71; 3.42) were associated with increased injury rate. Previous injury was identified as an effect-measure modifier on weekly volume (relative excess risk due to interaction = 4.69; 95% confidence intervals = 1.42; 7.95; p = 0.005) and session frequency (relative excess risk due to interaction = 2.44; 95% confidence intervals = 0.48; 4.39; p = 0.015). A negative synergy was found between body mass index and weekly volume (relative excess risk due to interaction = -2.88; 95% confidence intervals = -5.10; -0.66; p = 0.018). The effect of a runner's training load on running-related injury is influenced by body mass index and previous injury. These results show the importance to distinguish between confounding and effect-measure modification in running-related injury research. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

In Situ Proximity Ligation Assays Indicate That Hemochromatosis Proteins Hfe and Transferrin Receptor 2 (Tfr2) Do Not Interact

PubMed Central

Rishi, Gautam; Crampton, Emily M.; Wallace, Daniel F.; Subramaniam, V. Nathan

2013-01-01

The hemochromatosis associated proteins HFE and Transferrin Receptor 2 (TFR2) have been shown to be important for the proper regulation of hepcidin. A number of in vitro studies using transient overexpression systems have suggested that an interaction between HFE and TFR2 is required for the regulation of hepcidin. This model of iron sensing which centers upon the requirement for an interaction between HFE and TFR2 has recently been questioned with in vivo studies in mice from our laboratory and others which suggest that Hfe and Tfr2 can regulate hepcidin independently of each other. To re-examine the postulated interaction between Hfe and Tfr2 we developed a novel expression system in which both proteins are stably co-expressed and used the proximity ligation assay to examine the interactions between Hfe, Tfr1 and Tfr2 at a cellular level. We were able to detect the previously described interaction between Hfe and Tfr1, and heterodimers between Tfr1 and Tfr2; however no interaction between Hfe and Tfr2 was observed in our system. The results from this study indicate that Hfe and Tfr2 do not interact with each other when they are stably expressed at similar levels. Furthermore, these results support in vivo studies which suggest that Hfe and Tfr2 can independently regulate hepcidin. PMID:24155934

The social-cognitive basis of infants' reference to absent entities.

PubMed

Bohn, Manuel; Zimmermann, Luise; Call, Josep; Tomasello, Michael

2018-04-06

Recent evidence suggests that infants as young as 12 month of age use pointing to communicate about absent entities. The tacit assumption underlying these studies is that infants do so based on tracking what their interlocutor experienced in a previous shared interaction. The present study addresses this assumption empirically. In three experiments, 12-month-old infants could request additional desired objects by pointing to the location in which these objects were previously located. We systematically varied whether the adult from whom infants were requesting had previously experienced the former content of the location with the infant. Infants systematically adjusted their pointing to the now empty location to what they experienced with the adult previously. These results suggest that infants' ability to communicate about absent referents is based on an incipient form of common ground. Copyright © 2018 Elsevier B.V. All rights reserved.

Genetic and environmental control of host-gut microbiota interactions.

PubMed

Org, Elin; Parks, Brian W; Joo, Jong Wha J; Emert, Benjamin; Schwartzman, William; Kang, Eun Yong; Mehrabian, Margarete; Pan, Calvin; Knight, Rob; Gunsalus, Robert; Drake, Thomas A; Eskin, Eleazar; Lusis, Aldons J

2015-10-01

Genetics provides a potentially powerful approach to dissect host-gut microbiota interactions. Toward this end, we profiled gut microbiota using 16s rRNA gene sequencing in a panel of 110 diverse inbred strains of mice. This panel has previously been studied for a wide range of metabolic traits and can be used for high-resolution association mapping. Using a SNP-based approach with a linear mixed model, we estimated the heritability of microbiota composition. We conclude that, in a controlled environment, the genetic background accounts for a substantial fraction of abundance of most common microbiota. The mice were previously studied for response to a high-fat, high-sucrose diet, and we hypothesized that the dietary response was determined in part by gut microbiota composition. We tested this using a cross-fostering strategy in which a strain showing a modest response, SWR, was seeded with microbiota from a strain showing a strong response, A×B19. Consistent with a role of microbiota in dietary response, the cross-fostered SWR pups exhibited a significantly increased response in weight gain. To examine specific microbiota contributing to the response, we identified various genera whose abundance correlated with dietary response. Among these, we chose Akkermansia muciniphila, a common anaerobe previously associated with metabolic effects. When administered to strain A×B19 by gavage, the dietary response was significantly blunted for obesity, plasma lipids, and insulin resistance. In an effort to further understand host-microbiota interactions, we mapped loci controlling microbiota composition and prioritized candidate genes. Our publicly available data provide a resource for future studies. © 2015 Org et al.; Published by Cold Spring Harbor Laboratory Press.

Assessment of interaction-strength interpolation formulas for gold and silver clusters

NASA Astrophysics Data System (ADS)

Giarrusso, Sara; Gori-Giorgi, Paola; Della Sala, Fabio; Fabiano, Eduardo

2018-04-01

The performance of functionals based on the idea of interpolating between the weak- and the strong-interaction limits the global adiabatic-connection integrand is carefully studied for the challenging case of noble-metal clusters. Different interpolation formulas are considered and various features of this approach are analyzed. It is found that these functionals, when used as a correlation correction to Hartree-Fock, are quite robust for the description of atomization energies, while performing less well for ionization potentials. Future directions that can be envisaged from this study and a previous one on main group chemistry are discussed.

Selection Devices for User of an Electronic Encyclopedia: An Empirical Comparison of Four Possibilities.

ERIC Educational Resources Information Center

Ostroff, Daniel; Shneiderman, Ben

1988-01-01

Describes a study that measured the speed, error rates, and subjective evaluation of arrow jump keys, a jump mouse, number keys, and a touch screen in an interactive encyclopedia. The results of previous studies are discussed as well as the findings of this study. Improvements in selection devices are suggested. (41 references) (Author/CLB)

Understanding students’ and clinicians’ experiences of informal interprofessional workplace learning: an Australian qualitative study

PubMed Central

Rees, Charlotte E; Kent, Fiona; Brown, Ted; Hood, Kerry; Leech, Michelle; Newton, Jennifer; Storr, Michael; Williams, Brett

2018-01-01

Objectives While postgraduate studies have begun to shed light on informal interprofessional workplace learning, studies with preregistration learners have typically focused on formal and structured work-based learning. The current study investigated preregistration students’ informal interprofessional workplace learning by exploring students’ and clinicians’ experiences of interprofessional student-clinician (IPSC) interactions. Design A qualitative interview study using narrative techniques was conducted. Setting Student placements across multiple clinical sites in Victoria, Australia. Participants Through maximum variation sampling, 61 participants (38 students and 23 clinicians) were recruited from six professions (medicine, midwifery, nursing, occupational therapy, paramedicine and physiotherapy). Methods We conducted 12 group and 10 individual semistructured interviews. Themes were identified through framework analysis, and the similarities and differences in subthemes by participant group were interrogated. Results Six themes relating to four research questions were identified: (1) conceptualisations of IPSC interactions; (2) context for interaction experiences; (3) the nature of interaction experiences; (4) factors contributing to positive or negative interactions; (5) positive or negative consequences of interactions and (6) suggested improvements for IPSC interactions. Seven noteworthy differences in subthemes between students and clinicians and across the professions were identified. Conclusions Despite the results largely supporting previous postgraduate research, the findings illustrate greater breadth and depth of understandings, experiences and suggestions for preregistration education. Educators and students are encouraged to seek opportunities for informal interprofessional learning afforded by the workplace. PMID:29666140

Matrix remodeling between cells and cellular interactions with collagen bundle

NASA Astrophysics Data System (ADS)

Kim, Jihan; Sun, Bo

When cells are surrounded by complex environment, they continuously probe and interact with it by applying cellular traction forces. As cells apply traction forces, they can sense rigidity of their local environment and remodel the matrix microstructure simultaneously. Previous study shows that single human carcinoma cell (MDA-MB-231) remodeled its surrounding extracellular matrix (ECM) and the matrix remodeling was reversible. In this study we examined the matrix microstructure between cells and cellular interaction between them using quantitative confocal microscopy. The result shows that the matrix microstructure is the most significantly remodeled between cells consisting of aligned, and densified collagen fibers (collagen bundle)., the result shows that collagen bundle is irreversible and significantly change micromechanics of ECM around the bundle. We further examined cellular interaction with collagen bundle by analyzing dynamics of actin and talin formation along with the direction of bundle. Lastly, we analyzed dynamics of cellular protrusion and migrating direction of cells along the bundle.

Strong electronic interaction and multiple quantum Hall ferromagnetic phases in trilayer graphene

NASA Astrophysics Data System (ADS)

Datta, Biswajit; Dey, Santanu; Samanta, Abhisek; Borah, Abhinandan; Agarwal, Hitesh; Watanabe, Kenji; Taniguchi, Takashi; Sensarma, Rajdeep; Deshmukh, Mandar

There is an increasing interest in the electronic properties of few layer graphene as it offers a platform to study electronic interactions because the dispersion of bands can be tuned with number and stacking of layers in combination with electric field. Here, we report evidence of strong electronic interactions and quantum Hall ferromagnetism (QHF) seen in a dual gated ABA trilayer graphene sample. Due to high mobility (500,000 cm2V-1s-1) in our device compared to previous studies, we find all symmetry broken states including ν = 0 filling factor at relatively low magnetic field (6T). Activation measurements show that Landau Level (LL) gaps are enhanced by interactions. Moreover, we observe hysteresis as a function of filling factor and spikes in the longitudinal resistance which, together, signal the formation of QHF states at low magnetic field.

The role of competitive binding to human serum albumin on efavirenz-warfarin interaction: a nuclear magnetic resonance study.

PubMed

Wanke, Riccardo; Harjivan, Shrika G; Pereira, Sofia A; Marques, M Matilde; Antunes, Alexandra M M

2013-11-01

The potential for co-prescription of the anti-human immunodeficiency virus (anti-HIV) drug efavirenz (EFV) and the oral anticoagulant warfarin (WAR) is currently high as EFV is a drug of choice for HIV type 1 infection and because cardiovascular disease is increasing among HIV-infected individuals. However, clinical reports of EFV-WAR interaction, leading to WAR overdosing, call for elucidation of the mechanisms involved in this drug-drug interaction. Here we present the first report demonstrating competition of the two drugs for the same binding site of human serum albumin. Using ligand-based nuclear magnetic resonance experiments, this study proves that EFV has an effect on the concentration of free WAR. This previously unidentified EFV-WAR interaction represents a potential risk factor that should be taken into account when considering treatment options. Copyright © 2013 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Flying relativistic mirrors for nonlinear QED studies.

NASA Astrophysics Data System (ADS)

Bulanov, Stepan; Schroeder, Carl; Esarey, Eric; Leemans, Wim

2017-10-01

Recent progress in laser technology has led to a dramatic increase of laser power and intensity. As a result, the laser-matter interaction will happen in the radiation dominated regimes. In a strong electromagnetic field, electrons can be accelerated to such high velocities that the radiation reaction starts to play an important role. The radiation effects change drastically the laser-plasma interaction leading to fast energy losses. Moreover, previously unexplored regimes of the interaction will be entered into, in which quantum electrodynamics (QED) can occur. Depending on the laser intensity and wavelength, either classical or quantum mode of radiation reaction prevail. In order to study different regimes of interaction as well as the transition from one into another the utilization of flying relativistic mirrors, which can generate electromagnetic pulses with varying frequency and intensity, is proposed. The scheme is demonstrated for multiphoton Compton scattering. Work supported by U.S. DOE under Contract No. DE-AC02-05CH11231.

Exotic topological density waves in cold atomic Rydberg-dressed fermions

PubMed Central

Li, Xiaopeng; Sarma, S Das

2015-01-01

Versatile controllability of interactions in ultracold atomic and molecular gases has now reached an era where quantum correlations and unconventional many-body phases can be studied with no corresponding analogues in solid-state systems. Recent experiments in Rydberg atomic gases have achieved exquisite control over non-local interactions, allowing novel quantum phases unreachable with the usual local interactions in atomic systems. Here we study Rydberg-dressed atomic fermions in a three-dimensional optical lattice predicting the existence of hitherto unheard-of exotic mixed topological density wave phases. By varying the spatial range of the non-local interaction, we find various chiral density waves with spontaneous time-reversal symmetry breaking, whose quasiparticles form three-dimensional quantum Hall and Weyl semimetal states. Remarkably, certain density waves even exhibit mixed topologies beyond the existing topological classification. Our results suggest gapless fermionic states could exhibit far richer topology than previously expected. PMID:25972134

Near-planar TS waves and longitudinal vortices in channel flow: Nonlinear interaction and focusing

NASA Technical Reports Server (NTRS)

Hall, P.; Smith, F. T.

1989-01-01

The nonlinear interaction between planar or near-planar Tollmien-Schlichting waves and longitudinal vortices, induced or input, is considered theoretically for channel flows at high Reynolds numbers. Several kinds of nonlinear interaction, dependent on the input amplitudes and wavenumbers or on previously occurring interactions, are found and inter-related. The first, Type 1, is studied the most here and it usually produces spanwise focusing of both the wave and the vortex motion, within a finite scaled time, along with enhancement of both their amplitudes. This then points to the nonlinear interaction Type 2 where new interactive effects come into force to drive the wave and the vortex nonlinearly. Types 3, 4 correspond to still higher amplitudes, with 3 being related to 2, while 4 is connected with a larger-scale interaction 5 studied in an allied paper. Both 3, 4 are subsets of the full three-dimensional triple-deck-lie interaction, 6. The strongest nonlinear interactions are those of 4, 5, 6 since they alter the mean-flow profile substantially, i.e., by an 0(1) relative amount. All the types of nonlinear interaction however can result in the formation of focussed responses in the sense of spanwise concentrations and/or amplifications of vorticity and wave amplitude.

Communication: Polymer entanglement dynamics: Role of attractive interactions

DOE PAGES

Grest, Gary S.

2016-10-10

The coupled dynamics of entangled polymers, which span broad time and length scales, govern their unique viscoelastic properties. To follow chain mobility by numerical simulations from the intermediate Rouse and reptation regimes to the late time diffusive regime, highly coarse grained models with purely repulsive interactions between monomers are widely used since they are computationally the most efficient. In this paper, using large scale molecular dynamics simulations, the effect of including the attractive interaction between monomers on the dynamics of entangled polymer melts is explored for the first time over a wide temperature range. Attractive interactions have little effect onmore » the local packing for all temperatures T and on the chain mobility for T higher than about twice the glass transition T g. Finally, these results, across a broad range of molecular weight, show that to study the dynamics of entangled polymer melts, the interactions can be treated as pure repulsive, confirming a posteriori the validity of previous studies and opening the way to new large scale numerical simulations.« less

The triel bond: a potential force for tuning anion-π interactions

NASA Astrophysics Data System (ADS)

Esrafili, Mehdi D.; Mousavian, Parisasadat

2018-02-01

Using ab-initio calculations, the mutual influence between anion-π and B···N or B···C triel bond interactions is investigated in some model complexes. The properties of these complexes are studied by molecular electrostatic potential, noncovalent interaction index, quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analyses. According to the results, the formation of B···N or B···C triel bond interactions in the multi-component systems makes a significant shortening of anion-π distance. Such remarkable variation in the anion-π distances has not been reported previously. The strengthening of the anion-π bonding in the multi-component systems depend significantly on the nature of the anion, and it becomes larger in the order Br- > Cl- > F-. The parameters derived from the QTAIM and NBO methodologies are used to study the mechanism of the cooperativity between the anion-π and triel bond interactions in the multi-component complexes.

Magnetic interaction reversal in watermelon nanostructured Cr-doped Fe nanoclusters

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

Kaur, Maninder; Qiang, You, E-mail: youqiang@uidaho.edu; Dai, Qilin

2013-11-11

Cr-doped core-shell Fe/Fe-oxide nanoclusters (NCs) were synthesized at varied atomic percentages of Cr from 0 at. % to 8 at. %. The low concentrations of Cr (<10 at. %) were selected in order to inhibit the complete conversion of the Fe-oxide shell to Cr{sub 2}O{sub 3} and the Fe core to FeCr alloy. The magnetic interaction in Fe/Fe-oxide NCs (∼25 nm) can be controlled by antiferromagnetic Cr-dopant. We report the origin of σ-FeCr phase at very low Cr concentration (2 at. %) unlike in previous studies, and the interaction reversal from dipolar to exchange interaction in watermelon-like Cr-doped core-shell NCs.

HI observations of dwarf galaxies out to a distance of 50 Mpc

NASA Technical Reports Server (NTRS)

Simpson, Caroline; Gottesman, S. T.

1993-01-01

Here we report our preliminary findings from an HI search for dwarf galaxies in three environmentally distinct regions of the sky: a galactic void, a galactic cluster, and an interaction field. This study is sensitive at the 5(sigma) level to hydrogen masses as low as 5 x 10(exp 5) solar mass. We have made three possible detections of previously uncatalogued objects: one in the void field, and two in the cluster field. Reduction of the interaction field is in progress.

The Correlation Fractal Dimension of Complex Networks

NASA Astrophysics Data System (ADS)

Wang, Xingyuan; Liu, Zhenzhen; Wang, Mogei

2013-05-01

The fractality of complex networks is studied by estimating the correlation dimensions of the networks. Comparing with the previous algorithms of estimating the box dimension, our algorithm achieves a significant reduction in time complexity. For four benchmark cases tested, that is, the Escherichia coli (E. Coli) metabolic network, the Homo sapiens protein interaction network (H. Sapiens PIN), the Saccharomyces cerevisiae protein interaction network (S. Cerevisiae PIN) and the World Wide Web (WWW), experiments are provided to demonstrate the validity of our algorithm.

The effects of chronic tinnitus caused by acoustic trauma on social behaviour and anxiety in rats.

PubMed

Zheng, Y; Hamilton, E; McNamara, E; Smith, P F; Darlington, C L

2011-10-13

Tinnitus is associated with significant increases in anxiety disorders in humans, which is thought to affect social interaction; however, there has been only one previous study of the effects of tinnitus on social interaction in animals treated with salicylate and no previous study of the effects of tinnitus on anxiety in animals. In the present study, we used acoustic trauma to induce tinnitus in rats and investigated its effects on social interaction and anxiety in animals confirmed to have tinnitus. When social behaviours were grouped, we found that animals with tinnitus engaged in significantly more aggressive behaviours toward both tinnitus and sham control animals (P=0.03). When individual social behaviours were analysed without considering whether a tinnitus or sham animal was interacting with a member of its own treatment group, tinnitus animals were found to engage in significantly more anogenital investigation (P=0.01) and significantly less social grooming (P=0.003). When the data were analysed according to whether an animal was interacting with a member of its own group, tinnitus animals were found to bite sham animals significantly more than other tinnitus animals (P=0.005). Sham animals also bit tinnitus animals significantly more than other sham animals (P=0.02), as well as climbing away from them more (P=0.04), kicking (P=0.003), nudging them more (P=0.04), and sleeping with them more (P=0.02). By contrast, sham animals sniffed tinnitus animals significantly less than sham animals (P=0.05). There were no significant differences between the sham and tinnitus animals in performance in the elevated plus and elevated T maze tests of anxiety. However, tinnitus animals displayed a slight but significant increase in locomotor activity in the open field (P=0.04). These data suggest that tinnitus results in complex changes in social interaction in rats, which are not due simply to increases in anxiety. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.

STUDIES OF VERAPAMIL BINDING TO HUMAN SERUM ALBUMIN BY HIGH-PERFORMANCE AFFINITY CHROMATOGRAPHY

PubMed Central

Mallik, Rangan; Yoo, Michelle J.; Chen, Sike; Hage, David S.

2008-01-01

The binding of verapamil to the protein human serum albumin (HSA) was examined by using high-performance affinity chromatography. Many previous reports have investigated the binding of verapamil with HSA, but the exact strength and nature of this interaction (e.g., the number and location of binding sites) is still unclear. In this study, frontal analysis indicated that at least one major binding site was present for R- and S-verapamil on HSA, with estimated association equilibrium constants on the order of 104 M−1 and a 1.4-fold difference in these values for the verapamil enantiomers at pH 7.4 and 37°C. The presence of a second, weaker group of binding sites on HSA was also suggested by these results. Competitive binding studies using zonal elution were carried out between verapamil and various probe compounds that have known interactions with several major and minor sites on HSA. R/S-Verapamil was found to have direct competition with S-warfarin, indicating that verapamil was binding to Sudlow site I (i.e., the warfarin-azapropazone site of HSA). The average association equilibrium constant for R- and S-verapamil at this site was 1.4 (±0.1) × 104 M−1. Verapamil did not have any notable binding to Sudlow site II of HSA but did appear to have some weak allosteric interactions with L-tryptophan, a probe for this site. An allosteric interaction between verapamil and tamoxifen (a probe for the tamoxifen site) was also noted, which was consistent with the binding of verapamil at Sudlow site I. No interaction was seen between verapamil and digitoxin, a probe for the digitoxin site of HSA. These results gave good agreement with previous observations made in the literature and help provide a more detailed description of how verapamil is transported in blood and of how it may interact with other drugs in the body. PMID:18980867

Inferred Early Permian Arc Rifting in Bogda Mountain, Southernmost of the Central Asia Orogenic Belt: Evidence from a Peperite Bearing Volcano-Sedimentary Succession

NASA Astrophysics Data System (ADS)

Memtimin, M.; Guo, Z.

2017-12-01

Late Paleozoic tectonic history, especially Carboniferous-Permian periods, of the Central Asia Orogenic Belt (CAOB) is considered to be the turning point for the termination of terrane amalgamation and closure of the Paleoasian Ocean. However, the debate about the paleoenvironment and tectonic setting of the region during the period is still not resolved. In this study, we report a set of volcano-sedimentary sequence in the Bogda Mountain of the southernmost of CAOB, which is associated with contemporaneous subaqueous emplacement of and interaction between mafic lava and carbonate sediments. The succession contains four distinct facies including closely packed pillow basalts, pillow basalts with interstitial materials, hyaloclastites and peperites. We discuss their formation and emplacement mechanism, interaction between hot magma-water/unconsolidated sediments and thermal metamorphism during the interaction. Textural features of the sequence, especially hyaloclastites and peperites, provide clear evidence for in situ autofragmentation of lava flows, synvolcanic sedimentation of carbonates, fuel coolant interaction when hot magma bulldozed into wet unconsolidated sediments, and represent autochthonous origin of the succession. Lateral transition of the lithofacies indicate a progressively deepening subaqueous environment, resembling a stepwise evolution from early stage of volcanic intrusion with lower lava flux in shallower water level to increasingly subsiding basin with more lava flux in greater depth. Previous studies determined that the mafic magma was intruded around the Carboniferous-Permian boundary ( 300Ma), and geochemical studies showed the magma was originated from dry depleted mantle with little crustal contamination. Nevertheless, the succession was thought to be fault related allochthones formation which was transferred in as part of a Carboniferous intraplate arc. Combining our findings with the previous study results, we propose a new model to reconstruct the paleoenvironemnt of the area and infer that the intraplate Carboniferous Bogda arc system was already evolved into an early stage of a post collisional rift basin by the Early Permian, and consolidate the previous model constraining the closure of the Paleoasian Ocean before the Late Carboniferous periods.

The Interaction of Temporal and Spectral Acoustic Information with Word Predictability on Speech Intelligibility

NASA Astrophysics Data System (ADS)

Shahsavarani, Somayeh Bahar

High-level, top-down information such as linguistic knowledge is a salient cortical resource that influences speech perception under most listening conditions. But, are all listeners able to exploit these resources for speech facilitation to the same extent? It was found that children with cochlear implants showed different patterns of benefit from contextual information in speech perception compared with their normal-haring peers. Previous studies have discussed the role of non-acoustic factors such as linguistic and cognitive capabilities to account for this discrepancy. Given the fact that the amount of acoustic information encoded and processed by auditory nerves of listeners with cochlear implants differs from normal-hearing listeners and even varies across individuals with cochlear implants, it is important to study the interaction of specific acoustic properties of the speech signal with contextual cues. This relationship has been mostly neglected in previous research. In this dissertation, we aimed to explore how different acoustic dimensions interact to affect listeners' abilities to combine top-down information with bottom-up information in speech perception beyond the known effects of linguistic and cognitive capacities shown previously. Specifically, the present study investigated whether there were any distinct context effects based on the resolution of spectral versus slowly-varying temporal information in perception of spectrally impoverished speech. To that end, two experiments were conducted. In both experiments, a noise-vocoded technique was adopted to generate spectrally-degraded speech to approximate acoustic cues delivered to listeners with cochlear implants. The frequency resolution was manipulated by varying the number of frequency channels. The temporal resolution was manipulated by low-pass filtering of amplitude envelope with varying low-pass cutoff frequencies. The stimuli were presented to normal-hearing native speakers of American English. Our results revealed a significant interaction effect between spectral, temporal, and contextual information in the perception of spectrally-degraded speech. This suggests that specific types and degradation of bottom-up information combine differently to utilize contextual resources. These findings emphasize the importance of taking the listener's specific auditory abilities into consideration while studying context effects. These results also introduce a novel perspective for designing interventions for listeners with cochlear implants or other auditory prostheses.

Numerical simulation of magnetic interactions in polycrystalline YFeO 3

NASA Astrophysics Data System (ADS)

Lima, E.; Martins, T. B.; Rechenberg, H. R.; Goya, G. F.; Cavelius, C.; Rapalaviciute, R.; Hao, S.; Mathur, S.

The magnetic behavior of polycrystalline yttrium orthoferrite was studied from the experimental and theoretical points of view. Magnetization measurements up to 170 kOe were carried out on a single-phase YFeO 3 sample synthesized from heterobimetallic alkoxides. The complex interplay between weak-ferromagnetic and antiferromagnetic interactions, observed in the experimental M( H) curves, was successfully simulated by locally minimizing the magnetic energy of two interacting Fe sublattices. The resulting values of exchange field ( HE=5590 kOe), anisotropy field ( HA=0.5 kOe) and Dzyaloshinsky-Moriya antisymmetric field ( HD=149 kOe) are in good agreement with previous reports on this system.

Effects of parent loss: interaction with family size and sibling order.

PubMed

Sklar, A D; Harris, R F

1985-06-01

The authors studied the effect of parent loss during the first 18 years of life and its interactions with family size and sibling order in a nonpsychiatric population of 247 men. Groups defined by loss type, family size, and sibling order were compared using MMPI scale scores. The results strongly suggest that parent loss and family size and their interaction have an important impact on adult personality traits as measured by MMPI scores. The strong adverse impact of intermittent loss and temporary loss in large families (much greater than that of permanent loss) is a crucial finding not previously noted in the literature.

Propagation of Sparkleberry (Vaccinium arboreum) improved via cutting type

USDA-ARS?s Scientific Manuscript database

The objectives of this study were to determine whether cutting type (softwood, semi-hardwood, or hardwood), cutting position (terminal or subterminal), IBA concentration, or the interaction of these treatments influence rooting of V. arboreum stem cuttings. Previous experiments did not specify if th...

Development Effects of Oxytocin in Piglets by Intranasal or Subcutaneous Administration

USDA-ARS?s Scientific Manuscript database

Oxytocin (OT) is implicated in the regulation of social behaviors and reactivity to various stressors. Previous studies have evidenced that the effects of early experience, including postnatal social interactions, on socio-behavioral development are partly mediated by plasticity in peptide systems o...

Role of hybridization in the superconducting properties of an extended d p Hubbard model: a detailed numerical study

NASA Astrophysics Data System (ADS)

Calegari, E. J.; Magalhães, S. G.; Gomes, A. A.

2005-04-01

The Roth's two-pole approximation has been used by the present authors to study the effects of the hybridization in the superconducting properties of a strongly correlated electron system. The model used is the extended Hubbard model which includes the d-p hybridization, the p-band and a narrow d-band. The present work is an extension of our previous work (J. Mod. Phys. B 18(2) (2004) 241). Nevertheless, some important correlation functions necessary to estimate the Roth's band shift, are included together with the temperature T and the Coulomb interaction U to describe the superconductivity. The superconducting order parameter of a cuprate system, is obtained following Beenen and Edwards formalism. Here, we investigate in detail the change of the order parameter associated to temperature, Coulomb interaction and Roth's band shift effects on superconductivity. The phase diagram with Tc versus the total occupation number nT, shows the difference respect to the previous work.

Ecologic Niche Modeling and Potential Reservoirs for Chagas Disease, Mexico.

PubMed Central

Sánchez-Cordero, Victor; Ben Beard, C.; Ramsey, Janine M.

2002-01-01

Ecologic niche modeling may improve our understanding of epidemiologically relevant vector and parasite-reservoir distributions. We used this tool to identify host relationships of Triatoma species implicated in transmission of Chagas disease. Associations have been documented between the protracta complex (Triatoma: Triatominae: Reduviidae) with packrat species (Neotoma spp.), providing an excellent case study for the broader challenge of developing hypotheses of association. Species pairs that were identified coincided exactly with those in previous studies, suggesting that local interactions between Triatoma and Neotoma species and subspecies have implications at a geographic level. Nothing is known about sylvatic associates of T. barberi, which are considered the primary Chagas vector in Mexico; its geographic distribution coincided closely with that of N. mexicana, suggesting interaction. The presence of the species was confirmed in two regions where it had been predicted but not previously collected. This approach may help in identifying Chagas disease risk areas, planning vector-control strategies, and exploring parasite-reservoir associations for other emerging diseases. PMID:12095431

Self-transcendence and nurse-patient interaction in cognitively intact nursing home patients.

PubMed

Haugan, Gørill; Rannestad, Toril; Hanssen, Brith; Espnes, Geir A

2012-12-01

The aim of this study was to test whether nurse-patient interaction affects cognitively intact nursing home patients' interpersonal and intrapersonal self-transcendence, as well as testing the psychometric properties of the Nurse-Patient Interaction Scale (NPIS). Self-transcendence is considered a spiritual developmental process of maturity in adulthood, and a vital resource of well-being at the end of life. The concept of self-transcendence has previously been explored in various populations, yet the nurse-patient interactions' potential influence on self-transcendence in nursing home patients has not been published previously. A cross-sectional design employing the Self-Transcendence Scale and the NPIS was adopted. A sample of 202 cognitively well-functioning nursing home patients in Norway was selected. The statistical analyses were carried out using lisrel 8.8 and structural equation modelling. Structural equation modelling-analysis indicates statistical significant effect of nurse-patient interaction on the patients' self-transcendence. Direct influence on the intrapersonal and indirect influence on the interpersonal self-transcendence aspects was disclosed. Nurse-patient interaction significantly affected both interpersonal and intrapersonal self-transcendence among cognitively intact nursing home patients. Hence, facilitating caring interventions can be significantly beneficial to older patients' self-transcendence and thereby well-being, both emotional and physical. Caring behaviour signifies the vital and ultimate qualitative nursing behaviour, which promotes self-transcendence and thereby well-being. These findings are important for clinical nursing that intends to increase patients' well-being. © 2012 Blackwell Publishing Ltd.

Three-body interactions and the elastic constants of hcp solid 4He

NASA Astrophysics Data System (ADS)

Barnes, Ashleigh L.; Hinde, Robert J.

2017-09-01

The effect of three-body interactions on the elastic properties of hexagonal close packed solid 4He is investigated using variational path integral (VPI) Monte Carlo simulations. The solid's nonzero elastic constants are calculated, at T = 0 K and for a range of molar volumes from 7.88 cm3/mol to 20.78 cm3/mol, from the bulk modulus and the three pure shear constants C0, C66, and C44. Three-body interactions are accounted for using our recently reported perturbative treatment based on the nonadditive three-body potential of Cencek et al. Previous studies have attempted to account for the effect of three-body interactions on the elastic properties of solid 4He; however, these calculations have treated zero point motions using either the Einstein or Debye approximations, which are insufficient in the molar volume range where solid 4He is characterized as a quantum solid. Our VPI calculations allow for a more accurate treatment of the zero point motions which include atomic correlation. From these calculations, we find that agreement with the experimental bulk modulus is significantly improved when three-body interactions are considered. In addition, three-body interactions result in non-negligible differences in the calculated pure shear constants and nonzero elastic constants, particularly at higher densities, where differences of up to 26.5% are observed when three-body interactions are included. We compare to the available experimental data and find that our results are generally in as good or better agreement with experiment as previous theoretical investigations.

Combination alpha-interferon and lamivudine therapy for alpha-interferon-resistant chronic hepatitis B infection: results of a pilot study.

PubMed

Mutimer, D; Naoumov, N; Honkoop, P; Marinos, G; Ahmed, M; de Man, R; McPhillips, P; Johnson, M; Williams, R; Elias, E; Schalm, S

1998-06-01

Alpha-interferon achieves seroconversion in about one third of naive patients. Attempts to achieve seroconversion in patients who have previously failed alpha-interferon have proved disappointing. Combination chemotherapy (alpha-interferon with a nucleoside analogue) might provide a treatment alternative for these patients. We have undertaken a phase 2 study in 20 patients who had previously failed at least one course of alpha-interferon. The study was designed to assess the safety, tolerability and efficacy of the combination. All patients were treated for 16 weeks with alpha-interferon in combination with 12 or 16 weeks of Lamivudine (3'TC). Patients were followed for 16 weeks post-treatment. Pharmacokinetic studies were performed to identify/exclude significant pharmacokinetic drug interaction. The combination was well tolerated, and side-effects of the combination were indistinguishable from the recognised side-effects of alpha-interferon. Pharmacokinetic studies performed on days 1 and 29 did not show any significant interaction. All patients achieved HBV DNA clearance during treatment, but 19 relapsed at the end of treatment. HBeAg/anti-HBe seroconversion was observed for four patients, but was sustained for a single patient (who also had sustained DNA clearance). Combination therapy with alpha-interferon and lamivudine given for 16 weeks appears safe and is well tolerated. However, for this group of patients who had previously failed interferon monotherapy, the efficacy of combination interferon/lamivudine therapy appears disappointing, and other treatment strategies should be investigated.

Dieting behaviours, obesity and predictors of dieting among female college students at Palestinian universities.

PubMed

Bayyari, W D; Henry, L J; Jones, C

2013-01-01

The purpose of this study was to explore dieting practices of female Palestinian college students. Participants ( = 410) were selected by cluster-sampling from 4 Palestinian universities. A regression model investigated dieting using: body mass index (BMI); body satisfaction; self-esteem; dress style; exercise; sociocultural factors; residence; strength of faith; perceived impact of weight on social interaction; and number of previous times dieting. Significant predictors of dieting were low body satisfaction, number of previous dieting times, perceived media pressure, regular exercising, BMI, and perceived impact of weight on social interaction, The model accounted for 45% of the variance in dieting. Body satisfaction was not significantly correlated with self-esteem or strength of faith, which indicates that "internalization of thinness" may be becoming evident among populations in certain developing countries, as in "Western" countries.

Ferroelectric-like hysteresis loop originated from non-ferroelectric effects

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

Kim, Bora; Seol, Daehee; Lee, Shinbuhm

Piezoresponse force microscopy (PFM) has provided advanced nanoscale understanding and analysis of ferroelectric and piezoelectric properties. In PFM-based studies, electromechanical strain induced by the converse piezoelectric effect is probed and analyzed as a PFM response. However, electromechanical strain can also arise from several non-piezoelectric origins that may lead to a misinterpretation of the observed response. Among them, electrostatic interaction can significantly affect the PFM response. Nonetheless, previous studies explored solely the influence of electrostatic interaction on the PFM response under the situation accompanied with polarization switching. Here, we show the influence of the electrostatic interaction in the absence of polarizationmore » switching by using unipolar voltage sweep. The obtained results reveal that the electromechanical neutralization between piezoresponse of polarization and electrostatic interaction plays a crucial role in the observed ferroelectric-like hysteresis loop despite the absence of polarization switching. Furthermore, our work can provide a basic guideline for the correct interpretation of the hysteresis loop in PFM-based studies.« less

Ferroelectric-like hysteresis loop originated from non-ferroelectric effects

DOE PAGES

Kim, Bora; Seol, Daehee; Lee, Shinbuhm; ...

2016-09-06

Piezoresponse force microscopy (PFM) has provided advanced nanoscale understanding and analysis of ferroelectric and piezoelectric properties. In PFM-based studies, electromechanical strain induced by the converse piezoelectric effect is probed and analyzed as a PFM response. However, electromechanical strain can also arise from several non-piezoelectric origins that may lead to a misinterpretation of the observed response. Among them, electrostatic interaction can significantly affect the PFM response. Nonetheless, previous studies explored solely the influence of electrostatic interaction on the PFM response under the situation accompanied with polarization switching. Here, we show the influence of the electrostatic interaction in the absence of polarizationmore » switching by using unipolar voltage sweep. The obtained results reveal that the electromechanical neutralization between piezoresponse of polarization and electrostatic interaction plays a crucial role in the observed ferroelectric-like hysteresis loop despite the absence of polarization switching. Furthermore, our work can provide a basic guideline for the correct interpretation of the hysteresis loop in PFM-based studies.« less

Interaction of a vortex ring and a bubble

NASA Astrophysics Data System (ADS)

Jha, Narsing K.; Govardhan, Raghuraman N.

2014-11-01

Micro-bubble injection in to boundary layers is one possible method for reducing frictional drag of ships. Although this has been studied for some time, the physical mechanisms responsible for drag reduction using microbubbles in turbulent boundary layers is not yet fully understood. Previous studies suggest that bubble-vortical structure interaction seems to be one of the important physical mechanisms for frictional drag reduction using microbubbles. In the present work, we study a simplification of this problem, namely, the interaction of a single vortical structure, in particular a vortex ring, with a single bubble for better understanding of the physics. The vortex ring is generated using a piston-cylinder arrangement and the bubble is generated by connecting a capillary to an air pump. The bubble dynamics is directly visualized using a high speed camera, while the vorticity modification is measured using time resolved PIV. The results show that significant deformations can occur of both the bubble and the vortex ring. Effect of different non-dimensional parameters on the interaction will be presented in the meeting.

Single molecular dynamic interactions between glycophorin A and lectin as probed by atomic force microscopy.

PubMed

Yan, Chao; Yersin, Alexandre; Afrin, Rehana; Sekiguchi, Hiroshi; Ikai, Atsushi

2009-09-01

Glycophorin A (GpA) is one of the most abundant transmembrane proteins in human erythrocytes and its interaction with lectins has been studied as model systems for erythrocyte related biological processes. We performed a force measurement study using the force mode of atomic force microscopy (AFM) to investigate the single molecular level biophysical mechanisms involved in GpA-lectin interactions. GpA was mounted on a mica surface or natively presented on the erythrocyte membrane and probed with an AFM tip coated with the monomeric but multivalent Psathyrella velutina lectin (PVL) through covalent crosslinkers. A dynamic force spectroscopy study revealed similar interaction properties in both cases, with the unbinding force centering around 60 pN with a weak loading rate dependence. Hence we identified the presence of one energy barrier in the unbinding process. Force profile analysis showed that more than 70% of GpAs are free of cytoskeletal associations in agreement with previous reports.

Kinetic Models for Topological Nearest-Neighbor Interactions

NASA Astrophysics Data System (ADS)

Blanchet, Adrien; Degond, Pierre

2017-12-01

We consider systems of agents interacting through topological interactions. These have been shown to play an important part in animal and human behavior. Precisely, the system consists of a finite number of particles characterized by their positions and velocities. At random times a randomly chosen particle, the follower, adopts the velocity of its closest neighbor, the leader. We study the limit of a system size going to infinity and, under the assumption of propagation of chaos, show that the limit kinetic equation is a non-standard spatial diffusion equation for the particle distribution function. We also study the case wherein the particles interact with their K closest neighbors and show that the corresponding kinetic equation is the same. Finally, we prove that these models can be seen as a singular limit of the smooth rank-based model previously studied in Blanchet and Degond (J Stat Phys 163:41-60, 2016). The proofs are based on a combinatorial interpretation of the rank as well as some concentration of measure arguments.

Frequency modulation atomic force microscopy: a dynamic measurement technique for biological systems

NASA Astrophysics Data System (ADS)

Higgins, Michael J.; Riener, Christian K.; Uchihashi, Takayuki; Sader, John E.; McKendry, Rachel; Jarvis, Suzanne P.

2005-03-01

Frequency modulation atomic force microscopy (FM-AFM) has been modified to operate in a liquid environment within an atomic force microscope specifically designed for investigating biological samples. We demonstrate the applicability of FM-AFM to biological samples using the spectroscopy mode to measure the unbinding forces of a single receptor-ligand (biotin-avidin) interaction. We show that quantitative adhesion force measurements can only be obtained provided certain modifications are made to the existing theory, which is used to convert the detected frequency shifts to an interaction force. Quantitative force measurements revealed that the unbinding forces for the biotin-avidin interaction were greater than those reported in previous studies. This finding was due to the use of high average tip velocities, which were calculated to be two orders of magnitude greater than those typically used in unbinding receptor-ligand experiments. This study therefore highlights the potential use of FM-AFM to study a range of biological systems, including living cells and/or single biomolecule interactions.

Reconsideration of dynamic force spectroscopy analysis of streptavidin-biotin interactions.

PubMed

Taninaka, Atsushi; Takeuchi, Osamu; Shigekawa, Hidemi

2010-05-13

To understand and design molecular functions on the basis of molecular recognition processes, the microscopic probing of the energy landscapes of individual interactions in a molecular complex and their dependence on the surrounding conditions is of great importance. Dynamic force spectroscopy (DFS) is a technique that enables us to study the interaction between molecules at the single-molecule level. However, the obtained results differ among previous studies, which is considered to be caused by the differences in the measurement conditions. We have developed an atomic force microscopy technique that enables the precise analysis of molecular interactions on the basis of DFS. After verifying the performance of this technique, we carried out measurements to determine the landscapes of streptavidin-biotin interactions. The obtained results showed good agreement with theoretical predictions. Lifetimes were also well analyzed. Using a combination of cross-linkers and the atomic force microscope that we developed, site-selective measurement was carried out, and the steps involved in bonding due to microscopic interactions are discussed using the results obtained by site-selective analysis.

A rice kinase-protein interaction map.

PubMed

Ding, Xiaodong; Richter, Todd; Chen, Mei; Fujii, Hiroaki; Seo, Young Su; Xie, Mingtang; Zheng, Xianwu; Kanrar, Siddhartha; Stevenson, Rebecca A; Dardick, Christopher; Li, Ying; Jiang, Hao; Zhang, Yan; Yu, Fahong; Bartley, Laura E; Chern, Mawsheng; Bart, Rebecca; Chen, Xiuhua; Zhu, Lihuang; Farmerie, William G; Gribskov, Michael; Zhu, Jian-Kang; Fromm, Michael E; Ronald, Pamela C; Song, Wen-Yuan

2009-03-01

Plants uniquely contain large numbers of protein kinases, and for the vast majority of the 1,429 kinases predicted in the rice (Oryza sativa) genome, little is known of their functions. Genetic approaches often fail to produce observable phenotypes; thus, new strategies are needed to delineate kinase function. We previously developed a cost-effective high-throughput yeast two-hybrid system. Using this system, we have generated a protein interaction map of 116 representative rice kinases and 254 of their interacting proteins. Overall, the resulting interaction map supports a large number of known or predicted kinase-protein interactions from both plants and animals and reveals many new functional insights. Notably, we found a potential widespread role for E3 ubiquitin ligases in pathogen defense signaling mediated by receptor-like kinases, particularly by the kinases that may have evolved from recently expanded kinase subfamilies in rice. We anticipate that the data provided here will serve as a foundation for targeted functional studies in rice and other plants. The application of yeast two-hybrid and TAPtag analyses for large-scale plant protein interaction studies is also discussed.

Polysyllabic Units in the Vocalizations of Children from 0 ; 6 to 1 ; 11: Intonation-Groups, Tones and Rhythms

ERIC Educational Resources Information Center

Snow, David

2007-01-01

Previous studies have suggested that intonation development in infants and toddlers reflects an interaction between physiological and linguistic influences. The immediate background research for this study, however, was based on vocalizations that were only one syllable in length. By extending the analysis to polysyllabic utterances, the present…

Participating with Experience--A Case Study of Students as Co-Producers of Course Design

ERIC Educational Resources Information Center

Reneland-Forsman, Linda

2016-01-01

Higher Education (HE) needs to handle a diverse student population. The role of student expectations and previous experience is a key to fully participate. This study investigates student meaning making and interaction in a course designed to stimulate student as co-creators of course content and aims. Results revealed that rich communication…

Roles of Parents and Annotation Sharing in Children's Learning Behavior and Achievement Using E-Readers

ERIC Educational Resources Information Center

Hwang, Wu-Yuin; Liu, Yi-Fan; Chen, Hon-Ren; Huang, Jian-Wun; Li, Jin-Yi

2015-01-01

Although previous studies have highlighted the advantages of using e-books for learning, most have compared learning achieved with traditional textbooks with that achieved with e-books in a classroom situation. These studies focused on individual learning instead of on interactions among learners, learning behavior using ebooks after school, and…

The Interaction between Family Structure and Child Gender on Behavior Problems in Urban Ethnic Minority Children

ERIC Educational Resources Information Center

Mokrue, Kathariya; Chen, Yung Y.; Elias, Maurice

2012-01-01

Previous studies have reported that children from single-parent households fare worse behaviorally than those from two-parent households. Studies examining single-parent households often fail to distinguish between single-mother and single-father households. Further, there are inconsistent findings regarding the effect of family structure on boys…

The Ras suppressor Rsu-1 binds to the LIM 5 domain of the adaptor protein PINCH1 and participates in adhesion-related functions

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

Dougherty, Gerard W.; Section on Structural Cell Biology, National Institute on Deafness and Communication Disorders; Chopp, Treasa

2005-05-15

Rsu-1 is a highly conserved leucine rich repeat (LRR) protein that is expressed ubiquitously in mammalian cells. Rsu-1 was identified based on its ability to inhibit transformation by Ras, and previous studies demonstrated that ectopic expression of Rsu-1 inhibited anchorage-independent growth of Ras-transformed cells and human tumor cell lines. Using GAL4-based yeast two-hybrid screening, the LIM domain protein, PINCH1, was identified as the binding partner of Rsu-1. PINCH1 is an adaptor protein that localizes to focal adhesions and it has been implicated in the regulation of adhesion functions. Subdomain mapping in yeast revealed that Rsu-1 binds to the LIM 5more » domain of PINCH1, a region not previously identified as a specific binding domain for any other protein. Additional testing demonstrated that PINCH2, which is highly homologous to PINCH1, except in the LIM 5 domain, does not interact with Rsu-1. Glutathione transferase fusion protein binding studies determined that the LRR region of Rsu-1 interacts with PINCH1. Transient expression studies using epitope-tagged Rsu-1 and PINCH1 revealed that Rsu-1 co-immunoprecipitated with PINCH1 and colocalized with vinculin at sites of focal adhesions in mammalian cells. In addition, endogenous P33 Rsu-1 from 293T cells co-immunoprecipitated with transiently expressed myc-tagged PINCH1. Furthermore, RNAi-induced reduction in Rsu-1 RNA and protein inhibited cell attachment, and while previous studies demonstrated that ectopic expression of Rsu-1 inhibited Jun kinase activation, the depletion of Rsu-1 resulted in activation of Jun and p38 stress kinases. These studies demonstrate that Rsu-1 interacts with PINCH1 in mammalian cells and functions, in part, by altering cell adhesion.« less

The Rhizoctonia solani AG1-IB (isolate 7/3/14) transcriptome during interaction with the host plant lettuce (Lactuca sativa L.).

PubMed

Verwaaijen, Bart; Wibberg, Daniel; Kröber, Magdalena; Winkler, Anika; Zrenner, Rita; Bednarz, Hanna; Niehaus, Karsten; Grosch, Rita; Pühler, Alfred; Schlüter, Andreas

2017-01-01

The necrotrophic pathogen Rhizoctonia solani is one of the most economically important soil-borne pathogens of crop plants. Isolates of R. solani AG1-IB are the major pathogens responsible for bottom-rot of lettuce (Lactuca sativa L.) and are also responsible for diseases in other plant species. Currently, there is lack of information regarding the molecular responses in R. solani during the pathogenic interaction between the necrotrophic soil-borne pathogen and its host plant. The genome of R. solani AG1-IB (isolate 7/3/14) was recently established to obtain insights into its putative pathogenicity determinants. In this study, the transcriptional activity of R. solani AG1-IB was followed during the course of its pathogenic interaction with the host plant lettuce under controlled conditions. Based on visual observations, three distinct pathogen-host interaction zones on lettuce leaves were defined which covered different phases of disease progression on tissue inoculated with the AG1-IB (isolate 7/3/14). The zones were defined as: Zone 1-symptomless, Zone 2-light brown discoloration, and Zone 3-dark brown, necrotic lesions. Differences in R. solani hyphae structure in these three zones were investigated by microscopic observation. Transcriptional activity within these three interaction zones was used to represent the course of R. solani disease progression applying high-throughput RNA sequencing (RNA-Seq) analysis of samples collected from each Zone. The resulting three transcriptome data sets were analyzed for their highest expressed genes and for differentially transcribed genes between the respective interaction zones. Among the highest expressed genes was a group of not previously described genes which were transcribed exclusively during early stages of interaction, in Zones 1 and 2. Previously described importance of up-regulation in R. solani agglutinin genes during disease progression could be further confirmed; here, the corresponding genes exhibited extremely high transcription levels. Most differentially higher expressed transcripts were found within Zone 2. In Zone 3, the zone with the strongest degree of interaction, gene transcripts indicative of apoptotic activity were highly abundant. The transcriptome data presented in this work support previous models of the disease and interaction cycle of R. solani and lettuce and may influence effective techniques for control of this pathogen.

A retrospective study on changes in residents' physical activities, social interactions, and neighborhood cohesion after moving to a walkable community.

PubMed

Zhu, Xuemei; Yu, Chia-Yuan; Lee, Chanam; Lu, Zhipeng; Mann, George

2014-12-01

This study is to examine changes in residents' physical activities, social interactions, and neighborhood cohesion after they moved to a walkable community in Austin, Texas. Retrospective surveys (N=449) were administered in 2013-2014 to collect pre- and post-move data about the outcome variables and relevant personal, social, and physical environmental factors. Walkability of each resident's pre-move community was measured using the Walk Score. T tests were used to examine the pre-post move differences in the outcomes in the whole sample and across sub-groups with different physical activity levels, neighborhood conditions, and neighborhood preferences before the move. After the move, total physical activity increased significantly in the whole sample and all sub-groups except those who were previously sufficiently active; lived in communities with high walkability, social interactions, or neighborhood cohesion; or had moderate preference for walkable neighborhoods. Walking in the community increased in the whole sample and all subgroups except those who were previously sufficiently active, moved from high-walkability communities, or had little to no preference for walkable neighborhoods. Social interactions and neighborhood cohesion increased significantly after the move in the whole sample and all sub-groups. This study explored potential health benefits of a walkable community in promoting physically and socially active lifestyles, especially for populations at higher risk of obesity. The initial result is promising, suggesting the need for more work to further examine the relationships between health and community design using pre-post assessments. Copyright © 2014 Elsevier Inc. All rights reserved.

Orientation-dependent interaction between Drosophila insulators is a property of this class of regulatory elements

PubMed Central

Kyrchanova, Olga; Chetverina, Darya; Maksimenko, Oksana; Kullyev, Andrey; Georgiev, Pavel

2008-01-01

Insulators are defined as a class of regulatory elements that delimit independent transcriptional domains within eukaryotic genomes. According to previous data, an interaction (pairing) between some Drosophila insulators can support distant activation of a promoter by an enhancer. Here, we have demonstrated that pairs of well-studied insulators such as scs–scs, scs’–scs’, 1A2–1A2 and Wari–Wari support distant activation of the white promoter by the yeast GAL4 activator in an orientation-dependent manner. The same is true for the efficiency of the enhancer that stimulates white expression in the eyes. In all insulator pairs tested, stimulation of the white gene was stronger when insulators were inserted between the eye enhancer or GAL4 and the white promoter in opposite orientations relative to each other. As shown previously, Zw5, Su(Hw) and dCTCF proteins are required for the functioning of different insulators that do not interact with each other. Here, strong functional interactions have been revealed between DNA fragments containing binding sites for either Zw5 or Su(Hw) or dCTCF protein but not between heterologous binding sites [Zw5–Su(Hw), dCTCF–Su(Hw), or dCTCF–Zw5]. These results suggest that insulator proteins can support selective interactions between distant regulatory elements. PMID:18987002

A mass spectrometry-based proteomic analysis of Homer2-interacting proteins in the mouse brain.

PubMed

Goulding, Scott P; Szumlinski, Karen K; Contet, Candice; MacCoss, Michael J; Wu, Christine C

2017-08-23

In the brain, the Homer protein family modulates excitatory signal transduction and receptor plasticity through interactions with other proteins in dendritic spines. Homer proteins are implicated in a variety of psychiatric disorders such as schizophrenia and addiction. Since long Homers serve as scaffolding proteins, identifying their interacting partners is an important first step in understanding their biological function and could help to guide the design of new therapeutic strategies. The present study set out to document Homer2-interacting proteins in the mouse brain using a co-immunoprecipitation-based mass spectrometry approach where Homer2 knockout samples were used to filter out non-specific interactors. We found that in the mouse brain, Homer2 interacts with a limited subset of its previously reported interacting partners (3 out of 31). Importantly, we detected an additional 15 novel Homer2-interacting proteins, most of which are part of the N-methyl-D-aspartate receptor signaling pathway. These results corroborate the central role Homer2 plays in glutamatergic transmission and expand the network of proteins potentially contributing to the behavioral abnormalities associated with altered Homer2 expression. Long Homer proteins are scaffolding proteins that regulate signal transduction in neurons. Identifying their interacting partners is key to understanding their function. We used co-immunoprecipitation in combination with mass spectrometry to establish the first comprehensive list of Homer2-interacting partners in the mouse brain. The specificity of interactions was evaluated using Homer2 knockout brain tissue as a negative control. The set of proteins that we identified minimally overlaps with previously reported interacting partners of Homer2; however, we identified novel interactors that are part of a signaling cascade activated by glutamatergic transmission, which improves our mechanistic understanding of the role of Homer2 in behavior. Copyright © 2017 Elsevier B.V. All rights reserved.

Potential involvement of kinesin-1 in the regulation of subcellular localization of Girdin

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

Muramatsu, Aya; Enomoto, Atsushi, E-mail: enomoto@iar.nagoya-u.ac.jp; Kato, Takuya

Girdin is an actin-binding protein that has multiple functions in postnatal neural development and cancer progression. We previously showed that Girdin is a regulator of migration for neuroblasts born from neural stem cells in the subventricular zone (SVZ) and the dentate gyrus of the hippocampus in the postnatal brain. Despite a growing list of Girdin-interacting proteins, the mechanism of Girdin-mediated migration has not been fully elucidated. Girdin interacts with Disrupted-In-Schizophrenia 1 and partitioning-defective 3, both of which have been shown to interact with the kinesin microtubule motor proteins. Based on this, we have identified that Girdin also interacts with kinesin-1,more » a member of neuronal kinesin proteins. Although a direct interaction of Girdin and kinesin-1 has not been determined, it is of interest to find that Girdin loss-of-function mutant mice with the mutation of a basic amino acid residue-rich region (Basic mut mice) exhibit limited interaction with kinesin-1. Furthermore, expression of a kinesin-1 mutant with motor defects, leads to Girdin mislocalization. Finally, consistent with previous studies on the role of kinesin proteins in trafficking a cell–cell adhesion molecule N-cadherin, Basic mut mice showed an aberrant expression pattern of N-cadherin in migrating SVZ neuroblasts. These findings suggest a potential role of Girdin/kinesin-1 interaction in the regulation of neuroblast migration in the postnatal brain. - Highlights: • Girdin is a regulator of migration for neuroblasts in the postnatal brain. • Girdin interacts with kinesin-1, a member of neuronal kinesin proteins. • Girdin mutant mice showed an aberrant expression of N-cadherin in neuroblasts.« less

Hi-C Chromatin Interaction Networks Predict Co-expression in the Mouse Cortex

PubMed Central

Hulsman, Marc; Lelieveldt, Boudewijn P. F.; de Ridder, Jeroen; Reinders, Marcel

2015-01-01

The three dimensional conformation of the genome in the cell nucleus influences important biological processes such as gene expression regulation. Recent studies have shown a strong correlation between chromatin interactions and gene co-expression. However, predicting gene co-expression from frequent long-range chromatin interactions remains challenging. We address this by characterizing the topology of the cortical chromatin interaction network using scale-aware topological measures. We demonstrate that based on these characterizations it is possible to accurately predict spatial co-expression between genes in the mouse cortex. Consistent with previous findings, we find that the chromatin interaction profile of a gene-pair is a good predictor of their spatial co-expression. However, the accuracy of the prediction can be substantially improved when chromatin interactions are described using scale-aware topological measures of the multi-resolution chromatin interaction network. We conclude that, for co-expression prediction, it is necessary to take into account different levels of chromatin interactions ranging from direct interaction between genes (i.e. small-scale) to chromatin compartment interactions (i.e. large-scale). PMID:25965262

Mouse Social Interaction Test (MoST): a quantitative computer automated analysis of behavior.

PubMed

Thanos, Panayotis K; Restif, Christophe; O'Rourke, Joseph R; Lam, Chiu Yin; Metaxas, Dimitris

2017-01-01

Rodents are the most commonly used preclinical model of human disease assessing the mechanism(s) involved as well as the role of genetics, epigenetics, and pharmacotherapy on this disease as well as identifying vulnerability factors and risk assessment for disease critical in the development of improved treatment strategies. Unfortunately, the majority of rodent preclinical studies utilize single housed approaches where animals are either entirely housed and tested in solitary environments or group housed but tested in solitary environments. This approach, however, ignores the important contribution of social interaction and social behavior. Social interaction in rodents is found to be a major criterion for the ethological validity of rodent species-specific behavioral characteristics (Zurn et al. 2007; Analysis 2011). It is also well established that there is significant and growing number of reports, which illustrates the important role of social environment and social interaction in all diseases, with particularly significance in all neuropsychiatric diseases. Thus, it is imperative that research studies be able to add large-scale evaluations of social interaction and behavior in mice and benefit from automated tracking of behaviors and measurements by removing user bias and by quantifying aspects of behaviors that cannot be assessed by a human observer. Single mouse setups have been used routinely, but cannot be easily extended to multiple-animal studies where social behavior is key, e.g., autism, depression, anxiety, substance and non-substance addictive disorders, aggression, sexual behavior, or parenting. While recent efforts are focusing on multiple-animal tracking alone, a significant limitation remains the lack of insightful measures of social interactions. We present a novel, non-invasive single camera-based automated tracking method described as Mouse Social Test (MoST) and set of measures designed for estimating the interactions of multiple mice at the same time in the same environment interacting freely. Our results show measurement of social interactions and designed to be adaptable and applicable to most existing home cage systems used in research, and provide a greater level of detailed analysis of social behavior than previously possible. The present study describes social behaviors assessed in a home cage environment setup containing six mice that interact freely over long periods of time, and we illustrate how these measures can be interpreted and combined to classify rodent social behaviors. In addition, we illustrate how these measures can be interpreted and combined to classify and analyze comprehensively rodent behaviors involved in several neuropsychiatric diseases as well as provide opportunity for the basic research of rodent behavior previously not possible.

Hypertension 2008--awareness, understanding, and treatment of previously diagnosed hypertension in baby boomers and seniors: a survey conducted by Harris interactive on behalf of the Preventive Cardiovascular Nurses Association.

PubMed

Miller, Nancy H; Berra, Kathy; Long, Janet

2010-05-01

A Harris Interactive survey of 1548 hypertensive persons aged 44 and older confirms the findings of previous studies that showed suboptimal rates of adherence to medication and lifestyle regimens to lower blood pressure, despite a high level of awareness of the health consequences of uncontrolled blood pressure. When the study population was analyzed by age group (baby boomers, ages 44 to 62 years, and seniors, ages >or=63 years), nonadherence was greater in the baby boomer cohort, which nevertheless had a higher level of concern than the seniors. Poor communication between patients and health care providers contributes to nonadherence to treatment regimens. Patients' age plays an important role in their attitudes and behaviors regarding illness and treatment as well as their preferences as to the types of educational materials they would find helpful and the ways those materials can best be delivered. Because of the growing population of baby boomers further studies are warranted to evaluate attitudes, knowledge, and behaviors concerning the identification and treatment of hypertension.

Social interaction anxiety and personality traits predicting engagement in health risk sexual behaviors.

PubMed

Rahm-Knigge, Ryan L; Prince, Mark A; Conner, Bradley T

2018-06-01

Individuals with social interaction anxiety, a facet of social anxiety disorder, withdraw from or avoid social encounters and generally avoid risks. However, a subset engages in health risk sexual behavior (HRSB). Because sensation seeking, emotion dysregulation, and impulsivity predict engagement in HRSB among adolescents and young adults, the present study hypothesized that latent classes of social interaction anxiety and these personality traits would differentially predict likelihood of engagement in HRSB. Finite mixture modeling was used to discern four classes: two low social interaction anxiety classes distinguished by facets of emotion dysregulation, positive urgency, and negative urgency (Low SIAS High Urgency and Low SIAS Low Urgency) and two high social interaction anxiety classes distinguished by positive urgency, negative urgency, risk seeking, and facets of emotion dysregulation (High SIAS High Urgency and High SIAS Low Urgency). HRSB were entered into the model as auxiliary distal outcomes. Of importance to this study were findings that the High SIAS High Urgency class was more likely to engage in most identified HRSB than the High SIAS Low Urgency class. This study extends previous findings on the heterogeneity of social interaction anxiety by identifying the effects of social interaction anxiety and personality on engagement in HRSB. Copyright © 2018 Elsevier Ltd. All rights reserved.

Interactions between human osteoblasts and prostate cancer cells in a novel 3D in vitro model

PubMed Central

Sieh, Shirly; Lubik, Amy A; Clements, Judith A; Nelson, Colleen C

2010-01-01

Cell-cell and cell-matrix interactions play a major role in tumor morphogenesis and cancer metastasis. Therefore, it is crucial to create a model with a biomimetic microenvironment that allows such interactions to fully represent the pathophysiology of a disease for an in vitro study. This is achievable by using three-dimensional (3D) models instead of conventional two-dimensional (2D) cultures with the aid of tissue engineering technology. We are now able to better address the complex intercellular interactions underlying prostate cancer (CaP) bone metastasis through such models. In this study, we assessed the interaction of CaP cells and human osteoblasts (hOBs) within a tissue engineered bone (TEB) construct. Consistent with other in vivo studies, our findings show that intercellular and CaP cell-bone matrix interactions lead to elevated levels of matrix metalloproteinases, steroidogenic enzymes and the CaP biomarker, prostate specific antigen (PSA); all associated with CaP metastasis. Hence, it highlights the physiological relevance of this model. We believe that this model will provide new insights for understanding of the previously poorly understood molecular mechanisms of bone metastasis, which will foster further translational studies, and ultimately offer a potential tool for drug screening. PMID:21197221

Estimating and testing interactions when explanatory variables are subject to non-classical measurement error.

PubMed

Murad, Havi; Kipnis, Victor; Freedman, Laurence S

2016-10-01

Assessing interactions in linear regression models when covariates have measurement error (ME) is complex.We previously described regression calibration (RC) methods that yield consistent estimators and standard errors for interaction coefficients of normally distributed covariates having classical ME. Here we extend normal based RC (NBRC) and linear RC (LRC) methods to a non-classical ME model, and describe more efficient versions that combine estimates from the main study and internal sub-study. We apply these methods to data from the Observing Protein and Energy Nutrition (OPEN) study. Using simulations we show that (i) for normally distributed covariates efficient NBRC and LRC were nearly unbiased and performed well with sub-study size ≥200; (ii) efficient NBRC had lower MSE than efficient LRC; (iii) the naïve test for a single interaction had type I error probability close to the nominal significance level, whereas efficient NBRC and LRC were slightly anti-conservative but more powerful; (iv) for markedly non-normal covariates, efficient LRC yielded less biased estimators with smaller variance than efficient NBRC. Our simulations suggest that it is preferable to use: (i) efficient NBRC for estimating and testing interaction effects of normally distributed covariates and (ii) efficient LRC for estimating and testing interactions for markedly non-normal covariates. © The Author(s) 2013.

Infrared laser ablation of polymeric nanocomposites: A study of surface structure and plume formation

NASA Astrophysics Data System (ADS)

Bartolucci, S. F.; Miller, M. J.; Warrender, J. M.

2016-12-01

The behavior of carbon nanotube composites subjected to laser pulse heating with a 1070 nm variable pulse duration laser has been studied. Previous work has shown that carbon nanotube composites form a protective network on the surface of a composite, which reduces heat input to the underlying polymer and slows mass loss. In this work, we have studied the interaction between the incident laser and the plume formed above the composite. We have correlated these interactions with features observed in the time-resolved mass loss data and confirmed them with observations using high-speed video of the laser irradiations. Beam interactions were studied as a function of laser irradiance and nanotube content. It is shown that beam-plume interactions occur for the carbon nanotube composites and that the interactions occur at shorter pulse durations for increased nanotube content and laser irradiance. When we eliminate beam-plume interaction through alteration of the sample orientation relative to the incident beam, we are able to elucidate the individual contributions of the carbon nanotube surface network and the plume to the observed decrease in mass loss after laser irradiation. We examine the plume content using microscopy and Raman spectroscopy and show that greater beam absorption occurs when there is a higher graphitic content in the plume.

Variation in the outcomes of an ant-plant system: Fire and leaf fungus infection reduce benefits to plants with extrafloral nectaries

PubMed Central

Pires, L. P.; Del-Claro, K.

2014-01-01

Abstract Interactions between species are evolutionary malleable and may suffer changes in small timescales. Environmental disturbances, such as fire, can deeply affect species interactions, but how they influence the outcome of a mutualistic interaction has yet to be studied. In order to test the hypothesis that an environmental disturbance, in this case fire, may produce differences in the outcome of the association of ants with the extrafloral-nectaries-bearing plant Qualea multiflora Mart. (Myrtales: Vochysiaceae), a previous study was replicated, but this time after fire incidence, at the same study site and with the same plant species. Eight ant species visited Q. multiflora , and the most abundant genera were Crematogaster , Cephalotes , and Camponotus . Herbivores were found in branches with and without ants with no statistical difference, but foliar herbivory was always higher in branchs where ants were absent. Leaves were infested by fungi, and fungi spots were higher in branches where ants were present. Compared to the previous study, it was clearly observed that ant benefits to Q. multiflora varied over time. The most common ant species still protected leaves against chewing herbivores, but a new kind of leaf damage appeared, namely fungi spots. Data also support that ants may be acting as vectors of fungi spores on plants, as ant visited branches had higher fungus incidence than non-visited branches. Fire is a major source of disturbance in tropical savannas, and we suggest that it can cause strong variation in the outcomes of interactions between ants and plants with extrafloral nectaries in the Brazilian tropical savanna. PMID:25368040

Interactome of the hepatitis C virus: Literature mining with ANDSystem.

PubMed

Saik, Olga V; Ivanisenko, Timofey V; Demenkov, Pavel S; Ivanisenko, Vladimir A

2016-06-15

A study of the molecular genetics mechanisms of host-pathogen interactions is of paramount importance in developing drugs against viral diseases. Currently, the literature contains a huge amount of information that describes interactions between HCV and human proteins. In addition, there are many factual databases that contain experimentally verified data on HCV-host interactions. The sources of such data are the original data along with the data manually extracted from the literature. However, the manual analysis of scientific publications is time consuming and, because of this, databases created with such an approach often do not have complete information. One of the most promising methods to provide actualisation and completeness of information is text mining. Here, with the use of a previously developed method by the authors using ANDSystem, an automated extraction of information on the interactions between HCV and human proteins was conducted. As a data source for the text mining approach, PubMed abstracts and full text articles were used. Additionally, external factual databases were analyzed. On the basis of this analysis, a special version of ANDSystem, extended with the HCV interactome, was created. The HCV interactome contains information about the interactions between 969 human and 11 HCV proteins. Among the 969 proteins, 153 'new' proteins were found not previously referred to in any external databases of protein-protein interactions for HCV-host interactions. Thus, the extended ANDSystem possesses a more comprehensive detailing of HCV-host interactions versus other existing databases. It was interesting that HCV proteins more preferably interact with human proteins that were already involved in a large number of protein-protein interactions as well as those associated with many diseases. Among human proteins of the HCV interactome, there were a large number of proteins regulated by microRNAs. It turned out that the results obtained for protein-protein interactions and microRNA-regulation did not depend on how well the proteins were studied, while protein-disease interactions appeared to be dependent on the level of study. In particular, the mean number of diseases linked to well-studied proteins (proteins were considered well-studied if they were mentioned in 50 or more PubMed publications) from the HCV interactome was 20.8, significantly exceeding the mean number of associations with diseases (10.1) for the total set of well-studied human proteins present in ANDSystem. For proteins not highly poorly-studied investigated, proteins from the HCV interactome (each protein was referred to in less than 50 publications) distribution of the number of diseases associated with them had no statistically significant differences from the distribution of the number of diseases associated with poorly-studied proteins based on the total set of human proteins stored in ANDSystem. With this, the average number of associations with diseases for the HCV interactome and the total set of human proteins were 0.3 and 0.2, respectively. Thus, ANDSystem, extended with the HCV interactome, can be helpful in a wide range of issues related to analyzing HCV-host interactions in the search for anti-HCV drug targets. The demo version of the extended ANDSystem covered here containing only interactions between human proteins, genes, metabolites, diseases, miRNAs and molecular-genetic pathways, as well as interactions between human proteins/genes and HCV proteins, is freely available at the following web address: http://www-bionet.sscc.ru/psd/andhcv/. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Three-factor models versus time series models: quantifying time-dependencies of interactions between stimuli in cell biology and psychobiology for short longitudinal data.

PubMed

Frank, Till D; Kiyatkin, Anatoly; Cheong, Alex; Kholodenko, Boris N

2017-06-01

Signal integration determines cell fate on the cellular level, affects cognitive processes and affective responses on the behavioural level, and is likely to be involved in psychoneurobiological processes underlying mood disorders. Interactions between stimuli may subjected to time effects. Time-dependencies of interactions between stimuli typically lead to complex cell responses and complex responses on the behavioural level. We show that both three-factor models and time series models can be used to uncover such time-dependencies. However, we argue that for short longitudinal data the three factor modelling approach is more suitable. In order to illustrate both approaches, we re-analysed previously published short longitudinal data sets. We found that in human embryonic kidney 293 cells cells the interaction effect in the regulation of extracellular signal-regulated kinase (ERK) 1 signalling activation by insulin and epidermal growth factor is subjected to a time effect and dramatically decays at peak values of ERK activation. In contrast, we found that the interaction effect induced by hypoxia and tumour necrosis factor-alpha for the transcriptional activity of the human cyclo-oxygenase-2 promoter in HEK293 cells is time invariant at least in the first 12-h time window after stimulation. Furthermore, we applied the three-factor model to previously reported animal studies. In these studies, memory storage was found to be subjected to an interaction effect of the beta-adrenoceptor agonist clenbuterol and certain antagonists acting on the alpha-1-adrenoceptor / glucocorticoid-receptor system. Our model-based analysis suggests that only if the antagonist drug is administer in a critical time window, then the interaction effect is relevant. © The authors 2016. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

An In Vivo Photo-Cross-Linking Approach Reveals a Homodimerization Domain of Aha1 in S. cerevisiae

PubMed Central

Berg, Michael; Michalowski, Annette; Palzer, Silke; Rupp, Steffen; Sohn, Kai

2014-01-01

Protein-protein interactions play an essential role in almost any biological processes. Therefore, there is a particular need for methods which describe the interactions of a defined target protein in its physiological context. Here we report a method to photo-cross-link interacting proteins in S. cerevisiae by using the non-canonical amino acid p-azido-L-phenylalanine (pAzpa). Based on the expanded genetic code the photoreactive non-canonical amino acid pAzpa was site-specifically incorporated at eight positions into a domain of Aha1 that was previously described to bind Hsp90 in vitro to function as a cochaperone of Hsp90 and activates its ATPase activity. In vivo photo-cross-linking to the cognate binding partner of Aha1 was carried out by irradiation of mutant strains with UV light (365 nm) to induce covalent intermolecular bonds. Surprisingly, an interaction between Aha1 and Hsp90 was not detected, although, we could confirm binding of suppressed pAzpa containing Aha1 to Hsp90 by native co-immunoprecipitation. However, a homodimer consisting of two covalently crosslinked Aha1 monomers was identified by mass spectrometry. This homodimer could also be confirmed using p-benzoyl-L-phenylalanine, another photoreactive non-canonical amino acid. Crosslinking was highly specific as it was dependent on irradiation using UV light, the exact position of the non-canonical amino acid in the protein sequence as well as on the addition of the non-canonical amino acid to the growth medium. Therefore it seems possible that an interaction of Aha1 with Hsp90 takes place at different positions than previously described in vitro highlighting the importance of in vivo techniques to study protein-protein interactions. Accordingly, the expanded genetic code can easily be applied to other S. cerevisiae proteins to study their interaction under physiological relevant conditions in vivo. PMID:24614167

Effects of Stress Related to the Gulf Oil Spill on Child and Adolescent Mental Health.

PubMed

Osofsky, Joy D; Osofsky, Howard J; Weems, Carl F; Hansel, Tonya C; King, Lucy S

2016-01-01

To examine the interactive effects of stress related to the Gulf oil spill on mental health of children and adolescents on the Gulf Coast who were also affected by previous hurricanes. A prospective design, with n = 1,577 youth (aged 3-18 years), evaluated pre-oil spill and again post-oil spill for posttraumatic stress disorder (PTSD) symptoms, previous hurricane exposure, and amount of oil spill stress. Stressors related to the spill were common and were associated with PTSD symptoms. Moreover, there was an interactive effect such that those with high preexisting PTSD symptoms, high previous hurricane exposure, and high oil spill stress had the most elevated post-oil spill PTSD symptoms. This study provides initial evidence linking stress related to the Gulf oil spill to youth mental health symptoms. The effects of the oil spill on youth mental health were most evident among those with cumulative risk. © The Author 2014. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Optimizing immobilized enzyme performance in cell-free environments to produce liquid fuels.

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

Kumar, Sanat

The overall goal of this project was to optimize enzyme performance for the production of bio-diesel fuel. Enzyme immobilization has attracted much attention as a means to increase productivity. Mesorporous silica materials have been known to be best suited for immobilizing enzymes. A major challenge is to ensure that the enzymatic activity is retained after immobilization. Two major factors which drive enzymatic deactivation are protein-surface and inter-protein interactions. Previously, we studied protein stability inside pores and how to optimize protein-surface interactions to minimize protein denaturation. In this work we studied eh effect of surface curvature and chemistry on inter-protein interactions.more » Our goal was to find suitable immobilization supports which minimize these inter-protein interactions. Our studies carried out in the frame work of Hydrophobic-Polar (HP) model showed that enzymes immobilized inside hydrophobic pores of optimal sizes are best suited to minimize these inter-protein interactions. Besides, this study is also of biological importance to understand the role of chaperonins in protein disaggregation. Both of these aspects profited immensely with collaborations with our experimental colleague, Prof. Georges Belfort (RPI), who performed the experimental analog of our theoretical works.« less

The interaction between NOLC1 and IAV NS1 protein promotes host cell apoptosis and reduces virus replication.

PubMed

Zhu, Chunyu; Zheng, Fangliang; Zhu, Junfeng; Liu, Meichen; Liu, Na; Li, Xue; Zhang, Li; Deng, Zaidong; Zhao, Qi; Liu, Hongsheng

2017-11-07

NS1 of the influenza virus plays an important role in the infection ability of the influenza virus. Our previous research found that NS1 protein interacts with the NOLC1 protein of host cells, however, the function of the interaction is unknown. In the present study, the role of the interaction between the two proteins in infection was further studied. Several analyses, including the use of a pull-down assay, Co-IP, western blot analysis, overexpression, RNAi, flow cytometry, etc., were used to demonstrate that the NS1 protein of H3N2 influenza virus interacts with host protein NOLC1 and reduces the quantity of NOLC1. The interaction also promotes apoptosis in A549 host cells, while the suppression of NOLC1 protein reduces the proliferation of the H3N2 virus. Based on these data, it was concluded that during the process of infection, NS1 protein interacts with NOLC1 protein, reducing the level of NOLC1, and that the interaction between the two proteins promotes apoptosis of host cells, thus reducing the proliferation of the virus. These findings provide new information on the biological function of the interaction between NS1 and NOLC1.

Genome-wide assessment of gene-by-smoking interactions in COPD.

PubMed

Park, Boram; Koo, So-My; An, Jaehoon; Lee, MoonGyu; Kang, Hae Yeon; Qiao, Dandi; Cho, Michael H; Sung, Joohon; Silverman, Edwin K; Yang, Hyeon-Jong; Won, Sungho

2018-06-18

Cigarette smoke exposure is a major risk factor in chronic obstructive pulmonary disease (COPD) and its interactions with genetic variants could affect lung function. However, few gene-smoking interactions have been reported. In this report, we evaluated the effects of gene-smoking interactions on lung function using Korea Associated Resource (KARE) data with the spirometric variables-forced expiratory volume in 1 s (FEV 1 ). We found that variations in FEV 1 were different among smoking status. Thus, we considered a linear mixed model for association analysis under heteroscedasticity according to smoking status. We found a previously identified locus near SOX9 on chromosome 17 to be the most significant based on a joint test of the main and interaction effects of smoking. Smoking interactions were replicated with Gene-Environment of Interaction and phenotype (GENIE), Multi-Ethnic Study of Atherosclerosis-Lung (MESA-Lung), and COPDGene studies. We found that individuals with minor alleles, rs17765644, rs17178251, rs11870732, and rs4793541, tended to have lower FEV 1 values, and lung function decreased much faster with age for smokers. There have been very few reports to replicate a common variant gene-smoking interaction, and our results revealed that statistical models for gene-smoking interaction analyses should be carefully selected.

Solar Filament Longitudinal Oscillations along a Magnetic Field Tube with Two Dips

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

Zhou Yu-Hao; Zhang Li-Yue; Ouyang, Y.

Large-amplitude longitudinal oscillations of solar filaments have been observed and explored for more than ten years. Previous studies are mainly based on the one-dimensional rigid flux tube model with a single magnetic dip. However, it has been noted that there might be two magnetic dips, and hence two threads, along one magnetic field line. Following previous work, we intend to investigate the kinematics of the filament longitudinal oscillations when two threads are magnetically connected, which is done by solving one-dimensional radiative hydrodynamic equations with the numerical code MPI-AMRVAC. Two different types of perturbations are considered, and the difference from previousmore » works resulting from the interaction of the two filament threads is investigated. We find that even with the inclusion of the thread–thread interaction, the oscillation period is modified weakly, by at most 20% compared to the traditional pendulum model with one thread. However, the damping timescale is significantly affected by the thread–thread interaction. Hence, we should take it into account when applying the consistent seismology to the filaments where two threads are magnetically connected.« less

Radiative and Physiological Effects of Increased CO2: How Does This Interaction Affect Climate?

NASA Technical Reports Server (NTRS)

Bounoua, Lahouari

2011-01-01

Several climate models indicate that in a 2xCO2 environment, temperature and precipitation would increase and runoff would increase faster than precipitation. These models, however, did not allow the vegetation to increase its leaf density as a response to the physiological effects of increased CO2 and consequent changes in climate. Other assessments included these interactions but did not account for the vegetation downregulation to reduce plant's photosynthetic activity and as such resulted in a weak vegetation negative response. When we combine these interactions in climate simulations with 2xCO2, the associated increase in precipitation contributes primarily to increase evapotranspiration rather than surface runoff, consistent with observations, and results in an additional cooling effect not fully accounted for in previous 2xCO2 simulations. By accelerating the water cycle, this feedback slows but does not alleviate the projected warming, reducing the land surface warming by 0.6 C. Compared to previous studies, these results imply that long term negative feedback from CO2-induced increases in vegetation density could reduce temperature following a stabilization of CO2 concentration.

CACTI: Free, Open-Source Software for the Sequential Coding of Behavioral Interactions

PubMed Central

Glynn, Lisa H.; Hallgren, Kevin A.; Houck, Jon M.; Moyers, Theresa B.

2012-01-01

The sequential analysis of client and clinician speech in psychotherapy sessions can help to identify and characterize potential mechanisms of treatment and behavior change. Previous studies required coding systems that were time-consuming, expensive, and error-prone. Existing software can be expensive and inflexible, and furthermore, no single package allows for pre-parsing, sequential coding, and assignment of global ratings. We developed a free, open-source, and adaptable program to meet these needs: The CASAA Application for Coding Treatment Interactions (CACTI). Without transcripts, CACTI facilitates the real-time sequential coding of behavioral interactions using WAV-format audio files. Most elements of the interface are user-modifiable through a simple XML file, and can be further adapted using Java through the terms of the GNU Public License. Coding with this software yields interrater reliabilities comparable to previous methods, but at greatly reduced time and expense. CACTI is a flexible research tool that can simplify psychotherapy process research, and has the potential to contribute to the improvement of treatment content and delivery. PMID:22815713

Analysis of three-phase equilibrium conditions for methane hydrate by isometric-isothermal molecular dynamics simulations.

PubMed

Yuhara, Daisuke; Brumby, Paul E; Wu, David T; Sum, Amadeu K; Yasuoka, Kenji

2018-05-14

To develop prediction methods of three-phase equilibrium (coexistence) conditions of methane hydrate by molecular simulations, we examined the use of NVT (isometric-isothermal) molecular dynamics (MD) simulations. NVT MD simulations of coexisting solid hydrate, liquid water, and vapor methane phases were performed at four different temperatures, namely, 285, 290, 295, and 300 K. NVT simulations do not require complex pressure control schemes in multi-phase systems, and the growth or dissociation of the hydrate phase can lead to significant pressure changes in the approach toward equilibrium conditions. We found that the calculated equilibrium pressures tended to be higher than those reported by previous NPT (isobaric-isothermal) simulation studies using the same water model. The deviations of equilibrium conditions from previous simulation studies are mainly attributable to the employed calculation methods of pressure and Lennard-Jones interactions. We monitored the pressure in the methane phase, far from the interfaces with other phases, and confirmed that it was higher than the total pressure of the system calculated by previous studies. This fact clearly highlights the difficulties associated with the pressure calculation and control for multi-phase systems. The treatment of Lennard-Jones interactions without tail corrections in MD simulations also contributes to the overestimation of equilibrium pressure. Although improvements are still required to obtain accurate equilibrium conditions, NVT MD simulations exhibit potential for the prediction of equilibrium conditions of multi-phase systems.

Analysis of three-phase equilibrium conditions for methane hydrate by isometric-isothermal molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Yuhara, Daisuke; Brumby, Paul E.; Wu, David T.; Sum, Amadeu K.; Yasuoka, Kenji

2018-05-01

To develop prediction methods of three-phase equilibrium (coexistence) conditions of methane hydrate by molecular simulations, we examined the use of NVT (isometric-isothermal) molecular dynamics (MD) simulations. NVT MD simulations of coexisting solid hydrate, liquid water, and vapor methane phases were performed at four different temperatures, namely, 285, 290, 295, and 300 K. NVT simulations do not require complex pressure control schemes in multi-phase systems, and the growth or dissociation of the hydrate phase can lead to significant pressure changes in the approach toward equilibrium conditions. We found that the calculated equilibrium pressures tended to be higher than those reported by previous NPT (isobaric-isothermal) simulation studies using the same water model. The deviations of equilibrium conditions from previous simulation studies are mainly attributable to the employed calculation methods of pressure and Lennard-Jones interactions. We monitored the pressure in the methane phase, far from the interfaces with other phases, and confirmed that it was higher than the total pressure of the system calculated by previous studies. This fact clearly highlights the difficulties associated with the pressure calculation and control for multi-phase systems. The treatment of Lennard-Jones interactions without tail corrections in MD simulations also contributes to the overestimation of equilibrium pressure. Although improvements are still required to obtain accurate equilibrium conditions, NVT MD simulations exhibit potential for the prediction of equilibrium conditions of multi-phase systems.

Structural Enhancement of Learning

ERIC Educational Resources Information Center

Trumpower, David L.; Goldsmith, Timothy E.

2004-01-01

Structural learning aids, such as interactive overviews (IOs), have previously been shown to facilitate text comprehension and recall. In this study, we examined the effects of structural aids on learners' structural knowledge and their performance on a procedural transfer task. In Experiment 1, 90 college students were presented definitions of…

SNPs located at CpG sites modulate genome-epigenome interaction

USDA-ARS?s Scientific Manuscript database

DNA methylation is an important molecular-level phenotype that links genotypes and complex disease traits. Previous studies have found local correlation between genetic variants and DNA methylation levels (cis-meQTLs). However, general mechanisms underlying cis-meQTLs are unclear. We conducted a cis...

Lifestyle in progression from hypertensive disorders of pregnancy to chronic hypertension in Nurses' Health Study II: observational cohort study.

PubMed

Timpka, Simon; Stuart, Jennifer J; Tanz, Lauren J; Rimm, Eric B; Franks, Paul W; Rich-Edwards, Janet W

2017-07-12

Objectives  To study the association between lifestyle risk factors and chronic hypertension by history of hypertensive disorders of pregnancy (HDP: gestational hypertension and pre-eclampsia) and investigate the extent to which these risk factors modify the association between HDP and chronic hypertension. Design  Prospective cohort study. Setting  Nurses' Health Study II (1991-2013). Participants  54 588 parous women aged 32 to 59 years with data on reproductive history and without previous chronic hypertension, stroke, or myocardial infarction. Main outcome measure  Chronic hypertension diagnosed by a physician and indicated through nurse participant self report. Multivariable Cox proportional hazards models were used to investigate the development of chronic hypertension contingent on history of HDP and four lifestyle risk factors: post-pregnancy body mass index, physical activity, adherence to the Dietary Approaches to Stop Hypertension (DASH) diet, and dietary sodium/potassium intake. Potential effect modification (interaction) between each lifestyle factor and previous HDP was evaluated with the relative excess risk due to interaction. Results  10% (n=5520) of women had a history of HDP at baseline. 13 971 cases of chronic hypertension occurred during 689 988 person years of follow-up. Being overweight or obese was the only lifestyle factor consistently associated with higher risk of chronic hypertension. Higher body mass index, in particular, also increased the risk of chronic hypertension associated with history of HDP (relative excess risk due to interaction P<0.01 for all age strata). For example, in women aged 40-49 years with previous HDP and obesity class I (body mass index 30.0-34.9), 25% (95% confidence interval 12% to 37%) of the risk of chronic hypertension was attributable to a potential effect of obesity that was specific to women with previous HDP. There was no clear evidence of effect modification by physical activity, DASH diet, or sodium/potassium intake on the association between HDP and chronic hypertension. Conclusion  This study suggests that the risk of chronic hypertension after HDP might be markedly reduced by adherence to a beneficial lifestyle. Compared with women without a history of HDP, keeping a healthy weight seems to be especially important with such a history.

Social risky decision-making reveals gender differences in the TPJ: A hyperscanning study using functional near-infrared spectroscopy.

PubMed

Zhang, Mingming; Liu, Tao; Pelowski, Matthew; Jia, Huibin; Yu, Dongchuan

2017-12-01

Previous neuroscience studies have investigated neural correlates of risky decision-making in a single-brain frame during pseudo social (predominantly non face-to-face) contexts. To fully understand the risky decision-making behavior in more natural social interactions, the present study employed a functional near-infrared spectroscopy (fNIRS) hyperscanning technique to simultaneously measure pairs of participants' fronto-temporal activations in a face-to-face gambling card-game. The intra-brain results revealed that both those who identified as males and as females showed higher activations in their mPFC and in the inferior parts of the frontopolar area, as well as in the tempo-parietal junction (TPJ) in cases involving higher versus lower risk. This is consistent with previous findings suggesting importance of the mentalizing network in decision tasks. The fNIRS results of inter-brain neural synchronization (INS) also revealed that males and females showed increased inter-brain coherence in the mPFC and dlPFC. Females, however, uniquely showed increased inter-brain coherence in the left TPJ. This INS result suggests that males may primarily depend on non-social cognitive ability to make a risky decision in a social interaction, while females may use both social and non-social cognitive abilities. The implications are also discussed for general topics of human interaction and two-person neuroscience. Copyright © 2017 Elsevier Inc. All rights reserved.

Cr(3+) Binding to DNA Backbone Phosphate and Bases: Slow Ligand Exchange Rates and Metal Hydrolysis.

PubMed

Zhou, Wenhu; Yu, Tianmeng; Vazin, Mahsa; Ding, Jinsong; Liu, Juewen

2016-08-15

The interaction between chromium ions and DNA is of great interest in inorganic chemistry, toxicology, and analytical chemistry. Most previous studies focused on in situ reduction of Cr(VI), producing Cr(3+) for DNA binding. Recently, Cr(3+) was reported to activate the Ce13d DNAzyme for RNA cleavage. Herein, the Ce13d is used to study two types of Cr(3+) and DNA interactions. First, Cr(3+) binds to the DNA phosphate backbone weakly through reversible electrostatic interactions, which is weakened by adding competing inorganic phosphate. However, Cr(3+) coordinates with DNA nucleobases forming stable cross-links that can survive denaturing gel electrophoresis condition. The binding of Cr(3+) to different nucleobases was further studied in terms of binding kinetics and affinity by exploiting carboxyfluorescein-labeled DNA homopolymers. Once binding takes place, the stable Cr(3+)/DNA complex cannot be dissociated by EDTA, attributable to the ultraslow ligand exchange rate of Cr(3+). The binding rate follows the order of G > C > T ≈ A. Finally, Cr(3+) gradually loses its DNA binding ability after being stored at neutral or high pH, attributable to hydrolysis. This hydrolysis can be reversed by lowering the pH. This work provides a deeper insight into the bioinorganic chemistry of Cr(3+) coordination with DNA, clarifies some inconsistency in the previous literature, and offers practically useful information for generating reproducible results.

The relationships of gender, ethnicity, past performance, pedagogy, and access to a role model/mentor with college student attitudes toward science

NASA Astrophysics Data System (ADS)

Kennedy-Hagan, Karla Jean

The purpose of this study was to explore the relationships of gender, ethnicity, past performance in science, experience with teaching pedagogy, and access to a role model/mentor with freshmen college student attitudes toward science. Specifically, the researcher wanted to know the relationship between these variables and incoming attitudes toward science at the beginning of the semester. The sample for this study consisted of 316 freshmen students enrolled in an entry-level chemistry course at a large midwestern university. The results indicate that students who received higher grades in previous science courses possessed more positive attitudes regarding their ability to perform in science compared to less successful students. Similarly, students who had previous exposure to interactive teaching pedagogy possessed more positive attitudes toward the use of interactive teaching pedagogy; felt supported by various people, including their teachers; and had more positive attitudes toward their personal world view of science compared to students that had not been exposed to interactive teaching pedagogy. Finally, the results indicated that attitudes toward science are multidimensional, meaning there is more than one attitude toward science. The results of this study add to the literature regarding attitudes toward science in freshmen students at a large midwestern university. Additional discussion and research is warranted. Specific recommendations for practice and future research are included in the document.

Probing the interaction of bisintercalating (2,2':6',2″-terpyridine)platinum(II) complexes with glutathione and rabbit plasma.

PubMed

Harper, Benjamin W J; Morris, Thomas T; Gailer, Jürgen; Aldrich-Wright, Janice R

2016-10-01

Platinum(II) complexes have demonstrated considerable success in the treatment of cancer, but severe toxic side effects drive the search for new complexes with increased tumour selectivity and better efficacy. A critical concept that has to be considered in the context of designing novel Pt complexes is their interactions with biomolecules other than DNA. To this end, here the interactions of 16 previously reported bisintercalating (2,2':6',2″-terpyridine)platinum(II) complexes, [{Pt(terpy)} 2 μ-(X)] n+ (where X is a linker) with glutathione (GSH) by means of 1 H and 195 Pt NMR spectroscopy were investigated. The GSH half-life (GSH t 1/2 ) was determined following the incubation of each [{Pt(terpy)} 2 μ-(X)] n+ complex with GSH (8mM). It was observed that complexes 1-7, 11, 12 and 14-16 reacted more rapidly than cisplatin, whereas complexes 8-10, 13 and 17 reacted more slowly (≥200min). There was no apparent correlation between linker length and the GSH t 1/2 . In order to understand these interactions, two complexes: 1 (t 1/2 <1min) and a previously studied 17 [Pt(5,6-dimethyl-1,10-phenanthroline)(1S,2S-diaminocyclohexane)] (56MESS) (GSH t 1/2 =4080min) were incubated with rabbit plasma. A "metallomics" approach was used to analyse plasma for all platinum species at the 5 and the 60min time point and provided results that were congruent with the reaction of the selected Pt complexes with GSH. Our studies demonstrate that the combined application of NMR spectroscopy, cytotoxicity studies and a metallomics approach can contribute to better understand the interaction of [{Pt(terpy)} 2 μ-(X)] n+ complexes with biomolecules to better assess which compounds may be advanced to in vivo studies. Copyright © 2016 Elsevier Inc. All rights reserved.

Student use of a Learning Management System for group projects: A case study investigating interaction, collaboration, and knowledge construction

NASA Astrophysics Data System (ADS)

Lonn, Steven D.

Web-based Learning Management Systems (LMS) allow instructors and students to share instructional materials, make class announcements, submit and return course assignments, and communicate with each other online. Previous LMS-related research has focused on how these systems deliver and manage instructional content with little concern for how students' constructivist learning can be encouraged and facilitated. This study investigated how students use LMS to interact, collaborate, and construct knowledge within the context of a group project but without mediation by the instructor. The setting for this case study was students' use in one upper-level biology course of the local LMS within the context of a course-related group project, a mock National Institutes of Health grant proposal. Twenty-one groups (82 students) voluntarily elected to use the LMS, representing two-thirds of all students in the course. Students' peer-to-peer messages within the LMS, event logs, online surveys, focus group interviews, and instructor interviews were used in order to answer the study's overarching research question. The results indicate that students successfully used the LMS to interact and, to a significant extent, collaborate, but there was very little evidence of knowledge construction using the LMS technology. It is possible that the ease and availability of face-to-face meetings as well as problems and limitations with the technology were factors that influenced whether students' online basic interaction could be further distinguished as collaboration or knowledge construction. Despite these limitations, students found several tools and functions of the LMS useful for their online peer interaction and completion of their course project. Additionally, LMS designers and implementers are urged to consider previous literature on computer-supported collaborative learning environments in order to better facilitate independent group projects within these systems. Further research is needed to identify the best types of scaffolds and overall technological improvements in order to provide support for online collaboration and knowledge construction.

Gene-Environment Interaction Effects of Peer Deviance, Parental Knowledge and Stressful Life Events on Adolescent Alcohol Use.

PubMed

Cooke, Megan E; Meyers, Jacquelyn L; Latvala, Antti; Korhonen, Tellervo; Rose, Richard J; Kaprio, Jaakko; Salvatore, Jessica E; Dick, Danielle M

2015-10-01

The purpose of this study was to address two methodological issues that have called into question whether previously reported gene-environment interaction (GxE) effects for adolescent alcohol use are 'real'. These issues are (1) the potential correlation between the environmental moderator and the outcome across twins and (2) non-linear transformations of the behavioral outcome. Three environments that have been previously studied (peer deviance, parental knowledge, and potentially stressful life events) were examined here. For each moderator (peer deviance, parental knowledge, and potentially stressful life events), a series of models was fit to both a raw and transformed measure of monthly adolescent alcohol use in a sample that included 825 dizygotic (DZ) and 803 monozygotic (MZ) twin pairs. The results showed that the moderating effect of peer deviance was robust to transformation, and that although the significance of moderating effects of parental knowledge and potentially stressful life events were dependent on the scale of the adolescent alcohol use outcome, the overall results were consistent across transformation. In addition, the findings did not vary across statistical models. The consistency of the peer deviance results and the shift of the parental knowledge and potentially stressful life events results between trending and significant, shed some light on why previous findings for certain moderators have been inconsistent and emphasize the importance of considering both methodological issues and previous findings when conducting and interpreting GxE analyses.

Mechanical stabilization of proteolytically degradable polyethylene glycol dimethacrylate hydrogels through peptide interaction.

PubMed

Lim, Hyun Ju; Khan, Zara; Lu, Xi; Perera, T Hiran; Wilems, Thomas S; Ravivarapu, Krishna T; Smith Callahan, Laura A

2018-04-15

Balancing enhancement of neurite extension against loss of matrix support in synthetic hydrogels containing proteolytically degradable and bioactive signaling peptides to optimize tissue formation is difficult. Using a systematic approach, polyethylene glycol hydrogels containing concurrent continuous concentration gradients of the laminin derived bioactive signaling peptide, Ile-Lys-Val-Ala-Val (IKVAV), and collagen derived matrix metalloprotease degradable peptide, GPQGIWGQ, were fabricated and characterized. During proteolytic degradation of the concentration gradient hydrogels, the IKVAV and IWGQ cleavage fragment from GPQGIWGQ were found to interact and stabilize the bulk Young's Modulus of the hydrogel. Further testing of discrete samples containing GPQGIWGQ or its cleavage fragments, GPQG and IWGQ, indicates hydrophobic interactions between the peptides are not necessary for mechanical stabilization of the hydrogel, but changes in the concentration ratio between the peptides tethered in the hydrogel and salts and ions in the swelling solution can affect the stabilization. Encapsulation of human induced pluripotent stem cell derived neural stem cells did not reduce the mechanical properties of the hydrogel over a 14 day neural differentiation culture period, and IKVAV was found to maintain concentration dependent effects on neurite extension and mRNA gene expression of neural cytoskeletal markers, similar to previous studies. As a result, this work has significant implications for the analysis of biological studies in matrices, as the material and mechanical properties of the hydrogel may be unexpectedly temporally changing during culture due to interactions between peptide signaling elements, underscoring the need for greater matrix characterization during the degradation and cell culture. Greater emulation of the native extracellular matrix is necessary for tissue formation. To achieve this, matrices are becoming more complex, often including multiple bioactive signaling elements. However, peptide signaling in polyethylene glycol matrices and amino acids interactions between peptides can affect hydrogel material and mechanical properties, but are rarely studied. The current study identifies such an interaction between laminin derived peptide, IKVAV, and collagen derived matrix metalloprotease degradable peptide, GPQGIWGQ. Previous studies using these peptides did not identify their interactions' ability to mechanically stabilize the hydrogel during degradation. This work underscores the need for greater matrix characterization and consideration of bioactive signaling element effects temporally on the matrix's material and mechanical properties, as they can contribute to cellular response. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Combustion of Interacting Droplet Arrays in a Microgravity Environment

NASA Technical Reports Server (NTRS)

Dietrich, D. L.; Struk, P. M.; Ikegami, M.; Nagaishi, H.; Honma, S.; Ikeda, K.

2001-01-01

Investigations into droplet interactions date back to Rex et al. Annamalai and Ryan and Annamalai published extensive reviews of droplet array and cloud combustion studies. In the majority of the reviewed studies, the authors examined the change in the burning rate constant, k, (relative to that of the single droplet) that results from interactions. More recently, Niioka and co-workers have examined ignition and flame propagation along arrays of interacting droplets with the goal of relating these phenomena in this simplified geometry to the more practical spray configuration. Our work has focussed on droplet interactions under conditions where flame extinction occurs at a finite droplet diameter. In our previous work, we reported that in normal gravity, reduced pressure conditions, droplet interactions improved flame stability and extended flammability limits (by inference). In our recent work, we examine droplet interactions under conditions where the flame extinguishes at a finite droplet diameter in microgravity. The microgravity experiments were in the NASA GRC 2.2 and 5.2 second drop towers, and the JAMIC (Japan Microgravity Center) 10 second drop tower. We also present progress on a numerical model of single droplet combustion that is in the process of being extended to model a binary droplet array.

Structural complexity of Dengue virus untranslated regions: cis-acting RNA motifs and pseudoknot interactions modulating functionality of the viral genome

PubMed Central

Sztuba-Solinska, Joanna; Teramoto, Tadahisa; Rausch, Jason W.; Shapiro, Bruce A.; Padmanabhan, Radhakrishnan; Le Grice, Stuart F. J.

2013-01-01

The Dengue virus (DENV) genome contains multiple cis-acting elements required for translation and replication. Previous studies indicated that a 719-nt subgenomic minigenome (DENV-MINI) is an efficient template for translation and (−) strand RNA synthesis in vitro. We performed a detailed structural analysis of DENV-MINI RNA, combining chemical acylation techniques, Pb2+ ion-induced hydrolysis and site-directed mutagenesis. Our results highlight protein-independent 5′–3′ terminal interactions involving hybridization between recognized cis-acting motifs. Probing analyses identified tandem dumbbell structures (DBs) within the 3′ terminus spaced by single-stranded regions, internal loops and hairpins with embedded GNRA-like motifs. Analysis of conserved motifs and top loops (TLs) of these dumbbells, and their proposed interactions with downstream pseudoknot (PK) regions, predicted an H-type pseudoknot involving TL1 of the 5′ DB and the complementary region, PK2. As disrupting the TL1/PK2 interaction, via ‘flipping’ mutations of PK2, previously attenuated DENV replication, this pseudoknot may participate in regulation of RNA synthesis. Computer modeling implied that this motif might function as autonomous structural/regulatory element. In addition, our studies targeting elements of the 3′ DB and its complementary region PK1 indicated that communication between 5′–3′ terminal regions strongly depends on structure and sequence composition of the 5′ cyclization region. PMID:23531545

The Interaction of TXNIP and AFq1 Genes Increases the Susceptibility of Schizophrenia.

PubMed

Su, Yousong; Ding, Wenhua; Xing, Mengjuan; Qi, Dake; Li, Zezhi; Cui, Donghong

2017-08-01

Although previous studies showed the reduced risk of cancer in patients with schizophrenia, whether patients with schizophrenia possess genetic factors that also contribute to tumor suppressor is still unknown. In the present study, based on our previous microarray data, we focused on the tumor suppressor genes TXNIP and AF1q, which differentially expressed in patients with schizophrenia. A total of 413 patients and 578 healthy controls were recruited. We found no significant differences in genotype, allele, or haplotype frequencies at the selected five single nucleotide polymorphisms (SNPs) (rs2236566 and rs7211 in TXNIP gene; rs10749659, rs2140709, and rs3738481 in AF1q gene) between patients with schizophrenia and controls. However, we found the association between the interaction of TXNIP and AF1q with schizophrenia by using the MDR method followed by traditional statistical analysis. The best gene-gene interaction model identified was a three-locus model TXNIP (rs2236566, rs7211)-AF1q (rs2140709). After traditional statistical analysis, we found the high-risk genotype combination was rs2236566 (GG)-rs7211(CC)-rs2140709(CC) (OR = 1.35 [1.03-1.76]). The low-risk genotype combination was rs2236566 (GT)-rs7211(CC)-rs2140709(CC) (OR = 0.67 [0.49-0.91]). Our finding suggested statistically significant role of interaction of TXNIP and AF1q polymorphisms (TXNIP-rs2236566, TXNIP-rs7211, and AF1q-rs2769605) in schizophrenia susceptibility.

Spatial proximity between the VPAC1 receptor and the amino terminus of agonist and antagonist peptides reveals distinct sites of interaction.

PubMed

Ceraudo, Emilie; Hierso, Régine; Tan, Yossan-Var; Murail, Samuel; Rouyer-Fessard, Christiane; Nicole, Pascal; Robert, Jean-Claude; Jamin, Nadège; Neumann, Jean-Michel; Robberecht, Patrick; Laburthe, Marc; Couvineau, Alain

2012-05-01

Vasoactive intestinal peptide (VIP) plays a major role in pathophysiology. Our previous studies demonstrated that the VIP sequence 6-28 interacts with the N-terminal ectodomain (N-ted) of its receptor, VPAC1. Probes for VIP and receptor antagonist PG97-269 were synthesized with a photolabile residue/Bpa at various positions and used to explore spatial proximity with VPAC1. PG97-269 probes with Bpa at position 0, 6, and 24 behaved as high-affinity receptor antagonists (K(i)=12, 9, and 7 nM, respectively). Photolabeling experiments revealed that the [Bpa(0)]-VIP probe was in physical contact with VPAC1 Q(135), while [Bpa(0)]-PG97-269 was covalently bound to G(62) residue of N-ted, indicating different binding sites. In contrast, photolabeling with [Bpa(6)]- and [Bpa(24)]-PG97-269 showed that the distal domains of PG97-269 interacted with N-ted, as we previously showed for VIP. Substitution with alanine of the K(143), T(144), and T(147) residues located in the first transmembrane domain of VPAC1 induced a loss of receptor affinity (IC(50)=1035, 874, and 2070 nM, respectively), and pharmacological studies using VIP2-28 indicated that these three residues play an important role in VPAC1 interaction with the first histidine residue of VIP. These data demonstrate that VIP and PG97-269 bind to distinct domains of VPAC1.

Envelope Interactions in Multi-Channel Amplitude Modulation Frequency Discrimination by Cochlear Implant Users.

PubMed

Galvin, John J; Oba, Sandra I; Başkent, Deniz; Chatterjee, Monita; Fu, Qian-Jie

2015-01-01

Previous cochlear implant (CI) studies have shown that single-channel amplitude modulation frequency discrimination (AMFD) can be improved when coherent modulation is delivered to additional channels. It is unclear whether the multi-channel advantage is due to increased loudness, multiple envelope representations, or to component channels with better temporal processing. Measuring envelope interference may shed light on how modulated channels can be combined. In this study, multi-channel AMFD was measured in CI subjects using a 3-alternative forced-choice, non-adaptive procedure ("which interval is different?"). For the reference stimulus, the reference AM (100 Hz) was delivered to all 3 channels. For the probe stimulus, the target AM (101, 102, 104, 108, 116, 132, 164, 228, or 256 Hz) was delivered to 1 of 3 channels, and the reference AM (100 Hz) delivered to the other 2 channels. The spacing between electrodes was varied to be wide or narrow to test different degrees of channel interaction. Results showed that CI subjects were highly sensitive to interactions between the reference and target envelopes. However, performance was non-monotonic as a function of target AM frequency. For the wide spacing, there was significantly less envelope interaction when the target AM was delivered to the basal channel. For the narrow spacing, there was no effect of target AM channel. The present data were also compared to a related previous study in which the target AM was delivered to a single channel or to all 3 channels. AMFD was much better with multiple than with single channels whether the target AM was delivered to 1 of 3 or to all 3 channels. For very small differences between the reference and target AM frequencies (2-4 Hz), there was often greater sensitivity when the target AM was delivered to 1 of 3 channels versus all 3 channels, especially for narrowly spaced electrodes. Besides the increased loudness, the present results also suggest that multiple envelope representations may contribute to the multi-channel advantage observed in previous AMFD studies. The different patterns of results for the wide and narrow spacing suggest a peripheral contribution to multi-channel temporal processing. Because the effect of target AM frequency was non-monotonic in this study, adaptive procedures may not be suitable to measure AMFD thresholds with interfering envelopes. Envelope interactions among multiple channels may be quite complex, depending on the envelope information presented to each channel and the relative independence of the stimulated channels.

Envelope Interactions in Multi-Channel Amplitude Modulation Frequency Discrimination by Cochlear Implant Users

PubMed Central

2015-01-01

Rationale Previous cochlear implant (CI) studies have shown that single-channel amplitude modulation frequency discrimination (AMFD) can be improved when coherent modulation is delivered to additional channels. It is unclear whether the multi-channel advantage is due to increased loudness, multiple envelope representations, or to component channels with better temporal processing. Measuring envelope interference may shed light on how modulated channels can be combined. Methods In this study, multi-channel AMFD was measured in CI subjects using a 3-alternative forced-choice, non-adaptive procedure (“which interval is different?”). For the reference stimulus, the reference AM (100 Hz) was delivered to all 3 channels. For the probe stimulus, the target AM (101, 102, 104, 108, 116, 132, 164, 228, or 256 Hz) was delivered to 1 of 3 channels, and the reference AM (100 Hz) delivered to the other 2 channels. The spacing between electrodes was varied to be wide or narrow to test different degrees of channel interaction. Results Results showed that CI subjects were highly sensitive to interactions between the reference and target envelopes. However, performance was non-monotonic as a function of target AM frequency. For the wide spacing, there was significantly less envelope interaction when the target AM was delivered to the basal channel. For the narrow spacing, there was no effect of target AM channel. The present data were also compared to a related previous study in which the target AM was delivered to a single channel or to all 3 channels. AMFD was much better with multiple than with single channels whether the target AM was delivered to 1 of 3 or to all 3 channels. For very small differences between the reference and target AM frequencies (2–4 Hz), there was often greater sensitivity when the target AM was delivered to 1 of 3 channels versus all 3 channels, especially for narrowly spaced electrodes. Conclusions Besides the increased loudness, the present results also suggest that multiple envelope representations may contribute to the multi-channel advantage observed in previous AMFD studies. The different patterns of results for the wide and narrow spacing suggest a peripheral contribution to multi-channel temporal processing. Because the effect of target AM frequency was non-monotonic in this study, adaptive procedures may not be suitable to measure AMFD thresholds with interfering envelopes. Envelope interactions among multiple channels may be quite complex, depending on the envelope information presented to each channel and the relative independence of the stimulated channels. PMID:26431043

Increasing the Use of Empathic Statements in the Presence of a Non-Verbal Affective Stimulus in Adolescents with Autism

ERIC Educational Resources Information Center

Argott, Paul; Townsend, Dawn Buffington; Sturmey, Peter; Poulson, Claire L.

2008-01-01

Previous studies have shown that most individuals with autism do not show empathic responding. The present study is an attempt to teach such skills. Script-fading procedures have been used to teach other social-interaction skills, so they are applied here to teach empathic responding. This study included three adolescents with autism, two males…

α7nAchR/NMDAR coupling affects NMDAR function and object recognition.

PubMed

Li, Shupeng; Nai, Qiang; Lipina, Tatiana V; Roder, John C; Liu, Fang

2013-12-20

The α7 nicotinic acetylcholine receptor (nAchR) and NMDA glutamate receptor (NMDAR) are both ligand-gated ion channels permeable to Ca2+ and Na+. Previous studies have demonstrated functional modulation of NMDARs by nAchRs, although the molecular mechanism remains largely unknown. We have previously reported that α7nAchR forms a protein complex with the NMDAR through a protein-protein interaction. We also developed an interfering peptide that is able to disrupt the α7nAchR-NMDAR complex and blocks cue-induced reinstatement of nicotine-seeking in rat models of relapse. In the present study, we investigated whether the α7nAchR-NMDAR interaction is responsible for the functional modulation of NMDAR by α7nAchR using both electrophysiological and behavioral tests. We have found that activation of α7nAchR upregulates NMDAR-mediated whole cell currents and LTP of mEPSC in cultured hippocampal neurons, which can be abolished by the interfering peptide that disrupts the α7nAchR-NMDAR interaction. Moreover, administration of the interfering peptide in mice impairs novel object recognition but not Morris water maze performance. Our results suggest that α7nAchR/NMDAR coupling may selectively affect some aspects of learning and memory.

A peptide disrupting the D2R-DAT interaction protects against dopamine neurotoxicity.

PubMed

Su, Ping; Liu, Fang

2017-09-01

Dopamine reuptake from extracellular space to cytosol leads to accumulation of dopamine, which triggers neurotoxicity in dopaminergic neurons. Previous studies have shown that both dopamine D2 receptor (D2R) and dopamine transporter (DAT) are involved in dopamine neurotoxicity. However, blockade of either D2R or DAT causes side effects due to antagonism of other physiological functions of these two proteins. We previously found that DAT can form a protein complex with D2R and its cell surface expression is facilitated via D2R-DAT interaction, which regulates dopamine reuptake and intracellular dopamine levels. Here we found that an interfering peptide (DAT-S1) disrupting the D2R-DAT interaction protects neurons against dopamine neurotoxicity, and this effect is mediated by inhibiting DAT cell surface expression and inhibiting both caspase-3 and PARP-1 cleavage. This study demonstrates the role of the D2R-DAT complex in dopamine neurotoxicity and investigated the potential mechanisms, which might help better understand the mechanisms of dopamine neurotoxicity. The peptide may provide some insights to improve treatments for dopamine neurotoxicity and related diseases, such as Parkinson's disease, as well as methamphetamine- and 3,4-methsylenedioxy methamphetamine-induced neurotoxicity. Copyright © 2017. Published by Elsevier Inc.

Network-based analysis of genotype-phenotype correlations between different inheritance modes.

PubMed

Hao, Dapeng; Li, Chuanxing; Zhang, Shaojun; Lu, Jianping; Jiang, Yongshuai; Wang, Shiyuan; Zhou, Meng

2014-11-15

Recent studies on human disease have revealed that aberrant interaction between proteins probably underlies a substantial number of human genetic diseases. This suggests a need to investigate disease inheritance mode using interaction, and based on which to refresh our conceptual understanding of a series of properties regarding inheritance mode of human disease. We observed a strong correlation between the number of protein interactions and the likelihood of a gene causing any dominant diseases or multiple dominant diseases, whereas no correlation was observed between protein interaction and the likelihood of a gene causing recessive diseases. We found that dominant diseases are more likely to be associated with disruption of important interactions. These suggest inheritance mode should be understood using protein interaction. We therefore reviewed the previous studies and refined an interaction model of inheritance mode, and then confirmed that this model is largely reasonable using new evidences. With these findings, we found that the inheritance mode of human genetic diseases can be predicted using protein interaction. By integrating the systems biology perspectives with the classical disease genetics paradigm, our study provides some new insights into genotype-phenotype correlations. haodapeng@ems.hrbmu.edu.cn or biofomeng@hotmail.com Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Elaborate cellulosome architecture of Acetivibrio cellulolyticus revealed by selective screening of cohesin-dockerin interactions.

PubMed

Hamberg, Yuval; Ruimy-Israeli, Vered; Dassa, Bareket; Barak, Yoav; Lamed, Raphael; Cameron, Kate; Fontes, Carlos M G A; Bayer, Edward A; Fried, Daniel B

2014-01-01

Cellulosic waste represents a significant and underutilized carbon source for the biofuel industry. Owing to the recalcitrance of crystalline cellulose to enzymatic degradation, it is necessary to design economical methods of liberating the fermentable sugars required for bioethanol production. One route towards unlocking the potential of cellulosic waste lies in a highly complex class of molecular machines, the cellulosomes. Secreted mainly by anaerobic bacteria, cellulosomes are structurally diverse, cell surface-bound protein assemblies that can contain dozens of catalytic components. The key feature of the cellulosome is its modularity, facilitated by the ultra-high affinity cohesin-dockerin interaction. Due to the enormous number of cohesin and dockerin modules found in a typical cellulolytic organism, a major bottleneck in understanding the biology of cellulosomics is the purification of each cohesin- and dockerin-containing component, prior to analyses of their interaction. As opposed to previous approaches, the present study utilized proteins contained in unpurified whole-cell extracts. This strategy was made possible due to an experimental design that allowed for the relevant proteins to be "purified" via targeted affinity interactions as a function of the binding assay. The approach thus represents a new strategy, appropriate for future medium- to high-throughput screening of whole genomes, to determine the interactions between cohesins and dockerins. We have selected the cellulosome of Acetivibrio cellulolyticus for this work due to its exceptionally complex cellulosome systems and intriguing diversity of its cellulosomal modular components. Containing 41 cohesins and 143 dockerins, A. cellulolyticus has one of the largest number of potential cohesin-dockerin interactions of any organism, and contains unusual and novel cellulosomal features. We have surveyed a representative library of cohesin and dockerin modules spanning the cellulosome's total cohesin and dockerin sequence diversity, emphasizing the testing of unusual and previously-unknown protein modules. The screen revealed several novel cell-bound cellulosome architectures, thus expanding on those previously known, as well as soluble cellulose systems that are not bound to the bacterial cell surface. This study sets the stage for screening the entire complement of cellulosomal components from A. cellulolyticus and other organisms with large cellulosome systems. The knowledge gained by such efforts brings us closer to understanding the exceptional catalytic abilities of cellulosomes and will allow the use of novel cellulosomal components in artificial assemblies and in enzyme cocktails for sustainable energy-related research programs.

A network meta-analysis on the effects of information technology application on preoperative knowledge of patients.

PubMed

Lai, Yi-Horng

2015-01-01

The application of information technology in health education plan in Taiwan has existed for a long time. The purpose of this study is to explore the relationship between information technology application in health education and patients' preoperative knowledge by synthesizing existing researches that compare the effectiveness of information technology application and traditional instruction in the health education plan. In spite of claims regarding the potential benefits of using information technology in health education plan, results of previous researches were conflicting. This study is carried out to examine the effectiveness of information technology by using network meta-analysis, which is a statistical analysis of separate but similar studies in order to test the pooled data for statistical significance. Information technology application in health education discussed in this study include interactive technology therapy (person-computer), group interactive technology therapy (person-person), multimedia technology therapy and video therapy. The result has shown that group interactive technology therapy is the most effective, followed by interactive technology therapy. And these four therapies of information technology are all superior to the traditional health education plan (leaflet therapy).

Electrostatic interactions and binding orientation of HIV-1 matrix studied by neutron reflectivity.

PubMed

Nanda, Hirsh; Datta, Siddhartha A K; Heinrich, Frank; Lösche, Mathias; Rein, Alan; Krueger, Susan; Curtis, Joseph E

2010-10-20

The N-terminal matrix (MA) domain of the HIV-1 Gag protein is responsible for binding to the plasma membrane of host cells during viral assembly. The putative membrane-binding interface of MA was previously mapped by means of mutagenesis and analysis of its trimeric crystal structure. However, the orientation of MA on membranes has not been directly determined by experimental measurements. We present neutron reflectivity measurements that resolve the one-dimensional scattering length density profile of MA bound to a biomimetic of the native viral membrane. A molecular refinement procedure was developed using atomic structures of MA to determine the orientation of the protein on the membrane. The orientation defines a lipid-binding interface consistent with previous mutagenesis results. The MA protein maintains this orientation without the presence of a myristate group, driven only by electrostatic interactions. Furthermore, MA is found to penetrate the membrane headgroup region peripherally such that only the side chains of specific Lys and Arg residues interact with the surface. The results suggest that electrostatic interactions are sufficient to favorably orient MA on viral membrane mimics. The spatial determination of the membrane-bound protein demonstrates the ability of neutron reflectivity to discern orientation and penetration under physiologically relevant conditions. Copyright © 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Interactome of E. piscicida and grouper liver proteins reveals strategies of bacterial infection and host immune response.

PubMed

Li, Hui; Zhu, Qing-Feng; Peng, Xuan-Xian; Peng, Bo

2017-01-03

The occurrence of infectious diseases is related to heterogeneous protein interactions between a host and a microbe. Therefore, elucidating the host-pathogen interplay is essential. We previously revealed the protein interactome between Edwardsiella piscicida and fish gill cells, and the present study identified the protein interactome between E. piscicida and E. drummondhayi liver cells. E. drummondhayi liver cells and bacterial pull-down approaches were used to identify E. piscicida outer membrane proteins that bind to liver cells and fish liver cell proteins that interact with bacterial cells, respectively. Eight bacterial proteins and 11 fish proteins were characterized. Heterogeneous protein-protein interactions between these bacterial cells and fish liver cells were investigated through far-Western blotting and co-immunoprecipitation. A network was constructed based on 42 heterogeneous protein-protein interactions between seven bacterial proteins and 10 fish proteins. A comparison of the new interactome with the previously reported interactome showed that four bacterial proteins overlapped, whereas all of the identified fish proteins were new, suggesting a difference between bacterial tricks for evading host immunity and the host strategy for combating bacterial infection. Furthermore, these bacterial proteins were found to regulate the expression of host innate immune-related proteins. These findings indicate that the interactome contributes to bacterial infection and host immunity.

Omnivore-herbivore interactions: thrips and whiteflies compete via the shared host plant.

PubMed

Pappas, Maria L; Tavlaki, Georgia; Triantafyllou, Anneta; Broufas, George

2018-03-05

Phytophagy is a common feature among pure herbivorous insects and omnivores that utilise both plant and prey as food resources; nevertheless, experimental evidence for factors affecting their interactions is restricted to intraguild predation and predator-mediated competition. We herein focused on plant-mediated effects that could result from plant defence activation or quality alteration and compared the performance of an omnivore, the western flower thrips Frankliniella occidentalis, and a pure herbivore, the greenhouse whitefly Trialeurodes vaporariorum, on cucumber plants previously infested with either species. Furthermore, we recorded their behavioural responses when given a choice among infested and clean plants. Whiteflies laid less eggs on plants previously exposed to thrips but more on whitefly-infested plants. Thrips survival was negatively affected on whitefly-infested than on thrips-infested or clean plants. Notably, whiteflies developed significantly faster on plants infested with conspecifics. In accordance, whiteflies avoided thrips-infested plants and preferred whitefly-infested over clean plants. Thrips showed no preference for either infested or clean plants. Our study is a first report on the role of plant-mediated effects in shaping omnivore-herbivore interactions. Considering the factors driving such interactions we will likely better understand the ecology of the more complex relationships among plants and pest organisms.

A Luciferase-fragment Complementation Assay to Detect Lipid Droplet-associated Protein-Protein Interactions*

PubMed Central

Kolkhof, Petra; Werthebach, Michael; van de Venn, Anna; Poschmann, Gereon; Chen, Lili; Welte, Michael; Stühler, Kai; Beller, Mathias

2017-01-01

A critical challenge for all organisms is to carefully control the amount of lipids they store. An important node for this regulation is the protein coat present at the surface of lipid droplets (LDs), the intracellular organelles dedicated to lipid storage. Only limited aspects of this regulation are understood so far. For the probably best characterized case, the regulation of lipolysis in mammals, some of the major protein players have been identified, and it has been established that this process crucially depends on an orchestrated set of protein-protein interactions. Proteomic analysis has revealed that LDs are associated with dozens, if not hundreds, of different proteins, most of them poorly characterized, with even fewer data regarding which of them might physically interact. To comprehensively understand the mechanism of lipid storage regulation, it will likely be essential to define the interactome of LD-associated proteins. Previous studies of such interactions were hampered by technical limitations. Therefore, we have developed a split-luciferase based protein-protein interaction assay and test for interactions among 47 proteins from Drosophila and from mouse. We confirmed previously described interactions and identified many new ones. In 1561 complementation tests, we assayed for interactions among 487 protein pairs of which 92 (19%) resulted in a successful luciferase complementation. These results suggest that a prominent fraction of the LD-associated proteome participates in protein-protein interactions. In targeted experiments, we analyzed the two proteins Jabba and CG9186 in greater detail. Jabba mediates the sequestration of histones to LDs. We successfully applied our split luciferase complementation assay to learn more about this function as we were e.g. able to map the interaction between Jabba and histones. For CG9186, expression levels affect the positioning of LDs. Here, we reveal the ubiquitination of CG9186, and link this posttranslational modification to LD cluster induction. PMID:27956707

Conflict and reconciliation behavior trends of the bottlenose dolphin (Tursiops truncatus).

PubMed

Holobinko, Anastasia; Waring, George H

2010-01-01

Wild bottlenose dolphin (Tursiops truncatus) populations display societal structures characterized by numerous and frequent changes in group composition, complex social relationships, and high levels of cooperation, attributes also observed in human and nonhuman primate cultures. Maintaining social relationships under such elemental conditions can frequently create conflict--and the opportunity for reconciliation--among group members. The conflict and reconciliation behavior patterns of the chimpanzee (Pan troglodytes) have been studied extensively; trends are well-documented in the wild and in captivity. Apparent cultural similarities have prompted several analogous studies on wild and captive bottlenose dolphins. This research attempted to corroborate previous efforts by analyzing the social behavior of seven captive bottlenose dolphins to determine the effects of sex and age on the frequency of conflict and reconciliation, and to investigate the incidence of consolatory behavior within the group. A total of 3,428 interactions involving focal animals, 414 of which were conflict episodes, were documented during 261 hr of videotaped observations. Although the sample size precluded meaningful statistical evaluation of the influence of sex on conflict and reconciliation, participant age was a significant determinant of conflict frequency. Conversely, age did not impact frequency of reconciliation, which only occurred after 18% of all conflict interactions. Little to no definitive evidence of consolation was apparent within the study group. While results partially support the findings of previous dolphin reconciliation research, extensive behavioral studies of wild populations should be conducted before generating broad comparisons between human terms and nonhuman behavioral interactions. © 2009 Wiley-Liss, Inc.

Music and Language Syntax Interact in Broca's Area: An fMRI Study.

PubMed

Kunert, Richard; Willems, Roel M; Casasanto, Daniel; Patel, Aniruddh D; Hagoort, Peter

2015-01-01

Instrumental music and language are both syntactic systems, employing complex, hierarchically-structured sequences built using implicit structural norms. This organization allows listeners to understand the role of individual words or tones in the context of an unfolding sentence or melody. Previous studies suggest that the brain mechanisms of syntactic processing may be partly shared between music and language. However, functional neuroimaging evidence for anatomical overlap of brain activity involved in linguistic and musical syntactic processing has been lacking. In the present study we used functional magnetic resonance imaging (fMRI) in conjunction with an interference paradigm based on sung sentences. We show that the processing demands of musical syntax (harmony) and language syntax interact in Broca's area in the left inferior frontal gyrus (without leading to music and language main effects). A language main effect in Broca's area only emerged in the complex music harmony condition, suggesting that (with our stimuli and tasks) a language effect only becomes visible under conditions of increased demands on shared neural resources. In contrast to previous studies, our design allows us to rule out that the observed neural interaction is due to: (1) general attention mechanisms, as a psychoacoustic auditory anomaly behaved unlike the harmonic manipulation, (2) error processing, as the language and the music stimuli contained no structural errors. The current results thus suggest that two different cognitive domains-music and language-might draw on the same high level syntactic integration resources in Broca's area.

Music and Language Syntax Interact in Broca’s Area: An fMRI Study

PubMed Central

Kunert, Richard; Willems, Roel M.; Casasanto, Daniel; Patel, Aniruddh D.; Hagoort, Peter

2015-01-01

Instrumental music and language are both syntactic systems, employing complex, hierarchically-structured sequences built using implicit structural norms. This organization allows listeners to understand the role of individual words or tones in the context of an unfolding sentence or melody. Previous studies suggest that the brain mechanisms of syntactic processing may be partly shared between music and language. However, functional neuroimaging evidence for anatomical overlap of brain activity involved in linguistic and musical syntactic processing has been lacking. In the present study we used functional magnetic resonance imaging (fMRI) in conjunction with an interference paradigm based on sung sentences. We show that the processing demands of musical syntax (harmony) and language syntax interact in Broca’s area in the left inferior frontal gyrus (without leading to music and language main effects). A language main effect in Broca’s area only emerged in the complex music harmony condition, suggesting that (with our stimuli and tasks) a language effect only becomes visible under conditions of increased demands on shared neural resources. In contrast to previous studies, our design allows us to rule out that the observed neural interaction is due to: (1) general attention mechanisms, as a psychoacoustic auditory anomaly behaved unlike the harmonic manipulation, (2) error processing, as the language and the music stimuli contained no structural errors. The current results thus suggest that two different cognitive domains—music and language—might draw on the same high level syntactic integration resources in Broca’s area. PMID:26536026

Diffusiophoresis of charged colloidal particles in the limit of very high salinity.

PubMed

Prieve, Dennis C; Malone, Stephanie M; Khair, Aditya S; Stout, Robert F; Kanj, Mazen Y

2018-06-13

Diffusiophoresis is the migration of a colloidal particle through a viscous fluid, caused by a gradient in concentration of some molecular solute; a long-range physical interaction between the particle and solute molecules is required. In the case of a charged particle and an ionic solute (e.g., table salt, NaCl), previous studies have predicted and experimentally verified the speed for very low salt concentrations at which the salt solution behaves ideally. The current study presents a study of diffusiophoresis at much higher salt concentrations (approaching the solubility limit). At such large salt concentrations, electrostatic interactions are almost completely screened, thus eliminating the long-range interaction required for diffusiophoresis; moreover, the high volume fraction occupied by ions makes the solution highly nonideal. Diffusiophoretic speeds were found to be measurable, albeit much smaller than for the same gradient at low salt concentrations.

Prohibitin as the Molecular Binding Switch in the Retinal Pigment Epithelium.

PubMed

Sripathi, Srinivas R; Sylvester, O'Donnell; He, Weilue; Moser, Trevor; Um, Ji-Yeon; Lamoke, Folami; Ramakrishna, Wusirika; Bernstein, Paul S; Bartoli, Manuela; Jahng, Wan Jin

2016-02-01

Previously, our molecular binding study showed that prohibitin interacts with phospholipids, including phosphatidylinositide and cardiolipin. Under stress conditions, prohibitin interacts with cardiolipin as a retrograde response to activate mitochondrial proliferation. The lipid-binding switch mechanism of prohibitin with phosphatidylinositol-3,4,5-triphosphate and cardiolipin may suggest the role of prohibitin effects on energy metabolism and age-related diseases. The current study examined the region-specific expressions of prohibitin with respect to the retina and retinal pigment epithelium (RPE) in age-related macular degeneration (AMD). A detailed understanding of prohibitin binding with lipids, nucleotides, and proteins shown in the current study may suggest how molecular interactions control apoptosis and how we can intervene against the apoptotic pathway in AMD. Our data imply that decreased prohibitin in the peripheral RPE is a significant step leading to mitochondrial dysfunction that may promote AMD progression.

Prohibitin as the Molecular Binding Switch in the Retinal Pigment Epithelium

PubMed Central

Sripathi, Srinivasa R.; Sylvester, O’Donnell; He, Weilue; Moser, Trevor; Um, Ji-Yeon; Lamoke, Folami; Ramakrishna, Wusirika; Bernstein, Paul S.; Bartoli, Manuela; Jahng, Wan Jin

2016-01-01

Previously, our study showed that prohibitin interacts with phospholipids, including phosphatidylinositide and cardiolipin. Under stress conditions, prohibitin interacts with cardiolipin as a retrograde response to activate mitochondrial proliferation. The lipid-binding switch mechanism of prohibitin with phosphatidylinositol-3,4,5-triphosphate (PIP3) and cardiolipin may suggest the role of prohibitin effects on energy metabolism and age-related diseases. The current study examined the region-specific expressions of prohibitin with respect to the retina and retinal pigment epithelium (RPE) in age-related macular degeneration (AMD). A detailed understanding of prohibitin binding with lipids, nucleotides, and proteins shown in the current study may suggest how molecular interactions control apoptosis and how we can intervene against the apoptotic pathway in AMD. Our data imply that decreased prohibitin in the peripheral RPE is a significant step leading to mitochondrial dysfunction that may promote AMD progression. PMID:26661103

Social inertia and diversity in collaboration networks

NASA Astrophysics Data System (ADS)

Ramasco, J. J.

2007-04-01

Random graphs are useful tools to study social interactions. In particular, the use of weighted random graphs allows to handle a high level of information concerning which agents interact and in which degree the interactions take place. Taking advantage of this representation, we recently defined a magnitude, the Social Inertia, that measures the eagerness of agents to keep ties with previous partners. To study this magnitude, we used collaboration networks that are specially appropriate to obtain valid statitical results due to the large size of publically available databases. In this work, I study the Social Inertia in two of these empirical networks, IMDB movie database and condmat. More specifically, I focus on how the Inertia relates to other properties of the graphs, and show that the Inertia provides information on how the weight of neighboring edges correlates. A social interpretation of this effect is also offered.

Yeast two-hybrid and pull-down assays propose an interaction between P50 of apple chlorotic leaf spot virus and PR-10 of Malus sylvestris cv. R12740-7A.

PubMed

Wang, Y; Li, N; Zhao, X; Hu, J; He, Y; Hu, T; Wang, S; Wang, Y; Cao, K

Apple chlorotic leaf spot virus (ACLSV) movement protein (P50) is involved in cell-to-cell transport and influences the long-distance spread of silencing activity. Previously, we obtained 69 P50-interacting proteins from Malus sylvestris cv. R12740-7A and using bioinformatics analyzed their biological functions. In this study, we used the GAL4-based two-hybrid yeast system and His pull-down assays to confirm an interaction between PR-10 of M. sylvestris cv. R12740-7A and ACLSV P50. Our results provide a theoretical basis for further research on the biological function of PR-10 in ACLSV infection and the interacting mechanism between host and virus.

Dextromethorphan Interactions with Histaminergic and Serotonergic Treatments to Reduce Nicotine Self-administration in Rats

PubMed Central

Briggs, Scott A.; Hall, Brandon J.; Wells, Corinne; Slade, Susan; Jaskowski, Paul; Morrison, Margaret; Rezvani, Amir H.; Rose, Jed E.; Levin, Edward D.

2015-01-01

Combining effective treatments with diverse mechanisms of action for smoking cessation may provide better therapy by targeting multiple points of control in the neural circuits underlying addiction. Previous research in a rat model has shown that dextromethorphan, which has α3β4 nicotinic and NMDA glutamatergic antagonist actions, significantly decreases nicotine self-administration. We have found in the rat model that the H1 histamine antagonist pyrilamine and the serotonin 5HT2c agonist lorcaserin also significantly reduce nicotine self-administration. The current studies were conducted to determine the interactive effects of dextromethorphan with pyrilamine and lorcaserin on nicotine self-administration in rats. Young adult female rats were fitted with jugular IV catheters and trained to self-administer a nicotine infusion dose of 0.03-mg/kg/infusion. In an initial dose-effect function study of dextromethorphan, we found a monotonic decrease in nicotine self-administration over a dose range of 1 to 30-mg/kg with a lowest effective dose of 3-mg/kg. Then, with two separate cohorts of rats, dextromethorphan (0, 3.3, and 10-mg/kg) interactions with pyrilamine (0, 4.43, and 13.3-mg/kg) were investigated as well as interactions with lorcaserin (0, 0.3125 and 0.625-mg/kg). In the pyrilamine-dextromethorphan interaction study, the acute dose of pyrilamine (13.3-mg/kg) as well as an acute dose of dextromethorphan caused a significant decrease in nicotine self-administration. There were mutually augmenting effects of these two drugs. The combination of dextromethorphan (10-mg/kg) and pyrilamine (13.3-mg/kg) significantly lowered nicotine self-administration relative to either 10-mg/kg of dextromethorphan alone (p<0.05) or 13.3-mg/kg of pyrilamine alone (p<0.0005). In the lorcaserin-dextromethorphan study, an acute dose of lorcaserin (0.312-mg/kg) as well as an acute dose of dextromethorphan (10-mg/kg) caused a significant decrease in nicotine self-administration replicating previous findings. Augmenting interactions were observed with dextromethorphan and pyrilamine as well as lorcaserin. These findings suggest that combination therapy may be more effective smoking cessation treatments than monotherapy. PMID:26704812

Dextromethorphan interactions with histaminergic and serotonergic treatments to reduce nicotine self-administration in rats.

PubMed

Briggs, Scott A; Hall, Brandon J; Wells, Corinne; Slade, Susan; Jaskowski, Paul; Morrison, Margaret; Rezvani, Amir H; Rose, Jed E; Levin, Edward D

2016-03-01

Combining effective treatments with diverse mechanisms of action for smoking cessation may provide better therapy by targeting multiple points of control in the neural circuits underlying addiction. Previous research in a rat model has shown that dextromethorphan, which has α3β4 nicotinic and NMDA glutamatergic antagonist actions, significantly decreases nicotine self-administration. We have found in the rat model that the H1 histamine antagonist pyrilamine and the serotonin 5HT2C agonist lorcaserin also significantly reduce nicotine self-administration. The current studies were conducted to determine the interactive effects of dextromethorphan with pyrilamine and lorcaserin on nicotine self-administration in rats. Young adult female rats were fitted with jugular IV catheters and trained to self-administer a nicotine infusion dose of 0.03-mg/kg/infusion. In an initial dose-effect function study of dextromethorphan, we found a monotonic decrease in nicotine self-administration over a dose range of 1 to 30-mg/kg with the lowest effective dose of 3-mg/kg. Then, with two separate cohorts of rats, dextromethorphan (0, 3.3, and 10-mg/kg) interactions with pyrilamine (0, 4.43, and 13.3-mg/kg) were investigated as well as interactions with lorcaserin (0, 0.3125 and 0.625-mg/kg). In the pyrilamine-dextromethorphan interaction study, an acute dose of pyrilamine (13.3-mg/kg) as well as an acute dose of dextromethorphan caused a significant decrease in nicotine self-administration. There were mutually augmenting effects of these two drugs. The combination of dextromethorphan (10-mg/kg) and pyrilamine (13.3-mg/kg) significantly lowered nicotine self-administration relative to either 10-mg/kg of dextromethorphan alone (p<0.05) or 13.3-mg/kg of pyrilamine alone (p<0.0005). In the lorcaserin-dextromethorphan study, an acute dose of lorcaserin (0.312-mg/kg) as well as an acute dose of dextromethorphan (10-mg/kg) caused a significant decrease in nicotine self-administration replicating previous findings. Augmenting interactions were observed with dextromethorphan and pyrilamine as well as lorcaserin. These findings suggest that combination therapy may be more effective smoking cessation treatments than monotherapy. Copyright © 2015 Elsevier Inc. All rights reserved.

Dynamic modeling of patient and physician eye gaze to understand the effects of electronic health records on doctor-patient communication and attention.

PubMed

Montague, Enid; Asan, Onur

2014-03-01

The aim of this study was to examine eye gaze patterns between patients and physicians while electronic health records were used to support patient care. Eye gaze provides an indication of physician attention to patient, patient/physician interaction, and physician behaviors such as searching for information and documenting information. A field study was conducted where 100 patient visits were observed and video recorded in a primary care clinic. Videos were then coded for gaze behaviors where patients' and physicians' gaze at each other and artifacts such as electronic health records were coded using a pre-established objective coding scheme. Gaze data were then analyzed using lag sequential methods. Results showed that there are several eye gaze patterns significantly dependent to each other. All doctor-initiated gaze patterns were followed by patient gaze patterns. Some patient-initiated gaze patterns were also followed by doctor gaze patterns significantly unlike the findings in previous studies. Health information technology appears to contribute to some of the new significant patterns that have emerged. Differences were also found in gaze patterns related to technology that differ from patterns identified in studies with paper charts. Several sequences related to patient-doctor-technology were also significant. Electronic health records affect the patient-physician eye contact dynamic differently than paper charts. This study identified several patterns of patient-physician interaction with electronic health record systems. Consistent with previous studies, physician initiated gaze is an important driver of the interactions between patient and physician and patient and technology. Published by Elsevier Ireland Ltd.

Dynamic modeling of patient and physician eye gaze to understand the effects of electronic health records on doctor-patient communication and attention

PubMed Central

Montague, Enid; Asan, Onur

2014-01-01

Objective The aim of this study was to examine eye gaze patterns between patients and physicians while electronic health records were used to support patient care. Background Eye gaze provides an indication of physician attention to patient, patient/physician interaction, and physician behaviors such as searching for information and documenting information. Methods A field study was conducted where 100 patient visits were observed and video recorded in a primary care clinic. Videos were then coded for gaze behaviors where patients’ and physicians’ gaze at each other and artifacts such as electronic health records were coded using a pre-established objective coding scheme. Gaze data were then analyzed using lag sequential methods. Results Results showed that there are several eye gaze patterns significantly dependent to each other. All doctor-initiated gaze patterns were followed by patient gaze patterns. Some patient-initiated gaze patterns were also followed by doctor gaze patterns significantly unlike the findings in previous studies. Health information technology appears to contribute to some of the new significant patterns that have emerged. Differences were also found in gaze patterns related to technology that differ from patterns identified in studies with paper charts. Several sequences related to patient-doctor- technology were also significant. Electronic health records affect the patient-physician eye contact dynamic differently than paper charts. Conclusion This study identified several patterns of patient-physician interaction with electronic health record systems. Consistent with previous studies, physician initiated gaze is an important driver of the interactions between patient and physician and patient and technology. PMID:24380671

The in Silico Insight into Carbon Nanotube and Nucleic Acid Bases Interaction.

PubMed

Karimi, Ali Asghar; Ghalandari, Behafarid; Tabatabaie, Seyed Saleh; Farhadi, Mohammad

2016-05-01

To explore practical applications of carbon nanotubes (CNTs) in biomedical fields the properties of their interaction with biomolecules must be revealed. Recent years, the interaction of CNTs with biomolecules is a subject of research interest for practical applications so that previous research explored that CNTs have complementary structure properties with single strand DNA (ssDNA). Hence, the quantum mechanics (QM) method based on ab initio was used for this purpose. Therefore values of binding energy, charge distribution, electronic energy and other physical properties of interaction were studied for interaction of nucleic acid bases and SCNT. In this study, the interaction between nucleic acid bases and a (4, 4) single-walled carbon nanotube (SCNT) were investigated through calculations within quantum mechanics (QM) method at theoretical level of Hartree-Fock (HF) method using 6-31G basis set. Hence, the physical properties such as electronic energy, total dipole moment, charge distributions and binding energy of nucleic acid bases interaction with SCNT were investigated based on HF method. It has been found that the guanine base adsorption is bound stronger to the outer surface of nanotube in comparison to the other bases, consistent with the recent theoretical studies. In the other words, the results explored that guanine interaction with SCNT has optimum level of electronic energy so that their interaction is stable. Also, the calculations illustrated that SCNT interact to nucleic acid bases by noncovalent interaction because of charge distribution an electrostatic area is created in place of interaction. Consequently, small diameter SCNT interaction with nucleic acid bases is noncovalent. Also, the results revealed that small diameter SCNT interaction especially SCNT (4, 4) with nucleic acid bases can be useful in practical application area of biomedical fields such detection and drug delivery.

Combining multiple positive training sets to generate confidence scores for protein-protein interactions.

PubMed

Yu, Jingkai; Finley, Russell L

2009-01-01

High-throughput experimental and computational methods are generating a wealth of protein-protein interaction data for a variety of organisms. However, data produced by current state-of-the-art methods include many false positives, which can hinder the analyses needed to derive biological insights. One way to address this problem is to assign confidence scores that reflect the reliability and biological significance of each interaction. Most previously described scoring methods use a set of likely true positives to train a model to score all interactions in a dataset. A single positive training set, however, may be biased and not representative of true interaction space. We demonstrate a method to score protein interactions by utilizing multiple independent sets of training positives to reduce the potential bias inherent in using a single training set. We used a set of benchmark yeast protein interactions to show that our approach outperforms other scoring methods. Our approach can also score interactions across data types, which makes it more widely applicable than many previously proposed methods. We applied the method to protein interaction data from both Drosophila melanogaster and Homo sapiens. Independent evaluations show that the resulting confidence scores accurately reflect the biological significance of the interactions.

The Burden of Leadership: Exploring the Principal's Role in Teacher Collaboration

ERIC Educational Resources Information Center

Szczesiul, Stacy; Huizenga, Jessica

2014-01-01

Based on qualitative data collected over a 6-month period, this article examines how teachers' experiences of principal leadership practice influence their capacity to engage in meaningful collegial interactions during structured collaboration. Similar to previous studies, our findings confirm the limitations of leadership that relies primarily on…

The social context moderates the relationships between neighborhood safety and adolescents’ physical activities

USDA-ARS?s Scientific Manuscript database

Background. Previous studies of neighborhood safety and physical (in)activity have typically neglected to consider the youth’s peer context as a modifier of these relationships. Objective. Test the independent and interactive effects of perceived neighborhood safety and time spent with friends and p...

Metaphors as Expressions of Followers' Experiences with Academic Leadership

ERIC Educational Resources Information Center

Skorobohacz, Christina; Billot, Jennie; Murray, Shannon; Khong, Lana Y. L.

2016-01-01

Researchers continue to investigate and understand leadership in higher education. However, leadership does not stand alone; it is part of an interactive dyad with followers. Building on a previous study that aimed to unpack academics' experiences of leadership in higher education with a view to enhancing leadership practices, this paper…

Multilingual Stroop Performance: Effects of Trilingualism and Proficiency on Inhibitory Control

ERIC Educational Resources Information Center

Marian, Viorica; Blumenfeld, Henrike K.; Mizrahi, Elena; Kania, Ursula; Cordes, Anne-Kristin

2013-01-01

Previous research suggests that multilinguals' languages are constantly co-activated and that experience managing this co-activation changes inhibitory control function. The present study examined language interaction and inhibitory control using a colour-word Stroop task. Multilingual participants were tested in their three most proficient…

Environmental Identity Development through Social Interactions, Action, and Recognition

ERIC Educational Resources Information Center

Stapleton, Sarah Riggs

2015-01-01

This article uses sociocultural identity theory to explore how practice, action, and recognition can facilitate environmental identity development. Recognition, a construct not previously explored in environmental identity literature, is particularly examined. The study is based on a group of diverse teens who traveled to South Asia to participate…

A Multivariate Model of Achievement in Geometry

ERIC Educational Resources Information Center

Bailey, MarLynn; Taasoobshirazi, Gita; Carr, Martha

2014-01-01

Previous studies have shown that several key variables influence student achievement in geometry, but no research has been conducted to determine how these variables interact. A model of achievement in geometry was tested on a sample of 102 high school students. Structural equation modeling was used to test hypothesized relationships among…

RELATION OF LEAD AND SOCIAL FACTORS TO IQ OF LOW-SES CHILDREN: A PARTIAL REPLICATION

EPA Science Inventory

An independent replication of a previous study (Schroeder et al., 1985) of the effects of interactive social environmental factors on the relationship of lead and Stanford-Binet IQ was performed on 75 of 80 low-Socioeconomic status black children screened by county health departm...

Using Virtual Reality with and without Gaming Attributes for Academic Achievement

ERIC Educational Resources Information Center

Vogel, Jennifer J.; Greenwood-Ericksen, Adams; Cannon-Bowers, Jan; Bowers, Clint A.

2006-01-01

A subcategory of computer-assisted instruction (CAI), games have additional attributes such as motivation, reward, interactivity, score, and challenge. This study used a quasi-experimental design to determine if previous findings generalize to non simulation-based game designs. Researchers observed significant improvement in the overall population…

Elementary Students' Laboratory Record Keeping during Scientific Inquiry

ERIC Educational Resources Information Center

Garcia-Mila, Merce; Andersen, Christopher; Rojo, Nubia E.

2011-01-01

The present study examines the mutual interaction between students' writing and scientific reasoning among sixth-grade students (age 11-12 years) engaged in scientific inquiry. The experimental task was designed to promote spontaneous record keeping compared to previous task designs by increasing the saliency of task requirements, with the design…

Assertive and Responsive Conversational Skills of Italian-Speaking Late Talkers

ERIC Educational Resources Information Center

Bonifacio, Serena; Girolametto, Luigi; Bulligan, Manuela; Callegari, Monica; Vignola, Sandra; Zocconi, Elisabetta

2007-01-01

Background: Previous research on the pragmatic abilities of late talkers at 24 months of age indicates that they have difficulties initiating conversational interactions, but possess intact responsiveness skills. This study uses a parent-administered questionnaire for evaluating the conversational skills of late talkers and suggesting pragmatic…

Behavioural Features of Italian Infants and Young Adults with Williams-Beuren Syndrome

ERIC Educational Resources Information Center

Gagliardi, C.; Martelli, S.; Tavano, A.; Borgatti, R.

2011-01-01

Background: The increased interest in social interaction in Williams-Beuren syndrome (WBS) is evident from infancy onwards, together not only with increased empathy, positive interpersonal bias, but also with social disinhibition. Previous studies have described behavioural and emotional problems as being widely represented in WBS. There is…

Interaction and dynamics of homologous pairing protein 2 (HOP2) and DNA studied by MD simulation

NASA Astrophysics Data System (ADS)

Moktan, Hem; Pezza, Roberto; Zhou, Donghua

2015-03-01

The homologous pairing protein 2 (Hop2) plays an important role in meiosis and DNA repair. Together with protein Mnd1, Hop2 enhances the strand invasion activity of recombinase Dmc1 by over 30 times, facilitating proper synapsis of homologous chromosomes. We recently determined the NMR structure of the N-terminal domain of Hop2 and proposed a model of Protein-DNA complex based on NMR chemical shift perturbations and mutagenesis studies (Moktan, J Biol Chem 2014 10.1074/jbc.M114.548180). However structure and dynamics of the complex have not been studied at the atomic level yet. Here, we used classical MD simulations to study the interactions between the N-terminal HOP2 and DNA. The simulated results indicate that helix3 (H3) interacts with DNA in major groove and wing1 (W1) interacts mostly in minor groove mainly via direct hydrogen bonds. Also it is found that binding leads to reduced fluctuations in both protein and DNA. Several water bridge interactions have been identified. The residue-wise contributions to the interaction energy were evaluated. Also the functional motion of the protein is analyzed using principal component analysis. The results confirmed the importance of H3 and W1 for the stability of the complex, which is consistent with our previous experimental studies.

Third-Party Social Interaction and Word Learning from Video

ERIC Educational Resources Information Center

O'Doherty, Katherine; Troseth, Georgene L.; Shimpi, Priya M.; Goldenberg, Elizabeth; Akhtar, Nameera; Saylor, Megan M.

2011-01-01

In previous studies, very young children have learned words while "overhearing" a conversation, yet they have had trouble learning words from a person on video. In Study 1, 64 toddlers (mean age = 29.8 months) viewed an object-labeling demonstration in 1 of 4 conditions. In 2, the speaker (present or on video) directly addressed the child, and in…

Comarison of Four Methods for Teaching Phases of the Moon

NASA Astrophysics Data System (ADS)

Upton, Brianna; Cid, Ximena; Lopez, Ramon

2008-03-01

Previous studies have shown that many students have misconceptions about basic concepts in astronomy. As a consequence, various interactive engagement methods have been developed for introductory astronomy. We will present the results of a study that compares four different teaching methods for the subject of the phases of the Moon, which is well known to produce student difficulties. We compare a fairly traditional didactic approach, the use of manipulatives (moonballs) in lecture, the University of Arizona Lecture Tutorials, and an interactive computer program used in a didactic fashion. We use pre- and post-testing with the Lunar Phase Concept Inventory to determine the relative effectiveness of these methods.

Earthquake stress triggers, stress shadows, and seismic hazard

USGS Publications Warehouse

Harris, R.A.

2000-01-01

Many aspects of earthquake mechanics remain an enigma at the beginning of the twenty-first century. One potential bright spot is the realization that simple calculations of stress changes may explain some earthquake interactions, just as previous and ongoing studies of stress changes have begun to explain human- induced seismicity. This paper, which is an update of Harris1, reviews many published works and presents a compilation of quantitative earthquake-interaction studies from a stress change perspective. This synthesis supplies some clues about certain aspects of earthquake mechanics. It also demonstrates that much work remains to be done before we have a complete story of how earthquakes work.

The impact of brain size on pilot performance varies with aviation training and years of education

PubMed Central

Adamson, Maheen M.; Samarina, Viktoriya; Xiangyan, Xu; Huynh, Virginia; Kennedy, Quinn; Weiner, Michael; Yesavage, Jerome; Taylor, Joy L.

2010-01-01

Previous studies have consistently reported age-related changes in cognitive abilities and brain structure. Previous studies also suggest compensatory roles for specialized training, skill, and years of education in the age-related decline of cognitive function. The Stanford/VA Aviation Study examines the influence of specialized training and skill level (expertise) on age-related changes in cognition and brain structure. This preliminary report examines the effect of aviation expertise, years of education, age, and brain size on flight simulator performance in pilots aged 45–68 years. Fifty-one pilots were studied with structural magnetic resonance imaging, flight simulator, and processing speed tasks. There were significant main effects of age (p < .01) and expertise (p < .01), but not of whole brain size (p > .1) or education (p > .1), on flight simulator performance. However, even though age and brain size were correlated (r = −0.41), age differences in flight simulator performance were not explained by brain size. Both aviation expertise and education were involved in an interaction with brain size in predicting flight simulator performance (p < .05). These results point to the importance of examining measures of expertise and their interactions to assess age-related cognitive changes. PMID:20193103

Understanding students' and clinicians' experiences of informal interprofessional workplace learning: an Australian qualitative study.

PubMed

Rees, Charlotte E; Crampton, Paul; Kent, Fiona; Brown, Ted; Hood, Kerry; Leech, Michelle; Newton, Jennifer; Storr, Michael; Williams, Brett

2018-04-17

While postgraduate studies have begun to shed light on informal interprofessional workplace learning, studies with preregistration learners have typically focused on formal and structured work-based learning. The current study investigated preregistration students' informal interprofessional workplace learning by exploring students' and clinicians' experiences of interprofessional student-clinician (IPSC) interactions. A qualitative interview study using narrative techniques was conducted. Student placements across multiple clinical sites in Victoria, Australia. Through maximum variation sampling, 61 participants (38 students and 23 clinicians) were recruited from six professions (medicine, midwifery, nursing, occupational therapy, paramedicine and physiotherapy). We conducted 12 group and 10 individual semistructured interviews. Themes were identified through framework analysis, and the similarities and differences in subthemes by participant group were interrogated. Six themes relating to four research questions were identified: (1) conceptualisations of IPSC interactions; (2) context for interaction experiences; (3) the nature of interaction experiences; (4) factors contributing to positive or negative interactions; (5) positive or negative consequences of interactions and (6) suggested improvements for IPSC interactions. Seven noteworthy differences in subthemes between students and clinicians and across the professions were identified. Despite the results largely supporting previous postgraduate research, the findings illustrate greater breadth and depth of understandings, experiences and suggestions for preregistration education. Educators and students are encouraged to seek opportunities for informal interprofessional learning afforded by the workplace. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Social Experience Is Sufficient to Modulate Sleep Need of Drosophila without Increasing Wakefulness.

PubMed

Lone, Shahnaz Rahman; Potdar, Sheetal; Srivastava, Manishi; Sharma, Vijay Kumar

2016-01-01

Organisms quickly learn about their surroundings and display synaptic plasticity which is thought to be critical for their survival. For example, fruit flies Drosophila melanogaster exposed to highly enriched social environment are found to show increased synaptic connections and a corresponding increase in sleep. Here we asked if social environment comprising a pair of same-sex individuals could enhance sleep in the participating individuals. To study this, we maintained individuals of D. melanogaster in same-sex pairs for a period of 1 to 4 days, and after separation, monitored sleep of the previously socialized and solitary individuals under similar conditions. Males maintained in pairs for 3 or more days were found to sleep significantly more during daytime and showed a tendency to fall asleep sooner as compared to solitary controls (both measures together are henceforth referred to as "sleep-enhancement"). This sleep phenotype is not strain-specific as it is observed in males from three different "wild type" strains of D. melanogaster. Previous studies on social interaction mediated sleep-enhancement presumed 'waking experience' during the interaction to be the primary underlying cause; however, we found sleep-enhancement to occur without any significant increase in wakefulness. Furthermore, while sleep-enhancement due to group-wise social interaction requires Pigment Dispersing Factor (PDF) positive neurons; PDF positive and CRYPTOCHROME (CRY) positive circadian clock neurons and the core circadian clock genes are not required for sleep-enhancement to occur when males interact in pairs. Pair-wise social interaction mediated sleep-enhancement requires dopamine and olfactory signaling, while visual and gustatory signaling systems seem to be dispensable. These results suggest that socialization alone (without any change in wakefulness) is sufficient to cause sleep-enhancement in fruit fly D. melanogaster males, and that its neuronal control is context-specific.

In-office distance learning for practitioners.

PubMed

Klein, Katherine P; Miller, Kenneth T; Brown, Matthew W; Proffit, William R

2011-07-01

Distance learning studies involving orthodontic residents have shown that, although residents prefer being live and interactive with an instructor, they learn almost as much from watching a recorded interactive seminar followed by a live discussion. Our objective in this study was to test the acceptability and perceived effectiveness of using recorded interactive seminars and video conference follow-up discussions for in-office continuing education. Four small groups of practitioners (total, n = 23) were asked to prepare for, view, and then discuss previously recorded interactive seminars on a variety of subjects; a fifth group (5 previous participants) had live discussions of 3 topics without viewing a prerecorded seminar. All discussions were via video conference through typical broadband Internet connections, by using either WebEx (Cisco, Santa Clara, Calif) or Elluminate (Pleasanton, Calif) software. The participants evaluated their experiences by rating presented statements on a 7-point Likert scale and by providing open-ended responses. Twenty-two of the 23 participants agreed (with varying degrees of enthusiasm) that this was an enjoyable, effective way to learn, and that they would like to participate in this type of learning in the future. Everyone agreed that they would recommend this method of learning to others. The age and experience of the participants had only minor effects on their perceptions of acceptance and acceptability. The use of recorded seminars followed by live interaction through videoconferencing can be an acceptable and effective method of providing continuing education to the home or office of orthodontists in private practice, potentially saving them both time and travel expenses. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Thalamic amplification of cortical connectivity sustains attentional control

PubMed Central

Schmitt, L. Ian; Wimmer, Ralf D.; Nakajima, Miho; Happ, Michael; Mofakham, Sima; Halassa, Michael M.

2017-01-01

While interactions between the thalamus and cortex are critical for cognitive function1–3, the exact contribution of the thalamus to these interactions is often unclear. Recent studies have shown diverse connectivity patterns across the thalamus 4,5, but whether this diversity translates to thalamic functions beyond relaying information to or between cortical regions6 is unknown. Here, by investigating prefrontal cortical (PFC) representation of two rules used to guide attention, we find that the mediodorsal thalamus (MD) sustains these representations without relaying categorical information. Specifically, MD input amplifies local PFC connectivity, enabling rule-specific neural sequences to emerge and thereby maintain rule representations. Consistent with this notion, broadly enhancing PFC excitability diminishes rule specificity and behavioral performance, while enhancing MD excitability improves both. Overall, our results define a previously unknown principle in neuroscience; thalamic control of functional cortical connectivity. This function indicates that the thalamus plays much more central roles in cognition than previously thought. PMID:28467827

Drug Target Optimization in Chronic Myeloid Leukemia Using Innovative Computational Platform

PubMed Central

Chuang, Ryan; Hall, Benjamin A.; Benque, David; Cook, Byron; Ishtiaq, Samin; Piterman, Nir; Taylor, Alex; Vardi, Moshe; Koschmieder, Steffen; Gottgens, Berthold; Fisher, Jasmin

2015-01-01

Chronic Myeloid Leukemia (CML) represents a paradigm for the wider cancer field. Despite the fact that tyrosine kinase inhibitors have established targeted molecular therapy in CML, patients often face the risk of developing drug resistance, caused by mutations and/or activation of alternative cellular pathways. To optimize drug development, one needs to systematically test all possible combinations of drug targets within the genetic network that regulates the disease. The BioModelAnalyzer (BMA) is a user-friendly computational tool that allows us to do exactly that. We used BMA to build a CML network-model composed of 54 nodes linked by 104 interactions that encapsulates experimental data collected from 160 publications. While previous studies were limited by their focus on a single pathway or cellular process, our executable model allowed us to probe dynamic interactions between multiple pathways and cellular outcomes, suggest new combinatorial therapeutic targets, and highlight previously unexplored sensitivities to Interleukin-3. PMID:25644994

Drug Target Optimization in Chronic Myeloid Leukemia Using Innovative Computational Platform

NASA Astrophysics Data System (ADS)

Chuang, Ryan; Hall, Benjamin A.; Benque, David; Cook, Byron; Ishtiaq, Samin; Piterman, Nir; Taylor, Alex; Vardi, Moshe; Koschmieder, Steffen; Gottgens, Berthold; Fisher, Jasmin

2015-02-01

Chronic Myeloid Leukemia (CML) represents a paradigm for the wider cancer field. Despite the fact that tyrosine kinase inhibitors have established targeted molecular therapy in CML, patients often face the risk of developing drug resistance, caused by mutations and/or activation of alternative cellular pathways. To optimize drug development, one needs to systematically test all possible combinations of drug targets within the genetic network that regulates the disease. The BioModelAnalyzer (BMA) is a user-friendly computational tool that allows us to do exactly that. We used BMA to build a CML network-model composed of 54 nodes linked by 104 interactions that encapsulates experimental data collected from 160 publications. While previous studies were limited by their focus on a single pathway or cellular process, our executable model allowed us to probe dynamic interactions between multiple pathways and cellular outcomes, suggest new combinatorial therapeutic targets, and highlight previously unexplored sensitivities to Interleukin-3.

The role of past interactions in great apes' communication about absent entities.

PubMed

Bohn, Manuel; Call, Josep; Tomasello, Michael

2016-11-01

Recent evidence suggests that great apes can use the former location of an entity to communicate about it. In this study we built on these findings to investigate the social-cognitive foundations of great apes' communicative abilities. We tested whether great apes (n = 35) would adjust their requests for absent entities to previous interactions they had with their interlocutor. We manipulated the apes' experience with respect to the interlocutor's knowledge about the previous content of the now-empty location as well as their experience with the interlocutor's competence to provide additional food items. We found that apes adjusted their requests to both of these aspects but failed to integrate them with one another. These results demonstrate a surprising amount of flexibility in great apes' communicative abilities while at the same time suggesting some important limitations in their social communicative skills. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Factors in Client–Clinician Interaction That Influence Hearing Aid Adoption

PubMed Central

Jennings, Mary Beth; Shaw, Lynn; Meston, Christine N.; Cheesman, Margaret F.

2011-01-01

The influence of client–clinician interactions has not been emphasized in hearing health care, despite the extensive evidence of the impact of the provider–patient interaction on health outcomes. The purpose of this study was to identify factors in the client–clinician interaction that may influence hearing aid adoption. Thirteen adults who had received a hearing aid recommendation within the previous 3 months and 10 audiologists participated in a study to generate, sort, and rate the importance of factors in client–clinician interaction that may influence the hearing aid purchase decision. A concept mapping approach was used to define meaningful clusters of factors. Quantitative analysis and qualitative interpretation of the statements resulted in eight concepts. The concepts in order of their importance are (a) Ensuring client comfort, (b) Understanding and meeting client needs, (c) Client-centered traits and actions, (d) Acknowledging client as an individual, (e) Imposing undue pressure and discomfort, (f) Conveying device information by clinician, (g) Supporting choices and shared decision making, and (h) Factors in client readiness. Two overarching themes of client-centered interaction and client empowerment were identified. Results highlight the influence of the client–clinician interaction in hearing aid adoption and suggest the possibility of improving hearing aid adoption by empowering clients through a client-centered interaction. PMID:22155784

Additivity vs Synergism: Investigation of the Additive Interaction of Cinnamon Bark Oil and Meropenem in Combinatory Therapy.

PubMed

Yang, Shun-Kai; Yusoff, Khatijah; Mai, Chun-Wai; Lim, Wei-Meng; Yap, Wai-Sum; Lim, Swee-Hua Erin; Lai, Kok-Song

2017-11-04

Combinatory therapies have been commonly applied in the clinical setting to tackle multi-drug resistant bacterial infections and these have frequently proven to be effective. Specifically, combinatory therapies resulting in synergistic interactions between antibiotics and adjuvant have been the main focus due to their effectiveness, sidelining the effects of additivity, which also lowers the minimal effective dosage of either antimicrobial agent. Thus, this study was undertaken to look at the effects of additivity between essential oils and antibiotic, via the use of cinnamon bark essential oil (CBO) and meropenem as a model for additivity. Comparisons between synergistic and additive interaction of CBO were performed in terms of the ability of CBO to disrupt bacterial membrane, via zeta potential measurement, outer membrane permeability assay and scanning electron microscopy. It has been found that the additivity interaction between CBO and meropenem showed similar membrane disruption ability when compared to those synergistic combinations which was previously reported. Hence, results based on our studies strongly suggest that additive interaction acts on a par with synergistic interaction. Therefore, further investigation in additive interaction between antibiotics and adjuvant should be performed for a more in depth understanding of the mechanism and the impacts of such interaction.

Effects of the Caregiver Interaction Profile Training on Caregiver-Child Interactions in Dutch Child Care Centers: A Randomized Controlled Trial.

PubMed

Helmerhorst, Katrien O W; Riksen-Walraven, J Marianne A; Fukkink, Ruben G; Tavecchio, Louis W C; Gevers Deynoot-Schaub, Mirjam J J M

2017-01-01

Previous studies underscore the need to improve caregiver-child interactions in early child care centers. In this study we used a randomized controlled trial to examine whether a 5-week video feedback training can improve six key interactive skills of caregivers in early child care centers: Sensitive responsiveness, respect for autonomy, structuring and limit setting, verbal communication, developmental stimulation, and fostering positive peer interactions. A total of 139 caregivers from 68 early child care groups for 0- to 4-year-old children in Dutch child care centers participated in this RCT, 69 in the intervention condition and 70 in the control condition. Caregiver interactive skills during everyday interactions with the children were rated from videotape using the Caregiver Interaction Profile (CIP) scales at pretest, posttest, and follow-up 3 months after the posttest. Results at posttest indicate a significant positive training effect on all six caregiver interactive skills. Effect sizes of the CIP training range between d  = 0.35 and d  = 0.79. Three months after the posttest, caregivers in the intervention group still scored significantly higher on sensitive responsiveness, respect for autonomy, verbal communication, and fostering positive peer interactions than caregivers in the control group with effect sizes ranging between d  = 0.47 and d  = 0.70. This study shows that the quality of caregiver-child interactions can be improved for all six important caregiver skills, with a relatively short training program. Possible ways to further improve the training and to implement it in practice and education are discussed.

Relationship Quality and Alcohol-Related Social Reinforcement during Couples Interaction.

PubMed

Fairbairn, Catharine E; Testa, Maria

2016-01-01

Individuals who are unhappy in their intimate partnerships are at risk for developing alcohol problems. But little is known about the mechanisms underlying this link. One possibility is that couples with poor relationship quality gain more reinforcement from alcohol in certain contexts-a possibility that has never previously been empirically examined. In the current study, 304 individuals (152 couples) were assigned to receive alcohol (target BAC .08%) or a non-alcoholic beverage. They then engaged in a conflict-resolution interaction with their partners. Videotaped interactions were coded by trained observers. Results revealed a significant interaction between alcohol and relationship quality across multiple measures. Alcohol decreased negative behaviors, decreased negative reciprocity, and enhanced self-reported experience to a greater extent during interactions involving individuals reporting low relationship quality and had comparatively little effect among those reporting high relationship quality. Findings point to a potential mechanism underlying problem drinking among couples with poor relationship quality.

Calcium accelerates SNARE-mediated lipid mixing through modulating α-synuclein membrane interaction.

PubMed

Zhang, Zeting; Jiang, Xin; Xu, Danrui; Zheng, Wenwen; Liu, Maili; Li, Conggang

2018-04-04

α-Synuclein is involved in Parkinson's disease, and its interaction with cell membrane is vital to its pathological and physiological functions. We have shown that Ca 2+ can regulate α-synuclein membrane interaction, but the physiological role of Ca 2+ in modulating α-synuclein membrane interaction is still unexplored. Based on the previous findings that α-synuclein inhibits membrane fusion and its inhibitory effect is highly related to its membrane binding, here we employed solution state Nuclear Magnetic Resonance (NMR) spectroscopy and the ensemble fluorescence fusion assay to show that Ca 2+ can modulate the inhibitory effect of α-synuclein on SNARE-mediated membrane fusion through disrupting α-synuclein membrane interaction, resulting in acceleration of SNARE-mediated membrane fusion. These results suggest a modulatory effect of Ca 2+ on membrane mediated normal function of α-synuclein, which of importance for the study of the Parkinson's disease. Copyright © 2018 Elsevier B.V. All rights reserved.

Thermodynamic investigation of the binding of dissymmetric pyrenyl-gemini surfactants to DNA.

PubMed

Wettig, Shawn D; Deubry, Rubena; Akbar, Javed; Kaur, Tranum; Wang, Haitang; Sheinin, Tatiana; Joseph, Jamie W; Slavcev, Roderick A

2010-05-14

Gemini surfactants have demonstrated significant potential for use in constructing non-viral transfection vectors for the delivery of genes into cells to induce protein expression. Previously, two asymmetric gemini surfactants containing pyrenyl groups in one of the alkyl tails of the surfactants were synthesized as fluorescence probes for use in mechanistic studies of the transfection process. Here we present the results of a thermodynamic investigation of the binding interaction(s) between the pyrenyl-modified surfactants and DNA. The thermodynamics of the interactions have been examined using isothermal titration calorimetry, light scattering, zeta potential, and circular dichroism measurements. Distinct differences are observed between the interaction of 12-s-12 vs. the pyrene modified py-s-12 surfactants with DNA; an intercalated binding is found for the py-s-12 surfactants that disrupts the typical interactions observed between DNA and gemini surfactants.

Investigating the Neural Correlates of Emotion–Cognition Interaction Using an Affective Stroop Task

PubMed Central

Raschle, Nora M.; Fehlbaum, Lynn V.; Menks, Willeke M.; Euler, Felix; Sterzer, Philipp; Stadler, Christina

2017-01-01

The human brain has the capacity to integrate various sources of information and continuously adapts our behavior according to situational needs in order to allow a healthy functioning. Emotion–cognition interactions are a key example for such integrative processing. However, the neuronal correlates investigating the effects of emotion on cognition remain to be explored and replication studies are needed. Previous neuroimaging studies have indicated an involvement of emotion and cognition related brain structures including parietal and prefrontal cortices and limbic brain regions. Here, we employed whole brain event-related functional magnetic resonance imaging (fMRI) during an affective number Stroop task and aimed at replicating previous findings using an adaptation of an existing task design in 30 healthy young adults. The Stroop task is an indicator of cognitive control and enables the quantification of interference in relation to variations in cognitive load. By the use of emotional primes (negative/neutral) prior to Stroop task performance, an emotional variation is added as well. Behavioral in-scanner data showed that negative primes delayed and disrupted cognitive processing. Trials with high cognitive demand furthermore negatively influenced cognitive control mechanisms. Neuronally, the emotional primes consistently activated emotion-related brain regions (e.g., amygdala, insula, and prefrontal brain regions) while Stroop task performance lead to activations in cognition networks of the brain (prefrontal cortices, superior temporal lobe, and insula). When assessing the effect of emotion on cognition, increased cognitive demand led to decreases in neural activation in response to emotional stimuli (negative > neutral) within prefrontal cortex, amygdala, and insular cortex. Overall, these results suggest that emotional primes significantly impact cognitive performance and increasing cognitive demand leads to reduced neuronal activation in emotion related brain regions, and therefore support previous findings investigating emotion–cognition interaction in healthy adults. Moreover, emotion and cognition seem to be tightly related to each other, as indicated by shared neural networks involved in both of these processes. Emotion processing, cognitive control, and their interaction are crucial for healthy functioning and a lack thereof is related to psychiatric disorders such as, disruptive behavior disorders. Future studies may investigate the neural characteristics of children and adolescents with disruptive behavior disorders. PMID:28919871

A cellular stress response (CSR) that interacts with NADPH-P450 reductase (NPR) is a new regulator of hypoxic response.

PubMed

Oguro, Ami; Koyama, Chika; Xu, Jing; Imaoka, Susumu

2014-02-28

NADPH-P450 reductase (NPR) was previously found to contribute to the hypoxic response of cells, but the mechanism was not clarified. In this study, we identified a cellular stress response (CSR) as a new factor interacting with NPR by a yeast two-hybrid system. Overexpression of CSR enhanced the induction of erythropoietin and hypoxia response element (HRE) activity under hypoxia in human hepatocarcinoma cell lines (Hep3B), while knockdown of CSR suppressed them. This new finding regarding the interaction of NPR with CSR provides insight into the function of NPR in hypoxic response. Copyright © 2014 Elsevier Inc. All rights reserved.

Challenges in design of Kitaev materials: Magnetic interactions from competing energy scales

NASA Astrophysics Data System (ADS)

Winter, Stephen M.; Li, Ying; Jeschke, Harald O.; Valentí, Roser

2016-06-01

In this study, we reanalyze the magnetic interactions in the Kitaev spin-liquid candidate materials Na2IrO3,α -RuCl3 , and α -Li2IrO3 using nonperturbative exact diagonalization methods. These methods are more appropriate given the relatively itinerant nature of the systems suggested in previous works. We treat all interactions up to third neighbors on equal footing. The computed terms reveal significant long-range coupling, bond anisotropy, and/or off-diagonal couplings which we argue naturally explain the observed ordered phases in these systems. Given these observations, the potential for realizing the spin-liquid state in real materials is analyzed, and synthetic challenges are defined and explained.

Nano- and microstructured materials for in vitro studies of the physiology of vascular cells

PubMed Central

Chen, Hao; Biela, Sarah A; Kaufmann, Dieter

2016-01-01

The extracellular environment of vascular cells in vivo is complex in its chemical composition, physical properties, and architecture. Consequently, it has been a great challenge to study vascular cell responses in vitro, either to understand their interaction with their native environment or to investigate their interaction with artificial structures such as implant surfaces. New procedures and techniques from materials science to fabricate bio-scaffolds and surfaces have enabled novel studies of vascular cell responses under well-defined, controllable culture conditions. These advancements are paving the way for a deeper understanding of vascular cell biology and materials–cell interaction. Here, we review previous work focusing on the interaction of vascular smooth muscle cells (SMCs) and endothelial cells (ECs) with materials having micro- and nanostructured surfaces. We summarize fabrication techniques for surface topographies, materials, geometries, biochemical functionalization, and mechanical properties of such materials. Furthermore, various studies on vascular cell behavior and their biological responses to micro- and nanostructured surfaces are reviewed. Emphasis is given to studies of cell morphology and motility, cell proliferation, the cytoskeleton and cell-matrix adhesions, and signal transduction pathways of vascular cells. We finalize with a short outlook on potential interesting future studies. PMID:28144512

Exploration of molecular interactions in cholesterol superlattices: effect of multibody interactions.

PubMed

Huang, Juyang

2002-08-01

Experimental evidences have indicated that cholesterol may adapt highly regular lateral distributions (i.e., superlattices) in a phospholipid bilayer. We investigated the formations of superlattices at cholesterol mole fraction of 0.154, 0.25, 0.40, and 0.5 using Monte Carlo simulation. We found that in general, conventional pairwise-additive interactions cannot produce superlattices. Instead, a multibody (nonpairwise) interaction is required. Cholesterol superlattice formation reveals that although the overall interaction between cholesterol and phospholipids is favorable, it contains two large opposing components: an interaction favoring cholesterol-phospholipid mixing and an unfavorable acyl chain multibody interaction that increases nonlinearly with the number of cholesterol contacts. The magnitudes of interactions are in the order of kT. The physical origins of these interactions can be explained by our umbrella model. They most likely come from the requirement for polar phospholipid headgroups to cover the nonpolar cholesterol to avoid the exposure of cholesterol to water and from the sharp decreasing of acyl chain conformation entropy due to cholesterol contact. This study together with our previous work demonstrate that the driving force of cholesterol-phospholipid mixing is a hydrophobic interaction, and multibody interactions dominate others over a wide range of cholesterol concentration.

A Traveling Wave Ion Mobility Spectrometry (TWIMS) Study of the Robo1-Heparan Sulfate Interaction

NASA Astrophysics Data System (ADS)

Zhao, Yuejie; Yang, Jeong Yeh; Thieker, David F.; Xu, Yongmei; Zong, Chengli; Boons, Geert-Jan; Liu, Jian; Woods, Robert J.; Moremen, Kelley W.; Amster, I. Jonathan

2018-03-01

Roundabout 1 (Robo1) interacts with its receptor Slit to regulate axon guidance, axon branching, and dendritic development in the nervous system and to regulate morphogenesis and many cell functions in the nonneuronal tissues. This interaction is known to be critically regulated by heparan sulfate (HS). Previous studies suggest that HS is required to promote the binding of Robo1 to Slit to form the minimal signaling complex, but the molecular details and the structural requirements of HS for this interaction are still unclear. Here, we describe the application of traveling wave ion mobility spectrometry (TWIMS) to study the conformational details of the Robo1-HS interaction. The results suggest that Robo1 exists in two conformations that differ by their compactness and capability to interact with HS. The results also suggest that the highly flexible interdomain hinge region connecting the Ig1 and Ig2 domains of Robo1 plays an important functional role in promoting the Robo1-Slit interaction. Moreover, variations in the sulfation pattern and size of HS were found to affect its binding affinity and selectivity to interact with different conformations of Robo1. Both MS measurements and CIU experiments show that the Robo1-HS interaction requires the presence of a specific size and pattern of modification of HS. Furthermore, the effect of N-glycosylation on the conformation of Robo1 and its binding modes with HS is reported. [Figure not available: see fulltext.

Psychophysiological Synchrony During Verbal Interaction in Romantic Relationships.

PubMed

Coutinho, Joana; Oliveira-Silva, Patrícia; Fernandes, Eugénia; Gonçalves, Oscar F; Correia, Diogo; Perrone Mc-Govern, Kristin; Tschacher, Wolfgang

2018-06-10

Previous studies about romantic relationships have shown that the reciprocal influence between partners occurs not only at the behavioral and socio-emotional levels, but also at the psychophysiological level. This reciprocal influence is expressed in a pattern of physiological synchrony between partners (i.e., coordinated dynamics of the physiological time series). The main aim of the present study was to explore the presence of a pattern of physiological synchrony in electrodermal activity (EDA) during a couple interaction task. A second objective was to compare the synchrony levels during a negative interaction condition versus a positive interaction condition. Finally, we analyzed the association between synchrony and self-perception of empathy, dyadic empathy, and relationship satisfaction. Thirty-two couples (64 individuals) participated in this study. Each couple performed a structured interaction task while the EDA of both partners was being registered. The quantification of synchrony was based on the cross-correlation of both members' EDA time-series. In order to control for coincidental synchrony, surrogate datasets were created by repeatedly shuffling the original data of spouses X and Y of a dyad and computing synchronies on the basis of the shuffled data (pseudosynchrony values). Our results confirmed the presence of significant EDA synchrony during the interaction. We also found that synchrony was higher during the negative interactions relative to the positive interactions. Additionally, physiological synchrony during positive interaction was higher for those couples in which males scored higher in dyadic empathy. The clinical implications of these findings are discussed. © 2018 Family Process Institute.

Prematurity, maternal stress and mother-child interactions.

PubMed

Muller-Nix, Carole; Forcada-Guex, Margarita; Pierrehumbert, Blaise; Jaunin, Lyne; Borghini, Ayala; Ansermet, François

2004-09-01

Previous studies have shown that premature birth and the immaturity of the child can affect the quality of the parent-child relationship. The present study examines the relationship between maternal and infant interactional behavior over time and infant perinatal risk factors as well as maternal perinatal recollected traumatic experience. Few studies have explored the relationship between maternal stress and the quality of parent-infant interaction. Mother-child interaction was recorded at 6 and 18 months of infant's age, in a population of 47 preterm infants (GA<34 weeks) and 25 full-term infants, born in 1998, during a play interaction. According to the Care Index, sensitivity, control and unresponsiveness have been used to code maternal interactional characteristics, and cooperation, compliance-compulsiveness, difficulty and passivity have been used to code the infant's interactional characteristics. The level of maternal stress was evaluated with the Perinatal Posttraumatic Stress Disorder Questionnaire (PPQ), and the infant's perinatal risk factors were assessed with the Perinatal Risk Inventory (PERI). Mothers of high-risk infants, as well as mothers that had experienced traumatic stress in the perinatal period, were less sensitive and more controlling at 6 months. The interactional behavior of the preterm infant was different from that of the full-term infant at 18 months of age, and was correlated with maternal traumatic stress but not with perinatal risk factors. These results underline the importance of maternal traumatic experience related to premature birth and its potential long lasting influence on mother-child interactional behavior.

Transcriptomic Studies of Malaria: a Paradigm for Investigation of Systemic Host-Pathogen Interactions

PubMed Central

2018-01-01

SUMMARY Transcriptomics, the analysis of genome-wide RNA expression, is a common approach to investigate host and pathogen processes in infectious diseases. Technical and bioinformatic advances have permitted increasingly thorough analyses of the association of RNA expression with fundamental biology, immunity, pathogenesis, diagnosis, and prognosis. Transcriptomic approaches can now be used to realize a previously unattainable goal, the simultaneous study of RNA expression in host and pathogen, in order to better understand their interactions. This exciting prospect is not without challenges, especially as focus moves from interactions in vitro under tightly controlled conditions to tissue- and systems-level interactions in animal models and natural and experimental infections in humans. Here we review the contribution of transcriptomic studies to the understanding of malaria, a parasitic disease which has exerted a major influence on human evolution and continues to cause a huge global burden of disease. We consider malaria a paradigm for the transcriptomic assessment of systemic host-pathogen interactions in humans, because much of the direct host-pathogen interaction occurs within the blood, a readily sampled compartment of the body. We illustrate lessons learned from transcriptomic studies of malaria and how these lessons may guide studies of host-pathogen interactions in other infectious diseases. We propose that the potential of transcriptomic studies to improve the understanding of malaria as a disease remains partly untapped because of limitations in study design rather than as a consequence of technological constraints. Further advances will require the integration of transcriptomic data with analytical approaches from other scientific disciplines, including epidemiology and mathematical modeling. PMID:29695497

Transcriptomic Studies of Malaria: a Paradigm for Investigation of Systemic Host-Pathogen Interactions.

PubMed

Lee, Hyun Jae; Georgiadou, Athina; Otto, Thomas D; Levin, Michael; Coin, Lachlan J; Conway, David J; Cunnington, Aubrey J

2018-06-01

Transcriptomics, the analysis of genome-wide RNA expression, is a common approach to investigate host and pathogen processes in infectious diseases. Technical and bioinformatic advances have permitted increasingly thorough analyses of the association of RNA expression with fundamental biology, immunity, pathogenesis, diagnosis, and prognosis. Transcriptomic approaches can now be used to realize a previously unattainable goal, the simultaneous study of RNA expression in host and pathogen, in order to better understand their interactions. This exciting prospect is not without challenges, especially as focus moves from interactions in vitro under tightly controlled conditions to tissue- and systems-level interactions in animal models and natural and experimental infections in humans. Here we review the contribution of transcriptomic studies to the understanding of malaria, a parasitic disease which has exerted a major influence on human evolution and continues to cause a huge global burden of disease. We consider malaria a paradigm for the transcriptomic assessment of systemic host-pathogen interactions in humans, because much of the direct host-pathogen interaction occurs within the blood, a readily sampled compartment of the body. We illustrate lessons learned from transcriptomic studies of malaria and how these lessons may guide studies of host-pathogen interactions in other infectious diseases. We propose that the potential of transcriptomic studies to improve the understanding of malaria as a disease remains partly untapped because of limitations in study design rather than as a consequence of technological constraints. Further advances will require the integration of transcriptomic data with analytical approaches from other scientific disciplines, including epidemiology and mathematical modeling. Copyright © 2018 Lee et al.

Identification of new protein interactions between dengue fever virus and its hosts, human and mosquito.

PubMed

Mairiang, Dumrong; Zhang, Huamei; Sodja, Ann; Murali, Thilakam; Suriyaphol, Prapat; Malasit, Prida; Limjindaporn, Thawornchai; Finley, Russell L

2013-01-01

The four divergent serotypes of dengue virus are the causative agents of dengue fever, dengue hemorrhagic fever and dengue shock syndrome. About two-fifths of the world's population live in areas where dengue is prevalent, and thousands of deaths are caused by the viruses every year. Dengue virus is transmitted from one person to another primarily by the yellow fever mosquito, Aedes aegypti. Recent studies have begun to define how the dengue viral proteins interact with host proteins to mediate viral replication and pathogenesis. A combined analysis of these studies, however, suggests that many virus-host protein interactions remain to be identified, especially for the mosquito host. In this study, we used high-throughput yeast two-hybrid screening to identify mosquito and human proteins that physically interact with dengue proteins. We tested each identified host protein against the proteins from all four serotypes of dengue to identify interactions that are conserved across serotypes. We further confirmed many of the interactions using co-affinity purification assays. As in other large-scale screens, we identified some previously detected interactions and many new ones, moving us closer to a complete host - dengue protein interactome. To help summarize and prioritize the data for further study, we combined our interactions with other published data and identified a subset of the host-dengue interactions that are now supported by multiple forms of evidence. These data should be useful for understanding the interplay between dengue and its hosts and may provide candidates for drug targets and vector control strategies.

Identification of New Protein Interactions between Dengue Fever Virus and Its Hosts, Human and Mosquito

PubMed Central

Mairiang, Dumrong; Zhang, Huamei; Sodja, Ann; Murali, Thilakam; Suriyaphol, Prapat; Malasit, Prida; Limjindaporn, Thawornchai; Finley, Russell L.

2013-01-01

The four divergent serotypes of dengue virus are the causative agents of dengue fever, dengue hemorrhagic fever and dengue shock syndrome. About two-fifths of the world's population live in areas where dengue is prevalent, and thousands of deaths are caused by the viruses every year. Dengue virus is transmitted from one person to another primarily by the yellow fever mosquito, Aedes aegypti. Recent studies have begun to define how the dengue viral proteins interact with host proteins to mediate viral replication and pathogenesis. A combined analysis of these studies, however, suggests that many virus-host protein interactions remain to be identified, especially for the mosquito host. In this study, we used high-throughput yeast two-hybrid screening to identify mosquito and human proteins that physically interact with dengue proteins. We tested each identified host protein against the proteins from all four serotypes of dengue to identify interactions that are conserved across serotypes. We further confirmed many of the interactions using co-affinity purification assays. As in other large-scale screens, we identified some previously detected interactions and many new ones, moving us closer to a complete host – dengue protein interactome. To help summarize and prioritize the data for further study, we combined our interactions with other published data and identified a subset of the host-dengue interactions that are now supported by multiple forms of evidence. These data should be useful for understanding the interplay between dengue and its hosts and may provide candidates for drug targets and vector control strategies. PMID:23326450

Lack of synergistic interaction between the two mechanisms of action of tapentadol in gastrointestinal transit.

PubMed

Cowan, A; Raffa, R B; Tallarida, C S; Tallarida, R J; Christoph, T; Schröder, W; Tzschentke, T M

2014-09-01

A multi-mechanistic approach offers potential enhancement of analgesic efficacy, but therapeutic gain could be offset by an increase in adverse events. The centrally acting analgesic tapentadol [(-)-(1R,2R)-3-(3-dimethylamino-1-ethyl-2-methyl-propyl)-phenol hydrochloride] combines μ-opioid receptor (MOR) agonism and neuronal noradrenaline reuptake inhibition (NRI), both of which contribute to its analgesic effects. Previously, isobolographic analysis of occupation-effect data and a theoretically equivalent methodology determining interactions from the effect scale demonstrated pronounced synergistic interaction between the two mechanisms of action of tapentadol in two models of antinociception (low-intensity tail-flick and spinal nerve ligation). The present study investigated the nature of interaction of the two mechanisms on a surrogate measure for gastrointestinal adverse effect (inhibition of gastrointestinal transit). Dose-response curves were generated in rats for tapentadol alone or in combination with the opioid receptor antagonist, naloxone, or the α2 -adrenoceptor antagonist, yohimbine, to reveal the effect of tapentadol based upon MOR agonism, NRI, and combined mechanisms. The dose-effect curve of tapentadol was shifted to the right by both antagonists, thereby providing data to distinguish between MOR agonism and NRI. Analysis revealed a simple additive interaction between the two mechanisms on this endpoint, in contrast to the synergistic interaction previously demonstrated for antinociception. We believe this is the first published evaluation of mechanistic interaction for a surrogate measure of adverse effect of a single compound with two mechanisms of action, and the results suggest that there is a greater separation between the analgesic and gastrointestinal effects of tapentadol than expected based upon its analgesic efficacy. © 2014 European Pain Federation - EFIC®

Many-Body Theory for Positronium-Atom Interactions

NASA Astrophysics Data System (ADS)

Green, D. G.; Swann, A. R.; Gribakin, G. F.

2018-05-01

A many-body-theory approach has been developed to study positronium-atom interactions. As first applications, we calculate the elastic scattering and momentum-transfer cross sections and the pickoff annihilation rate 1Zeff for Ps collisions with He and Ne. For He the cross section is in agreement with previous coupled-state calculations, while comparison with experiment for both atoms highlights discrepancies between various sets of measured data. In contrast, the calculated 1Zeff (0.13 and 0.26 for He and Ne, respectively) are in excellent agreement with the measured values.

Congestion relaxation due to density-dependent junction rules in TASEP network

NASA Astrophysics Data System (ADS)

Tannai, Takahiro; Nishinari, Katsuhiro

2017-09-01

We now consider a small network module of Totally Asymmetric Simple Exclusion Process with branching and aggregation points, and rules of junctions dependent on the densities of segments of the network module. We also focus on the interaction among junctions which are branching and aggregation. The interaction among junctions with density-dependent rules possesses more complexity than those with density-independent rules studied in the previous papers. In conclusion, we confirm the result that density-dependent rules enable vehicles to move more effectively than the density-independent rules.

Charmonium-nucleon interactions from the time-dependent HAL QCD method

NASA Astrophysics Data System (ADS)

Sugiura, Takuya; Ikeda, Yoichi; Ishii, Noriyoshi

2018-03-01

The charmonium-nucleon effective central interactions have been computed by the time-dependent HAL QCD method. This gives an updated result of a previous study based on the time-independent method, which is now known to be problematic because of the difficulty in achieving the ground-state saturation. We discuss that the result is consistent with the heavy quark symmetry. No bound state is observed from the analysis of the scattering phase shift; however, this shall lead to a future search of the hidden-charm pentaquarks by considering channel-coupling effects.

Dissecting partner recognition by an intrinsically disordered protein using descriptive random mutagenesis.

PubMed

Gruet, Antoine; Dosnon, Marion; Vassena, Andrea; Lombard, Vincent; Gerlier, Denis; Bignon, Christophe; Longhi, Sonia

2013-09-23

In view of getting insights into the molecular determinants of the binding efficiency of intrinsically disordered proteins (IDPs), we used random mutagenesis. As a proof of concept, we chose the interaction between the intrinsically disordered C-terminal domain of the measles virus nucleoprotein (NTAIL) and the X domain (XD) of the viral phosphoprotein and assessed how amino acid substitutions introduced at random within NTAIL affect partner recognition. In contrast with directed evolution approaches, we did not apply any selection and used the gene library approach not for production purposes but for achieving a better understanding of the NTAIL/XD interaction. For that reason, and to differentiate our approach from similar approaches that make use of systematic (i.e., targeted) mutagenesis, we propose to call it "descriptive random mutagenesis" (DRM). NTAIL variants generated by error-prone PCR were picked at random in the absence of selection pressure and were characterized in terms of sequence and binding abilities toward XD. DRM not only identified determinants of NTAIL/XD interaction that were in good agreement with previous work but also provided new insights. In particular, we discovered that the primary interaction site is poorly evolvable in terms of binding abilities toward XD. We also identified a critical NTAIL residue whose role in stabilizing the NTAIL/XD complex had previously escaped detection, and we identified NTAIL regulatory sites that dampen the interaction while being located outside the primary interaction site. Results show that DRM is a valuable approach to study binding abilities of IDPs. © 2013 Elsevier Ltd. All rights reserved.

Oxytocin and Cortisol Levels in Dog Owners and Their Dogs Are Associated with Behavioral Patterns: An Exploratory Study

PubMed Central

Petersson, Maria; Uvnäs-Moberg, Kerstin; Nilsson, Anne; Gustafson, Lise-Lotte; Hydbring-Sandberg, Eva; Handlin, Linda

2017-01-01

We have previously shown that dog–owner interaction results in increasing oxytocin levels in owners and dogs, decreasing cortisol levels in owners but increasing cortisol levels in dogs. The present study aimed to further investigate whether oxytocin and cortisol levels in the previously tested owners and dogs were associated with their behaviors during the interaction experiment. Ten female volunteer dog–owners and their male Labrador dogs participated in a 60 min interaction experiment with interaction taking place during 0–3 min and blood samples for analysis of oxytocin and cortisol were collected at 0, 1, 3, 5, 15, 30, and 60 min. The entire experiment was videotaped and the following variables were noted; the different types (stroking, scratching, patting and activating touch, i.e., scratching and patting combined) as well as the frequency of touch applied by the owner, the number of times the owner touched her dog, the dog’s positions and time spent in each position. Correlations were analyzed between the behavioral variables and basal oxytocin levels, maximum oxytocin levels, delta oxytocin levels, basal cortisol levels and cortisol levels at 15 min. Owners with low oxytocin levels before and during the interaction touched their dogs more frequently (0 min: Rs = -0.683, p = 0.042; oxytocin maximum: Rs = -0.783, p = 0.013). The lower the dogs’ oxytocin levels during the interaction, the more stroking they received (Rs = -0.717, p = 0.041). The more frequently activating touch was applied by the owner, the higher the dogs’ cortisol levels became (15 min: Rs = 0.661, p = 0.038). The higher the owners’ maximum oxytocin level the fewer position changes the dogs made (Rs = -0.817, p = 0.007) and the shorter time they spent sitting (Rs = -0.786, p = 0.036), whereas the higher the owners’ basal cortisol levels, the longer time the dogs spent standing (0 min: Rs = 0.683, p = 0.041). In conclusion, oxytocin and cortisol levels, both in dogs and in their owners, are associated with the way the owners interact with their dogs and also with behaviors caused by the interaction. PMID:29081760

Oxytocin and Cortisol Levels in Dog Owners and Their Dogs Are Associated with Behavioral Patterns: An Exploratory Study.

PubMed

Petersson, Maria; Uvnäs-Moberg, Kerstin; Nilsson, Anne; Gustafson, Lise-Lotte; Hydbring-Sandberg, Eva; Handlin, Linda

2017-01-01

We have previously shown that dog-owner interaction results in increasing oxytocin levels in owners and dogs, decreasing cortisol levels in owners but increasing cortisol levels in dogs. The present study aimed to further investigate whether oxytocin and cortisol levels in the previously tested owners and dogs were associated with their behaviors during the interaction experiment. Ten female volunteer dog-owners and their male Labrador dogs participated in a 60 min interaction experiment with interaction taking place during 0-3 min and blood samples for analysis of oxytocin and cortisol were collected at 0, 1, 3, 5, 15, 30, and 60 min. The entire experiment was videotaped and the following variables were noted; the different types (stroking, scratching, patting and activating touch, i.e., scratching and patting combined) as well as the frequency of touch applied by the owner, the number of times the owner touched her dog, the dog's positions and time spent in each position. Correlations were analyzed between the behavioral variables and basal oxytocin levels, maximum oxytocin levels, delta oxytocin levels, basal cortisol levels and cortisol levels at 15 min. Owners with low oxytocin levels before and during the interaction touched their dogs more frequently (0 min: R s = -0.683, p = 0.042; oxytocin maximum: R s = -0.783, p = 0.013). The lower the dogs' oxytocin levels during the interaction, the more stroking they received ( R s = -0.717, p = 0.041). The more frequently activating touch was applied by the owner, the higher the dogs' cortisol levels became (15 min: R s = 0.661, p = 0.038). The higher the owners' maximum oxytocin level the fewer position changes the dogs made ( R s = -0.817, p = 0.007) and the shorter time they spent sitting ( R s = -0.786, p = 0.036), whereas the higher the owners' basal cortisol levels, the longer time the dogs spent standing (0 min: R s = 0.683, p = 0.041). In conclusion, oxytocin and cortisol levels, both in dogs and in their owners, are associated with the way the owners interact with their dogs and also with behaviors caused by the interaction.

Solvent-mediated nonelectrostatic ion-ion interactions predicting anomalies in electrophoresis.

PubMed

Goswami, Prakash; Dhar, Jayabrata; Ghosh, Uddipta; Chakraborty, Suman

2017-03-01

We study the effects of solvent-mediated nonelectrostatic ion-ion interactions on electrophoretic mobility of a charged spherical particle. To this end, we consider the case of low surface electrostatic potential resulting in the linearization of the governing equations, which enables us to deduce a closed-form analytical solution to the electrophoretic mobility. We subsequently compare our results to the standard model using Henry's approach and report the changes brought about by the nonelectrostatic potential. The classical approach to determine the electrophoretic mobility underpredicts the particle velocity when compared with experiments. We show that this issue can be resolved by taking into account nonelectrostatic interactions. Our analysis further reveals the phenomenon of electrophoretic mobility reversal that has been experimentally observed in numerous previous studies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Submonolayer Ag films on Fe(100): A first-principles analysis of energetics controlling adlayer thermodynamics and kinetics

DOE PAGES

Li, Wei; Huang, Li; Evans, James W.; ...

2016-04-11

Epitaxial growth of Ag on Fe(100) and postdeposition relaxation have been studied in several experiments. We provide a first-principles density functional theory analysis of key adatom interaction energies and diffusion barriers controlling growth and relaxation kinetics for the submonolayer regime, as these have not been assessed previously. A cluster expansion approach is used to obtain an extensive set of conventional lateral interactions between adatoms on fourfold hollow adsorption sites. We find robust oscillatory decay of pair interactions with increasing separation, and of trio interactions with increasing perimeter length. First- and second-nearest-neighbor pair interactions, as well as compact linear and bentmore » trio interactions, dominate. The adatom terrace diffusion barrier is estimated to be E d ≈ 0.39 eV. We also provide a limited analysis of unconventional interactions for which one adatom is at the bridge-site transition state for hopping and one or more others are at fourfold hollow sites. Furthermore, energy barriers for diffusion along island edges can be determined with the aid of both conventional and unconventional interactions.« less

Parent-child interactions during traditional and interactive media settings: A pilot randomized control study.

PubMed

Skaug, Silje; Englund, Kjellrun T; Saksvik-Lehouillier, Ingvild; Lydersen, Stian; Wichstrøm, Lars

2018-04-01

Parent-child interactions are pivotal for children's socioemotional development, yet might suffer with increased attention to screen media, as research has suggested. In response, we hypothesized that parent-child play on a tablet computer, as representative of interactive media, would generate higher-quality parent-child interactions than toy play or watching TV. We examined the emotional availability of mothers and their 2-year-old child during the previous three contexts using a randomized crossover design (n = 22) in a laboratory room. Among other results, mothers were more sensitive and structuring during joint gaming on a tablet than when engaged in toy play or watching TV. In addition, mothers were more hostile toward their children during play with traditional toys than during joint tablet gaming and television co-viewing. Such findings provide new insights into the impact of new media on parent-child interactions, chiefly by demonstrating that interactive media devices such as tablets can afford growth-enhancing parent-child interactions. © 2017 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Structure and expression of a novel compact myelin protein – Small VCP-interacting protein (SVIP)

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

Wu, Jiawen; Peng, Dungeng; Voehler, Markus

2013-10-11

Highlights: •SVIP (small p97/VCP-interacting protein) co-localizes with myelin basic protein (MBP) in compact myelin. •We determined that SVIP is an intrinsically disordered protein (IDP). •The helical content of SVIP increases dramatically during its interaction with negatively charged lipid membrane. •This study provides structural insight into interactions between SVIP and myelin membranes. -- Abstract: SVIP (small p97/VCP-interacting protein) was initially identified as one of many cofactors regulating the valosin containing protein (VCP), an AAA+ ATPase involved in endoplasmic-reticulum-associated protein degradation (ERAD). Our previous study showed that SVIP is expressed exclusively in the nervous system. In the present study, SVIP and VCPmore » were seen to be co-localized in neuronal cell bodies. Interestingly, we also observed that SVIP co-localizes with myelin basic protein (MBP) in compact myelin, where VCP was absent. Furthermore, using nuclear magnetic resonance (NMR) and circular dichroism (CD) spectroscopic measurements, we determined that SVIP is an intrinsically disordered protein (IDP). However, upon binding to the surface of membranes containing a net negative charge, the helical content of SVIP increases dramatically. These findings provide structural insight into interactions between SVIP and myelin membranes.« less

Investigating the importance of Delaunay-based definition of atomic interactions in scoring of protein-protein docking results.

PubMed

Jafari, Rahim; Sadeghi, Mehdi; Mirzaie, Mehdi

2016-05-01

The approaches taken to represent and describe structural features of the macromolecules are of major importance when developing computational methods for studying and predicting their structures and interactions. This study attempts to explore the significance of Delaunay tessellation for the definition of atomic interactions by evaluating its impact on the performance of scoring protein-protein docking prediction. Two sets of knowledge-based scoring potentials are extracted from a training dataset of native protein-protein complexes. The potential of the first set is derived using atomic interactions extracted from Delaunay tessellated structures. The potential of the second set is calculated conventionally, that is, using atom pairs whose interactions were determined by their separation distances. The scoring potentials were tested against two different docking decoy sets and their performances were compared. The results show that, if properly optimized, the Delaunay-based scoring potentials can achieve higher success rate than the usual scoring potentials. These results and the results of a previous study on the use of Delaunay-based potentials in protein fold recognition, all point to the fact that Delaunay tessellation of protein structure can provide a more realistic definition of atomic interaction, and therefore, if appropriately utilized, may be able to improve the accuracy of pair potentials. Copyright © 2016 Elsevier Inc. All rights reserved.

Older Adults Perceptions of Technology and Barriers to Interacting with Tablet Computers: A Focus Group Study.

PubMed

Vaportzis, Eleftheria; Clausen, Maria Giatsi; Gow, Alan J

2017-10-04

New technologies provide opportunities for the delivery of broad, flexible interventions with older adults. Focus groups were conducted to: (1) understand older adults' familiarity with, and barriers to, interacting with new technologies and tablets; and (2) utilize user-engagement in refining an intervention protocol. Eighteen older adults (65-76 years old; 83.3% female) who were novice tablet users participated in discussions about their perceptions of and barriers to interacting with tablets. We conducted three separate focus groups and used a generic qualitative design applying thematic analysis to analyse the data. The focus groups explored attitudes toward tablets and technology in general. We also explored the perceived advantages and disadvantages of using tablets, familiarity with, and barriers to interacting with tablets. In two of the focus groups, participants had previous computing experience (e.g., desktop), while in the other, participants had no previous computing experience. None of the participants had any previous experience with tablet computers. The themes that emerged were related to barriers (i.e., lack of instructions and guidance, lack of knowledge and confidence, health-related barriers, cost); disadvantages and concerns (i.e., too much and too complex technology, feelings of inadequacy, and comparison with younger generations, lack of social interaction and communication, negative features of tablets); advantages (i.e., positive features of tablets, accessing information, willingness to adopt technology); and skepticism about using tablets and technology in general. After brief exposure to tablets, participants emphasized the likelihood of using a tablet in the future. Our findings suggest that most of our participants were eager to adopt new technology and willing to learn using a tablet. However, they voiced apprehension about lack of, or lack of clarity in, instructions and support. Understanding older adults' perceptions of technology is important to assist with introducing it to this population and maximize the potential of technology to facilitate independent living.

Older Adults Perceptions of Technology and Barriers to Interacting with Tablet Computers: A Focus Group Study

PubMed Central

Vaportzis, Eleftheria; Giatsi Clausen, Maria; Gow, Alan J.

2017-01-01

Background: New technologies provide opportunities for the delivery of broad, flexible interventions with older adults. Focus groups were conducted to: (1) understand older adults' familiarity with, and barriers to, interacting with new technologies and tablets; and (2) utilize user-engagement in refining an intervention protocol. Methods: Eighteen older adults (65–76 years old; 83.3% female) who were novice tablet users participated in discussions about their perceptions of and barriers to interacting with tablets. We conducted three separate focus groups and used a generic qualitative design applying thematic analysis to analyse the data. The focus groups explored attitudes toward tablets and technology in general. We also explored the perceived advantages and disadvantages of using tablets, familiarity with, and barriers to interacting with tablets. In two of the focus groups, participants had previous computing experience (e.g., desktop), while in the other, participants had no previous computing experience. None of the participants had any previous experience with tablet computers. Results: The themes that emerged were related to barriers (i.e., lack of instructions and guidance, lack of knowledge and confidence, health-related barriers, cost); disadvantages and concerns (i.e., too much and too complex technology, feelings of inadequacy, and comparison with younger generations, lack of social interaction and communication, negative features of tablets); advantages (i.e., positive features of tablets, accessing information, willingness to adopt technology); and skepticism about using tablets and technology in general. After brief exposure to tablets, participants emphasized the likelihood of using a tablet in the future. Conclusions: Our findings suggest that most of our participants were eager to adopt new technology and willing to learn using a tablet. However, they voiced apprehension about lack of, or lack of clarity in, instructions and support. Understanding older adults' perceptions of technology is important to assist with introducing it to this population and maximize the potential of technology to facilitate independent living. PMID:29071004

Neck motion kinematics: an inter-tester reliability study using an interactive neck VR assessment in asymptomatic individuals.

PubMed

Sarig Bahat, Hilla; Sprecher, Elliot; Sela, Itamar; Treleaven, Julia

2016-07-01

The use of virtual reality (VR) for assessment and intervention of neck pain has previously been used and shown reliable for cervical range of motion measures. Neck VR enables analysis of task-oriented neck movement by stimulating responsive movements to external stimuli. Therefore, the purpose of this study was to establish inter-tester reliability of neck kinematic measures so that it can be used as a reliable assessment and treatment tool between clinicians. This reliability study included 46 asymptomatic participants, who were assessed using the neck VR system which displayed an interactive VR scenario via a head-mounted device, controlled by neck movements. The objective of the interactive assessment was to hit 16 targets, randomly appearing in four directions, as fast as possible. Each participant was tested twice by two different testers. Good reliability was found of neck motion kinematic measures in flexion, extension, and rotation (0.64-0.93 inter-class correlation). High reliability was shown for peak velocity globally (0.93), in left rotation (0.9), right rotation and extension (0.88), and flexion (0.86). Mean velocity had a good global reliability (0.84), except for left rotation directed movement with moderate reliability (0.68). Minimal detectable change for peak velocity ranged from 41 to 53 °/s, while mean velocity ranged from 20 to 25 °/s. The results suggest high reliability for peak and mean velocity as measured by the interactive Neck VR assessment of neck motion kinematics. VR appears to provide a reliable and more ecologically valid method of cervical motion evaluation than previous conventional methodologies.

Interactions between household air pollution and GWAS-identified lung cancer susceptibility markers in the Female Lung Cancer Consortium in Asia (FLCCA).

PubMed

Hosgood, H Dean; Song, Minsun; Hsiung, Chao Agnes; Yin, Zhihua; Shu, Xiao-Ou; Wang, Zhaoming; Chatterjee, Nilanjan; Zheng, Wei; Caporaso, Neil; Burdette, Laurie; Yeager, Meredith; Berndt, Sonja I; Landi, Maria Teresa; Chen, Chien-Jen; Chang, Gee-Chen; Hsiao, Chin-Fu; Tsai, Ying-Huang; Chien, Li-Hsin; Chen, Kuan-Yu; Huang, Ming-Shyan; Su, Wu-Chou; Chen, Yuh-Min; Chen, Chung-Hsing; Yang, Tsung-Ying; Wang, Chih-Liang; Hung, Jen-Yu; Lin, Chien-Chung; Perng, Reury-Perng; Chen, Chih-Yi; Chen, Kun-Chieh; Li, Yao-Jen; Yu, Chong-Jen; Chen, Yi-Song; Chen, Ying-Hsiang; Tsai, Fang-Yu; Kim, Christopher; Seow, Wei Jie; Bassig, Bryan A; Wu, Wei; Guan, Peng; He, Qincheng; Gao, Yu-Tang; Cai, Qiuyin; Chow, Wong-Ho; Xiang, Yong-Bing; Lin, Dongxin; Wu, Chen; Wu, Yi-Long; Shin, Min-Ho; Hong, Yun-Chul; Matsuo, Keitaro; Chen, Kexin; Wong, Maria Pik; Lu, Dara; Jin, Li; Wang, Jiu-Cun; Seow, Adeline; Wu, Tangchun; Shen, Hongbing; Fraumeni, Joseph F; Yang, Pan-Chyr; Chang, I-Shou; Zhou, Baosen; Chanock, Stephen J; Rothman, Nathaniel; Lan, Qing

2015-03-01

We previously carried out a multi-stage genome-wide association study (GWAS) on lung cancer among never smokers in the Female Lung Cancer Consortium in Asia (FLCCA) (6,609 cases, 7,457 controls) that identified novel susceptibility loci at 10q25.2, 6q22.2, and 6p21.32, and confirmed two previously identified loci at 5p15.33 and 3q28. Household air pollution (HAP) attributed to solid fuel burning for heating and cooking, is the leading cause of the overall disease burden in Southeast Asia, and is known to contain lung carcinogens. To evaluate the gene-HAP interactions associated with lung cancer in loci independent of smoking, we analyzed data from studies participating in FLCCA with fuel use information available (n = 3; 1,731 cases; 1,349 controls). Coal use was associated with a 30% increased risk of lung cancer (OR 1.3, 95% CI 1.0-1.6). Among the five a priori SNPs identified by our GWAS, two showed a significant interaction with coal use (HLA Class II rs2395185, p = 0.02; TP63 rs4488809 (rs4600802), p = 0.04). The risk of lung cancer associated with coal exposure varied with the respective alleles for these two SNPs. Our observations provide evidence that genetic variation in HLA Class II and TP63 may modify the association between HAP and lung cancer risk. The roles played in the cell cycle and inflammation pathways by the proteins encoded by these two genes provide biological plausibility for these interactions; however, additional replication studies are needed in other non-smoking populations.

The afterlife of interspecific indirect genetic effects: genotype interactions alter litter quality with consequences for decomposition and nutrient dynamics.

PubMed

Genung, Mark A; Bailey, Joseph K; Schweitzer, Jennifer A

2013-01-01

Aboveground-belowground linkages are recognized as divers of community dynamics and ecosystem processes, but the impacts of plant-neighbor interactions on these linkages are virtually unknown. Plant-neighbor interactions are a type of interspecific indirect genetic effect (IIGE) if the focal plant's phenotype is altered by the expression of genes in a neighboring heterospecific plant, and IIGEs could persist after plant senescence to affect ecosystem processes. This perspective can provide insight into how plant-neighbor interactions affect evolution, as IIGEs are capable of altering species interactions and community composition over time. Utilizing genotypes of Solidago altissima and Solidago gigantea, we experimentally tested whether IIGEs that had affected living focal plants would affect litter decomposition rate, as well as nitrogen (N) and phosphorous (P) dynamics after the focal plant senesced. We found that species interactions affected N release and genotype interactions affected P immobilization. From a previous study we knew that neighbor genotype influenced patterns of biomass allocation for focal plants. Here we extend those previous results to show that these changes in biomass allocation altered litter quality, that then altered rates of decomposition and nutrient cycling. Our results provide insights into above- and belowground linkages by showing that, through their effects on plant litter quality (e.g., litter lignin:N), IIGEs can have afterlife effects, tying plant-neighbor interactions to ecosystem processes. This holistic approach advances our understanding of decomposition and nutrient cycling by showing that evolutionary processes (i.e., IIGEs) can influence ecosystem functioning after plant senescence. Because plant traits are determined by the combined effects of genetic and environmental influences, and because these traits are known to affect decomposition and nutrient cycling, we suggest that ecosystem processes can be described as gene-less products of genetic interactions among the species comprising ecological communities.

The Afterlife of Interspecific Indirect Genetic Effects: Genotype Interactions Alter Litter Quality with Consequences for Decomposition and Nutrient Dynamics

PubMed Central

Genung, Mark A.; Bailey, Joseph K.; Schweitzer, Jennifer A.

2013-01-01

Aboveground-belowground linkages are recognized as divers of community dynamics and ecosystem processes, but the impacts of plant-neighbor interactions on these linkages are virtually unknown. Plant-neighbor interactions are a type of interspecific indirect genetic effect (IIGE) if the focal plant’s phenotype is altered by the expression of genes in a neighboring heterospecific plant, and IIGEs could persist after plant senescence to affect ecosystem processes. This perspective can provide insight into how plant-neighbor interactions affect evolution, as IIGEs are capable of altering species interactions and community composition over time. Utilizing genotypes of Solidago altissima and Solidago gigantea, we experimentally tested whether IIGEs that had affected living focal plants would affect litter decomposition rate, as well as nitrogen (N) and phosphorous (P) dynamics after the focal plant senesced. We found that species interactions affected N release and genotype interactions affected P immobilization. From a previous study we knew that neighbor genotype influenced patterns of biomass allocation for focal plants. Here we extend those previous results to show that these changes in biomass allocation altered litter quality, that then altered rates of decomposition and nutrient cycling. Our results provide insights into above- and belowground linkages by showing that, through their effects on plant litter quality (e.g., litter lignin:N), IIGEs can have afterlife effects, tying plant-neighbor interactions to ecosystem processes. This holistic approach advances our understanding of decomposition and nutrient cycling by showing that evolutionary processes (i.e., IIGEs) can influence ecosystem functioning after plant senescence. Because plant traits are determined by the combined effects of genetic and environmental influences, and because these traits are known to affect decomposition and nutrient cycling, we suggest that ecosystem processes can be described as gene-less products of genetic interactions among the species comprising ecological communities. PMID:23349735

Interactive Education in Public Administration (2): Strategies for Teachers

ERIC Educational Resources Information Center

Brock, Jonathan; Alford, John

2015-01-01

The previous article ("Interactive education in public administration (1): The role of teaching 'objects'") described the benefits of "moving from behind the lectern" to engage in interactive teaching in public policy and administration, and the central role of "objects" in that process. But teaching…

Yakima River Species Interactions Studies, Annual Report 1993.

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

Pearsons, Todd N.

Species interactions research was initiated in 1989 to investigate ecological interactions among fish in response to proposed supplementation of salmon and steelhead in the upper Yakima River basin. Data have been collected prior to supplementation to characterize the rainbow trout population, predict the potential interactions that may occur as a result of supplementation, and develop methods to monitor interactions. Major topics of this report are associated with the life history of rainbow trout, interactions experimentation, and methods for sampling. This report is organized into nine chapters with a general introduction preceding the first chapter and a general discussion following themore » last chapter. This annual report summarizes data collected primarily by the Washington Department of Fish and Wildlife (WDFW) between January 1 and December 31, 1993 in the upper Yakima basin above Roza Dam, however these data were compared to data from previous years to identify preliminary trends and patterns. Major preliminary findings from each of the chapters included in this report are described.« less

Similarity-transformed chiral NN + 3N interactions for the ab initio description of 12C and 16O.

PubMed

Roth, Robert; Langhammer, Joachim; Calci, Angelo; Binder, Sven; Navrátil, Petr

2011-08-12

We present first ab initio no-core shell model (NCSM) calculations using similarity renormalization group (SRG) transformed chiral two-nucleon (NN) plus three-nucleon (3N) interactions for nuclei throughout the p-shell, particularly (12)C and (16)O. By introducing an adaptive importance truncation for the NCSM model space and an efficient JT-coupling scheme for the 3N matrix elements, we are able to surpass previous NCSM studies including 3N interactions. We present ground and excited states in (12)C and (16)O for model spaces up to N(max) = 12 including full 3N interactions. We analyze the contributions of induced and initial 3N interactions and probe induced 4N terms through the sensitivity of the energies on the SRG flow parameter. Unlike for light p-shell nuclei, SRG-induced 4N contributions originating from the long-range two-pion terms of the chiral 3N interaction are sizable in (12)C and (16)O.

Adaptation of Tri-molecular fluorescence complementation allows assaying of regulatory Csr RNA-protein interactions in bacteria.

PubMed

Gelderman, Grant; Sivakumar, Anusha; Lipp, Sarah; Contreras, Lydia

2015-02-01

sRNAs play a significant role in controlling and regulating cellular metabolism. One of the more interesting aspects of certain sRNAs is their ability to make global changes in the cell by interacting with regulatory proteins. In this work, we demonstrate the use of an in vivo Tri-molecular Fluorescence Complementation assay to detect and visualize the central regulatory sRNA-protein interaction of the Carbon Storage Regulatory system in E. coli. The Carbon Storage Regulator consists primarily of an RNA binding protein, CsrA, that alters the activity of mRNA targets and of an sRNA, CsrB, that modulates the activity of CsrA. We describe the construction of a fluorescence complementation system that detects the interactions between CsrB and CsrA. Additionally, we demonstrate that the intensity of the fluorescence of this system is able to detect changes in the affinity of the CsrB-CsrA interaction, as caused by mutations in the protein sequence of CsrA. While previous methods have adopted this technique to study mRNA or RNA localization, this is the first attempt to use this technique to study the sRNA-protein interaction directly in bacteria. This method presents a potentially powerful tool to study complex bacterial RNA protein interactions in vivo. © 2014 Wiley Periodicals, Inc.

A Bayesian mixture model for chromatin interaction data.

PubMed

Niu, Liang; Lin, Shili

2015-02-01

Chromatin interactions mediated by a particular protein are of interest for studying gene regulation, especially the regulation of genes that are associated with, or known to be causative of, a disease. A recent molecular technique, Chromatin interaction analysis by paired-end tag sequencing (ChIA-PET), that uses chromatin immunoprecipitation (ChIP) and high throughput paired-end sequencing, is able to detect such chromatin interactions genomewide. However, ChIA-PET may generate noise (i.e., pairings of DNA fragments by random chance) in addition to true signal (i.e., pairings of DNA fragments by interactions). In this paper, we propose MC_DIST based on a mixture modeling framework to identify true chromatin interactions from ChIA-PET count data (counts of DNA fragment pairs). The model is cast into a Bayesian framework to take into account the dependency among the data and the available information on protein binding sites and gene promoters to reduce false positives. A simulation study showed that MC_DIST outperforms the previously proposed hypergeometric model in terms of both power and type I error rate. A real data study showed that MC_DIST may identify potential chromatin interactions between protein binding sites and gene promoters that may be missed by the hypergeometric model. An R package implementing the MC_DIST model is available at http://www.stat.osu.edu/~statgen/SOFTWARE/MDM.

Interaction location outweighs the competitive advantage of numerical superiority in Cebus capucinus intergroup contests.

PubMed

Crofoot, Margaret C; Gilby, Ian C; Wikelski, Martin C; Kays, Roland W

2008-01-15

Numerical superiority confers a competitive advantage during contests among animal groups, shaping patterns of resource access, and, by extension, fitness. However, relative group size does not always determine the winner of intergroup contests. Smaller, presumably weaker social groups often defeat their larger neighbors, but how and when they are able to do so remains poorly understood. Models of competition between individuals suggest that location may influence contest outcome. However, because of the logistical difficulties of studying intergroup interactions, previous studies have been unable to determine how contest location and group size interact to shape relationships among groups. We address this question by using an automated radio telemetry system to study intergroup interactions among six capuchin monkey (Cebus capucinus) social groups of varying sizes. We find that the odds of winning increase with relative group size; one additional group member increases the odds of winning an interaction by 10%. However, this effect is not uniform across space; with each 100 m that a group moves away from the center of its home range, its odds of winning an interaction decrease by 31%. We demonstrate that contest outcome depends on an interaction between group size and location, such that small groups can defeat much larger groups near the center of their home range. The tendency of resident groups to win contests may help explain how small groups persist in areas with intense intergroup competition.

A Genome-wide Trans-ethnic Interaction Study Links the PIGR ...

EPA Pesticide Factsheets

Air pollution is a worldwide contributor to cardiovascular disease mortality and morbidity. Traffic air pollution is a ubiquitous source of air pollution in developed nations, and is associated with multiple cardiovascular outcomes such as: coronary atherosclerosis, peripheral arterial disease, and myocardial infarction. Despite the recognition of the importance of both genetic and environmental exposures to the pathogenesis of cardiovascular disease, studies of these two contributors jointly are rare. We performed a genome-wide interaction study (GWIS) to examine gene-traffic exposure interactions associated with coronary atherosclerosis. Using race-stratified cohorts of 554 African-Americans (AA) and 1623 European-Americans (EA) from a cardiac catheterization cohort (CATHGEN), we identify gene-by-traffic exposure interactions associated with the number of significantly diseased coronary vessels as a measure of chronic atherosclerosis. We found five suggestive (P<1x10-5) interactions in the AA GWIS, of which two (rs1856746 and rs2791713) replicated in the EA cohort (P < 0.05). Both SNPs are in the PIGR-FCAMR locus and are eQTLs in lymphocytes. The protein products of both PIGR and FCAMR are implicated in inflammatory processes. In the EA GWIS, there were three suggestive interactions; none of these replicated in the AA GWIS. All three were intergenic; the most significant interaction was in a regulatory region associated with SAMSN1, a gene previously associate

Predicting protein-protein interactions from protein domains using a set cover approach.

PubMed

Huang, Chengbang; Morcos, Faruck; Kanaan, Simon P; Wuchty, Stefan; Chen, Danny Z; Izaguirre, Jesús A

2007-01-01

One goal of contemporary proteome research is the elucidation of cellular protein interactions. Based on currently available protein-protein interaction and domain data, we introduce a novel method, Maximum Specificity Set Cover (MSSC), for the prediction of protein-protein interactions. In our approach, we map the relationship between interactions of proteins and their corresponding domain architectures to a generalized weighted set cover problem. The application of a greedy algorithm provides sets of domain interactions which explain the presence of protein interactions to the largest degree of specificity. Utilizing domain and protein interaction data of S. cerevisiae, MSSC enables prediction of previously unknown protein interactions, links that are well supported by a high tendency of coexpression and functional homogeneity of the corresponding proteins. Focusing on concrete examples, we show that MSSC reliably predicts protein interactions in well-studied molecular systems, such as the 26S proteasome and RNA polymerase II of S. cerevisiae. We also show that the quality of the predictions is comparable to the Maximum Likelihood Estimation while MSSC is faster. This new algorithm and all data sets used are accessible through a Web portal at http://ppi.cse.nd.edu.

The core planar cell polarity gene prickle interacts with flamingo to promote sensory axon advance in the Drosophila embryo.

PubMed

Mrkusich, Eli M; Flanagan, Dustin J; Whitington, Paul M

2011-10-01

The atypical cadherin Drosophila protein Flamingo and its vertebrate homologues play widespread roles in the regulation of both dendrite and axon growth. However, little is understood about the molecular mechanisms that underpin these functions. Whereas flamingo interacts with a well-defined group of genes in regulating planar cell polarity, previous studies have uncovered little evidence that the other core planar cell polarity genes are involved in regulation of neurite growth. We present data in this study showing that the planar cell polarity gene prickle interacts with flamingo in regulating sensory axon advance at a key choice point - the transition between the peripheral nervous system and the central nervous system. The cytoplasmic tail of the Flamingo protein is not required for this interaction. Overexpression of another core planar cell polarity gene dishevelled produces a similar phenotype to prickle mutants, suggesting that this gene may also play a role in regulation of sensory axon advance. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

Data-driven modelling of social forces and collective behaviour in zebrafish.

PubMed

Zienkiewicz, Adam K; Ladu, Fabrizio; Barton, David A W; Porfiri, Maurizio; Bernardo, Mario Di

2018-04-14

Zebrafish are rapidly emerging as a powerful model organism in hypothesis-driven studies targeting a number of functional and dysfunctional processes. Mathematical models of zebrafish behaviour can inform the design of experiments, through the unprecedented ability to perform pilot trials on a computer. At the same time, in-silico experiments could help refining the analysis of real data, by enabling the systematic investigation of key neurobehavioural factors. Here, we establish a data-driven model of zebrafish social interaction. Specifically, we derive a set of interaction rules to capture the primary response mechanisms which have been observed experimentally. Contrary to previous studies, we include dynamic speed regulation in addition to turning responses, which together provide attractive, repulsive and alignment interactions between individuals. The resulting multi-agent model provides a novel, bottom-up framework to describe both the spontaneous motion and individual-level interaction dynamics of zebrafish, inferred directly from experimental observations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Interactome INSIDER: a structural interactome browser for genomic studies.

PubMed

Meyer, Michael J; Beltrán, Juan Felipe; Liang, Siqi; Fragoza, Robert; Rumack, Aaron; Liang, Jin; Wei, Xiaomu; Yu, Haiyuan

2018-01-01

We present Interactome INSIDER, a tool to link genomic variant information with structural protein-protein interactomes. Underlying this tool is the application of machine learning to predict protein interaction interfaces for 185,957 protein interactions with previously unresolved interfaces in human and seven model organisms, including the entire experimentally determined human binary interactome. Predicted interfaces exhibit functional properties similar to those of known interfaces, including enrichment for disease mutations and recurrent cancer mutations. Through 2,164 de novo mutagenesis experiments, we show that mutations of predicted and known interface residues disrupt interactions at a similar rate and much more frequently than mutations outside of predicted interfaces. To spur functional genomic studies, Interactome INSIDER (http://interactomeinsider.yulab.org) enables users to identify whether variants or disease mutations are enriched in known and predicted interaction interfaces at various resolutions. Users may explore known population variants, disease mutations, and somatic cancer mutations, or they may upload their own set of mutations for this purpose.

Simulations of stellar winds and planetary bodies: Magnetized obstacles in a super-Alfvénic flow with southward IMF

NASA Astrophysics Data System (ADS)

Vernisse, Y.; Riousset, J. A.; Motschmann, U.; Glassmeier, K.-H.

2018-03-01

This study addresses the issue of the electromagnetic interactions between a stellar wind and planetary magnetospheres with various dipole field strengths by means of hybrid simulations. Focus is placed on the configuration where the upstream plasma magnetic field is parallel to the planetary magnetic moment (also called "Southward-IMF" configuration), leading to anti-parallel magnetic fields in the dayside interaction region. Each type of plasma interaction is characterized by means of currents flowing in the interaction region. Reconnection triggered in the tail in such configuration is shown to affect significantly the structure of the magnetotail at early stages. On the dayside, only the magnetopause current is observable for moderate planetary dipole field amplitude, while both bow-shock and magnetotail currents are identifiable downtail from the terminator. Strong differences in term of temperature for ions are particularly noticeable in the magnetosheath and in the magnetotail, when the present results are compared with our previous study, which focused on "Northward-IMF" configuration.

Studies of supersonic, radiative plasma jet interaction with gases at the Prague Asterix Laser System facility

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

Nicolaie, Ph.; Stenz, C.; Tikhonchuk, V.

2008-08-15

The interaction of laser driven jets with gas puffs at various pressures is investigated experimentally and is analyzed by means of numerical tools. In the experiment, a combination of two complementary diagnostics allowed to characterize the main structures in the interaction zone. By changing the gas composition and its density, the plasma cooling time can be controlled and one can pass from a quasiadiabatic outflow to a strongly radiation cooling jet. This tuning yields hydrodynamic structures very similar to those seen in astrophysical objects; the bow shock propagating through the gas, the shocked materials, the contact discontinuity, and the Machmore » disk. From a dimensional analysis, a scaling is made between both systems and shows the study relevance for the jet velocity, the Mach number, the jet-gas density ratio, and the dissipative processes. The use of a two-dimensional radiation hydrodynamic code, confirms the previous analysis and provides detailed structure of the interaction zone and energy repartition between jet and surrounding gases.« less

The influence of metoprolol dosage release formulation on the pharmacokinetic drug interaction with paroxetine

PubMed Central

Stout, Stephen M.; Nielsen, Jace; Welage, Lynda S.; Shea, Michael; Brook, Robert; Kerber, Kevin; Bleske, Barry E.

2010-01-01

Studies have demonstrated an influence of dosage release formulations on drug interactions and enantiomeric plasma concentrations. Metoprolol is a commonly used β-adrenergic antagonist metabolized by CYP2D6. The CYP2D6 inhibitor paroxetine has previously been shown to interact with metoprolol tartrate. This open-label, randomized, 4 phase crossover study assessed the potential differential effects of paroxetine on stereoselective pharmacokinetics of immediate release (IR) tartrate and extended release (ER) succinate metoprolol formulations. Ten healthy subjects received metoprolol IR (50 mg) and ER (100 mg) with and without paroxetine coadministration. Blood samples were collected over 24 hours for determination of metoprolol plasma enantiomer concentrations. Paroxetine coadministration significantly increased S and R metoprolol AUC0–24h by 4 and 5 fold, respectively for IR, and 3 and 4 fold, respectively for ER. S/R AUC ratios significantly decreased. These results demonstrate a pharmacokinetic interaction between paroxetine and both formulations of metoprolol. The interaction is greater with R metoprolol and stereoselective metabolism is lost. This could theoretically result in greater β-blockade and lost cardioselectivity. The magnitude of the interaction was similar between metoprolol formulations, which may be attributable to low doses / drug input rates employed. PMID:20400652

The interactive effects of estrogen and progesterone on changes in emotional eating across the menstrual cycle.

PubMed

Klump, Kelly L; Keel, Pamela K; Racine, Sarah E; Burt, S Alexandra; Burt, Alexandra S; Neale, Michael; Sisk, Cheryl L; Boker, Steven; Hu, Jean Yueqin

2013-02-01

Studies suggest that within-person changes in estrogen and progesterone predict changes in binge eating across the menstrual cycle. However, samples have been extremely small (maximum N = 9), and analyses have not examined the interactive effects of hormones that are critical for changes in food intake in animals. The aims of the current study were to examine ovarian hormone interactions in the prediction of within-subject changes in emotional eating in the largest sample of women to date (N = 196). Participants provided daily ratings of emotional eating and saliva samples for hormone measurement for 45 consecutive days. Results confirmed that changes in ovarian hormones predict changes in emotional eating across the menstrual cycle, with a significant estradiol × progesterone interaction. Emotional eating scores were highest during the midluteal phase, when progesterone peaks and estradiol demonstrates a secondary peak. Findings extend previous work by highlighting significant interactions between estrogen and progesterone that explain midluteal increases in emotional eating. Future work should explore mechanisms (e.g., gene-hormone interactions) that contribute to both within- and between-subjects differences in emotional eating. 2013 APA, all rights reserved

A numerical investigation of the airfoil-gust interaction noise in transonic flows: Acoustic processes

NASA Astrophysics Data System (ADS)

Zhong, Siyang; Zhang, Xin; Gill, James; Fattah, Ryu; Sun, Yuhao

2018-07-01

The sound produced by airfoil-gust interaction is a significant source of broadband noise in turbofan engines or contra-rotating open rotors (CRORs). There are competing mechanisms in this regime because of the presence of shocks that were seldom considered in the previous subsonic studies. A numerical investigation of airfoil-gust interaction noise at transonic speeds is undertaken in this work. By introducing vortical gust/synthetic turbulence to specified regions in the computational domain to interact with different elements in the flow field, it is shown that the dominant sound source is caused by leading edge-gust interaction. It is demonstrated that both streamwise and transverse disturbances interact with the near-field non-uniform mean flow and shocks can produce sound using a local gust injection method. The propagation of sound is significantly influenced by the presence of the shocks, and the far field radiation pattern is changed. We also study the effect of gust strength on the near and far field properties. The linearity is maintained for gust strength smaller than 1.0% of the mean flow velocity. Otherwise, the shocks may experience oscillations that will alter the near-field aerodynamics and far-field radiation.

Family, friends, and 12-month PTSD among African Americans.

PubMed

Nguyen, Ann W; Chatters, Linda M; Taylor, Robert Joseph; Levine, Debra Siegel; Himle, Joseph A

2016-08-01

Despite a growing literature on the influence of social support on mental health, little is known about the relationship between social support and specific psychiatric disorders for African Americans, such as PTSD. This study investigated the relationship between social support, negative interaction with family and 12-month PTSD among African Americans. Analyses were based on a nationally representative sample of African Americans from the National Survey of American Life (n = 3315). Social support variables included emotional support from family, frequency of contact with family and friends, subjective closeness with family and friends, and negative interactions with family. Results indicated that emotional support from family is negatively associated with 12-month PTSD while negative interaction with family is predictive of 12-month PTSD. Additionally, a significant interaction indicated that high levels of subjective closeness to friends could offset the impact of negative family interactions on 12-month PTSD. Overall, study results converged with previously established findings indicating that emotional support from family is associated with 12-month PTSD, while, negative interaction with family is associated with increased risk of 12-month PTSD. The findings are discussed in relation to prior research on the unique association between social support and mental health among African Americans.

Personal vulnerability and work-home interaction: the effect of job performance-based self-esteem on work/home conflict and facilitation.

PubMed

Innstrand, Siw Tone; Langballe, Ellen Melbye; Espnes, Geir Arild; Aasland, Olaf Gjerløw; Falkum, Erik

2010-12-01

The aim of the present study was to examine the longitudinal relationship between job performance-based self-esteem (JPB-SE) and work-home interaction (WHI) in terms of the direction of the interaction (work-to-home vs. home-to-work) and the effect (conflict vs. facilitation). A sample of 3,475 respondents from eight different occupational groups (lawyers, physicians, nurses, teachers, church ministers, bus drivers, and people working in advertising and information technology) supplied data at two points of time with a two-year time interval. The two-wave, cross-lagged structural equations modeling (SEM) analysis demonstrated reciprocal relationships between these variables, i.e., job performance-based self-esteem may act as a precursor as well as an outcome of work-home interaction. The strongest association was between job performance-based self-esteem and work-to-home conflict. Previous research on work-home interaction has mainly focused on situational factors. This longitudinal study expands the work-home literature by demonstrating how individual vulnerability (job performance-based self-esteem) contributes to the explanation of work-home interactions. © 2010 The Authors. Scandinavian Journal of Psychology © 2010 The Scandinavian Psychological Associations.

Interactions of Condensed Tannins with Saccharomyces cerevisiae Yeast Cells and Cell Walls: Tannin Location by Microscopy.

PubMed

Mekoue Nguela, Julie; Vernhet, Aude; Sieczkowski, Nathalie; Brillouet, Jean-Marc

2015-09-02

Interactions between grape tannins/red wine polyphenols and yeast cells/cell walls was previously studied within the framework of red wine aging and the use of yeast-derived products as an alternative to aging on lees. Results evidenced a quite different behavior between whole cells (biomass grown to elaborate yeast-derived products, inactivated yeast, and yeast inactivated after autolysis) and yeast cell walls (obtained from mechanical disruption of the biomass). Briefly, whole cells exhibited a high capacity to irreversibly adsorb grape and wine tannins, whereas only weak interactions were observed for cell walls. This last point was quite unexpected considering the literature and called into question the real role of cell walls in yeasts' ability to fix tannins. In the present work, tannin location after interactions between grape and wine tannins and yeast cells and cell walls was studied by means of transmission electron microscopy, light epifluorescence, and confocal microscopy. Microscopy observations evidenced that if tannins interact with cell walls, and especially cell wall mannoproteins, they also diffuse freely through the walls of dead cells to interact with their plasma membrane and cytoplasmic components.

Cloud-Resolving Model Simulations of Aerosol-Cloud Interactions Triggered by Strong Aerosol Emissions in the Arctic

NASA Astrophysics Data System (ADS)

Wang, H.; Kravitz, B.; Rasch, P. J.; Morrison, H.; Solomon, A.

2014-12-01

Previous process-oriented modeling studies have highlighted the dependence of effectiveness of cloud brightening by aerosols on cloud regimes in warm marine boundary layer. Cloud microphysical processes in clouds that contain ice, and hence the mechanisms that drive aerosol-cloud interactions, are more complicated than in warm clouds. Interactions between ice particles and liquid drops add additional levels of complexity to aerosol effects. A cloud-resolving model is used to study aerosol-cloud interactions in the Arctic triggered by strong aerosol emissions, through either geoengineering injection or concentrated sources such as shipping and fires. An updated cloud microphysical scheme with prognostic aerosol and cloud particle numbers is employed. Model simulations are performed in pure super-cooled liquid and mixed-phase clouds, separately, with or without an injection of aerosols into either a clean or a more polluted Arctic boundary layer. Vertical mixing and cloud scavenging of particles injected from the surface is still quite efficient in the less turbulent cold environment. Overall, the injection of aerosols into the Arctic boundary layer can delay the collapse of the boundary layer and increase low-cloud albedo. The pure liquid clouds are more susceptible to the increase in aerosol number concentration than the mixed-phase clouds. Rain production processes are more effectively suppressed by aerosol injection, whereas ice precipitation (snow) is affected less; thus the effectiveness of brightening mixed-phase clouds is lower than for liquid-only clouds. Aerosol injection into a clean boundary layer results in a greater cloud albedo increase than injection into a polluted one, consistent with current knowledge about aerosol-cloud interactions. Unlike previous studies investigating warm clouds, the impact of dynamical feedback due to precipitation changes is small. According to these results, which are dependent upon the representation of ice nucleation processes in the employed microphysical scheme, Arctic geoengineering/shipping could have substantial local radiative effects, but is unlikely to be effective as the sole means of counterbalancing warming due to climate change.

Land-atmosphere interaction patterns in southeastern South America using satellite products and climate models

NASA Astrophysics Data System (ADS)

Spennemann, P. C.; Salvia, M.; Ruscica, R. C.; Sörensson, A. A.; Grings, F.; Karszenbaum, H.

2018-02-01

In regions of strong Land-Atmosphere (L-A) interaction, soil moisture (SM) conditions can impact the atmosphere through modulating the land surface fluxes. The importance of the identification of L-A interaction regions lies in the potential improvement of the weather/seasonal forecast and the better understanding of the physical mechanisms involved. This study aims to compare the terrestrial segment of the L-A interaction from satellite products and climate models, motivated by previous modeling studies pointing out southeastern South America (SESA) as a L-A hotspot during austral summer. In addition, the L-A interaction under dry or wet anomalous conditions over SESA is analyzed. To identify L-A hotspots the AMSRE-LPRM SM and MODIS land surface temperature products; coupled climate models and uncoupled land surface models were used. SESA highlights as a strong L-A interaction hotspot when employing different metrics, temporal scales and independent datasets, showing consistency between models and satellite estimations. Both AMSRE-LPRM bands (X and C) are consistent showing a strong L-A interaction hotspot over the Pampas ecoregion. Intensification and a larger spatial extent of the L-A interaction for dry summers was observed in both satellite products and models compared to wet summers. These results, which were derived from measured physical variables, are encouraging and promising for future studies analyzing L-A interactions. L-A interaction analysis is proposed here as a meeting point between remote sensing and climate modelling communities of Argentina, within a region with the highest agricultural and livestock production of the continent, but with an important lack of in-situ SM observations.

Using Media While Interacting Face-to-Face Is Associated With Psychosocial Well-Being and Personality Traits.

PubMed

Lee, Mindy; Murphy, Karen; Andrews, Glenda

2018-01-01

Positive face-to-face human interactions are known to benefit well-being. Drawing upon previous work regarding the interference of media (via technological devices or print) in social interaction, the aim of this study was to identify whether using media during face-to-face interaction could potentially limit the positive effect of interaction on well-being. Participants were 437 university students who completed an online survey which assessed media multitasking behaviors, well-being (trait depression, trait anxiety, social anxiety, empathy, and psychological well-being), and personality traits (Big-5 and narcissism). Face-to-face interaction was positively associated with well-being. However, when media use during face-to-face interaction was considered, there was a negative relationship with well-being (more depression, more anxiety, and less psychological well-being). Those who used certain media types, such as phone or video chatting, listening to music, and gaming, while interacting with others, also had lower scores on measures of empathy. Regression analyses showed significant contributions by these media types to empathy levels, even after controlling for age, gender, and personality traits. Face-to-face media multitasking was related to higher levels of narcissism and neuroticism, and lower levels of agreeableness, conscientiousness, and openness. This study provides insight into the possible role of media multitasking during face-to-face interaction on psychosocial outcomes.

TPPII, MYBBP1A and CDK2 form a protein-protein interaction network.

PubMed

Nahálková, Jarmila; Tomkinson, Birgitta

2014-12-15

Tripeptidyl-peptidase II (TPPII) is an aminopeptidase with suggested regulatory effects on cell cycle, apoptosis and senescence. A protein-protein interaction study revealed that TPPII physically interacts with the tumor suppressor MYBBP1A and the cell cycle regulator protein CDK2. Mutual protein-protein interaction was detected between MYBBP1A and CDK2 as well. In situ Proximity Ligation Assay (PLA) using HEK293 cells overexpressing TPPII forming highly enzymatically active oligomeric complexes showed that the cytoplasmic interaction frequency of TPPII with MYBBP1A increased with the protein expression of TPPII and using serum-free cell growth conditions. A specific reversible inhibitor of TPPII, butabindide, suppressed the cytoplasmic interactions of TPPII and MYBBP1A both in control HEK293 and the cells overexpressing murine TPPII. The interaction of MYBBP1A with CDK2 was confirmed by in situ PLA in two different mammalian cell lines. Functional link between TPPII and MYBBP1A has been verified by gene expression study during anoikis, where overexpression of TPP II decreased mRNA expression level of MYBBP1A at the cell detachment conditions. All three interacting proteins TPPII, MYBBP1A and CDK2 have been previously implicated in the research for development of tumor-suppressing agents. This is the first report presenting mutual protein-protein interaction network of these proteins. Copyright © 2014 Elsevier Inc. All rights reserved.

Comparison of weighting approaches for genetic risk scores in gene-environment interaction studies.

PubMed

Hüls, Anke; Krämer, Ursula; Carlsten, Christopher; Schikowski, Tamara; Ickstadt, Katja; Schwender, Holger

2017-12-16

Weighted genetic risk scores (GRS), defined as weighted sums of risk alleles of single nucleotide polymorphisms (SNPs), are statistically powerful for detection gene-environment (GxE) interactions. To assign weights, the gold standard is to use external weights from an independent study. However, appropriate external weights are not always available. In such situations and in the presence of predominant marginal genetic effects, we have shown in a previous study that GRS with internal weights from marginal genetic effects ("GRS-marginal-internal") are a powerful and reliable alternative to single SNP approaches or the use of unweighted GRS. However, this approach might not be appropriate for detecting predominant interactions, i.e. interactions showing an effect stronger than the marginal genetic effect. In this paper, we present a weighting approach for such predominant interactions ("GRS-interaction-training") in which parts of the data are used to estimate the weights from the interaction terms and the remaining data are used to determine the GRS. We conducted a simulation study for the detection of GxE interactions in which we evaluated power, type I error and sign-misspecification. We compared this new weighting approach to the GRS-marginal-internal approach and to GRS with external weights. Our simulation study showed that in the absence of external weights and with predominant interaction effects, the highest power was reached with the GRS-interaction-training approach. If marginal genetic effects were predominant, the GRS-marginal-internal approach was more appropriate. Furthermore, the power to detect interactions reached by the GRS-interaction-training approach was only slightly lower than the power achieved by GRS with external weights. The power of the GRS-interaction-training approach was confirmed in a real data application to the Traffic, Asthma and Genetics (TAG) Study (N = 4465 observations). When appropriate external weights are unavailable, we recommend to use internal weights from the study population itself to construct weighted GRS for GxE interaction studies. If the SNPs were chosen because a strong marginal genetic effect was hypothesized, GRS-marginal-internal should be used. If the SNPs were chosen because of their collective impact on the biological mechanisms mediating the environmental effect (hypothesis of predominant interactions) GRS-interaction-training should be applied.

Molecular interactions between photosystem I and ferredoxin: an integrated energy frustration and experimental model

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

Cashman, Derek J.; Zhu, Tuo; Simmerman, Richard F.

2014-08-01

The stromal domain (PsaC, PsaD, and PsaE) of photosystem I (PSI) reduces transiently bound ferredoxin (Fd) or flavodoxin. Experimental structures exist for all of these protein partners individually, but no experimental structure of the PSI/Fd or PSI/flavodoxin complexes is presently available. Molecular models of Fd docked onto the stromal domain of the cyanobacterial PSI site are constructed here utilizing X-ray and NMR structures of PSI and Fd, respectively. Moreover, predictions of potential protein-protein interaction regions are based on experimental site-directed mutagenesis and cross-linking studies to guide rigid body docking calculations of Fd into PSI, complemented by energy landscape theory tomore » bring together regions of high energetic frustration on each of the interacting proteins. Results identify two regions of high localized frustration on the surface of Fd that contain negatively charged Asp and Glu residues. Our study predicts that these regions interact predominantly with regions of high localized frustration on the PsaC, PsaD, and PsaE chains of PSI, which include several residues predicted by previous experimental studies.« less

The Effects of Avatars' Age on Older Adults' Self-Disclosure and Trust.

PubMed

Lee, Yu-Hao; Xiao, Min; Wells, Robert H

2018-03-01

Older adults are increasingly interacting with other people online via virtual avatars, yet little is known about how avatars affect older adults' behavior. This study examines how interacting avatars' age affects older adult's self-disclosure and trust in a relation-building context. Previous studies have found that users can take on behaviors consistent with characteristics of the avatars. In social interactions, people also assess their avatar in relation to other avatars for similarity or differences. We conducted a 2 (self-avatar: old vs. young) × 2 (other's avatar: old vs. young) experiment with older-adult participants aged 60+ (n = 95). The findings show that using younger avatars did not increase self-disclosure. However, the older-adult participants disclosed more information when their avatar's age matched their partner avatar's age (i.e., old to old, young to young). They also trust their partners more when the interacting avatars shared similar age. This study provides theoretical insights into the role of avatars in online relationship-building and extends our understanding of the avatar effects on older adults.

Spectra, current flow, and wave-function morphology in a model PT -symmetric quantum dot with external interactions

NASA Astrophysics Data System (ADS)

Tellander, Felix; Berggren, Karl-Fredrik

2017-04-01

In this paper we use numerical simulations to study a two-dimensional (2D) quantum dot (cavity) with two leads for passing currents (electrons, photons, etc.) through the system. By introducing an imaginary potential in each lead the system is made symmetric under parity-time inversion (PT symmetric). This system is experimentally realizable in the form of, e.g., quantum dots in low-dimensional semiconductors, optical and electromagnetic cavities, and other classical wave analogs. The computational model introduced here for studying spectra, exceptional points (EPs), wave-function symmetries and morphology, and current flow includes thousands of interacting states. This supplements previous analytic studies of few interacting states by providing more detail and higher resolution. The Hamiltonian describing the system is non-Hermitian; thus, the eigenvalues are, in general, complex. The structure of the wave functions and probability current densities are studied in detail at and in between EPs. The statistics for EPs is evaluated, and reasons for a gradual dynamical crossover are identified.

Block Play and Mathematics Learning in Preschool: The Effects of Building Complexity, Peer and Teacher Interactions in the Block Area, and Replica Play Materials

ERIC Educational Resources Information Center

Trawick-Smith, Jeffrey; Swaminathan, Sudha; Baton, Brooke; Danieluk, Courtney; Marsh, Samantha; Szarwacki, Monika

2017-01-01

Block play has been included in early childhood classrooms for over a century, yet few studies have examined its effects on learning. Several previous investigations indicate that the complexity of block building is associated with math ability, but these studies were often conducted in adult-guided, laboratory settings. In the present…

An Interactive Learning Environment Designed to Increase the Possibilities for Learning and Communicating about Radioactivity

ERIC Educational Resources Information Center

Mork, Sonja M.

2011-01-01

Information and communication technology (ICT) is a natural part of most people's everyday life, and has also been introduced in schools. Previous studies have tended to focus on issues related to competency of teachers and lack of computer technology in schools. Focus now seems to be moving towards studies that help us understand how ICT may be…

Characterization of the synergistic interaction between Beauveria bassiana strain GHA and Bacillus thuringiensis morrisoni strain tenebrionis applied against Colorado potato beetle

USDA-ARS?s Scientific Manuscript database

Studies were undertaken to further characterize the previously identified synergistic activity of Bacillus thuringiensis- and Beauveria bassiana-based biopesticides against Colorado potato beetle (CPB). A flowable concentrate of B. thuringiensis morrisoni strain tenebrionis (Bt) (Novodor® FC) and a ...

Do the Contents of Visual Working Memory Automatically Influence Attentional Selection during Visual Search?

ERIC Educational Resources Information Center

Woodman, Geoffrey F.; Luck, Steven J.

2007-01-01

In many theories of cognition, researchers propose that working memory and perception operate interactively. For example, in previous studies researchers have suggested that sensory inputs matching the contents of working memory will have an automatic advantage in the competition for processing resources. The authors tested this hypothesis by…

A Resource-Oriented Functional Approach to English Language Learning

ERIC Educational Resources Information Center

Li, Jia

2018-01-01

This article reports on a case study that investigates the learning preferences and strategies of Chinese students learning English as a second language (ESL) in Canadian school settings. It focuses on the interaction between second language (L2) learning methods that the students have adopted from their previous learning experience in China and…

The arabidopsis polyamine transporter LHRI/AtPUT3 modulates heat responsive gene expression by regulating mRNA stability

USDA-ARS?s Scientific Manuscript database

Polyamines (PA) involve in the gene regulation by interacting with various anionic macromolecules such as DNA, RNA and proteins and modulating their structure and function. Previous studies have showed that changing in polyamine biosynthesis alters plant response to different abiotic stresses. Here,...

Some Notes on Conversational Fission. Sociolinguistic Working Paper Number 91.

ERIC Educational Resources Information Center

Sigman, Stuart J.

While most previous research has implied or assumed that the conversational structure giving each speaker a turn to speak is universally normative, findings of one study suggest that in interactions with at least four participants, alternatives to this rule are possible. A phenomenon called "conversational fission" occurs when a four-…

Affective and Cognitive Responses to Insects and Other Arthropods

ERIC Educational Resources Information Center

Lorenz-Reaves, Amanda R.

2017-01-01

Insects are the most abundant and diverse group of animals on Earth. Though as a group they do far more ecological good than harm, previous studies have shown that human attitudes toward insects are mainly negative. Attitudes have affective (emotions) and cognitive (beliefs, mental representations) components that interact to influence behavior.…

Children of the U.S. National Guard: Making Meaning and Responding to Parental Deployment

ERIC Educational Resources Information Center

Thompson, David E.; Baptist, Joyce; Miller, Bryant; Henry, Una

2017-01-01

This qualitative study explored how 24 youths' behaviors during deployment were influenced by their perceptions of their non-deployed parents. Interviews were conducted with youths of previously deployed National Guard parents. Analysis of interviews suggests that the youths' interactions with their non-deployed parents strongly influence their…

Mentoring Factors in Doctoral Programs of Mexican American and American Indian Students.

ERIC Educational Resources Information Center

Williamson, Madeline J.; Fenske, Robert H.

The purpose of this study was to determine factors affecting satisfaction of Mexican American (MA) and American Indian (AI) students with their doctoral programs. Faculty mentoring plays an extremely significant role in minority education. Previous research indicates differences between males and females in their interaction with faculty. Minority…

Focal Points, Endogenous Processes, and Exogenous Shocks in the Autism Epidemic

ERIC Educational Resources Information Center

Liu, Kayuet; Bearman, Peter S.

2015-01-01

Autism prevalence has increased rapidly in the United States during the past two decades. We have previously shown that the diffusion of information about autism through spatially proximate social relations has contributed significantly to the epidemic. This study expands on this finding by identifying the focal points for interaction that drive…