Multiple Modes Of Interaction Research Articles

Open, Online, and Blended: Transactional Interactions with MOOC Content by Learners in Three Different Course Formats

During the 2013-14 academic year, Harvard University piloted the use of MOOCs as tools for blended learning in select undergraduate and graduate residential and online courses. One of these courses, The Ancient Greek Hero, combined for—credit (Harvard College and Harvard Extension School) and open online (HarvardX) groups into a single online unit, marking the first time the same instance of a MOOC was used simultaneously by both tuition—paying, credit—seeking students and non—paying, non—credit students enrolled exclusively online. In this article, we analyze and compare the online behavior of students and participants in the three groups that simultaneously participated in The Ancient Greek Hero via the edX platform. We find that, in similar fashion to a traditional learning setting, students enrolled in all three versions of the course engaged the online content in a transactional way, spending their time and effort on activities and exercises in ways that would optimize their desired outcomes. While user behavior was diverse, HarvardX participant engagement tended to be either very deep or virtually nonexistent, while College and Extension School students displayed relatively homogenous patterns of participation, viewing most of the content but interacting mostly with that which affected their overall course grades. Ultimately, we conclude that educators who intend to utilize MOOC content in an effort to apply blended learning techniques to their classrooms should carefully consider how best to incorporate each online element into their overall pedagogical strategy, including how to incentivize interaction with those elements. Further, for MOOCs to have maximum impact, they must address multiple learner motivations and provide participants with multiple modes of interaction with the content and with their peers.

A robotic platform for customized and interactive rehabilitation of persons with disabilities

In this work, we have developed a multisensor system for rehabilitation and interaction with persons with motor and cognitive disabilities. The system enables them to perform different therapies using multiple modes of interaction (head and body pose, hand gestures, voice, touch and gaze) depending on the type and degree of disability. Through a training process, the system can be customized enabling the definition of patients’ own gestures for each sensor. The system is integrated with a range of applications for rehabilitation. Examples of these applications are puzzle solving, mazes and text writing using predictive text tools. The system also provides a flexible and modular framework for the development of new applications oriented towards novel rehabilitation therapies. The proposed system has been integrated in a mobile robotic platform and uses low-cost sensors allowing to perform non-intrusive rehabilitation therapies at home. Videos showing the proposed system and users interacting in different ways (multimodal) are available on our project website www.rovit.ua.es/patente/.

Assembly studies of six intestinal intermediate filament (IF) proteins B2, C1, C2, D1, D2, and E1 in the nematode C. elegans.

The dimerisation properties of six intestine-expressed intermediate filament (IF) proteins (B2, C1, C2, D1, D2, E1) were analysed in blot overlay assay on membranes containing all of the eleven recombinant C. elegans IF proteins (A1, A2, A3, A4, B1, B2, C1, C2, D1, D2, and E1). The interactions detected in the blot assays exclusively comprise intestine-expressed IF proteins and the protein A4, which is found in the dauer larva intestine. About 86% of these interactions are heterotypic, while the remaining interactions relate to C1, C2, and D2 homodimers. These multiple modes of interaction were also supported by calculations of the numbers of possible interchain ionic interactions derived from the individual rod sequences. The results predict that the six B2, C1, C2, D1, D2, and E1 IF proteins are able to form as many as eleven different heteropolymeric and three homopolymeric IFs in the C. elegans intestine. This simple model of the intestinal IF meshwork enables us to speculate that our previously reported triple RNAi worms arrested or decreased their growth because of feeding reduction due to morphological defects of the mechanically compromised intestine.

Replica Exchange Molecular Dynamics Study of Dimerization in Prion Protein: Multiple Modes of Interaction and Stabilization.

The pathological forms of prions are known to be a result of misfolding, oligomerization, and aggregation of the cellular prion. While the mechanism of misfolding and aggregation in prions has been widely studied using both experimental and computational tools, the structural and energetic characterization of the dimer form have not garnered as much attention. On one hand dimerization can be the first step toward a nucleation-like pathway to aggregation, whereas on the other hand it may also increase the conformational stability preventing self-aggregation. In this work, we have used extensive all-atom replica exchange molecular dynamics simulations of both monomer and dimer forms of a mouse prion protein to understand the structural, dynamic, and thermodynamic stability of dimeric prion as compared to the monomeric form. We show that prion proteins can dimerize spontaneously being stabilized by hydrophobic interactions as well as intermolecular hydrogen bonding and salt bridge formation. We have computed the conformational free energy landscapes for both monomer and dimer forms to compare the thermodynamic stability and misfolding pathways. We observe large conformational heterogeneity among the various modes of interactions between the monomers and the strong intermolecular interactions may lead to as high as 20% β-content. The hydrophobic regions in helix-2, surrounding coil regions, terminal regions along with the natively present β-sheet region appear to actively participate in prion-prion intermolecular interactions. Dimerization seems to considerably suppress the inherent dynamic instability observed in monomeric prions, particularly because the regions of structural frustration constitute the dimer interface. Further, we demonstrate an interesting reversible coupling between the Q160-G131 interaction (which leads to inhibition of β-sheet extension) and the G131-V161 H-bond formation.

Linker histones: novel insights into structure-specific recognition of the nucleosome.

Linker histones (H1s) are a primary component of metazoan chromatin, fulfilling numerous functions, both in vitro and in vivo, including stabilizing the wrapping of DNA around the nucleosome, promoting folding and assembly of higher order chromatin structures, influencing nucleosome spacing on DNA, and regulating specific gene expression. However, many molecular details of how H1 binds to nucleosomes and recognizes unique structural features on the nucleosome surface remain undefined. Numerous, confounding studies are complicated not only by experimental limitations, but the use of different linker histone isoforms and nucleosome constructions. This review summarizes the decades of research that has resulted in several models of H1 association with nucleosomes, with a focus on recent advances that suggest multiple modes of H1 interaction in chromatin, while highlighting the remaining questions.

Effects of substitution position on crystal packing, polymorphism and crystallization-induced emission of (9-anthryl)vinylstyrylbenzene isomers

Three (9-anthryl)vinylstyrylbenzene (ASB) position isomers were synthesized and compared. Substitution position affects temperature-induced polymorphism, crystal packing and crystallization-induced emission (CIE) properties. Different from 1,2-ASB and 1,4-ASB, 1,3-ASB undergoes a crystal-to-crystal phase transition upon heating. The crystal structure of a new phase (1,3-ASB-β) was successfully solved. Thus, the solid emission of 1,3-ASB could be tuned by polymorphism. In contrast, the solid emission of 1,4-ASB is controlled by its crystallinity. In the crystal structures of 1,2-ASB and 1,3-ASB-β, the adjacent interacting anthryls are inclined to adopt an edge-to-face configuration with C–H⋯π interactions. In contrast, the adjacent anthracene rings in the 1,4-ASB crystals are parallel to each other with π⋯π interactions. Furthermore, multiple intermolecular interaction modes such as C–H⋯π and H⋯H interactions coexist in the crystal structure of 1,4-ASB, which collectively results in a closer packing. Interestingly, 1,4-ASB displays CIE behaviour. In contrast, the emission of the other two isomers is quenched in the solid state. The effect of substitution position on the photophysical properties is systematically studied.

Causal Role of Motor Simulation in Turn-Taking Behavior.

Even during passive observation, seeing or hearing somebody execute an action from within our repertoire activates motor cortices of our brain. But what is the functional relevance of such "motor simulation"? By combining a musical duet task with a real-time repetitive transcranial magnetic stimulation protocol, we provide evidence indicating that the dorsal premotor cortex plays a causal role in accurate turn-taking coordination between a pianist and their observed interaction partner. Given that turn-taking behavior is a fundamental feature of human communication, we suggest that simulation is a foundational mechanism underlying the temporal dynamics of communicative joint action.

Open, Online, and Blended: Transactional Interactions with MOOC Content by Learners in Three Different Course Formats

In 2013-14, Harvard University piloted the use of MOOCs as tools for blended learning in select undergraduate and graduate residential and online courses. One of these courses, The Ancient Greek Hero, combined for-credit (Harvard College and Harvard Extension School) and open online (HarvardX) groups into a single online unit, marking the first time the same instance of a MOOC was used simultaneously by both tuition-paying, credit-seeking students and non-paying, non-credit students enrolled exclusively online. In this article, we analyze and compare the online behavior of students and participants in the three groups that simultaneously participated in The Ancient Greek Hero via the edX platform. We find that, in similar fashion to a traditional learning setting, students enrolled in all three versions of the course engaged the online content in a transactional way, spending their time and effort on activities and exercises in ways that would optimize their desired outcomes. While user behavior was diverse, HarvardX participant engagement tended to be either very deep or virtually nonexistent, while College and Extension School students displayed relatively homogenous patterns of participation, viewing most of the content but interacting mostly with that which affected their overall course grades. Ultimately, we conclude that educators who intend to utilize MOOC content in an effort to apply blended learning techniques to their classrooms should carefully consider how best to incorporate each online element into their overall pedagogical strategy, including how to incentivize interaction with those elements. Further, for MOOCs to have maximum impact, they must address multiple learner motivations and provide participants with multiple modes of interaction with the content and with their peers.

Crumbs and Xpd in mitosis.

Crumbs and Xpd in mitosis.

Deterritorialized, multilocated and distributed: Musical space, poietic domains and cognition in distance collaboration

Abstract This article presents detailed descriptions of a series of distance collaborations between two institutions of music education; the State University of New York, Oneonta, in the United States, and the Musrara Naggar School of Art in Jerusalem, Israel. The collaborations between Oneonta and Musrara encompass multiple modes of collaborative interaction, including asynchronous, interstitial and synchronized collaboration. As such the collaborations between the two institutions provide a rich case for understanding practical considerations for and implications of technologically mediated and distributed distance collaborations in music. The authors analyse the collaborations between the two institutions to demonstrate how the increasingly deterritorialized, multilocated nature of technologically mediated distance collaborations generates and encompasses multiple levels of poietic space. Those poietic spaces include micro poietic spaces representative of the individual participants, larger poetic spaces representative of co-located collaborators and contributors, and still larger macro poietic spaces that do not exist in anyone single locale but, instead, encompass the entire poietic sphere of such collaborations. To further understand the dynamics of technologically mediated distance collaboration, the authors introduce an emerging model for understanding such collaborations. That model draws on the philosophical concept of poiesis and on distributed cognition theory, framework drawn from the field of human–computer interaction (HCI).

Interaction of the 5-fluorouracil analog 5-fluoro-2'-deoxyuridine with 'N' and 'B' isoforms of human serum albumin: a spectroscopic and calorimetric study.

Drugs and metabolites are transported in the blood by plasma proteins, such as human serum albumin (HSA). The uridine analog 2'dFUrd, which is a cytotoxic prodrug metabolite of capecitabine, has remarkable activity against solid tumors when administered orally. We report the results of an in vitro experimental study on the interactions of 2'-dFUrd with the N-isoform (at pH 7.4) and B-isoform (at pH 9.0) of HSA, investigated using fluorescence spectroscopy, circular dichroism (CD), isothermal titration calorimetry (ITC), differential scanning calorimetry (DSC), and molecular docking. The binding constant (Kb) was higher for the N-isoform than for the B-isoform. Thermodynamic parameters, such as enthalpy change (ΔH°), entropy change (ΔS°), and Gibbs free energy change (ΔG°), were also calculated for both isoform interactions using calorimetric techniques. The thermostabilities of HSA and the HSA-2'dFUrd complex were found to be higher for the N-isoform. The interaction of 2'dFUrd with HSA was also explored in molecular docking studies, which revealed that 2'dFUrd was bound to the Sudlow site I in subdomain IIA through multiple modes of interaction, such as hydrophobic interactions and hydrogen bonding. These results suggest that 2'dFUrd has higher binding affinity for the N-isoform of HSA.

Large Display Interaction via Multiple Acceleration Curves and Multifinger Pointer Control

Large high-resolution displays combine high pixel density with ample physical dimensions. The combination of these factors creates a multiscale workspace where interactive targeting of on-screen objects requires both high speed for distant targets and high accuracy for small targets. Modern operating systems support implicit dynamic control-display gain adjustment (i.e., a pointer acceleration curve) that helps to maintain both speed and accuracy. However, large high-resolution displays require a broader range of control-display gains than a single acceleration curve can usably enable. Some interaction techniques attempt to solve the problem by utilizing multiple explicit modes of interaction, where different modes provide different levels of pointer precision. Here, we investigate the alternative hypothesis of using asingle modeof interaction for continuous pointing that enables both (1) standardimplicitgranularity control via an acceleration curve and (2)explicitswitching between multiple acceleration curves in an efficient and dynamic way. We evaluate a sample solution that augments standard touchpad accelerated pointer manipulation with multitouch capability, where the choice of acceleration curve dynamically changes depending on the number of fingers in contact with the touchpad. Specifically, users can dynamically switch among three different acceleration curves by using one, two, or three fingers on the touchpad.

Membrane Dynamics and Lipid Interactions of Influenza Fusion Proteins

Viral fusion peptides interact with lipid membranes to promote membrane fusion and viral entry. Data on fusion-defective mutants of influenza virus suggest that these interactions are in fact required for efficient fusion. Fusion peptides appear to be at least structurally plastic if not highly dynamic, adopting multiple conformations and potentially multiple interaction modes with lipid membranes. It remains unclear, however, how these structural properties are linked to physiologic function. We have used molecular dynamics simulation to probe the conformational transitions and membrane interactions of influenza hemagglutinin. Based on these simulations, we obtain models of 1) how fusion peptides can lower the activation barrier to the first lipidic intermediates in membrane fusion, 2) how structural plasticity may be important to this activity, and 3) how inactive mutants of influenza fusion peptides may be functionally impaired. We have also performed functional experiments on how the membrane environment affects fusion kinetics of live influenza virus. Correlation of models from simulation with spectroscopic and functional data can help to further elucidate the mechanisms by which fusion peptides promote membrane fusion and how structure and dynamics relate to function.

Mobilising meaning: multimodality, translocation, technology and heritage

This special issue explores how meaning is created, conveyed and transformed through multiple modes of communication, representation and interaction (the textual, the visual, the material, the spat...

Development of chromatofocusing techniques employing mixed-mode column packings for protein separations

Recent studies reported in the literature using mixed-mode chromatography (MMC) column packings have shown that multiple modes of interactions between the column packing and proteins can be usefully exploited to yield excellent resolution as well as salt-tolerant adsorption of the target protein. In this study, a mixed-mode separation method using commercially available column packings was explored which combines the techniques of hydrophobic-interaction chromatography and chromatofocusing. Two different column packings, one based on mercapto-ethyl-pyridine (MEP) and the other based on hexylamine (HEA) were investigated with regard to their ability to separate proteins when using internally generated, retained pH gradients. The effects of added salt and urea on the behavior of the retained pH gradient and the protein separation achieved when using MMC column packings for chromatofocusing were also investigated. Numerical simulations using methods developed in previous work were shown to agree with experimental results when using reasonable physical parameters. These numerical simulations were also shown to be a useful qualitative method to select the compositions of the starting and elution buffers in order to achieve desired shapes for the pH and ionic strength gradients. The use of the method to fractionate blood serum was explored as a prototype example application.

Modeling local behavior for predicting social interactions towards human tracking

Human interaction dynamics are known to play an important role in the development of robust pedestrian trackers that are needed for a variety of applications in video surveillance. Traditional approaches to pedestrian tracking assume that each pedestrian walks independently and the tracker predicts the location based on an underlying motion model, such as a constant velocity or autoregressive model. Recent approaches have begun to leverage interaction, especially by modeling the repulsion forces among pedestrians to improve motion predictions. However, human interaction is more complex and is influenced by multiple social effects. This motivates the use of a more complex human interaction model for pedestrian tracking. In this paper, we propose a novel human tracking method by modeling complex social interactions. We present an algorithm that decomposes social interactions into multiple potential interaction modes. We integrate these multiple social interaction modes into an interactive Markov Chain Monte Carlo tracker and demonstrate how the developed method translates into a more informed motion prediction, resulting in robust tracking performance. We test our method on videos from unconstrained outdoor environments and evaluate it against common multi-object trackers.

Ecology and conservation of strangler figs in urban wall habitats

Hong Kong’s rugged topography demands creation of developable land by reclaiming the harbor and terracing hillslopes. The vertical faces between adjoining hillslope-platforms are often stabilized by stone retaining walls. Such artificial cliffs embedded in the urban matrix, as a habitat analogue of rocky cliffs, have been colonized by spontaneous-ruderal vegetation. Detailed field assessment of 289 walls with 793 trees permitted in-depth analysis of this unique tropical urban ecology to inform conservation. The 28 stonewall tree species, mainly native, are dominated by six keystone and companion Ficus (Moraceae) species. They can develop into large cliff hangers > 20 m height on the apparently precarious and inhospitable walls. The many joints between masonry blocks provide opportunities for lodging and germination of seeds brought by frugivorous birds and bats. The aft-soil behind walls provides catchment for normal root functions. Beginning as pioneers and persisting as climax members, they short-circuit the seral processes. Wall-gripping capability as large epilithic woody hemi-epiphytes is due to the strangler-fig habit, an evolutionary trait that originated in the tropical forest. The polymorphic roots with morphological plasticity and self-grafting ability, and their multiple modes of interactions with wall niches, account for firm attachment on the vertical habitat and exploration of proximal soils. A model of strangler-fig growth on stone walls serving as surrogate host tree is developed. The diverse and versatile rooting modes are the basis to sustain strangler-fig wall conditions to permit continuation of strangler-fig habit. Such unique nature-in-city and natural-cum-cultural gems deserve conservation as urban ecological heritage.

Deciphering Metastable EphA1 Transmembrane Helices Association using PMF Calculations and Multiscale Molecular Dynamics Simulations

The association of transmembrane helices plays a significant role in the signalling of receptor tyrosine kinases. Recently the structures of the transmembrane domain of EphA1, which is a receptor tyrosine kinase implicated in a variety of cancers, were obtained via NMR spectroscopy [1]. Recent studies present the existence of multiple possible interaction modes for EphA1 which has lead to the suggestion that this system is governed by the rotation-coupled activation mechanism, with packing via different interaction motifs corresponding to active and inactive states of the dimers.To investigate further these results we performed potential of mean force (PMF) calculations for the association of the transmembrane helices of the receptor tyrosine kinases EphA1 using coarse-grained (CG) molecular dynamics calculations. The resulting profiles suggest two stable or metastable states for this system, consistent with the idea of a rotation-coupled activation mechanism. The most stable state for EphA1 involves a right-handed dimer interacting via an N-terminal glycine zipper motif, consistent with a recent structure from NMR spectroscopy. Interestingly the second state involves a left-handed dimer with interacting residues different from the glycine zipper. Analysis of unrestrained CG molecular dynamics based on the NMR structure of this dimer seems correlate these two states. The final analysis based on all atom simulations for the most representative structures of CG MDs give also valuable details for these interactions. So, multiscale molecular dynamics and PMF calculations shed a new light of the dynamical behaviour of such a system.Reference:1.Bocharov EV, Mayzel ML, Volynsky PE, Goncharuk MV, Ermolyuk YS, et al. (2008) Spatial structure and pH-dependent conformational diversity of dimeric transmembrane domain of the receptor tyrosine kinase EphA1. J Biol Chem 283: 29385-29395. doi:10.1074/jbc.M803089200.

Surfactant controlled aggregation of conjugated polyelectrolytes

We investigate the interaction between conjugated polyelectrolytes and surfactants in solution and solid phases. We identify multiple modes of interaction and propose a model that accounts for their interplay and pronounced variation in photophysics over a wide range of conditions.

SYBR Green I: Fluorescence Properties and Interaction with DNA

In this study, we have investigated the fluorescence properties of SYBR Green I (SG) dye and its interaction with double-stranded DNA (dsDNA). SG/dsDNA complexes were studied using various spectroscopic techniques, including fluorescence resonance energy transfer and time-resolved fluorescence techniques. It is shown that SG quenching in the free state has an intrinsic intramolecular origin; thus, the observed >1,000-fold SG fluorescence enhancement in complex with DNA can be explained by a dampening of its intra-molecular motions. Analysis of the obtained SG/DNA binding isotherms in solutions of different ionic strength and of SG/DNA association in the presence of a DNA minor groove binder, Hoechst 33258, revealed multiple modes of interaction of SG inner groups with DNA. In addition to interaction within the DNA minor groove, both intercalation between base pairs and stabilization of the electrostatic SG/DNA complex contributed to increased SG affinity to double-stranded DNA. We show that both fluorescence and the excited state lifetime of SG dramatically increase in viscous solvents, demonstrating an approximate 200-fold enhancement in 100% glycerol, compared to water, which also makes SG a prospective fluorescent viscosity probe. A proposed structural model of the SG/DNA complex is compared and discussed with results recently reported for the closely related PicoGreen chromophore.