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Spatial perspective‐taking (SPT) ability positively influences performance in STEM fields. While limited research studies have been done with school students, they have yielded inconclusive findings and, hence, here we report findings from our study with an augmented reality (AR) enhanced learning environment (ARELE), GeoSolvAR, on middle‐school students' SPT ability. We conducted a sequential explanatory mixed‐method study with 90 students to test GeoSolvAR's twin features of augmented systems and inquiry‐based activities. The study had one experimental (n = 30) and two control groups (n = 30 × 2), where students were individually administered an online pre‐ and posttest to measure their SPT ability. The experimental group worked with both the features of GeoSolvAR, while the control group worked with only the AR feature or had no intervention. Our findings reveal that the experimental group showed significant improvement in SPT ability while students in the control groups showed non‐significant improvement or no change. Furthermore, we found that all experimental group students used certain body movements and imagined shifts in spatial positions while solving the activity questions. Thus, we conjecture that GeoSolvAR affords thinking and imagining with the body which makes it a potent tool for improving students' SPT ability. Practitioner notesWhat is already known about this topic Spatial perspective taking (SPT) belongs to a set of spatial abilities that have been shown to positively influence academic success and career success in STEM fields.Augmented reality systems with their ability to augment 2D images into 3D forms are being explored mostly in college and above levels to improve SPT ability.Limited research investigating the improvement of SPT in school students has used VR digital games or robots. These have either yielded inconclusive findings or not found any improvement in school students' SPT abilities.What this paper adds Conclusive evidence for improving SPT ability in middle‐school students.Empirical evidence for a design to effectively combine augmenting abilities of AR systems with inquiry‐based learning scaffolds to improve the SPT ability of middle‐school students.A conjecture about the mechanism by which middle‐school children's spatial perspective taking improves when scaffolded with an Augmented Reality Enhanced Learning Environment (ARELE) tool.Implications for practice and policy Practitioners such as teachers may directly use GeoSolvAR (the ARELE tool) to help middle‐school students improve their spatial perspective‐taking abilities.Researchers from the fields of both technology‐enhanced learning and science education may use the findings to design improved AR tools and test their impact on students' SPT ability. This work can serve as the basis for further investigating the effect of improved SPT ability on students' performance in STEM subjects.Our work provides support for embodied cognition being used as a strategy for solving SPT tasks. The identification of specific head and hand movements (gestures) can be further probed to understand the exact mechanism of how the ARELE mediates students' performance on the SPT tasks. [ABSTRACT FROM AUTHOR]

In science and engineering education, the use of heuristics has been introduced as a way of understanding the world, and as a way to approach problem-solving and design. However, important consequences for the use of heuristics are that they do not always guarantee a correct solution. Learning by Design has been identified as a pedagogical strategy that can guide individuals to properly connect science learning via design challenges. Specifically, we focus on the effect of simulation-enabled Learning by Design learning experiences on student-generated heuristics that can lead to solutions to problems. A total of 318 middle school students were exposed to a lesson that integrated design practices in the context of energy consumption and energy conservation considerations when designing buildings using an educational CAD tool. The students were pre- and posttested before and after the 2-week long intervention. The data analysis procedures combined qualitative with quantitative methods along with machine learning approaches. Our analysis revealed two distinct groups of students based on their learning achievement: the naive developing heuristic group and semi-knowledgeable fixated heuristic group. Differences between the groups are discussed in terms of performance, as well as implications for the use of computer simulations to improve student learning.

Background: There is a need to find ways of productively engaging K-12 students with engineering design. I investigate a new class of physical models, referred to as Improvable Models, as scaffolds for helping middle school students productively engage in engineering design practices. Purpose/Hypothesis: The purpose of this study is to answer two questions: (a) How do students use Improvable Models? and (b) How does the use of Improvable Models as scaffolds support students' design of engineering solutions? Design/Method: Design-based research was conducted in a sixth-grade classroom. Students used a type of Improvable Model, specifically the Suboptimal System (SS) seed model. Improvable Models make the entire design space accessible and enable iterative design optimization. An SS seed model represents inefficient design decisions and is used as an initiator for iterative design optimization. The study spanned 10 lessons, each 45 min long, totaling 8 days of instructional activity spread across 1 month. Data sources included student conversations, design work, and presentations. The productive disciplinary engagement framework was used to analyze the data. Results: Students used the seed model for productively engaging with five disciplinary practices: decomposing the design challenge into individual design parameters, considering the relationship between design parameters, reasoning through multiple design parameters and making trade-offs, weighing multiple solutions, and using design heuristics for ideation and design optimization. The seed model scaffolded students' productive engagement in various disciplinary practices such as informed decision-making and systematic exploration. Conclusion: This study provides an approach for designing learning environments for productively engaging K-12 students in engineering design practices using a suboptimal model.

Engineering design thinking is hard to teach and still harder to learn by novices primarily due to the undetermined nature of engineering problems that often results in multiple solutions. In this paper, we investigate the effect of teaching engineering design thinking to freshmen students by using a computer-aided Design (CAD) simulation software. We present a framework for characterizing different levels of engineering design thinking displayed by students who interacted with the CAD simulation software in the context of a collaborative assignment. This framework describes the presence of four levels of engineering design thinking--beginning designer, adept beginning designer, informed designer, adept informed designer. We present the characteristics associated with each of these four levels as they pertain to four engineering design strategies that students pursued in this study--understanding the design challenge, building knowledge, weighing options and making tradeoffs, and reflecting on the process. Students demonstrated significant improvements in two strategies--understanding the design challenge and building knowledge. We discuss the affordances of the CAD simulation tool along with the learning environment that potentially helped students move towards Adept informed designers while pursuing these design strategies.

This paper examines the extent to which an initiative in India, namely EdTech Tulna, has been able to move towards decolonization of EdTech by shaping the discourse around the adoption and use of good quality and contextual educational technology solutions for Indian learners. Set up as a collaboration among researchers, practitioners, teachers and governments, EdTech Tulna aims to encourage the selection of EdTech solutions that are appropriate for the community they are designed for, rather than adopting solutions that market themselves or those that have been successful in Western countries. The paper adopts the lens of justice-oriented design and first critically examines the design of the EdTech Tulna index. Then, it examines the success and hurdles of the collaborative efforts towards the implementation of contextualized and evidence-based solutions in the ecosystem. By analyzing stakeholder interviews and meeting notes, this paper addresses two questions. First, how does Tulna assist in identifying quality contextual solutions that are likely to enhance the learning of children in India? Second, how do state government officials and practitioners collaborate with researchers to use research-based standards for selecting such solutions? The discussions outline the progress and draw a broad contour of the road ahead. [ABSTRACT FROM AUTHOR]

A recent study introduced a novel mean-field model system where each particle over and above the interaction with its regular neighbors interacts with k extra pseudo-neighbors. Here, we present an extensive study of thermodynamics and its correlation with the dynamics of this system. We surprisingly find that the well-known thermodynamic integration (TI) method of calculating the entropy provides unphysical results. It predicts vanishing of the configurational entropy at temperatures close to the onset temperature of the system and negative values of the configurational entropy at lower temperatures. Interestingly, well below the temperature at which the configurational entropy vanishes, both the collective and the single-particle dynamics of the system show complete relaxation. Negative values of the configurational entropy are unphysical, and complete relaxation when the configurational entropy is zero violates the prediction of the random first-order transition theory (RFOT). However, the entropy calculated using the two-phase thermodynamics (2PT) method remains positive at all temperatures for which we can equilibrate the system, and its values are consistent with RFOT predictions. We find that with an increase in k, the difference in the entropy computed using the two methods increases. A similar effect is also observed for a system where a randomly selected fraction of the particles are pinned in their positions in the equilibrated liquid. We show that the difference in entropy calculated via the 2PT and TI methods increases with pinning density. [ABSTRACT FROM AUTHOR]

Dealing with uncertainties is inherent in the engineering design process and often poses challenges for young learners. This necessitates providing learners with adequate support to navigate their uncertainties effectively. However, achieving this requires a deeper understanding of the factors influencing learners' uncertainty management processes. In this paper, we analyze learners' framing of uncertain situations in collaborative engineering design tasks. Using the case study method, we explore two framing dimensions—epistemological and positional—to understand their impact on collaborative uncertainty management processes. Specifically, we examine how learners' framing dynamically shifts during uncertainty management activities by analyzing two contrasting cases from a sixth-grade classroom where groups tackled an engineering design problem, employing interaction analysis. Learners' epistemological and positional framings are intertwined, collectively influencing their own and their team members' uncertainty management actions. Additionally, contextual factors such as mentor intervention, early success, affect induced by prolonged failure, and time constraints can prompt shifts in learners' framing, both in productive and unproductive manners. The paper provides nuanced insights into how learners' evolving epistemological orientations and positioning influence uncertainty management, offering practical insights into supporting learners' uncertainty management processes in problem-solving contexts such as engineering design. [ABSTRACT FROM AUTHOR]

This paper presents a new mobile software tool, PhotoMAT (Photo Management and Analysis Tool), and students' experiences with this tool within a scaffolded curricular unit--Neighborhood Safari. PhotoMAT was designed to support learners' investigations of backyard animal behavior and works with image sets obtained using fixed-position field cameras ("camera traps") that capture "bursts" of images in response to motion. PhotoMAT was designed to help learners emulate two ways wildlife researchers use camera traps: documenting wildlife diversity via the relative frequency of appearances of different species, and exploring species' behavior.

The Kauzmann temperature (TK) of a supercooled liquid is defined as the temperature at which the liquid entropy becomes equal to that of the crystal. The excess entropy, the difference between liquid and crystal entropies, is routinely used as a measure of the configurational entropy, whose vanishing signals the thermodynamic glass transition. The existence of the thermodynamic glass transition is a widely studied subject, and of particular recent interest is the role of dimensionality in determining the presence of a glass transition at a finite temperature. The glass transition in water has been investigated intensely and is challenging as the experimental glass transition appears to occur at a temperature where the metastable liquid is strongly prone to crystallization and is not stable. To understand the dimensionality dependence of the Kauzmann temperature in water, we study computationally bulk water (three-dimensions), water confined in the slit pore of the graphene sheet (two-dimensions), and water confined in the pore of the carbon nanotube of chirality (11,11) having a diameter of 14.9 Å (one-dimension), which is the lowest diameter where amorphous water does not always crystallize into nanotube ice in the supercooled region. Using molecular dynamics simulations, we compute the entropy of water in bulk and under reduced dimensional nanoscale confinement to investigate the variation of the Kauzmann temperature with dimension. We obtain a value of TK (133 K) for bulk water in good agreement with experiments [136 K (C. A. Angell, Science 319, 582–587 (2008) and K. Amann-Winkel et al., Proc. Natl. Acad. Sci. U. S. A. 110, 17720–17725 (2013)]. However, for confined water, in two-dimensions and one-dimension, we find that there is no finite temperature Kauzmann point (in other words, the Kauzmann temperature is 0 K). Analysis of the fluidicity factor, a measure of anharmonicity in the oscillation of normal modes, reveals that the Kauzmann temperature can also be computed from the difference in the fluidicity factor between amorphous and ice phases. [ABSTRACT FROM AUTHOR]

Byline: Satadru. Biswas, Santanu. Acharyya, Pritha. Roy, Debdeep. Samaddar, Chandan. Dasgupta, Debarshi. Jana Context: Aside abdominal discomfort and pain, upper gastrointestinal bleeding (UGIB) significantly disgraces the quality of life (QoL), [...]

Background: The use of combined modality therapy including surgery, chemotherapy, and radiotherapy increases five survival rates in stage IIA and stage IIIB disease to 80% and 45%, respectively. Neoadjuvant chemotherapy (NACT) eradicates micro metastasis present in the body and also improves resectability. Aims and Objectives: The main aim of this study was to determine the locoregional recurrence and distant recurrence rates and thereby define clinical and pathological predictive factors for recurrence. Materials and Methods: This was a single institutional prospective study carried out in the Department of Radiotherapy, RG Kar Medical College and Hospital, Kolkata. From January 2017 to December 2019, according to inclusion and exclusions criteria, a total of 1183 histologically and/or cytologically proven breast carcinoma patients were included in this prospective study. Results: Breast conservative surgery was done in 16.5% of patients and the rest of the patients underwent modified radical mastectomy. Seven patients had undergone toilet mastectomy with the specimen. From the pathological review of the surgical specimens, 15.0% of patients achieved pathological complete response, while 19.4% of patients had clinical complete response. A total of 150 patients out of 1183 patients (12.67%) had disease recurrence. Conclusion: Local treatments, either surgery alone and/or RT alone, are inadequate therapies for locally advanced breast cancer patients, and multidisciplinary treatment should be used, to reach better management. Inoperable locally advanced breast carcinoma can be converted into operable by NACT. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations are carried out for a single component, monatomic Lennard-Jones fluid confined between two mica surfaces to investigate the structure and relaxation dynamics of the confined fluid as a function of surface separation. Due to the underlying symmetry of the potassium ions on the mica surface, the contact layers prefer to adopt an incommensurate square or rhombic symmetry. The inner layers adopt a symmetry varying between rhombic, triangular, and square, depending on the density and surface separation. When the surface separation is an integral multiple of the particle diameter, distinct layering is observed, whereas jammed layers are formed at intermediate surface separations. This leads to the formation of both commensurate and incommensurate layering with varying intralayer symmetry. The self-intermediate scattering function exhibits a gamut of rich dynamics ranging from a distinct two-step relaxation indicative of glassy dynamics to slow relaxation processes where the correlations do not relax to zero over a microsecond for specific surface separations. An extended β relaxation is observed for both commensurate and incommensurate layering. Stretched exponential fits are used to obtain the relaxation times for the late α-relaxation regime of the self-intermediate scattering function. In some cases, we also observed dynamic and structural heterogeneities within individual layers. Although a single-component Lennard-Jones fluid does not exhibit a glass transition in the bulk, this study reveals that such a fluid can display, without supercooling, complex relaxation dynamics with signatures of a fluid approaching a glass transition upon confinement at constant temperature. [ABSTRACT FROM AUTHOR]

Confinement by walls usually produces a strong modulation in the density of dense liquids near the walls. Using molecular dynamics simulations, we examine the effects of the density modulation on the spatially resolved dynamics of a liquid confined between two parallel walls, using a resolution of a fraction of the interparticle distance in the liquid. The local dynamics is quantified by the relaxation time associated with the temporal autocorrelation function of the local density. We find that this local relaxation time varies in phase with the density modulation. The amplitude of the spatial modulation of the relaxation time can be quite large, depending on the characteristics of the wall and thermodynamic parameters of the liquid. To disentangle the effects of confinement and density modulation on the spatially resolved dynamics, we compare the dynamics of a confined liquid with that of an unconfined one in which a similar density modulation is induced by an external potential. We find several differences indicating that density modulation alone cannot account for all the features seen in the spatially resolved dynamics of confined liquids. We also examine how the dynamics near a wall depends on the separation between the two walls and show that the features seen in our simulations persist in the limit of large wall separation. [ABSTRACT FROM AUTHOR]

Extensive computer simulations are performed for a few model glass-forming liquids in both two and three dimensions to study their dynamics when a randomly chosen fraction of particles are frozen in their equilibrium positions. For all the studied systems, we find that the temperature-dependence of the α relaxation time extracted from an overlap function related to the self-part of the density autocorrelation function can be explained within the framework of the Random First Order Transition (RFOT) theory of the glass transition. We propose a scaling description to rationalize the simulation results and show that our data for the α relaxation time for all temperatures and pin concentrations are consistent with this description. We find that the fragility parameter obtained from fits of the temperature dependence of the α relaxation time to the Vogel-Fulcher-Tammann form decreases by almost an order of magnitude as the pin concentration is increased from zero. Our scaling description relates the fragility parameter to the static length scale of RFOT and thus provides a physical understanding of fragility within the framework of the RFOT theory. Implications of these findings for the values of the exponents appearing in the RFOT theory are discussed. [ABSTRACT FROM AUTHOR]

The problem of spurious patterns in neural associative memory models is discussed. Some suggestions to solve this problem from the literature are reviewed and their inadequacies are pointed out. A solution based on the notion of neural self-interaction with a suitably chosen magnitude is presented for the Hebb learning rule. For an optimal learning rule based on linear programming, asymmetric dilution of synaptic connections is presented as another solution to the problem of spurious patterns. With varying percentages of asymmetric dilution it is demonstrated numerically that this optimal learning rule leads to near total suppression of spurious patterns. For practical usage of neural associative memory networks a combination of the two solutions with the optimal learning rule is recommended to be the best proposition. Index Terms - Associative memory, asymmetric dilution, basin of attraction, learning rule, neural network, optimal learning, self-interaction, spurious pattern.

Engineering design problems are ill‐structured, and as a result, learners find it challenging to engage productively in relevant practices of analysis, synthesis, and evaluation for solving problems in the domain. Teachers find it particularly difficult to effectively support such engagement. Thus, there is a need to understand how teachers orchestrate their classrooms for maximizing opportunities for students to engage in these practices. In this paper, we use the case study methodology to investigate how teachers materialize and enact engineering design practices in a CAD simulation‐enhanced learning environment. Three teachers (cases) provide evidence for the following orchestration techniques—scaffolding development of students' expertise via teacher‐guided decomposition of problem space, apriori teacher‐led parameter determination, and student‐generated contrasting cases. These techniques scaffolded students' engagement in engineering design practices in all three cases. Common themes across the three cases—problem decomposition, modeling of expert practices, and facilitating students' active involvement—revealed a combination of pedagogical strategies that were interconnected and made evident through the cognitive apprenticeship model. The strategies suggest the integration of types of knowledge and engineering practices required for effective apprenticeships in similar contexts. [ABSTRACT FROM AUTHOR]

We have performed fully atomistic classical molecular dynamics simulations to calculate the effective interaction between two polyamidoamine dendrimers. Using the umbrella sampling technique, we have obtained the potential of mean force (PMF) between the dendrimers and investigated the effects of protonation level and dendrimer size on the PMF. Our results show that the interaction between the dendrimers can be tuned from purely repulsive to partly attractive by changing the protonation level. The PMF profiles are well-fitted by the sum of an exponential and a Gaussian function with the weight of the exponential function dominating over that of the Gaussian function. This observation is in disagreement with the results obtained in previous analytic [C. Likos, M. Schmidt, H. Löwen, M. Ballauff, D. Pötschke, and P. Lindner, Macromolecules 34, 2914 (2001)] and coarse-grained simulation [I. Götze, H. Harreis, and C. Likos, J. Chem. Phys. 120, 7761 (2004)] studies which predicted the effective interaction to be Gaussian. [ABSTRACT FROM AUTHOR]

We present detailed results from a molecular dynamics (MD) simulation of phase-separation kinetics in polymer mixtures. Our MD simulations naturally incorporate hydrodynamic effects. We find that polymeric phase separation (with dynamically symmetric components) is in the same universality class as segregation of simple fluids: the degree of polymerization only slows down the segregation kinetics. For d = 2 polymeric fluids, the domain growth law is L(t) ∼ tø with f showing a crossover from 1/3 → 1/2 → 2/3. For d = 3 polymeric fluids, we see the crossover ø = 1/3 → 1. Our MD simulations do not yet access the inertial hydrodynamic regime (with L ∼ t2/3) of phase separation in 3-d fluids. [ABSTRACT FROM AUTHOR]

Experiments and computer simulations demonstrate that water spontaneously fills the hydrophobic cavity of a carbon nanotube. To gain a quantitative thermodynamic understanding of this phenomenon, we use the recently developed two phase thermodynamics method to compute translational and rotational entropies of confined water molecules inside single-walled carbon nanotubes and show that the increase in energy of a water molecule inside the nanotube is compensated by the gain in its rotational entropy. The confined water is in equilibrium with the bulk water and the Helmholtz free energy per water molecule of confined water is the same as that in the bulk within the accuracy of the simulation results. A comparison of translational and rotational spectra of water molecules confined in carbon nanotubes with that of bulk water shows significant shifts in the positions of the spectral peaks that are directly related to the tube radius. [ABSTRACT FROM AUTHOR]

The authors have used atomistic molecular dynamics (MD) simulations to study the structure and dynamics of water molecules inside an open ended carbon nanotube placed in a bath of water molecules. The size of the nanotube allows only a single file of water molecules inside the nanotube. The water molecules inside the nanotube show solidlike ordering at room temperature, which they quantify by calculating the pair correlation function. It is shown that even for the longest observation times, the mode of diffusion of the water molecules inside the nanotube is Fickian and not subdiffusive. They also propose a one-dimensional random walk model for the diffusion of the water molecules inside the nanotube. They find good agreement between the mean-square displacements calculated from the random walk model and from MD simulations, thereby confirming that the water molecules undergo normal mode diffusion inside the nanotube. They attribute this behavior to strong positional correlations that cause all the water molecules inside the nanotube to move collectively as a single object. The average residence time of the water molecules inside the nanotube is shown to scale quadratically with the nanotube length. [ABSTRACT FROM AUTHOR]

We calculate the dislocation glide mobility in solid $$^4$$ He within a model that assumes the existence of a superfluid field associated with dislocation lines. Prompted by the results of this mobility calculation, we study within this model the role that such a superfluid field may play in the motion of the dislocation line when a stress is applied to the crystal. To do this, we relate the damping of dislocation motion, calculated in the presence of the assumed superfluid field, to the shear modulus of the crystal. As the temperature increases, we find that a sharp drop in the shear modulus will occur at the temperature where the superfluid field disappears. We compare the drop in shear modulus of the crystal arising from the temperature dependence of the damping contribution due to the superfluid field, to the experimental observation of the same phenomena in solid $$^4$$ He and find quantitative agreement. Our results indicate that such a superfluid field plays an important role in dislocation pinning in a clean solid $$^4$$ He at low temperatures and in this regime may provide an alternative source for the unusual elastic phenomena observed in solid $$^4$$ He. [ABSTRACT FROM AUTHOR]