Search for: All records

Much research attention has been focused on learning through game playing. However, very little has been focused on student learning through game making, especially in science. Moreover, none of the studies on learning through making games has presented an account of how students engage in the process of game design in real time. The present study seeks to address that gap. We report an exploratory embedded case study in which three groups of students in one classroom created a computer game designed to teach peers about climate science, while drawing on scientific knowledge, principles of game design, and computational thinking practices. Data sources were student design sheets, computer video, and audio screen capture while students created their game, and interviews after completing the curriculum unit. A theme‐driven framework was used to code the data. A curricular emphasis on systems across climate systems, game design, and computational thinking practices provided a context designed to synergistically supported student learning. This embedded case study provides a rich example of what a collaborative game design task in a constructionist context looks like in a middle school science classroom, and how it supports student learning. Game design in a constructionist learning environment that emphasized learning through building a game allowed students to choose their pathways through the learning experience and resulted in learning for all despite various levels of programming experience. Our findings suggest that game design may be a promising context for supporting student learning in STEM disciplines.

 

Hydrodynamic flow produced by multiciliated cells is critical for fluid circulation and cell motility. Hundreds of cilia beat with metachronal synchrony for fluid flow. Cilia-driven fluid flow produces extracellular hydrodynamic forces that cause neighboring cilia to beat in a synchronized manner. However, hydrodynamic coupling between neighboring cilia is not the sole mechanism that drives cilia synchrony. Cilia are nucleated by basal bodies (BBs) that link to each other and to the cell’s cortex via BB-associated appendages. The intracellular BB and cortical network is hypothesized to synchronize ciliary beating by transmitting cilia coordination cues. The extent of intracellular ciliary connections and the nature of these stimuli remain unclear. Moreover, how BB connections influence the dynamics of individual cilia has not been established. We show by focused ion beam scanning electron microscopy imaging that cilia are coupled both longitudinally and laterally in the ciliate Tetrahymena thermophila by the underlying BB and cortical cytoskeletal network. To visualize the behavior of individual cilia in live, immobilized Tetrahymena cells, we developed Delivered Iron Particle Ubiety Live Light (DIPULL) microscopy. Quantitative and computer analyses of ciliary dynamics reveal that BB connections control ciliary waveform and coordinate ciliary beating. Loss of BB connections reduces cilia-dependent fluid flow forces. 

Social learning theory posits that adolescents learn to adopt social norms by observing the behaviors of others and internalizing the associated outcomes. However, the underlying neural processes by which social learning occurs is less well-understood, despite extensive neurobiological reorganization and a peak in social influence sensitivity during adolescence. Forty-four adolescents (Mage = 12.2 years) completed an fMRI scan while observing their older sibling within four years of age (Mage = 14.3 years) of age complete a risky decision-making task. Group iterative multiple model estimation (GIMME) was used to examine patterns of directional brain region connectivity supporting social learning. We identified group-level neural pathways underlying social observation including the anterior insula to the anterior cingulate cortex and mentalizing regions to social cognition regions. We also found neural states based on adolescent sensitivity to social learning via age, gender, modeling, differentiation, and behavior. Adolescents who were more likely to be influenced elicited neurological up-regulation whereas adolescents who were less likely to be socially influenced elicited neurological down-regulation during risk-taking. These findings highlight patterns of how adolescents process information while a salient influencer takes risks, as well as salient neural pathways that are dependent on similarity factors associated with social learning theory.

 

Abstract As demonstrated at Anak Krakatau on December 22 nd , 2018, tsunamis generated by volcanic flank collapse are incompletely understood and can be devastating. Here, we present the first high-resolution characterisation of both subaerial and submarine components of the collapse. Combined Synthetic Aperture Radar data and aerial photographs reveal an extensive subaerial failure that bounds pre-event deformation and volcanic products. To the southwest of the volcano, bathymetric and seismic reflection data reveal a blocky landslide deposit (0.214 ± 0.036 km 3 ) emplaced over 1.5 km into the adjacent basin. Our findings are consistent with en-masse lateral collapse with a volume ≥0.175 km 3 , resolving several ambiguities in previous reconstructions. Post-collapse eruptions produced an additional ~0.3 km 3 of tephra, burying the scar and landslide deposit. The event provides a model for lateral collapse scenarios at other arc-volcanic islands showing that rapid island growth can lead to large-scale failure and that even faster rebuilding can obscure pre-existing collapse. 

Abstract Numerous climate models display large-amplitude, long-period variability associated with quasiperiodic convection in the Southern Ocean, but the mechanisms responsible for producing such oscillatory convection are poorly understood. In this paper we identify three feedbacks that help generate such oscillations within an Earth system model with a particularly regular oscillation. The first feedback involves increased (decreased) upward mixing of warm interior water to the surface, resulting in more (less) evaporation and loss of heat to the atmosphere which produces more (less) mixing. This positive feedback helps explain why temperature anomalies are not damped out by surface forcing. A second key mechanism involves convective (nonconvective) events in the Weddell Sea causing a relaxation (intensification) of westerly winds, which at some later time results in a pattern of currents that reduces (increases) the advection of freshwater out of the Weddell Sea. This allows for the surface to become lighter (denser) which in turn can dampen (trigger) convection—so that the overall feedback is a negative one with a delay—helping to produce a multidecadal oscillation time scale. The decrease (increase) in winds associated with convective (nonconvective) states also results in a decrease (increase) in the upward mixing of salt in the Eastern Weddell Sea, creating a negative (positive) salinity anomaly that propagates into the Western Weddell Sea and dampens (triggers) convection—again producing a negative feedback with a delay. A principal oscillatory pattern analysis yields a reasonable prediction for the period of oscillation. Strengths of the feedbacks are sensitive to parameterization of mesoscale eddies. 

Microalgae within the Scenedesmaceae are often distinguished by spines, bristles, and other wall characteristics. We examined the dynamic production and chemical nature of bristles extruded from the poles ofTetradesmus deserticolapreviously isolated from microbiotic crust. Rapidly growing cells in a liquid growth medium were established in polydimethylsiloxane microfluidic chambers specially designed to maintain aerobic conditions over time within a chamber 6–12 μm deep. This geometry enabled in‐focus imaging of single cells over long periods. Differential interference contrast (DIC) imaging revealed that after multiple fission of mother cells, the newly released, lemon‐shaped daughter cells began extruding bristles from each pole. In some instances, the bristles became stuck to either the glass floor or polydimethylsiloxane (PDMS) walls of the chamber, and the force by which the new bristle was extruded was sufficient to propel the cells across the field of view at ~1.2 μm · h⁻¹. Confocal fluorescence and DIC imaging of cells stained with pontamine fast scarlet and calcofluor, and treated with proteinase K, suggested that bristles are proteinaceous and may also host carbohydrate modifications. The polar bristles extruded by this desert‐derivedT. deserticolamay simply be relics of bristles produced by an aquatic ancestor for flotation or predator deterrence. But, their tendency to attach to glass (silicate) and/or PDMS surfaces suggests a potential role in tethering cells in place or binding soil particles.T. deserticolais closely related toT. obliquus, which is of interest for biofuels development; extruded bristles inT. deserticolamay offer tethers for industrial use of these stress‐tolerant algae.

 

There is broad belief that preparing all students in preK-12 for a future in STEM involves integrating computing and computational thinking (CT) tools and practices. Through creating and examining rich “STEM+CT” learning environments that integrate STEM and CT, researchers are defining what CT means in STEM disciplinary settings. This interactive session brings together a diverse spectrum of leading STEM researchers to share how they operationalize CT, what integrated CT and STEM learning looks like in their curriculum, and how this learning is measured. It will serve as a rich opportunity for discussion to help advance the state of the field of STEM and CT integration. 

There is broad belief that preparing all students in preK-12 for a future in STEM involves integrating computing and computational thinking (CT) tools and practices. Through creating and examining rich “STEM+CT” learning environments that integrate STEM and CT, researchers are defining what CT means in STEM disciplinary settings. This interactive session brings together a diverse spectrum of leading STEM researchers to share how they operationalize CT, what integrated CT and STEM learning looks like in their curriculum, and how this learning is measured. It will serve as a rich opportunity for discussion to help advance the state of the field of STEM and CT integration.