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Physical computing enables learners to create interactive projects using tangible materials and electronic components. These projects commonly utilize microcontroller boards like the micro:bit. In contrast, computer vision (CV) is a powerful technique for detecting input through interaction with everyday materials like paper, and it can be utilized for physical computing projects. However, CV-based toolkits are typically limited to input detection and rely on screen-based or projected outputs. This paper presents a hybrid approach that integrates a CV-based platform called Paper Playground with the micro:bit electronics platform. By combining CV-detected, paper-based inputs with the rich input-output possibilities of microcontroller-based systems, we showcase a multimodal physical computing toolkit. Through three project examples, we explore how this hybrid approach can enhance the creative possibilities in physical computing, and develop a preliminary design space combining CV-based and electronics-based physical computing. 

Early investments in regional hydrogen systems carry two distinct types of risk: (1) economic risk that projects will not be financially viable, resulting in stranded capital, and (2) environmental risk that projects will not deliver deep reductions in greenhouse gas emissions and through leaks, perhaps even contribute to climate change. This article systematically reviews the literature and performs analysis to describe both types of risk in the context of recent efforts in the United States and worldwide to support the development of “hydrogen hubs” or regional systems of hydrogen production and use. We review estimates of hydrogen production costs and projections of how future costs are likely to change over time for different production routes, environmental impacts related to hydrogen and methane leaks, and the availability and effectiveness of carbon capture and sequestration. Finally, we consider system‐wide risks associated with evolving regional industrial structures, including job displacement and underinvestment in shared components, such as refueling. We conclude by suggesting a set of design principles that should be applied in developing early hydrogen hubs if they are to be a successful step toward creating a decarbonized energy system. 

Paper prototyping presents a low-entry barrier method to engaging youth in interaction design. Purely paper-based designs leave a large gap between ideation and implementation. Paper Playground is a prototyping tool that connects physical and virtual papers with JavaScript programs, enabling the creation of multimodal prototypes in both face-to-face and virtual settings. Paper Playground is being designed and developed through iterative co-design activities including youth and adults. Here we present findings from remote co-design sessions with youth, investigating what affordances the participants requested from a multimodal prototyping tool. We reflect on the co-designers desires and remarks on paper use for interactive project design, remote collaborative use, and extensibility for physical computing. 

Gene expression has a key role in reproductive isolation, and studies of hybrid gene expression have identified mechanisms causing hybrid sterility. Here, we review the evidence for altered gene expression following hybridization and outline the mechanisms shown to contribute to altered gene expression in hybrids. Transgressive gene expression, transcending that of both parental species, is pervasive in early generation sterile hybrids, but also frequently observed in viable, fertile hybrids. We highlight studies showing that hybridization can result in transgressive gene expression, also in established hybrid lineages or species. Such extreme patterns of gene expression in stabilized hybrid taxa suggest that altered hybrid gene expression may result in hybridization‐derived evolutionary novelty. We also conclude that while patterns of misexpression in hybrids are well documented, the understanding of the mechanisms causing misexpression is lagging. We argue that jointly assessing differences in cell composition and cell‐specific changes in gene expression in hybrids, in addition to assessing changes in chromatin and methylation, will significantly advance our understanding of the basis of altered gene expression. Moreover, uncovering to what extent evolution of gene expression results in altered expression for individual genes, or entire networks of genes, will advance our understanding of how selection moulds gene expression. Finally, we argue that jointly studying the dual roles of altered hybrid gene expression, serving both as a mechanism for reproductive isolation and as a substrate for hybrid ecological adaptation, will lead to significant advances in our understanding of the evolution of gene expression. 

Pigment patterns are incredibly diverse across vertebrates and are shaped by multiple selective pressures from predator avoidance to mate choice. A common pattern across fishes, but for which we know little about the underlying mechanisms, is repeated melanic vertical bars. To understand the genetic factors that modify the level or pattern of vertical barring, we generated a genetic cross of 322 F₂hybrids between two cichlid species with distinct barring patterns,Aulonocara koningsiandMetriaclima mbenjii. We identify 48 significant quantitative trait loci that underlie a series of seven phenotypes related to the relative pigmentation intensity, and four traits related to patterning of the vertical bars. We find that genomic regions that generate variation in the level of eumelanin produced are largely independent of those that control the spacing of vertical bars. Candidate genes within these intervals include novel genes and those newly-associated with vertical bars, which could affect melanophore survival, fate decisions, pigment biosynthesis, and pigment distribution. Together, this work provides insights into the regulation of pigment diversity, with direct implications for an animal’s fitness and the speciation process. 

Many studies anticipate that carbon capture and sequestration (CCS) will be essential to decarbonizing the U.S. economy. However, prior work has not estimated the time required to develop, approve, and implement a geologic sequestration site in the United States. We generate such an estimate by identifying six clearance points that must be passed before a sequestration site can become operational. For each clearance point (CP), we elicit expert judgments of the time required in the form of probability distributions and then use stochastic simulation to combine and sum the results. We find that, on average, there is a 90% chance that the time required lies between 5.5 and 9.6 y, with an upper bound of 12 y. Even using the most optimistic expert judgements, the lower bound on time is 2.7 y, and the upper bound is 8.3 y. Using the most pessimistic judgements, the lower bound is 3.5 y and the upper bound is 19.2 y. These estimates suggest that strategies must be found to safely accelerate the process. We conclude the paper by discussing seven potential strategies. 

Environmental hypoxia challenges female reproductive physiology in placental mammals, increasing rates of gestational complications. Adaptation to high elevation has limited many of these effects in humans and other mammals, offering potential insight into the developmental processes that lead to and protect against hypoxia-related gestational complications. However, our understanding of these adaptations has been hampered by a lack of experimental work linking the functional, regulatory, and genetic underpinnings of gestational development in locally adapted populations. Here, we dissect high-elevation adaptation in the reproductive physiology of deer mice (Peromyscus maniculatus), a rodent species with an exceptionally broad elevational distribution that has emerged as a model for hypoxia adaptation. Using experimental acclimations, we show that lowland mice experience pronounced fetal growth restriction when challenged with gestational hypoxia, while highland mice maintain normal growth by expanding the compartment of the placenta that facilitates nutrient and gas exchange between gestational parent and fetus. We then use compartment-specific transcriptome analyses to show that adaptive structural remodeling of the placenta is coincident with widespread changes in gene expression within this same compartment. Genes associated with fetal growth in deer mice significantly overlap with genes involved in human placental development, pointing to conserved or convergent pathways underlying these processes. Finally, we overlay our results with genetic data from natural populations to identify candidate genes and genomic features that contribute to these placental adaptations. Collectively, these experiments advance our understanding of adaptation to hypoxic environments by revealing physiological and genetic mechanisms that shape fetal growth trajectories under maternal hypoxia. 

Sensory extensions enhance our awareness by transforming variations in stimuli normally undetectable by human senses into perceivable outputs. Similarly, interactive simulations for learning promote an understanding of abstract phenomena. Combining sensory extension devices with interactive simulations gives users the novel opportunity to connect their sensory experiences in the physical world to computer-simulated concepts. We explore this opportunity by designing a suite of wearable sensory extension devices that interface with a uniquely inclusive PhET Simulation, Ratio and Proportion. In this simulation, two hands can be moved on-screen to various values, representing different mathematical ratios. Users explore changing hand heights to find and maintain ratios through visual and auditory feedback. Our sensory extension devices translate force, distance, sound frequency, and magnetic field strength to quantitative values in order to control individual hands in the computer simulation. This paper describes the design of the devices and our analysis of feedback from 23 high-school aged youth who used our designs to interact with the Ratio and Proportion simulation. 

The evolution of Web Speech has increased the ease of development and public availability of auditory description without the use of screen reader software, broadening its exposure to users who may benefit from spoken descriptions. Building off an existing design framework for auditory description of interactive web media, we have designed an optional Voicing feature instantiated in two PhET Interactive Simulations regularly used by students and educators globally. We surveyed over 2000 educators to investigate their perceptions and preferences of the Web Speech-based Voicing feature and its broad appeal and effectiveness for teaching and learning. We find a general approval by educators of the Voicing feature and more moderate statement ratings than expected to the different preset speech levels we presented to them. We find that educators perceive the feature as beneficial both broadly and for specific populations while some acknowledge particular populations for whom it remains ineffective. Lastly, we identify some variance in the perceptions of the feature based on different aspects of the simulation experience.