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Emerging satellite networks integrated with terrestrial and aerial systems form a key part of next-generation infrastructures supporting the Internet of Everything (IoE). This chapter outlines the current status of PQC-based authentication in integrated Space-Aerial-Terrestrial Networks (SATIN), highlighting the technical challenges in achieving quantum-resilient security within constrained and complex environments. While quantum computing necessitates migration to post-quantum cryptography (PQC), existing standards often demand resources that are unsuited for SATIN’s limited hardware and fragile links. We analyze leading NIST PQC signature and key encapsulation schemes in the SATIN context, evaluating trade-offs in computational cost, signature size, and protocol compatibility. Emerging directions, including broader algorithm evaluations, advanced protocol integrations (e.g., EMSS and NIST-PQC with terrestrial backbone, PQ group key management), and some alternative PQ technologies are discussed. Addressing these challenges requires advanced simulation and experimental frameworks to enable scalable, practical, and quantum-resilient secure communications in future integrated networks. 

ABSTRACT: We review in this Viewpoint recent progress on the development of a new class of sustainable electrocatalytic systems for water-splitting and molecular hydrogen generation using diiron disulfide ([2Fe-2S]) active site methacrylate metallopolymers. To date, noble metal catalysts (e.g, platinum) remain the best electrocatalysts for molecular hydrogen generation using water as the chemical feedstock and proton donor. However, there remains a need for the synthesis of efficient electrocatalytic systems using low cost, earth abundant materials for sustainable H2 generation. We focus on our recent work in this area using well-defined single site [2Fe-2S]-metallopolymer catalysts. Thus far, these systems have demonstrated rates of hydrogen production >25 times faster than [FeFe]-hydrogenase enzymes and match the current densities of platinum with only 0.2 V higher potential when operating in water at neutral pH with tris(hydroxymethyl)aminoethane (TRIS) buffer (Faradaic yields 100±3%). The molecular design and synthesis of [2Fe-2S]-metallopolymers are reviewed along with mechanistic studies unraveling the causality of efficient H2 production from this catalytic system. The overall current output and overpotential are improved by (a) the reversible electrostatic adsorption of the metallopolymer on the carbon electrode surface that enhances the proton and electron transfer rates and (b) the use of protic buffer electrolytes (PBEs) that enhance the availability of protons. The schemes summarized here to improve the performance of [2Fe-2S] catalysts by incorporation into metallopolymers may be used to enhance the performance of other molecular electrocatalysts at the electrode surface. 

This paper directly links the abstract geometry of structural form-finding to the fabrication-aware design of discrete shells and spatial structures for 3D concrete printing through a bidirectional approach, where it creates surface-toolpath twins for the components, optimizing the buildability of the parts and their surface quality. The design-to-production process of efficient structural systems for 3D printing is often a top-down unidirectional process involving form-finding, segmentation, and slicing, where results face printability challenges due to incompatibility between the initial geometry and the printing system, as well as material constraints. We introduce surface-toolpath twins that can be interconverted and synchronized through efficient slicing and surface reconstruction algorithms to allow the combination of optimizations and modifications on either part of the twin in flexible orders. We provide two core methods for fabrication rationalization: (1) global buildability optimization on the surface mesh by normal-driven shape stylization and (2) local surface quality optimization on toolpath curves through intra-layer iterative adjustments. The result is a bidirectional design-to-production process where one can plug and play different form-finding results, assess and optimize their fabrication schemes, or leverage knowledge in fabrication design, model toolpath curves as sections, reconstruct surfaces, and merge them into form-finding and segmentation in an inverse way. The proposed framework enables the integration of form-finding expertise with fabrication-oriented design, allowing the realization of spatial shell structures with complex topologies or extreme geometrical features through 3D concrete printing. 

Abstract Experimental studies have demonstrated that solid solutions of minerals from the alunite group, with chemical compositions intermediate between the Al and Fe end-members, can be readily synthesized in the laboratory. In contrast, up until about a dozen years ago, there were no confirmed reports of alunite group minerals with intermediate Al-Fe compositions in natural settings, leading some to suggest that minerals with such compositions might not exist in nature. In recent years, however, alunite group minerals with intermediate Al-Fe compositions have been documented in a few isolated locations, which were previously limited to basalt-hosted acid-sulfate fumarole deposits and acid mine drainage pit lakes. These occurrences contrast with nearly all other reports of minerals from this group, whose measured chemical compositions are very close to either the Al or Fe end-members. Here, we report jarosite-alunite solid solutions containing approximately equal amounts of Al and Fe, which are found in mineralized fractures of the Aztec Sandstone in southeast Nevada. Analysis of the minerals by X-ray diffraction, Raman spectroscopy, and visible-near infrared spectroscopy confirms that they are bona fide solid solutions and not intimate mixtures of end-member minerals. This study represents the first documented occurrence of alunite group solid solutions with intermediate Al-Fe compositions in sedimentary rocks. The results further demonstrate that alunite group minerals with a wide range of Al-Fe compositions occur naturally and can persist for millions of years or more in natural systems. 

Xanthine dehydrogenase (XDH) is a molybdenum cofactor (Moco) requiring enzyme that catabolizes hypoxanthine into xanthine and xanthine into uric acid, the final steps in purine catabolism. Human patients with mutations in XDH develop xanthinuria which can lead to xanthine stones in the kidney, recurrent urinary tract infections, and renal failure. Currently, there are no therapies for treating human XDH deficiency. Thus, understanding mechanisms that maintain purine homeostasis is an important goal of human health. Here, we used the nematodeCaenorhabditis elegansto model human XDH deficiency using two clinically relevant paradigms: Moco deficiency or loss-of-function mutations inxdh-1,theC. elegansortholog of XDH.Both Moco deficiency andxdh-1loss of function caused the formation of autofluorescent xanthine stones inC. elegans. Surprisingly, only 2% ofxdh-1null mutantC. elegansdeveloped a xanthine stone, suggesting additional pathways may regulate this process. To uncover such pathways, we performed a forward genetic screen for mutations that enhance the penetrance of xanthine stone formation inxdh-1null mutantC. elegans. We isolated multiple loss-of-function mutations in the genesulp-4which encodes a sulfate permease homologous to human SLC26 anion exchange proteins. We demonstrated that SULP-4 acts cell-nonautonomously in the excretory cell to limit xanthine stone accumulation. Interestingly,sulp-4mutant phenotypes were suppressed by mutations in genes that encode for cystathionase (cth-2)or cysteine dioxygenase (cdo-1), members of the sulfur amino acid catabolism pathway required for production of sulfate, a substrate of SULP-4. We propose that sulfate accumulation caused bysulp-4loss of function promotes xanthine stone accumulation. We speculate that sulfate accumulation causes osmotic imbalance, creating conditions in the intestinal lumen that favor xanthine stone accumulation. Supporting this model, a mutation inosm-8that constitutively activates the osmotic stress response also promoted xanthine stone accumulation in anxdh-1mutant background. Thus, our work establishes aC. elegansmodel for human XDH deficiency and identifies the sulfate permeasesulp-4as a critical player controlling xanthine stone accumulation. 

Real-time Hybrid Simulation (RTHS) is a technique wherein a structural system is divided into an analytical and an experimental substructure. The former is modeled numerically while the latter is physically present in the laboratory. The two substructures are kinematically linked together at their interface degrees of freedom (DOFs) and the equations of motion are solved in real-time to determine the structure’s response. One of the main challenges of RTHS is to include the effects of soil–foundation–structure interaction (SFSI), which can have a substantial effect on the overall response. The soil domain cannot be modeled experimentally due to the large payload size. On the other hand, modeling the soil domain numerically, using a continuum-based approach, in real-time is challenging due to the associated computational cost. To address these issues, this paper presents a framework for seismic RTHS of SFSI systems using a Neural Network (NN)-based macroelement model of the soil–foundation system. A coupled SFSI model is used to train the NN model and the loss function is based on dynamic equilibrium at the interface between the foundation and the structure. The framework is demonstrated using a three-story building with the lateral load resisting system comprised of moment resisting and damped brace frames. The proposed framework ensures a stable and accurate RTHS, accounting for SFSI by incorporating: (a) spring elements at the output DOFs of the NN model to remove rigid body modes; (b) dashpot elements at the output DOFs of the NN model to mitigate spurious higher frequencies of vibration; and (c) regularization in the NN model’s architecture with data augmentation to reduce overfitting. 

Science instruction in elementary school provides a base for student understanding of the natural world, yet policies prioritizing mathematics and reading have marginalized science. In response, some teachers have enhanced their science instruction by introducing students to participatory science (PS) projects. Using data from a larger study that examines the development of educative support materials for two existing PS projects, this embedded mixed methods study focuses on teachers’ and students’ experiences learning outdoors. We compare teachers’ weekly log data, surveys, interviews, observations, and student focus groups to document teachers’ applications of PS in their science classrooms and outdoors. Teachers report benefits (e.g., purposeful science learning) and challenges (e.g., time constraints, testing pressure) of implementing outdoor PS projects. Teacher and student data document cognitive and affective benefits of students’ participation. Implications support the potential for PS projects that include schoolyard activities to supplement elementary science teaching and learning. 

The Mississippi River Basin (MRB), the fourth-largest river basin in the world, is an important corridor for hy- droelectric power generation, agricultural and industrial production, riverine transportation, and ecosystem goods and services. Historically, flooding of the Mississippi River has resulted in significant economic losses. In a future with an intensified global hydrological cycle, the altered discharge of the river may jeopardize commu- nities and infrastructure situated in the floodplain. This study utilizes output from the Community Earth System Model version 2 (CESM2) large ensemble simulations spanning 1930 to 2100 to quantify changes in future MRB discharge under a high greenhouse gas emissions scenario (SSP3–7.0). The simulations show that increasing precipitation trends exceed and dominate increased evapotranspiration (ET), driving an overall increase in total discharge in the Ohio and Lower Mississippi River basins. On a seasonal scale, reduced spring snowmelt is projected in the Ohio and Missouri River basins, leading to reduced spring runoff in those regions. However, decreased snowmelt and spring runoff is overshadowed by a larger increase in projected precipitation minus ET over the entire basin and leads to an increase in mean river discharge. This increase in discharge is linked to a relatively small increase in the magnitude of extreme floods (2 % and 3 % for 100-year and 1000-year floods, respectively) by the late 21st century relative to the late 20th century. Our analyses imply that under SSP3–7.0 forcing, the Mississippi River and Tributaries (MR&T) project design flood would not be exceeded at the 100-year return period. Our results harbor implications for water resources management including increased vulnerability of the Mississippi River given projected changes in climate.