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Abstract Calcium (Ca2+) is an essential mineral nutrient and a vital signaling molecule for plant growth and development. Ca2+/calmodulins (CaMs) can bind proteins, called CaM-binding proteins (CBPs), to relay Ca2+ signals and modulate transcriptional activity. In this study, we demonstrate that AtCBP60b, a member of the CBP60 family, is an essential factor in regulating plant growth and development. AtCBP60b loss-of-function plants showed impaired seedling growth, leaf development, and plant structural architecture under normal growth conditions. Transcriptomic profiles indicated a central role for AtCBP60b in the transcriptional regulation of the Ca2+ signaling pathway, growth homeostasis, and immune and stress responses. Disruption of AtCBP60b leads to Ca2+ deficiency hypersensitivity and altered regulation of Ca2+ dynamics and Ca2+ signaling responses. AtCBP60b was found to bind CaM which was determined to be required for AtCBP60b function in transcriptional regulation of the genes encoding the pathways maintaining cytosolic Ca2+ homeostasis, regulating defense, growth, and development. In addition, we show that elevated temperatures can rescue the atcpb60b growth and development defects through reprogramming of the transcriptional profiles of the genes regulating these processes. Overall, our findings demonstrate that AtCBP60b plays an important role in regulating plant Ca2+ signaling response, growth and development, and responses to elevated temperature. 

Protein expression levels optimize cell fitness: Too low an expression level of essential proteins will slow growth by compromising essential processes, whereas overexpression slows growth by increasing the metabolic load. This trade-off naïvely predicts that cells maximize their fitness by sufficiency, expressing just enough of each essential protein for function. We test this prediction in the naturally competent bacteriumAcinetobacter baylyiby characterizing the proliferation dynamics of essential-gene knockouts at a single-cell scale (by imaging) as well as at a genome-wide scale. In these experiments, cells proliferate for multiple generations as target protein levels are diluted from their endogenous levels. This approach facilitates a proteome-scale analysis of the fitness landscape with respect to protein abundance. We find that most essential proteins are subject to a threshold-like fitness landscape: Growth is independent of protein abundance above a critical threshold and arrests below that threshold. We have recently analyzed the implications of this landscape for growth robustness. Confirming signature predictions of this model, we find that (i) roughly 70% of essential proteins are overabundant, (ii) overabundance increases as the expression level decreases, and (iii) the lowest abundance proteins are in vast excess (>10×) of what is required for growth in the typical cell. These results reveal that robustness plays a fundamental role in determining the expression levels of essential genes and that overabundance is a key mechanism for ensuring robust growth. 

Abstract Collisionless plasma shocks are a common feature of many space and astrophysical systems. They are sources of high-energy particles and nonthermal emission, channeling as much as 20% of the shock’s energy into nonthermal particles. The generation and acceleration of these nonthermal particles have been previously studied and shown to affect shock hydrodynamics to the zeroth order. In this work, we use self-consistent hybrid particle-in-cell simulations to examine the effect of self-generated nonthermal ion populations on the nature of collisionless, quasi-parallel shocks. Accelerated nonthermal particles downstream of the shock diffuse into the upstream region, taking energy away from the shock, which increases the compression ratio, slows the shock down, and flattens the nonthermal population’s spectral index for lower-Mach-number shocks. We show that this enhances shock compressibility when the heat flux is included in the Rankine–Hugoniot jump conditions, results that are roughly consistent with previous theories of “cosmic-ray-modified shocks.” Additionally, the simulation data show that heat flux and enthalpy flux cancels out in the upstream region, yielding a relatively simple, alternative closure for the jump conditions which accurately predict for the shock speed and compression ratio. The results have the potential to explain discrepancies between predictions and observations in a wide range of systems, such as inaccuracies in predictions of the arrival times of coronal mass ejections and the conflicting radio and X-ray observations of intracluster shocks. These effects will likely need to be included in fluid modeling to predict shock evolution accurately. 

Background The rapid advancement of artificial intelligence (AI) is reshaping industrial workflows and workforce expectations. After its breakthrough year in 2023, AI has become ubiquitous, yet no standardized approach exists for integrating AI into engineering and computer science undergraduate curricula. Recent graduates find them- selves navigating evolving industry demands surrounding AI, often without formal preparation. The ways in which AI impacts their career decisions represent a critical perspective to support future students as graduates enter AI-friendly industries. Our work uses social cognitive career theory (SCCT) to qualitatively investigate how 14 recent engineering graduates working in a variety of industry sectors perceived the impact of AI on their careers and industries. Results Given the rapid and ongoing evolution of AI, findings suggested that SCCT may have limited applicability until AI technology has matured further. Many recent graduates lacked prior exposure to or a clear understanding of AI and its relevance to their professional roles. The timing of direct, practical exposure to AI emerged as a key influ- ence on how participants perceived AI’s impact on their career decisions. Participants emphasized a need for more customizable undergraduate curricula to align with industry trends and individual interests related to AI. While many acknowledged AI’s potential to enhance efficiency in data management and routine administrative tasks, they largely did not perceive AI as a direct threat to their core engineering functions. Instead, AI was viewed as a supplemen- tal tool requiring critical oversight. Despite interest in AI’s potential, most participants lacked the time or resources to independently pursue integrating AI into their professional roles. Broader concerns included ethical considerations, industry regulations, and the rapid pace of AI development. Conclusions This exploratory work highlights an urgent need for collaboration between higher education and industry leaders to more effectively integrate direct, hands-on experience with AI into engineering education. A personalized, context-driven approach to teaching AI that emphasizes ethical considerations and domain-specific applications would help better prepare students for evolving workforce expectations by highlighting AI’s relevance and limitations. This alignment would support more meaningful engagement with AI and empower future engineers to apply it responsibly and effectively in their fields. 

Abstract The hydrogen produced by Al‐doped SrTiO₃/TiO₂core‒shell catalysts with a range of Al‐doped SrTiO₃cores and the same TiO₂shell are compared. The study included SrTiO₃cores doped with different amounts of Al (0, 1, 2, or 3 mol%) added at different points in the synthesis (prior to or during the molten salt treatment) and at different temperatures (900°C, 1000°C, and 1100°C). It was found that core‒shell catalysts with different cores had hydrogen generation rates that varied by a factor of more than 40 and varied with the processing parameters in the same way as the hydrogen generation rates of the cores alone. The best catalysts had 2 or 3 mol% added Al, added during treatment in a SrCl₂molten salt at 1000°C or 1100°C. Because the core absorbs most of the light, its ability to separate and transport photogenerated charge carriers dominates the properties of the core‒shell catalyst. This indicates that, to optimize the properties of core‒shell catalysts, it is essential to optimize the properties of the core. While the shell can be important to protect the core from degradation, it is not as important to the overall reactivity as the core.