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The McMurdo Dry Valleys (MDVs) of Antarctica are a mosaic of extreme habitats which are dominated by microbial life. The MDVs include glacial melt holes, streams, lakes, and soils, which are interconnected through the transfer of energy and flux of inorganic and organic material via wind and hydrology. For the first time, we provide new data on the viral community structure and function in the MDVs through metagenomics of the planktonic and benthic mat communities of Lakes Bonney and Fryxell. Viral taxonomic diversity was compared across lakes and ecological function was investigated by characterizing auxiliary metabolic genes (AMGs) and predicting viral hosts. Our data suggest that viral communities differed between the lakes and among sites: these differences were connected to microbial host communities. AMGs were associated with the potential augmentation of multiple biogeochemical processes in host, most notably with phosphorus acquisition, organic nitrogen acquisition, sulfur oxidation, and photosynthesis. Viral genome abundances containing AMGs differed between the lakes and microbial mats, indicating site specialization. Using procrustes analysis, we also identified significant coupling between viral and bacterial communities (p = 0.001). Finally, host predictions indicate viral host preference among the assembled viromes. Collectively, our data show that: (i) viruses are uniquely distributed through the McMurdo Dry Valley lakes, (ii) their AMGs can contribute to overcoming host nutrient limitation and, (iii) viral and bacterial MDV communities are tightly coupled. 

Background and Context. This innovative practice full paper describes the development and implementation of a professional development (PD) opportunity for secondary teachers to learn about ChatGPT. Incorporating generative AI techniques from Large Language Models (LLMs) such as ChatGPT into educational environments offers unprecedented opportunities and challenges. Prior research has highlighted their potential to personalize feedback, assist in lesson planning, generate educational content, and reduce teachers' workload, alongside concerns such as academic integrity and student privacy. However, the rapid adoption of LLMs since ChatGPT's public release in late 2022 has left educators, particularly at the secondary level, with a lack of clear guidance on how LLMs work and can be effectively adopted. Objective. This study aims to introduce a comprehensive, free, and vetted ChatGPT course tailored for secondary teachers, with the objective of enhancing their technological competencies in LLMs and fostering innovative teaching practices. Method. We developed a five-session interactive course on ChatGPT capabilities, limitations, prompt-engineering techniques, ethical considerations, and strategies for incorporating ChatGPT into teaching. We introduced the course to six middle and high school teachers. Our curriculum emphasized active learning through peer discussions, hands-on activities, and project-based learning. We conducted pre- and post-course focus groups to determine the effectiveness of the course and the extent to which teachers' attitudes toward the use of LLMs in schools had changed. To identify trends in knowledge and attitudes, we asked teachers to complete feedback forms at the end of each of the five sessions. We performed a thematic analysis to classify teacher quotes from focus groups' transcripts as positive, negative, and neutral and calculated the ratio of positive to negative comments in the pre- and post-focus groups. We also analyzed their feedback on each individual session. Finally, we interviewed all participants five months after course completion to understand the longer-term impacts of the course. Findings. Our participants unanimously shared that all five of the sessions provided a deeper understanding of ChatGPT, featured enough opportunities for hands-on practice, and achieved their learning objectives. Our thematic analysis underlined that teachers gained a more positive and nuanced understanding of ChatGPT after the course. This change is evidenced quantitatively by the fact that quotes with positive connotations rose from 45% to 68% of the total number of positive and negative quotes. Participants shared that in the longer term, the course improved their professional development, understanding of ChatGPT, and teaching practices. Implications. This research underscores the effectiveness of active learning in professional development settings, particularly for technological innovations in computing like LLMs. Our findings suggest that introducing teachers to LLM tools through active learning can improve their work processes and give them a thorough and accurate understanding of how these tools work. By detailing our process and providing a model for similar initiatives, our work contributes to the broader discourse on teaching professional educators about computing and integrating emerging technologies in educational and professional development settings. 

ABSTRACT We examine the evolution of the phase diagram of the low-density intergalactic medium during the Epoch of Reionization in simulation boxes with varying reionization histories from the Cosmic Reionization on Computers project. The probability density function (PDF) of gas temperature at fixed density exhibits two clear modes: a warm and a cold temperature mode, corresponding to the gas inside and outside of ionized bubbles. We find that the transition between the two modes is ‘universal’ in the sense that its timing is accurately parametrized by the value of the volume-weighted neutral fraction for any reionization history. This ‘universality’ is more complex than just a reflection of the fact that ionized gas is warm and neutral gas is cold: it holds for the transition at a fixed value of gas density, and gas at different densities transitions from the cold to the warm mode at different values of the neutral fraction, reflecting a non-trivial relationship between the ionization history and the evolving gas density PDF. Furthermore, the ‘emergence’ of the tight temperature–density relation in the warm mode is also approximately ‘universally’ controlled by the volume-weighted neutral fraction for any reionization history. In particular, the ‘emergence’ of the temperature–density relation (as quantified by the rapid decrease in its width) occurs when the neutral fraction is 10−4 ≲ XH i ≲ 10−3 for any reionization history. Our results indicate that the neutral fraction is a primary quantity controlling the various properties of the temperature–density relation, regardless of reionization history. 

Abstract The field of plant cell biology has a rich history of discovery, going back to Robert Hooke’s discovery of cells themselves. The development of microscopes and preparation techniques has allowed for the visualization of subcellular structures, and the use of protein biochemistry, genetics, and molecular biology has enabled the identification of proteins and mechanisms that regulate key cellular processes. In this review, seven senior plant cell biologists reflect on the development of this research field in the past decades, including the foundational contributions that their teams have made to our rich, current insights into cell biology. Topics covered include signaling and cell morphogenesis, membrane trafficking, cytokinesis, cytoskeletal regulation, and cell wall biology. In addition, these scientists illustrate the pathways to discovery in this exciting research field. 

Abstract The Hawaiian archipelago was formerly home to one of the most species-rich land snail faunas (> 752 species), with levels of endemism > 99%. Many native Hawaiian land snail species are now extinct, and the remaining fauna is vulnerable. Unfortunately, lack of information on critical habitat requirements for Hawaiian land snails limits the development of effective conservation strategies. The purpose of this study was to examine the plant host preferences of native arboreal land snails in Puʻu Kukui Watershed, West Maui, Hawaiʻi, and compare these patterns to those from similar studies on the islands of Oʻahu and Hawaiʻi. Concordant with studies on other islands, we found that four species from three diverse families of snails in Puʻu Kukui Watershed had preferences for a few species of understorey plants. These were not the most abundant canopy or mid canopy species, indicating that forests without key understorey plants may not support the few remaining lineages of native snails. Preference for Broussaisia arguta among various island endemic snails across all studies indicates that this species is important for restoration to improve snail habitat. As studies examining host plant preferences are often incongruent with studies examining snail feeding, we suggest that we are in the infancy of defining what constitutes critical habitat for most Hawaiian arboreal snails. However, our results indicate that preserving diverse native plant assemblages, particularly understorey plant species, which facilitate key interactions, is critical to the goal of conserving the remaining threatened snail fauna. 

Educational institutions increasingly recognize the role that student belonging plays in retention. Many studies in this area focus on helping students improve a sense of belonging before they matriculate or identifying belonging as a reason for their departure. This study measures students’ sense of belonging at key transition points during the first year and finds that social belonging and academic performance are both strong predictors of retention that are not necessarily correlated. These results suggest that a comprehensive, focused outreach protocol that encompasses both social and academic factors could have a positive impact on student persistence. 

Noetzli, J., Christiansen, H.H, Guglielmin, M., Hrbáček, F., Hu, G., Isaksen, K., Magnin, F., Pogliotti, P., Smith, S. L., Zhao, L. and Streletskiy, D. A. 2024. Permafrost temperature and active layer thickness. In: State of the Climate in 2023. Bulletin of the American Meteorological Society, 105 (8), S43–S44, https://doi.org/10.1175/BAMS-D-24-0116.1