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  1. Phage emit communication signals that inform their lytic and lysogenic life cycles. However, little is known regarding the abundance and diversity of the genes associated with phage communication systems in wastewater treatment microbial communities. This study focused on phage communities within two distinct biochemical wastewater environments, specifically aerobic membrane bioreactors (AeMBRs) and anaerobic membrane bioreactors (AnMBRs) exposed to varying antibiotic concentrations. Metagenomic data from the bench-scale systems were analyzed to explore phage phylogeny, life cycles, and genetic capacity for antimicrobial resistance and quorum sensing. Two dominant phage families, Schitoviridae and Peduoviridae, exhibited redox-dependent dynamics. Schitoviridae prevailed in anaerobic conditions, while Peduoviridae dominated in aerobic conditions. Notably, the abundance of lytic and lysogenic proteins varied across conditions, suggesting the coexistence of both life cycles. Furthermore, the presence of antibiotic resistance genes (ARGs) within viral contigs highlighted the potential for phage to transfer ARGs in AeMBRs. Finally, quorum sensing genes in the virome of AeMBRs indicated possible molecular signaling between phage and bacteria. Overall, this study provides insights into the dynamics of viral communities across varied redox conditions in MBRs. These findings shed light on phage life cycles, and auxiliary genetic capacity such as antibiotic resistance and bacterial quorum sensing within wastewater treatment microbial communities. 
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    Free, publicly-accessible full text available June 1, 2025
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  3. Free, publicly-accessible full text available November 27, 2024
  4. Abstract

    Predicting insect responses to climate change is essential for preserving ecosystem services and biodiversity. Due to high daytime temperatures and low humidity levels, nocturnal insects are expected to have lower heat and desiccation tolerance compared to diurnal species. We estimated the lower (CTMin) and upper (CTMax) thermal limits ofMegalopta, a group of neotropical, forest-dwelling bees. We calculated warming tolerance (WT) as a metric to assess vulnerability to global warming and measured survival rates during simulated heatwaves and desiccation stress events. We also assessed the impact of body size and reproductive status (ovary area) on bees’ thermal limits.Megaloptadisplayed lower CTMin, CTMax, and WTs than diurnal bees (stingless bees, orchid bees, and carpenter bees), but exhibited similar mortality during simulated heatwave and higher desiccation tolerance. CTMinincreased with increasing body size across all bees but decreased with increasing body size and ovary area inMegalopta, suggesting a reproductive cost or differences in thermal environments. CTMaxdid not increase with increasing body size or ovary area. These results indicate a greater sensitivity ofMegaloptato temperature than humidity and reinforce the idea that nocturnal insects are thermally constrained, which might threaten pollination services in nocturnal contexts during global warming.

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  5. Abstract

    The dimensions of past ice sheets provide a record of palaeoclimate but depend on underlying topography, which evolves over geological timescales by tectonic uplift and erosional downcutting. Erosion during the Pleistocene epoch (2,580 to 11.650 thousand years ago) reduced glacier extent in some locations even as climate cooled, but whether other non-climatic influences impacted the glacial–geological record is poorly known. The Antarctic Peninsula provides an opportunity to examine this issue because of its long glacial history and preservation of remnants of a low-relief pre-glacial land surface. Here we reconstructed both palaeo-surface topography and long-wavelength variations of surface uplift for the Antarctic Peninsula by using inverse analysis that assimilates local topographic remnants with the branching structures of entire modern drainage networks. We found that the Antarctic Peninsula rose tectonically by up to 1.5 km due to dynamical support from the mantle. Glaciological models using the current climate and our palaeotopography show greatly reduced ice extent in the northern Antarctic Peninsula compared with modern, indicating that the onset of glaciation identified at offshore sites reflects tectonic uplift of the topography rather than climatic cooling. In the southern Antarctic Peninsula, however, we suggest the low-relief pre-glacial landscape supported a considerably greater ice volume than the modern mountainous topography, illustrating the influence of erosional sculpting on glaciation patterns.

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