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The impact of extratropical transition (ET) on tropical cyclone (TC) tornadoes is not fully understood with no prior tornado climatologies for ET cases. Hence, this study investigates how ET impacts tornadoes and convective-scale environments within TCs using multidecadal tornado and radiosonde data from North Atlantic TCs. This research divides ET into three phases: tropical (i.e., pre-ET), transition (i.e., during ET), and extratropical (i.e., post-ET). These results show that the largest portion of tornadoes occurs before and during ET, with the greatest frequencies during ET. As TCs progress through ET, tornado location shifts north and east in the United States but farther south or more strongly downshear right relative to the TC center. Tornadoes also tend to occur later in the day and are more likely to be associated with greater damage. Evaluation of radiosondes shows that the downshear-right quadrant of the TC is frequently the most favorable for tornado production, with sufficient entrainment CAPE (ECAPE) and strong storm-relative helicity (SRH). Specifically, the downshear-right quadrant shows slower decreases in ECAPE (associated with synoptic-scale cooling and drying) and increased SRH and associated lower-tropospheric vertical wind shear through ET, relative to the other quadrants relative to the deep-tropospheric (i.e., 850–200-hPa) vertical wind shear vector. These results inform the physical model and prediction of ET-related TC structure, both in terms of their convective-scale environments and subsequent hazard production. 

Abstract Anthropogenic greenhouse gas emissions significantly impact the middle and upper atmosphere. They cause cooling and thermal shrinking and affect the atmospheric structure. Atmospheric contraction results in changes in key atmospheric features, such as the stratopause height or the peak ionospheric electron density, and also results in reduced thermosphere density. These changes can impact, among others, the lifespan of objects in low Earth orbit, refraction of radio communication and GPS signals, and the peak altitudes of meteoroids entering the Earth's atmosphere. Given this, there is a critical need for observational capabilities to monitor the middle and upper atmosphere. Equally important is the commitment to maintaining and improving long‐term, homogeneous data collection. However, capabilities to observe the middle and upper atmosphere are decreasing rather than improving. 

ABSTRACT PocheinaandAcrasisare two genera of heterolobosean sorocarpic amoebae within Acrasidae that have historically been considered close relatives. The two genera were differentiated based on their differing fruiting body morphologies. The validity of this taxonomic distinction was challenged when a SSU rRNA phylogenetic study placed an isolate morphologically identified as ‘Pocheina’roseawithin a clade ofAcrasis roseaisolates. The authors speculated that pocheinoid fruiting body morphology might be the result of aberrantA. roseafruiting body development, which if true, would nullify this taxonomic distinction between genera. To clarify Acrasidae systematics, we analyzed SSU rRNA and ITS region sequences from multiple isolates ofPocheina, Acrasis, andAllovahlkampfiagenerated by PCR and transcriptomics. We demonstrate that the initial SSU sequence attributed to ‘P. rosea’ originated from anA. roseaDNA contamination in its amplification reaction. Our analyses, based on morphology, SSU and 5.8S rRNA genes phylogenies, as well as comparative analyses of ITS1 and ITS2 sequences, resolve Acrasidae into three major lineages;Allovahlkampfiaand the strongly supported clades comprisingPocheinaandAcrasis. We confirm that the latter two genera can be identified by their fruiting body morphologies. 

We compare the signal-to-noise ratio for different measurements that could be used for stellar interferometry. We find that single-photon sources with number-resolved detection outperform other weak local oscillator states. 

The frequently encountered macroscopic slime molds of the genus Ceratiomyxa have long been recognized by mycologists and protistologists for hundreds of years. These organisms are amoebozoan amoebae that live and grow inside and on the surface of decaying wood. When conditions are favorable, they form subaerial sporulating structures called fruiting bodies which take on a variety of forms. These forms are typically some arrangement of column and/or branches, but one is uniquely poroid, forming folds instead. Originally, this poroid morphology was designated as its own species. However, it was not always clear what significance fruiting body morphology held in determining species. Currently, Ceratiomyxa fruticulosa var. porioides, the poroid form, is considered a taxonomic variety of Ceratiomyxa fruticulosa based on morphological designation alone. Despite its long history of observation and study, the genus Ceratiomyxa has been paid little molecular attention to alleviate these morphological issues. We have obtained the first transcriptomes of the taxon C. fruticulosa var. porioides and found single gene phylogenetic and multigene phylogenomic support to separate it from C. fruticulosa. This provides molecular evidence that fruiting body morphology does correspond to species level diversity. Therefore, we formally restore Ceratiomyxa porioides stat. nov. to its original status. 

ABSTRACT Phylogenies built from multiple genes have become a common component of evolutionary biology studies. Molecular phylogenomic matrices used to build multi-gene phylogenies can be built from either nucleotide or protein matrices. Nucleotide-based analyses are often more appropriate for addressing phylogenetic questions in evolutionarily shallow timescales (i.e., less than 100 million years) while protein-based analyses are often more appropriate for addressing deep phylogenetic questions. PhyloFisher is a phylogenomic software package written in Python3. The manually curated PhyloFisher database contains 240 protein-coding genes from 304 eukaryotic taxa. Here we presentnucl_matrix_constructor.py, an expansion of the PhyloFisher starting database, and an update to PhyloFisher that maintains DNA sequences. This combination will allow users the ability to easily build nucleotide phylogenomic matrices while retaining the benefits of protein-based pre-processing used to identify contaminants and paralogy. 

Heterotrophic protists are vital in Earth’s ecosystems, influencing carbon and nutrient cycles and occupying key positions in food webs as microbial predators. Fossils and molecular data suggest the emergence of predatory microeukaryotes and the transition to a eukaryote-rich marine environment by 800 million years ago (Ma). Neoproterozoic vase-shaped microfossils (VSMs) linked to Arcellinida testate amoebae represent the oldest evidence of heterotrophic microeukaryotes. This study explores the phylogenetic relationship and divergence times of modern Arcellinida and related taxa using a relaxed molecular clock approach. We estimate the origin of nodes leading to extant members of the Arcellinida Order to have happened during the latest Mesoproterozoic and Neoproterozoic (1054 to 661 Ma), while the divergence of extant infraorders postdates the Silurian. Our results demonstrate that at least one major heterotrophic eukaryote lineage originated during the Neoproterozoic. A putative radiation of eukaryotic groups (e.g., Arcellinida) during the early-Neoproterozoic sustained by favorable ecological and environmental conditions may have contributed to eukaryotic life endurance during the Cryogenian severe ice ages. Moreover, we infer that Arcellinida most likely already inhabited terrestrial habitats during the Neoproterozoic, coexisting with terrestrial Fungi and green algae, before land plant radiation. The most recent extant Arcellinida groups diverged during the Silurian Period, alongside other taxa within Fungi and flowering plants. These findings shed light on heterotrophic microeukaryotes’ evolutionary history and ecological significance in Earth’s ecosystems, using testate amoebae as a proxy.