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Eddy covariance (EC) air–sea CO₂flux measurements have been developed for large research vessels, but have yet to be demonstrated for smaller platforms. Our goal was to design and build a complete EC CO₂flux package suitable for unattended operation on a buoy. Published state-of-the-art techniques that have proven effective on research vessels, such as airstream drying and liquid water rejection, were adapted for a 2-m discus buoy with limited power. Fast-response atmospheric CO₂concentration was measured using both an off-the-shelf (“stock”) gas analyzer (EC155, Campbell Scientific, Inc.) and a prototype gas analyzer (“proto”) with reduced motion-induced error that was designed and built in collaboration with an instrument manufacturer. The system was tested on the University of New Hampshire (UNH) air–sea interaction buoy for 18 days in the Gulf of Maine in October 2020. The data demonstrate the overall robustness of the system. Empirical postprocessing techniques previously used on ship-based measurements to address motion sensitivity of CO₂analyzers were generally not effective for the stock sensor. The proto analyzer markedly outperformed the stock unit and did not require ad hoc motion corrections, yet revealed some remaining artifacts to be addressed in future designs. Additional system refinements to further reduce power demands and increase unattended deployment duration are described.

 

As genetic code expansion advances beyondl-α-amino acids to backbone modifications and new polymerization chemistries, delineating what substrates the ribosome can accommodate remains a challenge. TheEscherichia coliribosome tolerates non-l-α-amino acids in vitro, but few structural insights that explain how are available, and the boundary conditions for efficient bond formation are so far unknown. Here we determine a high-resolution cryogenic electron microscopy structure of theE. coliribosome containing α-amino acid monomers and use metadynamics simulations to define energy surface minima and understand incorporation efficiencies. Reactive monomers across diverse structural classes favour a conformational space where the aminoacyl-tRNA nucleophile is <4 Å from the peptidyl-tRNA carbonyl with a Bürgi–Dunitz angle of 76–115°. Monomers with free energy minima that fall outside this conformational space do not react efficiently. This insight should accelerate the in vivo and in vitro ribosomal synthesis of sequence-defined, non-peptide heterooligomers.

 

ABSTRACT We report the 3.5-Mb draft genome sequence of the cyanobacterium Synechococcus sp. strain Nb3U1, which was isolated from a microbial mat sample collected from Nakabusa Hot Spring, Nagano, Japan. 

Abstract Friction surfacing is a new variation of friction stir processing for surface property modification of metallic substrates. There is an increasing body of literature about friction surfacing by deposition of metal from a consumable tool to a solid substrate. Friction surfacing has many potential applications in joining, coating for corrosion resistance, and repair of degraded components. This article presents a review of the basic principles and latest research organized by processing techniques and variations, thermomechanical transfer and deposition of material, and finally metallurgical, mechanical, and chemical properties of the resulting deposition. Different friction surfacing processes are reviewed of novel tool–substrate configurations for material deposition for noncoating purposes like keyhole filling and joining dissimilar materials. Possible future topics of study for this area are discussed, which include deeper understanding of material transfer through metallurgy, FEM, and scale up of the technique for practical application. 

We performed a molecular phylogenetic analysis on the family Euteliidae to clarify deep divergences and elucidate evolutionary relationships at the level of the subfamily, tribe, and genus. Our dataset consists of 6.3 kbp of one mitochondrial and seven nuclear DNA loci and was analysed using model‐based phylogenetic methods, that is, maximum likelihood and Bayesian inference. Based on the recovered topology, we recognize two subfamilies, Euteliinae and Stictopterinae, and the tribes Stictopterini and Odontini. We identify apomorphic morphological character states for Euteliidae and its component subfamilies and tribes. Several genera (e.g.,Targalla, Paectes, Marathyssa, Eutelia) were found polyphyletic and require taxonomic revision. Two new genera (NiklasteliaZahiri & Hollowaygen.nov.andPellinenteliaHolloway & Zahirigen.nov.) are described and a number of taxonomic changes (new combinations and new synonymies) are established. The Neotropical genusThyriodes, currently included in Euteliidae, is found to be associated with Erebinae (Erebidae). The divergence time estimate for the split between the Euteliidae and Noctuidae is at 53 Ma, and the Euteliidae subfamilies Euteliinae and Stictopterinae are estimated to have diverged at 42 Ma. In Stictopterinae, the tribes Stictopterini and Odontodini split at 31 Ma, while Euteliinae began diversifying at 34 Ma. Malpighiales are inferred to have been the ancestral larval hostplant order for Euteliidae. The ancestors of Stictopterinae also appear to have been Malpighiales feeders, but then diverged to Malvales specialists (Odontodini) and Malpighiales specialists (Stictopterini) hostplants. Larvae of Stictopterini appear to be restricted primarily to Clusiaceae, apart from a few records from Dipterocarpaceae. In Euteliinae, Anacardiaceae are predominant as larval hosts. Thus, all hosts in the family are lactiferous, possibly providing some degree of pre‐adaptation for exploiting Dipterocarpaceae.