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1. Mantle Q structure from S ,  SS ,  SSS and SSSS amplitude measurements

   https://doi.org/10.1093/gji/ggac217  

   Zhu, Min; Sun, Shuyang; Zhou, Ying; Wu, Qingju (June 2022, Geophysical Journal International)

   SUMMARY The seismic quality factor (Q) of the Earth’s mantle is of great importance for the understanding of the physical and chemical properties that control mantle anelasticity. The radial structure of the Earth’s Q is less well resolved compared to its wave speed structure, and large discrepancies exist among global 1-D Q models. In this study, we build a global data set of amplitude measurements of S, SS, SSS and SSSS waves using earthquakes that occurred between 2009 and 2017 with moment magnitudes ranging from 6.5 to 8.0. Synthetic seismograms for those events are computed in a 1-D reference model PREM, and amplitude ratios between observed and synthetic seismograms are calculated in the frequency domain by spectra division, with measurement windows determined based on visual inspection of seismograms. We simulate wave propagation in a global velocity model S40RTS based on SPECFEM3D and show that the average amplitude ratio as a function of epicentral distance is not sensitive to 3-D focusing and defocusing for the source–receiver configuration of the data set. This data set includes about 5500 S and SS measurements that are not affected by mantle transition zone triplications (multiple ray paths), and those measurements are applied in linear inversions to obtain a preliminary 1-D Q model QMSI. This model reveals a high Q region in the uppermost lower mantle. While model QMSI improves the overall datafit of the entire data set, it does not fully explain SS amplitudes at short epicentral distances or the amplitudes of the SSS and SSSS waves. Using forward modelling, we modify the 1-D model QMSI iteratively to reduce the overall amplitude misfit of the entire data set. The final Q model QMSF requires a stronger and thicker high Q region at depths between 600 and 900 km. This anelastic structure indicates possible viscosity layering in the mid mantle. 

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2. Estimating bonobo ( Pan paniscus ) and chimpanzee ( Pan troglodytes ) evolutionary history from nucleotide site patterns

   https://doi.org/10.1073/pnas.2200858119  

   Brand, Colin M.; White, Frances J.; Rogers, Alan R.; Webster, Timothy H. (April 2022, Proceedings of the National Academy of Sciences)

   Admixture appears increasingly ubiquitous in the evolutionary history of various taxa, including humans. Such gene flow likely also occurred among our closest living relatives: bonobos ( Pan paniscus ) and chimpanzees ( Pan troglodytes ). However, our understanding of their evolutionary history has been limited by studies that do not consider all Pan lineages or do not analyze all lineages simultaneously, resulting in conflicting demographic models. Here, we investigate this gap in knowledge using nucleotide site patterns calculated from whole-genome sequences from the autosomes of 71 bonobos and chimpanzees, representing all five extant Pan lineages. We estimated demographic parameters and compared all previously proposed demographic models for this clade. We further considered sex bias in Pan evolutionary history by analyzing the site patterns from the X chromosome. We show that 1) 21% of autosomal DNA in eastern chimpanzees derives from western chimpanzee introgression and that 2) all four chimpanzee lineages share a common ancestor about 987,000 y ago, much earlier than previous estimates. In addition, we suggest that 3) there was male reproductive skew throughout Pan evolutionary history and find evidence of 4) male-biased dispersal from western to eastern chimpanzees. Collectively, these results offer insight into bonobo and chimpanzee evolutionary history and suggest considerable differences between current and historic chimpanzee biogeography. 

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3. Synthesis of metastable Ruddlesden–Popper titanates, ( A TiO3) n A O, with n ≥ 20 by molecular-beam epitaxy

   https://doi.org/10.1063/5.0101202  

   Barone, Matthew_R; Jeong, Myoungho; Parker, Nicholas; Sun, Jiaxin; Tenne, Dmitri_A; Lee, Kiyoung; Schlom, Darrell_G (September 2022, APL Materials)

   We outline a method to synthesize (ATiO3)nAO Ruddlesden–Popper phases with high-n, where the A-site is a mixture of barium and strontium, by molecular-beam epitaxy. The precision and consistency of the method described is demonstrated by the growth of an unprecedented (SrTiO3)50SrO epitaxial film. We proceed to investigate barium incorporation into the Ruddlesden–Popper structure, which is limited to a few percent in bulk, and we find that the amount of barium that can be incorporated depends on both the substrate temperature and the strain state of the film. At the optimal growth temperature, we demonstrate that as much as 33% barium can homogeneously populate the A-site when films are grown on SrTiO3 (001) substrates, whereas up to 60% barium can be accommodated in films grown on TbScO3 (110) substrates, which we attribute to the difference in strain. This detailed synthetic study of high n, metastable Ruddlesden–Popper phases is pertinent to a variety of fields from quantum materials to tunable dielectrics. 

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4. Nesting biology of Centris ( Paracentris ) burgdorfi (Apidae: Centridini)

   https://doi.org/10.1080/00218839.2020.1717760  

   Sabino, William O.; Alves-dos-Santos, Isabel; Queiroz, Elisa Pereira; de Faria, Letícia Biral; Papaj, Daniel R.; Buchmann, Stephen L.; da Silva, Cláudia Inês (January 2020, Journal of Apicultural Research)

   We describe the nesting biology of Centris (Paracentris) burgdorfi, a solitary bee that nests in sandstone in northeastern Brazil. The nest consists of a shallow tunnel with access to the brood cells. Females of C. burgdorfi made 1–7 brood cells per nest with each cell requiring 2.58 ± 0.40 (X ± SD) days to construct. The average cell-building construction time was longer when compared to other Centris species. Females were larger than males, and this difference was reflected in the size of their respective emergence cells. The temperature within C. burgdorfi nests was lower when compared to ambient temperature. Our study is the first to report the nesting biology of C. burgdorfi. The detailed behavior of the female inside the nest was also described, which is unusual in the study of solitary bee nesting biology. 

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5. Molecular phylogeny of Spirotrichonymphea (Parabasalia) with emphasis on Spironympha , Spirotrichonympha , and three new genera Pseudospironympha , Nanospironympha , and Brugerollina

   https://doi.org/10.1111/jeu.12967  

   Noda, Satoko; Kitade, Osamu; Jasso‐Selles, Daniel E.; Taerum, Stephen J.; Takayanagi, Miki; Radek, Renate; Lo, Nathan; Ohkuma, Moriya; Gile, Gillian H. (February 2023, Journal of Eukaryotic Microbiology)

   Abstract Spirotrichonymphea, one of the six classes of phylum Parabasalia, are characterized by bearing many flagella in spiral rows, and they occur exclusively in the guts of termites. Phylogenetic relationships among the 13 described genera are not well understood due to complex morphological evolution and a paucity of molecular data. One such understudied genus isSpironympha. It has been variously considered a valid genus, a subgenus ofSpirotrichonympha, or an “immature” life cycle stage ofSpirotrichonympha. To clarify this, we sequenced the small subunit rRNA gene sequences ofSpironymphaandSpirotrichonymphacells isolated from the hindguts ofReticulitermesspecies andHodotermopsis sjostedtiand confirmed the molecular identity ofH. sjostedtisymbionts using fluorescence in situ hybridization.Spironymphaas currently circumscribed is polyphyletic, with bothH. sjostedtisymbiont species branching separately from the “true”SpironymphafromReticulitermes. Similarly, theSpirotrichonymphasymbiont ofH. sjostedtibranches separately from the “true”Spirotrichonymphafound inReticulitermes. Our data supportSpironymphafromReticulitermesas a valid genus most closely related toSpirotrichonympha, though its monophyly and interspecific relationships are not resolved in our molecular phylogenetic analysis. We propose three new genera to accommodate theH. sjostedtisymbionts and two new species ofSpirotrichonymphafromReticulitermes. 

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