Synthesis and crystal structure of (±)-Goniotamirenone C

The structure of the racemic version of the natural product Goniotamirenone C [racemic anti-6-(2-chloro-1-hydroxy-2-phenylethyl)-2H-pyran-2-one, C13H11ClO3] at 150 K is reported. The compound crystallizes with monoclinic (P21/n) symmetry and with Z′ = 2. One independent molecule is ordered while the other independent molecule exhibits an interesting whole-molecule enantiomeric disorder with occupancies of 0.846 (4) and 0.154 (4). The independent molecules are hydrogen bonded with –OH...O=C linkages into chains that run parallel to the a axis. This structural analysis corrects our previous assignment as the syn isomer [Meesakul et al. (2020). Phytochemistry, 171, 112248–112255].

A poorly diversified trilobite association from the lower Emsian (Lower Devonian) in the Sankt Vith area (East Belgium)

A poorly diversified trilobite association is recorded from an outcrop near the village of Breitfeld, Sankt Vith area, East Belgium. The co-occurrence of Arduennella maillieuxi (Asselberghs, 1923) and Burmeisterella quadrispinosa Wenndorf, 1990 in the Breitfeld locality is suggestive of an early lower Emsian age. The outcropping rocks are provisionally attributed to the lower part of the Our Formation (lower Emsian) as opposed to previous assignment to the “Quartzophyllades de Saint Vith” or Sankt Vith Formation (Pragian). Some nomenclatoral notes are provided on the types of A. maillieuxi as the lectotype could not be traced; a cast of the lectotype as well as several paralectotypes of this species are illustrated. Our material of B. quadrispinosa includes cephalic remains that bring new insights into the morphology of this species. A third species, Treveropyge hellemondi sp. nov., is furthermore described. Palaeobiogeographic affiliations of the trilobite association are discussed. A tentative first step is proposed towards trilobite-based correlations of Emsian strata in the Ardenno-Rhenish Mountains.

Further Disruption of the TAS3 Pathway via the Addition of the AGO7 Mutation to the DRB1, DRB2 or DRB4 Mutations Severely Impairs the Reproductive Competence of Arabidopsis thaliana

The previous assignment of functional roles for AGO7, and the DOUBLE-STRANDED RNA BINDING (DRB) proteins, DRB1, DRB2, and DRB4, in either microRNA (miRNA) or trans-acting small-interfering RNA (tasiRNA) production allowed for use of the loss-of-function mutant lines, drb1, drb2, drb4, and ago7, to further functionally characterize the TAS3 pathway in Arabidopsis thaliana (Arabidopsis). Towards achieving this goal, we also describe the developmental and molecular phenotypes expressed by three newly generated Arabidopsis lines, the drb1ago7, drb2ago7, and drb4ago7 double mutants. We show that the previously reported developmental abnormalities displayed by the drb1, drb2, drb4, and ago7 single mutants, are further exacerbated in the drb1ago7, drb2ago7, and drb4ago7 double mutants, with rosette area, silique length, and seed set all impaired to a greater degree in the double mutants. Molecular assessment of the TAS3 pathway in the floral tissues of the seven analyzed mutants revealed that DRB1 is the sole DRB required for miR390 sRNA production. However, DRB2 and DRB4 appear to play secondary roles at this stage of the TAS3 pathway to ensure that miR390 sRNA levels are tightly maintained. We further show that the expression of the TAS3-derived tasiARF target genes, AUXIN RESPONSE FACTOR2 (ARF2), ARF3, and ARF4, was altered in drb1ago7, drb2ago7, and drb4ago7 flowers. Altered ARF2, ARF3, and ARF4 expression was in turn demonstrated to lead to changes in the level of expression of KAN1, KAN3, and KAN4, three KANADI transcription factor genes known to be transcriptionally regulated by ARF2, ARF3, and ARF4. Taken together, the demonstrated relationship between altered ARF and KAN gene expression in drb1ago7, drb2ago7 and drb4ago7 flowers, could, in part, explain the more severe developmental defects displayed by the double mutants, compared to milder impact that loss of only a single piece of TAS3 pathway protein machinery was demonstrated to have on drb1, drb2, drb4 and ago7 reproductive development.

RAILWAY DIRECTION OPTIMIZATION USING GENETIC ALGORITHM

These days the development of “clever cities” with a high level of nice of existence is turning into a previous assignment to be addressed. In this framework, promoting the model shift closer to extra dependable, greener and in widespread extra sustainable transportation modes, specifically toward a “smart mobility” should appreciably make contributions to reap this aim. The goal of this paper is to offer customers with greater regular and reliable rail machine through optimizing the direction among stations.

First Principles Identification of Divacancy Related Photoluminescence Lines in 4H and 6H-SiC

Nowadays, computational techniques can greatly facilitate the identification of point defect related photoluminescence and EPR centers in semiconductors. Once the identification has been achieved, one can gain a detailed description of the microstructure and the electron configuration of the defect, providing a basis for further understanding and development. Recently, the importance of divacancy and related point defects in different polytypes of SiC has substantially increased due to their possible quantum bit application. However, their different configurations have not been satisfactorily identified yet. In our study, we carry out large-scale first principles supercell calculations to identify the divacancy related point defects in 4H and 6H-SiC. By resolving some general accuracy issues of usual ab initio supercell techniques, we are able to obtain convergent photoluminescence (PL) energies, zero-field-splitting, and hyperfine parameters. Our results confirm the previous assignment of the PL1-4 PL lines in 4H-SiC (also known as UD-2 luminescence lines previously) to the four possible divacancy configurations and provide the identification of QL1,QL2, and QL6 PL lines in 6H-SiC. In all cases the calculated zero-field and hyperfine tensors’ parameters are provided.

Parents’ experiences of having a baby with ambiguous genitalia

Health professionals must be aware of the impact on parents of the birth of children with ambiguous genitalia. This study aimed to analyze the experiences and perceptions of such parents. Parents of 30 children who were evaluated in a reference center for disorders of sex development (DSD) were interviewed. The questionnaire covered the prenatal period, the moment they were told about the disorder, initial management by health professionals, and problems they experienced. Only two cases were detected during pregnancy. The news was usually given to the mother alone by pediatricians. Most parents kept it secret and avoided exposing the baby to the prejudice of others. Parents of children who were referred without sex assignment usually held a personal belief of their child’s sex. Previous assignment was based on clinical examination and/or karyotype. Spreading knowledge about DSD could increase awareness of this issue, thus reducing parents’ shock and societal stigma. Training of neonatal care teams is required to avoid assignment before evaluation.

Interactions of Self-Interstitials with Interstitial Carbon-Interstitial Oxygen Center in Irradiated Silicon: An Infrared Absorption Study

The evolution of radiation-induced carbon-oxygen related defects with the fluence of MeV electrons and upon subsequent isochronal annealing (75-350 °C) in Si crystals with different carbon and oxygen content has been studied by means of Local Vibrational Mode (LVM) spectroscopy. In particular, the generation kinetics of the bands at 998 and 991 cm-1 is considered and additional arguments supporting their previous assignment to the I2CiOi and I3CiOi complexes are found. An annealing behaviour of the LVMs related to the C4 (ICiOi) defect has been studied in the various Si crystals irradiated with different particles. In all the samples studied the bands at 940 and 1024 cm-1 are found to disappear at about 200 °C while three new LVM bands, at 724 cm-1 (O-related) and at 952 and 973 cm-1 (both C-related) are emerging. Further increase in annealing temperature up to 250-275 °C results in a transformation of the latter bands into another set of LVM bands at 969 cm-1 (O-related) and at 951 and 977 cm-1 (both C-related). These bands disappear upon annealing in the temperature range 300-325 °C. The ratios of all the bands intensities as well as their transformation rates do not depend on the oxygen and carbon content in the Si samples nor on the kind of irradiation (2.5 and 10 MeV electrons, fast neutrons) and irradiation doses. These facts confirm our previous conclusion that all the above-mentioned LVMs arise from the C4 defect being in different configurations (ICiOi, ICiOi*, and ICiOi**).

Basal ornithopod (Dinosauria: Ornithischia) teeth from the Prince Creek Formation (early Maastrichtian) of Alaska

A diverse and prolific record of polar dinosaurs comes from the Upper Cretaceous (Campanian–Maastrichtian) sediments of the Prince Creek Formation exposed on Alaska’s North Slope. Previous assignment of basal ornithopod material from this formation has been based solely on teeth, which have either been referred to “hypsilophodontid” indet. or Thescelosaurus sp. Here, we re-examine this material and describe several new specimens, including five isolated premaxillary teeth and three cheek teeth. The premaxillary teeth are most similar to those of Thescelosaurus , whereas the cheek teeth are more similar to its sister taxon Parksosaurus , for which premaxillary teeth are unknown. Referral of this new material to Thescelosaurus would represent the oldest occurrence of this taxon and considerably extend its stratigraphic range. A more likely possibility is that the premaxillary teeth are referable to Parksosaurus, an interpretation that is more parsimonious from a stratigraphic perspective. Intriguingly, one cheek tooth previously referred to as “hypsilophodontid” cannot be referred to either Thescelosaurus or Parksosaurus. Previously, faunal comparisons of the Prince Creek Formation have largely been made with non-contemporaneous formations, including the Campanian-aged Judith River and Aguja formations, or to the latest Maastrichtian Hell Creek Formation. On the basis of age and faunal similarities, a more appropriate comparison should be made with coeval rocks of the Horseshoe Canyon. This study expands our knowledge of Cretaceous ornithischian diversity at polar paleolatitudes and underscores the importance of small, rare, or easily misidentified fossils in paleoecological studies.

Revision of the status of Saurolophus (Hadrosauridae) from California, USA

The occurrence of Saurolophus from the Moreno Formation (late Maastrichtian) of California is investigated and an incomplete, poorly preserved, skull (LACM/CIT 2852) is described. The skull lacks the braincase (including the frontals) and much of the nasals, and the preserved portions are crushed or plastically deformed, which makes anatomical interpretations difficult. A preserved midline fragment of the conjoined nasals suggests that it lacked a gryposaur-like “Roman nose”, but the nature of the crest, if present, is impossible to determine with certainty. A phylogenetic analysis places this specimen as either the sister taxon of Saurolophus or as the sister taxon to a clade comprising Edmontosaurus and Anatotitan . There is no compelling morphological evidence to support the previous assignment of LACM/CIT 2852 to Saurolophus rather than to Edmontosaurus, and its poor preservation prevents positive assignment to any taxon below Hadrosaurinae indet. Given its geographic setting and morphological uncertainties, it is also possible that this specimen represents a separate taxon, but more material is needed to clarify the identity of the Moreno hadrosaurine. LACM/CIT 2852 does, however, provide evidence that Maastrichtian hadrosaurines ranged west of the Sierra Nevada magmatic arc, in an area where dinosaur diversity is poorly known.

Complete assignment of the 1H and 13C NMR spectra and conformational analysis of bonellin dimethyl ester

The use of a high-field NMR instrument (ν(1 H ) = 500 MHz ) and 2-dimensional NMR techniques (HMQC, HMBC, ROESY) enabled us to fully assign the 1 H and 13 C chemical shifts of bonellin dimethyl ester. The β-pyrrolic proton of C -3 appeared as a broad singlet at δ = 8.93, whereas that of C -8 gave a quartet with δ = 8.69 and 4J H - H = |1.28| Hz . The C -21 methyl protons appeared as a doublet with δ = 3.55 and 4J H - H = |1.07| Hz , while the C -71 methyl protons afforded a doublet with δ = 3.51 and 4J H - H = |1.28| Hz . These results suggest that the β-pyrrolic carbons of ring A belong to the aromatic 18 π-electron [18]diazaannulene delocalization pathway, whereas those of ring B remain outside the aromatic pathway. The broadening of the C -3 β-pyrrolic proton signal can be attributed to the allylic 3- CH - 21- CH 3 coupling and the 3- CH - 21- NH coupling. At 330 K, the tautomeric exchange 21- NH a ⇌ 23- NH b is fast and only one broad signal at δ = -2.49 is seen for these protons. The ROESY spectrum showed clear correlation signals between the 182- CH 3 and 171- CH 2 protons, the 182- CH 3 and 174- CH 3 protons, as well as between the 181- CH 3 and 17- CH protons. These results are compatible with the previous assignment that the absolute configuration at C-17 is S. Application of spin simulation enabled us to determine the chemical shifts and the 3J H - H coupling constants of the 17-propionate side-chain. The 3J H - H -values were used to calculate the populations for the 171-17 and 172-171 rotamers. A relatively high population value of 0.41 was found for the 171-17 g--rotamer, whose methoxycarbonylmethyl group points to the C -15 methine-bridge. This was interpreted as explaining the high tendency of bonellin to form anhydrobonellin. The rotational freedoms in the 13-propionate side-chain were studied by measuring the 1 H NMR spectra of the side-chain at temperatures between 300 and 195 K. At 300 K, the 131- and 132- CH 2 proton signals appeared as deceptively simple triplets, which at 195 K were split into complex multiplets. At 195 K, the signal arising from the 131- CH 2 protons exhibited more splitting, which indicates that these protons have less rotational freedom than the 132- CH 2 protons.