Galactic Phylogenetics

Phylogenetics is a widely used concept in evolutionary biology. It is the reconstruction of evolutionary history by building trees that represent branching patterns and sequences. These trees represent shared history, and it is our intention for this approach to be employed in the analysis of Galactic history. In Galactic archaeology the shared environment is the interstellar medium in which stars form and provides the basis for tree-building as a methodological tool. Using elemental abundances of solar-type stars as a proxy for DNA, we built in Jofre et al 2017 such an evolutionary tree to study the chemical evolution of the solar neighbourhood. In this proceeding we summarise these results and discuss future prospects.Comment: Contribution to IAU Symposium No. 334: Rediscovering our Galax

A Mode-Sum Prescription for Vacuum Polarization in Even Dimensions

We present a mode-sum regularization prescription for computing the vacuum polarization of a scalar field in static spherically-symmetric black hole spacetimes in even dimensions. This is the first general and systematic approach to regularized vacuum polarization in higher even dimensions, building upon a previous scheme we developed for odd dimensions. Things are more complicated here since the even-dimensional propagator possesses logarithmic singularities which must be regularized. However, in spite of this complication, the regularization parameters can be computed in closed form in arbitrary even dimensions and for arbitrary metric function $f(r)$. As an explicit example of our method, we show plots for vacuum polarization of a massless scalar field in the Schwarzschild-Tangherlini spacetime for even $d=4,...,10$. However, the method presented applies straightforwardly to massive fields or to nonvacuum spacetimes.Comment: arXiv admin note: text overlap with arXiv:1609.0816

Total Synthesis of (±)-Cavicularin: Control of Pyrone Diels–Alder Regiochemistry Using Isomeric Vinyl Sulfones

An intramolecular pyrone Diels–Alder reaction–elimination retro-Diels–Alder cascade of a vinyl sulfone was used in the synthesis of cavicularin, a molecule possessing conformational chirality. The vinyl sulfone substitution pattern allowed for regiocontrol in the Diels–Alder cascade event

Water Oxidation Catalysis: Effects of Nickel Incorporation on the Structural and Chemical Properties of the α‑Fe₂O₃(0001) Surface

Photoelectrochemical solar fuel synthesis devices based on photoactive hematite (α-Fe₂O₃) anodes have been extensively investigated, yet a fundamental understanding regarding its associated water oxidation surface reaction mechanism is still lacking. To help elucidate detailed reaction mechanisms, we studied water chemisorption and reaction as well as structural changes induced by Ni incorporation into the α-Fe₂O₃(0001) surface. Investigation by scanning probe and electron diffraction techniques show that vapor deposition of Ni and subsequent annealing to 700 K leads to the interdiffusion and incorporation of Ni into the near-surface region of hematite and changes the structure of the (0001) surface by the formation of FeO-like domains on the topmost layer. These results are discussed in the context of a proposed water oxidation mechanism on this surface in which Ni doping facilitates water oxidation by increasing O hole concentrations and forms less negatively charged O anions (*O) and *O···OH species [Liao, P. L.; Keith, J. A.; Carter, E. A. J. Am. Chem. Soc. 2012, 134, 13296−13309.]. Consistent with predictions from this theory, electrochemical measurements using cyclic voltammetry carried out on the ultrahigh vacuum-prepared surfaces demonstrated that Ni incorporation leads to higher current density and lower onset potential than the unmodified α-Fe₂O₃ surface. Our work utilizing a surface science approach helps to connect such theoretical predictions of reaction thermodynamics on well-defined structures and the performance of modified hematite model electrocatalysts for water oxidation

MeOTf-Induced Carboannulation of Isothiocyanates and Aryl Alkynes with CS Bond Cleavage: Access to Indenones

MeOTf-induced carboannulation of alkyl isothiocyanates and aryl alkynes for the synthesis of indenones in good yields under metal-free conditions with CS bond cleavage is described. The thioalkoxy group at the 3-position of the indenone can also be converted into other functional groups, such as phenyl, methylsulfonyl, amino, and ethoxy groups

Germanene Growth on Al(111): A Case Study of Interface Effect

Using density functional theory calculations, we have studied germanene growth on Al(111) in detail. According to the polygons in Ge<i>_N</i> (<i>N</i> = 1–12) structures on a substrate, three structural growth modes are studied, which would lead to the growths of single-atom-thick hexagonal lattice, Kagome lattice, and buckled hexagonal superlattice germanenes. The buckled superlattices grown on pure Al(111) could reproduce the experimental scanning tunneling microscopy images, which however do not have good energetic and thermal stabilities. Detailed energy analyses suggest the possibility of forming an Al₂Ge surface alloy, on which the growths of the buckled superlattices turn to be preferable. Furthermore, such superlattice configurations become energetically and thermally stable. Their adhesive energy is ∼83 meV/Ų, which could be further decreased by hydrogenation to facilitate their separations from the Al₂Ge substrate. These studies highlight the effects of interface modification on tuning two-dimensional material growth. Also, surface alloying could be used as an effective pretreatment method to facilitate large-quantity fabrication of germanene on Al(111)

Additional file 1: Table S1-S3. of Comparison of different therapeutic strategies for complete hydatidiform mole in women at least 40Â years old: a retrospective cohort study

Comparisons were conducted among groups based on different therapeutic strategies and no significant differences were found. Comparison of clinical characteristics between prophylactic chemotherapy group and expectant group was presented in Table S1. Comparison of clinical characteristics between expectant group and hysterectomy group was presented in Table S2. Comparison of clinical characteristics between prophylactic chemotherapy group and hysterectomy group was presented in Table S3. (DOCX 20 kb

Additional file 2: Table S4-S5. of Comparison of different therapeutic strategies for complete hydatidiform mole in women at least 40Â years old: a retrospective cohort study

Comparisons were conducted between groups of patients with GTN based on therapeutic strategies and no significant differences were noted. Comparison of clinical characteristics between prophylactic chemotherapy group and expectant group was presented in Table S4. Comparison of clinical characteristics between hysterectomy group and expectant group was presented in Table S5. (DOCX 19 kb

Data_Sheet_1_Signatures of Selection in the Genomes of Chinese Chestnut (Castanea mollissima Blume): The Roots of Nut Tree Domestication.XLSX

<p>Chestnuts (Castanea) are major nut crops in East Asia and southern Europe, and are unique among temperate nut crops in that the harvested seeds are starchy rather than oily. Chestnut species have been cultivated for three millennia or more in China, so it is likely that artificial selection has affected the genome of orchard-grown chestnuts. The genetics of Chinese chestnut (Castanea mollissima Blume) domestication are also of interest to breeders of hybrid American chestnut, especially if the low-growing, branching habit of Chinese chestnut, an impediment to American chestnut restoration, is partly the result of artificial selection. We resequenced genomes of wild and orchard-derived Chinese chestnuts and identified selective sweeps based on pooled whole-genome SNP datasets. We present candidate gene loci for chestnut domestication and discuss the potential phenotypic effects of candidate loci, some of which may be useful genes for chestnut improvement in Asia and North America. Selective sweeps included predicted genes potentially related to flower phenology and development, fruit maturation, and secondary metabolism, and included some genes homologous to domestication candidates in other woody plants.</p

Data_Sheet_1_Origin of Cave Fungi.ZIP

<p>Karst caves are obviously characterized by darkness, constantly low temperature, high humidity, and oligotrophy. Previous studies revealed that Karst caves have a high and specific bio-diversity. A large number of troglobiont animals had been discovered and their evolution and speciation have been well investigated. However, the origin and evolution of cave fungi remain unknown. In a previous study, we have identified 20 new species, which accounted for 49% of the total number of new species of fungi ever described from caves. In this study, we inferred the divergence times of these 20 new species and compared to the cave formation geologic age. The fossil-calibrated molecular clock showed that the divergence times of these 20 suspected troglobitic fungi are between late Miocene (7.2 Mya for Metapochonia variabilis) and late Jurassic (158 Mya for Gymnoascus exasperates). While based on the historical geological movement and the paleoclimate of Guizhou, it has been estimated that the development of caves in this area was later than middle Pliocene (3.5–4 Mya). It is therefore concluded that the new species described from these caves are unlikely troglobitic fungi but travelers from other environments. The geographic history of caves appeared to be too short for fungal speciation.</p