Single Crystal Growth at High Pressure (SOLID STATE CHEMISTRY-Multicomponent Materials)

Single crystals of a spin-1/2 Heisenberg alternating chain compound, high pressure phase of (VO)2P2O7 , was grown by slowly cooling the melt at 3 GPa. Powder XRD study at high pressure using synchrotron radiation was performed in advance to observe the formation and the melting of this compound

Independent evolution of the specialized pharyngeal jaw apparatus in cichlid and labrid fishes

BACKGROUND: Fishes in the families Cichlidae and Labridae provide good probable examples of vertebrate adaptive radiations. Their spectacular trophic radiations have been widely assumed to be due to structural key innovation in pharyngeal jaw apparatus (PJA), but this idea has never been tested based on a reliable phylogeny. For the first step of evaluating the hypothesis, we investigated the phylogenetic positions of the components of the suborder Labroidei (including Pomacentridae and Embiotocidae in addition to Cichlidae and Labridae) within the Percomorpha, the most diversified (> 15,000 spp) crown clade of teleosts. We examined those based on 78 whole mitochondrial genome sequences (including 12 newly determined sequences) through partitioned Bayesian analyses with concatenated sequences (13,933 bp). RESULTS: The resultant phylogenies indicated that the Labridae and the remaining three labroid families have diverged basally within the Percomorpha, and monophyly of the suborder was confidently rejected by statistical tests using Bayes factors. CONCLUSION: The resultant phylogenies indicated that the specified PJA evolved independently at least twice, once in Labridae and once in the common ancestor of the remaining three labroid families (including the Cichlidae). Because the independent evolution of pharyngeal jaws appears to have been followed by trophic radiations, we consider that our result supports, from the aspect of historical repeatability, the idea that the evolution of the specialized PJA provided these lineages with the morphological potential for their spectacular trophic radiations. The present result will provide a new framework for the study of functional morphology and genetic basis of their PJA

Phonon anomalies and lattice dynamics in superconducting oxychlorides Ca2−x_{2-x}CuO2_2Cl

We present a comprehensive study of the phonon dispersion in an underdoped, superconducting Ca$_{2-x}$CuO$_2$Cl$_2$ crystal. We interpret the results using lattice dynamical calculations based on a shell model, and we compare the results, to other hole-doped cuprates, in particular to the ones isomorphic to La$_{2-x}$Sr$_x$CuO$_4$ (LSCO). We found that an anomalous dip in the Cu-O bond stretching dispersion develops in oxychlorides with a simultaneous marked broadening of the mode. The broadening is maximum at $\approx (\pi / (2a) ~ 0 ~ 0)$ that corresponds to the charge-modulations propagation vector. Our analysis also suggests that screening effects in calculations may cause an apparent cosine-shaped bending of the Cu-O bond-stretching dispersion along both the ($q$ 0 0) and ($q$ $q$ 0) directions, that is not observed on the data close to optimal doping. This observation suggests that the discrepancy between experimental data and \textit{ab-initio} calculations on this mode originates from an overestimation of the doping effects on the mode

Mitogenomic evaluation of the historical biogeography of cichlids toward reliable dating of teleostean divergences

<p>Abstract</p> <p>Background</p> <p>Recent advances in DNA sequencing and computation offer the opportunity for reliable estimates of divergence times between organisms based on molecular data. Bayesian estimations of divergence times that do not assume the molecular clock use time constraints at multiple nodes, usually based on the fossil records, as major boundary conditions. However, the fossil records of bony fishes may not adequately provide effective time constraints at multiple nodes. We explored an alternative source of time constraints in teleostean phylogeny by evaluating a biogeographic hypothesis concerning freshwater fishes from the family Cichlidae (Perciformes: Labroidei).</p> <p>Results</p> <p>We added new mitogenomic sequence data from six cichlid species and conducted phylogenetic analyses using a large mitogenomic data set. We found a reciprocal monophyly of African and Neotropical cichlids and their sister group relationship to some Malagasy taxa (Ptychochrominae <it>sensu </it>Sparks and Smith). All of these taxa clustered with a Malagasy + Indo/Sri Lankan clade (Etroplinae <it>sensu </it>Sparks and Smith). The results of the phylogenetic analyses and divergence time estimations between continental cichlid clades were much more congruent with Gondwanaland origin and Cretaceous vicariant divergences than with Cenozoic transmarine dispersal between major continents.</p> <p>Conclusion</p> <p>We propose to add the biogeographic assumption of cichlid divergences by continental fragmentation as effective time constraints in dating teleostean divergence times. We conducted divergence time estimations among teleosts by incorporating these additional time constraints and achieved a considerable reduction in credibility intervals in the estimated divergence times.</p

Multiple Hepatic Lesions During Acute Leukemia Remissions

The US and CT manifestations of multiple small hepatic lesions of 15 patients during their remissions following chemotherapy for acute leukemia were reviewed. Liver biopsies established the diagnoses in 5 of the 15 patients. Despite their remissions, two cases had leukemic involvement. Others had microabscesses, 2 due to candida and 1 due to peptostreptococcus. Ultrasonographically, the microabscesses and leukemic involvement in the liver consisted of multiple round hypoechoic and target-like masses. With CT, these appeared as multiple zones of diminished attenuation. Only distal acoustic enhancement with US could differentiate these disease processes

Two-Dimensional Band Dispersion of Ultra-Flat Hexagonal Bismuthene Grown on Ag(111) Bulk and Quantum-Well Films

Two-dimensional band dispersion of (2$\times$2) superstructure with Bi grown on Ag(111), which has been urged as an ultraflat hexagonal bismuthene, is investigated using angle-resolved photoemission spectroscopy (ARPES). The (2$\times$2)-Bi superstructure can be grown on the Ag(111) surface at low temperatures; it transforms into a surface alloy with a ($\sqrt{3}\times\sqrt{3}$) superstructure at 300 K. ARPES measurements reveal the consistency with the band structure of ultraflat bismuthene in previous reports. The band structure of (2$\times$2)-Bi surface remains unchanged with decreasing Ag layer thickness, indicating the limited penetration of Bi p-orbitals into the Ag layer.Comment: 6 pages, 4 figure