ALBERT

Description: Despite much attention, history of sheep ( Ovis aries ) evolution, including its dating, demographic trajectory and geographic spread, remains controversial. To address these questions, we generated 45 complete and 875 partial mitogenomic sequences, and performed a meta-analysis of these and published ovine mitochondrial DNA sequences ( n = 3,229) across Eurasia. We inferred that O. orientalis and O. musimon share the most recent female ancestor with O. aries at approximately 0.790 Ma (95% CI: 0.637–0.934 Ma) during the Middle Pleistocene, substantially predating the domestication event (~8–11 ka). By reconstructing historical variations in effective population size, we found evidence of a rapid population increase approximately 20–60 ka, immediately before the Last Glacial Maximum. Analyses of lineage expansions showed two sheep migratory waves at approximately 4.5–6.8 ka (lineages A and B: ~6.4–6.8 ka; C: ~4.5 ka) across eastern Eurasia, which could have been influenced by prehistoric West–East commercial trade and deliberate mating of domestic and wild sheep, respectively. A continent-scale examination of lineage diversity and approximate Bayesian computation analyses indicated that the Mongolian Plateau region was a secondary center of dispersal, acting as a "transportation hub" in eastern Eurasia: Sheep from the Middle Eastern domestication center were inferred to have migrated through the Caucasus and Central Asia, and arrived in North and Southwest China (lineages A, B, and C) and the Indian subcontinent (lineages B and C) through this region. Our results provide new insights into sheep domestication, particularly with respect to origins and migrations to and from eastern Eurasia.

Description: Stress waves, known as acoustic emissions (AEs), are released by localized inelastic deformation events during the progressive failure of brittle rocks. Although several numerical models have been developed to simulate the deformation and damage processes of rocks, such as non-linear stress–strain behaviour and localization of failure, only a limited number have been capable of providing quantitative information regarding the associated seismicity. Moreover, the majority of these studies have adopted a pseudo-static approach based on elastic strain energy dissipation that completely disregards elastodynamic effects. This paper describes a new AE modelling technique based on the combined finite-discrete element method (FEM/DEM), a numerical tool that simulates material failure by explicitly considering fracture nucleation and propagation in the modelling domain. Given the explicit time integration scheme of the solver, stress wave propagation and the effect of radiated seismic energy can be directly captured. Quasi-dynamic seismic information is extracted from a FEM/DEM model with a newly developed algorithm based on the monitoring of internal variables (e.g. relative displacements and kinetic energy) in proximity to propagating cracks. The AE of a wing crack propagation model based on this algorithm are cross-analysed by traveltime inversion and energy estimation from seismic recordings. Results indicate a good correlation of AE initiation times and locations, and scaling of energies, independently calculated with the two methods. Finally, the modelling technique is validated by simulating a laboratory compression test on a granite sample. The micromechanical parameters of the heterogeneous model are first calibrated to reproduce the macroscopic stress–strain response measured during standard laboratory tests. Subsequently, AE frequency–magnitude statistics, spatial clustering of source locations and the evolution of AE rate are investigated. The distribution of event magnitude tends to decay as power law while the spatial distribution of sources exhibits a fractal character, in agreement with experimental observations. Moreover, the model can capture the decrease of seismic b value associated with the macrorupture of the rock sample and the transition of AE spatial distribution from diffuse, in the pre-peak stage, to strongly localized at the peak and post-peak stages, as reported in a number of published laboratory studies. In future studies, the validated FEM/DEM-AE modelling technique will be used to obtain further insights into the micromechanics of rock failure with potential applications ranging from laboratory-scale microcracking to engineering-scale processes (e.g. excavations within mines, tunnels and caverns, petroleum and geothermal reservoirs) to tectonic earthquakes triggering.

Description: NF-κB and Nrf2 signaling pathways contribute to wogonin-mediated inhibition of inflammation-associated colorectal carcinogenesis Cell Death and Disease 5, e1283 (June 2014). doi:10.1038/cddis.2014.221 Authors: J Yao, L Zhao, Q Zhao, Y Zhao, Y Sun, Y Zhang, H Miao, Q-D You, R Hu & Q-L Guo

Description: 〈span〉〈div〉ABSTRACT〈/div〉Wave-equation datuming (WED) techniques have demonstrated superiority when waves occur on the acquisition surface nonvertically, and traditional static corrections based on the time shift become inaccurate. Meanwhile, as for multicomponent data, those scalar techniques can hardly maintain the vector characteristics for the following multicomponent data processing flows. Considering this, we have developed an elastic-wave datuming approach to handle the static corrections for multicomponent data. Different from those existing scalar WED techniques, the multicomponent data are first decomposed into multicomponent P- and S-wave data. Then, the decomposed data are transformed into the f-k domain, and they are extrapolated from the acquisition surface to the datum using the one-way elastic-wave continuation. Finally, the datumed multicomponent data are reconstructed at the output datum by adding up the datumed P- and S-wave data. This elastic WED can guarantee that the same wave modes on different components are equally datumed, and the data remain multicomponent so that they are still applicable to multicomponent-joint processing techniques. Finally, several test examples involved in this paper have proved our method’s effectiveness in multicomponent data datuming application.〈/span〉

Description: An appropriate network model and some suitable performance evaluation criterions including handoff delay and mobility management cost were proposed in this paper. And in this base the performance of Mobile IP protocol and various micromobility protocols was comprehensively compared and investigated. The research results show that the performance is mainly influenced by two factors which are route update methods of mobility support protocols and mobile network parameters. The route update time and mobility management cost of micromobility protocol are obviously shorter than that of Mobile IP. In all researched micromobility protocols, the route update method of Mobile IP Regional Registration protocol has the optimal performance.

Description: A study of whole-rock major and trace element and Sr–Nd–Pb–Hf isotope compositions, combined with zircon U–Pb ages and Hf–O isotopes, for postcollisional intermediate volcanic rocks from the Dabie orogen, China provides constraints on the origin of andesitic magmas and insights into slab–mantle interaction in continental subduction channels. The volcanic rocks exhibit variable contents of SiO 2 (50·28–63·86 wt %), MgO (1·18–4·65 wt %), (Fe 2 O 3 ) T (3·60–8·53 wt %), Al 2 O 3 (12·92–18·95 wt %), Na 2 O (2·08–6·30 wt %) and K 2 O (0·73–5·25 wt %). They are mainly trachyandesites, with lesser amounts of basaltic trachyandesite, andesite, dacite and trachyte, characterized by subduction-like trace element distribution patterns showing enrichment of large ion lithophile elements and light rare earth elements but depletion of high field strength elements. The volcanic rocks have relatively enriched Sr–Nd–Pb–Hf isotope compositions, with high initial 87 Sr/ 86 Sr ratios of 0·7075–0·7110, highly negative Nd ( t ) values of –23·1 to –15·0, Hf ( t ) values of –29·8 to –18·3 and elevated 207 Pb/ 204 Pb and 208 Pb/ 204 Pb ratios at given 206 Pb/ 204 Pb ratios. Zircon Hf–O isotope analyses yield negative Hf ( t ) values of –31·0 to –17·8 and 18 O values of 4·4–6·8 for syn-magmatic domains. Zircon U–Pb dating yields consistent Early Cretaceous ages of 124 ± 3 to 130 ± 2 Ma for magma emplacement. Residual zircon cores yield Triassic, Neoproterozoic and Paleoproterozoic U–Pb ages, consistent with the ages of tectonothermal events involving ultrahigh-pressure metamorphism and protolith formation in the Dabie orogen. The zircon cores also yield a few low to negative 18 O values. An integrated interpretation of these geochemical characteristics is that the andesitic magmas were derived by partial melting of metasomatized zones in the orogenic lithospheric mantle. The metasomatites were generated by reaction of subcontinental lithospheric mantle wedge peridotite with felsic melts that originated from deeply subducted continental crust during continental collision in the Triassic. Melt–peridotite reaction in a subduction channel is therefore a key to the origin of the mantle sources of andesitic magmas in collisional orogens.

Description: Electron-cyclotron maser (ECM) is one of the most important emission mechanisms in astrophysics and can be excited efficiently by lower-energy cutoffs of power-law electrons. These non-thermal electrons probably propagate as a directed collimated beam along ambient magnetic fields. This paper investigates the ECM, in which the effect of electron beams is emphasized. Results show the dependence of emission properties of the ECM on the beam feature. The maximum growth rate of the extraordinary mode (X2) rapidly decreases as the beam momentum increases, while the growth rate of the ordinary mode (O1) changes slightly. In particular, the ordinary mode can overcome the extraordinary mode and becomes the fastest growth mode once the beam momentum is large enough. This research presents an extension of the conventional studies on ECM driven by lower-energy cutoffs and may be helpful to understand better the emission process of solar type I radio bursts, which are dominated by the ordinary mode emission.

Description: Immunoglobulin-like domain containing receptor 1 ( ILDR1 ) is a poorly characterized gene that was first identified in lymphoma cells. Recently, ILDR1 has been found to be responsible for autosomal recessive hearing impairment DFNB42. Patients with ILDR1 mutations cause bilateral non-progressive moderate-to-profound sensorineural hearing impairment. However, the etiology and mechanism of ILDR1 -related hearing loss remains to be elucidated. In order to uncover the pathology of DFNB42 deafness, we used the morpholino injection technique to establish an ildr1b -morphant zebrafish model. Ildr1b -morphant zebrafish displayed defective hearing and imbalanced swimming, and developmental delays were seen in the semicircular canals of the inner ear. The gene expression profile and real-time PCR revealed down-regulation of atp1b2b (encoding Na + /K + transporting, beta 2b polypeptide) in ildr1b -morphant zebrafish. We found that injection of atp1b2b mRNA into ildr1b -knockdown zebrafish could rescue the phenotype of developmental delay of the semicircular canals. Moreover, ildr1b -morphant zebrafish had reduced numbers of lateral line neuromasts due to the disruption of lateral line primordium migration. In situ hybridization showed the involvement of attenuated FGF signaling and the chemokine receptor 4b ( cxcr4b ) and chemokine receptor 7b ( cxcr7b ) in posterior lateral line primordium of ildr1b -morphant zebrafish. We concluded that Ildr1b is crucial for the development of the inner ear and the lateral line system. This study provides the first evidence for the mechanism of Ildr1b on hearing in vivo and sheds light on the pathology of DFNB42.

Description: Author(s): Y. Gim, A. Sethi, Q. Zhao, J. F. Mitchell, G. Cao, and S. L. Cooper A major focus of experimental interest in Sr 2 IrO 4 has been to clarify how the magnetic excitations of this strongly spin-orbit coupled system differ from the predictions of an isotropic 2D spin-1/2 Heisenberg model and to explore the extent to which strong spin-orbit coupling affects the magnetic pr... [Phys. Rev. B 93, 024405] Published Mon Jan 11, 2016