Description: Cases of convergent evolution, particularly within ecomorphological contexts, are instructive in identifying universally adaptive morphological features across clades. Tracing of evolutionary pathways by which ecomorphological convergence takes place can further reveal mechanisms of adaptation, which may be strongly influenced by phylogeny. Ecomorphologies of carnivorous mammals represent some of the most outstanding cases of convergent evolution in the Cenozoic radiation of mammals. This study examined patterns of cranial shape change in the dog (Canidae) and hyena (Hyaenidae) families, in order to compare the evolutionary pathways that led to the independent specialization of bone-cracking hypercarnivores within each clade. Geometric morphometrics analyses of cranial shape in fossil hyaenids and borophagine canids provided evidence for deep-time convergence in morphological pathways toward the independent evolution of derived bone-crackers. Both clades contained stem members with plesiomorphic generalist/omnivore cranial shapes, which evolved into doglike species along parallel pathways of shape change. The evolution of specialized bone-crackers from these doglike forms, however, continued under the constraint of a full cheek dentition and restriction on rostrum length reduction in canids, but not hyaenids. Functionally, phylogenetic constraint may have limited borophagine canids to crack bones principally with their carnassial instead of the third premolar as in hyaenids, but other cranial shape changes associated with durophagy nevertheless evolved in parallel in the two lineages. Size allometry was not a major factor in cranial shape evolution in either lineage, supporting the interpretation of functional demands as drivers for the observed convergence. The comparison between borophagines and hyaenids showed that differential effects of alternative functional "solutions" that arise during morphological evolution may be multiplied with processes of the "macroevolutionary ratchet" already in place to further limit the evolutionary pathways available to specialized lineages.

Description: AmyP is a raw-starch-degrading α-amylase newly identified from a marine metagenome library. It shares low sequence similarity with characterized glycoside hydrolases and was classified into a new subfamily of GH13. In particular, it showed preferential degradation to raw rice starch. Full-length AmyP was cloned and overexpressed in Escherichia coli , then purified and crystallized in the presence of its substrate analogue β-cyclodextrin. X-ray diffraction data were collected to a resolution of 2.1 Å. The crystal belonged to space group P 2 1 2 1 2, with unit-cell parameters a = 129.824, b = 215.534, c = 79.699 Å, α = β = γ = 90°, and was estimated to contain two molecules in one asymmetric unit.

Description: Nature Chemical Biology 9, 84 (2013). doi:10.1038/nchembio.1153 Authors: Gelin Wang, Xiaoming Wang, Hong Yu, Shuguang Wei, Noelle Williams, Daniel L Holmes, Randal Halfmann, Jacinth Naidoo, Lai Wang, Lin Li, She Chen, Patrick Harran, Xiaoguang Lei & Xiaodong Wang

Description: In this paper, we extend the deterministic single-group MSIRS epidemic model to a multi-group model, and we also extend the deterministic multi-group framework to a stochastic one and formulate it as a stochastic differential equation. In the deterministic multi-group model, the basic reproduction number R0 is a threshold that completely determines the persistence or extinction of the disease. By using Lyapunov function techniques, we show that if R0〉1, then the disease will prevail, the infective condition persists and the endemic state is asymptotically stable in a feasible region. If R0⩽1, then the infective condition disappears and the disease dies out. For the stochastic version, we perform a detailed analysis on the asymptotic behavior of the stochastic model, which also depends on the value of R0, when R0〉1, we determine the asymptotic stability of the endemic equilibrium by measuring the difference between the solution and the endemic equilibrium of the deterministic model in time-averaged data. Numerical methods are used to illustrate the dynamic behavior of the model and to solve the systems.

Description: Purpose To investigate the diffusion abnormalities in the brain of children with idiopathic generalized epilepsy (IGE) with generalized tonic-clonic seizure (GTCS) by using diffusion kurtosis imaging (DKI). Materials and Methods Twenty-one IGE children with GTCS and 16 controls were recruited. DKI was performed and maps of radial diffusivity (λ ⊥ ), axial diffusivity (λ // ), mean diffusivity (MD), fractional anisotropy (FA), radial kurtosis (K ⊥ ), axial kurtosis (K // ) and mean kurtosis (MK) were calculated. Voxel-based analyses were employed to compare diffusion metrics in epilepsy versus the controls. Results In the case group, MD was found significantly higher in the right temporal lobe, the right occipital lobe, hippocampus, and some subcortical regions, while FA increased in bilateral supplementary motor area and the left superior frontal lobe (false discovery rate corrected P  〈 0.05). Analysis of λ ⊥ and λ // showed that the increased MD was mainly due to the elevated λ // . Significantly decreased MK was also detected in bilateral temporo-occipital regions, the right hippocampus, the left insula, the left post-central area, and some subcortical regions (false discovery rate corrected P  〈 0.05). In most regions the changed MK were due to the decreased K // . Conclusion The kurtosis parameters (K ⊥ , K // , and MK) reflect different microstructural information in the IGE children with GTCS, and this support the value of DKI in studying children GTCS. J. Magn. Reson. Imaging 2014 . © 2014 Wiley Periodicals, Inc .

Description: Both direct current (DC) and alternating current (AC) driving electroluminescence were obtained from isotype heterojunction ( n-i-n : n-ZnO/i-HfO 2 /n-GaN) light-emitting diodes (LEDs) fabricated by a pulsed laser deposition system. The n-ZnO film maintained the same growth orientation as the n-GaN film and was of high crystalline quality even on a polycrystalline high- k HfO 2 thin film. The as-produced n-i-n LEDs can emit strong visible light or dominant ultraviolet light at ∼392 nm, depending on the polarity of the applied DC voltages. The individual spectrum under either forward or reverse bias can be integrated to one spectrum by applying 50 Hz AC driving voltages (sinusoidal signals). More importantly, near white-light can be obtained by tuning the symmetric driving AC sinusoidal signals to the asymmetric ones. This simple and facile method only by applying AC asymmetric signals to achieve white light emission on one single chip may provide an easy route for the white-light solid-state lighting industry.