ALBERT

Description: Nature Materials 14, 325 (2015). doi:10.1038/nmat4155 Authors: X. F. Lu, N. Z. Wang, H. Wu, Y. P. Wu, D. Zhao, X. Z. Zeng, X. G. Luo, T. Wu, W. Bao, G. H. Zhang, F. Q. Huang, Q. Z. Huang & X. H. Chen

Description: Triazophos is a broad-spectrum and highly effective insecticide, and the residues of triazophos have been frequently detected in the environment. A triazophos-degrading bacterium, Burkholderia sp. SZL-1, was isolated from a long-term triazophos-polluted soil. Strain SZL-1 could hydrolyze triazophos to 1-phenyl-3-hydroxy-1,2,4-triazole, which was further utilized as the carbon sources for growth. The triazophos hydrolase gene trhA , cloned from strain SZL-1, was expressed and homogenously purified using Ni-nitrilotriacetic acid affinity chromatography. TrhA is 55 kDa and displays maximum activity at 25°C, pH 8.0. This enzyme still has nearly 60% activity at the range of 15°C–50°C for 30 min. TrhA was mutated by sequential error prone PCR and screened for improved activity for triazophos degradation. One purified variant protein (Val89-Gly89) named TrhA-M1 showed up to 3-fold improvement in specific activity against triazophos, and the specificity constants of K cat and K cat / K m for TrhA-M1 were improved up to 2.3- and 8.28-fold, respectively, compared to the wild-type enzyme. The results in this paper provided potential material for the contaminated soil remediation and hydrolase genetic structure research.

Description: Synthetic gengenbachite, KH 8 (Fe 2.66 Al 0.34 )(PO 4 ) 6 ·6H 2 O, has been prepared hydrothermally at 423–393 K. Single-crystal X-ray structure refinements ( R 1 = 0.035 for 1838 [ I 〉 2( I )] unique reflections and wR 2 = 0.083 for all 1863 reflections) confirm that gengenbachite crystallizes in the trigonal space group P 31 c (No. 159) and is isotypic with synthetic (NH 4 ) H 8 Fe 3+ 3 (PO 4 ) 6 ·6H 2 O. The crystal structure consists of [FeO 6 ] octahedra and [PO 4 ] tetrahedra forming a three-dimensional framework with eight-membered-ring channels running along the [100], [010], and [110] directions. All but one hydrogen atom have been located to allow description of the hydrogen bonds in gengenbachite. Magnetic susceptibility analysis of gengenbachite yielded the Curie constant C = 12.07 emu·K·mol –1 and the Weiss constant P = –58.9 K. The effective magnetic moment per Fe atom μ eff = 6.03 μ B provides further support for high-spin Fe 3+ in octahedral coordination.

Description: Aims The hypothesis of predator satiation has been proposed to explain mast fruiting in various flowering plants. It considers that the simultaneous production of large numbers of seeds by a plant population reduces the risk of seed predation for each individual. Orchids produce huge numbers of seeds per fruit and rarely experience seed predation. It remains unclear which factors may affect fluctuating fruit production in orchids, which generally suffer a widespread pollen limitation. To explore the temporal pattern of fruiting and potential factors related to fluctuation in fruit production, we investigated reproductive success of a long-spurred orchid ( Habenaria glaucifolia ) in an alpine meadow with thousands of individuals over 8 years. Methods To estimate reproductive success, pollinator observation was conducted by day and at night, and pollinia removal and receipt were recorded in the field population for 8 years. To examine whether fruit set and seed set are pollen limited, we conducted supplementary pollination experiments and compared fruit set, seed set and pollinia movement of open-pollinated flowers from 2011 to 2013. We measured lengths of spurs and pollinator proboscises, and nectar volume and concentration, to identify potential pollinators. Important Findings Hawkmoths were seen to be effective pollinators for H. glaucifolia in 3 years, whereas in the remaining 5 years no pollinators were observed, and consequently pollinia were rarely transferred. Numerous pollinia movements were observed in 2012, 2013 and 2014 (pollinia removal: 48, 59 and 85%; pollinia receipt 51, 70 and 80%), and correspondingly fruit set was significantly higher in 2012 and 2013 (59 and 46%) than in 2011 (25%). It was fruit set, rather than seed set, that was pollen limited in this orchid in the 3 years, in that supplementary pollination increased fruit set but did not increase seed set per fruit compared to natural. Three species of hawkmoths had proboscis lengths that matched the spur length of H. glaucifolia . Fruit set in this long spurred orchid depends on the activity of long-tongued hawkmoths, resulting in significant temporal variation in fruit production. Mast fruiting in this alpine orchid could be attributed to a ‘sit and wait’ strategy, awaiting an abundance of effective pollinators.

Description: Author(s): J. Yang, C. Duan, Q. Huang, C. Brown, J. Neuefeind, and Despina Louca The coexistence of magnetic and nonmagnetic phases in the superconducting potassium iron selenide, K x Fe 2 − y Se 2 , has been intensely debated. With superconductivity proposed to appear in a stoichiometric, nonmagnetic phase with I4/mmm crystal symmetry, the proposed nonsuperconducting phase is magnetic … [Phys. Rev. B 94, 024503] Published Tue Jul 05, 2016

Description: The protein kinase maternal and embryonic leucine zipper kinase (MELK) is critical for mitotic progression of cancer cells; however, its mechanisms of action remain largely unknown. By combined approaches of immunoprecipitation/mass spectrometry and peptide library profiling, we identified the eukaryotic translation initiation factor 4B (eIF4B) as a MELK-interacting protein during...

Description: In the context of global climate change, human activities dramatically damage the consistency of hydrological time series. Peak Over Threshold (POT) series have become an alternative to the traditional Annual Maximum series, but it is still underutilized due to its complexity. Most literature about POT tended to employ only one threshold regardless of the non-stationarity of the whole series. Obviously, it is unwise to ignore the fact that our hydrological time series may no longer be a stationary stochastic process. Hence, in this paper, we take the daily runoff time series of the Yichang gauge station on the Yangtze River in China as an example, and try to shed light on the selection of the threshold provided non- stationarity of our time series. The Mann-Kendall test is applied to detect the change points; then, we gave different thresholds according to the change points to the sub-series. Comparing the goodness-of-fit of the series with one and several thresholds, it clearly...

Description: Author(s): N. Ni, S. Jia, Q. Huang, E. Climent-Pascual, and R. J. Cava We report the structural, transport, and thermodynamic properties of the semiconducting, layered rare-earth iron oxyselenides R 2 O 3 Fe 2 Se 2 ( R =Ce, Pr, Nd, and Sm ), which have crystal structures related to the arsenide superconductors except with in-plane oxygens within the Fe square planes. The activat... [Phys. Rev. B 83, 224403] Published Fri Jun 17, 2011

Description: Invasion ecologists have often found that exotic invaders evolve to be more plastic than conspecific populations from their native range. However, an open question is why some exotic invaders can even evolve to be more plastic given that there may be costs to being plastic. Investigation into the benefits and costs of plasticity suggests that stress may constrain the expression of plasticity (thereby reducing the benefits of plasticity) and exacerbate the costs of plasticity (although this possibility might not be generally applicable). Therefore, evolution of adaptive plasticity is more likely to be constrained in stressful environments. Upon introduction to a new range, exotic species may experience more favorable growth conditions (e.g., because of release from natural enemies). Therefore, we hypothesize that any factors mitigating stress in the introduced range may promote exotic invaders to evolve increased adaptive plasticity by reducing the costs and increasing the benefits of plasticity. Empirical evidence is largely consistent with this hypothesis. This hypothesis contributes to our understanding of why invasive species are often found to be more competitive in a subset of environments. Tests of this hypothesis may not only help us understand what caused increased plasticity in some exotic invaders, but could also tell us if costs (unless very small) are more likely to inhibit the evolution of adaptive plasticity in stressful environments in general. An open question in invasion ecology is why some exotic invaders can even evolve to be more plastic given that there may be costs to being plastic. We propose a hypothesis stating that any factors mitigating stress in the introduced range may promote exotic invaders to evolve increased adaptive plasticity by reducing the costs and increasing the benefits of plasticity.

Description: Article Sc 3 In and ZrZn 2 are the only two known itinerant ferromagnets that form from non-magnetic constituents. Now, Svanidze et al., evidence itinerant antiferromagnetism in TiAu below 36 K using thermodynamic, transport, muon-based and neutron-based measurements, and density functional analysis. Nature Communications doi: 10.1038/ncomms8701 Authors: E. Svanidze, Jiakui K. Wang, T. Besara, L. Liu, Q. Huang, T. Siegrist, B. Frandsen, J. W. Lynn, Andriy H. Nevidomskyy, Monika B. Gamża, M. C. Aronson, Y. J. Uemura, E. Morosan