The first record of the family Euscorpiidae (Arachnida: Scorpiones) from Central China, with a key of Chinese species of the genus \u3cem\u3eScorpiops\u3c/em\u3e

The genus Scorpiops (Euscorpiidae) is recorded for the first time in Central China. Two immature specimens of a form belonging to Scorpiops hardwickii (Gervais, 1843) “complex” were collected from Huzhaoshan Mountains in Hubei Province. A discussion of Chinese species of genus Scorpiops is provided, as well as a key of Scorpiops from China

Gene coexpression network analysis of fruit transcriptomes uncovers a possible mechanistically distinct class of sugar/acid ratio-associated genes in sweet orange

Background: The ratio of sugars to organic acids, two of the major metabolites in fleshy fruits, has been considered the most important contributor to fruit sweetness. Although accumulation of sugars and acids have been extensively studied, whether plants evolve a mechanism to maintain, sense or respond to the fruit sugar/acid ratio remains a mystery. In a prior study, we used an integrated systems biology tool to identify a group of 39 acid-associated genes from the fruit transcriptomes in four sweet orange varieties (Citrus sinensis L. Osbeck) with varying fruit acidity, Succari (acidless), Bingtang (low acid), and Newhall and Xinhui (normal acid). Results: We reanalyzed the prior sweet orange fruit transcriptome data, leading to the identification of 72 genes highly correlated with the fruit sugar/acid ratio. The majority of these sugar/acid ratio-related genes are predicted to be involved in regulatory functions such as transport, signaling and transcription or encode enzymes involved in metabolism. Surprisingly, only three of these sugar/acid ratio-correlated genes are weakly correlated with sugar level and none of them overlaps with the acid-associated genes. Weighted Gene Coexpression Network Analysis (WGCNA) has revealed that these genes belong to four modules, Blue, Grey, Brown and Turquoise, with the former two modules being unique to the sugar/acid ratio control. Conclusion: Our results indicate that orange fruits contain a possible mechanistically distinct class of genes that may potentially be involved in maintaining fruit sugar/acid ratios and/or responding to the cellular sugar/acid ratio status. Therefore, our analysis of orange transcriptomes provides an intriguing insight into the potentially novel genetic or molecular mechanisms controlling the sugar/acid ratio in fruits

Linkages between nitrogen cycling, nitrogen isotopes, and environmental properties in paleo-lake basins

This work was funded by the National Natural Science Foundation of China (no. 41830425). E.E. Stüeken acknowledges funding from a Natural Environment Research Council grant (no. NE/V010824/1).The linkages between nitrogen cycling, nitrogen isotopes, and environmental properties are fundamental for reconstructing nitrogen biogeochemistry. While the impact of ocean redox changes on nitrogen isotopes is relatively well understood, it is poorly known how nitrogen responds to changes in pH and salinity. To fill the knowledge gap, we explore the effects of these environmental parameters using a well-controlled set of samples from Carboniferous−Paleogene lake sediments in China. Our results show that the threshold of 10−12‰ in δ15N works to distinguish alkaline (pH > 9) from circum-neutral conditions. Elevated Mo levels in the alkaline samples support the idea of NH3 volatilization from a reducing water column in an alkaline setting. For non-alkaline lakes, δ15N values tend to be higher (up to +10‰) in more saline, anoxic settings, which is attributed to either the expansion of stagnant anoxic waters spurring water-column denitrification or a shift from plant-based toward more microbially dominated ecosystems or both. Our results imply that salinity-induced redox stratification and basicity can alter nitrogen biogeochemical cycling beyond what is shown by the marine nitrogen isotope record alone. This finding will result in an improved understanding of the dynamic controls of δ15N in sediments and lead to better biogeochemical interpretations of paleo-environmental conditions from unknown environmental settings on Earth and beyond Earth.PostprintPeer reviewe

The scorpions of Hainan Island, China (Arachnida: Scorpiones)

The redescriptions and illustrations of three species, Isometrus (Isometrus) maculatus (DeGeer, 1778), Lychas mucronatus (Fabricius, 1798) (Buthidae), and Liocheles australasiae (Fabricius, 1775) (Hemiscorpiidae) from Hainan Island, China are presented. Distribution data and updated key of Hainan scorpions are provided

A Three-Dimensional Tight-Binding Model and Magnetic Instability of KFe2e2

For a newly discovered iron-based high T_c superconducting parent material KFe2Se2, we present an effective three-dimensional five-orbital tight-binding model by fitting the band structures. The three t2g-symmetry orbitals of the five Fe 3d orbitals mainly contribute to the electron-like Fermi surface, in agreement with recent angle-resolved photoemission spectroscopy experiments. To understand the groundstate magnetic structure, the two- and three-dimensional dynamical spin susceptibilities within the random phase approximation are investigated. It obviously shows a sharp peak at wave vector $\mathbf{Q}$ $\thicksim$ ($\pi$, $\pi$), indicating the magnetic instability of {\it N$\acute{e}$el}-type antiferromagnetic rather than ($\pi$/2, $\pi$/2)-type antiferromagnetic ordering. While along \emph{c} axis, it exhibits a ferromagnetic coupling between the nearest neighboring FeSe layers. The difference between the present results and the experimental observation in KxFe2-ySe2 is attributed to the presence of Fe vacancy in the latter.Comment: 14 pages, 8 figure