Genomic evidence for adaptive differentiation among Microhyla fissipes populations : Implications for conservation

Aim Amphibians require both terrestrial and aquatic environments to complete their life cycles. Thus, they are subject to complex selection pressures stemming from different environments, and these selection pressures are likely to vary geographically with variation in temperature and precipitation. Studies of genetic differentiation along geographical clines allow identification of footprints of these selection pressures. Location China. Methods To identify possible signatures of local adaptation to particular environmental conditions, we conducted a genome-scan with 20,572 single-nucleotide polymorphisms (SNPs) obtained with restriction site-associated DNA sequencing of pooled samples from 10 Microhyla fissipes populations spanning a 1,398 km long latitudinal gradient in China. Results The results revealed significant genetic differentiation among populations (F-ST =0.090). Numerous outlier SNPs associated with variation in both annual average temperature (n = 69) and precipitation (n = 248) were detected. Main conclusions The degree and pattern of population differentiation in the SNPs supported the hypothesis that these SNPs have been subject to directional natural selection associated with temperature and precipitation and, hence, are reflective of geographically varying local adaptation. Hence, conservation and management plans for Microhyla fissipes should take into account this heterogeneity in genetic constitution in its populations.Peer reviewe

Improved ACD-based financial trade durations prediction leveraging LSTM networks and Attention Mechanism

The liquidity risk factor of security market plays an important role in the formulation of trading strategies. A more liquid stock market means that the securities can be bought or sold more easily. As a sound indicator of market liquidity, the transaction duration is the focus of this study. We concentrate on estimating the probability density function p({\Delta}t_(i+1) |G_i) where {\Delta}t_(i+1) represents the duration of the (i+1)-th transaction, G_i represents the historical information at the time when the (i+1)-th transaction occurs. In this paper, we propose a new ultra-high-frequency (UHF) duration modelling framework by utilizing long short-term memory (LSTM) networks to extend the conditional mean equation of classic autoregressive conditional duration (ACD) model while retaining the probabilistic inference ability. And then the attention mechanism is leveraged to unveil the internal mechanism of the constructed model. In order to minimize the impact of manual parameter tuning, we adopt fixed hyperparameters during the training process. The experiments applied to a large-scale dataset prove the superiority of the proposed hybrid models. In the input sequence, the temporal positions which are more important for predicting the next duration can be efficiently highlighted via the added attention mechanism layer

Atmospheric chemistry of CH\u3csub\u3e3\u3c/sub\u3eCHO: the hydrolysis of CH\u3csub\u3e3\u3c/sub\u3eCHO catalyzed by H\u3csub\u3e2\u3c/sub\u3eSO\u3csub\u3e4\u3c/sub\u3e

Elucidating atmospheric oxidation mechanisms and the reaction kinetics of atmospheric compounds is of great importance and necessary for atmospheric modeling and the understanding of the formation of atmospheric organic aerosols. While the hydrolysis of aldehydes has been detected in the presence of sulfuric acid, the reaction mechanism and kinetics remain unclear. Herein, we use electronic structure methods with CCSD(T)/CBS accuracy and canonical variational transition state theory combined with small-curvature tunneling to study the reaction mechanism and kinetics of the hydrolysis of CH3CHO. The calculated results show that the hydrolysis of CH3CHO needs to overcome an energy barrier of 37.21 kcal mol−1, while the energy barrier is decreased to −9.79 kcal mol−1 with a sulfuric acid catalyst. In addition, the calculated kinetic results show that the H2SO4⋯H2O + CH3CHO reaction is faster than H2SO4 + CH3CHO⋯H2O. Additionally, the H2SO4⋯H2O + CH3CHO reaction can play an important role in the sink of CH3CHO below 260 K occurring during the night period when OH, H2SO4, and H2O concentrations are 104, 108, and 1017 molecules cm−3, respectively, because it can compete well with the CH3CHO + OH reaction. There are wide implications in atmospheric chemistry from these findings because of the potential importance of the catalytic effect of H2SO4 on the hydrolysis of CH3CHO in the atmosphere and in the formation of secondary organic aerosols

{μ-6,6′-Dimeth­oxy-2,2′-[propane-1,3-diylbis(nitrilo­methyl­idyne)]diphenolato}trinitratocopper(II)erbium(III) acetone solvate

In the title complex, [CuEr(C19H20N2O4)(NO3)3]·CH3COCH3, the CuII ion is coordinated in a square-planar environment by two O atoms and two N atoms of a Schiff base ligand. The ErIII ion is bis-chelated by three nitrate ligands and coordinated by four O atoms of the Schiff base ligand in a slightly distorted bicapped square-anti­prismatic environment

Triply charmed baryons mass decomposition from lattice QCD

We present the first lattice QCD calculation about the mass decomposition of triply charmed baryons with $J^{P}$ as $\frac{3}{2}^{+}$ and $\frac{3}{2}^{-}$. The quark mass term $\langle H_{M} \rangle$ contributes about 66\% to the mass of $\frac{3}{2}^+$ state, which is slightly lower than that of the meson system with the same valence charm quark. Furthermore, based on our results, the total contribution of sea quarks, the gluons and the QCD anomaly accounts for about a quarter of the mass of these two triply charmed baryons. The mass difference of $\frac{3}{2}^+$ and $\frac{3}{2}^-$ states is mainly from the quark energy $\langle H_{E} \rangle$ of the QCD energy-momentum tensor. For comparison, the mass splitting is also calculated under the framework of the constituent quark model.Comment: 7 page, 14 figure

Modulation of Gene Expression in Liver of Hibernating Asiatic Toads (Bufo gargarizans)

Hibernation is an effective energy conservation strategy that has been widely adopted by animals to cope with unpredictable environmental conditions. The liver, in particular, plays an important role in adaptive metabolic adjustment during hibernation. Mammalian studies have revealed that many genes involved in metabolism are differentially expressed during the hibernation period. However, the differentiation in global gene expression between active and torpid states in amphibians remains largely unknown. We analyzed gene expression in the liver of active and torpid Asiatic toads (Bufo gargarizans) using RNA-sequencing. In addition, we evaluated the differential expression of genes between females and males. A total of 1399 genes were identified as differentially expressed between active and torpid females. Of these, the expressions of 395 genes were significantly elevated in torpid females and involved genes responding to stresses, as well as contractile proteins. The expression of 1004 genes were significantly down-regulated in torpid females, most which were involved in metabolic depression and shifts in the energy utilization. Of the 715 differentially expressed genes between active and torpid males, 337 were up-regulated and 378 down-regulated. A total of 695 genes were differentially expressed between active females and males, of which 655 genes were significantly down-regulated in males. Similarly, 374 differentially expressed genes were identified between torpid females and males, with the expression of 252 genes (mostly contractile proteins) being significantly down-regulated in males. Our findings suggest that expression of many genes in the liver of B. gargarizans are down-regulated during hibernation. Furthermore, there are marked sex differences in the levels of gene expression, with females showing elevated levels of gene expression as compared to males, as well as more marked down-regulation of gene-expression in torpid males than females.Peer reviewe

Phase transition and hysteresis in scale-free network traffic

We model information traffic on scale-free networks by introducing the node queue length L proportional to the node degree and its delivering ability C proportional to L. The simulation gives the overall capacity of the traffic system, which is quantified by a phase transition from free flow to congestion. It is found that the maximal capacity of the system results from the case of the local routing coefficient \phi slightly larger than zero, and we provide an analysis for the optimal value of \phi. In addition, we report for the first time the fundamental diagram of flow against density, in which hysteresis is found, and thus we can classify the traffic flow with four states: free flow, saturated flow, bistable, and jammed.Comment: 5 pages, 4 figure