A taxonomic and phylogenetic perspective on plant community assembly along an elevational gradient in subtropical forests

亚热带森林植物群落沿海拔梯度的分类与系统发育研究 生物多样性沿海拔梯度的分布格局已受到广泛关注。然而,生物多样性格局沿海拔梯度的变异及其潜在机制尚不清楚。整合生物多样性的多维度信息为理解群落构建机制提供了新思路。本研究在我国东部亚热带森林沿海拔270–1470 m的梯度上设置了17个木本植物固定样地,分析了沿海拔梯度植物群落 构建的生态和进化驱动力。基于样地内物种出现(0–1数据)和多度信息,计算群落内被子植物的物种和系统发育alpha和beta多样性、系统发育结构等,并量化多样性指标与微气候和地形之间的关系。研究发现,不论多度加权与否,物种alpha多样性均沿海拔升高而增加,物种和系统发育的相似性随海拔距离的增加而呈衰减趋势。然而,多度加权与否会形成不同的系统发育alpha多样性格局。对于系统发育结构而言,沿海拔增加并无明显趋势。地形和微气候是多样性格局和系统发育结构的主要驱动力。与未考虑物种多度的多样性指标相比,多度加权的指标与坡度和胸高断面积相关性更高。这些结果表明,由局域物种多度介导的确定性过程对沿海拔梯度的植物群落构建具有一定影响。     

Economic and disease burden of Japanese encephalitis in Zhejiang Province, 2013–2018

BackgroundJapanese encephalitis (JE) is a mosquito-borne disease and associated with high mortality and disability rate among symptomatic cases. In the absence of local data, this study estimated the economic burden and the disability-adjusted life years (DALYs) due to JE in Zhejiang Province, China during 2013–2018, to increase disease awareness and provide evidence for effective health policy.Methodology/Principle findingsWe merged multiple data sources, including National Notifiable Disease Registry System (NNDRS), patient interviews and medical records from corresponding hospitals for JE cases which occurred during 2013–2018 in Zhejiang Province. Direct costs were extracted from hospitals’ billing systems and patient interviews. Indirect costs and disease burden were calculated based on questionnaire survey from patient interviews and follow-up assessment by general practitioners. Given under-reporting, an expansion factor (EF) was applied to extrapolate the JE burden to the provincial level. The total economic burden of JE during 2013–2018 was estimated at US $12.01 million with an EF = 3. Of this, $8.32 million was due to direct economic cost and $3.69 million to indirect cost. The disease burden of JE was 42.75 DALYs per million population (28.44 YLD, 14.28 YLL) according to the 1990 Global Burden of Disease (GBD 1990) methodology and 80.01 DALYs (53.67YLD, 26.34YLL) according to the GBD 2010 methodology. Sensitivity analysis demonstrated that the overall economic burden varied from US$ 1.73–36.42 million. The greatest variation was due to the prognosis of illness (-85.57%-203.17%), followed by occupation (-34.07%-134.12%) and age (-72.97%-47.69%).Conclusions/SignificanceJE imposes a heavy burden for families and society in Zhejiang Province. This study provides comprehensive empirical estimates of JE burden to increase awareness and strengthen knowledge of the public. These data may support provincial level public health decision making for prevention and control of JE. Ongoing surveillance for acute meningitis and encephalitis syndrome (AEMS) in sentinel hospitals, is needed to further refine estimates of JE burden.     

PUGSVM: a caBIG™ analytical tool for multiclass gene selection and predictive classification

Phenotypic Up-regulated Gene Support Vector Machine (PUGSVM) is a cancer Biomedical Informatics Grid (caBIG?) analytical tool for multiclass gene selection and classification. PUGSVM addresses the problem of imbalanced class separability, small sample size and high gene space dimensionality, where multiclass gene markers are defined by the union of one-versus-everyone phenotypic upregulated genes, and used by a well-matched one-versus-rest support vector machine. PUGSVM provides a simple yet more accurate strategy to identify statistically reproducible mechanistic marker genes for characterization of heterogeneous diseases. AVAILABILITY: http://www.cbil.ece.vt.edu/caBIG-PUGSVM.htm.     

重组人MASP2蛋白在大肠杆菌中的表达和纯化

目的:获得酶原形式的重组人甘露聚糖结合凝集素相关丝氨酸蛋白酶2(MASP2)。方法:在大肠杆菌中诱导表达重组人MASP2全长蛋白,包涵体裂解后,经复性、透析、浓缩、考马斯亮蓝染色、SDS-PAGE及Western印迹,鉴定纯化结果及酶活性。结果:复性后的MASP2蛋白经考马斯亮蓝染色未见杂带。自激活实验表明,当MASP2浓度在1μmool/L以下时,无论在4℃还是37℃,都能较稳定地保持酶原形式;蛋白浓度为3.5μmool/L时只能在4℃保持稳定,37℃发生自激活;蛋白浓度达到12μmool/L后,在4℃时已不能稳定存在。结论:获得了较纯的重组人MASP2蛋白,且具有自激活活性。     

Structural characterization and anti-HIV-1 activities of arginine/glutamate-rich polypeptide Luffin P1 from the seeds of sponge gourd (Luffa cylindrica)

Luffin P1, the smallest ribosome-inactivating peptide from the seeds of Luffa cylindrica was found to have anti-HIV-1 activity in HIV-1 infected C8166 T-cell lines and be able to bind with HIV Rev Response Element. Nuclear magnetic resonance spectroscopy revealed that the Luffin P1 comprises a helix-loop-helix motif, with the two alpha helices tightly associated by two disulfide bonds. Based on our findings, we conclude that unlike the well-studied ribosome-inactivating proteins, which exert their action through N-glycosidase activities, Luffin P1 demonstrates a novel inactivation mechanism probably through the charge complementation with viral or cellular proteins. Our work also provides a new scaffold for the design of novel inhibitors from a simple helical motif.     

ROS-mediated p53 induction of Lpin1 regulates fatty acid oxidation in response to nutritional stress

The p53 protein is activated by stress signals and exhibits both protective and death-promoting functions that are considered important for its tumor suppressor function. Emerging evidence points toward an additional role for p53 in metabolism. Here, we identify Lpin1 as a p53-responsive gene that is induced in response to DNA damage and glucose deprivation. Lpin1 is essential for adipocyte development and fat metabolism, and mutation in this gene is responsible for the lypodystrophy phenotype in fld mice. We show that p53 and Lpin1 regulate fatty acid oxidation in mouse C2C12 myoblasts. p53 phosphorylation on Ser18 in response to low glucose is ROS and ATM dependent. Lpin1 expression in response to nutritional stress is controlled through the ROS-ATM-p53 pathway and is conserved in human cells. Lpin1 provides a critical link between p53 and metabolism that may be an important component in mediating the tumor suppressor function of p53.     

Solvent-dependent intramolecular charge transfer dual fluorescence of p-dimethylaminobenzanilide bearing steric ortho,ortho-dimethyl substituents at amido aniline

Intramolecular charge transfer (ICT) dual fluorescence was observed in various organic solvents with p-dimethylaminobenzanilide (DMBA) derivatives bearing ortho-methyl (DMOMBA) and ortho,ortho-dimethyl (DMDMBA) substituents at amido aniline moiety. Ab initio calculation and absorption spectral data indicated that high steric hindrance was introduced by the ortho,ortho-dimethyl substitutions. It was found that, with DMDMBA, the CT emission initially shifted to the red with increasing solvent polarity from cyclohexane (CHX, 480 nm) to diethyl ether (DEE, 520 nm), similar to those of DMBA derivatives with the ortho-, meta- or para-methyl substitutions at amido aniline moiety. However, there is a characteristic blue-shift of the long wavelength emission between DEE and tetrahydrofuran (THF, 424 nm) then a bathochromic shift again in highly polar solvent acetonitrile (ACN, 484 nm). The unusual solvent-dependent CT emission was ascribed to two competitive CT channels. One is benzanilide (BA)-like CT, whose CT reaction occurs from amido aniline to benzoyl moiety in nonpolar solvent CHX and DEE; the other one is p-dimethylaminobenzamide (DMABA)-like, whose CT reaction occurs from dimethylamino to benzanilide moiety in highly polar solvent THF and ACN. These findings revealed the steric effect plays an important role in the ICT process, which may alter the properties of the electron donor and/or acceptor, but also change the reaction potential.     

Determination of trace carvedilol by solid substrate–room temperature phosphorimetry,based on its activating effect on hypochlorite‐oxidizing amaranth using sodium dodecyl benzene sulphonate as sensitizer

This work proposes a simple and sensitive solid substrate–room temperature phosphorimetry (SS–RTP) for the selective determination of carvedilol (CV). The method is based on the sensitizing effect of sodium dodecyl benzene sulphonate (SDBS) on CV to activate the oxidation between NaClO and amaranth, resulting in the intense quenching of room temperature phosphorescence (RTP) of the system. Compared with non‐SDBS system, the reduction of phosphorescence intensity (ΔI_p) with SDBS is 16.5 times higher and is directly proportional to the content of CV, covering a wide range 0.080–16.00 fg/spot. The regression equation of the working curve can be expressed as ΔI_p = 0.7780 + 7.057 m_CV (fg/spot) (correlation coefficient (r) = 0.9976, n = 8), with a detection limit (LD) of 0.020 fg/spot (corresponding concentration is 5.1 × 10⁻¹⁴ g/mL, sample volume is 0.40 μL/spot). This sensitive method has also been applied to determine trace CV in human plasma and the results agreed with synchronous fluorimetry (SF). The activation energy (E) and rate constant (k) of this activating reaction were 69.04 kJ/mol and 3.580 × 10⁻⁴ s⁻¹, respectively. The reaction mechanism is also discussed. Copyright © 2011 John Wiley & Sons, Ltd.