林业资源型城市生态-经济-社会协调发展的定量测度——以黑龙江省伊春市为例

把握城市独特的生态-经济-社会系统协调优化特性是实现林业资源型城市可持续发展的重要前提。研究从生态、经济、社会3个维度构建了林业资源型城市复合系统的测度评价指标体系,应用熵值法、耦合协调度模型,采用2005-2018年时段生态、经济、社会数据,对伊春协调发展状况进行实证测度评价,运用障碍度模型分析影响系统协调发展的主要因素,采用GM （1,1）灰色预测模型进行发展预测。结果表明：（1）综合发展指数呈上升态势,促进生态-经济-社会综合发展的主要动能历经了从生态到经济,再到生态为主要动力的发展过程,三个子系统发展水平呈趋同态势,推动三维系统的均衡协同是未来发展的重要方向;（2）三维系统耦合度稳定在较高水平,系统间相互依赖、相互作用程度较高,协调度呈波动上升,实现了由勉强协调、经济滞后发展向良好协调、同步发展的转变,协调状态趋向良好;（3）三维系统中社会子系统对协调发展的障碍度最大;人口自然增长率、建成区绿化覆盖率、GDP增长率、第三产业就业人数比重4个指标是制约近期协调发展的主要障碍因子;（4）2019-2030年,生态、经济、社会子系统发展指数及协调度的预测值均呈上升态势,生态-经济-社会复合系统将向更高级的协调发展状态演进,经济发展将再次成为促进生态-经济-社会综合发展的主要动力;加强生态建设,引领生态创新,大力发展生态经济,提高社会发展水平,着力降低障碍因子对协调发展的阻力作用,实现生态-经济-社会的联动健康发展是伊春未来重要的努力方向。     

Thermoanaerobacter thermohydrosulfuricus WC1 Shows Protein Complement Stability during Fermentation of Key Lignocellulose-Derived Substrates

Thermoanaerobacter spp. have long been considered suitable Clostridium thermocellum coculture partners for improving lignocellulosic biofuel production through consolidated bioprocessing. However, studies using “omic”-based profiling to better understand carbon utilization and biofuel producing pathways have been limited to only a few strains thus far. To better characterize carbon and electron flux pathways in the recently isolated, xylanolytic strain, Thermoanaerobacter thermohydrosulfuricus WC1, label-free quantitative proteomic analyses were combined with metabolic profiling. SWATH-MS proteomic analysis quantified 832 proteins in each of six proteomes isolated from mid-exponential-phase cells grown on xylose, cellobiose, or a mixture of both. Despite encoding genes consistent with a carbon catabolite repression network observed in other Gram-positive organisms, simultaneous consumption of both substrates was observed. Lactate was the major end product of fermentation under all conditions despite the high expression of gene products involved with ethanol and/or acetate synthesis, suggesting that carbon flux in this strain may be controlled via metabolite-based (allosteric) regulation or is constrained by metabolic bottlenecks. Cross-species “omic” comparative analyses confirmed similar expression patterns for end-product-forming gene products across diverse Thermoanaerobacter spp. It also identified differences in cofactor metabolism, which potentially contribute to differences in end-product distribution patterns between the strains analyzed. The analyses presented here improve our understanding of T. thermohydrosulfuricus WC1 metabolism and identify important physiological limitations to be addressed in its development as a biotechnologically relevant strain in ethanologenic designer cocultures through consolidated bioprocessing.     

太行山东北部哺乳动物区系及多样性

为研究太行山东北部的哺乳动物区系及多样性格局, 2019年7月1日至10月30日间, 作者采用样线调查和红外相机监测、访谈、文献查阅等多种方法, 对该区域的哺乳动物进行调查, 分析了区系构成, 并基于多样性指数比较了太行山片区和燕山片区哺乳动物多样性及动物分布型的差异。结果表明: 太行山东北部区域分布有哺乳动物7目22科68种, 其中啮齿目种类最多(24种), 灵长目最少, 仅猕猴(Macaca mulatta) 1种; 区域内分布有2种国家I级(金钱豹Panthera pardus、豺Cuon alpinus)和10种国家II级重点保护野生动物。太行山片区和燕山片区的哺乳动物区系的平均动物区系相似性(average faunal resemblance)系数为0.844, 相似性较大, 太行山片区的哺乳动物种数(66)高于燕山片区(50), 其科的多样性指数(D_F= 2.994 ± 0.251, n = 13)和属的多样性指数(D_G = 2.443 ± 0.161, n = 13)也略高于燕山片区(D_F = 2.458 ± 0.170, D_G = 2.259 ± 0.149, n = 10), 但无显著差异(P> 0.05)。太行山片区哺乳动物G-F指数(D_G-F= 0.145 ± 0.022, n = 13)显著高于燕山片区(0.078 ± 0.014, n = 10) (P< 0.05)。研究结果表明, 太行山片区和燕山片区的哺乳动物的科、属组成相同, 但太行山片区的物种多样性高于燕山片区; 太行山东北部区域分布的哺乳动物以古北界物种为主, 太行山片区和燕山片区均有10类动物分布型的哺乳动物; 因太行山片区的纬度相对较低, 其东洋界物种比例(19.11%)略高于燕山片区(17.64%)。     

Gastrointestinal Hyperplasia with Altered Expression of DNA Polymerase β

Background

Altered expression of DNA polymerase β (Pol β) has been documented in a large percentage of human tumors. However, tumor prevalence or predisposition resulting from Pol β over-expression has not yet been evaluated in a mouse model.

Methodology/Principal Findings

We have recently developed a novel transgenic mouse model that over-expresses Pol β. These mice present with an elevated incidence of spontaneous histologic lesions, including cataracts, hyperplasia of Brunner''s gland and mucosal hyperplasia in the duodenum. In addition, osteogenic tumors in mice tails, such as osteoma and osteosarcoma were detected. This is the first report of elevated tumor incidence in a mouse model of Pol β over-expression. These findings prompted an evaluation of human gastrointestinal tumors with regard to Pol β expression. We observed elevated expression of Pol β in stomach adenomas and thyroid follicular carcinomas, but reduced Pol β expression in esophageal adenocarcinomas and squamous carcinomas.

Conclusions/Significance

These data support the hypothesis that balanced and proficient base excision repair protein expression and base excision repair capacity is required for genome stability and protection from hyperplasia and tumor formation.     

A paleosol record of the evolution of Cr redox cycling and evidence for an increase in atmospheric oxygen during the Neoproterozoic

Atmospheric oxygen levels control the oxidative side of key biogeochemical cycles and place limits on the development of high‐energy metabolisms. Understanding Earth's oxygenation is thus critical to developing a clearer picture of Earth's long‐term evolution. However, there is currently vigorous debate about even basic aspects of the timing and pattern of the rise of oxygen. Chemical weathering in the terrestrial environment occurs in contact with the atmosphere, making paleosols potentially ideal archives to track the history of atmospheric O₂ levels. Here we present stable chromium isotope data from multiple paleosols that offer snapshots of Earth surface conditions over the last three billion years. The results indicate a secular shift in the oxidative capacity of Earth's surface in the Neoproterozoic and suggest low atmospheric oxygen levels (<1% PAL pO₂) through the majority of Earth's history. The paleosol record also shows that localized Cr oxidation may have begun as early as the Archean, but efficient, modern‐like transport of hexavalent Cr under an O₂‐rich atmosphere did not become common until the Neoproterozoic.     

棉铃虫的谷胱甘肽S-转移酶(GSTs):杀虫药剂和植物次生性物质的诱导与GSTs对杀虫药剂的代谢

棉铃虫Helicoverpaarmigera（Hubner）中肠谷胱甘肽S-转移酶（GSTs）对甲基对硫磷和灭多威的代谢能力明显高于对马来酸二乙酯（DEM）和两个混剂。LD5剂量的对硫磷和灭多威对棉铃虫3龄幼虫GSTs的活性均没有诱导增加的影响,用LD50的选择剂量仅对硫磷组GSTs活性增加15％。用含0．01％的芸香苷、2-十三烷酮和槲皮素的人工饲料饲养棉铃虫经1～4代后,GSTs活性提高4～18倍。3种植物次生性物质诱导组对灭多威和溴氰菊酯的敏感度均没有明显的变化,而槲皮素组对甲基对硫磷的敏感度则降低近一半,芸香苷和2-十三烷酮组对甲基对硫磷的敏感度略有降低。这种对甲基对硫磷敏感度的变化可能与上述GSTs活性的变化有关。