蜡梅研究进展

对1992—2008年蜡梅类植物的研究成果进行了分析。在此基础上,从种质资源、形态分类、繁殖栽培、新品种选育、生物学特性、化学成分研究以及蜡梅的园林用途、切花保鲜等方面进行了论述,并对今后一段时期研究的重点提出了建议。     

独特的大果青杄群落吸引国际保护组织关注

湖北省保康县歇马镇施家沟村三组肖洞坡分布有一个举世独特、绝无仅有的大果青杄群落,其面积约有6hm2,总数约1000～1500株,年龄为1～300年,呈现不同龄级。其中包括132株高30m、胸径40cm以上的大树。近年来,这一群落已引起中外学者和专家的关注,当地被认为很有可能是大果青杄的残遗中心。     

Frequent mutation of BAP1 in metastasizing uveal melanomas

Metastasis is a defining feature of malignant tumors and is the most common cause of cancer-related death, yet the genetics of metastasis are poorly understood. We used exome capture coupled with massively parallel sequencing to search for metastasis-related mutations in highly metastatic uveal melanomas of the eye. Inactivating somatic mutations were identified in the gene encoding BRCA1-associated protein 1 (BAP1) on chromosome 3p21.1 in 26 of 31 (84%) metastasizing tumors, including 15 mutations causing premature protein termination and 5 affecting its ubiquitin carboxyl-terminal hydrolase domain. One tumor harbored a frameshift mutation that was germline in origin, thus representing a susceptibility allele. These findings implicate loss of BAP1 in uveal melanoma metastasis and suggest that the BAP1 pathway may be a valuable therapeutic target.     

高产苜蓿的种植与收获技术研究

苜蓿是具有高产潜力的多年生豆科牧草,不用氮肥就可达到高产生产。苜蓿生产中应及时去除杂草,控制生长阶段肥力和虫害以获取高产,并及时收割保证优质。阐述高产苜蓿的种植和收获技术及其经济价值。     

Synchronizing rock clocks of Earth history

Calibration of the geological time scale is achieved by independent radioisotopic and astronomical dating, but these techniques yield discrepancies of approximately 1.0% or more, limiting our ability to reconstruct Earth history. To overcome this fundamental setback, we compared astronomical and 40Ar/39Ar ages of tephras in marine deposits in Morocco to calibrate the age of Fish Canyon sanidine, the most widely used standard in 40Ar/39Ar geochronology. This calibration results in a more precise older age of 28.201 +/- 0.046 million years ago (Ma) and reduces the 40Ar/39Ar method's absolute uncertainty from approximately 2.5 to 0.25%. In addition, this calibration provides tight constraints for the astronomical tuning of pre-Neogene successions, resulting in a mutually consistent age of approximately 65.95 Ma for the Cretaceous/Tertiary boundary.     

园林植物抗旱性研究进展

干旱是主要的环境胁迫因子之一,严重影响了植物的分布与生长发育,研究和探索植物的抗旱性已经成为众多研究者关注的焦点。从干旱胁迫下植物的形态结构特征、生长状况、生理生化反应等方面综述了园林植物抗旱性的研究进展,并在此基础上提出今后的研究重点。     

大豆抗原蛋白对草鱼肌肉营养成分的影响

以健康的初始体质量(50.66±0.26)g草鱼(Ctenopharyngodon idellus)为试验对象,在室内[(19±3)℃]单循环控温养殖系统中进行6周饲养试验,以鱼粉为对照组,β-伴大豆球蛋白的添加量为40 mg/g,大豆球蛋白的添加量为60 mg/g,配制成3种等氮(粗蛋白质量分数为30%)、等能(15.6 MJ/kg)的半精制饲料,探讨大豆主要抗原蛋白对草鱼肌肉主要营养成分的影响。结果表明:大豆主要抗原蛋白使草鱼肌肉中粗蛋白含量极显著下降(P0.01),对肌肉中水分、粗脂肪、粗灰分、氨基酸总量、必需氨基酸总量和鲜味氨基酸总量影响不显著(P0.05)。可见,在本试验条件下,草鱼配合饲料蛋白水平为30%时,在其配合饲料中分别添加β-伴大豆球蛋白(40 mg/g)和大豆球蛋白(60 mg/g)显著影响了草鱼肌肉中粗蛋白的含量。     

高吞吐量协作防火墙的双向去冗余方法

针对协作防火墙中冗余规则会降低其吞吐量的问题,提出一种基于双向去冗余的高吞吐量协作防火墙优化方法.该方法通过比对协作防火墙中双方的防火墙规则,双向去除域内防火墙之间的冗余规则,提高整个协作防火墙的数据包过滤能力.仿真实验结果表明,该方法的冗余率达到了22.7%,提高了8.2%吞吐量,明显优于已有协作防火墙优化方法.     

EVALUATION OF POTENTIAL SUBSTRATES TO MONITOR RESPIRATORY NITRATE REDUCTASE ACTIVITY IN SOILS

Different inorganic ions were tested for their ability to replace nitrate as the terminal oxidant for bacterial respiration in anaerobic soils. Chlorate, bromate. selenate. tellurite and ferric ions were all unsuitable substitutes, lodate reduction in soils was similar to nitrate reduction because it required anaerobic conditions, was increased by glucose amendment and decreased by phenylmercuric acetate. Amendment of soils with iodate and measurement of iodide production can be used to measure nitrate reductase activity in a soil and so give a qualitative indication, and possibly a quantitative estimate, of the denitrification capacity of soils.     

Immunohistochemical study on changes in gill Na+/K+-ATPase α-subunit during smoltification in the wild masu salmon, Oncorhynchus masou

Changes in immunoreactivity of Na⁺/K⁺-ATPase -subunit in gill sections of wild masu salmon (Oncorhynchus masou) during the parr-smolt transformation (smoltification) were compared with changes in gill Na⁺/K⁺-ATPase specific activity. Gill Na⁺/K⁺-ATPase specific activity increased from April and peaked in May. Immunohistochemical analysis, using an antiserum against a synthetic oligopeptide based on the conserved region of the Na⁺/K⁺-ATPase -subunit, revealed that immunoreactivity was confined to chloride cells in the surface layer of primary lamellae and the proximal end of secondary lamellae. The size and number of these cells increased gradually from February to May; however, the number of chloride cells of the secondary lamellae decreased in May. These data suggest that the synthesis of Na⁺/K⁺-ATPase and the proliferation of chloride cells occur prior to the elevation of enzyme activity. Moreover, it is likely the proliferation and hypertrophy of chloride cells on primary lamellae prepare smolts for entry into seawater and migration in the ocean.