Weed biological control: applying science to solve seemingly intractable problems

Abstract   Exotic weeds pose a problem of considerable economic and environmental importance to Australia. As a consequence, Australia has developed into a leading centre of research on weed biological control, with over 60 weeds the targets of past and current projects. Using primarily entomological examples, this review highlights the contributions made by Australian scientists to the development of theory and the improvement of practice in weed biological control. It also shows how biological control practitioners have made use of, and contributed to, broader theory and knowledge of plant-herbivore relationships. Finally, it concludes with some reflections on the future direction of biological control in Australia.     

93例糖尿病住院患者的营养状况评价

对糖尿病住院患者入院时进行营养评价,分别对93例30～60岁糖尿病患者入院时做人体测量和生化检查,与正常人群作对照.结果显示,观察组患者的体质量、体质指数、总蛋白、白蛋白、低密度酯蛋白以及三酰甘油的平均值均高于正常组、而高密度脂蛋白低于正常组,差异有显著性意义(p＜0.05).结果表明,采用多项综合指标评价糖尿病患者的...     

沙坡头地区人工林生态系统健康的评价分析

生态系统健康是生态环境管理的一个新问题。健康的生态系统意味着生态系统能正常发挥功能,实现生态系统的最佳服务。生态系统健康可以通过活力、组织和恢复力3个特征来测定。以沙区植物为研究对象,选择植物的新生枝长、株高、基径、冠幅和水分生态位适宜度等,作为评价生态健康的主要指标,建立了新的评价方法。依据试验进行计算,结果表明：油蒿与柠条混播下,具有较高的健康指数;单播情况下,以密度为2500株／hm^2的柠条样地具有较高的健康指数。该结果为沙区人工植被生态健康与可持续发展提供定量依据。     

川渝77县长防林(一期)工程的综合效益评价与分析

本文利用中国生态林业工程综合评价指标体系对川渝77县长防林一期工程的效益进行了综合评价。迄今综合效益提高了6倍,到2010年提高约9倍。还对川江各支流的林分结构调整与新建长防林提出了建议。     

城市森林公园景观环保型林相改造模式比较及评价——以老山国家森林公园为例

以实现景观和环保2项功能为主要目标,对老山国家森林公园的4类群落林相进行改造,分别将马尾松(Pinus massoniana)纯林群落(A1)、朴树(Celtis sinensis)纯林群落(B1)、水杉-侧柏(Metasequoia glyptostroboides-Platycladus orientalis)针叶混交林群落(C1)和以落叶树为主的麻栎-朴树(Quercus acutissima-Celtis sinensis)阔叶混交林群落(D1)改造成马尾松-锦绣杜鹃(P.massoniana-Rhododendron pulchrum)群落(A2)、朴树-乌桕-桂花-枸骨-红叶石楠-绵枣儿(C.sinensis-Sapium sebiferum-Osmanthus fragrans-Ilex cornuta-Photinia×fraseri‘Red Robin’-Scilla scilloides)混交林群落(B2)、水杉-侧柏-枫香树-构树-棕榈-阔叶山麦冬(M.glyptostroboides-P.orientalis-Liquidambar formosana-Broussonetia papyrifera-Trachycarpus fortunei-Liriope platyphylla)针阔叶混交林群落(C2)和以常绿树为主的麻栎-朴树-香樟-女贞-桂花-凤尾丝兰-海桐-阔叶山麦冬-络石(Q.acutissima-C.sinensis-Cinnamomum camphora-Ligustrum lucidum-Osmanthus fragran-Yucca gloriosa-Pittosporum tobira-Liriope platyphylla-Trachelospermum jasminoides)阔叶混交林群落(D2)。应用层次分析法(AHP),从群落结构和群落效益2方面,选取郁闭度、物种丰富度、构景层次、树冠水平投影重叠面积、常绿落叶比、吸收有害气体能力、滞尘与杀菌能力、季相变化、景观优美度和游憩资源10项评价指标,根据各指标的权重和赋值建立了城市森林公园景观环保型林相改造模式的评价体系。评价结果显示:改造后的群落林相各项指标得分值及综合评分值均高于改造前的群落,特别是群落D2的构景层次、季相变化与景观优美度最佳,对环境的净化功能最强,实现了景观与环境保护的有机结合。结果表明:城市森林公园景观环保型群落模式改造既要考虑植物自身的生理生态特征,也要注重植物的个体美与群体美等因素。     

湿地功能评价的尺度效应——以盐城滨海湿地为例

湿地功能与空间尺度大小有着密切的联系,研究湿地功能的空间尺度效应对从功能上指导湿地系统的空间保护与管理工作有着重要意义。文章借助生态位理论构建了湿地功能的生态经济位评价模型,并以四个不同空间尺度为评价单元,探讨盐城滨海湿地功能评价的空间尺度响应特征。结果表明：随着评价尺度变大,高生态功能和高经济功能湿地面积表现为减少且减幅不断加大,较低和较高功能级别的湿地面积则随着尺度的变大而成倍增加;各功能级别湿地的空间形态也随之变化,且较低和较高功能级别的湿地空间扩展形态变化尤为突出;其原因是评价单元的变化,改变了单元内的地类结构,从而使其对应的某个湿地功能的主导优势地位发生了变化。研究结论表明大尺度评价结果更符合盐城滨海湿地“滚动开发”模式的特点,在湿地功能区划和湿地资源利用规划与管理方面更具有指导意义。     

The effects of orientation, temperature, and displacement magnitude changes on the sonometrics system accuracy

The accuracy and reliability of a sonomicrometry system (Sonometrics Corporation, Ontario, Canada) was evaluated for its potential use in measuring 3-D in vivo joint kinematics. Distances between different sets of piezoelectric crystals were measured through a salt solution using ultrasound technology. We evaluated crystal-to-crystal distance under simulated in vivo conditions of changing crystal orientation and displacement magnitude. Crystal-to-crystal distance was also evaluated under changing solution temperature, since the crystals may be used at different temperatures. The 2 mm round and peg crystals were accurate to within 0.5mm for 0 through 180 degrees rotations, but the 2mm round suture loop crystals were only reliable at 0 degrees rotation. The speed of sound through a salt solution (and hence the distance between crystals) versus temperature was fit using a second order polynomial, C=1421.1+3.9808T-3.09x10(-2)T2, with an R2 value of 0.9998. The translational error was less than 0.072 mm for crystal displacements of 0.012, 0.2, 1.0, and 5.0 mm. The system was also accurate under dynamic conditions with translational errors that were less than 0.045 mm under 0.65 Hz motion. These results suggest that the Sonometrics crystals possess attributes (translational accuracy and rotational independence) that could provide the basis for a system capable of measuring joint kinematics.     

重点脆弱生态区生态恢复综合效益评估指标体系

生态恢复是扭转由人类活动引起的生态环境退化和生物多样性损失,并保证生态系统服务可持续供给的一项主要战略措施。20世纪90年代以来我国针对重点脆弱生态区(北方风沙区、黄土高原区、西北干旱区、青藏高原区和西南喀斯特地区)实施了一系列的生态恢复工程。科学合理地评估重点脆弱生态区生态恢复综合效益,对生态恢复措施的进一步优化调整具有重要的理论与实践意义。然而,在重点脆弱生态区生态恢复综合效益评估的集成研究方面,由于缺乏统一的指标体系,阻碍了区域内综合性和长期性的生态恢复综合效益评估和监测,因此亟需构建一套面向我国重点脆弱生态区的生态恢复综合效益评估指标体系。以我国5个重点脆弱生态区为研究区,根据"生态恢复-生态系统结构-质量-服务-效益"级联式概念框架,在指标筛选原则和方法的指导下,参考现有的生态恢复评估成果,构建科学化、系统化和规范化的生态恢复综合效益评估指标体系。研究结果以期为重点脆弱生态区生态恢复评估研究和管理应用提供理论与技术支撑。     

Synthesis of 3‐Methylidene‐1‐tosyl‐2,3‐dihydroquinolin‐4(1H)‐ones as Potent Cytotoxic Agents

An efficient synthetic strategy to 3‐methylidene‐2,3‐dihydroquinolin‐4(1H)‐ones variously substituted in position 2 has been developed. The title compounds were synthesized in the reaction sequence involving reaction of diethyl methylphosphonate with methyl 2‐(tosylamino)benzoate, condensation of thus formed diethyl 2‐oxo‐2‐(2‐N‐tosylphenyl)ethylphosphonate with various aldehydes followed by successful application of the obtained 3‐(diethoxyphosphoryl)‐1,2‐dihydroquinolin‐4‐ols as Horner–Wadsworth–Emmons reagents for the olefination of formaldehyde. Also, enantioselective approach to the target compounds has been evaluated using 3‐dimenthoxyphosphoryl group as a chiral auxiliary. Single X‐ray crystal analysis of (2S)‐3‐(dimenthoxyphosphoryl)‐2‐phenyl‐1‐tosyldihydroquinolin‐4‐ol revealed the presence of strong resonance‐assisted hydrogen bond (RAHB). The obtained 3‐methylidene‐2,3‐dihydroquinolin‐4(1H)‐ones were then tested for their cytotoxic activity against two leukemia cell lines NALM‐6 and HL‐60 and a breast cancer MCF‐7 cell line. All compounds showed very high cytotoxic activity with the IC₅₀ values mostly below 1 μm in all three cancer cell lines. The selected analogs were also tested on human umbilical vein endothelial cells (HUVEC) and on human mammary gland/breast cells (MCF‐10A) to evaluate their influence on normal cells. Since one of the most serious problems in cancer chemotherapy is the development of drug resistance, the mRNA levels and activity of ABCB1 transporter considered to be the most important factor engaged in drug resistance, were evaluated in MCF‐7 cells treated with two selected analogs. Both compounds were strong ABCB1 transporter inhibitors that could prevent efflux of anticancer drugs from cancer cells.     

卒中后疲劳的最新研究进展

脑卒中是仅次于缺血性心脏病位于全球第二位导致死亡的疾病,通常遗留神经功能缺损症状,需要一个长期的康复过程,而卒中后疲劳(PSF)是卒中患者的常见症状,显著影响患者的康复治疗及远期预后。卒中后疲劳发病率高,机制尚未明确,受多因素共同作用,然而一直以来并未得到医护人员及卒中患者的足够重视,目前对卒中后疲劳的相关研究甚少,缺乏有效的治疗方法。本文就卒中后疲劳的定义、发病率、诊断与评估、影响因素、发病机制及治疗统一做一综述,以增进临床医师对其了解,指导患者的康复治疗。