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1.
生态旅游研究方法综述   总被引:17,自引:0,他引:17  
全华 《生态学报》2004,24(6):1267-1278
生态旅游研究成为当前热门研究领域之一 ,但尚未形成自己独特的研究方法体系 ,缺乏深入研究的技术支撑。回顾近 2 0年生态旅游乃至旅游学科 ,使用过或具有应用前景的研究方法主要有 :定性描述方法、生态实验方法、环境监测方法、理化分析方法、数理统计方法、客流量测方法、抽样调查方法、图表分析方法、“3S”技术方法、图象数据分析处理、计算机模拟、数学建摸方法、会议研讨等等。首先从分析生态旅游研究方法构成出发 ,逐步剖析国内生态旅游研究方法的应用、国外研究方法及其演变、生态旅游实证研究等核心问题。简洁地勾勒出生态旅游研究方法的历史轨迹和现时轮廓。最后提出了生态旅游研究方法中出现的主要问题及方法论建设的措施 :(1)稳定并壮大锲而不舍的研究队伍 ;(2 )加强生态旅游特殊矛盾的针对性 ;(3)注重研究方法的可操作性 ;(4 )重复实验或检测已有方法的普适性 (5 )及时总结、研讨 ,不作重复研究。  相似文献   

2.
杨扇舟蛾的生物学特性及其防治方法   总被引:16,自引:0,他引:16  
杨树是世界上最有价值的树种之一,近年来杨扇舟蛾Clostera anachoreta(Fabricius)对之造成的危害日益突出,但是目前有关该害虫的综合报道尚十分少见。文献报道显示,该害虫在我国大部分省区都有不同程度地发生,每年大多发生4~5代,5~8月份的2龄和3龄幼虫危害最重,老熟幼虫结茧越冬;其天敌大约有30种以上。目前害虫的防治方法较多,主要包括人工消灭方法、诱杀方法、树干内外施药方法、微生物方法、寄生蜂方法、生物导弹方法以及农业智能专家系统辅助方法。其中微生物方法、生物导弹方法以及农业智能专家系统辅助方法具有十分广阔的应用前景。  相似文献   

3.
目的探讨高效建立小鼠心肌梗死模型的方法。方法分别采用右侧卧位及仰卧位两种方法来建立模型,通过观察心电图变化、检测cTNT、病理检测等方法来证明模型成功,并以比较其存活率、手术时间、出血量、肺损伤率等来评价两种方法的高效性。结果结扎后心肌局部变苍白,心电图ST-T段抬高,cTNT呈阳性,心肌纤维化,右侧卧位方法建模小鼠存活率显著提高。结论右侧卧位横切口开胸结扎冠脉是一种更高效的建模方法。  相似文献   

4.
旅游生态学研究方法评述   总被引:1,自引:0,他引:1  
晋秀龙    陆林   《生态学报》2008,28(5):2343-2343~2356
从旅游生态学的源起、发生和发展入手,通过大量旅游生态研究文献的分析,总结了旅游生态学4类主要研究方法,即:野外研究法,包括野外描述、野外对比和野外模拟等方法;空间分析研究方法,包括景观生态学、地理学及"3S"技术的空间分析等方法;生态环境评价研究方法,包括空气质量评价、旅游区生态容量评价和生态安全(风险)评价等方法;旅游生态管理方法,包括旅游地环境质量价值测算、旅游地规划设计和可持续旅游发展等方法.指出了旅游生态学研究方法存在着难以精确量化和指导性不强等缺限和不足,提出了进一步改进和完善的方向和途径.  相似文献   

5.
X、Y精子分离纯度评价方法的研究进展   总被引:2,自引:0,他引:2       下载免费PDF全文
郭家明  朱化彬  王栋  张林波  郝海生  杜卫华 《遗传》2008,30(9):1115-1120
对检测分析分离精液中X、Y精子纯度的方法进行了综述, 并将各种方法的原理、技术操作过程和方法的优缺点进行了比较分析。认为如能在技术上有所突破, 提高方法的灵敏度、精确性, 降低检测时间, 单精子巢式PCR方法将可能成为一种低成本、常规化的检测手段, 在精子分离方法优化研究中发挥更大的作用, 并推动其他单精子遗传检测技术取得新进展。  相似文献   

6.
基于物种的大尺度生物多样性热点研究方法   总被引:3,自引:1,他引:2  
生物多样性热点是建立保护区、制定保护决策的依据,是生物保护研究的热点问题之一。基于物种的研究方法是大尺度陆地生物多样性热点的主要研究方法,但数据的缺乏限制了直接根据物种丰富度确定热点的方法,因此研究中经常采用其他方法间接的反映物种情况,介绍了4种主要的基于物种的替代方法:指示种、高级分类单元、环境模型和景观异质性,详细阐述了各种方法存在的利弊,并从数据的可获取性、操作的便捷性和对物种特征的反映3个方面对各种方法进行了评价。任何单一的方法都无法准确反映出生物多样性热点的真实分布。合适的研究方法是权衡研究目的、时间和资金的结果,建议选择优势互补的多种方法。  相似文献   

7.
美国、加拿大环境和健康风险管理方法   总被引:2,自引:0,他引:2  
贺桂珍  吕永龙 《生态学报》2011,31(2):556-564
对目前美国和加拿大多个部门使用的风险评价与风险管理方法进行了全面回顾和综合分析,论述各种不同方法的特征,深入探讨各种管理方法的基础、利弊、使用经验,辨识环境、人类健康和职业健康风险综合方法中应该包含的要素,阐述风险管理目标的确定方法,以期为中国的环境风险管理提供经验。  相似文献   

8.
采用经验贝叶斯方法、非参数方法(刀切法和自助法)和种-面积曲线外推方法对北京东灵山地区5种类型植物群落的物种数目进行了估计,考察了这些方法的估计行为,从中得出如下结论:(1)只要抽样强度不是很小,经验贝叶斯方法就能给出群落物种数目很好的估计,但与非参数方法相比,其估计的标准差较大;(2)在适当的抽样强度下,非参数方法也能给出群落物种数目很好的估计。如果抽样强度过低,则估计值也偏低;相反,如果抽样强度过高,则估计值也偏高。但在各种抽样强度下,非参数方法估计的标准差都比经验贝叶斯方法的小;(3)种-面积曲线2、3、4、5、6可以给出群落物种数目较好的估计,曲线1的估计值偏高,而曲线7、8、9、10的估计值则偏低;(4)经过几种方法的综合比较,可以对群落1、2、3、4、5的各层及整个群落的物种数目分别做出如下估计;乔木层16、19、21、12、16,灌木层13、15、21、14、21,草本层49、46、54、82、55,整个群落79、80、96、107、92。  相似文献   

9.
microRNA计算发现方法的研究进展   总被引:5,自引:0,他引:5       下载免费PDF全文
侯妍妍  应晓敏  李伍举 《遗传》2008,30(6):687-696
microRNA (miRNA)是近几年发现的一类长度为~21 nt的内源非编码小RNA, 在植物和动物中发挥着重要而广泛的调控功能。它的发现主要有cDNA克隆测序和计算发现两条途径。由于cDNA克隆测序方法受miRNA表达的时间和组织特异性以及表达水平的影响, 而计算发现可以弥补其不足, 因此miRNA的计算发现方法研究受到了广泛的重视。文章对近几年计算发现miRNA的研究进展进行了综述, 根据计算发现方法的本质, 将计算发现方法归纳为5类, 分别是同源片段搜索方法、基于比较基因组学的预测方法、基于序列和结构特征打分的预测方法、结合作用靶标的预测方法和基于机器学习的预测方法, 并对各类方法的原理、核心思想、优点和局限性进行了分析, 最后探讨了进一步的发展方向。  相似文献   

10.
酒精使用障碍(alcohol use disorder, AUD)是一种与行为学、社会心理学和神经生物学等方面相关的神经精神疾病,也定义为酗酒和酒精依赖。由于AUD的诊断主要依赖于行为标准的判断,诊断具有复杂性,难以建立包含所有AUD特征的动物模型。本文对国内外相关文献总结归纳,将AUD模型分为强迫给药模型和自身给药模型,比较了两种模型所包含的酒精唯一饮用方法、酒精灌胃方法、酒精流食方法、慢性间歇性酒精蒸气暴露方法、两瓶选择方法、操作性自身给药方法的优缺点,从表观效度、预测效度和结构效度三方面对造模方法进行探究,以期为AUD研究者在动物造模方法的选择上提供有益参考。  相似文献   

11.
激光微切割与定量PCR技术分析肾脏病理切片RNA   总被引:1,自引:0,他引:1  
采用激光微切割与定量PCR技术,分析使用不同提取方法从不同固定方法固定的病理切片中提取的RNA.用70%乙醇、丙酮、甲醇、4%多聚甲醛固定肾脏冰冻切片,使用激光微切割技术切取肾小球,用硫氰酸胍方法(guanidinethiocyanatemethods,GTC)和Trizol试剂方法提取RNA,使用Taqman定量PCR方法分析比较各组RNA的量;选取丙酮固定的石蜡切片,使用激光微切割技术切取肾小球,采用RNA裂解液提取RNA,使用Taqman定量PCR方法,比较石蜡切片和冰冻切片中RNA含量.结果显示:提取沉淀性固定剂如乙醇、丙酮、甲醇固定的冰冻切片的RNA时,2种提取方法和3种固定方法对RNA含量的影响都无明显差异;但在提取4%多聚甲醛固定冰冻切片时,使用Trizol提取RNA含量明显高于使用GTC方法,且其含量与沉淀性固定剂固定的切片RNA含量无明显差异.石蜡切片中经激光微切割肾小球的RNA含量与冰冻切片经激光微切割肾小球的RNA含量无明显差异.结果提示:切片的固定方法和RNA的提取方法是影响切片RNA提取量的主要原因.  相似文献   

12.
Ribonucleases (RNases), which are essential for cleavage of RNA, may be cytotoxic due to undesired cleavage of RNA in the cell. The quest for small molecule inhibitors of members of the ribonuclease superfamily has become indispensable with a growing number exhibiting unusual biological properties. Thus, inhibitors of RNases may serve as potential drug candidates. Green tea catechins (GTC), particularly its major constituent (-)-epigallocatechin-3-gallate (EGCG), have reported potential against cell proliferation and angiogenesis induced by several growth factors including angiogenin, a member of the RNase superfamily. This study reports the inhibition of bovine pancreatic ribonuclease A (RNase A) by EGCG and GTC. This has been checked qualitatively by an agarose gel based assay. Enzyme kinetic studies with cytidine 2',3' cyclic monophosphate as the substrate have also been conducted. Results indicate substantial inhibitory activity of a noncompetitive nature with an inhibition constant of approximately 80 microM for EGCG and approximately 100 microM for GTC measured in gallic acid equivalents.  相似文献   

13.
Gentamicin-thallous-carbonate (GTC) medium contained (per liter): 40.0 g of Trypticase soy agar, 5.0 g of KH(2)PO(4), 2.0 g of NaHCO(2), 1.0 g of glucose, 1.0 g of esculin, 0.5 g of thallous acetate (TA), 0.5 g of ferric citrate, 0.75 ml of Tween 80, and 2.5 mg of gentamicin sulfate. The NaHCO(3) (20 ml of a 10% solution that had been heated to boiling) was added after sterilization of the basal medium. The spread plate technique was used to compare GTC agar with Pfizer selective enterococcus, TA, and KF agars by using sewage as well as bovine and swine fecal samples. Significantly greater numbers of group D streptococci were recovered on GTC agar than on Pfizer selective enterococcus or KF agars, within and over all samples. Higher counts also were obtained on GTC than on TA agar, but the differences were not statistically significant. The percentage of false positives was about the same for all four media. Samples of riverwater also were plated on GTC, TA, and KF agars, and significantly higher recoveries were obtained with GTC agar. GTC agar was superior to the other media examined primarily because of increased recoveries of Streptococcus bovis and S. equinus; other advantages of GTC agar were large colony size and short (24-h) incubation period. The percentage of false positives from riverwater was 13% for GTC agar and 0% for TA and KF agars; therefore, confirmation would be necessary when GTC agar is used with some types of environmental samples.  相似文献   

14.
Amyloid β (Αβ) has been reported to be responsible for the functional and structural abnormalities of Alzheimer's disease (AD) through the induction of oxidative stress. The aim of this study was to determine whether or not treatment of transgenic (Tg) mice with green tea catechin (GTC), a radical scavenger, improves AD phenotypes. To test this, 7-month-old Tg mice were treated with a low (1 mg) or high (10 mg) dose of GTC for 6 months. Surprisingly, GTC-treated Tg mice exhibited significant decreases in behavioral impairment, Aβ-42 production, APP-C99/89 expression, γ-secretase component and Wnt protein levels, γ-secretase activity and MAPK activation. In contrast, the levels of APP-C83 protein and enzyme activities (α-secretase, neprilysin and Pin1) were elevated in the GTC-treated groups. Moreover, GTC-treated groups showed lower levels of total cholesterol and low-density lipoprotein cholesterol, whereas the level of high-density lipoprotein cholesterol increased. These results provide the first experimental evidence that GTC improves AD phenotypes, thereby suggesting that GTC can be used in the prevention of AD or treatment of AD patients.  相似文献   

15.
Gentamicin-thallous-carbonate (GTC) medium contained (per liter): 40.0 g of Trypticase soy agar, 5.0 g of KH2PO4, 2.0 g of NaHCO2, 1.0 g of glucose, 1.0 g of esculin, 0.5 g of thallous acetate (TA), 0.5 g of ferric citrate, 0.75 ml of Tween 80, and 2.5 mg of gentamicin sulfate. The NaHCO3 (20 ml of a 10% solution that had been heated to boiling) was added after sterilization of the basal medium. The spread plate technique was used to compare GTC agar with Pfizer selective enterococcus, TA, and KF agars by using sewage as well as bovine and swine fecal samples. Significantly greater numbers of group D streptococci were recovered on GTC agar than on Pfizer selective enterococcus or KF agars, within and over all samples. Higher counts also were obtained on GTC than on TA agar, but the differences were not statistically significant. The percentage of false positives was about the same for all four media. Samples of riverwater also were plated on GTC, TA, and KF agars, and significantly higher recoveries were obtained with GTC agar. GTC agar was superior to the other media examined primarily because of increased recoveries of Streptococcus bovis and S. equinus; other advantages of GTC agar were large colony size and short (24-h) incubation period. The percentage of false positives from riverwater was 13% for GTC agar and 0% for TA and KF agars; therefore, confirmation would be necessary when GTC agar is used with some types of environmental samples.  相似文献   

16.
17.
AIMS: To characterize gram-positive, catalase-negative, psychrotrophic, lactic acid-homofermentative, non-motile cocci isolated from vacuum-packaged refrigerated beef using phenotypic and genotypic methods. METHODS AND RESULTS: A total of 89 strains was isolated at 2 and 6 weeks as one of the predominant microflora of five samples of vacuum-packaged beef stored at 2 degrees C. The strains were compared with reference strains of some gram-positive, catalase-negative cocci using SDS-PAGE whole-cell protein pattern analysis, biochemical characterization and 16S rDNA sequencing. The biochemical and physiological characteristics of the isolates resembled those of Lactococcus piscium GTC 552(T). Numerical analysis of the SDS-PAGE whole-cell protein patterns resulted in close clustering of the strains with L. piscium GTC 552(T) (r > 0.68). Other Lactococcus and Leuconostoc species could be distinguished from the isolates using SDS-PAGE whole-cell protein patterns (r < 0.58) and biochemical characteristics. The 16S rDNA sequencing of four randomly selected strains showed that the strains differed from L. piscium GTC 552(T) by two to three bases in the highly variable region of the sequence. This is the first report on the isolation of L. piscium from vacuum-packaged beef. CONCLUSIONS: The gram-positive catalase-negative cocci isolated from vacuum-packaged refrigerated beef have been identified as L. piscium. SIGNIFICANCE AND IMPACT OF THE STUDY: The findings of this work contribute to the knowledge of the microflora of vacuum-packaged refrigerated beef.  相似文献   

18.
The use of biosafety level 3 pathogens is an essential element of education and training at medical schools. We previously reported on invasion-defective strains of Salmonella enterica serovar Typhi, GTC 3P408 (DeltainvA, DeltasipB) and GTC 3P409 (DeltainvA, DeltasipB, and DeltaviaB), as candidates for use in educational programs. Vi negative strains of S. enterica serovar Typhi became extremely sensitive to complement attack but showed increased invasiveness. Therefore, this study was conducted to construct two virulencedefective strains, GTC 3P460 (DeltainvA, DeltasipB, and DeltarpoS) and GTC 3P461 (DeltainvA, DeltasipB, DeltaviaB, and DeltarpoS), of S. enterica serovar Typhi by deleting rpoS from the GTC 3P409 and GTC 3P408 strains. Stress tests demonstrated that GTC 3P460 and GTC 3P461 are sensitive to conditions of starvation, acid stress and oxidative stress. These results suggest that these virulence-defective strains have difficulty surviving in the gastric environment and in macrophages, characteristics that make them ideal candidates for education at level 2 facilities. Colony morphology and conventional biochemical features of these strains are identical to the parent strain S. enterica serovar Typhi GIFU 10007.  相似文献   

19.
We have previously reported that green tea catechins (GTC) showed an antithrombotic activity, which might be due to antiplatelet effect rather than anticoagulation. The present study was performed to investigate the effect of GTC on the arachidonic acid (AA) metabolism in order to elucidate a possible antiplatelet mechanism. GTC inhibited the collagen-, AA- and U46619-induced rabbit platelet aggregation in vitro in a concentration-dependent manner, with IC50 values of 61.0+/-2.5, 105.0+/-4.9 and 67.0+/-3.2 microg/ml, respectively. Moreover, GTC administered orally into rats inhibited the AA-induced platelet aggregation ex vivo by 46.9+/-6.1% and 95.4+/-2.2% at the doses of 25 and 50 mg/kg, respectively. [3H]AA liberation induced by collagen in [3H]AA incorporated rabbit platelets was significantly suppressed by GTC compared to the control. GTC also significantly inhibited the thromboxane A2 (TXA2) and prostaglandin D2 (PGD2) generations induced by addition of AA in intact rabbit platelets. GTC significantly inhibited TXA2 synthase activity in a concentration-dependent manner. Moreover, adenosine triphosphate (ATP) release from dense granule was inhibited by GTC in washed platelets. These results suggest that the antiplatelet activity of GTC may be due to the inhibition of TXA2 formation through the inhibition of AA liberation and TXA2 synthase.  相似文献   

20.
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