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21.
Deryabuyi, a small isolated town in the Takla Makan desert in Xinjiang, China, is viewed from the perspective of its rural economy. The minority Uyghur inhabitants are similar to other rural minority communities in China. In particular, focus is placed on the digging of rabbit carrots, a medicinal herb that grows on the roots of mesquite trees. Just as the Tibetan caterpillar-fungus collection has brought cash, and problems, to rural Tibetans, the collection of rabbit carrots has brought cash to Deryabuyi. However, the loss of the ability to engage in sustainable economic activities due to environmental degradation, loss of grazing land, overharvesting of scarce resources, diversion of water resources, government neglect along with scarce and/or inadequate social services such as health care and education, and job discrimination among others, may mean the destruction of this unique cultural community. As such, Deryabuyi can be seen as a microcosm of the challenges facing rural minorities in Xinjiang and in other parts of China.  相似文献   
22.
目的研究DNA降解过程中STR基因座与性别基因座Amelogenin(AMEL)峰面积比(STR/AMEL)的变化规律,探讨STR/AMEL值在评估DNA降解程度中的应用。方法取人体髂腰肌组织抽提DNA,分析DNaseⅠ酶人工降解后STR/AMEL值(Penta E/AMEL、Penta D/AMEL、FGA/AMEL)的变化,并分析室外环境自然降解的髂腰肌组织中三者比值的变化。以降解时间为自变量(x),STR/AMEL值为因变量(y),进行回归曲线分析,建立两种条件下三组曲线方程。结果人工降解及自然降解条件下STR/AMEL值与降解时间均呈负相关,一元三次方程能够较好地模拟STR/AMEL值随降解时间的变化规律。人工降解条件下,R~2均大于0.99;自然降解条件下,R~2均大于0.86。结论 STR/AMEL值(Penta E/AMEL、Penta D/AMEL、FGA/AMEL)与DNA降解程度呈负相关,有望应用于DNA降解程度的评估。  相似文献   
23.
Shu XJ  Liu LJ  Hu JW 《法医学杂志》2004,20(3):140-142
目的运用图像分析技术探讨人脾脏细胞核几何参数变化与死亡时间的关系。方法选31例已知死亡时间的人离体脾组织,在死后36h内每h细胞学涂片、Feulgen-Vans染色,对人脾细胞核的异形指数等5个几何参数进行图像分析。结果脾脏细胞核异形指数在死后5~36h呈上升趋势,r=0.983,线性回归方程y=11.334x-33.339,面积、等效直径、平均直径、周长均与死亡时间无明显的相关性。结论异形指数能较客观地反映人脾细胞核DNA降解后的离散分布状况,与死亡时间有明显相关性,可能是推断早期准确死亡时间的较好形态学指标。  相似文献   
24.
侗族大歌赖以产生的生态环境及其嬗变与保护   总被引:14,自引:0,他引:14  
本文运用生态学理念对侗族大歌赖以产生的环境、嬗变与保护进行了实证的分析与研究。我们认为,侗族大歌的产生和传承与其自然的和人文的生态环境密切相关,生态环境的变化诸如语言的改变、传承的断裂和传承载体的变化以及经济社会的发展,引发大歌的历史嬗变和濒临失传的危险。据此,作者从用生态保护的理念、对大歌进课堂的再认识和定位、培养专业创作人员和大歌名人、构建大歌文化产业机构等方面,提出了对侗族大歌进行保护的思路与视角。  相似文献   
25.
彗星试验检测死后DNA降解推断PMI的参数选择研究   总被引:1,自引:0,他引:1  
目的筛选出彗星试验检测死后DNA降解推断死亡时间(PMI)的合适彗星参数。方法大鼠断颈处死后置于10℃和20℃环境中44h,每4h取材脑和骨髓组织制成细胞悬液进行彗星电泳,CASP软件测量彗星参数,线性回归分析和比较各参数与PMI的相关关系。结果死后DNA随PMI的延长逐渐降解,彗星头和尾DNA百分比、尾DNA、Olive尾矩、尾面积、尾矩等参数与PMI呈稳定的线性相关关系。结论彗星头和尾DNA百分比、尾DNA、Olive尾矩、尾面积、尾矩等参数是彗星试验检测死后DNA降解推断PMI的合适参数。  相似文献   
26.
死亡方式对大鼠DNA降解影响的图像分析研究   总被引:1,自引:1,他引:0  
探讨不同的死亡方式对组织细胞核 DNA 降解的速率是否存在影响。选取20只大鼠随机分为4组,分别采用失血性休克、断颈、溺死及扼死等4种方式处死,每2 h 取材一次(脑、脾、肝组织),Carnoy 液固定,VANS 改良法染色,选取7个指标进行图像分析,数据经一元回归及多元回归统计处理,对不同死亡方式组的一元回归方程进行多组间分析。结果显示,7个指标与死亡时间明显相关,但在不同死亡方式组间各指标相关性存在差异,一元回归方程比较显示,溺死组与其他组肝组织 ID、AOD、LDC 3个指标存在差异,显示其 DNA 降解较慢,脾脏在溺死组 A、MD、ID、AOD、LDC、AG 等6个指标以及失血性休克组 MD、ID、AOD、AG 等4个指标与其他组间存在明显差异,而脑组织在不同组间则差异较小。多元回归分析进一步印证了上述差异。在失血性休克、溺死、断颈及扼死致死的尸体间其组织细胞 DNA 降解速率存在差异,其原因可能与淤血程度及尸体所处环境有关。在本实验条件下,脑是受影响最小的器官,而脾是较易受影响的器官。  相似文献   
27.
Following forensic DNA profiling (extraction, quantification and STR typing) the remaining extract is generally stored frozen. Our routine at the Swedish National Forensic Centre is to immediately after analysis freeze the sample. If a subsequent reanalysis is needed the sample is thawed and then refrozen. In this study the effects of freezing and thawing as well as long-term storage of DNA extracts in refrigerator or freezer have been investigated. The following sample types were extracted: two levels of blood and saliva, saliva on cigarette filter paper, saliva on cotton swabs and a combination of saliva and semen to mimic samples from sexual assaults. All extraction methods used were Chelex-based, DNA quantification was performed using PowerQuant System and STR profiling with PowerPlex ESX 16 Fast System. The study was divided into three parts: 1) freezing and thawing the extracts up to ten times, 2) storage in refrigerator or freezer up to four weeks and 3) long-term storage in refrigerator or freezer for 3, 6, 9, 12 and 35 months. Generally, the quantification and STR typing results show no indication of degradation after repeated freezing and thawing or long-term storage in refrigerator or freezer.  相似文献   
28.
Identification of cocaine and subsequent quantification immediately after seizure are problems for the police in developing countries such as Brazil. This work proposes a comparison between the Raman and FT‐IR techniques as methods to identify cocaine, the adulterants used to increase volume, and possible degradation products in samples seized by the police. Near‐infrared Raman spectra (785 nm excitation, 10 sec exposure time) and FT‐IR‐ATR spectra were obtained from different samples of street cocaine and some substances commonly used as adulterants. Freebase powder, hydrochloride powder, and crack rock can be distinguished by both Raman and FT‐IR spectroscopies, revealing differences in their chemical structure. Most of the samples showed characteristic peaks of degradation products such as benzoylecgonine and benzoic acid, and some presented evidence of adulteration with aluminum sulfate and sodium carbonate. Raman spectroscopy is better than FT‐IR for identifying benzoic acid and inorganic adulterants in cocaine.  相似文献   
29.
徐威  车向明 《法医学杂志》1996,12(1):17-18,16
本文研究了灌服短柄乌头(AconitumbrachypodumDiels,简称AbD)后,乌头碱(A-conitine,简称AC)在4℃保存兔厂中的降解动力学规律。结果显示,乌头碱在克厂中的降解符合表观二级动力学过程,乌头碱在肝、肾中的降解动力学方程分别为:C-1(肝)=0.0339(t—5)+0.1918,c-1(肾)=0.0788(t—5)+0.5176,其半衰期分别为5.66和6.57天。  相似文献   
30.
Manufactured fibers derived from natural origins include viscose rayon, azlon, and polylactic acid (PLA). A 2‐year study was conducted to document any changes these fibers undergo as a result of exposure to various environmental conditions. Fabric swatches representing each fiber type were exposed to freshwater, saltwater, heat, cold, ultraviolet light, or composter conditions. Fibers from the swatches were periodically analyzed using polarized light microscopy and Fourier transform infrared microspectroscopy. Fiber solubility and melting‐point behavior were measured every 6 months. Except for the complete degradation of viscose rayon in the composter, saltwater, and freshwater environs, no changes in the optical properties, infrared spectra, solubility, or melting points of the remaining fibers in any of the environments were observed. However, microscopic morphological changes were observed in fibers from two azlon swatches submerged in freshwater and saltwater, two PLA swatches exposed to ultraviolet light, and two viscose rayon swatches exposed to ultraviolet light.  相似文献   
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