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1.
D6S2418在中国(汉族)、泰国和德国人群中的遗传多态性   总被引:2,自引:0,他引:2  
目的获得D6S2418基因座的群体遗传学数据,分析其基因频率在不同群体间的分布情况是否存在差异,并分析其在法医学中的应用价值。方法采用PCR、非变性聚丙烯酰胺凝胶电泳(PAGE)及银染技术分析中国成都地区汉族、泰国曼谷地区泰国人群以及德国Maint地区德国人群中D6S2418基因座的遗传多态性,获得三个群体D6S2418基因座的群体遗传学数据。结果从300份分别采自成都地区汉族、泰国曼谷地区泰国人群以及德国Maint地区德国人群三个群体的无血缘关系个体的静脉血,共发现9个等位基因,观测到31种基因型。观测杂和度为64%~81%,个人识别机率为84.2%~93.5%,经统计学检验,基因型的频率分布符合Hardy-Weinberg平衡定律。等位基因频率的分布在三个群体间有显著差异。结论D6S2418基因座的个人识别能力高,在法医学个人识别和亲子鉴定应用中有较高价值。  相似文献   
2.
目的 了解中国5个群体D20S85基因座的群体遗传学数据,比较它们之间的遗传学差异,探讨其在法医学应用中的意义。方法 分别收集5个群体622名无关个体的血样,Chelex-100快速抽提法或饱和酚/氯仿法抽提DNA;扩增后经PAGE垂直板电泳、银染,进行D20S85基因座分型。结果 在5个群体622名无关个体中,共检出9个等位基因,并首次在广东汉族和广西壮族群体中检出等位基因14;每个群体基因频率大于0.05的均为6个,D20S85*6为最常见等位基因。5个群体共观察到35种基因型,群体内基因型频率分布均符合Hardy-Weinberg氏平衡,各群体间基因型构成比无显著性差异。观察140次减数分裂未发现突变。各群体的期望杂合度为0.7720~0.7912;非父排除率,在三联体为0.7538~0.7594,二联体为0.3988~0.4297;个人识别率为0.9175~0,9272;多态信息含量为0.7442~0.7656。应用于亲子鉴定和个人识别案例,效果满意。结论 D20S85基因座是法医学应用价值较高的遗传标记系统。  相似文献   
3.
The forensic science community raised the need for improved evidence recognition, collection, and visualization analytical instrumentation for field and laboratory use. While the 3D optical techniques for imaging static objects have been extensively studied, there is still a major gap between current knowledge and collecting high‐quality footwear and tire impression evidence. Among optical means for 3D imaging, digital fringe projection (DFP) techniques reconstruct 3D shape from phase information, achieving camera‐pixel spatial resolution. This paper presents a high‐resolution 3D imaging technology using DFP techniques dedicated to footwear and tire impression capture. We developed fully automated software algorithms and a graphical user interface (GUI) that allow anyone without training to operate for high‐quality 3D data capture. We performed accuracy evaluations and comparisons comparing with the commercial high‐end 3D scanner and carried out qualitative tests for various impressions comparing with the current practices. Overall, our technology achieves similar levels of accuracy and resolution with a high‐end commercially available 3D scanner, while having the merits of being (1) more affordable; (2) much easier to operate; and (3) more robust. Compared with the current practice of casting, our technology demonstrates its superiority because it (1) is non‐destructive; (2) collects more evidence detail than casts, especially when an impression is fragile; (3) requires less time and money to collect each piece of evidence; and (4) results in a digital file that can easily be shared with other examiners.  相似文献   
4.
"公爵同志"米尔斯基是20世纪二三十年代欧美和苏联文学界、知识界的重要人物之一,他充满突转的生活经历和坚忍不拔的文学活动构成文坛的一段传奇,甚或那一代俄国知识分子之命运的缩影和象征。他用英文撰写的《俄国文学史》被纳博科夫称为"用包括俄语在内的所有语言写就的最好一部俄国文学史",所谓"米尔斯基文学史"因其"折中主义"的文学史观、主客观统一的批评手法和极富个性的话语风格而独树一帜,被视为西方俄国文学研究的奠基之作,长期被欧美高校斯拉夫系用作俄国文学史教材,其影响历久不衰。  相似文献   
5.
复制生产权是知识产权人独占性权利的重要组成部分,因此,权利人拒绝向第三方授予许可的行为本身并不当然构成《欧共体条约》第82条(以下简称ECT82)意义上之市场支配地位的滥用,但是,这并不排除某些特殊情况下滥用行为的存在。通过一系列案件的审判,欧洲法院对知识产权人滥用市场支配地位的判断总结出了一些标准,一旦符合这些标准,权利人就会被强行要求向市场提供某些产品或服务,尤其是当权利人凭借知识产权垄断了市场“基础设施”的时候,欧盟竞争法就会赋予权利人开放这种“特定门槛”的强制性义务。  相似文献   
6.
Virtual anthropology (VA) is based on applying anthropological methods currently used to analyse bones to 3D models of human remains. While great advances have been made in this endeavour in the past decade, several interrogations concerning how reliable these models are and what their proper use should be remain unanswered. In this research, a fundamental assumption of VA has been investigated: if the way we perceive and apply an anthropological method is truly similar when looking at bones macroscopically and through various 3D media. In order to answer, 10 skulls of known age and sex were scanned using a computed tomography (CT) scanner and a 3D surface scanner. Two observers separately applied a defined staging method to eight suture sites on these skulls, first looking at the bone macroscopically, then at the 3D surface scan, and finally on the CT scan. Two rounds of observation were carried out by each observer. Intra- and inter-observer error were evaluated, and two sample t-tests used to evaluate if the different types of medium used yielded significantly different observations. The results show a high degree of inter-observer error, and that data obtained from 3D surface scans differ from macroscopic observation (confidence level 95%, P ≤ 0.05). CT scans, in these settings, yielded results comparable to those obtained through macroscopic observations. These results offer many possibilities for future research, including indications on the kind of anthropological methods and anatomical landmarks that might be reliably transferable to the virtual environment. All current methods used in traditional anthropology should be tested, and if they prove unreliable, new techniques to analyse bones from virtual models should be developed.

Key points

  • Large discrepancies between observation on dry bones and computer-generated 3D models (surface scans or CT scans) could lead to the re-evaluation of the suitability of traditional anthropological methods for application on 3D models.
  • This preliminary study evaluates whether macroscopic, 3D surface scans, and CT scans viewings generate different observations.
  • The results indicate that the data are not always coherent across all three media of observation.
  • Explanations include the aspect given to the bone by the 3D software, differences between handling bones in real life versus on a computer, and level of expertise of the observers.
  相似文献   
7.
It may be difficult to distinguish the cause of death in drowning cases without specific findings. The aim of this study was to explore the forensic value of thoracic postmortem computed tomography (PMCT) using routine images and three-dimensional (3D) image reconstructions. The imaging data of PMCT examinations of six drowning cadavers, aged 21–54 years, were analyzed. Twelve victims of sudden death from coronary artery disease (CAD) were chosen as a control group. After 3D bilateral lung images were reconstructed using image processing software, an interactive medical image control system was used to measure and analyze parameters including lung volume, lung volume ratio, mean CT value of the whole lung, and lung CT value distribution curves. Lung volume and lung volume ratio were used to assess the shape changes of the lung. Lung CT value distribution curves showed the corresponding number of pixels of the different CT values in the lung image. Lung volume was not significantly larger in drowning cases (mean 2 958 cm3) than in controls (mean 2 342 cm3). Lung volume ratio values in the drowning group (mean 0.3156) were greater than those in the control group (mean 0.2763); (P = 0.02). There was no significant difference between the drowning and control group in the mean CT value of the whole lung. There were differences between lung CT value distribution curves in drowning victims and controls, with drowning victims showing a single peak and CAD cases showing a bimodal distribution. Thoracic PMCT is helpful for the forensic medical diagnosis of drowning. Lung volume ratio and lung CT value distribution are potential indicators to distinguish between drowning and CAD.  相似文献   
8.
This paper examines the reliability of Structure from Motion (SfM) photogrammetry as a tool in the capture of forensic footwear marks. This is applicable to photogrammetry freeware DigTrace but is equally relevant to other SfM solutions. SfM simply requires a digital camera, a scale bar, and a selection of oblique photographs of the trace in question taken at the scene. The output is a digital three-dimensional point cloud of the surface and any plastic trace thereon. The first section of this paper examines the reliability of photogrammetry to capture the same data when repeatedly used on one impression, while the second part assesses the impact of varying cameras. Using cloud to cloud comparisons that measure the distance between two-point clouds, we assess the variability between models. The results highlight how little variability is evident and therefore speak to the accuracy and consistency of such techniques in the capture of three-dimensional traces. Using this method, 3D footwear impressions can, in many substrates, be collected with a repeatability of 97% with any variation between models less than ~0.5 mm.  相似文献   
9.
Do online and offline voters differ in terms of policy preferences? The growth of Internet voting in recent years has opened up new channels of participation. Whether or not political outcomes change as a consequence of new modes of voting is an open question. Here we analyze all the votes cast both offline (n = 5.7 million) and online (n = 1.3 million) and compare the actual vote choices in a public policy referendum, the world's largest participatory budgeting process, in Rio Grande do Sul in June 2014. In addition to examining aggregate outcomes, we also conducted two surveys to better understand the demographic profiles of who chooses to vote online and offline. We find that policy preferences of online and offline voters are no different, even though our data suggest important demographic differences between offline and online voters.  相似文献   
10.
本研究以中国创业板首批上市公司的792个创业团队为样本,从财务和人本角度研究了创业团队组成特征对企业研发强度的影响。结果发现:创业团队教育水平与四类研发强度均显著正相关,职称与员工人均研发费用显著正相关,平均年龄与研发费用占总资产比例显著负相关,职称与研发费用占总资产比例、员工人均研发费用显著负相关;创业团队组成特征和人本角度研发强度的相关显著水平高于财务角度研发强度;董事长个人职称与员工人均研发费用显著正相关,创业团队特征能解释更多的研发强度变化,支持了高层梯队理论。  相似文献   
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