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SYDNEY: Forensic scientists in the Netherlands have developed a reliable technique for estimating human age from just a single drop of blood.
在各种潜在的应用工具中,这种从犯罪现场收集血液的技术对于判定失踪的人或犯罪嫌疑人进行执法尤其有用。鹿特丹伊拉斯姆斯医学中心分子生物学家Manfred Kayser ,也是《现代生物学》杂志的一项研究的合作者说:“我们的测试在法学年龄的估计上有很好的应用,尤其是在现场只有血液的时候,比如在暴力犯罪现场。
Of the tool's various potential applications, it could be especially useful to law enforcement seeking to determine the identity of missing persons or criminal suspects from blood collected at a crime scene. "Our test holds great promise for application in forensic age estimation, particularly in cases where only blood is available, such as is usually the case with violent crimes", said molecular biologist Manfred Kayser from Erasmus MC in Rotterdam, a co-author of the study published in Current Biology .
Vastly superior technique
Until now, crime scene investigators have depended on the availability of specific body parts, such as teeth, bones or ligaments, for estimating the age of otherwise unidentifiable persons. This new technique is vastly superior because it relies solely on the availability of a relatively small blood sample. It takes advantage of a phenomenon known as thymus involution, which begins shortly after birth. As a person ages and the thymus tissue degrades, the quantity of a particular type of DNA molecule within our immune cells - signal joint T-cell receptor excision circles, or simply sjTRECs - declines at a steady rate.
Accuracy of nine years
在他们的研究中,Kayser和他的团队从195个健康的荷兰人体采取血液样本,年龄从出生后几周到80岁。计算每个样本的sjTRECs的数量,同时混合一些参考基因来补偿开始的DNA物质的总体数量之后,研究者作出一个sjTREC数量和年龄的回归模型。他们发现sjTREC数量与年龄有巨大的关系,差异在9年内。它表明这种技术将一个不在现场的人的年龄划归到某一组别中具有高度准确性,每个组别的年龄段跨度为20岁。在这项测试中的为人类特质的预测准确性水平是高度依赖目前人类DNA信息的。这种技术建立在快速增长探索人体研究的新方法,通过犯罪现场遗留先来的DNA来预测人类的特征。来自科隆大学的法学生物学家Peter Schneider认为这项研究是具有新颖性和独创性,强调这种技术优于其他的方法在于仅仅通过血迹就可以作出预测。
In their study, Kayser and his team took blood samples from 195 healthy Dutch individuals, ranging in age from a few weeks to 80 years of age. After quantifying the amount of sjTRECs in each sample, together with a reference gene to compensate for the total amount of starting DNA material, the researchers ran a regression model comparing sjTREC abundance and age. They discovered that sjTREC abundance accounted for a highly significant portion of the total age variance, with an accuracy of around nine years. It suggests the tool would be highly accurate in assigning unidentified persons into generational categories, each spanning 20 years. The level of predictive accuracy achieved with the test is the highest obtained so far from DNA information for any human trait. It builds upon a rapidly growing body of research investigating new methods for predicting human appearance from DNA left at a crime scene. Peter Schneider, a forensic biologist at the University of Cologne described the study as "innovative" and "original", and emphasised the technique's superiority over other methods in its reliance on only "a reasonably good blood stain to make the prediction".
Further research needed before cops use it
Schneider认为这仅仅只是开始,在不久的将来会有更多的用新的分子标记和新颖的方法来估测年龄。通过来自维多利亚警察局的法学科学家Roland Van Oorschot说:“这种新颖的研究给法学科学家估计人类的年龄提供了另一种方法。” 但是Van Oorschot认为在实际应用到执法之前还需要进一步的研究。除了以上的犯罪法学上的明显作用外,这种工具也可以应用到其他的生物科学领域。Kayser说:“其他的在人类学研究上的应用,比如估计一个历史任务的年龄(如果血液是可取的话),我们的研究也可以用于野生动物的管理和保护的生物学,以此来监测野生动物的数量的年龄。”
Schneider believes this is just the beginning, with new types of molecular markers and more innovative approaches for age estimation to be discovered in the very near future. According to forensic scientist Roland Van Oorschot of the Victoria Police Department, "the novel research done by [the authors] provides another step towards improving the ability of forensic scientists to estimate human age." Van Oorschot, however, cautions that further research is required before the test can be implemented practically by law enforcement. Aside from its obvious role in criminal forensics, the tool may also be of use in various other areas of bioscience. "Other applications are in anthropological studies, such as to estimate the age of a historical person (if old blood is available), and our test may also serve in wildlife management and conservation biology to monitor age in wildlife populations," said Kayser.
标签:年龄 健康
2010-12-10 16:02 编辑:kuaileyingyu