Strontium and geolocation, the pathway to identification for deceased undocumented mexican border-crossers: a preliminary report

Much of the difficulty associated with identifying and repatriating deceased undocumented border-crossers stems from an inability to narrow down the search area to more probable options. Analysis of the isotopic variation in the tooth enamel of modern Mexican populations is currently underway at the University of California Santa Cruz. Using Thermo Ionization Mass Spectrometry, the pilot research analyzed strontium isotopes located in the donated permanent teeth of Mexican-born individuals of known origin from four states. The preliminary results reveal the formation of three distinctly significant regions in the data set. Using the technology outlined here, a map documenting the isotopic variation in modern Mexican tooth enamel is being complied to use for cross comparison with deceased border crossers of unknown origin.     

Can Stable Isotopes and Radiocarbon Dating Provide a Forensic Solution for Curbing Illegal Harvesting of Threatened Cycads?

Cycads in South Africa are facing an extinction crisis due to the illegal extraction of plants from the wild. Proving wild origin of suspect ex situ cycads to the satisfaction of a court of law is difficult, limiting law enforcement efforts. We investigated the feasibility of using multiple stable isotopes to identify specimens removed from the wild. Relocated and wild specimens from two species in the African genus Encephalartos (E. lebomboensis and E. arenarius) were sampled. ¹⁴C analysis indicated that a ± 30‐year chronology could be reliably obtained from the cycads. For E. arenarius, pre‐relocation tissue was consistent with a wild origin, whereas tissue grown post‐relocation was isotopically distinct from the wild for ⁸⁷Sr/⁸⁶Sr and δ¹⁵N. For E. lebomboensis, δ³⁴S, δ¹⁸O, and ⁸⁷Sr/⁸⁶Sr were different between relocated and control plants, consistent with the >30 years since relocation. Our findings demonstrate the potential for a forensic isotope approach to identify illegal ex situ cycads.     

Using Carbon,Oxygen, Strontium,and Lead Isotopes in Modern Human Teeth for Forensic Investigations: A Critical Overview Based on Data from Bulgaria

Isotopic data obtained from human remains can provide information about an individual's origin, migration, and diet. We evaluate the usefulness of carbon, oxygen, strontium, and lead isotopes for forensic investigations by comparing data from Bulgarian teeth with data from other regions. Geo‐referencing based on oxygen or strontium isotopes can be misleading due to overlap with other countries in Europe and other continents. Carbon and lead isotopes, in combination with oxygen and strontium isotopes, provide the most useful information for identification of local vs foreigner status. In particular, high‐precision Pb isotopes show a distinct “Bulgarian” range; however, it is possible that individuals from other countries in Eastern Europe and/or central to western Asia could have overlapping isotopic values. Additional high‐precision multi‐isotope data from modern humans from different regions in the world are required to transition from speculative to more quantitative estimation of a geographical place of origin for unidentified human remains.     

测定肺锶含量鉴定溺死的研究

作者借助ICP 检测溺死和死后沉入水中,浸泡不同时间家兔及对照组肺腮含量。结果表明,溺死组肺锶含量显著高于死后入水组和对照组(P<0. 01) ;无论溺死或死后沉入水中浸泡不同时间,家兔肺锶含量之间无明显差异(P>0. 05) ,提示肺锶含量受水中浸泡时间或腐败因素的影响并不显著。2例实际案例的肺锶含量测定支持实验性研究结果,说明肺锶含量测定可用于鉴定溺死,具有实用价值。     

Preparation of a low-cost fingerprint powder that harnesses white light to emit long-lived phosphorescence

An inexpensive, commercially available doped strontium aluminate phosphor with long-lived afterglow has been prepared and assessed in the role of a luminescent fingerprint dusting powder. Blue, green, and aqua phosphorescence persisting for ca. 30 s was obtainable from treated fingermarks after charging the powders with the white light (400–700 nm) setting of a forensic light source. Imaging the phosphorescent afterglow enabled the elimination of background emissions encountered during latent fingermark examination. This was demonstrated by visualising fingermarks on substrates that possess inbuilt fluorescent security features and highly patterned substrate backgrounds, without any need for bespoke scientific equipment.