THE STUDY OF POPULATION GENETIC RELATION AMONG TEN ETHNIC GROUPS IN NORTHWEST CH INA

Objective To investigate the genetic relation am on g ten ethnic groups in northwest China. Methods Allele frequ encies of six STR(short tandem repeat ) loci in D13S1358, VWA, FGA, D5S818, D13S 317, and D7S820 were collected from Lasa Tibetan, Changdu Tibetan, Xi'an Han, G ansu Dongxiang, Gansu Yugu, Xinjiang Uygur, Ozbak, Kirgiz, Sibe, Ningxia Hui by the results of State Key laboratory, Forensic Science Department, school of medi cal, Xi'an Jiaotong University and internet biological information data bank, a nd compared with that of the Mongolian, Zhuang in China, and White and Negro in USA. The polymorphism index (H, DP, PPE, PIC) and genetic distance, then the phy logenetic tree of all population were reported. Results The res ulting tree topology exhibited strong geographic and racial partitioning consist ent with that obtained with HLA and classical genetic polymorphisms. Conclusion The results suggest that forensic STR loci may be particular ly powerful tools and provide the necessary fine resolution for the reconstructi on of recent human evolutionary history.

Molecular Mechanisms of Raccoon Rabies Virus Progression in Its Natural Host

Rabies virus presents a global public health problem. Our current understanding of the molecular determinants of rabies virulence stems from rodent models and laboratory strains of the virus, however, it is unclear how well rodent models represent viral response in natural reservoirs. Here, we examined interactions between the raccoon variant of rabies virus (RRV) and its natural host, raccoons, to gain a better understanding of molecular determinants of virulence in this system. We found expression patterns of RRV genes under tight control until the virus reached the central nervous system where replication increased significantly. Further, our examination of viral variants within an individual revealed that variant diversity may have an effect on virulence. We found that a mutation at a region of a T helper cell epitope on the nucleoprotein was associated with viral challenge outcomes and could be associated with RRV pathogenicity.

Haplotype analysis for Irish ancestry

Forensic haplotype analysis of the male Y chromosome is currently used to establish the number of male donors in sexual assaults,the number of male bleeders in blood pattern analysis,and for ancestry correlation to genetic founder populations in biogeographic studies.In forensic laboratory applications,its primary use is for DNA profile generation with trace amounts of male DNA in the presence of excess female DNA(e.g.spermatozoa identification,male component of fingernail scrapings).Our study supports the potential use of the Y chromosome in a"dragnet"approach(most haplotypes are unique)similar to that described by Kayser in 2017 for solving a cold case sex assault and homicide in The Netherlands.Our study also researched the potential for the identification of an ancestral Irish genetic"footprint"linked to surname O'Brien and identified multiple founder group origins in Ireland and England as well as three samples with the Dal Riata(a Gaelic overkingdom)ancestral haplotype.This study indicates correlation to ancestral Irish ancestry by haplotype but not conclusively to the O'Brien surname.

Optimum conditions and application of one-step fluorescent cyanoacrylate fuming method for fingermark development based on PolyCyano UV

Cyanoacrylate fluorescent staining has become a common method for developing latent fingermarks on light-coloured or white objects.The method requires two steps and skilled operation,and the handling process has the risk of damaging the ridge details or even biological samples.To take full advantage of the high-sensitivity fluorescence,recent research efforts on fluorescent cyanoacrylate have aimed to avoid rinsing after staining,add fluorescence to the cyanoacrylate,increase the fluorescence intensity and broaden the fluorescence spectral range.PolyCyano UV is a novel product that can be used to overcome the disadvantages associated with progressing to one-step fuming to directly develop fingermarks.To explore the optimal development conditions and application effects of PolyCyano UV,thermogravimetric differential thermal analysis,fluorescence spectroscopy and control variable analysis are used to determine and analyse the best conditions for using the reagent,including temperature,fluorescence excitation band,relative humidity and fuming concentration.The temperature range of the one-step fuming development method is 212.14℃–275.16℃,the wavelength range of the excitation light source is 235–580 nm,the relative humidity is 60%–80%,the concentration of the fume is 1–3g/m^(3) and the specific value is related to the surface properties of the object and the aged time of the fingermarks.Additionally,fluorescence spectroscopy shows that the excitation wavelength range of the light source is 235–580nm.Based on the best fuming condition,many common objects were selected to proceed to the application experiments,which allowed for a comparison with the traditional visualisation method,namely the Cyanobloom reagent+dyeing two-step development method.The comparison showed that latent fingermarks on most non-porous smooth surfaces,especially on light-coloured or white objects,were developed successfully.In addition,a comparative study with the conventional cyanoacrylate glue–fluorescent staining experiments showed that the effect of dyeing afterwards with Rhodamine 6G is better than the one-step method.The effect of dyeing with BBD is basically the same as that of the one-step method.

Detecting Latent Prints on Stone and Other Difficult Porous Surfaces via Indanedione/Zinc Chloride and Laser

Lasers and alternate light sources have been recognized as effective tools for latent print detection for over three decades.Luminescence often increases friction ridge contrast to reveal impressions otherwise undetectable.Indanedione/zinc chloride excited by a forensic light source is widely recognized as an effective process for developing latent prints on porous surfaces.This study was designed to evaluate the use of a combination of luminescence excitation and indanedione with zinc chloride to detect latent prints on stones,bricks,and similar difficult porous surfaces.The wavelengths evaluated included 400 nm(violet),447 nm(blue),532 nm(green),and 645 nm(red).Latent prints were deposited on a variety of porous surfaces including bricks,cement stones,wood,and cotton fabric,all commonly encountered at crime scenes in China.The surfaces were examined using white light(light‑emitting diode flashlight)and laser light sources separately,both before and after treatment with indanedione/zinc chloride.The goal of this study was to evaluate various light sources for their effectiveness in detecting impressions developed by indanedione/zinc chloride on difficult porous surfaces.Results indicated that latent prints on some brick and cement stone surfaces may be effectively detected using 532 nm laser excitation after indanedione/zinc chloride processing.