The Micro‐Taphonomy of Cold: Differential Microcracking in Response to Experimental Cold‐Stresses

Cold is a central feature of environments at higher latitudes and elevations. Thus, cold‐induced taphonomic changes are relevant in many forensic contexts. Fifty‐two lamb bone segments were used to assess the impact of cold, freeze‐thaw cycles, freeze‐drying, and water immersion on microstructural cracking of bone in a series of controlled exposure experiments. For each bone segment, three thin sections were examined under a light microscope. Cold exposure caused taphonomic changes in the form of microscopic cracking. Transverse cracks occurred in all treatments, whereas osteonal cracks were restricted to rapid freezing treatments. Type of cold exposure had a statistically significant effect on both the total number of cracks and each type of crack observed. Skeletal microcracking could potentially be used as a taphonomic indicator of postmortem bone exposure to sub‐zero temperatures. The type and prevalence of this damage could also be used to distinguish between different types of cold exposure.     

Optimization and validation of a fast amplification protocol for AmpFlSTR Profiler Plus for rapid forensic human identification

The goal of this work was to optimize and validate a fast amplification protocol for the multiplex amplification of the STR loci included in AmpFlSTR^® Profiler Plus^® to expedite human DNA identification. By modifying the cycling conditions and by combining the use of a DNA polymerase optimized for high speed PCR (SpeedSTAR™ HS) and a more efficient thermal cycler instrument (Bio-RAD C1000™), we were able to reduce the amplification process from 4 h to 26 min. No modification to the commercial AmpFlSTR^® Profiler Plus^® primer mix was required. When compared to the current Royal Canadian Mounted Police (RCMP) amplification protocol, no differences with regards to specificity, sensitivity, heterozygote peak height ratios and overall profile balance were noted. Moreover, complete concordance was obtained with profiles previously generated with the standard amplification protocol and minor alleles in mixture samples were reliably typed. An increase in n − 4 stutter ratios (2.2% on average for all loci) was observed for profiles amplified with the fast protocol compared to the current procedure. Our results document the robustness of this rapid amplification protocol for STR profiling using the AmpFlSTR^® Profiler Plus^® primer set and demonstrate that comparable data can be obtained in substantially less time. This new approach could provide an alternative option to current multiplex STR typing amplification protocols in order to increase throughput or expedite time-sensitive cases.     

Characteristics Differentiating Neglected Children from Other Reported Children

The aims of this study were twofold: first, to identify the characteristics that distinguish neglected children from other children reported to youth protection services; and second, to assess the relative importance of each of these characteristics in the differentiation of such children. Researchers analyzed data from the Quebec Incidence Study (QIS), which documented all reports retained for in-depth assessment out of 4,774 reports filed with youth protection services over a 3-month period. Univariate and multivariate regression analyses examined variables on different levels to establish which of the factors linked to the phenomenon of neglect were most significant. Results indicate that neglected children tend to be younger than other reported children, and have a greater frequency of prior referrals and a greater number of learning and development problems; their parents have a greater tendency to have personal, economic, and social problems and childhood histories of maltreatment.

伊维菌素微量给药法对牛皮蝇蛆病的防治效果观察

牛皮蝇蛆病是由狂蝇科皮蝇属的牛皮蝇 (Hypo dermabovis)、纹皮蝇 (H .lineatum)及中华皮蝇 (H .sinense)的幼虫寄生于牛的背部皮下组织所引起的一类慢性寄生虫病。在我国本病主要分布于西北、东北和华北地区 ,其中内蒙古、甘肃、青海、新疆和西藏 5个省 (区 )尤为严重。皮蝇蛆病的危害主要表现为幼虫在动物体内移行造成的组织损害 ,使幼畜发育受阻 ,成年牛消瘦 ,产奶量下降 ,皮革的质量降低 ,其中以对制革业造成的损失最大。多年来 ,我国对牛皮蝇蛆病的防治技术进行了广泛而深入的研究 ,如采用倍硫磷、阿维菌素注射或浇泼等 ,取得了显著…     

The Use of Hemastix® and the Subsequent Lack of DNA Recovery Using the Promega DNA IQTM System

Abstract:  Following implementation of our automated process incorporating the Promega DNA IQ^TM system as a DNA extraction method, a large number of blood-containing exhibits failed to produce DNA. These exhibits had been tested with the Hemastix^® reagent strip, commonly used by police investigators and forensic laboratories as a screening test for blood. Some exhibits were even tainted green following transfer of the presumptive test reagents onto the samples. A series of experiments were carried out to examine the effect of the Hemastix^® chemistries on the DNA IQ^TM system. Our results indicate that one or more chemicals imbedded in the Hemastix^® reagent strip severely reduce the ability to recover DNA from any suspected stain using the DNA IQ^TM magnetic bead technology. The 3,3',5,5'-tetramethylbenzidine (TMB) used as the reporting dye appears to interact with the magnetic beads to prevent DNA recovery. Hydrogen peroxide does not seem to be involved. The Hemastix^® chemistries do not interfere in any way with DNA extraction performed using phenol-chloroform. The incompatibility of the Hemastix^® chemistries on the DNA IQ^TM system forced us to adopt an indirect approach using filter paper to carry out the presumptive test.