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241.
The Use of Laser Microdissection in Forensic Sexual Assault Casework: Pros and Cons Compared to Standard Methods
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Sergio Costa M.Sc. Paulo Correia‐de‐Sá M.D. Ph.D. Maria J. Porto Ph.D. Laura Cainé Ph.D. 《Journal of forensic sciences》2017,62(4):998-1006
Sexual assault samples are among the most frequently analyzed in a forensic laboratory. These account for almost half of all samples processed routinely, and a large portion of these cases remain unsolved. These samples often pose problems to traditional analytic methods of identification because they consist most frequently of cell mixtures from at least two contributors: the victim (usually female) and the perpetrator (usually male). In this study, we propose the use of current preliminary testing for sperm detection in order to determine the chances of success when faced with samples which can be good candidates to undergo analysis with the laser microdissection technology. Also, we used laser microdissection technology to capture fluorescently stained cells of interest differentiated by gender. Collected materials were then used for DNA genotyping with commercially available amplification kits such as Minifiler, Identifiler Plus, NGM, and Y‐Filer. Both the methodology and the quality of the results were evaluated to assess the pros and cons of laser microdissection compared with standard methods. Overall, the combination of fluorescent staining combined with the Minifiler amplification kit provided the best results for autosomal markers, whereas the Y‐Filer kit returned the expected results regardless of the used method. 相似文献
242.
Quantitative Determination of Cannabinoids in Cannabis and Cannabis Products Using Ultra‐High‐Performance Supercritical Fluid Chromatography and Diode Array/Mass Spectrometric Detection
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Mei Wang Ph.D. Yan‐Hong Wang Ph.D. Bharathi Avula Ph.D. Mohamed M. Radwan Ph.D. Amira S. Wanas Ph.D. Zlatko Mehmedic M.Sc. John van Antwerp B.Sc. Mahmoud A. ElSohly Ph.D. Ikhlas A. Khan Ph.D. 《Journal of forensic sciences》2017,62(3):602-611
Ultra‐high‐performance supercritical fluid chromatography (UHPSFC ) is an efficient analytical technique and has not been fully employed for the analysis of cannabis. Here, a novel method was developed for the analysis of 30 cannabis plant extracts and preparations using UHPSFC /PDA ‐MS . Nine of the most abundant cannabinoids, viz . CBD , ?8‐THC , THCV , ?9‐THC , CBN , CBG , THCA ‐A, CBDA , and CBGA , were quantitatively determined (RSD s < 6.9%). Unlike GC methods, no derivatization or decarboxylation was required prior to UHPSFC analysis. The UHPSFC chromatographic separation of cannabinoids displayed an inverse elution order compared to UHPLC . Combining with PDA ‐MS , this orthogonality is valuable for discrimination of cannabinoids in complex matrices. The developed method was validated, and the quantification results were compared with a standard UHPLC method. The RSD s of these two methods were within ±13.0%. Finally, chemometric analysis including principal component analysis (PCA ) and partial least squares‐discriminant analysis (PLS ‐DA ) were used to differentiate between cannabis samples. 相似文献
243.
Chengzhi Li Ph.D. Dong Ma Ph.D. Kaifei Deng B.Sc. Yijiu Chen M.Sc. Ping Huang Ph.D. Zhenyuan Wang Ph.D. 《Journal of forensic sciences》2017,62(5):1345-1350
Estimating the postmortem interval (PMI) is very important in the forensic sciences. Although many approaches have been used for estimating the PMI, accurate PMI calculations are still difficult. In this study, four Sprague Dawley (SD) rats were sacrificed by suffocation, and muscle samples were collected by dissection at various time intervals (0, 48, 96, and 144 h) after death. All samples were probed using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) to obtain molecular images and data for principal component analysis (PCA). The results showed that the peaks at m/z 1511, 1543, 1564, 1586 clearly decreased in intensity from 0 to 144 h postmortem and that the time groups were separated from each other on the PCA score plot. The prediction model showed high recognition capability (95.93%) and cross‐validation (83.72%). Our work suggests that MALDI‐TOF MS can be used to determine the PMI. 相似文献
244.
James W. Rajotte M.Sc. Jean‐Paul F.P. Palmentier M.Sc. Helena Rachelle Wallage M.Sc. 《Journal of forensic sciences》2017,62(5):1410-1413
This case report details an individual arrested for drug‐impaired driving after leaving the scene of multiple motor vehicle collisions and evading police. The driver was examined by a drug recognition expert and failed the drug recognition evaluation. The driver admitted to using cocaine, marijuana, an antidepressant medication and “N‐bomb,” a novel psychoactive substance that possesses hallucinogenic properties. Toxicological analyses at the Centre of Forensic Sciences’ Toronto laboratory revealed only the substance 2‐[4‐chloro‐2,5‐dimethoxyphenyl]‐N‐[(2‐methoxyphenyl)methyl]ethanamine (25C‐NBOMe) in the accused's urine. This is the first report in which 25C‐NBOMe was identified through DRE and toxicological analyses in a drug‐impaired driver. 相似文献
245.
A Computational Framework for Age‐at‐Death Estimation from the Skeleton: Surface and Outline Analysis of 3D Laser Scans of the Adult Pubic Symphysis
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Bridget F. B. Algee‐Hewitt Ph.D. Jieun Kim Ph.D. Dennis E. Slice Ph.D. 《Journal of forensic sciences》2017,62(6):1434-1444
In forensic anthropology, age‐at‐death estimation typically requires the macroscopic assessment of the skeletal indicator and its association with a phase or score. High subjectivity and error are the recognized disadvantages of this approach, creating a need for alternative tools that enable the objective and mathematically robust assessment of true chronological age. We describe, here, three fully computational, quantitative shape analysis methods and a combinatory approach that make use of three‐dimensional laser scans of the pubic symphysis. We report a novel age‐related shape measure, focusing on the changes observed in the ventral margin curvature, and refine two former methods, whose measures capture the flatness of the symphyseal surface. We show how we can decrease age‐estimation error and improve prior results by combining these outline and surface measures in two multivariate regression models. The presented models produce objective age‐estimates that are comparable to current practices with root‐mean‐square‐errors between 13.7 and 16.5 years. 相似文献
246.
247.
248.
Predictors of Initial Court Agreement and 1‐Year Relitigation in Title IV‐D Contested Paternity Cases
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Ani R. Poladian Brittany N. Rudd Amy Holtzworth‐Munroe Amy G. Applegate Brian M. D'Onofrio 《Family Court Review》2017,55(2):243-259
We examined potential predictors of initial court agreement and 1‐year relitigation in a sample of contested paternity cases involving unmarried parents coming to court to establish paternity, child support, and other issues. Cases participated in an RCT of a parent program and of a waiting period between establishment of paternity and court hearing. We controlled for RCT study factors and used baseline assessment data to predict likelihood of reaching full agreement in the initial court hearing and relitigation in the following year. Findings suggest that cases in which parents get along better outside of court are more likely to reach agreement and less likely to return to court. Additionally, particular parent demographics predict lower likelihood of reaching initial agreement (e.g., parents are non‐White, father earns below $10,000 yearly), more relitigation (e.g., parents are non‐White, mother earns above $10,000 yearly, father has children with others), and less relitigation (e.g., father earns above $10,000 yearly). Child demographics and most parent relationship characteristics did not predict outcomes. We discuss findings and offer suggestions for court interventions. 相似文献
249.
Adaptive and Maladaptive Gatekeeping Behaviors and Attitudes: Implications for Child Outcomes After Separation and Divorce
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Gatekeeping has been used as a theory and a measure to describe and assess family dynamics within the context of separation and divorce. In this article, we explore adaptive and maladaptive gatekeeping behaviors and attitudes that can affect the other parent's relationship with the child. Implications are presented for connecting adaptive and maladaptive gatekeeping responses to child outcomes of safety, well‐being, and positive parent–child relationships following separation and divorce. We build on the recent attention to gatekeeping as a potential framework within the child custody context. 相似文献
250.
MARVIN D. KROHN JEFFREY T. WARD TERENCE P. THORNBERRY ALAN J. LIZOTTE REBEKAH CHU 《犯罪学》2011,49(4):991-1028
The short‐run deleterious effects of gang involvement during adolescence have been well researched. However, surprisingly little empirical attention has been devoted to understanding how gang involvement in adolescence influences life chances and criminal behavior in adulthood. Drawing on the life‐course perspective, this study argues that gang involvement will lead to precocious transitions that, in turn, will have adverse consequences on the fulfillment of adulthood roles and statuses in the economic and family spheres. Moreover, problems fulfilling these conventional roles are hypothesized then to lead to sustained involvement in criminal behavior in adulthood. Using data from a sample of males from the Rochester Youth Development Study, results from structural equation models support the indirect link between gang membership and noncriminal and criminal outcomes in adulthood. Specifically, gang involvement leads to an increase in the number of precocious transitions experienced that result in both economic hardship and family problems in adulthood. These failures in the economic and family realms, in turn, contribute to involvement in street crime and/or arrest in adulthood. Implications for the criminal desistance process are discussed. 相似文献