Multiplex short tandem repeat amplification of low template DNA samples with the addition of proofreading enzymes

Abstract:  With <100 pg of template DNA, routine short tandem repeat (STR) analysis often fails, resulting in no or partial profiles and increased stochastic effects. To overcome this, some have investigated preamplification methods that include the addition of proofreading enzymes to the PCR cocktail. This project sought to determine whether adding proofreading polymerases directly in the STR amplification mixture would improve the reaction when little template DNA is available. Platinum Taq High Fidelity and GeneAmp High Fidelity were tested in Profiler Plus? STR reactions alone and in combination with AmpliTaq^® Gold. All reactions included the additional step of a post‐PCR purification step. With both pristine low template DNA and casework samples, the addition of these polymerases resulted in comparable or no improvement in the STR amplification signal. Further, stochastic effects and artifacts were observed equally across all enzyme conditions. Based on these studies, the addition of these proofreading enzymes to a multiplex STR amplification is not recommended for low template DNA work.     

Y-STRs in forensic medicine: DNA analysis in semen samples of azoospermic individuals

ABSTRACT: The incidence of rape has increased, especially in metropolitan areas, such as the city of São Paulo. In Brazil, studies about it have shown that the majority of this type of crime is committed by the relatives and persons close to the victim. This has made the crime more difficult to be denounced, as only 10% of the cases are reported to competent police authorities. Usually, cytological exams are carried out in sex crime investigations. The difficulty in showing the presence of spermatozoa is frequent, but it does not exclude the presence of male DNA. The absence of spermatozoa in material collected from rape victims can be due to several factors, including the fact that the agressor suffers from azoospermia. This condition can be the result of a successful vasectomy. As the majority of DNA in the ejaculation sample is from spermatozoa, there is much less DNA to be analyzed. This study presents the application of Y‐STRs (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, and DYS393) in DNA analysis of sperm samples from 105 vasectomized men. The study demonstrated a great variation in DNA concentration. DNA extraction and amplification was possible in all sperm samples even in the absence of spermatozoa. The same profile was observed, for each individual, from DNA extracted from blood, pre‐ and postvasectomy semen samples. The use of markers specific for Y chromosome in sex crime cases, especially in the absence of spermatozoa, is very important, mainly because in most situations there is a small quantity of the agressor's DNA in the medium and a large quantity of the victim's DNA.     

Significance of additional RFLP single locus probes analysis after STR based determination of sibship

Autosomal STR typing alone seems to be no sufficient tool for resolving deficiency cases (e.g. cases of questioned paternity or half-sibships). Therefore, we investigated whether the additional analysis of RFLP single locus probes can improve the solution of such complicated kinship cases. We analyzed 207 children and men from 101 families using the AmpFlSTRIdentifiler multiplex PCR kit and three RFLP single locus probes. A comparison between each child and all unrelated men resulted in 11,023 man / child pairs. Less than three excluding STRs were found in 125 child / unrelated man pairs (1.13%). Additional analysis of RFLP results reduced the number of ambiguous cases to 35. Half-sibling pairs were simulated using STR results from 20 cases with high paternity probabilities (group 1) and relatively low paternity probabilities (group 2). Using a commercially available computer program we calculated probabilities for 778 half-sibling pairs. In 35 pairs (4.49%) half-sibling probabilities over 90.0% could be calculated. Additional investigation of RFLP single locus probes did not lead to a more reliable evaluation of these results. The combined investigation of autosomal STRs and RFLP single locus probes can satisfactorily solve deficient paternities but does not contribute to the solution of questioned half-sibships.     

The Reliability of Visually Comparing Small Frontal Sinuses*

Abstract: Several studies have investigated frontal sinus comparison for personal identification. One study addressed the statistical reliability of correct identification using automated digital methods and resulted in a 96% accuracy rate. Missed matches with the digital methods generally involved small, less featured sinuses. This study investigates the hypothesis that human examiners may be able to more accurately identify correct matches than digital methods, even when the comparisons involve small frontal sinuses. Participants were provided two sets of 28 radiographs and were instructed to identify matching radiographs and list the radiographs that did not have a corresponding match. Overall, error rates were low, with correct associations identified at a rate of 0.983. No incorrect associations (“false positives”) were made. Correct association rates were highest among participants “experienced” examining radiographs. Results support previous assertions that frontal sinus radiographs are a reliable means of personal identification even when the frontal sinuses are small.     

The influence of job assignment on community engagement: bicycle patrol and community-oriented policing

The purpose of this study is to compare a specialized community-oriented policing (COP) unit to a reactive unit on officer perceptions of public contact and officer perceptions of job performance. We also compare bicycle patrol officers to motor vehicle patrol officers within these units. Using a static group comparison design, questionnaires were distributed to officers within the Toronto Police Service (n = 178). Bicycle patrol is associated with more contacts with the public and higher rates of proactive policing when compared to motor vehicle patrol and bicycle officers are more likely to rate higher on several measures of crime control. Officers with a COP mandate engage with the public for a wider variety of reasons compared to those with a reactive mandate, and are more likely to rate higher on perceptions of performing job duties in a procedurally just manner. This study demonstrates the value of a specialized COP unit that includes bicycle patrol in achieving tenets of COP. It contributes to the literature on COP and the use of bicycle patrol in law enforcement by presenting the perspective of the police officer.     

China's ‘win-win’ cooperation: Unpacking the impact of infrastructure-for-resources deals in Africa

This paper discusses China's use of infrastructure-for-resources loans in Africa as a win–win economic cooperation tool. This formula, offering generous loans for infrastructure in exchange for resource access, came into being largely as a default cooperation tool, inspired by China's own domestic experience, its competitive advantages and Africa's receptivity to this kind of barter deal. Embodying the principle of mutual benefit, China has consistently combined the extension of financial assistance for infrastructure construction in Africa with the expansion of Chinese business interests and the pursuit of resource security goals. The analysis focuses on whether this instrument is actually promoting African development or fuelling instead China's economic growth at the expense of African economies. The author argues that the impact has been mixed. Although there are some meaningful positive signs, many challenges persist, and as such the long-term developmental impact of this particular tool remains uncertain. The responsibility to ensure a positive outcome rests, however, on the African side as much as on China.     

Discussion Content and Perception of Deliberation in Western European Versus American Juries

Jury research has dealt almost exclusively with the American system wherein 6-12 laypersons decide verdicts under a unanimity or non-unanimity rule. However, most Western European countries follow the escabinado system, in which laypersons and judges together decide verdict and sentence, under a non-unanimous rule. We experimentally compared the processes and outcomes of both types of juries. Under the guise of a Student Judicial panel, seven undergraduate students in Spain comprised 10 juries, whereas five undergraduates and two fifth-year Law students comprised 10 escabinado juries. We assessed pre- and post-discussion verdict, penalty, and confidence, discussion content, and subjective reactions to the discussion and outcome. Escabinado jury deliberations were driven by the imbalance of power between trained and lay jurors. Escabinado and lay juries differed in their perception of the deliberation but not in their outcomes. Implications for the impact of cultural differences and task requirements in jury decision-making are drawn.     

Teaching Criminological Theory: The Power of Film and Music

Interest in utilizing pop culture as a means of teaching and enhancing students’ understanding of complex or abstract ideas in the classroom has increased over the course of the past decade. This includes the use of film, television, fiction books, the internet, and music. The fields of criminology and criminal justice have also increasingly noted the value of using such means to teach about atrocities such as state crime, transnational crime and corporate crimes as well as issues of inequality, racism, and classism. Film, music and television can also be great tools to enhance the understanding of and ability to apply criminological theory. Most articles that have focused on incorporating the use of a ‘popular criminology’ within the classroom, however, have concentrated on one form or another of ‘pop culture’ (i.e., film). This article seeks to add to the existing literature by providing an example of how the use of film combined with music can not only enhance undergraduate criminology and criminal justice students’ ability to grasp criminological theory and apply it in their everyday lives, but also can be utilized as tools for exams.     

The urban household in Russia and the Soviet Union, 1900–2000: Patterns of family formation in a turbulent century

Starting from census data on co-residence and household composition, the authors analyse principles of family organisation and family formation in twentieth-century urban Russia and the Soviet Union. The article uses an adapted version of the classification of households developed by Peter Laslett and Eugene Hammel to study variation in household structure for successive population censuses. Changes in this variation between cross-sections are explained with the help of additional quantitative and qualitative data and are linked to the fundamental demographic, social and economic shifts which took place in Russian society in the course of the twentieth century. The article finds a family system characterised by a tendency towards nuclear family formation, but incorporating a fairly stable element of household extension. Co-residence of three generations was both an answer to a perennial housing problem and offered important advantages in the sphere of childcare and care for the elderly. Variation and fluctuation in household structure are found to be most pronounced during the turbulent first half of the century. After a period of stability during the post-war decades of Soviet rule, post-Soviet transformations provoke new changes.