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.     

Legal Statements and Normative Language

Can there be a non-reductivist, source-based explanation of the use of normative language in statements describing the law and legal situations? This problem was formulated by Joseph Raz, who also claimed to have solved it. According to his well-known doctrine of ‘detached’ statements, normative legal statements can be informatively made by speakers who merely adopt, without necessarily sharing, the point of view of someone who accepts that legal norms are justified and ought to be followed. In this paper I defend two theses. I argue, first, that the notion of a detached statement cannot be made to work, and that Raz’s problem is thus not thereby solved. But the problem itself, I also suggest, is a false one.     

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.     

Heat Induced Changes to Dental Resin Composites: A Reference in Forensic Investigations?*

The objective was to investigate color change and surface damage in dental resin composites exposed to high temperatures over different time intervals for comparative purposes. Samples were prepared using two resins - Z100(R) (R1) and Charisma (R2), heated at the following temperatures: 200 degrees C, 400 degrees C, 600 degrees C, 1000 degrees C, for 15, 30 and 45 min (n = 104 for each resin sample). Color (DeltaE) and brightness (DeltaL) changes were analyzed by spectrophotometry using the CIE Lab system and surface changes by Scanning Electron Microscopy (SEM). R1 showed more intense color changes after heat exposure than R2. DeltaL values were found to be the best parameter for evaluation of light and color change. A biphasic pattern after thermal exposure was detected, from dark brown to light white. SEM showed more intense alterations in R2 than in R1. These results indicate that the parameters observed in both resins are useful as a guide in forensic analyses.     

Psychological adjustment in a forensic sample: relationship with approach- and avoidance-coping typologies

Most studies that relate coping strategies with psychological symptoms usually consider a single coping dimension. This means that interpretation of the results is unclear and only partially true as subjects activate different types of coping strategies simultaneously when faced with a stressor. The objective of the present study is to analyze the relationships between coping and psychopathology in young inmates, taking into account the number of approach and avoidance answers simultaneously. The results show that the inmates with above-average scores in avoidance coping and below average in those of approach (coping responses inventory--adult form, [CRI-A]) show higher symptomatology (MMPI-2) than the inmates who obtain above-average scores in both avoidance and approach strategies. It can be deduced that it is not the high use of avoidance coping that is related to psychopathology, but rather the combined use of many avoidance strategies and few approach strategies. The convenience of jointly taking into account both types of coping is discussed.     

Body Height Estimation from Head and Face Dimensions: A Different Method*

Abstract: As there are cases brought for forensic examination where only the craniofacial region is available, estimation of stature from craniofacial dimensions is without doubt important in forensic cases. The study presented here attempts to estimate stature from craniofacial dimensions in the Turkish population. In the second phase of the study, the correlations between craniofacial dimensions and stature were also evaluated according to different head and face types. All measurements were taken from 286 healthy males with a mean age of 22.71 ± 4.86 years. The sample was then reclassified according to different head and face indexes. For the whole sample, correlation coefficients were low, changing only between 0.012 and 0.229. Thus, no significant increase in correlation coefficients was observed after the samples had been reevaluated according to different head and face types. As a conclusion, craniofacial dimensions are not good predictors for body height for the Turkish population.     

<Emphasis Type="Bold">A</Emphasis>nti-corruption agencies: between empowerment and irrelevance

The anti-corruption activity of the 1990s is characterized by the rise of new players, such as specialized anti-corruption bodies. Anti-corruption agencies (ACAs) are public bodies of a durable nature, with a specific mission to fight corruption and reducing the opportunity structures propitious for its occurrence in society through preventive and/or repressive measures. Independently of their format and powers, ACAs encounter various constraints to their mandate, which explains the meagre results obtained by some of them. This introductory paper tries to understand the rise, future, and implications of this new kind of “integrity warrior” and to locate them in the evolving doctrine of corruption control. The objective of this edited volume is to re-launch the debate on ACAs as the most innovative feature of the anti-corruption movement of the last two decades.     

National survey of the incidence of missing anterior teeth: Potential use in bite mark analysis in the Brazilian context

Bite mark analysis in forensic dentistry presupposes that the human dentition is unique and that its characteristics can be transferred precisely to several materials. The aim of the present study was to register the frequency of missing anterior teeth in the Brazilian adult population, discussing its potential importance in bite mark analysis. Data from the Brazilian Oral Health Survey were used; 13,431 male and female individuals aged 35 to 44 were examined according to the criteria of the World Health Organization. The analysis of Poisson regression was performed in order to calculate the rating ratios and the respective confidence interval at 95%. A total of 13,431 adults participated in the study. Among male individuals, 2063 (47.00%) were dentate and 2036 (46.40%) had at least one missing tooth. Only 254 (5.83%) were totally edentulous. A significant number of males and females presented 6 missing teeth in the same dental arch, revealing the poor state of oral health of adult Brazilians. Missing teeth were more frequent in the upper dental arch than in the lower arch. In the upper dental arch, the incisor group (central and lateral) was missing the most. In the lower dental arch, however, a certain lack of homogeneity was observed among the different dental groups as regards missing teeth. White individuals presented a smaller proportion of missing teeth compared to the other ethnic groups. Females were 1.61 (CI 1.50–1.73) times more likely than males to present missing teeth. The absence of upper teeth and the presence of lower teeth were observed in 16.10% of the individuals. Further research should also include an analysis of different age groups. This would increase the potential of applying this kind of information to bite mark analysis.