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.     

Forensic Use of the Piracatinga Fish (Callophysius macropterus) to Locate and Identify Human Remains Retrieved From the Amazon River

Piracatinga (Callophysius macropterus) are a type of bottom feeder catfish encountered in the Amazon River and its tributaries. We report two cases in which human remains were first located based on a characteristic circular distortion of the surface of the river that the Piracatinga make while they feed. Human skin samples of one of the victims recovered from the Piracatinga digestive tract were subjected to mitochondrial DNA analysis that allowed identification of the body of Case 1; the family recognized body parts of Case 2. Importantly, the location of human body parts and their identification based on DNA analysis enabled the respective families to obtain a death certificate expeditiously in the absence of identifiable remains—a process that normally requires 5 years under current Brazilian law, and in the absence of closure, imposes severe emotional stress on the family of the deceased.     

Population and income: Is there a puzzle?

Abstract

This note presents wide evidence on the relationship between population and income for 125 countries for which data was available for the period 1950–2000. The main result is that there is a weak but negative relationship between population growth and per capita GDP, as income increases population expands at a slower rate. This relationship appears to be stronger for African countries and for Asian countries before 1970.     

STR data from S. Tomé e Príncipe (Gulf of Guinea, West Africa)

Allele frequencies for eight STRs (CD4, FES/FPS, MBPB, TH01, TP53, TPO, F13A1, VWA) were estimated from samples (sized between 279 and 328) of unrelated individuals born in S. Tomé e Príncipe (Gulf of Guinea, West Africa).     

STR data (AmpFlSTR Profiler Plus and GenePrint CTTv) from Mozambique

Allele frequencies for twelve STRs included in the AmpFlSTR Profiler Plus kit (D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820) and GenePrint CTTv kit (VWA, TH01, TPO and CSF1PO) were estimated from a sample of 110 unrelated individuals from Mozambique.     

Statistical analyses of 14 short tandem repeat loci in Brazilian populations from Rio de Janeiro and Mato Grosso do Sul states for forensic and identity testing purposes

This work describes the statistical features of a database for two Brazilian populations (one from the Rio de Janeiro State (southeast region), and one from the Mato Grosso do Sul State (central western region) using fourteen short tandem repeat loci (STR).     

Chimpanzee homologous of human Y specific STRs. A comparative study and a proposal for nomenclature

Eleven Y specific microsatellites, previously studied in humans, were typed for fragment length and sequenced in chimpanzees (Pan troglodytes).The primers described by Ayub et al. (Nucleic Acids Res. 28, 2000, 2) for amplifying DYS434, DYS435, DYS436, DYS437, DYS438, DYS439 and those described by White et al. (Genomics, 57, 1999, 433) for GATA A10, A7.1, A7.2, C4, and H4, were used to amplify DNA samples from chimpanzees.Primers described for Y GATA A4 were found to amplify the same region as reported for DYS439. Moreover, the GATA A4 forward primer only matches the repeat flanking region in 14 of the 28bp, being responsible for a very weak amplification. Therefore, this system was not included in this study.The analysis of the repeat and sequence structure observed in chimpanzee and human Y chromosomes allowed evolutionary comparisons as well as the basis for improving Y STR nomenclature and therefore, a unified nomenclature for these novel STRs is proposed to the scientific community following ISFG recommendations.     

Forensic determination of hair deposition time in crime scenes using electron paramagnetic resonance

Several types of biological samples, including hair strands, are found at crime scenes. Apart from the identification of the value and the contributor of the probative evidence, it is important to prove that the time of shedding of hair belonging to a suspect or victim matches the crime window. To this end, to estimate the ex vivo aging of hair, we evaluated time‐dependent changes in melanin‐derived free radicals in blond, brown, and black hairs by using electron paramagnetic resonance spectroscopy (EPR). Hair strands aged under controlled conditions (humidity 40%, temperature 20–22°C, indirect light, with 12/12 hour of light/darkness cycles) showed a time‐dependent decay of melanin‐derived radicals. The half‐life of eumelanin‐derived radicals in hair under our experimental settings was estimated at 22 ± 2 days whereas that of pheomelanin was about 2 days suggesting better stabilization of unpaired electrons by eumelanin. Taken together, this study provides a reference for future forensic studies on determination of degradation of shed hair in a crime scene by following eumelanin radicals by utilizing the non‐invasive, non‐destructive, and highly specific EPR technique.     

Waiting for Godot: Sustainable development,international trade and governance in environmental policies

The current environmental crisis calls for a sustainable style of development and draws attention to a new ecological dimension in social life that poses hitherto unforeseen challenges to the social sciences and to the everyday concerns of citizens, governments and private interests. Consequently, it is appropriate to attempt a critical overview of governance issues around the formation and implementation of environmental policies designed under the framework of sustainable development. After a brief introduction on how global perceptions about sustainable development have evolved, this article subsequently focuses attention on the main thrust of the emerging international environmental regime, and the multilateral environmental treaties embodied in it. Specific governance issues pertaining to environmental policies are also critically reviewed, particularly interrelations with the trade regime. The article concludes by spelling out some comments on research issues for the future, with a view to charting the environmental governance agenda lying ahead of us.