31 research outputs found

    Comparison of geophysical and botanical results in simulated clandestine graves in rural and tropical environments in Colombia, South America

    Get PDF
    In most Latin American countries there are significant numbers of both missing people and forced disappearances, ~84,000 alone in Colombia. Successful detection of buried human remains by forensic search teams can be difficult in varying terrain and climates. This paper reports on the geophysical and botanical monitoring of simulated clandestine graves in two different environments over 24 months to establish optimal detection methods and equipment configurations. Twelve clandestine burials were simulated at three different burial depths (0.5m, 0.8 m and 1.2 m) commonly encountered in Latin America. The simulated targets were three pig carcasses, three human skeletons, three graves with burnt human beheaded skeletons and finally three empty graves to act as control. Geophysical detection methods included ground penetrating radar, magnetic susceptibility, bulk ground conductivity and electrical resistivity. Geophysical results showed apparent electrical resistivity was optimal to detect targets (85% success) in semi-rural areas and GPR was optimal to detect targets (92%) in tropical rainforest areas, followed by magnetic susceptibility and bulk ground conductivity. Botanical results evidenced variations in both study sites which should be noted by forensic search investigators, with rapid growth of Raphanus in the tropical rainforest graves and Malvaceae and Petiveria in the rural study site respectively. This paper shows the importance of conducting long-term controlled studies to assist forensic search teams with expected results and optimum equipment configuration(s)

    Cooperative Lewis pairs based on late transition metals: activation of small molecules by platinum(0) and B(C6F5)3

    Get PDF
    A Lewis basic platinum(0)–CO complex supported by a diphosphine ligand and B(C6F5)3 act cooperatively, in a manner reminiscent of a frustrated Lewis pair, to activate small molecules such as hydrogen, CO2, and ethene. This cooperative Lewis pair facilitates the coupling of CO and ethene in a new way

    Semblance analysis to assess GPR data from a five-year forensic study of simulated clandestine graves

    Get PDF
    Ground penetrating radar (GPR) surveys have proven useful for locating clandestine graves in a number of forensic searches. There has been extensive research into the geophysical monitoring of simulated clandestine graves in different burial scenarios and ground conditions. Whilst these studies have been used to suggest optimum dominant radar frequencies, the data themselves have not been quantitatively analysed to-date. This study uses a common-offset configuration of semblance analysis, both to characterise velocity trends from GPR diffraction hyperbolae and, since the magnitude of a semblance response is proportional to signal-to-noise ratio, to quantify the strength of a forensic GPR response. 2D GPR profiles were acquired over a simulated clandestine burial, with a wrapped-pig cadaver monitored at three-month intervals between 2008 and 2013 with GPR antennas of three different centre-frequencies (110, 225 and 450 MHz). The GPR response to the cadaver was a strong diffraction hyperbola. Results show, in contrast to resistivity surveys, that semblance analysis show little sensitivity to changes attributable to decomposition, and only a subtle influence of seasonality: velocity increases (0.01–0.02 m/ns) were observed in summer, associated with a decrease (5–10%) in peak semblance magnitude, SM, and potentially in the reflectivity of the cadaver. The lowest-frequency antennas consistently gave the highest signal-to-noise ratio although the grave was nonetheless detectable by all frequencies trialled. These observations suggest that forensic GPR surveys could be undertaken with little seasonal hindrance. Whilst GPR analysis cannot currently provide a quantitative diagnostic proxy for time-since-burial, the consistency of responses suggests that graves will remain detectable beyond the five years shown here

    Geophysical monitoring of simulated homicide burials for forensic investigations

    Get PDF
    Finding hidden bodies, believed to have been murdered and buried, is problematic, expensive in terms of human resource and currently has low success rates for law enforcement agencies. Here we present, for the first time, ten years of multidisciplinary geophysical monitoring of simulated clandestine graves using animal analogues. Results will provide forensic search teams with crucial information on optimal detection techniques, equipment configuration and datasets for comparison to active and unsolved cold case searches. Electrical Resistivity (ER) surveys showed a naked burial produced large, low-resistivity anomalies for up to four years, but then the body became difficult to image. A wrapped burial had consistent small, high-resistivity anomalies for four years, then large high-resistivity anomalies until the survey period end. Ground Penetrating Radar (GPR) 110-900 MHz surveys showed the wrapped burial could be detected throughout. 225 MHz GPR data was optimal, but the naked burial was poorly imaged after six years. Results suggested conducting both ER and GPR surveys if the burial style was unknown when searching for interred remains. Surveys in winter and spring produced the best datasets, and, as post-burial time increases, surveying in these seasons became increasingly important. This multidisciplinary study provides critical new insights for law enforcement and families of the disappeared worldwide

    Geophysical and botanical monitoring of simulated graves in a tropical rainforest, Colombia, South America

    Get PDF
    In most Latin American countries there are significant numbers of missing people and forced disappearances, currently ~74,000 only in Colombia. Successful detection of shallow buried human remains by forensic search teams is currently difficult in varying terrain and climates. Within this research we built four simulated clandestine burial styles in tropical rainforests, as this is a common scenario and depositional environment encountered in Latin America, to gain knowledge of optimum forensic geophysics detection techniques. The results of geophysically monitoring these burials using ground penetrating radar, magnetic susceptibility, bulk ground conductivity and electrical resistivity are presented from one to forty three weeks post-burial. Radar survey results with both the 250 MHz and 500 MHz frequency antennae showed good detection of modern simulated burials on 2D profiles and horizontal time slices but poor detection on the other simulated graves. Magnetic susceptibility, bulk ground conductivity and electrical resistivity results were generally poor at detecting the simulated targets. Observations of botanical variations on the test site show rapid re-growth of Malvaceae and Petiveria alliacea vegetation over all burials that are common in these forests, which can make detection more difficult

    The International Olympic Committee framework on fairness, inclusion and nondiscrimination on the basis of gender identity and sex variations does not protect fairness for female athletes

    Get PDF
    The International Olympic Committee (IOC) recently published a framework on fairness, inclusion, and nondiscrimination on the basis of gender identity and sex variations. Although we appreciate the IOC's recognition of the role of sports science and medicine in policy development, we disagree with the assertion that the IOC framework is consistent with existing scientific and medical evidence and question its recommendations for implementation. Testosterone exposure during male development results in physical differences between male and female bodies; this process underpins male athletic advantage in muscle mass, strength and power, and endurance and aerobic capacity. The IOC's “no presumption of advantage” principle disregards this reality. Studies show that transgender women (male-born individuals who identify as women) with suppressed testosterone retain muscle mass, strength, and other physical advantages compared to females; male performance advantage cannot be eliminated with testosterone suppression. The IOC's concept of “meaningful competition” is flawed because fairness of category does not hinge on closely matched performances. The female category ensures fair competition for female athletes by excluding male advantages. Case-by-case testing for transgender women may lead to stigmatization and cannot be robustly managed in practice. We argue that eligibility criteria for female competition must consider male development rather than relying on current testosterone levels. Female athletes should be recognized as the key stakeholders in the consultation and decision-making processes. We urge the IOC to reevaluate the recommendations of their Framework to include a comprehensive understanding of the biological advantages of male development to ensure fairness and safety in female sports
    corecore