Founding editorial--forensics and TheScientificWorld.
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At the beginning of a new millennium it seems a good idea to stop for a moment and take stock of the current state of forensic science. As a field of scientific research and scientific application, forensic science is a little more than a century old. Forensic science may be said to have begun in 1887 with the simultaneous publication of A. Conan Doyle's A Study in Scarlet and Hans Gross's Handbuch f1/4r Untersuchungsrichter. Conan Doyle's novel introduced to the world the character of Sherlock Holmes, whose literary career would popularize the use of physical evidence in criminal investigations. Gross's manual for examining magistrates suggests ways in which the expertise of chemists, biologists, geologists, and other natural scientists could contribute to investigations. Gross's book was translated into a number of languages and went through various updated editions during the course of the century. The intervening century saw the development and application of fingerprinting, firearm and tool mark identification, forensic chemistry, forensic biology, forensic toxicology, forensic odontology, forensic pathology, and forensic engineering. Increasingly, the judicial systems of the industrial nations of the world have come to rely upon the expertise of scientists in a variety of disciplines. In most advanced countries, virtually all criminal prosecutions now involve the presentation of scientific testimony. This has had the beneficial effect of diminishing the reliance of courts on eyewitness testimony and defendant confessions. (+info)
Confirmatory analysis of ethylglucuronide in urine by liquid-chromatography/electrospray ionization/tandem mass spectrometry according to forensic guidelines.
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beta-D-ethylglucuronide (EtG) is a stable Phase II metabolite of ethanol which can be detected in urine samples several days after elimination of ethanol. It is a useful diagnostic parameter for monitoring abstinence of alcoholics in alcohol withdrawal treatment. For this purpose, determination in urine is mainly performed by LC-MS, LC-MS/MS, or by GC-MS. For the mass spectrometric identification and detection of controlled substances in more sensitive fields such as forensic toxicology, workplace drug testing, doping analysis, and veterinary organic residue control, official guidelines have been released requiring a chromatographic separation and a minimum of two mass spectrometric transitions of the analyte. However, for detection of EtG none of the published LC-MS/MS methods could fulfill the minimum requirements of any of these guidelines. Therefore, an existing LC-MS/MS method has been modified by monitoring further MS/MS transitions instead of only one (deprotonated molecule [M - H](-)/product ions: m/z 75, 85, 113, and 159 optional) with the aim of withstanding administrative or court scrutiny in forensic or workplace drug testing cases. Full method validation has been performed in accordance to guidelines of the German Society of Toxicology and Forensic Chemistry (GTFCh) and requirements of ISO 17025. One application field in the United States is a workplace monitoring program to detect surreptitious alcohol use among recovering health professionals, who by contract had agreed on total abstinence after drug and alcohol withdrawal therapy. (+info)
Teaching cell biology to nonscience majors through forensics, or how to design a killer course.
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Nonscience majors often do not respond to traditional lecture-only biology courses. However, these students still need exposure to basic biological concepts. To accomplish this goal, forensic science was paired with compatible cell biology subjects. Several topics such as human development and molecular biology were found to fulfill this purpose. Another goal was to maximize the hands-on experience of the nonscience major students. This objective was fulfilled by specific activities such as fingerprinting and DNA typing. One particularly effective teaching tool was a mock murder mystery complete with a Grand Jury trial. Another objective was to improve students' attitudes toward science. This was successful in that students felt more confident in their own scientific abilities after taking the course. In pre/post tests, students answered four questions about their ability to conduct science. All four statements showed a positive shift after the course (p values ranging from.001 to.036, df = 23; n = 24). The emphasis on experiential pedagogy was also shown to increase critical thinking skills. In pre/post testing, students in this course significantly increased their performance on critical thinking assessment tests from 33.3% correct to 45.3% (p =.008, df = 4; n = 24). (+info)
Gas chromatographic optimization studies on the side chain and ring regioisomers of methylenedioxymethamphetamine.
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Gas chromatographic (GC) optimization studies are conducted for the 10 methylenedioxyphenethylamine regioisomeric substances related to the drug of abuse 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy). These 10 compounds, having the same molecular weight and equivalent major mass spectral fragments, are not completely resolved using typical GC-mass spectrometry screening methods for illicit drugs. MDMA coelutes with at least one nondrug regioisomer under standard drug screening conditions. Separation of the 10 regioisomers is studied using stationary phases of varying polarities. Resolution optimization shows that very slow program rates give the best separation for the nonpolar stationary phases, requiring analysis times of as much as 85 min. Narrow-bore columns containing the same nonpolar stationary phases improve the analysis time to approximately 29 min. The polar stationary phase DB-35MS allows high-temperature programming rates, yielding complete resolution of all 10 compounds in less than 7 min. Temperature program optimization studies on the DB-35MS phase allow the separation time to be reduced to approximately 4.5 min. (+info)
Forensic genetics and ethical, legal and social implications beyond the clinic.
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Data on human genetic variation help scientists to understand human origins, susceptibility to illness and genetic causes of disease. Destructive episodes in the history of genetic research make it crucial to consider the ethical and social implications of research in genomics, especially human genetic variation. The analysis of ethical, legal and social implications should be integrated into genetic research, with the participation of scientists who can anticipate and monitor the full range of possible applications of the research from the earliest stages. The design and implementation of research directs the ways in which its results can be used, and data and technology, rather than ethical considerations or social needs, drive the use of science in unintended ways. Here we examine forensic genetics and argue that all geneticists should anticipate the ethical and social issues associated with nonmedical applications of genetic variation research. (+info)
After the Indian Ocean tsunami: Singapore's contribution to the international disaster victim identification effort in Thailand.
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This paper describes the international disaster victim identification (DVI) response mounted in Thailand, with particular reference to Singapore's contribution to this process, in the wake of the Asian tsunami of 26 December, 2004, which devastated parts of more than 10 countries in and around the Indian Ocean and claimed more than 200,000 lives. Although Singapore was unscathed by this natural calamity, over 30 Singaporean visitors were counted amongst the thousands of deceased victims, mostly in Thailand. The systematic application of forensic pathology, forensic dentistry, DNA profiling, and fingerprinting to human identification, especially of the bodies of various nationalities that were in advanced states of putrefaction, was crucial to the entire DVI process. The authors perceive that the resource implications arising from such a disaster, which is unprecedented in both its scale and reach in the international history of DVI, are immense. Forward planning, adequate funding and international cooperation are essential to mounting an effective response to any major mass disaster of the future. (+info)
Differentiation of spores of Bacillus subtilis grown in different media by elemental characterization using time-of-flight secondary ion mass spectrometry.
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We demonstrate the use of time-of-flight secondary ion mass spectrometry (TOF-SIMS) in a forensics application to distinguish Bacillus subtilis spores grown in various media based on the elemental signatures of the spores. Triplicate cultures grown in each of four different media were analyzed to obtain TOF-SIMS signatures comprised of 16 elemental intensities. Analysis of variance was unable to distinguish growth medium types based on 40Ca-normalized signatures of any single normalized element. Principal component analysis proved successful in separating the spores into groups consistent with the media in which they were prepared. Confusion matrices constructed using nearest-neighbor classification of the PCA scores confirmed the predictive utility of TOF-SIMS elemental signatures in identifying sporulation medium. Theoretical calculations based on the number and density of spores in an analysis area indicate an analytical sample size of about 1 ng, making this technique an attractive method for bioforensics applications. (+info)
Photofading of ballpoint dyes studied on paper by LDI and MALDI MS.
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The determination of the age of an ink entry from a questioned document is often a major problem and a controversial issue in forensic sciences. Therefore, it is important to understand the aging process of the different components found in ink. The aim of this work is to characterize the degradation processes of methyl violet and ethyl violet, two typical ballpoint dyes by using laser desorption/ionization (LDI) and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS), and to evaluate the possible application of the method to forensic examination of documents. The mass spectrometric methods were first tested and were found to be adequate for the purpose of this work. Moreover, it is possible to analyze the dye from a stroke directly from the paper (LDI-MS), so the sample preparation is minimized. The degradation of the dyes methyl violet and ethyl violet in strokes from a ballpoint pen was studied under laboratory conditions influenced by different factors such as light, wavelength of light, heat, and humidity. Then, strokes from the same ballpoint were aged naturally in the dark or under the influence of light over one year and then analyzed. The results show that the degradation of these dyes strongly depends on light fluence. Humidity also increases degradation, which can be explained by the basicity of the paper. The influence of heat on the degradation process was found to be rather weak. It was also observed that the dyes from the ink strokes did not show significant degradation after one year of storage in the dark. In conclusion, the storage conditions of a questioned document and the initial composition of the dyes in the ink have to be known for correct interpretation of the age of an ink entry. Measurements over longer periods of time are necessary to follow the degradation of dyes exempt from light exposure. LDI was found adequate and very useful for the analysis of ballpoint dyes directly from paper without further pretreatment. (+info)