A quantitative comparison of smokeless measurements

Measurements of the type and concentration of propellant and stabilizer additives in smokeless gunpowder are used by forensic scientists investigating the source of explosives and by military laboratories assuring the safety and efficacy of munitions. The National Institute of Standards and Technology recently assessed the state-of-the-practice of smokeless powder measurements through an international measurement comparison exercise. We here present results provided by the five participants (of 20 total) reporting quantitative as well as qualitative values for two handgun reloading powders. All five of these participants reported values for nitroglycerin (NG), ethyl centralite (EC), diphenylamine (DPA), and N-nitrosodiphenylamine (NnDPA). Several participants additionally reported the concentrations of secondary stabilizer decomposition products. The unstable NG propellant additive appears to be more susceptible to method-specific calibration biases then are the stabilizer additives. All results from one participant were strongly biased relative to those of the other four. The within-participant measurement uncertainties for all analytes were self-reported to be 1 to 5% relative; among the four concordant participants, the measurement ranges are 5 to 10% relative. There was little consistency among the participants as to what components of measurement variance were included in their uncertainty statements. A discussion of the certainties in these measurements and factors that affect the accuracy of gunpowder additive determinations is presented.     

Stature and gender estimation using foot measurements

In forensic investigation difficulties are being experienced in the stature and gender estimation of bodies dismembered in mass destruction. So as to eliminate these difficulties, new methods are being developed. The aim of this study is to develop formulae for estimation of the stature and gender through foot measurements when necessary. For this purpose, the length, width, malleol height, navicular height measurements of the right and left foot as well as stature have been taken from the 249 subjects who are attending Medical Faculty of Dokuz Eylul University and School of Physical Therapy and Rehabilitation in Turkey. In males, stature and foot measurements were higher than in females, and the difference between the average measures was significant. The highest correlation was observed in the right and left foot length for female, male and study (mix-gender group) groups when stature and foot measurement relations were evaluated. The lowest correlation was observed in foot width for the right foot in all groups but, differed in left foot measurements for each group. Formulae were obtained by using multiple regression analysis for stature estimation and logistic regression analysis for gender estimation. As a consequence, whilst stature estimation formulae, depending on the gender, allow 9-10 cm errors, those that are independent on the gender help make estimation with less than 4 cm errors. Gender estimation formula can help determine the gender with 95.6% accuracy via right foot measurements, and 96.4% accuracy via left foot measurements. In population similar to our subjects, stature and gender estimation can be made by using foot measurements.     

Sexing of human clavicles using length and circumference measurements

Measurement of clavicular length and circumference, and computation of clavicular robustness and length-circumference product from 724 autopsied adults of known age, sex, and body length between the ages of 15 and 96 years produced useful sex-predictive values. This predominantly North American white population contained 560 males and 164 females with intact, nondeformed clavicles. Clavicle length and circumference and particularly their product have been found useful in sexing, but robustness as a single trait has not. Despite a significant overlap of male and female values, the use of single cutoff values allowed correct sex assignment of up to 93% of the entire study population, including 94% of males and 89% of females. The ratios of body length to clavicle circumference and to clavicle length are on average greater in women than in men. The former ratio yields male predictive values greater than 95% for those individuals with ratios falling below the cutoff value of 43, whereas the latter ratio is a relatively poor sex predictor.     

Haptoglobin typing of human bloodstains using a specific DNA probe

The stability of DNA in human bloodstains and various post mortem tissues has been investigated. High molecular weight (HMW) DNA was usually recovered from dried bloodstains, even those up to a few years old, but very rapid degradation was found to occur post mortem in the liver, pancreas, spleen and kidney. Other tissues such as the heart, thyroid and skeletal muscle were found to give a reasonable yield of HMW DNA during the first few days after death. The feasibility of using DNA extracted from forensic bloodstain specimens for the detection of DNA polymorphisms was explored using a human haptoglobin (Hp) alpha chain specific probe. Using HindIII and XbaI digests the Hp genotypes Hp2, Hp1F and Hp1S were distinguished by Southern blot analysis in DNA prepared from 1 cm2 bloodstains up to 15-18 months old.     

Colorimetric measurements on small paint fragments using microspectrophotometry

The use of the Nanospec 10S microspectrophotometer (Nanometrics Inc.) as a colour-coding instrument for small paint fragments and individual layers within a layer structure is described.The CIE system of colour notation is discussed and numerical values for colours within the CIE system are derived from reflectance measurements made with the microspectrophotometer.     

Sex assessment using measurements of the first lumbar vertebra

Sex determination is a vital part of the medico-legal system but can be difficult in cases where the integrity of the body has been compromised. The purpose of this study was to develop a technique for sex assessment from measurements of the first lumber vertebrate. Twenty-nine linear measurements and five ratios were collected from 113 Chinese adult males and 97 Chinese adult females using digital three-dimensional anthropometry methods. By using discriminant analysis, we found that 23 linear measurements and two ratios identified sexual dimorphism (P<0.01), with predictive accuracy ranging from 57.1% to 86.6%. Using a stepwise method of discriminant function analysis, we found three dimensions predicted sex with 88.6% accuracy: (a) upper end-plate width (EPWu), (b) left pedicle height (PHl), and (c) middle end-plate depth (EPDm). This study shows that a single first lumber vertebra can be used for this purpose, and that the discriminant equation will help forensic determination of sex in the Chinese population.     

An evaluation of determination of handedness using standard osteological measurements

Numerous studies have assessed side dominance assuming arm bones on the side of handedness will be larger, but concerns over sample size or replicability of measurements usually emerged. Attempting to improve upon these limitations, this investigation analyzes patterns of side difference for standard length and transverse dimensions of the scapula, clavicle, humerus, ulna, and radius for 137 individuals of known handedness. The results showed that with few exceptions, the right side of the skeleton was consistently larger in most individuals regardless of side dominance. Combinations of other measurements previously suggested to be indicative of handedness as well as the use of discriminant analysis also failed to provide reliable estimators. These findings are likely related to the fact that activities of modern individuals are generally not sufficiently unilateral in their stresses to cause asymmetrical development in the arm bones. Therefore, it is recommended that other means be developed to assess side dominance.     

Long‐term Geophysical Monitoring of Simulated Clandestine Graves using Electrical and Ground Penetrating Radar Methods: 4–6 Years After Burial

This ongoing monitoring study provides forensic search teams with systematic geophysical data over simulated clandestine graves for comparison to active cases. Simulated “wrapped,” “naked,” and “control” burials were created. Multiple geophysical surveys were collected over 6 years, here showing data from 4 to 6 years after burial. Electrical resistivity (twin electrode and ERI), multifrequency GPR, grave and background soil water were collected. Resistivity surveys revealed that the naked burial had low‐resistivity anomalies up to year four but then difficult to image, whereas the wrapped burial had consistent large high‐resistivity anomalies. GPR 110‐ to 900‐MHz frequency surveys showed that the wrapped burial could be detected throughout, but the naked burial was either not detectable or poorly resolved. 225‐MHz frequency GPR data were optimal. Soil water analyses showed decreasing (years 4 to 5) to background (year 6) conductivity values. Results suggest both resistivity and GPR surveying if burial style unknown, with winter to spring surveys optimal and increasingly important as time increases.     

不同方式标记非放射性探针原位杂交效果评价

目的比较不同方式标记非放射性探针的原位杂交效果。方法通过两种方法标记地高辛随机引物DNA探针和反意RNA探针,在大鼠损伤模型的皮肤组织上进行原位杂交。结果两种探针均可满足要求,以反意RNA探针在阳性染色深度和背景方面效果更佳。结论RNA探针在杂交效果方面优于DNA探针。     

Automated detection and classification of counterfeit banknotes using quantitative features captured by spectral-domain optical coherence tomography

Counterfeiting of banknotes is still a severe crime problem in many countries. One of the most significant issue for solving the crime is to classify the counterfeit types and identify the sources. Most of the current methods to classify counterfeit banknotes rely on manual examination that is time-consuming and labor-intensive. Moreover, these methods only detect surface features which can be easily imitated through advanced printing technology. In this study, an automated method based on optical coherence tomography (OCT) and machine-learning algorithms was proposed to classify different types of banknotes based on the internal features. A spectral-domain OCT (SD-OCT) system was employed for sub-surface imaging and quantitative assessment of banknotes. A total of 29 Chinese 100-Yuan banknotes were collected, in which 4 of them were real and 25 of them were counterfeiting by three different printing processes. Each banknote was imaged 10 times in 3 distinct regions, which resulted in a dataset of 290 samples. Each sample was characterized by extracting 2 A-scan (OCT signal intensity along depth) based features and 14B-scan (cross-sectional OCT images) based features. Several machine-learning models, including logistic regression (LR), support vector machines (SVM), K-nearest neighbor (KNN) and random forest (RF), were built and optimized as the classifiers that were trained using 203 samples and applied to predict 87 testing samples. The best performance was achieved by SVM classifier in which the sensitivity of 96.55% and specificity of 98.85% were obtained in discriminating between authentic and counterfeit banknotes, and the sensitivity of 94.67% and specificity of 98.22% were obtained in predicting the types of counterfeit banknotes. These classifiers were also evaluated using the receiver operating characteristic (ROC) curves. To the best of our knowledge, this is the first study where A-scan and B-scan derived features from OCT images have been used for the detection and classification of different types of counterfeit banknotes.     

Report of a European collaborative exercise comparing DNA typing results using a single locus VNTR probe

A collaborative exercise was carried out in 1989 among 12 European forensic laboratories using the single locus VNTR probe pYNH24, the restriction enzyme HinfI, the same set of human genomic DNA samples, and a standardized DNA size marker. The objectives of the exercise were: (1) to study the degree of variation within and between laboratories, (2) to obtain information on requirements for technical standardization allowing the exchange of typing results and (3) to compare different approaches for the identification of allelic DNA fragments of unknown size. Each laboratory carried out up to 10 independent typing experiments using the same DNA samples. The results were analysed independently by two laboratories using three different methods. The results of the exercise demonstrate the correlation of typing that can be achieved within and between laboratories under conditions of minimal standardization.     

Burial Patterns during Times of Armed Conflict in Cyprus in the 1960s and 1970s

The island of Cyprus experienced two periods of intercommunal conflict during which c. 2000 individuals went missing. The Committee on Missing Persons in Cyprus began a program of exhumations in 2005, through which more than 185 burial sites pertaining to the two periods of conflict have been identified and excavated. The aim of this study was twofold: (i) to present a classification of the main types of clandestine burial and (ii) to test the hypothesis that the nature of conflict influences the mode of interment. Burials can be divided into “public burials” and “concealed burials,” based on the possible motives of those involved in the interment and then subdivided into smaller categories based on similarities in archeological context. A comparison of results from the two periods of conflict reveals that there are statistical differences (p < 0.005), which indicate that the mode of interment may reflect the nature, character, and atmosphere of conflict.     

The accuracy of three methods of age estimation using radiographic measurements of developing teeth

The accuracy of age estimation using three quantitative methods of developing permanent teeth was investigated. These were M?rnstad et al. [Scand. J. Dent. Res. 102 (1994) 137], Liversidge and Molleson [J. For. Sci. 44 (1999) 917] and Carels et al. [J. Biol. Bucc. 19 (1991) 297]. The sample consisted of 145 white Caucasian children (75 girls, 70 boys) aged between 8 and 13 years. Tooth length and apex width of mandibular canine, premolars and first and second molars were measured from orthopantomographs using a digitiser. These data were substituted into equations from the three methods and estimated age was calculated and compared to chronological age. Age was under-estimated in boys and girls using all the three methods; the mean difference between chronological and estimated ages for method I was -0.83 (standard deviation +/-0.96) years for boys and -0.67 (+/-0.76) years for girls; method II -0.79 (+/-0.93) and -0.63 (+/-0.92); method III -1.03 (+/-1.48) and -1.35 (+/-1.11) for boys and girls, respectively. Further analysis of age cohorts, found the most accurate method to be method I for the age group 8.00-8.99 years where age could be predicted to 0.14+/-0.44 years (boys) and 0.10+/-0.32 years (girls). Accuracy was greater for younger children compared to older children and this decreased with age.     

Location,location, location: Interdistrict and intercircuit variation in sentencing outcomes for federal drug-trafficking offenses

Research on sentencing has made clear that factors beyond case and offenders' attributes influence court decisions. Environmental and procedural characteristics also significantly affect the sentences of criminal courts. Yet, while state-level studies regularly control for such factors, most research on modern federal determinate sentencing has neglected jurisdictional attributes and variation as sources of extralegal sentence disparity. Using the organizational context and social worlds theoretical perspectives with a multilevel analytical approach, this study assessed how district and circuit of adjudication affect case-level lengths of sentences for federal drug-trafficking offenses, finding that both significantly affect sentencing outcomes and their predictors.     

A multivariate method for classifying third to seventh cervical newborn vertebrae using bone measurements.

This research provides a method to classify human newborn (9 to 10 lm) third to seventh cervical ossification centers. Nine linear measurements on the cervical neural arch were defined from 35 human neonates. Four discriminant functions were performed using the stepwise method. The model classifies 82.8% of grouped cases and 77.9% of cross-validated cases correctly. The model is useful in cases with isolated or commingled remains during anthropological or forensic investigations.     

Biostatistical basis of individualization and segregation analysis using the multilocus DNA probe MZ 1.3: results of a collaborative study.

A collaborative study using the multilocus minisatellite DNA probe MZ 1.3 was carried out to investigate segregation information, mutation rate, DNA fragment frequencies as well as band sharing characteristics. The fingerprint patterns of 393 children as well as 694 unrelated individuals were analysed after digestion of DNA with the restriction enzyme HinfI. A mutation rate of 1% per meiosis or 0.04% per band was found with a mean number of 26 bands/individual. It was shown that maternal and paternal fragments are inherited in equal proportions. Population frequencies of restriction fragments demonstrated a distribution with increasing frequencies in the small fragment size range below 10 kb as well as the absence of very common or very rare fragments. Our data can be used to calculate simple exclusion probabilities based on the number of non-maternal bands in the child.     

Detection of human proteins in buried blood using ELISA and monoclonal antibodies: towards the reliable species indentification of blood stains on buried material.

The survival of human proteins in blood stains on fragments of cloth buried in exposed soil was examined in a 15-month investigation carried out from September 1990 to December 1991. During this period there was a wide variety of weather conditions. Samples were exhumed at 4-weekly intervals for 16 weeks and finally at 65 weeks; extracts of the stains were tested for albumin and IgG using a highly specific and sensitive enzyme-linked immunosorbent assay (ELISA) performed with monoclonal antibodies. Human albumin survived well throughout the 15 months of study, but IgG could be detected only in the 4- and 8-week samples. The reactions for IgG were weaker than those for albumin, although the method's sensitivity (10 ng) was the same for each protein. Appropriate buried and non-buried control experiments were carried out using cloth, either unstained or stained with human blood or animal sera; there was no cross-reactivity between human and the other species investigated and soil did not affect the assay; under laboratory conditions, IgG and albumin survived equally well. The system's versatility was illustrated by using monoclonal anti-bovine-albumin to detect specific albumin in the extracts of buried cloth which has been stained with bovine serum. It was concluded that ELISA performed with monoclonal antibodies could be of great value in identifying blood stains for forensic purposes.(ABSTRACT TRUNCATED AT 250 WORDS)