The influence of right or left handedness on the ability to simulate handwritten signatures and some elements of signatures: A study of Arabic writers

It has been widely assumed since the 1970s that right-handed writers, on average, do not write or simulate handwriting any better than left-handed writers. This study has dug deeper into that question, to find narrow language environments which left-handed and right-handed writers simulate with different degrees of success or making different types of errors. These might provide useful markers of handedness in writers or forgers. The sample of 823 native Arabic-writing adults, 763 right handed and 60 left handed, first attempted to simulate two Arabic signatures. As expected, the accuracy of the simulations of the two groups was not significantly different. Simulation accuracy of a variety of narrower elements was then measured to search for small environments in which the two groups performed differently. Two elements – slant and alignment – were significantly more poorly simulated by left-handed subjects than right-handed subjects, although the differences were not great enough to be useful in suggesting the handedness of a forger. These differences in simulation accuracy were not totally explored or explained. Instead, the differences in types of errors to slant and to alignment were investigated. Left-handed simulators, but not right-handed simulators, showed a strong tendency that had been predicted for both groups: to slant strokes and letters toward the side of the writing hand, when the target strokes and letters slanted in the opposite direction. The difference between the handedness groups was great enough that a strong preference for leftward slant in an Arabic writer or forger might suggest left handedness, but not, of course, rule out right handedness. Right-handed simulators, but not left-handed simulators, showed a strong tendency that had also been predicted for both groups: for the line of writing to be higher on the side where the writing hand was located. Again, the difference between handedness groups was great enough that a strong tendency for the writing line to fall to the left in Arabic writing and simulation might suggest right handedness, but would certainly not rule out left handedness. Thus, suggestive, but not absolute, markers of handedness have been found. In an effort to explain these almost mirror-image patterns, it was noticed that the operation of two more tendencies, in addition to the operation in both groups of the two predicted tendencies, might explain the patterns of the data. If we assume that both handedness groups tended to slant toward the writing hand and tended to make the writing line higher on the side of the writing hand, the two other tendencies operating in both groups would have been a tendency to slant strokes and letters toward the end of the writing line, and a tendency for writing to fall toward the end of the writing line. The operation of these four tendencies would account quite well for the right-handed and left-handed patterns in the two groups.     

Suicidal single gunshot injury to the head: differences in site of entrance wound and direction of the bullet path between right- and left-handed--an autopsy study

The aim of this study was to determine the differences in the anatomical site of a gunshot entrance wound and the direction of the bullet path between right- and left-handed subjects who committed a suicide by a single gunshot injury to the head. The retrospective autopsy study was performed for a 10-year period, and it included selected cases of single suicidal gunshot head injury, committed by handguns. We considered only contact or near-contact wounds. The sample included 479 deceased, with average age 47.1 ± 19.1 years (range, 12-89 years): 432 males and 47 females, with 317 right-handed, 25 left-handed, and 137 subjects with unknown dominant hand. In our observed sample, most cases involved the right temple as the site of entrance gunshot wound (about 67%), followed by the mouth (16%), forehead (7%), left temple (6%), submental (2%), and parietal region (1%). The left temple, right temple, and forehead were the sites of the gunshot entrance wounds, which were the best predictors of the handedness of the deceased (Spearman ρ = 0.149, P = 0.006). Our study showed that the direction of the bullet intracranial path in cases of suicide was even a more potent predictor of the handedness of the deceased (Spearman ρ = 0.263, P = 0.000; Wald = 149.503, P = 0.000).     

Bilateral asymmetry of long arm bones and jugular foramen: implications for handedness

The analysis of asymmetry of the arm long bones and of the cranial jugular foramen has been used to suggest handedness in humans. However, because of the unavailability of documented skeletal material, neither criterion has been systematically tested. If both criteria are associated with handedness, they should also be intercorrelated within individuals. Data were collected from skeletal material of 125 males and 57 females to test whether this intercorrelation exists. According to Chi-square analysis, no statistically significant association was identified. After examining several hypotheses, it was concluded that until further substantiation, neither criterion is related to handedness to a degree appropriate for forensic science identification from skeletal remains.     

浅谈左手书写者左右手笔迹的特点及变化规律

目的为左手书写者左手笔迹及右手笔迹的检验鉴定提供参考依据。方法收集左手书写者的左手正常笔迹和其右手笔迹,进行比对检验和实验数据统计分析。探讨左手书写者左手笔迹和右手笔迹的特点及变化规律。将左手书写者的左、右手笔迹的特点和变化规律与右手书写者的右、左手笔迹的特点和变化规律进行比较。结果左手书写者的左手笔迹和右手笔迹在笔顺、写法、错别字等特征上保持稳定。结论左手书写者的笔迹检验应结合其左手笔迹和右手笔迹的特点和变化规律,并注意其与右手书写者的右手笔迹和左手笔迹的特点和变化规律的区别与联系。     

Development and morphology of the sternal foramen

Bony defects (foramina) in the sternum were found in 6.7% of a large contemporary autopsy population. Usually solitary and located in the body of the sternum, these defects rarely occur multiply and in the manubrium. They have been found in children as young as 8 years as well as in persons of advanced age. Multiple mesosternal foramina and a manubrial foramen are described here for the first time. Sternal foramina form along lines of fusion of multiple centers of ossification and are the result of incomplete fusion. They have been misinterpreted as acquired lesions, usually gunshot wounds.     

Testing the effectiveness of two cranial base foramina for metric sex assessment of fragmentary remains

Sex differences in linear and area dimensions of the foramen ovale and external opening of the carotid canal were analyzed in a documented French sample (35 men and 32 women). The results demonstrated that a low level of sexual dimorphism is present in the cranial base foramina of this sample, with only two-thirds of the examined variables exhibiting statistically significant differences (p < 0.05) between the sexes. The cross-validated sex classification accuracy rates obtained for univariate and multivariate discriminant functions ranged from only 54.7 to 72.1%. In addition, measurements of the cranial base foramina were found to be difficult to record with precision, with intra-observer error percentages ranging from 2.35 to 4.23%. Error rates of this magnitude may result in the misallocation of specimens. Therefore, osteometric analysis of the foramen ovale and carotid canal external opening cannot be recommended as a useful method for cranial sex assessment in this population group.     

Cone‐beam Computed Tomography for Analyzing Variations in Inferior Alveolar Canal Location in Adults in Relation to Age and Sex*

Abstract: Previous studies have indicated that the relative position of the inferior alveolar canal and its mental and mandibular foramina in adults vary with age and show sexual dimorphism. Conceivably, these purported differences could be of forensic value for determining identity of human remains. This study was designed to determine the influence of age and sex on the relative position of inferior alveolar canal and its foramina in cone‐beam computed tomography (CBCT) studies of adults. Existing CBCT studies of the maxillofacial region from dentate adult patients selected at random and ranging in age from 18 to 80 years (110 women and 55 men) were acquired, and the location of the inferior alveolar canal was assessed at three points: the mandibular foramen in axial view, the inferior alveolar canal in coronal view, and the mental foramen in coronal view. Measurements were also expressed for the mental foramen as the percentile position from the nearest superior bony crest to the inferior border; corresponding position of the mandibular foramen from the anterior to the posterior border of the mandibular ramus; and for the inferior alveolar canal at the level of first permanent molar from the nearest buccal bony surface to the lingual surface and from the superior alveolar crest to the inferior border. Regression analyses were performed on the variables with regard to the effects of age and sex. Most analyses resulted in no statistical significance (p < 0.05). A few of the sex‐specific traits demonstrated near‐statistically significant effects; however, these characterizations generally resulted in a 1% or less change per age decade. Overall, the results demonstrated that the relative location of the inferior alveolar canal and associated foramina in adults remain fairly constant without regard to age and sex.     

Can Handedness be Determined from Skeletal Remains? A Chronological Review of the Literature

Abstract: Research indicates that considerable bilateral asymmetry exists in the skeletons of primates, including humans. The published literature suggests that although this asymmetry may be influenced by handedness, it reflects other factors as well. Although exact statistics of handedness in the modern population are not available because definitions of handedness vary greatly, it is known that we live in a predominantly right‐handed world. This knowledge makes the determination of handedness in forensic cases not as paramount in importance as other determinations. Review of the published scientific evidence clearly reveals that observations and measurements of the human skeleton cannot determine handedness with the degree of confidence needed for forensic applications.     

Bilateral Asymmetry of Nutrient Foramen Position in Forearm Bones: Implications for its Use in Sorting Commingled Remains

Commingling is frequently encountered in cases examined by the Committee on Missing Persons in Cyprus, and pair‐matching is routinely used as a preliminary segregation method. Here we examine the degree of bilateral asymmetry in nutrient foramen position of the radius and ulna to determine whether nutrient foramen position may be useful in visual and/or ostetometric pair‐matching. Differences in nutrient foramen position between left‐right pairs from the same individual were compared with differences in nutrient foramen position between different individuals. Bilateral asymmetry in nutrient foramen position was found to be high, indicating that it is not a reliable trait for pair‐matching. Bilateral asymmetry and between‐person variation were found to differ between the two bones examined, suggesting that nutrient foramen position in other long bones should also be tested.     

Fatal paradoxical air embolism diagnosed by postmortem imaging and autopsy

The recognition and visualization of an arterial gas embolism are difficult. We report a case of sudden death caused by paradoxical air embolism of coronary and cerebral arteries, diagnosed by the pre autopsy computed tomography (CT) scanning. A 54-year-old woman suddenly died after the self-removal of the jugular vein catheter. Postmortem imaging examination using CT scanning showed multiple gas embolisms in the cerebral arteries, pulmonary artery, right atrium and ventricle, left ventricle, aorta, and coronary arteries. These findings suggested that the occurrence of acute ischemia of the brain and heart caused by massive air inflow to the artery. Conventional autopsy revealed a patent foramen ovale of the heart. These results indicated that the patient died of paradoxical air embolization of the coronary and cerebral arteries through a patent foramen ovale because of right-to-left shunting. The use of postmortem imaging as an aid for conventional autopsy has proved to be of advantage in the case of gas embolism.     

Roadside detection of impairment under the influence of ketamine--evaluation of ketamine impairment symptoms with reference to its concentration in oral fluid and urine

Although there are many roadside testing devices available for the screening of abused drugs, none of them can be used for the detection of ketamine, a popular abused drug in Hong Kong. In connection to local drug driving legislation, effective roadside detection of ketamine in suspected drug-impaired drivers has to be established. According to the drug evaluation and classification program (DEC), ketamine is classified in the phencyclidine (PCP) category. However, no study has been performed regarding the signs and symptoms exhibited by users under the influence of ketamine. In a study to develop a protocol for effective roadside detection of drug-impaired drivers, 62 volunteers exiting from discos were assessed using field impairment tests (FIT) that included measurements of three vital signs (i.e. body temperature, pulse rate and blood pressure), three eye examinations [pupil size, lack of convergence (LOC) and horizontal gaze nystagmus (HGN)] and four divided attention tests (Romberg, one-leg stand, finger-to-nose and walk-and-turn tests). Subsequent laboratory analysis of oral fluid and urine samples from the participants revealed the presence of common abused drugs in both the urine and oral fluid samples of 55 subjects. The remaining 7 subjects with no drug in their oral fluid samples were used as drug-free subjects. In addition, 10 volunteers from the laboratory who were regarded as drug-free subjects were also assessed using the same FIT. Among the 62 volunteers, 39 of them were detected with ketamine in their oral fluid. Of these ketamine users, 21 of them (54%) with only ketamine found in their oral fluid samples while the rest (18 subjects) of them had other drugs (i.e. MA, MDMA, benzodiazepines and/or THC) in addition to ketamine. Of the 21 ketamine-only users, 15 of them (71%) were successfully identified by FIT. It was found that when salivary ketamine concentrations were greater than 300 ng/mL, signs of impairment became evident, with over 90% detection rate using the FIT. By comparing the FIT observations on the 21 ketamine-only users with the drug-free subjects, the typical signs and symptoms observable for subjects under the influence of ketamine included LOC, HGN, elevated pulse rate and in general, failing the divided attention tests, especially the walk-and-turn and one-leg stand.     

Sexual Dimorphism in the 7th Cervical and 12th Thoracic Vertebrae from a Mediterranean Population

Sex determination is an important task in physical anthropology and forensic medicine. The study sample comprised 121 individuals of known sex, age, and cause of death from San Jose cemetery in Granada (Spain). Eight dimensions were analyzed, and discriminant function analysis was performed for each vertebra to obtain discriminating functions and study the percentage of correct assignations of these functions. The percentage accuracy was approximately 80% for both vertebrae, but varied according to the sex, being higher for the 7th cervical in males and higher for the 12th thoracic in females. As reported in other populations, the greatest dimorphism values were found for the length of the inferior surface of the vertebral body and the width and length of the vertebral foramen of the 7th cervical vertebra and for the length of the inferior surface of the vertebral body of the 12th thoracic vertebra.     

Anomalies of the human chest plate area. Radiographic findings in a large autopsy population

Anomalies of the sternal rib ends and costal cartilages, sternal foramina, and epi(supra)sternal bones from a large, modern autopsy population have been described. Rib abnormalities (duplications, fusions, and spurs) were found in 55 of 2,016 plastron roentgenograms, sternal foramina were found in 135, and episternal bones were found in 51. Sternal foramina were significantly more common in blacks than in whites and episternal bones more common in whites than blacks; rib anomalies had no recognizable racial predilection. Rib anomalies were almost three times more common in males than females, whereas episternal bones were only slightly more common in males. Sternal foramina had no sex predilection. Episternal bones were slightly more often unilateral than bilateral and, when unilateral, were twice as often located on the left. While none of the malformations studied appeared to be of clinical significance, they are of potential forensic value in individual identification.     

Suicide by carbon monoxide from car exhaust-gas in Denmark 1995-1999

In the period 1995-1999 there were 388 car exhaust-gas suicides in Denmark. Of these 343 (88.4%) were men and 45 (11.6%) were women, the average age being 47 years. The car exhaust-gas suicides made up 9.3% of all suicides in Denmark in the period. The corresponding rate was 11.7% for men and 3.7% for women. In rural areas a larger part of all suicides were committed with car exhaust-gas compared to the more densely populated areas. Mental disease was diagnosed in 124 (32.0%) cases. A suicide note was found in 165 (42.5%) cases. A hose was fitted to the exhaust pipe in 334 (86.1%) cases. Of these the 234 (60.3%) occurred outside, typically in a forest area, while 76 (19.6%) occurred in a closed garage. All the 54 (13.9%) cases with no hose fitted to the exhaust pipe occurred in a garage. Seven (1.8%) victims were found in a burning or burnt-out car, where the following investigation revealed that it was actually a car exhaust-gas suicide. Carboxyhemoglobin was measured in 26 (6.7%) victims. In two of these victims no carboxyhemoglobin was found, as they had survived for some time after the poisoning. The average saturation of the remaining victims was 67%, the lowest saturation being 20% and the highest being 84%. In the period 1969-1987 the number of car exhaust-gas suicides in Denmark increased from 50 to approximately 190 per year and the rate of car exhaust-gas suicides compared to all suicides increased from approximately 5% to approximately 13%. In 1987-1999 these figures decreased from approximately 190 to 63 per year and from 13% to approximately 8%. During these 30 years the number of passenger cars in Denmark doubled, which explains the increase in car exhaust-gas suicides during 1969-1987. A possible explanation for the decrease in 1987-1999 is the introduction of the catalytic converter, which was made mandatory in 1990. We anticipate that car exhaust-gas suicides will continue to decrease in numbers, as more cars are equipped with catalytic converters.     

Time of fusion of the basisphenoid with the basilar part of the occipital bone in northwest Indian subjects

To find out the time of fusion of the basisphenoid with the basilar part of the occipital bone in Northwest Indian subjects, a quadrilateral piece of bone extending from the posterior clinoid processes to the jugular tubercles was removed from 50 male and 34 female autopsy subjects between the ages of 10 and 20 years. The piece of bone was X-rayed and then macerated. In addition CT scan cuts of the basisphenoid were obtained in 46 male and 27 female living subjects between the age of 10 and 19 years. In the males, partial fusion was seen at 13 years while a complete fusion was noticed at 15 years in 25% of the subjects. The age of a boy showing complete fusion should be 15 years or above. If there is no fusion or partial fusion he should be below 19 years as complete fusion is seen in all male subjects at 19 years. In females, the earliest partial fusion was noted at 12 years and complete fusion was present at 13 years in 16.6%. All female subjects showed complete fusion at 17 years. The minimum age of a girl showing complete fusion should be 13 years; if no fusion or partial fusion is seen, her age should be below 17 years.     

枪弹创前置物射入口形态学的实验研究

为建立前置物射入口与典型射入口的检验鉴别方法，使用国产54式7.62mm口径手枪及56式7．62mm口径半自动步枪，以3m的距离射击约克夏种白猪义3只，同时以各种玻璃、木板。汽车门、动物躯干等物质作为中间障碍物，制成前置物射入口36例，并与对照组6例射入口进行对比观察。结果显示，前置物射入口较典型射入口增大，撕裂，创线挫伤增宽，创周出现卫星创或假点彩，创道内异物及弹头严重变形。此检验诊断方法有助于法医在实际检验中对射击距离的判断和对现场环境的分析。     

Handedness identification from intertubercular sulcus of the humerus by discriminant function analysis

The accurate determination of skeletal handedness is a critical requirement in physical anthropology and forensic science. To differentiate handedness, discriminant function analysis is applied using the parameters of right and left intertubercular sulci. A total of 200 matched unpaired adult humeri (100 right and 100 left), collected from the Department of Anatomy, were used to measure four parameters of the intertubercular sulcus namely, width (X1), depth (X2), angle of medial wall (X3) and angle of lateral wall (X4) and to note the presence of supratubercular ridge of Meyer (X5). The discriminant function obtained with the significant variables, angle of medial wall (X3), angle of lateral wall (X4) and presence of the supratubercular Meyer (X5) is: Y = 0.093X3 + 0.056X4 + 0.775X5 - 13.46. The accuracy of correct classification using the discriminant function is 89% which is the best starting point for handedness determination approach. The methodology of using discriminant function can be crucial for medicolegal jurisprudence.     

An assessment of early mandibular growth

Quantification of skeletal data has been shown to be an effective and reliable method of demonstrating variation in human growth as well as for monitoring and interpreting growth. In South Africa as well as internationally, few researchers have assessed mandibular growth in late fetal period and early childhood and therefore standards for growth and age determination in these groups are limited. The purpose of this study was to evaluate growth in the mandible from the period of 31 gestational weeks to 36 months postnatal. A total of 74 mandibles were used. Dried mandibles were sourced from the Raymond A. Dart Collection (University of Witwatersrand), and cadaveric remains were obtained from the Universities of Pretoria and the Witwatersrand. The sample was divided into four groups; 31-40 gestational weeks (group 1), 0-11 months (group 2), 12-24 months (group 3), and 25-36 months (group 4). Twenty-one osteological landmarks were digitized using a MicroScribe G2. Ten standard measurements were created and included: the maximum length of mandible, mandibular body length and width, mandibular notch width and depth, mental foramen to inferior border of mandible, mandibular basilar widths bigonial and biantegonial, bigonial width of mental foramen and mental angle. Data were analyzed using PAST statistical software and Morphologika2 v2.5. Statistically significant differences were noted in the linear measurements for all group comparisons except between groups 3 and 4. The mandible morphologically changed from a round, smooth contour anteriorly to adopt a more sharp and narrow adult shape. A progressive increase in the depth and definition of the mandibular arch was also noted. In conclusion, the mandible initially grows to accommodate the developing tongue (up to 11 months), progressive dental eruption and mastication from 12 to 36 months. Mastication is associated with muscle mass development; this would necessitate an increase in the dimensions of the mandibular notch and associated muscle attachment sites. These findings might be valuable in the estimation of age in unidentified individuals and to monitor prenatal growth of the mandible for the early diagnosis of conditions associated with stunted mandibular growth.     

Discriminant function sexing of fragmentary and complete tibiae from medieval Croatian sites

Previous studies have demonstrated that populations differ from each other in size and proportion and that these differences can affect metric assessment of sex. This paper establishes standards for determining sex from fragmentary and complete tibiae in the medieval Croatian population. The sample is composed of 180 tibiae (96 males and 84 females) from six medieval archaeological sites in Croatia. Three of the sites were located in continental Croatia, three on the eastern Adriatic coast and its immediate hinterland. Six tibial dimensions were measured: (1) length of the tibia; (2) maximum epiphyseal breadth of the proximal tibia; (3) maximum epiphyseal breadth of the distal tibia; (4) maximum diameter of the tibia at the nutritient foramen; (5) transverse diameter of the tibia at the nutritient foramen; and (6) circumference of the tibia at the nutritient foramen. Unifactorial and multifactorial analyses were performed on the collected data. Six discriminant functions were generated, one using six variables, two using two variables, and three employing one variable. Results show that complete tibiae can be sexed with 92.2% accuracy. Slightly lower accuracies (91.7 and 87.8%) were achieved using a combination of two variables, while functions employing one variable were accurate from 85.6 to 81.7%. The results of this study show that the medieval Croatian tibia is a good skeletal component for determining sex. Standardized coefficients of the discriminant functions generated in this study support the results of previous studies that found that breadth dimensions provide better separation of the sexes than length.