Age Estimation by Amino Acid Racemization in Human Teeth

Abstract: When an unidentified body is found, it is essential to establish the personal identity of the body in addition to investigating the cause of death. Identification is one of the most important functions of forensic dentistry. Fingerprint, dental, and DNA analysis can be used to accurately identify a body. However, if no information is available for identification, age estimation can contribute to the resolution of a case. The authors have been using aspartic acid racemization rates in dentin (D‐aspartic acid/L ‐ aspartic acid : D/L Asp) as an index for age estimation and have obtained satisfactory results. We report five cases of age estimation using the racemization method. In all five cases, estimated ages were accurate within a range ±3 years. We conclude that the racemization method is a reliable and practical method for estimating age.     

Marine bacteria comprise a possible indicator of drowning in seawater

To investigate the effectiveness of marine bacteria as a new marker of drowning in seawater, we determined the optimal conditions of media required to selectively detect marine bacteria and applied the technique to drowned cadavers. We incubated model blood samples (n=20 per group) mixed with seawater, river, tap or muddy water on agar plates (Todd Hewitt, TH; Marine 2216, M2216) and determined the NaCl concentration required to selectively detect marine bacteria. We also used TCBS agar plates without manipulation to isolate Vibrio spp. Among the culture media, TH agar was superior. Bioluminescent colonies were detected only in blood mixed with seawater. Blue colonies stained using the cytochrome oxidase test (COT), were detected in blood mixed with both sea and river water. However when the NaCl concentration was above 4%, COT stained colonies were detectable only in blood mixed with seawater. We subsequently used 2, 3 and 4% NaCl in TH and TCBS agar to examine blood from victims who had drowned in seawater (n=8) and in fresh water (n=7), as well as from victims who died near aquatic environments (non drowned; dry-land control, n=7). Bioluminescent colonies were detectable on 2-4% NaCl TH agar only from two victims that drowned in seawater. Bioluminescent colonies did not grow on TCBS agar. Blue colonies from all cadavers that had drowned in seawater (8/8) and in four of those that had drowned in fresh water (4/7) proliferated on TH agar containing 2% and/or 3% NaCl, but at 4% NaCl such colonies were detected only from cadavers that had drowned in seawater (8/8). Colonies from only one cadaver from seawater grew on TCBS agar. Furthermore, neither bioluminescent nor blue colonies were detected on TH agar containing 4% NaCl in samples from two cadavers found in an estuary (brackish water) who were thought to have been carried from areas of fresh water. Homologous analyses of the 16S rRNA gene revealed that the dominant colonies on TH agar containing 4% NaCl were marine bacteria (Photobacterium, Vibrio, Shewanella, Psychrobacter). Thus, proliferating bioluminescent and/or blue colonies detected in the blood of immersed cadavers using 4% NaCl TH agar, could help to establish drowning in seawater.     

Japan＇s ＂unsettling＂ past： Article 11 of San Francisco Peace Treaty and its ramlncatlons

Article 11 of the Treaty of Peace with Japan （San Francisco Peace Treaty） has become a rallying point for some activists and historians in their endeavor to have Japan recognize its ＂war responsibility＂ and redress its ＂unsettled past＂. The provision stipulates Japan＇s acceptance of the ＂judgments of the International Military Tribunal for the Far East and of other Allied War Crimes Courts both within and outside Japan＂. The wording of this provision, which is ambiguous enough to leave a room for its re-interpretation later, was a result of a compromise among the World War lI Allies. Yet, neither archival investigation of the article＇s drafting process nor a survey of the opinions of U.S. legal experts in the public international did not prove the validity of the revisionist thesis. Nevertheless, the treaties Japan signed with its former colony （Korea） and belligerent （China） left the settlement of war-related issues obscure, creating a leeway for initiating later controversies. The end of the Cold War heralded the re-evaluation of World War I1 settlements. The subsequently created agitated environment surrounding the historical discussion of Japan＇s so-called ＂unsettled＂ past has been ＂unsettling＂ enough to prevent the Japanese leaders from establishing a uniform interpretation of Article l l, and has added impetus to the movements pressuring Japan to recognize its ＂war responsibility＂. Although interested parties have so far cited Article 11 mainly to demand ＂inaction＂ from Japan, such as to discourage Japanese political leaders from visiting the Yasukuni Shrine, there is a growing indication that some may well utilize it to demand Japan＇s ＂action＂--to pay indemnities to the victims of Japan＇s alleged atrocities through various forms of redress movements.     

Defendant and juror race in a necessity case: An ultimate attribution error

This study investigated whether Black and White mock jurors would commit the ultimate attribution error (i.e., over-rely on dispositional explanations to understand the negative actions of out-group members) in a necessity defense case. Participants (N = 97) read a fictional looting case, in which the race of the defendant varied. Mock jurors were expected to show out-group severity through more guilty verdicts and blame attributions. Mock juror and defendant race were not significantly related to verdicts, but for the Black defendant, White mock jurors attributed more control to him, and believed he was likely to reoffend more so than did Black mock jurors. This study adds to the literature on the mechanism by which racial bias interferes with juror decisions.     

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.     

Discrimination of paper-based kraft tapes using Fourier transform of transmitted light images

This study focused on two-dimensional fast Fourier transform (2D-FFT) as a new technique for the discrimination of kraft tapes, which is a kind of adhesive packing tape. The 2D power spectrum (2D-PS) obtained by applying 2D-FFT to an image enables us to obtain information about the spatial periodicity, even if the periodicity is invisible within the image. However, in the case of kraft tape, peaks in the 2D-PS are too unclear to determine its periodicity. We developed novel analytical image processes combined with 2D-FFT. 2D-FFT was applied to 50 randomly selected areas in a transmitted light image of kraft tape. The 2D-PSs were calculated from each area without applying a logarithmic transformation, accumulated, and processed by the removal of the area surrounding the center, and finally normalized for visualization. These processes enhanced the peaks and eliminated local variations. Through an intra-roll comparison, the 2D-PSs collected from a roll were similar in the location of the peaks and in their patterns at low frequency area. Using an inter-roll comparison, the 2D-PSs from 50 commercially available brand-name products were classified into 26 groups based on these peaks and patterns. All results demonstrate that this method, which is convenient, rapid, and non-destructive, could be a valuable tool for the identification of kraft tapes.     

Case illustrations of negative sexual experiences among university women in Japan: victimization disclosure and reactions of the confidant

A retrospective study of negative sexual experiences (NSEs) was conducted among 532 Japanese university women. More than one third of the respondents reported having experienced at least one NSE, and two thirds were victimized by strangers. When the woman knew the perpetrator well, the NSE was more likely to be repeated. One sixth of victims did not disclose the incident. Older children disclosed incidents more frequently than did younger children. Women in the total disclosure group disclosed the incidents more quickly than did those in the partial disclosure group. Women victimized by strangers were more likely to disclose the incident completely. Less than 10% of women were disappointed with the reaction of the first-disclosure receiver. Unlike results obtained in previous studies, the victims did not necessarily regard it negatively when the incident was viewed less seriously or they were criticized by first-disclosure receivers. On the other hand, instrumental support was not always supportive.     

Proposal for internet-based Digital Dental Chart for personal dental identification in forensics

A dental chart is very useful as a standard source of evidence in the personal identification of bodies. However, the kind of dental chart available will often vary as a number of types of odontogram have been developed where the visual representation of dental conditions has relied on hand-drawn representation. We propose the Digital Dental Chart (DDC) as a new style of dental chart, especially for open investigations aimed at establishing the identity of unknown bodies. Each DDC is constructed using actual oral digital images and dental data, and is easy to upload onto an Internet website. The DDC is a more useful forensic resource than the standard types of dental chart in current use as it has several advantages, among which are its ability to carry a large volume of information and reproduce dental conditions clearly and in detail on a cost-effective basis.