Postmortem iris recognition and its application in human identification

Iris recognition is a validated and non-invasive human identification technology currently implemented for the purposes of surveillance and security (i.e. border control, schools, military). Similar to deoxyribonucleic acid (DNA), irises are a highly individualizing component of the human body. Based on a lack of genetic penetrance, irises are unique between an individual’s left and right iris and between identical twins, proving to be more individualizing than DNA. At this time, little to no research has been conducted on the use of postmortem iris scanning as a biometric measurement of identification. The purpose of this pilot study is to explore the use of iris recognition as a tool for postmortem identification. Objectives of the study include determining whether current iris recognition technology can locate and detect iris codes in postmortem globes, and if iris scans collected at different postmortem time intervals can be identified as the same iris initially enrolled. Data from 43 decedents involving 148 subsequent iris scans demonstrated a subsequent match rate of approximately 80%, supporting the theory that iris recognition technology is capable of detecting and identifying an individual’s iris code in a postmortem setting. A chi-square test of independence showed no significant difference between match outcomes and the globe scanned (left vs. right), and gender had no bearing on the match outcome. There was a significant relationship between iris color and match outcome, with blue/gray eyes yielding a lower match rate (59%) compared to brown (82%) or green/hazel eyes (88%), however, the sample size of blue/gray eyes in this study was not large enough to draw a meaningful conclusion. An isolated case involving an antemortem initial scan collected from an individual on life support yielded an accurate identification (match) with a subsequent scan captured at approximately 10 hours postmortem. Falsely rejected subsequent iris scans or "no match" results occurred in about 20% of scans; they were observed at each PMI range and varied from 19-30%. The false reject rate is too high to reliably establish non-identity when used alone and ideally would be significantly lower prior to implementation in a forensic setting; however, a "no match" could be confirmed using another method. Importantly, the data showed a false match rate or false accept rate (FAR) of zero, a result consistent with previous iris recognition studies in living individuals. The preliminary results of this pilot study demonstrate a plausible role for iris recognition in postmortem human identification. Implementation of a universal iris recognition database would benefit the medicolegal death investigation and forensic pathology communities, and has potential applications to other situations such as missing persons and human trafficking cases

Immune reconstitution syndrome presenting as probable AIDS-related lymphoma: a case report

We report an unusual case of HIV-related immune reconstitution inflammatory syndrome, presenting as suspected AIDS-related lymphoma. Symptoms, initial investigations including fine-needle biopsy and 18F-FDG PET/CT scan were highly compatible with high grade AIDS-related lymphoma, however subsequently IRIS was diagnosed. We discuss pitfalls in the interpretation of diagnostic results in ARL versus IRIS

Operative strategy for large brain abscess resulting from immune reconstitution inflammatory syndrome in an AIDS patient in Swaziland

SummaryThe objective of our study was to report a rare case with a large brain abscess related to central nervous system immune reconstitution inflammatory syndrome (IRIS) and to discuss the operative strategy for it. Brain abscess with HIV co-infection is considered to be a critical infectious condition that requires neurosurgical intervention. The presentation of IRIS may worsen the patient’s condition after the initiation of antiretroviral therapy, especially in IRIS of the central nervous system. Only a few cases of IRIS-related brain abscess have been reported in the current literature, with discussion of the operative strategy. A 30-year-old man was diagnosed with HIV infection in 2007 and he developed right-sided convulsion episodes in 2008. His first brain computed tomography (CT) scan revealed two intracranial cysts, and his symptoms were well controlled by anticonvulsant treatment. He also initiated antiretroviral therapy in the same year. However, his neurological conditions gradually worsened with sensory loss, weakness, visual impairment on the right side, as well as motor aphasia. A CT scan in 2011 revealed a well-encapsulated, hypodense 8 cm × 9 cm intracranial lesion in the left frontal parietal lobe with a 3-cm midline shift. Surgery was performed with a combination of direct suction and quick-suturing of the incision. The abscess capsule was enucleated completely. After surgical removal, he recovered well and remains functional at work in the following year with only minor neurological sequelae. In conclusion, this case illustrates well the clinical course of brain abscess resulting from IRIS in Swaziland, where the prevalence rate of HIV infection is relatively high and delay in diagnosis and treatment is common. The use of a modified excision method for HIV co-infection brain abscess may be considered the operative strategy, with a probable good outcome in such a resource-limited area as Swaziland

Observations of Ellerman bomb emission features in He I D3 and He I 10830 {\AA}

Context. Ellerman bombs (EBs) are short-lived emission features, characterized by extended wing emission in hydrogen Balmer lines. Until now, no distinct signature of EBs has been found in the He I 10830 {\AA} line, and conclusive observations of EBs in He I D 3 have never been reported. Aims. We aim to study the signature of EBs in neutral helium triplet lines. Methods. The observations consist of 10 consecutive SST/TRIPPEL raster scans close to the limb, featuring the H$\beta$, He I D3 and He I 10830 {\AA} spectral regions. We also obtained raster scans with IRIS and make use of the SDO/AIA 1700 {\AA} channel. We use Hazel to invert the neutral helium triplet lines. Results. Three EBs in our data show distinct emission signatures in neutral helium triplet lines, most prominently visible in the He I D3 line. The helium lines have two components: a broad and blue-shifted emission component associated with the EB, and a narrower absorption component formed in the overlying chromosphere. One of the EBs in our data shows evidence of strong velocity gradients in its emission component. The emission component of the other two EBs could be fitted using a constant slab. Our analysis hints towards thermal Doppler motions having a large contribution to the broadening for helium and IRIS lines. We conclude that the EBs must have high temperatures to exhibit emission signals in neutral helium triplet lines. An order of magnitude estimate places our observed EBs in the range of $T\sim 2\cdot 10^4-10^5$ K.Comment: 15 pages, 14 figure