Microbiomes Germ Clouds and the Future of DNA Jurisprudence

A scientific study published in Science in August 2014 revealed that every human lives inside their own microbial germ cloud, which is both mobile and traceable.  While microbiomes can potentially revolutionize the field of medicine, they may also transform the field of law by its use in tracking and identifying criminals.  

Presumption of Innocence, Probable Cause, and Prior Probability—Bayes Meets Due Process

This presentation is from the 76th Annual Conference of the American Academy of Forensic Sciences (AAFS), Denver, Colorado, February 19-24, 2024. Copyright 2024, The Author. Posted with permission of CSAFE

Probabilistic Evidence Assessment Tools

This presentation is from the 2024 American Society of Crime Laboratory Directors (ASCLD) Symposium, Birmingham, Alabama, April 28-May 2, 2024. Copyright 2024, The Authors. Posted with permission of CSAFE

Statistical Learning Algorithms for Forensic Scientists

Learning Overview: The goals of this workshop are to: (1) introduce attendees to the basics of supervised learning algorithms in the context of forensic applications, including firearms and footwear examination and trace evidence, while placing emphasis on classification trees, random forests, and, time permitting, neural networks; (2) introduce the concept of a similarity score to quantify the similarity between two items; (3) show how learning algorithms can be trained to classify objects into pre-determined classes; (4) discuss limitations of Machine Learning (ML) algorithms and introduce methods for assessing their performance; and (5) discuss the concept of a Score-based Likelihood Ratio (SLR): computation, advantages, and limitations

Implementing blind proficiency testing in forensic laboratories: Motivation, obstacles, and recommendations

Regular proficiency testing of forensic examiners is required at accredited laboratories and widely accepted as an important component of a functioning quality assurance program. Yet, unlike in other testing industries, the majority of forensic laboratories testing programs rely entirely on declared proficiency tests. Some laboratories, primarily federal forensic facilities, have adopted blind proficiency tests, which are also used in the medical and drug testing industries. Blind tests offer advantages. They must resemble actual cases, can test the entire laboratory pipeline, avoid changes in behavior from an examiner knowing they are being tested, and are one of the only methods that can detect misconduct. However, the forensic context present both logistical and cultural obstacles to the implementation of blind proficiency tests. In November 2018, we convened a meeting of directors and quality assurance managers of local and state laboratories to discuss obstacles to the adoption of blind testing and assess successful and potential strategies to overcome them. Here, we compare the situation in forensic science to other testing disciplines, identifying obstacles to the implementation of blind proficiency testing in forensic contexts, and proposing ways to address those issues and increase the ecological validity of proficiency tests at forensic laboratories

Paleomagnetic measurement of nonbrittle coseismic deformation across the San Andreas Fault at Pallett Creek

Paleomagnetic data have been obtained to address a problem at the Pallett Creek paleoseismological site: the 9 mm/yr slip rate determined from three-dimensional mapping of late Holocene offsets across discrete faults is only a quarter of the expected value. We suspected that nonbrittle deformation adjacent to the faults might account for the 26 mm/yr discrepancy. In our search for the missing slip we collected and analyzed 264 paleomagnetic samples from a 53-m-wide transect across the fault zone. Half the samples came from a unit deposited immediately after a large earthquake of about A.D. 1480; these samples were affected by two large earthquakes that involved rupture at the site in 1812 and 1857. We collected the other half of the samples from a slightly older bed, one that was deposited before the earthquake of about A.D. 1480. Relative to “control” groups composed of 10 samples and collected 50 m from the fault, samples closer to the fault display clockwise rotations of 30° or less. If interpreted as block rotations, the data from the older unit imply that it has sustained a total of 14.0 ± 2.9 m of dextral warp during the past three major earthquakes and that the younger unit has experienced a total of 8.5 ± 1.0 m of warp during the most recent two. Combining these values with the amounts of dextral slip across the mapped fault planes yields dextral offsets of 5.5, 6.25, and 6.25 m for the events of A.D. 1480, 1812, and 1857 and a slip rate of 35.6 ± 6.7 mm/yr. This slip rate, averaged over the past three complete seismic cycles, is consistent with published rates from other sites. Offsets associated with the past three events are remarkably similar. These amounts, however, appear independent of the length of interseismic cycles. These observations suggest (1) that this part of the San Andreas fault has a characteristic strength and (2) that conventional concepts of strain accumulation and relief (for example, time- and slip-predictable models of earthquake occurrence) are unrealistic

Presence of virus neutralizing antibodies in cerebral spinal fluid correlates with non-lethal rabies in dogs.

BACKGROUND: Rabies is traditionally considered a uniformly fatal disease after onset of clinical manifestations. However, increasing evidence indicates that non-lethal infection as well as recovery from flaccid paralysis and encephalitis occurs in laboratory animals as well as humans. METHODOLOGY/PRINCIPAL FINDINGS: Non-lethal rabies infection in dogs experimentally infected with wild type dog rabies virus (RABV, wt DRV-Mexico) correlates with the presence of high level of virus neutralizing antibodies (VNA) in the cerebral spinal fluid (CSF) and mild immune cell accumulation in the central nervous system (CNS). By contrast, dogs that succumbed to rabies showed only little or no VNA in the serum or in the CSF and severe inflammation in the CNS. Dogs vaccinated with a rabies vaccine showed no clinical signs of rabies and survived challenge with a lethal dose of wild-type DRV. VNA was detected in the serum, but not in the CSF of immunized dogs. Thus the presence of VNA is critical for inhibiting virus spread within the CNS and eventually clearing the virus from the CNS. CONCLUSIONS/SIGNIFICANCE: Non-lethal infection with wt RABV correlates with the presence of VNA in the CNS. Therefore production of VNA within the CNS or invasion of VNA from the periphery into the CNS via compromised blood-brain barrier is important for clearing the virus infection from CNS, thereby preventing an otherwise lethal rabies virus infection

Celebrating 20 Years of the ExCEEd Teaching Workshop

In response to the clear need for faculty training, the American Society of Civil Engineers (ASCE) developed and funded Project ExCEEd (Excellence in Civil Engineering Education) which is celebrating its twentieth year of existence. For the past two decades, 38 ExCEEd Teaching Workshops (ETW) have been held at six different universities. The program has 910 graduates from over 267 different U.S. and international colleges and universities. The ExCEEd effort has transformed from one that relied on the grass roots support of its participants to one that is supported and embraced by department heads and deans. This paper summarizes the history of Project ExCEEd, describes the content of the ETW, assesses its effectiveness, highlights changes in the program as a result of the assessment, and outlines the future direction of the program