DNA integrity in forensic samples

When packaged genetic evidence samples are stored in close proximity, there is a higher chance for cross-contamination, which can lead to potential false results. The goal of this study was to test DNA storage methods and environments to determine the best way to avoid potential cross-contamination. Established protocols for storing different types of genetic evidence samples were evaluated: biological swabs and DNA cards. A known concentration of pig DNA was introduced to the evidence samples. Three different evidence drying times of the DNA-free swabs and cards were implemented before packaging: immediate packaging, an hour drying, and 24 hours drying. The samples were then placed in the evidence envelopes in one of two ways. The first was with a DNA carrying swab/card in an envelope next to a non-DNA carrying swab/card in a separate envelope. The second was with two swabs/cards in the same envelope, one carrying DNA and the other not. The three drying methods and two packaging methods were completed in triplicate. A control sample of a non-DNA carrying sample was also included for both packaging techniques. The samples were placed into room temperature storage and aligned next to each other for different intervals: 72 hours, two weeks, and two months. Once the sample exposed to DNA was removed from storage, DNA analysis was completed to determine if cross-contamination occurred on the blank sample at the same time. DNA can be a vital piece of evidence in a court of law, therefore the integrity of the DNA is important. If cross-contamination occurs during storage, then the integrity of the evidence becomes jeopardized. Not only does cross-contamination render the genetic evidence problematic; but if left undetected, it has the potential to link an individual to a case they were not actually associated with, or render a genetic profile contaminated and unusable. Either scenario is not ideal and can be detrimental to individual’s lives and the judicial system. If storage methods can cause evidence contamination, then new ways to preserve the integrity of evidence must be analyzed. Cross-contamination is a rising problem throughout all aspects of a case. Prior studies have found cross-contamination occurring during collection and transportation due to materials or procedures (Fonneløp et al., 2016; Basset and Castella, 2018). Little prior research focused on contamination occurring during storage. This paper will impact the forensic science community by introducing the need for strict regulation and procedures for genetic evidence storage due to the potential of evidence cross-contamination

The effects humidity & temperature has on DNA contamination during storage

Studies have been conducted on DNA cross-contamination throughout the criminal investigation process in order to evaluation the possibility that DNA from one sample could potentially influence the outcome of another. However, no published studies have examined the potential for contamination during the storage of genetic evidence after samples have been taken from crime scenes or suspects. This study is a continuation of a preliminary project, which examined storage drying time in relation to cross-contamination. The current study tested temperature and humidity for the potential of cross-contamination during storage prior to extraction. Prior to storage, 50 μl of male saliva was aliquoted to buccal swabs and then dried for 20 minutes in a Dry-Fast swab dryer. Each variable tested consisted of five buccal swabs that were introduced to DNA and five swabs that remained unopened, in order to see if the male DNA could then be detected on the unopened swabs. Cross-contamination was not detected below 8 °C or 35% relative humidity. Any DNA that was detected was unable to produce a STR profile either as result of nonspecific amplification or extremely low levels of DNA, suggesting that if it did move, it was not enough DNA to alter results. However, further research is needed to determine if higher levels of humidity impact the movement of DNA

DNA integrity in forensic samples

DNA can be a vital piece of evidence in a court of law; therefore, the integrity of the DNA is essential. If cross-contamination occurs during storage, then the integrity of the evidence becomes jeopardized. Not only does cross-contamination render the genetic evidence problematic, but if left undetected, it has the potential to link an individual to a case they were not previously associated with or compromise DNA what is associated with a case so that it is unusable. Either scenario is not ideal, and every step should be taken to avoid such a situation. The goal of this project is to test DNA storage methods and environments to determine the best way to avoid potential cross-contamination. Known protocols for storing different types of genetic evidence samples are evaluated. When packaged genetic evidence samples are stored in close proximity to one another, there is a higher chance for cross-contamination. Studies have been conducted on cross-contamination throughout the investigation process. However, no published studies have examined the potential for contamination during the storage process. This study tested two DNA collection methods for the potential of cross-contamination during storage. Three different dry times of buccal swabs and Whatman cards were tested: none, one hour and 24 hours, in triplicate, and then placed into storage with an uncontaminated sample for one of the following times: 72 hours, 14 days, or 45 days. Cross-contamination was detected in the 72 hours and 45 days blank samples. There was no detection of cross-contamination in any of the blank 14 days samples. The statistics revealed there is a statistical significance for the storage time but not dry time. The fisher exact test yielded a 0.00 p-value (α = 0.05) for the Whatman card, while the buccal swabs yielded a 0.054 p-value (α = 0.05). Cross-contamination was detected upon removal from storage demonstrating that further research is needed to better understand cross-contamination during storage

“Is this my Great Aunt?”: An Analysis of Human Skeletal Remains to Construct a Biological Profile

Forensic anthropology is the sub-discipline that applies the principles and methods of physical anthropology to medico-legal cases. Forensic anthropologists have a multiplicity of skills that are used in various ways, but amongst those is the ability to construct a biological profile from a set, or sets of, unknown, skeletonized remains. Biological profiles of adult human skeletal remains consist of sex, age-at-death, ancestry, stature, trauma, and pathology. The information gained through these analyses are used in two ways: to provide immediate supporting evidence for identification, and to provide a means of narrowing potential lists of individuals. There are various methods to complete this process, but the most common include analyzing the morphoscopic traits of the skeleton, particularly the cranium and pelvis, and using various measurements of the long bones (humerus, femur, etc.). This research will focus on the process of creating a biological profile for an unknown historic skeleton brought to the University of Montana Forensic Anthropology Laboratory (UMFAL). This individual represents one of three historic skeletons found in unmarked graves in Beaverhead County, MT. The goal of this research was to aid in the identification of these remains using multiple methods to create a complete biological profile for the individual. Our analysis found that the remains are most consistent with a female individual aged 35-45 years at death, with a height between 4 ft 9 ins and 5 ft 5 ins, most likely of European ancestry with some Asian admixture, and no perimortem trauma. This individual likely died in the early to mid 1900’s based on artifacts associated with the remains. Biological profiles are the backbone of Forensic Anthropology and this research is unique in that it combines the profile based on the skeletal analysis with historic artifact analysis all with the goal of identification

THE EFFECTS HUMIDITY & TEMPERATURE HAS ON DNA CONTAMINATION DURING STORAGE

Studies have been conducted on DNA cross-contamination throughout the criminal investigation process in order to evaluation the possibility that DNA from one sample could potentially influence the outcome of another. However, no published studies have examined the potential for contamination during the storage of genetic evidence after samples have been taken from crime scenes or suspects. This study is a continuation of a preliminary project, which examined storage drying time in relation to cross-contamination. The current study tested temperature and humidity for the potential of cross-contamination during storage prior to extraction. Prior to storage, 50 μl of male saliva was aliquoted to buccal swabs and then dried for 20 minutes in a Dry-Fast swab dryer. Each variable tested consisted of five buccal swabs that were introduced to DNA and five swabs that remained unopened, in order to see if the male DNA could then be detected on the unopened swabs. Cross-contamination was not detected below 8 °C or 35% relative humidity. Any DNA that was detected was unable to produce a STR profile either as result of nonspecific amplification or extremely low levels of DNA, suggesting that if it did move, it was not enough DNA to alter results. However, further research is needed to determine if higher levels of humidity impact the movement of DNA

Whose Land Is It Anyway? Navigating Ghana\u27s Complex Land System

This Article dives into Ghana’s complex land-registration system, which is influenced by both statutory and customary law. Section II discusses Ghana’s statutory land laws. Section III provides a brief overview of Ghana’s customary land laws. Section IV discusses several obstacles within Ghana’s land-administration system

Genesis and spread of multiple reassortants during the 2016/2017 H5 avian influenza epidemic in Eurasia

Highly pathogenic avian influenza (HPAI) viruses of the H5 A/goose/Guangdong/1/96 lineage can cause severe disease in poultry and wild birds, and occasionally in humans. In recent years, H5 HPAI viruses of this lineage infecting poultry in Asia have spilled over into wild birds and spread via bird migration to countries in Europe, Africa, and North America. In 2016/2017, this spillover resulted in the largest HPAI epidemic on record in Europe and was associated with an unusually high frequency of reassortments between H5 HPAI viruses and cocirculating low-pathogenic avian influenza viruses. Here, we show that the seven main H5 reassortant viruses had various combinations of gene segments 1, 2, 3, 5, and 6. Using detailed time-resolved phylogenetic analysis, most of these gene segments likely originated from wild birds and at dates and locations that corresponded to their hosts' migratory cycles. However, some gene segments in two reassortant viruses likely originated from domestic anseriforms, either in spring 2016 in east China or in autumn 2016 in central Europe. Our results demonstrate that, in addition to domestic anseriforms in Asia, both migratory wild birds and domestic anseriforms in Europe are relevant sources of gene segments for recent reassortant H5 HPAI viruses. The ease with which these H5 HPAI viruses reassort, in combination with repeated spillovers of H5 HPAI viruses into wild birds, increases the risk of emergence of a reassortant virus that persists in wild bird populations yet remains highly pathogenic for poultry

Lung microenvironments harbor Mycobacterium tuberculosis phenotypes with distinct treatment responses.

Tuberculosis lung lesions are complex and harbor heterogeneous microenvironments that influence antibiotic effectiveness. Major strides have been made recently in understanding drug pharmacokinetics in pulmonary lesions, but the bacterial phenotypes that arise under these conditions and their contribution to drug tolerance are poorly understood. A pharmacodynamic marker called the RS ratio® quantifies ongoing rRNA synthesis based on the abundance of newly synthesized precursor rRNA relative to mature structural rRNA. Application of the RS ratio in the C3HeB/FeJ mouse model demonstrated that Mycobacterium tuberculosis populations residing in different tissue microenvironments are phenotypically distinct and respond differently to drug treatment with rifampin, isoniazid, or bedaquiline. This work provides a foundational basis required to address how anatomic and pathologic microenvironmental niches may contribute to long treatment duration and drug tolerance during the treatment of human tuberculosis

Combination of Mycobacterium tuberculosis RS Ratio and CFU Improves the Ability of Murine Efficacy Experiments to Distinguish between Drug Treatments.

Murine tuberculosis drug efficacy studies have historically monitored bacterial burden based on CFU of Mycobacterium tuberculosis in lung homogenate. In an alternative approach, a recently described molecular pharmacodynamic marker called the RS ratio quantifies drug effect on a fundamental cellular process, ongoing rRNA synthesis. Here, we evaluated the ability of different pharmacodynamic markers to distinguish between treatments in three BALB/c mouse experiments at two institutions. We confirmed that different pharmacodynamic markers measure distinct biological responses. We found that a combination of pharmacodynamic markers distinguishes between treatments better than any single marker. The combination of the RS ratio with CFU showed the greatest ability to recapitulate the rank order of regimen treatment-shortening activity, providing proof of concept that simultaneous assessment of pharmacodynamic markers measuring different properties will enhance insight gained from animal models and accelerate development of new combination regimens. These results suggest potential for a new era in which antimicrobial therapies are evaluated not only on culture-based measures of bacterial burden but also on molecular assays that indicate how drugs impact the physiological state of the pathogen

Heterozygous variants in PRPF8 are associated with neurodevelopmental disorders

The pre-mRNA-processing factor 8, encoded by PRPF8, is a scaffolding component of a spliceosome complex involved in the removal of introns from mRNA precursors. Previously, heterozygous pathogenic variants in PRPF8 have been associated with autosomal dominant retinitis pigmentosa. More recently, PRPF8 was suggested as a candidate gene for autism spectrum disorder due to the enrichment of sequence variants in this gene in individuals with neurodevelopmental disorders. We report 14 individuals with various forms of neurodevelopmental conditions, found to have heterozygous, predominantly de novo, missense, and loss-of-function variants in PRPF8. These individuals have clinical features that may represent a new neurodevelopmental syndrome