Separation of Blood Mixtures Using Fluorescently Labeled Antibodies

Identifying and analyzing biological mixture samples at a crime scene are of paramount concern for forensic scientists, especially if that type of evidence contains only one cell type. The presence of multiple contributors in a biological evidence sample reduces the probative value of DNA evidence and can sometimes lead to its eventual loss of value. As such, this study was performed in an attempt to examine and evaluate flow cytometry analysis as a means to separate blood mixture samples labeled with fluorescent antibodies. Fluorescein Isothiocyanate (FITC) antibodies were specifically targeted and bound to HLA (Human Leukocyte Antigens) markers present on nucleated cells in the blood, after which they were isolated from the blood mixture utilizing Fluorescent Activated Cell Sorting (FACS) - A high throughput technique that separates cell populations based on their optical activity, followed by STR analysis. This approach was tested on fresh blood mixtures containing two contributors, where one contributor possessed an HLA A*02 allele that was not shared with the other contributor. We hypothesize that HLA A*02 positive samples would exhibit fluorescence when bound with the fluorescently labeled antibodies while the HLA A*02 samples would not. As such, we would be able to separate both cell populations using FACS followed by STR analysis. Such a work flow is believed to yield discriminant STR profiles unique to each contributor thus increasing the probative value of the evidence at hand. Results supported our hypothesis and yielded discriminant STR profiles for both contributors, with minor peaks from the A*02 negative contributor being observed in A*02 positive contributor sample. We can then conclude that HLA-A*02 antibodies coupled to FACS is a suitable method that can be utilized to evaluate and separate blood mixture samples in an attempt to yield discriminant STR profiles.https://scholarscompass.vcu.edu/uresposters/1265/thumbnail.jp

Separation of Blood Mixtures Using Fluorescently Labeled Antibodies

Identifying and analyzing biological mixture samples at a crime scene are of paramount concern for forensic scientists, especially if that type of evidence contains only one cell type. The presence of multiple contributors in a biological evidence sample reduces the probative value of DNA evidence and can sometimes lead to its eventual loss of value. As such, this study was performed in an attempt to examine and evaluate flow cytometry analysis as a means to separate blood mixture samples labeled with fluorescent antibodies. Fluorescein Isothiocyanate (FITC) antibodies were specifically targeted and bound to HLA (Human Leukocyte Antigens) markers present on nucleated cells in the blood, after which they were isolated from the blood mixture utilizing Fluorescent Activated Cell Sorting (FACS) - A high throughput technique that separates cell populations based on their optical activity, followed by STR analysis. This approach was tested on fresh blood mixtures containing two contributors, where one contributor possessed an HLA A*02 allele that was not shared with the other contributor. We hypothesize that HLA A*02 positive samples would exhibit fluorescence when bound with the fluorescently labeled antibodies while the HLA A*02 samples would not. As such, we would be able to separate both cell populations using FACS followed by STR analysis. Such a work flow is believed to yield discriminant STR profiles unique to each contributor thus increasing the probative value of the evidence at hand. Results supported our hypothesis and yielded discriminant STR profiles for both contributors, with minor peaks from the A*02 negative contributor being observed in A*02 positive contributor sample. We can then conclude that HLA-A*02 antibodies coupled to FACS is a suitable method that can be utilized to evaluate and separate blood mixture samples in an attempt to yield discriminant STR profiles.https://scholarscompass.vcu.edu/uresposters/1264/thumbnail.jp

ASSESSING THE FISHERY AND ECOLOGY OF SHARKS IN THE UNITED ARAB EMIRATES

Large scale shark population declines have been documented worldwide due to overexploitation and the lack of adequate management frameworks to conserve shark stocks. This study aimed at gaining an understanding of the national shark fishery and the trade in shark products from the United Arab Emirates (UAE). Data were collected from June 2010 to October 2012 through interviews with local fishermen, market and landing site surveys, fishery independent surveys, and stomach content analysis. Interviews with local fishermen (n=126) provided information on the fishery characteristics and established that sharks were increasingly targeted due to their high value in the global fin trade industry. Fishermen confirmed that changes in species composition, abundance, and size of sharks have been ongoing for over two decades raising concerns about the sustainability of this fishery. Catch data and genetic analyses established that 30 species of sharks were found in UAE Gulf waters. Landings were dominated by six species, Carcharhinus sorrah, Rhizoprionodon acutus, Carcharhinus limbatus, Loxodon macrorhinus, Carcharhinus dussumieri, and Mustelus mosis, representing over 90% of the total catches. Most of these species were small bodied sharks while large bodied species were mostly below the size of maturation possibly suggesting recruitment overfishing. A fishery independent survey of sharks in nearshore areas also indicated a low level of abundance of sharks in waters off Dubai and Abu Dhabi. Data on the relative abundance, distribution, and various aspects of the biology of all species encountered were collected. Furthermore, a dietary study of stomach contents of R. acutus and L. macrorhinus provided information on their feeding habits suggesting that they have viii different preferences for their prey. Trade data were limited to products from the UAE and Oman, including meat and fins, and indicated that the majority of species traded were at global risk of extinction based on IUCN Red List classification. Results from the various studies undertaken suggest that these species are likely to be overexploited and that management measures will need to take into account the precautionary principle. There is an urgent need to formulate effective conservation and management plans to prevent further declines in a number of species. The data gathered can now serve as a reference to managers, fisheries scientists, and other stakeholders to prioritize future research, as well as lay foundations for the development and implementation of national management plans for the protection and conservation of sharks

Forensic Signatures for Production Conditions of Bacillus thuringiensis (str. HD1) Spore Cultures

Chemical signatures that can indicate growth medium recipes or other key aspects of the production conditions are an important goal for forensic and biodefense agencies. In this study, Fatty Acid Methyl Ester (FAME) profiles were analyzed from Bacillus thuringiensis spores grown five different published medium recipes. B. thuringiensis was chosen due to its biochemical, structural, and genetic similarity to B. anthracis, a Biosafety Level III select agent and the organisms used in the Amerithrax attacks in 2001. The relative abundance of 13 different fatty acid biomarkers, spanning four structure classes, was compared across all spore samples. Differences in the types and relative abundance of specific fatty acids was observed across each medium formulation, particularly within branched-odd and anteiso structure classes (e.g.15:0 iso, 17:0 iso, 15:0 anteiso). Spore cultures also varied in the proportion of unsaturated and saturated fatty acid biomarkers. When examining specific FAME biomarkers, CAD medium showed an average abundance of 30% for 15:0 iso, whereas LD 97 and Sch media showed average abundances of 23% and 27% respectively, and G-medium and G+Peptone exhibited average abundances of 22.5% and 23% respectively for the same fatty acid. Examination of the 17:0 iso fatty acid showed higher average abundances of 12% in CAD and 13.5% in G+Peptone, while showing lower average abundances of 10%, 8.5%, and 6% in LD, G-Medium, and Sch media respectively. Further differences in fatty acid content were also noted across the sporulation media, whereby CAD, G-Medium, and G+Peptone media exhibited an average abundance of 11.8%, 11.5%, and 11% respectively for 15:0 anteiso meanwhile lower abundances of the same fatty acid were noted in LD (8.5%) and Sch (9%) media. The results indicate that determining FAME profiles can be used to discriminate between a Bacillus thuringiensis species grown in different mediums, and that the amino acid content of each medium affects the FAME profile of the species in question.https://scholarscompass.vcu.edu/uresposters/1233/thumbnail.jp

Pediatric Hemophagocytic Syndromes: A Diagnostic and Therapeutic Challenge

Pediatric hemophagocytic syndrome (HS) is a severe and often fatal clinical disorder. This syndrome is frequently unrecognized, and thus, affected children may receive suboptimal management, leading to an increase in mortality. The purpose of this review is to provide a clinical guide to (1) the recognition of HS based on clinical, biologic, and pathologic features; (2) the identification of the primary cause of HS in a given affected child; and (3) the initiation of effective treatment in a timely manner

Population genetics of four heavily exploited shark species around the Arabian Peninsula.

The northwestern Indian Ocean harbors a number of larger marine vertebrate taxa that warrant the investigation of genetic population structure given remarkable spatial heterogeneity in biological characteristics such as distribution, behavior, and morphology. Here, we investigate the genetic population structure of four commercially exploited shark species with different biological characteristics (Carcharhinus limbatus, Carcharhinus sorrah, Rhizoprionodon acutus, and Sphyrna lewini) between the Red Sea and all other water bodies surrounding the Arabian Peninsula. To assess intraspecific patterns of connectivity, we constructed statistical parsimony networks among haplotypes and estimated (1) population structure; and (2) time of most recent population expansion, based on mitochondrial control region DNA and a total of 20 microsatellites. Our analysis indicates that, even in smaller, less vagile shark species, there are no contemporary barriers to gene flow across the study region, while historical events, for example, Pleistocene glacial cycles, may have affected connectivity in C. sorrah and R. acutus. A parsimony network analysis provided evidence that Arabian S. lewini may represent a population segment that is distinct from other known stocks in the Indian Ocean, raising a new layer of conservation concern. Our results call for urgent regional cooperation to ensure the sustainable exploitation of sharks in the Arabian region

Troubled waters: Threats and extinction risk of the sharks, rays and chimaeras of the Arabian Sea and adjacent waters

The extinction risk of sharks, rays and chimaeras is higher than that for most other vertebrates due to low intrinsic population growth rates of many species and the fishing intensity they face. The Arabian Sea and adjacent waters border some of the most important chondrichthyan fishing and trading nations globally, yet there has been no previous attempt to assess the conservation status of species occurring here. Using IUCN Red List of Threatened Species Categories and Criteria and their guidelines for application at the regional level, we present the first assessment of extinction risk for 153 species of sharks, rays and chimaeras. Results indicate that this region, home to 15% of described chondrichthyans including 30 endemic species, has some of the most threatened chondrichthyan populations in the world. Seventy‐eight species (50.9%) were assessed as threatened (Critically Endangered, Endangered or Vulnerable), and 27 species (17.6%) as Near Threatened. Twenty‐nine species (19%) were Data Deficient with insufficient information to assess their status. Chondrichthyan populations have significantly declined due to largely uncontrolled and unregulated fisheries combined with habitat degradation. Further, there is limited political will and national and regional capacities to assess, manage, conserve or rebuild stocks. Outside the few deepsea locations that are lightly exploited, the prognosis for the recovery of most species is poor in the near‐absence of management. Concerted national and regional management measures are urgently needed to ensure extinctions are avoided, the sustainability of more productive species is secured, and to avoid the continued thinning of the regional food security portfolio

The Authenticity Factor: Understanding the Impact of User-Generated Content Sponsorship on Consumer Behaviour for Value-Expressive Products

In a world where social media has transformed the way consumers make purchasing decisions, user-generated content (UGC) has become a powerful tool for marketers to reach and engage with their target audience. This study examines the impact of UGC sponsorship on consumer behaviour, focusing on the mediating role of perceived authenticity and the moderating impact of source familiarity, specifically in the context of value-expressive products within the fashion industry. A quantitative research design was employed, utilizing two online questionnaires to gather data. The findings demonstrate that non-sponsored UGC is perceived as more authentic than sponsored UGC and has a stronger influence on consumer intentions to search, share, and purchase. On the other hand, source familiarity was found to have no significant impact on these effects. Given the limited research on this topic, the findings of this study will provide valuable insights into the factors that determine the effectiveness of sponsored and non-sponsored UGC. The study will also contribute to the existing literature on UGC and offer practical implications for marketers in effectively managing user-generated marketing messages and a better understanding of the importance of perceived authenticity in shaping consumer intentions. Keywords: User-Generated Content (UGC), Perceived Authenticity, Consumer Behaviour, Value-Expressive Products, Source Familiarity, Sponsorship, Marketing Strateg

Catch composition and life history characteristics of sharks and rays (Elasmobranchii) landed in the Andaman and Nicobar Islands, India

Detailed information on shark and ray fisheries in the Andaman and Nicobar Islands, India are limited, including information on the diversity and biological characteristics of these species. We carried out fish landing surveys in South Andamans from January 2017 to May 2018, a comprehensive and cost-effective way to fill this data gap. We sampled 5,742 individuals representing 57 shark and ray species landed from six types of fishing gears. Of the 36 species of sharks and 21 species of rays landed, six species of sharks (Loxodon macrorhinus, Carcharhinus amblyrhynchos, Sphyrna lewini, C. albimarginatus, C. brevipinna, and Paragaleus randalli) comprised 83.35% of shark landings, while three species of rays (Pateobatis jenkinsii, Himantura leoparda and H. tutul) comprised 48.82% of ray landings, suggesting a species dominance in the catch or fishing region. We provide insights into the biology of species with extensions in maximum size for seven shark species. Additionally, we document an increase in the known ray diversity for the islands and for India with three previously unreported ray species. We found that amongst sharks, mature individuals of small-bodied species (63.48% males of total landings of species less than 1.5 m total length when mature) and immature individuals of larger species (84.79% males of total landings of species larger than 1.5 m total length when mature) were mostly landed; whereas for rays, mature individuals were predominantly landed (80.71% males of total landings) likely reflecting differences in habitat preferences along life-history stages across species and fishing gear. The largest size range in sharks was recorded in landings from pelagic longlines and gillnets. Further, the study emphasizes the overlap between critical habitats and fishing grounds, where immature sharks and gravid females were landed in large quantities which might be unsustainable in the long-term. Landings were female-biased in C. amblyrhynchos, S. lewini and P. jenkinsii, and male-biased in L. macrorhinus and H. leoparda, indicating either spatio-temporal or gear-specific sexual segregation in these species. Understanding seasonal and biological variability in the shark and ray landings over a longer study period across different fisheries will inform future conservation and fishery management measures for these species in the Andaman and Nicobar Islands

Low genetic diversity after a bottleneck in a population of a critically endangered migratory marine turtle species

Hawksbill turtles (Eretmochelys imbricata), which are distributed throughout the world's oceans, have undergone drastic declines across their range, largely due to anthropogenic factors. Assessing sizes, genetic variability and structure of their populations at global and regional levels is critical to the development of conservation management strategies. Here, nuclear and mitochondrial markers were used to analyse patterns of parentage and population structure in hawksbill turtles in United Arab Emirates (UAE) waters, utilizing samples from two life stages (hatchlings and juveniles), and to compare the UAE population with neighboring populations. Weak genetic differentiation was detected between juveniles and hatchlings and between the nesting sites of Dubai and Sir Bu Nair. Parentage analysis suggested that only 53 females and 74–80 males contributed to the hatchlings from 67 nests across three nesting sites in UAE (Dubai, Sir Bu Nair, Abu Dhabi). No females were identified as nesting in more than one location. In Dubai and Abu Dhabi, single paternity was the norm (75%), whereas on Sir Bu Nair, multiple paternity was detected in the majority of nests (67%). Polygyny was also frequently detected on Sir Bu Nair (15% of the overall number of males), but not in the other nesting sites. Comparison of the UAE population with published data from other populations suggests that population structure exists both within the Gulf and between the Gulf and Indian Ocean populations, and that the UAE population has lower genetic variability than the Seychelles population. Finally, the data suggest that the UAE population, and the Gulf population overall, experienced a bottleneck/founder event. The observed overall low genetic variability, evidence of population structure in the Gulf, and strong differentiation between the Gulf and the Indian Ocean populations, raises concerns about the sustainability of this species in this near-enclosed basin. These results highlight the need for regional collaboration in the development of management measures for the long-term conservation of this Critically Endangered specie