Spider Mediation of Polychlorinated Biphenyl Transport and Transformation Across Riparian Ecotones

Polychlorinated biphenyls (PCBs) contaminate the sediment of the Twelvemile Creek / Lake Hartwell Superfund Site, and are known to be transported throughout the resident biota via trophic transport. Riparian spiders have recently become of interest because they are terrestrial organisms that have significant PCB exposures derived from aquatic sources. Many riparian spiders primarily consume insects emerging from contaminated aquatic systems, and these spiders can have a body burden as high as 2900 ng/g lipid. These emergent insects carry contaminants out of the river and into the riparian zone where they are captured by spiders, which effectively directs the contamination towards arachnivorous predators such as lizards, frogs, and birds. The enantiomeric fraction (EF) was measured for chiral congeners to investigate the role of biological systems on transport of PCBs between trophic levels. The EF values varied between spider species, and indicate that foraging behavior may influence those parameters. Tetragnathid and basilica spiders were most similar, whereas both were different from araneid spiders despite all three spiders belonging to the same order of spiders. All spider taxa were significantly different from the aquatic prey source Chironomidae. Two approaches were used to confirm that spiders have the capacity to metabolize their PCB body burdens. Tetragnathidae spiders were collected along Twelvemile Creek, their enzymes isolated, and exposed to individual non-planar and co-planar congeners. PCBs 88 and 149 were incubated with S9 fractions (extracts containing microsomal and cytosolic enzymes) from the spiders and qualitatively assessed for evidence of biotransformation. Tandem mass spectroscopy provided evidence to support the hypothesis that spiders have the capacity to biotransform PCBs. Additionally, PCB 61 was incubated with S9 fractions for quantitative analysis of a planar congener. Numerous compounds were detected after exposure, but OH-PCB 61 was measured at 1.63 (±0.35 SD) ng/g lipid at the Reese Mill sampling site for enzymes obtained with liquid nitrogen, thus indicating that spiders have the capacity to metabolize their PCB body burden. In the second approach mass spectroscopy of whole spider extracts of spiders obtained along the Twelvemile Creek arm of Lake Hartwell provided structural evidence that spiders can transform their body burden of PCBs to OH-PCBs for congeners with six or fewer chlorines. Lastly, webs are hypothesized to play a protective role in spider ecotoxicology. Tetragnathid spiders are able to recycle approximately 90% of their web material without metabolizing it, thus creating an opportunity for web material to act as a storage location external to the body. Concentrations in webs ranged between 154 and 356 ppm, whereas concentrations for spiders at the same sampling locations ranged from 284 ng/g lipid to 2900 ng/g lipid. The enantiomeric fraction was also utilized to determine if storage in webs is an enantioselective process. Results indicate that web storage is enantioselective for PCB 149, with the (−) enantiomer being preferentially retained in web materials, which differs from that seen in spider samples, where the EF is approximately racemic. These investigations examined the exposure and toxicological model for spiders, with the intent of aiding understanding the role spiders play in mediating transport and transformation across riparian ecotones. Results indicate that spiders may use a variety of strategies to manage their PCB body burdens ranging from enantioselective uptake of parent compounds, metabolism to hydroxylated metabolites, and transfer to web material. Understanding spider mediation of PCB transport and transformation can help development of strategies that both manage and mitigate the risks posed to the environment by PCBs at Twelvemile Creek and Lake Hartwell

DEVELOPING A CHIRAL AUXILIARY PLATFORM FOR THE ASYMMETRIC SYNTHESIS OF GAMMA-AMINO ACIDS LYRICA, BACLOFEN, AND ROLIPRAM: SYNTHESIS AND ASYMMETRIC ALDOL REACTIONS WITH AN OXIDATIVELY CLEAVABLE N-4-2-NAPHTHYLMETHYLOXADIAZINONE.

Our research group is focused on the development of synthetic methodologies that allow for the synthesis of enantiomerically enriched materials. The primary reaction that we have investigated is the asymmetric aldol addition reaction. We developed a chiral template for this reaction from enantiomerically pure materials such as the Ephedra alkaloids and alpha-amino acids. Once prepared, these compounds are known as oxadiazinones and they can serve as templates for the aldol reaction. The success of the asymmetric induction in the oxadiazinone mediated aldol reaction is believed to be due to the stereogenic N4-nitrogen. This is based on the observed diastereoselectivities for the asymmetric aldol reaction which ranges from 3:1 to 99:1 when the N4-substituent is a sterically undemanding methyl group, and ranges from 10:1 to 99:1 when the N4-substituent is a more sterically demanding isopropyl group. The conformation and, consequently, the configuration of the N4-nitrogen is a result of chiral relay where stereochemical information is relayed from the C5 and C6 positions of the oxadiazinone ring system. The diastereoselectivity of the asymmetric aldol increases as the steric demand of the N4-position increases. However, the ease of the cleavage of the newly formed asymmetric aldol chain becomes compromised. We determined that it would be of more value to have a stereodirecting N4-group that could be removed under oxidative conditions so as to facilitate the cleavage of the side-chain. We were able to prove this proposed ideal with an oxidatively sensitive p-methoxyphenyl group. However, this group is not sterically demanding. To further pursue this chemistry, we have engaged in the synthesis of an N4-2-naphthylmethyloxadiazinone. This group is more sterically demanding and is expected to enhance the diastereoselectivity of the overall asymmetric process. This poster presents the work that has been achieved thus far in the development of a new class of oxadiazenones and their ultimate usage in the synthesis of gamma-amino acid lyrica

Transitions to Preschool Special Education: The Relationship of Child, Family, and Early Intervention Characteristics

Infants and toddlers with developmental disabilities and certain medical conditions are at risk for a variety of adverse outcomes in childhood as well as into adulthood. Early identification and early intervention are essential for improving the trajectories and outcomes of these children. The Individuals with Disabilities Education Act (IDEA) is a federal law that affords protections to children with disabilities and those at risk for developmental delays. IDEA provides guidance and regulations to early intervention programs, schools, and states for identifying and delivering intervention services to children ages birth through 21 years. Although the provision of early intervention services are regulated by the federal government through IDEA, states have autonomy to decide how they define and measure disabilities and developmental delays. As a result, states differ greatly in their eligibility criteria as well as in the percentages of children identified for early intervention (IDEA Part C) and preschool special education (IDEA Part B). Thus, children who receive early intervention services may or may not continue to meet criteria for special education once they reach age 3. Few studies have examined the child, family, and early intervention characteristics that relate to how, when, and if children will transition from Part C to Part B. Those studies that have examined these relationships have not focused specifically on how these transitions occur in Florida. The purpose of the present study was to examine child, family, and early intervention characteristics that increase the likelihood of children transitioning from Part C to Part B in Florida. Participants in this study included infants and toddlers who exited the Bay Area Early Steps Program (one of Florida’s Part C providers) in 2016. Archival data were examined using a combination of descriptive statistics, Chi-squares, independent t-tests, and logistic regression analyses. Results of this study indicate that children exiting the Bay Area Early Steps Program were more likely to be eligible for preschool special education (Part B) if they were Black/African American, Hispanic, had an established/diagnosed condition, had a lower socioeconomic status, received speech/language services in Early Steps, received multiple different service types in Early Steps, and/or received Early Steps services in Polk County (as opposed to Hillsborough County). Children were not more likely to be eligible for Part B based on their gender, primary language, length of time in Early Steps, or receipt of occupational therapy, physical therapy, or early intervention services while in Early Steps. The findings of this study provide preliminary information about factors that relate to children’s transitions from early intervention to preschool special education in Florida. The findings also offer practical implications for the day-to-day operations of the Bay Area Early Steps program and the local school districts to which these children transition

Parent Perceptions of the Acceptability, Effectiveness, and Experience of Engaging in the Group Stepping Stones Triple P Intervention for Parents of Children with Disabilities

The challenges associated with parenting are often compounded for parents of children with developmental disabilities. Children with developmental disabilities are at increased risk for exhibiting mental health concerns and challenging behavior compared to their typically developing peers. Parents who are raising a child with a disability tend to experience increased demands, higher levels of stress, and greater challenges associated with the physical, emotional, and behavioral needs of their children than do parents of typically developing children. Parent training interventions grounded in social learning theory and behavioral principles have proven to be effective in improving both child and parent outcomes in these families. One evidence-based parent training intervention that targets parents of children with disabilities is the Group Stepping Stones Triple P (GSSTP) intervention. Research supports the effectiveness of GSSTP for decreasing children’s challenging behavior, decreasing parent stress, improving parental self-efficacy and competence, and increasing positive interactions between parents and their children, among other positive outcomes. Despite the extensive research on the efficacy of the GSSTP, few studies have examined the qualitative accounts of parents who have participated in this group intervention. The purpose of this study was to explore the perceptions that parents of children with disabilities or developmental delays have about the acceptability, effectiveness, and overall experience of engaging in Group Stepping Stones Triple P. Using a case study approach, this study attempted to gain an in-depth account of the experiences of parents of children with a disability who participated in the GSSTP intervention. Findings from the present study suggest that the parents who engaged in GSSTP were experiencing numerous challenges related to parenting one or more children who have a disability. The majority of parents described positive parent-child relationships with some improvements noted post-intervention. Parents who enrolled in GSSTP expressed a desire to learn new strategies for helping their children develop new skills and they also were seeking help with preventing and manage their children’s challenging behavior. Overall, parents found the GSSTP intervention to be acceptable and they reported that the most beneficial aspect was learning new parenting strategies, such as new ways of communicating with their child, planning ahead to prevent and manage challenging behavior, and using rewards to encourage desirable behavior. Other benefits parents noted were the support they received from other parents as well as GSSTP facilitators and improvements in their co-parenting relationships. Parents provided recommendations for changes to the content and delivery of the intervention, as well as suggestions for grouping participants according to specific characteristics, such as marital status and cultural background. Based on the findings of the present study, future research should examine parent perceptions and outcomes following a shortened GSSTP intervention, such as a 4- or 5-week class. Future research also should examine the impact of various formats of the intervention, such as briefer sessions or multiple sessions per week. It also would be of interest to compare outcomes of participants who receive GSSTP alone and those who receive GSSTP enhanced with some level of Partner Support. Lastly, future studies would benefit from examining the outcomes and qualitative perceptions of parents from various cultural groups who have completed GSSTP as well as parent perceptions at 6 months or 1 year following the intervention