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Assessing the sublethal impacts of sulfoxaflor on the physiology and behavior of Daphnia magna
Get PDFAgricultural pest species are a growing concern due to increasing resistance to neonicotinoids. Sulfoxaflor, a sulfoximine pesticide recently approved by the USEPA, was developed to replace neonicotinoids and has shown to have high efficacy in the field. Environmental introduction is primarily caused by wet spray application or agricultural runoff. Sulfoxaflor binds to insect nicotinic acetylcholine receptors, triggering overactivation that leads to paralysis and death. Preliminary exposure studies have shown neonatal effects and development of liver tumors in rats and mice at 500 and 750 ppm, respectively. Little research into the effects on aquatic nontarget invertebrates has been conducted; as such, this research aims to identify potential physiological and behavioral impacts of sulfoxaflor on juvenile Daphnia magna at concentrations of 0, 0.1, 0.5, 1, 5, and 10 µg/L. HPLC analysis indicated that sulfoxaflor does not readily degrade under laboratory conditions. Despite low sample sizes, trends in increased mortality and length of apical spine were observed for 7-day exposures. Potential decreases in heart rate and mobility parameters such as average speed, acceleration, and total distance after 7-day exposures were also identified. This research aims to help elucidate the potential sublethal impacts of sulfoxaflor on non-target aquatic invertebrates at environmentally relevant concentration
Holocaust Memory Reframed
No full textSince it opened in 1993, millions of people have visited the Holocaust Memorial Museum in Washington, D.C. How does their experience compare to that of visitors to other Holocaust museums, such as the Yad Vashem in Jerusalem or the Jewish Museum Berlin? Jennifer Hansen-Glucklich is the author of Holocaust Memory Reframed: Museums and the Challenges of Representation
Synthesis of the Oxidative Metabolites of Di(2-ethylhexyl) phthalate and Analysis of Metabolite Binding with Peroxisome Proliferator-Activated Receptors
Get PDFDi(2-ethylhexyl) phthalate (DEHP) is a persistent organic pollutant that is added to increase the flexibility of soft plastics, such as polyvinyl chloride (PVC). Since DEHP is not bound to the polymer, it leaches into the environment, leading to human exposure. When DEHP is metabolized by the body, it is cleaved into mono-(2-ethylhexyl) phthalate (MEHP). MEHP is then oxidized to produce the secondary-oxidized metabolites mono-(2-ethyl-5-carboxypentyl)phthalate (5cx-MEPP), mono-(2-ethyl-5-oxohexyl)phthalate (5oxo-MEHP), and mono-[2-(carboxymethyl)hexyl]phthalate (2cx-MMHP). DEHP and its metabolites interact with peroxisome proliferator-activated receptors (PPARs), which can alter lipid metabolism. To synthesize 5cx-MEHP, an enolate alkylation was performed with ethyl butyrate to form ethyl 2-ethyl-6-heptenoate. A reduction with LiAlH4 was performed to produce 2-ethyl-6-hepten-1-ol. The alcohol was esterified with phthalic anhydride and subsequently oxidized to produce 5cx-MEHP. This procedure was then repeated to synthesize 2cx-MMHP and 5oxo-MEPP, replacing the enolate alkylation with a malonic ester alkylation and modifying the final oxidation. Binding of the metabolites of DEHP to PPARγ can be assessed using a thermal shift assay. A protocol for the thermal shift assay was developed using the binding of PPARγ and rosiglitazone, a known PPARγ ligand. The information gained surrounding the binding of DEHP and its metabolites to PPARγ may explain the endocrine-disrupting effects seen from exposure to phthalate plasticizers by addressing the fundamental question of their cellular targets
Herstory: An Analysis of the Representation of Women in Middle Grades U.S. History Textbooks
Get PDFResearch has demonstrated state standards, which often marginalize, stereotype, or exclude women, influence textbook content. Stereotypical and superficial representations of women can trivialize their importance to history, undermine student self-esteem and self-image, and diminish student interest in history. This study identified how women are represented in middle grades history textbooks. A qualitative content analysis of two middle grades United States history textbooks was conducted to identify how women have been included and represented within the textbooks. The findings show the women and women’s history included in the textbooks are largely derived from state standards. Ultimately, the textbooks used in the analysis fail to provide a nuanced account of women’s experiences throughout history and women and women’s history continues to be marginalized or excluded entirely. This research can be utilized to encourage content developers and educators to appropriately and effectively incorporate women and their experiences into middle grades social studies textbooks in meaningful ways
Caregivers’ Failure Mindset, Helicopter Parenting, and Emerging Adults’ Intelligence Mindset
Get PDFPeople may view intelligence as an innately fixed trait that cannot be changed or as something that can grow over time with effort. Growth mindsets are related to more favorable outcomes than fixed mindsets because children with growth mindsets are more likely to persevere during difficult times and see failure as an opportunity to learn (Dweck et al., 1995). When parents convey that “failure-is-debilitating” to their children, it increases the likelihood that they will develop a fixed mindset (Haimovitz & Dweck, 2016). One-way parents might make their failure mindset observable to their children is through helicopter parenting (i.e., parents with failure-is-debilitating mindsets might intervene to prevent their children from failing). Helicopter parenting refers to developmentally inappropriate levels of involvement and control in children’s lives (Segrin et al., 2012), which have damaging effects on the well-being (Schiffrin et al., 2014) and academic outcomes (Schiffrin & Liss, 2017) of emerging adults. A mediation analysis was conducted using bias-corrected 95% confidence intervals based on 10,000 bootstrap samples (Hayes, 2013). For maternal caregivers, failure mindset was significantly associated with maternal helicopter parenting, and maternal helicopter parenting was associated with emerging adults having a fixed mindset. There was an indirect effect of maternal failure mindset on emerging adults’ intelligence mindset through maternal helicopter parenting. For paternal caregivers, failure mindset was significantly associated with paternal helicopter parenting behaviors. However, the path from paternal helicopter parenting to emerging adults’ intelligence mindset and the indirect path were both nonsignificant. The paths from maternal failure mindset through paternal helicopter parenting and vice versa were not significant. Thus, when mothers view failure-as-debilitating, they engage in more helicopter parenting, and their children are more likely to develop fixed mindsets. These findings have implications for emerging adults’ career and academic success
Embryonic development of the stress hormone axis in two model teleost species
Get PDFGlucocorticoid hormones mediate stress responses in all vertebrates, from teleost fishes to mammals. In adult teleosts, the primary glucocorticoid, cortisol, is synthesized within interrenal tissue via enzyme-mediated reactions regulated by the hypothalamic-pituitary-interrenal (HPI) axis in response to stressors. The hypothalamic peptide corticotropin-releasing hormone (CRH) stimulates release of the pituitary protein adrenocorticotropin hormone (ACTH), which stimulates cortisol production in interrenal cells. Cortisol affects target cells via two types of receptors, the glucocorticoid receptor (GR) and mineralocorticoid receptor (MR). The timing and sequence of events leading to a fully functioning HPI axis in developing nonmammalian vertebrates is not fully known. Addressing this gap, we measured expression of genes involved in cortisol synthesis and signaling throughout embryogenesis in two teleosts, the zebrafish (Danio rerio) and Japanese medaka (Oryzias latipes). We isolated RNA from pools of embryos collected at multiple developmental stages and synthesized complementary DNA (cDNA) by reverse transcription. Using cDNA as a template, we measured relative expression of key HPI genes, including CRH, melanocortin type 2 receptor (MC2R), steroidogenic acute regulatory protein (StAR), 11 β hydroxysteroid dehydrogenase (HSD2), and MR by quantitative polymerase chain reaction (qPCR). We measured cortisol throughout embryogenesis using an enzyme-linked immunosorbent assay (ELISA). We found noteworthy differences in expression profiles for all measured genes between species. Notably, we saw large differences in magnitude for changes in CRH, MC2R, and StAR expression. HSD2 showed different patterns of expression in zebrafish and medaka. Temporal cortisol patterns differed between species. Medaka cortisol increased significantly for hatch, whereas zebrafish saw a significant decrease
Finding Quiyough: A Preliminary Site Report for 44ST1164
Get PDFIn March 2019, Dr. McMillan and the Historic Preservation Department participated in an archaeological excavation in conjunction with the Patawomeck Tribe of Virginia. The goal of this excavation was to find evidence of the village of Quiyough, which appears on John Smith’s 1612 Map of the Chesapeake. Our work was an extension of other investigations led by Mike Clem and the Virginia Department of Historic Resources. This presentation is an analysis of our findings as well as a comparison with those made by the DHR
Connect Fred: Enhancing Trail Connectivity through Historic Fredericksburg
No full textThe students of HISP 469: Laboratory in Preservation Planning worked under Dr. Smith to develop new bike and pedestrian paths for historic downtown Fredericksburg in order to improve the wayfinding and connectivity of existing trails. Students researched successful trails in urban settings comparable to Fredericksburg to gain an understanding of the positive and negative qualities of those trails, and how they could be applied or avoided in the new trails created by this project. Research into local and state ordinances regarding signage, bike paths, and similar details was also completed. Using GIS, Survey123, and Google Maps, students conducted extensive surveying of the existing trails and downtown area. The class selected the most ideal pedestrian and bike trails based on the data collected. After these trail paths were tentatively established, the class carried out two interviews with Fredericksburg locals to gain a better understanding of how users interact with the existing infrastructure and how to effectively integrate our plan in a way that benefits the city. For the plan proposed by the students to effectively connect to the existing network of trails, designs for signage that will aid in wayfinding while creating a unified aesthetic for each path were included. With these trails, the class hopes to further improve the walkability of downtown Fredericksburg and increase accessibility to local resources both historic and natural
Owning the Birthing Room: Self-advocacy and Proof of Authority in Seventeenth Century Midwifery Manuals
Get PDFMidwives had long been considered experts in pregnancy and childbirth prior to the Scientific Revolution and the professionalization of the medical field. However, in the late seventeenth century, we see an interest in the realm of childbirth from male surgeons and physicians seeking scientific understandings of pregnancy and women’s bodies, who began to publish pamphlets and treatises on their findings. However, by analyzing midwifery manuals written by seventeenth-century women, such as Justine Siegemund and Jane Sharp, we can see midwives were on an equal level of medical and anatomical understanding as male practitioners from their experiential education and were uniquely qualified for their position
Food Waste
Get PDFMy project talks about the high amounts of food waste in America and around the word. It talks about problems that food waste causes, causes of food waste, and recommendations on how to slow down food waste