Environmental contaminants, parasitism, and neoplasia in white perch Morone americana from Chesapeake Bay, USA

White perch are an abundant demersal fish species in freshwater and oligohaline habitats of the Chesapeake Bay. An avoidance of salinity \u3e 12-15 ppt generally restricts the distribution and movements of fish to within tributaries in the mid to lower Bay, which over time has resulted in the formation of at least three separate stocks in Chesapeake Bay. Sub-populations of white perch that are partially isolated may serve as sentinels of the conditions or stressors in the tributaries in which they reside. Fish are exposed to a variety of environmental contaminants and other anthropogenic stressors that can vary in magnitude based on regional differences in land-use patterns. Health studies of white perch conducted in the 1980s and 1990s revealed a variety of hepatic lesions, including two reports of liver neoplasms, which suggested a sensitivity to degraded habitat or pollution. However, surveys to determine prevalences and potential etiologies of tumors were not determined and the health of white perch in Chesapeake Bay was not investigated again until the studies reported herein. Recent health investigations has revealed associations between neoplasms (cholangiocarcinomas) and bile duct parasites (coccidian and myxozoan) that were not previously described from white perch. These findings raised questions concerning the potential roles of contaminants and parasitism in liver tumor induction in this species. To address knowledge gaps associated with the prevalence and etiology of tumors in white perch, an assessment of environmental contaminants, biomarkers of exposure, biliary parasites, and liver histopathology was required. This study was conducted in two tributaries of the Bay: the Choptank River, an eastern shore tributary with extensive watershed agriculture, and the Severn River, a western shore tributary with extensive development. This dissertation addresses: 1) descriptions and taxonomic placement of the coccidian and myxozoan parasites; 2) measurement of waterborne concentrations of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides, and brominated diphenyl ethers; 3) detection of biliary metabolites as a biomarker of exposures to PAHs; 4) a histopathological description of parasitic infections, neoplasms and other lesions in the liver of fish; 5) an assessment of the biological and anthropogenic risk factors for neoplasia; and 6) an assessment of splenic and hepatic macrophage aggregates as an alternate biomarker of contaminant exposure

The Relationship Between Social Support and Distress Following Perinatal Loss

Perinatal loss can be a traumatic event associated with high levels of distress and potentially PTSD (Berry, 2022). Strong social support is crucial in trauma recovery, though it is often counterproductive following perinatal loss (Meyer, 2016). Recent quantitative research done by Dr. Agata Freedle has shown that lack of adequate, culturally sensitive social support can contribute to elevated levels of PTSD. The specific experiences of perinatally bereaved women have not been captured in this data. Further exploration of this relationship to include the lived experiences of women is needed. The purpose of this study is to qualitatively explore how women experience the relationship between their distress and social support, as well as how women utilize formal and informal social supports to reduce their distress after perinatal loss. Findings will provide insight to both the population that is affected, and also to practitioners in the field who serve this underserved population

Explore, Exploit or Listen: Combining Human Feedback and Policy Model to Speed up Deep Reinforcement Learning in 3D Worlds

We describe a method to use discrete human feedback to enhance the performance of deep learning agents in virtual three-dimensional environments by extending deep-reinforcement learning to model the confidence and consistency of human feedback. This enables deep reinforcement learning algorithms to determine the most appropriate time to listen to the human feedback, exploit the current policy model, or explore the agent's environment. Managing the trade-off between these three strategies allows DRL agents to be robust to inconsistent or intermittent human feedback. Through experimentation using a synthetic oracle, we show that our technique improves the training speed and overall performance of deep reinforcement learning in navigating three-dimensional environments using Minecraft. We further show that our technique is robust to highly innacurate human feedback and can also operate when no human feedback is given

Quantitative monitoring of an activated sludge reactor using on-line UV-visible and near infrared spectroscopy

The performance of an activated sludge reactor can be significantly enhanced through use of continuous and real-time process-state monitoring, which avoids the need to sample for off-line analysis and to use chemicals. Despite the complexity associated with wastewater treatment systems, spectroscopic methods coupled with chemometric tools have been shown to be powerful tools for bioprocess monitoring and control. Once implemented and optimized, these methods are fast, nondestructive, user friendly, and most importantly, they can be implemented in situ, permitting rapid inference of the process state at any moment. In this work, UV-visible and NIR spectroscopy were used to monitor an activated sludge reactor using in situ immersion probes connected to the respective analyzers by optical fibers. During the monitoring period, disturbances to the biological system were induced to test the ability of each spectroscopic method to detect the changes in the system. Calibration models based on partial least squares (PLS) regression were developed for three key process parameters, namely chemical oxygen demand (COD), nitrate concentration (N-NO3−), and total suspended solids (TSS). For NIR, the best results were achieved for TSS, with a relative error of 14.1% and a correlation coefficient of 0.91. The UV-visible technique gave similar results for the three parameters: an error of ~25% and correlation coefficients of ~0.82 for COD and TSS and 0.87 for N-NO3−. The results obtained demonstrate that both techniques are suitable for consideration as alternative methods for monitoring and controlling wastewater treatment processes, presenting clear advantages when compared with the reference methods for wastewater treatment process qualification.Fundação para a Ciência e Tecnologia (FCT) - PPCDT/AMB/60141/2004, bolsa de doutoramento SFRH/BD/32614/200

Herkules – Held zwischen Tugend und Hybris. Ein europäischer Erinnerungsort der Frühen Neuzeit?

This essay traces some of the contexts and media in which "Heracles-Hercules" - as a hero between virtue and hubris - was visible in European societies from the end of the middle ages onwards. It discusses whether this example of the reception, appropriation and transformation of classical myths in the early modern period can be understood as a European "lieu de mémoire", and to what extent the concept of "lieux de mémoire" (or sites of memory) can foster our understanding of a particular object of study (here the Heracles/Hercules myth). Against this backdrop, we conclude with some general questions about the more ambitious project* of a comprehensive register of European "lieux de mémoire". * * Published as: Boer, Pim den / Duchhardt, Heinz / Kreis, Georg / Schmale, Wolfgang (eds.): Europäische Erinnerungsorte, 3 vols., Munich 2011–201