Coastal Sediment Response to the Diel Oxygen Cycle

Shallow coastal sediments are sites of intense respiration and organic matter breakdown. Macroinfauna bioturbate and bioirrigate sediments which supplies microbes with oxygen and newly deposited organic material from surface sediments, facilitating microbial remineralization of organic matter. These processes depend heavily on the concentration of dissolved oxygen in overlying water. Shallow water oxygen patterns often follow a diel cycle as dissolved oxygen decreases at night due to respiration and then increases during the day with photosynthesis, creating recurring suboxic conditions that are potentially stressful to organisms. Sediment oxygen flux is known to depend on ambient dissolved oxygen concentration, but behavioral responses of macrofauna to low oxygen can be complex and diverse, introducing variability into sediment metabolism rates. This dissertation research examined the effects of diel changes in dissolved oxygen on macrofaunal behavior and activities and corresponding changes in sediment metabolism throughout the diel cycle. I constructed a simple laboratory system to manipulate dissolved oxygen concentrations into a diel pattern and exposed sediment infauna to repeated diel oxygen cycles. Sediment mixing in all three of the tested taxa decreased overall throughout the experiment and over two diel cycles, but also varied proportionally with oxygen within each diel exposure. Behaviors did not show significant variation with the diel cycle, though this is likely because behaviors relevant to sediment x mixing activity were not easily detected or quantified with the employed methods. These results indicate that experiments quantifying sediment mixing by macrofauna that occur in fully oxygenated conditions may not be representative of in situ rates, and that it may require more even than a single diel cycle for representative rates to emerge. To better understand how natural macrofaunal assemblages affect sediment metabolism when exposed to diel cycling oxygen, I conducted a field sediment metabolism experiment. Flow-through sediment metabolism chambers were constructed and deployed to measure in situ sediment oxygen consumption. The presence of macrofauna drove overall greater and more variable rates sediment oxygen demand particularly at night, presumably due to fauna responding to low oxygen by increasing their irrigation activity. This research shows that in coastal sediments, variation on small temporal and spatial scales interact to affect sediment metabolism. Sediment metabolism, a key ecosystem function, is controlled by complex networks of interactions and feedbacks between biogeochemical and ecological processes. This research sheds new light on the connection between oxygen concentration and oxygen consumption in these dynamic, productive marine systems and improves our understanding of the role of macrofauna in modulating that relationship

Multivalent Epigraph Hemagglutinin Vaccine Protects against Influenza B Virus in Mice

Influenza B virus is a respiratory pathogen that contributes to seasonal epidemics, accounts for approximately 25% of global influenza infections, and can induce severe disease in young children. While vaccination is the most commonly used method of preventing influenza infections, current vaccines only induce strain-specific responses and have suboptimal efficacy when mismatched from circulating strains. Further, two influenza B virus lineages have been described, B/Yamagatalike and B/Victoria-like, and the limited cross-reactivity between the two lineages provides an additional barrier in developing a universal influenza B virus vaccine. Here, we report a novel multivalent vaccine using computationally designed Epigraph hemagglutinin proteins targeting both the B/Yamagata-like and B/Victoria-like lineages. When compared to the quadrivalent commercial vaccine, the Epigraph vaccine demonstrated increased breadth of neutralizing antibody and T cell responses. After lethal heterologous influenza B virus challenge, mice immunized with the Epigraph vaccine were completely protected against both weight loss and mortality. The superior cross-reactive immunity conferred by the Epigraph vaccine immunogens supports their continued investigation as a universal influenza B virus vaccine

Oil disturbance reduces infaunal family richness but does not affect phylogenetic diversity

Infaunal organisms are susceptible to disturbances such as hypoxia and sediment contamination; changes in infaunal community structure are therefore often used as indicators of anthropogenic disturbance. Susceptibility to disturbance varies across taxa, either due to physiological factors or to behaviors or functional roles that increase exposure. Both sources of variability are likely to be heritable and shared among related taxa. Thus, we would expect oil disturbance to disproportionately affect related taxa and therefore decrease phylogenetic diversity (PD). We test this hypothesis for a shallow water marine infaunal community using a simulation approach that iteratively removes clades with shared vulnerability to oil exposure. Infauna were sampled at two sites in the Chandeleur Islands, LA, that reflect different exposures to crude oil after the Deepwater Horizon event. Seagrass and adjacent bare sediment habitats were sampled in 2015, 5 years after initial oil exposure, and again in 2016 after an acute re-oiling event. We found that strong correlation between PD and family richness masked any detectable PD patterns with oil exposure. For our full community tree, sensitivity analysis indicated that the removal of larger clades did not disproportionately reduce PD, against our prediction. For this pair of sites, PD did not provide a better metric for assessing the impacts of oil exposure than family richness alone. It is possible, however, that finer-scale taxonomic resolution of infaunal communities may better decouple PD from taxonomic richness. More work is needed to fully evaluate the impacts of disturbance on PD

FFTF implementation of training requirments for government owned facilities

The Fst Flux Facility (FFTF) is a liquid metal cooled, fast flux reactor plant. It is owned by the Department of Energy (DOE) and is operated by the Hanford Engineering Development Laboratory (HEDL) under a DOE contract with Westinghouse Hanford Company. The FFTF is presently undergoing acceptance testing of sodium systems in preparation for initial criticality in August 1979. It will be used to test fuels and materials, to develop associated components and to gain operating experience for future LMFBR's. The FFTF Training Program is a specific example of how training guidelines provided by NRC can be implemented in principle in a DOE owned reactor. The DOE requirements for government owned facilities and the NRC requirements for commercially owned facilities are compared to components of the FFTF Training program. These components will be described, actual status provided and evaluated as to meeting requirements. Cold Plant Qualification (equivalent to NRC Col Plant Licensing) is the next major milestone for FFTF Operator training. Additional requirements or constraints such as operator time utilization, recruiting and turnover, plant availbility and startup testing greatly affect the ability to meet this milestone. These constraints and requirements and the resulting compromises will be evaluated relative to meeting DOE requirements

Predicting subsurface sonar observations with satellite-derived ocean surface data in the California Current Ecosystem

Vessel-based sonar systems that focus on the water column provide valuable information on the distribution of underwater marine organisms, but such data are expensive to collect and limited in their spatiotemporal coverage. Satellite data, however, are widely available across large regions and provide information on surface ocean conditions. If satellite data can be linked to subsurface sonar measurements, it may be possible to predict marine life over broader spatial regions with higher frequency using satellite observations. Here, we use random forest models to evaluate the potential for predicting a sonar-derived proxy for subsurface biomass as a function of satellite imagery in the California Current Ecosystem. We find that satellite data may be useful for prediction under some circumstances, but across a range of sonar frequencies and depths, overall model performance was low. Performance in spatial interpolation tasks exceeded performance in spatial and temporal extrapolation, suggesting that this approach is not yet reliable for forecasting or spatial extrapolation. We conclude with some potential limitations and extensions of this work. &nbsp;</p

Dalhart post shot investigation

The nuclear test Dalhart, U4u, was executed at a depth of 2100 ft on October 13, 1988. This test has multiple radioactive isotopes or fission products associated with it and knowledge of the distribution of these isotopes is desirable for the Nuclear Test Program. A slant post shot hole was drilled in late August 1990 to sample the geologic material from the collapsed zone or chimney above Dalhart. This 9 7/8 inch borehole was drilled at approximately 19 degrees from the vertical toward the Dalhart executive depth. This borehole started at approximately 734 ft due south of the Dalhart event. Drilling circulation was lost at a slant depth of 1030 ft (980 ft True Vertical Depth, TVD). Drilling was completed to 2280 ft (2156 ft TVD). The water level was encountered at a depth of 1063 ft (1513 ft TVD). A Halliburton 1 11/16 in diameter TracerScan gamma-ray-spectroscopy log was run inside the drill string at a speed of 10 ft/min. Spectra were obtained from TD to the surface. Radioactive material produced by the test was present from TD to 1850 ft (1746 ft TVD). Spectra were acquired at .025 ft depth intervals and averages recorded digitally every ten ft and thirty ft were displayed on the blue line log together with the total observed gamma ray and casing collar locater signal. Also a DOE high intensity gamma log was run by Atlas Wireline Services from TD to the surface. This log did not detect any radioactive activity in the hole. The gamma-ray photo peaks on the spectroscopy log were used to determine the depths for sampling with the Hunt sidewall sampling tool. Eleven samples were acquired from the depth interval 2212 ft to 1823 ft (2089 to 1721 ft TVD). None of these samples contained enough activity to be measured with normal drillback survey instruments. 7 refs., 8 figs., 3 tabs

Early Career Aquatic Scientists Forge New Connections at Eco-DAS XV

A sense of kuleana (personal responsibility) in caring for the land and sea. An appreciation for laulima (many hands cooperating). An understanding of aloha ’āina (love of the land). The University of Hawai’i at Manoa hosted the 2023 Ecological Dissertations in Aquatic Sciences (Eco-DAS) program, which fostered each of these intentions by bringing together a team of early career aquatic ecologists for a week of networking and collaborative, interdisciplinary project development (Fig. 1)

Designing an Urban Meditation Centre

When we, as students, design architecture we tend to conceptualize built space as form and gesture - as one grand, unified whole. However, that is not how the built environment is experienced. Architecture exists not simply as architectonic expression or as conceptual meaning, but also as an experienced series of physical spaces connected to each other and to their surroundings by the movement of people through these spaces. In approaching this project, I chose to experiment with a process based on designing spaces in much the same way that they are experienced. The entire development of this project was informed by this process, everything from the program to the proposed site. The stated fundamental DESIGN GOALS of the project where: To explore an experiential and phenomenological approach to design rather than designing ‘building-as-object.’ - to design a building with which the user can interact and which has a designed effect upon the user’s state of mind and emotions. - to incorporate various natural elements materials and spatial arrangements to further these goals. To create a sustainable project not just in resources but in use of spaces and relation to the surrounding community as well. - to create flexible adaptable spaces that can remain functional as needs change. - to create an appropriately regulated continuity between the streetscape and the building’s interior that enhances the experience of both environments

Cycle 7 outage experience. [Fast Flux Test Facility (FFTF)]

The scheduled 58-day refueling outage in preparation for the seventh operating cycle of the Fast Flux Test Facility (FFTF) was successfully completed three days ahead of schedule. The planning and execution of the outage was greatly aided by Project/2 automated scheduling capabilities. For example, the use of ''maintenance windows'' and resource loading capabilities was particularly effective. The value of the planning process was demonstrated by the smooth transition into the outage phase after an early shutdown and set the stage for our best outage to date