For ethical and logistical reasons, population-genetic studies of parasites often rely on the non-invasive sampling of offspring shed from their definitive hosts. However, if the sampled offspring are naturally derived from a small number of parents, then the strong family structure can result in biased population-level estimates of genetic parameters,...
The data presented in this report demonstrate significant improvements
in the ability to constrain trace element and Sr isotopic
concentrations in sediments overlying ridge-flank hydrothermal
systems. Improved sampling methods orchestrated by the Integrated
Ocean Drilling Program (i.e., advanced piston coring and
anoxic sample processing) enabled the collection of reactive pore...
We present concentrations of germanium and silicon in sediment pore waters, basaltic formation fluids,
and bulk sediment from three ridge flank hydrothermal systems (RFHS). Basaltic formation fluids from
warm (>30°C) RFHS have much higher Ge concentrations and Ge:Si molar ratios than overlying sediment
pore waters, requiring seawater-basalt reactions to dominate...
We propose three sampling-based motion planning algorithms for generating informative mobile robot trajectories. The goal is to find a trajectory that maximizes an information quality metric (e.g. variance reduction, information gain, or mutual information) and also falls within a pre-specified budget constraint (e.g. fuel, energy, or time). Prior algorithms have...
This work proposes a technique for distributed multi-robot exploration that leverages novel methods of map inference. The inference technique uses observed map structure to infer unobserved map features. The team then coordinates to explore both the inferred and observed portions of the map. Individual robots select exploration poses by accounting...
Structured estuarine habitats, such as salt marshes, seagrass beds, and oyster reefs, are recognized as critical nurseries for juvenile fish and crustaceans. Estuarine habitat usage by fish, including juvenile Pacific salmon Oncorhynchus spp., was characterized by sampling with a modified tow net in Willapa Bay, Washington, where 20% of the...
Environmental history recorded in estuarine sediment describes water quality regimes through the use of geochemical and biological proxies. We collected sediment cores from two locations in the Coos Estuary, Oregon, at South Slough and Haynes Inlet, spanning from ~ 1680 AD to the present. To reconstruct the historical water column oxygen...
Impact of reproductive processes upon female health has yielded conflicting results; particularly in relation to the role of
reproduction-associated stress. We used the viviparous tsetse fly to determine if lactation, birth and involution lead to
damage from oxidative stress (OS) that impairs subsequent reproductive cycles. Tsetse females carry an intrauterine...
We present a new estimate for the crustal phosphorous sink that results from reactions among seawater, basalt, and sediment blanketing low temperature mid-ocean ridge flank hydrothermal systems. New estimates for global hydrothermal power output, sediment thickness, and the dissolved phosphate concentrations in basement formation fluids indicate that fluid flow through...
In this paper, we introduce a novel algorithm for incorporating uncertainty into lookahead planning. Our algorithm searches through connected graphs with uncertain edge costs represented by known probability distributions. As a robot moves through the graph, the true edge costs of adjacent edges are revealed to the planner prior to...