Since 1982, the Levitus Climatological Atlas of the World's Ocean and each succeeding World Ocean Atlas have been used to provide initial and boundary conditions for modeling studies, as well as baselines for climate studies. However, there has been a broadening demand for ocean modeling on spatial scales finer than 1‐degree resolution [e.g., Penduff et al., 2010]. Likewise, vertical resolution for isobaric coordinate models is important for realistic representation of ocean processes [Wang et al., 2008].

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Background A core symptom of post traumatic stress disorder (PTSD) is persistent fear memory, which can be defined as fear memory that is resistant to updating, inhibition, or extinction. PTSD emerges after traumatic stress exposure, but neurobiological mechanisms via which traumatic stress leads to persistent fear memory are not well defined. Akt signaling within the amygdala (Amy) is enhanced with traumatic stress and phosphatidylinositol kinase 3 (PI3K) activation of Akt within the basolateral amygdala (BLA) has been implicated as critical to fear memory formation. These findings raise the possibility that traumatic stress enhances PI3K → Akt signaling in the BLA, which leads to persistent fear memory. Methods To test this hypothesis rats were exposed to traumatic stress, using the single prolonged stress model, and changes in Akt phosphorylation (pAkt) were assayed in the Amy at 0 and 30 min after fear conditioning (FC). In a separate experiment we inhibited PI3K → Akt signaling in the BLA prior to FC and observed the effect this had on acquisition, expression, and extinction of FC in stressed and control rats. Results Enhanced pAkt in the Amy at both time points was observed in stressed rats, but not in control rats. PI3K → Akt inhibition in the BLA had no effect on freezing in control rats, but decreased freezing during extinction training and testing in stressed rats. Conclusion These findings suggest that PI3K → Akt signaling in the BLA could be a mechanism via which traumatic stress leads to fear memory that is resistant to extinction.

Submersed aquatic vegetation is an important modulator of sediment delivery from the Susquehanna River through the Susquehanna Flats into the Chesapeake Bay. However, the impact of vegetation coupled with the physical drivers of sediment transport through the region are not well understood. This study used a new vegetation component in a coupled flow-wave-sediment transport modeling system (COAWST) to simulate summer through fall 2011, when the region experienced a sequence of events including Hurricane Irene and Tropical Storm Lee. Fine sediment was exported under normal flows and high wind forcing but accumulated under high flows. The relative effect of vegetation under normal and high wind forcing depended on previous sediment dynamics. Vegetation doubled the accumulation of fine sediments under high flows. While further refinement of the bed model may be needed to capture some nuances, the COAWST modeling system provides new insights into detailed sediment dynamics in complex vegetated deltaic systems.

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