Enhancing the liquidity of U.S. Treasury securities in an era of surpluses

Treasury bills ; Government securities ; Liquidity (Economics) ; Debts, Public

Response to Uncertain Threat in Acute Trauma Survivors

Uncertainty is often associated with subjective distress and a potentiated anxiety response. The heightened response to uncertainty may be a central mechanism via which anxiety-, trauma-, and stressor-related disorders are developed and maintained. The current study compared the neural response to predictable and unpredictable threat in acute trauma survivors to clarify the role of the response to uncertain threat in fear circuitry and further inform the nature of the development of PTSD in the context of uncertain threat. The novel study showed that anticipating unpredictable (primarily negative images) relative to predictable images increased activation in a frontoparietal network and was associated with decreased acute trauma symptoms, suggesting this network may be associated with an adaptive mechanism for responding to unpredictable threat. Results also showed increased PTSD symptoms was associated with more sustained activation during unpredictable vs. predictable blocks in the insula. Additionally, those with more severe PTSD symptoms had greater response to transient relative to sustained unpredictable (vs. predictable) conditions in the superior frontal gyrus. These findings extend previous work highlighting the insula’s role in sustained responsivity to unpredictability in anxiety disorders and PTSD to symptomatology in acute trauma survivors. Finally, widespread sustained activation of predominantly frontocentral and frontoparietal regions in unpredictable relative to predictable blocks was associated with increased intolerance of uncertainty

If or When? Uncertainty\u27s Role in Anxious Anticipation

Uncertainty is often associated with subjective distress and a potentiated anxiety response. Occurrence uncertainty (OU), or the inability to predict if a threat will occur, has never been compared experimentally with temporal uncertainty (TU), or the inability to predict when a threat will occur. The current study aimed to 1) directly compare the eye-blink startle responsivity of OU and TU, 2) develop a more effective task for isolating uncertain anticipation, and 3) better understand the relationship between individual differences in the intolerance of uncertainty and uncertain anticipation startle responsivity. The novel study showed that OU anticipation is more anxiety provoking than certain threat, but TU anticipation is superior at eliciting anxiety overall. This suggests that in the context of uncertainty, there must be some level of certainty or threat proximity to elicit a robust anxiety response. Individual difference in the intolerance of uncertainty were not related to anticipatory startle responsivity

Fundamental Chemistry of U and Pu in the TBP-Dodecane-Nitric Acid System

The research objectives of this project are as follows: To determine the influence of nitrate on the speciation of U and Pu in the TBP-dodecane-nitric acid system. The aqueous and organic speciation of U and Pu are examined as a function of the nitric acid concentration, nitrate concentration (by the addition of NaNO3), actinide ion concentration, temperature, and time. To determine the speciation of U and Pu with AHA in the presence and absence of TBP-dodecane organic phase. The aqueous and organic speciation of U and Pu are evaluated as a function of AHA concentration, metal ion concentration, metal ion redox state, pH, and temperature. Experiments will initially examine the aqueous phase then examine the two phase system. To incorporate thermodynamic and kinetic data into existing modeling codes

Fundamental Chemistry of U and Pu in the TBP-Dodecane-Nitric Acid System: Quaterly Report

The speciation of hexavalent U and tetravalent Pu will be examined in the TBP-dodecane- nitric acid systems. This topic is chosen based on data needs for separation modeling identified by the AFCI. Emphasis will be placed on studying the influence of nitrate and acetohydroxamic acid on U and Pu speciation as well as conditions where a third phase forms in the organic phase. The organic phase will be 30 % TBP in dodecane. Equal volumes of aqueous and organic phase will be used. The speciation of the actinides in the aqueous and organic phase will be determined by a number of different spectroscopic and radiochemical techniques. Additionally the actinide distribution between the phases as a function of conditions will be determined. The project data will be incorporated into models to evaluate separations under a variety of conditions