The Balloon Analogue Risk Task and Behavioral Correlates in Pigeons

Individuals experience risk ubiquitously, but measuring risk taking is difficult. The balloon analogue risk task (BART) was developed in order to assess risk taking through having subjects press a key that accrues reward but also risk losing all reward with each press. In humans, greater responding in this task is associated with other maladaptive risk taking behaviors. The present research modeled this relationship in pigeons due to their previously shown propensity towards risk taking behavior. Experiment 1 used an unsignaled balloon task in which losing could only occur after 5 pecks. Results showed below optimal performance with greater pecks associated with faster acquisition of risk taking in the suboptimal choice task and evidence of modulation by delay discounting measures. Experiment 2 signaled the number of pecks with colors and tested multiple hoppers as a reinforcement modality to increase performance. Results showed only signaling the number of pecks improved performance and was related to performance in the high risk BART task. Both the low and high risk variants were associated with slower suboptimal choice acquisition and again had evidence of modulation by delay discounting measures. Potential shared underlying mechanisms are discussed

Modeling Pine as a Carbon Sequestering Crop in Arkansas

Carbon Sequestration, Loblolly Pine, Carbon Offset, Carbon Policy, Environmental Economics and Policy, Land Economics/Use, Resource /Energy Economics and Policy,

Space Shuttle Orbiter: Countdown

The launch of Space Shuttle into low earth orbit late this year will herald a new era in space transportation. As a transporter and as an experimental platform, the Shuttle will make possible low cost development of space manufacturing processes, products, scientific opportunities, and large scale pub I ic services. And, as the Shuttle becomes operational, its role in the military space mission will gain added importance. Timelines in the completion of each increment of development of the first Orbital Flight Vehicle - successfully achieved to date - becomes increasingly crucial as the scheduled launch date approaches. Concurrent with the testing and final- Ization of this vehicle f s software and hardware construction are the preliminary developmental stages of future Shuttle Orbiters. The status of each Shuttle Orbiter is - and will continue to be - of particular interest as the Space Shuttle becomes the key In the operation of the space transportation system\u27

Ethylene\u27s role in phosphate starvation signaling: More than just a root growth regulator

Phosphate (Pi) is a common limiter of plant growth due to its low availability in most soils. Plants have evolved elaborate mechanisms for sensing Pi deficiency and for initiating adaptive responses to low Pi conditions. Pi signaling pathways are modulated by both local and long-distance, or systemic, sensing mechanisms. Local sensing of low Pi initiates major root developmental changes aimed at enhancing Pi acquisition, whereas systemic sensing governs pathways that modulate expression of numerous genes encoding factors involved in Pi transport and distribution. The gaseous phytohormone ethylene has been shown to play an integral role in regulating local, root developmental responses to Pi deficiency. Comparatively, a role for ethylene in systemic Pi signaling has been more circumstantial. However, recent studies have revealed that ethylene acts to modulate a number of systemically controlled Pi starvation responses. Herein we highlight the findings from these studies and offer a model for how ethylene biosynthesis and responsiveness are integrated into both local and systemic Pi signaling pathways. © 2011 The Author

Futures Prices in Supply Analysis: Are Instrumental Variables Necessary?

Citation: Nathan P. Hendricks, Joseph P. Janzen, Aaron Smith; Futures Prices in Supply Analysis: Are Instrumental Variables Necessary?, American Journal of Agricultural Economics, Volume 97, Issue 1, 1 January 2015, Pages 22–39, https://doi.org/10.1093/ajae/aau062Crop yield shocks are partially predictable—high planting-time futures prices have tended to indicate that yield would be below trend. As a result, regressions of total caloric production on futures prices produce estimates of the supply elasticity that are biased downwards by up to 75%. Regressions of the world’s growing area on futures prices have a much smaller bias of about 20% because although yield shocks are partially predictable, this predictability has a relatively small effect on land allocation. We argue that the preferred method for estimating the crop supply elasticity is to use regressions of growing area on futures prices and to include the realized yield shock as a control variable. An alternative method for bias reduction is to use instrumental variables (IVs). We show that the marginal contribution of an IV to bias reduction is small—IVs are not necessary for futures prices in supply analysis

Aerial Inventories of Waterfowl in Illinois and Estimation of Moist-soil Plant Seed Abundance for Waterfowl on Lands Managed by Illinois Department of Natural Resources

Grant/Contract No: W-43-R 53-54-55Reports on progress and results of inventories of waterfowl along the Illinois and central Mississippi rivers during fall and winter and estimation of moist-soil plant seed abundance for waterfowl on lands managed by Illinois Department of Natural ResourcesINHS Technical Report Prepared for U.S. Fish & Wildlife Service, Illinois Department of Natural Resource

Mechanisms of Individual Differences in Impulsive and Risky Choice in Rats

Citation: Kirkpatrick, K., Marshall, A. T., & Smith, A. P. (2015). Mechanisms of Individual Differences in Impulsive and Risky Choice in Rats. Comparative Cognition & Behavior Reviews, 10. Retrieved from http://comparative-cognition-and-behavior-reviews.org/2015/vol10_kirkpatrick_marshall_smith/Mechanisms of Individual Differences in Impulsive and Risky Choice in Rats Kimberly Kirkpatrick Department of Psychological Sciences, Kansas State University Andrew T. Marshall Department of Psychological Sciences, Kansas State University Aaron P

Gambling-Like Behavior in Pigeons: \u27Jackpot\u27 Signals Promote Maladaptive Risky Choice

Individuals often face choices that have uncertain outcomes and have important consequences. As a model of this environment, laboratory experiments often offer a choice between an uncertain, large reward that varies in its probability of delivery against a certain but smaller reward as a measure of an individual’s risk aversion. An important factor generally lacking from these procedures are gambling related cues that may moderate risk preferences. The present experiment offered pigeons choices between unreliable and certain rewards but, for the Signaled group on winning choices, presented a ‘jackpot’ signal prior to reward delivery. The Unsignaled group received an ambiguous stimulus not informative of choice outcomes. For the Signaled group, presenting win signals effectively blocked value discounting for the large, uncertain outcome as the probability of a loss increased, whereas the Unsignaled group showed regular preference changes similar to previous research lacking gambling related cues. These maladaptive choices were further shown to be unaffected by more salient loss signals and resistant to response cost increases. The results suggest an important role of an individual’s sensitivity to outcome-correlated cues in influencing risky choices that may moderate gambling behaviors in humans, particularly in casino and other gambling-specific environments

Correlating the Energetics and Atomic Motions of the Metal-Insulator Transition of M1 Vanadium Dioxide

Materials that undergo reversible metal-insulator transitions are obvious candidates for new generations of devices. For such potential to be realised, the underlying microscopic mechanisms of such transitions must be fully determined. In this work we probe the correlation between the energy landscape and electronic structure of the metal-insulator transition of vanadium dioxide and the atomic motions occurring using first principles calculations and high resolution X-ray diffraction. Calculations find an energy barrier between the high and low temperature phases corresponding to contraction followed by expansion of the distances between vanadium atoms on neighbouring sub-lattices. X-ray diffraction reveals anisotropic strain broadening in the low temperature structure's crystal planes, however only for those with spacings affected by this compression/expansion. GW calculations reveal that traversing this barrier destabilises the bonding/anti-bonding splitting of the low temperature phase. This precise atomic description of the origin of the energy barrier separating the two structures will facilitate more precise control over the transition characteristics for new applications and devices.Comment: 11 Pages, 8 Figure