A Complete Characterization of Nash Solutions in Ordinal Games

The traditional field of cardinal game theory requires that the objective functions, which map the control variables of each player into a decision space on the real numbers, be well defined. Often in economics, business, and political science, these objective functions are difficult, if not impossible to formulate mathematically. The theory of ordinal games has been described, in part, to overcome this problem.Ordinal games define the decision space in terms of player preferences, rather than objective function values. This concept allows the techniques of cardinal game theory to be applied to ordinal games. Not surprisingly, an infinite number of cardinal games of a given size exist. However, only a finite number of corresponding ordinal games exist.This thesis seeks to explore and characterize this finite number of ordinal games. We first present a general formula for the number of two-player ordinal games of an arbitrary size. We then completely characterize each 2x2 and 3x3 ordinal game based on its relationship to the Nash solution. This categorization partitions the finite space of ordinal games into three sectors, those games with a single unique Nash solution, those games with multiple non-unique Nash solutions, and those games with no Nash solution. This characterization approach, however, is not scalable to games larger than 3x3 due to the exponentially increasing dimensionality of the search space. The results for both 2x2 and 3x3 ordinal games are then codified in an algorithm capable of characterizing ordinal games of arbitrary size. The output of this algorithm, implemented on a PC, is presented for games as large as 6x6. For larger games, a more powerful computer is needed. Finally, two applications of this characterization are presented to illustrate the usefulness of our approach

Good prospects: high-resolution telemetry data suggests novel brood site selection behaviour in waterfowl

Breeding success should increase with prior knowledge of the surrounding environment, which is dependent upon an animal\u27s ability to evaluate habitat. Prospecting for nesting locations and migratory stopover sites are well-established behaviours among bird species. We assessed whether three species of California dabbling ducks – mallards, Anas platyrhynchos, gadwall, Mareca strepera, and cinnamon teal, Spatula cyanoptera – in Suisun Marsh, California, U.S.A., a brackish marsh, prospect for suitable wetlands in the week prior to brooding. K-means cluster analyses grouped 29 mallard and gadwall hens into three groups. One group (N = 13) demonstrated evidence of brood site prospecting, with the fewest and latest prebrooding wetland visits. Of these hens, seven visited their future brood pond an average of 1.14 times and only shortly before brooding (1.29 days), obtaining current information on habitat suitability. For the remaining six hens, we did not detect a brooding wetland visit, possibly due to data limitations or because these hens acquired sufficient familiarity with the wetland habitat during nest breaks in adjacent wetlands, obviating the need to prospect the specific brood pond. The second identified group of hens (N = 11) visited the brooding wetland most frequently (on 4.55 days), further in advance (5.27 days), with the fewest unique wetland visits and the earliest brooding date (26 May). The final group of hens (N = 5) were the latest to brood (21 June) and visited the most wetlands, possibly due to less water or more broods present across the landscape. Brood ponds were always farther from the nest than the nearest ponds, indicating that habitat suitability or presence of conspecifics is more important to brood site selection. Prospecting provides hens with knowledge about current habitat conditions and allows them to ‘crowdsource’ public information regarding use of that habitat by other brooding hens. Prospecting may, therefore, benefit ducks inhabiting ephemeral habitats like those within Suisun Marsh, where brood habitat is limited and water cover changes rapidly during the breeding season

Dietary Nitrate Increases VO2peak and Performance but Does Not Alter Ventilation or Efficiency in Patients With Heart Failure With Reduced Ejection Fraction

Background Patients with heart failure with reduced ejection fraction (HFrEF) exhibit lower efficiency, dyspnea, and diminished peak oxygen uptake (VO2peak) during exercise. Dietary nitrate (NO3−), a source of nitric oxide (NO), has improved these measures in some studies of other populations. We determined the effects of acute NO3− ingestion on exercise responses in 8 patients with HFrEF using a randomized, double-blind, placebo-controlled, crossover design. Methods and Results Plasma NO3−, nitrite (NO2−), and breath NO were measured at multiple time points and respiratory gas exchange was determined during exercise after ingestion of beetroot juice containing or devoid of 11.2 mmol of NO3−. NO3− intake increased (P < .05–0.001) plasma NO3− and NO2− and breath NO by 1469 ± 245%, 105 ± 34%, and 60 ± 18%, respectively. Efficiency and ventilation during exercise were unchanged. However, NO3− ingestion increased (P < .05) VO2peak by 8 ± 2% (ie, from 21.4 ± 2.1 to 23.0 ± 2.3 mL.min−1.kg−1). Time to fatigue improved (P < .05) by 7 ± 3 % (ie, from 582 ± 84 to 612 ± 81 seconds). Conclusions Acute dietary NO3− intake increases VO2peak and performance in patients with HFrEF. These data, in conjunction with our recent data demonstrating that dietary NO3− also improves muscle contractile function, suggest that dietary NO3− supplementation may be a valuable means of enhancing exercise capacity in this population

Mapping our Universe in 3D with MITEoR

Mapping our universe in 3D by imaging the redshifted 21 cm line from neutral hydrogen has the potential to overtake the cosmic microwave background as our most powerful cosmological probe, because it can map a much larger volume of our Universe, shedding new light on the epoch of reionization, inflation, dark matter, dark energy, and neutrino masses. We report on MITEoR, a pathfinder low-frequency radio interferometer whose goal is to test technologies that greatly reduce the cost of such 3D mapping for a given sensitivity. MITEoR accomplishes this by using massive baseline redundancy both to enable automated precision calibration and to cut the correlator cost scaling from N^2 to NlogN, where N is the number of antennas. The success of MITEoR with its 64 dual-polarization elements bodes well for the more ambitious HERA project, which would incorporate many identical or similar technologies using an order of magnitude more antennas, each with dramatically larger collecting area.Comment: To be published in proceedings of 2013 IEEE International Symposium on Phased Array Systems & Technolog

Eclipse-Ballooning 2017: The U of MN – Twin Cities Experience

The stratospheric ballooning team at the U of MN – Twin Cities started working on eclipse-ballooning in the fall of 2013, even before the Montana Space Grant announced their plan to organize a national Eclipse Ballooning Project. Our team promptly signed up to assist their effort, and have been heavily involved ever since. This presentation will discuss our eclipse-ballooning efforts and progress over the past 4 years. Our experiences include experimenting with a GoPro-based video-telemetry system (which ultimately was not as successful as Montana’s Raspberry-Pi-based system), adopting (then helping test, modify, and teach other teams to learn to use) the Montana telemetry system, practicing with up-range and down-range ground station placement, developing and testing passive anti-rotation devices and active camera-pointing devices to improve video quality, landing two eclipse-telemetry systems in Minnesota lakes one week before the eclipse (ouch!), flying five balloon stacks during the eclipse from near Grand Island, NE, and organizing/hosting AHAC 2017. We will also discuss ways in which we have already begun to use the telemetry equipment for non-eclipse balloon missions. The eclipse project has greatly expanded our HAB network and ballooning capabilities in multiple different directions, and will continue to strongly influence our stratospheric ballooning program for years to come

Report to the DOE on the “Crud II” project

This report documents SEM, TEM, and chemical analyses from crud samples from a commercially operating reactor

Scleraxis‐Lineage Cells Contribute to Ectopic Bone Formation in Muscle and Tendon

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136325/1/stem2515_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136325/2/stem2515.pd

Explanatory Style as a Risk Factor for Traumatic Mishaps

Six studies investigated a possible link between hopeless explanatory style—that is, the habitual explanation of bad events with stable and global causes—and risk for traumatic injuries. In samples of college students, dancers, athletes, and trauma patients (total n = 2274), stable and global explanations for bad events correlated with the occurrence of mishaps. The link appeared to be mediated in part by a preference for potentially hazardous settings and activities in response to negative moods associated with hopelessness. Taken together, these findings suggest that catastrophizing individuals may be motivated to escape negative moods by preferring exciting but risky courses of action.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44339/1/10608_2004_Article_363208.pd