Changing Groundwater Levels in the Cambrian-Ordovician Sandstone Aquifers of Northern Illinois, 1980-2014

published or submitted for publicationis peer reviewedOpe

Effects of rapid prey evolution on predator-prey cycles

We study the qualitative properties of population cycles in a predator-prey system where genetic variability allows contemporary rapid evolution of the prey. Previous numerical studies have found that prey evolution in response to changing predation risk can have major quantitative and qualitative effects on predator-prey cycles, including: (i) large increases in cycle period, (ii) changes in phase relations (so that predator and prey are cycling exactly out of phase, rather than the classical quarter-period phase lag), and (iii) "cryptic" cycles in which total prey density remains nearly constant while predator density and prey traits cycle. Here we focus on a chemostat model motivated by our experimental system [Fussmann et al. 2000,Yoshida et al. 2003] with algae (prey) and rotifers (predators), in which the prey exhibit rapid evolution in their level of defense against predation. We show that the effects of rapid prey evolution are robust and general, and furthermore that they occur in a specific but biologically relevant region of parameter space: when traits that greatly reduce predation risk are relatively cheap (in terms of reductions in other fitness components), when there is coexistence between the two prey types and the predator, and when the interaction between predators and undefended prey alone would produce cycles. Because defense has been shown to be inexpensive, even cost-free, in a number of systems [Andersson and Levin 1999, Gagneux et al. 2006,Yoshida et al. 2004], our discoveries may well be reproduced in other model systems, and in nature. Finally, some of our key results are extended to a general model in which functional forms for the predation rate and prey birth rate are not specified.Comment: 35 pages, 8 figure

Quantum Algorithms for Fermionic Simulations

We investigate the simulation of fermionic systems on a quantum computer. We show in detail how quantum computers avoid the dynamical sign problem present in classical simulations of these systems, therefore reducing a problem believed to be of exponential complexity into one of polynomial complexity. The key to our demonstration is the spin-particle connection (or generalized Jordan-Wigner transformation) that allows exact algebraic invertible mappings of operators with different statistical properties. We give an explicit implementation of a simple problem using a quantum computer based on standard qubits.Comment: 38 pages, 2 psfigur

Water Supply Planning: Middle Illinois Assessment of Water Resources for Water Supply-Final Report

Illinois Department of Natural Resourcespublished or submitted for publicationis peer reviewedOpe

Water supply planning: Kankakee watershed assessment of water resources for water supply

This report examines the impacts of current and future demands on water supplies for the Kankakee Watershed Water Supply Planning Subregion (WSPR) in northeastern Illinois, an area comprising most of Kankakee and Iroquois Counties and portions of Ford, Will, Vermilion, and Grundy Counties that intersects the Kankakee River watershed boundary. Initial water demand scenarios were developed for a three-county region (Ford, Iroquois, and Kankakee) out to 2060 for five major water sectors, including thermoelectric power generation, public supply, self-supplied domestic, self-supplied industrial and commercial (IC), and self-supplied irrigation, livestock, and environmental (ILE), and are described in a companion report (Meyer et al., 2019). Total water usage in 2010 was estimated to be 39 million gallons per day (mgd), with two sectors, public supply and ILE, accounting for more than 80 percent of the demand in the region. Most of the ILE demand was for crop irrigation. Self-supplied IC accounted for 13 percent and the domestic sector 6 percent of the usage. Significant water resources are available to meet demands in the Kankakee WSPR, including both groundwater and surface water. Two major aquifer systems occur in the region: (1) productive sand and gravel aquifers, primarily in the south where the Mahomet Aquifer is encountered; and (2) weathered Silurian-Devonian dolomite, which is the most productive aquifer system in the region. Both the dolomite and Mahomet Aquifers are overlain by clay over most of the watershed, limiting leakage from shallower sources. The deeper Cambrian-Ordovician sandstones are generally too saline in this area to use as a water supply, although they are heavily used just outside of the watershed boundary in Will, Kendall, and Grundy Counties. Although the aquifers are generally thought to be adequate to meet most expected future demands, there are some sensitive areas that should be monitored closely. The most important area appears to be southeastern Kankakee and northeastern Iroquois Counties, where demands for irrigation water are highest on account of sandy soils. These demands are met from the dolomite aquifers and have been shown to result in dewatering of the dolomite during the irrigation season.Water quality in the Silurian-Devonian dolomite aquifer system is generally good. At a few locations, nitrate and chloride concentrations are elevated, but at concentrations below their respective drinking water standards. Water moves relatively rapidly from land surface into the Silurian-Devonian dolomite aquifer where it is near land surface, especially in the northern half of the region; aquifer protection activities should be a priority in these areas. The primary surface water sources in the Kankakee WSPR are the Kankakee and Iroquois Rivers. Currently there are four entities withdrawing water from the Kankakee River in the planning region: Aqua Illinois-Kankakee Division, which supplies the city of Kankakee, the city of Wilmington, Exelon Dresden Station, and Exelon Braidwood Generation Station.Although the Kankakee River has reliable water for meeting current power generation and public water supply needs, the cooling water withdrawals from the river could be limited on account of protected minimum flows and water temperature criteria. Therefore, both Dresden and Braidwood plants have a considerable storage capacity in their cooling ponds to buffer the impact of the minimum flow restriction. With increasing water demand and potential climate change, the frequency and duration of the minimum flow restriction may be increased in the 2 future. Both power plants using the Kankakee River for cooling water may rely on storage water more frequently.Water demand from within the watershed is not expected to increase dramatically in the future. However, large portions of Will County are at risk to dewatering of the Cambrian-Ordovician sandstone aquifers. As a result, communities within these at-risk areas are seeking alternate water supplies in anticipation of these impacts. One possible option is the Kankakee River. As part of the process of exploring alternative supplies, both Joliet and Godley have requested withdrawing a large amount of water from the lower reach of the Kankakee River. The communities served by this water lie primarily outside of the watershed, so both withdrawal and consumptive use of Kankakee River water could increase substantially. Unlike within the watershed, water demand for these communities outside of the watershed is expected to increase. Another unknown is how water demand will be met in the future by industries along the Des Plaines River. Many of these industries also rely on the at-risk sandstone aquifers, so the long-term viability of their sandstone wells is contingent on decisions by communities.The major concern with increasing water demand on the Kankakee River is the minimum flow restriction and how to supplement the river water when it is not available during drought conditions, especially when the water is diverted out of the watershed, as the wastewater may not be returned to the river. Other backup supplies are of limited availability in areas of sandstone risk, as currently the sandstone aquifers are likely to be the only viable backup option; however, there are questions about its viability under increasing demand. Off-channel storages and/or abandoned storage pits could also be explored to provide additional backup supply.As a result, conjunctive water management that accounts for impacts on both river and groundwater supplies will be essential moving forward. Water users within the Kankakee River watershed should be cognizant of this potential future demand on the river. Available flow on the Kankakee River during low-flow periods may be contingent on whether the communities in Will County also tap into it as a water supply, so water planners currently using or anticipating growth in use of the Kankakee River water should stay informed on planning decisions outside of the region. Sandstone users considering using the Kankakee River as a backup supply are also currently working with the ISWS to evaluate the viability of the Kankakee River as a backup supply under low-flow scenarios on the Kankakee River. This is critically important because of the rapid response of the sandstone aquifer when demands change.Illinois Department of Natural Resourcespublished or submitted for publicationis peer reviewedOpe

Upper limb and eye movement coordination during reaching tasks in people with stroke

Purpose: To enhance understanding of the relationship between upper limb and eye movements during reaching tasks in people with stroke. Methods: Eye movements were recorded from 10 control participants and 8 chronic stroke participants during a visual orienting task (Experiment 1) and a series of reaching tasks (Experiment 2). Stroke participants completed the reaching tasks using (i) their less impaired upper limb, (ii) their more impaired upper limb without support, and (iii) their more impaired upper limb, with support (SaeboMAS gravitational support and/or electrical stimulation). Participants were tested individually and completed both experiments in the same session. Results: Oculomotor control and the coordination between the upper limb and the oculomotor system were found to be intact in stroke participants when no limb movements were required, or when the less impaired upper limb was used. However, when the more impaired upper limb was used, success and accuracy in reaching decreased and patterns of eye movements changed, with an observed increase in eye movements to the limb itself. With upper limb support, patterns of hand-eye coordination were found to more closely resemble those of the control group. Conclusion: Deficits in upper limb motor systems result in changes in patterns of eye movement behavior during reaching tasks. These changes in eye movement behavior can be modulated by providing upper limb support. -Implications for Rehabilitation -Deficits in upper limb motor systems can result in changes in patterns of eye movement behavior during reaching tasks. -Upper limb support can reduce deficits in hand-eye coordination. -Stroke rehabilitation outcomes should consider motor and oculomotor performance

Testing foundations of quantum mechanics with photons

The foundational ideas of quantum mechanics continue to give rise to counterintuitive theories and physical effects that are in conflict with a classical description of Nature. Experiments with light at the single photon level have historically been at the forefront of tests of fundamental quantum theory and new developments in photonics engineering continue to enable new experiments. Here we review recent photonic experiments to test two foundational themes in quantum mechanics: wave-particle duality, central to recent complementarity and delayed-choice experiments; and Bell nonlocality where recent theoretical and technological advances have allowed all controversial loopholes to be separately addressed in different photonics experiments.Comment: 10 pages, 5 figures, published as a Nature Physics Insight review articl

Measurement of the Branching Fraction for B- --> D0 K*-

We present a measurement of the branching fraction for the decay B- --> D0 K*- using a sample of approximately 86 million BBbar pairs collected by the BaBar detector from e+e- collisions near the Y(4S) resonance. The D0 is detected through its decays to K- pi+, K- pi+ pi0 and K- pi+ pi- pi+, and the K*- through its decay to K0S pi-. We measure the branching fraction to be B.F.(B- --> D0 K*-)= (6.3 +/- 0.7(stat.) +/- 0.5(syst.)) x 10^{-4}.Comment: 7 pages, 1 postscript figure, submitted to Phys. Rev. D (Rapid Communications

A Study of Time-Dependent CP-Violating Asymmetries and Flavor Oscillations in Neutral B Decays at the Upsilon(4S)

We present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at the Stanford Linear Accelerator Center. The data sample consists of 29.7 ${\rm fb}^{-1}$ recorded at the $\Upsilon(4S)$ resonance and 3.9 ${\rm fb}^{-1}$ off-resonance. One of the neutral B mesons, which are produced in pairs at the $\Upsilon(4S)$, is fully reconstructed in the CP decay modes $J/\psi K^0_S$, $\psi(2S) K^0_S$, $\chi_{c1} K^0_S$, $J/\psi K^{*0}$ ($K^{*0}\to K^0_S\pi^0$) and $J/\psi K^0_L$, or in flavor-eigenstate modes involving $D^{(*)}\pi/\rho/a_1$ and $J/\psi K^{*0}$ ($K^{*0}\to K^+\pi^-$). The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. The proper time elapsed between the decays is determined by measuring the distance between the decay vertices. A maximum-likelihood fit to this flavor eigenstate sample finds $\Delta m_d = 0.516\pm 0.016 {\rm (stat)} \pm 0.010 {\rm (syst)} {\rm ps}^{-1}$. The value of the asymmetry amplitude $\sin2\beta$ is determined from a simultaneous maximum-likelihood fit to the time-difference distribution of the flavor-eigenstate sample and about 642 tagged $B^0$ decays in the CP-eigenstate modes. We find $\sin2\beta=0.59\pm 0.14 {\rm (stat)} \pm 0.05 {\rm (syst)}$, demonstrating that CP violation exists in the neutral B meson system. (abridged)Comment: 58 pages, 35 figures, submitted to Physical Review