Effect of Reservoir Function on Water Quality and Phytoplankton in Lake Taylorville, Christian County, Illinois

As is true for most reservoirs in agricultural areas, Lake Taylorville is currently impacted by excess sedimentation. A system of floodplain wetlands, holding ponds, and sediment basins is being constructed on the tributaries to the reservoir in effort to reduce sediment and nutrient loads. A comprehensive twelve-month assessment of water quality has been conducted to provide a baseline for evaluating the success of this restoration project and to allow predictions regarding future management strategies. In reservoirs, a continuum of longitudinal gradients result in the establishment of three distinct zones possessing unique physical, chemical and biological properties. The function of these zones (termed the riverine zone, transitional zone and the lacustrine zone) can be used to characterize the ecosystem of a reservoir. In Lake Taylorville, only the riverine and transitional zones were found. The elimination of the lacustrine zone in Lake Taylorville is consistent with the large watershed to surface area ratio found there. Lake Taylorville can be characterized as a high flow reservoir that is more river like than lake like in function. Light penetration in Lake Taylorville was usually limited to less than a meter at the surface by high suspended solids concentrations and although nutrient concentrations were high, phytoplankton density, primary productivity and chlorophyll a concentrations were lower than expected. Carlson Trophic State Index (TSI) calculated for total phosphorus and Secchi depth suggest hypereutrophy while those calculated from chlorophyll a data indicate a lower trophic state. Algae may be unable to maximize utilization of available nutrients as a result of low light availability. Because algal bioassays and nitrogen : phosphorus ratios indicate phosphorus limitation of primary productivity, productivity and phytoplankton standing crop may increase if light regimes are improved by sediment reduction resulting from wetland creation. Wetlands have been found to be effective at denitrification as well as sediment reduction. The combination of reduced sediments and nitrates coupled with high in-lake phosphate levels could cause a shift in algal community structure from a currently Chlorophycean dominated community to a community dominated by Cyanophyceae. Future reservoir management may need to address the possibility of frequent blue-green algal blooms and perhaps target phosphorus reduction

In Silico Prediction of Changes in Intrinsic Network Functional Connectivity Following Repetitive Transcranial Magnetic Stimulation

Targeted transcranial magnetic stimulation (TMS) is a non-invasive brain stimulation technique that can influence brain activity, psychiatric features, and cognitive performance. While TMS has been reported to affect cognitive performance across a variety of domains, substantial gaps in knowledge remain regarding the association of these TMS-based cognitive changes and functional connectivity in the brain. In this project, we aim to build a computational model to simulate the effects of TMS on functional associations between a stimulated brain region and the brain networks connected to that brain region. Using data from the Human Connectome Project as the basis for the brain’s functional connectivity, we built a prototypical matrix that models all cortical brain regions (“parcels”) and the functional connections between them. From this starting point, our computational model predicts the effects of stimulating a specific parcel with TMS. Further, our model includes variable parameters to support estimation of functional effects associated with differences in TMS delivery (applying excitatory or inhibitory stimulation), stimulation intensity, stimulation duration (days of TMS), etc. Finally, the model supports estimation of not only local results, but also whole-brain changes in functional connectivity. Based on the quantitative changes in the model estimates associated with different parameter settings, we were able to predict the effects on functional connectivity both within the parcel’s network as well as across the entire cortex. Our approach is an important first step toward individualized in silico computation of how TMS affects the brain, and our work may have implications for developing more effective treatment with TMS.https://digitalcommons.unmc.edu/surp2020/1017/thumbnail.jp

Parallelization of the Naval Space Surveillance Satellite Motion Model

SIAM News, 30, November 1997.The Naval Space Surveillance Center (NAVSPASUR) uses an analytic satellite motion model based on the Brouwer-Lyddane theory to track objects orbiting the Earth. In this paper we develop several parallel algorithms based on this model. These have been implemented on the INTEL iPSC/2 hypercube multi-computer. The speed-up and efficiency of these algorithms will be obtained. We show that the best of these algorithms achieves 87% efficiency if one uses at 16-node hypercube

Experiences with the Streptococcus mutans in Lakota Sioux (SMILeS) Study: Risk Factors for Caries in American Indian Children 0-3 Years

Severe Early Childhood Caries (S-ECC) is a terribly aggressive and devastating disease that is all too common in lower socio-economic children, but none more so that what is encountered in American Indian Tribes. Nationwide, approximately 27% of 2-5 year olds have decay while 62% percent of American Indian/Alaska Native children in the same age group have a history of decay (IHS 2010, NHANES 1999-2002). We have conducted a study of children from birth to 36 months of age on Pine Reservation to gain a better understanding of the variables that come into play in the development of this disease, from transmission and acquisition of Streptococcus mutans genotypes from mother to child to multiple dietary and behavioral components. This article describes how we established a direct partnership with the Tribe and the many opportunities and challenges we faced in performing this 5-year field study

Effect of Targeted Transcranial Magnetic Stimulation on Hippocampal-Dependent Declarative Memory in Older Adults

https://digitalcommons.unmc.edu/emet_posters/1027/thumbnail.jp