Nebraska Earth Science Education Network: Enhancing the NASA, University, and Pre-College Science Teacher Connection with Electronic Communication

The primary goals of this project were to: 1. Promote and enhance K-12 earth science education; and enhance the access to and exchange of information through the use of digital networks in K-12 institutions. We have achieved these two goals. Through the efforts of many individuals at the University of Nebraska-Lincoln (UNL), Nebraska Earth Science Education Network (NESEN) has become a viable and beneficial interdisciplinary outreach program for K-12 educators in Nebraska. Over the last three years, the NASA grant has provided personnel and equipment to maintain, expand and develop NESEN into a program that is recognized by its membership as a valuable source of information and expertise in earth systems science. Because NASA funding provided a framework upon which to build, other external sources of funding have become available to support NESEN programs

A Black Hills-Madison Aquifer Origin for Dakota Aquifer Groundwater in Northeastern Nebraska

Previous studies of the Dakota Aquifer in South Dakota attributed elevated groundwater sulfate concentrations to Madison Aquifer recharge in the Black Hills with subsequent chemical evolution prior to upward migra¬tion into the Dakota Aquifer. This study examines the plausibility of a Madison Aquifer origin for groundwater in northeastern Nebraska. Dakota Aquifer water samples were collected for major ion chemistry and isotopic analysis (18O, 2H, 3H, 14C, 13C, 34S, 18O-SO4, 87Sr, 37Cl). Results show that groundwater beneath the eastern, un¬confined portion of the study area is distinctly different from groundwater sampled beneath the western, con¬fined portion. In the east, groundwater is calcium-bicarbonate type, with δ18O values (−9.6‰ to −12.4‰) simi¬lar to local, modern precipitation (−7.4‰ to −10‰), and tritium values reflecting modern recharge. In the west, groundwater is calcium-sulfate type, having depleted δ18O values (−16‰ to −18‰) relative to local, modern precipitation, and 14C ages 32,000 to more than 47,000 years before present. Sulfate, δ18O, δ2H, δ34S, and δ18O-SO4 concentrations are similar to those found in Madison Aquifer groundwater in South Dakota. Thus, it is pro¬posed that Madison Aquifer source water is also present within the Dakota Aquifer beneath northeastern Ne¬braska. A simple Darcy equation estimate of groundwater velocities and travel times using reported physical parameters from the Madison and Dakota Aquifers suggests such a migration is plausible. However, discrep¬ancies between 14C and Darcy age estimates indicate that 14C ages may not accurately reflect aquifer residence time, due to mixtures of varying aged water

A Black Hills-Madison Aquifer Origin for Dakota Aquifer Groundwater in Northeastern Nebraska

Previous studies of the Dakota Aquifer in South Dakota attributed elevated groundwater sulfate concentrations to Madison Aquifer recharge in the Black Hills with subsequent chemical evolution prior to upward migra¬tion into the Dakota Aquifer. This study examines the plausibility of a Madison Aquifer origin for groundwater in northeastern Nebraska. Dakota Aquifer water samples were collected for major ion chemistry and isotopic analysis (18O, 2H, 3H, 14C, 13C, 34S, 18O-SO4, 87Sr, 37Cl). Results show that groundwater beneath the eastern, un¬confined portion of the study area is distinctly different from groundwater sampled beneath the western, con¬fined portion. In the east, groundwater is calcium-bicarbonate type, with δ18O values (−9.6‰ to −12.4‰) simi¬lar to local, modern precipitation (−7.4‰ to −10‰), and tritium values reflecting modern recharge. In the west, groundwater is calcium-sulfate type, having depleted δ18O values (−16‰ to −18‰) relative to local, modern precipitation, and 14C ages 32,000 to more than 47,000 years before present. Sulfate, δ18O, δ2H, δ34S, and δ18O-SO4 concentrations are similar to those found in Madison Aquifer groundwater in South Dakota. Thus, it is pro¬posed that Madison Aquifer source water is also present within the Dakota Aquifer beneath northeastern Ne¬braska. A simple Darcy equation estimate of groundwater velocities and travel times using reported physical parameters from the Madison and Dakota Aquifers suggests such a migration is plausible. However, discrep¬ancies between 14C and Darcy age estimates indicate that 14C ages may not accurately reflect aquifer residence time, due to mixtures of varying aged water

Improving Surgical Care in Low- and Middle-Income Countries: A Pivotal Role for the World Health Organization

In response to increasing evidence that surgical conditions are an important global public health problem, and data suggesting that essential surgical services can be delivered in a cost-effective manner in low- and middle-income countries, the World Health Organization (WHO) has expanded its interest in surgical care. In 2004, WHO established a Clinical Procedures Unit within the Department of Essential Health Technologies. This unit has developed the Emergency and Essential Surgical Project (EESC), which includes a basic surgical training program based on the “Integrated Management of Emergency and Essential Surgical Care” Toolkit and the textbook “Surgery at the District Hospital.” To promote the importance of emergency and essential surgical care, a Global Initiative for Emergency and Essential Care was launched in 2005. In what maybe the most important development, surgical care is included in WHO’s new comprehensive primary health care plan. Given these rapid developments, surgical care at WHO may be approaching a critical “tipping point.” Lobbying for a World Health Assembly resolution on emergency and essential surgical care, and developing “structured collaborations” between WHO and various stakeholders are potential ways to ensure that the global surgery agenda continues to move forward

Groundwater level assessment and prediction in the Nebraska Sand Hills using LIDAR-derived lake water level

The spatial variability of groundwater levels is often inferred from sparsely located hydraulic head observations in wells. The spatial correlation structure derived from sparse observations is associated with uncertainties that spread to estimates at unsampled locations. In areas where surface water represents the nearby groundwater level, remote sensing techniques can estimate and increase the number of hydraulic head measurements. This research uses light detection and ranging (LIDAR) to estimate lake surface water level to characterize the groundwater level in the Nebraska Sand Hills (NSH), an area with few observation wells. The LIDAR derived lake groundwater level accuracy was within 40 cm mean square error (MSE) of the nearest observation wells. The lake groundwater level estimates were used to predict the groundwater level at unsampled locations using universal kriging (UK) and kriging with an external drift (KED). The results indicate unbiased estimates of groundwater level in the NSH. UK showed the influence of regional trends in groundwater level while KED revealed the local variation present in the groundwater level. A 10-fold cross-validation demonstrated KED with better mean squared error (ME) [–0.003, 0.007], root mean square error (RMSE) [2.39, 4.46], residual prediction deviation (RPD) [1.32, 0.71] and mean squared deviation ratio (MSDR) [1.01, 1.49] than UK. The research highlights that the lake groundwater level provides an accurate and cost-effective approach to measure and monitor the subtle changes in groundwater level in the NSH. This methodology can be applied to other locations where surface water bodies represent the water level of the unconfined aquifer and the results can aid in groundwater management and modeling

Cx3cr1-deficient microglia exhibit a premature aging transcriptome.

CX3CR1, one of the highest expressed genes in microglia in mice and humans, is implicated in numerous microglial functions. However, the molecular mechanisms underlying Cx3cr1 signaling are not well understood. Here, we analyzed transcriptomes of Cx3cr1-deficient microglia under varying conditions by RNA-sequencing (RNA-seq). In 2-mo-old mice, Cx3cr1 deletion resulted in the down-regulation of a subset of immune-related genes, without substantial epigenetic changes in markers of active chromatin. Surprisingly, Cx3cr1-deficient microglia from young mice exhibited a transcriptome consistent with that of aged Cx3cr1-sufficient animals, suggesting a premature aging transcriptomic signature. Immunohistochemical analysis of microglia in young and aged mice revealed that loss of Cx3cr1 modulates microglial morphology in a comparable fashion. Our results suggest that CX3CR1 may regulate microglial function in part by modulating the expression levels of a subset of inflammatory genes during chronological aging, making Cx3cr1-deficient mice useful for studying aged microglia