320 research outputs found

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

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    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 migraĀ¬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, unĀ¬confined portion of the study area is distinctly different from groundwater sampled beneath the western, conĀ¬fined portion. In the east, groundwater is calcium-bicarbonate type, with Ī“18O values (āˆ’9.6ā€° to āˆ’12.4ā€°) simiĀ¬lar to local, modern precipitation (āˆ’7.4ā€° to āˆ’10ā€°), and tritium values reflecting modern recharge. In the west, groundwater is calcium-sulfate type, having depleted Ī“18O values (āˆ’16ā€° to āˆ’18ā€°) relative to local, modern precipitation, and 14C ages 32,000 to more than 47,000 years before present. Sulfate, Ī“18O, Ī“2H, Ī“34S, and Ī“18O-SO4 concentrations are similar to those found in Madison Aquifer groundwater in South Dakota. Thus, it is proĀ¬posed that Madison Aquifer source water is also present within the Dakota Aquifer beneath northeastern NeĀ¬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, discrepĀ¬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

    Get PDF
    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 migraĀ¬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, unĀ¬confined portion of the study area is distinctly different from groundwater sampled beneath the western, conĀ¬fined portion. In the east, groundwater is calcium-bicarbonate type, with Ī“18O values (āˆ’9.6ā€° to āˆ’12.4ā€°) simiĀ¬lar to local, modern precipitation (āˆ’7.4ā€° to āˆ’10ā€°), and tritium values reflecting modern recharge. In the west, groundwater is calcium-sulfate type, having depleted Ī“18O values (āˆ’16ā€° to āˆ’18ā€°) relative to local, modern precipitation, and 14C ages 32,000 to more than 47,000 years before present. Sulfate, Ī“18O, Ī“2H, Ī“34S, and Ī“18O-SO4 concentrations are similar to those found in Madison Aquifer groundwater in South Dakota. Thus, it is proĀ¬posed that Madison Aquifer source water is also present within the Dakota Aquifer beneath northeastern NeĀ¬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, discrepĀ¬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

    Field Guide to the Geology of the Harlan County Lake Area, Harlan County, Nebraska ā€” with a History of Events Leading to Construction of Harlan County Dam

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    The year 2002 will mark the fiftieth anniversary of completion of the Harlan County Dam and Multi-Purpose Reservoir. This seems a good time to write about the history of and reasons for building the dam, the effects of the dam and reservoir on the Republican River valley, and the geologic features seen along the shores of the lake and areas nearby. As many junior authors helped produced this educational circular, they are listed in the table of contents. All other sections were written by the senior author. Includes July 2016 update: Addendum of photographs showing fault traces on drought-exposed lake bottom. Cretaceous Niobrara Chalk Formation and the younger Pierre Shale are also shown. Table of Contents Introduction 1 Location 1 Republican River Floods 1 The Republican River Flood of 1935 - D R Mohlman 1 Cautionary Notes (sidebar) 1 Events After the Flood Leading to Creation of Harlan County Lake 9 Stormer Ford Dog Town (sidebar) 10 Water 10 Surface Water Hydrology - S Summerside 10 Shoreline Springs and Seeps - F: E Harvey and K J Warren 12 Introduction 12 Using Water Chemistry to Identify Spring and Seep Origin 1 2 Geology 15 General Conditions Leading to Good Exposures 15 Stratigraphy of Unconsolidated Sediments and Rock Strata 15 Cretaceous System - Upper Cretaceous Series 15 Niobrara Formation - Smoky Hill Chalk Member 15 Pierre Shale 15 Tertiary System - Miocene Series 16 Ogallala Group -Ash Hollow Formation 16 Quaternary System - Pleistocene Series 16 Crete (?) Formation (Sands and Gravels) 1 6 Loveland Loess 16 Gliman Canyon Formation 16 Peoria and Bignell Loesses 16 Quaternary System - Holocene (Recent) Series 1 6 Unnamed Fluvial, Eolian, and Colluvial Deposits 16 Paleontology of the Various Formations 16 Plants 16 Invertebrates - R K Pabian 17 Cretaceous Marine Fossils 17 Niobrara Formation 17 Foraminifers 17 Post-Devonian Stromatoporoids 1 9 Mollusks 19 Bivalves 19 Ammonites 19 Pierre Shale Formation 19 Bivalves 19 Ammonites 19 Quaternary - Pleistocene (Ice Age) Invertebrate Fossils 19 Vertebrate Fossils - R G Corner 24 Late Cretaceous Fossils 24 Niobrara Formation 24 Niobrara Fishes 24 Niobrara Mosasaurs 29 Pierre Shale Formation 30 Protosphyvaena gladius: Giant Mystery Fish 30 Pierre Mosasaurs 32 Late Miocene Ogallala Group 32 Bone Cove I Fauna 32 Bone Cove II Fauna 32 Quaternary - Pleistocene (Ice Age) 33 Crete (?) Sands and Gravels 33 Gilman Canyon Formation 33 Peoria Loess 35 Late Pleistocene Fauna 35 Late Pleistocene Environments 37 Geologic Processes Affecting the Strata 37 Modem and Ancient Landslides 37 Modern Landslides D A Eversoll 37 Ancient Landslides - D A Eversoll and R F Diffendal, Jr 39 Geologic Structures 41 Introduction and Previous Work 41 Angular Unconformities 45 Joints 45 Faults and Folds 45 Ancient Landscapes (Paleotopography) 50 Quaternary River Terraces 50 Concluding Remarks 50 References Cited 51 Glossary Keywords: flooding 1930s, vertebrate fossils, earthquake faults, landslides, groundwater qualit

    Training of Instrumentalists and Development of New Technologies on SOFIA

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    This white paper is submitted to the Astronomy and Astrophysics 2010 Decadal Survey (Astro2010)1 Committee on the State of the Profession to emphasize the potential of the Stratospheric Observatory for Infrared Astronomy (SOFIA) to contribute to the training of instrumentalists and observers, and to related technology developments. This potential goes beyond the primary mission of SOFIA, which is to carry out unique, high priority astronomical research. SOFIA is a Boeing 747SP aircraft with a 2.5 meter telescope. It will enable astronomical observations anywhere, any time, and at most wavelengths between 0.3 microns and 1.6 mm not accessible from ground-based observatories. These attributes, accruing from the mobility and flight altitude of SOFIA, guarantee a wealth of scientific return. Its instrument teams (nine in the first generation) and guest investigators will do suborbital astronomy in a shirt-sleeve environment. The project will invest $10M per year in science instrument development over a lifetime of 20 years. This, frequent flight opportunities, and operation that enables rapid changes of science instruments and hands-on in-flight access to the instruments, assure a unique and extensive potential - both for training young instrumentalists and for encouraging and deploying nascent technologies. Novel instruments covering optical, infrared, and submillimeter bands can be developed for and tested on SOFIA by their developers (including apprentices) for their own observations and for those of guest observers, to validate technologies and maximize observational effectiveness.Comment: 10 pages, no figures, White Paper for Astro 2010 Survey Committee on State of the Professio

    The Origin and Nature of Tightly Clustered BTG1 Deletions in Precursor B-Cell Acute Lymphoblastic Leukemia Support a Model of Multiclonal Evolution

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    Recurrent submicroscopic deletions in genes affecting key cellular pathways are a hallmark of pediatric acute lymphoblastic leukemia (ALL). To gain more insight into the mechanism underlying these deletions, we have studied the occurrence and nature of abnormalities in one of these genes, the B-cell translocation gene 1 (BTG1), in a large cohort of pediatric ALL cases. BTG1 was found to be exclusively affected by genomic deletions, which were detected in 65 out of 722 B-cell precursor ALL (BCP-ALL) patient samples (9%), but not in 109 T-ALL cases. Eight different deletion sizes were identified, which all clustered at the telomeric site in a hotspot region within the second (and last) exon of the BTG1 gene, resulting in the expression of truncated BTG1 read-through transcripts. The presence of V(D)J recombination signal sequences at both sites of virtually all deletions strongly suggests illegitimate RAG1/RAG2-mediated recombination as the responsible mechanism. Moreover, high levels of histone H3 lysine 4 trimethylation (H3K4me3), which is known to tether the RAG enzyme complex to DNA, were found within the BTG1 gene body in BCP-ALL cells, but not T-ALL cells. BTG1 deletions were rarely found in hyperdiploid BCP-ALLs, but were predominant in other cytogenetic subgroups, including the ETV6-RUNX1 and BCR-ABL1 positive BCP-ALL subgroups. Through sensitive PCR-based screening, we identified multiple additional BTG1 deletions at the subclonal level in BCP-ALL, with equal cytogenetic distribution which, in some cases, grew out into the major clone at relapse. Taken together, our results indicate that BTG1 deletions may act as ā€œdriversā€ of leukemogenesis in specific BCP-ALL subgroups, in which they can arise independently in multiple subclones at sites that are prone to aberrant RAG1/RAG2-mediated recombination events. These findings provide further evidence for a complex and multiclonal evolution of ALL

    Association Between Interstitial Lung Abnormalities and All-Cause Mortality.

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    To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.Interstitial lung abnormalities have been associated with lower 6-minute walk distance, diffusion capacity for carbon monoxide, and total lung capacity. However, to our knowledge, an association with mortality has not been previously investigated.To investigate whether interstitial lung abnormalities are associated with increased mortality.Prospective cohort studies of 2633 participants from the FHS (Framingham Heart Study; computed tomographic [CT] scans obtained September 2008-March 2011), 5320 from the AGES-Reykjavik Study (Age Gene/Environment Susceptibility; recruited January 2002-February 2006), 2068 from the COPDGene Study (Chronic Obstructive Pulmonary Disease; recruited November 2007-April 2010), and 1670 from ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints; between December 2005-December 2006).Interstitial lung abnormality status as determined by chest CT evaluation.All-cause mortality over an approximate 3- to 9-year median follow-up time. Cause-of-death information was also examined in the AGES-Reykjavik cohort.Interstitial lung abnormalities were present in 177 (7%) of the 2633 participants from FHS, 378 (7%) of 5320 from AGES-Reykjavik, 156 (8%) of 2068 from COPDGene, and in 157 (9%) of 1670 from ECLIPSE. Over median follow-up times of approximately 3 to 9 years, there were more deaths (and a greater absolute rate of mortality) among participants with interstitial lung abnormalities when compared with those who did not have interstitial lung abnormalities in the following cohorts: 7% vs 1% in FHS (6% difference [95% CI, 2% to 10%]), 56% vs 33% in AGES-Reykjavik (23% difference [95% CI, 18% to 28%]), and 11% vs 5% in ECLIPSE (6% difference [95% CI, 1% to 11%]). After adjustment for covariates, interstitial lung abnormalities were associated with a higher risk of death in the FHS (hazard ratio [HR], 2.7 [95% CI, 1.1 to 6.5]; Pā€‰=ā€‰.03), AGES-Reykjavik (HR, 1.3 [95% CI, 1.2 to 1.4]; Pā€‰<ā€‰.001), COPDGene (HR, 1.8 [95% CI, 1.1 to 2.8]; Pā€‰=ā€‰.01), and ECLIPSE (HR, 1.4 [95% CI, 1.1 to 2.0]; Pā€‰=ā€‰.02) cohorts. In the AGES-Reykjavik cohort, the higher rate of mortality could be explained by a higher rate of death due to respiratory disease, specifically pulmonary fibrosis.In 4 separate research cohorts, interstitial lung abnormalities were associated with a greater risk of all-cause mortality. The clinical implications of this association require further investigation.National Institutes of Health (NIH) T32 HL007633 Icelandic Research Fund 141513-051 Landspitali Scientific Fund A-2015-030 National Cancer Institute grant 1K23CA157631 NIH K08 HL097029 R01 HL113264 R21 HL119902 K25 HL104085 R01 HL116931 R01 HL116473 K01 HL118714 R01 HL089897 R01 HL089856 N01-AG-1-2100 HHSN27120120022C P01 HL105339 P01 HL114501 R01 HL107246 R01 HL122464 R01 HL111024 National Heart, Lung, and Blood Institute's Framingham Heart Study contract N01-HC-2519.5 GlaxoSmithKline NCT00292552 5C0104960 National Institute on Aging (NIA) grant 27120120022C NIA Intramural Research Program, Hjartavernd (the Icelandic Heart Association) Althingi (the Icelandic Parliament) NIA 27120120022
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