417 research outputs found

    Asymmetry and vulnerability in amyotrophic lateral sclerosis

    Get PDF

    Petrographic Controls on Weathering of the Haney Limestone

    Get PDF
    Although karst processes in south central Kentucky have been studied extensively, the Haney Limestone Member of the Golconda Formation has not been studied in detail in contrast to limestones stratigraphically below it that are thicker. In addition, the relationship between petrographic features of the Haney Limestone and the formation of caves and karst features has not been studied extensively compared to lithographic, petrographic, or structural variables Petrographic data were collected using core and surface exposures across the study area of south central Kentucky from northern Logan and Warren counties up toward the Rough Creek Graben region, and stratigraphic columns were constructed. Twenty-three petrographic thin-sections were made from samples collected at these sites, described, and photo documented. These studies have revealed that grain size and silica content play a role in how the Haney weathers both in surface exposure and in a cave setting. Petrographic thin-section analysis suggests that the Haney possesses a complex diagenetic history that involves several generations of calcite cementation, dolomitization, silicification, and pressure-dissolution features in the form of microstylolites and stylolites. A basal shale in the Big Clifty occurs commonly at the Big Clifty/Haney contact and acts as a confining hydrogeologic unit, which is favorable for the development of springs and caves. Studying the Haney Limestone petrographically provides an opportunity not only to study a lesser known unit, but also in the context of relating petrographic influences or controls on the morphology of Haney cave-passage development under both vadose and phreatic hydrologic regimens. Heretofore, the vast majority of cave morphological studies have only linked the hydrologic regimen to formation of cave passages, but such studies have not considered petrographic variance. This study not only relates karst features to petrographic variance, but also provides a petrographical description of the Haney across south central Kentucky, whereas many previous studies focused on Illinois and Indiana. Understanding Haney petrographic characteristics also provides context for potential carbonate hydrocarbon reservoirs and groundwater resources in the Illinois Basin region

    The Two Sides of Silicon Detectors

    Get PDF
    Results are presented on in situ irradiation of silicon detector's at cryogenic temperature. The results show that irradiation at cryogenic temperatures does not detrimentally effect a silicon detectors performance when compared to its irradiation at room temperature. Operation of silicon devices at cryogenic temperatures offers the advantage of reducing radiation-induced leakage current to levels of a few pA, while at 130K the Lazarus Effect plays an important role i.e. minimum voltage required for full depletion. Performing voltage scans on a 'standard' silicon pad detector pre- and post-annealing, the charge collection efficiency was found to be 60% at 200V and 95% at 200V respectively. Time dependence measurements are presented, showing that for a dose of 6.5x10e14 p/cm2 (450GeV protons) the time dependence of the charge collection efficiency is negligible. However, for higher doses, 1.2x10e15 p/cm2, the charge collection efficiency drops from an initial measured value of 67% to a stable value of 58% over a period of 15 minutes for reversed biased diodes. An analysis of the "double junction" effect is also presented. A comparison between the Transient Current Technique and an X-ray technique is presented. The double junction has been observed in p+/n/n+ silicon detectors after irradiation beyond "type inversion", corresponding to a fluence equivalent to ~3xl013cm-2 1MeV neutrons, producing p+/p/n+ and essentially two p-n junctions within one device. With increasing bias voltage, as the electric field is extending into the detector bulk from opposite sides of the silicon detector, there are two distinct depletion regions that collect charge signal independently. Summing the signal charge from the two regions, one is able to reconstruct the initial energy of the incident particle. From Transient Current measurements it is apparent that E-field manipulation is possible by excess carrier injection, enabling a high enough E-field to extend across the width of the detector, allowing for efficient charge collection

    In the Eye of the Beholder? Motivated Reasoning in Disputed Elections

    Get PDF
    This study uses an experimental design to simulate the ballot counting process during a hand-recount after a disputed election. Applying psychological theories of motivated reasoning to the political process, we find that ballot counters’ party identification conditionally influences their ballot counting decisions. Party identification’s effect on motivated reasoning is greater when ballot counters are given ambiguous, versus specific, instructions for determining voter intent. This study’s findings have major implications for ballot counting procedures throughout the United States and for the use of motivated reasoning in the political science literature

    A new approach to modelling natural gas markets. ESRI Research Bulletin 2015/4/2

    Get PDF
    International gas markets are becoming interdependent and global due to the shale gas revolution and the increasing ability of countries to import/export liquefied natural gas. As a result, there is an increased need for international and realistic gas market models. Research into natural gas markets is intrinsically an interdisciplinary field involving researchers from mathematics, engineering and economics. Hence, there are several examples of natural gas market models in the literature

    Registration of ‘Purple Bounty’ and ‘Purple Prosperity’ hairy vetch

    Get PDF
    The hairy vetch (Vicia villosa Roth) cultivars ‘Purple Bounty’ (Reg. no. CV-12, PI 648342) and ‘Purple Prosperity’ (Reg. no. CV-11, PI 654047) were released in 2007 and 2008, respectively, by the USDA–ARS in collaboration with the Rodale Institute and the agricultural experiment stations of Pennsylvania State University and Cornell University. Hairy vetch is a commonly used annual legume cover crop grown for its cold tolerance, fast growth, large biomass production, and ability to fix N2. However, this species has not been selected for the traits needed to optimize its use as a cover crop. Our breeding program focused on developing a cultivar that was both early flowering and had adequate winter survival and therefore adapted to mechanical termination in organic no-till production in the U.S. Northeast and Mid-Atlantic. Purple Bounty and Purple Prosperity were developed between 1998 and 2005 using recurrent selection at nurseries in Beltsville and Keedysville, MD. In 2005–2006, selections were evaluated against commercial checks for flowering time in Maryland and Pennsylvania, and in the 2006–2007 and 2007–2008 seasons they were evaluated in 10 locations (12 total site-years) across the United States for winter survival. Purple Bounty and Purple Prosperity both flowered earlier than the commercial material against which they were tested (significance depended on the date and site); Purple Bounty was the earlier flowering of the two cultivars. Purple Bounty and Purple Prosperity also had equivalent or improved winter survival compared with ‘AU Early Cover’, an early-maturing cultivar developed in the southern United States, at all test locations. Purple Prosperity is no longer commercially available, but Purple Bounty is currently licensed and distributed by Allied Seed (Nampa, ID)

    Survival of Patients with Acute Myeloid Leukemia Relapsing after Allogeneic Hematopoietic Cell Transplantation: A Center for International Blood and Marrow Transplant Research Study

    Get PDF
    AbstractAcute myeloid leukemia (AML) relapse after allogeneic hematopoietic cell transplantation (alloHCT) remains a major therapeutic challenge. We studied outcomes of 1788 AML patients relapsing after alloHCT (1990 to 2010) during first or second complete remission (CR) to identify factors associated with longer postrelapse survival. Median time to post-HCT relapse was 7 months (range, 1 to 177). At relapse, 1231 patients (69%) received intensive therapy, including chemotherapy alone (n = 660), donor lymphocyte infusion (DLI) ± chemotherapy (n = 202), or second alloHCT ± chemotherapy ± DLI (n = 369), with subsequent CR rates of 29%. Median follow-up after relapse was 39 months (range, <1 to 193). Survival for all patients was 23% at 1 year after relapse; however, 3-year overall survival correlated with time from HCT to relapse (4% for relapse during the 1- to 6-month period, 12% during the 6-month to 2-year period, 26% during the 2- to 3-year period, and 38% for ≄3 years). In multivariable analysis, lower mortality was significantly associated with longer time from alloHCT to relapse (relative risk, .55 for 6 months to 2 years; relative risk, .39 for 2 to 3 years; and relative risk, .28 for ≄3 years; P < .0001) and a first HCT using reduced-intensity conditioning (relative risk, .77; 95% confidence interval [CI], .66 to .88; P = .0002). In contrast, inferior survival was associated with age >40 years (relative risk, 1.42; 95% CI, 1.24 to 1.64; P < .0001), active graft-versus-host disease at relapse (relative risk, 1.25; 95% CI, 1.13 to 1.39; P < .0001), adverse cytogenetics (relative risk, 1.37; 95% CI, 1.09 to 1.71; P = .0062), mismatched unrelated donor (relative risk, 1.61; 95% CI, 1.22 to 2.13; P = .0008), and use of cord blood for first HCT (relative risk, 1.23; 95% CI, 1.06 to 1.42; P = .0078). AML relapse after alloHCT predicted poor survival; however, patients who relapsed ≄6 months after their initial alloHCT had better survival and may benefit from intensive therapy, such as second alloHCT ± DLI

    On the response of a buoyant plume to downwelling-favorable wind stress

    Get PDF
    Author Posting. © American Meteorological Society, 2012. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 42 (2012): 1083–1098, doi:10.1175/JPO-D-11-015.1.Here, the response of a coastally trapped buoyant plume to downwelling-favorable wind forcing is explored using a simplified two-dimensional numerical model and a prognostic theory for the resulting width, depth, and density anomaly and along-shelf transport of the plume. Consistent with the numerical simulations, the analytical model shows that the wind causes mixing of the plume water and that the forced cross-shelf circulation can also generate significant deepening and surface narrowing, as well as increased along-shelf transport. The response is due to a combination of the purely advective process that leads to the steepening of the isopycnals and the entrainment of ambient water into the plume. The advective component depends on the initial plume geometry: plumes that have a large fraction of their total width in contact with the bottom (“bottom trapped”) suffer relatively small depth and width changes compared to plumes that have a large fraction of their total width detached from the bottom (“surface trapped”). Key theoretical parameters are WÎł/Wα, the ratio of the width of the plume detached from the bottom to the width of the plume in contact with it, and the ratio of the wind-generated mixed layer ÎŽe to the initial plume depth hp, which determines the amount of water initially entrained into the plume. The model results also show that the cross-shelf circulation can be strongly influenced by the wind-driven response in combination with the geostrophic shear of the plume. The continuous entrainment into the plume, as well as transient events, is also discussed.This work has been supported by FONDECYT Grant 1070501. S. Lentz received support by theNational Science Foundation GrantOCE-0751554. C. Moffat had additional support from the National Science Foundation Office of Polar Programs through U.S. Southern Ocean GLOBEC Grants OPP 99-10092 and 06- 23223.2013-01-0
    • 

    corecore