73 research outputs found

    Hemoglobin level is an independent predictor for adverse cardiovascular outcomes in women undergoing evaluation for chest pain Results from the National Heart, Lung, and Blood Institute women's ischemia syndrome evaluation study

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    AbstractObjectivesThis study was designed to investigate the relationship between hemoglobin level (Hgb) and adverse cardiovascular outcomes in women with suspected ischemia.BackgroundLow Hgb levels correlate with increased cardiovascular morbidity and mortality in patients presenting with acute myocardial infarction (MI) or congestive heart failure (CHF). However, the prognostic significance of Hgb in women with suspected ischemia is unclear.MethodsAs part of the National Heart, Lung, and Blood Institute (NHLBI)-sponsored Women's Ischemia Syndrome Evaluation (WISE), we prospectively studied 936 women referred for coronary angiography to evaluate suspected ischemia. We compared Hgb levels with cardiovascular risk factors, core lab interpreted angiograms, inflammatory markers, and adverse cardiovascular outcomes.ResultsOf women enrolled, 864 (mean age 58.4 ±11.6 years) had complete Hgb, angiogram, and follow-up (mean 3.3 ± 1.7 years) data. The mean Hgb was 12.9 g/dl (range 7.7 to 16.4 g/dl) and 184 women (21%) were anemic (Hgb <12 g/dl). Anemic women had higher creatinine and were more likely to be nonwhite and have a history of diabetes, hypertension, and CHF (p < 0.05). However, we found no difference in EF or severity of coronary artery disease. Anemic women had a higher risk of death from any cause (10.3% vs. 5.4%; p = 0.02) and total adverse outcomes (26% vs. 16%, p < 0.01). In a multivariable model, decreasing Hgb was associated with significantly higher risk of adverse outcomes (hazard ratio = 1.20, p = 0.002). Also, anemic women had shorter survival time free of adverse outcome (p < 0.001).ConclusionsOur findings extend previous reports, linking lower hemoglobin levels with higher risk for adverse cardiovascular outcomes, to women evaluated for suspected ischemia in the absence of acute MI or CHF

    Increased Oxidative Burden Associated with Traffic Component of Ambient Particulate Matter at Roadside and Urban Background Schools Sites in London

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    As the incidence of respiratory and allergic symptoms has been reported to be increased in children attending schools in close proximity to busy roads, it was hypothesised that PM from roadside schools would display enhanced oxidative potential (OP). Two consecutive one-week air quality monitoring campaigns were conducted at seven school sampling sites, reflecting roadside and urban background in London. Chemical characteristics of size fractionated particulate matter (PM) samples were related to the capacity to drive biological oxidation reactions in a synthetic respiratory tract lining fluid. Contrary to hypothesised contrasts in particulate OP between school site types, no robust size-fractionated differences in OP were identified due high temporal variability in concentrations of PM components over the one-week sampling campaigns. For OP assessed both by ascorbate (OPAA m−3) and glutathione (OPGSH m−3) depletion, the highest OP per cubic metre of air was in the largest size fraction, PM1.9–10.2. However, when expressed per unit mass of particles OPAA µg−1 showed no significant dependence upon particle size, while OPGSH µg−1 had a tendency to increase with increasing particle size, paralleling increased concentrations of Fe, Ba and Cu. The two OP metrics were not significantly correlated with one another, suggesting that the glutathione and ascorbate depletion assays respond to different components of the particles. Ascorbate depletion per unit mass did not show the same dependence as for GSH and it is possible that other trace metals (Zn, Ni, V) or organic components which are enriched in the finer particle fractions, or the greater surface area of smaller particles, counter-balance the redox activity of Fe, Ba and Cu in the coarse particles. Further work with longer-term sampling and a larger suite of analytes is advised in order to better elucidate the determinants of oxidative potential, and to fuller explore the contrasts between site types.\ud \u

    Explosive volcanism on the ultraslow-spreading Gakkel ridge, Arctic Ocean

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    Author Posting. © Nature Publishing Group, 2008. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature 453 (2008): 1236-1238, doi:10.1038/nature07075.Roughly 60% of the Earth’s outer surface is comprised of oceanic crust formed by volcanic processes at mid-ocean ridges (MORs). Although only a small fraction of this vast volcanic terrain has been visually surveyed and/or sampled, the available evidence suggests that explosive eruptions are rare on MORs, particularly at depths below the critical point for steam (3000 m). A pyroclastic deposit has never been observed on the seafloor below 3000 m, presumably because the volatile content of mid-ocean ridge basalts is generally too low to produce the gas fractions required to fragment a magma at such high hydrostatic pressure. We employed new deep submergence technologies during an International Polar Year expedition to the Gakkel Ridge in the Arctic Basin at 85°E, to acquire the first-ever photographic images of ‘zero-age’ volcanic terrain on this remote, ice-covered MOR. Our imagery reveals that the axial valley at 4000 m water depth is blanketed with unconsolidated pyroclastic deposits, including bubble wall fragments (limu o Pele), covering a large area greater than 10 km2. At least 13.5 wt% CO2 is required to fragment magma at these depths, which is ~10x greater than the highest values measured to-date in a MOR basalt. These observations raise important questions regarding the accumulation and discharge of magmatic volatiles at ultra-slow spreading rates on the Gakkel Ridge (6- 14 mm yr-1, full-rate), and demonstrate that large-scale pyroclastic activity is possible along even the deepest portions of the global MOR volcanic system.This research was funded by the National Aeronautics and Space Administration, the National Science Foundation, and the Woods Hole Oceanographic Institution

    The tectonics of the western Ordos Plateau, Ningxia, China: Slip rates on the Luoshan and East Helanshan Faults

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    Analysis of the locus, style, and rate of faulting is fundamental to understanding the kinematics of continental deformation. The Ordos Plateau lies to the northeast of Tibet, within the India-Eurasia collision zone. Previous studies have suggested that it behaves rigidly and rotates anticlockwise within a large-scale zone of ENE-WSW left-lateral shearing. For this rotation to be accommodated, the eastern and western margins of the Ordos Plateau should be undergoing right-lateral shearing and yet the dominant faulting style appears to be extensional. We focus specifically on the kinematics of the faults bounding the western margin of the Ordos Plateau and make new slip rate estimates for two of the major faults in the region: the right-lateral strike-slip Luoshan Fault and the normal-slip East Helanshan Fault. We use a combination of infrared stimulated luminescence dating of offset landforms with high-resolution imagery and topography from the Pleiades satellites to determine an average right-lateral slip rate of 4.3 ± 0.4 mm/a (1σ uncertainty) on the Luoshan Fault. Similarly, we use 10Be exposure dating to determine a vertical throw rate on the East Helanshan Fault of <0.6 ± 0.1 mm/a, corresponding to an extension rate of <0.7 ± 0.1 mm/a (1σ uncertainty). Both of these results agree well with slip rates determined from the latest campaign GPS data. We therefore conclude that right-lateral shearing is the dominant motion occurring in the western Ordos region, supporting a kinematic model of large-scale anticlockwise rotation of the whole Ordos Plateau

    Comparison of Marine Spatial Planning Methods in Madagascar Demonstrates Value of Alternative Approaches

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    The Government of Madagascar plans to increase marine protected area coverage by over one million hectares. To assist this process, we compare four methods for marine spatial planning of Madagascar's west coast. Input data for each method was drawn from the same variables: fishing pressure, exposure to climate change, and biodiversity (habitats, species distributions, biological richness, and biodiversity value). The first method compares visual color classifications of primary variables, the second uses binary combinations of these variables to produce a categorical classification of management actions, the third is a target-based optimization using Marxan, and the fourth is conservation ranking with Zonation. We present results from each method, and compare the latter three approaches for spatial coverage, biodiversity representation, fishing cost and persistence probability. All results included large areas in the north, central, and southern parts of western Madagascar. Achieving 30% representation targets with Marxan required twice the fish catch loss than the categorical method. The categorical classification and Zonation do not consider targets for conservation features. However, when we reduced Marxan targets to 16.3%, matching the representation level of the “strict protection” class of the categorical result, the methods show similar catch losses. The management category portfolio has complete coverage, and presents several management recommendations including strict protection. Zonation produces rapid conservation rankings across large, diverse datasets. Marxan is useful for identifying strict protected areas that meet representation targets, and minimize exposure probabilities for conservation features at low economic cost. We show that methods based on Zonation and a simple combination of variables can produce results comparable to Marxan for species representation and catch losses, demonstrating the value of comparing alternative approaches during initial stages of the planning process. Choosing an appropriate approach ultimately depends on scientific and political factors including representation targets, likelihood of adoption, and persistence goals

    Empirical Evaluation of Bone Extraction Protocols

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    The application of high-resolution analytical techniques to characterize ancient bone proteins requires clean, efficient extraction to obtain high quality data. Here, we evaluated many different protocols from the literature on ostrich cortical bone and moa cortical bone to evaluate their yield and relative purity using the identification of antibody-antigen complexes on enzyme-linked immunosorbent assay and gel electrophoresis. Moa bone provided an ancient comparison for the effectiveness of bone extraction protocols tested on ostrich bone. For the immunological part of this study, we focused on collagen I, osteocalcin, and hemoglobin because collagen and osteocalcin are the most abundant proteins in the mineralized extracellular matrix and hemoglobin is common in the vasculature. Most of these procedures demineralize the bone first, and then the remaining organics are chemically extracted. We found that the use of hydrochloric acid, rather than ethylenediaminetetraacetic acid, for demineralization resulted in the cleanest extractions because the acid was easily removed. In contrast, the use of ethylenediaminetetraacetic acid resulted in smearing upon electrophoretic separation, possibly indicating these samples were not as pure. The denaturing agents sodium dodecyl sulfate, urea, and guanidine HCl have been used extensively for the solubilization of proteins in non-biomineralized tissue, but only the latter has been used on bone. We show that all three denaturing agents are effective for extracting bone proteins. One additional method tested uses ammonium bicarbonate as a solubilizing buffer that is more appropriate for post-extraction analyses (e.g., proteomics) by removing the need for desalting. We found that both guanidine HCl and ammonium bicarbonate were effective for extracting many bone proteins, resulting in similar electrophoretic patterns. With the increasing use of proteomics, a new generation of scientists are now interested in the study of proteins from not only extant bone but also from ancient bone

    Playing Games with Tito:Designing Hybrid Museum Experiences for Critical Play

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    This article brings together two distinct, but related perspectives on playful museum experiences: Critical play and hybrid design. The article explores the challenges involved in combining these two perspectives, through the design of two hybrid museum experiences that aimed to facilitate critical play with/in the collections of the Museum of Yugoslavia and the highly contested heritage they represent. Based on reflections from the design process as well as feedback from test users, we describe a series of challenges: Challenging the norms of visitor behaviour, challenging the role of the artefact, and challenging the curatorial authority. In conclusion, we outline some possible design strategies to address these challenges

    Rare and low-frequency coding variants alter human adult height

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    Height is a highly heritable, classic polygenic trait with ~700 common associated variants identified so far through genome - wide association studies . Here , we report 83 height - associated coding variants with lower minor allele frequenc ies ( range of 0.1 - 4.8% ) and effects of up to 2 16 cm /allele ( e.g. in IHH , STC2 , AR and CRISPLD2 ) , >10 times the average effect of common variants . In functional follow - up studies, rare height - increasing alleles of STC2 (+1 - 2 cm/allele) compromise d proteolytic inhibition of PAPP - A and increased cleavage of IGFBP - 4 in vitro , resulting in higher bioavailability of insulin - like growth factors . The se 83 height - associated variants overlap genes mutated in monogenic growth disorders and highlight new biological candidates ( e.g. ADAMTS3, IL11RA, NOX4 ) and pathways ( e.g . proteoglycan/ glycosaminoglycan synthesis ) involved in growth . Our results demonstrate that sufficiently large sample sizes can uncover rare and low - frequency variants of moderate to large effect associated with polygenic human phenotypes , and that these variants implicate relevant genes and pathways

    Normal faulting sequence in the Pumqu-Xainza Rift constrained by InSAR and teleseismic body-wave seismology

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    Normal faulting earthquakes play an important role in the deformation of continents, and pose significant seismic hazard, yet important questions remain about their mechanics. We use InSAR and body-wave seismology to compute dislocation models and centroid moment solutions for four normal-faulting earthquakes (Mw 5.7–6.2) that occurred in the Pumqu-Xainza Rift (PXR), southern Tibet, a region where low-angle normal faulting has previously been inferred. We also use the fault locations and slip to investigate the correlation between earthquakes and surface topography, and to calculate stress interactions between the earthquakes. The InSAR and body-wave models give consistent focal mechanisms except for the magnitude of the 1996 event, which may be overestimated due to postseismic deformation in the long-interval interferograms. We calculate the static stress changes due to coseismic slip and find that the 1993 event was too distant to cause triggering of the later events, but that the 1998 event pair occurred in regions of increased Coulomb stress resulting from the 1996 event. All the fault planes found here dip at 40–60°, reinforcing the absence in observations for low-angle normal faulting earthquakes (dip < 30°) whose focal planes can be determined unambiguously. The fault planes of the 1993 and 1996 events are not associated with any obvious surface geomorphology, suggesting that sometimes it is unreliable to resolve the focal plane ambiguity by geomorphology, even for Mw 6.2 events. Furthermore, these events occurred outside the center of the rift, indicating that the active faulting is more distributed and over a length-scale at least 25–50 km east-west in extent, rather than confined to the 20 km width seen in the current mapped faulting and topography. These results suggest that seismic hazard in other extensional zones worldwide might also be more broadly distributed than suggested by geomorphology
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