763 research outputs found
Nonsolvable number fields ramified only at 3 and 5
No full textFor p = 3 and p = 5, we exhibit a finite nonsolvable extension of Q which is ramified only at p, proving in the affirmative a conjecture of Gross. Our construction involves explicit computations with Hilbert modular forms
The amplitude modulation of the quadriceps H-reflex in relation to mechanical output during walking
No full textAmplitude modulation of the quadriceps H reflex was investigated during the early part of the stance phase of gait in normal human subjects. Stability of the M wave was used to ensure constancy of the effective stimulus strength. In all subjects there was a progressive decrease in the reflex amplitude throughout the early knee flexion (yield of the knee), whereas the quadriceps EMG activity remained constant or even increased. At an equal stimulus strength and EMG level, the reflex was often larger at the onset of the stance phase of gait than during voluntary contraction, whereas it was always smaller during the knee extension following the yield of the knee. It is argued that changes in presynaptic inhibition of quadriceps Ia terminals could account for this amplitude modulation of the monosynaptic reflex during gait. The possible role of changes in the gain of the quadriceps stretch reflex during bipedal gait is discussed
Three-dimensional seismic velocity tomography of Montserrat from the SEA-CALIPSO offshore/onshore experiment
No full textThe SEA-CALIPSO experiment in December 2007 incorporated a sea-based airgun source, and seismic recorders both on Montserrat and on the adjacent sea floor. A high quality subset of the data was used for a first arrival P-wave velocity tomographic study. A total of more than 115,000 traveltime data from 4413 airgun shots, and 58 recording stations, were used in this highresolution tomographic inversion. The experiment geometry limited the depth of well resolved structures to about 5 km. The most striking features of the tomography are three relatively high velocity zones below each of the main volcanic centers on Montserrat, and three low velocity zones flanking Centre Hills. We suggest that the high velocity zones represent the solid andesitic cores of the volcano complexes, characterized by wave speeds faster than adjacent volcaniclastic material. The low velocity zones may reflect porous volcaniclastic material and/or alteration by formerly active hydrothermal systems. Copyright © 2010 by the American Geophysical Union
Upper crustal structure of an active volcano from refraction/reflection tomography, Montserrat, Lesser Antilles
No full textTo better understand the volcanic phenomena acting on Montserrat, the SEA-CALIPSO seis-mic experiment (Seismic Experiment with Airgun-source – Caribbean Andesitic Lava Island Precision Seismo-geodetic Observatory) was conducted in 2007 December with the aim of imaging the upper crust and the magmatic system feeding the active Soufri ?ere Hills Volcano. The 3-D survey covered an area of about 50
× 40 km and involved the deployment of 247 land stations and ocean-bottom seismometers (OBSs). A subset of the data, recorded by four OBSs and four land stations on a southeast to northwest line, has been analysed, and traveltimes have been inverted to obtain a 2-D seismic velocity model through the island. Inverted phases include crustal and sediment P waves and wide-angle reflections. The resulting velocity model reveals the presence of a high velocity body (3.5–5.5 km s?1 ) beneath the island, with highest velocities beneath the Soufri ?ere and Centre Hills, cor responding primarily to the cores of these volcanic edifices, built of a pile of andesite lava domes and subsequent intrusions. In the off-shore region, velocities in the surficial sediment layer vary from 1.5 to 3.0 km s?1 , consistent with a mainly calcareous and volcaniclastic composition. A wide-angle reflector is observed at a depth of ?1200 m below the seabed, and appears to deepen beneath the island. The upper crust beneath this reflector has velocities of 4.0–6.0 km s?1 and is infer red to cor respond to plutonic and hypabyssal rocks and sedimentary material of the old arc. The high velocity region beneath the island, extends into the crust to a depth of at least 5 km, and is believed to be caused by an intrusive complex, possibly of intermediate composition. A low velocity zone, as would be expected in the presence of an active magma chamber, was not observed perhaps due to the limited resolution beneath ?5 km depth. Our results so far provide the first wide-angle seismic constraints on the upper crustal structure of the island to a depth of 10 km, and will help understanding the processes that drive volcanism at Montserrat and other island arc volcanoes
An overview of the eruption of Soufriere Hills Volcano, Montserrat from 2000 to 2010
No full textThe 1995–present eruption of Soufrière Hills Volcano on Montserrat has produced over a cubic kilometre of andesitic magma, creating a series of lava domes that were successively destroyed, with much of their mass deposited in the sea. There have been five phases of lava extrusion to form these lava domes: November 1995–March 1998; November 1999–July 2003; August 2005–April 2007; July 2008–January 2009; and October 2009–February 2010. It has been one of the most intensively studied volcanoes in the world during this time, and there are long instrumental and observational datasets. From these have sprung major new insights concerning: the cyclicity of magma transport; low-frequency earthquakes associated with conduit magma flow; the dynamics of lateral blasts and Vulcanian explosions; the role that basalt–andesite magma mingling in the mid-crust has in powering the eruption; identification using seismic tomography of the uppermost magma reservoir at a depth of 5.5 > 7.5 km; and many others. Parallel to the research effort, there has been a consistent programme of quantitative risk assessment since 1997 that has both pioneered new methods and provided a solid evidential source for the civil authority to use in mitigating the risks to the people of Montserrat
Letter from [Minna A. Newman], Carson Estate Company to Mr. A. [Al] G. Hemming, February 1, 1946
No full textRefers to two enclosed leases: #3-B for "G. V. Voight" and #1 for John Hajime Masuzumi
Dissecting the pleiotropic effects of established type 2 diabetes and other cardiometabolic trait loci to define pathways and gene networks involved in type 2 diabetes pathogenesis
No full textBackground and aims: Recent genome-wide association studies (GWAS) for human complex phenotypes have identified hundreds of genetic variants for cardio-metabolic traits and risk of disease. At many loci or specific variants associations are observed with multiple epidemiologically correlated traits. We formed the Cross-Consortia Pleiotropy Group to investigate the patterns of multi-cardio-metabolic trait associations across the genome. We aimed (a) to examine the associations of cardio-metabolic trait loci with epidemiologically correlated traits by grouping shared patterns of individual trait effects; (b) to define pathway and gene networks involved in the trait variability within the association pattern groups.
Materials and methods: We evaluated the genetic effects of 544 independent variants (r2<0.8) from a total of 687 SNPs from published GWAS meta-analyses (thru Sep 2012) of 20 quantitative cardio-metabolic traits, including systolic/diastolic blood pressure, 8 glycaemic, 6 obesity/anthropometric, 4 lipid traits, and 2 diseases (Type 2 Diabetes (T2D), hypertension). We applied a complete hierarchical cluster analysis, which grouped variants according to their impact on the cardio-metabolic traits. We combined these data with annotated pathways, protein-protein interactions and semantic relationships from the published literature using GRAIL and DAPPLE software tools, which estimated the significance of connections between putative genes
Chapter 18 Characterization of mafic enclaves in the erupted products of Soufrière Hills Volcano, Montserrat, 2009 to 2010
No full textLavas from the current eruption of the Soufrière Hills Volcano (SHV), Montserrat exhibit evidence for magma mingling, related to the intrusion of mafic magma at depth. We present detailed field, petrological, textural and geochemical descriptions of mafic enclaves in andesite erupted during 2009–2010, and subdivide the enclaves into three distinct types: type A are mafic, glassy with chilled margins and few inherited phenocrysts; type B are more evolved with high inherited phenocryst content and little glass, and are interpreted as significantly hybridized; type C are composite, with a mafic interior (type A) and a hybrid exterior (type B). All enclaves define tight linear compositional trends, interpreted as mixing between a mafic end member (type A) and host andesite. Enclave glasses are rhyolitic, owing to extensive crystallization during quenching. Type A quench crystallization is driven by rapid thermal equilibration during injection into the andesite. Conversely, type B enclaves form in a hybridized melt layer, which ponded near the base of the chamber and cooled more slowly. Vesiculation near the mafic–silicic interface resulted in disruption of the hybridized layer and the formation of the type B enclaves. The composite enclaves represent an interface between types A and B, suggesting multiple episodes of mafic injection
Group B Streptococcus and Pregnancy
No full textThe information provided in this handout does not necessarily reflect the views of the University of Minnesota Medical School physicians and faculty. These materials are provided for informational purposes only and are in no way intended to take the place of the advice and recommendations of your personal health care provider. You use the information provided in these handouts at your own risk.The birth canal of some pregnant women can contain Group B Strep bacteria even though the women may have no symptoms. These bacteria pose a risk to their babies who can pick up the Group B Strep during delivery and develop an infection. All pregnant women should get tested for the bacteria at week 36 of their pregnancy, and those who carry the bacteria need antibiotics during their delivery to prevent an infection in their baby.Voight, Jessica M.. (2010). Group B Streptococcus and Pregnancy. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/92288
Revised Figure 4
No full text<p>(A) Previous published and (B) corrected simulation results for the central 99% range of unstandardized iHS for SNPs in the Yoruba data and for SNPs in matched neutral simulations, originally presented as Figure 4 in Voight et al. As before, the upper and lower lines mark the boundaries of the central 99% distribution of the unstandardized iHS ratio, as a function of derived allele frequency. The gray lines plot results for a range of plausible demographic models. Note the similarity of the revised figure (panel B) to the previously published figure 4 (panel A), which continue to demonstrate that the observed iHS scores for the Yoruban Hapmap sample are more extreme than under the (correctly) simulated growth models presented in panel B, above.</p
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