15 research outputs found

    Enhanced lipid isomer separation in human plasma using reversed-phase UPLC with ion-mobility/high-resolution MS detection

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    An ultraperformance LC (UPLC) method for the separation of different lipid molecular species and lipid isomers using a stationary phase incorporating charged surface hybrid (CSH) technology is described. The resulting enhanced separation possibilities of the method are demonstrated using standards and human plasma extracts. Lipids were extracted from human plasma samples with the Bligh and Dyer method. Separation of lipids was achieved on a 100 × 2.1 mm inner diameter CSH C18 column using gradient elution with aqueous-acetonitrile-isopropanol mobile phases containing 10 mM ammonium formate/0.1% formic acid buffers at a flow rate of 0.4 ml/min. A UPLC run time of 20 min was routinely used, and a shorter method with a 10 min run time is also described. The method shows extremely stable retention times when human plasma extracts and a variety of biofluids or tissues are analyzed [intra-assay relative standard deviation (RSD) Analytical BioScience

    The spin polarization of Mn atoms in paramagnetic CuMn alloys induced by a Co layer

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    Copyright © 2009 American Institute of PhysicsUsing the surface, interface, and element specificity of x-ray resonant magnetic scattering in combination with x-ray magnetic circular dichroism, we have spatially resolved the polarization, and hence the spin accumulation in Mn high susceptibility material in close proximity to a ferromagnetic layer. The magnetic polarization of Mn and Cu 3d electrons in paramagnetic CuMn layers is detected in a Co/Cu x /CuMn structure for varying copper layer thicknesses x . The size of the Mn and Cu L2–3-edge dichroism shows a decrease in the polarization for increasing copper thickness indicating the dominant interfacial nature of the Cu and Mn spin polarization. The Mn polarization appears to be much higher than that of Cu

    Holocene to latest Pleistocene incremental slip rates from the east-central Hope fault (Conway segment) at Hossack Station, Marlborough fault system, South Island, New Zealand: Towards a dated path of earthquake slip along a plate boundary fault

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    Geomorphic field and aerial lidar mapping, coupled with fault-parallel trenching, reveals four progressive offsets of a stream channel and an older offset of the channel headwaters and associ­ated fill terrace–bedrock contact at Hossack Station along the Conway segment of the Hope fault, the fastest-slipping fault within the Marlborough fault system in northern South Island, New Zealand. Radiocarbon and luminescence dating of aggra­dational surface deposition and channel initiation and abandonment event horizons yields not only an average dextral rate of ~15 mm/yr since ca. 14 ka, but also incremental slip rates for five different time periods (spanning hundreds to thousands of years) during Holocene to latest Pleistocene time. These incremental rates vary through time and are, from youngest to oldest: 8.2 +2.7/−1.5 mm/yr averaged since 1.1 ka; 32.7 +~124.9/−10.1 mm/yr averaged over 1.61–1.0 ka; 19.1 ± 0.8 mm/yr between 5.4 and 1.6 ka; 12.0 ± 0.9 mm/yr between 9.4 and 5.4 ka, and 13.7 +4.0/−3.4 mm/yr from 13.8 to 9.4 ka, with generally faster rates in the mid- to late Holocene relative to slower rates prior to ca. 5.4 ka. The most pronounced variation in rates occurs between the two youngest intervals, which are averaged over shorter time spans (≤1700 yr) than the three older incremental rates (3700–4500 yr). This suggests that the factor of ~1.5× variations in Hope fault slip rate observed in the three older, longer- duration incremental rates may mask even greater temporal variations in rate over shorter time scales

    Variability in the total and reactive lysine content of soybean meal

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    The hypothesis tested in this study was that reactive lysine can not be accurately predicted from total lysine content in soybean meal

    One tune, many tempos: faults trade off slip in time and space to accommodate relative plate motions

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    Analysis of incremental slip rates from the four major strike-slip faults of the Marlborough fault system (MFS) of northern South Island, New Zealand, provides a first-ever record at the scale of an entire plate-boundary fault system of how relative plate motions are accommodated in time and space. This record, which spans the past 350–450 m of relative plate motion and ca. 12–14 ky, demonstrates that the fault system as a whole accommodates a steady plate-boundary slip rate, with the MFS faults “keeping up” with the overall rate of relative Pacific-Australia plate motion at relatively short displacement (10 s of meters) and time (102–103 yr) scales. These results affirm the often-assumed but until now unproven assumption that the relative plate-motion rate provides a robust basic constraint on both geodynamical models and analyses of system-level seismic hazard at these scales. In marked contrast, the incremental slip rates of each of the four main Marlborough faults are highly variable through time, marked by coordinated accelerations and decelerations spanning 4–6 earthquakes and several millennia as the faults trade off slip to accommodate a steady relative plate motion rate. These results suggest that (a) the weakest fault in the system will slip faster than average while adjacent mechanically complementary faults slip more slowly, and (b) that these patterns switch back and forth through time, likely reflecting reversible changes in the strength (i.e., resistance to shear) of the individual faults as they collectively accommodate relative plate motion. Interestingly, the periods of fast slip on the MFS faults exhibit ∼20–25 m of displacement, suggesting that these may record periods of fast slip on a weakened fault/ductile shear zone that continues until it uses up all locally stored elastic strain energy, thus potentially approaching local complete stress drop, albeit during a few tens of meters of rapid fault slip during multiple earthquakes, rather than during a single event. This hypothesis is consistent with typical earthquake stress drops of ∼1–10 MPa and estimates of depth-averaged crustal shear stress of a few 10 s of MPa, such as might be released in clusters of 4–6 earthquakes. These results emphasize the need to analyze the collective behavior of the entire fault systems, rather than just individual faults, to understand the mechanics of the system. Moreover, these patterns suggest a potential path forward for more accurate estimation of time-dependent seismic hazard, with the possible incorporation of current position of a fault within a fast- or slow/no-slip period into the probability analysis, as well as a means of potentially estimating crustal shear stress

    New firms and high technology industry in Newbury district, Berkshire

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    SIGLEAvailable from British Library Lending Division - LD:9350.608(5) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    Drilling reveals fluid control on architecture and rupture of the Alpine Fault, New Zealand

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    Rock damage during earthquake slip affects fluid migration within the fault core and the surrounding damage zone, and consequently coseismic and postseismic strength evolution. Results from the first two boreholes (Deep Fault Drilling Project DFDP-1) drilled through the Alpine fault, New Zealand, which is late in its 200–400 yr earthquake cycle, reveal a >50-m-thick “alteration zone” formed by fluid-rock interaction and mineralization above background regional levels. The alteration zone comprises cemented low-permeability cataclasite and ultramylonite dissected by clay-filled fractures, and obscures the boundary between the damage zone and fault core. The fault core contains a <0.5-m-thick principal slip zone (PSZ) of low electrical resistivity and high spontaneous potential within a 2-m-thick layer of gouge and ultracataclasite. A 0.53 MPa step in fluid pressure measured across this zone confirms a hydraulic seal, and is consistent with laboratory permeability measurements on the order of 10?20 m2. Slug tests in the upper part of the boreholes yield a permeability within the distal damage zone of ?10?14 m2, implying a six-orders-of-magnitude reduction in permeability within the alteration zone. Low permeability within 20 m of the PSZ is confirmed by a subhydrostatic pressure gradient, pressure relaxation times, and laboratory measurements. The low-permeability rocks suggest that dynamic pressurization likely promotes earthquake slip, and motivates the hypothesis that fault zones may be regional barriers to fluid flow and sites of high fluid pressure gradient. We suggest that hydrogeological processes within the alteration zone modify the permeability, strength, and seismic properties of major faults throughout their earthquake cycles

    Milling quality and protein properties of autumn-sown Chinese wheats evaluated through multi-location trials

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    Eight milling quality and protein properties of autumn-sown Chinese wheats were investigated using 59 cultivars and advanced lines grown in 14 locations in China from 1995 to 1998. Wide ranges of variability for all traits were observed across genotypes and locations. Genotype, location, year, and their interactions all significantly influenced most of the quality parameters. Kernel hardness, Zeleny sedimentation value, and mixograph development time were predominantly influenced by the effects of genotype. Genotype, location and genotype x location interaction were all important sources of variation for thousand kernel weight, test weight, protein content, and falling number, whereas genotype x location interaction had the largest effect on flour yield. Most of the genotypes were characterized by weak gluten strength with Zeleny sedimentation values less than 40 ml and mixograph development time shorter than 3 min. Eight groups of genotypes were recognized based on the average quality performance, grain hardness and gluten strength were the two parameters that determined the grouping, with contributions from protein content. Genotypes such as Zhongyou 16 and Annong 8903 displayed good milling quality, high grain hardness, protein content and strong gluten strength with high sedimentation value and long mixograph development time. Genotypes such as Lumai 15 and Yumai 18 were characterized by low grain hardness, protein content and weak gluten strength. Genotypes such as Yannong 15 and Chuanmai 24 were characterized by strong gluten strength with high sedimentation value and long mixograph development time, but low grain hardness and protein content lower than 12.3%. Genotypes such as Jingdong 6 and Xi'an 8 had weak gluten strength, but with high grain hardness and protein content higher than 12.2%. Five groups of locations were identified, and protein content and gluten strength were the two parameters that determined the grouping. Beijing, Shijiazhuang, Nanyang, Zhumadian and Nanjing produced wheats with medium to strong gluten strength and medium protein content, although there was still a large variation for most of the traits investigated between the locations. Wheat produced in Yantai was characterized by strong gluten strength, but with low protein content. Jinan, Anyang and Linfen locations produced wheats with medium to weak gluten strength and medium to high protein content. Wheats produced in Yangling, Zhenzhou, and Chengdu were characterized by weak gluten strength with medium to low protein content, whereas wheats produced in Xuzhou and Wuhan were characterized by weak gluten strength with low protein content. Industrial grain quality could be substantially improved through integrating knowledge of geographic genotype distribution with key location variables that affected end-use quality
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