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81.
82.
Glomalin was measured in soil from farming systems managed for 8 years by chisel tillage (CT), more intensive tillage for organic (ORG) production, and no tillage (NT) on Acrisols (FAO Soil Units) in the Mid-Atlantic region of the U.S. Whole soil and aggregate size classes of >2.00, 0.50–2.00 and 0.21–0.50 mm (macroaggregates), 0.05–0.21 mm (microaggregates), and <0.05 mm (fine material) were examined. Glomalin-related soil protein (GRSP) was extracted from 1-g samples (four plots per treatment) with 100 mM sodium pyrophosphate, pH 9.0, at 121 °C in three extraction cycles. Extracts were pooled and quantified by using the Bradford protein assay. Concentrations of GRSP and total carbon (C) in aggregates were linearly related across aggregate size classes for all treatments (GRSP = 0.101C + 0.56, r2 = 0.95). No tillage had significantly greater whole soil GRSP than did CT or ORG (P = 0.01). Mean values for GRSP in aggregates of NT were higher than for CT or ORG aggregates by 0.53 and 0.66 mg g−1 aggregates, respectively. There were no differences among treatments in GRSP concentrations in fine material. In NT the concentration of GRSP increased as aggregate size increased in contrast to the disturbed treatments, CT or ORG, where there were no differences in GRSP concentration across aggregate size fractions. Larger proportions of GRSP were distributed in macroaggregates of NT compared to CT and ORG in contrast to larger proportions in microaggregates of CT and ORG than in NT. Although soil disturbance in ORG farming is greater than for CT farming, both treatments had similar GRSP concentrations and distributions. 相似文献
83.
Quantitative trait loci (QTL) analysis was conducted to identify QTL for seed yield and color retention following processing
of a recombinant inbred line (RIL) black bean population. A population of 96 RILs were derived from the cross of black bean
cultivars ‘Jaguar’ and 115M and evaluated in replicated trials at one location over 4 years (2004–2007) in Michigan. A 119-point
genetic map constructed using simple sequence repeat (SSR), sequence related amplified polymorphism (SRAP), target region
amplified polymorphism (TRAP) and phenotypic markers spanned fifteen linkage groups (LG) or 460 cM of the bean genome. Fourteen
QTL for yield and color retention in four environments were identified by composite interval mapping on six linkage groups.
A major QTL SY10.2J115 for seed yield was identified on LG B10 with additional QTL on B3, B5, and B11. Color retention following processing was
associated with loci on B1, B3, B5, B8, and B11. 115M possessed positive alleles for yield, but negative alleles for color
retention. Some QTL for yield and color retention co-localized with regions identified in previous studies while others, particularly
for color retention, were unique. Additional QTL for agronomic and canning quality traits were detected and individual contributions
to future black bean breeding are discussed. 相似文献
84.
The addition of succinylsulfathiazole to highly purified diets containing all dietary factors known to be required by the rat, including pantothenic acid, results in the appearance of signs of severe pantothenic acid deficiency, including achromotrichia and porphyrin-caked whiskers. These changes are accompanied by a marked reduction in the pantothenic acid content of the liver, and are corrected by the inclusion in such diets of crystalline biotin and "folic acid" concentrates. The utilization of pantothenic acid by the rat appears to depend on the availability of biotin and "folic acid." Under normal conditions these are supplied by the diet and synthesized by intestinal bacteria. A hypothesis is offered in explanation of the chromotrichial actions of "folic acid," biotin and p-aminobenzoic acid. 相似文献
85.
86.
Faham S Watanabe A Besserer GM Cascio D Specht A Hirayama BA Wright EM Abramson J 《Science (New York, N.Y.)》2008,321(5890):810-814
Membrane transporters that use energy stored in sodium gradients to drive nutrients into cells constitute a major class of proteins. We report the crystal structure of a member of the solute sodium symporters (SSS), the Vibrio parahaemolyticus sodium/galactose symporter (vSGLT). The approximately 3.0 angstrom structure contains 14 transmembrane (TM) helices in an inward-facing conformation with a core structure of inverted repeats of 5 TM helices (TM2 to TM6 and TM7 to TM11). Galactose is bound in the center of the core, occluded from the outside solutions by hydrophobic residues. Surprisingly, the architecture of the core is similar to that of the leucine transporter (LeuT) from a different gene family. Modeling the outward-facing conformation based on the LeuT structure, in conjunction with biophysical data, provides insight into structural rearrangements for active transport. 相似文献
87.
88.
J E Wright 《Science (New York, N.Y.)》1969,163(865):390-391
The molting hormone, alpha-ecdysone, and an analog triangle up(7)-5beta-cholestene-2beta,3beta, 14alpha-triol-6-one when applied externally, terminates diapause in larvae of the winter tick, Dermacentor albpictus. This is the first reported hormonal termination of diapause in an arthropod other than an insect. 相似文献
89.
90.