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141.
The measurement of plasma vitellogenin levels in a marine teleost, the spotted seatrout (Cynoscion nebulosus) by homologous radioimmunoassay 总被引:1,自引:0,他引:1
P A Copeland P Thomas 《Comparative biochemistry and physiology. B, Comparative biochemistry》1988,91(1):17-23
1. Vitellogenin was purified from plasma of estrogen-treated spotted seatrout (Cynoscion nebulosus) and was shown to be a protein of approximately 200,000 mol. wt. 2. Antisera were raised against the isolated protein and were used to develop a radioimmunoassay for spotted seatrout vitellogenin. 3. The substance measured was shown to be female-specific, hepatically-derived, estrogen-inducible and immunologically related to oocyte yolk proteins. 4. Vitellogenin levels in the plasma of female spotted seatrout were shown to rise dramatically during the period of ovarian recrudescence. 相似文献
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Sumangala P. Shetty Ravi Shah Paul R. Copeland 《The Journal of biological chemistry》2014,289(36):25317-25326
Selenoproteins are unique as they contain selenium in their active site in the form of the 21st amino acid selenocysteine (Sec), which is encoded by an in-frame UGA stop codon. Sec incorporation requires both cis- and trans-acting factors, which are known to be sufficient for Sec incorporation in vitro, albeit with low efficiency. However, the abundance of the naturally occurring selenoprotein that contains 10 Sec residues (SEPP1) suggests that processive and efficient Sec incorporation occurs in vivo. Here, we set out to study native SEPP1 synthesis in vitro to identify factors that regulate processivity and efficiency. Deletion analysis of the long and conserved 3′-UTR has revealed that the incorporation of multiple Sec residues is inherently processive requiring only the SECIS elements but surprisingly responsive to the selenium concentration. We provide evidence that processive Sec incorporation is linked to selenium utilization and that reconstitution of known Sec incorporation factors in a wheat germ lysate does not permit multiple Sec incorporation events, thus suggesting a role for yet unidentified mammalian-specific processes or factors. The relationship between our findings and the channeling theory of translational efficiency is discussed. 相似文献
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Long‐term trends in restoration and associated land treatments in the southwestern United States
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Stella M. Copeland Seth M. Munson David S. Pilliod Justin L. Welty John B. Bradford Bradley J. Butterfield 《Restoration Ecology》2018,26(2):311-322
Restoration treatments, such as revegetation with seeding or invasive species removal, have been applied on U.S. public lands for decades. Temporal trends in these management actions have not been extensively summarized previously, particularly in the southwestern United States where invasive plant species, drought, and fire have altered dryland ecosystems. We assessed long‐term (1940–2010) trends in restoration using approximately 4,000 vegetation treatments conducted on Bureau of Land Management lands across the southwestern United States. We found that since 1940, the proportions of seeding and vegetation/soil manipulation (e.g. vegetation removal or plowing) treatments have declined, while the proportions of prescribed burn and invasive species treatments have increased. Treatments in pinyon‐juniper and big sagebrush communities declined in comparison to treatments in desert scrub, creosote bush, and riparian woodland communities. Restoration‐focused treatment objectives increased relative to resource extraction objectives. Species richness and proportion of native species used in seeding treatments also increased. Inflation‐adjusted costs per area rose 750% for vegetation/soil manipulation, 600% for seeding, and 400% for prescribed burn treatments in the decades from 1981 to 2010. Seeding treatments were implemented in warmer and drier years when compared to the climate conditions of the entire study period and warmer and wetter years relative to several years before and after the treatment. These results suggest that treatments over a 70‐year period on public lands in the southwestern United States are shifting toward restoration practices that are increasingly large, expensive, and related to fire and invasive species control. 相似文献
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Mode of Transmission of Pseudomonas aeruginosa in a Burn Unit and an Intensive Care Unit in a General Hospital 总被引:4,自引:2,他引:2
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The transmission of Pseudomonas aeruginosa was studied in the burn unit and the intensive care unit of a 650-bed hospital. There was a tendency among patients in the burn unit to yield more than one type of P. aeruginosa, and several patients shared the same types at a particular point in time, suggesting cross-contamination among patients. Similar observations were made in the intensive care unit. Cultures from the hands of nurses caring for these patients yielded the same types of P. aeruginosa, suggesting the direct handling of patients by the nursing personnel to be the principal mode of transmission. 相似文献
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Summary Seven morphologically different types of neurosecretory granules have been found in the axon terminals of the sinus gland of the blue crab, Callinectes sapidus. They differ from each other in size, shape, staining characteristics, solubility characteristics, core matrix characteristics, axon terminal matrix characteristics, presence or absence of space between the granule membrane and granule core matrix, and frequency of occurrence. Five of the types are segregated in different axon terminals and are believed to represent different hormone-protein complexes. Two of the types, which have lost part or all of their granular contents, are thought to be variants of the other five types. The differences in granular morphology are better revealed by some fixation procedures than others. Palade's acetate-veronal buffered osmium tetroxide, in particular, reveals striking differences. The following observations suggest that different hormone-protein complexes are segregated in different axon terminals and that these complexes may be morphologically distinguished at the level of the electron microscope.Supported by USPHS-NIH Training Grant GM-00669 and Grant GB-7595X from the National Science Foundation. 相似文献
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