698 research outputs found
Fred R. Merrifield
No full textThe Oklahoma A&M College World War I Veterans collection captures the memories and experiences of the men and women of Oklahoma Agricultural and Mechanical College who served in World War I. In 1919, a project headed by Maude Cass, the editor of the 1919 Redskin; Professor Maroney of the Department of History; Margaret Walters, Librarian; and J.W. Cantwell, the College President, was undertaken to survey these veterans. The surveys were returned along with photographs, letters, and newspaper clippings documenting these veterans’ experiences during World War I
IS THERE A DICHOTOMY IN THE DARK MATTER AS WELL AS IN THE BARYONIC MATTER PROPERTIES OF ELLIPTICALS?
No full textAn alternative mechanism of clathrin-coated pit closure revealed by ion conductance microscopy
No full textCurrent knowledge of the structural changes taking place during clathrin-mediated endocytosis is largely based on electron microscopy images of fixed preparations and x-ray crystallography data of purified proteins. In this paper, we describe a study of clathrin-coated pit dynamics in living cells using ion conductance microscopy to directly image the changes in pit shape, combined with simultaneous confocal microscopy to follow molecule-specific fluorescence. We find that 70% of pits closed with the formation of a protrusion that grew on one side of the pit, covered the entire pit, and then disappeared together with pit-associated clathrin-enhanced green fluorescent protein (EGFP) and actin-binding protein-EGFP (Abp1-EGFP) fluorescence. This was in contrast to conventionally closing pits that closed and cleaved from flat membrane sheets and lacked accompanying Abp1-EGFP fluorescence. Scission of both types of pits was found to be dynamin-2 dependent. This technique now enables direct spatial and temporal correlation between functional molecule-specific fluorescence and structural information to follow key biological processes at cell surfaces
Planetary Nebulae as Dynamical Tracers: Mass-to-Light-Ratio Gradients in Early-Type Galaxies
No full textPlanetary Nebulae (PNe) have enabled mass-to-light ratios (M/L) in early-type galaxies to be constrained to unprecedented distance from the center, showing in some cases clear evidence of increasing M/L, in other cases fairly constant M/L. We combine the information obtained from PN kinematics with radially extended long-slit spectroscopy data in order to constrain the M/L trends in a heterogeneous sample of early-type galaxies. We discuss whether these trends are expected in the Lambda CDM framework of galaxy formation.</p
Sea-Level Rise by 2100
No full textISI Document Delivery No.: 274ZI Times Cited: 0 Cited Reference Count: 0 Church, John A. Clark, Peter U. Cazenave, Anny Gregory, Jonathan M. Jevrejeva, Svetlana Levermann, Anders Merrifield, Mark A. Milne, Glenn A. Nerem, R. Steven Nunn, Patrick D. Payne, Antony J. Pfeffer, W. Tad Stammer, Detlef Unnikrishnan, Alakkat S. payne, antony/A-8916-2008; Church, John/A-1541-2012 payne, antony/0000-0001-8825-8425; Church, John/0000-0002-7037-8194 0 AMER ASSOC ADVANCEMENT SCIENCE WASHINGTON SCIENC
Elemental concentrations as a means of early evaluation of open-pollinated families of loblolly pine
No full textThis study was initiated to evaluate elemental concentrations, and seedling traits measured in the greenhouse and in the field for use with early testing programs. Instrumental neutron activation analysis (INAA) was employed to determine the elements present and their concentration. The experimental population was established from two subpopulations: one containing half-sib families with a potential for fast growth and the other containing half-sib families with a potential for slow growth. In wood of 15-year-old half-sibs families 23 elements were detected, and 17 elements were detected in the wood of one-year-old half-sib seedlings. The elemental concentrations with exception of manganese were all high in wood of slow-growing 15-year-old families; however, these differences were statistically significant for only aluminum and lanthanum. The wood of one-year-old seedlings from slow-growing families was found to contain higher concentrations of aluminum, bromine, chlorine, sodium and zinc, and lower concentrations of calcium, magnesium. Manganese and potassium than wood of fast-growing families. These differences were statistically significant for calcium and potassium only. Comparison of the intraclass correlations for elements identified in wood of one-year-old seedlings with those of 15-year height, 15-year dbh and specific gravity suggested that some degree of genetic control may operate for elemental concentration. Relationships between seedling traits measured in the greenhouse and traits measured at age 15 were found to be negative implying that the growth of a family under greenhouse conditions may not parallel the growth of that family in the field.
Fungi associated with Pinus taeda L. seeds and effects on early seedling development
No full textIsolations from loblolly pine conelets, cones, seeds, and young seedlings yielded 61 fungous isolates. These isolates included one or more species of Aspergillis, Alternaria, Chaetomium, Cladosporium, Curvularia, Epicoccum, Fusarium, Gilmaniella, Geotrichum, Hyalodendron, Pestalotia, Penicillium, Rhizoupus, Syncephalastrum, and Trichothecium, plus 22 unidentified isolates. Pathogenicity was indicated for 16 of the 61 isolates in inoculation tests. Germination was reduced by 8 isolates (three Pestalotia, one F. moniliforme, and four unidentified isolates. Seven isolates were shown to be associated with high levels of seedling damping-off (50 - 100% of germinated seeds). These included three isolates of F. moniliforme, one Geotrichium, Pestalotia, Trichothecium, and one unidentified isolate. Reisolations from these diseased seedlings often yielded pure cultures of F. moniliforme. One isolate of Trichothecium was consistently associated with significant levels of abnormal seed germination in which the radicle did not penetrate the soil, with the seedling dying on the soil surface
Differential response of half-sib families of American sycamore (Platanus occidentalis L.) to contrasting moisture, pH, and fertilizer conditions
No full textVita.This study was initiated to determine if differential response in growth and uptake of nutrients occurred among open-pollinated families of American sycamore when they were subjected to all combinations of three moisture levels, three pH levels, and three fertilizer concentrations in a greenhouse. A majority of the variation in survival was attributed to the main effects. Survival increased with increasing moisture, decreasing pH, and decreasing fertilizer concentration. The families from southwest Texas survived best and those from northeast Texas the poorest. Some families survived well over all conditions suggesting that selections for increased survival could be made. Seedling growth under alkaline pH was less than under acid conditions. The best overall growth for height, diameter, and stem weight occurred in the high moisture x neutral pH x medium fertilizer plots. Although survival was best among the west Texas families, growth was generally poorest for these families. Root weight decreased with increasing fertilizer in the acidic and neutral pH treatments hut this trend was reversed in the alkaline treatments. Root weight of the western families increased under the medium moisture level. Family variation in these growth traits was large enough in magnitude that gains in seedling size can he made by selecting the best families. Genotype x environmental interactions were found to be significant in several instances hut the magnitude of the variation attributed to them was relatively small in comparison to the total genetic variation. The content of potassium and sodium in the leaf tissue increased with increasing pH, whereas the content of calcium decreased. All elements analyzed increased with increasing fertilizer concentration. Families and geographic sources differed in their ability to absorb potassium, calcium, and magnesium. A significant fertilizer x family interaction indicates that nitrogen, potassium, calcium, and sodium are differentially taken up depending on the fertilizer concentration. However, the magnitude of this variation was small.
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