1,224 research outputs found

    Leaf cuticular morphology links Platanaceae and Proteaceae

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    Int. J. Plant Sci. 166(5):843–855. © 2005 by The University of Chicago.The leaf cuticular morphology of extant species of Platanus was investigated using light and scanning electron microscopy. All species are shown to possess trichome bases of the same type as those commonly found in Proteaceae. Of particular significance are compound forms that consist of an annular surface scar associated with more than one underlying epidermal cell. These are found on the adaxial leaf surfaces of all species of Platanus and are also clearly evident on the abaxial surface of Platanus orientalis. This type of trichome base is therefore interpreted as the first detected nonreproductive morphological synapomorphy linking Proteaceae and Platanaceae. Also, the laterocytic, sometimes paracytic, or anomocytic arrangement of subsidiary cells in Platanus is distinct from the general state in Proteaceae, which is brachyparacytic and presumably derived. In Bellendena, possibly the most basal genus of extant Proteaceae, subsidiary cell arrangements resemble those of Platanus. These results are discussed with respect to leaf fossil records of Proteales, where it is concluded that the combination of brachyparacytic stomata and compound trichome bases is strong evidence for Proteaceae.Raymond J. Carpenter, Robert S. Hill, and Gregory J. Jorda

    Lunar surface exploration by satellite. An integrated experiment package to perform measurements of the composition of the lunar surface Final report

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    Integrated experiment package to measure lunar surface composition - gamma ray, alpha particle, X ray fluorescence, and neutron albedo experiment

    The macrofossil record of Proteaceae in Tasmania: a review with new species

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    About ten taxa of Proteaceae are known from the Early Eocene in Tasmania, one from a Late Eocene site, 22 from four Early Oligocene sites, one from a Late Oligocene/Early Miocene site, 12 or 13 from two Early Pleistocene sites, and five or six from the Middle and Late Pleistocene. Most of the Tertiary fossils are of extinct species, but the extant species Lomatia fraxinifolia and Telopea truncata have been recorded from the Early Oligocene as well as apparent close relatives of the subalpine rainforest species Orites milliganii, and the sub-tropical rainforest species, O. excelsa. None of the Early Oligocene species are known from more than one site, implying very high regional diversity, and floristic differentiation among the sites. High diversity of Proteaceae at some sites may be associated with oligotrophic soils. There is no evidence of any of the modern species-rich scleromorphic groups of Proteaceae except Banksiinae. Scleromorphy was well established in Oriteae, Embothrieae and Banksiinae by the Early Oligocene. The Early Eocene fossils have very small stomata, sparsely distributed on the leaf, which may have been due to elevated atmospheric CO2. All extant Tasmanian genera and many extant species were present by the Early Pleistocene as well as some extinct species. The specific diversity within the region was probably higher than it is now. In order to resolve a nomenclatural problem with the genus Proteaciphyllum, Euproteaciphyllum G.J.Jord., R.J.Carp. & R.S.Hill, gen. nov. is proposed and this name is applied to 10 previously described species. The Tasmanian fossil taxa include three new records, and nine new species: Euproteaciphyllum brookerensis G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., and E. tasmanicum G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov. from Early Eocene sediments; and Orites milliganoides G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., O. scleromorpha G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., E. papillosum G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., E. polymorphum G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., E. microlobium G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., E. falcatum G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov., and E. serratum G.J.Jord., R.J.Carp. & R.S.Hill, sp. nov. from Early Oligocene sediments

    Need for social cognition: devising and testing a measurement scale

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    This paper describes a theorized individual difference in a need for social cognition (NFSC). We defined need for social cognition as a motivation to understand the thoughts and perspectives of others. Studies 1-3 were performed to devise a reliable scale for measuring this construct as well as establish acceptable convergent and divergent validity with several related scales. Finally, we performed the Two-Stories experiment, which explored one aspect of NFSC's role in narrative transportation and attitude change by testing whether high levels of NFSC increase transportation and persuasion in stories that require more reader involvement. The hypotheses of the Two-Stories experiment failed. We discuss possible reasons for this result and explore potentially important conclusions from the experiment

    Forewarning, defensive strategies, and narrative persuasion

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    Narrative transportation is a process of emotional, cognitive, and mental imagery engagement with a story, which often results in greater agreement with that story's themes (e.g., Green & Brock, 2000). Previous research (e.g., Green & Donahue, 2011) has shown that people are often unwilling or unable to resist narrative persuasion, despite a motivation to do so. The current studies directly examine different defensive strategies to resist narrative persuasion. Study 1 directed participants to adopt strategies to either attempt to remain unaffected by a narrative or to actively counterargue counter-attitudinal themes of the narrative. It found that, contrary to the hypothesis, preparing counterarguments may be more effective than attempting to remain emotionally unaffected, although neither strategy entirely eliminated persuasion. Study 2 attempted to demonstrate that people spontaneously are less transported into a story after being previously warned of the author's persuasive intent, but are more transported when warned of the topics and themes advocated by a persuasive narrative. Again, the hypotheses were not confirmed. Possible reasons for the studies' failures are discussed, as well as findings that may be useful for future research.Doctor of Philosoph

    VEPCO Surry Power Plant Study, river biota and phytoplankton entrainment sections : progress report July 1975

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    This report summarizes the biological data collected from January through June 1975 in the river and phytoplankton entrainment portions of the VEPCO Surry Power Plant Study. The sampling program conducted during this period in the Hog Island area of the James River consisted of an expanded version of a study initiated in May 1969 to monitor certain aquatic communities that could be affected by the operation of the power plant. The river phytoplankton, zooplankton, benthos and fouling organism communities have been included in the past and present study designs. The phytoplankton entrainment substudy was begun in April 1975 with the objective of providing a direct assessment of the impact of passage through the power plant condensers on the abundance and species composition of the entrained algal community

    A Comparison of Methods for Determining the Age Distribution of Star Clusters: Application to the Large Magellanic Cloud

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    The age distribution of star clusters in nearby galaxies plays a crucial role in evaluating the lifetimes and disruption mechanisms of the clusters. Two very different results have been found recently for the age distribution chi(t) of clusters in the Large Magellanic Cloud (LMC). We found that chi(t) can be described approximately by a power law chi(t) propto t^{gamma}, with gamma -0.8, by counting clusters in the mass-age plane, i.e., by constructing chi(t) directly from mass-limited samples. Gieles & Bastian inferred a value of gamma~, based on the slope of the relation between the maximum mass of clusters in equal intervals of log t, hereafter the M_max method, an indirect technique that requires additional assumptions about the upper end of the mass function. However, our own analysis shows that the M_max method gives a result consistent with our direct counting method for clusters in the LMC, namely chi(t) propto t^-0.8 for t<10^9 yr. The reason for the apparent discrepancy is that our analysis includes many massive (M>1.5x10^3 M_sol), recently formed (t<10^7 yr) clusters, which are known to exist in the LMC, whereas Gieles & Bastian are missing such clusters. We compile recent results from the literature showing that the age distribution of young star clusters in more than a dozen galaxies, including dwarf and giant galaxies, isolated and interacting galaxies, irregular and spiral galaxies, has a similar declining shape. We interpret this approximately "universal" shape as due primarily to the progressive disruption of star clusters over their first ~few x 10^8 yr, starting soon after formation, and discuss some observational and physical implications of this early disruption for stellar populations in galaxies.Comment: 21 pages, 5 figures, published in the Astrophysical Journal, volume 713, page 134

    When Stars Align: Redesigning an instruction and assessment program to align with the Framework for Information Literacy

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    Presentation at LOEX, Houston, TX, May 2018The University of Maryland Libraries’ instruction program serves nearly 20,000 students per year. In 2015, with the introduction of the ACRL Framework, we began the process of redesigning this program; starting with learning outcomes and moving up through curriculum mapping and assessment. We present a case study for how a library system can work together to create a collaborative, cohesive, and diverse instruction and assessment program that is structured but flexible enough to meet the needs of individual librarians and units. The breakout session will feature concrete strategies for learning outcomes development, curriculum mapping, and programmatic assessment
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