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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

Spikelet morphology in relation to grain yield and physical grain quality of some oat varieties and their F[subscript 2] progenies

Wesenberg, Darrell Marvin, January 1965 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1965. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 97-102.
172

Morphological studies of laticifer rupture and leaf development in lettuce, Lactuca sativa L.

Olson, Kenton Carl, January 1968 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1968. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
173

Comparative morphology : three dimensional renderings of the glossopodia North American Isoetes ligules /

Shaw, Shane William. January 2004 (has links)
Thesis (M.S.)--Miami University, Dept. of Botany, 2004. / Typescript (photocopy). Includes bibliographical references (p. 31-33). Also available as a PDF online via OhioLINK's ETD Center; mode of access: World Wide Web.
174

Comparative morphology of some Leguminosae ... /

Martin, John N. January 1914 (has links)
Thesis (Ph. D.)--University of Chicago, 1913. / "Reprinted from the Botanical gazette, vol. LVIII, no. 2." "Literature cited": p. 164-165. Also available on the Internet.
175

Functional morphology of vertebral foramina : a comparison of fossil hominids to Homo sapiens, Pan troglodytes and Papio sp., with particular attention to KNM WT 1500 /

Mirsky, Douglas Elgart. January 2001 (has links)
Thesis (Ph. D.)--University of Chicago, Dept. of Anthropology, March 2001. / Includes bibliographical references. Also available on the Internet.
176

Assessment of VE-Cadherin Stability at Endothelial Cell-Cell Junctions Using Photoconvertible Fluorescence Microscopy

Harvey, Taylor R. 19 December 2018 (has links)
<p> Regulation of barrier function is critical for patients who suffer from inflammatory diseases such as acute respiratory distress syndrome (ARDS) and sepsis. A major regulator of endothelial barrier function is vascular endothelial cadherin (VE-cad). Cellular levels of VE-cad are known to be regulated by p120 catenin. Loss of p120 leads to decreased barrier function as a result of the endocytosis of VE-cad. However, recent work from our lab shows that expression of an endocytic defective VE-cad mutant was not able to rescue barrier function, as measured using transendothelial electrical resistance (TEER). In contrast, expression of a non-phosphorylatable VE-cad mutant was able to restore barrier function independent of p120 binding. These results suggest that endocytosis is not the only mechanism regulating VE-cad localization to the cell-cell junctions, but rather the phosphorylation state of the protein may play a more critical role to stabilizing VE-cad at the junction. In order to investigate junctional stability of VE-cad, we created a recombinant form of VE-cad by cloning mEos2 into a plasmid containing the VE-cad gene. This fluorophore is photoconvertible, thus allowing for tracking protein movement at the cell-cell junction. The VE-cad proteins, labeled with mEos2 at the C-terminus, were introduced via adenoviral infection into human umbilical vein endothelial cells (HUVEC). Initially, mEos2 fluoresces green, in order to induce photoconversion, a 405nm laser is directed in a specific region of interest (ROI) at the junction. A conformational change in the mEos2 protein will cause irreversible red fluorescence. Tracking the change in fluorescence intensity in the ROI will provide insight into the localization of VE-cad at endothelial cell junctions. We now have a model that can be used to test junctional localization and stability of endocytic defective and non-phosphorylatable mutants of VE-cad.</p><p>
177

Engineered Micro and Nanotopography for Neuron and Glial Guidance after Spinal Cord Injury

Johnson, Christopher David Landis 09 August 2018 (has links)
<p> Spinal cord injury presents many barriers to regeneration that have yet to be solved. Guidance conduits are a promising approach that allow regenerating tissue to bypass or traverse the injury site. Peripheral nerve autografts into the spinal cord have guided neurons and glia around an injury site and resulted in some functional recovery [1]. Synthetic guidance conduits made from electrospun fibers have shown an ability to guide robust regeneration after spinal cord injury [2]&ndash;[4]. The surface topography of the electrospun fiber scaffolds is important for cell guidance, and can be modified by changing the fiber diameter, fiber alignment, and fiber surface nanotopography, among others. While the effects of these fiber physical characteristic on neuron guidance has been determined, it remains unknown how fiber diameter and surface nanotopography affect astrocytes - the most abundant cells in the CNS. Astrocytes maintain homeostasis in the healthy CNS and provide guidance and protection to neurons after injury. As a result, astrocytes should be considered an important therapeutic target for biomaterial approaches. The current thesis studied the effects of surface topography on astrocyte morphology and astrocyte phenotype. </p><p> First, the astrocyte response to fiber surface nanotopography was tested. Astrocytes were cultured on three engineered surface topographies - smooth, pitted, or divoted fiber surfaces. Astrocytes isolated from the spinal cord were compared to astrocytes isolated from the cortex, to determine if there was a different response from astrocytes selected from different anatomical locations. The astrocyte morphological response was measured with immunocytochemistry, while the GFAP and vinculin protein expression was measured using Western blot techniques. The findings suggest that smooth fiber surfaces allowed for the longest cortical astrocyte extension after 4 days in culture, while the pits and divots reduced astrocyte elongation. The spinal cord astrocytes exhibited smaller elongation ratios over the times tested, compared to the cortical astrocytes, and did not have significantly different responses to the fiber surfaces tested. Since astrocyte elongation is correlated with neurite outgrowth, these data shows that the smooth fibers provide the greatest astrocyte elongation. The GFAP and vinculin expression were not significantly different among any of the surfaces or cell types tested. </p><p> Second, the astrocyte response to fiber diameter was tested. Astrocytes were cultured on large (800nm) diameter, small (386nm) diameter, and film substrates, and the astrocyte morphology was analyzed over the first four days in culture. Astrocytes became significantly more elongated on the large fibers as early as two hours after culture, and remained significantly more elongated after four days. The effect of fiber diameter on GLT-1, GLAST, and GFAP expression were examined by western blot. GLT-1 was significantly increased on the fiber substrates, compared to the film, but GLT-1 expression was not dependent on fiber diameter. A glutamate excitotoxicity assay was performed on an astrocyte/neuron coculture to determine if the increased astrocyte GLT-1 expression improved neuron protection. The findings suggest that fibrous surfaces improved cell survival, however, the differences were not statistically significant from the film control. Next neuron outgrowth was observed on the astrocyte surfaces prepared on each of the three topographies - small fiber, large fiber, and film. Neurons were cultured on the astrocyte/fiber surfaces and compared to an astrocyte/film control. The results suggest that after 4 days in culture, the astrocytes on the large fibers induced longer more directed growth, while the astrocytes on the small fibers induced comparatively shorter neurite growth with more neurite branching. </p><p> Third, a novel biomaterial scaffold was prepared by incorporating superparamagnetic iron oxide nanoparticles (SPIONs) into the electrospinning solution. The purpose was to prepare an injectable electrospun fiber scaffold that could be magnetically oriented <i>in situ</i>. The surface topography was carefully controlled. The effect of incorporating increased amounts of SPIONs on the fiber diameter, fiber surface nanotopography, and fiber alignment was measured, and compared against the previous findings in this thesis and against a similar scaffold that has been successful <i>in vivo</i>. The effect of the increasing SPION concentration on the fiber magnetization and on the speed of fiber alignment in viscous solutions was measured. From these data, the 6% SPION concentration exhibited the fastest fiber realignment times without significant changes to the fiber topography. As a result the 6% SPION fibers were tested in vitro by orienting the fibers to provide an aligned fiber scaffold within either a collagen/Matrigel or fibrin/Matrigel hydrogel. (Abstract shortened by ProQuest.)</p><p>
178

The morphological and phonological structures of Spokane lexemes

Black, Deirdre Jean 01 August 2018 (has links)
The primary purpose of this study is to specify the structural characteristics of the phonological representations of Spokane lexemes which are relevant for the rules of the morphology and the rules of the phonology. In order to reveal the complexity of the issue of structure, it is necessary to examine three sets of data: non-compound forms, compound forms, and structurally reanalyzed forms. These data provide evidence that the phonological representation of each lexeme includes specifications for both form and structure. Framed within the Lexeme-Morpheme Base Morphology of Beard (1987, 1993, 1995), this study establishes that certain morphological spelling operations necessarily refer to a specific sub-string of the phonological representation which cannot be isolated phonologically. The phonological representations of Spokane lexemes are, therefore, analyzed as composite structures. As such, the phonological representations of non-compounds possess (at least potentially) complex morphological structure which includes the notions Root and Stem, while those of compounds possess additional specifications for structure based on the fact that each comprises two distinct Stems. Conversely, the structurally reanalyzed forms provide evidence that historically complex structure has been reduced to simplex form. Structurally reanalyzed forms possess morphological structures which are identical to that of the non-compound but which are distinct from that of their historically related forms. This study also establishes that the structural characteristics of a lexeme’s phonological representation remain salient for the phonology. It is demonstrated that the domains of the phonological representation to which the phonology attends are isomorphic with the domains of the phonological representation which emerge from the Morphological Spelling component (at least at the lowest level of structure). I utilize the facts of primary stress assignment, as well as the facts of retraction and nasal shift, to provide evidence for such phonological structures and. further, to specify the parameters of primary stress assignment in Spokane. / Graduate
179

Functional Anatomy of the Forelimb in Terrestrial and Arboreal African Cercopithecoids

Whitehead, Paul Frederick 21 August 2018 (has links)
<p> The cercopithecoid monkeys, though sharing a common body-plan, exhibit considerable behavioral, ecological, and anatomical diversity. The theme of this work is the relationship between anatomy, postural behavior, and habitat use, concentrating upon the distal forearm, wrist and hand. It incorporates an initial review of the relevant empirical and theoretical literature, and original research including anatomy, naturalistic and experimental observation, and a first detailed description of fossil forelimb material of the "giant" extinct baboon, <i>Theropithecus oswaldi</i>. Two modes of contact between hand and substrate in monkeys are distinguished. Palmigrady is characteristic of predominately arboreal species, while species that habitually walk on the ground do so using a distinctive <i>digitigrade</i> gait. The vervet monkey (<i>Cercopithecus</i> [now <i>Chiorocebus</i>] <i> aethiops</i>, s.l.) occupies many tropical, seasonal habitats, and, uniquely, is both polymorphic and polytypic with respect to hand posture. The author's fieldwork found that as expected, digitigrady is apparently favored by vervets living in drier, more open habitats. The mid section of the dissertation reviews in depth the copious and often confusing literature on primate, especially cercopithecoid, taxonomy, and the many contradictory schemes that have attempted to categorize primate positional behavior.</p><p> Variation in the intermetacarpal and other wrist joints in human subjects provides background for recognition of character states distinguishing obligate digitigrade (patas and baboon) from palmigrade (colobus) monkey genera. It is then demonstrated that, consistent with the observation of hand posture variation in living subjects, anatomical variation among individual vervet skeletons encompasses both types. Unexpectedly, the large fossil <i> T. oswaldi</i> (but not <i>T. geiada</i>) shows palmigrade features in some aspects of carpal structure. This theme is pursued in the most extensive section of the dissertation, which includes a detailed description and interpretation of fossil forelimb specimens assigned to <i>Theropithecus oswaldi</i>, from the sites of Olorgesailie (Kenya) and Olduvai Gorge (Tanzania) . The descriptions include notes comparing the fossils with extant cercopithecoids, and interpreting similarities and differences. These comparisons suggest that <i>T. oswaldi</i> did not closely resemble extant baboons in locomotor behavior, and may have been palmigrade on the ground. Finally, the concluding sections describe an innovative set of techniques that were used successfully to collect electromyographic and cineradiographic data on monkeys locomoting in a controlled laboratory setting, with a view to confirming the functional interpretation of anatomical features of living and fossil forms, and the naturalistic behavior of living vervets.</p><p>
180

Molecular studies of potato leafroll luteovirus multiplication

Miller, Jane S. January 1993 (has links)
Potato leafroll luteovirus is an aphid-transmissible virus which has isometric particles and is confined to the phloem tissue of infected plants. Its multiplication was investigated by using plant protoplasts as a model system. In protoplasts, net accumulation of PLRV ceased at approximately 48 his post-inoculation. Virus-specific products were detectable 15 hrs or more post-inoculation and remained detectable at approximately 100 hrs postinoculation. The amount of PLRV accumulated depended on the conditions in which protoplasts were incubated. Incubation at 25&deg;C rather than 20&deg;C and incubation in the dark for a period rather than continuous light resulted in more PLRV accumulation. RNA extracted from PLRV-infected protoplasts was identical on northern blots to that extracted from leaf tissue of PLRV-infected Maris Piper potato plants. Northern blots of RNA from other plants, some resistant, some susceptible to PLRV multiplication, were very similar. Resistant plants appeared to contain smaller quantities of subgenomic RNA. The genes at the 3'-end of the genome are expressed by translation of a subgenomic RNA. This was mapped to position 3376 on the PLRV genome and is therefore 2505 nucleotides long. The untranslated leader sequence of 212 nucleotides contains some putative promoter sequences although not in the same order as described for other viruses. A sequence of 8 nucleotides at the 5'-end of the genomic RNA was found to be repeated at the 5'-end of subgenomic RNA. The complement of this sequence may form part of an internal initiation site for the viral replicase complex in the minus strand RNA. The possibility of the untranslated leader sequence containing several promoters for both subgenomic RNA synthesis and ORF expression is discussed. Protoplast lysates contained a component that sedimented nearer the top of a sucrose gradient than virus particles. This contained subgenomic RNA and was detectable by ELISA but not by electron microscopy. It was not present in extracts of PLRV-infected plant tissue or in preparations of purified virus particles and may therefore be an unstable structure possibly - playing a role in particle assembly.

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