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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.
31

Effects of unilateral masticatory function on craniofacial and temporomandibular joint growth:an experimental study

Poikela, A. (Aila) 13 September 2000 (has links)
Abstract The study was undertaken to determine effects of unilateral masticatory function on craniofacial growth and temporomandibular joint structures in young rabbits. Right-side maxillary and mandibular molars were ground out of occlusion under general anesthesia. Macroscopic measurements were made using the skulls and mandibular halves. Articular surface inclinations were determined using photographs. Positions of articular eminences on crania were determined using machine-vision technique. Changes to extracellular matrix of condylar cartilage were studied histochemically and biochemically. Unilateral masticatory function resulted in changes in the shapes and dimensions of the mandible, maxilla and glenoid fossa. Maxillary widths, lengths of half-mandibles, and angles between the ramus and corpus were lower on the right than on the left side of each animal that had been subjected to right-side molar grinding, and in comparison with controls. As the rabbits grew, there was no recovery from the changes that had been brought about by the asymmetric function, even after occlusal function was reversed or left unmodified after a period of unilateral function. Inclinations of articular surfaces became shallower and positions of articular eminences and glenoid fossae more anterior in animals that had been subjected to molar grinding than in controls. Proteoglycan contents of condylar cartilage extracellular matrix were also affected by molar grinding: amounts of the aggregated proteoglycans in particular were low. We concluded, that the shape and the sagittal and vertical position of the articular eminence is highly adaptive to the function of the condyle process, and that there were associated alterations in the dimensions and shapes of mandible and maxilla. Unilateral masticatory function resulted in significant changes in condylar cartilage extracellular matrix. Normal occlusion and bilaterally symmetric masticatory function during early phases of growth is important for normal development of the maxilla, mandible and articular cartilage.
32

Examining the Role of Latitude and Differential Insolation in Asymmetrical Valley Development

Curran, Lorna L. 08 1900 (has links)
Valley development through erosional processes typically tends to create symmetrical valleys. Over time, water cuts through the substrate to create valleys, gorges, and canyons for which the sides are the valley are evenly sloped. However, there are anomalies to this process. Asymmetrical valleys have been well-documented even in areas of uniform substrate or little tectonic uplift. One proposed explanation for the asymmetry of these valleys is differential insolation. This may lead to different microclimates from one slope to another which alter the rate and extent of erosion. Since the differences in received insolation vary with latitude (especially in streams that flow along an east/west axis), it follows that the degree of asymmetry should also vary with latitude if differential insolation is a primary driving factor in the development of these valleys. To evaluate if insolation plays a role in the development of asymmetrical valleys, this study examines variability in asymmetry across 447 valleys in nine study areas located at different latitudes. The degree of asymmetry for each valley was measured by using 30 meter resolution digital elevation models (DEMs) to determine the slope angle of each side of the valley. Asymmetry was measured by computing a ratio of the average slope angle for each side of the valley (larger value divided by smaller). If the resulting value is one, the valley is deemed symmetrical. As the value increases, the degree of asymmetry increases. This investigation found that contrary to expectations, valleys at lower latitudes tend to have a higher degree of asymmetry than those at higher latitudes, which suggests that differential insolation does not play a major role in the development of these valleys. Instead, this study found that high altitudes and low latitudes are more frequently associated with a higher degree of asymmetry. These unexpected findings open the door to new avenues of investigation into the causes of asymmetrical valley development.
33

Understanding Hard Interaction in QCD and the Search for the Gluon Spin Contribution to the Spin of the Proton

Datta, Amaresh 01 May 2012 (has links)
In the following discourse unpolarized cross sections and double helicity asymmetries of single inclusive positive and negative charged hadrons at mid-rapidity from p + p collisions at p s = 62:4 GeV are presented. Measurements for the transverse momentum range 1:0 < pT < 4:5 GeV/c are done with PHENIX detector at Relativistic Heavy-Ion Collider (RHIC) and are consistent with calculations based on perturbative quantum chromodynamics (pQCD) at next-to-leading order (NLO) in the strong coupling constant, s. Resummed pQCD calculations including terms with next-to-leading log (NLL) accuracy, yielding reduced theoretical uncertainties, also agree with the data. The double helicity asymmetry, sensitive at leading order to the gluon polarization in a momentum fraction range of 0:05
34

Asymmetry of the Mitochondrial Inner Membrane

Wrona, Lynne 09 1900 (has links)
<p> The mitochondrial inner membrane is highly selective with regard to permeability to solutes and the movement of a large number of large or charged molecules across it therefore requires specific transport processes provided by specific membrane proteins. </p> <p> In order to study the spatial arrangement of one such protein the adenine nucleotide translocator protein which transports ADP and ATP across the mitochondrial inner membrane, a number of chemical labelling studies of the mitochondrial inner membrane were carried out. </p> <p> Mitochondrial inner membrane preparations of normal (mitoplasts) and inverted (submitochondrial particles) config~ration with respect to mitochondria have been isolated and the external phosphatidylethanolamine and proteins modified by 3H isethionyl acetimidate. An upper limit of 40-46% of the total PE in mitoplasts was found to be located in the external monolayer. </p> <p> Differences in protein labelling patterns of isethionyl acetimidate modified mitochondria and SMP was observed. JAI was found to penetrate the outer membrane but not the inner membrane of intact mitochondria. </p> <p> A tritiated photoreactive phospholipid, 1 palmitoyl-2-(mdiazirinophenoxynonanoyl) phosphatidylcholine (DAP-PC) was incorporated into mitoplasts and submitochondrial particles symmetrically into both monolayers by sonication and asymmetrically using phospholipid exchange protein isolated from beef heart. Photolysis yielded the translocator as a major crosslinked product in both types of particles and with both methods of incorporation. </p> <p> It was shown that the adenine nucleotide translocator can be asymmetrically labelled by modification of membrane.particles of opposite orientation by water soluble and membrane soluble probes. </p> / Thesis / Master of Science (MSc)
35

Effect of Lifting Straps on Peak Force During an Isometric Mid-thigh Pull

Elkins, Ethan A 01 January 2020 (has links)
Objectives: The primary purpose of this study was to examine the difference in peak force (PF) production with and without the inclusion of lifting straps (LS) during an isometric mid-thigh pull (IMTP). An additional goal of this study was to identify potential asymmetry during the two protocols while evaluating the potential use of a dual force plate IMTP as a tool for player monitoring programs. Methods: Twenty-one NCAA division I men (n=10) and women (n=11) soccer players performed a maximal IMTP over dual force plates with and without the assistance of LS. The PF total between the two plates for both conditions was used to examine the effect of LS. Asymmetry was assessed by the PF of the separate force plates by calculation of a symmetry index (SI). Results: The PF achieved with the assistance of LS was significantly greater for males (strapped: 2102.3±506.2N, unstrapped: 1468.6±286.0N; p 1105.0±294.7N, unstrapped: 940.6±155.7N; pConclusion: The inclusion of LS on the IMTP allowed for a significantly greater PF production for male and female soccer athletes. However, the increase in PF with the inclusion of LS was greater in the males who saw a large effect size (d=1.959, pp=0.024). Both male and female soccer players possessed some level of asymmetry that did increase with the inclusion of LS, but no significant difference was found between conditions.
36

A FIBER TYPE ASSESSMENT OF MASSETER MUSCLES IN FIVE ASYMMETRY CLASSIFICATIONS

Gray, Holly Rose January 2019 (has links)
ABSTRACT: Objectives: Masseter muscle fast-fiber composition is reportedly increased on the deviant facial asymmetry side in dentofacial deformities patients. Recently, four distinct asymmetry classes have been identified, based on posterior-anterior cephalometrics in this same population, which may have different functional etiologies. Our aim is to relate muscle fiber type properties with specific asymmetric craniofacial growth in these asymmetry groups. Methods: Diagnostic evaluations, radiographs, and masseter specimens were obtained from orthognathic surgery patients at the University of Lille. Immunohistochemical muscle staining and morphometrics determined the mean areas and percent occupancies of slow-I, fast-II, neonatal, atrial and hybrid fiber types. Eighty-three subjects (twenty nine symmetric, fifty-four asymmetric) had at least unilateral (left or right) fiber type information, while twenty-seven had bilateral (left and right) data. Fiber data were compared between symmetry and asymmetry subjects and between the four asymmetry classes. Significant differences between groups were determined by Fisher’s and ANOVA tests. Results: Type-II mean fiber area (p&lt;0.006) and percent occupancy (p&lt;0.018) were significantly greater on shorter ramal sides in asymmetric compared to symmetric subjects, supporting previous data for facial vertical dimension asymmetry. Neonatal- atrial mean fiber area (p&lt;0.017) and percent occupancy (p&lt;0.027) were decreased in 3 asymmetric groups. No significant difference was found amongst the four asymmetry classes (p&lt;0.05). Conclusions: Imbalanced skeletal proportions are associated with similar imbalances in fiber type properties in left versus right masseter muscle biopsies sampled in the same patient at the time of orthognathic surgery. Specific to our findings, there is an association between increase in neo-atrial and decrease in type II fiber type area and percent occupancy in symmetric patients. / Oral Biology
37

Human skeletal asymmetry. A study of directional and fluctuating asymmetry in assessing health, environmental conditions, and social status in English populations from the 7th to the 19th centuries.

Storm, Rebecca A. January 2009 (has links)
Volume 1 = Thesis, Volume 2 = Appendices / Asymmetry is a useful tool for osteological analysis as it detects disruptions in the developmental stability of osseous structures attributed to environmental and biomechanical environments. The primary aim of this study is to establish a baseline for normal levels of asymmetry in English archaeological populations in order to distinguish between normal population variation and increased developmental instability or biomechanical stress. Directional and fluctuating asymmetry is assessed through a database of a comprehensive selection of osteological measurements throughout the skeletons of 1753 adults and subadults. The sample is from 11 archaeological sites spanning the Anglo-Saxon to the Victorian periods. The extent of developmental instability is also determined, for the first time, by employing the prevalence of population outliers. The normal range for directional asymmetry was found to be -5.79 to 6.62%, while fluctuating asymmetry was found to be 0 to 6.53%. The extent of asymmetry, however, was found to be trait specific. Deviations from normal population levels of asymmetry were found to be due to a complex mixture of biomechanical and environmental stresses influenced by age, sex, settlement type, socio-economic status, and period-specific origins of the sample populations. Possible causes of asymmetry could be discerned from comparisons of the levels of population asymmetry when placed in the context of physical activity, social networking, health, and environment developed from the historical, archaeological and osteological record. / Andy Jagger Fund and the Francis Raymond Hudson Memorial Fund
38

Collection of essays on mergers & acquisitions

Ploskonka, Karolina January 2015 (has links)
This PhD thesis consists of three essays which are interlinked by two themes - the problem of risk and information asymmetry in cross-border mergers and acquisitions carried out by UK investors. Majority of empirical research in finance, and in particular in mergers and acquisitions focuses on the US outward investments. However, UK investors are the second most active when it comes to international acquisitions. The country's physical proximity to continental Europe and common legal system make UK transactions a particularly interesting dataset. In the first essay we try to understand how UK investors decide in which country to invest. We investigate in which cases increased level of risk and higher information asymmetry are desired by UK investors and find that higher corporate governance standards, more stringent accounting standards and strong creditor and shareholder protection deter investors. Legal system seems to be of no statistical significance indicating that the law of the host country does not fully reflect the level of such standards, while lack of significance of media coverage indicates that investors are not concerned about the public scrutiny. The second paper looks at how increased risk and information asymmetry impact the likelihood of using a contingent payout agreement and if investors always will use this method to reduce the risk of overpaying for the target. The evidence shows that deal-specific features reflecting higher asymmetry of information and risk increase the chances of using an earnout contract. However, cross-border transactions do not involve earnout contracts more often than the domestic ones which is most likely due to potential enforcement issues resulting from different legal systems. The last chapter of this thesis looks at the ways in which the acquirer can structure the transaction to reduce the risk that the offer will be rejected. Our results stress the importance of bilateral negotiations. Although the size of the premium is significant, its importance is fairly negligible when compared with the impact of hostile transactions, competing bids and the inclusions of a termination fee. From the above we can infer that carefully planned bilateral negotiations leading to a high premium would maximise the chances of deal completion. Recapitulating, in this collection of essays we try to answer the questions of how risk and information asymmetry influence UK investors' decision where to invest, how to pay for the target and whom and how to acquire in order to maximise the chances that the transaction will be successfully finalised.
39

Is there a casual link between disclosure for fair value assets and information asymmetry?

Ezdri, Elon January 2016 (has links)
Following an attempt to harmonize the U.S. GAAP and IFRS a new IFRS standard became mandatory in the EU known as IFRS 13 “Fair value measurement” in 2013. The new accounting standard aims to decrease inconsistencies with fair value measurement by introducing new disclosure requirements for fair value assets with no active market (level 3). This study investigates how well Swedish listed firms have complied with the new disclosure requirements, and whether their compliance level has affected the information asymmetry between market participants. The sample consists of Swedish listed firms from Nasdaq OMX within the banking, forestry and real estate industry where fair value assets on level 3 are prevalent. The result revealed that Swedish firms had increased their compliance level with the disclosure requirements; furthermore, the regression analysis indicated a negative relation between an increase in disclosure level and information asymmetry after controlling for some variables. However, since the result was not significant suggestions for future research is to increase the sample size outside of the Swedish context.
40

Tolai women and development

Bradley, Susan Christine January 1982 (has links)
No description available.

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