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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

Sonografické hodnocení n. Ischiadicus u jedinců s radikulární symptomatikou S1 / Sonographic evaluation of the ischial nerve in individuals with radicular symptoms S1

Kurková, Simona January 2019 (has links)
Bibliographical record: KURKOVÁ, Simona. Sonographic evaluation of sciatic nerve in individuals with radicular symptoms S1, Charles University, 2nd Faculty of Medicine, Department of Rehabilitation and Sports Medicine, 2019, p. 99, Thesis Supervisor: Mgr. Stanislav Machač Ph.D. Abstract The thesis deals with radicular symptomatics S1 and sonographic imaging and evaluation of sciatic nerve in individuals with unilateral radicular manifestation. The theoretical part describes anatomy and biomechanics of nerve structures, radicular syndrome and its clinical image, diagnostics and treatment. The theory also includes the less known extraspinal causes manifesting themselves as radicular syndrome, the effects of which may be equally important in differential diagnosis. It describes classical and new possibilities of nerve imaging with emphasis on sonography and approach of new procedures such as MRI tractography. In the practical part, the aim of the thesis is to evaluate morphological changes of sciatic nerve in patients with unilateral symptomatic S1 by sonographic imaging of the nerve during its course, from the subgluteal groove to the popliteal groove. It also examines the relationship between the pathophysiology and symptomatology of these patients, comparing whether changes in nerve size correlate with...
32

N-methyl 4-methyl amphetamine N-alkyl chain extension differentially affects ion flux at the human dopamine and norepinephrine transporters

Harris, Alan C., Jr. 01 January 2016 (has links)
Amphetamine (AMPH) and its derivatives embody a remarkable breadth of pharmacology. These molecules exert their effects, both therapeutic and pathological, at the human monoamine transporters, which tune synaptic dynamics by evacuating monoamine neuromodulators from the synapse subsequent to neuronal impulses. These transporters are electrogenic, and the transporter-mediated current can be correlated to a surrogate measure of the change in membrane voltage: Ca++ currents from co-transfected L-type Ca++ channels. The present work makes use of this assay, with which it is possible to derive pharmacodynamic metrics from both substrates and inhibitors. This work presents data on a heretofore-unstudied class of amphetamine analogs: the enantiomers of N-Me 4-Me AMPH and N-Et 4-Me AMPH. Remarkably, while both enantiomers of the N-Me version of this compound function as substrates at hDAT, both enantiomers of the N-Et version are inhibitors. This switch does not occur at hNET, where all enantiomers of both N-Me and N-Et 4-Me AMPH function as substrates. Further, (S)-N-Et 4-Me AMPH is a substrate at dDAT. EC50 and IC50 values for all drugs at both transporters are presented. I present the results of super-resolution microscopic co-localization studies on the plasmalemmal spatial relation of the human dopamine transporter and voltage gated calcium channel, L-type 1.2 (CaV1.2). I discuss future aims toward a unified understanding of the mechanisms of monoamine transporter function, with an emphasis on what amphetamine can illuminate in this regard.
33

Charles Jennens's collection of Handel's sacred oratorios from 'Saul' to 'Jephtha' : sources, contexts, and revisions

Varka, Natassa Elizabeth January 2019 (has links)
Charles Jennens (1700-1773), the librettist of 'Saul', 'Messiah', 'Belshazzar', the final part of 'L'Allegro, il Penseroso ed il Moderato', and probably 'Israel in Egypt', amassed a huge library of music that forms the bulk of what is now known as the Aylesford collection. Jennens's collection of Handel's music was unique among those of his contemporaries, not only because it includes part-books, but also because it is unusually comprehensive. The dissertation focuses on his copies of the sacred oratorios beginning with 'Saul' (1739) because most of the collection was copied in the 1740s, the sacred oratorios were the works that Jennens was most interested in, and 'Saul' was his first collaboration with Handel. As many of these manuscripts have not been the focus of modern scholarly attention, I first establish how, when, and by whom each manuscript was copied, in order to achieve a greater understanding of how and when Jennens assembled his collection, and what his reasons were for doing so. This close study of the manuscripts reveals that Jennens made extensive alterations to the verbal text, the structure, and the music of several oratorios in his collection. His amendments to 'Saul' and 'Belshazzar' shed light on his collaboration with Handel; and his amendments to 'Samson' and 'Joseph and his Brethren' provide insights into his attitude to Handel in the mid-1740s, his approach to word-setting, his views on the adaptation of Scripture for oratorio, and his beliefs and commitments. Jennens was a highly educated man whose activities were informed by two deeply held, conflicting allegiances: to the Anglican Church and to the deposed Stuarts. An examination of how he harnessed Handel's music to deliver his religious and political messages leads to a richer and more profound understanding of the works, of the relationship between Jennens, Handel, and Handel's music, and of their place in the religious and political context of the mid-eighteenth century.
34

LTE SYSTEM ARCHITECTURE FOR COVERAGE AND DOPPLER REDUCTION IN RANGE TELEMETRY

Kogiantis, Achilles, Rege, Kiran, Triolo, Anthony A. 10 1900 (has links)
A novel approach employing 4G LTE Cellular Technology for Test Range Telemetry is presented. Providing aeronautical mobile telemetry using commercial off the shelf (COTS) cellular equipment poses many challenges, including: Three-dimensional (3D) coverage, need for uninterrupted high data throughputs, and very high Doppler speeds of the Test Articles (TA). Each of these requirements is difficult to meet with a standard cellular approach. We present a novel architecture that provides 3D coverage over the span of a test range, allowing the TA to establish a radio link with base stations that have a manageable Doppler due to the reduced projected TA speed on the radio link line. Preliminary results illustrate that a variety of flight plans can be accommodated with commercial LTE technology by employing LTE’s mobility mechanisms and adding centralized control. The resulting network architecture and Radio Access Network topology allow very high throughputs to be delivered throughout the test range with a judicious placement of base stations.
35

Local Prime Factor Decomposition of Approximate Strong Product Graphs: Local Prime Factor Decompositionof Approximate Strong Product Graphs

Hellmuth, Marc 22 April 2010 (has links)
In practice, graphs often occur as perturbed product structures, so-called approximate graph products. The practical application of the well-known prime factorization algorithms is therefore limited, since most graphs are prime, although they can have a product-like structure. This work is concerned with the strong graph product. Since strong product graphs G contain subgraphs that are itself products of subgraphs of the underlying factors of G, we follow the idea to develop local approaches that cover a graph by factorizable patches and then use this information to derive the global factors. First, we investigate the local structure of strong product graphs and introduce the backbone B(G) of a graph G and the so-called S1-condition. Both concepts play a central role for determining the prime factors of a strong product graph in a unique way. Then, we discuss several graph classes, in detail, NICE, CHIC and locally unrefined graphs. For each class we construct local, quasi-linear time prime factorization algorithms. Combining these results, we then derive a new local prime factorization algorithm for all graphs. Finally, we discuss approximate graph products. We use the new local factorization algorithm to derive a method for the recognition of approximate graph products. Furthermore, we evaluate the performance of this algorithm on a sample of approximate graph products.
36

EFFECTS OF INCREASED BODY MASS ON BIOMECHANICAL STRESSES AFFECTING WORKER SAFETY AND HEALTH DURING STATIC LIFTING TASKS

BLANTON, DOUGLAS MATTHEW 02 July 2004 (has links)
No description available.
37

Periodic Forcing of a System near a Hopf Bifurcation Point

Zhang, Yanyan 17 December 2010 (has links)
No description available.
38

Organic matter dynamics in mixed-farming systems of the West African savanna: a village case study from south Senegal

Manlay, Raphael 05 1900 (has links)
Organic matter (OM) is a multi-purpose tool in West African smallholder mixed-farming systems, but its supply has been decreasing for several decades. To assess the viability of a mixed-farming system of south Senegal, carbon (C), nitrogen (N) and phosphorus (P; available in soil and noted POD) budgets (stocks and flows) were thus quantified.The village territory of the study showed a ring-like organisation with growing intensification of fertilization and cropping practices from the periphery (bush ring) to the compounds (compound fields).Stocks in plant and soil averaged 54.7 tC, 2.63 tN and 43.5 kgP ha 1 in old fallows. They were 97, 29 and 251 % higher than in the bush cropped fields, plant biomass accounting for nearly all of the rise. C, N and P amounts recorded in the soil of compound fields were higher than those of the bush field, but the increase was restricted mainly to the 0 10 cm layer. However, the rather weak response of local sandy soils to management can be interpreted only by reassessing the bio-thermodynamical signification of soil organic carbon cycling in the maintenance of the integrity of local agroecosystems.Manageable stocks of the whole village territory were estimated to 29.7 tC, 1.52 tN and 28.6 kgP ha 1 in 1997. Carbon was stored mainly in soil. Livestock, crop harvest and wood collecting were responsible for respectively 59, 27 and 14 % of the C uptake on the village territory. As a result, large C flows were set towards the compound ring (3.8 tC ha 1 y 1). N and P depletion of the system amounted to 4 kgN and 1 kgP ha 1 y 1, suggesting that the system was close to nutrient balance.Under current demographic growth rate, C depletion may reach 0.38 tC ha 1 y 1 and C demand may double during the next three decades. Without any intensification of farming practices, the viability of the system might soon be called into question.
39

Diabetes impairs cortical map plasticity and functional recovery following ischemic stroke

Sweetnam-Holmes, Danielle 19 December 2011 (has links)
One of the most common risk factors for stroke is diabetes. Diabetics are 2 to 4 times more likely to have a stroke and are also significantly more likely to show poor functional recovery. In order to determine why diabetes is associated with poor stroke recovery, we tested the hypotheses that diabetes either exacerbates initial stroke damage, or inhibits neuronal circuit plasticity in surviving brain regions that is crucial for successful recovery. Type 1 diabetes was chemically induced in mice four weeks before receiving a targeted photothrombotic stroke in the right forelimb somatosensory cortex to model a chronic diabetic condition. Following stroke, a subset of diabetic mice were treated with insulin to determine if controlling blood glucose levels could improve stroke recovery. Consistent with previous studies, one behavioural test revealed a progressive improvement in sensory function of the forepaw in non-diabetic mice after stroke. By contrast, diabetic mice treated with and without insulin showed persistent deficits in sensori-motor forepaw function. To determine whether these different patterns of stroke recovery correlated with changes in functional brain activation, forepaw evoked responses in the somatosensory cortex were imaged using voltage sensitive dyes at 1 and 14 weeks after stroke. In both diabetic and non-diabetic mice that did not have a stroke, brief mechanical stimulation of the forepaw evoked a robust and near simultaneous depolarization in the primary (FLS1) and secondary somatosensory (FLS2) cortex. One week after stroke, forepaw-evoked responses had not been remapped in the peri-infarct cortex in both diabetic and non-diabetic mice. Fourteen weeks after stroke, forepaw evoked responses in non-diabetic mice re-emerged in the peri-infarct cortex whereas diabetic mice showed very little activation, reminiscent of the 1 week recovery group. Moreover, controlling hyperglycemia using insulin therapy failed to restore sensory evoked responses in the peri-infarct cortex. In addition to these differences in peri-infarct responsiveness, we discovered that stroke was associated with increased responsiveness in FLS2 of non-diabetic, but not diabetic or insulin treated mice. To determine the importance of FLS2 in stroke recovery, we silenced the FLS2 cortex and found that it re-instated behavioural impairments in stroke recovered mice, significantly more so than naïve mice that still had a functioning FLS1. Collectively, these results indicate that both diabetes and the secondary somatosensory cortex play an important role in determining the extent of functional recovery after ischemic cortical stroke. Furthermore, the fact that insulin therapy after stroke did not normalize functional recovery, suggests that prolonged hyperglycemia (before stroke) may induce pathological changes in the brain’s circulation or nervous system that cannot be easily reversed. / Graduate
40

Numerical analysis of shallow circular foundations on sands

Yamamoto, Nobutaka January 2006 (has links)
This thesis describes a numerical investigation of shallow circular foundations resting on various types of soil, mainly siliceous and calcareous sands. An elasto-plastic constitutive model, namely the MIT-S1 model (Pestana, 1994), which can predict the rate independent behaviour of different types of soils ranging through uncemented sands, silts and clays, is used to simulating the compression, drained triaxial shear and shallow circular foundation responses. It is found that this model provides a reasonable fit to measured behaviour, particularly for highly compressible calcareous sands, because of the superior modelling of the volumetric compression. The features of the MIT-S1 model have been used to investigate the effects of density, stress level (or foundation size), inherent anisotropy and material type on the response of shallow foundations. It was found that the MIT-S1 model is able to distinguish responses on dilatant siliceous and compressible calcareous sands by relatively minor adjustment of the model parameters. Kinematic mechanisms extracted from finite element calculations show different deformation patterns typical for these sands, with a bulb of compressed material and punching shear for calcareous sand, and a classical rupture failure pattern accompanied by surface heave for siliceous sand. Moreover, it was observed that the classical failure pattern transforms gradually to a punching shear failure pattern as the foundation size increases. From this evidence, a dimensional transition between these failure mechanisms can be defined, referred to as the critical size. The critical size is also the limiting foundation size to apply conventional bearing capacity analyses. Alternative approaches are needed, focusing mainly on the soil compressibility, for shallow foundations greater than the critical size. Two approaches, 1-D compression and bearing modulus analyses, have been proposed for those foundation conditions. From the validations, the former is applicable for extremely large foundations, very loose soil conditions and highly compressible calcareous materials, while the latter is suitable for moderate levels of compressibility or foundation size. It is suggested that appropriate assessment of compression features is of great importance for shallow foundation analysis on sand.

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