• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 653
  • 286
  • 65
  • 65
  • 56
  • 52
  • 15
  • 9
  • 8
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • Tagged with
  • 1546
  • 150
  • 120
  • 117
  • 106
  • 105
  • 78
  • 78
  • 78
  • 78
  • 74
  • 74
  • 69
  • 67
  • 63
  • 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.
131

An evaluation of changes over time in serum creatine kinase activity and c-reactive protein concentration in dogs undergoing hemilaminectomy or ovariohysterectomy

Nevill, Bruce Guy 21 December 2010 (has links)
Trauma of diverse origins is a common reason for presentation of pets for treatment. It is often difficult clinically to objectively measure the severity of any trauma to an animal. One approach is to measure the changes in the various serum parameters which are known to alter in response to trauma or inflammation. If the changes over time of relevant and easily measurable parameters can be established under two controlled but different conditions of surgical trauma, it may provide the foundation for evaluating their future use in establishing the severity of trauma in a patient. A prospective study was performed on animals presented to the Onderstepoort Veterinary Academic Hospital for either thoracolumbar disc disease or for elective ovariohysterectomy. The two surgical procedures chosen for the study involved significant surgical trauma, particularly to muscle, in the case of thoracolumbar decompression and relatively minor surgical trauma in the case of ovariohysterectomy. Serial evaluation of creatine kinase (CK) and C-reactive protein (CRP) were performed both pre- and post-operatively on two sets of patients derived from the two surgical categories. CK is an enzyme found predominantly in skeletal muscle and significantly elevated serum activity is largely associated with muscle damage. CRP is an acute phase protein which shows elevated serum concentration in response to a broad range of inflammatory stimuli. Analysis of the data showed a very wide range of results at each time point for both CK and CRP. There were no significant differences between the two surgical groups for either analyte preoperatively. Thereafter CK results were markedly and significantly different between the two groups. CRP results were very similar in the two groups with no statistical difference at any time point. The results of this study suggest that the evaluation of CK and CRP at any one time point in a traumatized animal is of limited value. However the evaluation of the trend of these two analytes, even over a relatively short time period, may allow for useful prognostication in clinical cases. / Dissertation (MMedVet)--University of Pretoria, 2008. / Companion Animal Clinical Studies / unrestricted
132

Utility of Rifampin Blood Levels in the Treatment and Follow-up of Active Pulmonary Tuberculosis in Patients Who Were Slow to Respond to Routine Directly Observed Therapy

Mehta, Jayant B., Shantaveerapa, Harsha, Byrd, Ryland P., Morton, Steven E., Fountain, Francis, Roy, Thomas M. 01 January 2001 (has links)
Study objective: The standard daily dose of rifampin in directly observed treatment of Mycobacterium tuberculosis (TB) is 600 mg, taken orally. The purpose of this study was to assess the efficacy of standard dose rifampin therapy in patients who were slow to respond to routine directly observed therapy (DOT). Methods: Patients with non-drug-resistant pulmonary TB who were receiving 600 mg of oral rifampin by DOT were eligible for inclusion. Patients were deemed slow to respond if their sputum smears and cultures remained positive for M tuberculosis and if the patient’s condition did not improve clinically or radiographically after 3 months of treatment. Serum rifampin levels were ascertained to determine the adequacy of the standard rifampin dosing. Patients with subtherapeutic blood levels had their rifampin dose increased to 900 mg, and rifampin levels were repeated. Rifampin dosage was increased again if blood levels were still subtherapeutic. No antitubercular medications were added to the treatment regimen. The total weekly dose of the other standard treatment drugs was not increased. Results: Of 124 new patients with active pulmonary TB, 6 patients were identified as slow to respond to the standard antitubercular DOT. All six patients had subtherapeutic serum rifampin levels. All six patients responded clinically, radiographically, and mycobacteriologically after an increase in rifampin dosage to reach target drug blood level. Conclusions: Standard dosing with rifampin resulted in a poor clinical response and subtherapeutic serum levels in six patients. Increasing the dosage of rifampin improved the outcome without additional side effects. In TB patients who are slow to respond to standard treatment, an inadequate dose of rifampin should be suspected. Current antituberculer drug administration does not include adjusted dosage for rifampin.
133

Light level contributes to habitat selection in the Common House Spider Parasteatoda tepidariorum (Araneae: Theridiidae)

Jones, Caitlin, Jones, Thomas C, Moore, Darrell, Petko, Jessica 07 April 2022 (has links)
Parasteatoda tepidariorum is a cob-web weaving spider abundant in both urban and rural areas across the temperate regions of the globe. They are typically found in sheltered areas such as garages, porches, caves, and between stones where they are able to construct a three-dimensional web structure. Because these organisms function as both predator and prey, proper habitat selection is vital for the survival of the individual. Individuals of this species must find locations that are conducive to high levels of prey availability but also sheltered to avoid undue predator exposure. In their natural habitats, these locations tend to be shaded. Because these spiders do not readily move locations once their webs are built, proper habitat choice is important. With this information in mind, these apparent preferences in habitat may infer specific inclinations towards light exposure. These interactions, however, have not been thoroughly investigated. Because of the natural variation of light levels in these habitats, we hypothesize that these spiders may be utilizing light levels in habitat choice. In this study, we aimed to detect any indications of preferences using adult female P. tepidariorum. Spiders were captured in Sullivan and Washington counties in Tennessee and were returned to the lab where they were maintained under standard conditions prior to being placed into the experimental chamber. This experimental chamber consisted of two concentric circles that created a consistent tunnel structure for web-building throughout. A light gradient was constructed so that one side of the circular tunnel had the maximum light exposure of 410 lux and the other side faded to 0 lux. The chamber was placed in a controlled environment with a 12 h light:12 h dark cycle at ~24° C. One spider was placed into the choice chamber at a time and allowed three full days to explore and choose an environment in which to build a web. After three days, the location of the spider was recorded, and the spider was removed. The chamber was cleaned with ethanol and allowed to dry before another spider was placed into the chamber. Each spider was repeated at least twice. All individuals built webs in the dark half of the arena, and there was a significant preference for very low light (but not complete darkness). These results indicate that P. tepidariorum may select habitats based on light exposures. By investigating these preferences, we are able to get a better understanding of how P. tepidariorum interpret their environment to choose proper web locations.
134

Steady-State Cord and Amniotic Fluid Ceftizoxime Levels Continuously Surpass Maternal Levels

Fortunato, Stephen J., Bawdon, Robert E., Welt, Selman I., Swan, Kenneth F. 01 January 1988 (has links)
As part of our management protocol for preterm premature rupture of membranes, ceftizoxime and tocolysis were used to prolong the latent period and prevent or treat concomitant infection. Ceftizoxime was selected for this protocol based on its physiochemical properties, which favor placental transfer of the drug. Patients achieving steady-state pharmacodynamics (more than three doses of the drug) were considered eligible for study. Ceftizoxime levels were determined by reverse-phase high-pressure liquid chromatography. All levels measured after the first hour of treatment were indicative of the relative concentration of ceftizoxime in the fetal and amniotic fluid compartments when compared with the maternal compartment. Mean (±SEM) ceftizoxime levels were 11.96 + 2.35 μg/ml in maternal serum, 24.54 ± 4.78 μg/ml in cord serum, and 43.45 ± 4.97 μg/ml in amniotic fluid. Based on its broad antibacterial activity and its high concentration in fetal blood and amniotic fluid, ceftizoxime appears to be an ideal agent for treatment of the intrauterine environment.
135

Designing games for learning: An investigation of instructional designers, game designers, and teachers design decisions and epistemological beliefs

Kepple, Michelle 01 January 2015 (has links)
Fields within education and training have been exploring the use of educational computer-based games, often referred to as serious games (SG), in multiple disciplines of academic research including the affective, cognitive, and psychomotor domains. Traditionally, game designers tend to represent a different viewpoint about learning than instructional designers, or even teachers. More so, one of the fundamental roles designers play in making decisions is based on multiple factors, which include personal assumptions about constraints and perceived constraints in instructional practice. In order for games to be successful in classroom environments, classroom teachers need to be involved in the design process to help identify and assist in mitigating the classroom-based challenges that will be faced during implementation. The study sought to extend research on serious game attributes by examining the instructional design decisions and beliefs of individuals involved in the design, development, or implementation of serious games in education or training environments, through a web-based survey. Within the serious game community there are multiple approaches to designing learning environments; some view serious games as virtual environments explicitly for education or training, while others include digital games, simulations, and virtual worlds. While there is debate over the type of games that are most effective for learning, researchers have provided guiding qualifications and lists of characteristics that effective games should possess to improve current practice and implementation. Two central aims guided the study: (a) to identify relationships between the mental models put forth by each discipline when selecting serious game attributes, and (b) to provide insight into each subpopulation's beliefs about learning. Suggested implications for the study extend to educational practice, policy, and future research on designing, developing, and implementing serious games in learning environments. Findings suggest that the sample portrayed similar epistemological beliefs between all subgroups. Participants had the most sophisticated beliefs toward quick learning. Limited relationships were evident between participant's epistemological beliefs and selection of serious game attributes (SGA). However, findings indicated that each discipline has unique models and frameworks for designing serious games and perspectives on serious game implementation.
136

Energy Levels in Samarium 151

Burke, D.G. 05 1900 (has links)
<p> The energy levels of Sm151 populated in the beta decay of Pm151 have been studied with the aid of magnetic spectrometers. The internal and external conversion spectra were examined with a π√2 spectrometer of 50 cm radius. A Gerholm-type double lens coincidence spectrometer was used to perform electron-beta, electron-electron, electron-gamma and gamma-beta coincidence experiments. In addition, precise measurements of the transition energies obtained by Geiger and Graham (1962) with the Chalk River π√2 iron-free spectrometer are included. A decay scheme based on these results is proposed and speculations are made concerning the possible interpretation of the levels on the basis of the Nilsson model. The results are also compared with other recently published data on this decay.</p> / Thesis / Doctor of Philosophy (PhD)
137

Tidal Propagation in Chesterfield Inlet, N.W.T.

Budgell, William Paul 09 1900 (has links)
<p> Chesterfield Inlet drains an area of 290,000 km^2, between Great Slave Lake and northern Hudson Bay, of predominantly continuous permafrost terrain. The 220-kilometre-long inlet may be used as an important navigation link to Baker Lake and potential pipeline sites. The inlet forms a complex network and is characterized by strong tidal forcing.</p> <p> A one-dimensional numerical model, using a weighted, implicit, finite difference scheme, was modified for application to the network. Sparse matrix techniques were incorporated into the model to speed Gaussian Elimination in the solution of the equations.</p> <p> Tidal constituents, derived from admittance calculations, were used to predict water levels at eight tide gauge locations. Tidal predictions at Sandpiper Island were used as the downstream boundary condition for the numerical model, while tidal predictions at the other gauge locations were used in the model calibration.</p> <p> The observed and model-computed water levels are in good agreement over the lower half of the inlet. Appreciable differences between the observed and computed values were encountered in the upper reaches. Although some of these discrepancies are attributable to errors in the upstream boundary condition and schematization of the model, there is evidence to suggest that time and range errors may exist in some of the recorded tidal data.</p> <p> The variation in the phase and amplitude of the tide throughout the inlet is determined through an examination of the tidal constituents and the model results. Power spectra of the observed and model-predicted water levels reveal that nonlinear interactions of the major tidal constituents take place in the upper portion of the inlet.</p> / Thesis / Master of Engineering (MEngr)
138

Energy Levels in Pt192 and Pt194

MacArthur, John Duncan 10 1900 (has links)
The technique of recording coincidence events has been applied in the study of several nuclei. Two platinum nuclides have been investigated experimentally through the use of two types of coincidence spectrometers. For both these nuclei, Pt^192 and Pt^194, the investigation included beta-gamma experiments which measured the intensities of the beta groups feeding some of the levels in these nuclei and directional correlation experiments which determined the spins of some of their excited states. A study of the gamma-gamma coincidences of Pt^194 confirmed the decay scheme proposed by previous workers. The directional correlation of the one cascade in Co^58 forms the part of the paper present in Chapter IV. Finally, the appendices contain a description of an apparatus for the preparation of beta sources and an explanation of a set of experiments designed to calibrate the gamma-gamma coincidence spectrometer for its tasks. / Thesis / Doctor of Philosophy (PhD)
139

Genetic and Molecular Dissection of Homocysteinemia in Mice

Ernest, Sheila 25 May 2004 (has links)
No description available.
140

COMPARING FOOT PRESSURES DURING FEEDING IN TWO DISTINCT GROUPS OF CHILDREN

Yakey, Abigail Brodrick 19 April 2007 (has links)
No description available.

Page generated in 0.5075 seconds