First, we investigate the Bouguer-Lambert-Beer (BLB) law as applied to the transmission of ultrashort pulses through water in the linear absorption regime. We present a linear theory for propagation of ultrashort laser pulses, and related experimental results are in excellent agreement with this theory. Thus we conclude that recent claims of the BLB law violations are inconsistent with the experimental data obtained by our group. Second, we study the dynamics of ultrashort pulses in a Lorentz medium and in water via the saddle point method. It shows that the saddle point method is a more efficient and faster method than the direct integration method to study one-dimensional pulse propagation over macroscopic distances (that is, distance comparable to the wavelength) in a general dielectric medium. Comments are also made about the exponential attenuation of the generalized Sommerfeld and Brillouin precursors. By applying the saddle point method, we also determined that the pulse duration estimated by the group velocity dispersion (GVD) approximation is within 2% of the value computed with the actual refractive index for a propagation distance of 6 m in water.

Recent short pulse (femtosecond) laser experiments have shown the existence of a so called superelastic precursor for short time periods after shock wave formation. The superelastic precursor is characterised as having amplitude far greater than the Hugoniot Elastic limit. This work reviews the current orthotropic thermoelastic plastic-damage model developed at Cranfield University, which includes the ability to model high velocity, shock wave forming impacts. The current model is unable to reproduce the superelastic precursor. Recent methods of looking at plasticity are reviewed and model improvements are suggested to enable the Cranfield model to reproduce superelastic precursor waves. The methods investigated are both dislocation based as it is determined that it is necessary to model deformation on the microscale in order to achieve reproduction of phenomena on the timescales of the early stages of shock wave formation and propagation. The methods investigated are the so-called self-organisation of dislocations and a mobile and immobile dislocation method proposed by Mayer. The plasticity part of the model proposed by Mayer is suggested for further investigation, including implementation into the DYNA 3D hydrocode which contains the current Cranfield model, to numerically asses the models capabilities. Similar, the self-organisation model is put forward for further numerical analysis. Further, calculation of the continuum Cauchy stress using purely atomistic variables is investigated in the form of the virial stress. It is determined that the virial stress calculation is unsuitable for modelling shock waves, however an alternative atomistic stress calculation which is more suited to shock waves is discussed. It is proposed that this stress calculation could be used to investigate the stresses contained within the thin shock front.

Appendum pasted into front end-papers. / Bibliography: leaves xiii-xliii. / xi, 195, xliii leaves : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Traumatic brain injury (TBI) effects neuronal cell bodies (NCBs), axons and dendrites in a complex fashion, producing a spectrum of damage dependent on the initial injury and secondary effects. Accumulation of amyloid precursor (APP) in NSBs and axons is a feature of TBI. This accumulation may be due to impairment of the axonal transport of APP and/or upregulation of APP mRNA synthesis. This thesis hypothesizes that mechanical deformation, which is not severe enough to cause immediate cell death, results in increased APP mRNA and antigen expression as an acute phase response to injury. / Thesis (Ph.D.)--University of Adelaide, Dept. of Pathology, 1999

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 100-123).

Each year, aging and age-related deficits in cognitive function affect larger population worldwide. Research on aging has focused on changes in gray matter and white matter with age. A quantitative analysis of magnetic resonance images from healthy subjects of 16-79 years showed a significant negative correlation between gray matter volume and age (Taki et al., 2004). In addition, age-related cognitive decline is reported to be associated with white matter changes such as myelin damage, a result of both the inability of microglia to clear out damaged myelin debris and oligodendrocyte to support remyelination. Eotaxin-1 (CCL11) belongs to a group of eosinophil-specific chemoattractant originally found in peripheral immune system mediating allergic inflammation, asthma and atopic dermatitis (Garcia-Zepeda et al., 1996; Spergel, Mizoguchi, Oettgen, Bhan, & Geha, 1999). Recently it has been reported to have endogenous sources in the CNS and to increase with age in cerebral spinal fluid (CSF) as well as periphery in blood plasma. While CCL11 has been identified to increase with age, injection of CCL11 inhibit neurogenesis in young mice, which is likely to be mediated by C-C chemokine receptor type 3 (CCR3). CCR3 is also the only receptor for CCL11 that is expressed by oligodendrocyte precursor cells (OPCs) and by activated microglia in mice, which means it may participate in the process of microglial phagocytosis and oligodendrocyte myelination. To investigate if CCR3 is an important factor in the normal aging brain and its potential role in these existing findings, immunohistochemistry, stereology and densitometry were performed in the anterior cingulate cortex and cingulum from brain tissue of 4 young adults and 6 aged rhesus monkeys that were behaviorally tested previously to 1) demonstrate any association between CCR3 expression level and age 2) characterize changes in CCR3 level in relation to cognitive impairment 3) identify cellular localization of CCR3. We found a significant increase in amount of CCR3 cingulate cortex with age, which suggests its pro-disease effect in other pathways such as the interaction between CNS and T cell immune system. Although for aged group increase in CCR3+ cell density in white matter appeared insignificant, we found that CCR3 was expressed exclusively in OPCs but was absent in mature oligodendrocytes. indicating its role in OPC proliferation, oligodendrocyte maturation and myelination.

M.Med.(Haematology), Faculty of Health Sciences, University of the Witwatersrand, 2008 / This study aimed to identify the relevance of these prognostic features in the modern treatment era in South African children. A retrospective analysis of the presentation clinical and laboratory features and treatment outcomes of all children treated for Precursor B cell ALL at the Johannesburg Hospital was performed. Between January 1997 and May 2007, 100 children were reviewed. Clinical features (age, race and gender) emerged as significant prognostic variables. Laboratory features (white cell count and genetic features) lacked significance. Early morphologic response on day 15 identified a subgroup associated with a favourable outcome. However the presence of > 5% blasts was not significantly predictive of relapse or death at this time point. Minimal residual disease (MRD) detection by modified immunoglobulin gene rearrangement and flow cytometry techniques did not improve the predictive value of the morphological assessment. In a low resource setting, the challenge is to design cost effective MRD detection methods to improve the identification of patients at risk for relapse.

No description available.

Thesis advisor: John E. Ebel / Power-law scaling relationships concerning the earthquake frequency-magnitude distribution and the fractal geometry of spatial seismicity patterns may provide applications to earthquake forecasting and earthquake hazard studies. Past studies on the fractal characteristics of seismic phenomena have observed spatial and temporal differences in earthquake clustering and b value in relation to fractal dimension value. In this thesis, an investigation of the spatiotemporal seismicity patterns in southern California for the years 1982 to 2020 was conducted. The range and temporospatial distribution of b and D2 values for earthquake hypocenters contained in the Southern California Earthquake Data Center catalogue were calculated and shown in time series and spatial distribution maps. b values were calculated using both the Least SquaresMethod and the Maximum Likelihood Method while D2 values were calculated for length scales between 1 km to 10 km. A set of b and D2 values were calculated after declustering for foreshocks and aftershocks using Gardner and Knopoff’s declustering algorithm. b values decreased while D2 values increased on the dates of M > 6.0 earthquakes, whereas b values increased and D2 values decreased on the dates after M > 6.0 earthquakes. Declustering results suggest an influence of earthquake aftershocks to increase D2 values while decreasing b values. The role for b values and D2 values to delineate both the temporal and spatial extent of aftershock sequences for large earthquakes may prove to have an application in earthquake hazard studies. / Thesis (MS) — Boston College, 2022. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.

A trade study is carried out for the design of electric propulsion based lunar robotic precursor missions. The focus is to understand the relationships between payload mass delivered, electric propulsion power, and trip time. The results are compared against a baseline system using chemical propulsion with LOX/H2. The major differences between the chemical propulsion based and electric propulsion based systems are presented in terms of the payload mass and trip time. It is shown that solar electric propulsion offers significant advantage over chemical propulsion in delivering non-time critical payloads to lunar orbit. / Master of Science