When an intense laser beam interacts with matter, the Kerr nonlinearity results in self-focusing. Above the critical intensity, self-focusing dominates pulse spreading through diffraction leading to continuous pulse narrowing and thus an increase of the laser peak intensity. Collapse is prevented through the fact that peak intensities ultimately reach a level where ionization occurs. The profile of ionized electrons represents a negative lens which balances Kerr nonlinear self-focusing and causes the formation of stable filaments. From filaments radiation is emitted in a cone around the filament which has been termed conical emission. Filament formation happens at non-perturbative intensities where the formalism of perturbative nonlinear optics loses its validity. This opens the question of how the Kerr nonlinearity behaves in the non-perturbative limit and how large the Kerr nonlinear coefficient is. The expression for the Kerr nonlinearity is derived by perturbation theory; the validity of this expression in the non-perturbative limit is questionable. Further, experimentally the Kerr nonlinear index is extracted from measurements of the self-focusing distance as a function of beam intensity which is called the Z-scan method. This method fails at non-perturbative intensities due to the presence of the negative lens coming from the ionized electrons. The effects of the positive focusing and negative self-defocusing lens cannot be separated by the Z-scan method. As a result, not much is known about the Kerr nonlinearity in the regime of non-perturbative nonlinear optics. The purpose of this thesis is twofold. First, recently it has been discovered that conical emission can be utilized as a broadband and very efficient amplification mechanism in the far infrared. The process has been dubbed Kerr instability amplification. The difference between conical emission and Kerr instability amplification is that they take place in two different regimes of the nonlinear interaction. Whereas conical emission grows out of noise and therewith only takes place once the pump pulse has been substantially restructured due to filamentation, Kerr instability amplification is seeded with a second pulse and therewith occurs long before filamentation happens. The theory developed for Kerr instability amplification has been developed based on a stability analysis of the scalar wave equation. This analysis has shown that with pump lasers in the 1-2 μm range amplification of infrared radiation up to the 10’s of μm can be achieved. For amplification over such a wide range it is not adhoc clear to which exent vectorial wave effects can be neglected. The first part of the thesis closes this gap by developing the vectorial theory of vector instability amplification. The second part uses the results derived for Kerr instability amplification to answer the question of how to measure the Kerr nonlinear index in the nonperturbative laser intensity limit. The idea rests on the fact that Kerr instability amplification is maximum for a specific angle between pump and seed beam which varies as a function of laser pump intensity. A relation is derived that connects this angle with the Kerr nonlinear refractive index. As a result, from the maximum angle measured as a function of pump intensity, both magnitude and functional form of the Kerr nonlinear index as a function of laser intensity can be determined.

La présente thèse de maîtrise vise à analyser les débats parlementaires sur la Loi sur l’arrestation par des citoyens et la légitime défense (loi C-26), aussi surnommée le Lucky Moose Bill. L’objectif était de voir comment s’est posée la question du respect des droits et libertés des citoyens au regard de l’élargissement de la capacité d’arrestation et de défense des biens et de la personne des citoyens, particulièrement du fait que cela touche aux pouvoirs des agents privés de sécurité, lesquels ont les mêmes pouvoirs que les citoyens sans être soumis à la Charte canadienne des droits et libertés. Une analyse de contenu qualitative des débats parlementaires nous a permis de constater que malgré quelques inquiétudes, le focusing event déclencheur du projet de loi, soit l’affaire Lucky Moose, a permis de balayer les craintes soulevées quant à l’impact de ce projet de loi sur les pouvoirs de la sécurité privée.

Cochlear implants are a recognised treatment for severe and profound hearing losses, and can greatly improve speech discrimination in a quiet listening environment. However, poor specificity of neural excitation resulting from wide current spread within the cochlea leads to inadequate complex pitch perception, affecting speech discrimination in noisy environments and music perception. Tripolar is a stimulation mode with a greater degree of current focusing than the monopolar mode currently used in the clinic. The overall aim of the experiments in this thesis was to evaluate the potential of tripolar stimulation mode to improve complex pitch perception compared to monopolar stimulation mode in a group of Advanced Bionics cochlear implant listeners. First, the place specificity of tripolar and monopolar stimulation was compared using a psychophysical forward masking task with a dual-electrode masking stimulus to limit off-site listening. An overall improvement in the place specificity of tripolar compared to monopolar stimulation indicated that current focusing may provide more independent transmission of temporal information from different electrode places. This conclusion was unaffected by the degree of residual masking which, although measurable, was similar in both modes. Second, the effect of current focusing on delivery of independent temporal patterns was evaluated, specifically whether transmission of fine temporal information about interpulse intervals was improved using tripolar over monopolar stimulation. No advantage was found for current focusing in the delivery of temporal patterns on either a single electrode site, or across-electrodes. Third, the effect of mode on complex pitch perception was investigated by comparing a tripolar with a monopolar listening program. Results showed no improvement in pitch ranking ability from current focusing using sung vowel stimuli, and further suggested that a cue related to the centroid of excitation was providing a stronger cue to pitch than the temporal modulations available in both modes in this group. In conclusion, tripolar stimulation, on average, improved place specificity using forward masking, but not temporal cues to pitch using the methods chosen to evaluate this. Furthermore, current focusing did not improve the ability to rank sung vowels based on pitch over monopolar mode. Current focusing, therefore, was not found to enhance perception of complex harmonic pitch in this group. However, a degree of inter-participant variability in amount of benefit from current focusing observed in this series of experiments suggests that it may be useful for some cochlear implant listeners if a predictive measure of benefit were developed.

Magister en Psicología Clínica de Adultos / El cuidado del terapeuta es un fenómeno que ha ido paulatinamente ganando relevancia debido a los efectos que tiene la práctica clínica sobre el desgaste personal del profesional. Sin embargo, hoy no se cuenta con una delimitación clara sobre qué es el cuidado en general y menos qué es el cuidado del psicoterapeuta. En la presente investigación se ha intentado dar respuesta a las anteriores interrogantes a partir de una revisión de 21 teorías del cuidado provenientes de la enfermería, antropología y filosofía. A partir de tal revisión es posible hablar de un cuidado nuclear que es transversal a las teorías y que se caracteriza por ser la intención de llevar a un ente hacia su ‘posibilidad más propia’, el cual se expresa bajo tres posibles modos: la perpetuación, la restauración o la trascendencia del ente. A partir del cuidado nuclear se considera que el cuidado profesional del terapeuta consiste en la posibilidad de trascenderse a sí mismo en pos de poder ayudar al cliente, siendo un ejemplo de tal postura la ‘actitud de focusing’ planteada por la terapia experiencial de E. Gendlin

No description available.

Synthetic Aperture Focusing Technique (SAFT) is a powerful method to createfocused images of the inside of opaque samples by using delay-and-sum of acquireddata. It gives a high resolution and when using a generation laser and a detectionlaser it is also non-contact. This thesis was made at Swerim, and the aim wasto create an 3D-SAFT algorithm and to visualise the reconstructed image. Twosamples were used, both were 3D-printed with known defects that varied in sizefrom 0.05 mm to 1 mm. The defects were lined up in rows, with 10 in each row.After the algorithm was used on the acquired data from the two samples, six toeight defects were found in each row. Both samples had three rows of defects. Themeasured sizes of the defects were not exactly as the actual size but ranged a fewmillimetre too small or big compared to the real size. Overall the algorithm workswell. The resolution of the 3D images are the same as for the 2D-SAFT algorithmalready made by Swerim. As of now the 3D images may not be worth the time ittakes to process, but if a better way to visualise the data is made in the future, itwill be good to be able to see the defects in 3D.

In this thesis, wave propagation through acoustic materials with subwavelength slits structures is studied. Guided by the findings, acoustic wave focusing is achieved with a specific material design. By using a parameter retrieving method, an effective medium theory for a slab with periodic subwavelength cut-through slits is successfully derived. The theory is based on eigenfunction solutions to the acoustic wave equation. Numerical simulations are implemented by the finite-difference time-domain (FDTD) method for the two-dimensional acoustic wave equation. The theory provides the effective impedance and refractive index functions for the equivalent medium, which can reproduce the transmission and reflection spectral responses of the original structure. I analytically and numerically investigate both the validity and limitations of the theory, and the influences of material and geometry on the effective spectral responses are studied. Results show that large contrasts in impedance and density are conditions that validate the effective medium theory, and this approximation displays a better accuracy for a thick slab with narrow slits in it. Based on the effective medium theory developed, a design of a at slab with a snake shaped" subwavelength structure is proposed as a means of achieving acoustic focusing. The property of focusing is demonstrated by FDTD simulations. Good agreement is observed between the proposed structure and the equivalent lens pre- dicted by the theory, which leads to robust broadband focusing by a thin at slab.

Small heat shock proteins (hsp) have been implicated in mediation of classic preconditioning in the rabbit. Hsp27 is a terminal substrate of the p38 MAPK cascade. One and 2D gel electrophoresis and immunoblotting of cell fractions was used to determine p38 MAPK and hsp27 phosphorylation levels, respectively, during in vitro ischemia in control, calyculin A (Cal A)-treated (protein phosphatase inhibitor), SB203580-treated (p38MAPK inhibitor) and preconditioned (IPC) isolated adult rabbit cardiomyocytes. The dual phosphorylation of p38 MAPK was increased by early ischemia (30-60 min), after which there was a loss of total cytosolic p38 MAPK. The ischemic increase of p38 MAPK dual phosphorylation was enhanced by IPC. Cal A strongly activated dual phosphorylation of p38 MAPK in oxygenated cells and this was maintained into early ischemia. SB203580 inhibited the dual phosphorylation of p38 MAPK and attenuated the loss of total cytosolic p38 MAPK. In each protocol, ischemia translocated hsp27 from the cytosolic fraction to the cytoskeletal fraction at similar rates and extents. Hsp27 phosphorylation was quantitated as the fraction of diphosphorylated hsp27, based on IEF mobility shifts of hsp27 phosphorylation isoforms. In oxygenated control cells, cytosolic and cytoskeletal hsp27 was highly phosphorylated. After 90 min ischemia, cytoskeletal hsp27 was markedly dephosphorylaled. Cal A slightly increased control cytoskeletal hsp27 phosphorylation. During ischemic incubation, Cal A blocked ischemic dephosphorylation. SB203580 accelerated ischemic hsp27 dephosphorylation and injury. IPC insignificantly decreased the initial rate of ischemic dephosphorylation of hsp27, but not the extent of dephosphorylation in later ischemia. Phosphorylation is regulated by both kinase and phosphatase activities. IPC protection was not correlated with a significant increase in cytosolic or cytoskeletal hsp27 phosphorylation levels during prolonged (> 60-90 min) ischemia.

Polymeric microchips have received increasing attention in chemical analysis because polymers have attractive properties, such as low cost, ease of fabrication, biocompatibility and high flexibility. However, commercial polymers usually exhibit analyte adsorption on their surfaces, which can interfere with microfluidic transport in, for example, chemical separations such as chromatography or electrophoresis. Usually, surface modification is required to eliminate this problem. To perform stable and durable surface modification, a new polymer, poly(methyl methacrylate-co-glycidyl methacrylate) (PGMAMMA) was prepared for microchip fabrication, which provides epoxy groups on the surface. Whole surface atom transfer radical polymerization (ATRP) and in-channel ATRP approaches were employed to create uniform and dense poly(ethylene glycol) (PEG)-functionalized polymer brush channel surfaces for capillary electrophoresis (CE) separation of biomolecules, such as peptides and proteins. In addition, a novel microchip material was developed for bioanalysis, which does not require surface modification, made from a PEG-functionalized copolymer. The fabrication is easy and fast, and the bonding is strong. Microchips fabricated from this material have been applied for CE separation of small molecules, peptides, proteins and enantiomers. Electric field gradient focusing (EFGF) is an attractive technique, which depends on an electric field gradient and a counter-flow to focus, concentrate and separate charged analytes, such as peptides and proteins. I used the PEG-functionalized copolymer to fabricate EFGF substrates. The separation channel was formed in an ionically conductive and protein resistant PEG-functionalized hydrogel, which was cast in a changing cross-sectional cavity in the plastic substrate. The hydrogel shape was designed to create linear or non-linear gradients. These EFGF devices were successfully used for protein focusing, and their performance was optimized. Use of buffers containing small electrolyte ions promoted rapid ion transport in the hydrogel for achieving the designed gradients. A PEG-functionalized monolith was incorporated in the EFGF separation channel to reduce dispersion and improve focusing performance. Improvement in peak capacity was proposed using a bilinear EFGF device. Protein concentration exceeding 10,000-fold was demonstrated using such devices.

Optical Coherence Tomography (OCT) is a novel optical imaging technique that has assumed significant importance in bio-medical imaging in the last two decades because it is non-invasive and provides accurate, high resolution images of three dimensional cross-sections of body tissue, exceeding the capabilities of the current predominant imaging technique –ultrasound. In this thesis, high resolution OCT is investigated for in vivo detection of abnormal skin pathology for the early diagnosis of cancer. The technology presented is based on a dynamic focusing microscopic imaging probe conceived for skin imaging and the detection of abnormalities in the epithelium. A novel method for dynamic focusing in the biological sample using liquid crystal (LC) lens technology to obtain three dimensional images with invariant resolution throughout the cross-section and depth of the sample is presented and discussed. Two different skin probe configurations that incorporate dynamic focusing with LC lenses, one involving a reflective microscope objective sub-system, and the other involving an all-refractive immersion microscope objective sub-system are investigated. In order to ensure high resolution imaging, a low coherence broadband source, namely a femtosecond mode-locked Ti: sapphire laser centered at a wavelength of approximately 800nm is used to illuminate the sample. An in-depth description and analysis of the optical design and predicted performance of the two microscope objectives designed for dynamic three dimensional imaging at 5ìm resolution for the chosen broadband spectrum is presented.