Spectral domain optical coherence tomography (SD-OCT) is a dispersed interferometric technology used to obtain tomographic images, typically of tissue for medical applications. OCT is a competing technology with confocal microscopy (CM) and confocal fluorescent microscopy (CFM), which are both used for biopsy imaging for pathology as the gold standard. OCT offers several advantages over CM/CFM: it is able to acquire a full 3D image in a single pass, it requires little or no sample preparation time, and the axial (depth) and lateral (transverse) resolution are not dependent on one another. SD-OCT is limited in imaging depth to a few millimetres due to the quality performance of the spectrograph section of the instrument--that which determines the sensitivity of the SD-OCT system. In this thesis a design for an SD-OCT system is presented that is suitable for biopsy imaging for pathological studies, i.e. an OCT microscope. The purpose of this system is to provide a fast diagnosis to be made in a surgical environment to reduce the amount of tissue removed from a patient and lower the chance of a returned visit at a later date due to insufficient tissue removal. The secondary purpose of the SD-OCT microscope is to serve as a research testbed system for implementing novel hardware advancements. One such technology, called an optical pupil slicer (OPS), will be implemented in the instrument to improve the depth imaging performance of the SD-OCT system over conventional SD-OCT systems. The OPS is a device that generally improves the performance of a dispersive-type spectrograph by increasing the spectral resolution without a loss in throughput, thereby increasing the sensitivity of the SD-OCT system.

Optical Coherence Tomography (OCT) is a relatively new interferometric technology that allows for high-resolution and non-destructive tomographic imaging. One of its primary current uses is for in vivo and ex vivo examination of medical samples. It is used for non-destructive examination of ocular disease, dermatological examination, blood vessel imaging, and many other applications. Some primary advantages of OCT imaging include rapid imaging of biological tissue with minimal sample preparation, 3D high-resolution imaging with depth penetrations of several millimeters, and the capability to obtain results in real time, allowing for fast and minimally invasive identification of many diseases. Current commercial OCT systems rely heavily on optical fiber-based designs. They depend on the robustness of the fiber to maintain system performance in variable environmental conditions but sacrifice the performance and flexibility of free-space optical designs. We discuss the design and implementation of a free-space OCT interferometer that can automatically maintain its alignment, allowing for the use of a free-space optical design outside of tightly controlled laboratory environments. In addition, we describe how similar enhancements can be made to other optical interferometric systems. By extending these techniques, we can provide similar improvements to many related fields, such as interferometric metrology and Fourier Transform Spectroscopy. Improvements in these technologies can help bring powerful interferometric tools to a wider audience.

The increase of antidumping measures could represent a source of mounting frictions in the trading systems among Canada, United States and Mexico. Mexico is an active user of antidumping measures suggesting that both private sector groups and government policy makers have found antidumping measures to be a convenient response to the pressures of import competition. / In the last two decades, Mexico has opened its economy to international commerce. Nevertheless, its economy and legal system are not comparable to those of the United States or Canada, although it has adopted analogous antidumping laws. The Mexican antidumping practice is based today on common law practices influencing civil law formalities. In the NAFTA context, more specifically, in its Chapter 19, legal problems facing the binational panel review system have arisen from Mexico's different legal tradition, notably in the areas of transparency and procedural issues, standard of review, parallel amparo and the power of panel vis-a-vis national courts. The procedural requirements of the Antidumping Agreement prove a challenge for Mexico and will likely lead to trade disputes concerning procedure because it lacks the tradition of administrative and legal process.

When recording music for surround audio engineers sometimes face limitations in time, ideal microphone positions or a noisy audience. If this cannot be dealt with at the location, artificial reverbs are often used in the mixing to “fill in the blanks”. In this study, three instruments were recorded separately with two 5.1 surround microphone setups. Two audio engineer students created artificial reverbs that replaced the back channels of each microphone setup. A listening test was conducted where test subjects compared the 5.1 real recording to the two other stimuli with artificial back channels in terms of realism, envelopment and preference. The result showed that the real recording and the artificial back channels were interchangeable, but that the artificial back channels pointed towards more envelopment, and that the real recording pointed towards more realism.

Particle simulation has become an important research technique in many scientific and engineering fields in latest years. However, these simulations will generate countless data, and database they required would therefore deal with very challenging tasks in terms of data management, storage, and query processing. The two-body correlation function (2-BCFs), a statistical learning measurement to evaluate the datasets, has been mainly utilized to measure the spatial distance histogram (SDH). By using a straightforward method, the process of SDH query takes quadratic time. Recently, a novel algorithm has been proposed to compute the SDH based on the concept of density map (DM), and it reduces the running time to ϴ(N(3/2)) for two-dimensional data and ϴ (N(5/3) ) for three-dimensional data, respectively. In the DM-SDH algorithm, there are two types of DMs that can be plugged in for computation: Quad-tree (Oct-tree for three-dimensional data) and k-d tree data structure. In this thesis paper, by using the geometric method, we prove the unre- solvable ratios on the k-d tree. Further, we analyze and compare the difference in the performance in each potential case generated by these DM-SDH algorithms. Experimental results confirm our analysis and show that the k-d tree structure has better performance in terms of time complexity in all cases. However, our qualitative analysis shows that the Quad-tree (Oct-tree) has an advantage over the k-d tree on aspect of space complexity.

Membrane distillation (MD) is a promising desalination technology which allows to achieve high salt rejection at low energy expenses as compared to conventional desalination processes. However, just like in any other membrane separation process, the MD membrane is susceptible to biofouling which is one of the critical problems in membrane-based systems. In this study, we investigated the effects of spacer design and feed temperature on the biofilm formation and proliferation in a flat-sheet direct contact membrane distillation (DCMD) used for desalination of the Red Sea water. Two types of spacers (Standard & 1-Hole) were designed to evaluate their efficiency in biofouling mitigation at three different feed water temperatures (47 °C, 55 °C and 65 °C). Our results showed that while 1-hole spacer was more efficient in reducing biofouling at 47 °C (permeate flux declines of 73.2% and 79.6% after 5 days of DCMD process using 1-hole and standard spacers, respectively). Standard spacer over-performed at higher feed water temperatures (65.7%, and 75.2% after 5 days of DCMD process at 55 °C and 65 °C, respectively). The Optical Coherence Tomography (OCT) revealed a significant transition of biofilm morphology with increasing feed water temperature for both types of spacers. While thicker and more porous biofouling structures were formed on the surface of MD membrane at 47 °C and 55 °C, thinner non-porous layer prevailed on the membrane surface at a feed water temperature of 65 °C. This observation was supported by direct enumeration of bacterial cells inside the biofilm by flow cytometry which revealed a significant decrease in the total number of cells when the feed water temperature was increased from 55 °C to 65 °C. Moreover, this process was accompanied by the permeate flux decline and increase of coolant water conductivity regardless of the spacer type. The results of our study have shown high rejection of dissolved organic carbon (DOC > 97%) and absence of bacterial contamination of permeate water which is important due to use of microporous polymeric membrane with 0.5 m pore size. The obtained results indicated the importance of operational conditions in controlling the biofouling in the MD system.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22369号 / 医博第4610号 / 新制||医||1043(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 大森 孝一, 教授 富樫 かおり, 教授 山下 潤 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Vernier Tuned Distributed Bragg Reflector (VT-DBR) lasers have had great success in the field of Swept-Source Optical Coherence Tomography (SS-OCT) due to their continuous and nearly 40 nm wavelength tuning range in a single longitudinal mode. Fast sweeps allow for real time imaging with micrometer resolution at a distance of a few centimeters. While this laser has proven quite useful as a medical imaging tool via OCT, it has yet to similarly prove itself for general light detection and ranging (LIDAR) applications due to range limitations that arise from a finite laser coherence length. The goal of this thesis is to explore LIDAR applications for VT-DBR lasers and how to improve VT-DBR performance for LIDAR. In the scope of this work, LIDAR is laser imaging at tens or hundreds of meters with a resolution finer than 10cm. In order to achieve this kind of LIDAR performance with a VT-DBR laser, the laser must have a linewidth less than 1MHz over a tuning range of around 10GHz. This thesis outlines two methods towards this goal. The bulk of this work is dedicated to looking for and characterizing VT-DBR tuning paths with fundamentally narrow linewidth using microampere currents in both forward and reverse bias conditions. The second part of this thesis is a preliminary design of an optical frequency-locked loop to reduce laser phase noise, which subsequently reduces the laser linewidth. By tuning with small currents in the forward bias condition, nearly the entire range of laser wavelengths could be tuned to, but areas of narrow linewidth were both sparse and very sensitive to any change in bias. The reverse bias case showed limited but continuous tuning with increased reverse current magnitude. In this reverse biased photo-detector mode the laser exhibited narrower linewidth less than 15MHz, with the linewidth at intrinsically narrow levels when all three sections reverse biased. Also promising was a subset of reverse bias conditions that only used a variable resistance across a laser section with no externally applied bias. This resistance tuning method gave a tuning range of more than 7GHz while maintaining an intrinsically narrow linewidth. The optical frequency-locked loop was able to achieve DC frequency locking but unable to reduce laser linewidth. More work needs to be done to achieve enough phase noise reduction to see an appreciable reduction in linewidth.

This diploma thesis deals with analysing of modern methods for cell detection, visualization and quantification in 3D space. The first section deals with optical methods for cells detection. There is detailed discussion about cell labeling and detection on confocal microscopy. There is also description about developed algorithm for whole cell volume quantification from microscopy images. This could made a comparsion of fluorescence signal according to time of cell labeling and according to cell shapes. There was also optimalization of handmade tissue phantoms visualization. It could be compared a possibilities of cell detections in these phantoms by confocal microscopy and OCT. It was also implemented algorithm for quantification of cells from OCT images. Besides confocal microscopy and OCT cells are also analyzed by other methods. The last part is the Conclusion of results and comparison of used methods.

C-reactive protein (CRP), a plasma protein of the innate immune system, is produced by hepatocytes. A critical regulatory region (-42 to -57) on the CRP promoter contains binding site for the IL-6-activated transcription factor C/EBPβ. The IL-1β-activated transcription factor NF-κB binds to a κB site located nearby (-63 to -74). The κB site overlaps an octamer motif (-59 to -66) which is the binding site for the constitutively active transcription factor Oct-1. Oct-1 is known to function both as a transcriptional repressor and as an activator depending upon the promoter context. Also, Oct-1 can regulate gene expression either by binding directly to the promoter or by interacting with other transcription factors bound to the promoter. The aim of this study was to investigate the functions of Oct-1 in regulating CRP expression. In luciferase transactivation assays, overexpressed Oct-1 inhibited (IL-6 + IL-1β)-induced CRP expression in Hep3B cells. Deletion of the Oct-1 site from the promoter drastically reduced the cytokine response because the κB site was altered as a consequence of deleting the Oct-1 site. Surprisingly, overexpressed Oct-1 inhibited the residual (IL-6 + IL-1β)-induced CRP expression through the promoter lacking the Oct-1 site. Similarly, deletion of the Oct-1 site reduced the induction of CRP expression in response to overexpressed C/EBPβ, and overexpressed Oct-1 inhibited C/EBPβ-induced CRP expression through the promoter lacking the Oct-1 site. We conclude that Oct-1 acts as a transcriptional repressor of CRP expression and it does so by occupying its cognate site on the promoter and also via other transcription factors by an as yet undefined mechanism.