ABSTRACT TRANSCRIPTION PATTERN COMPARISON OF TWO UBIQUITIN SPECIFIC PROTEASES (USP6 AND USP32) Akhavan Tabasi, Shiva M.Sc., Department of Biology Supervisor: Assist. Prof. Dr. A. Elif Erson August 2007, 93 pages Breast cancer is the most common type of cancer among women worldwide. The incidence of breast cancer is 1 in 8 among women. Usually loss of tumor suppressor genes and overexpression of proto-oncogenes are known to be involved during mammary tumorigenesis. USP32 (Ubiquitin Specific Protease 32) gene is located on chromosomal band 17q23, a region of amplification in breast cancer. Gene amplification is known to be a common mechanism in breast cancer cells, through which proto-oncogenes are overexpressed and contribute to tumor progression. Presence of multiple oncogene candidates on 17q23 requires individual characterization of these genes. USPs (Ubiquitin Specific Protease), have various roles in protein degradation pathways (e.g / by editing the ubiquitin chains, recycling of ubiquitin, v deubiquitinating the target proteins and inhibiting their degradation by the proteasome). Deregulated expression of USPs is likely to interfere with the degradation of many key regulatory proteins in the cell. Therefore, USP32 becomes an interesting oncogene candidate that may have roles in protein degradation pathways based on the fact that it is located on an amplicon region and that it is overexpressed in breast tumors. On the other hand, USP6 (Ubiquitin Specific Protease 6), a known oncogene on 17p13, is also a deubiquitinating enzyme, with conserved histidine and cysteine domains, which are also shared by USP32. Interestingly there is a 97% sequence similarity between bases 3,197 to 7,831 of USP6 and 2,390 to 7,024 of USP32 gene. In this study, we aimed to investigate the expression patterns of USP32 and USP6 (including alternative transcripts) in breast tissue to avoid any possibility of overlapping functions of two enzymes due to their high sequence similarity. In addition, we sub-cloned USP32 gene into TOPO-TA vector, so that further functional studies (e.g / localization and overexpression) can be performed. Further characterizations of Ubiquitin Specific Protease 32, may help us understand its importance in the protein degradation pathway during breast tumorigenesis.

In the laser market, there have been various kinds of lasers designed and utilized for different purposes. As time goes on, their powers have been gradually increased from kilowatts (kW) to terawatts (TW). One of the most famous methods in laser science technology is Chirped Pulse Amplification (CPA) which enables table-top terawatt laser systems. This method provides high output power (tens of TW), very short pulse duration (few tens of femtoseconds) and large energy (mJ) for ultrafast lasers. One of the most well-known ultrafast lasers is Titanium:Sapphire laser. This thesis work concentrates on how delay a pulse generator should work so that Verdi and the oscillator pulse coincide. Moreover, by assembling a terawatt laser system, the most important issues are timing between seed pulse and pump pulse and time delays of all components of this system / autocorrelator, pump source, photodiode, Pockels cell, stretcher and dazzler were examined. This timing and the time delays were separately identified for terawatt laser systems. In this study, the aim is to attain the terawatt level output by arranging pump and seed pulses timing and the time delay on the components of the laser system setup.

In this thesis a single stage detector logarithmic video amplifier is designed with a dynamic range of 40dB in 2-6GHz frequency band. Since the detector logarithmic video amplifier (DLVA) is used to convert the power of the RF signals to video voltages in logarithmic scale, it can be regarded as a logarithmic converter instead of logarithmic amplifier. The design is composed of two main parts: The Schottky diode detector rectifies the incoming RF signal and produces a video voltage and the logarithmic amplifier transforms the scale of the video voltage from linear scale to logarithmic scale in order to observe the RF signals with a wide amplitude range. The approximation of the logarithmic function is obtained by the summation of the output currents of the differential amplifiers operating as logarithmic stages. Offset voltage of the DLVA is minimized in order to obtain maximum sensitivity / this makes the detection of RF signals with low power possible. The study is composed of mainly three parts: First, brief information about logarithmic amplification techniques is given and the circuit architecture is developed for logarithmic amplification and video detection, second these circuits are simulated and finally the design is implemented and tested.

<p>The work presented in this thesis studies the load and loadeffects of traffic loads on railway bridges. The increasedknowledge of the traffic loads, simulated using fieldmeasurements of actual trains, are employed in a reliabilityanalysis in an attempt at upgrading existing railwaybridges.</p><p>The study utilises data from a weigh-in-motion site whichrecords, for each train, the train speed, the loads from eachaxle and the axle spacings. This data of actual trainconfigurations and axle loads are portrayed as moving forcesand then used in computer simulations of trains crossing twodimensional simply supported bridges at constant speed. Onlysingle track short to medium span bridges are considered in thethesis. The studied load effect is the moment at mid-span. Fromthe computer simulations the moment history at mid-span isobtained.</p><p>The load effects are analysed by two methods, the first isthe classical extreme value theory where the load effect ismodelled by the family of distributions called the generalisedextreme value distribution (GEV). The other method adopts thepeaks-over-threshold method (POT) where the limiting family ofdistributions for the heights to peaks-over-threshold is theGeneralised Pareto Distribution (GPD). The two models aregenerally found to be a good representation of the data.</p><p>The load effects modelled by either the GEV or the GPD arethen incorporated into a reliability analysis in order to studythe possibility of raising allowable axle loads on existingSwedish railway bridges. The results of the reliabilityanalysis show that they are sensitive to the estimation of theshape parameter of the GEV or the GPD.</p><p>While the study is limited to the case of the ultimate limitstate where the effects of fatigue are not accounted for, thefindings show that for the studied cases an increase inallowable axle load to 25 tonnes would be acceptable even forbridges built to the standards of 1940 and designed to LoadModel A of that standard. Even an increase to both 27.5 and 30tonnes appears to be possible for certain cases. It is alsoobserved that the short span bridges ofapproximately fourmetres are the most susceptible to a proposed increase inpermissible axle load.</p><p><b>Keywords:</b>bridge, rail, traffic load, load effect,dynamic amplification factor, extreme value theory,peaks-over-threshold, reliability theory, axle loads, fielddata.</p>

<p>This thesis explores the use of engineered nonlinear crystals from the KTiOPO4 (KTP) family as the gain material in optical parametric amplifiers (OPAs), with the aim to achieve more knowledge about the benefits and limitations of these devices. The work aims further at extending the possible applications of OPAs by constructing and investigating several efficient and well performing amplifiers.</p><p>An OPA consists of a strong pump source, which transfers its energy to a weak seed beam while propagating through a nonlinear crystal. The crystals employed in this work are members of the KTP family, which are attractive due to their large nonlinear coefficients, high resistance to damage and wide transparency range. The flexibility of OPAs with respect to different wavelength regions and pulse regimes was examined by employing various dissimilar seed and pump sources.</p><p>The possibility to adapt an OPA to a specific pump and seed wavelength and achieve efficient energy conversion between the beams, originates from quasi-phasematching, which is achieved in periodically poled (PP) nonlinear crystals. Quasi-phasematched samples can be obtained by changing the position of certain atoms in a ferroelectric crystal and thereby reversing the spontaneous polarisation.</p><p>In this thesis several material properties of PP crystals from the KTP family were examined. The wavelength and temperature dispersion of the refractive index were determined for PP RbTiOPO4, which is essential for future use of this material. Another experiment helped to increase the insight into the volumes close to domain walls in PP crystals</p><p>Further, several OPAs were built and their ability to efficiently amplify the seed beam without changing its spectral or spatial properties was studied. Small signal gains of up to 55 dB and conversion efficiencies of more than 35 % were achieved for single pass arrangements employing 8 mm long PPKTP crystals. Apart from constructing three setups, which generated powerful nanosecond, picosecond and femtosecond pulses, the possibility to amplify broadband signals was investigated. An increase of the OPA bandwidth by a factor of approximately three was achieved in a noncollinear configuration.</p>

Thesis (M. Med. Sc.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 35-42).

This thesis describes the study of the thermal response of the pyroelectric material named lithium tantalate or LT (LiTaO3) in aid of this material's possible use for temperature measurement. The temperature range studied was between 5-99oC. The sensor was excited using a silicon rubber heater. The lithium tantalate sensor and the rubber heater were enclosed such that the temperature would reach steady state faster. The enclosure was a small insulated box in order to reduce any extraneous effects on the sensor. The output signal of the lithium tantalate sensor was then amplified by using four different amplifying circuits and the voltage output was studied. The amplifying circuits included Current Mode, double Current Mode, Voltage Mode, and a modified Wien Oscillator. Results demonstrated linear dependencies of the voltage output as a function of temperature for the Voltage Mode and the modified Wien Oscillator. Using the modified Wien Oscillator amplifying circuit the slope of the line a 2.1mV/oC and for the Voltage Mode the slope was 1mV/oC. For both cases it was found that the range for the standard deviation of the measurements was 0.5< The data showed that the lithium tantalate sensor could be used as a temperature measuring device for the range mentioned above. The resolution of the data is high enough to be able to be detected with modern measuring devices and the standard deviation is low enough to allow for such measurements. Moreover, the linear dependence of the data allows for accurate measurements at each temperature within the range.

Over one million acres of land and water in Florida has been classified as impaired by mercury. Approximately 80% of national fish advisories are issued due to mercury contamination. There have been a number of consumption advisories in the Tampa Bay Region for locally eaten fish such as largemouth bass ( Micropterus salmoides), bowfin (Amia calva), and alligator gar (Lepisosteus osseus). The main purpose of this study was to determine if there is adequate dissemination of mercury related risk information by government agencies to recreational and subsistence fishermen in the Tampa Bay Region. This research revealed that government agencies utilized simplified models when addressing mercury consumption risks in Tampa Bay. Most of the popular fishing sites and public parks in the Tampa Bay Region have no advisory signs warning fishers of possible mercury contamination in fish. The majority of survey respondents (88.4%) consumed the fish they caught. There was statistically significant evidence suggesting online sources of public health information influenced viewing of fish advisories. This study determined factors: sex of licensee, above median levels of income and type of license also influenced viewing of fish advisories. Results indicated that women were less likely to view fish advisories than men. In addition, the viewing of fish advisory information by women of reproductive age was not significantly different to all other female age groups. Behavior among participants varied and was dependent on individual perception of mercury risks and nutritional benefits associated with consumption of fish.

Over the years, considerable research has been done showing the advantages of early identification of hearing loss and its impact on children in developing speech and language skills. Although the universal early hearing detection and intervention (EHDI) program is fully functional in developed countries it has not been actualized in developing global regions like Asia, Africa and Latin America. The primary reason could be precise government policies and the necessary funds to support them. There is also a lack of awareness and initiative form the parent's side. The purpose of this paper is to describe and support the need for a universal early detection of hearing loss and intervention program in India. Objectives for developing a universal early identification and intervention program and the recommendations for actualizing them have been included. / text

published_or_final_version / Pathology / Master / Master of Medical Sciences