There is a large amount of geotechnical data. By putting it into a database, it can be applied to design reliable offshore foundations. The goal of this research is to improve the efficiency and transparency of the implementation of the previously developed reliability-based framework to streamline the process for analyzing and developing an offshore site in the Gulf of Mexico by looking at spatial variations among data sets. This thesis documents how to store soil behavior information in the database and how to use that information for offshore foundation design. The process is illustrated through observing the steps with figures provided directly from the database so the user can more readily use the database to produce results. This makes the database more transparent for the user to follow the flow of information from input to analysis and to follow the calculation process as well. Enhancements were also made to the database to provide a more readily accessible interface. There is now an allowance of data to streamline the data input process. There is also a set amount of fifty data points to be used in each spatially conditioned analysis. These detailed explanations and consistencies in data collection help the user to understand the models. This database provides a synthetic image of the site using both physical and statistical parameters where there might not be exact data at a desired foundation location. By providing the industry with a database that uses reliability-based design from actual data and spatial variation analysis, this project will continue to provide a more efficient design process. / text

Radiofrequency ablation (RFA) is a clinic tool for the treatment of various target tissues. However, one of the major limitations with RFA is the ‘small’ size of target tissues that can be effectively ablated. By small it is meant the size of the target tissue is less than 3 cm in diameter of the tissue otherwise ‘large’ size of tissue in this thesis. A typical problem with RFA for large target tissue is the incompleteness of tumour ablation, which is an important reason for tumour recurring. It is widely agreed that two reasons are responsible for the tumour recurring: (1) the tissue charring and (2) the ‘heat-sink’ effect of large blood vessels (i.e. ≥3 mm in diameter). This thesis study was motivated to more quantitatively understand tissue charring during the RFA procedure and to develop solutions to increase the size of target tissues to be ablated. The thesis study mainly performed three tasks: (1) evaluation of the existing devices and protocols to give a clear understanding of the state of arts of RFA devices in clinic, (2) development of an accurate mathematical model for the RFA procedure to enable a more quantitative understanding of the small target tissue size problem, and (3) development of a new protocol based on the existing device to increase the size of target tissues to be ablated based on the knowledge acquired from (1) and (2). In (1), a design theory called axiomatic design theory (ADT) was applied in order to make the evaluation more objective. In (2), a two-compartment finite element model was developed and verified with in vitro experiments, where liver tissue was taken and a custom-made RFA system was employed; after that, three most commonly used internally cooled RFA systems (constant, pulsed, and temperature-controlled) were employed to demonstrate the maximum size of tumour that can be ablated. In (3) a novel feedback temperature-controlled RFA protocol was proposed to overcome the small target tissue size problem, which includes (a) the judicious selection of control areas and target control temperatures and (b) the use of the tissue temperature instead of electrode tip temperature as a feedback for control. The conclusions that can be drawn from this thesis are given as follows: (1) the decoupled design in the current RFA systems can be a critical reason for the incomplete target tissue necrosis (TTN), (2) using both the constant RFA and pulsed RFA, the largest TTN can be achieved at the maximum voltage applied (MVA) without the roll-off occurrence. Furthermore, the largest TTN sizes for both constant RFA and pulsed RFA are all less than 3 cm in diameter, (3) for target tissues of different sizes, the MVA without the roll-off occurrence is different and it decreases with increase of the target tissue size, (4) the largest TTN achieved by using temperature-controlled RFA under the current commercial protocol is still smaller 3 cm in diameter, and (5) the TTN with and over 3 cm in diameter can be obtained by using temperature-controlled RFA under a new protocol developed in this thesis study, in which the temperature of target tissue around the middle part of electrode is controlled at 90 ℃ for a standard ablation time (i.e. 720 s). There are a couple of contributions with this thesis. First, the underlying reason of the incomplete TTN of the current commercially available RFA systems was found, which is their inadequate design (i.e. decoupled design). This will help to give a guideline in RFA device design or improvement in the future. Second, the thesis has mathematically proved the empirical conclusion in clinic that the limit size of target tissue using the current RFA systems is 3 cm in diameter. This has advanced our understanding of the limit of the RFA technology in general. Third, the novel protocol proposed by the thesis is promising to increase the size of TTN with RFA technology by about 30%. The new protocol also reveals a very complex thermal control problem in the context of human tissues, and solving this problem effectively gives implication to similar problems in other thermal-based tumour ablation processes.

Micro-Doppler is defined as scattering produced by non-rigid-body motion. This dissertation involves the design of a multiple frequency continuous wave (MFCW) radar for micro-Doppler research and detection and classification algorithm design. First, sensor hardware is developed and tested. Various design tradeoffs are considered, with the application of micro-Doppler based detection and classification in mind. A diverse database of MFCW radar micro-Doppler signatures was collected for this dissertation. The micro-Doppler signature database includes experimental data from human, vehicle, and animal targets. Signatures are acquired from targets with varying ranges, velocities, approach angles, and postures. The database is analyzed for micro-Doppler content with a focus on its application to target classification. Joint time-frequency detection algorithms are developed to improve detection performance by exploiting noise-spreading and the micro-Doppler phenomenon. Following detection algorithm development, this dissertation covers the design of micro- Doppler feature extraction, feature selection, and classification algorithms. Feature selection is performed automatically via a Fisher score initialized sequential backward selection algorithm. Classification is performed using two distinct approaches: a generative statistical classification algorithm based on Gaussian mixture models (GMMs) and a discriminative statistical classification algorithm based on support vector machines (SVMs). Classifier performance is analyzed in detail on a micro-Doppler signature database acquired over a three-year period. Both the SVM and GMM classifiers perform well on the radar target classification task (high accuracy, low nuisance alarm probability, high F-measure, etc.). The performance of both classifiers is remarkably similar, and neither algorithm dominates the other in any performance metric when using the chosen feature set. (However, the difference between SVM and GMM classification accuracy becomes statistically significant when many redundant features are present in the feature set.) The accuracy of both classifiers is shown to vary as a function of approach angle, which physically corresponds to the angular dependence of micro-Doppler. The results suggest that overall classifier performance is more sensitive to feature selection than classifier selection (with GMM being more sensitive to redundant features than SVM). Both classifiers are robust enough to handle human targets attempting to evade detection by either army crawling or hands-and-knees crawling. / text

Repair of DNA double-strand breaks is critical to the maintenance of genomic stability, and failure to repair these DNA lesions can cause loss of chromosome telomeric regions, complex translocations, or cell death. In humans this can lead to severe developmental abnormalities and cancer. A central pathway for double-strand break repair is homologous recombination (HR), a mechanism that operates during the S and G2 phases of the cell cycle and primarily utilizes the replicated sister chromatid as a template for repair. Most knowledge of HR is derived from work carried out in prokaryotic and eukaryotic model organisms. To probe the HR pathway in human cells, we performed a genome-wide siRNA-based screen; and through this screen, we uncovered cellular functions required for HR and identified proteins that localize to sites of DNA damage. Among positive regulators of HR, we identified networks of pre-mRNA-processing factors and canonical DNA damage response effectors. Within the former, we found RBMX, a heterogeneous nuclear ribonucleoprotein (hnRNP) that associates with the spliceosome, binds RNA, and influences alternative splicing. We found that RBMX is required for cellular resistance to genotoxic stress, accumulates at sites of DNA damage in a poly(ADP-ribose) polymerase 1-dependent manner and through multiple domains, and promotes HR by facilitating proper BRCA2 expression. Screen data also revealed that the mammalian recombinase RAD51 is commonly off-targeted by siRNAs, presenting a cautionary note to those studying HR with RNAi and highlighting the vulnerability of RNAi screens to off-target effects in general. Candidate validation through secondary screening with independent reagents successfully circumvented the effects of off-targeting and set a new standard for reagent redundancy in RNAi screens.

The concept driver distraction is diffuse and no clear definition exists, which causes troubles when it comes to driver attention monitoring. This thesis takes an approach where eyetracking data from experienced drivers along with radar data has been used and analysed in an attempt to set up adaptive rules of how and how often the driver needs to attend to different objects in its surroundings, which circumvents the issue of not having a clear definition of driver distraction. In order to do this, a target tracking algorithm has been implemented that refines the output from the radar, subsequently used together with the eye-tracking data to in a statistical manner, in the long term, try to answer the question for how long is the driver allowed to look away in different driving scenarios? The thesis presents a proof of concept of this approach, and the results look promising.

No description available.

We determined whether children older than 1 year from non-western immigrant families had lower serum 25-hydroxyvitamin D levels than children from western born families. Children ages 1-6 years were recruited through the TARGet Kids! practice based research network. Univariable analysis revealed that non-western immigrant children had 4 nmol/L lower 25-hydroxyvitamin D (p=0.006; 95% CI:1.4-8.0) and increased odds of 25-hydroxyvitamin D <50 nmol/L (OR 1.9, 95% CI:1.3–2.9). After adjustment for known vitamin D determinants, cow’s milk intake, vitamin D supplements, season and age were significant covariates and current vitamin D supplementation had the strongest confounding effect. In order to use the ethnicity variable, we developed a new standardized geographically based closed-ended ethnicity question, which was a practical alternative to the widely used open-ended ethnicity questions. There was an association between non-western immigration and lower 25-hydroxyvitamin D in early childhood and this appears primarily related to known vitamin D determinants.

We determined whether children older than 1 year from non-western immigrant families had lower serum 25-hydroxyvitamin D levels than children from western born families. Children ages 1-6 years were recruited through the TARGet Kids! practice based research network. Univariable analysis revealed that non-western immigrant children had 4 nmol/L lower 25-hydroxyvitamin D (p=0.006; 95% CI:1.4-8.0) and increased odds of 25-hydroxyvitamin D <50 nmol/L (OR 1.9, 95% CI:1.3–2.9). After adjustment for known vitamin D determinants, cow’s milk intake, vitamin D supplements, season and age were significant covariates and current vitamin D supplementation had the strongest confounding effect. In order to use the ethnicity variable, we developed a new standardized geographically based closed-ended ethnicity question, which was a practical alternative to the widely used open-ended ethnicity questions. There was an association between non-western immigration and lower 25-hydroxyvitamin D in early childhood and this appears primarily related to known vitamin D determinants.

Introduction A new high current (up to 50 kW) solid target irradiation system is being built. While retaining the same beam power capability of the previous target generation, the system is a totally new design with many improvements, simplified constriction, more reliable operation and a novel approach to target handling, beam collimation and beam diagnostic. Unlike the previous, three-part soldered target, the new target is fabricated from a single piece of metal. Material and Methods The target (or rather the target-material holder) is a single metal plate (usually copper or silver) incorporating the seals and the cooling channels (FIG. 1). The target is placed in the beam at 7°. Depending on target material and coolant flow the target can handle beam powers up to 50 kW (FIG. 2). Target transfer (utilizing a special shuttle) is pneumatic. Part of the transfer pipe is shown above the target station. Except the target o-rings (a part of each target) there are no elastomer seals in the system; all is of soldered/welded construction and metal seals. Sectional view (FIG. 3.) shows that target in place in the chamber. The target and the chamber are electrically insulated from the rest of the system, thus forming a Faraday cup for accurate current measurement. The collimator is formed of a two part silver casting. It is designed to handle up to 10 kW of beam power. Four-sector silver mask in front of the collimator allows precise beam cantering. The collimator parts were cast using 3D printed wax patterns. This allowed to create a complex pattern of cooling channels that are difficult to produce by machining (FIG. 4.) All the actions of target shuttle landing and the target placing are performed by three air cylinders. All three are fitted with Vespel SP22 (Du Pond) seals. Unlike previous systems that used mechanical grabbers to manipulate the target, low vacuum is employed to hold the target during removal from the shuttle and placing in the irradiation chamber. This greatly simplifies the operation and is more reliable. The pneumatic transfer system is using two vacuum producer to transfer the target shuttle between the target station and the hotcell. Both landing terminals in the target station and hotcell, as well as the transfer line itself, are under negative pressure preventing any spread of contamination. The hotcell landing terminal incorporates a fully automatic target-material dissolution system. After landing, the target is removed from the shuttle and the active face pressed against a reaction vessel where the dissolution takes place (FIG. 5.) All the functions of target transfer, placing and manipulations are controlled by a simple PLC (FMD88-10 PLC, Triangle Research) Results and Conclusion While intended mostly for cladding with metallic target materials, a special version of the target was designed to handle salts or oxides that can be fused and retained in grooves on the target face (FIG. 6.) Despite the poor thermal conduc-tivity of most of those materials, this target can handle high beam currents. FIGURE 7 shows a thermal modelling of the cen-tral 10×25 mm segment of the target (highest heat flux region under a Gaussian beam). Copper target with rubidium chloride fused in 0.8 mm wide and 1.7 mm deep grooves and spaced by 0.5 mm (60% coverage). Beam of 70 MeV energy and 400 μA intensity is collimated 20 % (320 μA on target). Cooling-water flow is set to 25 l/min. Cladding the target face with a thin metallic layer can help containing the target material. This process is currently under development. Most aspects of the system operation and con-striction were successfully used in the previous “generations” of targets in the last 30 years. The new system will provide improved performance with a simpler and more reliable design, lower maintenance and lower consumables cost. FIGURE 8 shows the “4th generation” system and target (2005). Dozens variants of this design are in use all over the world.

Introduction Krypton-81m is a radioactive gas with a half-life of 13 s, and found to be useful in many applications in nuclear medicine, particularly for lung perfusion studies and ventilations. Due to high demands for 81mKr, we have developed an automated Krypton system to be installed in one of the Cyclotron’s beamlines at King Faisal Specialist Hospital and Research Centre (KFSH&RC) and to deliver large activity of the radioactive gas. Material and Methods The effective cross section of producing 81Rb is between 15 and 30 MeV [1]. Therefore, range and stopping power of the effective cross section were calculated with respect to gas density of 0.0185 g/cm3. This value is equivalent to gas density at 5.0 bars at room temperature. SRIM calculations resulted in a range of 589 mm. However, due to limitation in fabricating such long target chamber, the target length is chosen to be 250 mm. Attached to the end of target body is a special water circulating flange ‘back-pool’, its purpose is to absorb the rest of the energy and protons Bragg peak. The target body is made of Aluminum with the inner part being electroplated with nickel. The target body is of conical shape. The target body is electrically isolated from other parts to allow accurate beam current reading. Full access to the target loading/unloading steps is made through touch screen technology (FIG. 2) for user access. Additionally, the target control system is designed to be protected through chain of interlock steps. The production cycle of 81Rb is explained as follow. Target is evacuated to approximately 10−3 mbar before being filled with natKr at pressure of 5 bars. At the end of bombardment, recovery of natKr is done via cryogenic vessel. Finally, the radioactivity is washed with KCl and pushed to Hotcells through the nitrogen gas for chemistry processing. Irradiation time was approximately 30 min. Results and Conclusion Experimental results clearly showed a fairly good activity of 81mKr as shown in TABLE 1. In all experiments, the radionuclidic purity of 81mKr was above 99.59%. 79mKr and 79Kr were also measured with a percentage of, respectively, 0.34 and 0.07 %. Special attention has to be drawn to last experiment where the yield significantly in-creased, due to the period where the KCl left inside the target (10 min) before pushing the solution to the Hotcells