The high affinity, selective dopamine transporter ligand GBR 12909 has served as a template for the design of two novel classes of dopamine transporter ligands. A series of 3-[2- (diarylmethoxyethyidenyl)]-N-substituted tropane derivatives were synthesized and the binding affinities of these compounds were determined at the dopamine (DAT), serotonin (SERT) and norepinephrine (NET) transporters in rat brain tissue preparations. The tropane derivatives were found to exhibit more potent affinity and selectivity for DAT than GBR 12909. From the SAR of the tropane analogues and GBR 12909, a novel series of 3-[2-(diarylmethoxyethylidenyl)]-Nsubstituted azetidine derivatives has been developed.

BACKGROUND: Bone decortication is essential to activate bone based on the Regional Acceleratory Phenomenon (RAP), a post-injury transient bone remodeling phenomenon. The Piezoelectric knife with low ultrasonic frequency has been shown to cut bone with minimal invasive effect on soft tissues, less inflammatory response compared to conventional Bur that causes trauma leading to excessive inflammation. Previous studies have shown that using graft materials for Guided Bone Regeneration (GBR) had a significant beneficial effect on the healing process and the thickness of new bone formation. This study hypothesized that the piezoelectric knife would create a better tissue response to different graft materials compared to conventional carbide bur with grafts or the graft alone. MATERIAL & METHOD: Eighteen 9-10 week male Sprague-Dawley rats (300-350g) were purchased from Charles River Laboratories. This study was approved by Boston Medical Center Institutional Animal Care and Use Committee. The piezoelectric knife (BS1 insert) of the Piezotome 2 (Acteon) was used for deep decortication and compared to a conventional carbide osteotomy bur (#1/2) with Mucograft (Geistlich) or OsteoGen (Impladent, Ltd) graft materials, Onlay graft material alone served as a control. Digital dentistry using Cone Beam Computed Tomography (CBCT) located and allowed precise cut of the area of interest without detached the surrounding soft tissue. Tissues collected from day 7 and day 28 were sectioned and stained with Hematoxylin/Eosin or Masson trichome stains. RESULTS: The Cone Beam Computed Tomography (CBCT) scans significantly increased the success rate in locating and cutting the area of interest. Hematoxylin & Eosin staining showed on day 7 that piezoelectric knife activated a broad bone response and less inflammatory response. While recruiting and enlarging chondrocytes to the Mucograft area which will turn to new bone. The use of OsteoGen combined with a piezoelectric knife resulted in thickening in the cortical bone around and above the defect area. CONCLUSION: Piezoelectric knife with Mucograft healed faster compared to bur or graft alone. The piezoelectric knife resulted in significantly increased bone thickness when combined with OsteoGen.

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The evolution of 3G systems has contributed to a significant amount of progress towards 4th generation wireless technology, Long Term Evolution (LTE). On the other hand, demand for more bandwidth has been evidenced by the ever growing usage of real-time application such as video conference. For instance, users tend to have reliable and efficient connection when they are on the go maintaining the minimum quality of the video conference. In order to meet these challenges, QoS of LTE makes it an ideal solution. A simplified IP-based system architecture and introduction of Orthogonal Frequency Division Multiplexing (OFDM) have made LTE possible to satisfy its promise targets. In addition, LTE capabilities are further improved with enhanced Quality of Service (QoS) support for multiple data services, such as voice and other multimedia applications. LTE packet scheduling plays an essential role as part of LTE's Radio Resource Management (RRM) to enhance the system's data rate and to support the diverse QoS requirements of mobile services. LTE packet scheduler should intelligently allocate radio resources to mobile User Equipment’s (UEs) such that the LTE network adheres to its performance requirements. In our thesis work, we conduct a comprehensive performance evaluation of LTE scheduling algorithms for real-time application such as video conferencing traffic. The evaluation is carried out using the OPNET simulator. In order to analyze the performance LTE scheduling algorithm, our analysis involved with LTE Admission Control is two fold. First, 6 scenarios have been modeled in way that 3 of 6 scenarios deals with no LTE admission control techniques applied in the proposed network models while other 3 scenarios deals with LTE scheduling techniques applied. Secondly, video conferencing sessions are configured between two LTE cells with same number of UEs in which all UEs under each cell in the entire proposed network modeling scenarios. In order to make our evaluation more realistic we have applied various network loads so that we can observe how LTE scheduling techniques work its best in the case of highly loaded network. Our simulation results show that video conferencing node with the highest priority maintains tolerable delay and loss while nodes without scheduling techniques experience worst performance.

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No description available.

Gamma-ray burst light curves are notoriously irregular, yet a significant number consists of a single fast-rising, exponentially decaying pulse. These are called single-peaked light curves. The goal of this thesis is to analyse a sample of 2710 GRBs collected by the Fermi space telescope by identifying single-peaked bursts and comparing their properties to those of the multi-peaked bursts. Furthermore, the validity of the relativistic shock breakout theory as an explanation for single-peaked, low-luminosity GRBs is investigated using a closure relation. For this investigation, the Fermi sample wascomplemented by low-luminosity GRBs observed by other instruments. A criterion for selecting single-peaked bursts was successfully developed, yielding 48% long and 79% short, single-peaked GRBs. Significant differences between the populations were found in multiple properties. In general, single-peaked GRBs appear to be weaker and more slowly varying than multi-peaked ones; however, a larger sample of GRBs with redshift measurements is needed to draw conclusions about possible intrinsic differences in energy connected to the progenitor systems. The investigation of low-luminosity GRBs’ compliance with the shock breakout closure relation showed that 64% of the low-luminosity GRBs were within a factor 5 of fulfilling the relation as opposed to only 24% of high-luminosity GRBs. It was further shown that only a small number (< 5%) of Fermi GRBs without redshift measurements could be low-luminosity shock breakout GRBs according to this theory. In conclusion, while the shock breakout closure relation does hold for a greater proportion of low-luminosity GRBs than high-luminosity GRBs, there is still a large number of low-luminosity GRBs left unexplained by this theory. / Gammablixtljuskurvor är ökänt oregelbundna men en betydande andel består av en enda snabbt stigande och exponentiellt avtagande puls. Dessa kallas singelpeakade ljuskurvor. Målet med detta examensarbete är att analysera de 2710 gammablixtar som Fermirymdteleskopet har observerat genom att identifiera singelpeakade blixtar och jämföra deras egenskaper med multipeakade blixtars. Dessutom undersöks den relativistiska shockbreakoutteorin som förklaringsmodell för singelpeakade lågluminositetsgammablixtar. I denna undersökning kompletterades fermiblixtarna med lågluminositetsblixtar från andra instrument. Ett kriterium för identifikation av singelpeakade gammablixtar utvecklades och detta resulterade i 48% långa och 70% korta, singelpeakade gammablixtar. Flertalet egenskaper uppvisade signifikanta skillnader mellan populationerna. I allmänhet verkar singelpeakade gammablixtar vara svagare och variera långsammare än multipeakade. Dock behövs en större population av gammablixtar med uppmätta rödskift för att med säkerhet kunna avgöra om singelpeakade blixtar verkligen släpper ut mindre energi. Undersökningen av huruvida lågluminositetsgammablixtar kan förklaras med shockbreakoutteorin visade att 64% av lågluminositetsblixtarna uppfyllde kravet upp till en faktor fem medan bara 24% av högluminositetsblixtarna gjorde det. Vidare visades att endast ett litet antal (<5%) av fermiblixtarna utan uppmätta rödskift skulle kunna vara lågluminositetsshockbreakoutblixtar enligt denna teori. Även om shockbreakoutteorin kan förklara en större andel av lågluminositetsblixtarna än högluminositetsblixtarna återstår ett stort antal oförklarade lågluminositetsblixtar.

Mobile data usage has been on the rise in relation to the streaming media such as video conferencing and online multimedia gaming. As a result, Long-Term Evolution (LTE) has earned a rapid rise in popularity during the past few years. The aim of this master’s thesis is to analyze the quality of service (QoS) performance and its effects when video is streamed over a GBR (Guaranteed bit rate) and non-GBR bearers over LTE. Using OPNET (Optimized Network Engineering Tool), the performance can be simulated having Downlink (DL) and Uplink (UL) scenarios for video conferencing including web traffic. Further we also measured the performance of packet End-to-End (E2E) delay, packet loss and packet delay variation (PDV). This thesis work is an empirical work, which can be followed up by further research propositions.

In this thesis, we investigate the formulation, optimization and ambiguities in single-image 3D surface reconstruction from geometric and photometric constraints. We examine linear, discrete and quadratic constraints for shape from planar curves, shape from texture, and shape from shading. The problem of recovering 3D shape from the projection of planar curves on a surface is strongly motivated by perception studies. Applications include single-view modeling and uncalibrated structured light. When the curves intersect, the problem leads to a linear system for which a direct least-squares method is sensitive to noise. We derive a more stable solution and show examples where the same method produces plausible surfaces from the projection of parallel (non-intersecting) planar cross sections. The problem of reconstructing a smooth surface under constraints that have discrete ambiguities arise in areas such as shape from texture, shape from shading, photometric stereo and shape from defocus. While the problem is computationally hard, heuristics based on semidefinite programming may reveal the shape of the surface. Finally, we examine the shape from shading problem without boundary conditions as a polynomial system. This formulation allows, in generic cases, a complete solution for ideal polyhedral objects. For the general case we propose a semidefinite programming relaxation procedure, and an exact line search iterative procedure with a new smoothness term that favors folds at edges. We use this numerical technique to inspect shading ambiguities.

In this thesis, we investigate the formulation, optimization and ambiguities in single-image 3D surface reconstruction from geometric and photometric constraints. We examine linear, discrete and quadratic constraints for shape from planar curves, shape from texture, and shape from shading. The problem of recovering 3D shape from the projection of planar curves on a surface is strongly motivated by perception studies. Applications include single-view modeling and uncalibrated structured light. When the curves intersect, the problem leads to a linear system for which a direct least-squares method is sensitive to noise. We derive a more stable solution and show examples where the same method produces plausible surfaces from the projection of parallel (non-intersecting) planar cross sections. The problem of reconstructing a smooth surface under constraints that have discrete ambiguities arise in areas such as shape from texture, shape from shading, photometric stereo and shape from defocus. While the problem is computationally hard, heuristics based on semidefinite programming may reveal the shape of the surface. Finally, we examine the shape from shading problem without boundary conditions as a polynomial system. This formulation allows, in generic cases, a complete solution for ideal polyhedral objects. For the general case we propose a semidefinite programming relaxation procedure, and an exact line search iterative procedure with a new smoothness term that favors folds at edges. We use this numerical technique to inspect shading ambiguities.