AUM QASR VALLEY ENVIRONMENTAL REHABILITATION PROJECT: A CONNECTION TO AN ELEVATED URBAN FABRIC

Natural drainages systems are known to be important areas for recreational uses and ecosystem productivity. However, they can cause significant problems such as poor water quality and soil contamination if they are left degraded and unproductive. It has been shown globally that such areas near development can bring various advantages to human interaction with the landscape and enhancing the quality of natural habitat, when rehabilitated. Valleys in the city of Riyadh have undergone dramatic degradation with a continuous uncontrolled exploitation. Environmental rehabilitation strategies have been established by local agencies to bring back such degraded areas to serve the city drainage system and community livability. The main focus of this project is to involve landscape architecture planning and greenways techniques to create a master plan that interprets convenient rehabilitation solutions to the site conditions and habitat. Establishing an informed master plan is intended to connect people with their adjacent valley, create a sense of place, and improve the natural valley appearance.This item is part of the College of Architecture, Planning, and Landscape Architecture Master's Theses and Reports collections. For more information about items in this collection, please contact the UA Campus Repository at [email protected]

A Cyclic Universe With Varying Cosmological Constant in f(R,T)f(R,T) gravity

A new kind of evolution for cyclic models in which the Hubble parameter oscillates and keeps positive has been explored in a specific $f(R,T)$ gravity reconstruction. A singularity-free cyclic universe with negative varying cosmological constant has been obtained which supports the role suggested for negative $\Lambda$ in stopping the eternal acceleration. The cosmological solutions have been obtained for the case of a flat universe, supported by observations. The cosmic pressure grows without singular values, it is positive during the early-time decelerated expansion and negative during the late-time accelerating epoch. The time varying EoS parameter $\omega(t)$ shows a quintom behavior and is restricted to the range $-2.25 \leq \omega(t) \lesssim \frac{1}{3}$. The validity of the classical linear energy conditions and the sound speed causality condition has been studied. The non-conventional mechanism of negative cosmological constant that are expected to address the late-time acceleration has been discussed.Comment: 15 pages, 10 figure

Neural Correlates of Gain Control in Drosophila and Humans

Previous research has shown that visual sensitivity in human epilepsy patients is abnormal – characterized by increased responses at high contrast levels. These abnormalities have been linked to changes in neuronal gain control. Using animal models to study these changes is a useful approach. In this thesis, we used a steady-state visually evoked potential (SSVEP) technique similar to that used in humans to study photoreceptor-level and neuronal gain control in wild type (w-) Drosophila across a range of ages. We then compared these responses to those obtained from Drosophila carrying the kcc potassium channel mutation that renders young flies susceptible to light and shock-induced seizures. By taking into account the age and temperature dependence of the mutant (kccDHS1) flies, we were able to identify increased neural activity that recovers to the normal profile as they get older. We also found that these kccDHS1 flies are hypersensitive to light, particularly when young. These two findings are consistent with the fact that the level of the KCC protein increases with age. In addition, we found that kccDHS1 flies generate high frequency oscillations in their ERGs in response (50 – 100 Hz) to abrupt light onsets and offsets – a phenomenon that might be linked to abnormal changes in the gain control of neuronal feedback circuits. Studying visual abnormalities in Drosophila can reveal important information but eventually we need to link any visual abnormalities observed in animal models to humans. We therefore, attempted to measure subtle changes in gain control in humans due to adaptation, and at the same time make use of the human mental ability to measure another measure of gain control, attention, using an fMRI technique. Although our data did not show any interaction between adaptation and attention, it suggests that attention in early visual pathways largely affects the level of suppression in non-stimulated regions around the adaptor rather than responses to the probe itself. This is a manipulation that links to our work on adaptation in Drosophila in Chapter 6. Overall, the results presented in this thesis showed that fly models of epilepsy can be useful for studying changes in visual gain control, and showed that this work might be extended to humans

Reconnection of superfluid vortex bundles

Using the vortex filament model and the Gross Pitaevskii nonlinear Schroedinger equation, we show that bundles of quantised vortex lines in helium II are structurally robust and can reconnect with each other maintaining their identity. We discuss vortex stretching in superfluid turbulence and show that, during the bundle reconnection process, Kelvin waves of large amplitude are generated, in agreement with the finding that helicity is produced by nearly singular vortex interactions in classical Euler flows.Comment: 10 pages, 7 figure

Optimized Load Balancing based Task Scheduling in Cloud Environment

The fundamental issue of Task scheduling is one important factor to load balance between the virtual machines in a Cloud Computing network. However, the optimal broadcast methods which have been proposed so far focus only on cluster or grid environment. In this paper, task scheduling strategy based on load balancing Quantum Particles Swarm algorithm (BLQPSO) was proposed. The fitness function based minimizing the makespan and data transmission cost. In addition, the salient feature of this algorithm is to optimize node available throughput dynamically using MatLab10A software. Furthermore, the performance of proposed algorithm had been compared with existing PSO and shows their effectiveness in balancing the load

Kinetic energy of vortex knots and unknots

New results on the kinetic energy of ideal vortex filaments in the shape of torus knots and unknots are presented. These knots are given by small-amplitude torus knot solutions (Ricca, 1993) to the Localized Induction Approximation (LIA) law. The kinetic energy of different knot and unknot types is calculated and presented for comparison. These results provide new information on relationships between geometry, topology and dynamics of complex vortex systems and help to establish possible connections between aspects of structural complexity of dynamical systems and vortical flows.Comment: 14 pages, 5 figure

Monitoring Moving Queries inside a Safe Region

With mobile moving range queries, there is a need to recalculate the relevant surrounding objects of interest whenever the query moves. Therefore, monitoring the moving query is very costly. The safe region is one method that has been proposed to minimise the communication and computation cost of continuously monitoring a moving range query. Inside the safe region the set of objects of interest to the query do not change; thus there is no need to update the query while it is inside its safe region. However, when the query leaves its safe region the mobile device has to reevaluate the query, necessitating communication with the server. Knowing when and where the mobile device will leave a safe region is widely known as a difficult problem. To solve this problem, we propose a novel method to monitor the position of the query over time using a linear function based on the direction of the query obtained by periodic monitoring of its position. Periodic monitoring ensures that the query is aware of its location all the time. This method reduces the costs associated with communications in client-server architecture. Computational results show that our method is successful in handling moving query patterns

Effect of Gallium-68 isotope injection on hemoglobin derivatives concentrations after instant injection and its recovery in male rabbits (Oryctolagus cuniculus)

Oxidizing effects of ionizing radiation are well established and almost understood. However, exposure to low doses of widely used isotopes may result in minor and hidden oxidative stress in some forms of hemoglobin. This formation alteration regarding the legends of hemoglobin's stereochemical function may play a role in hemoglobin dysfunction. There are limited studies related to the effect of gallium isotope injections.  The study intends to find the effect of gallium-68 isotope injection on male rabbits. It was conducted on thirty-two male rabbits (Orycytolagus cuniculus) divided into Group I: control and Group II: animals exposed to gallium-68 isotope at a similar dose commonly used in diagnostic protocols for humans. Blood samples were collected twice: the first was after two hours of injection with isotopes and the second was after twelve hours of injection. A linear, four-mathematical-equations matrix based on the Lamber-Beer law was used to measure the concentration of different hemoglobin derivatives. Results revealed a significant elevation (P<0.05) of methemoglobin, the oxidized form of hemoglobin, two hours after injection (Total hemoglobin = 4.463 ± 0.83), but this effect was completely reversed after twelve hours. This concluded that even low doses of isotopes result in oxidation of hemoglobin that recovers shortly. Furthermore, the outcome of the study supports the healthcare centres to understand the effect of gallium-68 injections on animals.