<p>Environmental exposure to lead (Pb) and cannabis use are two of the largest public health issues facing modern society in the United States and around the world. Exposure to Pb in early life has been unequivocally shown to have negative impacts on development, and recent research is mounting showing that it may also predispose individuals for risk of developing substance use disorders (SUD). At the same time, societal and legal attitudes towards cannabis (main psychoactive component delta-9-tetrahydrocannabinol) have been shifting, and many American states have legalized the recreational use of cannabis. It is also the 3^rdmost widely used drug of abuse in the US, and rates of cannabis use disorder are on the rise. This thesis sets out to establish whether there is a link between early life Pbexposure and later THC-related behavior in C57BL6/J mice, as has been demonstrated for other drugs of abuse. The first aim seeks to answer whether Pbexposure affects physiological THC sensitivity (as measured by the cannabinoid-induced tetrad). The secondaimseeks to answer whether Pbexposure affects edible THC self-administration and the development of THC tolerance (also measured by the tetrad).It was hypothesized that Pbexposure would decrease THC sensitivity (Aim 1), would enhance THC self-administration (Aim 2), enhance the development of THC tolerance (Aim 2), and finally that sex-dependent effects of Pb-exposure and THC would be observed (Aims 1 & 2). These hypotheses ended up not being supported, but Aim 1 produced findings indicating that THC sensitivity was increased by Pbexposure, but only in female mice. Future researchwill hopefully be able to fully explore the implications of these findings.</p>

Nigeria’s petroleum industry is the lynchpin of its economy. While oil has been the source of immense wealth for the nation, that wealth has come at a cost. Nigeria’s main oilproducing region of the Niger River Delta has experienced tremendous environmental degradation as a result of decades of oil exploration and production. Although there have been numerous historical works on Nigeria’s oil industry, there have been no in-depth analyses of the historical roots of environmental degradation over the full range of time from the colonial period to the present. This thesis contends that the environmental degradation of Nigeria’s oil producing region of the Niger Delta is the direct result of the persistent non-implementation of regulatory policies by post-independence Nigerian governments working in collusion with oil multinationals. Additionally, the environmental neglect of Nigeria’s primary oil-producing region is directly traceable back to the time of colonial rule. Vital to this argument is the view that the British colonial state created the economic institutions which promoted Nigerian economic dependency after independence was achieved in 1960. The weakness of Nigeria’s post-colonial dependent system is exposed presently through the continued neglect of regulatory policies by successive post-colonial Nigerian governments.

The quality of the flow over a 75 degree-sweep delta wing was documented for steady angles of attack and during dynamic maneuvers with and without the use of two control surfaces. The three-dimensional velocity field over a delta wing at a steady angle of attack of 38 degrees and Reynolds number of 72,000 was mapped out using laser-Doppler velocimetry over one side of the wing. The three-dimensional streamline and vortex line distributions were visualized. Isosurfaces of vorticity, planar distributions of helicity and all three vorticity components, and the indicator of the stability of the core were studied and compared to see which indicated breakdown first. Visualization of the streamlines and vortex lines near the core of the vortex indicate that the core has a strong inviscid character, and hence Reynolds number independence, upstream of breakdown, with viscous effects becoming more important downstream of the breakdown location. The effect of cavity flaps on the flow over a delta wing was documented for steady angles of attack in the range 28 degrees to 42 degrees by flow visualization and surface pressure measurements at a Reynolds number of 470,000 and 1,000,000, respectfully. It was found that the cavity flaps postpone the occurrence of vortex breakdown to higher angles of attack than can be realized by the basic delta wing. The effect of continuously deployed cavity flaps during a dynamic pitch-up maneuver of a delta wing on the surface pressure distribution were recorded for a reduced frequency of 0.0089 and a Reynolds number of 1,300,000. The effect of deploying a set of cavity flaps <u>during</u> a dynamic pitch-up maneuver on the surface pressure distribution was recorded for a reduced frequency of 0.0089 and a Reynolds number of 1,300,000 and 187,000. The active deployment of the cavity flaps was shown to have a short-lived beneficial effect on the surface pressure distribution. The effect on the surface pressure distribution of the varying the reduced frequency at constant Reynolds number for a plain delta wing was documented in the reduced frequency range of 0.0089 to 0.0267. The effect of the active deployment of an apex flap <u>during</u> a pitch-up maneuver on the surface pressure distribution at Reynolds numbers of 532,000, 1,000,000, and 1,390,000 were documented with reduced frequencies of 0.0053 to 0.0114 with flap deployment locations in the range of 21° to 36° . The apex flap deployment was found to have a beneficial effect on the surface pressure distribution during the maneuver and in the post-stall regime after the maneuver is completed. / Ph. D.

This thesis discusses the need for more courses particularly suited to the educational requirements of non-transfer students in San Joaquin Delta College with special reference to the Home Economics Curriculum. In 1955, Mr. Frank Jacobs, Director ,of Technological Education, San Joaquin Delta College~ did a survey on transfer and non-transfer students and concluded that 80% did not complete the baccalaureate requirements. This thesis will develop the pertinence of these findings to Home Economics course offerings for Associate of Arts degree or Part-time students. The San Joaquin Delta College bulletin includes in its philosophy vocational education for those students who complete their education at the end of two years.

Wax has been extracted from pest formations in Europe and especially in Britain. However, little or no work have been done in the United States. The increased demand for waxes and the limited supply of domestic origin has made the study of the sources and characteristics of domestic waxes desirable. Extensive work have been done with montan wax, which is similar to peat wax, in the United States. The object of this research is to establish a suitable process for extraction of wax from pest material, and to determine the chemical and physical nature of the wax. The process may not be made economically sound, yet it may be of value to the nation's economy.

Years of intensive tillage operations and heavy winter rainfalls have taken a toll on the soils in the Mississippi Delta causing compaction and nutrient losses due to runoff. The purpose of this research was to determine the effects of tillage systems and P and K fertilizer placement methods on corn and soybean production, as well as soil properties in the Mississippi Delta. The tillage treatments included conventional tillage, conventional tillage with subsoiling, and strip-tillage. The fertilizer placement treatments included a non-treated control, incorporated with tillage, and broadcast after tillage. Strip-tillage treatments reduced soil compaction and maintain nutrient levels while improving or maintaining yields in both crops. A more long term study is needed to determine if incorporating fertilizer with tillage will impact crop yields.

Rewilding theory appeared 20 years ago as a new conservation narrative based on the regula- tory roles of large predators and the importance to protect core reserves and their connectivity to maintain the resilience and complexity of core ecosystems (Perino et al., 2019). In Europe, despite a growing popularity, rewilding remains very criticized, due to a still non-understood concept (Torres et al. 2018). Assessing rewilding is crucial to overcoming conflicts and oppo- sition, and maximizing its benefits. Yet, such a process is complex and resource-demanding (Mata et al., 2018). In this thesis, we spatially assessed indicators of rewilding progress in the German Oder Delta (GOD), a site that joined Rewilding Europe Network (REN) in 2012. Those indicators include connectivity between three land cover types (Arable lands, Vegetation coverage and Water bodies), analysis of land use changes and assessment of iconic species population changes for the years 2006, 2012 and 2018. We addressed the question “How much did the 2012 rewilding policy in the German Oder Delta impact the return of iconic species?”. The connectivity between the different types of animal’s habitats is measured based on evalu- ating the evolution of landscape fragmentation in the area. Through gathering and analyzing land fragmentation data for the years 2006, 2012 and 2018, we found that the level of land- scape fragmentation between the same land types has not changed in the GOD after 2012. The overall connectivity between water bodies was found to be higher in the GOD than in MV and the connectivity between arable lands higher in MV than in the GOD. Surfaces and patches dedicated to water have increased between 2006 and 2012 in the GOD, which coincides with rewetting programs implemented in the region since the late 1990s. Moreover, the land use change in the GOD between 2006 and 2018 especially happened be- tween urban fabric to pasture and from pasture to inland marshes. Eventually, observation of iconic species including the White-Tailed Eagle, the Grey Seal, the Bison and the Beaver has continuously increased since 2006 in the region. From a large-scale perspective, it is hard to conclude rewilding policy’s success. We can however suggest that the combination of rewilding with conservation programs seems to have contributed to increasing the population of some iconic species as well as water bodies' sur- faces.

Homomorphic encryption is an encryption scheme that allows for simple operations on encrypted data. These operations are mainly boolean circuits combined into more complexarithmetic operations, rotations, and others. Homomorphic encryption was first implemented in 2009, and in the following decade, many different versions emerged. The early schemes were mainly proof of concepts. In contrast, the later schemes have been used in practical applications such as databases where queries were done without any decryption on the server. Another practical example is genome sequencing which benefits from utilizing supercomputers but the data is very sensitive. With the help of homomorphic encryption it was shown that this could be done without having any unencrypted data on the server. While these applications have different success rates, a field that have not been investigated is the use of homomorphic encryption with delta encoding. Delta encoding is a method of encoding a set (e.g., a set of characters) such that the set is expressed as an original (a starting point) with deltas (changes). A typical use case for delta encoding is: A user wants to edit a file located on the cloud and to save bandwidth, the user could encode a delta locally. This delta could then be sent to the cloud service and decoded together with the original version to create the updated version on the cloud. However, there is a privacy infringement risk with this. When standard encryption is used, the delta and the original must be decrypted to perform the decoding. If a malicious actor gains access to the data on the cloud machine, they would then have access to unencrypted data. For example, the cloud provider could snoop on its customers or have a policy that lets them use the users’ data. Homomorphic encryption would make it much harder since the data would still be encrypted while the decoding is performed. However, homomorphic encryption comes with a great overhead and is complex to tune, even with today’s libraries.To investigate the combination of homomorphic encryption and delta encoding, a testbed is created where a client and server act as user and cloud provider. Thetest bed consists of different configurations of delta encodings and homomorphic encryption schemes running different test cases. The configurations range from non-encrypted to homomorphically encrypted with different kinds of delta encodings to investigate the performance overhead of utilizing homomorphic encryption. The different tests are created to show what kind of overhead can be expected in different scenarios and which operations take the most time. With this testbed and these test cases, the results showed a substantial overhead with using homomorphic encryption. However, many optimizations could be done to increase efficiency and make homomorphic encryption a viable solution. For example, the decoding algorithm could be optimized to use homomorphic operations more efficiently. The tests showed that most of the runtime, when using homomorphic encryption, is on the server. Most of the runtime for the client are one-time operations, which consist of creating keys that can be reused.

The lower Mississippi River alluvial valley (LMRAV) in northwestern Mississippi is characterized by a flat landscape and predominantly agricultural land use. The fluctuations in surface heat flux throughout the crop cycle due to land cover modifications are thought to have an impact on the regional weather. This research analyzes changes in convective patterns over the LMRAV based on the rapid variations in land cover as a result of the seasonal harvest cycle. Focusing on synoptically weak days between 2012-2016, data from the GOES 13-15 satellite visible imagers were used due to their 1-km spatial resolution and ability to distinguish lower clouds over a warm surface. By comparing the spatial and temporal patterns of convective clouds, the study confirmed that convective patterns do change based on land cover evolution resulting from the harvest cycle. These changes were likely a result of low-level thermal and moisture changes resulting from variations in evapotranspiration.

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