Mountain laurel (Kalmia latifolia L.) is relatively difficult to establish in landscapes. One experiment tested the effect of container size on the water relations of pinebark substrate embedded in field soil. Two other experiments tested the effects of transplant season and container size on landscape establishment of nursery-produced mountain laurel. Experiment one compared volumetric water content of embedded substrate of five sizes (4-L to 100-L) to adjacent field soil at two depths with time domain reflectometry (TDR) during a dry down cycle. Available water was calculated by subtracting unavailable water (estimated with pressure plates) from volumetric water content (TDR measurements). Adjacent soil contained more available water than embedded substrate. The middle depth held more water than the top. Larger pinebark substrate volumes retained higher volumetric water content than smaller volumes. The second experiment consisted of 7.6- and 19-L containers of Kalmia latifolia L. ‘Olympic Wedding’, transplanted into field soil in October or May. Larger container plants generally had lower xylem potential than smaller plants, but better visual ratings. Root growth into surrounding soil was negligible for all treatments. Leaf area was higher for spring transplants than fall transplants. Experiment three was a rhizotron study with 19-L plants, transplanted in October or May. Canopy growth of spring transplants was greater than fall transplants, but fall transplants had longer roots into the backfill. Overall, our data suggest that fall transplanting will potentially allow faster plant establishment than spring transplanting. The effect of container size on plant establishment could not be determined. / Master of Science

Osteoarthritis (OA) is one of the leading causes of disability world-wide. It affects 12% of all Americans ages 25-74 [1]. One of the challenges with OA, is that there are currently no clinically viable methods to measure the health of the cartilage before cartilage loss. There are no ways to replace or heal the cartilage after it has been lost. It is known that the early stages of OA involve a decrease in the amount of glycosaminoglycans (GAG), one of the main molecules in cartilage. This decrease in GAG leads to a change in the fixed charge density of the cartilage and a higher water content with higher diffusivity. The development of techniques to measure the PG content in the cartilage could lead to early diagnosis and the development of effective preventative treatments.One of the suggested methods for measuring the PG content is through quantitative magnetic resonance imaging (MRI). MRI is a non-invasive medical imaging technique known for it's ability to image soft tissue. MRI measures the reaction of the nuclear spin in a magnetic field to a radio frequency (RF) pulse. These spins, and the signal they produce, are sensitive to magnetic fields. This makes it possible to measure small changes in anatomical structure, like a decrease in PG content, because the magnetic spins are sensitive to the local magnetic environment. There are several MRI techniques that are able to measure the PG content in the cartilage.The behavior of the MR signal can be affected by changes in the molecular environment. This effect can by measured through changes in the MR signal parameters T1r and T2. More complex MRI techniques such as chemical exchange saturation transfer (CEST) can be used to directly measure the amount of GAG by taking advantage of the transfer of proton magnetization between the GAG molecules and the surrounding fluids. There are even MRI techniques such as balanced steady state free precession (bSSFP) which makes it possible to measure high resolution morphological images, making it easier to interpret the quantitative scans.This thesis will describe methods employed to improve MRI imaging of cartilage. One method is the developing and testing a new technique for creating maps of the local magnetic field. These field maps can help scans that are particularly sensitive to non-homogeneities in the field. Another method is improving the parameter estimation algorithms which make it easier to more accurately predict values of signal parameters like T1r and T2. This thesis will also describe ongoing efforts to create, and optimize a clinically viable whole-joint cartilage imaging protocol that can be used for early OA detection and diagnosis.

Standoff detection of targets using volatiles is essential when considering substances that are hazardous or dangerous, or for which the presence or location is unknown. For many invasive biological threats, their presence is often not realized until they have begun visibly affecting and spreading through crops or forests. The fungus Raffaelea lauricola is a biothreat vectored by the invasive beetle Xyleborus glabratus, or redbay ambrosia beetle (RAB), whose presence in avocado groves is currently detectable by visual inspection. Once visually identified, the affected trees must be removed and destroyed to protect those remaining trees. However, if the fungus is identified via standoff volatile detection, there is anecdotal evidence that it can be treated with propiconazole and saved from progression to the fatal laurel wilt disease. As a result of the rapid spread of R. lauricola and the quick death of trees, early detection through standoff methods is essential. The only current method of pre-symptomatic identification is canine detection. Canines are sensitive and selective biological detectors that can trace odors to their source, despite the presence of a variety of background odors. The present research evaluated the volatile organic compounds (VOCs) of the laurel wilt disease and R. lauricola using headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). Additionally, a new method for odor collection and presentation to trained detection canines was developed. Knowledge of the disease and standoff volatile detection capabilities are improved using this information.

The cover of the ericaceous shrub Kalmia angustifolia L. (sheep's laurel or lamb's kill) expands rapidly on many clear-cut sites through central Newfoundland and northern Quebec. Previous laboratory and greenhouse studies on the effect of Kalmia on black spruce (Picea mariana (Mill.) B.S.P.) germinants and seedlings have demonstrated that extracts of Kalmia leaves and soil can reduce the germination rate and early root and shoot growth of black spruce. Observations in the field have suggested that Kalmia leaves and soil can reduce the germination rate and early rot and shoot growth of black spruce. Observations in the field have suggested that Kalmia reduces the growth of planted spruce seedlings. The experiments presented in this thesis were designed to determine the importance of Kalmia in controlling spruce growth and nutrition, and to document how the importance of Kalmia varies from site to site. Spruce seedlings growing in close proximity to Kalmia were found to be shorter and had lower foliar concentrations of N and P, and the roots of these seedlings had lower rates of mycorrhization and a more frequent occurrence of the pseudo-mycorrhizal/pathogenic fungus Phialocephala dimorphospora Kendrick. Results suggest that Kalmia impedes the N nutrition of spruce seedlings through the reduction of N mineralization rates and N availability. The results of path analysis further suggest that Kalmia had a direct effect on both spruce foliar N concentration and spruce growth. These findings do not demonstrate, though they are consistent with the suggestion, that Kalmia can affect spruce through allelopathic processes. Although we could not demonstrate that the reduction of rates of mycorrhization were due to indirect effects of Kalmia on spruce nutrition, we demonstrated that improving spruce nutrition in close proximity to Kalmia increased, though not significantly, the occurrence of mycorrhizae on spruce roots. Mycorrhizal symbiosis was shown to play a key role in t

Laurel wilt disease is a vascular wilt affecting the xylem and water conductivity in trees belonging to the family Lauraceae. The disease was introduced by an invasive species of ambrosia beetle, Xyleborus glabratus. The beetle, together with its newly described fungal symbiont Raffaelea lauricola (pathogenic to host trees), has lead to the devastation and destruction of over 300 million wild redbay trees in southeastern forests. Ambrosia beetles make up a very unique clade of beetle and share a co-evolved obligatory mutualistic relationship with their partner fungi. Rather than consuming host tree material, the beetles excavate galleries or canals within them. These galleries serve two purposes: reproduction and fungal gardening. The beetles house fungal spores within specialized sacs, mycangia, and essentially inoculate host trees with the pathogenic agent. They actively grow and cultivate gardens of the fungus in galleries to serve as their sole food source. Once the fungus reaches the xylem vessels of the host tree, it thrives and leads to the blockage of water flow, both because of fungal accumulation and to the host response of secreting gels, gums and tyloses to occlude vessels in an attempt to quarantine the fungus. This disease spreads rapidly, and as a result, once symptoms become visible to the naked eye, it is already too late to save the tree, and it has likely already spread to adjacent ones. The present study presents the first documented study involving the early detection of disease from deep within a tree through the use of scent-discriminating canines. In addition, the present study has lead to the development of a novel sample collection device enabling the non-destructive sampling of beetle galleries. Finally, a metabolomics approach revealed key biochemical pathway modifications in the disease state, as well as potential clues to disease development.

Taking into account an indigenous pre-colonial, a European colonial and a hybrid postcolonial history, in addition to cruel post-independence authoritarian regimes, postcolonial literatures reflect very often the difficult experiences of nations who struggle to find their identities. This is the case of Equatorial Guinea, whose writers, many of them in exile, use their works to raise both national and international awareness about the miserable conditions of a people suffering the consequences of colonialism and two dictatorships. One of these writers is Juan Tomás Ávila Laurel (1966), the subject of this thesis. This dissertation explores how Ávila Laurel’s writings dialogue with Western literary tradition to represent a postcolonial society still in the process of nation-building. In the second chapter, we study Avión de ricos, ladrón de cerdos (2008) as a picaresque novel, and in the third, Arde el monte de noche (2009) as a Bildungsroman. After presenting an overview of the main characteristics of these genres, we demonstrate the similarities of Ávila Laurel’s narratives with the canonical texts, and at the same time, how their rewriting in a postcolonial context leads to fundamental revisions. The final chapter is devoted to Ávila Laurel’s blog Malabo that he has been publishing in the digital journal FronteraD since 2009. We understand his blog as the author’s effort to write political essay, a genre with a longstanding tradition, benefitting from the advantages the new media and communication tools provide. As we argue in this thesis, the author uses Western literary genres that also surfaced in times of deep social and political crisis, to protest against poverty, corruption and abuse of authority, and to denounce hypocrisy and the persistence of colonial and neocolonial structures in Equatorial Guinea. Writing from a hybrid “third space,” Ávila Laurel’s works are, above all, a desire to tell a collective story and create an archive for generations to come.

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The middle landscape, more commonly referred to as Suburbia, has become spatially discontinuous, lacking the cohesive union, open spaces and city centers that once defined community. Presently, the middle landscape's community spaces do not offer the opportunity for familiar and chance encounters or ritual activity. Large-scale housing development in Northern Virginia and in the mid-Atlantic region is continually segregating and ultimately destroying community and all links to the area's history. Located in Southern Fairfax County, the newly abandoned Lorton Central and Maximum Security Prison Facility provides an opportunity to serve as a catalyst for community in this area. This thesis investigates the historic precedence for creating successful community centers. The author's personal investigation is focused upon using form and function to accomplish this vision. By adaptively reusing the existing architecture alongside new construction, the intent is to create a dense urban town center at the abandoned historic site. / Master of Landscape Architecture

Call number: LD2668 .T4 1985 S245 / Master of Science

In this paper I looked at the actions that were taken by Jose P. Laurel and Jorge Vargas during the occupation of the Philippines country by Japanese Imperial forces during World War II. I was mostly interested in the idea of loyalties that occurred in places that were occupied throughout history and what constituted the lines that would be drawn when the leaders of those countries decided to do what was best for their people. I started by researching the many of the Occupied countries of Japan and determined one in which there was a more controversial and grayed line of collaboration that occurred. I chose the Philippines mostly because of their relationship with the United States and to see how that factor affected the ideas of collaboration and loyalty. I mostly found that these men got most of their influences from their previous experiences in life but mostly form the last instructions that were given to them by Gen. MacArthur and their President. Ultimately they did not claim loyalty to the Japanese even though they collaborated with the Japanese. This is important in giving a good view into what needs to be done in order t preserve the nation state when being occupied by an invading force. It also explores the lines and interpretations of the definition of loyalty in these situations.