Long chain fatty acids (LCFA) constitute a particular class of lipids whose developmental roles are coming under increasing scrutiny. These LCFAs not only have important cell specific functions but their dysregulation also forms the underlying cause of several lipid based disorders. Fatty acids are elongated in vivo by multi-enzymatic machinery in a stepwise manner. The first step of this process is carried out by a family of enzymes, conserved from yeast to humans, known as Elongases (Elos). It has been suggested that Elos work independently to elongate a fatty acid to a distinct length and perform distinct functions. Work in different species has implicated Elos in different biological roles such as barrier function, fertility, behavior and lipid homeostasis, but our understanding of the precise roles of these elongases in fatty acid elongation and how it relates to their physiological roles is not very well understood. To better understand the functions of Elos, I have characterized all Drosophila elongases for their developmental roles. In this thesis, I have shown that Drosophila elongases that are more conserved across species have more important functions (eg viability) as compared to the less conserved elongases. More specifically, I have discovered an elongases, sit still (sits), disruption of which in the nervous system results in striking locomotor and behavior defects, as well as decreased lifespan. I have also characterized another elongase, baldspot, which is important for imparting the epidermal barrier function in Drosophila, a conserved function of elongases across species. By elucidating the in vivo functions of these two Drosophila elongases, this work provides insight into the developmental roles of Elos and their links to diseases such as psoriasis, icthyosis, macular degeneration, Adrenoleukodystrophy (ALD) and Multiple Sclerosis (MS).

acase@tulane.edu / The Louisiana coast is an invaluable asset to the nation's human, economic, and ecological welfare. However, due to the combined effects of coastal erosion, subsidence, and sea level rise, Louisiana is losing on average 25 km2 of its valuable coastal wetlands per year. Terrebonne Bay and the associated Lafourche deltaic lobe headland is a critical section of this coast for wetlands and infrastructure protection and restoration in the State’s Master Plan. Historical imagery and bathymetry clearly show the rapid transgression and erosional degradation of both sets of headland-flanking barrier island shorelines due to wave attack and relative sea level rise in the past 150 y. The focus of the present study is a barrier island system: an ocean-fronting modern- barrier shoreline (Timbalier) and a paleo-deltaic headland barrier arc (Terrebonne) inland of the active barrier. The evolution of the modern barrier arc is closely tied to the shallow geologic framework over which it is transgressing, and specifically the sand re-activation capacity of the antecedent geology once erosional forces are introduced. To understand the evolution of these barrier systems and how to address their protection and re-nourishment, it is important to quantify (1) the depositional facies geometry and (2) the volume of sand in these back-barrier sandy lithosomes. Here we present new observations from CHIRP sub-bottom seismic, multibeam bathymetry, and surface grab and vibracore sampling in an effort to quantify the sediment availability within the underlying geologic framework and reconstruct the geomorphic evolution of these barrier shorelines. Observations of sandy units agree with results from Kulp et al. (2005), who showed the presence and extent of sandy lithofacies within 3 m of the surface proximal to the Raccoon Pass tidal-inlet. We provide evidence to suggest that this sand is an important potential resource for the longevity of proximal sandy barrier islands as transgression continues. / 1 / Daniel Culling

Electroreflectance (ER) spectra of Schottky-barrier Au/n-GaN have been measured at various dc biased voltages (Vbias). The ER spectra have exhibited excitonic signals beneath band-gap energy (Eg ). In addition, Franz-Keldysh oscillations (FKOs) were also observed above Eg. The FKOs come from the former region, and the excitonic signals come from the latter region. When Vbias = 0, they are mixed. As reverse Vbias is increased, they become more separated. Furthermore, strength of surface electric field (Fs) can be deduced from the period of the FKOs. From the plot of versus Vbias, barrier height of 1.2 V and carrier concentration were obtained.

Thesis (M.S.)--Mississippi State University. Department of Electrical and Computer Engineering. / Title from title screen. Includes bibliographical references.

Thesis (M.S. in Electrical Engineering)--Vanderbilt University, 2003. / Title from PDF title screen. Includes bibliographical references.

A capillary barrier develops and restricts water flow when two porous materials with dissimilar pore structures (e.g., a coarse-grained soil overlain by a fine-grained soil) are in contact with one another. This is due to a difference in the unsaturated hydraulic conductivity of the two materials at a given suction. Geotextiles are utilized in a variety of civil engineering applications and have a pore structure similar to that of a coarse-grained soil. This can be problematic in unsaturated soil as the capillary barrier caused by the geotextile may instigate undesirable moisture buildup in the overlying soil and undermine any benefit provided by the geotextile. Various versions of a new geotextile have been manufactured to help dissipate a capillary barrier by "wicking" or laterally draining excess moisture away from the soil. Additionally, nonwoven blends of the unique wicking fiber combined with standard polymeric fibers are tested to assess their ability to minimize the development of a geotextile capillary barrier and not cause additional moisture accumulation in the first place. The unsaturated properties of both woven and nonwoven configurations of these wicking geotextiles were investigated as part of a comprehensive an experimental testing program. The testing program includes small soil column infiltration tests to assess geotextile capillary barrier performance with moisture monitored by time domain reflectometers and capacitance probes. Also, modified hanging column tests were conducted to define the hydraulic properties of the geotextiles in the form of water retention curves. Finally, a microscopy study, involving both optical and scanning electron microscopes, was conducted to observe the wicking behavior of the geotextiles at a micro-scale level. Test results illustrate the enhanced lateral drainage and reduced moisture accumulation of the wicking geotextiles when compared to regular geotextiles. Additionally, the woven version of the wicking geotextile has the potential to perform the functions of separation, filtration, protection, reinforcement, and drainage. All of these functions in a single geosynthetic product could lead to significant cost savings compared to the use of separate products to perform each one of the various functions. / text

With rights to access now become basic human rights, it demands a tool for building disability inclusiveness assessment to tell how far we have gone to include persons with disabilities (PWDs) in buildings. Calling for more researches in disability inclusive facilities and inclusive education in various international conventions and statements such as the UN Convention on the Rights of Persons with Disabilities (2006) and the UNESCO Salamanca Statement (1994), the Physical Disability Inclusion Sub-score (PDIS) and the Visual Impairment Inclusion Sub-score (VIIS) as simple, quantitative and more objective tools for assessing higher education buildings were developed here. Other than that whether building professionals have knowledge of the way PWDs access and use buildings were at the same time examined. This study consists of four parts with (1) conception, (2) the PDIS and the VIIS for assessing the disability inclusiveness of buildings, (3) main survey and (4) conclusion. By way of literature review, the PDIS and the VIIS frameworks were constructed and they were fine-tuned with inputs from building professionals and users with impairments in the pilot phase. NSFDSS but not the far more popular AHP was applied to weight the elements under the PDIS and the VIIS for both credibility and practicality reasons. In all, between March and July 2012, 20 building professionals, 22 persons with physical disability and 21 persons with visual impairment were surveyed. The PDIS and the VIIS then developed were much simplified with around 200 items under about 20 categories. Design was weighed by all to be more important than Management. Following that 48 higher education buildings from four universities in Hong Kong were assessed in March to September 2013. The dispersal of the PDIS and the VIIS were found largely due to Design rather than Management. In the disability inclusion performance of different categories, Operations and Maintenance, and Management Approaches were respectively the best and the least well performed categories, and Vertical Circulation and Entrance were the more disability inclusive Design categories. As for hypothesis testing, 13 working hypotheses were developed from 4 main hypotheses. By Spearman’s rank correlation test or the t-test, it was found that building professionals and both persons with physical disability and persons with visual impairment did not weigh the elements under the PDIS and the VIIS differently, and the mean values of the standard deviation of the weightings given by users with impairments were not greater than those given by building professionals. It is evidenced that building professionals somehow have knowledge of the way the physically impaired and the visually impaired access and use buildings, and impaired users are not biased on their experience. Having the PDIS and the VIIS developed, it is in pole position to adjust and apply them to study other buildings such as health care facilities and office buildings. Towards a more progressively aggressive step is to make changes to them to examine the more complex issue of ageing friendliness of buildings for the grey population following WHO Age-friendly Environments Programme. / published_or_final_version / Real Estate and Construction / Doctoral / Doctor of Philosophy

No description available.

Thesis (M.S. )--Youngstown State University, 2007. / Includes bibliographical references (leaves 68-69).

Thesis--Wisconsin. / Vita. Includes bibliographical references (leaves 82-85).