Though heating, insulation, wall claddings and cavity-wall construction are considered as measures for remediating moisture and condensation in buildings, ventilation of wall cavities has however become a mantra among architects and other building professionals. Holes of any size and shape are made and located on building facades based on the accepted wisdom that a little air movement will keep the wall cavities dry. Whilst ventilation has been found to be successful in the control of moisture and condensation in rooms and larger enclosures, there is however insufficient understanding of how it works in thin spaces with high aspect ratios, such as the wall cavities studied in this thesis.In order to put in place good control and management practices in the remediation of moisture and condensation in vertical wall cavities by natural ventilation, it is vital to understand the dynamics of airflow in these cavities. In this thesis therefore, different size and shape of slots were employed to numerically investigate the effects of size, spacing and number of the slots on the characteristics of the velocity fields (patterns of airflow and distributions of velocity) in different cavity models. The Reynolds-Averaged-Navier-Stokes (RANS) methodology was employed to simulate the cavity flows under different modelling conditions using FLUENT. The BS 5925 model, an empirical relation for predicting ventilation rates in rooms and other larger enclosures, was employed and modified to predict ventilation rates in these cavities. Experimentally, the mapping of the airstreams in these cavities was obtained under similar reference (inlet) wind speeds employed for the numerical investigations.The results of this study show that there exists a potential at higher wind speeds for natural ventilation in the remediation of moisture and condensation in the cavities of vertical walls. The steady state approach employed in the RANS-based computation of cavity flows in this thesis averages out the peak values of air velocities and therefore gives no information about regions of maxima or minima velocity values even at higher wind speeds. This makes the predicted air change rates insensitive to the inlet air velocities from the ventilation slots and therefore makes the results more applicable for long term control and management of moisture in these cavities. In order to therefore put in place short, medium and long term plans for remediation of moisture in these wall cavities, a time-dependent computation is required. This will also allow the efficiency of the cavity ventilation to be properly assessed. Using the modified BS 5925 model, reasonable predictions were obtained for the air change rates of the wall cavities with the different size of ventilation slots employed. Close agreements are also obtained at lower and higher wind speeds between the predicted ventilation rates from the modified BS 5925 model and the experimental results employed as benchmark for validating the results.

The yeast cell wall provides a first barrier to the environment, confers shape and stability to the cells, and serves as a model for fungal cell wall biosynthesis and function in general. During normal growth, during mating and upon cell surface stress, new wall synthesis is induced by a conserved signaling cascade, the cell wall integrity (CWI) pathway. A signal is initiated by plasma membrane-spanning sensors and transduced through a mitogen-activated protein kinase (MAPK) cascade, which ultimately activates a transcriptional activator, Rlm1. The first part of this thesis analyses the role of this MADS-box transcription factor in the milk yeast Kluyveromyces lactis, which has not been investigated, until now. With respect to the distribution of the upstream CWI sensors, evidence for the existence of a special plasma membrane microcompartment, generally referred to as eisosomes, in the milk yeast is provided in the second part of the thesis. Regarding the transcription factor KlRlm1, its impact on the physiology of K. lactis seems to be different from its homolog in Saccharomyces cerevisiae, ScRlm1, although it clearly acts in CWI signaling, too. Thus, in contrast to the Scrlm1 mutant, a Klrlm1 deletion is sensitive, rather than hyper-resistant, towards Congo red and Calcofluor white, typical stress agents used in cell wall research. Data on cross-complementation of the two genes in the respective heterologous yeast indicate that KlRlm1 and ScRlm1 each perform their optimal function only in the native host.To investigate the impact of a Klrlm1 deletion on the transcriptional profile of K. lactis, data from total mRNA sequencing were analyzed in comparison to a wild-type strain. Many of the genes identified did not correspond to known Rlm1 target genes in S. cerevisiae, but many relate to other stress responses (e.g. KlGRE1, KlFMP16, KLLA0C05324g, KLLA0F18766g, KlUGX2) and to chitin synthesis (KlCHS1, KlSKT5 and KlYEA1), both probably connected to cell wall composition. The functions of a large group of KlRlm1 dependent genes identified here are yet uncharacterized or lack homologs in S. cerevisiae. The plasma membrane of fungi is a specialized organelle, which is ordered into several lateral domains, which we define as microcompartments, since each is composed of a special combination of proteins in their lipid environment. Such microcompartments are believed to control a variety of signaling (and transport) processes in all sorts of eukaryotic cells. Microcompartmentalization is also observed in the yeast plasma membrane, e.g. displayed by the CWI sensors in K. lactis, as shown in this thesis. Since distribution of the latter sensors is reminiscent of that of eisosomes, it was also investigated by live-cell fluorescence microscopy, how KlPil1, KlLsp1 and KlSur7 (all homologs of eisosomal proteins in S. cerevisiae) are distributed. Since they form the typical membrane patches, which are not present in deletion mutants of KlPIL1, the major structural component of eisosomes, one can conclude, that eisosomal microcompartments form in K. lactis and are composed similar to their counterparts in S. cerevisiae. The CWI sensors are excluded from these structures and form their separate microcompartments. The exact physiological function of eisosomes in fungi is still a matter of debate and future studies in K. lactis may help to address this role.

Although the cell wall is an essential plant cell structure influencing several important aspects of plant development, little is known about the genes and proteins that regulate its structure and function. In this dissertation, we first examined the regulation of the nuclear proteome of rice (Oryza sativa) in response to cell wall removal. Using labelree comparative proteome analysis we found that, upon removal of the cell wall, 142 nuclear proteins were up regulated and 112 nuclear proteins were down regulated. The differentially expressed proteins included transcription factors, histones, histone domain containing proteins, and histone modification enzymes. This study led to a novel discovery that removal of the cell wall results in dynamic changes in the nuclear proteome affecting the regulation of proteins involved in various molecular processes such as chromatin and nucleosome assembly, protein-DNA complex assembly, and DNA packaging. To further study cell wall development, we utilized the unique features of cotton fiber and performed a proteomic study using four stages during cotton fiber cell wall development including 10 days post anthesis (dpa), 15 dpa, 25 dpa, and 35 dpa. In addition, we aimed to improve protein extraction for recalcitrant fiber stages using pressure cycling technology (PCT). To our knowledge, this study identified the largest number of proteins and differentially expressed proteins in the G. hirsutum cotton species including the 35 dpa fiber proteome which has not been examined in prior reports. Additionally, in order to identify key genes regulating cell wall cellulose content, a mutant with a substantial reduction in cellulose was characterized in Arabidopsis. It was found that the mutated gene was VHA-E1. We found that the VHA-E1 protein formed a distinct plate in the boundary of two fusion-destined vacuoles to tether vacuoles together. The eventual vacuole fusion was achieved by pinching off the vacuole-boundary plate producing a stable membrane-bound intravacuolar globoid. These observations demonstrate that VHA-E1 may be involved in a novel cellular process regulating fusion of vacuoles by forming a cellular structure referred to as the vacuole boundary plate. Altogether, these findings suggest plant vacuole fusion and central vacuole biogenesis involve an unprecedented mechanism in Arabidopsis.

The first centuries BC and AD encompassed the first great period of Roman silverware production. Wall-paintings, surviving pieces, and textual references all testify to the importance of silverware, in particular the silver vessels and implements used in the preparation, service, and drinking of wine, during this period. Besides the functional aspects, possession of silverware served also as an indicator of one's wealth and status. In a number of wall-paintings with banqueting or related themes, primarily from Campania but also from Rome, silverware plays a prominent role. The painted vessels are often viewed, by modern scholars, as representative of the kinds of vessels then current in the Roman world, as if the painters were using actual pieces for models. This provides the point of departure for this dissertation, a detailed study of drinking silver in Romano-Campanian wall-painting. Such a study reveals more than just whether or not the painters were closely copying actual vessels; it is, in fact, argued here that such copying was not part of their usual procedure. The paintings also reveal what kinds of vessels were considered relevant in a banqueting context, and at times, how these vessels were used. Other areas onto which the paintings cast light include the working methods in general of the painters, the question of prototypes and their possible contents, and the role of the patron. The paintings studied in this dissertation cannot be divorced from Roman wall-paintings as a whole. The conclusions drawn here, therefore, have relevance for all Roman wall-paintings and, to some degree, for Roman art in general. / Thesis / Doctor of Philosophy (PhD)

The fungal cell wall serves as the interface between the organism and its environment. Complex carbohydrates are a major component of the cell wall, , glucan, mannan and chitin. β-Glucan is a pathogen associated molecular pattern (PAMP) composed of β-(1 → 3,1 → 6)-linked glucopyranosyl repeat units. This PAMP plays a key role in fungal structural integrity and immune recognition. Glycogen is an α-(1 → 4,1 → 6)-linked glucan that is an intracellular energy storage carbohydrate. We observed that glycogen was co-extracted during the isolation of β-glucan from SC5314. We hypothesized that glucan and glycogen may form a macromolecular species that links intracellular glycogen with cell wall β-(1 → 3,1 → 6)-glucan. To test this hypothesis, we examined glucan-glycogen extracts by multi-dimensional NMR to ascertain if glycogen and β-glucan were interconnected. H NMR analyses confirmed the presence of glycogen and β-glucan in the macromolecule. Diffusion Ordered SpectroscopY (DOSY) confirmed that the β-glucan and glycogen co-diffuse, which indicates a linkage between the two polymers. We determined that the linkage is not via peptides and/or small proteins. Our data indicate that glycogen is covalently linked to β-(1 → 3,1 → 6) glucan via the β -(1 → 6)-linked side chain. We also found that the glucan-glycogen complex was present in , and , but was not present in or hyphal glucan. These data demonstrate that glucan and glycogen form a novel macromolecular complex in the cell wall of and other species This new and unique structure expands our understanding of the cell wall in species.

The present day duplex wall receptacle in the United States provides 120Vrms AC at 60Hz, which comes from a standard set for AC loads by the National Electrical Manufacturers Association. With a DC system, such as what is used in the DC House project currently being developed at Cal Poly, providing DC power to DC loads presents a technical challenge due to the different required DC operating voltages of the loads. This thesis entails the design and construction of a Smart DC/DC Wall Plug, which can automatically adjust its output voltage to match any required DC load voltages. In the DC House implementation, renewable energy sources generate power to feed a 48V DC Bus. The Smart DC/DC Wall Plug converts power from the 48V bus to the appropriate voltage and power levels needed by the DC loads. The Smart DC/DC Wall Plug relies on load current detection, and uses a 10-bit digital potentiometer and a programmable current DAC to adjust the feedback network, thereby changing the output voltage. A dual channel 100W PCB prototype utilizing a STMF302R8 microcontroller is implemented for this design while confining to the NEMA wall outlet form factor. Results of hardware test verify the functionality of the Smart DC/DC Wall Plug in producing the required DC load voltages. Technical issues during the development of the Smart DC/DC Wall Plug will be described, along with suggestions to further improve from the current design.

In a vast majority of cases, seepage barriers increase the reliability of dams. However, it is important to recognize that seepage barriers often drastically increase hydraulic gradients around the boundaries of the barrier, and through any windows or defects in the barrier. The result is increased water pressures and hydraulic gradients behind and around the barrier. These increased pressures and gradients have potential to provide the catalyst for initiation of several modes of internal erosion that were either unlikely or less likely without the seepage barrier. As a consequence, seepage barriers give rise to the potential for additional mechanisms of internal erosion and piping in the dam and the foundation. Mechanisms of erosion and piping that are uniquely related to seepage barriers have been investigated through review of measured performance of existing dams, and through analytical studies. A compendium of 30 case studies of dams that have had seepage barriers in place for over 10 years has been assembled, and observations and insights garnered from these case studies were compiled. Finite element seepage and deformation analyses have been performed to provide better understanding of the performance of seepage barriers and the mechanisms that affect their performance. Based on the findings from the case studies and analyses, potential failure modes specific to dams with seepage barriers were identified, and the sequences of events required for the propagation of these failure modes were developed. The observations and insights acquired in this study were distilled into conclusions regarding the long-term performance of dams with seepage barriers. The information derived from this study will be useful in 1) assessing the potential for internal erosion and piping developing in dams with seepage barriers, 2) designing to minimize that possibility, and 3) assessing the risks associated with these mechanisms of erosion and piping. It is envisioned that the results of this study will provide dam owners and engineers with a better understanding of the issues involved with dams having seepage barriers and that this understanding will lead to improved practices in assessing, designing, and monitoring of dam seepage barriers. In addition, by improving the means by which seepage barriers can be assessed and designed, it is hoped that the confidence level that dam engineers have with regard to properly designed seepage barriers will be increased, and that properly designed seepage barriers can be viewed as safe and viable alternatives for mitigation of seepage problems. / Ph. D.

Plants as sessile organisms are susceptible to many environmental stresses such as drought, and salinity. They have therefore evolved mechanisms to acclimate and tolerate environmental stresses. Knowledge of the molecular aspects of abiotic stress gleaned from extensive studies in Arabidopsis has provided much information on the complex processes underlying plant response to abiotic stresses. Nevertheless, there is a need for integration of the knowledge gained and a systematic molecular genetic dissection of the complex responses to abiotic stress. In this study in Arabidopsis, comparative expression profiling analysis of progressive (pDr) and moderate (mDr) drought treatments revealed common drought responses, as well as treatment specific signatures responses to drought stress. Under prolonged moderate drought plants develop different mechanisms for acclimation: induction of cell wall loosening at early stage, and a change in hormonal balance (ABA: JA) at late stage of moderate drought. Taking a reverse genetics approach, a MYB transcription factor (MYB109) has been identified as a regulator of growth under drought and salt stress. Global expression profiling showed possible mechanisms of how MYB109 modulates growth under drought conditions: as a regulator of RNA processing and splicing and as a negative regulator of jasmonic acid biosynthesis and signaling. A forward genetics screen for drought and salt tolerance of transposon activation tag (ATag) lines led to the discovery of novel genes, which shed light on unexplored areas of abiotic stress biology. Utilizing this strategy, a potential role for cell wall modification and MATE transporters in response to drought and salt stress has been discovered, which needs further analysis to integrate this information on the role of these biological processes in plant stress biology. / Ph. D.

Key Words: Thrombosis, Vascular Graft, Microfluidics, Wall Shear Stress / Vascular grafts are essential for the management of cardiovascular disease. However, the lifesaving potential of these devices is undermined by thrombosis arising from material and flow interactions on the blood contacting surface. To combat this issue, the use of antithrombogenic coatings has emerged as a promising strategy for modulating blood and graft interaction in vivo. Although an important determinant of graft performance, hemodynamics are frequently overlooked in the in vitro testing of coatings and their translatability remains poorly understood. We address this limitation with a microscale platform that incorporates vascular prosthesis and coatings with tuneable flow and surface conditions in vitro. As a proof of concept, we use the platform to test the thrombogenic performance of a novel class of lubricant infused (LIS) and antibody lubricant infused (anti-CD34 LIS) coated ePTFE vascular grafts in the presence of arterial wall shear stress, with and without the presence of endothelial cells. Our findings suggest lubricant infused coated ePTFE vascular grafts are thromboresistant under flow and may have potential for in vivo arterial grafting applications. It is moreover apparent that the microscale properties of the device could be advantageous for the testing and translation of novel antithrombogenic coatings or blood contacting prosthesis in general. / Thesis / Master of Applied Science (MASc)