Over the last two decades, dual-polarimetric weather radar has proven to be a valuable instrument providing critical precipitation information through remote sensing of the atmosphere. Modern weather radar systems operate with high sampling rates and long dwell times on targets. Often only limited target information is desired, leading to a pertinent question: could lesser samples have been acquired in the first place? Recently, a revolutionary sampling paradigm – compressed sensing (CS) – has emerged, which asserts that it is possible to recover signals from fewer samples or measurements than traditional methods require without degrading the accuracy of target information. CS methods have recently been applied to point target radars and imaging radars, resulting in hardware simplification advantages, enhanced resolution, and reduction in data processing overheads. But CS applications for volumetric radar targets such as precipitation remain relatively unexamined. This research investigates the potential applications of CS to radar remote sensing of precipitation. In general, weather echoes may not be sparse in space-time or frequency domain. Therefore, CS techniques developed for point targets, such as in aircraft surveillance radar, are not directly applicable to weather radars. However, precipitation samples are highly correlated both spatially and temporally. We, therefore, adopt latest advances in matrix completion algorithms to demonstrate the sparse sensing of weather echoes. Several extensions of this approach are then considered to develop a more general CS-based weather radar processing algorithms in presence of noise, ground clutter and dual-polarimetric data. Finally, a super-resolution approach is presented for the spectral recovery of an undersampled signal when certain frequency information is known.

CD8 T cells play a critical role in the clearance of pathogenic bacteria, viruses, and protozoan parasites. Upon encountering their cognate antigen through either infection or vaccination, naïve CD8 T cells undergo robust proliferative expansion, which is followed by contraction and the formation of a memory population. Memory CD8 T cells are long-lived, and because they persist in increased numbers and possess enhanced functional abilities compared to naïve CD8 T cells, they are able to provide the host with increased protection following re-infection. Because of these properties, vaccines designed to elicit memory CD8 T cells have the potential to reduce health care burdens related to infection with pathogens including human immuno deficiency virus (HIV), malaria, influenza, and hepatitis virus. However, stimulating protective CD8 T cell responses against these pathogens through vaccination has proven challenging. Therefore, a better understanding of the properties of memory CD8 T cells generated following vaccination, and the characteristics of memory CD8 T cells best suited for providing protection against diverse pathogens is needed. While memory CD8 T cells can be maintained for as long as the life of the host, evidence suggests that their properties change with time after infection. Because CD8 T cell-mediated protection is based upon both the numbers and quality or functional abilities of memory cells present at the time of re-infection, changes in memory CD8 T cell function over time could impact their ability to provide protection upon re-infection. Therefore, a better understanding of how memory CD8 T cells change with time after infection is needed. As part of the studies presented in this thesis, I found that the phenotype and function of memory CD8 T cells including localization, interleukin (IL)-2 cytokine production, responsiveness to homeostatic cytokines, metabolic capabilities, and proliferation and secondary memory generation potential change with time after infection. Interestingly functional changes could not be completely explained by changes in subset composition that occur with time, as changes over time were also seen in defined CD62Lhi subsets. Importantly, functional changes of memory CD8 T cells that occurred with time led to an increased ability to provide protection against a chronic viral infection. These data improve our knowledge of the capabilities of memory CD8 T cells generated following infection, and suggests that the outcome of vaccination strategies designed to elicit protective memory CD8 T cells using single or prime-boost immunizations will depend upon the timing between antigen encounters. Following re-infection, memory CD8 T cells become activated and produce effector cytokines and cytolytic molecules that aid the host in clearing invading microbes. Activation can be triggered not only through cognate antigen recognition, but also by antigen-independent cytokine driven signals. However, our knowledge of how antigen-dependent and –independent signals contribute to CD8 T cell activation and protection following infection is incomplete. In the second part of my thesis, I show that the ability of memory CD8 T cells to become activated in response to inflammation decreases with time after infection, that antigen and inflammation act synergistically to induce activation of memory CD8 T cells, that the presence of cognate antigen enhances activation of memory CD8 T cells that contribute to clearance of infection, and that bystander memory CD8 T cell responses following unrelated bacterial infection do not provide the host with a protective benefit. Together, the data in this thesis further our understanding of memory CD8 T cells generated following infection and/or vaccination, and the properties of memory CD8 T cells important for providing protection upon re-infection with invading pathogens.

This thesis compared tooth widths, arch widths, and arch lengths; their differences between males and females, and changes from early mixed dentitions to adult dentitions. Comparing subjects who were known to have Angle Class I normal occlusion in their permanent dentitions to subjects who were known to be Class I or Class II crowded malocclusions in their permanent dentitions. These comparisons can only be achieved utilizing data from a longitudinal study, such as the Iowa Growth Study. Dental casts in the early mixed dentition (average age of 8.85 years) and in the adult dentition (average age 15.45 years) taken from subjects who did not receive orthodontic treatment during or in the dates prior to data collection were measured for this study. The casts utilized were from the Iowa Growth Study; all of the subjects were of European descent. The longitudinal sample of casts in the Iowa Growth study were made from white dental stone poured into alginate impressions from 1946 until 1960. The objectives of this study were to compare individual tooth widths, mean sum tooth widths, arch widths, arch length segments, and arch perimeters of Class I Normal (CIN) and Class I and II crowded dentitions (CD) in the early mixed (MD) and permanent (PD) dentitions to explore new methods of predicting crowding. The goal was to evaluate the significance of differences between MD and PD for tooth widths, arch lengths, and arch widths in both arches of CIN and CD subjects to determine values that may be useful for MD space analysis. Thirty males and thirty females from the Iowa Growth Study with CIN and CD occlusions were selected from the longitudinal study. Casts of MD and PD subjects were double measured with digital calipers by both the primary and secondary investigators. The average of each investigator's two measurements were used to determine measurement error. All other statistical analysis was based on the mean measurements taken by CPW. Descriptive statistics were computed. The normal non-crowded and crowded samples were compared with two-sample t-test, and changes from MD to PD with paired-sample t-test. Examiner measurement errors were tested with intra-class correlation coefficients. When the mean sums of MD and PD tooth widths were compared, using data from all 60 subjects, the CD group had a significantly greater mean sum of tooth widths than the CIN group. In both genders, crowded dentitions had significantly greater mean sum of tooth widths than CIN's for both the maxilla and mandible in MD and PD. When the mean sums of the arch lengths [Perimeters] were compared using data from all 60 subjects, the arch perimeters of the CD and CIN samples did not differ. It was concluded that total arch lengths Perimeters] were not significant indicators for crowding. Gender comparisons: Within the CIN group, males had numerically larger tooth width sums and arch length sums than females. The sum of maxillary and mandibular tooth widths for CIN's and CD (both males and females) mandibular tooth widths for CIN's and CD (both males and females pooled together and sexes separately. In the MD stage the mean sum of maxillary and mandibular arch lengths in the MD were significantly greater than those in the PD, because arch perimeters decrease during the transition from mixed to permanent dentitions. In summary, the results of this research thesis study showed that the sum of tooth widths in both arches had a significant association with dental crowding. In contrast, the sum of arch lengths [perimeter in both arches] did not differ between the normal and crowded samples. Additional analysis of the measurements taken in this thesis research project, the individual arch length segments, especially the canine and posterior arch length segments in the right and left sides of the lower arch in the mixed dentition casts, and their relation to the sum of the widths of the lower permanent canines and premolars in the normal and crowded malocclusions may give us important information about the development of crowded malocclusions.

My work is a response to the miraculous energy exhibited in nature, an invisible power that creates exquisite structures and designs in every living thing around us only to destroy them and begin again. Specifically, it is inspired by a lifelong fascination with the detritus left behind. Shimmering maple tree seeds, decaying oak leaves, or delicate marine relics awash on the beach are tangible (and daily) reminders that life is precious and fleeting, but also hopeful as that energy is always transformed into something new. The drawings, pulp prints and sculptures produced for my thesis are futher animated by the belief that nature is telling us something with its expressive vocabulary of lines, shapes, textures and colors. In every weather-worn remnant, there is a narrative—a life history and lessons to be learned. Captivated by the recurring forms and patterns found on land and in the sea, I find myself trying to decipher this language through close observation and interaction with the objects I collect, study and draw from, as well as the natural materials used to produce the work. Through the rituals of drawing and erasing, steaming, cooking and preparing fiber, concealing and revealing imagery, form and text, I find myself connecting with these narratives and participating in an age-old dialogue with nature.

Angiotensin II (Ang II) promotes vascular disease and hypertension, in part, by activating the interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) signaling pathway. Extensive studies have demonstrated that SOCS3 plays an important role in suppressing the IL-6/STAT3 pathway in the immune system and in cancer biology. In contrast, the functional importance of SOCS3 in cardiovascular disease is largely unknown. Thus, the overall goal of these studies was to investigate the role of SOCS3 in models of Ang II-dependent vascular disease and hypertension. To examine direct effects of Ang II on the vessel wall, carotid arteries from SOCS3 haplodeficient (SOCS3+/-) mice and wild-type littermates (SOCS3+/+) were incubated with the peptide or vehicle for 22 hrs, followed by examination of endothelial function using acetylcholine. Relaxation to acetylcholine was similar in all arteries incubated with vehicle. A low concentration of Ang II (1 nmol/L) did not affect acetylcholine-induced vasodilation in SOCS3+/+ mice, but reduced responses in arteries from SOCS3+/- mice by ~50% (P<0.05). This Ang II-induced endothelial dysfunction in SOCS3+/- mice was prevented by inhibitors of NF-êB or STAT3, an IL-6 neutralizing antibody, or a scavenger of superoxide. Responses to nitroprusside, an endothelium-independent vasodilator, were similar in all groups. To test the importance of SOCS3 in vivo, mice were infused systemically with a pressor dose of Ang II (1.4 mg/kg per day) or vehicle for 14 days via osmotic mini-pumps. Acetylcholine-induced vasodilation in carotid and resistance arteries in brain from SOCS3+/- mice was reduced by ~60% (P<0.05). Surprisingly, genetic deficiency in SOCS3 prevented the majority of Ang II-induced endothelial dysfunction without affecting the pressor response to Ang II. To investigate potential mechanisms underlying divergent results when studying effects of local versus systemic effects of Ang II, we performed bone marrow transplantation followed by infusion of vehicle or Ang II for two weeks. Lethally irradiated WT (CD45.1) mice reconstituted with SOCS3+/- bone marrow were protected from Ang II-induced endothelial dysfunction (P<0.05), while reconstitution of irradiated SOCS3+/- mice with WT (CD45.1) bone marrow exacerbated Ang II-induced vascular dysfunction (P<0.05). WT (CD45.1) into SOCS3+/+ and SOCS3+/- into SOCS3+/- bone marrow chimeras exhibited vascular function consistent with non-irradiated controls. In addition, the pressor response to Ang II was reduced by ~50% in WT mice reconstituted with bone marrow from SOCS3+/- mice (P<0.05). These data suggest that SOCS3 exerts divergent or context-dependent effects depending on whether vascular dysfunction was due to local versus systemic administration of Ang II. SOCS3 deficiency in the vessel wall enhanced local detrimental effects of Ang II on vascular function. In contrast, bone marrow-derived cells that are haplodeficient in SOCS3 protect against systemically administered Ang II and the resulting vascular dysfunction and hypertension. To my knowledge, these are the first experimental studies that begin to define the importance of SOCS3 in Ang II-induced hypertension and endothelial dysfunction. Results obtained from these experiments provide new insight into mechanisms which regulate oxidative stress and inflammation within the vasculature. The studies also revealed that bone marrow-derived cells that are haplodeficient in SOCS3 protect against pressor and endothelial effects of Ang II. These findings may eventually contribute to the development of novel therapeutic approaches for hypertension and hypertension associated end-organ damage.

Articular cartilage is a complex soft tissue covering the end of moving bones in joints which provide pressure load distribution over the joint surface and smooth lubrication with little friction for establishing movement. Articular cartilage has an intrinsically limited capacity for self-repair when injured due to the lack of nerve and blood supply. Considered that injured cartilage is left untreated, it is likely to undergo progressive cartilage degeneration without pain which may lead to posttraumatic osteoarthritis. Therefore functional and physiologic restoration of injured cartilage back to a normal condition has long been in demand, yet current available repairing methods in clinics have met with limited success. Mechanically applied loads to articular cartilage is necessary for chondrocytes, cartilage cells, since they are responsible for cartilage matrix turnover by synthesizing extracellular matrix (ECM) molecules in response to bio- chemical and mechanical changes in ECM. Ultrasound has emerged as an anabolic stimulator over the past few decades and a number of studies have proven that ultrasound therapy is beneficial for cartilage repair by synthesizing cartilage ECM components such as type II collagen and proteoglycan. Ultrasound therapy has also proven its potential for the attenuation of progressive cartilage degradation and induction of chondrogenic differentiation of mesenchymal stem cells. The use of ultrasound as an anabolic stimulator would be valuable with respect to cartilage repair since ultrasound as a form of mechanical energy can be non-invasively transferred into a human body. However, understanding the underlying mechanisms has been slow and the mechanisms have been roughly classified into thermal and non-thermal effects. Biologically detailed underlying mechanisms have not been sufficiently studied. That might be the reason why the application of ultrasound as a therapeutic tool has been limitedly available in clinics. In this study, mechanism involved biophysical effects of low intensity ultrasound has been studied for cartilage regeneration. First of all, the effect of ultrasound therapy as a mechanical stimulator on chondrogenic progenitor cell homing toward injured sites in cartilage was investigated with underlying biologic mechanisms. And the feasibility of ultrasound therapy for reactive oxygen species production mediated cartilage energy modulation was evaluated. There have been extensive preclinical studies about the effects of microbubble mediated ultrasound therapy on the targeted drugs or gene delivery into tissues of interest. Mechanical shock waves are released during ultrasound mediated microbubble destruction and the waves facilitate drug delivery into target tissues through transient blood vessel disruption. However, the clinical use of this technique has been limited through vascular system. In this study, the effects of microbubble mediated low intensity ultrasound therapy on directly delivered mechanical shock waves and controlled drug release were investigated. In conclusion, low intensity ultrasound therapy accelerates the homing of chondrogeic progenitor cells toward injured sites in cartilage via triggering mechanotransductive cell signaling pathways. This may result in speed up the return to normal cellularity and cartilage integrity by accelerating cartilage matrix repair. Low intensity ultrasound therapy was investigated as an energy modulator for chondrocytes via reactive oxygen species production in articular cartilage; however, little effects of ultrasound therapy driven cartilage energy modulation were found. The strong relationship between microbubbles mediated low intensity ultrasound therapy and the controlled release of drugs and mechanical shock waves was found. This strongly suggests that low intensity ultrasound therapy can play a role as a non-invasive controller for the release of drugs and lethal shock waves upon request.

Lubricin, or proteoglycan 4 (PRG4), is a secreted, glycosylated protein that binds to cartilage surfaces, which functions as a boundary lubricant. The loss of lubricin from cartilage is identified as a major pathogenic factor in post-traumatic osteoarthritis (PTOA) that has now been the aim of therapeutic intervention. Intra-articular injection of PRG4 protein provides short-term benefits that might be extended using sustained delivery methods such as in gene therapy. Here we describe the development and testing of such therapy using adeno-associated virus (AAV) as a vector for the transfer of PRG4-green fluorescent protein (GFP) fusion gene. Our recombinant PRG4 gene produces a PRG4-GFP fusion protein to facilitate tracking of its expression and distribution on joint surfaces. We hypothesized that PRG4-GFP is fully functional as a cartilage lubricant and that PRG4-GFP produced in vivo is expressed by synoviocytes and other joint cells, and cartilage surfaces remained coated for several weeks up to months after intra-articular injection of the virus. PRG4-GFP showed lubricin-like cartilage binding in vitro, and lubrication immunoblot analysis confirmed that purified PRG4-GFP from cultured media conditioned by PRG4-GFP-transduced synoviocytes was heavily glycosylated, while confocal microscopy revealed binding of the fluorescent fusion protein to cartilage surfaces. Metal-on-cartilage friction tests showed that PRG4-GFP reduced friction coefficients to a degree comparable to that of synovial fluid and had strong chondro-protective effects in explanted cartilage exposed to shear loading. The chondrocyte viability after shear loading showed that PRG4-GFP had a strong chondro-protective effect on par with that of the synovial fluid. Confocal microscopy and immunohistology confirmed that cartilage surfaces in the stifle joints of mice injected with viruses were coated with PRG4-GFP for up to 2 or 4 weeks after the treatment. The overexpression of PRG4-GFP and coating of cartilage surfaces in the stifle joints of mice injected with Adeno-Associated Virus for the transfer of PRG4-GFP fusion gene (AAV-PRG4-GFP) was confirmed by confocal microscopy and immunohistology for up to 2 or 4 weeks post-injection. The μCT imaging and immunohistology in AAV-PRG4-GFP injected rabbit knees showed stronger inhibition in degeneration of damaged tissues than in AAV-GFP injected control group. Collectively these findings indicate that AAV-PRG4-GFP transduction is a valuable new tool for evaluating the effects of long-term lubricant supplementation on PTOA in animal models.

Nanoporous materials have been widely used in the fields of biological and chemical sensing, chemical separation, heterogeneous catalysis and biomedicine due to their merits of high surface area-to-volume ratio, chemical and thermal stabilities, and flexible surface modification. However, as the nature of nanoporous materials, they are inherently heterogeneous in the micro- and nanoenvironments. The environmental heterogeneity plays a decisive role in determining the performance of various applications of nanoporous materials. In order to provide an in-depth understanding of the nanoporous materials, it is of great interest to investigate the environmental heterogeneity in them. Single molecule spectroscopy, combined the quantitative confocal fluorescence imaging which possesses the capability of optical sectioning, has demonstrated to be a powerful tool to approach the environmental heterogeneity inside nanoporous materials. Single molecule spectroscopy is an ultrasensitive technique for probing molecular transport and properties of individual molecules. This technique has been extensively used in the research of environmental heterogeneity in nanoporous materials since it removes the issues of ensemble averaging and directly approaches detailed information that is obscured in ensemble measurements. In order to proficiently interpret single molecule data, we developed a comprehensive methodology – single molecule counting – for characterizing molecular transport in nanoporous silica. With this methodology as a tool, the nanoenvironmental heterogeneity inside the nanopores of C18-derivatized silica particles was explored by probing single molecular diffusion inside the pores. By employing single molecule ratiometric spectroscopy and a solvatochromic fluorophore as viii reporter of local environment, the gradient in nanopolarity as well as the nanoviscosity along the C18 layer after the inclusion of solvent was uncovered. The chemical properties of solute molecules at the nanopore surface are ultimately controlled by the energetics of the solute-interface interactions. The imaging of distribution of energies would be a decisive approach to assess the fundamental heterogeneity of the interface. To this end, we investigated the ΔG distribution of C18-derivatized nanoporous silica particles with quantitative confocal imaging. The pixel-to-pixel and particle-to-particle analysis showed the existence of ΔG heterogeneity between particles as well as within individual particles. The heterogeneity in ΔG could be partially responsible for band broadening in chemical separations and significantly affect overall reaction yield when using nanoporous materials as solid support for heterogeneous catalysis.

Ultraluminous X-ray (ULX) sources are non-nuclear extragalactic accreting compact objects whose X-ray luminosities exceed the Eddington limit for stellar mass black hole binaries (BHB). Their high luminosities suggest they are either intermediate mass black holes, that their emission is beamed, or that they are emitting at super-Eddington rates. We observed the ULX IC 342 X-1 simultaneously in X-ray and radio with Chandra and the VLA to investigate previously reported unresolved radio emission coincident with the ULX. The Chandra spectrum appears to be consistent with an accretion disc-dominated thermal state and suggests a mass of the black hole using the modeled inner disc temperature to be 157Mʘ ≤ M √ (cosi) ≤ 200 Mʘ. No significant radio emission was observed, consistent with the source being in a thermal disc-dominated state. Reanalysis of previous X-ray observations of the source shows that high energy curvature often interpreted as evidence for supercritical accretion cannot confidently be identified using the 2-10 keV energy band. Black hole systems such as BHBs, ULXs, and AGN represent the greatest test labs in the universe for the study of extreme gravity. Emission from the accretion disk and scattering from the surrounding corona allow study of the ultra-strong gravity and magnetic fields very near the central BH engine. However, many of these effects are imprinted as polarization of the emission and are invisible to spectral and timing studies alone. The outflows from AGN are also thought to play a key role in galaxy shaping and cluster formation. High efficiency and spectral resolution are required to measure ionization-velocities and density parameters from these sources to constrain the outflow structure. Beamline studies and theoretical modeling were carried out to characterize the throughput and spectral resolving power of off-plane gratings for use in future x-ray observatories which will make these measurements. Additionally, synchrotron measurements were carried out to test theoretical predictions of strong polarization response for off-plane diffraction gratings. The empirical results of this study are the first to demonstrate a lack of polarization sensitivity for grazing-incidence off-plane gratings and support more complex modeling results than used previously.

The overall aim of this current research was to investigate effects of individual differences and task demand on co-speech gestures in communication. Specifically, we examined whether gesture use affected speakers' information content, and whether individual differences in working memory (WM) profiles and lexical retrieval, and task demand could account for variability in gesture use. Forty-four speaker-listener pairs of Mandarin-speaking adults participated in a video description task. The speaker watched and described motion event videos to the listener, who had two options to choose from. The speaker's descriptions were transcribed and coded for motion element type (manner, path, source, goal, and trajectory), modality use (speech vs. gesture), gesture type (deictic vs. iconic), gestures' relation to speech (complementary vs. supplementary), and information type carried by gesture (spatial vs. semantic). A WM profile/discrepancy was measured by a difference between visuo-spatial and verbal working memory using Automated Working Memory Asessment (Alloway, 2007). Lexical retrieval was measured using a semantic fluency task (naming `animals' or `foods' in a one-minute interval). Task demand was manipulated by changing number of motion elements to be described in each video, ranging from two to four. The results of an ANOVA showed that speakers did not include more information when they chose to gesture, although they sometimes used supplementary gestures that carried information absent from speech. However, a series of mixed model regression analyses showed that spatial complementary gestures decreased with task demand, whereas spatial supplementary gestures increased with task demand. Also, Individual differences in WM discrepancy and spatial WM capacity, not lexical retrieval, predicted production of semantic supplementary gestures. The interaction between task demand and WM discrepancy predicted spatial complementary gestures. Also, the interaction between task demand and WM discrepancy predicted semantic supplementary gestures. Most importantly, we found that verbal dominant speakers produced fewer spatial complementary gestures when task demand was high, whereas spatial dominant speakers used these gestures similarly across task demands. Also, spatial dominant speakers tended to use more semantic supplementary gestures than verbal dominant speakers when task demand was low, but no such differences were found when task demand was high. Taken together, our findings reveal that individuals' gesture production is a complex process, in which speaker-internal factors, such as WM, and speaker-external factors, such as task demand, and even interactions between the two factors could play a role. Given that communication is dynamic and complex, instead of restricting to one factor at a time, we may need to expand our scope to more influencing factors and their interactions to fully understand the underlying mechanism of multi-modal communication.