Self-assembly of nanoscale materials to form intriguing structures has garnered considerable attention due to their potential applications in optical, electronic, magnetic and information storage devices. Among all the efforts to pattern functional polymers and nano materials, flow-enabled self-assembly (FESA) stands out as a lithography-free evaporation-induced self-assembly technique to construct large-scale 0D, 1D and 2D periodic structures in a simple, robust and cost effective manner. In the first part of the thesis, flow-enabled self-assembly of polystyrene is chosen as the model system, and systematic experiments have been conducted to reveal intrinsic and external variables that lead to 3 possible FESA patterns (i.e., coffee ring induced spoke pattern, fingering instability induced strip pattern, and their intermediate network-like structures). In the second part of the thesis, applications of FESA in patterning electrochromic polymers and fabricating PS-PMMA strips as etching mask of Si microchannels are demonstrated. Both applications convincingly illustrate the advantages of cost effective, large yield and flexible control of flow-enabled self-assembly.

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Assessing the conditions of productivity of individual workers who process information and use IT has been a concern for many researchers. Prior studies have applied different theoretical foundations to study the relationship between IT use and productivity at individual level in post adoption scenarios and have provided mixed results. In the last decades, the proposition that there is a need for a set of factors to be changed in a synchronized fashion when using an IT system has received particular attention. Very little, however, is known about the configurations of these factors at individual level. To investigate this gap, we have designed a new research model of an information worker’s individual productivity when a more aligned IT system is used in a synchronized manner with both individual and organizational factors. The formulated research model is grounded on the complementarity theory, functioning here as a meta-theory guiding the linking of productivity theory, Kirton’s adaption-innovation theory, and several theoretical bodies on the structure of production processes and human resource management. The formulated model was tested in two empirical studies – a longitudinal quasi-randomized field experiment and an online experiment – conducted to investigate configurations of complementary factors that increase productivity when a new, more aligned IT system is used. Overall, the two studies shed important light on configurations of complementary factors and the improvement of the research design to study their impact on IT-enabled productivity. The obtained results contribute to the research that focuses on individual information worker IT-enabled productivity as well as research that rests on the complementarity theory with new configurations of complementary factors that, when matched correctly, can increase individual productivity of information workers. Eventually, the studies presented here advocate that further research is needed to increase our in-depth understanding of complementary factors and their impact on individual IT-enabled productivity of information workers.

Approved for public release, distribution is unlimited / The Basic School (TBS) is the first school assignment for all Marine Officers. While assigned to TBS unrestricted ground officers compete for and are assigned a Military Occupational Skill (MOS). The process of educating the Marine Officers about the different MOSs is primarily accomplished by word of mouth at MOS Mixers (social events) and one-on-one discussions. The assignment of the MOS to the Marine Officer is based on the officer's lineal standing within his/her company. Officers are ranked lineally based on a composite score of academic and leadership grades. To ensure a quality distribution of officers into MOSs, the company is divided into thirds (Top, Middle, Bottom) and the vacancies assigned to the company are divided into thirds (Top, Middle, Bottom). Officers compete for an MOS within their assigned third. The current assignment system has remained virtually unchanged over the last thirty years. It is a mostly manually process that provides little visibility of the data, and does not utilize automated information tools for report generation of statistical information. This joint thesis team has developed a Two-Tier Client/Server Information Management System for use by the lieutenants and staff officers of The Basic School and it is called MyMOS. This system was developed using current industry standards that are compliant with those of the Department of Defense. It is the first of its kind at TBS and is designed to be employed as an operational system. MyMOS was designed with an interface that would maximize acceptance and reduce total ownership cost. / Captain, United States Marine Corps / Lieutenant Colonel, United States Marine Corps

Accumulating evidence highlights the importance of studying the migration of cells within the context of their natural environment as manipulating the substrate on which a cell is migrating can have a dramatic impact on the mode/mechanisms employed by cells during migration. Central to this phenomenon is the requirement of adhesion to the ECM in order to gain traction during migration. Integrins constitute the main family of cell receptors involved in mediating cell-ECM interactions during motility. Whilst traditionally two-dimensional cell culture studies have placed emphasis on the importance of these receptors for spreading and migration, it has become evident that within more confined environments these receptors, at least for some cell types, are less crucial. In this research we utilise Drosophila embryonic hemocytes as an in vivo model for cell migration. We show that whilst hemocytes migrate within confined environments in vivo, these cells depend on integrins for powering both developmental and inflammatory migrations. Given the close association between these receptors and the actin cytoskeleton we were surprised to discover that removal of the main β integrin subunit, Myospheroid, did not affect cell spreading in vivo and had only a small impact on lamellipodial structure and dynamics. Furthermore we discovered that, in contrast to other cell types previously analysed, removal of this integrin subunit in hemocytes was not accompanied by an increase in the rate of actin retrograde flow within the protrusions, which we believe could reflect abrogation of a positive feedback between Rho, ROCK and Myosin II contraction. Instead, we discover a key role for integrins in regulating the microtubule cytoskeleton, in the maintenance of a polarised microtubule bundle, termed a ‘microtubule-arm’. Although the molecular mechanisms by which this stabilisation is coordinated have yet to be identified, this provides important insight into the co-regulation of adhesion and microtubule cytoskeleton important for the migratory behaviour of these cells. Cell migration reflects the complex and integrated regulation of the actin cytoskeleton by diverse families of actin regulatory proteins. Using hemocytes as a model system, we also explore the regulatory interactions between two main actin regulatory proteins, Diaphanous and Enabled, in vivo. Whilst the function of these proteins in the formation of filopodial protrusions is overlapping, recent research has highlighted the ability of these proteins to regulate the activity of one another. We find that co-expression of Enabled in hemocytes is able to rescue the morphological and migratory defects resulting from overexpression of active Diaphanous. Thus, data here presents Enabled as a negative regulator of Diaphanous, which may play an important role in the migration of hemocytes in vivo.

Prostaglandins (PGs) are small, lipid signaling molecules produced downstream of cyclooxygenase (COX) enzymes. PG signaling regulates many processes including pain, inflammation, fertility, cardiovascular function and disease, and cancer. One mechanism by which PG signaling exerts its function is by regulating the dynamics of the actin cytoskeleton; however, the exact mechanisms remain largely undefined. Drosophila oogenesis provides an ideal system to determine how PG signaling regulates the actin cytoskeleton. Drosophila follicles, or eggs, pass through 14 well- characterized, morphologically defined stages of development. Each developing follicle is comprised of 16 interconnected germline-derived cells (15 nurse cells and 1 oocyte) that are surrounded by a layer of somatically derived epithelial cells. During Stage 10B (S10B), the nurse cells form a cage-like network of parallel actin filament bundles that extend from the nurse cell membranes inward, toward the nurse cell nuclei. During Stage 11 (S11), the nurse cells rapidly transfer their cytoplasmic contents into the oocyte in an actomysoin-dependent contraction termed nurse cell dumping. Previous work uncovered that the Drosophila COX-like enzyme, Peroxinectin-like (Pxt), and thus PG signaling, is required to promote both actin filament bundle formation during S10B and subsequent nurse cell dumping. This finding established Drosophila oogenesis as a genetically tractable model in which to elucidate the conserved mechanisms underlying PG- dependent actin remodeling. The research presented in this dissertation focused on identifying actin-binding proteins that are regulated by PG signaling during Drosophila oogenesis. To identify these downstream effectors, we performed a dominant modifier screen to uncover factors that could suppress or enhance the ability of COX inhibitors to block nurse cell dumping in vitro. This screen revealed a number of actin-binding proteins that enhance the dumping defects caused by COX-inhibition, including the actin bundling protein, Fascin (Drosophila Singed, Sn); the actin filament elongation factor, Enabled (Ena); and the actin filament capper, Capping protein (Drosophila Capping protein alpha, Cpa, and beta, Cpb). Through a collaborative effort between Christopher Groen and myself, Fascin was shown to mediate PG-dependent cortical actin integrity and actin bundle formation during Drosophila ooogenesis. Ena and Capping protein regulate actin filament elongation through opposing actions: Ena promotes their elongation, while Capping protein binds to, or caps, the growing end of actin filaments to prevent their further elongation. However, genetic reduction of either Ena or Capping protein enhance the nurse cell dumping defects caused by COX inhibition. These findings suggest that Ena activity must be balanced to promote proper actin remodeling during S10B. Ena localization to the growing ends of actin filament bundles is reduced in pxt mutants during S10B, suggesting that PG signaling is required to promote Ena localization at this stage. Together, these data support a model in which PG signaling promotes actin remodeling during S10B, at least in part, by modulating Ena-dependent actin remodeling. While PG signaling promotes parallel actin filament bundle formation during S10B, PGs also restrict actin remodeling during Stage 9 (S9). Loss of Pxt results in early actin remodeling, including the formation of extensive actin filaments and actin aggregate structures within the posterior nurse cells of S9 follicles. Wild-type follicles exhibit similar structures at a low frequency. Ena preferentially localizes to the early actin structures observed in pxt mutants and reduced Ena levels strongly suppress early actin remodeling in pxt mutants. These data indicate that PG signaling temporally restricts actin remodeling during Drosophila oogenesis, at least in part, through negative regulation of Ena localization or activity during S9. The data presented here support a model in which PG signaling coordinates the concerted activity of a number of actin-binding proteins to regulate actin remodeling during Drosophila oogenesis. Specifically, PG signaling temporally restricts actin remodeling during S9 of Drosophila oogenesis, but promotes parallel actin filament bundle formation during S10B. PG signaling achieves this temporal regulation, at least in part, through differential regulation of Ena-dependent actin remodeling. Based on prior pharmacologic studies, we hypothesize that PGE2 is required to restrict Ena-dependent actin remodeling during S9, while PGF2Α; is required to promote Ena-dependent actin remodeling during S10B. Determining how these signaling cascades achieve differential regulation of Ena throughout Drosophila oogenesis is an important area for future investigation. As both the actin cytoskeletal machinery and PG signaling are conserved across species, the data presented here provide new and significant insights into the likely conserved mechanisms by which PG signaling regulates actin remodeling across species.

This exploratory research used a mixed-methods design to compare the effectiveness of a telepresence-enabled cognitive apprenticeship model of teacher professional development (TEAM-PD) to that of a traditional workshop model by examining outcomes in teacher pedagogy and student achievement. Measures of the lll degree to which teachers in both groups enacted mathematics pedagogy provided mixed results. Both groups demonstrated similar patterns of behavior and cognition, indicating modest levels of pedagogy implementation. Although the experimental group demonstrated higher levels of enactment of the mathematics pedagogy, the comparison group demonstrated a faster rate of growth. Student outcome data were clear: students of teachers in the experimental group scored substantially higher on a test of relevant mathematics content than students of teachers in the comparison group. Collectively the results suggest that TEAM-PD has potential to be an effective model of teacher professional development.

The development of a general approach for non-destructive chemical and biological functionalization of materials could expand opportunities for both fundamental studies and creating various device platforms. Phage display has emerged as a powerful method for selecting peptides that possess enhanced selectivity and binding affinity toward a variety of targets. In this study, a powerful yet benign approach for identifying binding motifs to materials like (Poly) dimethylsiloxane, epoxy, and (Poly) ethylenetetraphthalate and peptide nanotubes has been demonstrated via comprehensively screened phage-displayed peptides. Further, along with the development of microstructures, micropatterns and micro-molecular self-assembly, recognition with phage-displayed peptides can be specifically localized in these microstructures. In addition, the development of a facile approach for fabricating a library of precisely positioned nanostructures and microfluidic systems based on mammalian hair offers exciting opportunities in fundamental research and practical applications. The current top-down and bottom-up nanofabrication methods have been restricted in accessibility in standard labs due to their high cost and complexity. Novel fabrication methods utilizing biomimetic materials and natural proteins for large-scale nanopatterning with hierarchical assembly of functional materials have been reported. It is anticipated that these results could open up exciting opportunities in the use of peptide-recognized materials in fundamental biochemical recognition studies, as well as in applications ranging from analytical storage devices, hybrid materials, sensors, surface and interface, to cell biology.

The IEEE 802.15.4 has attracted time-critical applications in wireless sensor networks (WSNs) because of its beacon-enabled mode and guaranteed timeslots (GTSs). However, the GTS scheme’s security still leave the 802.15.4 MAC vulnerable to attacks. Further, the existing techniques in the literature for securing 802.15.4 either focus on non beacon-enabled 802.15.4 or cannot defend against insider attacks for beacon-enabled 802.15.4. In this thesis, we illustrate this by demonstrating attacks on the availability and integrity of the beacon-enabled 802.15.4. To proof the attacks, we implement the attacks using Tmote Sky motes for a malicious node along with regular nodes. We show that the malicious node can freely exploit the beacon frames to compromise the integrity and availability of the network. For the defense, we present beacon-enabled MiniSec (BCN-MiniSec) and analyze its cost.

In this study, we seek to contribute to theoretical understanding of the effect of trust on supply chain performance under different market environments. We are aiming to design the trust mechanisms suitable for network enabled organizations (Straub and Watson, 2002) to evaluate partners¡¦ trustworthiness on the fly of supplier choice. The sophistication of agent technologies in the future also can execute such supply chain negotiation based on the developed trust mechanisms. Before that, in this research, we use the multi-agent simulation system, Swarm, for simulating and analyzing the supply chain performance in four different market environments. Supply chain performance is evaluated using an example order fulfillment process of the mold industry to compare its performance with versus without trust mechanisms. Sensitivity analysis is used for examining the properties of the proposed trust mechanisms. We found that the trust mechanism will reduce the average cycle time rate and raise the in-time order fulfillment rate, but increase the unit cost of materials. Higher of trustor's propensity to trust results in higher in-time order fulfillment rate. This mechanism is better than just using quote price and due date, but it raises the unit cost of materials. The range of raised cost are controlled within 3%. We can consider this 3% additional material cost as the premium of the expectation of better quality and shorter cycle time.