Optimal control-based inverse determination of electrode distribution for electroosmotic micromixer

This paper presents an optimal control-based inverse method used to determine the distribution of the electrodes for the electroosmotic micromixers with external driven flow from the inlet. Based on the optimal control method, one Dirichlet boundary control problem is constructed to inversely find the optimal distribution of the electrodes on the sidewalls of electroosmotic micromixers and achieve the acceptable mixing performance. After solving the boundary control problem, the step-shaped distribution of the external electric potential imposed on the sidewalls can be obtained and the distribution of electrodes can be inversely determined according to the obtained external electric potential. Numerical results are also provided to demonstrate the effectivity of the proposed method

Emerald Ash Borer and the application of biological control in Virginia

The emerald ash borer (Agrilus planipennis; EAB) is an invasive wood-boring beetle whose larvae feed on ash phloem. After only 1-5 years of infestation, the larvae create extensive tunnels under the bark that disrupt the tree’s ability to transport water and nutrients, which eventually girdles and kills the tree. Since 2008, EAB has spread to all but the eastern-most counties in Virginia. Bological control is one strategy to limit EAB populations. In this project we study control by native agents (woodpeckers) and imported agents (parasitoid wasps). Mathematical models of host-parasitoid interactions and simulations based on both models and field studies will be presented. Our novel contribution extends the basic Nicholson-Bailey model to a partial refuge system, realized in Virginia where EAB infests both ash and white fringetrees with fringetrees less attractive to the parasitoids. We determine ranges for model parameters that result in stable equilibrium populations

Studies towards a Solution Structure of the Peptidoglycan Glycosyltransferases

Peptidoglycan glycosyltransferases (PGTs) are highly conserved bacterial enzymes that catalyze the polymerization of the lipidic disaccharide, Lipid II, to form individual peptidoglycan (PG) strands which are subsequently cross-linked to form mature PG, the major skeletal component of the bacterial cell wall. Recent advances in the preparation of well-defined PGT substrates have enabled the biochemical characterization of Lipid II polymerization by the PGTs. In the course of these studies, we have observed that a distinctive lag phase in the initial rate of PG synthesis by the PGTs can be abrogated if the enzyme is preincubated with Lipid IV, the shortest PG fragment. The origins of this lag phase are intriguing because the chemical transformation involved in coupling Lipid II to yield Lipid IV is identical to the transformation involved in the synthesis of longer PG fragments from Lipid II. Crystallographic structures of the PGTs with Moenomycin A, an inhibitor that is believed to bind to the same site as Lipid IV, suggest that the PGTs possess flexible regions near the putative active site that can undergo substrate-induced conformational changes to accelerate PG synthesis. However, there is currently no structural evidence on how the PGTs interact with its substrates. The work in this thesis lays the foundation for pursuing a solution structure of a Lipid IV bound PGT complex by Nuclear Magnetic Resonance (NMR) spectroscopy, enabling the study of important enzyme conformational states and structural dynamics involved in PG synthesis. Specifically, Chapter 2 of this thesis presents the biochemical evidence that the preincubation of the PGTs with a Lipid IV derivative, Gal-Lipid IV abrogates the lag phase and accelerates the initial rate of PG synthesis. Chapter 3 presents a robust methodology for obtaining multimilligram quantities of isotope labeled, monodisperse and monomeric SgtB, a PGT from a clinically relevant pathogen, Staphylococcus aureus for solution structural studies. Chapter 4 describes the systematic development of a methodology for producing a well-behaved, stable sample of Moenomycin A bound SgtB for NMR spectroscopy. Chapter 5 delineates the adaptation of the methodology described in Chapter 4 for pursuing the solution structure of Lipid IV bound SgtB.Chemistry and Chemical Biolog

Trifluorobenzamidine prevents allergic rhinitis by regulating IgE, IL-4 and IL-5 in T-cells

Purpose: To investigate the effect of trifluorobenzamidine (TBI) on a mouse model of ovalbumin (OVA)- induced allergic rhinitis. Methods: Allergic rhinitis was established in mice via sensitization on days 1, 5 and 14 through intraperitoneal injection of OVA (100 μg) in PBS. On day 15, the mice were subjected to intranasal exposure to OVA (1.5 mg dissolved in PBS). Prior to 10 days of intranasal exposure to OVA, the micewere treated with TBI at doses of 5, 10 and 20 μg/kg. Cytokine levels were determined using enzymelinked immunosorbent assay (ELISA) kits, while cyclooxygenase (COX)-2 and caspase-1 activity were assayed with western blotting. Results: Treatment with TBI significantly (p < 0.05) reduced OVA-mediated increases in nasal rub scores, and decreased serum levels of IgE, TNF-α, thymic stromal lymphopoietin (TSLP), IL-1β and histamine in mice. It also significantly regulated spleen weight and IL-4 secretion (p < 0.05) in OVAadministered mice. TBI significantly downregulated the expressions of IL-5, IL-13, TNFα, TSLP, IL-1β and IL-6 (p < 0.05). Administration of TBI caused a marked reduction in OVA-mediated increase in caspase-1 activity in mice intranasal tissues, and also significantly reduced OVA-induced excessive production of MIP-2 and ICAM-1 (p < 0.05). Moreover, TBI prevented OVA-induced infiltration of eosinophils and mast cells into intranasal tissues (p < 0.05). Conclusion: TBI reduces levels of IgE and various pro-inflammatory cytokines in OVA-administered mice. It also regulates Th1:Th2 ratio, inhibited activity of caspase-1, suppressed mast cell/eosinophil infiltration and reduced ICAM-1 and MIP-2 levels. Therefore, TBI possesses inhibitory potential against rhinitis allergy, and thus can potentially be developed as a new treatment strategy for asthma. Keywords: Trifluorobenzamidine, Anti-inflammation, Allergic rhinitis, Cytokines, Caspase-1, Itchin

An Efficient Estimation of the Mean Residual Life Function with Length-Biased Right-Censored Data

The mean residual life (MRL) function for a lifetime random variable T0 is one of the basic parameters of interest in survival analysis. In this paper, we propose a new estimator of the MRL function with length-biased right-censored data and evaluate its performance through a small Monte Carlo simulation study. The results of the simulations show that the proposed estimator outperforms the existing one referred to in Data and Model Setup Section in terms of Monte Carlo bias and mean square error, especially when the censoring rate is heavy. We also show that the proposed estimator converges in distribution under some conditions

Optimal Control-Based Inverse Determination of Electrode Distribution for Electroosmotic Micromixer

This paper presents an optimal control-based inverse method used to determine the distribution of the electrodes for the electroosmotic micromixers with external driven flow from the inlet. Based on the optimal control method, one Dirichlet boundary control problem is constructed to inversely find the optimal distribution of the electrodes on the sidewalls of electroosmotic micromixers and achieve the acceptable mixing performance. After solving the boundary control problem, results are also provided to demonstrate the effectiveness of the proposed method; the step-shaped distribution of the external electric potential imposed on the sidewalls is obtained, and the electrodes with an interlaced arrangement are inversely derived according to the obtained external electric potential

Research on the Protection and Renewal of Wanshougong Historical and Cultural Block from the Perspective of Living Inheritance

As an important part of the historical and cultural city, with the acceleration of urbanization, the protection of the block will face many challenges, aiming at the problems of breaking the traditional texture of the streets and alleys, the carrier of cultural inheritance has been destroyed, how to achieve the connection between historical inheritance and the development of the times, it is urgent to study the corresponding mode and method. From the perspective of living inheritance, this paper compares the before and after the renovation of Nanchang Wanshougong historical and cultural district through the field research and literature investigation of Nanchang Wanshougong, explores the application of intangible cultural heritage in the renewal and transformation of historical and cultural districts, and puts forward feasible suggestions for the shortcomings of historical and cultural districts after transformation