State Space Modelling of Dynamic Choice Behavior with Habit Persistence

In this dissertation, I present a new approach to capturing dependence across time in dynamic choice data. To achieve this, I develop a state space dynamic choice model and a novel algorithm to fit the data. Instead of capturing dependence in outcomes through lagged response variables, referred to as state dependence, I introduce a lagged utility term through the latent state equation. The lagged utility term captures habit persistence, which has not been explored directly in earlier models (Heckman, 1981b). The autoregressive nature of the lagged utility provides a significantly richer summary of prior utility than a lagged outcome variable. The fitting algorithm combines a non-linear particle filter with a standard Metropolis-Hastings step to compute Bayesian posterior estimates of the parameters. The model can capture habit persistence (inertia), variety seeking, serial correlation, and unobserved heterogeneity. Through simulation analysis, I demonstrate that while the proposed method is effective in estimating the parameters, both a large sample size and the number of simulated particles are critical. Misspecification in serial correlation in the random component of the utility function is shown to result in biased estimates for certain coefficients, although not the habit persistence term. This method avoids the initial conditions problem common with lagged variables (Wooldridge, 2010). From the perspective of a marketer, the value of the proposed model stems from its ability to distinguish the effects of habit, variety seeking, and heterogeneity. The algorithm is applied to case studies involving the sales of fast-moving consumer goods, as recorded in scanner data furnished by a major grocery store. The studies demonstrate the wide-ranging variation in purchasing habits and price sensitivity across customers; this variation highlights the value of the individual-level models applied in this study. Specifically, we find the existence of habitual purchasing behavior in utilitarian goods (e.g., cereal and soft drinks). However, in hedonic goods (e.g., beer), we find no evidence of habit persistence, which is in agreement with earlier studies

Topical Application of Chrysanthemum indicum L. Attenuates the Development of Atopic Dermatitis-Like Skin Lesions by Suppressing Serum IgE Levels, IFN-γ, and IL-4 in Nc/Nga Mice

Chrysanthemum indicum L. (CIL) is widely used as an anti-inflammatory agent in Asia and our preliminary study revealed that CIL reduced interleukin (IL)-4 and IL-13 in 2,4-dinitrochlorobenzene (DNCB)-treated HaCaT cells, a human keratinocyte cell line. We investigated the atopic dermatitis (AD) effect of topically applied CIL in mice with AD-like symptoms. After topical application of 1,3-butylen glycol (control), CIL-Low (5%), CIL-High (30%), or 0.1% hydrocortisone (HC) on the AD-like skin lesions in DNCB-treated NC/Nga mice for 5 weeks, the ear thickness, mast cell infiltration, and serum immunoglobulin E (IgE), IgG1, IL-4 and interferon (IFN)-γ were measured. The gene expressions of IL-4, IL-13, and IFN-γ in the dorsal skin were assayed. CIL treatment dosedependently reduced severity of clinical symptoms of dorsal skin, ear thickness, and the number of mast cells and eosinophils. CIL-High significantly decreased serum IgE, IgG1, IL-4, and IFN-γ levels and reduced mRNA levels of IFN-γ, IL-4, and IL-13 in dorsal skin lesion. The improvement by CIL-High was similar to HC, but without its adverse effects such as skin atrophy maceration, and secondary infection. In conclusion, CIL may be an effective alternative substance for the management of AD

Luxury Fashion Consumption: The Interplay of Guilt and Pleasure

We draw on the Affect Balance Theory to (a) explore whether two distinct modes of luxury consumption (i.e., conspicuous consumption and style consumption) are related to pleasure (i.e., positive affect) and guilt (i.e., negative affect); and (b) determine whether pleasure and guilt interplay to make interactive impacts, as well as independent impacts, on consumers’ repurchase intention

Flow-Induced Voltage Generation Over Monolayer Graphene in the Presence of Herringbone Grooves

While flow-induced voltage over a graphene layer has been reported, its origin remains unclear. In our previous study, we suggested different mechanisms for different experimental configurations: phonon dragging effect for the parallel alignment and an enhanced out-of-plane phonon mode for the perpendicular alignment (Appl. Phys. Lett. 102:063116, 2011). In order to further examine the origin of flow-induced voltage, we introduced a transverse flow component by integrating staggered herringbone grooves in the microchannel. We found that the flow-induced voltage decreased significantly in the presence of herringbone grooves in both parallel and perpendicular alignments. These results support our previous interpretation

Preparative Synthesis of dTDP-L-Rhamnose Through Combined Enzymatic Pathways

dTDP-L-rhamnose, an important precursor of O-antigen, was prepared on a large scale from dTMP by executing an one-pot reaction in which six enzymes are involved. Two enzymes, dTDP-4-keto-6-deoxy-D-glucose 3,5-epimerase and dTDP-4-keto-rhamnose reductase, responsible for the conversion of dTDP-4-keto-6-deoxy- D-glucose to dTDP-L-rhamnose, were isolated from their putative sequences in the genome of Mesorhizobium loti, functionally expressed in Escherichia coli, and their enzymatic activities were identified. The two enzymes were combined with an enzymatic process for dTDP-4- keto-6-deoxy-D-glucose involving TMP kinase, acetate kinase, dTDP-glucose synthase, and dTDP-glucose 4,6- dehydratase, which allowed us to achieve a preparative scale synthesis of dTDP-L-rhamnose using dTMP and glucose-1-phosphate as starting materials. About 82% yield of dTDP-L-rhamnose was obtained based on initial dTMP concentration at 20 mM dTMP, 1 mM ATP, 10 mM NADH, 60 mM acetyl phosphate, and 80 mM glucose-1- phosphate. From the reaction with 20 ml volume, approximately 180 mg of dTDP-L-rhamnose was obtained in an overall yield of 60% after two-step purification, that is, anion exchange chromatography and gel filtration for desalting. The purified product was identifiedbyHPLC, ESI-MS,andNMR,showingabout95%purity

Characterization of GDP-mannose Pyrophosphorylase from Escherichia Coli O157:H7 EDL933 and Its Broad Substrate Specificity

GDP-mannose pyrophosphorylase gene (ManC) of Escherichia coli (E. coli) O157 was cloned and expressed as a highly soluble protein in E. coli BL21 (DE3). The enzyme was subsequently purified using hydrophobic and ion exchange chromatographies. ManC showed very broad substrate specificities for four nucleotides and various hexose-1-phosphates, yielding ADP-mannose, CDP-mannose, UDP-mannose, GDP-mannose, GDP-glucose and GDP-2-deoxy-glucose

One-pot Enzymatic Synthesis of Deoxy-thymidine-diphosphate (TDP)-2-deoxy-∝-d-glucose Using Phosphomannomutase

Production of deoxy-thymidine-diphosphate (TDP)-sugars as substrates of glycosyltransferases, has been one of main hurdles for combinatorial antibiotic biosynthesis, which combines sugar moiety with aglycon of various antibiotics. Here, we report the one-pot enzymatic synthesis of TDP-2-deoxy-glucose employing high efficient TMP kinase (TMK; E.C. 2.7.2.12), acetate kinase (ACK; E.C. 2.7.1.21), and TDP-glucose synthase (TGS; E.C. 2.7.7.24) with phosphomannomutase (PMM; E.C. 5.4.2.8). In this study, replacing phosphoglucomutase (PGM; E.C. 5.4.2) by PMM from Escherichia coli gave four times higher specific activity on 2-deoxy-6-phosphate glucose, suggesting that the activity on 2-deoxy-glucose-6-phosphate was mainly affected by PMM activity, not PGM activity. Using an in vitro system starting from TMP and 2-deoxy-glucose-6-phosphate glucose, TDP-2-deoxy-glucose (63% yield) was successfully synthesized. Considering low productivity of NDP-sugars from cheap starting materials, this paper showed how production of NDP-sugars could be enhanced by controlling mutase activity