Inclusion complexes of cyclodextrins with hydrophobic ionic liquids

Two imidazolium-based hexafluorophosphate ionic liquids (ILs), 1-butyl-3-methylimidazolium hexafluorophosphate and 1-dodecyl-3-methylimidazolium hexafluorophosphate, were used to form inclusion complexes (ICs) with α- and β-cyclodextrins (CDs). Formation of the ICs of each CD with each IL was confirmed by the appearance of a characteristic peak in the UV region. Characterisation of the ICs by NMR and FT-IR spectroscopy provided information about the interactions between the host and guest molecules and the structure of the ICs. Temperature-dependent particle size analysis by dynamic light scattering suggested that the size of the host and the guest governs their stability.     

Higher order fully discrete scheme combined withH 1-Galerkin mixed finite element method for semilinear reaction-diffusion equations

We first apply a first order splitting to a semilinear reaction-diffusion equation and then discretize the resulting system by anH ¹-Galerkin mixed finite element method in space. This semidiscrete method yields a system of differential algebraic equations (DAEs) ofindex one. Apriori error estimates for semidiscrete scheme are derived for both differential as well as algebraic components. For fully discretization, an implicit Runge-Kutta (IRK) methods is applied to the temporal direction and the error estimates are discussed for both components. Finally, we conclude the paper with a numerical example.     

A general framework for frequentist model averaging In Celebration of Professor Lincheng Zhao's 75th Birthday

Model selection strategies have been routinely employed to determine a model for data analysis in statistics, and further study and inference then often proceed as though the selected model were the true model that were known a priori. Model averaging approaches, on the other hand, try to combine estimators for a set of candidate models. Specifically, instead of deciding which model is the 'right' one, a model averaging approach suggests to fit a set of candidate models and average over the estimators using data adaptive weights.In this paper we establish a general frequentist model averaging framework that does not set any restrictions on the set of candidate models. It broaden, the scope of the existing methodologies under the frequentist model averaging development. Assuming the data is from an unknown model, we derive the model averaging estimator and study its limiting distributions and related predictions while taking possible modeling biases into account.We propose a set of optimal weights to combine the individual estimators so that the expected mean squared error of the average estimator is minimized. Simulation studies are conducted to compare the performance of the estimator with that of the existing methods. The results show the benefits of the proposed approach over traditional model selection approaches as well as existing model averaging methods.     

Induced Biofilm Cultivation Enhances Riboflavin Production by an Intertidally Derived <Emphasis Type="Italic">Candida famata</Emphasis>

The aim of the investigation was to ascertain if surface attachment of Candida famata and aeration enhanced riboflavin production. A newly designed polymethylmethacrylate (PMMA) conico-cylindrical flask (CCF) holding eight equidistantly spaced rectangular strips mounted radially on a circular disk allowed comparison of riboflavin production between CCFs with hydrophobic surface (PMMA-CCF), hydrophilic glass surface (GS-CCF), and 500-ml Erlenmeyer flask (EF). Riboflavin production (mg/l) increased from 12.79 to 289.96, from 54.44 to 238.14, and from 36.98 to 158.71 in the GS-CCF, EF, and PMMA-CCF, respectively, when C. famata was grown as biofilm-induced cultures in contrast to traditional planktonic culture. Production was correlated with biofilm formation and planktonic growth was suppressed in cultivations that allowed higher biofilm formation. Enhanced aeration increased riboflavin production in hydrophilic vessels. Temporal pattern of biofilm progression based on two-channel fluorescence detection of extracellular polymeric substances and whole cells in a confocal laser scanning microscope followed by application of PHLIP and ImageJ volume viewer software demonstrated early maturity of a well-developed, stable biofilm on glass in contrast to PMMA surface. A strong correlation between hydrophilic reactor surface, aeration, biofilm formation, and riboflavin production was established in C. famata. Biofilm culture is a new-found means to improve riboflavin production by C. famata.     

A (2+1)-dimensional combined KdV–mKdV equation: integrability,stability analysis and soliton solutions

Nonlinear Dynamics - In this study, the (2+1)-dimensional combined Korteweg–de Vries and modified Korteweg–de Vries equation has been considered for the first time. Firstly, we check...     

Impairing effect of fibrinogen on the mono-/bi-layer form of bovine lung surfactant

Lung surfactant (LS), a lipid–protein mixture responsible for alveolar stability, is inhibited by serum proteins leaked into the lungs in disease. Interaction of bovine lipid extract surfactant (BLES), a clinical replacement lung surfactant, with serum protein fibrinogen (Fbg) was studied employing various structural and biophysical techniques in adsorbed films and bulk bilayer dispersions. Surface tension area isotherms of the adsorbed films revealed the suppression of interfacial activity of BLES by Fbg (adsorption and surface tension reduction). Fbg, predominantly associated with the fluid phase of BLES films, resulted in the aggregation of the gel lipid domains as evidenced by atomic force microscopy. BLES bilayer dispersion showed phase transition from a diffused gel to liquid–crystalline phase in the temperature range 10–35 °C as studied by differential scanning calorimetry (DSC). Fbg resulted in the shift of peak to a higher transition temperature for the maximal heat flow (T _max) of BLES dispersions. Combined Raman and FTIR spectral studies of the BLES/Fbg dispersions revealed that Fbg altered the –CH₂–, –CH₃, and –PO₄ ^? vibrational modes of the phospholipids present in BLES, suggesting the condensing and dehydrating effect of the protein on surfactant. Studies suggest that Fbg, by directly interacting with the gel lipids in LS in bulk dispersions, alter the packing of the films formed at the interface, and can be used as a specific model for lung disease.     

Components of optimal price under logit demand

Demand for durables can be modeled using a logit framework in which a customer chooses one brand from several alternatives, or buys nothing at all. In this framework, optimal prices for competing brands can be expressed as a system of non-linear equations, which, however, do not have closed form solutions. Although the optimal price can be determined by numerical search, the solution offers limited understanding of its components. In this article, we develop a linear approximation of the Nash equilibrium optimal price of a brand as its marginal cost plus a weighted sum of: (1) the inverse of the price sensitivity of the market, (2) the average value added by all brands in the market, and (3) the value advantage (or disadvantage) of the brand. The weights depend primarily upon the number of competing brands, with price insensitivity having the strongest impact, followed by value advantage of the brand, and average value added by all brands. This approximation for optimal price is found to be robust under a wide range of conditions. Additionally, we demonstrate that using the approximation results in only marginal deviation of profits from the theoretical Nash optimal.     

A note on equivariant Euler characteristic

We give a new equivariant cohomological characterization of the equivariant Euler characteristic of aG-simplicial set as defined by Brown. This implies in particular that the equivariant Euler characteristic is aG-homotopy invariant.