By the content of their character? Discrimination,social identity,and observed distributions of income

ABSTRACT

This paper applies information-theoretic measures to consider the systemic effects on individual incomes of complex patterns of social and economic discrimination by race, ethnicity, and gender in the U.S. It estimates non-parametric indices of joint, conditional or incremental, and mutual information between income, social identity, and observable economic characteristics obtained using large-scale cross-sectional data from that economy. The paper advances new conceptual and empirical approaches to the nature and measurement of economic discrimination and inequalities of opportunity, founded on the formal informativeness of measures of social identity on economic outcomes. Estimated values for indices of informational association also cast new light on the effects of the intersections of gender and race/ethnicity on income, perverse patterns in the effects of education across different groups, and a few notable dynamic changes in patterns of income distribution in that economy over the past 40 years.     

Damage identification in a concrete dam by fitting measured modal parameters

We propose a method, based on an inverse problem, to obtain numerically the material parameters that characterize the elasticity tensor of a body with linear elastic behavior, using accurate measurements of the first modal parameters, namely the natural frequencies and the modes of vibration (the eigenfrequencies and the eigenvectors). Appropriate functionals are defined, whose minimum points correspond to the unknown material parameters. To obtain these minimum points a highly nonlinear parametric optimization problem is solved. Its resolution involves specific mathematical tools like the derivative of the eigenvalues and eigenvectors with respect to the material parameters, the adjoint method, and gradient methods for the minimization of the functional. An application is presented, which considers a cracked dam in which is assumed the presence of transversely isotropic material in the cracked zone. The material parameters of the transversely isotropic material are obtained by minimizing the distance between the modal parameters (eigenfrequencies and eigenvectors) of a numerical model of the dam and the observed modal parameters physically measured in the dam. The algorithm is implemented in a C++ home made code with the aid of open-source libraries for scientific computation.     

High-temperature Raman spectra of KDP:Ni crystal

High-temperature Raman scattering measurements of KDP doped with Ni (1% weight) were performed over the spectral range 50–1200 cm^?1. The X-ray powder diffraction patterns taken at room temperature and analyzed by Rietveld refinement showed that doped samples of KDP:Ni have the same tetragonal structure of a pure KDP crystal, but with a contraction of the crystalline cell. The behavior of the high-temperature Raman spectra indicate that two phase transitions occur, one at 413 K and another one at 443 K. These phase transitions occur at temperatures below the thermal dehydratation point, 488 K. DTA and TGA measurements reveals that KDP:Ni and pure KDP have the same thermal dehydratation temperature.     

Ultrasound-assisted conversion of alpha-chitin into chitosan

This paper discusses the production of chitosan by applying high intensity ultrasound irradiation to alpha-chitin suspended in 40% aqueous sodium hydroxide. The average degree of acetylation (DA) of chitosan was determined by ¹H NMR spectroscopy and titrimetry while its viscosity average molecular weight (Mv) was calculated from the intrinsic viscosity as determined by capillary viscometry. The results show that fully acid-soluble chitosans (DA < 32%; 100,000 g/mol ? Mv ? 200,000 g/mol) are produced at very high yield (>95%) by applying non-isothermal ultrasound-assisted N-deacetylation process to alpha-chitin suspension (44 mg/mL). It is also shown that such a process is more efficient than thermochemical N-deacetylation, even being carried out at a lower temperature due to the effects of high intensity ultrasound irradiation.     

Stability and enzymatic studies with omeprazole:hydroxypropyl-β-cyclodextrin

Omeprazole (OME) exhibits low stability to light, heat and humidity. In stress conditions OME stability should improve under inclusion complex form with hydroxypropyl-β-cyclodextrin (HPβCD). Stability of OME, its physical mixture (PM) with HPβCD and OME:HPβCD inclusion complex was assessed during 60 days. The inclusion complexes were prepared by kneading and freeze-drying techniques and characterized by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). A molecular modelling was also held to predict the most probable tridimensional conformation of inclusion complex OME:HPβCD. The inhibitory activity of free and complexed OME on selected enzymes, namely, papain (protease model of the proton pump) and acetylcholinesterase (enzyme present in cholinergic neurons and also involved in Alzheimer’s disease) was compared. The results obtained show that HPβCD do not protect against OME degradation, in any prepared powder, in the presence of light, heat and humidity. This may indicate that the reactive group of OME is not included in the HPβCD cavity. This fact is supported by molecular modelling data, which demonstrated that 2-pyridylmethyl group of OME is not included into the cyclodextrin cavity. In relation to enzymatic assays it was observed that free OME and OME in the binary systems showed identical inhibitory activity on papain and acethylcolinesterase, concluding that HPβCD do not affect OME activity on these two enzymes.     

Innovative Cross-Linked Polyurethane Networks Based on Cyclodextrins and Polyethylene Glycols: Inclusion Capacity and Potential Use as Controlled Release Carrier for Nifedipine

Summary: Polymers derived from cyclodextrins show several biomedical applications. In this paper, six cross-linked polyurethane networks based on β-cyclodextrin (βCD) or hydroxypropyl-β-cyclodextrin (HPβCD) and polyethylene glycols (PEG 400, PEG 1500 or PEG 4000) were synthesized by the usual two-step polymerization method. The polymers were characterized by Fourier-transformed infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The inclusion capacity was evaluated by the discoloration method of a phenolphthalein solution. In order to explore their potential use as controlled drug delivery systems, dissolution profiles and release behavior of inclusion complexes between PUR/TDI/βCD/PEG4000 or PUR/TDI/HPβCD/PEG1500 and nifedipine (NIF) were investigated. FTIR assignments confirmed the formation of urethane linkages. XRD patterns revealed that the crystallinity decreased mainly due to the crosslinking process. TGA showed three stages of mass loss attributed to water loss, cleavage of urethane bonds and volatilization of decomposition products. The inclusion capacity of cyclodextrins cross-linked with polyurethane was suitably maintained. Dissolution profiles demonstrated that the inclusion complexes PUR/TDI/βCD/PEG4000-NIF and PUR/TDI/HPβCD/PEG1500-NIF are feasible systems for controlling drug release, showing a biexponential release behavior.