University of Nebraska Omaha

About: University of Nebraska Omaha is a education organization based out in Omaha, Nebraska, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 4526 authors who have published 8905 publications receiving 213914 citations. The organization is also known as: UNO & University of Omaha.

Is Preferential Treatment of Female Offenders a Thing of the Past? A Multisite Study of Gender, Race, and Imprisonment

Abstract: Dramatic increases in the number of women incarcerated in state and federal prisons have led some researchers to conclude that differential sentencing of female offenders is a thing of the past. This study uses data on offenders convicted of felonies in Chicago, Miami, and Kansas City to address this issue. The authors find no evidence to support this “gender neutrality” hypothesis. In all three jurisdictions, women face significantly lower odds of incarceration than do men. The results also reveal that the effect of race is conditioned by gender but the effect of gender, with only one exception, is not conditioned by race; harsher treatment of racial minorities is confined to men but more lenient treatment of women is found for both racial minorities and Whites.

The perception of face gender: the role of stimulus structure in recognition and classification.

Abstract: The perception of face gender was examined in the context of extending “face space” models of human face representations to include the perceptual categories defined by male and female faces. We collected data on the recognizability, gender classifiability (reaction time to classify a face as male/female), attractiveness, and masculinity/femininity of individual male and female faces. Factor analyses applied separately to the data for male and female faces yielded the following results. First, for both male and female faces, the recognizability and gender classifiability of faces were independent—a result inconsistent with the hypothesis that both recognizability and gender classifiability depend on a face’s “distance” from the subcategory gender prototype. Instead, caricatured aspects of gender (femininity/masculinity ratings) related to the gender classifiability of the faces. Second, facial attractiveness related inversely to face recognizability for male, but not for female, faces—a result that resolves inconsistencies in previous studies. Third, attractiveness and femininity for female faces were nearly equivalent, but attractiveness and masculinity for male faces were not equivalent. Finally, we applied principal component analysis to the pixel-coded face images with the aim of extracting measures related to the gender classifiability and recognizability of individual faces. We incorporated these model-derived measures into the factor analysis with the human rating and performance measures.

Linear and nonlinear optical properties of carbon nanotubes from first-principles calculations

Abstract: A systematic ab initio study of the optical as well as structural and electronic properties of the carbon nanotubes within density-functional theory in the local-density approximation has been performed. Highly accurate full-potential projected augmented wave method was used. Specifically, the optical dielectric function $\ensuremath{\varepsilon}$ and second-order optical susceptibility ${\ensuremath{\chi}}^{(2)}$ as well as the band structure of a number of the armchair [(3,3),(5,5),(10,10),(15,15),(20,20)], zigzag [(5,0),(10,0),(15,0),(20,0)] and chiral [(4,2),(6,2),(6,4),(8,4), (10,5)] carbon nanotubes have been calculated. The underlying atomic structure of the carbon nanotubes was determined theoretically. It is found that for the electric field parallel to the nanotube axis $(E\ensuremath{\Vert}\mathrm{z\ifmmode \hat{}\else \^{}\fi{}}),$ the absorptive part ${\ensuremath{\varepsilon}}^{\ensuremath{''}}$ of the optical dielectric function for the small nanotubes (the diameter being smaller than, say, 25 \AA{}) in the low-energy range (0--8 eV) consists of a few distinct peaks. Furthermore, the energy position, the shape, and the number of the peaks depend rather strongly on the diameter and chirality. This suggests that one could use these distinct optical features to characterize the chirality and diameter of the grown nanotubes. In contrast, for the electric field perpendicular to the nanotube axis $(E\ensuremath{\perp}\mathrm{z\ifmmode \hat{}\else \^{}\fi{}}),$ the ${\ensuremath{\varepsilon}}^{\ensuremath{''}}$ spectrum of all the nanotubes studied except the three 4 \AA{} nanotubes in the low-energy region is made up of a broad hump. The bandwidth of the hump increases with the nanotube diameter and the magnitude of the hump is in general about half of that of the ${\ensuremath{\varepsilon}}^{\ensuremath{''}}$ for $E\ensuremath{\Vert}\mathrm{z\ifmmode \hat{}\else \^{}\fi{}}.$ Surprisingly, given their one-dimensional character, the optical anisotropy of the nanotubes is smaller than that of graphite. For the nanotubes with a moderate diameter (say, 30 \AA{}) such as the (20,20) nanotube, the optical anisotropy is not large and the ${\ensuremath{\varepsilon}}^{\ensuremath{''}}$ spectrum for both electric-field polarizations becomes rather similar to that of graphite with electric-field parallel to the graphene layers $(E\ensuremath{\perp}c).$ The calculated static polarizability $\ensuremath{\alpha}(0)$ for the semiconducting nanotubes is rather anisotropic with $\ensuremath{\alpha}(0)$ for $E\ensuremath{\Vert}\mathrm{z\ifmmode \hat{}\else \^{}\fi{}}$ being several times larger than that for $E\ensuremath{\perp}\mathrm{z\ifmmode \hat{}\else \^{}\fi{}}.$ For both electric-field polarizations, $\ensuremath{\alpha}(0)$ is nearly proportional to the square of the tube diameter. The calculated electron energy loss spectra of all the nanotubes studied here for both electric field polarizations are similar to that of $E\ensuremath{\perp}c$ of graphite, being dominated by a broad $(\ensuremath{\pi}+\ensuremath{\sigma})$-electron plasmon peak at near 27 eV and a small $\ensuremath{\pi}$-electron plasmon peak at 5--7 eV. Only the chiral nanotubes would exhibit second-order nonlinear optical behavior. Furthermore, only two tensor elements ${\ensuremath{\chi}}_{\mathrm{xyz}}^{(2)}$ and ${\ensuremath{\chi}}_{\mathrm{yzx}}^{(2)}$ are possibly nonzero with ${\ensuremath{\chi}}_{\mathrm{xyz}}^{(2)}=\ensuremath{-}{\ensuremath{\chi}}_{\mathrm{yzx}}^{(2)}.$ For all the chiral nanotubes studied here, both the real and imaginary parts of ${\ensuremath{\chi}}_{\mathrm{xyz}}^{(2)}(\ensuremath{-}2\ensuremath{\omega},\ensuremath{\omega},\ensuremath{\omega})$ show an oscillatory behavior. The absolute value of ${\ensuremath{\chi}}_{\mathrm{xyz}}^{(2)}(\ensuremath{-}2\ensuremath{\omega},\ensuremath{\omega},\ensuremath{\omega})$ of all the chiral nanotubes in the photon energy range of 0.1--3.0 eV is huge, being up to ten times larger than that of GaAs, suggesting that chiral nanotubes have potential applications in nonlinear optics, e.g., second-harmonic generation and sum-frequency generation. Nevertheless, the static value of both ${\ensuremath{\chi}}_{\mathrm{xyz}}^{(2)}$ and ${\ensuremath{\chi}}_{\mathrm{yzx}}^{(2)}$ is zero.

A Framework for Assessing the Global Diffusion of the Internet

Abstract: This paper presents a comprehensive framework for describing the diffusion of the Internet in a country. It incorporates insights gained from in-depth studies of about 25 countries undertaken since 1997. The framework characterizes diffusion using six dimensions, defining them in detail, and examines how the six dimensions relate to underlying bodies of theory from the national systems of innovation and diffusion of innovations approaches. It addresses how to apply the framework in practice, highlighting Internet diffusion determinants. This framework is useful for business stakeholders wanting to make use of and invest in the Internet, for policy makers debating how to positively (or negatively) influence its use and development, and for researchers studying the large-scale diffusion of complex, interrelated technologies.