University of Colorado Colorado Springs

About: University of Colorado Colorado Springs is a education organization based out in Colorado Springs, Colorado, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 6664 authors who have published 10872 publications receiving 323416 citations. The organization is also known as: UCCS & University of Colorado at Colorado Springs.

Convergence of the many-body expansion of interaction potentials: From van der Waals to covalent and metallic systems

Abstract: The many-body expansion of the interaction potential between atoms and molecules is analyzed in detail for different types of interactions involving up to seven atoms. Elementary clusters of Ar, Na, Si, and, in particular, Au are studied, using first-principles wave-function- and density-functional-based methods to obtain the individual n-body contributions to the interaction energies. With increasing atom number the many-body expansion converges rapidly only for long-range weak interactions. Large oscillatory behavior is observed for other types of interactions. This is consistent with the fact that Au clusters up to a certain size prefer planar structures over the more compact three-dimensional Lennard-Jones-type structures. Several Au model potentials and semiempirical PM6 theory are investigated for their ability to reproduce the quantum results. We further investigate small water clusters as prototypes of hydrogen-bonded systems. Here, the many-body expansion converges rapidly, reflecting the localized nature of the hydrogen bond and justifying the use of two-body potentials to describe water-water interactions. The question of whether electron correlation contributions can be successfully modeled by a many-body interaction potential is also addressed.

The formation of linear aggregates in magnetic hyperthermia: implications on specific absorption rate and magnetic anisotropy.

Abstract: The design and application of magnetic nanoparticles for use as magnetic hyperthermia agents has garnered increasing interest over the past several years. When designing these systems, the fundamentals of particle design play a key role in the observed specific absorption rate (SAR). This includes the particle's core size, polymer brush length, and colloidal arrangement. While the role of particle core size on the observed SAR has been significantly reported, the role of the polymer brush length has not attracted as much attention. It has recently been reported that for some suspensions linear aggregates form in the presence of an applied external magnetic field, i.e. chains of magnetic particles. The formation of these chains may have the potential for a dramatic impact on the biomedical application of these materials, specifically the efficiency of the particles to transfer magnetic energy to the surrounding cells. In this study we demonstrate the dependence of SAR on magnetite nanoparticle core size and brush length as well as observe the formation of magnetically induced colloidal arrangements. Colloidally stable magnetic nanoparticles were demonstrated to form linear aggregates in an alternating magnetic field. The length and distribution of the aggregates were dependent upon the stabilizing polymer molecular weight. As the molecular weight of the stabilizing layer increased, the magnetic interparticle interactions decreased therefore limiting chain formation. In addition, theoretical calculations demonstrated that interparticle spacing has a significant impact on the magnetic behavior of these materials. This work has several implications for the design of nanoparticle and magnetic hyperthermia systems, while improving understanding of how colloidal arrangement affects SAR.

Terrorism, Violence, and Hope for Peace A Terror Management Perspective

Abstract: Terror management theory (TMT) is used to explore psychological forces that act to promote or discourage support for terrorism and violent counterterrorist policies. According to TMT, domination, humiliation, and perceived injustice threaten the self-esteem and cultural worldviews that protect people from death-related anxiety; the result may be hostility and violence directed against the threatening out-group as a way of defusing this threat. We review research documenting the role of terror management processes in promoting and discouraging support for terrorism and violent counterterrorist policies and discuss the implications of this research. The studies we review suggest that the same psychological forces that promote support for terrorist violence also promote support for aggressive counterterrorist policies and that these forces can be redirected to encourage support for more peaceful solutions on both sides of the current conflict between Islamic radical groups and Western nations.

Mild Depression, Mortality Salience and Defense of the Worldview Evidence of Intensified Terror Management in the Mildly Depressed:

Abstract: Based on a terror management analysis of depression, the authors hypothesized that mildly depressed individuals would engage in especially vigorous worldview defense after mortality salience. Two studies were conducted in which mildly depressed and nondepressed American college students contemplated their own mortality or a neutral topic and then evaluated targets who supported or threatened aspects of their worldviews. Replicating previous research, subjects who contemplated their own mortality engaged in more defense of the worldview (more positive reactions to worldview supporters and more negative reactions to worldview threateners). Moreover, as predicted, mildly depressed subjects in both studies responded to mortality salience with significantly more worldview defense than did nondepressed subjects. Implications of these results for understanding and treating depression are briefly considered.

Virtual reality teleoperated remote control vehicle

Abstract: A steerable motor vehicle is remotely controlled by a human operator at a remote control station with the operator being supplied with three-dimensional realistic visual representations of scenes in the vicinity of the vehicle to allow him to exercise more accurate control of the vehicle taking into account objects and other features occurring in the environment immediately encountered by the vehicle. The vehicle carries two vehicle cameras for binocularly viewing scenes, and the viewed scenes are transmitted by RF communication links to the remote control station where the scenes are recreated on two display screens, forming part of a virtual reality headset worn by the operator, viewed separately by separate eyes of the operator to create a three-dimensional and realistic impression of the scenes seen by the two cameras.