Time filter

Source Type

Siloam Springs, AR, United States

JBU redirects here. For Jydsk Boldspil-Union, see Jutland Football Association.JBU redirects here. For the US Airline with the ICAO identifier JBU, see JetBlue Airways.John Brown University is a private, interdenominational, Christian liberal arts college in Siloam Springs, in the U.S. state of Arkansas. Founded in 1919, JBU also has regional educational centers in Rogers, Little Rock and Fort Smith, Arkansas.The 200-acre main campus in northwest Arkansas has been the site of the university since it was founded in 1919. JBU has 2,183 students as of the 2011-2012 school year, 1,279 of which are traditional undergraduates. Of these, 878 live on campus. The Graduate School has 468 students. JBU is home to students from 41 states and 44 countries.JBU is accredited by the Higher Learning Commission of the North Central Association of Colleges and Schools. JBU competes athletically in the Sooner Athletic Conference. In 2011 , US News & World Report ranked JBU first among regional baccalaureate colleges in the Southern region. Wikipedia.

Main D.S.,John Brown University | Newman D.L.,University of Colorado at Boulder | Ergun R.E.,University of Colorado at Boulder
Physics of Plasmas | Year: 2010

The strength and stability of simulated double layers at the ionosphere-auroral cavity boundary have been studied as a function of cold ionospheric electron temperature and density. The simulations are performed with an open boundary one-dimensional particle-in- cell (PIC) simulation and are initialized by imposing a density cavity within the simulation domain. The PIC simulation includes H+ and O+ ion beams, a hot H+ background population, cold ionospheric electrons, and a hot electron population. It is shown that a double layer remains quasistable for a variety of initial conditions and plasma parameters. The average potential drop of the double layer is found to increase as the cold electron temperature decreases. However, in terms of cold electron density, the average potential drop of the double layer is found to increase up to some critical cold electron density and decreases above this value. Comparisons with FAST observations are made and agreement is found between simulation results and observations in the shape and width of the double layer. This study helps put a constraint on the plasma conditions in which a DL can be expected to form and remain quasistable. © 2010 American Institute of Physics.

Main D.S.,John Brown University
Journal of Geophysical Research: Space Physics | Year: 2013

The evolution of the ionosphere-auroral cavity boundary is studied using a two-dimensional electrostatic particle-in-cell simulation. The boundary is modeled as a double layer which forms by imposing a density cavity as part of the initial conditions. The density cavity consists of a contact discontinuity which separates the cold, dense ionosphere on one side and the hot, tenuous auroral cavity on the other side. The simulation consists of hot electrons, H+ and O+ antiearthward traveling ion beams, hot magnetospheric H+and cold ionospheric electrons. A U-shaped double layer is formed by initializing the ion beams with a perpendicular shear in the parallel drift velocity. We show that the strength and obliqueness angle of the evolved double layer depends most strongly on the ratio of the ion beam's gyrofrequency to the plasma frequency, and that the U-shaped double layer is quasi-stable on simulation time scales. Finally, we show that the oblique double layer causes perpendicular ion heating in the ion beams and that a ring distribution forms in a weakly magnetized species. However, we find that at high altitudes above the double layer, the dominant effect on the shape of ion phase space and the ion temperature is the turbulence in the auroral cavity, leading to the conclusion that oblique double layers have little lasting effect on the shape and temperature of the ion beams. Key Points U-shaped double layers shown to be quasi-stable Strength of double layer depends on ion magnetization Perpendicular heating of ion beams mainly due to turbulence in auroral cavity ©2013. American Geophysical Union. All Rights Reserved.

Liu L.,University of Arkansas | Zhou J.,University of Arkansas | Wang Y.,University of Arkansas | Mason R.J.,National Jewish Medical and Research Center | And 2 more authors.
Journal of Proteome Research | Year: 2012

To obtain a global picture of how alveolar macrophages respond to influenza A virus (IAV) infection, we used a quantitative proteomics method to systematically examine protein expression in the IAV-infected primary human alveolar macrophages. Of the 1214 proteins identified, 43 were significantly up-regulated and 63 significantly down-regulated at >95% confidence. The expression of an array of interferon (IFN)-induced proteins was significantly increased in the IAV-infected macrophages. The protein with the greatest expression increase was ISG15, an IFN-induced protein that has been shown to play an important role in antiviral defense. Concomitantly, quantitative real-time PCR analysis revealed that the gene expression of type I IFNs increased substantially following virus infection. Our results are consistent with the notion that type I IFNs play a vital role in the response of human alveolar macrophages to IAV infection. In addition to the IFN-mediated responses, inflammatory response, apoptosis, and redox state rebalancing appeared also to be major pathways that were affected by IAV infection. Furthermore, our data suggest that alveolar macrophages may play a crucial role in regenerating alveolar epithelium during IAV infection. © 2012 American Chemical Society.

Yang Z.,University of Colorado at Boulder | Eichelberger B.,University of Colorado at Boulder | Eichelberger B.,John Brown University | Martinez Jr. O.,University of Colorado at Boulder | And 3 more authors.
Journal of the American Chemical Society | Year: 2010

Molecular anions have been recently detected in the denser regions of the interstellar medium. However, the chemical reactions of molecular anions with atomic species that are abundant in the ISM remain largely unexplored. This work is an experimental and computational study of CH2CN-, CH3CHCN-, (CH3)2CCN-, and CH2CHO- reacting with N and O atoms. In all cases the reactions of anions with O atoms exhibit larger reaction rate constants compared to the corresponding reactions with N atoms. Our study indicates that spin-forbidden reactions are the probable pathways in the reactions with N atoms, whereas spin-allowed reactions are the dominant processes in the reactions with O atoms. The major factor influencing the reaction rate constants of anions with N and O atoms is whether a spin-allowed barrierless pathway exists. The rich chemistry observed in this work provides a greater understanding of the ion-atom reaction processes, as well as some new avenues for further spin chemistry research. © 2010 American Chemical Society.

Cornett N.,John Brown University | Bratton S.C.,University of North Texas
Journal of Marital and Family Therapy | Year: 2014

Research supports that child parent relationship therapy (CPRT), a filial therapy approach, has strong effects on participating parents and children. Some speculate that filial therapy improves the family system; however, minimal research exists to support this claim. Using a single-case design, researchers examined CPRT's impact on the functioning of 8 families. Results revealed that 6 families experienced statistically significant improvements in targeted areas of family functioning. Results from self-reported measures indicated that 7 families improved in family satisfaction, 4 in cohesion, 3 in communication, and 1 in flexibility. Observational measures also revealed improvements: 5 families in flexibility, 4 families in cohesion, and 4 families in communication. The results support that the benefits of CPRT may extend to the family system. © 2013 American Association for Marriage and Family Therapy.

Discover hidden collaborations