An Experimental Nexos Laboratory Using Virtual Xinu

The Nexos Project is a joint effort between Marquette University, the University of Buffalo, and the University of Mississippi to build curriculum materials and a supporting experimental laboratory for hands-on projects in computer systems courses. The approach focuses on inexpensive, flexible, commodity embedded hardware, freely available development and debugging tools, and a fresh implementation of a classic operating system, Embedded Xinu, that is ideal for student exploration. This paper describes an extension to the Nexos laboratory that includes a new target platform composed of Qemu virtual machines. Virtual Xinu addresses two challenges that limit the effectiveness of Nexos. First, potential faculty adopters have clearly indicated that even with the current minimal monetary cost of installation, the hardware modifications, and time investment remain troublesome factors that scare off interested educators. Second, overcoming the inherent complications that arise due to the shared subnet that result in students\u27 projects interfering with each other in ways that are difficult to recreate, debug, and understand. Specifically, this paper discusses porting the Xinu operating systems to Qemu virtual hardware, developing the virtual networking platform, and results showing success using Virtual Xinu in the classroom during one semester of Operating Systems at the University of Mississippi

Ten tips to help students become more employable

One of the main reasons given by students for going to university is to get a good job afterwards, but with around 500,000 people graduating each year the job market is extremely competitive. A university course will help you develop some of the skills that employers are looking for, but you need more than a degree certificate to get a graduate-level job

Sri Lanka’s Post-Tsunami Recovery: Cultural Traditions, Social Structures and Power Struggles

The Indian Ocean Tsunami of December 26, 2004 killed over 220,000 people and affected two million more in Indonesia, Thailand, Sri Lanka, India and other Indian Ocean nations. As the world reels under the impact of more recent disasters in Haiti, Peru and Pakistan, we consider lessons learned about postdisaster relief and recovery from the aftermath of the tsunami in Sri Lanka. The tsunami waves caused by an undersea subduction earthquake off the coast of Sumatra devastated 70% of Sri Lanka’s coastline and killed 35,000 people. Days after the disaster, Dennis McGilvray joined forces with Michele Gamburd to organize an interdisciplinary team funded by NSF’s Human and Social Dynamics program to conduct research on the aftermath of the tsunami. The team included a political scientist, a demographer, and three cultural anthropologists; two disaster studies specialists later joined the group. All team members had prior experience working in Sri Lanka and South Asia, and collaborated on a project implemented in 2005-06 to compare the importance of cultural, regional and political factors in post-disaster governmental and NGO efforts. Results of the research appear in the volume Tsunami Recovery in Sri Lanka: Ethnic and Regional Dimensions, edited by McGilvray and Gamburd (2010). Here we discuss what anthropology—in collaboration with related disciplines—has to offer discussions of post-disaster development and diplomacy

Perturbations of Cosmological Redshift Drift

In this paper we calculate the linear perturbations of the cosmological redshift drift. We show explicitly that our expressions are gauge-invariant and compute the power spectrum of the redshift drift perturbations and its correlations with galaxy number counts within linear perturbation theory. Our findings show that the perturbations are small, and that the peculiar velocity and acceleration terms are dominating and cannot be neglected when modeling the full perturbative expression for the redshift drift. We also find that the cross-correlations with galaxy number count fluctuations might increase the detectability of the effect and can help to separate the perturbative effects from the background cosmological redshift drift signal.Comment: Matches published version in JCA

Related Services for Vermont\u27s Students with Disabilities

The purpose of Related Services for Vermont’s Students with Disabilities is to offer information regarding related services that is consistent with IDEA and with Vermont Law and regulations. It also describes promising or exemplary practices in education, special education, and related services. The manual’s content applies to all related services disciplines which serve students with disabilities, ages 3 through 21, who have an Individualized Education Program (IEP)

Genistein Affects HER2 Protein Concentration, Activation and Promoter Regulation via Estrogen Receptor-and non-Estrogen Receptor-Mediated Mechanisms

The HER2 proto-oncogene, a member of the epidermal growth factor receptor family, is overexpressed in 20–30% of breast cancers. Genistein, the main soy isoflavone, interacts with estrogen receptors (ER) and it is also a potent tyrosine kinase inhibitor. Previously, our laboratory found that genistein delayed mammary tumor onset in transgenic mice that overexpress HER2 gene. Our goal was to define the mechanism through which genistein affects mammary tumorigenesis inHER2 overexpressing mice. We hypothesized that genistein inhibits HER2 activation and expression through ER-dependent and ER-independent mechanisms. Genistein inhibited total HER2 protein expression and tyrosine phosphorylation in BT-474, an ERα (−) and ERβ (+) human breast cancer cell line, however, E2 had no effect. Taken together, these data suggest that genistein has an ER-independent inhibitory effect, presumably, through tyrosine kinase inhibition activity. Genistein at 1.0 μM mimicked E2 and down-regulated HER2 protein phosphorylation when BT-474 was co-transfected with ERα, but not ERβ. Although E2 and overexpression of HER2 can promote mammary tumorigenesis, an inverse relationship between ER expression and HER2 overexpression has been found in human breast cancer. We cloned a 500-bp promoter region upstream of theHER2 transcription initiation site. Co-transfection with ERα, but not with ERβ, down-regulated HER2promoter reporter in BT-474. At concentrations ≥1 μM, genistein inhibited HER2 promoter reporter in the absence of ERα. In conclusion, genistein at ≥1 μM inhibited HER2 protein expression, phosphorylation, and promoter activity through an ER-independent mechanism. In the presence of ERα, genistein mimicked E2 and inhibited HER2 protein phosphorylation. These data support genistein’s chemo-prevention and potential chemo-therapeutic roles in breast cancer

The Hawking Energy in a Perturbed Friedmann-Lema\^{i}tre Universe

Hawking's quasi-local energy definition quantifies the energy enclosed by a spacelike 2-sphere in terms of the amount of lightbending on the sphere caused by the energy distribution inside the sphere. This paper establishes for the first time a direct connection between the formal mathematical definition of a quasi-local energy and observations, in the context of cosmological perturbation theory. This is achieved by studying the Hawking Energy of spherical sections of the past lightcone of a cosmic observer in a perturbed Friedmann-Lema\^{i}tre spacetime. We express the Hawking Energy in terms of gauge-invariant perturbation variables and comment on the cosmic observables needed to in principle measure it. We then calculate its angular power spectrum and interpret its contributions.Comment: matches published version; Mathematica file attache