The XMM-Newton EPIC X-ray Light Curve Analysis of WR 6

We obtained four pointings of over 100 ks each of the well-studied Wolf-Rayet star WR 6 with the XMM-Newton satellite. With a first paper emphasizing the results of spectral analysis, this follow-up highlights the X-ray variability clearly detected in all four pointings. However, phased light curves fail to confirm obvious cyclic behavior on the well-established 3.766 d period widely found at longer wavelengths. The data are of such quality that we were able to conduct a search for "event clustering" in the arrival times of X-ray photons. However, we fail to detect any such clustering. One possibility is that X-rays are generated in a stationary shock structure. In this context we favor a co-rotating interaction region (CIR) and present a phenomenological model for X-rays from a CIR structure. We show that a CIR has the potential to account simultaneously for the X-ray variability and constraints provided by the spectral analysis. Ultimately, the viability of the CIR model will require both intermittent long-term X-ray monitoring of WR 6 and better physical models of CIR X-ray production at large radii in stellar winds.Comment: to appear in Ap

Particle Removal by Electrostatic and Dielectrophoretic Forces for Dust Control During Lunar Exploration Missions

Particle removal during lunar exploration activities is of prime importance for the success of robotic and human exploration of the moon. We report on our efforts to use electrostatic and dielectrophoretic forces to develop a dust removal technology that prevents the accumulation of dust on solar panels and removes dust adhering to those surfaces. Testing of several prototypes showed solar shield output above 90% of the initial potentials after dust clearing

The radioprotectant nano-genistein enhances radiotherapy efficacy of lung tumors in mice

BACKGROUND: Radiotherapy for non-small cell lung cancer (NSCLC) can be dose-limiting due to treatment-related toxicities. Genistein has been shown to be a robust radioprotective agent in preclinical models. A novel genistein oral nanosuspension formulation (nano-genistein) has demonstrated efficacy in mitigating radiation-induced lung damage in preclinical animal models. However, while those studies have confirmed that nano-genistein can protect normal lung tissue from radiation-induced toxicities, no studies have assessed the effect of nano-genistein on lung tumors. Here, we evaluated the impact of nano-genistein on the efficacy of radiation treatment of lung tumors in a mouse xenograft model. METHODS: Two separate studies were conducted utilizing human A549 cells implanted either dorsally within the upper torso or in the flank. Daily oral administration of nano-genistein (200 or 400 mg/kg/day) occurred prior to and after exposure to a single dose of thoracic or abdominal 12.5 Gy radiation. Tumor growth was monitored twice weekly, nano-genistein treatment continued for up to 20 weeks and histopathology of tissues was completed post euthanasia. RESULTS: Continuous nano-genistein dosing was safe across all study groups in both studies. Animals receiving nano-genistein better maintained body weight following irradiation compared to corresponding vehicle treated animals. Animals that received nano-genistein also had reduced tumor growth and improved normal lung histopathology compared to those receiving vehicle suggesting that nano-genistein does not protect tumors from radiotherapy but is radioprotective of the lungs. There were no treatment-related histopathological findings noted in the skin adjacent to the tumor, esophagus, or uterus. CONCLUSIONS: These results, including the safety following extended dosing, support the continued evaluation of nano-genistein as an adjunctive treatment for patients with NSCLC undergoing radiotherapy and serve as the basis of a phase 1b/2a multicenter clinical trial

Financial phantasmagoria: corporate image-work in times of crisis

Our purpose in this article is to relate the real movements in the economy during 2008 to the ?image-work? of financial institutions. Over the period January?December 2008 we collected 241 separate advertisements from 61 financial institutions published in the Financial Times. Reading across the ensemble of advertisements for themes and evocative images provides an impression of the financial imaginaries created by these organizations as the global financial crisis unfolded. In using the term ?phantasmagoria? we move beyond its colloquial sense of a set of strange images designed to dazzle towards the more technical connotation used by Ranci�re (2004) who suggested that words and images can offer a trace of an overall determining set-up if they are torn from their obviousness so they become phantasmagoric figures. The key phantasmagoric figure we identify here is that of the financial institution as timeless, immortal and unchanging; a coherent and autonomous entity amongst other actors. This notion of uniqueness belies the commonality of thinking which precipitated the global financial crisis as well as the limited capacity for control of financial institutions in relation to market events. It also functions as a powerful naturalizing force, making it hard to question certain aspects of the recent period of ?capitalism in crisis?

Status of U.S. testing of the High Performance Hall System SPT-140 Hall thruster

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77315/1/AIAA-2000-1053-280.pd