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The divertor of the Alcator C-Mod tokamak routinely radiates a large fraction of the power entering the scrape-off layer. This dissipative divertor operation occurs whether the divertor is detached or not, and large volumetric radiative emissivities, up to 60 MW-m-3 in ICRF-heated discharges, have been measured using bolometer arrays. An analysis of both ohmic and ICRF-heated discharges has demonstrated some of the relative merits of detached divertor operation versus high-recycling divertor operation.An advantage of detached divertor operation is that the power flux to the divertor plates is decreased even further than its already low value. Some disadvantages are that volumetric losses outside the separatrix in the divertor region are decreased, the neutral compression ratio is decreased, and the penetration efficiency of impurities increases. a) Present address, University of California at San Diego, San Diego, CA b) Present address,

The two Rho kinase isoforms ROCK1 and ROCK2 are downstream effectors of the small GTPase RhoA, although relatively little is known about potential isoform specific functions or the selective control of their cellular activities. Using Con8 rat mammary epithelial cells, we show that the synthetic glucocorticoid dexamethasone strongly stimulates the level of ROCK2 protein, which accounts for the increase in total cellular ROCK2 activity, whereas, steroid treatment down-regulated ROCK1 specific kinase activity without altering ROCK1 protein levels. In Con8 cells, the glucocorticoid induced formation of tight junctions requires the steroid-mediated down-regulation RhoA and function of the RhoA antagonist Rnd3. Treatment with the ROCK inhibitor Y-27632 ablated both the glucocorticoid-induced and Rnd3-mediated stimulation in tight junction sealing. Taken together, our results demonstrate that the expression and activity of ROCK1 and ROCK2 can be uncoupled in a signal-dependent manner, and further implicate a new function for ROCK2 in the steroid control of tight junction dynamics.

Abstruct-Modeling results are presented for proton-induced degradation of chargecoupled devices (CCDs) used in the Advanced CCD Imaging Spectrometer instrument on the Chandra X-Ray Observatory. A methodology is described that provides insights regarding degradation mechanism and onorbit performance for front-illuminated and back-illuminated CCDs Proton-induced changes in charge transfer inefficiency are modeled. The observed amount of on-orbit degradation can be accounted for using a proton spectrum at the CCD location that is reduced in magnitude by a factor of -1E5 compared to the spectrum incident on the spacecraft.

A Texas Nuclear Cockcroft–Walton neutron generator was refurbished for use as a general fusion-product source. This well-calibrated source is now used routinely for characterizing energetic charged-particle detectors, for the development of nuclear fusion diagnostics, for studying radiation damage, and for calibrating x-ray detectors for laboratory and space plasmas. This paper is an overview of the facility. We describe the main accelerator operating systems, the primary fusion reactions studied, and several diagnostics used to characterize the fusion-product source.

A multimessenger analysis optimized for a correlation of arrival directions of ultra-high energy cosmic rays (UHECRs) and neutrinos is presented and applied to 2190 neutrino candidate events detected in 2007-2008 by the ANTARES telescope and 69 UHECRs observed by the Pierre Auger Observatory between 2004 January 1 and 2009 December 31. No significant correlation is observed. Assuming an equal neutrino flux (E~2 energy spectrum) from all UHECR directions, a 90% CL upper limit on the neutrino flux of 5.0 x 1(U8 GeV c u r 2 s_1 per source is derived.