DNA Double-Strand Break Repair: A Relentless Hunt Uncovers New Prey

A major pathway for repair of DNA double-strand breaks is nonhomologous end-joining (NHEJ). In this issue of Cell, Buck et al. (2006a) and Ahnesorg et al. (2006) report the discovery of a new NHEJ factor called Cernunnos-XLF. Both groups report that this protein is mutated in a rare inherited human syndrome characterized by severe immunodeficiency, developmental delay, and hypersensitivity to agents that cause DNA double-strand breaks

DNA Double-Strand Break Repair: A Relentless Hunt Uncovers New Prey

A major pathway for repair of DNA double-strand breaks is nonhomologous end-joining (NHEJ). In this issue of Cell, Buck et al. (2006a) and Ahnesorg et al. (2006) report the discovery of a new NHEJ factor called Cernunnos-XLF. Both groups report that this protein is mutated in a rare inherited human syndrome characterized by severe immunodeficiency, developmental delay, and hypersensitivity to agents that cause DNA double-strand breaks

Performance Improvements from Heat Acclimation, Heat Acclimatization

Heat acclimation/acclimatization (HA/HAz) are important heat mitigation strategies that help develop heat tolerance from prolonged and repeated exposure to a hot environment, subsequently improving exercise performance in the heat. PURPOSE: To assess and quantify the magnitude of performance benefits of short- (STHA), medium- (MTHA), and long-term HA (LTHA) in endurance-trained athletes. METHODS: A literature search was conducted in PubMed, SPORTDiscus, Scopus, and Cochrane-Library, with data from 23 studies extracted for analysis. Subgroup analysis distinguished differences in performance and thermoregulatory adaptations between short-, medium- and long-term HA interventions. RESULTS: HA produced significant improvements in time trial performance (Effect size [95% confidence intervals] 0.72 [0.42– 1.03]), with LTHA displaying the most significant performance time decrease (-15.29%). MTHA and STHA showed a slight reduction in time trial performance time (-4.28% and -4.40%, respectively). Mean power output during exercise in the heat increased by 7.2% following MTHA, which was greater than STHA (-3.4%). HA showed a significant, small reduction in mean resting skin temperature (Tsk) (0.34 [0.00–0.68]) and core temperature (Tc) (0.40 [0.16–0.63]). Subgroup analysis demonstrated that mean Tsk reduction was more significant in the STHA (-0.35 ± 0.32°C) compared to MTHA (-0.24 ± 0.40°C), whereas Tc showed the greatest decrease in temperature from LTHA (0.66 [0.40–0.92]). CONCLUSION: Results indicate a noticeable improvement in endurance performances in the heat, with a trend towards longer-duration protocols eliciting the greatest performance adaptations. Findings show that long-term HA/HAz results in improved endurance performance in the heat which is influenced by thermoregulatory adaptations that increase thermal tolerance in hot and humid environments. These findings are important for athletes and their support teams to evidence-inform and individualize HA prescription

Effects of Dissipation Energy on Vibrational and Sound Energy Flow

  &nbsp

Affleck-Dine leptogenesis via multiscalar evolution in a supersymmetric seesaw model

A leptogenesis scenario in a supersymmetric standard model extended with introducing right-handed neutrinos is reconsidered. Lepton asymmetry is produced in the condensate of a right-handed sneutrino via the Affleck-Dine mechanism. The LH_u direction develops large value due to a negative effective mass induced by the right-handed sneutrino condensate through the Yukawa coupling of the right-handed neutrino, even if the minimum during the inflation is fixed at the origin. The lepton asymmetry is nonperturbatively transfered to the LH_u direction by this Yukawa coupling.Comment: 19 pages, 3 figures. Revised version for publication. The model was modified to fix some problem

Performance of the helical coils for the large helical device in six years\u27 operation

A pair of helical coils of the large helical device is the largest pool-cooled superconducting magnet. The first excitation test up to 1.5 T was carried out at the end of March, 1998. In the first trial to charge up to the design value of 3 T, wide propagation of a normal-zone was induced at 11.45 kA, and the quench detection system acted. It was revealed that a normal-zone could propagate below the cold-end recovery current by additional heat generation due to the slow current diffusion into the thick pure aluminum stabilizer. In these six years\u27 operation, propagation of a normal-zone has been observed 17 times at almost the same current. The normal-zones were recovered within several seconds except for the wide propagation. By a detection system of the propagation with pick-up coils along the helical coils, it was disclosed that the recovered normal-zones propagated in only one side. In order to attain plasma experiments near 3 T, higher excitations were tried by the current grading method, in which the current of the innermost block is decreased and those of the other two blocks are increased. The average current of 11.67 kA was attained. The excitation tests up to the highest currents have been carried out after each cool-down. Degradation is not observed in the coil performance, and the stable operation has been demonstrated

Building A High Performance Parallel File System Using Grid Datafarm and ROOT I/O

Sheer amount of petabyte scale data foreseen in the LHC experiments require a careful consideration of the persistency design and the system design in the world-wide distributed computing. Event parallelism of the HENP data analysis enables us to take maximum advantage of the high performance cluster computing and networking when we keep the parallelism both in the data processing phase, in the data management phase, and in the data transfer phase. A modular architecture of FADS/ Goofy, a versatile detector simulation framework for Geant4, enables an easy choice of plug-in facilities for persistency technologies such as Objectivity/DB and ROOT I/O. The framework is designed to work naturally with the parallel file system of Grid Datafarm (Gfarm). FADS/Goofy is proven to generate 10^6 Geant4-simulated Atlas Mockup events using a 512 CPU PC cluster. The data in ROOT I/O files is replicated using Gfarm file system. The histogram information is collected from the distributed ROOT files. During the data replication it has been demonstrated to achieve more than 2.3 Gbps data transfer rate between the PC clusters over seven participating PC clusters in the United States and in Japan.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 4 pages, PDF. PSN TUDT01

Thermal infrared observations of near-Earth asteroid 2002 NY40

We obtained N-band observations of the Apollo asteroid 2002 NY40 during its close Earth fly-by in August 2002 with TIMMI2 at the ESO 3.6 m telescope. The photometric measurement allowed us to derive a radiometric diameter of 0.28+/-0.03 km and an albedo of 0.34+/-0.06 through the near-Earth asteroid thermal model (NEATM) and a thermophysical model (TPM). The values are in agreement with results from radar data, visual and near-IR observations. In this first comparison between these two model approaches we found that the empirical NEATM beaming parameter $\eta$=1.0 corresponds to a thermal inertia values of about 100 $\mathrm{J m^{-2} s^{-0.5} K^{-1}}$ for a typical range of surface roughness, assuming an equator-on viewing angle. Our TPM analysis indicated that the surface of 2002 NY40 consists of rocky material with a thin or no dust regolith. The asteroid very likely has a prograde sense of rotation with a cold terminator at the time of our observations. Although both model approaches can fit the thermal spectra taken at phase angles of 22$^{\circ}$ and 59$^{\circ}$, we did not find a consistent model solution that describes all pieces of photometric and spectroscopic data. In addition to the 2002 NY40 analysis, we discuss the possibilities to distinguish between different models with only very few photometric and/or spectroscopic measurements spread over a range of phase angles.Comment: 6 pages, 4 figures, A&A accepte

General relativistic radiation hydrodynamics of accretion flows. I: Bondi-Hoyle accretion

We present a new code for performing general-relativistic radiation-hydrodynamics simulations of accretion flows onto black holes. The radiation field is treated in the optically-thick approximation, with the opacity contributed by Thomson scattering and thermal bremsstrahlung. Our analysis is concentrated on a detailed numerical investigation of hot two-dimensional, Bondi-Hoyle accretion flows with various Mach numbers. We find significant differences with respect to purely hydrodynamical evolutions. In particular, once the system relaxes to a radiation-pressure dominated regime, the accretion rates become about two orders of magnitude smaller than in the purely hydrodynamical case, remaining however super-Eddington as are the luminosities. Furthermore, when increasing the Mach number of the inflowing gas, the accretion rates become smaller because of the smaller cross section of the black hole, but the luminosities increase as a result a stronger emission in the shocked regions. Overall, our approach provides the first self-consistent calculation of the Bondi-Hoyle luminosity, most of which is emitted within r~100 M from the black hole, with typical values L/L_Edd ~ 1-7, and corresponding energy efficiencies eta_BH ~ 0.09-0.5. The possibility of computing luminosities self-consistently has also allowed us to compare with the bremsstrahlung luminosity often used in modelling the electromagnetic counterparts to supermassive black-hole binaries, to find that in the optically-thick regime these more crude estimates are about 20 times larger than our radiation-hydrodynamics results.Comment: With updated bibliographyc informatio