The new surprising behaviour of the two "prototype" blazars PKS 2155-304 and 3C 279

Recent VHE observations have unveiled a surprising behaviour in two well-known blazars at opposite sides of the blazar sequence. PKS 2155-304 have shown for the first time in an HBL a large Compton dominance, high gamma-ray luminosities and a cubic relation between X-ray and VHE fluxes. 3C 279 is the first FSRQ detected at VHE. The high luminosity required to overcome the significant absorption caused by the BLR emission cannot be easily reconciled with the historical and quasi-simultaneous SED properties. Both cases shed a new light on the structure and ambient fields of blazars. Contrary to previous claims, it is also shown that 3C 279 --as any FSRQ-- cannot in general provide robust constraints on the EBL.Comment: Proceedings of "4th Heidelberg International Symposium on High Energy Gamma-Ray Astronomy 2008" (Gamma 2008), July 7-11, 2008. Slightly refined text with updated reference

Electron Signal and Detector Strategy

The scintillator-photomultiplier combination (Everhart-Thornley detector) for detecting secondary and backscattered electrons (SE and BSE) has the best properties concerning signal-to-noise ratio and bandwidth as compared to other detectors (semiconductor detectors or channel plates). Two opposite Everhart-Thornley detectors A and B are proposed for a better and reproducible angular selection of the SE. The field strength at the specimen is reduced either by a grid or ring electrode to separate the SE with regard to their exit momenta. This offers the possibility to record the signals A, B, A+B, and A-B. The signal A+B shows material and channelling contrast and the signal A-B topography with a clear distinction of elevations and indentations. Furthermore, this signal A-B is proportional to dz/dx for tilt angles ϕ=0- 60° and the surface profile can be recorded by analogue or digital on-line integration. Backscattered electrons can be recorded optimally by using scintillators or a conversion of BSE to SE at plates covered with MgO. Multi-detector systems offer a determination of the specimen tilt ϕ and azimuth which can be used for a surface reconstruction or in x-ray microanalysis for a ZAF-program of tilted surfaces. The signal A+B shows predominately material and channelling contrast and A-B the topography, however, with a worse resolution than the SE mode and with image artifacts like steps at flat interfaces between materials of different Z. The electron-backscattering pattern (EBSP) shows advantages compared to an electron channelling pattern (ECP), and methods have been developed to record EBSPs and to use the shadow of the \u27skyline\u27 in an EBSP for a three-dimensional reconstruction of the specimen surface. Energy-selection of the BSE and digital image processing will be further improvements for these imaging and recording techniques

The Molecular Genetics Of Mouse Catalase

Catalases provide cellular protection against the effects of oxygen free radicals. In mice, catalase is coded for by a single gene, Cas-1, located on Chromosome 2, 48 cM from the centromere. A number of genetic strains with variable tissue-specific expression patterns permit the evaluation of molecular mechanisms for the regulation of this housekeeping enzyme.;Transcriptional and post-transcriptional mechanisms of catalase regulation were investigated. The first complete cDNA sequence of Cas-1 is presented and includes 1584 nucleotides encoding 528 amino acids. In addition, 659 bp of 5{dollar}\sp\prime{dollar} genomic upstream region of Cas-1 were sequenced revealing a CG island , two putative CCAAT boxes, and a GC box. This promoter was examined for patterns of methylation which suggest that the tissue-specific expression of catalase is transcriptionally regulated.;Cas-1 expression was evaluated in mouse tissues of genetic strains and genotypes using enzyme activity assays, polypeptide (western blot) and mRNA analyses. The tissue-specific expression of catalase activity is reflected in the levels of mRNA and suggests transcriptional regulation. The variability in enzyme activity among strains/genotypes is not correlated with mRNA levels, rather it correlates with the level of polypeptide (western blot) suggesting post-transcriptional control. Post-transcriptional regulation is also evident during fetal development and differentiation including birth. The 3{dollar}\sp\prime{dollar} untranslated region (3{dollar}\sp\prime{dollar} UTR) of Cas-1 mRNA reveals several unusual near repeats ((CA){dollar}\sb{lcub}31{rcub},{dollar} (U){dollar}\sb{lcub}15{rcub}{dollar} and (UGUGC){dollar}\sb7\rbrack.{dollar} The mRNA gel shift assay was used to identify proteins which specifically complexed with (CA){dollar}\sb{lcub}31{rcub}{dollar} ({dollar}\sim{dollar}69 kDa) and (U){dollar}\sb{lcub}15{rcub}{dollar} ({dollar}\sim{dollar}38 and 47 kDa) sequences. In addition, the {dollar}\sim{dollar}69 kDa and the {dollar}\sim{dollar}38 kDa proteins are found associated with polysomes. The (U){dollar}\sb{lcub}15{rcub}{dollar}-protein complex may be involved in mRNA stability. Although the function of the (CA){dollar}\sb{lcub}31{rcub}{dollar}-protein complex was not established, it may aid in translational regulation by an undetermined mechanism. One possible model could involve cross-talk between the 5{dollar}\sp\prime{dollar} and 3{dollar}\sp\prime{dollar} UTRs of this mRNA via associated proteins. The sequence-specific proteins identified in these experiments may represent the trans-acting factors alluded to in a number of segregation studies on mouse catalases

OTV bearing deflection investigation

The primary goal of the Bearing Deflectometer Investigation was to gain experience in the use of fiber optic displacement probe technology for bearing health monitoring in a liquid hydrogen turbo pump. The work specified in this Task Order was conducted in conjunction with Air Force Rocket Propulsion Laboratory Contract F04611-86-C-0010. APD conducted the analysis and design coordination to provide a displacement probe design compatible with the XLR-134 liquid hydrogen turbo pump assembly (TPA). Specifications and requirements of the bearing deflectometer were established working with Mechanical Technology Instruments, Inc. (MTI). The TPA design accommodated positioning of the probe to measure outer race cyclic deflections of the pump inlet bearing. The fiber optic sensor was installed as required in the TPA and sensor output was recorded during the TPA testing. Data review indicated that no bearing deflection signature could be differentiated from the inherent system noise. Alternate sensor installations were not investigated, but might yield different results

Non-adiabatic effects in periodically driven-dissipative open quantum systems

We present a general method to calculate the quasi-stationary state of a driven-dissipative system coupled to a transmission line (and more generally, to a reservoir) under periodic modulation of its parameters. Using Floquet's theorem, we formulate the differential equation for the system's density operator which has to be solved for a single period of modulation. On this basis we also provide systematic expansions in both the adiabatic and high-frequency regime. Applying our method to three different systems -- two- and three-level models as well as the driven nonlinear cavity -- we propose periodic modulation protocols of parameters leading to a temporary suppression of effective dissipation rates, and study the arising non-adiabatic features in the response of these systems.Comment: 12 pages, 8 figure

Electron-beam-induced shift in the apparent position of a pinned vortex in a thin superconducting film

When an electron beam strikes a superconducting thin film near a pinned vortex, it locally increases the temperature-dependent London penetration depth and perturbs the circulating supercurrent, thereby distorting the vortex's magnetic field toward the heated spot. This phenomenon has been used to visualize vortices pinned in SQUIDs using low-temperature scanning electron microscopy. In this paper I develop a quantitative theory to calculate the displacement of the vortex-generated magnetic-flux distribution as a function of the distance of the beam spot from the vortex core. The results are calculated using four different models for the spatial distribution of the thermal power deposited by the electron beam.Comment: 9 pages, 6 figures, resubmitted to PRB with referee-suggested revisions, includes new paragraph on numerical evaluatio