ERIS is the new AO instrument for VLT-UT4 led by a Consortium of Max-Planck Institut fuer Extraterrestrische Physik, UK-ATC, ETH-Zurich, ESO and INAF. The ERIS AO system provides NGS mode to deliver ...high contrast correction and LGS mode to extend high Strehl performance to large sky coverage. The AO module includes NGS and LGS wavefront sensors and, with VLT-AOF Deformable Secondary Mirror and Laser Facility, will provide AO correction to the high resolution imager NIX (1-5um) and the IFU spectrograph SPIFFIER (1-2.5um). In this paper we present the preliminary design of the ERIS AO system and the estimated correction performance.
The National Airspace System suffers from a reduction in airport throughput or even closure when weather or traffic volume constrains arrival or departure gates to and from the Terminal Radar ...Approach Control (TRACON) facilities. To alleviate this, the Federal Aviation Administration introduced the Integrated Arrival and Departure Control Services (IADCS) concept that would extend terminal separations and procedures to the adjacent Air Route Traffic Control Center (ARTCC) sectors for more flexible traffic. It proposes the use of resectorization, bidirectional gates, bidirectional routes, and Air Traffic Control assigned routes. We evaluated them in the human-in-the-loop high-fidelity experiment and collected objective and subjective data. Our results clearly showed that all IADCS procedures except the vertically separated/bidirectional gate procedure were more effective than the Baseline condition that controllers currently use in the field. We conjecture the vertically separated/bidirectional gate procedure requires more complex perceptual and cognitive processes than the other procedures.
Context. Since 1997, BL Lacertae has undergone a phase of high optical activity, with the occurrence of several prominent outbursts. Starting from 1999, the Whole Earth Blazar Telescope (WEBT) ...consortium has organized various multifrequency campaigns on this blazar, collecting tens of thousands of data points. One of the main issues in the study of this huge dataset has been the search for correlations between the optical and radio flux variations, and for possible periodicities in the light curves. The analysis of the data assembled during the first four campaigns (comprising also archival data to cover the period 1968–2003) revealed a fair optical-radio correlation in 1994–2003, with a delay of the hard radio events of ~100 days. Moreover, various statistical methods suggested the existence of a radio periodicity of ~8 years. Aims. In 2004 the WEBT started a new campaign to extend the dataset to the most recent observing seasons, in order to possibly confirm and better understand the previous results. Methods. In this campaign we have collected and assembled about 11 000 new optical observations from twenty telescopes, plus near-IR and radio data at various frequencies. Here, we perform a correlation analysis on the long-term R-band and radio light curves. Results. In general, we confirm the ~100-day delay of the hard radio events with respect to the optical ones, even if longer (~200–300 days) time lags are also found in particular periods. The radio quasi-periodicity is confirmed too, but the “period” seems to progressively lengthen from 7.4 to 9.3 years in the last three cycles. The optical and radio behaviour in the last forty years suggests a scenario where geometric effects play a major role. In particular, the alternation of enhanced and suppressed optical activity (accompanied by hard and soft radio events, respectively) can be explained in terms of an emitting plasma flowing along a rotating helical path in a curved jet.
PKCs are serine-threonine kinases that play an important role in many cellular functions. Almost all the 12 PKC isoforms described so far are expressed throughout erythroid differentiation of human ...CD34pos cells. Besides the downmodulation of PKCε expression (Bassini et al, Blood 93; 1178, 1999), little is known on the role exerted by each PKC on erythroid differentiation. PKCα and PKCδ are two isoforms expressed at comparable levels (as mRNA and protein) throughout differentiation of CD36highCD235alow pro-erythroblasts into orthochromatic erythroblasts. For both proteins, the ratio between phosphorylated and total form remains constant during the differentiation of adult cells. In contrast, the ratio P-PKCα/total PKCα (but not that of P-PKCδ/total PKCδ) increases by 3-fold (with slight donor-to-donor variability) during the differentiation of CD36highCD235alow cells from cord blood. Furthermore, the protein becomes prominently localized in the nucleus of these cells. Since the most stricking difference in the differentiation of adult vs. neonatal erythroblasts is the γ/γ+β globin expression ratio (0.02–0.08 vs. 0.20–0.40 by Taqman, respectively), we hypothesized that the levels of PKCα activity might affect γ-globin expression in erythroblasts. To test this hypothesis, we used two in vitro models of HbF switching. The first model is represented by GM979 cells stably transfected with a dual luciferase (Renilla, R - Firefly, F) reporter driven by either the human γ- or β-globin promoter. The second model is represented by human erythroblasts obtained in HEMA culture. GM979 cells were transiently transfected with expression constructs encoding either the catalytic subunit (sPKCα) or the catalytic inactive (iPKCα) PKCα. The levels of expression of the γ-driven and β-driven luciferase reporters were then measured 24 hrs after transfection. Alternatively, GM979 cells were incubated with concentrations of rottlerin (30 μM) that specifically inhibit PKCα activity. sPKCα increased by 2–3-fold the expression of the luciferase driven by the γ-promoter but did not affect expression from the β promoter. Therefore, the ratio Aγ-F/(Aγ-F+2β-R) was also increased by 2–3 fold. Conversely, rottlerin inhibited (by 50%) both expression of the γ-driven luciferase and the Aγ-F/(Aγ-F+2β-R) ratio. On the other hand, transfection of the double luciferase reporter gene into adult and neonatal CD36highCD235alow cells (30–50% transfection efficiency) resulted in high levels of expression of both reporters, in a ratio consistent with the ontogenic stage of the cells high Aγ-F/(Aγ-F+2β-R) in neonatal erythroblasts; low Aγ-F/(Aγ-F+2β-R) in adult erythroblasts. Co-trasfection of sPKCα with this luciferase reporter in CD36highCD235alow cells (both adult and neonatal) increased by 5–6-fold the expression of the luciferase driven from the γ-promoter. Co-trasfection of iPKCα, sPKCδ and iPKCδ had no effect on the expression of the reporters in these cells. In conclusion, using several models of erythroid differentiation, we observed that increased levels of PKCα activity results in increased activity of the γ-promoter, suggesting that element(s) of the haemoglobin switching machinery may represent a specific PKCα substrate in erythroid cells.
The status of the AMICA project is reported. Final tests are currently running at Teramo Observatory before moving the instrument to Antarctica. AMICA is a camera equipped with two array detectors to ...perform astronomical imaging in the 2–28 μm band. It will be mounted at the IRAIT focal plane. Its very special feature is the antarctic operability. AMICA subsystems have been tested at typical antarctic conditions, in order to adopt technological solutions that ensure the correct operation of AMICA even on the antarctic plateau. Moreover, since human operations are not possible during the antarctic “winter", AMICA has been designed to operate in a completely automatic mode. AMICA is essentially aimed to demonstrate the potential of Antarctica for Infrared Astronomy and should therefore produce significant data, both for astronomy and site-testing. In addition, the experience gained in its technological development will be useful for building future astronomical instruments for extreme environment sites.
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