Observational constraints to boxy/peanut bulge formation time

Boxy/peanut bulges are considered to be part of the same stellar structure as bars and both could be linked through the buckling instability. The Milky Way is our closest example. The goal of this letter is determining if the mass assembly of the different components leaves an imprint in their stellar populations allowing to estimate the time of bar formation and its evolution. To this aim we use integral field spectroscopy to derive the stellar age distributions, SADs, along the bar and disc of NGC 6032. The analysis shows clearly different SADs for the different bar areas. There is an underlying old (>=12 Gyr) stellar population for the whole galaxy. The bulge shows star formation happening at all times. The inner bar structure shows stars of ages older than 6 Gyrs with a deficit of younger populations. The outer bar region presents a SAD similar to that of the disc. To interpret our results, we use a generic numerical simulation of a barred galaxy. Thus, we constrain, for the first time, the epoch of bar formation, the buckling instability period and the posterior growth from disc material. We establish that the bar of NGC 6032 is old, formed around 10 Gyr ago while the buckling phase possibly happened around 8 Gyr ago. All these results point towards bars being long-lasting even in the presence of gas.Comment: Accepted for publication in MNRAS Letter

Long-term optical/infrared variability in the quiescent X-ray transient V404 Cyg

We present the results of optical and infrared photometry of the quiescent X-ray transient V404 Cyg during the period 1992-2003. The ellipsoidal modulations extracted from the most complete databases (years 1992, 1998 and 2001) show unequal maxima and minima with relative strength varying from year to year although their peak to peak amplitudes remain roughly constant at 0.24+-0.01 magnitudes. Fast optical variations superimposed on the secondary star's double-humped ellipsoidal modulation were detected every year with a mean amplitude of ~0.07 mags. We have not found significant changes in the activity during this decade which indicates that this variability is probably not connected to the 1989 outburst. We have found periodicities in the 1998 and 2001 data near the 6 hr quasi-periodicity observed in 1992, although we interpret it as consequence of the appearance of a flare event almost every night. Significant variability is also present in the I and near infrared (J and K_short) bands and this decreases slightly or remains approximately constant at longer wavelengths. A cross correlation analysis shows that both the R and I emission are simultaneous down to 40 s.Comment: 13 pages, 11 figures; accepted for publication in MNRA

A ZZ Ceti white dwarf in SDSS J133941.11+484727.5

We present time-resolved spectroscopy and photometry of the cataclysmic variable (CV) SDSSJ133941.11+484727.5 (SDSS1339) which has been discovered in the Sloan Digital Sky Survey Data Release 4. The orbital period determined from radial velocity studies is 82.524(24)min, close to the observed period minimum. The optical spectrum of SDSS1339 is dominated to 90% by emission from the white dwarf. The spectrum can be successfully reproduced by a three-component model (white dwarf, disc, secondary) with Twd=12500K for a fixed log g=8.0, d=170pc, and a spectral type of the secondary later than M8. The mass transfer rate corresponding to the optical luminosity of the accretion disc is very low,~1.7x10^-13Msun/yr. Optical photometry reveals a coherent variability at 641s with an amplitude of 0.025mag, which we interpret as non-radial pulsations of the white dwarf. In addition, a long-period photometric variation with a period of either 320min or 344min and an amplitude of 0.025mag is detected, which bears no apparent relation with the orbital period of the system. Similar long-period photometric signals have been found in the CVs SDSSJ123813.73-033933.0, SDSSJ204817.85-061044.8, GW Lib and FS Aur, but so far no working model for this behaviour is available.Comment: MNRAS, in press, 8 pages, 10 figures, some figures downgraded to meet the file size constraint of arxiv.or

The 2005 outburst of the halo black hole X-ray transient XTE J1118+480

We present optical and infrared monitoring of the 2005 outburst of the halo black hole X-ray transient XTE J1118+480. We measured a total outburst amplitude of ~5.7 ± 0.1 mag in the R band and ~5 mag in the infrared J, H, and Ks bands. The hardness ratio HR2 (5-12 keV : 3-5 keV) from the RXTE ASM data is 1.53 ± 0.02 at the peak of the outburst, indicating a hard spectrum. Both the shape of the light curve and the ratio LX(1-10 keV)/Lopt resemble the minioutbursts observed in GRO J0422+32 and XTE J1859+226. During early decline, we find a 0.02 mag amplitude variation consistent with a superhump modulation, like the one observed during the 2000 outburst. Similarly, XTE J1118+480 displayed a double-humped ellipsoidal modulation distorted by a superhump wave when settled into a near-quiescence level, suggesting that the disk expanded to the 3 : 1 resonance radius after outburst, where it remained until early quiescence. The system reached quiescence at R = 19.02 ± 0.03, about 3 months after the onset of the outburst. The optical rise preceded the X-ray rise by at most 4 days. The spectral energy distributions (SEDs) at the different epochs during outburst are all quasi-power laws with Fν να increasing toward the blue. At the peak of the outburst, we derived α = 0.49 ± 0.04 for the optical data alone and α = 0.1 ± 0.1 when fitting solely the infrared. This difference between the optical and the infrared SEDs suggests that the infrared is dominated by a different component (a jet?), whereas the optical is presumably showing the disk evolution

Synthesis and Biological Activity of Triterpene-Coumarin Conjugates.

A set of 12 maslinic acid-coumarin conjugates was synthesized, with 9 being maslinic acid-diamine-coumarin conjugates at the C-28 carboxylic acid group of triterpene acid and the other three being maslinic acid-coumarin conjugates at C-2/C-3 and/or C-28 of the triterpene skeleton. The cytotoxic effects of these 12 triterpene conjugates were evaluated in three cancer cell lines (B16-F10, HT29, and Hep G2) and compared, respectively, with three nontumor cell lines from the same or similar tissue (HPF, IEC-18, and WRL68). The most potent cytotoxic results were achieved by a conjugate with two molecules of coumarin-3-carboxylic acid coupled through the C-2 and C-3 hydroxy groups of maslinic acid. This conjugate showed submicromolar IC50 values in two of the three cancer cell lines tested (0.6, 1.1, and 0.9 μM), being between 110- and 30-fold more effective than its corresponding precursor. Furthermore, this conjugate (10) showed percentages of cell viability for the three nontumor lines of 90%. Four maslinic acid-coumarin conjugates displayed apoptotic effects in the treated cells, with total apoptosis rates of between 40 and 85%, relative to the control. Almost all the compounds assayed caused cell-cycle arrest in all cancer cell lines, increasing the number of these cells in the G0/G1 phase

A Comprehensive Analysis of Choroideremia: From Genetic Characterization to Clinical Practice.

Choroideremia (CHM) is a rare X-linked disease leading to progressive retinal degeneration resulting in blindness. The disorder is caused by mutations in the CHM gene encoding REP-1 protein, an essential component of the Rab geranylgeranyltransferase (GGTase) complex. In the present study, we evaluated a multi-technique analysis algorithm to describe the mutational spectrum identified in a large cohort of cases and further correlate CHM variants with phenotypic characteristics and biochemical defects of choroideremia patients. Molecular genetic testing led to the characterization of 36 out of 45 unrelated CHM families (80%), allowing the clinical reclassification of four CHM families. Haplotype reconstruction showed independent origins for the recurrent p.Arg293* and p.Lys178Argfs*5 mutations, suggesting the presence of hotspots in CHM, as well as the identification of two different unrelated events involving exon 9 deletion. No certain genotype-phenotype correlation could be established. Furthermore, all the patients´ fibroblasts analyzed presented significantly increased levels of unprenylated Rabs proteins compared to control cells; however, this was not related to the genotype. This research demonstrates the major potential of the algorithm proposed for diagnosis. Our data enhance the importance of establish a differential diagnosis with other retinal dystrophies, supporting the idea of an underestimated prevalence of choroideremia. Moreover, they suggested that the severity of the disorder cannot be exclusively explained by the genotype