Wide-field mid-infrared and millimetre imaging of the high-redshift radio galaxy, 4C41.17

We present deep 350- and 1200-micron imaging of the region around 4C41.17 -- one of the most distant (z = 3.792) and luminous known radio galaxies -- obtained with the Submillimeter High Angular Resolution Camera (SHARC-II) and the Max Planck Millimeter Bolometer Array (MAMBO). The radio galaxy is robustly detected at 350- and 1200-micron, as are two nearby 850-micron-selected galaxies; a third 850-micron source is detected at 350-micron and coincides with a ~ 2-sigma feature in the 1200-micron map. Further away from the radio galaxy an additional nine sources are detected at 1200-micron, bringing the total number of detected (sub)millimeter selected galaxies (SMGs) in this field to 14. Using radio images from the Very Large Array (VLA) and Spitzer mid-infrared (mid-IR) data, we find statistically robust radio and/or 24-micron counterparts to eight of the 14 SMGs in the field around 4C41.17. Follow-up spectroscopy with Keck/LRIS has yielded redshifts for three of the eight robustly identified SMGs, placing them in the redshift range 0.5 < z < 2.7, i.e. well below that of 4C41.17. We infer photometric redshifts for a further four sources using their 1.6-micron (rest-frame) stellar feature as probed by the IRAC bands; only one of them is likely to be at the same redshift as 4C41.17. Thus at least four, and as many as seven, of the SMGs within the 4C41.17 field are physically unrelated to the radio galaxy. With the redshift information at hand we are able to constrain the observed over-densities of SMGs within radial bins stretching to R=50 and 100" (~ 0.4 and ~ 0.8Mpc at z ~ 3.8) from the radio galaxy to ~ 5x and ~ 2x that of the field, dropping off to the background value at R=150". [Abridged]Comment: 20 pages, 9 figures, accepted for publication in MNRA

Application of Raman Microspectroscopic and Raman imaging techniques for cell biological studies

Raman spectroscopy is being used to study biological molecules for some three decades now. Thanks to continuing advances in instrumentation more and more applications have become feasible in which molecules are studied in situ, and this has enabled Raman spectroscopy to enter the realms of biomedicine and cell biology [1-5].\ud Here we will describe some of the recent work carried out in our laboratory, concerning studies of human white blood cells and further instrumentational developments

DNA bending by photolyase in specific and non-specific complexes studied by atomic force microscopy

Specific and non-specific complexes of DNA and photolyase are visualised by atomic force microscopy. As a substrate for photolyase a 1150 bp DNA restriction fragment was UV-irradiated to produce damaged sites at random positions. Comparison with a 735 bp undamaged DNA fragment made it possible to separate populations of specific and non-specific photolyase complexes on the 1150 bp fragment, relieving the need for highly defined substrates. Thus it was possible to compare DNA bending for specific and non-specific interactions. Non-specific complexes show no significant bending but increased rigidity compared to naked DNA, whereas specific complexes show DNA bending of on average 36°and higher flexibility. A model obtained by docking shows that photolyase can accommodate a 36°bent DNA in the vicinity of the active site

HI distribution and kinematics of NGC 1569

We present WSRT observations of high sensitivity and resolution of the neutral hydrogen in the starburst dwarf galaxy NGC 1569. Assuming a distance of 2.2 Mpc, we find a total HI mass of 1.3 * 10^8 M_sun to be distributed in the form of a dense, clumpy ridge surrounded by more extended diffuse HI containing a few additional discrete features, such as a Western HI Arm and an HI bridge reaching out to a small counterrotating companion cloud. About 10% by mass of all HI in NGC 1569 is at unusually high velocities. Some of this HI may be associated with the mass outflow evident from H-alpha measurements, but some may also be associated with NGC 1569's HI companion and intervening HI bridge, in which case, infall rather than outflow might be the cause of the discrepant velocities. No indication of a large bubble structure was found in position-velocity maps of the high-velocity HI. The galaxy as a whole is in modest overall rotation, but the HI gas lacks any sign of rotation within 60'' (0.6 kpc) from the center, i.e. over most of the optical galaxy. Here, turbulent motions resulting from the starburst appear to dominate over rotation. In the outer disk, the rotational velocities reach a maximum of 35 \pm 6 km/s, but turbulent motion remains significant. Thus, starburst effects are still noticeable in the outer HI disk, although they are no longer dominant beyond 0.6 kpc. Even excluding the most extreme high-velocity HI clouds, NGC 1569 still has an unusually high mean HI velocity dispersion of sigma_v=21.3 km/s, more than double that of other dwarf galaxies.Comment: Figure 11a,b and Figure 14 separately in jpg forma

Treatment algorithm in patients with ovarian cancer

Most ovarian cancer patients are diagnosed only at advanced stages when survival outcomes are worse, and when therapeutic decisions might prove challenging. The fundamental treatment for women with ovarian cancer includes debulking surgery whenever possible and appropriate systemic therapy (chemotherapy, targeted and antiangiogenic agents). In the last few years, knowledge about histological and molecular characteristics of ovarian cancer subtypes and stages has increased considerably. This has enabled the development and improvement of several options for the diagnosis and treatment of ovarian cancer in a patient-tailored approach. Accordingly, therapeutic decisions are guided by the characteristics of the patient and the tumour, especially the molecular features of the cancer subtype and disease stage. Particularly relevant are the advances in early genetic testing of germline and somatic mutations involved in DNA repair, and the clinical development of targeted agents. In order to implement the best individual medical strategies, in this article, we present an algorithm of treatment options, including recently developed targeted agents, for primary and recurrent ovarian cancer patients in Belgium

From the Heart of The Ghoul: C and N Abundances in the Corona of Algol B

Chandra Low Energy Transmission Grating Spectrograph observations of Algol have been used to determine the abundances of C and N in the secondary star for the first time. The analysis was performed relative to similar observations of an adopted "standard" star HR 1099. It is demonstrated that HR 1099 and Algol are coronal twins in many respects and that their X-ray spectra are very similar in nearly all details, except for the observed strengths of C and N lines. The H-like transitions of C and N in the coronae of Algol and HR 1099 demonstrate that the surface abundances of Algol B have been strongly modified by CN-processing, as shown earlier by Schmitt & Ness (2002). It is found that N is enhanced in Algol B by a factor of 3 compared to HR 1099. No C lines are detected in the Algol spectrum, indicating a C depletion relative to HR 1099 by a factor of 10 or more. These C and N abundances indicate that Algol B must have lost at least half of its initial mass, and are consistent with predictions of evolutionary models that include non-conservative mass transfer and angular momentum loss through magnetic activity. Little or no dredge-up of material subjected to CN-processing has occurred on the subgiant component of HR 1099. It is concluded that Fe is very likely depleted in the coronae of both Algol and HR 1099 relative to their photospheres by 0.5 dex, and C, N and O by 0.3 dex. Instead, Ne is enhanced by up to 0.5 dex.Comment: 17 pages, 4 figures, ApJ accepte

CO line emission in the halo of a radio galaxy at z=2.6

We report the detection of luminous CO(3-2) line emission in the halo of the z=2.6 radio galaxy (HzRG) TXS0828+193, which has no detected counterpart at optical to mid-infrared wavelengths implying a stellar mass < few x10^9 M_sun and relatively low star-formation rates. With the IRAM PdBI we find two CO emission line components at the same position at ~80 kpc distance from the HzRG along the axis of the radio jet, with different blueshifts of few 100 km s^-1 relative to the HzRG and a total luminosity of ~2x10^10 K km s^-1 pc^2 detected at 8 sigma significance. HzRGs have significant galaxy overdensities and extended halos of metal-enriched gas often with embedded clouds or filaments of denser material, and likely trace very massive dark-matter halos. The CO emission may be associated with a gas-rich, low-mass satellite galaxy with little on-going star formation, in contrast to all previous CO detections of galaxies at similar redshifts. Alternatively, the CO may be related to a gas cloud or filament and perhaps jet-induced gas cooling in the outer halo, somewhat in analogy with extended CO emission found in low-redshift galaxy clusters.Comment: MNRAS Letters, accepte

Extended warm and dense gas towards W49A: starburst conditions in our Galaxy?

The star formation rates in starburst galaxies are orders of magnitude higher than in local star-forming regions, and the origin of this difference is not well understood. We use sub-mm spectral line maps to characterize the physical conditions of the molecular gas in the luminous Galactic star-forming region W49A and compare them with the conditions in starburst galaxies. We probe the temperature and density structure of W49A using H_2CO and HCN line ratios over a 2'x2' (6.6x6.6 pc) field with an angular resolution of 15" (~0.8 pc) provided by the JCMT Spectral Legacy Survey. We analyze the rotation diagrams of lines with multiple transitions with corrections for optical depth and beam dilution, and estimate excitation temperatures and column densities. Comparing the observed line intensity ratios with non-LTE radiative transfer models, our results reveal an extended region (about 1'x1', equivalent to ~3x3 pc at the distance of W49A) of warm (> 100 K) and dense (>10^5 cm^-3) molecular gas, with a mass of 2x10^4 - 2x10^5 M_Sun (by applying abundances derived for other regions of massive star-formation). These temperatures and densities in W49A are comparable to those found in clouds near the center of the Milky Way and in starburst galaxies. The highly excited gas is likely to be heated via shocks from the stellar winds of embedded, O-type stars or alternatively due to UV irradiation, or possibly a combination of these two processes. Cosmic rays, X-ray irradiation and gas-grain collisional heating are less likely to be the source of the heating in the case of W49A.Comment: Accepted for publication in A&A; 11 pages, 9 figure