We present H alpha integral field spectroscopy of well-resolved, UV/optically selected image star-forming galaxies as part of the SINS survey with SINFONI on the ESO VLT. Our laser guide star ...adaptive optics and good seeing data show the presence of turbulent rotating star-forming outer rings/disks, plus central bulge/inner disk components, whose mass fractions relative to the total dynamical mass appear to scale with the N ii/H alpha flux ratio and the star formation age. We propose that the buildup of the central disks and bulges of massive galaxies at image can be driven by the early secular evolution of gas-rich proto-disks. High-redshift disks exhibit large random motions. This turbulence may in part be stirred up by the release of gravitational energy in the rapid 'cold' accretion flows along the filaments of the cosmic web. As a result, dynamical friction and viscous processes proceed on a timescale of <1 Gyr, at least an order of magnitude faster than in image disk galaxies. Early secular evolution thus drives gas and stars into the central regions and can build up exponential disks and massive bulges, even without major mergers. Secular evolution along with increased efficiency of star formation at high surface densities may also help to account for the short timescales of the stellar buildup observed in massive galaxies at image.
In order to understand which process (e.g. galactic winds, cold accretion) is responsible for the cool (T ∼ 104 K) halo gas around galaxies, we embarked on a programme to study the star formation ...properties of galaxies selected by their Mg ii absorption signature in quasar spectra. Specifically, we searched for the Hα line emission from galaxies near very strong z ≃ 2 Mg ii absorbers (with rest-frame equivalent width
Å) because these could be the signposts of outflows or inflows. Surprisingly, we detect Hα from only four hosts out of 20 sightlines (and two out of the 19 H i-selected sightlines), despite reaching a star formation rate (SFR) sensitivity limit of 2.9 M⊙ yr−1 (5σ) for a Chabrier initial mass function. This low success rate (4/20) is in contrast with our z ≃ 1 survey where we detected 66 per cent (14/21) of the Mg ii hosts (down to 0.6 M⊙ yr−1; 5σ). Taking into account the difference in sensitivity between the two surveys, we should have been able to detect ≥11.4 (≥7.6) of the 20 z ≃ 2 hosts - assuming that SFR evolves as ∝(1 + z)γ with γ= 2.5 (or γ= 0) respectively - whereas we found only four galaxies. Interestingly, all the z = 2 detected hosts have observed SFRs ≳ 9 M⊙ yr−1, well above our sensitivity limit, while at z = 1 they all have SFR < 9 M⊙ yr−1, an evolution that is in good agreement with the evolution of the SFR main sequence, i.e. with γ= 2.5. Moreover, we show that the z = 2 undetected hosts are not hidden under the quasar continuum after stacking our data. They also cannot be outside our surveyed area as this latter option runs against our sample selection criteria (
Å) and the known W
λ2796
r-impact parameter relation for low-ionization ions. Hence, strong Mg ii absorbers could trace star-formation-driven winds in low-mass haloes (M
h≤ 1010.6 M⊙), provided that the winds do not extend beyond 20 kpc in order not to violate the evolution of the absorber number density dN/dz (Mg ii). Alternatively, our results imply that z = 2 galaxies traced by strong Mg ii absorbers do not form stars at a rate expected (3-10 M⊙ yr−1) for their (halo or stellar) masses, supporting the existence of a transition in accretion efficiency at M
h≃ 1011 M⊙. This scenario can explain both the detections and the non-detections.
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BFBNIB, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Screening of cDNA expression libraries derived from plants exposed to stress, with 35 S-labeled recombinant calmodulin as a probe, revealed a new family of proteins containing a transcription ...activation domain
and two types of DNA-binding domains designated the CG-1 domain and the transcription factor immunoglobulin domain, ankyrin
repeats, and a varying number of IQ calmodulin-binding motifs. Based on domain organization and amino acid sequence comparisons,
similar proteins, with the same domain organization, were identified in the genomes of other multicellular organisms including
human, Drosophila , and Caenorhabditis , whereas none were found in the complete genomes of single cell eukaryotes and prokaryotes. This family of proteins was designated
calmodulin-binding transcription activators (CAMTAs). Arabidopsis thaliana contains six CAMTA genes ( AtCAMTA1âAtCAMTA6 ). The transcription activation domain of AtCAMTA1 was mapped by testing a series of protein fusions with the DNA-binding
domain of the bacterial LexA transcription factor and two reporter genes fused to LexA recognition sequences in yeast cells.
Two human proteins designated HsCAMTA1 and HsCAMTA2 were also shown to activate transcription in yeast using the same reporter
system. Subcellular fractionation of Arabidopsis tissues revealed the presence of CAMTAs predominantly in the nucleus. Calmodulin binding assays identified a region of 25
amino acids capable of binding calmodulin with high affinity ( K
d = 1.2 n m ) in the presence of calcium. We suggest that CAMTAs comprise a conserved family of transcription factors in a wide range
of multicellular eukaryotes, which possibly respond to calcium signaling by direct binding of calmodulin.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
It remains a challenge to assess the merger fraction of galaxies at different cosmic epochs in order to probe the evolution of their mass assembly. Using the ILLUSTRIS cosmological simulation ...project, we investigate the relation between the separation of galaxies in a pair, both in velocity and projected spatial separation space, and the probability that these interacting galaxies will merge in the future. From this analysis, we propose a new set of criteria to select close pairs of galaxies along with a new corrective term to be applied to the computation of the galaxy merger fraction. We then probe the evolution of the major and minor merger fraction using the latest Multi-Unit Spectroscopic Explorer (MUSE) deep observations over the Hubble Ultra Deep Field, Hubble Deep Field South, COSMOS-Gr30, and Abell 2744 regions. From a parent sample of 2483 galaxies with spectroscopic redshifts, we identify 366 close pairs spread over a large range of redshifts (0.2 < z < 6) and stellar masses (107 − 1011M⊙). Using the stellar mass ratio between the secondary and primary galaxy as a proxy to split the sample into major, minor, and very minor mergers, we found a total of 183 major, 142 minor, and 47 very minor close pairs corresponding to a mass ratio range of 1:1–1:6, 1:6–1:100, and lower than 1:100, respectively. Due to completeness issues, we do not consider the very minor pairs in the analysis. Overall, the major merger fraction increases up to z ≈ 2−3 reaching 25% for pairs where the most massive galaxy has a stellar mass M⋆ ≥ 109.5 M⊙. Beyond this redshift, the fraction decreases down to ∼5% at z ≈ 6. The major merger fraction for lower-mass primary galaxies with M⋆ ≤ 109.5 M⊙ seems to follow a more constant evolutionary trend with redshift. Thanks to the addition of new MUSE fields and new selection criteria, the increased statistics of the pair samples allow us to significantly shorten the error bars compared to our previous analysis. The evolution of the minor merger fraction is roughly constant with cosmic time, with a fraction of 20% at z < 3 and a slow decrease to 8−13% in the redshift range 3 ≤ z ≤ 6.
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The structure of a sample of high-redshift (z ~ 2), rotating galaxies with high star formation rates and turbulent gas velocities of Delta *s 40-80 km s--1 is investigated. Fitting the observed disk ...rotational velocities and radii with a Mo et al. (MMW) model requires unusually large disk spin parameters Delta *l d >0.1 and disk-to-dark halo mass fractions of m d 0.2, close to the cosmic baryon fraction. The galaxies segregate into dispersion-dominated systems with 1 <= v max/ Delta *s <= 3, maximum rotational velocities v max<= 200 km s--1, and disk half-light radii r 1/2 1-3 kpc, and rotation-dominated systems with v max> 200 km s--1, v max/ Delta *s>3, and r 1/2 4-8 kpc. For the dispersion-dominated sample, radial pressure gradients partly compensate the gravitational force, reducing the rotational velocities. Including this pressure effect in the MMW model, dispersion-dominated galaxies can be fitted well with spin parameters of Delta *l d = 0.03-0.05 for high disk mass fractions of m d 0.2 and with Delta *l d = 0.01-0.03 for m d 0.05. These values are in good agreement with cosmological expectations. For the rotation-dominated sample, however, pressure effects are small and better agreement with theoretically expected disk spin parameters can only be achieved if the dark halo mass contribution in the visible disk regime (2-3 X r 1/2) is smaller than predicted by the MMW model. We argue that these galaxies can still be embedded in standard cold dark matter halos if the halos do not contract adiabatically in response to disk formation. In this case, the data favor models with small disk mass fractions of m d = 0.05 and disk spin parameters of Delta *l d 0.035. It is shown that the observed high turbulent gas motions of the galaxies are consistent with a Toomre instability parameter Q = 1 which is equal to the critical value, expected for gravitational disk instability to be the major driver of turbulence. The dominant energy source of turbulence is then the potential energy of the gas in the disk.
At redshifts larger than 2, a large fraction (80 per cent) of the metals is apparently as yet undetected. We use a sample of submillimetre-selected galaxies (SMGs) with molecular gas and dynamical ...mass measurements from the literature in order to put constraints on the contribution of such galaxies to the total metal budget. Compared with Lyman break galaxies (LBGs), for example, SMGs are rarer (by a factor of 10 or more), but contain much more gas and are more metal-rich. We estimate that SMGs brighter than 3 mJy contain only ≲9 per cent of the metals, when we combine the observed dynamical masses (〈Mdyn〉~ few × 1011 M⊙), number density (n≃s 10−4 Mpc−3), observed gas metallicity (Z≃ 1–2 Z⊙), and observed gas fractions (fgas~ 40 per cent), assuming a molecular to neutral hydrogen ratio of 1. Including SMGs fainter than 3 mJy, we estimate that SMGs contain about =15 per cent of the metals, where our incompleteness correction is estimated from the dust mass function. Our results are strong upper limits, given that high gas fractions and high overall metallicity are mutually exclusive. In summary, SMGs make a significant contribution to the metal budget (≲15 per cent) but not sufficient to solve the ‘missing metal problem’. A consequence of our results is that SMGs can only add ≈3.5 per cent to ΩDLA, and cannot be the source of a significant population of dusty DLAs.
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BFBNIB, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Granulocyte-macrophage colony-stimulating factor (GM-CSF) as an adjuvant in autologous cell-based anti-tumor immunotherapy has recently been approved for clinical application. To avoid the need for ...individualized processing of autologous cells, we developed a novel strategy based on the encapsulation of GM-CSF-secreting human allogeneic cells. GM-CSF-producing K562 cells showed high, stable and reproducible cytokine secretion when enclosed into macrocapsules. For clinical development, the cryopreservation of these devices is critical. Thawing of capsules frozen at different time points displayed differences in GM-CSF release shortly after thawing. However, similar secretion values to those of non-frozen control capsules were obtained 8 days after thawing at a rate of >1000 ng GM-CSF per capsule every 24 h. For future human application, longer and reinforced capsules were designed. After irradiation and cryopreservation, these capsules produced >300 ng GM-CSF per capsule every 24 h 1 week after thawing. The in vivo implantation of encapsulated K562 cells was evaluated in mice and showed preserved cell survival. Finally, as a proof of principle of biological activity, capsules containing B16-GM-CSF allogeneic cells implanted in mice induced a prompt inflammatory reaction. The ability to reliably achieve high adjuvant release using a standardized procedure may lead to a new clinical application of GM-CSF in cell-based cancer immunization.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We used the large binocular camera (LBC) mounted on the large binocular telescope (LBT) to observe the Lockman Hole in the U, B, and V bands. Our observations cover an area of 925 arcmin2. We reached ...depths of 26.7, 26.3, and 26.3 mag(AB) in the three bands, respectively, in terms of 50% source detection efficiency, making this survey the deepest U-band survey and one of the deepest B and V band surveys with respect to its covered area. We extracted a large number of sources (~89 000), detected in all three bands and examined their surface density, comparing it with models of galaxy evolution. We find good agreement with previous claims of a steep faint-end slope of the luminosity functions, caused by late-type and irregular galaxies at $z>1.5$. A population of dwarf star-forming galaxies at $1.5<z<2.5$ is needed to explain the U-band number counts. We also find evidence of strong supernova feedback at high redshift. This survey is complementary to the r, i, and z Lockman Hole survey conducted with the Subaru telescope and provides the essential wavelength coverage to derive photometric redshifts and select different types of sources from the Lockman Hole for further study.
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