We present the results of a new search for bright star-forming galaxies at redshift z ... 7 within the UltraVISTA second data release (DR2) and UKIDSS (UKIRT Infrared Deep Sky Survey) UDS (Ultra Deep ...Survey) DR10 data, which together provide 1.65 deg^sup 2^ of near-infrared imaging with overlapping optical and Spitzer data. Using a full photometric redshift analysis, to identify high-redshift galaxies and reject contaminants, we have selected a sample of 34 luminous (-22.7<M^sub UV^<-21.2) galaxies with 6.5 < z < 7.5. Crucially, the deeper imaging provided by UltraVISTA DR2 confirms all of the robust objects previously uncovered by Bowler et al., validating our selection technique. Our new expanded galaxy sample includes the most massive galaxies known at z ... 7, with M* ... 10^sup 10^ M..., and the majority are resolved, consistent with larger sizes (r^sub ...^ ... 1-1.5 kpc) than displayed by less massive galaxies. From our final robust sample, we determine the form of the bright end of the rest-frame UV galaxy luminosity function (LF) at z ... 7, providing strong evidence that it does not decline as steeply as predicted by the Schechter-function fit to fainter data. We exclude the possibility that this is due to either gravitational lensing, or significant contamination of our galaxy sample by active galactic nuclei (AGN). Rather, our results favour a double power-law form for the galaxy LF at high redshift, or, more interestingly, an LF which simply follows the form of the dark matter halo mass function at bright magnitudes. This suggests that the physical mechanism which inhibits star formation activity in massive galaxies (i.e. AGN feedback or some other form of 'mass quenching') has yet to impact on the observable galaxy LF at z ... 7, a conclusion supported by the estimated masses of our brightest galaxies which have only just reached a mass comparable to the critical 'quenching mass' of M* ... 10^sup 10.2^ M... derived from studies of the mass function of star-forming galaxies at lower redshift. (ProQuest: ... denotes formulae/symbols omitted.)
Abstract
To advance our understanding of the fuelling and feedback processes which power the Universe’s most massive black holes, we require a significant increase in our knowledge of the molecular ...gas which exists in their immediate surroundings. However, the behaviour of this gas is poorly understood due to the difficulties associated with observing it directly. We report on a survey of 18 brightest cluster galaxies lying in cool cores, from which we detect molecular gas in the core regions of eight via carbon monoxide (CO), cyanide (CN) and silicon monoxide (SiO) absorption lines. These absorption lines are produced by cold molecular gas clouds which lie along the line of sight to the bright continuum sources at the galaxy centres. As such, they can be used to determine many properties of the molecular gas which may go on to fuel supermassive black hole accretion and AGN feedback mechanisms. The absorption regions detected have velocities ranging from −45 to 283 km s−1 relative to the systemic velocity of the galaxy, and have a bias for motion towards the host supermassive black hole. We find that the CN N = 0 − 1 absorption lines are typically 10 times stronger than those of CO J = 0 − 1. This is due to the higher electric dipole moment of the CN molecule, which enhances its absorption strength. In terms of molecular number density CO remains the more prevalent molecule with a ratio of CO/CN ∼10, similar to that of nearby galaxies. Comparison of CO, CN, and H i observations for these systems shows many different combinations of these absorption lines being detected.
ABSTRACT
We present Atacama Large Millimetre/submillimetre Array observations of the brightest cluster galaxy Hydra-A, a nearby (z = 0.054) giant elliptical galaxy with powerful and extended radio ...jets. The observations reveal CO(1−0), CO(2–1), 13CO(2–1), CN(2–1), SiO(5–4), HCO+(1–0), HCO+(2–1), HCN(1–0), HCN(2–1), HNC(1–0), and H2CO(3–2) absorption lines against the galaxy’s bright and compact active galactic nucleus. These absorption features are due to at least 12 individual molecular clouds that lie close to the centre of the galaxy and have velocities of approximately −50 to +10 km s−1 relative to its recession velocity, where positive values correspond to inward motion. The absorption profiles are evidence of a clumpy interstellar medium within brightest cluster galaxies composed of clouds with similar column densities, velocity dispersions, and excitation temperatures to those found at radii of several kpc in the Milky Way. We also show potential variation in a ∼10 km s−1 wide section of the absorption profile over a 2 yr time-scale, most likely caused by relativistic motions in the hot spots of the continuum source that change the background illumination of the absorbing clouds.
Active galactic nuclei play a crucial role in the accretion and ejection of gas in galaxies. Although their outflows are well studied, finding direct evidence of accretion has proved very difficult ...and has so far been done for very few sources. A promising way to study the significance of cold accretion is by observing the absorption of an active galactic nucleus's extremely bright radio emission by the cold gas lying along the line of sight. As such, we present ALMA CO(1-0) and CO(2-1) observations of the Hydra-A brightest cluster galaxy (z = 0.054) which reveal the existence of cold, molecular gas clouds along the line of sight to the galaxy's extremely bright and compact mm-continuum source. They have apparent motions relative to the central supermassive black hole of between -43 and -4 km s-1 and are most likely moving along stable, low ellipticity orbits. The identified clouds form part of a ˜109 M⊙, approximately edge-on disc of cold molecular gas. With peak CO(2-1) optical depths of τ = 0.88 ^{+0.06}_{-0.06}, they include the narrowest and by far the deepest absorption of this type which has been observed to date in a brightest cluster galaxy. By comparing the relative strengths of the lines for the most strongly absorbing region, we are able to estimate a gas temperature of 42^{+25}_{-11} K and line of sight column densities of N_{CO}=2^{+3}_{-1}× 10 ^{17} {cm}^{-2} and N_{H2 }=7^{+10}_{-4}× 10 ^{20} {cm}^{-2}.
To study patients with ALS to determine the following: 1) the relationship between physical function and quality of life (QOL); 2) the instruments that best reflect patients' own ratings of QOL; and ...3) whether spiritual/religious factors play a role in determining QOL.
The authors prospectively studied 96 patients with ALS using several instruments, including the McGill Quality of Life (MQOL) instrument, the Idler Index of Religiosity, the Sickness Impact Profile (SIP)/ALS-19, and several measures of strength and physical function.
QOL as assessed by patients (MQOL single item score) did not correlate with measures of physical function and strength, but correlated with the total MQOL score (p < 0.0005), the psychological and existential subscores of MQOL (p < 0. 0005), the support subscore of MQOL (p = 0.001), and the total Idler score (p = 0.001). In contrast, correlations between SIP/ALS-19 and these measures were not significant, although SIP/ALS-19 correlated with measures of physical function and strength.
QOL, as assessed by the patient with ALS, does not correlate with measures of strength and physical function, but appears to depend on psychological and existential factors, and thus may be measured well by the MQOL scale. Spiritual factors and support systems appear to play roles as well. SIP/ALS-19 is a good measure of physical function, but not of overall QOL.
To study patients with ALS to determine how physical function, quality of life (QOL), and spirituality or religiousness change over time, and what relationship these changes have to one another.
...Sixty patients with ALS were studied prospectively. They were assessed at baseline, 3 months, and 6 months, using questionnaires designed to measure general quality of life (McGill Quality of Life questionnaire), religiosity (Idler Index of Religiosity), ALS-specific health-related quality of life (SIP/ALS-19), and ALS-specific function (ALS functional rating scale).
A two-way repeated measures multivariate analysis of variance revealed that both the passage of time and the specific QOL scales used were factors in predicting patient quality of life (F1, 59= 9.87, p < 0.003 and F3, 177= 16.90, p < 0.001) Despite a progressive decline in physical function as measured by the ALS-specific function score, the general QOL and religiosity scores changed little. In contrast, the ALS-specific health-related QOL score declined in parallel with the ALS-specific function score.
QOL in patients with ALS appears to be independent of physical function, which agrees with a previous cross-sectional study. The ALS-specific health-related QOL score is primarily a measure of physical function. QOL instruments that assess spiritual, religious, and psychological factors produce different results than those obtained using measures of physical function alone.
There is no generally accepted instrument for measuring quality of life (QOL) in patients with ALS. Current instruments are either too heavily weighted toward strength and physical function or useful ...for the evaluation of individuals but of less utility in assessing large samples.
To develop and evaluate the psychometric properties of an ALS-specific QOL instrument (the ALSSQOL) that would reflect overall QOL as assessed by the patient and would be valid and reliable across large samples.
The ALSSQOL is based on the McGill Quality of Life Questionnaire (MQOL), modified by changes in format and by adding questions on religiousness and spirituality, items derived from interviews with ALS patients, and items identified from open-ended questions administered during the MQOL. The psychometric properties of the ALSSQOL were assessed by a prospective multicenter study in which participants completed the ALSSQOL, other instruments measuring overall QOL, and instruments assessing religiousness, spirituality, and psychological distress.
A 59-item ALSSQOL was developed; 342 patients evaluated its psychometric properties. Completion time averaged 15 minutes. Forty-six items loaded on six factors. The ALSSQOL demonstrated concurrent, convergent, and discriminant validity for the overall instrument and convergent validity for its subscales. Analysis of individual items permitted insight into variables of clinical importance.
This new ALS-specific quality of life instrument is a practical tool for the assessment of overall quality of life in individuals with ALS and appears to be valid and useful across large samples. Validation studies of a shortened version are now under way.
We report the detection of the Sunyaev-Zel'dovich (SZ) effect of galaxy cluster XLSSU J021744.1 -034536, using 30 GHz Combined Array for Research in Millimeter-wave Astronomy (CARMA) data. This ...cluster was discovered via its extended X-ray emission in the XMM-Newton Large Scale Structure survey, the precursor to the XXL survey. It has a photometrically determined redshift z = 1.91 super(+0.19) sub(-0.21), making it among the most distant clusters known, and nominally the most distant for which the SZ effect has been measured. The spherically integrated Comptonization is Y sub(500) = (3.0 + or - 0.4) x 10 super(-12), a measurement that is relatively insensitive to assumptions regarding the size and redshift of the cluster, as well as the background cosmology. Using a variety of locally calibrated cluster scaling relations extrapolated to z ~ 2, we estimate a mass M sub(500) ~ (1-2) x 10 super(14) M sub(middot in circle) from the X-ray flux and SZ signal. The measured properties of this cluster are in good agreement with the extrapolation of an X-ray luminosity-SZ effect scaling relation calibrated from clusters discovered by the South Pole Telescope at higher masses and lower redshifts. The full XXL-CARMA sample will provide a more complete, multi-wavelength census of distant clusters in order to robustly extend the calibration of cluster scaling relations to these high redshifts.
The immunopotentiator tucaresol was modified for incorporation into liposomes, where it was found to be a superior adjuvant to MPLA for vaccination against methamphetamine.
Eukaryotic translation initiation factor 4B (eIF4B) plays a critical role during the initiation of protein synthesis and its activity can be regulated by multiple phosphorylation events. In a search ...for novel protein kinase B (PKB/c-akt) substrates, we identified eIF4B as a potential target. Using an in vitro kinase assay, we found that PKB can directly phosphorylate eIF4B on serine 422 (ser422). Activation of a conditional PKB mutant, interleukin-3 (IL-3) or insulin stimulation resulted in PKB-dependent phosphorylation of this residue in vivo. This was prevented by pretreatment of cells with the phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 or pharmacological inhibition of PKB. Pretreatment of cells with rapamycin, inhibiting mTOR or U0126 to inhibit MEK, had little effect on eIF4B ser422 phosphorylation. In contrast, following amino-acid refeeding, eIF4B ser422 phosphorylation was found to be mammalian target of rapamycin (mTOR)-dependent. We further identified eIF4B ser406 as a novel mitogen-regulated phosphorylation site. Insulin-induced phosphorylation of eIF4B ser406 was dependent on both MEK and mTOR activity. Utilizing a novel translational control luciferase assay, we could further demonstrate that phosphorylation of ser406 or ser422 is essential for optimal translational activity of eIF4B. These data provide novel insights into complex multikinase regulation of eIF4B phosphorylation and reveal an important mechanism by which PKB can regulate translation, potentially critical for the transforming capacity of this AGC kinase family member.
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