Galaxy Counterparts of metal-rich Damped Lyman-alpha Absorbers - I: The case of the z=2.35 DLA towards Q2222-0946

We have initiated a survey using the newly commissioned X-shooter spectrograph to target candidate relatively metal-rich damped Lyman-alpha absorbers (DLAs). The spectral coverage of X-shooter allows us to search for not only Lyman-alpha emission, but also rest-frame optical emission lines. We have chosen DLAs where the strongest rest-frame optical lines ([OII], [OIII], Hbeta and Halpha) fall in the NIR atmospheric transmission bands. In this first paper resulting from the survey, we report on the discovery of the galaxy counterpart of the z_abs = 2.354 DLA towards the z=2.926 quasar Q2222$-0946. This DLA is amongst the most metal-rich z>2 DLAs studied so far at comparable redshifts and there is evidence for substantial depletion of refractory elements onto dust grains. We measure metallicities from ZnII, SiII, NiII, MnII and FeII of -0.46+/-0.07, -0.51+/-0.06, -0.85+/-0.06, -1.23+/-0.06, and -0.99+/-0.06, respectively. The galaxy is detected in the Lyman-alpha, [OIII] lambda4959,5007 Halpha emission lines at an impact parameter of about 0.8 arcsec (6 kpc at z_abs = 2.354). We infer a star-formation rate of 10 M_sun yr^-1, which is a lower limit due to the possibility of slit-loss. Compared to the recently determined Halpha luminosity function for z=2.2 galaxies the DLA-galaxy counterpart has a luminosity of L~0.1L^*_Halpha. The emission-line ratios are 4.0 (Lyalpha/Halpha) and 1.2 ([OIII]/Halpha). The Lyalpha line shows clear evidence for resonant scattering effects, namely an asymmetric, redshifted (relative to the systemic redshift) component and a much weaker blueshifted component. The fact that the blueshifted component is relatively weak indicates the presence of a galactic wind. The properties of the galaxy counterpart of this DLA is consistent with the prediction that metal-rich DLAs are associated with the most luminous of the DLA-galaxy counterparts.Comment: 9 pages, 7 figures. Accepted for publication in MNRA

Enriched haloes at redshift z=2z=2 with no star-formation: Implications for accretion and wind scenarios

[Abridged] In order to understand which process (e.g. galactic winds, cold accretion) is responsible for the cool (T~10^4 K) halo gas around galaxies, we embarked on a program to study the star-formation properties of galaxies selected by their MgII absorption signature in quasar spectra. Specifically, we searched for the H-alpha line emission from galaxies near very strong z=2 MgII absorbers (with rest-frame equivalent width EW>2 \AA) because these could be the sign-posts of outflows or inflows. Surprisingly, we detect H-alpha from only 4 hosts out of 20 sight-lines (and 2 out of the 19 HI-selected sight-lines), despite reaching a star-formation rate (SFR) sensitivity limit of 2.9 M/yr (5-sigma) for a Chabrier initial mass function. This low success rate is in contrast with our z=1 survey where we detected 66%\ (14/21) of the MgII hosts. Taking into account the difference in sensitivity between the two surveys, we should have been able to detect >11.4 of the 20 z=2 hosts whereas we found only 4 galaxies. Interestingly, all the z=2 detected hosts have observed SFR greater than 9 M/yr, well above our sensitivity limit, while at z=1 they all have SFR less than 9 M/yr, an evolution that is in good agreement with the evolution of the SFR main sequence. Moreover, we show that the z=2 undetected hosts are not hidden under the quasar continuum after stacking our data and that they also cannot be outside our surveyed area. Hence, strong MgII absorbers could trace star-formation driven winds in low-mass halos (Mhalo < 10^{10.6} Msun). Alternatively, our results imply that z=2 galaxies traced by strong MgII absorbers do not form stars at a rate expected (3--10 M/yr) for their (halo or stellar) masses, supporting the existence of a transition in accretion efficiency at Mhalo ~ 10^{11} Msun. This scenario can explain both the detections and the non-detections.Comment: 14 pages, 4 fig.; MNRAS in press, minor corrections to match proof

Stress management interventions in the workplace improve stress reactivity: a randomised controlled trial

Objective To examine the long-term effects of a stress management intervention (SMI) based on the effort-reward imbalance (ERI) model, on psychological and biological reactions to work stress. Methods 174 lower or middle management employees (99% male) were randomly assigned to an intervention or a waiting control group. The programme comprised 24×45 min group sessions (2 full days followed by two 4×45 min sessions within the next 8 months) on individual work stress situations. The primary endpoint was perceived stress reactivity (Stress Reactivity Scale, SRS), while secondary endpoints were salivary cortisol and α-amylase, anxiety and depression, and ERI. Assessments were repeated in 154 participants 1 year later. Results SRS score decreased in both groups. A two-factor ANOVA with repeated measures showed a significant time×group effect (F=5.932; p=0.016) with the greater reduction in the intervention group. For SRS, the effect size (Cohen`s d) after 1 year was d=0.416 in the intervention and d=0.166 in the control group. α-Amylase as a measure of sympathetic nervous system activation, decreased more strongly in the intervention group (area under the daytime curve and daytime slope: time×group effect p=0.076 and p=0.075). No difference was observed for cortisol. For depression, anxiety and ERI, improvements were higher in the intervention group but did not reach statistical significance. Conclusions SMI based on work stress theory, is effective in reducing perceived stress reactivity and sympathetic activation in lower and middle management employees. Other mental health parameters and ERI show a tendency towards improvement. These beneficial effects are present 1 year later

Results on the mandatory notification of carbapenem-resistant Gram-negative bacteria, Hesse, Germany, January 2012 - April 2013

Carbapenems are important therapeutic agents for treating infections caused by multidrug-resistant Gram-negative bacteria. Mandatory reporting of carbapenem-resistant Gram-negative bacteria (CR-GN) can allow for a better understanding of the changing CR-GN burden and can help facilitate intervention. In November 2011, identification of CR-GN with acquired carbapenem resistance became notifiable in Hesse, Germany. Hesse is one of the 16 German federal states, with a population of 6.1 million. We report on CR-GN notified between 1 January and 8 April 2013, when reporting requirements were changed. During this period, 549 CR-GN were isolated from 525 patients. Of these, 67.0% (368/549) were Pseudomonas aeruginosa . The remaining 181 CR-GN comprised 59 (32.6%) K. pneumoniae , 53 (29.3%) Acinetobacter baumannii , 28 (15.5%) Enterobacter spp., 20 (11.5%) E. coli , and 21 (11.6%) other CR-GN. Seventy-three (13.3%) CR-GN were reported to harbour a carbapenemase. Fourteen different carbapenemase types were reported, with the most frequent being OXA-23 (n=18), OXA-48 (n= 16), VIM-2 (n=12), VIM-1 (n=11), and NDM (n=5). Our results suggest the widespread presence of CR-GN, a high diversity of identified carbapenemases, autochthonous transmissions, and regional differences in incidence for the different species and carbapenemases, even in the absence of major outbreaks of infection

Carbapenem-Resistant spp. as an Emerging Concern in the Hospital-Setting: Results From a Genome-Based Regional Surveillance Study.

The rise of Carbapenem-resistant Enterobacterales (CRE) represents an increasing threat to patient safety and healthcare systems worldwide. Citrobacter spp., long considered not to be a classical nosocomial pathogen, in contrast to Klebsiella pneumoniae and Escherichia coli, is fast gaining importance as a clinical multidrug-resistant pathogen. We analyzed the genomes of 512 isolates of 21 CRE species obtained from 61 hospitals within a three-year-period and found that Citrobacter spp. (C. freundii, C. portucalensis, C. europaeus, C. koseri and C. braakii) were increasingly detected (n=56) within the study period. The carbapenemase-groups detected in Citrobacter spp. were KPC, OXA-48/-like and MBL (VIM, NDM) accounting for 42%, 31% and 27% respectively, which is comparable to those of K. pneumoniae in the same study. They accounted for 10%, 17% and 14% of all carbapenemase-producing CRE detected in 2017, 2018 and 2019, respectively. The carbapenemase genes were almost exclusively located on plasmids. The high genomic diversity of C. freundii is represented by 22 ST-types. KPC-2 was the predominantly detected carbapenemase (n=19) and was located in 95% of cases on a highly-conserved multiple-drug-resistance-gene-carrying pMLST15 IncN plasmid. KPC-3 was rarely detected and was confined to a clonal outbreak of C. freundii ST18. OXA-48 carbapenemases were located on plasmids of the IncL/M (pOXA-48) type. About 50% of VIM-1 was located on different IncN plasmids (pMLST7, pMLST5). These results underline the increasing importance of the Citrobacter species as emerging carriers of carbapenemases and therefore as potential disseminators of Carbapenem- and multidrug-resistance in the hospital setting