17 research outputs found
An ISOCAM survey through gravitationally lensing galaxy clusters
ISOCAM was used to perform a deep survey through three gravitationally
lensing clusters of galaxies. Nearly seventy sq. arcmin were covered over the
clusters A370, A2218 and A2390. We present maps and photometry at 6.7 & 14.3
microns, showing a total of 145 mid-IR sources and the associated source
counts. The 15 micron counts reach the faintest level yet recorded. All sources
have counterparts in the optical or near-IR. Models of the clusters were used
to correct for the effects of lensing, which increases the sensitivity of the
survey. Seven of fifteen SCUBA sources were detected at 15 microns. Five have
redshift between 0.23 & 2.8, with a median of 0.9. The field sources were
counted to a lensing-corrected sensitivity of 30 microJy at 15 microns, and 14
microJy at 7 microns. The counts, corrected for completeness, contamination by
cluster sources and lensing, confirm and extend findings of an excess by a
factor of ten in the 15 micron population with respect to source models with no
evolution. Source redshifts are mostly between 0.4 and 1.5. For the counts at 7
microns, integrating from 14 microJy to 460 microJy, we resolve 0.49+/-0.2
nW.m^(-2).sr^(-1) of the infrared background light (IBL) into discrete sources.
At 15 microns we include the counts from other ISOCAM surveys to integrate from
30 microJy to 50 mJy, two to three times deeper than unlensed surveys, to
resolve 2.7+/-0.62 nW.m^(-2).sr^(-1) of the IBL. These values are 10% and 55%,
respectively, of the upper limit to the IBL, derived from photon-photon pair
production of the TeV gamma rays from BL-Lac sources on the IBL photons.
However, recent detections of TeV gamma rays from the z=0.129 BL Lac H1426+428
suggest that the 15 micron background reported implies substantial absorption
of TeV photons from that source.Comment: 35 pages, 17 figures, to appear in Astronomy and Astrophysics, full
paper with high-resolution figures available at
http://www.iso.vilspa.esa.es/science/pub/2003
Chasing highly obscured QSOs in the COSMOS field
(abridged) We take advantage of the deep Chandra and Spitzer coverage of a
large area (more than 10 times the area covered by the Chandra deep fields,
CDFs in the COSMOS field, to extend the search of highly obscured,
Compton-thick active nuclei to higher luminosity. These sources have low
surface density and large samples can be provided only through large area
surveys, like the COSMOS survey. We analyze the X-ray properties of COSMOS MIPS
sources with 24m fluxes higher than 550Jy. For the MIPS sources not
directly detected in the Chandra images we produce stacked images in soft and
hard X-rays bands. To estimate the fraction of Compton-thick AGN in the MIPS
source population we compare the observed stacked count rates and hardness
ratios to those predicted by detailed Monte Carlo simulations including both
obscured AGN and star-forming galaxies. The density of lower luminosity
Compton-thick AGN (logL(2-10keV)=43.5-44) at z=0.7--1.2 is Mpc, corresponding to of that of X-ray selected
AGN. The comparison between the fraction of infrared selected, Compton thick
AGN to the X-ray selected, unobscured and moderately obscured AGN at high and
low luminosity suggests that Compton-thick AGN follow a luminosity dependence
similar to that discovered for Compton-thin AGN, becoming relatively rarer at
high luminosities. We estimate that the fraction of AGN (unobscured, moderately
obscured and Compton thick) to the total MIPS source population is ,
a value significantly higher than that previously estimated at similar 24m
fluxes. We discuss how our findings can constrain AGN feedback models.Comment: Paper submitted to ApJ. This is the revised version after all
referee's comments have been addresse
Novel inhibitors of the calcineurin/NFATc hub - alternatives to CsA and FK506?
The drugs cyclosporine A (CsA) and tacrolimus (FK506) revolutionized organ transplantation. Both compounds are still widely used in the clinic as well as for basic research, even though they have dramatic side effects and modulate other pathways than calcineurin-NFATc, too. To answer the major open question - whether the adverse side effects are secondary to the actions of the drugs on the calcineurin-NFATc pathway - alternative inhibitors were developed. Ideal inhibitors should discriminate between the inhibition of (i) calcineurin and peptidyl-prolyl cis-trans isomerases (PPIases; the matchmaker proteins of CsA and FK506), (ii) calcineurin and the other Ser/Thr protein phosphatases, and (iii) NFATc and other transcription factors. In this review we summarize the current knowledge about novel inhibitors, synthesized or identified in the last decades, and focus on their mode of action, specificity, and biological effects
HerMES: Candidate Gravitationally Lensed Galaxies and Lensing Statistics at Submillimeter Wavelengths
We present a list of 13 candidate gravitationally lensed submillimeter galaxies (SMGs) from 95 deg2 of the Herschel Multi-tiered Extragalactic Survey, a surface density of 0.14 ± 0.04 deg-2. The selected sources have 500 Όm flux densities (S 500) greater than 100 mJy. Gravitational lensing is confirmed by follow-up observations in 9 of the 13 systems (70%), and the lensing status of the four remaining sources is undetermined. We also present a supplementary sample of 29 (0.31 ± 0.06 deg-2) gravitationally lensed SMG candidates with S 500 = 80-100 mJy, which are expected to contain a higher fraction of interlopers than the primary candidates. The number counts of the candidate lensed galaxies are consistent with a simple statistical model of the lensing rate, which uses a foreground matter distribution, the intrinsic SMG number counts, and an assumed SMG redshift distribution. The model predicts that 32%-74% of our S 500 >= 100 mJy candidates are strongly gravitationally lensed (Ό >= 2), with the brightest sources being the most robust; this is consistent with the observational data. Our statistical model also predicts that, on average, lensed galaxies with S 500 = 100 mJy are magnified by factors of ~9, with apparently brighter galaxies having progressively higher average magnification, due to the shape of the intrinsic number counts. 65% of the sources are expected to have intrinsic 500 Όm flux densities less than 30 mJy. Thus, samples of strongly gravitationally lensed SMGs, such as those presented here, probe below the nominal Herschel detection limit at 500 Όm. They are good targets for the detailed study of the physical conditions in distant dusty, star-forming galaxies, due to the lensing magnification, which can lead to spatial resolutions of ~0.''01 in the source plane
Postpartum traditions and nutrition practices among urban Lao women and their infants in Vientiane Lao PDR
Postpartum traditions and nutrition practices among urban Lao women and their infants in Vientiane, Lao PDR (vol 63, pg 323, 2009)
Erratum: Postpartum traditions and nutrition practices among urban Lao women and their infants in Vientiane, Lao PDR (European Journal of Clinical Nutrition (2009) vol. 63 (323-331) 10.1038/sj.ejcn.1602928)
Erratum: Postpartum traditions and nutrition practices among urban Lao women and their infants in Vientiane, Lao PDR (European Journal of Clinical Nutrition (2009) vol. 63 (323-331) 10.1038/sj.ejcn.1602928)
Postpartum traditions and nutrition practices among urban Lao women and their infants in Vientiane, Lao PDR
BACKGROUND/OBJECTIVE: To assess the traditional postpartum practices, mother and child nutritional status and associated factors. SUBJECTS/METHODS: A cross-sectional study in 41 randomly selected villages on the outskirts of Vientiane capital city, Lao PDR (Laos). 300 pairs of infants (> 6 months of age) and their mothers were enrolled. Information was collected about pregnancy, delivery and traditional practices through a standardized questionnaire. Dietary intake and food frequency were estimated using the 24 h recall method, calibrated bowls and FAO food composition tables. Mothers' and infants' anthropometry was assessed and multivariate analysis performed. RESULTS: Contrasting with a high antenatal care attendance (91%) and delivery under health professional supervision (72%), a high prevalence of traditional practices was found, including exposure to hot beds of embers (97%), use of traditional herb tea as the only beverage (95%) and restricted diets (90%). Twenty-five mothers (8.3%) were underweight. Mothers had insufficient intake of calories (55.6%), lipids (67.4%), iron (92.0%), vitamins A (99.3%) and C (45%), thiamin (96.6%) and calcium (96.6%). Chewed glutinous rice was given to infants as an early (mean 34.6, 95% CI:29.3-39.8 days) complementary food by 53.7% of mothers, and was associated with stunting in 10% children (OR=1.35, 95% CI:1.04-1.75). CONCLUSION: The high prevalence of traditional postpartum restricted diets and practices, and inadequate maternal nutritional intake in urban Laos, suggest that antenatal care may be an important opportunity to improve postpartum diet