28 research outputs found
CRIRES-VLT high-resolution spectro-astrometry as a tool in the search of small structures at the cores of Planetary Nebulae
The onset of the asymmetry in planetary nebulae (PNe) occurs during the short
transition between the end of the asymptotic giant branch (AGB) phase and the
beginning of the PN phase. Sources in this transition phase are compact and
emit intensely in infrared wavelengths, making high spatial resolution
observations in the infrared mandatory to investigate the shaping process of
PNe. Interferometric VLTI IR observations have revealed compelling evidence of
disks at the cores of PNe, but the limited sensitivity, strong observational
constraints, and limited spatial coverage place severe limits on the universal
use of this technique. Inspired by the successful detection of proto-planetary
disks using spectro-astrometric observations, we apply here for the first time
this technique to search for sub-arcsecond structures in PNe. Our exploratory
study using CRIRES (CRyogenic high-resolution Infra-Red Echelle Spectrograph)
commissioning data of the proto-PN IRAS 17516-2525 and the young PN SwSt 1 has
revealed small-sized structures after the spectro-astrometric analysis of the
two sources. In IRAS 17516-2525, the spectro-astrometric signal has a size of
only 12 mas, as detected in the Brackett-gamma line, whereas the structures
found in SwSt 1 have sizes of 230 mas in the [Fe III] line and 130 mas in the
Brackett-gamma line. The spectroscopic observations required to perform
spectro-astrometry of sources in the transition towards the PN phase are less
time consuming and much more sensitive than VLTI IR observations. The results
presented here open a new window in the search of the small-sized collimating
agents that shape the complex morphologies of extremely axisymmetric PNe.Comment: 6 pages, 4 figure
VISIR-VLT Images of the Water Maser Emitting Planetary Nebula K 3-35
K3-35 is an extremely young bipolar planetary nebula that contains a
precessing bipolar jet and a small (radius 80 AU) water maser equatorial ring.
We have obtained VISIR- VLT images of K 3-35 in the PAH1 ({\lambda}=8.6
{\mu}m), [S iv] ({\lambda}=10.6 {\mu}m), and SiC ({\lambda}=11.85 {\mu}m)
filters to analize the mid-IR morphology and the temperature structure of its
dust emission. The images show the innermost nebular regions undetected at
optical wavelegths and the precessing bipolar jets. The temperature map shows
variations in the temperature in the equatorial zone and in regions associated
to its jets.Comment: 2 pages, 2 figures, 283 IAU Symp. Planetary Nebulae an Eye to the
Futur
A genome-wide association study follow-up suggests a possible role for PPARG in systemic sclerosis susceptibility
Introduction:
A recent genome-wide association study (GWAS) comprising a French cohort of systemic sclerosis (SSc) reported several non-HLA single-nucleotide polymorphisms (SNPs) showing a nominal association in the discovery phase. We aimed to identify previously overlooked susceptibility variants by using a follow-up strategy.<p></p>
Methods:
Sixty-six non-HLA SNPs showing a P value <10-4 in the discovery phase of the French SSc GWAS were analyzed in the first step of this study, performing a meta-analysis that combined data from the two published SSc GWASs. A total of 2,921 SSc patients and 6,963 healthy controls were included in this first phase. Two SNPs, PPARG rs310746 and CHRNA9 rs6832151, were selected for genotyping in the replication cohort (1,068 SSc patients and 6,762 healthy controls) based on the results of the first step. Genotyping was performed by using TaqMan SNP genotyping assays.
Results:
We observed nominal associations for both PPARG rs310746 (PMH = 1.90 × 10-6, OR, 1.28) and CHRNA9 rs6832151 (PMH = 4.30 × 10-6, OR, 1.17) genetic variants with SSc in the first step of our study. In the replication phase, we observed a trend of association for PPARG rs310746 (P value = 0.066; OR, 1.17). The combined overall Mantel-Haenszel meta-analysis of all the cohorts included in the present study revealed that PPARG rs310746 remained associated with SSc with a nominal non-genome-wide significant P value (PMH = 5.00 × 10-7; OR, 1.25). No evidence of association was observed for CHRNA9 rs6832151 either in the replication phase or in the overall pooled analysis.<p></p>
Conclusion:
Our results suggest a role of PPARG gene in the development of SSc
Analysis of SLX4/FANCP in non-BRCA1/2-mutated breast cancer families
<p>Abstract</p> <p>Background</p> <p>Genes that, when mutated, cause Fanconi anemia or greatly increase breast cancer risk encode for proteins that converge on a homology-directed DNA damage repair process. Mutations in the <it>SLX4 </it>gene, which encodes for a scaffold protein involved in the repair of interstrand cross-links, have recently been identified in unclassified Fanconi anemia patients. A mutation analysis of <it>SLX4 </it>in German or Byelorussian familial cases of breast cancer without detected mutations in <it>BRCA1 </it>or <it>BRCA2 </it>has been completed, with globally negative results.</p> <p>Methods</p> <p>The genomic region of <it>SLX4</it>, comprising all exons and exon-intron boundaries, was sequenced in 94 Spanish familial breast cancer cases that match a criterion indicating the potential presence of a highly-penetrant germline mutation, following exclusion of <it>BRCA1 </it>or <it>BRCA2 </it>mutations.</p> <p>Results</p> <p>This mutational analysis revealed extensive genetic variation of <it>SLX4</it>, with 21 novel single nucleotide variants; however, none could be linked to a clear alteration of the protein function. Nonetheless, genotyping 10 variants (nine novel, all missense amino acid changes) in a set of controls (138 women and 146 men) did not detect seven of them.</p> <p>Conclusions</p> <p>Overall, while the results of this study do not identify clearly pathogenic mutations of <it>SLX4 </it>contributing to breast cancer risk, further genetic analysis, combined with functional assays of the identified rare variants, may be warranted to conclusively assess the potential link with the disease.</p
Cross-disease Meta-analysis of Genome-wide Association Studies for Systemic Sclerosis and Rheumatoid Arthritis Reveals IRF4 as a New Common Susceptibility Locus
Objectives: Systemic sclerosis (SSc) and rheumatoid arthritis (RA) are autoimmune diseases that share clinical and immunological characteristics. To date, several shared SSc- RA loci have been identified independently. In this study, we aimed to systematically search for new common SSc-RA loci through an inter-disease meta-GWAS strategy. Methods: We performed a meta-analysis combining GWAS datasets of SSc and RA using a strategy that allowed identification of loci with both same-direction and opposingdirection allelic effects. The top single-nucleotide polymorphisms (SNPs) were followed-up in independent SSc and RA case-control cohorts. This allowed us to increase the sample size to a total of 8,830 SSc patients, 16,870 RA patients and 43,393 controls. Results: The cross-disease meta-analysis of the GWAS datasets identified several loci with nominal association signals (P-value < 5 x 10-6), which also showed evidence of association in the disease-specific GWAS scan. These loci included several genomic regions not previously reported as shared loci, besides risk factors associated with both diseases in previous studies. The follow-up of the putatively new SSc-RA loci identified IRF4 as a shared risk factor for these two diseases (Pcombined = 3.29 x 10-12). In addition, the analysis of the biological relevance of the known SSc-RA shared loci pointed to the type I interferon and the interleukin 12 signaling pathways as the main common etiopathogenic factors. Conclusions: Our study has identified a novel shared locus, IRF4, for SSc and RA and highlighted the usefulness of cross-disease GWAS meta-analysis in the identification of common risk loci
Complement component C4 structural variation and quantitative traits contribute to sex-biased vulnerability in systemic sclerosis
Altres ajuts: Fondo Europeo de Desarrollo Regional (FEDER), "A way of making Europe".Copy number (CN) polymorphisms of complement C4 play distinct roles in many conditions, including immune-mediated diseases. We investigated the association of C4 CN with systemic sclerosis (SSc) risk. Imputed total C4, C4A, C4B, and HERV-K CN were analyzed in 26,633 individuals and validated in an independent cohort. Our results showed that higher C4 CN confers protection to SSc, and deviations from CN parity of C4A and C4B augmented risk. The protection contributed per copy of C4A and C4B differed by sex. Stronger protection was afforded by C4A in men and by C4B in women. C4 CN correlated well with its gene expression and serum protein levels, and less C4 was detected for both in SSc patients. Conditioned analysis suggests that C4 genetics strongly contributes to the SSc association within the major histocompatibility complex locus and highlights classical alleles and amino acid variants of HLA-DRB1 and HLA-DPB1 as C4-independent signals
Higher COVID-19 pneumonia risk associated with anti-IFN-α than with anti-IFN-ω auto-Abs in children
We found that 19 (10.4%) of 183 unvaccinated children hospitalized for COVID-19 pneumonia had autoantibodies (auto-Abs) neutralizing type I IFNs (IFN-alpha 2 in 10 patients: IFN-alpha 2 only in three, IFN-alpha 2 plus IFN-omega in five, and IFN-alpha 2, IFN-omega plus IFN-beta in two; IFN-omega only in nine patients). Seven children (3.8%) had Abs neutralizing at least 10 ng/ml of one IFN, whereas the other 12 (6.6%) had Abs neutralizing only 100 pg/ml. The auto-Abs neutralized both unglycosylated and glycosylated IFNs. We also detected auto-Abs neutralizing 100 pg/ml IFN-alpha 2 in 4 of 2,267 uninfected children (0.2%) and auto-Abs neutralizing IFN-omega in 45 children (2%). The odds ratios (ORs) for life-threatening COVID-19 pneumonia were, therefore, higher for auto-Abs neutralizing IFN-alpha 2 only (OR [95% CI] = 67.6 [5.7-9,196.6]) than for auto-Abs neutralizing IFN-. only (OR [95% CI] = 2.6 [1.2-5.3]). ORs were also higher for auto-Abs neutralizing high concentrations (OR [95% CI] = 12.9 [4.6-35.9]) than for those neutralizing low concentrations (OR [95% CI] = 5.5 [3.1-9.6]) of IFN-omega and/or IFN-alpha 2
Nuevos métodos observacionales de estrellas post-AGB y nebulosas planetarias
Tesis Univ. Granada. Departamento de Física Teórica y del Cosmo
The finiteness threshold width of lattice polytopes
In each dimension d there is a constant woo(d) [épsilon] N such that for every n [épsilon] N all but finitely many lattice d-polytopes with n lattice points have llattice width at most woo(d). We call woo(d) the finiteness threshold width in dimension d and show that d - 2 woo(d) O _d4/3_. Blanco and Santos determined the value woo(3) = 1. Here, we establish woo(4) = 2. This implies, in particular, that there are only finitely many empty 4-simplices of width larger than two. (This last statement was claimed by Barile et al. in [Proc. Am. Math. Soc. 139 (2011), pp. 4247-4253], but we have found a gap in their proof.) Our main tool is the study of d-dimensional lifts of hollow (d-1)-polytopes.The first and fourth authors were supported by grants MTM2014-54207-P, MTM2017-83750-P, and the first author was also supported by BES-2012-058920 of the Spanish Ministry of Science. The fourth author was also supported by the Einstein Foundation Berlin under grant EVF-2015-230. The third author was supported by the Berlin Mathematical School