Abstract
We present observations of the Herbig Ae star HD 169142 with the VLT/SPHERE instruments InfraRed Dual-band Imager and Spectrograph (IRDIS) (K1K2 and H2H3 bands) and the Integral Field ...Spectrograph (IFS) (Y, J and H bands). We detect several bright blobs at ∼180 mas separation from the star, and a faint arc-like structure in the IFS data. Our reference differential imaging (RDI) data analysis also finds a bright ring at the same separation. We show, using a simulation based on polarized light data, that these blobs are actually part of the ring at 180 mas. These results demonstrate that the earlier detections of blobs in the H and KS bands at these separations in Biller et al. as potential planet/substellar companions are actually tracing a bright ring with a Keplerian motion. Moreover, we detect in the images an additional bright structure at ∼93 mas separation and position angle of 355°, at a location very close to previous detections. It appears point-like in the YJ and K bands but is more extended in the H band. We also marginally detect an inner ring in the RDI data at ∼100 mas. Follow-up observations are necessary to confirm the detection and the nature of this source and structure.
HIP 65426 b is a recently discovered exoplanet imaged during the course of the SPHERE-SHINE survey. Here we present new L′ and M′ observations of the planet from the NACO instrument at the VLT from ...the NACO-ISPY survey, as well as a new Y –H spectrum and K-band photometry from SPHERE-SHINE. Using these data, we confirm the nature of the companion as a warm, dusty planet with a mid-L spectral type. From comparison of its SED with the BT-Settl atmospheric models, we derive a best-fit effective temperature of Teff = 1618 ± 7 K, surface gravity log g = 3.78−0.03+0.04 $\log g\,{=}\,3.78^{+0.04}_{-0.03}$logg = 3.78−0.03+0.04 and radius R = 1.17 ± 0.04RJ (statistical uncertainties only). Using the DUSTY and COND isochrones we estimate a mass of 8 ± 1MJ. Combining the astrometric measurements from our new datasets and from the literature, we show the first indications of orbital motion of the companion (2.6σ significance)and derive preliminary orbital constraints. We find a highly inclined orbit ( i = 1.07−10+13 $i\,{=}\,107^{+13}_{-10}$i = 107−10+13 deg) with an orbital period of 800−400+1200 $800^{+1200}_{-400}$800−400+1200 yr. We also report SPHERE sparse aperture masking observations that investigate the possibility that HIP 65426 b was scattered onto its current orbit by an additional companion at a smaller orbital separation. From this data we rule out the presence of brown dwarf companions with masses greater than 16 MJ at separations larger than 3 AU, significantly narrowing the parameter space for such a companion.
Context.
Detecting and characterizing substellar companions for which the luminosity, mass, and age can be determined independently is of utter importance to test and calibrate the evolutionary ...models due to uncertainties in their formation mechanisms. HD 19467 is a bright and nearby star hosting a cool brown dwarf companion detected with radial velocities and imaging, making it a valuable object for such studies.
Aims.
We aim to further characterize the orbital, spectral, and physical properties of the HD 19467 system.
Methods.
We present new high-contrast imaging data with the SPHERE and NaCo instruments. We also analyze archival data from the instruments HARPS, NaCo, HIRES, UVES, and ASAS. Furthermore, we use proper motion data of the star from H
IPPARCOS
and
Gaia
.
Results.
We refined the properties of the host star and derived an age of 8.0
+2.0
−1.0
Gyr based on isochrones, gyrochronology, and chemical and kinematic arguments. This age estimate is slightly younger than previous age estimates of ~9–11 Gyr based on isochrones. No orbital curvature is seen in the current imaging, radial velocity, and astrometric data. From a joint fit of the data, we refined the orbital parameters for HD 19467B, including: a period of 398
+95
−93
yr, an inclination of 129.8
+8.1
−5.1
deg, an eccentricity of 0.56 ± 0.09, a longitude of the ascending node of 134.8 ± 4.5 deg, and an argument of the periastron of 64.2
+5.5
−6.3
deg. We assess a dynamical mass of 74
+12
−9
M
J
. The fit with atmospheric models of the spectrophotometric data of the companion indicates an atmosphere without clouds or with very thin clouds, an effective temperature of 1042
+77
−71
K, and a high surface gravity of 5.34
+0.8
−0.9
dex. The comparison to model predictions of the bolometric luminosity and dynamical mass of HD 19467B, assuming our system age estimate, indicates a better agreement with the Burrows et al. (1997, ApJ, 491, 856) models; whereas, the other evolutionary models used tend to underestimate its cooling rate.
Mycobacterium tuberculosis complex (MTBC), the causative agent of tuberculosis (TB), is characterized by low sequence diversity making this bacterium one of the classical examples of a genetically ...monomorphic pathogen. Because of this limited DNA sequence variation, routine genotyping of clinical MTBC isolates for epidemiological purposes relies on highly discriminatory DNA fingerprinting methods based on mobile and repetitive genetic elements. According to the standard view, isolates exhibiting the same fingerprinting pattern are considered direct progeny of the same bacterial clone, and most likely reflect ongoing transmission or disease relapse within individual patients.
Here we further investigated this assumption and used massively parallel whole-genome sequencing to compare one drug-susceptible (K-1) and one multidrug resistant (MDR) isolate (K-2) of a rapidly spreading M. tuberculosis Beijing genotype clone from a high incidence region (Karakalpakstan, Uzbekistan). Both isolates shared the same IS6110 RFLP pattern and the same allele at 23 out of 24 MIRU-VNTR loci. We generated 23.9 million (K-1) and 33.0 million (K-2) paired 50 bp purity filtered reads corresponding to a mean coverage of 483.5 fold and 656.1 fold respectively. Compared with the laboratory strain H37Rv both Beijing isolates shared 1,209 SNPs. The two Beijing isolates differed by 130 SNPs and one large deletion. The susceptible isolate had 55 specific SNPs, while the MDR variant had 75 specific SNPs, including the five known resistance-conferring mutations.
Our results suggest that M. tuberculosis isolates exhibiting identical DNA fingerprinting patterns can harbour substantial genomic diversity. Because this heterogeneity is not captured by traditional genotyping of MTBC, some aspects of the transmission dynamics of tuberculosis could be missed or misinterpreted. Furthermore, a valid differentiation between disease relapse and exogenous reinfection might be impossible using standard genotyping tools if the overall diversity of circulating clones is limited. These findings have important implications for clinical trials of new anti-tuberculosis drugs.
To review and describe in detail the clinical course, functional and anatomic characteristics of RP2-associated retinal degeneration.
Retrospective case series.
Male participants with disease-causing ...variants in the RP2 gene.
Review of all case notes and results of molecular genetic testing, retinal imaging (fundus autofluorescence FAF imaging, OCT), and electrophysiology assessment.
Molecular genetic testing, clinical findings including best-corrected visual acuity (BCVA), qualitative and quantitative retinal imaging analysis, and electrophysiology parameters.
Fifty-four molecularly confirmed patients were identified from 38 pedigrees. Twenty-eight disease-causing variants were identified, with 20 not previously clinically characterized. Fifty-three patients (98.1%) presented with retinitis pigmentosa. The mean age of onset (range ± standard deviation SD) was 9.6 years (1-57 ± 9.2 years). Forty-four patients (91.7%) had childhood-onset disease, with mean age of onset of 7.6 years. The most common first symptom was night blindness (68.8%). Mean BCVA (range ± SD) was 0.91 logarithm of the minimum angle of resolution (logMAR) (0-2.7 ± 0.80) and 0.94 logMAR (0-2.7 ± 0.78) for right and left eyes, respectively. On the basis of the World Health Organization visual impairment criteria, 18 patients (34%) had low vision. The majority (17/22) showed electroretinogram (ERG) evidence of a rod-cone dystrophy. Pattern ERG P50 was undetectable in all but 2 patients. A range of FAF findings was observed, from normal to advanced atrophy. There were no statistically significant differences between right and left eyes for ellipsoid zone width (EZW) and outer nuclear layer (ONL) thickness. The mean annual rate of EZW loss was 219 μm/year, and the mean annual decrease in ONL thickness was 4.93 μm/year. No patient with childhood-onset disease had an identifiable ellipsoid zone (EZ) after the age of 26 years at baseline or follow-up. Four patients had adulthood-onset disease and a less severe phenotype.
This study details the clinical phenotype of RP2 retinopathy in a large cohort. The majority presented with early-onset severe retinal degeneration, with early macular involvement and complete loss of the foveal photoreceptor layer by the third decade of life. Full-field ERGs revealed rod-cone dystrophy in the vast majority, but with generalized (peripheral) cone system involvement of widely varying severity in the first 2 decades of life.
Proprietary or commercial disclosure may be found after the references.
PurposeInherited cataract, opacification of the lens, is the most common worldwide cause of blindness in children. We aimed to identify the genetic cause of isolated autosomal-dominant lamellar ...cataract in a five-generation British family.MethodsWhole exome sequencing (WES) was performed on two affected individuals of the family and further validated by direct sequencing in family members.ResultsA novel missense mutation NM_001040667.2:c.190A>G;p.K64E was identified in the DNA-binding-domain of heat-shock transcription factor 4 (HSF4) and found to co-segregate with disease.ConclusionWe have identified a novel mutation in HSF4 in a large British pedigree causing dominant congenital lamellar cataract. This is the second mutation in this gene found in the British population. This mutation is likely to be dominant negative and affect the DNA-binding affinity of HSF4.
Retinitis pigmentosa (RP) is a progressive retinal degeneration that affects about 1 in 4000 of the population. 1 Approximately 15-30% of patients with RP have X linked retinitis pigmentosa (XLRP), ...which is the most severe form of RP consistently manifesting early in life. 2, 3 Night blindness is usually present in early childhood with loss of peripheral visual fields and ultimately central vision, resulting in registered blindness by the end of the third decade. 16- 18 This protein also localises to the photoreceptor connecting cilium and is thought to be a structural component of the ciliary axoneme. 18 Subsequent mutation screening in patients suffering from retinal diseases has identified mutations in RPGRIP1 as a cause of Leber congenital amaurosis. 19, 20 In this report, we present the phenotype of a family suffering from XLRP associated with hearing loss, sinusitis, and chronic recurrent respiratory tract infections.
Motile and non-motile cilia are associated with mutually-exclusive genetic disorders. Motile cilia propel sperm or extracellular fluids, and their dysfunction causes primary ciliary dyskinesia. ...Non-motile cilia serve as sensory/signalling antennae on most cell types, and their disruption causes single-organ ciliopathies such as retinopathies or multi-system syndromes. CFAP20 is a ciliopathy candidate known to modulate motile cilia in unicellular eukaryotes. We demonstrate that in zebrafish, cfap20 is required for motile cilia function, and in C. elegans, CFAP-20 maintains the structural integrity of non-motile cilia inner junctions, influencing sensory-dependent signalling and development. Human patients and zebrafish with CFAP20 mutations both exhibit retinal dystrophy. Hence, CFAP20 functions within a structural/functional hub centered on the inner junction that is shared between motile and non-motile cilia, and is distinct from other ciliopathy-associated domains or macromolecular complexes. Our findings suggest an uncharacterised pathomechanism for retinal dystrophy, and potentially for motile and non-motile ciliopathies in general.
The valence state of uranium has been confirmed for the three sodium uranates NaUVO3/Rn(5f1), Na4UVIO5/Rn(5f0), and Na2UVI 2O7/Rn(5f0), using X-ray absorption near-edge structure (XANES) ...spectroscopy. Solid-state 23Na magic angle spinning nuclear magnetic resonance (MAS NMR) measurements have been performed for the first time, yielding chemical shifts at −29.1 (NaUO3), 15.1 (Na4UO5), and −14.1 and −19 ppm (Na1 8-fold coordinated and Na2 7-fold coordinated in Na2U2O7), respectively. The Rn5f1 electronic structure of uranium in NaUO3 causes a paramagnetic shift in comparison to Na4UO5 and Na2U2O7, where the electronic structure is Rn5f0. A 23Na multi quantum magic angle spinning (MQMAS) study on Na2U2O7 has confirmed a monoclinic rather than rhombohedral structure with evidence for two distinct Na sites. DFT calculations of the NMR parameters on the nonmagnetic compounds Na4UO5 and Na2U2O7 have permitted the differentiation between the two Na sites of the Na2U2O7 structure. The linear thermal expansion coefficients of all three compounds have been determined using high-temperature X-ray diffraction: α a = 22.7 × 10–6 K–1, α b = 12.9 × 10–6 K–1, α c = 16.2 × 10–6 K–1, and αvol = 52.8 × 10–6 K–1 for NaUO3 in the range 298–1273 K; α a = 37.1 × 10–6 K–1, α c = 6.2 × 10–6 K–1, and αvol = 81.8 × 10–6 K–1 for Na4UO5 in the range 298–1073 K; α a = 6.7 × 10–6 K–1, α b = 14.4 × 10–6 K–1, α c = 26.8 × 10–6 K–1, αβ = −7.8 × 10–6 K–1, and αvol = −217.6 × 10–6 K–1 for Na2U2O7 in the range 298–573 K. The α to β phase transition reported for the last compound above about 600 K was not observed in the present studies, either by high-temperature X-ray diffraction or by differential scanning calorimetry.
Summary
Antibody detection against selected potentially zoonotic vector‐borne alphaviruses and flaviviruses was conducted on sera from bats from all six parishes in Grenada, West Indies. Sera were ...tested for (i) antibodies to flaviviruses West Nile virus, St. Louis encephalitis virus, Ilhéus virus, Bussuquara virus (BSQV), Rio Bravo virus and all four serotypes of dengue virus (DENV) by plaque reduction neutralization test (PRNT); (ii) antibodies to alphaviruses western equine encephalitis virus, Venezuelan equine encephalitis virus and eastern equine encephalitis virus by epitope‐blocking enzyme‐linked immunosorbent assay (ELISA); and (iii) antibodies to the alphavirus chikungunya (CHIKV) by PRNT. Two species of fruit bats were sampled, Artibeus jamaicensis and Artibeus lituratus, all roosting in or within 1,000 m of human settlements. Fifteen (36%) of the 42 bats tested for neutralizing antibodies to CHIKV were positive. The CHIKV‐seropositive bats lived in localities spanning five of the six parishes. All 43 bats tested for epitope‐blocking ELISA antibody to the other alphaviruses were negative, except one positive for Venezuelan equine encephalitis virus. All 50 bats tested for neutralizing antibody to flaviviruses were negative, except one that had a BSQV PRNT80 titre of 20. The CHIKV serology results indicate that bats living close to and within human settlements were exposed to CHIKV in multiple locations. Importantly, bats for this study were trapped a year after the introduction and peak of the human CHIKV epidemic in Grenada. Thus, our data indicate that bats were exposed to CHIKV possibly during a time of marked decline in human cases.
PDF
