49 research outputs found
Metal and dust evolution in ALMA REBELS galaxies: insights for future JWST observations
ALMA observations revealed the presence of significant amounts of dust in the
first Gyr of Cosmic time. However, the metal and dust buildup picture remains
very uncertain due to the lack of constraints on metallicity. JWST has started
to reveal the metal content of high-redshift targets, which may lead to firmer
constraints on high-redshift dusty galaxies evolution. In this work, we use
detailed chemical and dust evolution models to explore the evolution of
galaxies within the ALMA REBELS survey, testing different metallicity scenarios
that could be inferred from JWST observations. In the models, we track the
buildup of stellar mass by using non-parametric SFHs for REBELS galaxies.
Different scenarios for metal and dust evolution are simulated by allowing
different prescriptions for gas flows and dust processes. The model outputs are
compared with measured dust scaling relations, by employing
metallicity-dependent calibrations for the gas mass based on the [CII]158micron
line. Independently of the galaxies metal content, we found no need for extreme
dust prescriptions to explain the dust masses revealed by ALMA. However,
different levels of metal enrichment will lead to different dominant dust
production mechanisms, with stardust production dominant over other ISM dust
processes only in the metal-poor case. This points out how metallicity
measurements from JWST will significantly improve our understanding of the dust
buildup in high-redshift galaxies. We also show that models struggle to
reproduce observables such as dust-to-gas and dust-to-stellar ratios
simultaneously, possibly indicating an overestimation of the gas mass through
current calibrations, especially at high metallicities.Comment: 16 pages + appendices, 9 Figures, 1 Table. Resubmitted to MNRAS after
moderate revisio
Cold dust and low [O iii]/[C ii] ratios: an evolved star-forming population at redshift 7
We present new ALMA Band 8 (rest-frame 90 μm) continuum observations of three massive (M⋆ ≈ 1010 M⊙) galaxies at z ≈ 7 previously detected in [C II]158 μm and underlying dust continuum emission in the Reionization Era Bright Emission Line Survey (REBELS). We detect dust emission from two of our targets in Band 8 (REBELS-25 and REBELS-38), while REBELS-12 remains undetected. Through optically thin modified blackbody fitting, we determine dust temperatures of Tdust ≈ 30 − 35 K in both of the dual-band detected targets, indicating they are colder than most known galaxies at z ∼ 7. Moreover, their inferred dust masses are large (Mdust ≈ 108 M⊙), albeit still consistent with models of high-redshift dust production. We furthermore target and detect [O III]88 μm emission in both REBELS-12 and REBELS-25, and find L[O III]/L[C II] ≈ 1 − 1.5 – low compared to the L[O III]/L[C II] ≳ 2 − 10 observed in the known z ≳ 6 population thus far. We argue the lower line ratios are due to a comparatively weaker ionizing radiation field resulting from the less starbursty nature of our targets, although the possibility of REBELS-12 being a merger of an [O III]-bright and [O III]-faint component prevents the unambiguous interpretation of its [O III]/[C II] ratio. Nevertheless, a low burstiness forms a natural explanation for the cold dust temperatures and low [O III]λλ4959, 5007 + Hβ equivalent widths of REBELS-25 and REBELS-38. Overall, these observations provide evidence for the existence of a massive, dust-rich galaxy population at z ≈ 7 which has previously experienced vigorous star formation, but is currently forming stars in a steady, as opposed to bursty, manner
Clinical Presentation of a Complex Neurodevelopmental Disorder Caused by Mutations in ADNP
Background
In genome-wide screening studies for de novo mutations underlying autism and intellectual disability, mutations in the ADNP gene are consistently reported among the most frequent. ADNP mutations have been identified in children with autism spectrum disorder comorbid with intellectual disability, distinctive facial features, and deficits in multiple organ systems. However, a comprehensive clinical description of the Helsmoortel-Van der Aa syndrome is lacking.
Methods
We identified a worldwide cohort of 78 individuals with likely disruptive mutations in ADNP from January 2014 to October 2016 through systematic literature search, by contacting collaborators, and through direct interaction with parents. Clinicians filled in a structured questionnaire on genetic and clinical findings to enable correlations between genotype and phenotype. Clinical photographs and specialist reports were gathered. Parents were interviewed to complement the written questionnaires.
Results
We report on the detailed clinical characterization of a large cohort of individuals with an ADNP mutation and demonstrate a distinctive combination of clinical features, including mild to severe intellectual disability, autism, severe speech and motor delay, and common facial characteristics. Brain abnormalities, behavioral problems, sleep disturbance, epilepsy, hypotonia, visual problems, congenital heart defects, gastrointestinal problems, short stature, and hormonal deficiencies are common comorbidities. Strikingly, individuals with the recurrent p.Tyr719* mutation were more severely affected.
Conclusions
This overview defines the full clinical spectrum of individuals with ADNP mutations, a specific autism subtype. We show that individuals with mutations in ADNP have many overlapping clinical features that are distinctive from those of other autism and/or intellectual disability syndromes. In addition, our data show preliminary evidence of a correlation between genotype and phenotype.This work was supported by grants from the European Research Area Networks Network of European Funding for Neuroscience Research through the Research Foundation–Flanders and the Chief Scientist Office–Ministry of Health (to RFK, GV, IG). This research was supported, in part, by grants from the Simons Foundation Autism Research Initiative (Grant No. SFARI 303241 to EEE) and National Institutes of Health (Grant No. R01MH101221 to EEE). This work was also supported by the Italian Ministry of Health and ‘5 per mille’ funding (to CR). For many individuals, sequencing was provided by research initiatives like the Care4Rare Research Consortium in Canada or the Deciphering Developmental Disorders (DDD) study in the UK. The DDD Study presents independent research commissioned by the Health Innovation Challenge Fund (Grant No. HICF-1009–003), a parallel funding partnership between the Wellcome Trust and the Department of Health, and the Wellcome Trust Sanger Institute (Grant No. WT098051). The views expressed in this publication are those of the author(s) and not necessarily those of the Wellcome Trust or the Department of Health. The study has UK Research Ethics Committee approval (10/H0305/83, granted by the Cambridge South Research Ethics Committee, and GEN/284/12 granted by the Republic of Ireland Research Ethics Committee). The research team acknowledges the support of the National Institute for Health Research, through the Comprehensive Clinical Research Network
The ALMA REBELS Survey: Dust Continuum Detections at z > 6.5
We report 18 dust continuum detections () at and out of 49 ultraviolet(UV)-bright galaxies (, observed by the Cycle-7 ALMA Large Program, REBELS
and its pilot programs. This has more than tripled the number of dust continuum
detections known at . Out of these 18 detections, 12 are reported for
the first time as part of REBELS. In addition, 15 of the dust continuum
detected galaxies also show a [CII] emission line,
providing us with accurate redshifts. We anticipate more line emission
detections from six targets (including three continuum detected targets) where
observations are still ongoing. The dust continuum detected sources in our
sample tend to have a redder UV spectral slope than the ones without a dust
continuum detection. We estimate that all of the sources have an infrared (IR)
luminosity () in a range of , except
for one with . Their
fraction of obscured star formation is significant at . Some of
the dust continuum detected galaxies show spatial offsets ()
between the rest-UV and far-IR emission peaks. These separations appear to have
an increasing trend against an indicator that suggests spatially decoupled
phases of obscured and unobscured star formation. REBELS offers the best
available statistical constraints on obscured star formation in UV-bright,
massive galaxies at .Comment: 17 pages, 9 figures, submitted to MNRA
A Robust Protocol to Increase NimbleGen SeqCap EZ Multiplexing Capacity to 96 Samples
<div><p>Contemporary genetic studies frequently involve sequencing of a targeted gene panel, for instance consisting of a set of genes associated with a specific disease. The NimbleGen SeqCap EZ Choice kit is commonly used for the targeted enrichment of sequencing libraries comprising a target size up to 7 Mb. A major drawback of this commercially available method is the exclusive use of single-indexing, meaning that at most 24 samples can be multiplexed in a single reaction. In case of relatively small target sizes, this will lead to excessive amounts of data per sample. We present an extended version of the NimbleGen SeqCap EZ protocol which allows to robustly multiplex up to 96 samples. We achieved this by incorporating Illumina dual-indexing based custom adapters into the original protocol. To further extend the optimization of cost-efficient sequencing of custom target panels, we studied the effect of higher pre-enrichment pooling factors and show that pre-enrichment pooling of up to 12 samples does not affect the quality of the data. To facilitate evaluation of capture efficiency in custom design panels, we also provide a detailed reporting tool.</p></div
Sleep to the beat: A nap favours consolidation of timing
Growing evidence suggests that sleep is important for procedural learning, but few studies have investigated the effect of sleep on the temporal aspects of motor skill learning. We assessed the effect of a 90-min day-time nap on learning a motor timing task, using 2 adaptations of a serial interception sequence learning (SISL) task. Forty-two right-handed participants performed the task before and after a 90-min period of sleep or wake. Electroencephalography (EEG) was recorded throughout. The motor task consisted of a sequential spatial pattern and was performed according to 2 different timing conditions, that is, either following a sequential or a random temporal pattern. The increase in accuracy was compared between groups using a mixed linear regression model. Within the sleep group, performance improvement was modeled based on sleep characteristics, including spindle- and slow-wave density. The sleep group, but not the wake group, showed improvement in the random temporal, but especially and significantly more strongly in the sequential temporal condition. None of the sleep characteristics predicted improvement on either general of the timing conditions. In conclusion, a daytime nap improves performance on a timing task. We show that performance on the task with a sequential timing sequence benefits more from sleep than motor timing. More important, the temporal sequence did not benefit initial learning, because differences arose only after an offline period and specifically when this period contained sleep. Sleep appears to aid in the extraction of regularities for optimal subsequent performance. (PsycINFO Database Recor
Sections from a coverage report.
<p>A) Representation of exon coverage, grouped by gene based on information in the provided BED file. The horizontal red line indicates a user-provided coverage threshold. B) Coverage at base level for one exon, allowing the identification of local drops in sequencing depth.</p