924 research outputs found
CLEAR II: Evidence for Early Formation of the Most Compact Quiescent Galaxies at High Redshift
The origin of the correlations between mass, morphology, quenched fraction,
and formation history in galaxies is difficult to define, primarily due to the
uncertainties in galaxy star-formation histories. Star-formation histories are
better constrained for higher redshift galaxies, observed closer to their
formation and quenching epochs. Here we use "non-parametric" star-formation
histories and a nested sampling method to derive constraints on the formation
and quenching timescales of quiescent galaxies at . We model deep
HST grism spectroscopy and photometry from the CLEAR (CANDELS Lyman
Emission at Reionization) survey. The galaxy formation redshifts,
(defined as the point where they had formed 50\% of their stellar mass) range
from (shortly prior to the observed epoch) up to . \editone{We find that early formation redshifts are correlated with high
stellar-mass surface densities, 10.25, where is the stellar mass within 1~pkpc (proper kpc).
Quiescent galaxies with the highest stellar-mass surface density, , } show a \textit{minimum} formation
redshift: all such objects in our sample have . Quiescent
galaxies with lower surface density, $\log \Sigma_1 / (M_\odot\
\mathrm{kpc}^{-2}) = 9.5 - 10.25z_{50}
\simeq 1.5 - 8\log\Sigma_1/(M_\odot\ \mathrm{kpc}^{-2})>10.25$ uniquely identifies galaxies
that formed in the first few Gyr after the Big Bang, and we discuss the
implications this has for galaxy formation models.Comment: 13 pages, 7 figures, accepted for publication in ApJ. Includes an
interactive online appendix (https://vince-ec.github.io/appendix/appendix
Novel strategy for generation of mucosal immune responses against HIV-1 following systemic vaccination
CLEAR I: Ages and Metallicities of Quiescent Galaxies at Derived from Deep Hubble Space Telescope Grism Data
We use deep \textit{Hubble Space Telescope} spectroscopy to constrain the
metallicities and (\editone{light-weighted}) ages of massive () galaxies selected to have quiescent stellar
populations at . The data include 12--orbit depth coverage with the
WFC3/G102 grism covering ~\AA\, at a spectral
resolution of taken as part of the CANDELS Lyman- Emission
at Reionization (CLEAR) survey. At , the spectra cover important
stellar population features in the rest-frame optical. We simulate a suite of
stellar population models at the grism resolution, fit these to the data for
each galaxy, and derive posterior likelihood distributions for metallicity and
age. We stack the posteriors for subgroups of galaxies in different redshift
ranges that include different combinations of stellar absorption features. Our
results give \editone{light-weighted ages of ~Gyr,
~Gyr, ~Gyr, and
~Gyr, \editone{for galaxies at , 1.2,
1.3, and 1.6. This} implies that most of the massive quiescent galaxies at
\% of their stellar mass by a redshift of }. The
posteriors give metallicities of \editone{~, ~, ~, and ~}. This is evidence
that massive galaxies had enriched rapidly to approximately Solar metallicities
as early as .Comment: 32 pages, 23 figures, Resubmited to ApJ after revisions in response
to referee repor
In Vivo Induction of Tr1 Cells via Mucosal Dendritic Cells and AHR Signaling
Background: Type 1 regulatory T (Tr1) cells, characterized by the secretion of high levels of the anti-inflammatory cytokine interleukin-10 (IL-10), play an important role in the regulation of autoimmune diseases and transplantation. However, effective strategies that specifically induce Tr1 cells in vivo are limited. Furthermore, the pathways controlling the induction of these cells in vivo are not well understood. Methodology/Principal Findings: Here we report that nasal administration of anti-CD3 antibody induces suppressive Tr1 cells in mice. The in vivo induction of Tr1 cells by nasal anti-CD3 is dependent on IL-27 produced by upper airway resident dendritic cells (DCs), and is controlled by the transcription factors aryl hydrocarbon receptor (AHR) and c-Maf. Subsequently, IL-21 acts in an autocrine fashion to expand and maintain the Tr1 cells induced in vivo by nasally administered anti-CD3. Conclusions/Significance: Our findings identify a unique approach to generate Tr1 cells in vivo and provide insights into the mechanisms by which these cells are induced
CKD classification based on estimated GFR over three years and subsequent cardiac and mortality outcomes: a cohort study
<p>Abstract</p> <p>Background</p> <p>It is unknown whether defining chronic kidney disease (CKD) based on one versus two estimated glomerular filtration rate (eGFR) assessments changes the prognostic importance of reduced eGFR in a community-based population.</p> <p>Methods</p> <p>Participants in the Atherosclerosis Risk in Communities Study and the Cardiovascular Health Study were classified into 4 groups based on two eGFR assessments separated by 35.3 ± 2.5 months: sustained eGFR < 60 mL/min per 1.73 m<sup>2 </sup>(1 mL/sec per 1.73 m<sup>2</sup>); eGFR increase (change from below to above 60); eGFR decline (change from above to below 60); and eGFR persistently ≥60. Outcomes assessed in stratified multivariable Cox models included cardiac events and a composite of cardiac events, stroke, and mortality.</p> <p>Results</p> <p>There were 891 (4.9%) participants with sustained eGFR < 60, 278 (1.5%) with eGFR increase, 972 (5.4%) with eGFR decline, and 15,925 (88.2%) with sustained eGFR > 60. Participants with eGFR sustained < 60 were at highest risk of cardiac and composite events [HR = 1.38 (1.15, 1.65) and 1.58 (1.41, 1.77)], respectively, followed by eGFR decline [HR = 1.20 (1.00, 1.45) and 1.32 (1.17, 1.49)]. Individuals with eGFR increase trended toward increased cardiac risk [HR = 1.25 (0.88, 1.77)] and did not significantly differ from eGFR decline for any outcome. Results were similar when estimating GFR with the CKD-EPI equation.</p> <p>Conclusion</p> <p>Individuals with persistently reduced eGFR are at highest risk of cardiovascular outcomes and mortality, while individuals with an eGFR < 60 mL/min per 1.73 m<sup>2 </sup>at any time are at intermediate risk. Use of even a single measurement of eGFR to classify CKD in a community population appears to have prognostic value.</p
Clinical Effectiveness, Access to, and Satisfaction with Care Using a Telehomecare Substitution Intervention: A Randomized Controlled Trial
Background.
Hospitalization accounts for 70% of heart
failure (HF) costs; readmission rates at 30 days
are 24% and rise to 50% by 90 days.
Agencies anticipate that telehomecare will
provide the close monitoring necessary to
prevent HF readmissions. Methods and
Results. Randomized controlled trial to
compare a telehomecare intervention for patients
55 and older following hospital discharge for HF
to usual skilled home care. Primary endpoints
were 30- and 60-day all-cause and HF readmission,
hospital days, and time to readmission or death.
Secondary outcomes were access to care,
emergency department (ED) use, and satisfaction
with care. All-cause readmissions at 30 days
(16% versus 19%) and over six months
(46% versus 52%) were lower in the
telehomecare group but were not statistically
significant. Access to care and satisfaction
were significantly higher for the telehomecare
patients, including the number of in-person
visits and days in home care.
Conclusions. Patient acceptance
of the technology and current home care policies
and processes of care were barriers to gaining
clinical effectiveness and
efficiency
The Holocene lake-evaporation history of the afro-alpine Lake Garba Guracha in the Bale Mountains, Ethiopia, based on δ18O records of sugar biomarker and diatoms
In eastern Africa, there are few long, high-quality records of environmental change at high altitudes, inhibiting a broader
understanding of regional climate change. We investigated a Holocene lacustrine sediment archive from Lake Garba Guracha,
Bale Mountains, Ethiopia, (3,950 m a.s.l.), and reconstructed high-altitude lake evaporation history using δ18O records derived from the analysis of compound-specific sugar biomarkers and diatoms. The δ18Odiatom and δ18Ofuc records are clearly correlated and reveal similar ranges (7.9‰ and 7.1‰, respectively). The lowest δ18O values occurred between 10 and 7 cal ka BP and
were followed by a continuous shift towards more positive δ18O values. Due to the aquatic origin of the sugar biomarker and
the similar trends of δ18Odiatom, we suggest that our lacustrine δ18Ofuc record reflects δ18Olake water. Therefore, without completely
excluding the influence of the ‘amount-effect’ and the ‘source-effect‘, we interpret our record to reflect primarily the
precipitation-to-evaporation ratio (P/E). We conclude that precipitation increased at the beginning of the Holocene, leading to
an overflowing lake between ~10 and ~8 cal ka BP, indicated by low δ18Olake water values interpreted as reduced evaporative
enrichment. This is followed by a continuous trend towards drier conditions, indicating at least a seasonally closed lake system
Dissecting the politics of “Obamacare”: The role of distributive justice, deservingness, and affect.
A WFC3 Grism Emission Line Redshift Catalog in the GOODS-South Field
We combine HST/WFC3 imaging and G141 grism observations from the CANDELS and
3D-HST surveys to produce a catalog of grism spectroscopic redshifts for
galaxies in the CANDELS/GOODS-South field. The WFC3/G141 grism spectra cover a
wavelength range of 1.1<lambda<1.7 microns with a resolving power of R~130 for
point sources, thus providing rest-frame optical spectra for galaxies out to
z~3.5. The catalog is selected in the H-band (F160W) and includes both galaxies
with and without previously published spectroscopic redshifts. Grism spectra
are extracted for all H-band detected galaxies with H<24 and a CANDELS
photometric redshift z_phot > 0.6. The resulting spectra are visually inspected
to identify emission lines and redshifts are determined using cross-correlation
with empirical spectral templates. To establish the accuracy of our redshifts,
we compare our results against high-quality spectroscopic redshifts from the
literature. Using a sample of 411 control galaxies, this analysis yields a
precision of sigma_NMAD=0.0028 for the grism-derived redshifts, which is
consistent with the accuracy reported by the 3D-HST team. Our final catalog
covers an area of 153 square arcmin and contains 1019 redshifts for galaxies in
GOODS-S. Roughly 60% (608/1019) of these redshifts are for galaxies with no
previously published spectroscopic redshift. These new redshifts span a range
of 0.677 < z < 3.456 and have a median redshift of z=1.282. The catalog
contains a total of 234 new redshifts for galaxies at z>1.5. In addition, we
present 20 galaxy pair candidates identified for the first time using the grism
redshifts in our catalog, including four new galaxy pairs at z~2, nearly
doubling the number of such pairs previously identified.Comment: 25 Pages, 9 Figures, submitted to A
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