We present a catalogue of 362 million stellar parameters, distances, and extinctions derived from
Gaia
’s Early Data Release (EDR3) cross-matched with the photometric catalogues of Pan-STARRS1, ...SkyMapper, 2MASS, and AllWISE. The higher precision of the
Gaia
EDR3 data, combined with the broad wavelength coverage of the additional photometric surveys and the new stellar-density priors of the
StarHorse
code, allows us to substantially improve the accuracy and precision over previous photo-astrometric stellar-parameter estimates. At magnitude
G
= 14 (17), our typical precisions amount to 3% (15%) in distance, 0.13 mag (0.15 mag) in
V
-band extinction, and 140 K (180 K) in effective temperature. Our results are validated by comparisons with open clusters, as well as with asteroseismic and spectroscopic measurements, indicating systematic errors smaller than the nominal uncertainties for the vast majority of objects. We also provide distance- and extinction-corrected colour-magnitude diagrams, extinction maps, and extensive stellar density maps that reveal detailed substructures in the Milky Way and beyond. The new density maps now probe a much greater volume, extending to regions beyond the Galactic bar and to Local Group galaxies, with a larger total number density. We publish our results through an ADQL query interface (
gaia.aip.de
) as well as via tables containing approximations of the full posterior distributions. Our multi-wavelength approach and the deep magnitude limit render our results useful also beyond the next
Gaia
release, DR3.
Multivariate Linear Regression (MLR) models utilizing computationally-derived and empirically-derived physical organic molecular descriptors are described in this review. Several reports ...demonstrating the effectiveness of this methodological approach towards reaction optimization and mechanistic interrogation are discussed. A detailed protocol to access quantitative and predictive MLR models is provided as a guide for model development and parameter analysis.
The utilization of physical organic molecular descriptors for the quantitative description of reaction outcomes in multivariate linear regression models is demonstrated as an effective tool for
a priori
prediction and mechanistic interrogation.
Adult neural stem/progenitor (B1) cells within the walls of the lateral ventricles generate different types of neurons for the olfactory bulb (OB). The location of B1 cells determines the types of OB ...neurons they generate. Here we show that the majority of mouse B1 cell precursors are produced between embryonic days (E) 13.5 and 15.5 and remain largely quiescent until they become reactivated postnatally. Using a retroviral library carrying over 100,000 genetic tags, we found that B1 cells share a common progenitor with embryonic cells of the cortex, striatum, and septum, but this lineage relationship is lost before E15.5. The regional specification of B1 cells is evident as early as E11.5 and is spatially linked to the production of neurons that populate different areas of the forebrain. This study reveals an early embryonic regional specification of postnatal neural stem cells and the lineage relationship between them and embryonic progenitor cells.
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•Postnatal neural stem cells (NSCs) become regionally specified early in development•Postnatal and fetal forebrain NSCs share common progenitors in the early embryo•Lineages for postnatal and embryonic NSCs diverge during mid-fetal development•After generated in the embryo, postnatal NSCs remain largely quiescent
Postnatal neural stem cells become regionally specified early in embryonic development and remain largely quiescent until reactivation.
Using combined asteroseismic and spectroscopic observations of 418 red-giant stars close to the Galactic disc plane (6 kpc < RGal ≲ 13 kpc, | ZGal| < 0.3 kpc), we measure the age dependence of the ...radial metallicity distribution in the Milky Way’s thin disc over cosmic time. The slope of the radial iron gradient of the young red-giant population (−0.058 ± 0.008 stat. ±0.003 syst. dex/kpc) is consistent with recent Cepheid measurements. For stellar populations with ages of 1−4 Gyr the gradient is slightly steeper, at a value of −0.066 ± 0.007 ± 0.002 dex/kpc, and then flattens again to reach a value of ~−0.03 dex/kpc for stars with ages between 6 and 10 Gyr. Our results are in good agreement with a state-of-the-art chemo-dynamical Milky-Way model in which the evolution of the abundance gradient and its scatter can be entirely explained by a non-varying negative metallicity gradient in the interstellar medium, together with stellar radial heating and migration. We also offer an explanation for why intermediate-age open clusters in the solar neighbourhood can be more metal-rich, and why their radial metallicity gradient seems to be much steeper than that of the youngest clusters. Already within 2 Gyr, radial mixing can bring metal-rich clusters from the innermost regions of the disc to Galactocentric radii of 5 to 8 kpc. We suggest that these outward-migrating clusters may be less prone to tidal disruption and therefore steepen the local intermediate-age cluster metallicity gradient. Our scenario also explains why the strong steepening of the local iron gradient with age is not seen in field stars. In the near future, asteroseismic data from the K2 mission will allow for improved statistics and a better coverage of the inner-disc regions, thereby providing tighter constraints on theevolution of the central parts of the Milky Way.
Combining the precise parallaxes and optical photometry delivered by Gaia’s second data release with the photometric catalogues of Pan-STARRS1, 2MASS, and AllWISE, we derived Bayesian stellar ...parameters, distances, and extinctions for 265 million of the 285 million objects brighter than G = 18. Because of the wide wavelength range used, our results substantially improve the accuracy and precision of previous extinction and effective temperature estimates. After cleaning our results for both unreliable input and output data, we retain 137 million stars, for which we achieve a median precision of 5% in distance, 0.20 mag in V-band extinction, and 245 K in effective temperature for G ≤ 14, degrading towards fainter magnitudes (12%, 0.20 mag, and 245 K at G = 16; 16%, 0.23 mag, and 260 K at G = 17, respectively). We find a very good agreement with the asteroseismic surface gravities and distances of 7000 stars in the Kepler, K2-C3, and K2-C6 fields, with stellar parameters from the APOGEE survey, and with distances to star clusters. Our results are available through the ADQL query interface of the Gaia mirror at the Leibniz-Institut für Astrophysik Potsdam (gaia.aip.de) and as binary tables at data.aip.de. As a first application, we provide distance- and extinction-corrected colour-magnitude diagrams, extinction maps as a function of distance, and extensive density maps. These demonstrate the potential of our value-added dataset for mapping the three-dimensional structure of our Galaxy. In particular, we see a clear manifestation of the Galactic bar in the stellar density distributions, an observation that can almost be considered direct imaging of the Galactic bar.
Surface populations of Astyanax mexicanus, living in rivers like their common ancestors, school, while several, independently derived cave populations of the same species have lost schooling ...behavior.
We quantify schooling behavior in individual A. mexicanus and identify quantitative trait loci (QTL) for this trait. We find that the evolutionary modulation of schooling has both vision-dependent and -independent components. We also quantify differences in the lateral line and vision between cavefish and surface fish and relate these differences to the evolutionary loss of schooling behavior. We provide evidence that a monoamine neurotransmitter may have played a role in the evolution of schooling behavior.
We find that vision is essential for schooling tendency in A. mexicanus, while the lateral line has a small effect on this behavior. Schooling behavior in A. mexicanus has evolved both through changes in sensory systems and through changes in genetic loci that likely act downstream of sensory inputs.
•Multiple, independently evolved cave populations have lost the tendency to school•Vision is necessary for schooling behavior•Cavefish have lost the tendency to school regardless of vision
In adults with active lupus nephritis, the efficacy and safety of intravenous belimumab as compared with placebo, when added to standard therapy (mycophenolate mofetil or ...cyclophosphamide-azathioprine), are unknown.
In a phase 3, multinational, multicenter, randomized, double-blind, placebo-controlled, 104-week trial conducted at 107 sites in 21 countries, we assigned adults with biopsy-proven, active lupus nephritis in a 1:1 ratio to receive intravenous belimumab (at a dose of 10 mg per kilogram of body weight) or matching placebo, in addition to standard therapy. The primary end point at week 104 was a primary efficacy renal response (a ratio of urinary protein to creatinine of ≤0.7, an estimated glomerular filtration rate eGFR that was no worse than 20% below the value before the renal flare (pre-flare value) or ≥60 ml per minute per 1.73 m
of body-surface area, and no use of rescue therapy), and the major secondary end point was a complete renal response (a ratio of urinary protein to creatinine of <0.5, an eGFR that was no worse than 10% below the pre-flare value or ≥90 ml per minute per 1.73 m
, and no use of rescue therapy). The time to a renal-related event or death was assessed.
A total of 448 patients underwent randomization (224 to the belimumab group and 224 to the placebo group). At week 104, significantly more patients in the belimumab group than in the placebo group had a primary efficacy renal response (43% vs. 32%; odds ratio, 1.6; 95% confidence interval CI, 1.0 to 2.3; P = 0.03) and a complete renal response (30% vs. 20%; odds ratio, 1.7; 95% CI, 1.1 to 2.7; P = 0.02). The risk of a renal-related event or death was lower among patients who received belimumab than among those who received placebo (hazard ratio, 0.51; 95% CI, 0.34 to 0.77; P = 0.001). The safety profile of belimumab was consistent with that in previous trials.
In this trial involving patients with active lupus nephritis, more patients who received belimumab plus standard therapy had a primary efficacy renal response than those who received standard therapy alone. (Funded by GlaxoSmithKline; BLISS-LN ClinicalTrials.gov number, NCT01639339.).
Quenching of fluorophores by the same proteins that they covalently label is a phenomenon that is neither well-known nor well-characterized. It is often assumed that fluorophores are unperturbed by ...their target proteins. However, it has been observed that attached fluorophores can be quenched by contact with amino acids within the same protein, and this property has been exploited to report on changing conformational states or intramolecular dynamics of proteins. We show in this communication that fluorescence of Alexa dyes is, in fact, quenched by interactions with Trp, Tyr, Met, and His residues through a combination of static and dynamic quenching mechanisms. In light of this finding, the potential effect of intramolecular quenching should be considered in the interpretation of data that involves quantitative measurements of fluorescence intensity in proteins.
The numerous connections between neuronal cell bodies, made by their dendrites and axons, are vital for information processing in the brain. While dendrites and synapses have been extensively ...studied, axons have remained elusive to a large extent. We present a novel platform to study axonal physiology and information processing based on combining an 11,011-electrode high-density complementary metal-oxide semiconductor microelectrode array with a poly(dimethylsiloxane) channel device, which isolates axons from somas and, importantly, significantly amplifies recorded axonal signals. The combination of the microelectrode array with recording and stimulation capability with the microfluidic isolation channels permitted us to study axonal signal behavior at great detail. The device, featuring two culture chambers with over 30 channels spanning in between, enabled long-term recording of single spikes from isolated axons with signal amplitudes of 100 μV up to 2 mV. Propagating signals along axons could be recorded with 10 to 50 electrodes per channel. We (i) describe the performance and capabilities of our device for axonal electrophysiology, and (ii) present novel data on axonal signals facilitated by the device. Spontaneous action potentials with characteristic shapes propagated from somas along axons between the two compartments, and these unique shapes could be used to identify individual axons within channels that contained many axonal branches. Stimulation through the electrode array facilitated the identification of somas and their respective axons, enabling interfacing with different compartments of a single cell. Complex spike shapes observed in channels were traced back to single cells, and we show that more complicated spike shapes originate from a linear superposition of multiple axonal signals rather than signal distortion by the channels.
We investigate the inner regions of the Milky Way using data from APOGEE and
Gaia
EDR3. Our inner Galactic sample has more than 26 500 stars within |
X
Gal
|< 5 kpc, |
Y
Gal
|< 3.5 kpc, |
Z
Gal
|< 1 ...kpc, and we also carry out the analysis for a foreground-cleaned subsample of 8000 stars that is more representative of the bulge–bar populations. These samples allow us to build chemo-dynamical maps of the stellar populations with vastly improved detail. The inner Galaxy shows an apparent chemical bimodality in key abundance ratios
α
/Fe, C/N, and Mn/O, which probe different enrichment timescales, suggesting a star formation gap (quenching) between the high- and low-
α
populations. Using a joint analysis of the distributions of kinematics, metallicities, mean orbital radius, and chemical abundances, we can characterize the different populations coexisting in the innermost regions of the Galaxy for the first time. The chemo-kinematic data dissected on an eccentricity–|
Z
|
max
plane reveal the chemical and kinematic signatures of the bar, the thin inner disc, and an inner thick disc, and a broad metallicity population with large velocity dispersion indicative of a pressure-supported component. The interplay between these different populations is mapped onto the different metallicity distributions seen in the eccentricity–|
Z
|
max
diagram consistently with the mean orbital radius and
V
ϕ
distributions. A clear metallicity gradient as a function of |
Z
|
max
is also found, which is consistent with the spatial overlapping of different populations. Additionally, we find and chemically and kinematically characterize a group of counter-rotating stars that could be the result of a gas-rich merger event or just the result of clumpy star formation during the earliest phases of the early disc that migrated into the bulge. Finally, based on 6D information, we assign stars a probability value of being on a bar orbit and find that most of the stars with large bar orbit probabilities come from the innermost 3 kpc, with a broad dispersion of metallicity. Even stars with a high probability of belonging to the bar show chemical bimodality in the
α
/Fe versus Fe/H diagram. This suggests bar trapping to be an efficient mechanism, explaining why stars on bar orbits do not show a significant, distinct chemical abundance ratio signature.
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