We present ground-based and Swift photometric and spectroscopic observations of the tidal disruption event (TDE) ASASSN-15oi, discovered at the centre of 2MASX J20390918-3045201 (d ... 216 Mpc) by ...the All-Sky Automated Survey for SuperNovae. The source peaked at a bolometric luminosity of L ... 1.3 x 10 super( 44) erg s... and radiated a total energy of E ... 6.6 x 1050 erg over the first ~3.5 months of observations. The early optical/UV emission of the source can be fit by a blackbody with temperature increasing from T ~ 2 x 10 super( 4) K to T ~ 4 x 10 super( 4) K while the luminosity declines from L ... 1.3 x 10 super( 44) erg s... to L ... 2.3 x 10 super( 43) erg s..., requiring the photosphere to be shrinking rapidly. The optical/UV luminosity decline during this period is most consistent with an exponential decline, ..., with t ... 46.5 d for t0 ... 57241.6 (MJD), while a power-law decline of L ... (t - t0)-a with t sub( 0) ... 57 212.3 and a = 1.62 provides a moderately worse fit. ASASSN-15oi also exhibits roughly constant soft X-ray emission that is significantly weaker than the optical/UV emission. Spectra of the source show broad helium emission lines and strong blue continuum emission in early epochs, although these features fade rapidly and are not present ~3 months after discovery. The early spectroscopic features and colour evolution of ASASSN-15oi are consistent with a TDE, but the rapid spectral evolution is unique among optically selected TDEs. (ProQuest: ... denotes formulae/symbols omitted.)
A
bstract
Using 24.1 fb
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1
of
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e
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collision data collected with the BESIII detector at the BEPCII collider, the Born cross sections and effective form factors of the
e
+
e
−
→
Σ
+
Σ
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−
reaction ...are measured. The measurements are performed at center-of-mass energies ranging from 3.510 to 4.951 GeV. No significant evidence for the decay of the charmonium(-like) states,
ψ
(3770),
ψ
(4040),
ψ
(4160),
Y
(4230),
Y
(4360),
ψ
(4415), and
Y
(4660), into a
Σ
+
Σ
¯
−
final state is observed. Consequently, upper limits for the products of the branching fractions and the electronic partial widths at the 90% confidence level are reported for these decays.
This study uses multiple satellite data sets to evaluate seasonal simulations of the Weather Research and Forecasting (WRF) model over Central and Eastern Pacific. Experiments with five different ...convective parameterizations all show reasonably good performance for precipitation simulations. However, large discrepancies exist in the model‐simulated ice clouds compared to CloudSat observations. Underestimations of ice clouds, mainly snow and graupel, are present in the Intertropical Convergence Zone (ITCZ) in all the experiments compared to CloudSat. In the ITCZ, all the experiments show a systematic overestimation of outgoing longwave radiation at the top of the atmosphere and downward shortwave radiation at the surface, along with biased cloud cooling in the middle and upper troposphere and biased cloud warming in the lower troposphere. Vertical motion is enhanced in the ITCZ compared to reanalysis. A weaker low‐level circulation over the midlatitude oceans is evidenced in all simulations with an eastward overextension of the South Pacific Convergence Zone and overestimated moisture over the Southern Hemisphere oceans when compared to Special Sensor Microwave/Imager observations. Sensitivity experiment demonstrates that doubling the radiative effect of snow can reduce high biases in vertical motion within the ITCZ and improve the large‐scale circulation and moisture over the midlatitude oceans.
Key Points
Underestimations of ice clouds are observed in the WRF experiments
The experiments show systematic biases in radiation, moisture, and circulation
Doubling the radiative effects of snow improves simulations in moisture and circulation
ABSTRACT
We present the discovery of ASASSN-18jd (AT 2018bcb), a luminous optical/ultraviolet(UV)/X-ray transient located in the nucleus of the galaxy 2MASX J22434289–1659083 at z = 0.1192. Over the ...year after discovery, Swift UltraViolet and Optical Telescope (UVOT) photometry shows the UV spectral energy distribution of the transient to be well modelled by a slowly shrinking blackbody with temperature $T \sim 2.5 \times 10^{4} \, {\rm K}$, a maximum observed luminosity of $L_{\rm max} = 4.5^{+0.6}_{-0.3}\times 10^{44} \, {\rm erg \,s}^{-1}$, and a radiated energy of $E = 9.6^{+1.1}_{-0.6} \times 10^{51} \, {\rm erg}$. X-ray data from Swift X-Ray Telescope (XRT) and XMM–Newton show a transient, variable X-ray flux with blackbody and power-law components that fade by nearly an order of magnitude over the following year. Optical spectra show strong, roughly constant broad Balmer emission and transient features attributable to He ii, N iii–v, O iii, and coronal Fe. While ASASSN-18jd shares similarities with tidal disruption events (TDEs), it is also similar to the newly discovered nuclear transients seen in quiescent galaxies and faint active galactic nuclei (AGNs).
During the initial phase of critical illness, the association between the dose of nutrition support and mortality risk may vary among patients in the intensive care unit (ICU) because the prevalence ...of malnutrition varies widely (28 to 78%), and not all ICU patients are severely ill. Therefore, we hypothesized that a prognostic model that integrates nutritional status and disease severity could accurately predict mortality risk and classify critically ill patients into low- and high-risk groups. Additionally, in critically ill patients placed on exclusive nutritional support (ENS), we hypothesized that their risk categories could modify the association between dose of nutrition support and mortality risk.
A prognostic model that predicts 28-day mortality was built from a prospective cohort study of 440 patients. The association between dose of nutrition support and mortality risk was evaluated in a subgroup of 252 mechanically ventilated patients via logistic regressions, stratified by low- and high-risk groups, and days of exclusive nutritional support (ENS) short-term (≤ 6 days) vs. longer-term (≥ 7 days). Only the first 6 days of ENS was evaluated for a fair comparison.
The prognostic model demonstrated good discrimination AUC 0.78 (95% CI 0.73-0.82), and a bias-corrected calibration curve suggested fair accuracy. In high-risk patients with short-term ENS (≤ 6 days), each 10% increase in goal energy and protein intake was associated with an increased adjusted odds (95% CI) of 28-day mortality 1.60 (1.19-2.15) and 1.47 (1.12-1.86), respectively. In contrast, each 10% increase in goal protein intake during the first 6 days of ENS in high-risk patients with longer-term ENS (≥ 7 days) was associated with a lower adjusted odds of 28-day mortality 0.75 (0.57-0.99). Despite the opposing associations, the mean predicted mortality risks and prevalence of malnutrition between short- and longer-term ENS patients were similar.
Combining baseline nutritional status and disease severity in a prognostic model could accurately predict 28-day mortality. However, the association between the dose of nutrition support during the first 6 days of ENS and 28-day mortality was independent of baseline disease severity and nutritional status.
New particle formation (NPF) is a significant source of atmospheric
particles, affecting climate and air quality. Understanding the mechanisms
involved in urban aerosols is important to develop ...effective mitigation
strategies. However, NPF rates reported in the polluted boundary layer span
more than 4 orders of magnitude, and the reasons behind this variability are the subject of intense scientific debate. Multiple atmospheric vapours have been
postulated to participate in NPF, including sulfuric acid, ammonia, amines
and organics, but their relative roles remain unclear. We investigated NPF
in the CLOUD chamber using mixtures of anthropogenic vapours that simulate
polluted boundary layer conditions. We demonstrate that NPF in polluted
environments is largely driven by the formation of sulfuric acid–base
clusters, stabilized by the presence of amines, high ammonia concentrations
and lower temperatures. Aromatic oxidation products, despite their extremely
low volatility, play a minor role in NPF in the chosen urban environment but
can be important for particle growth and hence for the survival of newly
formed particles. Our measurements quantitatively account for NPF in highly
diverse urban environments and explain its large observed variability. Such
quantitative information obtained under controlled laboratory conditions
will help the interpretation of future ambient observations of NPF rates in
polluted atmospheres.
Genome-wide association studies (GWAS) have identified rs11672691 at 19q13 associated with aggressive prostate cancer (PCa). Here, we independently confirmed the finding in a cohort of 2,738 PCa ...patients and discovered the biological mechanism underlying this association. We found an association of the aggressive PCa-associated allele G of rs11672691 with elevated transcript levels of two biologically plausible candidate genes, PCAT19 and CEACAM21, implicated in PCa cell growth and tumor progression. Mechanistically, rs11672691 resides in an enhancer element and alters the binding site of HOXA2, a novel oncogenic transcription factor with prognostic potential in PCa. Remarkably, CRISPR/Cas9-mediated single-nucleotide editing showed the direct effect of rs11672691 on PCAT19 and CEACAM21 expression and PCa cellular aggressive phenotype. Clinical data demonstrated synergistic effects of rs11672691 genotype and PCAT19/CEACAM21 gene expression on PCa prognosis. These results provide a plausible mechanism for rs11672691 associated with aggressive PCa and thus lay the ground work for translating this finding to the clinic.
Display omitted
•SNP rs11672691 at 19q13 associates with aggressive PCa, PCAT19, and CEACAM21 expression•rs11672691 G empowers prognostic factor HOXA2 to elevate its eQTL gene expression•rs11672691 directly impacts gene regulation, PCa cellular phenotype, and progression•rs11672691 genotype and PCAT19 or CEACAM21 expression synergize in PCa prognosis
A non-coding risk allele associated with aggressive prostate cancer creates a transcription factor binding site that in turn promotes oncogenesis by impacting expression of nearby genes.
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Using
e
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e
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collision data corresponding to a total integrated luminosity of 12.9 fb
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1
collected with the BESIII detector at the BEPCII collider, the exclusive Born cross sections and ...the effective form factors of the reaction
e
+
e
−
→
Ξ
−
Ξ
¯
+
are measured via the single baryon-tag method at 23 center-of-mass energies between 3.510 and 4.843 GeV. Evidence for the decay
ψ
3770
→
Ξ
−
Ξ
¯
+
is observed with a significance of 4.5
σ
by analyzing the measured cross sections together with earlier BESIII results. For the other charmonium(-like) states
ψ
(4040),
ψ
(4160),
Y
(4230),
Y
(4360),
ψ
(4415), and
Y
(4660), no significant signal of their decay to
Ξ
−
Ξ
¯
+
is found. For these states, upper limits of the products of the branching fraction and the electronic partial width at the 90% confidence level are provided.
Our goal is to request input from the lunar and planetary community regarding issues of planetary coordinate systems and cartography standards. We begin with an overview of the work of the ...International Astronomical Union Working Group on Cartographic Coordinates and Rotational Elements. We briefly describe the operations and membership of the Working Group, some of the various uses of the recommendations it makes, our most recent (2018) published report and the recommendations therein, and the outlook for our next such report. We then consider several issues and questions regarding the future of the Working Group and regarding planetary cartography and planetary data spatial infrastructure in general. This includes possible near-term projects, how we and others might collect and consider community input and includes some ideas regarding possible outcomes or future work that will need to be addressed by the Working Group or other organizations.
We present comprehensive observations and analysis of the energetic H-stripped SN 2016coi (a.k.a. ASASSN-16fp), spanning the γ-ray through optical and radio wavelengths, acquired within the first ...hours to ∼420 days post explosion. Our observational campaign confirms the identification of He in the supernova (SN) ejecta, which we interpret to be caused by a larger mixing of Ni into the outer ejecta layers. By modeling the broad bolometric light curve, we derive a large ejecta-mass-to-kinetic-energy ratio (Mej ∼ 4-7 M , Ek ∼ (7-8) × 1051 erg). The small Ca ii λλ7291,7324 to O i λλ6300,6364 ratio (∼0.2) observed in our late-time optical spectra is suggestive of a large progenitor core mass at the time of collapse. We find that SN 2016coi is a luminous source of X-rays (LX > 1039 erg s−1 in the first ∼100 days post explosion) and radio emission (L8.5 GHz ∼ 7 × 1027 erg s−1 Hz−1 at peak). These values are in line with those of relativistic SNe (2009bb, 2012ap). However, for SN 2016coi, we infer substantial pre-explosion progenitor mass loss with a rate ∼ (1-2) × and a sub-relativistic shock velocity vsh ∼ 0.15c, which is in stark contrast with relativistic SNe and similar to normal SNe. Finally, we find no evidence for a SN-associated shock breakout γ-ray pulse with energy Eγ > 2 × 1046 erg. While we cannot exclude the presence of a companion in a binary system, taken together, our findings are consistent with a massive single-star progenitor that experienced large mass loss in the years leading up to core collapse, but was unable to achieve complete stripping of its outer layers before explosion.
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