54 research outputs found
BEER analysis of Kepler and CoRoT light curves: I. Discovery of Kepler-76b: A hot Jupiter with evidence for superrotation
We present the first case in which the BEER algorithm identified a hot
Jupiter in the Kepler light curve, and its reality was confirmed by orbital
solutions based on follow-up spectroscopy. The companion Kepler-76b was
identified by the BEER algorithm, which detected the BEaming (sometimes called
Doppler boosting) effect together with the Ellipsoidal and Reflection/emission
modulations (BEER), at an orbital period of 1.54 days, suggesting a planetary
companion orbiting the 13.3 mag F star. Further investigation revealed that
this star appeared in the Kepler eclipsing binary catalog with estimated
primary and secondary eclipse depths of 5e-3 and 1e-4 respectively.
Spectroscopic radial-velocity follow-up observations with TRES and SOPHIE
confirmed Kepler-76b as a transiting 2.0+/-0.26 Mjup hot Jupiter. The mass of a
transiting planet can be estimated from either the beaming or the ellipsoidal
amplitude. The ellipsoidal-based mass estimate of Kepler-76b is consistent with
the spectroscopically measured mass while the beaming-based estimate is
significantly inflated. We explain this apparent discrepancy as evidence for
the superrotation phenomenon, which involves eastward displacement of the
hottest atmospheric spot of a tidally-locked planet by an equatorial
super-rotating jet stream. This phenomenon was previously observed only for HD
189733b in the infrared. We show that a phase shift of 10.3+/-2.0 degrees of
the planet reflection/emission modulation, due to superrotation, explains the
apparently inflated beaming modulation, resolving the ellipsoidal/beaming
amplitude discrepancy. Kepler-76b is one of very few confirmed planets in the
Kepler light curves that show BEER modulations and the first to show
superrotation evidence in the Kepler band. Its discovery illustrates for the
first time the ability of the BEER algorithm to detect short-period planets and
brown dwarfs.Comment: 28 pages, 6 tables and 7 figures. Planet name changed to Kepler-76b.
Accepted for publication in the Astrophysical Journa
A red giant orbiting a black hole
We report spectroscopic and photometric follow-up of a dormant black hole
(BH) candidate from Gaia DR3. We show that the system, which we call Gaia BH2,
contains a red giant and a dark companion with mass that is very likely a BH. The orbital period, days, is much longer than that of any previously studied BH
binary. Our radial velocity (RV) follow-up over a 6-month period spans most of
the orbit's dynamic range in RV and is in excellent agreement with predictions
of the Gaia solution. UV imaging and high-resolution optical spectra rule out
all plausible luminous companions that could explain the orbit. The star is a
bright (), slightly metal-poor () low-luminosity
giant (; ; ). The binary's orbit is moderately eccentric
(). The giant is strongly enhanced in elements, with , but the system's Galactocentric orbit is typical of the
thin disk. We obtained X-ray and radio nondetections of the source near
periastron, which support BH accretion models in which the net accretion rate
at the horizon is much lower than the Bondi-Hoyle-Lyttleton rate. At a distance
of 1.16 kpc, Gaia BH2 is the second-nearest known BH, after Gaia BH1. Its orbit
-- like that of Gaia BH1 -- seems too wide to have formed through common
envelope evolution. Gaia BH1 and BH2 have orbital periods at opposite edges of
the Gaia DR3 sensitivity curve, perhaps hinting at a bimodal intrinsic period
distribution for wide BH binaries. Dormant BH binaries like Gaia BH1 and Gaia
BH2 likely significantly outnumber their close, X-ray bright cousins, but their
formation pathways remain uncertain.Comment: 22 pages, 15 figures. Submitted to MNRA
To which world regions does the valence–dominance model of social perception apply?
Over the past 10 years, Oosterhof and Todorov’s valence–dominance model has emerged as the most prominent account of
how people evaluate faces on social dimensions. In this model, two dimensions (valence and dominance) underpin social
judgements of faces. Because this model has primarily been developed and tested in Western regions, it is unclear whether
these findings apply to other regions. We addressed this question by replicating Oosterhof and Todorov’s methodology across
11 world regions, 41 countries and 11,570 participants. When we used Oosterhof and Todorov’s original analysis strategy,
the valence–dominance model generalized across regions. When we used an alternative methodology to allow for correlated
dimensions, we observed much less generalization. Collectively, these results suggest that, while the valence–dominance
model generalizes very well across regions when dimensions are forced to be orthogonal, regional differences are revealed
when we use different extraction methods and correlate and rotate the dimension reduction solution.C.L. was supported by the Vienna Science and Technology Fund (WWTF VRG13-007);
L.M.D. was supported by ERC 647910 (KINSHIP); D.I.B. and N.I. received funding from
CONICET, Argentina; L.K., F.K. and Á. Putz were supported by the European Social
Fund (EFOP-3.6.1.-16-2016-00004; ‘Comprehensive Development for Implementing
Smart Specialization Strategies at the University of Pécs’). K.U. and E. Vergauwe were
supported by a grant from the Swiss National Science Foundation (PZ00P1_154911 to E.
Vergauwe). T.G. is supported by the Social Sciences and Humanities Research Council
of Canada (SSHRC). M.A.V. was supported by grants 2016-T1/SOC-1395 (Comunidad
de Madrid) and PSI2017-85159-P (AEI/FEDER UE). K.B. was supported by a grant
from the National Science Centre, Poland (number 2015/19/D/HS6/00641). J. Bonick
and J.W.L. were supported by the Joep Lange Institute. G.B. was supported by the Slovak
Research and Development Agency (APVV-17-0418). H.I.J. and E.S. were supported
by a French National Research Agency ‘Investissements d’Avenir’ programme grant
(ANR-15-IDEX-02). T.D.G. was supported by an Australian Government Research
Training Program Scholarship. The Raipur Group is thankful to: (1) the University
Grants Commission, New Delhi, India for the research grants received through its
SAP-DRS (Phase-III) scheme sanctioned to the School of Studies in Life Science;
and (2) the Center for Translational Chronobiology at the School of Studies in Life
Science, PRSU, Raipur, India for providing logistical support. K. Ask was supported by
a small grant from the Department of Psychology, University of Gothenburg. Y.Q. was
supported by grants from the Beijing Natural Science Foundation (5184035) and CAS
Key Laboratory of Behavioral Science, Institute of Psychology. N.A.C. was supported
by the National Science Foundation Graduate Research Fellowship (R010138018). We
acknowledge the following research assistants: J. Muriithi and J. Ngugi (United States
International University Africa); E. Adamo, D. Cafaro, V. Ciambrone, F. Dolce and E.
Tolomeo (Magna Græcia University of Catanzaro); E. De Stefano (University of Padova);
S. A. Escobar Abadia (University of Lincoln); L. E. Grimstad (Norwegian School of
Economics (NHH)); L. C. Zamora (Franklin and Marshall College); R. E. Liang and R.
C. Lo (Universiti Tunku Abdul Rahman); A. Short and L. Allen (Massey University, New
Zealand), A. Ateş, E. Güneş and S. Can Özdemir (Boğaziçi University); I. Pedersen and T.
Roos (Åbo Akademi University); N. Paetz (Escuela de Comunicación Mónica Herrera);
J. Green (University of Gothenburg); M. Krainz (University of Vienna, Austria); and B.
Todorova (University of Vienna, Austria). The funders had no role in study design, data
collection and analysis, decision to publish or preparation of the manuscript.https://www.nature.com/nathumbehav/am2023BiochemistryGeneticsMicrobiology and Plant Patholog
Self-association of the SET domains of human ALL-1 and of Drosophila TRITHORAX and ASH1 proteins
The human ALL-1 gene is involved in acute leukemia through gene fusions, partial tandem duplications or a specific deletion. Several sequence motifs within the ALL-1 protein, such as the SET domain, PHD fingers and the region with homology to DNA methyl transferase are shared with other proteins involved in transcription regulation through chromatin alterations. However, the function of these motifs is still not clear. Studying ALL-1 presents an additional challenge because the gene is the human homologue of Drosophila trithorax. The latter is a member of the trithorax-Polycornb gene family which acts to determine the body pattern of Drosophila by maintaining expression or repression of the Antennapedia-bithorax homeotic gene complex. Here we apply yeast two hybrid methodology, in vivo immunoprecipitation and in vitro 'pull down' techniques to show self association of the SET motifs of ALL-1, TRITHORAX and ASH1 proteins (Drosophila ASH1 is encoded by a trithorax-group gene). Point mutations in evolutionary conserved residues of TRITHORAX SET, abolish the interaction. SET-SET interactions might act in integrating the activity of ALL-1 (TRX and ASH1) protein molecules, simultaneously positioned at different maintenance elements and directing expression of the same or different target genes
Trithorax and ASH1 interact directly and associate with the trithorax group-responsive bxd region of the Ultrabithorax promoter
Trithorax (TRX) and ASH1 belong to the trithorax group (trxG) of transcriptional activator proteins, which maintains homeotic gene expression during Drosophila development. TRX and ASH1 are localized on chromosomes and share several homologous domains with other chromatin-associated proteins, including a highly conserved SET domain and PHD fingers. Based on genetic interactions between trx and ash1 and our previous observation that association of the TRX protein with polytene chromosomes is ash1 dependent, we investigated the possibility of a physical linkage between the two proteins. We found that the endogenous TRX and ASH1 proteins coimmunoprecipitate from embryonic extracts and colocalize on salivary gland polytene chromosomes. Furthermore, we demonstrated that TRX and ASH1 bind in vivo to a relatively small (4 kb) bxd subregion of the homeotic gene Ultrabithorax (Ubx), which contains several trx response elements. Analysis of the effects of ash1 mutations on the activity of this regulatory region indicates that it also contains ash1 response element(s). This suggests that ASH1 and TRX act on Ubx in relatively close proximity to each other. Finally, TRX and ASH1 appear to interact directly through their conserved SET domains, based on binding assays in vitro and in yeast and on coimmunoprecipitation assays with embryo extracts. Collectively, these results suggest that TRX and ASH1 are components that interact either within trxG protein complexes or between complexes that act in close proximity on regulatory DNA to maintain Ubx transcription
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