Context. Extreme-precision radial velocity observations used to search for low-mass extrasolar planets are hampered by astrophysical noise originating from stellar photospheres. Starspots are a ...particular nuisance when observing young and active stars. New algorithms are needed to overcome the stellar noise barrier in radial velocity measurements. Aims. Using simulations of stellar spectra, we aim to test a technique, which we call GUSTS, that directly measures the contribution from starspots by using spectral features that are distinct from the rest of the stellar photosphere. Their contributions are expected to be anti-correlated with the starspot-induced radial velocity jitter of the star. This is reminiscent of high-dispersion observations of a transiting planet, which causes a Rossiter-McLaughlin effect but also leaves an atmospheric transmission signature that, in the case of spin-orbital alignment, is anti-correlated in radial velocity with the Rossiter-McLaughlin effect. Methods. We simulated rotating stars with a single starspot to test the method. Synthetic spectral time series were averaged to obtain a virtual spot-free star spectrum. The individual spectra were subsequently convolved with a kernel, using single value decomposition, to match the average spectrum as closely as possible, after which this average spectrum was removed from the individual spectra. The residual spectra were subsequently searched for spot signatures using the template spot spectrum used to make the synthetic stars. We tested this method on a variety of spectra with different signal-to-noise ratios and investigated what data quality is needed to use this technique in practice. Results. We demonstrate that the new GUSTS technique can work to reduce radial velocity jitter from starspots given a highly sampled, high S/N dataset. Though this alone cannot take radial velocity jitter down to the level to see Earth-like planets, it can be combined with other methods and can be used on starspot-dominated stars to detect smaller and farther planets. This technique could be useful for the future Terra Hunting Experiment, which will provide high S/N data with large samples.
Context.
The Multi-site All-Sky CAmeRA (MASCARA) and bRing are both photometric ground-based instruments with multiple stations that rely on interline charge-coupled devices with wide-field lenses to ...monitor bright stars in the local sky for variability. MASCARA has already discovered several planets in the northern sky, which are among the brightest known transiting hot Jupiter systems.
Aims.
In this paper, we aim to characterize a transiting planetary candidate in the southern skies found in the combined MASCARA and bRing data sets of HD 85628, an A7V star of
V
= 8.2 mag at a distance 172 pc, to establish its planetary nature.
Methods.
The candidate was originally detected in data obtained jointly with the MASCARA and bRing instruments using a Box Least-Square search for transit events. Further photometry was taken by the 0.7 m Chilean-Hungarian Automated Telescope (CHAT), and radial velocity measurements with the Fiber Dual Echelle Optical Spectrograph on the European Southern Observatory 1.0 m Telescope. High-resolution spectra during a transit were taken with the CTIO high-resolution spectrometer (CHIRON) on the Small and Moderate Aperture Research Telescope System 1.5 m telescope to target the Doppler shadow of the candidate.
Results.
We confirm the existence of a hot Jupiter transiting the bright A7V star HD 85628, which we co-designate as MASCARA-4b and bRing-1b. It is in an orbit of 2.824 days, with an estimated planet radius of 1.53
−0.04
+0.07
R
Jup
and an estimated planet mass of 3.1 ± 0.9
M
Jup
, putting it well within the planetary regime. The CHAT observations show a partial transit, reducing the probability that the transit was around a faint background star. The CHIRON observations show a clear Doppler shadow, implying that the transiting object is in a retrograde orbit with |
λ
| =244.9
−3.6
+2.7
°. The planet orbits at a distance of 0.047 ± 0.004 AU from the star and has a zero-albedo equilibrium temperature of 2100 ± 100 K. In addition, we find that HD 85628 has a previously unreported stellar companion star in the
Gaia
DR2 data demonstrating common proper motion and parallax at 4.3′′ separation (projected separation ~740 AU), and with absolute magnitude consistent with being a K/M dwarf.
Conclusions.
MASCARA-4 b/bRing-1 b is the brightest transiting hot Jupiter known to date in a retrograde orbit. It further confirms that planets in near-polar and retrograde orbits are more common around early-type stars. Due to its high apparent brightness and short orbital period, the system is particularly well suited for further atmospheric characterization.
Consumption of typical quantities of grapefruit juice (GFJ) increases the oral bioavailability of several CYP3A4 substrates without affecting their elimination, consistent with selective inhibition ...of intestinal but not hepatic CYP3A4. However, increases in the AUCs of CYP3A4 substrates recently associated with the consumption of large amounts of GFJ were similar to those observed with potent inhibitors of hepatic CYP3A4. The current study compared the effects of consuming large quantities and more typical amounts of GFJ on the activity of hepatic and intestinal cytochrome P450 3A4 in vivo, employing the erythromycin breath test (EBT) and oral midazolam pharmacokinetics. This was a two-phase, randomized, placebo-controlled crossover study, with each phase conducted with a separate panel of subjects. In Phase I, 8 male volunteers were randomized to the order of receiving one glass (240 mL) of water (placebo) or double-strength (DS) GFJ tid for 2 days and then 90, 60, and 30 minutes prior to administration of probe drugs on the 3rd day. In Phase II, 16 male volunteers were randomized to the order of receiving one glass of (1) single-strength (SS) GFJ, (2) DS GFJ, and (3) water (placebo). All treatments were administered in a fasted state. There was at least a 7-day washout period between treatments. Probe drugs, administered 30 minutes or 1 hour following each treatment in Phase I or II, respectively, consisted of oral midazolam (2 mg) coadministered with IV 14G N-methyl erythromycin (0.03 mg). The EBT was performed 20 minutes following erythromycin administration. Blood was collected during the 24 hours following probe drug administration for the analysis of midazolam pharmacokinetics. In Phase I, consumption of one glass of DS GFJ tid for 3 days increased the Cmax of midazolam 3-fold, the AUC 6-fold, and the t1/2 2-fold and decreased the amount of exhaled 14CO2 in all 8 subjects, with a mean decrease in EBT of 18%. In Phase II, consumption of one glass of DS GFJ significantly increased the AUC and Cmax of midazolam approximately 2-fold without a significant effect on the t1/2 of midazolam or the EBT. The effects of consuming one glass of SS GFJ on midazolam pharmacokinetics and the EBT were not significantly different from those of one glass of DS GFJ. It was concluded that consumption of one glass of DS GFJ tid for 3 days significantly increased the AUC, Cmax, and t1/2 of midazolam and reduced EBT values, reflecting inhibition of both hepatic and intestinal CYP3A4. In contrast, consumption of one glass of SS or DS GFJ increased midazolam AUC and Cmax, with little effect on the midazolam t1/2 and EBT values, reflecting preferential inhibition of intestinal CYP3A4. Alterations of midazolam AUC and Cmax induced by nine glasses of DS GFJ were significantly greater than those produced by one glass of SS or DS GFJ. These data suggest that GFJ inhibits intestinal and hepatic CYP3A4 in an exposure-dependent fashion and that patients taking medications that are CYP3A4 substrates are at risk for developing drug-related adverse events if they consume large amounts of grapefruit juice.
Aims. We describe the design and first light observations from the β Pictoris b Ring (“bRing”) project. The primary goal is to detect photometric variability from the young star β Pictoris due to ...circumplanetary material surrounding the directly imaged young extrasolar gas giant planet β Pictoris b. Methods. Over a nine month period centred on September 2017, the Hill sphere of the planet will cross in front of the star, providing a unique opportunity to directly probe the circumplanetary environment of a directly imaged planet through photometric and spectroscopic variations. We have built and installed the first of two bRing monitoring stations (one in South Africa and the other in Australia) that will measure the flux of β Pictoris, with a photometric precision of 0.5% over 5 min. Each station uses two wide field cameras to cover the declination of the star at all elevations. Detection of photometric fluctuations will trigger spectroscopic observations with large aperture telescopes in order to determine the gas and dust composition in a system at the end of the planet-forming era. Results. The first three months of operation demonstrate that bRing can obtain better than 0.5% photometry on β Pictoris in five minutes and is sensitive to nightly trends enabling the detection of any transiting material within the Hill sphere of the exoplanet.
“CHEMINI” is a new instrument developed for the measurement of seawater chemical parameters. It is a mono-parameter
in situ chemical analyzer based on flow injection analysis and colorimetric ...detection. The deep-sea version of CHEMINI combines two modules to perform the analysis of dissolved iron Fe (II) or Fe (II+III) and total sulphide (H
2S+HS
−+S
2−) up to 6000
m depth. Detection limits are, respectively, 0.3 and 0.1
μM for iron and sulphide. The system proved highly reliable during the MoMARETO cruise on the Mid-Atlantic Ridge. The two CHEMINIs were used to describe the chemical environment in 12 mussel beds on the Tour Eiffel hydrothermal edifice.
MASCARA-3b Hjorth, M.; Albrecht, S.; Talens, G. J. J. ...
Astronomy & astrophysics,
11/2019, Letnik:
631
Journal Article
Recenzirano
Odprti dostop
We report the discovery of MASCARA-3b, a hot Jupiter orbiting its bright (V = 8.33) late F-type host every 5.55149 ± 0.00001 days in an almost circular orbit ( e = 0.050−0.017+0.020 $e = ...0.050^{+0.020}_{-0.017}$ e=0.050−0.017+0.020 ). This is the fourth exoplanet discovered with the Multi-site All-Sky CAmeRA (MASCARA), and the first of these that orbits a late-type star. Follow-up spectroscopic measurements were obtained in and out of transit with the Hertzsprung SONG telescope. Combining the MASCARA photometry and SONG radial velocities reveals a radius and mass of 1.36 ± 0.05 RJup and 4.2 ± 0.2 MJup. In addition, SONG spectroscopic transit observations were obtained on two separate nights. From analyzing the mean out-of-transit broadening function, we obtain v sin i⋆ = 20.4 ± 0.4 km s−1. In addition, investigating the Rossiter-McLaughlin effect, as observed in the distortion of the stellar lines directly and through velocity anomalies, we find the projected obliquity to be λ = 1.2−7.4+8.2 $\lambda = 1.2^{+8.2}_{-7.4}$λ=1.2−7.4+8.2 deg, which is consistent with alignment.
Context.
The derivation of accurate and precise masses and radii is possible for eclipsing binary stars, allowing for insights into their evolution. When residing in star clusters, they provide ...measurements of even greater precision, along with additional information on their properties. Asteroseismic investigations of solar-like oscillations offers similar possibilities for single stars.
Aims.
We wish to improve the previously established properties of the Hyades eclipsing binary HD 27130 and re-assess the asteroseismic properties of the giant star
ϵ
Tau. The physical properties of these members of the Hyades can be used to constrain the helium content and age of the cluster.
Methods.
New multi-colour light curves were combined with multi-epoch radial velocities to yield masses and radii of HD 27130. Measurements of
T
eff
were derived from spectroscopy and photometry, and verified using the
Gaia
parallax. We estimated the cluster age from re-evaluated asteroseismic properties of
ϵ
Tau while using HD 27130 to constrain the helium content.
Results.
The masses, radii, and
T
eff
of HD 27130 were found to be
M
= 1.0245 ± 0.0024
M
⊙
,
R
= 0.9226 ± 0.015
R
⊙
,
T
eff
= 5650 ± 50 K for the primary, and
M
= 0.7426 ± 0.0016
M
⊙
,
R
= 0.7388 ± 0.026
R
⊙
,
T
eff
= 4300 ± 100 K for the secondary component. Our re-evaluation of
ϵ
Tau suggests that the previous literature estimates are trustworthy and that the
HIPPARCOS
parallax is more reliable than the
Gaia
DR2 parallax.
Conclusions.
The helium content of HD 27130 and, thus, of the Hyades is found to be
Y
= 0.27 but with a significant model dependency. Correlations with the adopted metallicity result in a robust helium enrichment law, with Δ
Y
/Δ
Z
close to 1.2 We estimate the age of the Hyades to be 0.9 ± 0.1 (stat) ±0.1 (sys) Gyr, which is in slight tension with recent age estimates based on the cluster white dwarfs. The precision of the age estimate can be much improved via asteroseismic investigations of the other Hyades giants and by future improvements to the
Gaia
parallax for bright stars.
Background
The neonatal period is associated with high morbidity and mortality in cloned calves.
Objective
To describe morbidity and mortality in cloned calves from birth to 2 years of age.
Animals
...Thirty‐one somatic cell‐derived Holstein calves delivered at a veterinary teaching hospital.
Methods
Medical files were retrospectively analyzed.
Results
Four calves were stillborn. Five calves born alive had physical congenital defects. Twenty‐three calves had an enlarged umbilical cord. Laboratory abnormalities included acidemia, respiratory acidosis, hyperlactatemia, anemia, stress leukogram, decreased total protein, albumin and globulins, and increased creatinine. Twenty‐five calves survived the 1st hour of life. Among them, 11 stood without assistance within 6 hours of birth, 10 calves took longer than 6 hours to stand, and 4 never stood. Twenty‐two calves suffered from anorexia. Twelve calves had complications arising from umbilical cord infections. Three calves developed idiopathic hyperthermia (>40°C). Eight calves suffered from gastrointestinal problems, including ruminal distension, abomasal ulcers, neonatal enteritis, intussusception, and abomasal displacement. Mortality between birth and 3 weeks of age was 32% (10/31). Causes of death and reasons for euthanasia included stillbirths, respiratory failure, and limb deformities. Mortality between 3 weeks and 2 years of age was 19% (4/21), with deaths in this group attributed to generalized peritonitis and complications arising from umbilical infections. Overall, mortality rate within 2 years of age was 14/31 (45%).
Conclusion and Clinical Importance
Respiratory problems, limb deformities, and umbilical infections were the most common causes of morbidity and mortality in these cloned calves.
Respiratory Disease in Neonatal Cloned Calves Brisville, A.C; Fecteau, G; Boysen, S ...
Journal of veterinary internal medicine,
March/April 2011, Letnik:
25, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Background: Numerous clinical abnormalities occur in cloned calves during the neonatal period. Objectives: Describe respiratory diseases affecting cloned calves. Animals: Twenty-five cloned Holstein ...calves. Methods: Retrospective clinical study of the cloned calves born at the Veterinary Teaching Hospital, Saint-Hyacinthe, QC. Results: Records of 31 cloned calves were reviewed. Twenty-five records were included. Four stillborn calves and 2 calves euthanized at birth were excluded. Twenty-two calves suffered from respiratory diseases. Nineteen calves received intranasal oxygen treatment (INO). They were tachypneic (78 breaths per minute) and 5 of them were hypoxemic (PaO2 < 55 mmHg). Two of 19 calves remained hypoxemic despite INO. Thirteen calves were weaned from INO after a median of 70 hours and were discharged at a median of 5 days of age. Nine calves required ventilatory support: 3 from birth and 6 after INO. Five were successfully weaned from the ventilator after a median of 32 hours and were discharged at a median of 8 days of age. Three calves died and 1 was euthanized because of respiratory disease. Necropsy revealed atelectasis, pulmonary congestion, and alveolar damages. Conclusion and Clinical Importance: Respiratory disease occurs frequently in cloned calves. The most frequent abnormality is hypoxemia because of V/Q mismatch. It is possible to successfully support these calves by INO and mechanical ventilation.
Effect of mibefradil on CYP3A4 in vivo Veronese, Maria L; Gillen, Lisa P; Dorval, Ellen P ...
Journal of clinical pharmacology,
2003-October, Letnik:
43, Številka:
10
Journal Article
Recenzirano
Mibefradil, a calcium channel blocker, was removed from the market because of adverse drug interactions with coadministered CYP3A4 substrates. This study examined the effect of mibefradil on the ...activity of hepatic and intestinal CYP3A4 in vivo, employing the erythromycin breath test (EBT) and oral midazolam pharmacokinetics. This was a two-period, single-blind, placebo-controlled crossover study in which 8 male volunteers were randomized to the order of receiving placebo and a single 100-mg oral dose of mibefradil. Oral midazolam was coadministered with intravenous 14C N-methyl erythromycin 1 hour after mibefradil/placebo administration. The EBT was performed 20 minutes following erythromycin administration. Blood and urine were collected during the 36 hours following probe drug administration for analysis of midazolam pharmacokinetics. Coadministration of mibefradil increased the Cmax of midazolam 3-fold, the AUC 8- to 9-fold, and the t1/2 4-fold. Mibefradil coadministration decreased the amount of exhaled 14CO2 in 6 of 8 subjects, with a mean decrease of 25%. It was concluded that a single oral dose of mibefradil significantly inhibits CYP3A4 in intestine and liver. These data support that adverse drug interactions involving mibefradil reflect inhibition of CYP3A4 in intestine and liver. Also, they suggest that the EBT, while a valid probe of in vivo hepatic CYP3A4 activity, is a single time point measurement and may be less sensitive than oral midazolam pharmacokinetics in detecting CYP3A4 inhibition.
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