ABSTRACT
We present the discovery of NGTS-7Ab, a high-mass brown dwarf transiting an M dwarf with a period of 16.2 h, discovered as part of the Next Generation Transit Survey (NGTS). This is the ...shortest period transiting brown dwarf around a main or pre-main sequence star to date. The M star host (NGTS-7A) has an age of roughly 55 Myr and is in a state of spin–orbit synchronization, which we attribute to tidal interaction with the brown dwarf acting to spin-up the star. The host star is magnetically active and shows multiple flares across the NGTS and follow-up light curves, which we use to probe the flare–star-spot phase relation. The host star also has an M star companion at a separation of 1.13 arcsec with very similar proper motion and systemic velocity, suggesting that the NGTS-7 system is a hierarchical triple. The combination of tidal synchronisation and magnetic braking is expected to drive on-going decay of the brown dwarf orbit, with a remaining lifetime of only 5–10 Myr.
► Aliphatic and aromatic terpene hydrocarbons used as flavor ingredients and resultant exposure are reported. ► Review of absorption, distribution, metabolism and elimination of terpene hydrocarbons. ...► Review of short- and long-term toxicology and reproductive toxicology of terpene hydrocarbons. ► Discussion of effects in bioassays and the relevance to humans. ► Review of genotoxicity data on aliphatic and aromatic terpene hydrocarbons.
This publication is the thirteenth in a series of safety evaluations performed by the Expert Panel of the Flavor and Extract Manufacturers Association (FEMA). In 1993, the Panel initiated a comprehensive program to re-evaluate the safety of more than 1700 GRAS flavoring substances under conditions of intended use. Since then, the number of flavoring substances has grown to more than 2600 substances. Elements that are fundamental to the safety evaluation of flavor ingredients include exposure, structural analogy, metabolism, pharmacokinetics and toxicology. Flavor ingredients are evaluated individually and in the context of the available scientific information on the group of structurally related substances. Scientific data relevant to the safety evaluation of the use of aliphatic and aromatic terpene hydrocarbons as flavoring ingredients are evaluated. The group of aliphatic and aromatic terpene hydrocarbons was reaffirmed as GRAS (GRASr) based, in part, on their self-limiting properties as flavoring substances in food; their rapid absorption, metabolic detoxication, and excretion in humans and other animals; their low level of flavor use; the wide margins of safety between the conservative estimates of intake and the no-observed-adverse effect levels determined from subchronic and chronic studies and the lack of significant genotoxic potential.
We report the independent discovery and characterization of two K2 planets: K2-180b, a mini-Neptune-sized planet in an 8.9-d orbit transiting a V = 12.6 mag, metal-poor (Fe/H = -0.65 ± 0.10) K2V star ...in K2 campaign 5; K2-140b, a transiting hot Jupiter in a 6.6-d orbit around a V = 12.6 mag G6V (Fe/H = + 0.10 ± 0.10) star in K2 campaign 10. Our results are based on K2 time-series photometry combined with high-spatial resolution imaging and high-precision radial velocity measurements. We present the first mass measurement of K2-180b. K2-180b has a mass of Mp = 11.3 ± 1.9 M_Earth and a radius of Rp = 2.2 ± 0.1 R_Earth, yielding a mean density of ρp = 5.6 ± 1.9 g cm-3, suggesting a rocky composition. Given its radius, K2-180b is above the region of the so-called `planetary radius gap'. K2-180b is in addition not only one of the densest mini-Neptune-sized planets, but also one of the few mini-Neptune-sized planets known to transit a metal-poor star. We also constrain the planetary and orbital parameters of K2-140b and show that, given the currently available Doppler measurements, the eccentricity is consistent with zero, contrary to the results of a previous study.
The NuMI neutrino beam Adamson, P.; Andrews, R.; Augustine, D. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
01/2016, Letnik:
806
Journal Article
Recenzirano
Odprti dostop
This paper describes the hardware and operations of the Neutrinos at the Main Injector (NuMI) beam at Fermilab. It elaborates on the design considerations for the beam as a whole and for individual ...elements. The most important design details of individual components are described. Beam monitoring systems and procedures, including the tuning and alignment of the beam and NuMI long-term performance, are also discussed.
Wildland fire occurrence has been increasing in peatland ecosystems during recent decades. As such, there is a need for broadly applicable tools to detect and monitor controls on combustion such as ...surface peat moisture and water-table position. A field portable spectroradiometer was used to measure surface reflectance of two Sphagnum moss-dominated peatland experiments, one being an experimental study utilizing a factorial experiment of vegetation and water-table manipulations and the other being a field site located in the Upper Peninsula of Michigan that is broadly representative of northern peatland ecosystems. Relationships were developed correlating spectral indices to surface moisture as well as water-table position using the surface reflectance data. Spectral convolutions, or integrations of the hyperspectral data with the relative spectral response curves of multispectral sensors, were also applied to represent spectral sensitivity of commonly used Earth observing sensors. Band ratios previously used to monitor surface moisture with these sensors were assessed. Strong relationships with surface moisture and water-table position are evident for both the narrow-band indices as well as broad-band indices. This study also revealed a dependence of spectral relationships on changes in vegetation cover, particularly ericoid shrubs, within the vegetation manipulation experiment.
•Spectral reflectance measurements of Sphagnum dominated peatlands were acquired.•Measurements were taken under an extreme range of moisture availability.•NIR spectral indices related best to water table position and moisture content.•Sensor specific spectral broadening did not greatly reduce these relationships.•Indices were altered by vegetation manipulations present in a mesocosm experiment.
Abstract Background Whereas sudden cardiac death (SCD) risk has been recognized in heart failure (HF) patients with reduced ejection fraction (HFrEF), less is known about SCD risk in HF patients with ...preserved EF (HFpEF). We examined the incidence and predictors of SCD in HFpEF in a large population sample. Methods and Results Medical records of patients discharged with a primary diagnosis of HF from hospitals in Minneapolis–St Paul in 1995 and 2000 were abstracted. HFpEF was defined as EF ≥45%. SCD was defined as cardiac arrest or out-of-hospital death due to coronary heart disease (CHD) on death certificates. A total of 2,203 patients (age 70 ± 11 years, 53% male) were included. The 787 patients (36%) with HFpEF were older, more often female and more likely to have hypertension than the 1,416 (64%) with HFrEF. All-cause mortality (52% vs 58%; P = .01) and SCD (6% vs 14%; P < .0001) rates were lower in HFpEF than in HFrEF 5 years after hospital discharge. Age, sex, CHD, and length of index hospitalization were the only independent predictors of SCD in HFpEF. Conclusions Incidence of SCD in HFpEF is lower than in HFrEF. Present markers of SCD in HFpEF are sparse and insufficient to identify the patient at risk.
Context.
Ultra-short-period (USP) planets are defined as planets with orbital periods shorter than one day. This type of planets is rare, highly irradiated, and interesting because their formation ...history is unknown.
Aims.
We aim to obtain precise mass and radius measurements to confirm the planetary nature of a USP candidate found by the Transiting Exoplanet Survey Satellite (TESS). These parameters can provide insights into the bulk composition of the planet candidate and help to place constraints on its formation history.
Methods.
We used TESS light curves and HARPS-N spectrograph radial velocity measurements to establish the physical properties of the transiting exoplanet candidate found around the star HD 20329 (TOI-4524). We performed a joint fit of the light curves and radial velocity time series to measure the mass, radius, and orbital parameters of the candidate.
Results.
We confirm and characterize HD 20329b, a USP planet transiting a solar-type star. The host star (HD 20329,
V
= 8.74 mag,
J
= 7.5 mag) is characterized by its G5 spectral type with
M
*
= 0.90 ± 0.05
M
⊙
,
R
*
= 1.13 ± 0.02
R
⊙
, and
T
eff
= 5596 ± 50 K; it is located at a distance
d
= 63.68 ± 0.29 pc. By jointly fitting the available TESS transit light curves and follow-up radial velocity measurements, we find an orbital period of 0.9261 ± (0.5 × 10
−4
) days, a planetary radius of 1.72 ± 0.07
R
⊗
, and a mass of 7.42 ± 1.09
M
⊗
, implying a mean density of
ρ
p
= 8.06 ± 1.53 g cm
−3
. HD 20329b joins the ~30 currently known USP planets with radius and Doppler mass measurements.
Animal models of cerebral amyloid angiopathy (CAA) exhibit abnormal vascular reactivity. We determined whether vascular reactivity, measured by transcranial Doppler ultrasound (TCD), is reduced in ...humans with CAA.
Cases were recruited from an established prospective study of CAA. Healthy controls were recruited from a study of normal aging. Evoked mean flow velocity increase in the posterior cerebral artery (PCA) was measured while subjects viewed a flashing alternating checkerboard stimulus. In a separate but partially overlapping cohort we measured the mean flow velocity increase in the middle cerebral artery (MCA) while subjects inhaled carbon dioxide.
The visual evoked mean flow velocity increase was 8.0 +/- 6.1% in CAA (n = 11) compared to 17.4 +/- 5.7% in controls (n = 9, p = 0.002). The PCA pulsatility index, a marker of distal vascular resistance, was higher in CAA (CAA 1.35 +/- 0.35, control 1.04 +/- 0.14, p = 0.03). Among CAA subjects, lower visual evoked mean flow velocity increase was associated with a higher number of hemorrhages seen on MRI (r = -0.87, p = 0.0005) and higher MRI white matter hyperintensity volume (r = -0.67, p = 0.02). The MCA response to carbon dioxide did not differ between CAA and control in 20 subjects (9 CAA, 11 control, p = 0.54).
Cerebral amyloid angiopathy (CAA) was associated with decreased vascular reactivity in response to visual stimulation, possibly reflecting the occipital predilection of the disease. The association of posterior cerebral artery (PCA) evoked flow velocity response with elevated PCA pulsatility index and MRI markers of small vessel disease suggests that abnormal PCA evoked flow velocity in CAA is caused by pathology of the distal resistance vessels.
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