1,320 research outputs found
Translation Recognition in Learners of Arabic
The current study explored the role of phonology in the processing of Arabic words in native English speakers learning Arabic. Previous research demonstrates that three factors play a role in the mental processing of multiple languages: orthography, phonology, and semantics. Cognate studies have revealed that orthography is not the most important factor, but the roles of phonology and semantics are still indistinguishable from one another. The current study utilized phonologically-embedded English words within Arabic words at three different points in the word, beginning, middle, and end, to determine the role of phonology separate from that of semantics (e.g., [written Arabic] pronounced tareekh, and tar is a beginning overlap pair). Participants from the University of Arkansas Arabic language program completed a translation recognition task. They were shown an Arabic word, followed by an English word, and asked to identify whether the English word was the correct translation. It was predicted that participants would take longer to say “no” to false translations with phonological overlap than to false translations without phonological overlap and that less experienced learners would exhibit this effect to a higher degree than more experienced learners. While, as predicted, the reaction times for false translations with phonological overlap were substantially slower than reaction times for false translations without phonological overlap in beginning and middle overlap conditions, no significant differences were found. Arabic proficiency was found to be negatively correlated with amount of phonological interference. The results generally support the importance of phonology in the mental processing of multiple languages, which can be combined with other findings in language research to supplement language learning programs
Complications of Cushing's syndrome: state of the art
Cushing's syndrome is a serious endocrine disease caused by chronic, autonomous, and excessive secretion of cortisol. The syndrome is associated with increased mortality and impaired quality of life because of the occurrence of comorbidities. These clinical complications include metabolic syndrome, consisting of systemic arterial hypertension, visceral obesity, impairment of glucose metabolism, and dyslipidaemia; musculoskeletal disorders, such as myopathy, osteoporosis, and skeletal fractures; neuropsychiatric disorders, such as impairment of cognitive function, depression, or mania; impairment of reproductive and sexual function; and dermatological manifestations, mainly represented by acne, hirsutism, and alopecia. Hypertension in patients with Cushing's syndrome has a multifactorial pathogenesis and contributes to the increased risk for myocardial infarction, cardiac failure, or stroke, which are the most common causes of death; risks of these outcomes are exacerbated by a prothrombotic diathesis and hypokalaemia. Neuropsychiatric disorders can be responsible for suicide. Immune disorders are common; immunosuppression during active disease causes susceptibility to infections, possibly complicated by sepsis, an important cause of death, whereas immune rebound after disease remission can exacerbate underlying autoimmune diseases. Prompt treatment of cortisol excess and specific treatments of comorbidities are crucial to prevent serious clinical complications and reduce the mortality associated with Cushing's syndrome
Quiescent and flaring X-ray emission from the nearby M/T dwarf binary SCR 1845-6357
We investigate an XMM-Newton observation of SCR 1845-6357, a nearby,
ultracool M8.5/T5.5 dwarf binary. The binary is unresolved in the XMM
detectors, however the X-ray emission is very likely from the M8.5 dwarf. We
compare its flaring emission to those of similar very low mass stars and
additionally present an XMM observation of the M8 dwarf VB 10. We detect
quasi-quiescent X-ray emission from SCR 1845-6357 at soft X-ray energies in the
0.2-2.0 keV band, as well as a strong flare with a count rate increase of a
factor of 30 and a duration of only 10 minutes. The quasi-quiescent X-ray
luminosity of log L_x = 26.2 erg/s and the corresponding activity level of log
L_x/L_bol = -3.8 point to a fairly active star. Coronal temperatures of up to 5
MK and frequent minor variability support this picture. During the flare, that
is accompanied by a significant brightening in the near-UV, plasma temperatures
of 25-30 MK are observed and an X-ray luminosity of L_x= 8 x 10^27 erg/s is
reached. SCR 1845-6357 is a nearby, very low mass star that emits X-rays at
detectable levels in quasi-quiescence, implying the existence of a corona. The
high activity level, coronal temperatures and the observed large flare point to
a rather active star, despite its estimated age of a few Gyr.Comment: Accepted by A&A, 6 pages, 5 figure
Levoketoconazole: a novel treatment for endogenous Cushing's syndrome.
Introduction: Endogenous Cushing's syndrome (CS) is a rare, life-threatening endocrine disorder that is caused by chronic exposure to cortisol overproduction. Levoketoconazole (Recorlev), a 2S, 4R stereoisomer of ketoconazole, is a steroidogenesis inhibitor under investigation for the treatment of CS. Areas covered: This review covers the pharmacology, efficacy, and safety of levoketoconazole for the treatment of patients with endogenous CS. Expert opinion: Based on the preclinical and clinical pharmacology findings, levoketoconazole appears to be the relevant enantiomer of ketoconazole for inhibition of steroidogenesis, with more potent inhibition of both cortisol and androgen synthesis relative to ketoconazole racemate and the 2R, 4S stereoisomer dextroketoconazole. Results from the phase III SONICS study showed that levoketoconazole was effective in normalizing cortisol levels and improving biomarkers of cardiovascular risk in a significant percentage of patients. In addition, treatment with levoketoconazole showed improvements in subjective clinical assessments of clinician-rated CS clinical signs and symptoms, patient-reported quality of life, and depression symptom severity. Testosterone levels decreased significantly in women. Levoketoconazole had an acceptable safety profile with no unexpected safety signals. The favorable pharmacology, efficacy, and safety profile of levoketoconazole supports its use as medical therapy for CS, if approved
A new white dwarf companion to the star GJ 3346
We present the discovery of a white dwarf companion at 3.6" from GJ3346, a
nearby (42 mas) K star observed with SPHERE@VLT as part of an open
time survey for faint companions to objects with significant proper motion
discrepancies () between Gaia DR1 and Tycho-2. Syrius-like systems
like GJ3346AB, which include a main sequence star and a white dwarf, can be
difficult to detect because of the intrinsic faintness of the latter. They
have, however, been found to be common contaminants for direct imaging
searches. White dwarfs have in fact similar brightness to sub-stellar
companions in the infrared, while being much brighter in the visible bands like
those used by Gaia. Combining our observations with Gaia DR2 and with several
additional archival data sets, we were able to fully constrain the physical
properties of GJ3346B, such as its effective temperature
(1110500 K) as well as the cooling age of the system (64858
Myrs). This allowed us to better understand the system history and to partially
explains the discrepancies previously noted in the age indicators for this
objects. Although further investigation is still needed, it seems that GJ3346,
which was previously classified as young, is in fact most likely to be older
than 4 Gyrs. Finally, given that the mass (0.580.01)} and
separation (85 au) of GJ3346B are compatible with the observed ,
this discovery represents a further confirmation of the potential of this kind
of dynamical signatures as selection methods for direct imaging surveys
targeting faint, sub-stellar companions.Comment: 10 pages, 7 figure
A high binary fraction for the most massive close-in giant planets and brown dwarf desert members
Stellar multiplicity is believed to influence planetary formation and
evolution, although the precise nature and extent of this role remain
ambiguous. We present a study aimed at testing the role of stellar multiplicity
in the formation and/or evolution of the most massive, close-in planetary and
substellar companions. Using direct imaging observations, as well as the Gaia
DR2 catalogue, we searched for wide binary companions to 38 stars hosting
massive giant planets or brown dwarfs (M > 7 MJup) on orbits shorter than ~1
AU. We report the discovery of a new component in the WASP-14 system, and
present an independent confirmation of a comoving companion to WASP-18. From a
robust Bayesian statistical analysis, we derived a binary fraction of
79.0+13.2-14.7% between 20-10,000 AU for our sample, twice as high as for field
stars with a 3-{\sigma} significance. This binary frequency was found to be
larger than for lower-mass planets on similar orbits, and we observed a
marginally higher binary rate for inner companions with periods shorter than 10
days. These results demonstrate that stellar companions greatly influence the
formation and/or evolution of these systems, suggesting that the role played by
binary companions becomes more important for higher-mass planets, and that this
trend may be enhanced for systems with tighter orbits. Our analysis also
revealed a peak in binary separation at 250 AU, highlighting a shortfall of
close binaries among our sample. This indicates that the mechanisms affecting
planet and brown dwarf formation or evolution in binaries must operate from
wide separations, although we found that the Kozai-Lidov mechanism is unlikely
to be the dominant underlying process. We conclude that binarity plays a
crucial role in the existence of very massive short-period giant planets and
brown dwarf desert inhabitants, which are almost exclusively observed in
multiple systems.Comment: Accepted for publication in MNRAS. 30 pages, 20 figures. Updated to
include proof correction
Properties of the T8.5 Dwarf Wolf 940 B
We present 7.5-14.2um low-resolution spectroscopy, obtained with the Spitzer
Infrared Spectrograph, of the T8.5 dwarf Wolf 940 B, which is a companion to an
M4 dwarf with a projected separation of 400 AU. We combine these data with
previously published near-infrared spectroscopy and mid-infrared photometry, to
produce the spectral energy distribution for the very low-temperature T dwarf.
We use atmospheric models to derive the bolometric correction and obtain a
luminosity of log L/Lsun = -6.01 +/- 0.05. Evolutionary models are used with
the luminosity to constrain the values of effective temperature (T_eff) and
surface gravity, and hence mass and age for the T dwarf. We further restrict
the allowed range of T_eff and gravity using age constraints implied by the M
dwarf primary, and refine the physical properties of the T dwarf by comparison
of the observed and modelled spectroscopy and photometry. This comparison
indicates that Wolf 940 B has a metallicity within 0.2 dex of solar, as more
extreme values give poor fits to the data - lower metallicity produces a poor
fit at lambda > 2um while higher metallicity produces a poor fit at lambda <
2um. This is consistent with the independently derived value of [m/H] = +0.24
+/- 0.09 for the primary star, using the Johnson & Apps (2008) M_K:V-K
relationship. We find that the T dwarf atmosphere is undergoing vigorous
mixing, with an eddy diffusion coefficient K_zz of 10^4 to 10^6 cm^2 s^-1. We
derive an effective temperature of 585 K to 625 K, and surface gravity log g =
4.83 to 5.22 (cm s^-2), for an age range of 3 Gyr to 10 Gyr, as implied by the
kinematic and H alpha properties of the M dwarf primary. The lower gravity
corresponds to the lower temperature and younger age for the system, and the
higher value to the higher temperature and older age. The mass of the T dwarf
is 24 M_Jupiter to 45 M_Jupiter for the younger to older age limit.Comment: 24 pages which include 5 Figures and 3 Tables. Accepted for
publication in the Astrophysical Journal July 2 201
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