2,425 research outputs found
Polarimetry in the Visible and Infrared: Application to CMB Polarimetry
Interstellar polarization from aligned dust grains can be measured both in
transmission at visible and near-infrared wavelengths and in emission at
far-infrared and sub-mm wavelengths. These observations can help predict the
behavior of foreground contamination of CMB polarimetry by dust in the Milky
Way. Fractional polarization in emission from aligned dust grains will be at
the higher range of currently observed values of 4-10%. Away from the galactic
plane, fluctuations in Q and U will be dominated by fluctuations in intensity,
and less influenced by fluctuations in fractional polarization and position
angle.Comment: To be published in the proceedings of "The Cosmic Microwave
Background and its Polarization", New Astronomy Reviews, (eds. S. Hanany and
K.A. Olive
Luminous and Variable Stars in M31 and M33. III. The Yellow and Red Supergiants and Post-Red Supergiant Evolution
Recent supernova and transient surveys have revealed an increasing number of
non-terminal stellar eruptions. Though the progenitor class of these eruptions
includes the most luminous stars, little is known of the pre-supernova
mechanics of massive stars in their most evolved state, thus motivating a
census of possible progenitors. From surveys of evolved and unstable luminous
star populations in nearby galaxies, we select a sample of yellow and red
supergiant candidates in M31 and M33 for review of their spectral
characteristics and spectral energy distributions. Since the position of
intermediate and late-type supergiants on the color-magnitude diagram can be
heavily contaminated by foreground dwarfs, we employ spectral classification
and multi-band photometry from optical and near-infrared surveys to confirm
membership. Based on spectroscopic evidence for mass loss and the presence of
circumstellar dust in their SEDs, we find that of the yellow
supergiants are likely in a post-red supergiant state. Comparison with
evolutionary tracks shows that these mass-losing, post-RSGs have initial masses
between . More than half of the observed red supergiants in
M31 and M33 are producing dusty circumstellar ejecta. We also identify two new
warm hypergiants in M31, J004621.05+421308.06 and J004051.59+403303.00, both of
which are likely in a post-RSG state.Comment: Accepted for publication in ApJ. 34 pages, 11 figure
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0153 Extreme Morning Chronotypes Are Often Familial And Not Exceedingly Rare: The Estimated Prevalence Of Familial Advanced Sleep Phase (FASP) In A Sleep Clinic Population
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Extreme morning chronotypes are often familial and not exceedingly rare: the estimated prevalence of advanced sleep phase, familial advanced sleep phase, and advanced sleep-wake phase disorder in a sleep clinic population.
Study objectivesReport the first prevalence estimates of advanced sleep phase (ASP), familial advanced sleep phase (FASP), and advanced sleep-wake phase disorder (ASWPD). This can guide clinicians on the utility of screening for extreme chronotypes both for clinical decision-making and to flag prospective participants in the study of the genetics and biology of FASP.MethodsData on morning or evening sleep schedule preference (chronotype) were collected from 2422 new patients presenting to a North American sleep center over 9.8 years. FASP was determined using a severity criterion that has previously identified dominant circadian mutations in humans. All patients were personally seen and evaluated by one of the authors (C.R.J.).ResultsOur results demonstrate an ASP prevalence of 0.33%, an FASP prevalence of 0.21%, and an ASWPD prevalence of at least 0.04%. Most cases of young-onset ASP were familial.ConclusionsAmong patients presenting to a sleep clinic, conservatively 1 out of every 300 patients will have ASP, 1 out of every 475 will have FASP, and 1 out of every 2500 will have ASWPD. This supports obtaining a routine circadian history and, for those with extreme chronotypes, obtaining a family history of circadian preference. This can optimize treatment for evening sleepiness and early morning awakening and lead to additional circadian gene discovery. We hope these findings will lead to improved treatment options for a wide range of sleep and medical disorders in the future
Effects of intervention upon precompetition state anxiety in elite junior tennis players: The relevance of the matching hypothesis
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Terry, P., Coakley, L., & Karageorghis, C. Effects of intervention upon precompetition state anxiety in elite junior tennis players: the relevance of the matching hypothesis. Perceptual and Motor Skills, 1995, 81, 287-296. © Perceptual and Motor Skills 1995The matching hypothesis proposes that interventions for anxiety should be matched to the modality in which anxiety is experienced. This study investigated the relevance of the matching hypothesis for anxiety interventions in tennis. Elite junior tennis players (N = 100; Age: M = 13.9 yr., SD = 1.8 yr.) completed the Competitive State Anxiety Inventory-2 before and after one of four randomly assigned intervention strategies approximately one hour prior to competition at a National Junior Championship. A two-factor multivariate analysis of variance (group x time) with repeated measures on the time factor gave no significant main effect by group but indicated significant reductions in somatic anxiety and cognitive anxiety and a significant increase in self-confidence following intervention. A significant group by time interaction emerged for self-confidence. The results question the need to match intervention strategy to the mode of anxiety experienced
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