640 research outputs found
Detection of thermal radio emission from a single coronal giant
We report the detection of thermal continuum radio emission from the K0 III
coronal giant Pollux ( Gem) with the Karl G. Jansky Very Large Array
(VLA). The star was detected at 21 and 9 GHz with flux density values of
and Jy, respectively. We also place a
upper limit of Jy for the flux density at 3
GHz. We find the stellar disk-averaged brightness temperatures to be
approximately 9500, 15000, and K, at 21, 9, and 3 GHz, respectively,
which are consistent with the values of the quiet Sun. The emission is most
likely dominated by optically thick thermal emission from an upper chromosphere
at 21 and 9 GHz. We discuss other possible additional sources of emission at
all frequencies and show that there may also be a small contribution from
gyroresonance emission above active regions, coronal free-free emission and
free-free emission from an optically thin stellar wind, particularly at the
lower frequencies. We constrain the maximum mass-loss rate from Pollux to be
less than yr (assuming a wind terminal
velocity of 215 km s), which is about an order of magnitude smaller than
previous constraints for coronal giants and is in agreement with existing
predictions for the mass-loss rate of Pollux. These are the first detections of
thermal radio emission from a single (i.e., non-binary) coronal giant and
demonstrate that low activity coronal giants like Pollux have atmospheres at
radio frequencies akin to the quiet Sun
THE OLD AND NEW DIVIDES OF PATENT LAW: FROM THE THEORY OF ANTEDATION TO DEFINING IMMEDIATELY ENVISAGEABLE LIMITED CLASSES
Recently, the United States Court of Appeals for the Federal Circuit (“Federal Circuit”) ruled on a patent case involving the application of pre-America Invents Act (“AIA”) antedation and the issue of when a genus of compounds is narrowly limited enough to anticipate an individual compound found within the genus.1 On appeal, this case generally discussed why the claimant’s anticipation and obviousness claims failed.2
While the entire Federal Circuit decision will be discussed, this Comment will discuss in greater depth the reasons why antedation is no longer applicable under the AIA, and the implications of the Federal Circuit’s decision to not set a standard for what defines a “limited class” under In re Petering
Multi-wavelength Radio Continuum Emission Studies of Dust-free Red Giants
Multi-wavelength centimeter continuum observations of non-dusty,
non-pulsating K spectral-type red giants directly sample their chromospheres
and wind acceleration zones. Such stars are feeble emitters at these
wavelengths however, and previous observations have provided only a small
number of modest S/N measurements slowly accumulated over three decades. We
present multi-wavelength Karl G. Jansky Very Large Array thermal continuum
observations of the wind acceleration zones of two dust-free red giants,
Arcturus (Alpha Boo: K2 III) and Aldebaran (Alpha Tau: K5 III). Importantly,
most of our observations of each star were carried out over just a few days, so
that we obtained a snapshot of the different stellar atmospheric layers sampled
at different wavelengths, independent of any long-term variability. We report
the first detections at several wavelengths for each star including a detection
at 10 cm (3.0 GHz: S band) for both stars and a 20 cm (1.5 GHz: L band)
detection for Alpha Boo. This is the first time single luminosity class III red
giants have been detected at these continuum wavelengths. Our long-wavelength
data sample the outer layers of Alpha Boo's atmosphere where its wind velocity
is approaching its terminal value and the ionization balance is becoming
frozen-in. For Alpha Tau, however, our long-wavelength data are still sampling
its inner atmosphere, where the wind is still accelerating probably due to its
lower mass-loss rate. We compare our data with published semi-empirical models
based on ultraviolet data, and the marked deviations highlight the need for new
atmospheric models to be developed. Spectral indices are used to discuss the
possible properties of the stellar atmospheres, and we find evidence for a
rapidly cooling wind in the case of Alpha Boo. Finally, we develop a simple
analytical wind model for Alpha Boo based on our new long-wavelength flux
measurements
Temporal Evolution of the Size and Temperature of Betelgeuse's Extended Atmosphere
We use the Very Large Array (VLA) in the A configuration with the Pie Town
(PT) Very Long Baseline Array (VLBA) antenna to spatially resolve the extended
atmosphere of Betelgeuse over multiple epochs at 0.7, 1.3, 2.0, 3.5, and 6.1
cm. The extended atmosphere deviates from circular symmetry at all wavelengths
while at some epochs we find possible evidence for small pockets of gas
significantly cooler than the mean global temperature. We find no evidence for
the recently reported e-MERLIN radio hotspots in any of our multi-epoch VLA/PT
data, despite having sufficient spatial resolution and sensitivity at short
wavelengths, and conclude that these radio hotspots are most likely
interferometric artefacts. The mean gas temperature of the extended atmosphere
has a typical value of 3000 K at 2 and decreases to 1800 K at 6
, in broad agreement with the findings of the single epoch study
from Lim et al. (1998). The overall temperature profile of the extended
atmosphere between can be
described by a power law of the form ,
with temporal variability of a few 100 K evident at some epochs. Finally, we
present over 12 years of V band photometry, part of which overlaps our
multi-epoch radio data. We find a correlation between the fractional flux
density variability at V band with most radio wavelengths. This correlation is
likely due to shock waves induced by stellar pulsations, which heat the inner
atmosphere and ionize the more extended atmosphere through radiative means.
Stellar pulsations may play an important role in exciting Betelgeuse's extended
atmosphere
CARMA CO(J = 2 - 1) Observations of the Circumstellar Envelope of Betelgeuse
We report radio interferometric observations of the 12C16O 1.3 mm J = 2-1
emission line in the circumstellar envelope of the M supergiant Alpha Ori and
have detected and separated both the S1 and S2 flow components for the first
time. Observations were made with the Combined Array for Research in
Millimeter-wave Astronomy (CARMA) interferometer in the C, D, and E antenna
configurations. We obtain good u-v coverage (5-280 klambda) by combining data
from all three configurations allowing us to trace spatial scales as small as
0.9\arcsec over a 32\arcsec field of view. The high spectral and spatial
resolution C configuration line profile shows that the inner S1 flow has
slightly asymmetric outflow velocities ranging from -9.0 km s-1 to +10.6 km s-1
with respect to the stellar rest frame. We find little evidence for the outer
S2 flow in this configuration because the majority of this emission has been
spatially-filtered (resolved out) by the array. We also report a SOFIA-GREAT
CO(J= 12-11) emission line profile which we associate with this inner higher
excitation S1 flow. The outer S2 flow appears in the D and E configuration maps
and its outflow velocity is found to be in good agreement with high resolution
optical spectroscopy of K I obtained at the McDonald Observatory. We image both
S1 and S2 in the multi-configuration maps and see a gradual change in the
angular size of the emission in the high absolute velocity maps. We assign an
outer radius of 4\arcsec to S1 and propose that S2 extends beyond CARMA's field
of view (32\arcsec at 1.3 mm) out to a radius of 17\arcsec which is larger than
recent single-dish observations have indicated. When azimuthally averaged, the
intensity fall-off for both flows is found to be proportional to R^{-1}, where
R is the projected radius, indicating optically thin winds with \rho \propto
R^{-2}.Comment: 11 pages, 8 figures To be published in the Astronomical Journal
(Received 2012 February 10; accepted 2012 May 25
Indications and Long-term Outcomes of Open Augmentation Rhinoplasty with Autogenous L-shaped Costal Cartilage Strut Grafts – A Single Plastic Surgeon’s Experience
Introduction: We present a single surgeon’s experience of open augmentation rhinoplasty with autogenous L-shaped costal cartilage grafts, with long-term patient-reported outcome data. We highlight the salient operative steps and outline the peri-operative care required to optimise outcomes. Materials and Methods: A retrospective review of eleven such augmentation rhinoplasties performed between 2008 and 2016 was undertaken. Indications included saddle nose deformity [granulomatosis with polyangiitis (n=7) and relapsing polychondritis (n=1)], post-traumatic nasal collapse (n=1) and advanced cosmetic westernisation of the nose (n=2). Long-term patient-reported outcome was assessed with a patient questionnaire. Results: All patients achieved marked improvement in nasal position, shape and function. There was no cartilage exposure, warping or resorption and no recurrent deformities. One patient’s dorsal graft was fractured two years later during an ophthalmological procedure and the deformity was re-corrected successfully, again with the above technique. Average follow up was 5.2 years. Of the nine patients who responded to the follow-up questionnaire, 100% were satisfied with their nasal appearance. 100% of responders at follow-up reported that they have had no problems relating to their nose (n=9). Discussion L-shaped costal cartilage grafts provided a reliable, reproducible approach in augmentation rhinoplasty for disparate indications (inflammatory, traumatic and cosmetic) in the hands of a low-volume operator. With careful patient selection and planning, this technique can provide pleasing aesthetic outcomes and high patient satisfaction, with good long-term outcomes
Extrasolar Planet Transits Observed at Kitt Peak National Observatory
We obtained J-, H- and JH-band photometry of known extrasolar planet
transiting systems at the 2.1-m Kitt Peak National Observatory Telescope using
the FLAMINGOS infrared camera between October 2008 and October 2011. From the
derived lightcurves we have extracted the mid-transit times, transit depths and
transit durations for these events. The precise mid-transit times obtained help
improve the orbital periods and also constrain transit-time variations of the
systems. For most cases the published system parameters successfully accounted
for our observed lightcurves, but in some instances we derive improved
planetary radii and orbital periods. We complemented our 2.1-m infrared
observations using CCD z'-band and B-band photometry (plus two Hydrogen Alpha
filter observations) obtained with the Kitt Peak Visitor's Center telescope,
and with four H-band transits observed in October 2007 with the NSO's 1.6-m
McMath-Pierce Solar Telescope. The principal highlights of our results are: 1)
our ensemble of J-band planetary radii agree with optical radii, with the
best-fit relation being: (Rp/R*)J = 0.0017 + 0.979 (Rp/R*)optical, 2) We
observe star spot crossings during the transit of WASP-11/HAT-P-10, 3) we
detect star spot crossings by HAT-P-11b (Kepler-3b), thus confirming that the
magnetic evolution of the stellar active regions can be monitored even after
the Kepler mission has ended, and 4) we confirm a grazing transit for
HAT-P-27/WASP-40. In total we present 57 individual transits of 32 known
exoplanet systems.Comment: 33 pages, 6 figures, accepted in Publications of the Astronomical
Society of the Pacifi
Vitamin D3 supplementation in healthy adults: a comparison between capsule and oral spray solution as a method of delivery in a wintertime, randomised, open-label, cross-over study
AbstractVitamin D is typically supplied in capsule form, both in trials and in clinical practice. However, little is known regarding the efficacy of vitamin D administered via oral sprays – a method that primarily bypasses the gastrointestinal absorption route. This study aimed to compare the efficacy of vitamin D3liquid capsules and oral spray solution in increasing wintertime total 25-hydroxyvitamin D (25(OH)D) concentrations. In this randomised, open-label, cross-over trial, healthy adults (n22) received 3000 IU (75 µg) vitamin D3daily for 4 weeks in either capsule or oral spray form. Following a 10-week washout phase, participants received the opposite treatment for a final 4 weeks. Anthropometrics and fasted blood samples were obtained before and after supplementation, with samples analysed for total 25(OH)D, creatinine, intact parathyroid hormone and adjusted Ca concentrations. At baseline, vitamin D sufficiency (total 25(OH)D>50 nmol/l), insufficiency (31–49 nmol/l) and clinical deficiency (<30 nmol/l) were evident in 59, 23 and 18 % of the participants, respectively. Overall, baseline total mean 25(OH)D concentration averaged 59·76 (sd29·88) nmol/l, representing clinical sufficiency. ANCOVA revealed no significant difference in the mean and standard deviation change from baseline in total 25(OH)D concentrations between oral spray and capsule supplementation methods (26·15 (sd17·85)v. 30·38 (sd17·91) nmol/l, respectively;F=1·044, adjustedr20·493,P=0·313). Oral spray vitamin D3is an equally effective alternative to capsule supplementation in healthy adults.</jats:p
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