1,916 research outputs found
Young GI angle: Choosing a mentor/mentee
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/166219/1/ueg2bf01002.pd
Concert recording 2015-04-05
[Track 01]. Corcovado / Antonio Carlos Jobim -- [Track 02]. One note samba / Antonio Carlos Jobim -- [Track 03]. Nuages / Django Reinhardt -- [Track 04]. Bok choy / Felipe Antonio & Baron Lyle -- [Track 05]. Limehouse blues / Philip Braham & Douglas Furber
Helium Emission in the Type Ic SN 1999cq
We present the first unambiguous detection of helium emission lines in
spectra of Type Ic supernovae (SNe Ic). The presence of He I lines, with full
width at half maximum ~ 2000 km/s, and the distinct absence of any other
intermediate-width emission (e.g., Halpha), implies that the ejecta of SN Ic
1999cq are interacting with dense circumstellar material composed of almost
pure helium. This strengthens the argument that the progenitors of SNe Ic are
core-collapse events in stars that have lost both their hydrogen and helium
envelopes, either through a dense wind or mass-transfer to a companion. In this
way, SN 1999cq is similar to supernovae such as SN 1987K and SN 1993J that
helped firmly establish a physical connection between Type Ib and Type II
supernovae. The light curve of SN 1999cq is very fast, with an extremely rapid
rise followed by a quick decline. SN 1999cq is also found to exhibit a high
level of emission at blue wavelengths (< 5500 A), likely resulting from either
an unusually large amount of iron and iron-group element emission or
uncharacteristically low reddening compared with other SNe Ic.Comment: 17 pages (AASTeX V5.0), 4 figures, accepted for publication in the
Astronomical Journa
Autonomy support, basic need satisfaction and the optimal functioning of adult male and female sport participants: A test of basic needs theory
Grounded in Basic Needs Theory (BNT; Ryan and Deci, American Psychologist, 55, 68–78, 2000a), the present study aimed to: (a) test a theoretically-based model of coach autonomy support, motivational processes and well-/ill being among a sample of adult sport participants, (b) discern which basic psychological need(s) mediate the link between autonomy support and well-/ill-being, and (c) explore gender invariance in the hypothesized model. Five hundred and thirty nine participants (Male = 271;Female = 268; Mage = 22.75) completed a multi-section questionnaire tapping the targeted variables. Structural Equation Modeling (SEM) analysis revealed that coach autonomy support predicted participants’ basic need satisfaction for autonomy, competence and relatedness. In turn, basic need satisfaction predicted greater subjective vitality when engaged in sport. Participants with low levels of autonomy were more susceptible to feeling emotionally and physically exhausted from their sport investment. Autonomy and competence partially mediated the path from autonomy support to subjective vitality. Lastly, the results supported partial invariance of the model with respect to gender
Improved Standardization of Type II-P Supernovae: Application to an Expanded Sample
In the epoch of precise and accurate cosmology, cross-confirmation using a
variety of cosmographic methods is paramount to circumvent systematic
uncertainties. Owing to progenitor histories and explosion physics differing
from those of Type Ia SNe (SNe Ia), Type II-plateau supernovae (SNe II-P) are
unlikely to be affected by evolution in the same way. Based on a new analysis
of 17 SNe II-P, and on an improved methodology, we find that SNe II-P are good
standardizable candles, almost comparable to SNe Ia. We derive a tight Hubble
diagram with a dispersion of 10% in distance, using the simple correlation
between luminosity and photospheric velocity introduced by Hamuy & Pinto 2002.
We show that the descendent method of Nugent et al. 2006 can be further
simplified and that the correction for dust extinction has low statistical
impact. We find that our SN sample favors, on average, a very steep dust law
with total to selective extinction R_V<2. Such an extinction law has been
recently inferred for many SNe Ia. Our results indicate that a distance
measurement can be obtained with a single spectrum of a SN II-P during the
plateau phase combined with sparse photometric measurements.Comment: ApJ accepted version. Minor change
The in situ near-total pancreatectomy (LIVOCADO procedure) for end-staged chronic pancreatitis
PURPOSE: Total pancreatectomy for severe pain in end-stage chronic pancreatitis may be the only option, but with vascular involvement, this is usually too high risk and/or technically not feasible. The purpose of the study was to present the clinical outcomes of a novel procedure in severe chronic pancreatitis complicated by uncontrollable pain and vascular involvement. METHODS: We describe an in situ near-total pancreatectomy that avoids peripancreatic vascular dissection (Livocado procedure) and report on surgical and clinical outcomes. RESULTS: The Livocado procedure was carried out on 18 (3.9%) of 465 patients undergoing surgery for chronic pancreatitis. There were 13 men and 5 women with a median (IQR) age of 48.5 (42.4–57) years and weight of 60.7 (58.0–75.0) kg. All had severe pain and vascular involvement; 17 had pancreatic parenchymal calcification; the median (IQR) oral morphine equivalent dose requirement was 86 (33–195) mg/day. The median (IQR) maximal pain scores were 9 (9–10); the average pain score was 6 (IQR 4–7). There was no peri-operative or 90-day mortality. At a median (IQR) follow-up of 32.5 (21–45.75) months, both maximal and average pain scores were significantly improved post-operatively, and at 12 months, two-thirds of patients were completely pain free. Six (33%) patients had employment pre-operatively versus 13 (72%) post-operatively (p = 0.01). CONCLUSIONS: The Livocado procedure was safe and carried out successfully in patients with chronic pancreatitis with vascular involvement where other procedures would be contraindicated. Perioperative outcomes, post-operative pain scores, and employment rehabilitation were comparable with other procedures carried out in patients without vascular involvement
The Massive Progenitor of the Possible Type II-Linear Supernova 2009hd in Messier 66
We present observations of SN2009hd in the nearby galaxy M66. This SN is one
of the closest to us in recent years but heavily obscured by dust, rendering it
unusually faint in the optical, given its proximity. We find that the observed
properties of SN2009hd support its classification as a possible Type II-L SN, a
relatively rare subclass of CC-SNe. High-precision relative astrometry has been
employed to attempt to identify a SN progenitor candidate, based on a
pixel-by-pixel comparison between HST F555W and F814W images of the SN site
prior to explosion and at late times. A progenitor candidate is identified in
the F814W images only; this object is undetected in F555W. Significant
uncertainty exists in the astrometry, such that we cannot definitively identify
this object as the SN progenitor. Via insertion of artificial stars into the
pre-SN HST images, we are able to constrain the progenitor's properties to
those of a possible supergiant, with M(F555W)0>-7.6 mag and (V-I) 0>0.99 mag.
The magnitude and color limits are consistent with a luminous RSG; however,
they also allow for the possibility that the star could have been more yellow
than red. From a comparison with theoretical massive-star evolutionary tracks,
which include rotation and pulsationally enhanced mass loss, we can place a
conservative upper limit on the initial mass for the progenitor of <20 M_sun.
If the actual mass of the progenitor is near the upper range allowed by our
derived mass limit, then it would be consistent with that for the identified
progenitors of the SNII-L 2009kr and the high-luminosity SNII-P 2008cn. The
progenitors of these three SNe may possibly bridge the gap between lower-mass
RSG that explode as SNeII-P and LBV, or more extreme RSG, from which the more
exotic SNeII-n may arise. Very late-time imaging of the SN2009hd site may
provide us with more clues regarding the true nature of its progenitor.Comment: 19 pages, 9 figures, 3 tables, accepted for publication in Ap
School Violence and the Culture of Honor
We investigated the hypothesis that a sociocultural variable known as the culture of honor would be uniquely predictive of school-violence indicators. Controlling for demographic characteristics associated in previous studies with violent crime among adults, we found that high-school students in culture-of-honor states were significantly more likely than high-school students in non-culture-of honor states to report having brought a weapon to school in the past month. Using data aggregated over a 20-year period, we also found that culture-of honor states had more than twice as many school shootings per capita as non-culture-of-honor states. The data revealed important differences between school violence and general patterns of homicide and are consistent with the view that many acts of school violence reflect retaliatory aggression springing from intensely experienced social-identity threats.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
Geographically touring the eastern bloc: British geography, travel cultures and the Cold War
This paper considers the role of travel in the generation of geographical knowledge of the eastern bloc by British geographers. Based on oral history and surveys of published work, the paper examines the roles of three kinds of travel experience: individual private travels, tours via state tourist agencies, and tours by academic delegations. Examples are drawn from across the eastern bloc, including the USSR, Poland, Romania, East Germany and Albania. The relationship between travel and publication is addressed, notably within textbooks, and in the Geographical Magazine. The study argues for the extension of accounts of cultures of geographical travel, and seeks to supplement the existing historiography of Cold War geography
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