8,799 research outputs found
12.2-GHz methanol maser MMB follow-up catalogue - II. Longitude range 186 to 330 degrees
We present the second portion of a catalogue of 12.2-GHz methanol masers
detected towards 6.7-GHz methanol masers observed in the unbiased Methanol
Multibeam (MMB) Survey. Using the Parkes radio telescope we have targeted all
207 6.7-GHz methanol masers in the longitude range 186 to 330 degrees for
12.2-GHz counterparts. We report the detection of 83 12.2-GHz methanol masers,
and one additional source which we suspect is thermal emission, equating to a
detection rate of 40 per cent. Of the 83 maser detections, 39 are reported here
for the first time. We discuss source properties, including variability and
highlight a number of unusual sources. We present a list of 45 candidates that
are likely to harbor methanol masers in the 107.0-GHz transition.Comment: Accepted MNRAS 19 July 201
Molecular modelling of dendrimers for nanoscale applications
Dendrimers are well defined, highly branched macromolecules that radiate from a central core and are synthesized through a stepwise, repetitive reaction sequence that guarantees complete shells for each generation, leading to polymers that are monodisperse. The synthetic procedures developed for dendrimer preparation permit nearly complete control over the critical molecular design parameters, such as size, shape, surface/interior chemistry, flexibility, and topology. Recent results suggest that dendritic polymers may provide the key to developing a reliable and economical fabrication and manufacturing route to functional nanoscale materials that would have unique properties (electronic, optical, opto-electronic, magnetic, chemical, or biological). In turn, these could be used in designing new nanoscale devices. In this paper, we determine the 3D molecular structure of various dendrimers with continuous configurational Boltzmann biased direct Monte Carlo method and study their energetic and structural properties using molecular dynamics after annealing these molecular representations
Non-Abelian Wilson Surfaces
A definition of non-abelian genus zero open Wilson surfaces is proposed. The
ambiguity in surface-ordering is compensated by the gauge transformations.Comment: JHEP Latex, 10 pages, 6 figures; v2, refs and comments added in sec.
What's the Risk? Older Women Report Fewer Symptoms for Suspected Acute Coronary Syndrome than Younger Women.
The purpose of the study was to determine whether older (≥65 years) and younger (<65 years) women presenting to the emergency department (ED) with symptoms suggestive of acute coronary syndrome (ACS) varied on risk factors, comorbid conditions, functional status, and symptoms that have implications for emergent cardiac care. Women admitted to five EDs were enrolled. The ACS Symptom Checklist was used to measure symptoms. Comorbid conditions and functional status were measured with the Charlson Comorbidity Index and Duke Activity Status Index. Logistic regression models were used to evaluate symptom differences in older and younger women adjusting for ACS diagnosis, functional status, body mass index (BMI), and comorbid conditions. Analyses were stratified by age, and interaction of symptom by age was tested. Four hundred women were enrolled. Mean age was 61.3 years (range 21-98). Older women (n = 163) were more likely to have hypertension, hypercholesterolemia, never smoked, lower BMI, more comorbid conditions, and lower functional status. Younger women (n = 237) were more likely to be members of minority groups, be college-educated, and have a non-ACS discharge diagnosis. Younger women had higher odds of experiencing chest discomfort, chest pain, chest pressure, shortness of breath, nausea, sweating, and palpitations. Lack of chest symptoms and shortness of breath (key symptoms triggering a decision to seek emergency care) may cause older women to delay seeking treatment, placing them at risk for poorer outcomes. Younger African American women may require more comprehensive risk reduction strategies and symptom management
12.2-GHz methanol maser MMB follow-up catalogue - I. Longitude range 330 to 10 degrees
We present a catalogue of 12.2-GHz methanol masers detected towards 6.7-GHz
methanol masers observed in the unbiased Methanol Multibeam (MMB) survey in the
longitude range 330\circ (through 360\circ) to 10\circ. This is the first
portion of the catalogue which, when complete, will encompass all of the MMB
detections. We report the detection of 184 12.2-GHz sources towards 400 6.7-GHz
methanol maser targets, equating to a detection rate of 46 per cent. Of the 184
12.2-GHz detections, 117 are reported here for the first time. We draw
attention to a number of 'special' sources, particularly those with emission at
12.2-GHz stronger than their 6.7-GHz counterpart and conclude that these
unusual sources are not associated with a specific evolutionary stage.Comment: accepted to MNRAS 21 Dec 201
Repetition enhances the musicality of speech and tone stimuli to similar degrees
Certain spoken phrases, when removed from context and repeated, begin to sound as if they
were sung. Prior work has uncover
ed
several
acoustic factors which
determine wh
ether a phrase
sounds sung after repetition
. However, the reason why repetition is necessary for
song to be
perceived in speech is unclear
. One possibility is that
by default
pitch is not a salient attribute of
speech in non
-
tonal languages, as spectral information is more vital for determining meaning.
However, repetition may satiate lexical
processing
, increas
ing
pitch salience. A second possibility is
that it takes time to e
stablish the precise
pitch perception
necessary for as
signing
each syllable a
musical scale degree
. Here we tested these hypotheses by asking participants to rate the musicality
of spoken phrases
and complex tones
with matching pitch contours
after each of
eight repetitions.
Although musicality ratings were overall higher for the tone stimuli, both the speech and complex
tone stimuli increased in musicality
to a similar degree
with repetition. Thus, although
the rapid
spectral
variation
of speech
may
inhibi
t
pitch salience
, this inhibition does not decrease with
repetition. Instead, repetition may be necessary for the perception of song in speech because the perception of exact pitch intervals takes time
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