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A survey of nearby galaxies for CO
We have made a survey of the nuclei of 81 galaxies for the 1-) line of CO. 38 of the galaxies are from a complete sample with recession velocity ≦400 km s-1 and 21-cm line strength ≧10-27 Wm-2, and the remainder represent nearby galaxies with weaker or no HI, early-type galaxies (E/SO/Sa) with detected HI and active/infrared galaxies.
Galaxies with strong CO lines like M82, NGC253 and IC342 are exceedingly rare: all the galaxies we observed are weaker than 0/2K except the irregular galaxy DDO133 with T*A=0.22K. We have new, confirmed detections of two other irregular galaxies, IC10 and Pegasus, at a weaker level, and unconfirmed detections of the irregular NGC3109 and the nearest Type I Seyfert galaxy NGC4051. We have confirmed the existence of CO in the nucleus of NGC6946 and obtained spectra of new positions in M82 and NGC253
Detection of coherent beam-beam modes with digitized beam position monitor signals
A system for bunch-by-bunch detection of transverse proton and antiproton
coherent oscillations in the Fermilab Tevatron collider is described. It is
based on the signal from a single beam-position monitor located in a region of
the ring with large amplitude functions. The signal is digitized over a large
number of turns and Fourier-analyzed offline with a dedicated algorithm. To
enhance the signal, band-limited noise is applied to the beam for about 1 s.
This excitation does not adversely affect the circulating beams even at high
luminosities. The device has a response time of a few seconds, a frequency
resolution of in fractional tune, and it is sensitive to
oscillation amplitudes of 60 nm. It complements Schottky detectors as a
diagnostic tool for tunes, tune spreads, and beam-beam effects. Measurements of
coherent mode spectra are presented and compared with models of beam-beam
oscillations.Comment: 7 pages, 4 figures. Submitted to the Proceedings of the ICFA
Mini-Workshop on Beam-beam Effects in Hadron Colliders (BB2013), Geneva,
Switzerland, 18-22 March 201
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High resolution CO observations of S88-B
CO J = 2-1 and 13CO J = 2-1 and 1-0 observations have been made of the H II region S88-B, using the 15-m James Clerk Maxwell telescope in Hawaii and the 20-m telescope at Onsala. The core of the cloud is resolved into a horseshoelike structure which surrounds a diffuse reflection nebula. The central core has a mass of ≥ 1000 M⊙, with 400 M⊙ in the horseshoe structure. The gas in the horse in the horseshoe appears highly fragmented, and has a kinetic temperature of ≈ 60 K, suggesting it is closely coupled to the dust temperature. A recently formed high mass star appears to be in the process of evacuating a cavity, possibly through a large molecular outflow that is found to show an accelerated component in its blue-shifted lobe. A velocity gradient across the horseshoe structure suggest ordered motion, and could represent rotation in the parental cloud
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High signal/noise <sup>13</sup>CO observations of the bipolar outflow in L1551
New high-signal/noise 13CO observations of the bipolar outflow in the molecular cloud L1551 are reported. Contrary to earlier observations of CO J = 1-0 and 2-1, no strong spatial dependence is found for the velocity profile of these spectra. The implications of these observations are such that the model of an empty shell for this source is less likely, and a model consisting of a shell which contains significant amounts of outflowing molecular gas inside the swept-up cavity walls is suggested
Comment on ``Density-matrix renormalization-group method for excited states''
In a Physical Review B paper Chandross and Hicks claim that an analysis of
the density-density correlation function in the dimerised Hubbard model of
polyacetylene indicates that the optical exciton is bound, and that a previous
study by Boman and Bursill that concluded otherwise was incorrect due to
numerical innacuracy. We show that the method used in our original paper was
numerically sound and well established in the literature. We also show that,
when the scaling with lattice size is analysed, the interpretation of the
density-density correlation function adopted by Chandross and Hicks in fact
implies that the optical exciton is unbound.Comment: RevTeX, 10 pages, 4 eps figures fixed and included now in tex
Developing a Conceptual Framework of Seroadaptive Behaviors in HIV-Diagnosed Men Who Have Sex With Men
Background. Seroadaptive behaviors are strategies employed by men who have sex with men (MSM) to reduce the transmission risk for human immunodeficiency virus (HIV). It has been suggested that they contribute to the increasing diagnoses of sexually transmitted infections in HIV-diagnosed MSM. To understand the context in which the reemerging sexually transmitted infections appear, we developed a social epidemiological model incorporating the multiple factors influencing seroadaptive behaviors. Methods. A literature review of seroadaptive behaviors in HIV-diagnosed MSM was conducted. The literature was synthesized using a social epidemiological perspective. Results. Seroadaptive behaviors are adopted by MSM in high-income countries and are a way for HIV-diagnosed men to manage and enjoy their sexual lives. Influences are apparent at structural, community, interpersonal, and intrapersonal levels. There is little evidence of whether and when the behavior forms part of a premeditated strategy; it seems dependent on the social context and on time since HIV diagnosis. Social rules of HIV disclosure and perception of risk depend on the setting where partners are encountered. Conclusions. Seroadaptive behaviors are strongly context dependent and can reduce or increase transmission risk for different infectious diseases. Further data collection and mathematical modeling can help us explore the specific conditions in more detail
Benchmarking the effectiveness of NDYP: a review of European and US literature on the microeconomic effects of labour market programmes for young people
Evaluation of lone parent adviser meetings: interim findings from administrative data analysis
Computation of Casimir Interactions between Arbitrary 3D Objects with Arbitrary Material Properties
We extend a recently introduced method for computing Casimir forces between
arbitrarily--shaped metallic objects [M. T. H. Reid et al., Phys. Rev.
Lett._103_ 040401 (2009)] to allow treatment of objects with arbitrary material
properties, including imperfect conductors, dielectrics, and magnetic
materials. Our original method considered electric currents on the surfaces of
the interacting objects; the extended method considers both electric and
magnetic surface current distributions, and obtains the Casimir energy of a
configuration of objects in terms of the interactions of these effective
surface currents. Using this new technique, we present the first predictions of
Casimir interactions in several experimentally relevant geometries that would
be difficult to treat with any existing method. In particular, we investigate
Casimir interactions between dielectric nanodisks embedded in a dielectric
fluid; we identify the threshold surface--surface separation at which
finite--size effects become relevant, and we map the rotational energy
landscape of bound nanoparticle diclusters
Hiding Ignorance Using High Dimensions
The absence of information -- entirely or partly -- is called ignorance.
Naturally, one might ask if some ignorance of a whole system will imply some
ignorance of its parts. Our classical intuition tells us yes, however quantum
theory tells us no: it is possible to encode information in a quantum system so
that despite some ignorance of the whole, it is impossible to identify the
unknown part arXiv:1011.6448. Experimentally verifying this counter-intuitive
fact requires controlling and measuring quantum systems of high dimension . We provide this experimental evidence using the transverse spatial
modes of light, a powerful resource for testing high dimensional quantum
phenomenon
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