9,262 research outputs found
The Automatic Real-Time GRB Pipeline of the 2-m Liverpool Telescope
The 2-m Liverpool Telescope (LT), owned by Liverpool John Moores University,
is located in La Palma (Canary Islands) and operates in fully robotic mode. In
2005, the LT began conducting an automatic GRB follow-up program. On receiving
an automatic GRB alert from a Gamma-Ray Observatory (Swift, INTEGRAL, HETE-II,
IPN) the LT initiates a special override mode that conducts follow-up
observations within 2-3 min of the GRB onset. This follow-up procedure begins
with an initial sequence of short (10-s) exposures acquired through an r' band
filter. These images are reduced, analyzed and interpreted automatically using
pipeline software developed by our team called "LT-TRAP" (Liverpool Telescope
Transient Rapid Analysis Pipeline); the automatic detection and successful
identification of an unknown and potentially fading optical transient triggers
a subsequent multi-color imaging sequence. In the case of a candidate brighter
than r'=15, either a polarimetric (from 2006) or a spectroscopic observation
(from 2007) will be triggered on the LT. If no candidate is identified, the
telescope continues to obtain z', r' and i' band imaging with increasingly
longer exposure times. Here we present a detailed description of the LT-TRAP
and briefly discuss the illustrative case of the afterglow of GRB 050502a,
whose automatic identification by the LT just 3 min after the GRB, led to the
acquisition of the first early-time (< 1 hr) multi-color light curve of a GRB
afterglow.Comment: PASP, accepted (8 pages, 3 figures
The analysis of the Saltzman Collection of Peruvian dyes by high performance liquid chromatography and ambient ionisation mass spectrometry
Yarn samples from the Saltzman Collection of Peruvian dyes were characterized by several different analytical techniques: high performance liquid chromatography with both diode array detection (HPLC-DAD) and electrospray ionisation with tandem mass spectrometry (HPLC-ESI-Q-ToF), direct analysis in real time (DART) mass spectrometry and paper spray mass spectrometry. This report serves primarily as a database of chemical information about the colorants in these dye materials for those studying ancient South American textiles and their colorants. We also provide a comparison of the results obtained by currently widespread HPLC techniques with those of two different ambient ionisation direct mass spectrometry methods to highlight the advantages and disadvantages of these approaches
Renormalization Group Flow Equations and the Phase Transition in O(N)-models
We derive and solve flow equations for a general O(N)-symmetric effective
potential including wavefunction renormalization corrections combined with a
heat-kernel regularization. We investigate the model at finite temperature and
study the nature of the phase transition in detail. Beta functions, fixed
points and critical exponents \beta, \nu, \delta and \eta for various N are
independently calculated which allow for a verification of universal scaling
relations.Comment: 34 pages, 3 tables, 11 postscript figures, LaTe
Inference for bounded parameters
The estimation of signal frequency count in the presence of background noise
has had much discussion in the recent physics literature, and Mandelkern [1]
brings the central issues to the statistical community, leading in turn to
extensive discussion by statisticians. The primary focus however in [1] and the
accompanying discussion is on the construction of a confidence interval. We
argue that the likelihood function and -value function provide a
comprehensive presentation of the information available from the model and the
data. This is illustrated for Gaussian and Poisson models with lower bounds for
the mean parameter
All change: job rotations as a workplace learning tool in the Flinders University Library Graduate Trainee Program
This paper examines the place of job rotations as a workplace learning tool in the Graduate
Trainee Librarian Program at Flinders University Library, Australia. Specifically, it asks two
questions: whether job rotation is an effective workplace learning tool for new librarians;
and, whether the trainee experience contributed to the retention in the Library and career
progression of those in the program. These questions are examined using Kirkpatrick's
Evaluation Framework. The findings indicate that while participants rate the trainee
program very positively overall, their satisfaction with workplace learning in their
placements was lower. The majority of former trainees have remained with the Library and
have progressed in their careers
Metabolite profiling characterises chemotypes of Musa diploids and triploids at juvenile and preflowering growth stages
Open Access Journal; Published online: 15 March 2019Bananas (Musa spp.) are consumed worldwide as dessert and cooking types. Edible banana varieties are for the most part seedless and sterile and therefore vegetatively propagated. This confers difficulties for breeding approaches against pressing biotic and abiotic threats and for the nutritional enhancement of banana pulp. A panel of banana accessions, representative of the diversity of wild and cultivated bananas, was analysed to assess the range of chemotypes available globally. The focus of this assessment was banana leaves at two growth stages (juvenile and pre-flowering), to see when during the plant growth metabolic differences can be established. The metabolic data corresponded to genomic trends reported in previous studies and demonstrated a link between metabolites/pathways and the genomes of M. acuminata and M. balbisiana. Furthermore, the vigour and resistance traits of M. balbisiana was connected to the phenolic composition and showed differences with the number of B genes in the hybrid accessions. Differences in the juvenile and pre-flowering data led to low correlation between the growth stages for prediction purposes
Early GRB Optical and Infrared Afterglow Observations with the 2-m Robotic Liverpool Telescope
We present the first optical observations of a Gamma Ray Burst (GRB)
afterglow using the 2-m robotic Liverpool Telescope (LT), which is owned and
operated by Liverpool John Moores University and situated on La Palma. We
briefly discuss the capabilities of LT and its suitability for rapid follow-up
observations of early optical and infrared GRB light curves. In particular, the
combination of aperture, site, instrumentation and rapid response (robotic
over-ride mode aided by telescope's rapid slew and fully-opening enclosure)
makes the LT ideal for investigating the nature of short bursts, optically-dark
bursts, and GRB blast-wave physics in general. We briefly describe the LT's key
position in the RoboNet-1.0 network of robotic telescopes. We present the LT
observations of GRB041006 and use its gamma-ray properties to predict the time
of the break in optical light curve, a prediction consistent with the
observations.Comment: 4 pages, 1 figure, accepted for publication in Il nuovo cimento (4th
Workshop Gamma-Ray Bursts in the Afterglow Era, Rome, 18-22 October 2004
Low-energy quenching of positronium by helium
Very low-energy scattering of orthopositronium by helium has been
investigated for simultaneous study of elastic cross section and pick-off
quenching rate using a model exchange potential. The present calculational
scheme, while agrees with the measured cross section of Skalsey et al,
reproduces successfully the parameter ^ 1Z_{\makebox{eff}}, the effective
number of electrons per atom in a singlet state relative to the positron.
Together with the fact that this model potential also leads to an agreement
with measured medium energy cross sections of this system, this study seems to
resolve the long-standing discrepancy at low energies among different
theoretical calculations and experimental measurements.Comment: 4 latex pages, 3 postscript figure
On the Derivative Expansion at Finite Temperature
In this short note, we indicate the origin of nonanalyticity in the method of
derivative expansion at finite temperature and discuss some of its
consequences.Comment: 7 pages, UR-1363, ER40685-81
The shape of equality: discourses around the Section 28 repeal in Scotland
This article focuses on conceptualizations of equality in the discourses deployed in the campaign to repeal Section 28 in Scotland. I use the parliamentary debates and two newspapers: the Daily Record, which supported the campaign to Keep the Clause, and The Guardian, which supported repeal, to exemplify the different discursive articulations around equality and citizenship. I suggest that the Scottish example provides further evidence of the ways in which liberalism naturalizes heterosexuality as the standard for citizenship and thus bequeaths a hierarchy of 'equality' and citizenship in the realm of sexuality, wherein lesbian and gay citizenship is either rendered invalid or characterized as 'special rights'. However, within the narrow confines of the parliamentary debates, more expansive and differentiated notions of citizenship and equality are evident. Whilst I conclude that the 'shape' of equality achieved through the repeal has been moulded to support institutionalized heterosexuality - with Section 28 replaced by statutory guidelines on sex education which advocate marriage - I also suggest equality is contested, both through the recognition of transformations in heterosexual family forms and the appeal to non-discrimination as a democratic principle. It is possible, therefore, that current destabilizations of the heterosexual social order simultaneously destabilize the precepts of liberal democracy
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