1,988 research outputs found
An integrated model of personal sector expenditure and portfolio decisions
In this study a quarterly model of UK Personal Sector portfolio and expenditure decisions over the period 1976 to 1967 is constructed and estimated. This model differs from most other empirical studies of Personal Sector portfolio behaviour in that separabililty of preferences is not assumed and so an integrated framework is adopted for estimation which allows for simultaneous interrelationships between the various decisions
The JCMT dense gas survey of the Perseus Molecular Cloud
We present the results of a large-scale survey of the very dense gas in the
Perseus molecular cloud using HCO+ and HCN (J = 4 - 3) transitions. We have
used this emission to trace the structure and kinematics of gas found in pre-
and protostellar cores, as well as in outflows. We compare the HCO+/HCN data,
highlighting regions where there is a marked discrepancy in the spectra of the
two emission lines. We use the HCO+ to identify positively protostellar
outflows and their driving sources, and present a statistical analysis of the
outflow properties that we derive from this tracer. We find that the relations
we calculate between the HCO+ outflow driving force and the Menv and Lbol of
the driving source are comparable to those obtained from similar outflow
analyses using 12CO, indicating that the two molecules give reliable estimates
of outflow properties. We also compare the HCO+ and the HCN in the outflows,
and find that the HCN traces only the most energetic outflows, the majority of
which are driven by young Class 0 sources. We analyse the abundances of HCN and
HCO+ in the particular case of the IRAS 2A outflows, and find that the HCN is
much more enhanced than the HCO+ in the outflow lobes. We suggest that this is
indicative of shock-enhancement of HCN along the length of the outflow; this
process is not so evident for HCO+, which is largely confined to the outflow
base.Comment: 25 pages, 14 figures, 9 table
Two new species of Sabacon harvestmen, with descriptions of the females of Sabacon astoriensis Shear and Sabacon sheari Cokendolpher, from Western North America. (Arachnida, Opiliones, Sabaconidae)
Two new species of Sabaconidae (Ischyropsalidoidea) are described: Sabacon # 1
from central Alberta and British Columbia and Sabacon # 2 from Oregon. Descriptions of the
females of Sabacon astoriensis Shear 1975, from Oregon, and Sabacon sheari Cokendolpher
1984, from Oregon and Idaho, are also given
Versatile liquid helium scintillation counter of large volume design
Design and performance of large liquid helium scintillation counter for meson experiment
Prairie spiders of Alberta and Saskatchewan
In the prairie ecozone of Alberta and Saskatchewan,
356 species of spiders in 2 I families have been
collected. The 10 families with the most species were
Linyphiidae (30%), Gnaphosidae (13%), Salticidae
(8%), Theridiidae (8%), Lycosidae (8%), Dictynidae
(6%), Thomisidae (6%), Araneidae (5%),
Philodromidae (5%) and Clubionidae (3%). These 10
families constituted 91% of the spider biodiversity. In
the grassland region ofthe prairie ecozone, there were
relatively more species of Gnaphosidae, Lycosidae,
Theridiidae, Thomisidae, Dictynidae and
Philodomidae and fewer Linyphiidae and Clubionidae
than for all provincial ecozones combined. The percentages
in the parkland region of the prairie ecozone
tended to be intermediate
On the ubiquity of molecular anions in the dense interstellar medium
Results are presented from a survey for molecular anions in seven nearby
Galactic star-forming cores and molecular clouds. The hydrocarbon anion C6H- is
detected in all seven target sources, including four sources where no anions
have been previously detected: L1172, L1389, L1495B and TMC-1C. The C6H-/C6H
column density ratio is greater than about 1.0% in every source, with a mean
value of 3.0% (and standard deviation 0.92%). Combined with previous
detections, our results show that anions are ubiquitous in dense clouds
wherever C6H is present. The C6H-/C6H ratio is found to show a positive
correlation with molecular hydrogen number density, and with the apparent age
of the cloud. We also report the first detection of C4H- in TMC-1 (at 4.8-sigma
confidence), and derive an anion-to-neutral ratio C4H-/C4H = (1.2 +- 0.4) x
10^-5 (= 0.0012 +- 0.0004%). Such a low value compared with C6H- highlights the
need for a revised radiative electron attachment rate for C4H. Chemical model
calculations show that the observed C4H- could be produced as a result of
reactions of oxygen atoms with C5H- and C6H-
Molecular line contamination in the SCUBA-2 450 {\mu}m and 850 {\mu}m continuum data
Observations of the dust emission using millimetre/submillimetre bolometer
arrays can be contaminated by molecular line flux, such as flux from 12CO. As
the brightest molecular line in the submillimetre, it is important to quantify
the contribution of CO flux to the dust continuum bands. Conversion factors
were used to convert molecular line integrated intensities to flux detected by
bolometer arrays in mJy per beam. These factors were calculated for 12CO line
integrated intensities to the SCUBA-2 850 {\mu}m and 450 {\mu}m bands. The
conversion factors were then applied to HARP 12CO 3-2 maps of NGC 1333 in the
Perseus complex and NGC 2071 and NGC 2024 in the Orion B molecular cloud
complex to quantify the respective 12CO flux contribution to the 850 {\mu}m
dust continuum emission. Sources with high molecular line contamination were
analysed in further detail for molecular outflows and heating by nearby stars
to determine the cause of the 12CO contribution. The majority of sources had a
12CO 3-2 flux contribution under 20 per cent. However, in regions of molecular
outflows, the 12CO can dominate the source dust continuum (up to 79 per cent
contamination) with 12CO fluxes reaching \sim 68 mJy per beam.Comment: Accepted 2012 April 19 for publication in MNRAS. 21 pages, 13
figures, 3 table
Molecular Tracers of Embedded Star Formation in Ophiuchus
In this paper we analyze nine SCUBA cores in Ophiuchus using the
second-lowest rotational transitions of four molecular species (12CO, 13CO,
C18O, and C17O) to search for clues to the evolutionary state and
star-formation activity within each core. Specifically, we look for evidence of
outflows, infall, and CO depletion. The line wings in the CO spectra are used
to detect outflows, spectral asymmetries in 13CO are used to determine infall
characteristics, and a comparison of the dust emission (from SCUBA
observations) and gas emission (from C18O) is used to determine the fractional
CO freeze-out.
Through comparison with Spitzer observations of protostellar sources in
Ophiuchus, we discuss the usefulness of CO and its isotopologues as the sole
indicators of the evolutionary state of each core. This study is an important
pilot project for the JCMT Legacy Survey of the Gould Belt (GBS) and the
Galactic Plane (JPS), which intend to complement the SCUBA-2 dust continuum
observations with HARP observations of 12CO, 13CO, C18O, and C17O J = 3 - 2 in
order to determine whether or not the cold dust clumps detected by SCUBA-2 are
protostellar or starless objects.
Our classification of the evolutionary state of the cores (based on molecular
line maps and SCUBA observations) is in agreement with the Spitzer designation
for six or seven of the nine SCUBA cores. However, several important caveats
exist in the interpretation of these results, many of which large mapping
surveys like the GBS may be able to overcome to provide a clearer picture of
activity in crowded fields.Comment: 43 pages including 19 postscript figures. Accepted for publication in
the PAS
Systems mapping workshops and their role in understanding medication errors in healthcare
In this paper for Applied Ergonomics, one of the two leading journals for ergonomics/human factors, Buckle et al. discuss the role of mapping workshops in understanding medication errors in healthcare. They draw upon research that used mapping workshops as a method that systems designers, including human factors/ergonomics specialists, can use to help generate a knowledge base for better design requirements.
Buckle et al. applied systems mapping workshops for the first time to the problem of medication errors in healthcare. The workshops were designed using experiential group work principles. They involved a range of stakeholders from within the health service as well as those who supply the health sector, including designers who may be able to enhance the safety of products and systems used in healthcare.
The opportunity for using these methods to study patient safety issues arose as a result of a scoping study undertaken on behalf of the UK Department of Health and The Design Council. As the scope of patient safety issues within the healthcare system and the range of stakeholder groups is large (National Patient Safety Agency 2005), it was believed that mapping workshops might enhance system design in health. The results were rich from a design perspective, giving specific details of actual incidences, contexts and practices, with further depth of information emerging in the group working sessions. A wealth of detail on aspects of medication error, especially in the community, emerged from creative, primary, secondary and patient-support group sessions. As a process, similar stakeholder workshops could help designers understand better the complexity and range of factors to be taken into account.
The methods are now being used in many areas of healthcare and social care design, for example by the Technology Strategy Board funded research into Telecare (see http://www.aktive.org.uk/)
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