42,259 research outputs found
High Spatial Resolution KAO Far-Infrared Observations of the Central Regions of Infrared-Bright Galaxies
We present new high spatial resolution Kuiper Airborne Observatory 50 micron
and/or 100 micron data for 11 infrared-bright galaxies. We also tabulate
previously published KAO data for 11 other galaxies, along with the IRAS data
for the bulges of M 31 and M 81. We find that L(FIR)/L(B) and L(FIR)/L(H)
correlate with CO (1 - 0) intensity and tau(100). Galaxies with optical or
near-infrared signatures of OB stars in their central regions have higher
values of I(CO) and tau(100), as well as higher far-infrared surface
brightnesses and L(FIR)/L(B) and L(FIR)/L(H) ratios. L(FIR)/L(H(alpha)) does
not correlate strongly with CO and tau(100). These results support a scenario
in which OB stars dominate dust heating in the more active galaxies and older
stars are important in quiescent bulges.Comment: 45 pages, to appear in Ap.J. vol. 468 (Sept. 1996). 17 postscript
figures and 10 postscript tables available at
ftp://ipac.caltech.edu/science/bsmith/ka
A Q-methodology study of parental understandings of infant immunisation : implications for health-care advice.
This study used Q-methodology to explore systematically parental judgements about infant immunisation. A total of 45 parents completed a 31-statement Q-sort. Data were collected after vaccination in general practitioner practices or a private day nursery. Q factor analysis revealed four distinct viewpoints: a duty to immunise based on medical benefits, child-orientated protection based on parental belief, concern and distress and surprise at non-compliance. Additionally, there was a common view among parents that they did not regret immunising their children. Implications of these results are discussed in terms of health-care policy and future research
Some Implications of the \u27Better Schools\u27 Report for School Management in Western Australia
The mid eighties has seen remarkable change to the policies of the State education system in Western Australia. The election of the State Labor government in early 1983 saw to the build up of a political agenda for system level change in education. The expectation of the Government was that public schools would raise their standards of achievement, be more responsive and be more accountable. Following a comprehensive review of educational policy and practice (Beazley 1984) it was announced that a Functional Review Committee would investigate the structure and operation of the educational bureaucracy. In January 1987 the newly established Ministry of Education (Western Australia) released \u27Better Schools in Western Australia: A Programme for Improvement.\u27 The document is a blue print for a new style of school operations. The determination of the Ministry of Education to commence implementation of the proposals according to a timeline brought criticism from the teachers\u27 union and the principals\u27 associations. The main contentious issue was the speed at which the proposals would be implemented. In the period of political brinkmanship which followed side issues emerged concerning the rights of groups to be consulted as well as concerns about staffing, workloads and career structures. Clearly there was a need to scrutinize the document. A period of review was agreed to between the Mil1istry of Education and the State School Teachers\u27 Union of Western Australia. This paper attempts to assess the implications of Better Schools for school management practices during the period of review
High spatial resolution 100 micron observations of the M83 bar
A program of high spatial resolution far-infrared observations of galaxies using the Kuiper Airborne Observatory (KAO), was conducted to better understand the role of star formation, the general interstellar radiation field, and non-thermal activity in powering the prodigious far-infrared luminosities seen in spiral and interacting galaxies. Here, researchers present observations of the central region of the well-known barred spiral M83 (NGC 5236). The resultant channel 3 scans for M83 and IRC + 10216, after co-addition and smoothing, are shown. These data show that M83 is extended at 100 microns compared to a point source. A simple Gaussian deconvolution of the M83 data with the point source profile from IRC+10216 gives a full width half maximum (FWHM) of about 19 seconds for M83. By comparison with IRC+10216, researchers obtain a flux for the unresolved component in M83 of about 110 Jy. This is about 1/6 the total flux for M83 (Rice et al. 1988) and about 1/2 the PSC flux. The M83 and IRC+10216 profiles in the cross-scan direction (SE-NW) were also compared, and show that M83 is extended in this direction as well, with a width of about 18 seconds. A comparison of the different channel profiles for M83 and IRC+10216 shows that there is an asymmetry in the M83 data, in that the maximum in the profiles shifts from southeast to northwest as channel number increases. This corresponds to the extension in the bar seen in the CO data. Thus the far-infrared emission in the central region of M83 tends to trace the CO bar. The new 100 micron data is also compared with previous H alpha observations from the literature, to determine how well the far-infrared traces the stellar structure, the star formation as measured by H alpha, and the optical colors
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Hand pollination to increase seed-set of red helleborine Cephalanthera rubra in the Chiltern Hills, Buckinghamshire, England
In 2007 and in previous years, as part of ongoing attempts to improve red helleborine Cephalanthera rubra seed-set, hand pollination of florets has been undertaken at a small colony of this species in Buckinghamshire, southern England. Natural pollination rarely occurs (one mature pod recorded in 10 years) at this site. In 2007, hand pollination resulted in the production of four seed pods, of which one withered and died. Upon ripening, the three remaining pods were removed for attempted micropropagation of the seeds. Ongoing conservation management has probably benefited the solitary bee Chelostoma campanularum which now appears fairly plentiful at the site, but despite the presence of this red helleborine flower visitor, natural pollination remains virtually unrecorded at this locality; field observations suggest that C.campanularum is in fact probably not large enough to act as an effective red helleborine pollinator as it can slip in and out of the flowers without removing the pollinia, unlike it larger relative C.fuliginosum, absent from the UK but which is a known pollinator of red helleborine in continental Europe
Trade studies for nuclear space power systems
As human visions of space applications expand and as we probe further out into the universe, our needs for power will also expand, and missions will evolve which are enabled by nuclear power. A broad spectrum of missions which are enhanced or enabled by nuclear power sources have been defined. These include Earth orbital platforms, deep space platforms, planetary exploration, and terrestrial resource exploration. The recently proposed Space Exploration Initiative (SEI) to the Moon and Mars has more clearly defined these missions and their power requirements. Presented here are results of recent studies of radioisotope and nuclear reactor energy sources, combined with various energy conversion devices for Earth orbital applications, SEI lunar/Mars rovers, surface power, and planetary exploration
The Influence of Bureau Scores, Customized Scores and Judgmental Review on the Bank Underwriting Decision-Making Process
In recent years commercial banks have moved toward automated forms of underwriting. This study employs unique bank loan-level data from a scoring lender to determine whether automated underwriting exhibits a potential ‘‘disparate impact’’ across income strata. The findings indicate that strict application of this custom scoring model leads to higher denial rates for low- to moderate-income borrowers when compared with both a naý¨ve judgmental system and a bureau scoring approach. These results suggest that financial regulators should focus more resources on the evaluation and study of customized scoring models.
Robust methods for detecting multiple level breaks in autocorrelated time series
In this paper we propose tests for the null hypothesis that a time series process displays a constant level against the alternative that it displays (possibly) multiple changes in level. Our proposed tests are based on functions of appropriately standardized sequences of the differences between sub-sample mean estimates from the series under investigation. The tests we propose differ notably from extant tests for level breaks in the literature in that they are designed to be robust as to whether the process admits an autoregressive unit root (the data are I(1)) or stable autoregressive roots (the data are I(0)). We derive the asymptotic null distributions of our proposed tests, along with representations for their asymptotic local power functions against Pitman drift alternatives under both I(0) and I(1) environments. Associated estimators of the level break fractions are also discussed. We initially outline our procedure through the case of non-trending series, but our analysis is subsequently extended to allow for series which display an underlying linear trend, in addition to possible level breaks. Monte Carlo simulation results are presented which suggest that the proposed tests perform well in small samples, showing good size control under the null, regardless of the order of integration of the data, and displaying very decent power when level breaks occur.Level breaks; unit root; moving means; long run variance estimation; robust tests; breakpoint estimation
The impact of the initial condition on robust tests for a linear trend
This paper examines the behaviour of some recently proposed robust (to the order of integration of the data) tests for the presence of a deterministic linear trend in a univariate times series in situations where the magnitude of the initial condition of the series is non-negligible. We demonstrate that the asymptotic size and/or local power properties of these tests are extremely sensitive to the initial condition. Straightforward modifications to the trend tests are suggested, based around the use of trimmed data, which are demonstrated to greatly reduce this sensitivity.Trend tests; initial condition; asymptotic local power
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