16,515 research outputs found
Evolution of magnetic fields in stars across the upper main sequence
To properly understand the physics of upper main sequence stars it is
particularly important to identify the origin of their magnetic fields.
Recently, we confirmed that magnetic fields appear in Ap stars of mass below 3
M_sun only if they have already completed at least approximately 30% of their
main-sequence lifetime. The absence of stars with strong magnetic fields close
to the ZAMS might be seen as an argument against the fossil field theories.
Here we present the results of our recent magnetic survey with FORS1 at the VLT
in polarimetric mode of a sample of A, B and Herbig Ae stars with previously
undetected magnetic fields and briefly discuss their significance for our
understanding of the origin of the magnetic fields in intermediate mass stars.Comment: 6 pages, 3 figures, to appear in "Magnetic Fields in the Universe:
From Laboratory and Stars to Primordial Structures", AIP Conference
Proceedings 78
Performance, physiological, and oculometer evaluation of VTOL landing displays
A methodological approach to measuring workload was investigated for evaluation of new concepts in VTOL aircraft displays. Physiological, visual response, and conventional flight performance measures were recorded for landing approaches performed in the NASA Visual Motion Simulator (VMS). Three displays (two computer graphic and a conventional flight director), three crosswind amplitudes, and two motion base conditions (fixed vs. moving base) were tested in a factorial design. Multivariate discriminant functions were formed from flight performance and/or visual response variables. The flight performance variable discriminant showed maximum differentation between crosswind conditions. The visual response measure discriminant maximized differences between fixed vs. motion base conditions and experimental displays. Physiological variables were used to attempt to predict the discriminant function values for each subject/condition trial. The weights of the physiological variables in these equations showed agreement with previous studies. High muscle tension, light but irregular breathing patterns, and higher heart rate with low amplitude all produced higher scores on this scale and thus represent higher workload levels
Between economic competitiveness and social inclusion: New Labour and the economic revival of deprived neighbourhoods.
Following the election of the first New Labour government in 1997 the revitalisation of deprived neighbourhoods quickly became a central feature of the policy landscape. Motivated by the desire to tackle processes of social exclusion and find a new economic basis for these areas, an array of policy experiments and interventions emerged. An increasing focus of these was to improve the economic conditions of deprived neighbourhoods with a particular emphasis upon tackling worklessness and promoting entrepreneurial activity. Yet despite this sustained activity, 13 years later the gap between the poorest neighbourhoods and the rest persisted. This paper reflects critically upon the development of this policy agenda, its aims, outcomes and effectiveness, and identifies the factors that constrained its ability to transform the economic fortunes of England’s most deprived neighbourhoods
Spatially-concentrated worklessness and neighbourhood policies: experiences from New Labour in England
The persistence and entrenchment of spatial concentrations of worklessness is a key characteristic of labour markets in advanced industrial economies. Understanding the causes of worklessness concentrated within particular neighbourhoods requires linking together an understanding of wider processes of labour market restructuring with the operation of various negative cycles that reinforce patterns of persistent worklessness. Such cycles are particularly rooted within person and household factors and the overall population mix, and are compounded by the operation of housing markets and neighbourhood effects. This chapter considers the precise role of neighbourhood effects in relation to the wider causes of concentrated worklessness and then considers the development and effectiveness of work-related neighbourhood policies. Through an examination of the extensive set of employment related initiatives developed under successive New Labour governments in relation to deprived neighbourhoods, this chapter considers the aims, outcomes and effectiveness of these initiatives and identifies the factors that constrained the ability of this policy agenda to transform the employment fortunes of England‟s most deprived neighbourhoods
“Hey, where’s my hay?” design fictions in horse-computer interaction
This is the author accepted manuscript. The final version is available from ACM via the DOI in this record.Horses (and other nonhuman animals) are increasingly encountering systems designed by human animals. Some of these systems are conceived with altruistic motives to enrich horses’ lives. Other systems are designed to facilitate human interaction, with little consideration for the animals forced to share the human environment. As with cognitively challenged humans, horses are ‘unaware’ and often ‘implicit’ interactors. This category of user is uniquely vulnerable to the projected requirements and needs of designers. To think like a horse (or any user without a voice) a designer must be able to embrace ‘the otherness’ of an unfamiliar perspective. This paper uses four examples of ‘design fiction’ to speculate about systems that might actually be meaningful to a horse. The intention is not to seriously propose these as prototypes. Rather, they are thought experiments, illustrating the inherent danger in trying to co-design with the voiceless
Imaginary studies: a science fiction autoethnography concerning the design, implementation and evaluation of a fictional quantitative study to evaluate the Umamimi robotic horse ears
This is the author accepted manuscript. The final version is available from the Association for Computing Machinery via the DOI in this record.In this paper, I use 'science fiction autoethnography’ to reflect on conducting an imaginary, quantitative study. My fictional study is intended to evaluate a real-life artefact: the ’umamimi’ robotic horse ears. This physical device provides a backdrop, against which my experiences and self-reflections are used to critique quantitative ’hard science’. My own cognitive bias, rigid attachment to a viewpoint and presumptions (concerning anticipated results) all provide the real story. When I conduct an imaginary study, what does the process and its speculative results say about my autobiographical story and both the object and subject’s broader societal and cultural meanings
The Potential Impact of a Proposed Ban on the Sale of U.S. Horses for Slaughter and Human Consumption
Both federal and state governments in the United States are being asked to enact laws that would make slaughtering of horses for human consumption illegal. In the past, the United States was one of the principal exporters of horsemeat to Europe. This paper examines the impacts of a proposed ban on the U.S. horse industry and the U.S. export market for horsemeat. Findings indicate a loss of approximately $300 per horse in the United States as a result of such a ban. The supply of U.S. exported horsemeat has declined during the past decade. The results suggest that the most significant factors influencing this decline are lower real prices and competing imports.horse slaughter, horsemeat, meat exports, Agricultural and Food Policy, Livestock Production/Industries,
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