159,907 research outputs found
What is behavioural medicine? Commentary on definition proposed by Dekker, Stauder & Penedo
Peer reviewedPublisher PD
13 Years of Timing of PSR B1259-63
This paper summarizes the results of 13 years of timing observations of a
unique binary pulsar, PSR B125963, which has a massive B2e star companion.
The data span encompasses four complete orbits and includes the periastron
passages in 1990, 1994, 1997 and 2000. Changes in dispersion measure occurring
around the 1994, 1997 and 2000 periastrons are measured and accounted for in
the timing analysis. There is good evidence for a small glitch in the pulsar
period in 1997 August, not long after the 1997 periastron, and a significant
frequency second derivative indicating timing noise. We find that spin-orbit
coupling with secular changes in periastron longitude and projected semi-major
axis () cannot account for the observed period variations over the whole
data set. While fitting the data fairly well, changes in pulsar period
parameters at each periastron seem ruled out both by X-ray observations and by
the large apparent changes in pulsar frequency derivative. Essentially all of
the systematic period variations are accounted for by a model consisting of the
1997 August glitch and step changes in at each periastron. These changes
must be due to changes in the orbit inclination, but we can find no plausible
mechanism to account for them. It is possible that timing noise may mask the
actual changes in orbital parameters at each periastron, but the good fit to
the data of the step-change model suggests that short-term timing noise is
not significant.Comment: 9 pages, 7 figures, accepted by MNRA
The 48th Highlanders in Sicily
Account by Lieutenant-Colonel I.S. Johnston, Officer Commanding 48 Highlanders given on 14 August 1943 at the Battalion Rest Area near SCORDIA
Conjugacy classes of parabolic subalgebras in complex semi-simple lie algebras
For a complex semi simple Lie algebra g, Richardson's dense orbit theorem gives a map between conjugacy classes of parabolic subalgebras in g and conjugacy classes of nilpotent elements. Unfortunately, this map is not surjective, in general, and hence does not give a direct classification of the nilpotent conjugacy classes in g. Despite this, the theorem is used by Bala and Carter to produce an indirect classification of the nilpotent conjugacy classes in g. The map is not injective, either, and this thesis attempts to discover a necessary and sufficient condition for two parabolic subalgebras to give the same nilpotent conjugacy class under the above map. Springer conjectured that associated parabolics would give the same nilpotent conjugacy class. The problem was also raised in another form by Dixmier in his work concerning the distribution of nilpotent polarisable elements in g. He conjectured a generalisation of Kostant's results on the regular nilpotent elements. We prove both these conjectures correct, the method of proof being inspired by Dixmier's work. Unfortunately, the necessary and sufficient condition is clearly more complicated than this and we give two examples (one trivial, one non-trivial) of non-associated parabolics giving the same nilpotent conjugacy class under Richard son's ma
Creating a Canadian profession: the nuclear engineer, c. 1940-1968
Canada, as one of the three Allied nations collaborating on atomic energy development during the Second World War, had an early start in applying its new knowledge and defining a new profession. Owing to postwar secrecy and distinct national aims for the field, nuclear engineering was shaped
uniquely by the Canadian context. Alone among the postwar powers, Canadian exploration of atomic energy eschewed military applications; the occupation emerged within a governmental monopoly; the intellectual content of the discipline was influenced by its early practitioners, administrators, scarce resources, and university niches; and a self-recognized profession coalesced later than did its American and British counterparts. This paper argues that the history of the emergence of Canadian nuclear engineers exemplifies unusually strong shaping of technical expertise by political and cultural context
The Topp Twins: Untouchable girls: The movie
The recently released documentary The Topp Twins: Untouchable Girls: The Movie (2009) has quickly become an important cultural text in Aotearoa New Zealand. It opened on April 9, 2009 and immediately broke records for best opening day and weekend in New Zealand’s movie history. For readers to get some sense of this documentary, it is worth watching the trailer (http://topptwins.com/tv-and-film/untouchable-girls) which provides a tantalising peak into the life story, so far, of the Topp Twins – much loved New Zealand entertainers. But the documentary does more than chart life stories, it highlights major social and political movements that helped shape national discourses of what it feels like to be a ‘Kiwi’ (the term ‘Kiwi’ is used by people – of all ethnicities and social classes - who feel they have a New Zealand national identity). I have chosen this documentary for this scholar’s choice essay because it links with a number of discourses that inspire my work on how emotions such as ‘pride’ shape people and place. Untouchable Girls illustrates the fluidity and partiality of subjectivities (both individually and collectively) and the ways in which subjectivities can be challenged and contested without humiliation
Imprisoned mothers in Victorian England, 1853–1900: Motherhood, identity and the convict prison
This article explores the experiences of imprisoned mothers in the Victorian convict prison system. It argues that motherhood, of central importance to the ideals of Victorian femininity, was disrupted and fractured by women's long-term imprisonment. Using 'whole life' history methodology, the paper draws on research into 288 women imprisoned and then released from the prison system, of whom half were mothers. It illuminates how the long term prison system dealt with pregnancy, childbirth and family contact for female prisoners. It argues that whilst institutional or state care was often an inevitable consequence for children of single or widowed mothers, women used their limited resources and agency to assert their identity as mothers and direct outcomes for their children. But for others, prolific offending and multiple long sentences would render any chance of motherhood impossible
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