27,617 research outputs found
, SL(32) and Central Charges
We show that the representation that contains the space-time
translation generators also contains the rank two and five totally
anti-symmetric representations of . By studying the behaviour of these
latter representations under SL(32), which we argue is contained in
the Cartan involution invariant sub-algebra of , we find that the rank
two and five totally anti-symmetric representations must be identified with the
central charges of the eleven dimensional supersymmetry algebra.Comment: 12 pages, plain tex, Typos corrected, one reference and three
sentences added and equation (3.8) change
E_{11} and Higher Spin Theories
We consider the previous proposal of the author to use an extension of
spacetime obtained by taking the non-linear realisation of the semi-direct
product of E_{11} with a set of generators belonging to one of the fundamental
representations of E_{11}. We determine, at low levels, the symmetries that the
associated point particle moving in this generalised spacetime should possess
and write down the corresponding action. Quantisation of similar actions has
been shown to lead to the unfolded formulation of higher spin theories and we
argue that the generalised coordinates will lead in the non-linear realisation
to an infinite number of propagating higher spin fields.Comment: 11 pages, some references and a few comments adde
Managing water conflicts through dialogue in Pangani Basin, Tanzania
River basinsWater resource managementConflictWater users
A 2-dimensional Geometry for Biological Time
This paper proposes an abstract mathematical frame for describing some
features of biological time. The key point is that usual physical (linear)
representation of time is insufficient, in our view, for the understanding key
phenomena of life, such as rhythms, both physical (circadian, seasonal ...) and
properly biological (heart beating, respiration, metabolic ...). In particular,
the role of biological rhythms do not seem to have any counterpart in
mathematical formalization of physical clocks, which are based on frequencies
along the usual (possibly thermodynamical, thus oriented) time. We then suggest
a functional representation of biological time by a 2-dimensional manifold as a
mathematical frame for accommodating autonomous biological rhythms. The
"visual" representation of rhythms so obtained, in particular heart beatings,
will provide, by a few examples, hints towards possible applications of our
approach to the understanding of interspecific differences or intraspecific
pathologies. The 3-dimensional embedding space, needed for purely mathematical
reasons, allows to introduce a suitable extra-dimension for "representation
time", with a cognitive significance.Comment: Presented in an invited Lecture, conference "Biologie e selezioni
naturali", Florence, December 4-8, 200
The Best Kind of Building The New Deal Landscape of the Northern Plains, 1993-42
\u27VWel are definitely in an era of building; the best kind of building-the building of great public projects for the benefit of the public and with the definite objective of building human happiness, proclaimed President Franklin D. Roosevelt as he introduced his New Deal programs of recovery and reform.1 From 1933 to 1942 such federal agencies as the Federal Emergency Relief Administration (FERA), the Public Works Administration (PW A), the Civilian Conservation Corps (CCC), and the Works Progress (later Projects) Administration (WPA) gave a new look to the northern plains landscape by placing a federal facade on the public architecture of local communities.
The money our fathers were accustomed to : banks and political culture in Rutherford County, Tennessee, 1800-1850
The creation of a new political culture, comprised of the Democratic and Whig parties, in Rutherford County, Tennessee, resulted from a community division over the desirability of both political and economic change. Before the early 1830s, Rutherford County had been a Democratic party stronghold. But when, in light of the community\u27s own economic stagnation, those who doubted the Democrats\u27 wisdom in opposing a national bank, joined John Bell and Hugh Lawson White\u27s political revolt in 1835, a new way of politics soon appeared in Rutherford County. The Depression of 1837, which severely rocked Rutherford Countians, turned more true Jackson men toward the ranks of the opposition. Once the financial policies of the Jackson and Van Buren administrations wre discredited, a consistent majority of Rutherford Countians became loyal members of the Whig party. Parties, therefore, had crystallized by 1839. Despite Democratic efforts at regaining the state capital for Rutherford County and maintaining the traditional character of the community, most Rutherford Countians opted for the Whig view of the world, even if that meant significant economic changes would occur.;The Whigs and Democrats of Rutherford County were different men. A majority of Whigs lived in the Garden of the community, while most Democrats lived in the Barrens. Whigs, therefore, were wealthier men. They also held different occupations, with one-fourth of the Whig party leaders engaged in commerce and/or manufacturing.;Quite possibly, the author suggests, the concept of modernization is a good explanation of the changes that Rutherford Countians experienced from 1800 to 1850. They did construct a recognizably modern political system and the issue of modern finance--the central banking system of Nicholas Biddle\u27s Bank of the United States--was the major issue undermining the county\u27s Democratic consensus
Community Planning with the Village Bloggurls- Incorporating planning concepts and inquiry into community programs with girls and youth
This report documents four months of study with the Village Bloggurls, a community group foryoung girls in Lotherton Pathway, North York. The purpose of this project was to investigate the potential for community programs to be places of learning about planning and space. This research relied upon feminist methodology and methods, and occurred through three main workshop activities with the Village Bloggurls. Results found that young girls are interested in and capable of ning processes, though they lack formal opportunities to do so. The participants also felt empowered to make changes in their community stemming from the work of this research. The report concludes with an assessment of challenges of working with youth in the context of planning as well as recommendations for future research in this area
NmPin from the marine thaumarchaeote Nitrosopumilus maritimus is an active membrane associated prolyl isomerase.
We cordially thank Alma Rute for excellent technical assistance and the DFG (GRK 1431-1 and 1431-2) for financial support (PB). We thank the Microscope and Histology Facility of the University of Aberdeen for providing their equipment. We also thank Jacob Hargreaves for proofreading the manuscript.Peer reviewedPublisher PD
Killing Spinor Equations from Nonlinear Realisations
Starting from a nonlinear realisation of eleven dimensional supergravity
based on the group G11, whose generators appear as low level generators of E11,
we present a super extended algebra, which leads to a covariant derivative of
spinors identical to the Killing spinor equation of this theory. A similar
construction leads to the Killing spinor equation of N=1 pure supergravity in
ten dimensions.Comment: 16 pages, typos correcte
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