7,794 research outputs found
Agricultural Labor Markets and Immigration
Labor and Human Capital, J43, J61, J68,
Community and Labor Issues in Animal Agriculture
Community/Rural/Urban Development, Labor and Human Capital, Livestock Production/Industries, Q13, R11, J61, J43, J28,
Extending invariant complex structures
We study the problem of extending a complex structure to a given Lie algebra
g, which is firstly defined on an ideal h of g. We consider the next
situations: h is either complex or it is totally real. The next question is to
equip g with an additional structure, such as a (non)-definite metric or a
symplectic structure and to ask either h is non-degenerate, isotropic, etc.
with respect to this structure, by imposing a compatibility assumption. We show
that this implies certain constraints on the algebraic structure of g.
Constructive examples illustrating this situation are shown, in particular
computations in dimension six are given.Comment: 22 pages, plus an Addendu
Recommended from our members
Evidence for clonal selection of gamma/delta T cells in response to a human pathogen.
T cells bearing gamma/delta antigen receptors comprise a resident population of intraepithelial lymphocytes in organs such as skin, gut, and lungs, where they are strategically located to contribute to the initial defense against infection. An important unsolved question about antigen-driven gamma/delta T cell responses regards the breadth of their T cell receptor (TCR) repertoire, since many specific epithelial compartments in mice display limited diversity. We have examined the diversity of TCR delta gene expression among human gamma/delta T cells from skin lesions induced by intradermal challenge with Mycobacterium leprae. We show that the vast majority of gamma/delta cells from M. leprae lesions use either V delta 1-J delta 1 or V delta 2-J delta 1 gene rearrangements and, within a given region of the lesion, display limited junctional diversity. This contrasts markedly with the extensive diversity of gamma/delta T cells from peripheral blood of these same individuals, as well as skin from normal donors. These results indicate that the gamma/delta response to M. leprae involves the selection of a limited number of clones from among a diverse repertoire, probably in response to specific mycobacterial and/or host antigens
Random walks reaching against all odds the other side of the quarter plane
For a homogeneous random walk in the quarter plane with nearest-neighbor
transitions, starting from some state , we study the event that the
walk reaches the vertical axis, before reaching the horizontal axis. We derive
an exact expression for the probability of this event, and derive an asymptotic
expression for the case when becomes large, a situation in which the
event becomes highly unlikely. The exact expression follows from the solution
of a boundary value problem and is in terms of an integral that involves a
conformal gluing function. The asymptotic expression follows from the
asymptotic evaluation of this integral. Our results find applications in a
model for nucleosome shifting, the voter model and the asymmetric exclusion
process.Comment: 18 pages, 2 figures, to appear in Journal of Applied Probabilit
The square-kagome quantum Heisenberg antiferromagnet at high magnetic fields: The localized-magnon paradigm and beyond
We consider the spin-1/2 antiferromagnetic Heisenberg model on the
two-dimensional square-kagome lattice with almost dispersionless lowest magnon
band. For a general exchange coupling geometry we elaborate low-energy
effective Hamiltonians which emerge at high magnetic fields. The effective
model to describe the low-energy degrees of freedom of the initial frustrated
quantum spin model is the (unfrustrated) square-lattice spin-1/2 model in
a -aligned magnetic field. For the effective model we perform quantum Monte
Carlo simulations to discuss the low-temperature properties of the
square-kagome quantum Heisenberg antiferromagnet at high magnetic fields. We
pay special attention to a magnetic-field driven
Berezinskii-Kosterlitz-Thouless phase transition which occurs at low
temperatures.Comment: 6 figure
Public crises, public futures
This article begins to map out a novel approach to analyzing contemporary contexts of public crisis, relationships between them and possibilities that these scenes hold out for politics. The article illustrates and analyses a small selection of examples of these kinds of contemporary scenes and calls for greater attention to be given to the conditions and consequences of different forms and practices of public and political mediation. In offering a three-fold typology to delineate differences between ‘abject’, ‘audience’ and ‘agentic’ publics the article begins to draw out how political and public futures may be seen as being bound up with how the potentialities, capacities and qualities that publics are imagined to have and resourced to perform. Public action and future publics are therefore analysed here in relation to different versions of contemporary crisis and the political concerns and publics these crises work to articulate, foreground and imaginatively and practically support
Capital stranding cascades: The impact of decarbonisation on productive asset utilisation
This article develops a novel methodological framework to investigate the exposure of eco-
nomic systems to the risk of physical capital stranding. Combining Input-Output (IO) and
network theory, we define measures to identify both the sectors likely to trigger relevant capital
stranding cascades and those most exposed to capital stranding risk. We show how, in a sample
of ten European countries, mining is among the sectors with the highest external asset strand-
ing multipliers. The sectors most affected by capital stranding triggered by decarbonisation
include electricity and gas; coke and refined petroleum products; basic metals; and transporta-
tion. From these sectors, stranding would frequently cascade down to chemicals; metal products;
motor vehicles water and waste services; wholesale and retail trade; and public administration.
Finally, we provide an estimate for the lower-bound amount of assets at risk of transition-related
stranding, which is in the range of 0.6-8.2% of the overall productive capital stock for our sample
of countries, mainly concentrated in the electricity and gas sector, manufacturing, and mining.
These results confirm the systemic relevance of transition-related risks on European societies.Series: Ecological Economic Paper
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