273 research outputs found
Strawson sobre o juízo estético em Kant
Este artigo parte da leitura que Strawson faz de Kant para enfatizar, a partir do Opus Posthumum, a autonomia da terceira crítica e do juízo reflexivo enquanto princípio novo e irredutível aos princípios regulativos da razão na primeira crítica. AbstractThis paper starts with an homage to Strawson's reading of Kant and emphasizes, based on the Opus Posthumum, the autonomy of the Third Critique and of the principle of reflexive judgment as a new and independent principle which cannot be reduced to any of the regulative principles in the Critique of Pure Reason
Discriminating Between the Physical Processes that Drive Spheroid Size Evolution
Massive galaxies at high-z have smaller effective radii than those today, but
similar central densities. Their size growth therefore relates primarily to the
evolving abundance of low-density material. Various models have been proposed
to explain this evolution, which have different implications for galaxy, star,
and BH formation. We compile observations of spheroid properties as a function
of redshift and use them to test proposed models. Evolution in progenitor
gas-richness with redshift gives rise to initial formation of smaller spheroids
at high-z. These systems can then evolve in apparent or physical size via
several channels: (1) equal-density 'dry' mergers, (2) later major or minor
'dry' mergers with less-dense galaxies, (3) adiabatic expansion, (4) evolution
in stellar populations & mass-to-light-ratio gradients, (5) age-dependent bias
in stellar mass estimators, (6) observational fitting/selection effects. If any
one of these is tuned to explain observed size evolution, they make distinct
predictions for evolution in other galaxy properties. Only model (2) is
consistent with observations as a dominant effect. It is the only model which
allows for an increase in M_BH/M_bulge with redshift. Still, the amount of
merging needed is larger than that observed or predicted. We therefore compare
cosmologically motivated simulations, in which all these effects occur, & show
they are consistent with all the observational constraints. Effect (2), which
builds up an extended low-density envelope, does dominate the evolution, but
effects 1,3,4, & 6 each contribute ~20% to the size evolution (a net factor
~2). This naturally also predicts evolution in M_BH-sigma similar to that
observed.Comment: 19 pages, 7 figures. accepted to MNRAS (matches accepted version
A Genetic Lesion that Arrests Plasma Cell Homing to the Bone Marrow
The coordinated regulation of chemokine responsiveness plays a critical role in the development of humoral immunity. After antigen challenge and B cell activation, the emerging plasma cells (PCs) undergo CXCL12-induced chemotaxis to the bone marrow, where they produce Ab and persist. Here we show that PCs, but not B cells or T cells from lupus-prone NZM mice, are deficient in CXCL12-induced migration. PC unresponsiveness to CXCL12 results in a marked accumulation of PCs in the spleen of mice, and a concordant decrease in bone marrow PCs. Unlike normal mice, in NZM mice, a majority of the splenic PCs are long-lived. This deficiency is a consequence of the genetic interactions of multiple systemic lupus erythematosus susceptibility loci
Disentangling Income Inequality and the Redistributive Effect of Social Transfers and Taxes in 36 LIS Countries
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