53 research outputs found
Neuroinflammation, Mast Cells, and Glia: Dangerous Liaisons
The perspective of neuroinflammation as an epiphenomenon following neuron damage is being replaced by the awareness of glia and their importance in neural functions and disorders. Systemic inflammation generates signals that communicate with the brain and leads to changes in metabolism and behavior, with microglia assuming a pro-inflammatory phenotype. Identification of potential peripheral-to-central cellular links is thus a critical step in designing effective therapeutics. Mast cells may fulfill such a role. These resident immune cells are found close to and within peripheral nerves and in brain parenchyma/meninges, where they exercise a key role in orchestrating the inflammatory process from initiation through chronic activation. Mast cells and glia engage in crosstalk that contributes to accelerate disease progression; such interactions become exaggerated with aging and increased cell sensitivity to stress. Emerging evidence for oligodendrocytes, independent of myelin and support of axonal integrity, points to their having strong immune functions, innate immune receptor expression, and production/response to chemokines and cytokines that modulate immune responses in the central nervous system while engaging in crosstalk with microglia and astrocytes. In this review, we summarize the findings related to our understanding of the biology and cellular signaling mechanisms of neuroinflammation, with emphasis on mast cell-glia interactions
Shedding Light on the Galaxy Luminosity Function
From as early as the 1930s, astronomers have tried to quantify the
statistical nature of the evolution and large-scale structure of galaxies by
studying their luminosity distribution as a function of redshift - known as the
galaxy luminosity function (LF). Accurately constructing the LF remains a
popular and yet tricky pursuit in modern observational cosmology where the
presence of observational selection effects due to e.g. detection thresholds in
apparent magnitude, colour, surface brightness or some combination thereof can
render any given galaxy survey incomplete and thus introduce bias into the LF.
Over the last seventy years there have been numerous sophisticated
statistical approaches devised to tackle these issues; all have advantages --
but not one is perfect. This review takes a broad historical look at the key
statistical tools that have been developed over this period, discussing their
relative merits and highlighting any significant extensions and modifications.
In addition, the more generalised methods that have emerged within the last few
years are examined. These methods propose a more rigorous statistical framework
within which to determine the LF compared to some of the more traditional
methods. I also look at how photometric redshift estimations are being
incorporated into the LF methodology as well as considering the construction of
bivariate LFs. Finally, I review the ongoing development of completeness
estimators which test some of the fundamental assumptions going into LF
estimators and can be powerful probes of any residual systematic effects
inherent magnitude-redshift data.Comment: 95 pages, 23 figures, 3 tables. Now published in The Astronomy &
Astrophysics Review. This version: bring in line with A&AR format
requirements, also minor typo corrections made, additional citations and
higher rez images adde
Dynamics of Disks and Warps
This chapter reviews theoretical work on the stellar dynamics of galaxy
disks. All the known collective global instabilities are identified, and their
mechanisms described in terms of local wave mechanics. A detailed discussion of
warps and other bending waves is also given. The structure of bars in galaxies,
and their effect on galaxy evolution, is now reasonably well understood, but
there is still no convincing explanation for their origin and frequency. Spiral
patterns have long presented a special challenge, and ideas and recent
developments are reviewed. Other topics include scattering of disk stars and
the survival of thin disks.Comment: Chapter accepted to appear in Planets, Stars and Stellar Systems, vol
5, ed G. Gilmore. 32 pages, 17 figures. Includes minor corrections made in
proofs. Uses emulateapj.st
Whole exome sequencing coupled with unbiased functional analysis reveals new Hirschsprung disease genes
Variability of solar/stellar activity and magnetic field and its influence on planetary atmosphere evolution
TGFÎČ-facilitated optic fissure fusion and the role of bone morphogenetic protein antagonism
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