Living by the Word Long, Thomas G
The Christian century (1902),
03/2006, Letnik:
123, Številka:
6
Magazine Article
Eventually shaking off the dust of his little town, he took his faith and his keyboard and headed off toward the bright lights of Nashville, aiming at a career in gospel music. To see this statement ...as applicable to us, to swallow even one ounce of this claim, we must admit a cluster of truths about ourselves we would rather not face-that we are captive to cultural and spiritual forces over which we have no control, that they have drained the life out of us, that we are unable to think or feel or crawl our way free, and that we are in urgent need of a God who comes to rescue.
Living by the Word Long, Thomas G
The Christian century (1902),
03/2006, Letnik:
123, Številka:
5
Magazine Article
Put simply, this abrupt appearance of a soaring mountain is an invitation to scale its heights with Peter, James and John so that we too can see what we cannot see in the valley. In his memoir A ...Dresser of Sycamore Trees, lay Episcopal minister Garret Keizer describes a Holy Saturday vigil held in his tiny Vermont parish.
Chromatin modifying activities inherent to polycomb repressive complexes PRC1 and PRC2 play an essential role in gene regulation, cellular differentiation, and development. However, the mechanisms by ...which these complexes recognize their target sites and function together to form repressive chromatin domains remain poorly understood. Recruitment of PRC1 to target sites has been proposed to occur through a hierarchical process, dependent on prior nucleation of PRC2 and placement of H3K27me3. Here, using a de novo targeting assay in mouse embryonic stem cells we unexpectedly discover that PRC1-dependent H2AK119ub1 leads to recruitment of PRC2 and H3K27me3 to effectively initiate a polycomb domain. This activity is restricted to variant PRC1 complexes, and genetic ablation experiments reveal that targeting of the variant PCGF1/PRC1 complex by KDM2B to CpG islands is required for normal polycomb domain formation and mouse development. These observations provide a surprising PRC1-dependent logic for PRC2 occupancy at target sites in vivo.
A
bstract
Several recent works 1-3 have claimed that the Weak Gravity Conjecture (WGC) excludes super-Planckian displacements of axion fields, and hence large-field axion inflation, in the absence of ...monodromy. We argue that in theories with
N
≫ 1 axions, super-Planckian axion diameters
D
are readily allowed by the WGC. We clarify the non-trivial relationship between the kinetic matrix
K
— unambiguously defined by its form in a Minkowski-reduced basis — and the diameter of the axion fundamental domain, emphasizing that in general the diameter is not solely determined by the eigenvalues
f
1
2
≤ ⋅ ⋅ ⋅ ≤
f
N
2
of
K
: the orientations of the eigenvectors with respect to the identifications imposed by instantons must be incorporated. In particular, even if one were to impose the condition
f
N
< M
pl
, this would imply neither
D
< M
pl
nor
D
<
N
M
pl
. We then estimate the actions of instantons that fulfill the WGC. The leading instanton action is bounded from below by
S
≥
S
M
pl
/
f
N
, with
S
a fixed constant, but in the universal limit
S
≳
S
N
M
pl
/
f
N
. Thus, having
f
N
> M
pl
does not immediately imply the existence of unsuppressed higher harmonic contributions to the potential. Finally, we argue that in effective axion-gravity theories, the zero-form version of the WGC can be satisfied by gravitational instantons that make negligible contributions to the potential.
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