62 research outputs found
Shaping black holes with free fields
Starting from a metric Ansatz permitting a weak version of Birkhoff's theorem
we find static black hole solutions including matter in the form of free scalar
and p-form fields, with and without a cosmological constant \Lambda. Single
p-form matter fields permit multiple possibilities, including dyonic solutions,
self-dual instantons and metrics with Einstein-Kaelher horizons. The inclusion
of multiple p-forms on the other hand, arranged in a homogeneous fashion with
respect to the horizon geometry, permits the construction of higher dimensional
dyonic p-form black holes and four dimensional axionic black holes with flat
horizons, when \Lambda<0. It is found that axionic fields regularize black hole
solutions in the sense, for example, of permitting regular -- rather than
singular -- small mass Reissner-Nordstrom type black holes. Their cosmic string
and Vaidya versions are also obtained.Comment: 38 pages. v2: minor changes, published versio
Integrability in conformally coupled gravity: Taub-NUT spacetimes and rotating black holes
COUP-TFII Controls Mouse Pancreatic β-Cell Mass through GLP-1-β-Catenin Signaling Pathways
Background: The control of the functional pancreatic beta-cell mass serves the key homeostatic function of releasing the right amount of insulin to keep blood sugar in the normal range. It is not fully understood though how beta-cell mass is determined
The Rosa genome provides new insights into the domestication of modern roses
Roses have high cultural and economic importance as ornamental plants and in the perfume industry. We report the rose whole-genome sequencing and assembly and resequencing of major genotypes that contributed to rose domestication. We generated a homozygous genotype from a heterozygous diploid modern rose progenitor, Rosa chinensis ‘Old Blush’. Using single-molecule real-time sequencing and a meta-assembly approach, we obtained one of the most comprehensive plant genomes to date. Diversity analyses highlighted the mosaic origin of ‘La France’, one of the first hybrids combining the growth vigor of European species and the recurrent blooming of Chinese species. Genomic segments of Chinese ancestry identified new candidate genes for recurrent blooming. Reconstructing regulatory and secondary metabolism pathways allowed us to propose a model of interconnected regulation of scent and flower color. This genome provides a foundation for understanding the mechanisms governing rose traits and should accelerate improvement in roses, Rosaceae and ornamentals
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