18,170 research outputs found
The hardwiring of development: Organization and function of genomic regulatory systems
The gene regulatory apparatus that directs development is
encoded in the DNA, in the form of organized arrays of
transcription factor target sites. Genes are regulated by
interactions with multiple transcription factors and the
target sites for the transcription factors required for the
control of each gene constitute its cis-regulatory system.
These systems are remarkably complex. Their hardwired
internal organization enables them to behave as genomic
information processing systems. Developmental gene regulatory
networks consist of the cis-regulatory systems of all
the relevant genes and the regulatory linkages amongst
them. Though there is yet little explicit information, some
general properties of genomic regulatory networks have
become apparent. The key to understanding how genomic
regulatory networks are organized, and how they work, lies
in experimental analysis of cis-regulatory systems at all
levels of the regulatory network
Phenomenological Consequences of Soft Leptogenesis
Soft supersymmetry breaking terms involving heavy singlet sneutrinos can be
the dominant source of leptogenesis. The relevant range of parameters is
different from standard leptogenesis: a lighter Majorana mass, M < 10^9 GeV
(allowing a solution of the gravitino problem), and smaller Yukawa couplings,
Y_N < 10^{-4}. We investigate whether the various couplings of the singlet
sneutrinos, which are constrained by the requirement of successful `soft
leptogenesis', can have observable phenomenological consequences. Specifically,
we calculate the contributions of the relevant soft supersymmetric breaking
terms to the electric dipole moments of the charged leptons and to lepton
flavor violating decays. Our result is that these contributions are small.Comment: 11 pages, 1 figure; v2: an additional contribution is considered
(modifying: fig. 1, eq. 10-13, 22) and a reference added. Conclusions
unchange
A compact spectroradiometer for solar simulator measurements
Compact spectral irradiance probe has been designed and built which uses wedge filter in conjunction with silicon cell and operational amplifier. Probe is used to monitor spectral energy distribution of solar simulators and other high intensity sources
Sequence organization of feline leukemis virus DNA in infected cells
A restriction site map has been deduced of unintegrated and integrated FeLV viral DNA found in human RD cells after experimental infection with the Gardner-Arnstein strain of FeLV. Restriction fragments were ordered by single and double enzyme digests followed by Southern transfer (1) and hybridization with 32P-labeled viral cDNA probes. The restriction map was oriented with respect to the 5' and 3' ends of viral RNA by using a 3' specific hybridization probe. The major form of unintegrated viral DNA found was a 8.7 kb linear DNA molecule bearing a 450 bp direct long terminal redundancy (LTR) derived from both 5' and 3' viral RNA sequences. Minor, circular forms, 8.7 kb and 8.2 kb in length were also detected, the larger one probably containing two adjacent copies of the LTR and the smaller one containing one copy of the LTR. Integrated copies of FeLV are colinear with the unintegrated linear form and contain the KpnI and SmaI sites found in each LTR
Hollowgraphy Driven Holography: Black Hole with Vanishing Volume Interior
Hawking-Bekenstein entropy formula seems to tell us that no quantum degrees
of freedom can reside in the interior of a black hole. We suggest that this is
a consequence of the fact that the volume of any interior sphere of finite
surface area simply vanishes. Obviously, this is not the case in general
relativity. However, we show that such a phenomenon does occur in various
gravitational theories which admit a spontaneously induced general relativity.
In such theories, due to a phase transition (one parameter family degenerates)
which takes place precisely at the would have been horizon, the recovered
exterior Schwarzschild solution connects, by means of a self-similar transition
profile, with a novel 'hollow' interior exhibiting a vanishing spatial volume
and a locally varying Newton constant. This constitutes the so-called
'hollowgraphy' driven holography.Comment: Honorable Mention Essay - Gravity Research Foundation (2010
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