383 research outputs found
The Astronomical Orientation of Ancient Greek Temples
Despite its appearing to be a simple question to answer, there has been no consensus as to whether or not the alignments of ancient Greek temples reflect astronomical intentions. Here I present the results of a survey of archaic and classical Greek temples in Sicily and compare them with temples in Greece. Using a binomial test I show strong evidence that there is a preference for solar orientations. I then speculate that differences in alignment patterns between Sicily and Greece reflect differing pressures in the expression of ethnic identity
The NANOG transcription factor induces type 2 deiodinase expression and regulates the intracellular activation of thyroid hormone in keratinocyte carcinomas
Type 2 deiodinase (D2), the principal activator of thyroid hormone (TH) signaling in target tissues, is expressed in cutaneous squamous cell carcinomas (SCCs) during late tumorigenesis, and its repression attenuates the invasiveness and metastatic spread of SCC. Although D2 plays multiple roles in cancer progression, nothing is known about the mechanisms regulating D2 in cancer. To address this issue, we investigated putative upstream regulators of D2 in keratinocyte carcinomas. We found that the expression of D2 in SCC cells is positively regulated by the NANOG transcription factor, whose expression, besides being causally linked to embryonic stemness, is associated with many human cancers. We also found that NANOG binds to the D2 promoter and enhances D2 transcription. Notably, blockage of D2 activity reduced NANOG-induced cell migration as well as the expression of key genes involved in epithelial–mesenchymal transition in SCC cells. In conclusion, our study reveals a link among endogenous endocrine regulators of cancer, thyroid hormone and its activating enzyme, and the NANOG regulator of cancer biology. These findings could provide the basis for the development of TH inhibitors as context-dependent anti-tumor agents
Three-loop \beta-functions for top-Yukawa and the Higgs self-interaction in the Standard Model
We analytically compute the dominant contributions to the \beta-functions for
the top-Yukawa coupling, the strong coupling and the Higgs self-coupling as
well as the anomalous dimensions of the scalar, gluon and quark fields in the
unbroken phase of the Standard Model at three-loop level. These are mainly the
QCD and top-Yukawa corrections. The contributions from the Higgs
self-interaction which are negligible for the running of the top-Yukawa and the
strong coupling but important for the running of the Higgs self-coupling are
also evaluated.Comment: 22 pages, 7 figures. Few extra citations are added; the plots are
improved. Results in computer readable form can be retrieved from
http://www-ttp.particle.uni-karlsruhe.de/Progdata/ttp12/ttp12-012
Anarchy and Leptogenesis
We study if leptogenesis works successfully together with the neutrino mass
anarchy hypothesis. We find that the predicted neutrino mass spectrum is
sensitive to the reheating temperature or the inflaton mass, while the
distributions of the neutrino mixing angles and CP violation phases remain
intact as determined by the invariant Haar measure of U(3). In the case of
thermal leptogenesis, the light neutrino mass distribution agrees well with the
observations if the reheating temperature is O(10^{9-11}) GeV. The mass
spectrum of the right-handed neutrinos and the neutrino Yukawa matrix exhibit a
certain pattern, as a result of the competition between random matrices with
elements of order unity and the wash-out effect. Non-thermal leptogenesis is
consistent with observation only if the inflaton mass is larger than or
comparable to the typical right-handed neutrino mass scale. Cosmological
implications are discussed in connection with the 125GeV Higgs boson mass.Comment: 29 pages, 6 figures. v2: figures and references added. v3: published
in JHE
Higgs Interference Effects in \Pg \Pg \to \PZ\PZ and their Uncertainty
Interference between the Standard Model Higgs boson and continuum
contributions is considered in the heavy-mass scenario. Results are available
at leading order for the background. It is discussed how to combine the result
with the next-to-next-to-leading order Higgs production cross-section and a
proposal for estimating the associated theoretical uncertainty is presented.Comment: 25 pages, 10 figures; improved numerical accuracy, Numerics updated,
conclusions unchanged, references added. v
Bilinear R-parity violation with flavor symmetry
Bilinear R-parity violation (BRPV) provides the simplest intrinsically
supersymmetric neutrino mass generation scheme. While neutrino mixing
parameters can be probed in high energy accelerators, they are unfortunately
not predicted by the theory. Here we propose a model based on the discrete
flavor symmetry with a single R-parity violating parameter, leading to
(i) correct Cabbibo mixing given by the Gatto-Sartori-Tonin formula, and a
successful unification-like b-tau mass relation, and (ii) a correlation between
the lepton mixing angles and in agreement with
recent neutrino oscillation data, as well as a (nearly) massless neutrino,
leading to absence of neutrinoless double beta decay.Comment: 16 pages, 3 figures. Extended version, as published in JHE
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