120,174 research outputs found
Extrinsic CPT Violation in Neutrino Oscillations
In this talk, we investigate extrinsic CPT violation in neutrino oscillations
in matter with three flavors. Note that extrinsic CPT violation is different
from intrinsic CPT violation. Extrinsic CPT violation is one way of quantifying
matter effects, whereas intrinsic CPT violation would mean that the CPT
invariance theorem is not valid. We present analytical formulas for the
extrinsic CPT probability differences and discuss their implications for
long-baseline experiments and neutrino factory setups.Comment: 4 pages, 1 figure, aipproc LaTeX. Talk presented at the 5th
International Workshop on Neutrino Factories & Superbeams (NuFact'03),
Columbia University, New York, USA, June 5-11, 2003. To be published in the
Proceedings of NuFact'03 (AIP Conference Proceedings
Identification of early gene expression changes in primary cultured neurons treated with topoisomerase I poisons.
Topoisomerase 1 (TOP1) poisons like camptothecin (CPT) are currently used in cancer chemotherapy but these compounds can have damaging, off-target effects on neurons leading to cognitive, sensory and motor deficits. To understand the molecular basis for the enhanced sensitivity of neurons to CPT, we examined the effects of compounds that inhibit TOP1-CPT, actinomycin D (ActD) and β-lapachone (β-Lap)-on primary cultured rat motor (MN) and cortical (CN) neurons as well as fibroblasts. Neuronal cells expressed higher levels of Top1 mRNA than fibroblasts but transcript levels are reduced in all cell types after treatment with CPT. Microarray analysis was performed to identify differentially regulated transcripts in MNs in response to a brief exposure to CPT. Pathway analysis of the differentially expressed transcripts revealed activation of ERK and JNK signaling cascades in CPT-treated MNs. Immediate-early genes like Fos, Egr-1 and Gadd45b were upregulated in CPT-treated MNs. Fos mRNA levels were elevated in all cell types treated with CPT; Egr-1, Gadd45b and Dyrk3 transcript levels, however, increased in CPT-treated MNs and CNs but decreased in CPT-treated fibroblasts. These transcripts may represent new targets for the development of therapeutic agents that mitigate the off-target effects of chemotherapy on the nervous system
Extrinsic and Intrinsic CPT Asymmetries in Neutrino Oscillations
We reconsider the extrinsic and possible intrinsic CPT violation in neutrino
oscillations, and point out an identity, i.e., , among the CP, T, and
CPT asymmetries in oscillations. For three-flavor oscillations in matter of
constant density, the extrinsic CPT asymmetries , , , and caused by
Earth matter effects have been calculated in the plane of different neutrino
energies and baseline lengths. It is found that two analytical conditions can
be implemented to describe the main structure of the contours of vanishing
extrinsic CPT asymmetries. Finally, without assuming intrinsic CPT symmetry in
the neutrino sector, we investigate the possibility to constrain the difference
of the neutrino CP-violating phase and the antineutrino one
using a low-energy neutrino factory and the super-beam
experiment ESSSB. We find that in the former case and
in the latter case can be achieved at the confidence level if is assumed.Comment: 26 pages, 6 figures, more discussions added, matches the published
versio
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