1,618 research outputs found
Policy Uncertainty and Informational Monopolies: The Case of Monetary Policy.
In this paper we have presented a model in which perfectly enticipated inflation is superneutral: if the variance of the money (or the growth rate of the money supply in the dynamic interpretation) supply is zero, the real equilibrium is independent of the mean of the money supply.ECONOMIC MODELS ; INFLATION ; MONETARY POLICY
Baryogenesis, Dark Matter and the Pentagon
We present a new mechanism for baryogenesis, which links the baryon asymmetry
of the universe to the dark matter density. The mechanism arises naturally in
the Pentagon model of TeV scale physics. In that context, it forces a
re-evaluation of some of the assumptions of the model, and we detail the
changes that are required in order to fit observations.Comment: JHEP3 LaTeX, 15 pages. New version corrects errors in the electroweak
baryon violating and matter radiation temperatures, which were pointed out by
the referee. Substantial quantitative but no qualitative change to our
conclusion
A rapid, chromatography-free route to substituted acridine–isoalloxazine conjugates under microwave irradiation
Microwave irradiation was applied to a sequence of condensation reactions from readily available 9-chloroacridines to provide a range of novel acridine–isoalloxazine conjugates. The combination of these two moieties, both of biological interest, was achieved by a chromatography free route
Anomaly Mediation, Fayet-Iliopoulos D-terms and the Renormalisation Group
We address renormalisation group evolution issues that arise in the Anomaly
Mediated Supersymmetry Breaking scenario when the tachyonic slepton problem is
resolved by Fayet-Iliopoulos term contributions. We present typical sparticle
spectra both for the original formulation of this idea and an alternative using
Fayet-Iliopoulos terms for a U(1) compatible with a straightforward GUT
embedding.Comment: 20 pages, 2 figure
Virus expression detection reveals RNA-sequencing contamination in TCGA
Background: Contamination of reagents and cross contamination across samples is a long-recognized issue in molecular biology laboratories. While often innocuous, contamination can lead to inaccurate results. Cantalupo et al., for example, found HeLa-derived human papillomavirus 18 (H-HPV18) in several of The Cancer Genome Atlas (TCGA) RNA-sequencing samples. This work motivated us to assess a greater number of samples and determine the origin of possible contaminations using viral sequences. To detect viruses with high specificity, we developed the publicly available workflow, VirDetect, that detects virus and laboratory vector sequences in RNA-seq samples. We applied VirDetect to 9143 RNA-seq samples sequenced at one TCGA sequencing center (28/33 cancer types) over 5 years. Results: We confirmed that H-HPV18 was present in many samples and determined that viral transcripts from H-HPV18 significantly co-occurred with those from xenotropic mouse leukemia virus-related virus (XMRV). Using laboratory metadata and viral transcription, we determined that the likely contaminant was a pool of cell lines known as the "common reference", which was sequenced alongside TCGA RNA-seq samples as a control to monitor quality across technology transitions (i.e. microarray to GAII to HiSeq), and to link RNA-seq to previous generation microarrays that standardly used the "common reference". One of the cell lines in the pool was a laboratory isolate of MCF-7, which we discovered was infected with XMRV; another constituent of the pool was likely HeLa cells. Conclusions: Altogether, this indicates a multi-step contamination process. First, MCF-7 was infected with an XMRV. Second, this infected cell line was added to a pool of cell lines, which contained HeLa. Finally, RNA from this pool of cell lines contaminated several TCGA tumor samples most-likely during library construction. Thus, these human tumors with H-HPV or XMRV reads were likely not infected with H-HPV 18 or XMRV
Inhomogeneous tachyon dynamics and the zipper
We study the process of inhomogeneous tachyon condensation in an intersecting
D1- and anti-D1-brane system using an effective tachyon DBI action. By
switching to the Hamiltonian formalism, we numerically solve for the dynamical
evolution of the system at a small intersection angle. We find that the decay
proceeds indefinitely and resembles the action of two zippers moving away from
the intersection point at the speed of light, zipping the branes together and
leaving inhomogeneous tachyon matter behind. We also discuss the range of
validity of our analysis and discuss the relation of the D1-anti-D1 description
of the system to one in terms of an intersecting D1-D1-brane pair.Comment: 23 pages, 12 figures. v2: added references; v3: more references,
published versio
On the Exact Evaluation of Certain Instances of the Potts Partition Function by Quantum Computers
We present an efficient quantum algorithm for the exact evaluation of either
the fully ferromagnetic or anti-ferromagnetic q-state Potts partition function
Z for a family of graphs related to irreducible cyclic codes. This problem is
related to the evaluation of the Jones and Tutte polynomials. We consider the
connection between the weight enumerator polynomial from coding theory and Z
and exploit the fact that there exists a quantum algorithm for efficiently
estimating Gauss sums in order to obtain the weight enumerator for a certain
class of linear codes. In this way we demonstrate that for a certain class of
sparse graphs, which we call Irreducible Cyclic Cocycle Code (ICCC_\epsilon)
graphs, quantum computers provide a polynomial speed up in the difference
between the number of edges and vertices of the graph, and an exponential speed
up in q, over the best classical algorithms known to date
New empirical fits to the proton electromagnetic form factors
Recent measurements of the ratio of the elastic electromagnetic form factors
of the proton, G_Ep/G_Mp, using the polarization transfer technique at
Jefferson Lab show that this ratio decreases dramatically with increasing Q^2,
in contradiction to previous measurements using the Rosenbluth separation
technique. Using this new high quality data as a constraint, we have reanalyzed
most of the world e-p elastic cross section data. In this paper, we present a
new empirical fit to the reanalyzed data for the proton elastic magnetic form
factor in the region 0 < Q^2 < 30 GeV^2. As well, we present an empirical fit
to the proton electromagnetic form factor ratio, G_Ep/G_Mp, which is valid in
the region 0.1 < Q^2 < 6 GeV^2
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