Do the gravitational corrections to the beta functions of the quartic and Yukawa couplings have an intrinsic physical meaning?

We study the beta functions of the quartic and Yukawa couplings of General Relativity and Unimodular Gravity coupled to the $\lambda\phi^4$ and Yukawa theories with masses. We show that the General Relativity corrections to those beta functions as obtained from the 1PI functional by using the standard MS multiplicative renormalization scheme of Dimensional Regularization are gauge dependent and, further, that they can be removed by a non-multiplicative, though local, field redefinition. An analogous analysis is carried out when General Relativity is replaced with Unimodular Gravity. Thus we show that any claim made about the change in the asymptotic behaviour of the quartic and Yukawa couplings made by General Relativity and Unimodular Gravity lack intrinsic physical meaning.Comment: 6 pages, 7 figure

Entanglement of two qubits mediated by one-dimensional plasmonic waveguides

We investigate qubit-qubit entanglement mediated by plasmons supported by one-dimensional waveguides. We explore both the situation of spontaneous formation of entanglement from an unentangled state and the emergence of driven steady-state entanglement under continuous pumping. In both cases, we show that large values for the concurrence are attainable for qubit-qubit distances larger than the operating wavelength by using plasmonic waveguides that are currently available.Comment: 4 pages, 4 figures. Minor Changes. Journal Reference added. Highlighted in Physic

VIMOS-VLT spectroscopy of the giant Ly-alpha nebulae associated with three z~2.5 radio galaxies

The morphological and spectroscopic properties of the giant (>60 kpc) Ly-alpha nebulae associated with three radio galaxies at z~2.5 (MRC 1558-003, MRC 2025-218 and MRC 0140-257) have been investigated using integral field spectroscopic data obtained with VIMOS on VLT. The morphologies are varied. The nebula of one source has a centrally peaked, rounded appearance. In the other two objects, it consists of two spatial components. The three nebulae are aligned with the radio axis within <30 deg. The total Ly-alpha luminosities are in the range (0.3-3.4) x 1e44 erg s-1. The Ly-alpha spectral profile shows strong variation through the nebulae, with FWHM values in the range ~400-1500 km s-1 and velocity shifts V~120-600 km s-1. We present an infall model which can explain successfully most Ly-alpha morphological and spectroscopic properties of the nebula associated with MRC 1558-003. This adds further support to our previous conclusion that the _quiescent_ giant nebulae associated with this and other high redshift powerful radio galaxies are in infall. A problem for this model is the difficulty to reproduce the large Ly-alpha FWHM values. We have discovered a giant (~85 kpc) Ly-alpha nebula associated with the radio galaxy MRC 0140-257 at z=2.64. It shows strikingly relaxed kinematics (FWHM2) radio galaxies.Comment: 14 pages, 13 figures. Accepted for publication in MNRA

High prevalence of scrapie in a dairy goat herd: tissue distribution of disease-associated PrP and effect of PRNP genotype and age

Following a severe outbreak of clinical scrapie in 2006–2007, a large dairy goat herd was culled and 200 animals were selected for post-mortem examinations in order to ascertain the prevalence of infection, the effect of age, breed and PRNP genotype on the susceptibility to scrapie, the tissue distribution of diseaseassociated PrP (PrP$^{\rm d}$), and the comparative efficiency of different diagnostic methods. As determined by immunohistochemical (IHC) examinations with Bar224 PrP antibody, the prevalence of preclinical infection was very high (72/200; 36.0%), with most infected animals being positive for PrP$^{\rm d}$ in lymphoreticular system (LRS) tissues (68/72; 94.4%) compared to those that were positive in brain samples (38/72; 52.8%). The retropharyngeal lymph node and the palatine tonsil showed the highest frequency of PrP$^{\rm d}$ accumulation (87.3% and 84.5%, respectively), while the recto-anal mucosa-associated lymphoid tissue (RAMALT) was positive in only 30 (41.7%) of the infected goats. However, the efficiency of rectal and palatine tonsil biopsies taken shortly before necropsy was similar. The probability of brain and RAMALT being positive directly correlated with the spread of PrP$^{\rm d}$ within the LRS. The prevalence of infection was influenced by PRNP genetics at codon 142 and by the age of the goats: methionine carriers older than 60 months showed a much lower prevalence of infection (12/78; 15.4%) than those younger than 60 months (20/42; 47.6%); these last showed prevalence values similar to isoleucine homozygotes of any age (40/80; 50.0%). Two of seven goats with definite signs of scrapie were negative for PrP$^{\rm d}$ in brain but positive in LRS tissues, and one goat showed biochemical and IHC features of PrP$^{\rm d}$ different from all other infected goats. The results of this study have implications for surveillance and control policies for scrapie in goats

SWI/SNF regulates a transcriptional programme that induces senescence to prevent liver cancer

Oncogene-induced senescence (OIS) is a potent tumour suppressor mechanism. To identify senescence regulators relevant to cancer, we screened an shRNA library targeting genes deleted in hepatocellular carcinoma (HCC). Here, we describe how knockdown of the SWI/SNF component ARID1B prevents OIS and cooperates with RAS to induce liver tumours. ARID1B controls p16INK4a and p21CIP1a transcription but also regulates DNA damage, oxidative stress and p53 induction, suggesting that SWI/SNF uses additional mechanisms to regulate senescence. To systematically identify SWI/SNF targets regulating senescence, we carried out a focused shRNA screen. We discovered several new senescence regulators including ENTPD7, an enzyme that hydrolyses nucleotides. ENTPD7 affects oxidative stress, DNA damage and senescence. Importantly, expression of ENTPD7 or inhibition of nucleotide synthesis in ARID1B-depleted cells results in re-establishment of senescence. Our results identify novel mechanisms by which epigenetic regulators can affect tumor progression and suggest that pro-senescence therapies could be employed against SWI/SNF-mutated cancers

Atmospheric lepton fluxes at ultrahigh energies

In order to estimate the possibility to observe exotic physics in a neutrino telescope, it is essential to first understand the flux of atmospheric neutrinos, muons and dimuons. We study the production of these leptons by high-energy cosmic rays. We identify three main sources of muons of energy E > 10^6 GeV: the weak decay of charm and bottom mesons and the electromagnetic decay of unflavored mesons. Contrary to the standard assumption, we find that eta mesons, not the prompt decay of charm hadrons, are the dominant source of atmospheric muons at these energies. We show that, as a consequence, the ratio between the neutrino and muon fluxes is significantly reduced. For dimuons, which may be a background for long-lived staus produced near a neutrino telescope, we find that pairs of E ~ 10^7 GeV forming an angle above 10^-6 rad are produced through D (80%) or B (10%) meson decay and through Drell-Yan proceses (10%). The frequency of all these processes has been evaluated using the jet code PYTHIA.Comment: 10 pages, 4 figures; published versio

The Pristine survey II: a sample of bright stars observed with FEROS

Extremely metal-poor (EMP) stars are old objects formed in the first Gyr of the Universe. They are rare and, to select them, the most successful strategy has been to build on large and low-resolution spectroscopic surveys. The combination of narrow- and broad band photometry provides a powerful and cheaper alternative to select metal-poor stars. The on-going Pristine Survey is adopting this strategy, conducting photometry with the CFHT MegaCam wide field imager and a narrow-band filter centred at 395.2 nm on the CaII-H and -K lines. In this paper we present the results of the spectroscopic follow-up conducted on a sample of 26 stars at the bright end of the magnitude range of the Survey (g<=15), using FEROS at the MPG/ESO 2.2 m telescope. From our chemical investigation on the sample, we conclude that this magnitude range is too bright to use the SDSS gri bands, which are typically saturated. Instead the Pristine photometry can be usefully combined with the APASS gri photometry to provide reliable metallicity estimates.Comment: AN accepte

Overcoming triple-negative breast cancer (TNBC) resistance to oncolytic virotherapy by histone deacetylase inhibitor, trichostatin A

"Triple-negative breast cancer (TNBC) is a tumor classification that lack receptors for the hormones estrogen, progesterone and HER2 protein. These malignancies are characterized to be of poor prognosis, refractoriness to conventional therapy and high rates of recurrence. Virotherapy with oncolytic adenovirus (OAd) consists of cancer selective viruses that replicate, spread, and kill cancer cells by oncolysis, without affecting the normal cells."--Introduction

Two-fluid turbulence including electron inertia

We present a full two-fluid magnetohydrodynamic (MHD) description for a completely ionized hydrogen plasma, retaining the effects of the Hall current, electron pressure and electron inertia. According to this description, each plasma species introduces a new spatial scale: the ion inertial length $\lambda_{i}$ and the electron inertial length $\lambda_{e}$, which are not present in the traditional MHD description. In the present paper, we seek for possible changes in the energy power spectrum in fully developed turbulent regimes, using numerical simulations of the two-fluid equations in two-and-a-half dimensions (2.5D). We have been able to reproduce different scaling laws in different spectral ranges, as it has been observed in the solar wind for the magnetic energy spectrum. At the smallest wavenumbers where plain MHD is valid, we obtain an inertial range following a Kolmogorov $k^{-5/3}$ law. For intermediate wavenumbers such that $\lambda_{i}^{-1} << k << \lambda_{e}^{-1}$, the spectrum is modified to a $k^{-7/3}$ power-law, as has also been obtained for Hall-MHD (HMHD) neglecting electron inertia terms. When electron inertia is retained, a new spectral region given by $k > \lambda_{e}^{-1}$ arises. The power spectrum for magnetic energy in this region is given by a $k^{-11/3}$ power law. Finally, when the terms of electron inertia are retained, we study the self-consistent electric field. Our results are discussed and compared with those obtained in solar wind observations and previous simulations