Infrared gluons, intrinsic transverse momentum and rising total cross-sections

We discuss the infrared limit for soft gluon kt-resummation and relate it to physical observables such as the intrinsic transverse momentum and the high energy limit of total cross-sections.Comment: 8 pages, 6 figures, Presented at Hadron Structure '09, Tatranska Strba, September 2009, Slovacchia, to be published in the Conference Proceeding

Soft gluon radiation and energy dependence of total hadronic cross-sections

An impact parameter representation for soft gluon radiation is applied to obtain both the initial decrease of the total cross-section ($\sigma_{tot}$) for proton-proton collisions as well as the later rise of $\sigma_{tot}$ with energy for both $pp$ and $p\bar{p}$. The non-perturbative soft part of the eikonal includes only limited low energy gluon emission and leads to the initial decrease in the proton-proton cross- section. On the other hand, the rapid rise in the hard, perturbative jet part of the eikonal is tamed into the experimentally observed mild increase by soft gluon radiation whose maximum energy rises slowly with energy.Comment: 30 pages, 6 figures. Version accepted for publication in Physical Review D. Additional section with explanatory material added making the paper more self contained and two figures changed to have a complete summary of the available accelerator dat

Single paternal dexamethasone challenge programs offspring metabolism and reveals multiple candidates in RNA-mediated inheritance.

Single traumatic events that elicit an exaggerated stress response can lead to the development of neuropsychiatric conditions. Rodent studies suggested germline RNA as a mediator of effects of chronic environmental exposures to the progeny. The effects of an acute paternal stress exposure on the germline and their potential consequences on offspring remain to be seen. We find that acute administration of an agonist for the stress-sensitive Glucocorticoid receptor, using the common corticosteroid dexamethasone, affects the RNA payload of mature sperm as soon as 3 hr after exposure. It further impacts early embryonic transcriptional trajectories, as determined by single-embryo sequencing, and metabolism in the offspring. We show persistent regulation of tRNA fragments in sperm and descendant 2-cell embryos, suggesting transmission from sperm to embryo. Lastly, we unravel environmentally induced alterations in sperm circRNAs and their targets in the early embryo, highlighting this class as an additional candidate in RNA-mediated inheritance of disease risk.KG was funded by the Swiss National Science Foundation early postdoc and advanced postdoc mobility a SPARK and Novartis foundation grant. Some of this work was supported by Cancer Research UK (C13474/A18583, C6946/A14492) and Wellcome (104640/Z/14/Z, 092096/Z/10/Z) to EAM. GP and MH were supported by a core grant from the Wellcome Trust. The lab of JB is currently funded by the ETH Zurich, SNSF Project Grant 310030_172889/1, ETH Research Grant ETH-20 19-1, the Kurt und Senta Herrmann-Stiftung, the Botnar Research Center for Child Health and a 3R Competence Center Project Grant. JK was supported by a Swiss-european mobility programme scholarship

p – air production cross-section and uncorrelated mini-jets processes in pp-scattering

For the p – air production cross-section, we use a Glauber formalism which inputs the pp inelastic cross-section from a mini-jet model embedded in a single-channel eikonal expression, that provides the needed contribution of uncorrelated processes. It is then shown that current LO parton density functions for the pp mini-jet cross-sections, with a rise tempered by acollinearity induced by soft gluon re-summation, are well suited to reproduce recent cosmic ray results. By comparing results for GRV, MRST72 and MSTW parametrizations, we estimate the uncertainty related to the low-x behavior of these densities.(FQM 6552, FQM 101). D.A.F. acknowledges the São Paulo Research Foundation (FAPESP) and the Coordination for the Improvement of Higher Education Personnel (CAPES) for financial support (contract: 2014/00337-8). O.S. acknowledges partial support from funds of Foundation of Polish Science grant POMOST/2013-7/12, that is co-financed from European Union, Regional Development Fund

Total photoproduction cross-section at very high energy

In this paper we apply to photoproduction total cross-section a model we have proposed for purely hadronic processes and which is based on QCD mini-jets and soft gluon re-summation. We compare the predictions of our model with the HERA data as well as with other models. For cosmic rays, our model predicts substantially higher cross-sections at TeV energies than models based on factorization but lower than models based on mini-jets alone, without soft gluons. We discuss the origin of this difference.Comment: 13 pages, 9 figures. Accepted for publication in EPJC. Changes concern added references, clarifications of the Soft Gluon Resummation method used in the paper, and other changes requested by the Journal referee which do not change the results of the original versio

Ldrb toxin with in vitro and in vivo antitumor activity as a potential tool for cancer gene therapy

Due to the high prevalence of cancer in recent years, it is necessary to develop new and more effective therapies that produce fewer side effects. Development of gene therapy for cancer based on the use of suicide genes that can damage the tumor cell, without requiring a prodrug for its lethal effect, is one of the recent foci of gene therapy strategies. We evaluated the cytotoxic impact of the LdrB toxin from Escherichia coli k12 as a possible tool for cancer gene therapy. For that, colorectal and breast cancer cells were transfected under the control of a TRE3G promoter inducible by doxycycline. Our results showed that ldrB gene expression induced a drastic inhibition of proliferation in vitro, in both 2D and 3D experimental models. Moreover, unlike conventional chemotherapy, the ldrB gene induced a severe loss of proliferation in vivo without any side effects in our animal model. This antitumor outcome was modulated by cell cycle arrest in the G0/G1 phase and apoptotic death. Scanning electronic microscopy demonstrates that the LdrB toxin conserves its pore-forming ability in HCT-116 cells as in E. coli k12. Taken together, our results provide, for the first time, a proof of concept of the antitumor capacity of the ldrB gene in colorectal and breast cancer.This research was supported by the Fundación Mutua Madrileña (project FMM-AP16683-2017), Consejería de Salud Junta de Andalucía (PI-0089-2017), the MNat Scientitc Unit of Excellence (UCE.PP2017.0f), and from the Chair “Doctors Galera-Requena in cancer stem cell research”

Solution of the Kwiecinski evolution equations for unintegrated parton distributions using the Mellin transform

The Kwiecinski equations for the QCD evolution of the unintegrated parton distributions in the transverse-coordinate space (b) are analyzed with the help of the Mellin-transform method. The equations are solved numerically in the general case, as well as in a small-b expansion which converges fast for b Lambda_QCD sufficiently small. We also discuss the asymptotic limit of large bQ and show that the distributions generated by the evolution decrease with b according to a power law. Numerical results are presented for the pion distributions with a simple valence-like initial condition at the low scale, following from chiral large-N_c quark models. We use two models: the Spectral Quark Model and the Nambu--Jona-Lasinio model. Formal aspects of the equations, such as the analytic form of the b-dependent anomalous dimensions, their analytic structure, as well as the limits of unintegrated parton densities at x -> 0, x -> 1, and at large b, are discussed in detail. The effect of spreading of the transverse momentum with the increasing scale is confirmed, with growing asymptotically as Q^2 alpha(Q^2). Approximate formulas for for each parton species is given, which may be used in practical applications.Comment: 18 pages, 6 figures, RevTe

A Q-Ising model application for linear-time image segmentation

A computational method is presented which efficiently segments digital grayscale images by directly applying the Q-state Ising (or Potts) model. Since the Potts model was first proposed in 1952, physicists have studied lattice models to gain deep insights into magnetism and other disordered systems. For some time, researchers have realized that digital images may be modeled in much the same way as these physical systems (i.e., as a square lattice of numerical values). A major drawback in using Potts model methods for image segmentation is that, with conventional methods, it processes in exponential time. Advances have been made via certain approximations to reduce the segmentation process to power-law time. However, in many applications (such as for sonar imagery), real-time processing requires much greater efficiency. This article contains a description of an energy minimization technique that applies four Potts (Q-Ising) models directly to the image and processes in linear time. The result is analogous to partitioning the system into regions of four classes of magnetism. This direct Potts segmentation technique is demonstrated on photographic, medical, and acoustic images.Comment: 7 pages, 8 figures, revtex, uses subfigure.sty. Central European Journal of Physics, in press (2010

Minijets, soft gluon resummation and photon cross-sections

We compare the high energy behaviour of hadronic photon-photon cross-sections in different models. We find that the photon-photon cross-section appears to rise faster than the purely hadronic ones (proton-proton and proton-antiproton).Comment: 7 pages, 5 figures. Presented at Photon2007, Paris, July 2007. Requires photon2007.cl

Theoretical expectations for total cross-sections at the large hadron collider

In this note, we summarize and compare various model predictions for $pp$ total cross-section $\sigma_{\rm tot}^{pp}$, giving an estimate of the range of predictions for the total cross-section, $\sigma_{\rm tot}^{pp}$ expected at the LHC. We concentrate on the results for \sigma_{\tot}^{pp} obtained in a particular QCD based model of the energy dependence of the total cross-section, including the effect of soft gluon radiation. We obtain the range of predictions in this model by exploring the allowed range of model parameters. We further give a handy parametrisation of these results which incidentally spans the range of various other available predictions at the LHC as well.Comment: 12 pages, 6 figures, laTeX, requires ias.cls, ias.sty include