Logistics global network connectivity and its determinants. A European City network analysis

The Globalization and World City Research Network classifies global cities according to their connectivity through advanced producer service activities. Recent studies have suggested there is scope to develop a new classification of cities based on advanced logistics services. Within this framework, the aim of this paper is twofold: (i) to develop an interlocking Logistics Global Network for advanced logistics in Europe and measure the Logistics Global Network Connectivity (LGNC) of the host cities; (ii) to explore the variables explaining each the cities' score on the LGNC. The aim is achieved by means of a mixed methodological approach based on Taylor's Interlocking Network Model and via econometric analysis through Ordinary Least Square regression (OLS)

Temperature dependent photoemission on 1T-TiSe2: Interpretation within the exciton condensate phase model

The charge density wave phase transition of 1T-TiSe2 is studied by angle-resolved photoemission over a wide temperature range. An important chemical potential shift which strongly evolves with temperature is evidenced. In the framework of the exciton condensate phase, the detailed temperature dependence of the associated order parameter is extracted. Having a mean-field-like behaviour at low temperature, it exhibits a non-zero value above the transition, interpreted as the signature of strong excitonic fluctuations, reminiscent of the pseudo-gap phase of high temperature superconductors. Integrated intensity around the Fermi level is found to display a trend similar to the measured resistivity and is discussed within the model.Comment: 8 pages, 6 figure

Prospects of detecting gamma-ray emission from galaxy clusters: cosmic rays and dark matter annihilations

We study the possibility for detecting gamma-ray emission from galaxy clusters. We consider 1) leptophilic models of dark matter (DM) annihilation that include a Sommerfeld enhancement (SFE), 2) different representative benchmark models of supersymmetric DM, and 3) cosmic ray (CR) induced pion decay. Among all clusters/groups of a flux-limited X-ray sample, we predict Virgo, Fornax and M49 to be the brightest DM sources and find a particularly low CR-induced background for Fornax. For a minimum substructure mass given by the DM free-streaming scale, cluster halos maximize the substructure boost for which we find a factor above 1000. Since regions around the virial radius dominate the annihilation flux of substructures, the resulting surface brightness profiles are almost flat. This makes it very challenging to detect this flux with imaging atmospheric Cherenkov telescopes. Assuming cold dark matter with a substructure mass distribution down to an Earth mass and using extended Fermi upper limits, we rule out the leptophilic models in their present form in 28 clusters, and limit the boost from SFE in M49 and Fornax to be < 5. This corresponds to a limit on SFE in the Milky Way of < 3, which is too small to account for the increasing positron fraction with energy as seen by PAMELA and challenges the DM interpretation. Alternatively, if SFE is realized in Nature, this would imply a limiting substructure mass of M_lim > 10^4 M_sol - a problem for structure formation. Using individual cluster observations, it will be challenging for Fermi to constrain our selection of DM benchmark models without SFE. The Fermi upper limits are, however, closing in on our predictions for the CR flux using an analytic model based on cosmological hydrodynamical cluster simulations. We limit the CR-to-thermal pressure in nearby bright galaxy clusters of the Fermi sample to < 10% and in Norma and Coma to < 3%.Comment: 43 pages, 23 figures, 10 tables. Accepted for publication in Phys. Rev. D: streamlined paper, added a paragraph about detectability to introduction, few references added, and few typos correcte

Generation and delivery of free hydroxyl radicals using a remote plasma

We demonstrate a new gas-based generation source using a low power radio frequency driven atmospheric pressure plasma configured to deliver the radical flux into the far effluent region, well away from interference from other plasma factors such as electric fields, currents, and ultraviolet radiation. Using He–H2O gas chemistry isolated from the laboratory air, the plasma generated flux contains and other radicals including, O and HO2 as well as H2O2 which, along with, was found to vary with H2O vapour content and absorbed power density. Peak flux values were 2.3 nmol s−1 and 0.23 nmol s1 for H2O2 and respectively at a distance of 50 mm from the plasma, with 790 ppmv H2O and a power density of ∼108 W m−3. The maximum flux density was 4.5 × 1019 m−2s−1 falling to 1.7 × 1019 m2 s1 at 110 mm, equivalent to generation rates of 74 µM s1 and 28 µM s−1. Despite high recombination rates at the plasma exit, the escaping flux is still significant, indicating a viable delivery capability to downstream targets. Its performance with regard to generation rates compares well with traditional generation techniques such as radiolysis, advanced oxidation processes and enhanced Fenton-chemistry approaches where production rates are sub-µM s−1. Delivering precisely quantifiable fluxes provides new opportunities for scientific studies and technological opportunities in cell biology, atmospheric chemistry, protein unfolding and systematic dose studies for plasma-based and other related potential medical treatments

Une initiative intéressante du Conseil général des Alpes-Maritimes : le programme triennal de débroussaillement

International audienc

An Alternative Interpretation of Recent ARPES Measurements on TiSe2

Recently there has been a renewed interest in the charge density wave transition of TiSe2, fuelled by the possibility that this transition may be driven by the formation of an excitonic insulator or even an excitonic condensate. We show here that the recent ARPES measurements on TiSe2 can also be interpreted in terms of an alternative scenario, in which the transition is due to a combination of Jahn-Teller effects and exciton formation. The hybrid exciton-phonons which cause the CDW formation interpolate between a purely structural and a purely electronic type of transition. Above the transition temperature, the electron-phonon coupling becomes ineffective but a finite mean-field density of excitons remains and gives rise to the observed diffuse ARPES signals.Comment: 4 pages, 2 figure

Rapamycin delays growth of Wnt-1 tumors in spite of suppression of host immunity

<p>Abstract</p> <p>Background</p> <p>Rapamycin, an inhibitor of mammalian target of Rapamycin (mTOR), is an immunosuppressive agent that has anti-proliferative effects on some tumors. However, the role of Rapamycin-induced immune suppression on tumor progression has not been examined.</p> <p>Methods</p> <p>We developed a transplantation model for generation of mammary tumors in syngeneic recipients that can be used to address the role of the immune system on tumor progression. We examined the effect of Rapamycin on the immune system and growth of MMTV-driven Wnt-1 mammary tumors which were transplanted into irradiated and bone marrow-reconstituted, or naïve mice.</p> <p>Results</p> <p>Rapamycin induced severe immunosuppression and significantly delayed the growth of Wnt-1 tumors. T cell depletion in spleen and thymus and reduction in T cell cytokine secretion were evident within 7 days of therapy. By day 20, splenic but not thymic T cell counts, and cytokine secretion recovered. We determined whether adoptive T cell therapy enhances the anti-cancer effect using <it>ex vivo </it>generated Rapamycin-resistant T cells. However, T cell transfer during Rapamycin therapy did not improve the outcome relative to drug therapy alone. Thus, we could not confirm that suppression of T cell immunity contributes to tumor growth in this model. Consistent with suppression of the mTOR pathway, decreased 4E-BP1, p70 S6-kinase, and S6 protein phosphorylation correlated with a decrease in Wnt-1 tumor cell proliferation.</p> <p>Conclusion</p> <p>Rapamycin has a direct anti-tumor effect on Wnt-1 breast cancer <it>in vivo </it>that involves inhibition of the mTOR pathway at doses that also suppress host immune responses.</p

Boson-boson scattering and Higgs production at the LHC from a six fermion point of view: four jets + lν\nu processes at \O(\alpha_{em}^6)

Boson-boson scattering and Higgs production in boson-boson fusion hold the key to electroweak symmetry breaking. In order to analyze these essential features of the Standard Model we have performed a partonic level study of all processes $q_1 q_2 \to q_3 q_4 q_5 q_6 l \nu$ at the LHC using the exact matrix elements at \O(\alpha_{em}^6) provided by \Phase, a new MC generator. These processes include also three boson production and the purely electroweak contribution to \toptop production as well as all irreducible backgrounds. Kinematical cuts have been studied in order to enhance the VV scattering signal over background. \Phase has been compared with different Monte Carlo's showing that a complete calculation is necessary for a correct description of the process.Comment: 26 pages, 19 figure