Harnack inequality and regularity for degenerate quasilinear elliptic equations

We prove Harnack inequality and local regularity results for weak solutions of a quasilinear degenerate equation in divergence form under natural growth conditions. The degeneracy is given by a suitable power of a strong $A_\infty$ weight. Regularity results are achieved under minimal assumptions on the coefficients and, as an application, we prove $C^{1,\alpha}$ local estimates for solutions of a degenerate equation in non divergence form

Rb, Rc and Jet Distributions at the Tevatron in a Model with an extra vector boson

We show that the reported anomalies in $R_b$ and $R_c$ can be interpreted as the effect of a heavy vector boson \zprime\ universally coupled to $u$- and $d$-type quarks separately and nearly decoupled from leptons. This extra vector boson could then also naturally explain the apparent excess of the jet rate at large transverse momentum observed at CDF.Comment: 10 pages, latex, 4 eps figures. Revised version, including corrected typos in figures and formulas, and addendum on low energy neutral current data. To appear on Phys Lett

Impact of different dosing regimens of clopidogrel on systemic oxidative stress in patients undergoing elective percutaneous coronary intervention.

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Social Media Data Can Be Used to Understand Tourists’ Preferences for Nature-Based Experiences in Protected Areas

Can social media data be used as an alternative to traditional surveys to understand tourists’ preferences for nature-based experiences in protected areas? We explored this by comparing preferences for biodiversity obtained from a traditional survey conducted in Kruger National Park, South Africa, with observed preferences assessed from over 13,600 pictures shared on Instagram and Flickr by tourists visiting the park in the same period. We found no significant difference between the preferences of tourists as stated in the surveys and the preferences revealed by social media content. Overall, large-bodied mammals were found to be the favorite group, both in the survey and on social media platforms. However, Flickr was found to better match tourists’ preference for less-charismatic biodiversity. Our findings suggest that social media content can be used as a cost-efficient way to explore, and for more continuous monitoring of, preferences for biodiversity and human activities in protected areas.Peer reviewe

Mesoscopic QCD and the Theta Vacua

The partition function of QCD is analyzed for an arbitrary number of flavors, N_f, and arbitrary quark masses including the contributions from all topological sectors in the Leutwyler--Smilga regime. For given N_f and arbitrary vacuum angle, \theta, the partition function can be reduced to N_f-2 angular integrations of single Bessel functions. For two and three flavors, the \theta dependence of the QCD vacuum is studied in detail. For N_f= 2 and 3, the chiral condensate decreases monotonically as \theta increases from zero to \pi and the chiral condensate develops a cusp at \theta=\pi for degenerate quark masses in the macroscopic limit. We find a discontinuity at \theta=\pi in the first derivative of the energy density with respect to \theta for degenerate quark masses. This corresponds to the first--order phase transition in which CP is spontaneously broken, known as Dashen's phenomena.Comment: 31 pages, revtex, 10 figures, final version to appear in Nucl. Phys.

Research on the strategy of multinational enterprises: Key approaches and new avenues

Over decades, research on multinational enterprises’ (MNEs) strategies has been anchored in internalization theory. Strongly grounded in transaction cost economics to explain foreign market entry, it hardly explains how MNEs can build and sustain a competitive advantage. Thus, this paper aims at understanding how the nature of strategic thinking has influenced the research in the field of MNEs’ strategy. A content analysis of 1116 papers was conducted. The intellectual structure and dynamics of research to date are provided, without losing sight of the key foundations of strategy and strategic management. The links between human capital and knowledge are the factors on which to underpin the explanation of the MNEs’ strategies and support the coevolving theory. This theory is a promising avenue of research under the umbrella of RBV and KBV approaches. The context-dependency of strategy implies that different contexts require different approaches. Accordingly, we provide insights for future research by combining main schools of strategy though

P and CP Violation and New Thermalization Scenario in Heavy Ion Collisions

The violation of local P and CP invariance in QCD, as it is observed at RHIC, has been a subject of intense discussions for the last couple of years.Separately, a new thermalization scenario for heavy ion collisions through the event horizon as a manifestation of the Unruh effect, has been also suggested. In this paper we argue that these two, naively unrelated phenomena, are actually two sides of the same coin as they are deeply rooted into the same fundamental physics related to some very nontrivial topological features of QCD. We formulate the universality conjecture for P and CP odd effects in heavy ion collisions analogous to the universal thermal behaviour observed in all other high energy interactions.Comment: Matches the journal versio

θ−\theta- Parameter in 2 Color QCD at Finite Baryon and Isospin Density

We use 2-color QCD as a model to study the effects of simultaneous presence of the so-called $\theta$ parameter, chemical potentials for baryon number, $\mu_B$ and for isospin charge, $\mu_I$. We pay special attention to $\theta$, $\mu_B$, $\mu_I$ dependence of different vacuum condensates, including chiral and diquark condensates, as well as the gluon condensate, $$, and the topological susceptibility. We find that two phase transitions of the second order will occur when $\theta$ relaxes from $\theta=2\pi$ to $\theta=0$, if $\mu$ is of order of the pion mass. We demonstrate that the transition to the superfluid phase at $\theta = \pi$ occurs at a much lower chemical potential than at $\theta = 0$. We also show that the strong $\theta$ dependence present near $\theta = \pi$ in vacuum (Dashen's phenomenon), becomes smoothed out in the superfluid phase. Finally, we comment on the relevance of this study for the real world with N_c=3

Multiwavelength study of TeV Blazar Mrk421 during giant flare

Context: The nearby (z=0.031) TeV blazar Mrk421 was reported to be in a high state of flux activity since November, 2009. Aims: To investigate possible changes in the physical parameters of Mrk421 during its high state of activity using multiwavelength data. Methods: We have observed this source in bright state using High Altitude GAmma Ray (HAGAR) telescope array at energies above 250 GeV during February 13 - 19, 2010. Optical, X-ray and gamma-ray archival data are also used to obtain the SEDs and light curves. Results: Mrk421 was found to undergo one of its brightest flaring episodes on February 17, 2010 by various observations in X-rays and gamma-rays. HAGAR observations during February 13 - 19, 2010 at the energies above 250 GeV show an enhancement in the flux level, with a maximum flux of ~ 7 Crab units being detected on February 17, 2010. We present the spectral energy distributions during this flaring episode and investigate the correlation of the variability in X-ray and gamma-ray bands. Conclusions: Our multiwavelength study suggests that the flare detected during February 16 and 17, 2010 could arise due to a passing shock in the jet.Comment: 9 pages, 10 figures, Accepted for publication in Astronomy and Astrophysics (A & A