Ground states and formal duality relations in the Gaussian core model

We study dimensional trends in ground states for soft-matter systems. Specifically, using a high-dimensional version of Parrinello-Rahman dynamics, we investigate the behavior of the Gaussian core model in up to eight dimensions. The results include unexpected geometric structures, with surprising anisotropy as well as formal duality relations. These duality relations suggest that the Gaussian core model possesses unexplored symmetries, and they have implications for a broad range of soft-core potentials.Comment: 7 pages, 1 figure, appeared in Physical Review E (http://pre.aps.org

Superposition in nonlinear wave and evolution equations

Real and bounded elliptic solutions suitable for applying the Khare-Sukhatme superposition procedure are presented and used to generate superposition solutions of the generalized modified Kadomtsev-Petviashvili equation (gmKPE) and the nonlinear cubic-quintic Schroedinger equation (NLCQSE).Comment: submitted to International Journal of Theoretical Physics, 23 pages, 2 figures, style change

A note on entropic uncertainty relations of position and momentum

We consider two entropic uncertainty relations of position and momentum recently discussed in literature. By a suitable rescaling of one of them, we obtain a smooth interpolation of both for high-resolution and low-resolution measurements respectively. Because our interpolation has never been mentioned in literature before, we propose it as a candidate for an improved entropic uncertainty relation of position and momentum. Up to now, the author has neither been able to falsify nor prove the new inequality. In our opinion it is a challenge to do either one.Comment: 2 pages, 2 figures, 2 references adde

Health effects of WiFi radiation: a review based on systematicquality evaluation

Although WiFi contributes little to totalradiofrequency electromagnetic field (RF-EMF) exposure in our everyday environ-ment, concern has raised whether this spe-cific type of modulated RF-EMF causeshealth problems. The aim of this review isto evaluate all types of studies that investi-gated biological and health effects of WiFiexposure and fulfilled basic quality criteria.Eligible for inclusion were epidemiological,human experimental,in vivoandin vitrostudies using realistic WiFi exposure set-tings. We conducted a systematic literaturesearch for all papers published betweenJanuary 1997 and August 2020 followed by a quality review addressing blinding and dosimetry inexperimental studies and various types of biases in epidemiological studies. All studies fulfilling thequality criteria were descriptively summarized in terms of observation or absence of associations.From 1385 articles identified by the literature search, 23 fulfilled basic quality criteria: 6 epidemio-logical papers, 6 human experimental articles, 9in vivoarticles, and 2in vitroarticles. Whereasinvivoandin vitrostudies applied exposure levels up to 4 W/kg, human studies dealt with exposurelevels several orders of magnitude below the ICNIRP guidelines, which are typical for WiFi exposuresituations in the everyday environment. Numerous outcomes ranging from biological markers tosymptoms were mostly found not to be associated with WiFi exposure. Sporadic findings were notconsistent in terms of outcomes or exposure-response associations. This review based on a system-atic literature search and quality evaluation does not suggest detrimental health effects from WiFiexposure below regulatory limits

Random perfect lattices and the sphere packing problem

Motivated by the search for best lattice sphere packings in Euclidean spaces of large dimensions we study randomly generated perfect lattices in moderately large dimensions (up to d=19 included). Perfect lattices are relevant in the solution of the problem of lattice sphere packing, because the best lattice packing is a perfect lattice and because they can be generated easily by an algorithm. Their number however grows super-exponentially with the dimension so to get an idea of their properties we propose to study a randomized version of the algorithm and to define a random ensemble with an effective temperature in a way reminiscent of a Monte-Carlo simulation. We therefore study the distribution of packing fractions and kissing numbers of these ensembles and show how as the temperature is decreased the best know packers are easily recovered. We find that, even at infinite temperature, the typical perfect lattices are considerably denser than known families (like A_d and D_d) and we propose two hypotheses between which we cannot distinguish in this paper: one in which they improve Minkowsky's bound phi\sim 2^{-(0.84+-0.06) d}, and a competitor, in which their packing fraction decreases super-exponentially, namely phi\sim d^{-a d} but with a very small coefficient a=0.06+-0.04. We also find properties of the random walk which are suggestive of a glassy system already for moderately small dimensions. We also analyze local structure of network of perfect lattices conjecturing that this is a scale-free network in all dimensions with constant scaling exponent 2.6+-0.1.Comment: 19 pages, 22 figure

Discovering SUSY in the first LHC run

4 páginas, 1 figura.-- Trabajo presentado a la Fifth Conference on Physics at LHC celebrada en Hamburgo (Alemania) del 7 al 12 de junio de 2010.We analyze the potential of the first LHC physics run, assuming 1 fb−1 at ps = 7 TeV, to discover Supersymmetry (SUSY). The results are based on SUSY parameter fits following a frequentist approach. They include the experimental constraints from electroweak precision data, (g − 2)μ, B physics and cosmological data. The two SUSY models under consideration are the constrained MSSM (CMSSM) with universal soft supersymmetry-breaking mass parameters, and a model with common non-universal Higgs mass parameters in the superpotential (NUHM1). We find that large parts of the regions preferred at the 68% C.L. are accessible to early LHC running.Work supported in part by the European Community’s Marie-Curie Research Training Network under contract MRTN-CT-2006-035505 ‘Tools and Precision Calculations for Physics Discoveries at Colliders’ (HEPTOOLS).Peer reviewe

Study of the 12C+12C fusion reactions near the Gamow energy

The fusion reactions 12C(12C,a)20Ne and 12C(12C,p)23Na have been studied from E = 2.10 to 4.75 MeV by gamma-ray spectroscopy using a C target with ultra-low hydrogen contamination. The deduced astrophysical S(E)* factor exhibits new resonances at E <= 3.0 MeV, in particular a strong resonance at E = 2.14 MeV, which lies at the high-energy tail of the Gamow peak. The resonance increases the present non-resonant reaction rate of the alpha channel by a factor of 5 near T = 8x10^8 K. Due to the resonance structure, extrapolation to the Gamow energy E_G = 1.5 MeV is quite uncertain. An experimental approach based on an underground accelerator placed in a salt mine in combination with a high efficiency detection setup could provide data over the full E_G energy range.Comment: 4 Pages, 4 figures, accepted for publication in Phys. Rev. Let

Early Appropriate Parenteral Antimicrobial Treatment of Complicated Skin and Soft Tissue Infections Caused by Methicillin-Resistant Staphylococcus aureus

Abstract Background: Complicated skin and soft tissue infections (cSSTIs) are a major clinical problem, in part because of the increasing resistance of infecting bacteria to our current antibiotic therapies. Prompt appropriate treatment of infections in hospitalized patients reduces the mortality rate. Furthermore, appropriate and timely antibiotic therapy improves outcomes for cSSTIs caused by methicillin-resistant Staphylococcus aureus (MRSA). This review delineates factors to consider in the choice of initial antibiotic treatment for cSSTIs and describes the antimicrobial agents available or under clinical development for the treatment of cSSTIs caused by MRSA. Methods: Review of the pertinent literature and recommendations. Results: The choice of antimicrobial agent for empiric treatment of cSSTIs should be guided by the site and type of infection, the presence of an immunocompromised state or neutropenia, and risk factors for hospital-acquired MRSA (HA-MRSA) or community-associated MRSA (CA-MRSA) infection. Most CA-MRSA strains remain susceptible to ciprofloxacin, clindamycin, gentamicin, and trimethoprim/sulfamethoxazole, although resistance to clindamycin can emerge during treatment. Of the agents available for the treatment of HA-MRSA cSSTIs, vancomycin has been the reference standard, but clinical failures have been reported increasingly. Alternative agents for HA-MRSA include linezolid, which has been well-studied for treatment of cSSTIs, as well as daptomycin and tigecycline. A number of antibiotic agents are undergoing clinical trials or are under development for the treatment of cSSTIs caused by MRSA. Conclusions: Severe and progressive cSSTIs should be treated promptly with appropriate antibiotic agents. The choice of agent should be guided by a number of factors, including suspected CA-MRSA or HA-MRSA infection. Available agents should be evaluated carefully for efficacy in the treatment of MRSA cSSTIs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63135/1/sur.2008.063.supp.pd