Chiral thermodynamics in a magnetic field

We study thermodynamic properties of the QCD vacuum in a magnetic field below chiral phase transition. The hadronic phase free energy in a constant homogeneous magnetic field is calculated in the framework of the chiral perturbation theory at non-zero pionic mass. It is demonstrated that the order parameter of the chiral phase transition remains constant provided temperature and magnetic field strength are related through obtained equation (the phenomenon of ''quark condensate freezing'').Comment: RevTeX4, 9 pages, no figure

Duality Symmetry in the Schwarz-Sen Model

The continuous extension of the discrete duality symmetry of the Schwarz-Sen model is studied. The corresponding infinitesimal generator $Q$ turns out to be local, gauge invariant and metric independent. Furthermore, $Q$ commutes with all the conformal group generators. We also show that $Q$ is equivalent to the non---local duality transformation generator found in the Hamiltonian formulation of Maxwell theory. We next consider the Batalin--Fradkin-Vilkovisky formalism for the Maxwell theory and demonstrate that requiring a local duality transformation lead us to the Schwarz--Sen formulation. The partition functions are shown to be the same which implies the quantum equivalence of the two approaches.Comment: 10 pages, latex, small changes, final version to appear in Phys. Rev.

Information entropy and nucleon correlations in nuclei

The information entropies in coordinate and momentum spaces and their sum ($S_r$, $S_k$, $S$) are evaluated for many nuclei using "experimental" densities or/and momentum distributions. The results are compared with the harmonic oscillator model and with the short-range correlated distributions. It is found that $S_r$ depends strongly on $\ln A$ and does not depend very much on the model. The behaviour of $S_k$ is opposite. The various cases we consider can be classified according to either the quantity of the experimental data we use or by the values of $S$, i.e., the increase of the quality of the density and of the momentum distributions leads to an increase of the values of $S$. In all cases, apart from the linear relation $S=a+b\ln A$, the linear relation $S=a_V+b_V \ln V$ also holds. V is the mean volume of the nucleus. If $S$ is considered as an ensemble entropy, a relation between $A$ or $V$ and the ensemble volume can be found. Finally, comparing different electron scattering experiments for the same nucleus, it is found that the larger the momentum transfer ranges, the larger the information entropy is. It is concluded that $S$ could be used to compare different experiments for the same nucleus and to choose the most reliable one.Comment: 14 pages, 4 figures, 2 table

Convective intensification of magnetic fields in the quiet Sun

Kilogauss-strength magnetic fields are often observed in intergranular lanes at the photosphere in the quiet Sun. Such fields are stronger than the equipartition field B_e, corresponding to a magnetic energy density that matches the kinetic energy density of photospheric convection, and comparable with the field B_p that exerts a magnetic pressure equal to the ambient gas pressure. We present an idealised numerical model of three-dimensional compressible magnetoconvection at the photosphere, for a range of values of the magnetic Reynolds number. In the absence of a magnetic field, the convection is highly supercritical and is characterised by a pattern of vigorous, time-dependent, “granular” motions. When a weak magnetic field is imposed upon the convection, magnetic flux is swept into the convective downflows where it forms localised concentrations. Unless this process is significantly inhibited by magnetic diffusion, the resulting fields are often much greater than B_e, and the high magnetic pressure in these flux elements leads to their being partially evacuated. Some of these flux elements contain ultra-intense magnetic fields that are significantly greater than B_p. Such fields are contained by a combination of the thermal pressure of the gas and the dynamic pressure of the convective motion, and they are constantly evolving. These ultra-intense fields develop owing to nonlinear interactions between magnetic fields and convection; they cannot be explained in terms of “convective collapse” within a thin flux tube that remains in overall pressure equilibrium with its surroundings

Evolution of hierarchical clustering in the CFHTLS-Wide since z~1

We present measurements of higher order clustering of galaxies from the latest release of the Canada-France-Hawaii-Telescope Legacy Survey (CFHTLS) Wide. We construct a volume-limited sample of galaxies that contains more than one million galaxies in the redshift range 0.2<z<1 distributed over the four independent fields of the CFHTLS. We use a counts in cells technique to measure the variance and the hierarchical moments S_n = /^(n-1) (3<n<5) as a function of redshift and angular scale.The robustness of our measurements if thoroughly tested, and the field-to-field scatter is in very good agreement with analytical predictions. At small scales, corresponding to the highly non-linear regime, we find a suggestion that the hierarchical moments increase with redshift. At large scales, corresponding to the weakly non-linear regime, measurements are fully consistent with perturbation theory predictions for standard LambdaCDM cosmology with a simple linear bias.Comment: 17 pages, 11 figures, submitted to MNRA

Fortification of dough with moringa, coriander, and amaranth improves the nutritional composition, health-benefiting properties, and sensory attributes of Nigerian wheat bread

Consumption of bread can be associated with some health issues, which can be improved by fortifying it with plants that are good sources of nutrients and bioactive compounds. This study investigated the effects of fortifying bread with 3 leafy vegetables on the quality of Nigerian wheat bread. Leave powders of coriander, moringa, and amaranths were added to wheat dough at 0% (control), 1%, 3%, 5%, or 7%, and the blends obtained were used to bake vegetable breads, which were then analyzed for proximate, minerals, total phenolics, antioxidant activity, reducing sugars, glycemic index, and sensory evaluation. Results showed that vegetable fortification significantly increased bread ash (from 0.84% in control up to 1.93% in fortified bread), crude fiber (from 1.68% to 3.29%), and nutritionally important minerals Ca, Mg, P, Fe, and Zn (up to 5.2-fold, 5.1-fold, 18.1-fold, 4.1-fold, and 14.0-fold, respectively); it reduced carbohydrates (from 65.65% down to 43.16%), crude lipids (from 2.25% down to 0.44%), and caloric value (from 1239.65 down to 1125.19 kJ/100 g), with little or no effect on proteins and moisture content. The fortification also improved the bioactive properties of the bread, as evidenced by a considerably higher phenolic content (from 0.40 up to 13.95 mg/100 g GAE) and increased antioxidant activities. There was a significant 1.1-to 3.4-fold decrease in the reducing sugars of composite breads with 5% and 7% vegetable powder, and the selected bread formulation with Moringa 7% lowered the glycemic index of rats by 3.5-fold. Fortification did not generally affect the appearance and taste of the breads but decreased other sensory parameters and overall acceptability; the bread sample enriched with 1% amaranth received the highest general acceptance. In conclusion, fortifying wheat bread with the 3 vegetables improves its nutritional quality and can be recommended as a new pathway for the development of more nutritious and healthy bread

The Físchlár digital video system: a digital library of broadcast TV programmes

Físchlár is a system for recording, indexing, browsing and playback of broadcast TV programmes which has been operational on our University campus for almost 18 months. In this paper we give a brief overview of how the system operates, how TV programmes are organised for browse/playback and a short report on the system usage by over 900 users in our University

Secondary organic aerosol (SOA) formation from reaction of isoprene with nitrate radicals (NO_3)

Secondary organic aerosol (SOA) formation from the reaction of isoprene with nitrate radicals (NO3) is investigated in the Caltech indoor chambers. Experiments are performed in the dark and under dry conditions (RH<10%) using N2O5 as a source of NO3 radicals. For an initial isoprene concentration of 18.4 to 101.6 ppb, the SOA yield (defined as the ratio of the mass of organic aerosol formed to the mass of parent hydrocarbon reacted) ranges from 4.3% to 23.8%. By examining the time evolutions of gas-phase intermediate products and aerosol volume in real time, we are able to constrain the chemistry that leads to the formation of low-volatility products. Although the formation of ROOR from the reaction of two peroxy radicals (RO2) has generally been considered as a minor channel, based on the gas-phase and aerosol-phase data it appears that RO2+RO2 reaction (self reaction or cross-reaction) in the gas phase yielding ROOR products is a dominant SOA formation pathway. A wide array of organic nitrates and peroxides are identified in the aerosol formed and mechanisms for SOA formation are proposed. Using a uniform SOA yield of 10% (corresponding to Mo≅10 μg m−3), it is estimated that ~2 to 3 Tg yr−1 of SOA results from isoprene + NO3. The extent to which the results from this study can be applied to conditions in the atmosphere depends on the fate of peroxy radicals (i.e. the relative importance of RO2+RO2 versus RO2+NO3 reactions) in the nighttime troposphere

A Minimum-Labeling Approach for Reconstructing Protein Networks across Multiple Conditions

The sheer amounts of biological data that are generated in recent years have driven the development of network analysis tools to facilitate the interpretation and representation of these data. A fundamental challenge in this domain is the reconstruction of a protein-protein subnetwork that underlies a process of interest from a genome-wide screen of associated genes. Despite intense work in this area, current algorithmic approaches are largely limited to analyzing a single screen and are, thus, unable to account for information on condition-specific genes, or reveal the dynamics (over time or condition) of the process in question. Here we propose a novel formulation for network reconstruction from multiple-condition data and devise an efficient integer program solution for it. We apply our algorithm to analyze the response to influenza infection in humans over time as well as to analyze a pair of ER export related screens in humans. By comparing to an extant, single-condition tool we demonstrate the power of our new approach in integrating data from multiple conditions in a compact and coherent manner, capturing the dynamics of the underlying processes.Comment: Peer-reviewed and presented as part of the 13th Workshop on Algorithms in Bioinformatics (WABI2013

Nonlinear Bogolyubov-Valatin transformations and quaternions

In introducing second quantization for fermions, Jordan and Wigner (1927/1928) observed that the algebra of a single pair of fermion creation and annihilation operators in quantum mechanics is closely related to the algebra of quaternions H. For the first time, here we exploit this fact to study nonlinear Bogolyubov-Valatin transformations (canonical transformations for fermions) for a single fermionic mode. By means of these transformations, a class of fermionic Hamiltonians in an external field is related to the standard Fermi oscillator.Comment: 6 pages REVTEX (v3: two paragraphs appended, minor stylistic changes, eq. (39) corrected, references [10]-[14], [36], [37], [41], [67]-[69] added; v4: few extensions, references [62], [63] added, final version to be published in J. Phys. A: Math. Gen.