Lepton asymmetry and the cosmic QCD transition

We study the influence of lepton asymmetry on the evolution of the early Universe. The lepton asymmetry $l$ is poorly constrained by observations and might be orders of magnitude larger than the baryon asymmetry $b$, $|l|/b \leq 2\times 10^8$. We find that lepton asymmetries that are large compared to the tiny baryon asymmetry, can influence the dynamics of the QCD phase transition significantly. The cosmic trajectory in the $\mu_B-T$ phase diagram of strongly interacting matter becomes a function of lepton (flavour) asymmetry. Large lepton asymmetry could lead to a cosmic QCD phase transition of first order.Comment: 23 pages, 14 figures; matches published version, including Erratum. Conclusions, pictures, numerics remained unchange

Heterocyst placement strategies to maximize growth of cyanobacterial filaments

Under conditions of limited fixed-nitrogen, some filamentous cyanobacteria develop a regular pattern of heterocyst cells that fix nitrogen for the remaining vegetative cells. We examine three different heterocyst placement strategies by quantitatively modelling filament growth while varying both external fixed-nitrogen and leakage from the filament. We find that there is an optimum heterocyst frequency which maximizes the growth rate of the filament; the optimum frequency decreases as the external fixed-nitrogen concentration increases but increases as the leakage increases. In the presence of leakage, filaments implementing a local heterocyst placement strategy grow significantly faster than filaments implementing random heterocyst placement strategies. With no extracellular fixed-nitrogen, consistent with recent experimental studies of Anabaena sp. PCC 7120, the modelled heterocyst spacing distribution using our local heterocyst placement strategy is qualitatively similar to experimentally observed patterns. As external fixed-nitrogen is increased, the spacing distribution for our local placement strategy retains the same shape while the average spacing between heterocysts continuously increases.Comment: This is an author-created, un-copyedited version of an article accepted for publication in Physical Biology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher-authenticated version will be available onlin

thermodynamic properties of pb3u11o36

Abstract In order to progress in the development of Lead-cooled Fast Reactors, from the safety point of view it is essential to understand the chemical compatibility between liquid lead and uranium oxide. In the present work, entropy and heat capacity of Pb3U11O36, a possible ternary compound coming from fuel-coolant chemical interaction, were determined for the first time. Entropy at 298.15 K was obtained from low temperature heat capacity measurements using the Physical Property Measurement System (PPMS) in the temperature range 2–300 K, while the high temperature heat capacity has been measured by a drop calorimeter from 373 K to 1200 K. The experimental thermodynamic properties were compared with the values computed by means of DFT-GGA simulations, obtaining a very good agreement

GENERAL CONSIDERATIONS CONCERNING THE EFFECTS OF ELECTRO-OSMOSIS ON DECREASING THE FORCES AND THE ENERGY NEEDED FOR TILLING THE SOIL

Electro-osmosis principle consists in the application of a direct current voltage for an anode-cathode system introduced into soil. The effect of this system consists of the mobilization of water particles from the soil and their transport, in a very short time, from the anode to cathode. The soil water transported from the anode to cathode, on the tool-soil contact surface, in consequence, will produce a lubrication of the active surface and thereby a considerable reduction of the friction forces and implicitly of the energy necessary to move the tool through the soil

Composition with Target Constraints

It is known that the composition of schema mappings, each specified by source-to-target tgds (st-tgds), can be specified by a second-order tgd (SO tgd). We consider the question of what happens when target constraints are allowed. Specifically, we consider the question of specifying the composition of standard schema mappings (those specified by st-tgds, target egds, and a weakly acyclic set of target tgds). We show that SO tgds, even with the assistance of arbitrary source constraints and target constraints, cannot specify in general the composition of two standard schema mappings. Therefore, we introduce source-to-target second-order dependencies (st-SO dependencies), which are similar to SO tgds, but allow equations in the conclusion. We show that st-SO dependencies (along with target egds and target tgds) are sufficient to express the composition of every finite sequence of standard schema mappings, and further, every st-SO dependency specifies such a composition. In addition to this expressive power, we show that st-SO dependencies enjoy other desirable properties. In particular, they have a polynomial-time chase that generates a universal solution. This universal solution can be used to find the certain answers to unions of conjunctive queries in polynomial time. It is easy to show that the composition of an arbitrary number of standard schema mappings is equivalent to the composition of only two standard schema mappings. We show that surprisingly, the analogous result holds also for schema mappings specified by just st-tgds (no target constraints). This is proven by showing that every SO tgd is equivalent to an unnested SO tgd (one where there is no nesting of function symbols). Similarly, we prove unnesting results for st-SO dependencies, with the same types of consequences.Comment: This paper is an extended version of: M. Arenas, R. Fagin, and A. Nash. Composition with Target Constraints. In 13th International Conference on Database Theory (ICDT), pages 129-142, 201

Synthesis of New Methionine Derivatives for the Treatment of Paracetamol - Induced Hepatic Injury

The direct pharmacological properties of amino acids and the possibility of using them as carriers for other active pharmacological substances are well known. Methionine, being able to yield the methyl group, is very important in the treatment of hepatic diseases. Paracetamol acute poisoning causes liver injury in both humans and animals. The study is designed to synthesize some new methionine derivatives and to establish a possible correlation between the new structure and the pharmacological properties. To this end, acute experimental poisoning with PanadolВ® (paracetamol) was performed while, for the treatment of liver injury caused by this compound, two original synthesis derivatives of methionine, namely N-(m-nitrobenzoyl)- L-methionine and N-(m-aminobenzoyl)-L-methionine, were used. Male Wistar rats were administered PanadolВ® (paracetamol) per oral (7500 mg/kg). N-(m-nitrobenzoyl)-L-methionine (m-NBM) 50 mg/kg and N-(m-aminobenzoyl)-L-methionine (m-ABM) 50 mg/kg were given intraperitoneally, 30 minutes after PanadolВ® administration. Biochemical parameters such as SGOT, SGPT, serum bilirubin and glycemia were estimated to assess the liver function. PanadolВ® (paracetamol) poisoning produced an increase in serum transaminases, bilirubin and glicemia. These effects were reduced by treatment with m-NBM and especially m-ABM. These biochemical observations were supplemented by histopathological examination of liver sections. The results obtained with m-ABM were comparable with those reported on methionine, which is a recognised antidote in paracetamol poisoning

Modelling of the effect of scale on the compressibility parameters of fine-grained soils

The effect of sample scale represents a challenge when obtaining engineering parameters in the laboratory compared to those obtained in the field. This study aimed at contributing to existing knowledge numerically using the finite element software PLAXIS 2D. The investigations were analysed in terms of height scale (HS) and diameter scale (DS) through a series of laboratory tests. Its effect on compressibility parameters such as coefficient of consolidation (cv) was noted experimentally and showed that the sample scale greatly influences soil parameters most particularly at DS. The soil behaviour was found to be dependent on both DS and HS with a correlation factor of 0.650 and 0.062, respectively. The experimental data were validated in PLAXIS and a new proposed model was developed in PLAXIS 2D under the DS. The new proposed model developed was found to show no significant difference with the laboratory data