The effective potential and resummation procedure to multidimensional complex cubic potentials for weak and strong-coupling

The method for the recursive calculation of the effective potential is applied successfully in case of weak coupling limit (g tend to zero) to a multidimensional complex cubic potential. In strong-coupling limit (g tend to infinity), the result is resumed using the variational perturbation theory (VPT). It is found that the convergence of VPT-results approaches those expected.Comment: 19 pages, 0 figur

Influence of gallic and tannic acids on enzymatic activity and growth of Pectobacterium chrysanthemi (Dickeya chrysanthemi bv. chrysanthemi)

The effect of phenolic acids (gallic and tannic acids) on growth of Pectobacterium chrysanhemi, and its protease and pectate lyase activities was tested. The results obtained showed a significant inhibitingeffect of the tannic and gallic acids on the growth of this strain. The growth rate decreases in the presence of 400 g/ml for gallic acid and 100 ìg/ml fortannic acid. The enzymatic activity retardationwas observed with the two phenolic compounds as well but the rate of inhibition varied from one compound to another. The highest antimicrobial potentials and the highest effect on enzymatic activities were observed with the tannic acid at 200 g/ml, which inhibited 91% of the tested microorganisms, and 88% of pectate lyase activity

A MEMS-based solid propellant microthruster array for space and military applications

Since combustion is an easy way to achieve large quantities of energy from a small volume, we developed a MEMS based solid propellant microthruster array for small spacecraft and micro-air-vehicle applications. A thruster is composed of a fuel chamber layer, a top-side igniter with a micromachined nozzle in the same silicon layer. Layers are assembled by adhesive bonding to give final MEMS array. The thrust force is generated by the combustion of propellant stored in a few millimeter cube chamber. The micro-igniter is a polysilicon resistor deposited on a low stress SiO2/SiNx thin membrane to ensure a good heat transfer to the propellant and thus a low electric power consumption. A large range of thrust force is obtained simply by varying chamber and nozzle geometry parameters in one step of Deep Reactive Ion Etching (DRIE). Experimental tests of ignition and combustion employing home made (DB+x% BP) propellant composed of a Double-Base and Black-Powder. A temperature of 250 therefore degrees C, enough to propellant initiation, is reached for 40 mW of electric power. A combustion rate of about 3.4 mm/s is measured for DB+20% BP propellant and thrust ranges between 0.1 and 3,5 mN are obtained for BP ratio between 10% and 30% using a microthruster of 100 mu m of throat wide

A generalized quantum nonlinear oscillator

We examine various generalizations, e.g. exactly solvable, quasi-exactly solvable and non-Hermitian variants, of a quantum nonlinear oscillator. For all these cases, the same mass function has been used and it has also been shown that the new exactly solvable potentials possess shape invariance symmetry. The solutions are obtained in terms of classical orthogonal polynomials

The Measurement of Territorial Differences in the Information Society

Glutamine synthetase (GS, EC 6.3.1.2; also known as γ-glutamyl:ammonia ligase) catalyzes the ATP-dependent condensation of glutamate and ammonia to form glutamine. The enzyme has essential roles in different tissues and species, which have led to its consideration as a drug or an herbicide target. In this article, we describe studies aimed at the discovery of new antimicrobial agents targeting Mycobacterium tuberculosis, the causative pathogen of tuberculosis. A number of distinct classes of GS inhibitors with an IC50 of micromolar value or better were identified via high-throughput screening. A commercially available purine analogue similar to one of the clusters identified (the diketopurines), 1-[(3,4-dichlorophenyl)methyl]-3,7-dimethyl-8-morpholin-4-yl-purine-2,6-dione, was also shown to inhibit the enzyme, with a measured IC50 of 2.5 ± 0.4 μM. Two X-ray structures are presented: one is a complex of the enzyme with the purine analogue alone (2.55-Å resolution), and the other includes the compound together with methionine sulfoximine phosphate, magnesium and phosphate (2.2-Å resolution). The former represents a relaxed, inactive conformation of the enzyme, while the latter is a taut, active one. These structures show that the compound binds at the same position in the nucleotide site, regardless of the conformational state. The ATP-binding site of the human enzyme differs substantially, explaining why it has an ∼ 60-fold lower affinity for this compound than the bacterial GS. As part of this work, we devised a new synthetic procedure for generating l-(SR)-methionine sulfoximine phosphate from l-(SR)-methionine sulfoximine, which will facilitate future investigations of novel GS inhibitors

The seven lives of Airbnb. The role of accommodation types

This paper investigates how COVID-19 is impacting different accommodation types, and whether travellers' choices regarding accommodation type are affected by the need for physical distance. Study 1 shows that travellers are very reluctant to book shared flats on Airbnb during the pandemic. However, full flats – controlling for price levels - are preferred to hotel rooms. Study 2 clarifies the process behind the increased choice for full flats, i.e., the need for physical distance. In Study 3, we actively manipulate physical distance and show that assuring physical distance will reduce the concerns towards hotel and shared flat options. Apart from enlightening the psychological process behind accommodation choice, the study offers operators actionable suggestions on how to maximise bookings despite the pandemic. © 202

How distinctive are indigenous ways of achieving influence? A comparative study of guanxi, wasta, jeitinho, and "pulling strings"

The purpose of the study was to investigate the cultural specificity of guanxi, wasta, and jeitinho, each of which has been identified as an indigenous process of informal influence. Students in Brazil, China, Lebanon, and the United Kingdom were presented with three scenarios derived from each of the nations sampled. They rated the extent to which each scenario was representative of the locally indigenous process, the typicality for their culture of the events portrayed in the scenarios, and the extent to which these interpersonal exchanges were perceived positively. While each type of scenario was perceived as representative and typical in its culture of origin, each was also perceived as somewhat typical by respondents in additional locations. Informal influence processes may vary between cultures more in frequency than in quality. Rated scenario positivity was significantly predicted by respondents’ values. The United Kingdom–based process of “pulling strings” was rated as typical in all locations and was more positively evaluated than the other influence processes by all respondents. It is concluded that in addition to the pragmatic value of these concepts locally, their comparative testing can contribute to the development of culture-general models of social influence processes