Моделирование рынка труда с использованием двухаргументной функции предложения труда

Розглянуто двохаргументну функцію індивідуальної пропозиції праці, аргументами якої є оплата праці та рівень безробіття. Досліджено умови виникнення прямої та зворотної залежності між цими двома економічними показниками. За допомогою двохаргументної функції проведено аналіз процесів на конкурентному та монопсонічному ринках праці. Обґрунтованo доцільність та умови застосування екзогенного підвищення оплати праці шляхом підвищення мінімальної заробітної плати.A two-argument function of individual labor supply is considered. Real wage and unemployment rate are the arguments of this function. The conditions of arising of direct and opposite dependence between these two economic indicators are investigated. This function is used to analyze processes in a competitive and monopsonic labor market. The expediency and conditions for applying the exogenous increase in labor compensation by fixing minimal wage are substantiated

Enhanced structural correlations accelerate diffusion in charge-stabilized colloidal suspensions

Theoretical calculations for colloidal charge-stabilized and hard sphere suspensions show that hydrodynamic interactions yield a qualitatively different particle concentration dependence of the short-time self-diffusion coefficient. The effect, however, is numerically small and hardly accessible by conventional light scattering experiments. Applying multiple-scattering decorrelation equipment and a careful data analysis we show that the theoretical prediction for charged particles is in agreement with our experimental results from aqueous polystyrene latex suspensions.Comment: 1 ps-file (MS-Word), 14 page

Multivalent Fucosides Targeting β-Propeller Lectins from Lung Pathogens with Promising Anti-Adhesive Properties

Fungal and bacterial pathogens causing lung infections often use lectins to mediate adhesion to glycoconjugates at the surface of host tissues. Given the rapid emergence of resistance to the treatments in current use, β-propeller lectins such as FleA from Aspergillus fumigatus, SapL1 from Scedosporium apiospermum, and BambL from Burkholderia ambifaria have become appealing targets for the design of anti-adhesive agents. In search of novel and cheap anti-infectious agents, we synthesized multivalent compounds that can display up to 20 units of fucose, the natural ligand. We obtained nanomolar inhibitors that are several orders of magnitude stronger than their monovalent analogue according to several biophysical techniques (i.e., fluorescence polarization, isothermal titration calorimetry, and bio-layer interferometry). The reason for high affinity might be attributed to a strong aggregating mechanism, which was examined by analytical ultracentrifugation. Notably, the fucosylated inhibitors reduced the adhesion of A. fumigatus spores to lung epithelial cells when administered 1 h before or after the infection of human lung epithelial cells. For this reason, we propose them as promising anti-adhesive drugs for the prevention and treatment of aspergillosis and related microbial lung infections

Permeability analysis in bisized porous media: wall effect between particles of different size

The permeability of binary packings of glass beads with different size ratio – 13.3, 20, and 26.7, was investigated. In the Kozeny–Carman equation, the dependence of the tortuosity τ on the mixture porosity ε(xD) was described according to τ = 1/εn for different volume fraction of large particles in the mixture, xD. Obtained data on packing permeability shows that the parameter n is a function of the volume fraction and particle size ratio, with values between 0.5 and 0.4. This can be explained by the wall effect resulting from the arrangement of the small particles occurring near the large particle surface. A model taking in account this effect was suggested that can be useful in the characterization of transport phenomena in granular beds as well as in engineering applications.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BPD/18128/2004; Project POCI_EQU_58337/2004

Structural insights into the contactin 1 - neurofascin 155 adhesion complex

Cell-surface expressed contactin 1 and neurofascin 155 control wiring of the nervous system and interact across cells to form and maintain paranodal myelin-axon junctions. The molecular mechanism of contactin 1 - neurofascin 155 adhesion complex formation is unresolved. Crystallographic structures of complexed and individual contactin 1 and neurofascin 155 binding regions presented here, provide a rich picture of how competing and complementary interfaces, post-translational glycosylation, splice differences and structural plasticity enable formation of diverse adhesion sites. Structural, biophysical, and cell-clustering analysis reveal how conserved Ig1-2 interfaces form competing heterophilic contactin 1 - neurofascin 155 and homophilic neurofascin 155 complexes whereas contactin 1 forms low-affinity clusters through interfaces on Ig3-6. The structures explain how the heterophilic Ig1-Ig4 horseshoe's in the contactin 1 - neurofascin 155 complex define the 7.4 nm paranodal spacing and how the remaining six domains enable bridging of distinct intercellular distances

Self-assembly: From nanoscale to microscale colloids

No abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34250/1/10413_ftp.pd

Sedimentation of bidisperse, uncharged colloidal sphere suspensions: Influence of viscosity and irregular surfaces

The sedimentation velocity of uncharged, nonaggregated silica spheres under gravity is strongly reduced after addition of small amounts of nonsedimenting small spheres. This reduction is largely due to surface irregularities on a nanoscale of the large spheres at which a limited number of small spheres adsorbs, leading to an increase of the hydrodynamic friction per particle. This adsorption also screens effectively any weak Van der Waals attraction between the large spheres, which despite its weakness, significantly influences the concentration dependence of settling in a pure solvent. The concentration dependence and magnitude of the large-sphere sedimentation velocity in a more concentrated dispersion of small spheres agree with the prediction by Batchelor that the small particles mainly manifest themselves as an effective viscosity increase

Sedimentation equilibria of ferrofluids: II. Experimental osmotic equations of state of magnetite colloids

The first experimental osmotic equation of state is reported for well-defined magnetic colloids that interact via a dipolar hard-sphere potential. The osmotic pressures are determined from the sedimentation equilibrium concentration profiles in ultrathin capillaries using a low-velocity analytical centrifuge, which is the subject of the accompanying paper I. The pressures of the magnetic colloids, measured accurately to values as low as a few pascals, obey Van 't Hoff's law at low concentrations, whereas at increasing colloid densities non-ideality appears in the form of a negative second virial coefficient. This virial coefficient corresponds to a dipolar coupling constant that agrees with the coupling constant obtained via independent magnetization measurements. The coupling constant manifests an attractive potential of mean force that is significant but yet not quite strong enough to induce dipolar chain formation. Our results disprove van der Waals-like phase behavior of dipolar particles for reasons that are ex

Tetravalent Pseudomonas aeruginosa Adhesion Lectin LecA Inhibitor for Enhanced Biofilm Inhibition

A potent divalent ligand of the Pseudomonas aeruginosa adhesion lectin LecA was elaborated into a tetravalent version. A polyethylene glycol (PEG) spacer was introduced to link two divalent galactosides. Each of the two divalent ligands contained a rigid spacer with a central phenyl group that is bridged by the PEG moiety. The resulting tetravalent ligand was found to bind LecA in the nanomolar range involving all of its sugar (sub)ligands. Analytical ultracentrifugation studies clearly showed that the tetravalent ligand was capable of aggregation the LecA tetramers in contrast to the divalent ligands. The aggregator behavior was found to be of importance in P. aeruginosa biofilm formation inhibition. Despite the weaker affinity it was a considerably better biofilm inhibitor with half inhibitory values around the 28 micromolar range