Kindlin-3–mediated signaling from multiple integrin classes is required for osteoclast-mediated bone resorption

Loss of kindlin-3 impairs activation of β1, β2, and β3 integrin classes, resulting in osteopetrotic defects in osteoclast adhesion and spreading

Theoretical Model for Cellular Shapes Driven by Protrusive and Adhesive Forces

The forces that arise from the actin cytoskeleton play a crucial role in determining the cell shape. These include protrusive forces due to actin polymerization and adhesion to the external matrix. We present here a theoretical model for the cellular shapes resulting from the feedback between the membrane shape and the forces acting on the membrane, mediated by curvature-sensitive membrane complexes of a convex shape. In previous theoretical studies we have investigated the regimes of linear instability where spontaneous formation of cellular protrusions is initiated. Here we calculate the evolution of a two dimensional cell contour beyond the linear regime and determine the final steady-state shapes arising within the model. We find that shapes driven by adhesion or by actin polymerization (lamellipodia) have very different morphologies, as observed in cells. Furthermore, we find that as the strength of the protrusive forces diminish, the system approaches a stabilization of a periodic pattern of protrusions. This result can provide an explanation for a number of puzzling experimental observations regarding cellular shape dependence on the properties of the extra-cellular matrix

Screening attenuation as the measure of electromagnetic properties of converter cables

Screening attenuation as the measure of electromagnetic properties of converter cables is one of screen effectiveness determinants. Catalogue data rarely includes this cable parameter, especially with division into frequency ranges. The paper presents results of investigations of screening attenuation in a wide frequency range for chosen types of screened cables. The triaxial method was used for testing cable parameters according to the standard PN-EN 50289-1-6 [1]. The rightness of using double screened cables in converter systems was confirmed. It will facilitate to provide electromagnetic compatibility of the system

Trams with asynchronous drive - estimation of energy consumption

Przedsiębiorstwa eksploatujące tabor trakcyjny ponoszą znaczne opłaty za zużycie energii elektrycznej. Zastosowanie nowego taboru z napędem przekształtnikowym związane było również z oczekiwaniami ograniczenia tego zużycia rejestrowanego na podstacjach trakcyjnych. Ponieważ zaczęty pojawiać się kontrowersje dotyczące ponoszonych kosztów, zaistniała potrzeba między innymi dokonania oceny energochłonności wdrażanych do użytku nowoczesnych tramwajów z napędem przekształtnikowym

The microcontroller system for the traction vehicle`s psophometric current determination

Badania homologacyjne nowych i modernizowanych pojazdów trakcyjnych wymagają m.in. pomiaru prądu psofometrycznego według PN-EN 50121-3-1. W artykule przedstawiono układ do wyznaczania tej wielkości, zbudowany w oparciu o mikrokontroler. System charakteryzuje się szybkim uzyskaniem wyniku podawanego w sposób ciągły, np. podczas całego przejazdu badanego pojazdu trakcyjnego oraz dodatkowo łatwością obsługi i małymi gabarytami.Many high power electronic devices working as main drive and auxiliary inverters are being installed in traction vehicles. It requires to pay particular attention to electromagnetic compatibility (EMC) of traction systems. Certification tests for new and modernized traction vehicles require among others the measurement of psophometric current according to PN-EN 50121-3-1. A system used for determination of this value, built on the basis of microcontroller is shown in the article. The task of this device is to measure (record) vehicle’s supply current, its FFT analysis and calculation of psophometric current in frequency range from 50Hz to 5kHz. Determined parameter has been defined and details related to normative measurement conditions have been specified. Individual blocks of presented system have been discussed, including with current measurement converter (Rogowski coil). Description and remarks related to configuration of used microcontroller were presented as well. Possibilities of using program libraries for FFT scope have been provided and results of initial test have been shown. Possibilities of system presented in the article facilitate significantly determining of measured value in heavy conditions of test site. System is characterized by fast result acquiring delivered continuously e.g. during the whole ride of tested vehicle and additional by service easiness and small gauge