Molecular Motors Interacting with Their Own Tracks

Dynamics of molecular motors that move along linear lattices and interact with them via reversible destruction of specific lattice bonds is investigated theoretically by analyzing exactly solvable discrete-state ``burnt-bridge'' models. Molecular motors are viewed as diffusing particles that can asymmetrically break or rebuild periodically distributed weak links when passing over them. Our explicit calculations of dynamic properties show that coupling the transport of the unbiased molecular motor with the bridge-burning mechanism leads to a directed motion that lowers fluctuations and produces a dynamic transition in the limit of low concentration of weak links. Interaction between the backward biased molecular motor and the bridge-burning mechanism yields a complex dynamic behavior. For the reversible dissociation the backward motion of the molecular motor is slowed down. There is a change in the direction of the molecular motor's motion for some range of parameters. The molecular motor also experiences non-monotonic fluctuations due to the action of two opposing mechanisms: the reduced activity after the burned sites and locking of large fluctuations. Large spatial fluctuations are observed when two mechanisms are comparable. The properties of the molecular motor are different for the irreversible burning of bridges where the velocity and fluctuations are suppressed for some concentration range, and the dynamic transition is also observed. Dynamics of the system is discussed in terms of the effective driving forces and transitions between different diffusional regimes

METHODS OF THE VALUES LEGITIMATION IN SOCIAL COMMUNITIES

В статье ценности рассматриваются как устойчивые убеждениялюдей в приоритетности одних жизненных целей перед другими, противоположными жизненными целями. Члены сообществ так или иначе идентифицируют свои индивидуальные убеждения с групповыми убеждениями. Идентификация проявляется в приверженности индивидов ценностям сообщества. Она сопровождается легитимацией ценностей, которая заключается в обосновании человеком его приверженности определенным жизненным целям, складывающейся на основе персонального выбора. Можно выделить три способа легитимации: традиционный, эмоциональный и рациональный, которые отличаются типом обоснования личных убеждений. Традиционная легитимация заключается в обосновании убеждений ссылкой на их соответствиеобычаям, привычному укладу жизни, воспитанию и т. д. Эмоциональная легитимация основана на ощущении близости, симпатии, уважения и доверия к их носителям. Рациональная легитимация обосновывает убеждения с помощью суждений об их значении для личной и общественной жизни. Эти типы легитимации являются теоретическими конструкциями, в той или иной степени отражающими различные аспекты реального обоснования убеждений. Обычно люди используют различные сочетания перечисленных способов легитимации. Анализ данных качественного эмпирического исследования способов обоснования приверженности жизненным целям свидетельствует о правомерности приведенных выше утверждений.In the article values are considered as stable beliefs of people in priority of one vital purpose before other, opposite vital purposes. Members of social communities to some extent identify the individual beliefs with group beliefs. Identification is shown in individuals’ adherence to values of community. It is accompanied with legitimating values which consists in substantiation the person of its adherence to the certain vital purposes developing on the basis of a personal choice. It is possible to allocate three methods of legitimation: traditional, emotional and rational, which differ in the types of a substantiation of personal beliefs. Traditional legitimation it is justification of beliefs according to their conformity to the customs, a habitual way of life, education etc. Emotional legitimation it is based on sensation of affinity, liking, respect and trust to their carriers. Rational legitimation proves beliefs by means of judgments about their value for a personal and public life. These methods of legitimation are the theoretical designs to some extent reflecting various aspects of a real substantiation of beliefs. Usually people use different combinations of these methods of legitimation. Data analysis of the qualitative empirical research devoted to the methods of the commitment life goals justification proves the legality of the above statements

Practical, Computation Efficient High-Order Neural Network for Rotation and Shift Invariant Pattern Recognition

In this paper, a modification for the high-order neural network (HONN) is presented. Third order networks are considered for achieving translation, rotation and scale invariant pattern recognition. They require however much storage and computation power for the task. The proposed modified HONN takes into account a priori knowledge of the binary patterns that have to be learned, achieving significant gain in computation time and memory requirements. This modification enables the efficient computation of HONNs for image fields of greater that 100 × 100 pixels without any loss of pattern information

Transport of Molecular Motor Dimers in Burnt-Bridge Models

Dynamics of molecular motor dimers, consisting of rigidly bound particles that move along two parallel lattices and interact with underlying molecular tracks, is investigated theoretically by analyzing discrete-state stochastic continuous-time burnt-bridge models. In these models the motion of molecular motors is viewed as a random walk along the lattices with periodically distributed weak links (bridges). When the particle crosses the weak link it can be destroyed with a probability $p$, driving the molecular motor motion in one direction. Dynamic properties and effective generated forces of dimer molecular motors are calculated exactly as a function of a concentration of bridges $c$ and burning probability $p$ and compared with properties of the monomer motors. It is found that the ratio of the velocities of the dimer and the monomer can never exceed 2, while the dispersions of the dimer and the monomer are not very different. The relative effective generated force of the dimer (as compared to the monomer) also cannot be larger than 2 for most sets of parameters. However, a very large force can be produced by the dimer in the special case of $c=1/2$ for non-zero shift between the lattices. Our calculations do not show the significant increase in the force generated by collagenase motor proteins in real biological systems as predicted by previous computational studies. The observed behavior of dimer molecular motors is discussed by considering in detail the particle dynamics near burnt bridges.Comment: 21 pages and 11 figure