Top-down inputs enhance orientation selectivity in neurons of the primary visual cortex during perceptual learning.

Perceptual learning has been used to probe the mechanisms of cortical plasticity in the adult brain. Feedback projections are ubiquitous in the cortex, but little is known about their role in cortical plasticity. Here we explore the hypothesis that learning visual orientation discrimination involves learning-dependent plasticity of top-down feedback inputs from higher cortical areas, serving a different function from plasticity due to changes in recurrent connections within a cortical area. In a Hodgkin-Huxley-based spiking neural network model of visual cortex, we show that modulation of feedback inputs to V1 from higher cortical areas results in shunting inhibition in V1 neurons, which changes the response properties of V1 neurons. The orientation selectivity of V1 neurons is enhanced without changing orientation preference, preserving the topographic organizations in V1. These results provide new insights to the mechanisms of plasticity in the adult brain, reconciling apparently inconsistent experiments and providing a new hypothesis for a functional role of the feedback connections

Use of Articulated Transport Systems in the Mining Industry

The work is devoted to the possibility and prospects of the use of all-wheels drive articulated transport systems in the mining complex. A comparative analysis of the traditional methods of exporting minerals in open pit mining and the method of using active trailed elements are given. The trailer has a load factor several times higher than the same rate for mining dump trucks. The use of an active trailer makes it possible to reduce the mass of the tractor and trailer by almost 40 tons and increase the specific power of the road train. © Published under licence by IOP Publishing Ltd

Using NLP to Define the Scope for Stakeholder Assessment of Simulated Service Qualities

The paper is devoted to defining the scope of research activities aimed at involving business stakeholders in a software process in a form of assessing the perceived quality of the service-oriented system in its usage context when the initial specification of the system is available in natural language form. We propose to use NLP techniques to extract the scope from this specification and to represent it in the format of specific predesign models compatible with the rest of the simulation solution.Стаття присвячена визначенню області проведення досліджень, пов’язаних з підключенням зацікавлених осіб до процесу розробки програмного забезпечення через оцінювання сприйманої якості сервіс-оріентованих систем в контексті їхнього використання, коли початкова специфікація системи задана природною мовою. Пропонується використання технології аналізу природної мови для отримання інформації про область застосування з цієї специфікації у форматі спеціальних моделей предпроектування, які є сумісними з основними модулями імітаційного рішення.Статья посвящена определению области проведения исследований, связанных с подключением заинтересованных лиц к процессу разработки программного обеспечения через оценивание воспринимаемого качества сервис-ориентированных систем в контексте их использования, в случае, если начальная спецификация системы задана естественным языком. Предлагается использование технологии анализа естественного языка для получения информации об области применения из этой спецификации в формате специальных моделей предпроектирования, которые являются совместимыми с основными модулями имитационного решения

Efficient generation and sorting of orbital angular momentum eigenmodes of light by thermally tuned q-plates

We present methods for generating and for sorting specific orbital angular momentum (OAM) eigenmodes of a light beam with high efficiency, using a liquid crystal birefringent plate with unit topological charge, known as \qo{q-plate}. The generation efficiency has been optimized by tuning the optical retardation of the q-plate with temperature. The measured OAM $m=\pm2$ eigenmodes generation efficiency from an input TEM$_{00}$ beam was of 97%. Mode sorting of the two input OAM $m=\pm2$ eigenmodes was achieved with an efficiency of 81% and an extinction-ratio (or cross-talk) larger than 4.5:1.Comment: 4 pages, 3 Figures and 1 table. Submitte