22 research outputs found

    THE MODELS FOR DESCRIPTION OF OPERATIONAL CHARACTERISTICS-DEVIATIONS OF VEHICLES

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    In the course of the operation of vehicles there are many stochastic influences which cannot be examined by means of simple methods at a given level of costs. So, the structural and operational characteristics of vehicles can considerably deviate from the specified values both in an individual and in a cumulative way, and their deviations exceed the given tolerance limits in many cases. The above mentioned deviations, deviation-combinations, and their influences on the characteristics and performance data of vehicles amount to 5-15% and are to be taken into consideration to ensure the necessary operational safety and the optimal cost level (minimal lifecycle-cost) in the operation. Today, this is one of the most important problems in vehicle operation. This paper shows the models recommended for the description of operational characteristics - deviations of vehicles. This models were made by using the probability theory and theorv of stochastic processes. New models can be made by using catastrophe theory and chaos

    Sustainability of Global Golden Inland Waterways

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    Sustainable inland waterways should meet the needs of navigation without compromising the health of riverine ecosystems. Here we propose a hierarchical model to describe sustainable development of the Golden Inland Waterways (GIWs) which are characterized by great bearing capacity and transport need. Based on datasets from 66 large rivers (basin area > 100,000 km2) worldwide, we identify 34 GIWs, mostly distributed in Asia, Europe, North America, and South America, typically following a three-stage development path from the initial, through to the developing and on to the developed stage. For most GIWs, the exploitation ratio, defined as the ratio of actual to idealized bearing capacity, should be less than 80% due to ecological considerations. Combined with the indices of regional development, GIWs exploitation, and riverine ecosystem, we reveal the global diversity and evolution of GIWs' sustainability from 2015 to 2050, which highlights the importance of river-specific strategies for waterway exploitation worldwide

    Voltage- and cold-dependent gating of single TRPM8 ion channels

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    Transient receptor potential (TRP) channels play critical roles in cell signaling by coupling various environmental factors to changes in membrane potential that modulate calcium influx. TRP channels are typically activated in a polymodal manner, thus integrating multiple stimuli. Although much progress has been made, the underlying mechanisms of TRP channel activation are largely unknown. The TRPM8 cation channel has been extensively investigated as a major neuronal cold sensor but is also activated by voltage, calcium store depletion, and some lipids as well as by compounds that produce cooling sensations, such as menthol or icilin. Several models of TRPM8 activation have been proposed to explain the interaction between these diverse stimuli. However, a kinetic scheme is not yet available that can describe the detailed single-channel kinetics to gain further insight into the underlying gating mechanism. To work toward this goal, we investigated voltage-dependent single-channel gating in cell-attached patches at two different temperatures (20 and 30°C) using HEK293 cells stably expressing TRPM8. Both membrane depolarization and cooling increased channel open probability (Po) mainly by decreasing the duration of closed intervals, with a smaller increase in the duration of open intervals. Maximum likelihood analysis of dwell times at both temperatures indicated gating in a minimum of five closed and two open states, and global fitting over a wide range of voltages identified a seven-state model that described the voltage dependence of Po, the single-channel kinetics, and the response of whole-cell currents to voltage ramps and steps. The major action of depolarization and cooling was to accelerate forward transitions between the same two sets of adjacent closed states. The seven-state model provides a general mechanism to account for TRPM8 activation by membrane depolarization at two temperatures and can serve as a starting point for further investigations of multimodal TRP activation

    Permeation, regulation and control of expression of TRP channels by trace metal ions

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    The role of inland waterway navigation in a sustainable transport system

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    Sustainable development has become a guiding principle of human activities nowadays. Sustainable transport can take a great part in future development. Today this is not the case, and road transport contributes to this above all. For sustainable transport development the necessity of modal shift is inevitable and the inland waterway navigation should get the higher share of the total transport where there is an alternative. This presentation shows the reasons why the inland waterway navigation can increase the level of sustainability

    Phosphoinositides regulate ion channels

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    Phosphoinositides serve as signature motifs for different cellular membranes and often are required for the function of membrane proteins. Here, we summarize clear evidence supporting the concept that many ion channels are regulated by membrane phosphoinositides. We describe tools used to test their dependence on phosphoinositides, especially phosphatidylinositol 4,5-bisphosphate, and consider mechanisms and biological meanings of phosphoinositide regulation of ion channels. This lipid regulation can underlie changes of channel activity and electrical excitability in response to receptors. Since different intracellular membranes have different lipid compositions, the activity of ion channels still in transit towards their final destination membrane may be suppressed until they reach an optimal lipid environment
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