Inorganic Polyphosphate Modulates TRPM8 Channels

Polyphosphate (polyP) is an inorganic polymer built of tens to hundreds of phosphates, linked by high-energy phosphoanhydride bonds. PolyP forms complexes and modulates activities of many proteins including ion channels. Here we investigated the role of polyP in the function of the transient receptor potential melastatin 8 (TRPM8) channel. Using whole-cell patch-clamp and fluorescent calcium measurements we demonstrate that enzymatic breakdown of polyP by exopolyphosphatase (scPPX1) inhibits channel activity in human embryonic kidney and F-11 neuronal cells expressing TRPM8. We demonstrate that the TRPM8 channel protein is associated with polyP. Furthermore, addition of scPPX1 altered the voltage-dependence and blocked the activity of the purified TRPM8 channels reconstituted into planar lipid bilayers, where the activity of the channel was initiated by cold and menthol in the presence of phosphatidylinositol 4,5-biphosphate (PtdIns(4,5)P2). The biochemical analysis of the TRPM8 protein also uncovered the presence of poly-(R)-3-hydroxybutyrate (PHB), which is frequently associated with polyP. We conclude that the TRPM8 protein forms a stable complex with polyP and its presence is essential for normal channel activity

Voltage-Dependent Gating in a “Voltage Sensor-Less” Ion Channel

An unusual mechanism of ion channel regulation generates voltage-dependent gating in the absence of a canonical voltage-sensing domain

Evolution of Thermal Response Properties in a Cold-Activated TRP Channel

Animals sense changes in ambient temperature irrespective of whether core body temperature is internally maintained (homeotherms) or subject to environmental variation (poikilotherms). Here we show that a cold-sensitive ion channel, TRPM8, displays dramatically different thermal activation ranges in frogs versus mammals or birds, consistent with variations in these species' cutaneous and core body temperatures. Thus, somatosensory receptors are not static through evolution, but show functional diversity reflecting the characteristics of an organism's ecological niche

Evaluation of the air transport efficiency definitions and their impact on the European Personal Air Transportation System Development

The large US SATS (Small Aircraft Transportation System and EU supported EPATS (European Personal Air Transportation System [4, 5]) projects target to develop and introduce new transportation system based on the newly designed small and smart aircraft mostly personal used in completely redesigned and rebuilt airport and ATM systems. Introduction of such innovative system can be characterized by innovation diffusion process. The diffusion of innovation is the process by which an innovation is communicated through certain channels over time among the members of social system. The penetration of the new innovative system into society and economy can be characterized by “S” curve. In case of earlier time of diffusion, when only the relatively small number of users, called innovators and early adaptors are applying the new system, the evaluation of efficiency of the new system plays a determining role. Generally, it seems the efficiency can be defined and applied for evaluation of the new technology easy. However, the efficiency means different meaning for different group of people, like designers, operators, users, owners, stakeholders, or simple “neutrals”, namely for those who does not belong no one from the named groups. So, the new system must be evaluated with use of different terms, different methods, as technical or energetic efficiency, benefits, etc. This short paper tries to summarize the different definitions of efficiency and their use for evaluating the EPATS and their impacts on the EPATS development process

Subiektywne decyzje pilota w aktywnym układzie sterowania samolotu

The aircraft conventional control systems including pilot-operators in loop are called as active endogenous systems, because the pilots react actively to real situations evaluated by them and their solutions origin from their minds, from the nervous system. The pilots must make decisions in situations characterised by lack of information, human robust behaviour and their individual capabilities. So, decisions born from reactions of pilot are an effect of subjective analysis. This paper investigates the aircraft landing. The subjective factor is the ratio of required and available time to decision on the go around. The decision depends on the available information and psycho-physiological condition of operator pilots and can be determined with the use of theory of statistical hypotheses. This paper introduces a modified Lorenz attractor for the modelling of the endogenous dynamics of the given active system.Konwencjonalne układy sterowania samolotem, włączając w to rolę pilotów, nazywane są aktywnymi układami endogennymi z racji znaczenia bieżącej oceny sytuacji i reakcji pilotów wynikających z ich świadomości i cech układu nerwowego. Piloci muszą podejmować decyzje w warunkach braku pełnej informacji o parametrach lotu, posiadając przy tym swoiste cechy reaktywnych zachowań i własny zestaw wytrenowanych nawyków. W ten sposób analiza właściwości monitorowania samolotu staje się badaniem układu zawierającego zmienne subiektywne. W pracy zbadano problem podejścia do lądowania. Za czynnik subiektywny wzięto stosunek czasu wymaganego do faktycznie posiadanego przed podjęciem decyzji o możliwej rezygnacji z lądowania. Decyzja ta zależy od ilości zgromadzonych informacji w danej chwili oraz kondycji psycho-fizjologicznej pilotów i została opisana za pomocą hipotez statystycznych. Do zamodelowania dynamiki rozważanego endogennego układu sterowania samolotem użyto zmodyfikowanego atraktora Lorentza