Fusicoccin Counteracts the Toxic Effect of Cadmium on the Growth of Maize Coleoptile Segments

The effects of cadmium (Cd; 0.1–1000 μM) and fusicoccin (FC) on growth, Cd2+ content, and membrane potential (Em) in maize coleoptile segments were studied. In addition, the Em changes and accumulation of Cd and calcium (Ca) in coleoptile segments treated with Cd2+ combined with 1 μM FC or 30 mM tetraethylammonium (TEA) chloride (K+-channel blocker) were also determined. In this study, the effects of Ca2+-channel blockers [lanthanum (La) and verapamil (Ver)] on growth and content of Cd2+ and Ca2+ in coleoptile segments were also investigated. It was found that Cd at high concentrations (100 and 1000 μM) significantly inhibited endogenous growth of coleoptile segments and simultaneously measured proton extrusion. FC combined with Cd2+ counteracted the toxic effect of Cd2+ on endogenous growth and significantly decreased Cd2+ content (not the case for Cd2+ at the highest concentration) in coleoptile segments. Addition of Cd to the control medium caused depolarization of Em, the extent of which was dependent on Cd concentration and time of treatment with Cd2+. Hyperpolarization of Em induced by FC was suppressed in the presence of Cd2+ at 1000 μM but not Cd2+ at 100 μM. It was also found that treatment of maize coleoptile segments with 30 mM TEA chloride caused hyperpolarization of Em and decreased Cd2+ content in coleoptile segments, suggesting that, in the same way as for FC, accumulation of Cd2+ was dependent on plasma membrane (PM) hyperpolarization. Similar to FC, TEA chloride also decreased Ca2+ content in coleoptile segments. La and Ver combined with Cd2+ (100 μM) significantly decreased Cd content in maize coleoptile segments, but only La completely abolished the toxic effect of Cd2+ on endogenous growth and growth in the presence of FC. Taken together, these results suggest that the mechanism by which FC counteracts the toxic effect of Cd2+ (except at 1000 μM Cd2+) on the growth of maize coleoptile segments involves both stimulation of PM H+-ATPase activity by FC as well as Cd2+-permeable, voltage-dependent Ca channels, which are blocked by FC and TEA chloride-induced PM hyperpolarization

Digital data recorder altitude for radio controlled model aircraft

V tomto príspevku sa venujeme návrhu a vyhotoveniu digitálneho zaznamenávača výšky rádiom riadeného modelu lietadla. Zariadenie ukladá namerané dáta z modelu lietadla, každú jednu sekundu po dobu viac ako dvoch hodín. Zariadenie pracuje pomocou mikrokontroléra ATmega 168 PA. ATmega 168 je 8-bit AVR RISC-based mikrokontrolér. Ďalšími dôležitými časťami zariadenia sú tlakový barometrický senzor BMP085 a sériová pamäť EEPROM 24LC256. Zariadenie pracuje s citlivosťou 25cm. Analýza nameraných hodnôt je možná cez MS Excel pomocou prevodníka PLX-DAQ.This post is devoted to design and construct the digital data recorder of altitude for radio controlled model aircraft. The Device stores data of model aircraft, every one second for more than two hours. The device works by using microcontroller ATmega 168 PA. ATmega 168 is high-performance, low-power Atmel 8-bit AVR RISC-based microcontroller. Microcontroller supports a throughput of 20 MIPS at 20 MHz and operates between 2.7-5.5 volts. Other important components are Barometric Pressure Sensor - BMP085 and 24LC256 Serial Electrically Erasable PROM. The device operates with sensitivity 25 cm. Analyzation of the measured data is possible via MS Excel, with using converter PLX-DAQ

Pomiar i analiza sił nacisku na pedały na stanowisku kierowcy

This paper describes a method for measuring the pressure forces on the pedals in the bus. Shows the results and the analysis of the measurements, in terms of using them to determine the level of fatigue of the driver and his driving style.W artykule opisano metodę pomiaru siły nacisku na pedały w autobusie. Pokazano wyniki oraz przeprowadzono analizę pomiarów, pod kątem wykorzystania ich do określenia stopnia zmęczenia kierowcy oraz jego stylu jazdy