Tetszőleges alakú, űreszközzel és földi állomáson mérhető elektromágneses jelek terjedésének és gerjesztésének vizsgálata = Investigation of propagation and excitation of arbitrary shaped e.m. signals measured by space vehicles and on ground stations

A 'Tetszőleges alakú, űreszközzel és földi állomáson mérhető elektromágneses jelek terjedésének és gerjesztésének vizsgálata' c. kutatás eredményei a 2002-2005 pályázati időtartam alatt: 1. Sikerült megoldani UWB gerjesztés által létrehozott e.m. jel terjedésének leírását tetszőlegesen erős inhomogenitást tartalmazó előmágnesezett plazmában, továbbá a vákuummal, és előmágnesezett homogén plazmával kitöltött hullámvezetőben. 2. A kifejlesztett elméleti modellekkel anomalisztikus jelenségek azonosítását végeztük el (tweek, spiky whistler, fecskefarkú whistler, X-típus, ferde, valamint ferde és vezetett terjedést mutató whistler-csoportok). A ferdén terjedő jelcsoportok vizsgálata a whistlerek kilépésének új mechanizmusát tárta fel, regisztrátumokból meghatározható a töredék-whistlereknél a műholdhoz viszonyítva az ionoszférába történő belépés helye. 3. A szeizmikus aktivitás és űridőjárási vizsgálatok keretében kifejlesztettük az automata trimpi-detektort. Sikerült megoldani a műholdas távérzékelt adatok georeferálását. Részt veszünk a Demeter-adatok quick-look értékelésében. 4. Sikeresen üzemeltetjük földi műhold-vevő állomásunkat, továbbá elért eredményeink alapján részt veszünk a Demeter-programban, a Kompasz-2 és Vulkan műholdflotta programjában 17 SAS műszerrel és elméleti modellfejlesztéssel, az ISS Obszanovka-1 kísérletében, az ESA-JAXA BepiColombo Merkur misszióban és az ESA Venus Entry Probe misszióban. (szeizmikus aktivitás e.m. jelei és űridőjárás) | Results of the research project titled as 'Investigation of the propagation and excitation of general shaped electromagnetic signals detected by terrestrial and satellite receivers' in the 2002-2005 period: 1. We derived the exact solution of e.m. signals excited UWB sources, that propagate in anisotropic plasma containing arbitrarily strong inhomogeneities. We solved this problem for wave-guides, filled by vacuum, or anisotropic, homogeneous plasma. 2. By the application of our models, we identified and interpreted anomalistic phenomena observed by satellite (tweeks, spiky whistlers, swallow tailed whistlers, 'X'-type, obliquely propagating and ducted oblique signal-groups). In the case of obliquely propagating signal-groups, we verified a new description of the entering and propagation of the whistlers, by that the localization of the entering points of fractional-hop whistlers related to the satellite are determinable. 3. Connecting to the space-weather and seismic activitiy research we developed the automatic trimpi-detector, and an automatic geocoding system for satellite RS data. We participate in the quick-look validation of Demeter-data. 4. We installed and keep in operation our satellite receiver station. We participate in the Demeter-program, the Kompas-2 and Vulkan projects, the ISS Obsztanovka-1 experiment, the ESA-JAXA BepiColombo mission to the Mercury, and the ESA Venus Entry Probe mission, (interplanetary, space weather and seismic e.m. activity research)

Automated Microscopy: Macro Language Controlling a Confocal Microscope and its External Illumination: Adaptation for Photosynthetic Organisms

Photosynthesis research employs several biophysical methods, including the detection of fluorescence. Even though fluorescence is a key method to detect photosynthetic efficiency, it has not been applied/adapted to single-cell confocal microscopy measurements to examine photosynthetic microorganisms. Experiments with photosynthetic cells may require automation to perform a large number of measurements with different parameters, especially concerning light conditions. However, commercial microscopes support custom protocols (through Time Controller offered by Olympus or Experiment Designer offered by Zeiss) that are often unable to provide special set-ups and connection to external devices (e.g., for irradiation). Our new system combining an Arduino microcontroller with the Cell plus sign in circleFinder software was developed for controlling Olympus FV1000 and FV1200 confocal microscopes and the attached hardware modules. Our software/hardware solution offers (1) a text file-based macro language to control the imaging functions of the microscope; (2) programmable control of several external hardware devices (light sources, thermal controllers, actuators) during imaging via the Arduino microcontroller; (3) the Cell plus sign in circleFinder software with ergonomic user environment, a fast selection method for the biologically important cells and precise positioning feature that reduces unwanted bleaching of the cells by the scanning laser. Cell plus sign in circleFinder can be downloaded from http://www.alga.cz/cellfinder. The system was applied to study changes in fluorescence intensity in Synechocystis sp. PCC6803 cells under long-term illumination. Thus, we were able to describe the kinetics of phycobilisome decoupling. Microscopy data showed that phycobilisome decoupling appears slowly after long-term (>1 h) exposure to high light

Palaeofluid evolution in a fractured basalt hosted reservoir in the Üllés-Ruzsa-Bordány area, southern sector of the Pannonian Basin

Extensive Miocene volcanic activity produced basaltic and pyroclastic successions, which were penetrated by many wells in the area of Üllés-Ruzsa-Bordány, in the western and central part of the Great Hungarian Plain. The Kecel Basalt comprises primary porosity from a high proportion of vesicles and significant secondary fracture porosity, as well. Due to the significant fracture porosity, some depth intervals show good reservoir characteristics, although the fractures crosscutting the rock body are partly or entirely cemented by various minerals. Based on the textural and mineralogical features, four distinct vein types can be distinguished, named after their volumetrically most abundant cement phases, i.e. potassium-feldspar (Kfp-), calcite (Cal-), laumontite (Lmt-) and analcime (Anl-) types. This study focuses on probably the youngest of these vein types, the Anl-type. Based on the study of veins and mineral sequences, the direction of temperature changes cannot be given unequivocally for every stage of cementation, but crystallization of the Anl-type veins might have occurred at lower temperatures than the formation of the Lmt-type veins. Fluid inclusion studies suggest that hydrocarbon migration and accumulation took place after cementation of the first three vein types (Kfp-, Cal- and Lmt-types). In the newly opened fracture system, two types of hydrocarbon (HC1 and HC2)-bearing fluid inclusion assemblages were captured during precipitation of analcime and later zeolites. This refers to two stages of hydrocarbon migration in the fracture system. Observations of the fluorescence colours and low temperature behaviours of the hydrocarbon-bearing inclusions, the earlier HC1 petroleum-inclusions captured heavier (presumably less mature oils), while the later ones (HC2) lighter (presumably more mature) oils. The HC2 petroleum seems to be very similar to the crude oil sampled in a well in the area based on their fluorescence parameters.</p

Fluorescence-detected linear dichroism imaging in a re-scan confocal microscope equipped with differential polarization attachment

Confocal laser scanning microscopy is probably the most widely used and one of the most powerful techniques in basic biology, medicine and material sciences that is employed to elucidate the architecture of complex cellular structures and molecular macro-assemblies. It has recently been shown that the information content, signal-to-noise ratio and resolution of such microscopes (LSMs) can be improved significantly by adding different attachments or modifying their design, while retaining their user-friendly features and relatively moderate costs. Differential polarization (DP) attachments, using high-frequency modulation/demodulation circuits, have made LSMs capable of high-precision 2D and 3D mapping of the anisotropy of microscopic samples-without interfering with their 'conventional' fluorescence or transmission imaging (Steinbach et al. in Methods Appl Fluoresc 2:015005, 2014). The resolution and the quality of fluorescence imaging have been enhanced in the recently constructed Re-scan confocal microscopy (RCM) (De Luca et al. in Biomed Opt Express 4:2644-2656, 2013). In this work, we developed the RCM technique further, by adding a DP-attachment modulating the exciting laser beam via a liquid crystal (LC) retarder synchronized with the data acquisition system; by this means, and with the aid of a software, fluorescence-detected linear dichroism (FDLD), characteristic of the anisotropic molecular organization of the sample, could be recorded in parallel with the confocal fluorescence imaging. For demonstration, we show FDLD images of a plant cell wall (Ginkgo biloba) stained with Etzold's staining solution

Imaging fluorescence detected linear dichroism of plant cell walls in laser scanning confocal microscope

Anisotropy carries important information on the molecular organization of biological samples. Its determination requires a combination of microscopy and polarization spectroscopy tools. The authors constructed differential polarization (DP) attachments; to a laser scanning microscope in order to determine physical quantities related to the anisotropic distribution of molecules in microscopic samples; here the authors focus on fluorescence-detected linear dichroism (FDLD). By modulating the linear polarization of the laser beam between two orthogonally polarized states and by using a demodulation circuit, the authors determine the associated transmitted and fluorescence intensity-difference signals, which serve the basis for LD (linear dichroism) and FDLD, respectively. The authors demonstrate on sections of Convallaria majalis root tissue stained with Acridin Orange that while (nonconfocal) LD images remain smeared and weak, FDLD images recorded in confocal mode reveal strong anisotropy of the cell wall. FDLD imaging is suitable for mapping the anisotropic distribution of transition dipoles in 3 dimensions. A mathematical model is proposed to account for the fiber-laminate ultrastructure of the cell wall and for the intercalation of the dye molecules in complex, highly anisotropic architecture. (c) 2007 International Society for Analytical Cytology

Termo-optikai szerkezetváltozások fotoszintetikus rendszerekben = Termo-optically induced structural changes in photosynthetic systems

Kutatásaink feltárták a korábban a laboratóriumunkban elsőként leírt biológiai termo-optikai effektus fizikai/molekuláris hátterének fontos sajátságait és az ezzel a mechanizmussal indukálható szerkezetváltozások természetét és fiziológiai jelentőségét valamint ezek szerkezeti hátterének fontos elemeit különböző fotoszintetikus fénybegyűjtő antenna rendszerekben ill. membránokban. Meghatároztuk a gerjesztési energia disszipációjából származó hőcsomagok szétoszlásának ultragyors kinetikáját. Megállapítottuk, hogy termo-optikailag kiváltható szerkezetváltozások több, egymástól jelentősen eltérő felépítésű antennarendszerben is megfigyelhetők. Eredményeink megerősítették azt a korábbi feltételezésünket, hogy a termo-optikai szerkezetváltozások fontos szerepet játszanak fényadaptációs és fotoprotektív regulációs mechanizmusokban. Feltártuk - a Bioszféra legelterjedtebb membrárendszerének - gránumos tilakoid membránoknak a 3 dimenziós szerkezetét. Vizsgálataink elsőként derítettek fényt arra, hogy intakt, funkcionális tilakoid membránok lipid fázis viselkedése egyetlen, kettősréteg struktúrával nem írható le, ami alapvetően befolyásolhatja a tilakoid membrán dinamikai sajátságait. | We have elucidated important elements of the physical/molecular basis of the biological thermo-optic effect, which had been described first in our laboratory, and revealed the nature, physiological significance and structural background of thermo-optically inducible reorhganizations in different photosynthetic light harvesting antennae and membranes. We have determined the 'spreading' kinetics of the heat-package induced by the dissipation of excess excitation energies. We have shown that thermo-optically induced reorganizations occur in different antenna systems with different molecular organizations. We have confirmed our assumption that these reorganizations play important roles in the regulatory processes of light adaptation and photoprotection of plants. We have revealed the 3 dimensional membrane organization of the granal thylakoid membranes, the most abundant membrane system of the Biosphere. We have shown, for the first time, that the lipid phase behavior of intact functional thylakoid membranes cannot be described by assuming a single phase, the bilyer organization of the lipids; this might have improtant consequences on the dynamic features of thyalkoid membranes

The balance between photosynthesis and respiration explains the niche differentiation between Crocosphaera and Cyanothece

Crocosphaera and Cyanothece are both unicellular, nitrogen-fixing cyanobacteria that prefer different environments. Whereas Crocosphaera mainly lives in nutrient-deplete, open oceans, Cyanothece is more common in coastal, nutrient-rich regions. Despite their physiological similarities, the factors separating their niches remain elusive. Here we performed physiological experiments on clone cultures and expand upon a simple ecological model to show that their different niches can be sufficiently explained by the observed differences in their photosynthetic capacities and rates of carbon (C) consumption. Our exper- iments revealed that Cyanothece has overall higher photosynthesis and respiration rates than Crocosphaera. A simple growth model of these microorganisms suggests that C storage and consumption are previously under-appreciated factors when evaluating the occupation of niches by different marine nitrogen fixers

The AtCRK5 Protein Kinase Is Required to Maintain the ROS NO Balance Affecting the PIN2-Mediated Root Gravitropic Response in Arabidopsis

The Arabidopsis AtCRK5 protein kinase is involved in the establishment of the proper auxin gradient in many developmental processes. Among others, the Atcrk5-1 mutant was reported to exhibit a delayed gravitropic response via compromised PIN2-mediated auxin transport at the root tip. Here, we report that this phenotype correlates with lower superoxide anion (O-2(center dot-)) and hydrogen peroxide (H2O2) levels but a higher nitric oxide (NO) content in the mutant root tips in comparison to the wild type (AtCol-0). The oxidative stress inducer paraquat (PQ) triggering formation of O-2(center dot-) (and consequently, H2O2) was able to rescue the gravitropic response of Atcrk5-1 roots. The direct application of H2O2 had the same effect. Under gravistimulation, correct auxin distribution was restored (at least partially) by PQ or H2O2 treatment in the mutant root tips. In agreement, the redistribution of the PIN2 auxin efflux carrier was similar in the gravistimulated PQ-treated mutant and untreated wild type roots. It was also found that PQ-treatment decreased the endogenous NO level at the root tip to normal levels. Furthermore, the mutant phenotype could be reverted by direct manipulation of the endogenous NO level using an NO scavenger (cPTIO). The potential involvement of AtCRK5 protein kinase in the control of auxin-ROS-NO-PIN2-auxin regulatory loop is discussed