44 research outputs found
VĂrusfertĹ‘zĂ©s hatása a növĂ©nyek fotokĂ©miai rendszereinek kialakulására Ă©s működĂ©sĂ©re = Effect of virus infection on the development and function of plant photosystems
A fotoszintetikus rendszer vĂrusfertĹ‘zĂ©sre kialakult morfolĂłgiai Ă©s molekuláris összetĂ©telben bekövetkezett változásait kĂ©t fĹ‘ gazdanövĂ©ny-kĂłrokozĂł kapcsolatban vizsgáltuk, egyrĂ©szt a teljes sötĂ©tben nevelt, árpa csĂkos mozaik vĂrussal magátvitel formájában fertĹ‘zött árpa csĂranövĂ©nyek leveleiben, másrĂ©szt TobamovĂrusokkal fertĹ‘zött paprika növĂ©nyekben. A fertĹ‘zött árpa növĂ©nyek sejtjeiben már az etioplasztiszok kialakulása is gátlást szenvedett, amit a prolammelláris testek (PLB) Ă©s a protilakoid membránok rendellenessĂ©geivel jellemeztĂĽnk. Bár a fertĹ‘zĂ©s közvetlenĂĽl nem befolyásolta a protoklorofillid oxidoreduktáz (POR) enzim szerepĂ©t, mĂ©gis a megvilágĂtás hatására a fertĹ‘zött szövetekben a zöldĂĽlĂ©si folyamatok jelentĹ‘s gátlást, kĂ©sĂ©st szenvedtek, ami arra utal, hogy ebben a folyamatban a membrán-protein rendszer tĂ©rbeli kialakulásában is zavar támad. A POR enzim immunolokalizálása során a kontroll csĂranövĂ©nyekben a jelölĂ©s nagymĂ©rtĂ©kben a PLB-kra koncentrálĂłdott. A vĂrusfertĹ‘zĂ©s csökkentette a POR enzim jelölĂ©st. A vĂrusfertĹ‘zĂ©s csökkentette a telĂtetlen zsĂrsavak Ă©s a galaktolipidek mennyisĂ©gĂ©t, Ă©s azok arányait is. A tobamovirusok fertĹ‘zĂ©se a kĂĽlönbözĹ‘ paprika fajták illetve vonalak leveleinek kloroplasztiszaiban a tilakoid membránok szerkezetĂ©ben Ă©s összetĂ©telĂ©ben is jellemzĹ‘ változásokat okozott az enyhe serkentĂ©stĹ‘l a sĂşlyos károsĂtásig, Ă©s rámutatott a PSII fotokĂ©miai rendszer mellett a PSI károsodására is. | Effects of virus infections on the morphology and molecular structure of chloroplasts were studied in two host-parasite systems: in etiolated barley seedlings infected with Barley stripe mosaic virus (BSMV); and in pepper varieties infected by different Tobamoviruses. Seed transmission of BSMV altered the membrane structure of dark-grown barley etioplasts and caused the delay of greening processes after illumination, suggesting the early damage of chloroplast development. Immunolabeling intensity of protochlorophyllide oxidoreductase enzyme (POR) in etioplasts of infected barley leaves was weaker and the amount of the enzyme was lower than in non-infected plants. The lower amount of highly unsaturated fatty acids and the reduced abundance of galactolipids correlated with the previously detected reduction in prolamellar body to prothylakoid membrane ratio. The effect pathogenically different Tobamoviruses on the photosynthetic structures and the chlorophyll protein complexes were studied. Virus infection caused characteristic differences in the chlorophyll-protein complexes from the slight increase to the serious damage, including the alterations in PSII as well as in PSI photosystems
Performance Modeling of Finite-Source Cognitive Radio Networks
This paper deals with performance modeling aspects of radio frequency licensing. The utilization of mobile cellular networks can be increased by the idea of the cognitive radio. Licensed users (Primary Users - PUs) and normál users (Secondary Users - SUs) are considered. The main idea is, that the SUs are able to access to the available non-licensed radio frequencies. A finite-source retrial queueing model with two non independent frequency bands (considered as service units) is proposed for the performance evaluation of the system. A service unit with a priority queue and another service unit with an orbit are assigned to the PUs and SUs, respectively. The users are classified into two classes: the PUs have got a licensed frequency, while the SUs have got a frequency band, too but it suffers from the overloading. We assume that during the service of the non-overloaded band the PUs have preemptive priority over SUs. The involved inter-event times are supposed to be independent and exponentially distributed random variables. The novelty of this work lies in the fact that we consider the effect of retrial phenomenon of SUs in performance modeling of radio frequency licensing by using a finite-source queueing model which takes the unreliability of radio transmission into account for the first time. In the literature, most work studied the performance of cognitive radio networks under a mixed spectrum environment of licensed and unlicensed bands where the blocked SUs and the preempted SUs are forced to leave the system forever when there are no idle channels in the system. But in practical situation, the blocked SUs and the preempted SUs may do not leave the system forever and try to continue their services after random amount of time. By the help of an appropriate continuous time Markov chain using MOSEL (MOdeling Specification and Evaluation Language) tool several numerical examples are provided showing the effects of different input parameters on the main performance measures of the cognitive radio networks. Our primary focus is to determine an optimal number of SUs, where at the secondary band the gained utilization, that is when switching to the cognitive radio, has a maximum value
Sorbanállási rendszerek a számĂtástudományban, távközlĂ©sben Ă©s megbĂzhatĂłság elmĂ©letben = Queueing Theory in Computer Sciences, Telecommunications, and Reliability Theory
Az elĂ©rt eredmĂ©nyek rövid ismertetĂ©se: Kutatásainkat lĂ©nyegĂ©ben a tervnek megfelelĹ‘en vĂ©geztĂĽk. Ă–sszessĂ©gĂ©ben: 15 nemzetközi folyĂłirat cikk, számos nemzetközi konferencia elĹ‘adás, 18 nemzetközi konferencia kiadványban megjelent cikk. Sztrik János szakmai egyĂĽttműködĂ©s keretĂ©ben vĂ©gzett kutatásokat DĂ©l-Koreában, NĂ©metországban, GrĂşziában. Lakatos LászlĂł számos konferencián tartott elĹ‘adást. ElĂ©rt eredmĂ©nyeink: I.Bonyolult rendszerek megbĂzhatĂłsági vizsgálatai 1. A Pollaczek-Hincsin formula vizsgálata ciklikus rendszerekben 2. VĂ©ges-forrásĂş, visszatĂ©tĹ‘ igĂ©nyeket tartalmazĂł sorbanállási rendszerek alkalmazása önszervezĹ‘dĹ‘ rendszereknĂ©l a MOSEL szoftver segĂtsĂ©gĂ©vel 3. Strukturált Markov-láncok analĂzise, kĂĽlönös tekintettel a vĂ©ges-forrásĂş sorbanállási rendszerekre II. InfokommunikáciĂłs hálĂłzatok hatĂ©konyságvizsgálata 1. SzĂ©tosztott protokollok modellezĂ©se 2. Proxy - Cache szerverek hatĂ©konysági vizsgálatai nem-megbĂzhatĂł kiszolgálĂłk esetĂ©n 3. Aszimmetrikus hálĂłzati protokollok működĂ©sĂ©nek modellezĂ©se 4. DiffServ modellek összehasonlĂtása szimuláciĂł Ă©s emuláciĂł segĂtsĂ©gĂ©vel Minden jog fenntartva ©, Országos Tudományos Kutatási Alapprogramok | The researcj was carried iut according to the plan. The accepted project was essentially fullfilled. In summary: 15 papers in international journals, several conference presentations, 18 papers in international conference Proceedings. János Sztrik carried researh in Korea, Germany and Georgia. LászlĂł Lakatos took part several international conference. Obtained results: I. Reliability investigations of complex systems 1. Pollaczek-Khintchine formalas in cyclic systems 2. Modelling of self-organizing systems by the help of finite-source retrial queueing systems via MOSEL 3. Structured Markov-chains with special respect to finite-source retrial queues II. Performance evaluation of info-communication systems 1. Modelling of distributed protocols 2. Performance of Proxy-Cache server systems with unreliable servers 3. Modelling of asymmetric network protocols 4. Comparing DiffServ models via simulation and emulation