Different sensing mechanisms in single wire and mat carbon nanotubes chemical sensors

Chemical sensing properties of single wire and mat form sensor structures fabricated from the same carbon nanotube (CNT) materials have been compared. Sensing properties of CNT sensors were evaluated upon electrical response in the presence of five vapours as acetone, acetic acid, ethanol, toluene, and water. Diverse behaviour of single wire CNT sensors was found, while the mat structures showed similar response for all the applied vapours. This indicates that the sensing mechanism of random CNT networks cannot be interpreted as a simple summation of the constituting individual CNT effects, but is associated to another robust phenomenon, localized presumably at CNT-CNT junctions, must be supposed.Comment: 12 pages, 5 figures,Applied Physics A: Materials Science and Processing 201

Satisfiability in multi-valued circuits

Satisfiability of Boolean circuits is among the most known and important problems in theoretical computer science. This problem is NP-complete in general but becomes polynomial time when restricted either to monotone gates or linear gates. We go outside Boolean realm and consider circuits built of any fixed set of gates on an arbitrary large finite domain. From the complexity point of view this is strictly connected with the problems of solving equations (or systems of equations) over finite algebras. The research reported in this work was motivated by a desire to know for which finite algebras $\mathbf A$ there is a polynomial time algorithm that decides if an equation over $\mathbf A$ has a solution. We are also looking for polynomial time algorithms that decide if two circuits over a finite algebra compute the same function. Although we have not managed to solve these problems in the most general setting we have obtained such a characterization for a very broad class of algebras from congruence modular varieties. This class includes most known and well-studied algebras such as groups, rings, modules (and their generalizations like quasigroups, loops, near-rings, nonassociative rings, Lie algebras), lattices (and their extensions like Boolean algebras, Heyting algebras or other algebras connected with multi-valued logics including MV-algebras). This paper seems to be the first systematic study of the computational complexity of satisfiability of non-Boolean circuits and solving equations over finite algebras. The characterization results provided by the paper is given in terms of nice structural properties of algebras for which the problems are solvable in polynomial time.Comment: 50 page

A ferritin szerepe a szőlő stressztűrő képességének fokozásában = The role of ferritin in enhancing the stress tolerance of grapevine

Embriogén kalluszt állítottuk elő Richter110 (alany) és Chardonnay (nemes) szőlő fajták portokajiból. Ezeket Medicago sativa ferritint (MsFerr) tartalmazó Agrobacterium vektorokkal transzformáltunk. A DNS beépülését genomikus PCR-rel ellenőriztük. Poliklonális ellenanyagot állítottunk elő, mellyel megállapítottuk, hogy a transzláció magas szintű volt, a transzkriptumból nagy mennyiségű, megfelelően processzált fehérjetermék keletkezett. A transzgenikus szőlő növények elkészültéig dohányban teszteltük az MsFerr gént tartalmazó konstrukciókat. A teljes növényeken végzett UV-B kezelés, ill. levélkorongok közvetlen oxidatív stresszre adott válaszai alapján megállapítottuk, hogy az MsFerr növények toleránsabbak voltak, mint a nem expresszáló kontrollok. Az MsFerr Richter 110 növények regenerálása, szelekciója és felszaporítása sikeres volt, az MsFerr Chardonnay növények felszaporítása azonban hajtásnövekedési problémák miatt nem sikerült. Három MsFerr Richter 110 vonalat vizsgáltunk. Gyökér stresszként fás szárú dugványok tápoldatához hidrogénkarbonátot adtunk, ami klorotikus és levél száradási tünetek okozott Ebben nem kaptunk lényeges különbséget a transzgenikus és transzformálatlan növények között. Ezzel szemben, a leveleket érő hatásokkal: paraquat, NaCl só-stressz és tBHP indukált lipid peroxidációval szemben az MsFerr expresszáló vonalak toleránsabbak voltak (kisebb stressz-indukált fotoszintézis csökkenést mutattak) mint a transzformálatlanok. | Embryogenic calli were started from anthers of Richter 110 (rootstock) and Chardonnay (scion) grapevine and transformed with Agrobacterium harbouring Medicago sativa ferritin gene (MsFerr). Genomic PCR and protein immunoblotting using a polyclonal antibody confirmed that the transcription and processing of MsFerr was successful. Regeneration, selection and propagation of MsFerr Richter 110 plants was successful, but transformed MsFerr Chardonnay plants did not grow sufficiently. Until transgenic grapevine plants became available, preliminary experiments were carried out with MsFerr expressing tobacco. UV-B irradiation of whole plants as well as treatments of leaf disks with various chemical elicitors showed that MsFerr plants were more stress tolerant than non-expressing controls. After regeneration and propagation, three transgenic MsFerr Richter 110 lines were tested. Roots of green cuttings were stressed by flooding and in this experiment transgenic plants did not show significantly higher tolerance to hypoxia/bicarbonate than non-transferred ones. Leaves, however, showed increased tolerance to paraquat, salt stress and tBHP induced lipid peroxidation: their photosynthesis was less affected by these stressors than those from non-transformed plants

Searching for electromagnetic counterpart of LIGO gravitational waves in the Fermi GBM data with ADWO

The Fermi collaboration identified a possible electromagnetic counterpart of the gravitational wave event of September 14, 2015. Our goal is to provide an unsupervised data analysis algorithm to identify similar events in Fermi's Gamma-ray Burst Monitor CTTE data stream. We are looking for signals that are typically weak. Therefore, they can only be found by a careful analysis of count rates of all detectors and energy channels simultaneously. Our Automatized Detector Weight Optimization (ADWO) method consists of a search for the signal, and a test of its significance. We developed ADWO, a virtual detector analysis tool for multi-channel multi-detector signals, and performed successful searches for short transients in the data-streams. We have identified GRB150522B, as well as possible electromagnetic candidates of the transients GW150914 and LVT151012. ADWO is an independently developed, unsupervised data analysis tool that only relies on the raw data of the Fermi satellite. It can therefore provide a strong, independent test to any electromagnetic signal accompanying future gravitational wave observations.Comment: 4 pages and 4 figures, A&A Letters accepte

MAP kináz jelátvitel funkcionális vizsgálat mitokondriumban = Functional studies on mitochondrial MAP kinase signalling

Munkánk során a növényekre specifikus, kevésbé vizsgált, D típusú MAPKok családjának egyik tagját az AtMPK9-t tanulmányoztuk. Élesztő kettős-hibrid rendszerrel a kalmodulint, mint lehetséges AtMPK9 fehérje partnert azonosítottuk, majd a kölcsönhatást in vitro transzlációval előállított fehérjékkel többféle megközelítéssel igazoltuk. Az AtMPK9 poszttranszlációs módosításokon keresztül történő szabályozása korábban ismeretlen volt. A pályázat keretében tömegspektrometriás vizsgálatokkal és in vitro mutagenezissel előállított AtMPK9 variánsokkal bizonyítottuk, hogy az aktiválásért felelős T hurok régióban elhelyezkedő TDY aminosav triplet treoninjának és tirozinjának foszforilálása nélkül a kináz nem rendelkezik aktivitással. A tömegspektrometriás adatok alapján az is nyilvánvaló vált, hogy az AtMPK9 kináz doménjét követő C-terminális doménben további négy aminosav foszforilálódik. Vizsgálataink szerint az összes általunk azonosított foszforiláció autofoszforiláció eredménye. Feltételezésünk szerint a kináz autofoszforilációs aktivitásának szabályozásában a kölcsönható partnerként azonosított kalmodulin kaphat szerepet. Az AtMPK9 in planta funkcióját protoplaszt tranziens expresszióval és null-mutáns növényekkel tanulmányoztuk. Vizsgálataink alapján a fehérje kináz abiotikus stresszel aktiválható, azonban ennek ellenére a null-mutáns növények fenotípusa még stressz körülmények között sem tér el a vadtípusétól, így az AtMPK9 valószínűsíthetően funkcionálisan redudáns kináz. | The project aimed at studying AtMPK9, a member of plant specific, D type mitogen activated protein kinase (MAPK). We identified calmodulin as its putative protein interacting partner by yeast two-hybrid assay. In order to evaluate this result, AtMPK9 and calmodulin were produced by in vitro translation and the interaction was confirmed by pull-down assays and surface plasmone resonance analysis. The kinase activity regulation of AtMPK9 was unknown previously. We demonstrated by mass spectrometry and in vitro mutagenesis studies that phosphorylation of threonine and tyrosine of TDY amino acid triad of T loop is inevitable for kinase activity. Further mass spectrometry analysis revealed another four phosphorylated amino acids in the C-terminal domain of AtMPK9. According to our in vitro translation based data, all the identified phosphorylations are caused by autophosphorylation. We hypothesize that the interacting partner calmodulin regulates the autophosphorylation activity of kinase. The in planta function of the protein kinase was studied by protoplast transient overexpression and application of AtMPK9 knock-out plants. Although the kinase activity of AtMPK9 was inducible by abiotic stress, the knock-out plants did not show any difference in phenotype, not even in stress conditions. These data imply that AtMPK9 is a functionally redundant protein kinase

Optically switched magnetism in photovoltaic perovskite CH3_3NH3_3(Mn:Pb)I3_3

The demand for ever-increasing density of information storage and speed of manipulation boosts an intense search for new magnetic materials and novel ways of controlling the magnetic bit. Here, we report the synthesis of a ferromagnetic photovoltaic CH$_3$NH$_3$(Mn:Pb)I$_3$ material in which the photo-excited electrons rapidly melt the local magnetic order through the Ruderman-Kittel-Kasuya-Yosida interactions without heating up the spin system. Our finding offers an alternative, very simple and efficient way of optical spin control, and opens an avenue for applications in low power, light controlling magnetic devices