Quantum corrections of Abelian Duality Transformations

A modification of the Abelian Duality transformations is proposed guaranteeing that a (not necessarily conformally invariant) $\sigma$-model be quantum equivalent (at least up to two loops in perturbation theory) to its dual. This requires a somewhat non standard perturbative treatment of the {\sl dual} $\sigma$-model. Explicit formulae of the modified duality transformation are presented for a special class of block diagonal purely metric $\sigma$-models.Comment: Latex 11 pages; remarks on a free model and references adde

The Nappi-Witten string in the light-cone gauge

Some of the motivations for as well as the main points of the quantization of the Nappi Witten string in the light cone gauge are reviewed.Comment: 21 pages, Plain Tex, to appear in the E.P. Wigner memorial volume of Acta Physica Hungaric

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

Exotic plasma as classical Hall Liquid

A non-relativistic plasma model endowed with an ``exotic'' structure associated with the two-parameter central extension of the planar Galilei group is constructed. Introducing a Chern-Simons statistical gauge field provides us with a self-consistent system; when the magnetic field takes a critical value determined by the extension parameters, the fluid becomes incompressible and moves collectively, according to the Hall law.Comment: 11 pages, LaTex, no figures. Revised version: Some details better explained. To appear in Int. Journ. Mod. Phys.

Factor analysis of the long gamma-ray bursts

We study statistically 197 long gamma-ray bursts, detected and measured in detail by the BATSE instrument of the Compton Gamma-Ray Observatory. In the sample 10 variables, describing for any burst the time behavior of the spectra and other quantities, are collected. The factor analysis method is used to find the latent random variables describing the temporal and spectral properties of GRBs. The application of this particular method to this sample indicates that five factors and the \REpk spectral variable (the ratio of peak energies in the spectrum) describe the sample satisfactorily. Both the pseudo-redshifts inferred from the variability, and the Amati-relation in its original form, are disfavored.Comment: 5 pages, acceptod to A&

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

Classification of Swift's gamma-ray bursts

Two classes of gamma-ray bursts have been identified in the BATSE catalogs characterized by durations shorter and longer than about 2 seconds. There are, however, some indications for the existence of a third class. Swift satellite detectors have different spectral sensitivity than pre-Swift ones for gamma-ray bursts. Therefore, it is worth to reanalyze the durations and their distribution. We analyze, the maximum likelihood estimation, the bursts duration distribution, published in The First BAT Catalog, whether it contains two, three or more groups. The three log-normal fit is significantly (99.54% probability) better than the two for the duration distribution. Monte-Carlo simulations also confirm this probability (99.2%). Similarly, in previous results we found that the fourth component is not needed. The relative frequencies of the distribution of the groups are 7% short 35% intermediate and 58% long. Although the relative frequencies of the groups are different than in the BATSE GRB sample, the difference in the instrument spectral sensitivities can explain this bias on a natural way. This means theoretical models may be needed to explain three different type of gamma-ray bursts.Comment: Accepted in AA, added bibliograph

Mikroszatellita lokuszok evolúciója a görögdinnyében (Citrullus lanatus) a középkor óta; (CT)3 deléció a (CT)26 nSSR-ban.

Görögdinnye (Citrullus lanatus) magleletekből (13. sz., Debrecen; 15. sz. Buda; 18. sz. Pannonhalma) DNS-izolálást, molekuláris (nSSR – nuclear simple sequence repeat; cpDNS – kloroplasztisz DNS) elemzést és fenotípusos fajtarekonstrukciót végeztünk 44 mai fajtával való összehasonlításban. Az elemzésben 47 primer-párt teszteltünk, ebből 26 primer-pár bizonyult hatékonynak a mai fajtákban, amelyek közül csak 16 volt aktív a középkori mintában. Az aktív primerek alkalmazásával szekvencia elemzést végeztünk a (CT)26-30 nSSR lokuszon, és a clp-12 cpDNS lokuszon. Megállapítottuk, hogy a középkori mintában még megtalálható (CT)3 szakasz a mai fajtában már delécióval kiesett az elmúlt 600 év során. Továbbá a cpDNS trnV (Jarret et al., 1997) lokuszán (tRNS-Valin; 299 bp) két szubsztitúciót azonosítottunk (102.196 és a 102.201 nt.-ben). A (CT)26-30 nSSR lokusz (196 bp) 122-130 bp szakaszán egy további (CT)4 inverziót is azonosítottunk, amely (CT)26-30 egyszerű mikroszatellita lokuszból kialakuló (CT)17-C-(TC)3-T-(CT)5 összetett mikroszatellita születését igazolja. Vizsgálataink során egy új retrotranszpozont (Cila-1) azonosítottunk. A középkori minta fajtarekonstrukciójához elkészítettük a 44 mai fajta morfológiai dendrogramját 25 fenotípusos bélyeg alapján. | The evolution of water melon (Citrullus lanatus) microsatellites from the 15th century (Debrecen); 13th (Buda); and 18th century, (Pannonhalma) were analyzed. Microsatellite (nSSR, nuclear simple sequence repeat) and cpDNA profiles of the aDNA (ancient DNA) of seed remains were compared to modern water melon cultivars and landraces. Sixteen primer pairs were applied. Sequence analysis at the (CT)26 and cpDNA trnV loci revealed a (CT)3 and Adenin deletions, respectively, form the current water melon cultivar compared to the medieval sample. Cila-1), a new LTR retrotansposon has been described. For morphological reconstruction, a dendrogram produced by SPSS11 based on the presence versus absence of 24 phenotypic characters were also analyzed

Morfológiai diverzitás sárgadinnyében (Cucumis melo); egy középkori típus fajtarekonstrukciója

47 mai sárgadinnye tájfajta illetve fajta morfológiai diverzitás vizsgálatát végeztük el 23 fenotípusos bélyeg alapján, egy középkori lelet (15. sz. eleje) rekonstrukciójához, valamint az eltet 600 év során végbement mikroevolúciós folyamatok nyomonkövetésére. A vizsgálatok során felvételezett 47 mai sárgadinnye fajta kivétel nélkül besorolható volt az Európában elterjedt három fő terméstípusú csoportba: a cikkelyesen barázdás Kantalup (cantalupensis), a hálózatos-recés terméshéjú Retikulatusz (reticulatus), és a simahéjú Inodorusz (inodorus) csoportba. A párhuzamosan végzett molekuláris vizsgálatok, valamint az itt közölt morfológiai diagramm segítségével a középkori minta fajta-típusa meghatározható volt, amely egy inodorusz típusú, sima héjú, zöld húsú sárgadinnye lehetett, átmeneti formával a „Hógolyó” és a „Kősárga” tájfajta között. | Morphological diversity of melon (Cucumis melo); phenotype reconstruction of a medieval sample. Morphological diversity among 47 melon (Cucumis melo) cultivars and landraces from Hungarian germplasm collection (ABI, Tápiószele) were analyzed with an ultimate aim to characterize morphologically cv. Hógolyó, which showed the closest genetic similarity to a medieval melon recovered from the 15th century. Cultivars based on fruit morphology were grouped into the three main types of melon as reticulatus, cantalupensis and inodorus. Cluster analysis (by SPSS-11) based on 23 morphological (quantitative and qualitative) traits recorded revealed an extreme diversity among accessions, nevertheless cultivars were clustered into main melon clusters with only two exceptions of inodorus type cv. Zimovka J. and Afghanistan. Cultivars Sweet ananas and Ezüst ananász; and two Hungarian landraces Kisteleki and Nagycserkeszi showed close similarity. Cultivars Hógolyó and Túrkeve of inodorus type were also grouped in one cluster, which provide insight into the morphological reconstruction of the medieval melon recovered from the 15th century. These results also indicate that old Hungarian landraces could be re-introduced into breeding programs for broadening genetic base of melon