Meron excitations in the nu =1 quantum Hall bilayer and the plasma analogy

We study meron quasiparticle excitations in the \nu = 1 quantum Hall bilayer. Considering the well known single meron state, we introduce its effective form, valid in the longdistance limit. That enables us to propose two (and more) meron states in the same limit. Further, establishing a plasma analogy of the (111) ground state, we find the impurities that play the role of merons and derive meron charge distributions. Using the introduced meron constructions in generalized (mixed) ground states and corresponding plasmas for arbitrary distance between the layers, we calculate the interaction between the construction implied impurities. We also find a correspondence between the impurity interactions and meron interactions. This suggests a possible explanation of the deconfinement of the merons recently observed in the experiments.Comment: 5 pages, 3 figure

Effect of acute experimental aluminum poisoning on hematologic parameters

Having in mind the presence of aluminum in industry, as well as in households, we wanted to define changes in the number of erythrocytes and aluminum content in the plasma and erythrocytes following acute aluminum poisoning under experimental conditions. The experiment involved gerbils which received intraperitoneally aluminum chloride solution at a dose of 3.7g per kg of body mass. The experimental group was sacrificed after 24, 48, 72 and 96 hours from the beginning of the experiment by cardiac punction or by abdominal artery punction. The control group was treated with saline, only. The number of erythrocytes and hemoglobin concentration were considerably reduced with respect to the control group, most likely as the result of cell membrane changes and reduced life cycle of erythrocytes. During the experiment, aluminum content in the plasma was increased in the first and second day of the experiment, it started to decline on the third day, while on the fourth day it returned to its original value, which proves again the existence of a special mechanism of "clearance" of aluminum in plasma

Lajm neuroborelioza

Lyme borreliosis (LB) is a multisystemic zoonotic disease which in humans can involve the skin, joints, heart and/or nervous system. In this study a total of 11 patients with clinical manifestations have been assessed at the Institute for Occupational Health. Evaluation of the patients was done in order to determine their working capability and further professional orientation. Patients were of different gender, age, education and profession. They fulfilled at least two of the three criteria: tick infestation data (epidemiological criteria), central and/or peripheral neurological symptoms (clinical criteria) and a positive serological finding. Diagnosis was done upon classical clinical criteria: electromyeloneurography (EMNG) analysis, neurological impairments, electroencephalography (EEG), computer tomography (CT) and/or magnetic resonance imaging (MRI). IgM and IgG antibodies against B. burgdorferi were determined by commercial ELISA kits. IgM antibodies were recorded in the serum of 4 (44.4%) and IgG in 6 (66.7%) patients. Electro-myeloneurography findings of the upper and lower limbs were positive in 5 (83.3%), electroencephalography in 4 (66.6%) of the 6 observed patients and CT was positive in 4 (36.4%) of the 5 observed patients. The study has established that in patients with neuroborreliosis (NB) the capability to carry out intellectual tasks, as well as responsible duties is impaired due to poor memory. Patients suffering from peripheral neuropathies are not fit to withstand longterm walks, weight lifting and carrying or any other form of physical stress.Lajm borelioza je multisistemsko oboljenje, iz grupe zoonoza koje kod ljudi može zahvatiti kožu, zglobove, srce i/ili nervni sistem. Istraživanjem je obuhvaćeno 11 bolesnika sa kliničkim manifestacijama neuroborelioze koji su ispitivani u Institutu za medicinu rada Srbije u cilju ocene radne sposobnosti i dalje profesionalne orijentacije. Ispitani su bolesnici različite starosti, pola, nivoa obrazovanja i različitih zanimanja koji su ispunili minimalno dva od tri kriterijuma i to: podatak o ubodu krpelja (epidemiološki kriterijum), ispoljavanje centralnih i/ili, perifernih neuroloških simptoma (klinički kriterijum) i pozitivan serološki nalaz. Dijagnoza neuroborelioze je postavljena na osnovu klasičnih kliničkih kriterijuma: neurološ kih ispada, analize elektro-mioneurografije (EMNG), elektroencefalografije (EEG), kompjuterske tomografije (CT) i/ili magnetne rezonance (MRI). Ispitivanje prisustva antitela IgM i IgG klase u krvnom serumu prema B. burgdorferi vršeno je komercijalnim ELISA testom. Antitela IgM klase registrovana su u serumu četiri (44,4%), dok su IgG antitela registrovana kod 6 (66,7%) ispitanih pacijenata. Nalaz elektro-mioneurografije gornjih i donjih ekstremiteta je bio pozitivan kod pet (83,3%), nalaz elektroencefalografije kod četiri (66,6%) od šest ispitanih pacijenata, dok je nalaz CT bio pozitivan kod 4 (36,4%) od pet ispitanih pacijenata. Sprovedenim ispitivanjem je utvrđeno da je kod bolesnika sa razvijenom neuroboreliozom smanjena sposobnost za bilo koju vrstu intelektualnog rada, kao i za poslove koji su povezani sa moralnom i materijalnom odgovornošću zbog problema sa pamćenjem. Kod bolesnika sa perifernim neuropatijama postoji nesposobnost za poslove koji uključuju dugotrajno stajanje i hodanje, dizanje i nošenje tereta, kao i bilo koju vrstu fizičkog rada

Tunneling-driven breakdown of the 331 state and the emergent Pfaffian and composite Fermi liquid phases

We examine the possibility of creating the Moore-Read Pfaffian in the lowest Landau level when the multicomponent Halperin 331 state (believed to describe quantum Hall bilayers and wide quantum wells at the filling factor $\nu=1/2$) is destroyed by the increase of tunneling. Using exact diagonalization of the bilayer Hamiltonian with short-range and long-range (Coulomb) interactions in spherical and periodic rectangular geometries, we establish that tunneling is a perturbation that drives the 331 state into a compressible composite Fermi liquid, with the possibility for an intermediate critical state that possesses some properties of the Moore-Read Pfaffian. These results are interpreted in the two-component BCS model for Cauchy pairing with a tunneling constraint. We comment on the conditions to be imposed on a system with fluctuating density in order to achieve the stable Pfaffian phase.Comment: 10 pages, 7 figure

Composite bosons in bilayer nu = 1 system: An application of the Murthy-Shankar formalism

We calculate the dispersion of the out-of-phase mode characteristic for the bilayer nu = 1 quantum Hall system applying the version of Chern-Simons theory of Murthy and Shankar that cures the unwanted bare electron mass dependence in the low-energy description of quantum Hall systems. The obtained value for the mode when d, distance between the layers, is zero is in a good agreement with the existing pseudospin picture of the system. For d nonzero but small we find that the mode is linearly dispersing and its velocity to a good approximation depends linearly on d. This is in agreement with the Hartree-Fock calculations of the pseudospin picture that predicts a linear dependance on d, and contrary to the naive Hartree predictions with dependence on the square-root of d. We set up a formalism that enables one to consider fluctuations around the found stationary point values. In addition we address the case of imbalanced layers in the Murthy-Shankar formalism.Comment: 10 pages, 1 figur

Topological d-wave pairing structures in Jain states

We discuss d-wave topological (broken time reversal symmetry) pairing structures in unpolarized and polarized Jain states. We demonstrate pairing in the Jain spin singlet state by rewriting it in an explicit pairing form, in which we can recognize d-wave weak pairing of underlying quasiparticles - neutral fermions. We find and describe the root configuration of the Jain spin singlet state and its connection with neutral excitations of the Haldane-Rezayi state, and study the transition between these states via exact diagonalization. We find high overlaps with the Jain spin singlet state upon a departure from the hollow core model for which the Haldane-Rezayi state is the exact ground state. Due to a proven algebraic identity we were able to extend the analysis of topological d-wave pairing structures to polarized Jain states and integer quantum Hall states, and discuss its consequences.Comment: 8 page

Variability of the chloroplast dna of sessile oak (Quercus petraea agg. Ehrendorfer, 1967) in Serbia

Genetic variability of sessile oak (Quercus petraea agg. Ehrendorfer, 1967) in Serbia is estimated applying cpDNA universal primer pairs that were characterized by a high informative level for chloroplast genome variability assessment in previous investigations. Five different haplotypes were detected in the analyzed sample material from populations in Serbia

Impact of the geographic factors on the transport of lead and cadmium in the air

The aim of this study is to describe the effect of geographical varieties on the transport of lead and cadmium in the air. During period between 1997- 2006, the concentrations of lead in suspended in the air at 5 measuring sites in Serbia were measured. The minimal measured daily concentrations of lead ranged from 0,42 μg/m3 (2002.) in Kraljevo. The maximal measured daily concentrations of lead to 251,8 μg/m3 (2004.) in Belgrade. During the period between 1997-2006., the concentrations of cadmium in suspended in the air at 5 measuring sites in Serbia were measured. The minimal measured daily concentrations of cadmium ranged from 0,1 μg/m3 (1999) in Kraljevo. The maximal measured daily concentrations of lead to 42,0 μg/m3 (2000) in Belgrade. Results from our experiments demonstrated that when rapid infiltration conditions or a rainstorm exist, particle-facilitated transport of contaminants is likely to the dominant metal transport pathway influenced by acid rain.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

The influence of drought on the occurrence of aflatoxins in maize

In this study, a total of 78 maize samples harvested during September and October 2012 in Vojvodina were analyzed. Presence of aflatoxins (AFs) was deter­mined by enzyme-linked immunosorbent assay (ELISA) method. Among the 78 analyzed maize samples, even 44 (56.4%) samples were contaminated with AFs. Concentration interval between 1-10 μg/kg, 10-50 μg/kg and 50-80 μg/kg were found in 23.1%, 17.9% and 15.4% of analyzed maize samples, respectively. It was supposed that prolonged drought during spring and summer of 2012 had a great influence on high contamination frequency and concentration of AFs. [Projekat Ministarstva nauke Republike Srbije, br. III 46001