1,094 research outputs found

    Energy Systematics of Low-lying Collective States within the Framework of the Interacting Vector Boson Model

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    In a new application of the algebraic Interacting Vector Boson Model (IVBM), we exploit the reduction of its Sp(12,R) dynamical symmetry group to Sp(4,R) x SO(3), which defines basis states with fixed values of the angular momentum L. The relationship of the latter to $U(6) \subset U(3)x U(2), which is the rotational limit of the model, means the energy distribution of collective states with fixed angular momentum can be studied. Results for low-lying spectra of rare-earth nuclei show that the energies of collective positive parity states with L=0,2,4,6... lie on second order curves with respect to the number of collective phonons n or vector bosons N=4n out of which the states are built. The analysis of this behavior leads to insight regarding the common nature of collective states, tracking vibrational as well as rotational features.Comment: 8 pages, 5 figures, 4 table

    INFORMATION VALUE OF PARAMETERS FOR HEART RHYTHM ANALYSIS UNDER CONDITIONS OF ANEMIC HYPOXIA

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    Analytic Formulae for the Matrix Elements of the Transition Operators in the Symplectic Extension of the Interacting Vector Boson Model

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    The tensor properties of all the generators of Sp(12,R) - the group of dynamical symmetry of the Interacting Vector Boson Model (IVBM), are given with respect to the reduction chain Sp(12,R) ⊃\supset U(6) ⊃\supset U(3) x U(2) ⊃\supset O(3) x U(1). Matrix elements of the basic building blocks of the model are evaluated in symmetry adapted basis along the considered chain. As a result of this, the analytic form of the matrix elements of any operator in the enveloping algebra of the Sp(12,R), defining a certain transition operator, can be calculated. The procedure allows further applications of the symplectic IVBM for the description of transition probabilities between nuclear collective states.Comment: 6 page

    Collective states of the odd-mass nuclei within the framework of the Interacting Vector Boson Model

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    A supersymmetric extension of the dynamical symmetry group SpB(12,R)Sp^{B}(12,R) of the Interacting Vector Boson Model (IVBM), to the orthosymplectic group OSp(2Ω/12,R)OSp(2\Omega/12,R) is developed in order to incorporate fermion degrees of freedom into the nuclear dynamics and to encompass the treatment of odd mass nuclei. The bosonic sector of the supergroup is used to describe the complex collective spectra of the neighboring even-even nuclei and is considered as a core structure of the odd nucleus. The fermionic sector is represented by the fermion spin group SOF(2Ω)⊃SUF(2)SO^{F}(2\Omega)\supset SU^{F}(2). The so obtained, new exactly solvable limiting case is applied for the description of the nuclear collective spectra of odd mass nuclei. The theoretical predictions for different collective bands in three odd mass nuclei, namely 157Gd^{157}Gd, 173Yb^{173}Yb and 163Dy^{163}Dy from rare earth region are compared with the experiment. The B(E2)B(E2) transition probabilities for the 157Gd^{157}Gd and 163Dy^{163}Dy between the states of the ground band are also studied. The important role of the symplectic structure of the model for the proper reproduction of the B(E2)B(E2) behavior is revealed. The obtained results reveal the applicability of the models extension.Comment: 18 pages, 8 figure

    14 challenges for conducting social neuroscience and longitudinal EEG research with infants

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    The use of electroencephalography (EEG) to study infant brain development is a growing trend. In addition to classical longitudinal designs that study the development of the neural, cognitive and behavioural function, new areas of EEG application are emerging, such as novel social neuroscience paradigms using dual infant-adult EEG recordings. However, most of the experimental designs, analysis methods, as well as EEG hardware were originally developed for single-person adult research. When applied to the study of infant development, adult-based solutions often pose unique problems that may go unrecognised. Here, we identify 14 challenges that infant EEG researchers may encounter when designing new experiments, collecting data, and conducting data analysis. Challenges related to the experimental design are: (1) small sample size and data attrition, and (2) varying arousal in younger infants. Challenges related to data acquisition are: (3) determining the optimal location for reference and ground electrodes, (4) control of impedance when testing with the high-density sponge electrode nets, (5) poor fit of standard EEG caps to the varying infant head shapes, and (6) ensuring a high degree of temporal synchronisation between amplifiers and recording devices during dual-EEG acquisition. Challenges related to the analysis of longitudinal and social neuroscience datasets are: (7) developmental changes in head anatomy, (8) prevalence and diversity of infant myogenic artefacts, (9) a lack of stereotypical topography of eye movements needed for the ICA-based data cleaning, (10) and relatively high inter-individual variability of EEG responses in younger cohorts. Additional challenges for the analysis of dual EEG data are: (11) developmental shifts in canonical EEG rhythms and difficulties in differentiating true inter-personal synchrony from spurious synchrony due to (12) common intrinsic properties of the signal and (13) shared external perturbation. Finally, (14) there is a lack of test-retest reliability studies of infant EEG. We describe each of these challenges and suggest possible solutions. While we focus specifically on the social neuroscience and longitudinal research, many of the issues we raise are relevant for all fields of infant EEG research

    Genotoxic effects of copper sulfate in rabbits

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    This study was carried out to determine the genotoxic effects of oral application of CuSO4 in rabbits by the chromosome aberration (CA) and sister chromatid exchange (SCE) tests. Ten male New Zealand rabbits (5 months old, weighing 3.5-4.0 kg) were allocated into two groups. The first group received CuSO4 (5H2O) in drinking water for 6 consecutive days. The second group was used as a control. On the 7th day, blood samples were taken from the ear marginal vein and the SCE and CA tests in peripheral lymphocytes were used as genotoxicity and mutagenicity endpoints, respectively. Results showed a significant increase in the frequencies of the aberrant cells (7.4±0.24, P<0.001) and CA (chromatid fragments 3.2±0.37, chromosome fragments 4.2±0.37, P<0.001), and total aberrations (7.4±0.24, P<0.001) after the treatment with CuSO4 when compared with the control group. The level of SCE per cell in the CuSO4-treated rabbits (9.66±0.062) was significantly higher than in rabbits from the control group. These findings show that copper exhibits a genotoxic and mutagenic potential in rabbits
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