Radiative activity of magnetic white dwarf undergoing Lorentz-force-driven torsional vibrations

We study radiative activity of magnetic white dwarf undergoing torsional vibrations about axis of its own dipole magnetic moment under the action of Lorentz restoring force. It is shown that pulsating white dwarf can convert its vibration energy into the energy of magneto-dipole emission, oscillating with the frequency equal to the frequency of Alfv\'en torsional vibrations, provided that internal magnetic field is decayed. The most conspicuous feature of the vibration energy powered radiation in question is the lengthening of periods of oscillating emission; the rate of period elongation is determined by the rate magnetic field decay.Comment: Mod. Phys. Lett. A 26 (2011) 359-36

Molecular Evolution of the Brain Transcription Regulatory Network Affecting Worker Behaviour of Honey Bees (Apis Mellifera)

The brain transcription regulatory network drives the behavioural states of honey bee workers. It is paradoxical that labile behaviour is guided by a network of evolutionary conserved pleiotropic transcription factors. So how does adaptive change in behaviour arise? I used a population genomics approach to estimate the strength of selection on coding and cis-regulatory mutations of transcription factors and their target genes in the honey bee brain transcription regulatory network. I found that replacement mutations in highly connected transcription factors and target genes experience significantly stronger negative selection relative to weakly connected transcription factors and targets. Interestingly, connectedness and network structure had minimal influence on the strength of selection on putative regulatory sequences for both transcription factors and their targets. This study suggests that adaptive evolution of complex behaviour can arise because of positive selection on protein-coding mutations in peripheral genes, and on regulatory sequence mutations in both transcription factors and their targets throughout the network

Orbital and spin scissors modes in superfluid nuclei

Nuclear scissors modes are considered in the frame of Wigner function moments method generalized to take into account spin degrees of freedom and pair correlations simultaneously. A new source of nuclear magnetism, connected with counter-rotation of spins up and down around the symmetry axis (hidden angular momenta), is discovered. Its inclusion into the theory allows one to improve substantially the agreement with experimental data in the description of energies and transition probabilities of scissors modes in rare earth nuclei.Comment: arXiv admin note: text overlap with arXiv:1301.251

A new type of nuclear collective motion - the spin scissors mode

The coupled dynamics of low lying modes and various giant resonances are studied with the help of the Wigner Function Moments method on the basis of Time Dependent Hartree-Fock equations in the harmonic oscillator model including spin-orbit potential plus quadrupole-quadrupole and spin-spin residual interactions. New low lying spin dependent modes are analyzed. Special attention is paid to the spin scissors mode.Comment: 21 page

Linking Local Weather To Climate Change: One Year Of Twitter In The US

There is a high level of scientific consensus on climate change. Nevertheless for climate change research to have any practical value, to develop public support for climate policies, the climate research results must find the way to general public. That is why it is important to understand how the public perception of climate change forms. During the last decades there have been a number of studies on the factors affecting the level of public concern on climate change. Two major groups of factors are hypothesized to have the biggest influence on the level of public concern on climate change: extreme weather events and the mass media topic coverage. Local studies confirm that the weather events experienced by people in certain locations might be related to climate change. In 1998 James Hansen hypothesized that two weather parameters\u27 variations, namely, temperature and precipitation, exceeding one standard deviation should be noticeable by people and result in increase of the level of public concern on the phenomena. Nevertheless no previous studies were able to test this hypothesis and demonstrate that people truly use the information about local weather to make assumptions about climate change. The other studies on public perception of climate change are generally based on the agenda-setting theory, stating that the level of public concern on the issue is a reflection of the extent and prominence of media coverage of the topic. The previous studies on how public perception of climate change forms are mainly based surveys, which is an active approach to collect social data. With the development of social media, however, a passive surveying of public perceptions on climate change has become possible. In this thesis the change in climate change microblogging intensity in Twitter was used as a proxy of change in the level of concern on the issue. The objectives of the study were to utilize the Twitter, a currently the most popular microblogging platform, as a source of public salience data to test if the changes in weather parameters and in media coverage result in changes of the level of public concern on climate change. For this purpose the multiple linear regression and multi-model inference statistical techniques were used on three geographical levels of data aggregation. The results clearly show that changes in weather parameters have significant effect on the level of public concern on climate change on the national, regional and local scales. The mass media topic coverage was also positively associated with the level of public concern on the national level. The study demonstrated that the social media data provides unprecedented opportunities for public opinion research

Vibration Powered Radiation of Quaking Magnetar

In juxtaposition with the standard model of rotation powered pulsar, the model of vibration powered magnetar undergoing quake-induced torsional Alfven vibrations in its own ultra strong magnetic field experiencing decay is considered. The presented line of argument suggests that gradual decrease of frequencies (lengthening of periods) of long-periodic pulsed radiation detected from a set of X-ray sources can be attributed to magnetic-field-decay induced energy conversion from seismic vibrations to magneto-dipole radiation of quaking magnetar.Comment: Text of talk presented at "Mini-Workshop on Pulsars", Nov. 12th, 2010; KIAA-PKU, Beijin

Exploring variable-based and case-based approaches to study multiple health behaviours and motivations of Canadian university students

Health behaviors tend to occur together. However, the research on what factors define and regulate their coexistence within individuals is still limited. There is also no established methodology to investigate regulation mechanisms of multiple health behaviours. The objectives of the study were to explore: 1) co-occurrence of multiple health behaviours (smoking, alcohol drinking, physical activity, and healthy eating) in a sample of Canadian university students; 2) the role of motivational (e.g., controlled, autonomous and intrinsic motivations), cognitive (e.g., health attitudes and health empowerment), and social contextual (e.g., family and friends) components in these regulation mechanisms; 3) the strengths and limitations of integrating variable-based and case-based methodological approaches to study the coexistence and regulation of multiple health behaviours. The research was based on the theoretical underpinnings of Self-Determination Theory (SDT) and a critical realism paradigm. College students (N==238) from the University of Saskatchewan completed a survey in Study 1. Six participants, purposefully selected from the sample were interviewed in Study 2. The most frequent multiple health behaviour cluster was ‘alcohol drinking+physical activity+healthy eating’ (62%; n=143). The results of multiple regression analysis (Study 1) confirmed that intrinsic and autonomous motivations were the best predictors of the frequency of alcohol consumption, physical activity, and healthy eating. Interview analyses in Study 2 also suggested that multiple health behaviours were best self-regulated when motivations were harmonized with individuals’ cognitions and emotions, and supported by their social contexts. Such balance could be achieved by exercising more self-control, making up for one health behaviour via another, or avoiding cognitive dissonance by ‘splitting up’ a negative concept into positive and negative ones (e.g., occasional smoking to release stress versus harmful chain smoking). Both Study 1 and Study 2 results present motivation as a hierarchical structure and provide evidence that motivational regulations across multiple health behaviours are interrelated. The comparative analysis of Studies 1 and 2 demonstrates that the integration of two different methodological approaches and the consilience between their results added to the validity and generalizability of the common findings. Importantly, contradictions in findings highlighted limitations of each methodological approach and were discussed in terms of implications for their methodological refinement

Alfven seismic vibrations of crustal solid-state plasma in quaking paramagnetic neutron star

Magneto-solid-mechanical model of two-component, core-crust, paramagnetic neutron star responding to quake-induced perturbation by differentially rotational, torsional, oscillations of crustal electron-nuclear solid-state plasma about axis of magnetic field frozen in the immobile paramagnetic core is developed. Particular attention is given to the node-free torsional crust-against-core vibrations under combined action of Lorentz magnetic and Hooke's elastic forces; the damping is attributed to Newtonian force of shear viscose stresses in crustal solid-state plasma. The spectral formulae for the frequency and lifetime of this toroidal mode are derived in analytic form and discussed in the context of quasi-periodic oscillations of the X-ray outburst flux from quaking magnetars. The application of obtained theoretical spectra to modal analysis of available data on frequencies of oscillating outburst emission suggests that detected variability is the manifestation of crustal Alfven's seismic vibrations restored by Lorentz force of magnetic field stresses.Comment: 10 pages, 10 figure