Light during embryonic development modulates patterns of lateralization strongly and similarly in both zebrafish and chick

Some aspects of lateralization are widespread. This is clear for the association between left-eye (LE) use and readiness to respond intensely to releasing stimuli presented by others, which has been found in representatives of all major groups of tetrapods and in fishes. In the chick, this behavioural asymmetry is linked developmentally to greater ability to sustain response against distracting stimuli with right-eye (RE) use, in that both reverse with the reversal of the normal RE exposure to light. In the zebrafish, the same two asymmetries (normally) have similar associations with the LE and the RE, and both also reverse together (owing to epithalamic reversal). Here, we show that light exposure early in development is needed in zebrafish to generate both asymmetries. Dark development largely abolishes both the enhanced abilities, confirming their linkage. Resemblance to the chick is increased by the survival in the chick, after dark development, of higher ability to assess familiarity of complex stimuli when using the LE. A somewhat similar ability survives in dark-developed zebrafish. Here, LE use causes lesser reliance on a single recent experience than on longer term past experience in the assessment of novelty. Such resemblances between a fish and a bird suggest that we should look not only for resemblances between different groups of vertebrates in the most common overall pattern of lateralization, but also for possible resemblances in the nature of inter-individual variation and in the way in which it is generated during development

SN1987A and the properties of neutrino burst

We reanalyze the neutrino events from SN1987A in IMB and Kamiokande-II (KII) detectors, and compare them with the expectations from simple theoretical models of the neutrino emission. In both detectors the angular distributions are peaked in the forward direction, and the average cosines are 2 sigma above the expected values. Furthermore, the average energy in KII is low if compared with the expectations; but, as we show, the assumption that a few (probably one) events at KII have been caused by elastic scattering is not in contrast with the 'standard' picture of the collapse and yields a more satisfactory distributions in angle and (marginally) in energy. The observations give useful information on the astrophysical parameters of the collapse: in our evaluations, the mean energy of electron antineutrinos is =12-16 MeV, the total energy radiated around (2-3)*1.E53 erg, and there is a hint for a relatively large radiation of non-electronic neutrino species. These properties of the neutrino burst are not in disagreement with those suggested by the current theoretical paradigm, but the data leave wide space to non-standard pictures, especially when neutrino oscillations are included.Comment: 14 pages, 5 figure

Modeling the multifractal dynamics of COVID-19 pandemic

We propose a mathematical model for the multifractal dynamics of COVID-19 pandemic. Within this model and the finite-difference parametric nonlinear equations of the reduced SIR (Susceptible-Infected-Removed) model we calculate the fractal dimensions of various segments of daily disease incidence in the world and the variations of COVID-19 basic reproduction number based on the COVID-19 World Statistics data. © 2022 SPIE

Effect of high alpha-particle fluences on phosphate-glass detectors

The effect of high alpha-particle fluences (3 x 10(13)-2 x 10(15) cm(-2)) on the line-recording properties of the two types of phosphate-glass detectors with different compositions was studied. The glass samples were exposed to accelerated Si ions and fission fragments before and after their irradiation with the accelerated 3.1-MeV alpha-particle beam, perpendicular to the sample surfaces, and with alpha-particles from a Ra-226 radioactive source in a solid angle of about 2 pi. It was shown that the recording properties of glass detectors depended on the alpha-particle fluence, spatial distribution of the alpha-particle paths, and glass type. The critical alpha-particle fluences, above which the detector properties changed, were determined