3,143 research outputs found
External control of the Drosophila melanogaster egg to imago development period by specific combinations of 3D low-frequency electric and magnetic fields
We report that the duration of the egg-to-imago development period of the Drosophila melanogaster, and the imago longevity, are both controllable by combinations of external 3-dimensional (3D) low-frequency electric and magnetic fields (LFEMFs). Both these periods may be reduced or increased by applying an appropriate configuration of external 3D LFEMFs. We report that the longevity of D. melanogaster imagoes correlates with the duration of the egg-to-imago development period of the respective eggs. We infer that metabolic processes in both eggs and imago are either accelerated (resulting in reduced time periods) or slowed down (resulting in increased time periods). We propose that external 3D LFEMFs induce electric currents in live systems as well as mechanical vibrations on sub-cell, whole-cell and cell-group levels. These external fields induce media polarization due to ionic motion and orientation of electric dipoles that could moderate the observed effects. We found that the longevity of D. melanogaster imagoes is affected by action of 3D LFEMFs on the respective eggs in the embryonic development period (EDP). We interpret this effect as resulting from changes in the regulation mechanism of metabolic processes in D. melanogaster eggs, inherited by the resulting imagoes. We also tested separate effects of either 3D electric or 3D magnetic fields, which were significantly weaker
HI properties of nearby galaxies from a volume-limited sample
We consider global HI and optical properties of about three hundred nearby
galaxies with V km/s. The majority of them have individual
photometric distance estimates. The galaxy sample parameters, e.g. their linear
diameters, their HI mass-to-luminosity ratio, their total mass-to-luminosity
ratio, their mean optical surface brightness show some known and some new
correlations implying a meaningful dynamic explanation. For the LV galaxies
their HI mass and angular momentum follow a nearly linear relation expected for
rotating gaseous disks being near the threashold of gravitational instability,
favourable for active star formation.Comment: 5 pages, 9 figures, uses laa.sty accepted by A&A Suppl. Serie
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