139 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

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    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

    Computational modeling of In vitro swelling of mitochondria: A biophysical approach

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    Swelling of mitochondria plays an important role in the pathogenesis of human diseases by stimulating mitochondria-mediated cell death through apoptosis, necrosis, and autophagy. Changes in the permeability of the inner mitochondrial membrane (IMM) of ions and other substances induce an increase in the colloid osmotic pressure, leading to matrix swelling. Modeling of mitochondrial swelling is important for simulation and prediction of in vivo events in the cell during oxidative and energy stress. In the present study, we developed a computational model that describes the mechanism of mitochondrial swelling based on osmosis, the rigidity of the IMM, and dynamics of ionic/neutral species. The model describes a new biophysical approach to swelling dynamics, where osmotic pressure created in the matrix is compensated for by the rigidity of the IMM, i.e., osmotic pressure induces membrane deformation, which compensates for the osmotic pressure effect. Thus, the effect is linear and reversible at small membrane deformations, allowing the membrane to restore its normal form. On the other hand, the membrane rigidity drops to zero at large deformations, and the swelling becomes irreversible. As a result, an increased number of dysfunctional mitochondria can activate mitophagy and initiate cell death. Numerical modeling analysis produced results that reasonably describe the experimental data reported earlier.National Institute of General Medical Sciences of the National Institutes of Health [SC1GM128210]; Puerto Rico Institute for Functional Nanomaterials (National Science Foundation Grant) [1002410]; National Aeronautics and Space Administration (NASA) Puerto Rico Established Program to Stimulate Competitive Research (EPSCoR) [NNX15AK43A

    Spin-anticrossing effects in Co-SiO2-Fe and ZnO-SiO2-CuO three-nanolayer devices

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    Presently we report measurements of the spin-anticrossing spectra in the Co-SiO2-Fe and ZnO-SiO2-CuO three-nanolayer sandwich structures. The spin-anticrossing spectra in these systems are quite specific, differing from those observed earlier in other similar structures built of different materials. The theoretical model developed earlier is extended and used to interpret the available experimental results. A detailed ab initio analysis of the magnetic-field dependence of the output magnetic moment is also performed. The model predicts a spin-anticrossing spectrum comprising a series of peaks, with the spectral structure determined by several factors, discussed in the paper. Published by Elsevier Ltd.DoE [DE-F602-o8ER46526]info:eu-repo/semantics/publishedVersio

    Spatial Chaos in a Chain of Coupled Bistable Oscillators

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    The spatiotemporal behavior of a chain of diffusively coupled bistable oscillators is investigated. It is stated that there is spatial disorder and its evolutionary character is demonstrated

    Spiking behavior in a noise-driven system combining oscillatory and excitatory properties

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    We show that firing activity (spiking) can be regularized by noise in a FitzHugh-Nagumo (FHN) neuron model when operating slightly beyond the supercritical Hopf bifurcation (in the "canard" region). We also provide the conditions for imperfect phase Locking between interspike intervals and low amplitude quasiharmonic oscillations. For the imperfect phase locking no need exists of an external signal as it follows from the FHN intrinsic dynamics

    Clustering and phase resetting in a chain of bistable nonisochronous oscillators

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    We consider a chain with many locally coupled bistable nonisochronous oscillators. We show that on the "background" of a disordered amplitude distribution either phase or frequency clusters form in the chain. Cluster location varies according to the amplitude distribution. In the case of frequency clusters their interaction leads to phase resetting in an isolated oscillator located between two neighboring frequency clusters

    Lignite from Central Watershed of the Yenisei River and Prospects for their use for Manufacture of Germanium

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    Π›ΠΈΠ³Π½ΠΈΡ‚Ρ‹ срСднСго тСчСния Ρ€. ЕнисСй, Π»ΠΎΠΊΠ°Π»ΠΈΠ·ΠΎΠ²Π°Π½Π½Ρ‹Π΅ Π² ΠΏΡ€Π΅Π΄Π΅Π»Π°Ρ… мСзокайнозойских ΠΎΡ‚Π»ΠΎΠΆΠ΅Π½ΠΈΠΉ Касской Π²ΠΏΠ°Π΄ΠΈΠ½Ρ‹, Ρ€Π°ΡΡΠΌΠ°Ρ‚Ρ€ΠΈΠ²Π°ΡŽΡ‚ΡΡ ΠΊΠ°ΠΊ Π½ΠΎΠ²Ρ‹ΠΉ пСрспСктивный источник Π³Π΅Ρ€ΠΌΠ°Π½ΠΈΠ΅Π²ΠΎΠ³ΠΎ ΡΡ‹Ρ€ΡŒΡ Π² России. ΠŸΡ€ΠΈΠ²Π΅Π΄Π΅Π½Ρ‹ Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹ изучСния Ρ„ΠΈΠ·ΠΈΠΊΠΎ-химичСских свойств ΠΈ тСхнологичСских исслСдований, ΠΏΠΎΠ·Π²ΠΎΠ»ΡΡŽΡ‰ΠΈΠ΅ ΠΎΡ†Π΅Π½ΠΈΡ‚ΡŒ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡ‚ΡŒ выдСлСния гСрмания ΠΈΠ· Π»ΠΈΠ³Π½ΠΈΡ‚ΠΎΠ² Π² процСссС ΠΈΡ… сТигания для ΠΎΡ‚Ρ€Π°Π±ΠΎΡ‚ΠΊΠΈ, Π° Π² ΠΏΠΎΡΠ»Π΅Π΄ΡƒΡŽΡ‰Π΅ΠΌ для ΠΏΡ€ΠΎΠΌΡ‹ΡˆΠ»Π΅Π½Π½ΠΎΠΉ Ρ‚Π΅Ρ…Π½ΠΎΠ»ΠΎΠ³ΠΈΠΈ Π΅Π³ΠΎ извлСчСнияLignite from central watershed of the Yenisei river localized within the Meso-Cenozoic cavity deposit considered as a promising new source of germanium raw materials in Russia. Germanium separating possibility from lignite during the combustion process has been studied on the base of physical and chemical properties research in order to develop the industrial technolog

    In silico simulation of reversible and irreversible swelling of mitochondria: The role of membrane rigidity

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    Mitochondria have been widely accepted as the main source of ATP in the cell. The inner mitochondrial membrane (IMM) is important for the maintenance of ATP production and other functions of mitochondria. The electron transport chain (ETC) generates an electrochemical gradient of protons known as the proton-motive force across the IMM and thus produces the mitochondrial membrane potential that is critical to ATP synthesis. One of the main factors regulating the structural and functional integrity of the IMM is the changes in the matrix volume. Mild (reversible) swelling regulates mitochondrial metabolism and function; however, excessive (irreversible) swelling causes mitochondrial dysfunction and cell death. The central mechanism of mitochondrial swelling includes the opening of non-selective channels known as permeability transition pores (PTPs) in the IMM by high mitochondrial Ca2+ and reactive oxygen species (ROS). The mechanisms of reversible and irreversible mitochondrial swelling and transition between these two states are still unknown. The present study elucidates an upgraded biophysical model of reversible and irreversible mitochondrial swelling dynamics. The model provides a description of the PTP regulation dynamics using an additional differential equation. The rigidity tensor was used in numerical simulations of the mitochondrial parameter dynamics with different initial conditions defined by Ca2+ concentration in the sarco/endoplasmic reticulum. We were able to estimate the values of the IMM rigidity tensor components by fitting the model to the previously reported experimental data. Overall, the model provides a better description of the reversible and irreversible mitochondrial swelling dynamics.Funding Agency USA NIGMS NIH SC1GM128210 Institute for Functional Nanomaterials (USA NSF) 1002410 PR NASA EPSCoR (USA NASA Cooperative Agreement) NNX15AK43Ainfo:eu-repo/semantics/publishedVersio
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