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

Outsized arbitrage

The paper studies incentives and trading decisions of an arbitrageur who can take concentrated bets in an illiquid market and who cares about interim as well as long-term performance. By scaling up his position and using price impact, the arbitrageur can prop up the value of his position, helping him weather periods of low valuation and successfully complete the arbitrage. But that approach also can trap him into building an outsized arbitrage position, which can cause persistent mispricing in the market, even in the presence of other arbitrageurs, and lead to large losses to investors

Debt Overhang and Barter in Russia

In this paper we study, both theoretically and empirically, the relationship between barter and the indebtedness of Russian firms. We build a model in which a firm uses barter to protect its working capital against outside creditors even when barter involves high transaction costs. The main innovation of our work is to allow renegotiation between the firm and its creditors. If the creditors are rational, they often agree to postpone debt payments in order to avoid destroying the firm's working capital. It turns out, however, that even if the firm cannot ensure it will not divert cash ex post, the outcome of renegotiation still provides ex ante incentives to use barter. We show that the greater the debt overhang, the more likely the use of barter, and although the possibility of debt restructuring reduces barter, it does not eliminate it altogether. We also discuss the role of the government bond market and weak bankruptcy legislation. The firm-level evidence is consistent with the model's predictions.barter, demonetisation, debt overhang, renegotiations

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

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