Bifurcations and bistability in cavity assisted photoassociation of Bose-Einstein condensed molecules

We study the photo-association of Bose-Einstein condensed atoms into molecules using an optical cavity field. The driven cavity field introduces a new dynamical degree of freedom into the photoassociation process, whose role in determining the stationary behavior has not previously been considered. The semiclassical stationary solutions for the atom and molecules as well as the intracavity field are found and their stability and scaling properties are determined in terms of experimentally controllable parameters including driving amplitude of the cavity and the nonlinear interactions between atoms and molecules. For weak cavity driving, we find a bifurcation in the atom and molecule number occurs that signals a transition from a stable steady state to nonlinear Rabi oscillations. For a strongly driven cavity, there exists bistability in the atom and molecule number

Optimal conversion of Bose condensed atoms into molecules via a Feshbach resonance

In many experiments involving conversion of quantum degenerate atomic gases into molecular dimers via a Feshbach resonance, an external magnetic field is linearly swept from above the resonance to below resonance. In the adiabatic limit, the fraction of atoms converted into molecules is independent of the functional form of the sweep and is predicted to be 100%. However, for non-adiabatic sweeps through resonance, Landau-Zener theory predicts that a linear sweep will result in a negligible production of molecules. Here we employ a genetic algorithm to determine the functional time dependence of the magnetic field that produces the maximum number of molecules for sweep times that are comparable to the period of resonant atom-molecule oscillations, $2\pi\Omega_{Rabi}^{-1}$. The optimal sweep through resonance indicates that more than 95% of the atoms can be converted into molecules for sweep times as short as $2\pi\Omega_{Rabi}^{-1}$ while the linear sweep results in a conversion of only a few percent. We also find that the qualitative form of the optimal sweep is independent of the strength of the two-body interactions between atoms and molecules and the width of the resonance

Melanocortins induce interleukin 6 gene expression and secretion through melanocortin receptors 2 and 5 in 3T3-L1 adipocytes

Interleukin 6 (IL6) is a pleiotropic cytokine that not only affects the immune system, but also plays an active role in many physiological events in various organs. Notably, 35% of systemic IL6 originates from adipose tissues under noninflammatory conditions. Here, we describe a previously unknown function of melanocortins in regulating Il6 gene expression and production in 3T3-L1 adipocytes through membrane receptors which are called melanocortin receptors (MCRs). Of the five MCRs that have been cloned, MC2R and MC5R are expressed during adipocyte differentiation. α-Melanocyte-stimulating hormone (α-MSH) or ACTH treatment of 3T3-L1 adipocytes induces Il6 gene expression and production in a time- and concentration-dependent manner via various signaling pathways including the protein kinase A, p38 mitogen-activated protein kinase, cJun N-terminal kinase, and IκB kinase pathways. Specific inhibition of MC2R and MC5R expression with short interfering Mc2r and Mc5r RNAs significantly attenuated the α-MSH-induced increase of intracellular cAMP and both the level of Il6 mRNA and secretion of IL6 in 3T3-L1 adipocytes. Finally, when injected into mouse tail vein, α-MSH dramatically increased the Il6 transcript levels in epididymal fat pads. These results suggest that α-MSH in addition to ACTH may function as a regulator of inflammation by regulating cytokine production

Degradation-Sensitive Control Algorithm Based on Phase Optimization for Interleaved DC–DC Converters

As the use of interleaved DC–DC converters in electric vehicles (EVs) increases, research on reliability improvement is required. In the case of interleaved DC–DC converters, degradation occurs between transistors and capacitors. In particular, transistor degradation imbalances cause an increase in output capacitor RMS current, which increases power loss and accelerates capacitor degradation. This degradation affects system reliability by increasing thermal stress. In this paper, based on a degraded 2-leg interleaved DC–DC boost converter, research to reduce the converter’s output capacitor RMS current was conducted. The output capacitor RMS current according to the transistor degradation imbalance was analyzed. As a result, it was confirmed that the transistor degradation imbalance causes an increase in the capacitor RMS current. To address this issue, a phase optimization algorithm for reducing increased capacitor RMS current is presented in this paper. Next, the phase optimization algorithm is mathematically analyzed. Finally, its efficacy is proved through simulations and experiments

CEO succession planning and market reactions to CEO turnover announcements

This study investigates how capital market investors assess CEO succession planning in the context of CEO turnover events. Conducting empirical tests using a manually collected sample of 676 CEO turnover cases, we find that CEO succession planning mitigates the negative association between CEO performance and market reactions to CEO turnover announcements. Further analyses reveal that our results are driven by firms with strong corporate governance. Overall, our findings suggest that CEO succession planning disclosure reduces investors??? concerns about firm performance in the event of CEO turnover

CEO succession planning and market reactions to CEO turnover announcements

This study investigates how capital market investors assess CEO succession planning in the context of CEO turnover events. Conducting empirical tests using a manually collected sample of 676 CEO turnover cases, we find that CEO succession planning mitigates the negative association between CEO performance and market reactions to CEO turnover announcements. Further analyses reveal that our results are driven by firms with strong corporate governance. Overall, our findings suggest that CEO succession planning disclosure reduces investors’ concerns about firm performance in the event of CEO turnover

Towards a distributed computing model for fog

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Stretchable E-Skin Apexcardiogram Sensor

A new strategy to measure the apex cardiogram with electronic skin technology is presented. An electronic skin apex-cardiogram sensor, which can compensate the conventional electrocardiogram for cardiac diagnosis, is demonstrated through a highly sensitive and stretchable strain sensor with gold-nanoparticle composites.114426Nsciescopu