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2006 2017

Photoconvertible fluorescent proteins (pcFPs) constitute a large group of fluorescent proteins related to green fluorescent protein (GFP) that, when exposed to blue light, bear the capability of irreversibly switching their emission color from green to red. Not surprisingly, this fascinating class of FPs has found numerous applications, in particular for the visualization of biological processes. A detailed understanding of the photoconversion mechanism appears indispensable in the design of improved variants for applications such as super-resolution imaging. In this article, recent work is reviewed that involves using pcFPs as a model system for studying protein dynamics. Evidence has been provided that ...

Contributors
Wachter, Rebekka, College of Liberal Arts and Sciences, School of Molecular Sciences, et al.
Created Date
2017-08-18

The smart-grid approach undergoes many difficulties regarding the strategy that will enable its actual implementation. In this paper, an overview of real-time simulation technologies and their applicability to the smart-grid approach are presented as enabling steps toward the smart-grid’s actual implementation. The objective of this work is to contribute with an introductory text for interested readers of real-time systems in the context of modern electric needs and trends. In addition, a comprehensive review of current applications of real-time simulation in electric systems is provided, together with the basis to understand real-time simulation and the topologies and hardware used to implement ...

Contributors
Ibarra, Luis, Rosales, Antonio, Ponce, Pedro, et al.
Created Date
2017-06-16

The ‘Hestia Project’ uses a bottom-up approach to quantify fossil fuel CO[subscript 2] (FFCO[subscript 2]) emissions spatially at the building/street level and temporally at the hourly level. Hestia FFCO[subscript 2] emissions are provided in the form of a group of sector-specific vector layers with point, line, and polygon sources to support carbon cycle science and climate policy. Application to carbon cycle science, in particular, requires regular gridded data in order to link surface carbon fluxes to atmospheric transport models. However, the heterogeneity and complexity of FFCO[subscript 2] sources within regular grids is sensitive to spatial resolution. From the perspective of ...

Contributors
Liang, Jianming, Gurney, Kevin, O'Keeffe, Darragh, et al.
Created Date
2017-05-19

The optical properties of bulk InAs[subscript 0.936]Bi[subscript 0.064] grown by molecular beam epitaxy on a (100)-oriented GaSb substrate are measured using spectroscopic ellipsometry. The index of refraction and absorption coefficient are measured over photon energies ranging from 44 meV to 4.4 eV and are used to identify the room temperature bandgap energy of bulk InAs[subscript 0.936]Bi[subscript 0.064] as 60.6 meV. The bandgap of InAsBi is expressed as a function of Bi mole fraction using the band anticrossing model and a characteristic coupling strength of 1.529 eV between the Bi impurity state and the InAs valence band. These results are programmed ...

Contributors
Webster, Preston, Shalindar Christaj, Arvind Joshua Jaydev, Riordan, Nathaniel, et al.
Created Date
2016-06-08

The valley degree of freedom in two-dimensional (2D) crystals recently emerged as a novel information carrier in addition to spin and charge. The intrinsic valley lifetime in 2D transition metal dichalcogenides (TMD) is expected to be markedly long due to the unique spin-valley locking behavior, where the intervalley scattering of the electron simultaneously requires a large momentum transfer to the opposite valley and a flip of the electron spin. However, the experimentally observed valley lifetime in 2D TMDs has been limited to tens of nanoseconds thus far. We report efficient generation of microsecond-long-lived valley polarization in WSe[subscript 2]/MoS[subscript 2] heterostructures ...

Contributors
Kim, Jonghwan, Jin, Chenhao, Chen, Bin, et al.
Created Date
2017-07-26

We introduce a non-Hermitian Schrödinger-type approximation of optical Bloch equations for two-level systems. This approximation provides a complete and accurate description of the coherence and decoherence dynamics in both weak and strong laser fields at the cost of losing accuracy in the description of populations. In this approach, it is sufficient to propagate the wave function of the quantum system instead of the density matrix, providing that relaxation and dephasing are taken into account via automatically adjusted time-dependent gain and decay rates. The developed formalism is applied to the problem of scattering and absorption of electromagnetic radiation by a thin ...

Contributors
Puthumpally-Joseph, Raiju, Sukharev, Maxim, Charron, Eric, et al.
Created Date
2016-04-20

Recently, near-field thermal radiation has attracted much attention in several fields since it can exceed the Planck blackbody limit through the coupling of evanescent waves. In this work, near-field radiative heat transfer between two semi-infinite dual uniaxial electromagnetic metamaterials with two different material property sets is theoretically analyzed. The near-field radiative heat transfer is calculated using fluctuational electrodynamics incorporated with anisotropic wave optics. The underlying mechanisms, namely, magnetic hyperbolic mode, magnetic surface polariton, electrical hyperbolic mode, and electrical surface polariton, between two homogeneous dual uniaxial electromagnetic metamaterials are investigated by examining the transmission coefficient and the spectral heat flux. The ...

Contributors
Chang, Jui-Yung, Basu, Soumyadipta, Yang, Yue, et al.
Created Date
2016-06-07

Pathogenic and nonpathogenic species of bacteria and fungi release membrane vesicles (MV), containing proteins, polysaccharides, and lipids, into the extracellular milieu. Previously, we demonstrated that several mycobacterial species, including bacillus Calmette-Guerin (BCG) and Mycobacterium tuberculosis, release MV containing lipids and proteins that subvert host immune response in a Toll-like receptor 2 (TLR2)-dependent manner (R. Prados-Rosales et al., J. Clin. Invest. 121:1471–1483, 2011, doi:10.1172/JCI44261). In this work, we analyzed the vaccine potential of MV in a mouse model and compared the effects of immunization with MV to those of standard BCG vaccination. Immunization with MV from BCG or M. tuberculosis elicited ...

Contributors
Prados-Rosales, Rafael, Carreno, Leandro J., Batista-Gonzalez, Ana, et al.
Created Date
2014-09-30

We report on a new numerical approach for multi-band drift within the context of full band Monte Carlo (FBMC) simulation and apply this to Si and InAs nanowires. The approach is based on the solution of the Krieger and Iafrate (KI) equations [J. B. Krieger and G. J. Iafrate, Phys. Rev. B 33, 5494 (1986)], which gives the probability of carriers undergoing interband transitions subject to an applied electric field. The KI equations are based on the solution of the time-dependent Schrödinger equation, and previous solutions of these equations have used Runge-Kutta (RK) methods to numerically solve the KI equations. ...

Contributors
Hathwar, Raghuraj, Saraniti, Marco, Goodnick, Stephen, et al.
Created Date
2016-07-29

Public power system test cases that are of high quality benefit the power systems research community with expanded resources for testing, demonstrating, and cross-validating new innovations. Building synthetic grid models for this purpose is a relatively new problem, for which a challenge is to show that created cases are sufficiently realistic. This paper puts forth a validation process based on a set of metrics observed from actual power system cases. These metrics follow the structure, proportions, and parameters of key power system elements, which can be used in assessing and validating the quality of synthetic power grids. Though wide diversity ...

Contributors
Birchfield, Adam B., Schweitzer, Eran, Athari, Mir Hadi, et al.
Created Date
2017-08-19