Light-Shaping of Valley States

The established paradigm to create valley states, excitations at local band extrema (“valleys”), is through selective occupation of specific valleys via circularly polarized laser pulses. Here we show a second way exists to create valley states, not by valley population imbalance but by “light-shaping” in momentum space, i.e. controlling the shape of the distribution of excited charge at each valley. While noncontrasting in valley charge, such valley states are instead characterized by a valley current, identically zero at one valley and finite and large at the other. We demonstrate that these (i) are robust to quantum decoherence, (ii) allow lossless toggling of the valley state with successive femtosecond laser pulses, and (iii) permit valley contrasting excitation both with and without a gap. Our findings open a route to robust ultrafast and switchable valleytronics in a wide scope of 2d materials, bringing closer the promise of valley-based electronics

Giant and Controllable Valley Currents in Graphene by Double Pumped THz Light

The field of valleytronics considers the creation and manipulation of “valley states”, charge excitations characterized by a particular value of the crystal momentum in the Brillouin zone. Here we show, using the example of minimally gapped (≤40 meV) graphene, that there exist lightforms that create almost perfect valley contrasting current states (up to ∼80% valley purity) in the absence of a valley contrasting charge excitation. These “momentum streaked” THz waveforms act by deforming the excited state population in momentum space such that current flows at one valley yet is blocked at the conjugate valley. This approach both unlocks the potential of graphene as a materials platform for valleytronics, as gaps of 10–40 meV are robustly found in useful experimental contexts such as graphene/hBN systems, while simultaneously providing a tool toward ultrafast light control of valley currents in diverse minimally gapped matter, including many topological insulator systems

Changes in Corporate Social Responsibility Activity during a Pandemic: The Case of Covid-19

This study examines the practice of corporate social responsibility (CSR) during Covid-19. Little is known about how organizations practice CSR during acute exogenous crises. Overlooking how CSR practices change during a crisis matters because organizations are compelled into trade-offs that carry implications for their CSR initiatives. Analysis of interview data with CSR managers, from 21 Dubai-based business organizations during Covid-19, uncovers changes in the content and process of CSR during the pandemic. The results show that the practice of CSR underwent a fundamental change in focus as organizations shifted to an employee-centric model of CSR and away from an environmental one. Measures placed on organizations and society to combat the pandemic also led to a recalibration of stakeholder and issue salience, with notable effects on CSR that challenge the capability of the power-legitimacy-urgency framework to anticipate these shifts. We consider the impacts associated with the shift in the content of CSR initiatives and process of their implementation and discuss the implications of the findings for CSR theory, research, policy, and practice.</p

Changes in Corporate Social Responsibility Activity during a Pandemic: The Case of Covid-19

This study examines the practice of corporate social responsibility (CSR) during Covid-19. Little is known about how organizations practice CSR during acute exogenous crises. Overlooking how CSR practices change during a crisis matters because organizations are compelled into trade-offs that carry implications for their CSR initiatives. Analysis of interview data with CSR managers, from 21 Dubai-based business organizations during Covid-19, uncovers changes in the content and process of CSR during the pandemic. The results show that the practice of CSR underwent a fundamental change in focus as organizations shifted to an employee-centric model of CSR and away from an environmental one. Measures placed on organizations and society to combat the pandemic also led to a recalibration of stakeholder and issue salience, with notable effects on CSR that challenge the capability of the power-legitimacy-urgency framework to anticipate these shifts. We consider the impacts associated with the shift in the content of CSR initiatives and process of their implementation and discuss the implications of the findings for CSR theory, research, policy, and practice

Perfect and Controllable Nesting in Minimally Twisted Bilayer Graphene

Parallel (“nested”) regions of a Fermi surface (FS) drive instabilities of the electron fluid, for example, the spin density wave in elemental chromium. In one-dimensional materials, the FS is trivially fully nested (a single nesting vector connects two “Fermi dots”), while in higher dimensions only a fraction of the FS consists of parallel sheets. We demonstrate that the tiny angle regime of twist bilayer graphene (TBLG) possesses a phase, accessible by interlayer bias, in which the FS consists entirely of nestable “Fermi lines”, the first example of a completely nested FS in a two-dimensional (2D) material. This nested phase is found both in the ideal as well as relaxed structure of the twist bilayer. We demonstrate excellent agreement with recent STM images of topological states in this material and elucidate the connection between these and the underlying Fermiology. We show that the geometry of the Fermi lines network is controllable by the strength of the applied interlayer bias, and thus TBLG offers unprecedented access to the physics of FS nesting in 2D materials

The distribution of −237 C/T polymorphism among patients, healthy contacts and volunteers.

<p>^<b>a</b> Subjects included in the study;</p><p>^<b>b</b> Polymorphism position ;</p><p>^<b>c</b> Individuals with C nucleotide at −237 position;</p><p>^<b>d</b> Individuals with T nucleotide at −237 position ;</p><p>^<b>e</b> Total number of individuals investigated;</p><p>^<b>f</b> Percentage of individuals.</p><p>^<b>g</b> pulmonary tuberculosis patients ;</p><p>^<b>h</b> healthy patients contacts ;</p><p>^<b>i</b> Healthy laboratory Volunteers.</p

Relative mRNA quantification of IL-12Rβ2 mRNA expression in tuberculosis patients (N = 28).

<p>Histogram shows the IL-12Rβ2 mRNA expression profile in the blood of the tuberculosis patients. The identification of the polymorphism at −237 site has been carried out by PCR amplification and sequencing (forward & reverse) of the 622 bp region spanning −780 to −159. The patients with the T at −237 polymorphic site has been indicated. The bars represent expression of IL-12Rβ2 mRNA in each individual. The fold activity pattern in real time PCR assay was calculated as described in methods, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034355#pone.0034355-Livak1" target="_blank">[15]</a>. The individuals with reduced / elevated IL-12Rβ2 mRNA expression have been designated as Low expressers / High expressers.</p

Multiple scattering correction factor estimation for aethalometer aerosol absorption coefficient measurement

We estimate the multiple scattering correction factor (Cref), which is an empirical constant required to correct aerosol absorption coefficient (σap) measurements for the multiple scattering artifacts of aethalometer, using a multiplier derived from a linear regression method (CrefLRL). Estimated CrefLRL values during the Cheju ABC Plume Monsoon EXperiment (CAPMEX) are 3.99 (405 nm), 4.48 (532 nm), and 5.46 (781 nm) using aethalometer and 3-wavelength PhotoAcoustic Soot Spectrometer (PASS-3). The difference between these CrefLRL values and those of a previous study (CrefW03) are ˗8.0% (405 nm), 20.1% (532 nm), and 30.2% (781 nm); the difference is greater at larger wavelengths because the linear regression line intercept is larger. CrefW03 varies by up to 121% with increasing aerosol absorption coefficient (σap) at 532 and 781 nm, whereas CrefLRL varies by only 36.8%. CrefW03 and CrefLRL determined during CAPMEX were applied to year-round aethalometer σap measurements (σapW03 and σapLRL, respectively) at Gosan (GSN), Lulin (LLN), and Alert (ALT) stations. σapW03 and σapLRL were compared to concurrent σap measurements from Continuous Light Absorption Photometer (CLAP; σapCLAP). At GSN, the bias difference and root mean square difference of σapW03 from σapCLAP are ˗23.1 and 25.8%; however, those of σapLRL from σapCLAP are ˗9.0 and 17.9%, respectively. LLN and ALT both exhibit a greater difference between σapW03 and σapCLAP than between σapLRL and σapCLAP. This suggests that CrefLRLcan be applied to year-round aethalometer measurements. Furthermore, σapLRL agrees better with σapCLAP than σapW03 in all three environments. Copyright © 2019 American Association for Aerosol Research</p

Supershift assay using AP-4 consensus, wild type and polymorphic type probe incubated with / without AP-4 polyclonal antibody.

<p>The assay carried out utilizing different probes without nuclear lysate ; (lanes 1 , 4 & 7); with Jurkat nuclear lysate ; (Lanes 2,5 & 8) Super shift assay with Jurkat cell nuclear extracts was carried out using anti AP-4 antibody (20 µl ) with specific AP- 4 probe (lane 3), C and T type probes, lanes 6 & 9 respectively. The arrow head indicates the shifted band corresponding to the different type of probes. The star symbol indicates supershifted complex corresponding to different probes. These data are representative of 2 independent experiments.</p

List of primers used in the study.

a<p>Amplicon size.</p>b<p><i>Sac</i>I site in bold incorporated in the −591F primer.</p>c<p><i>Nhe</i>I site in bold incorporated in the +55R primer.</p