Controlling complexity in assemblies of metal and semiconductor nanoparticles has the potential to expand the utilization of photonic devices into wavelength regimes that are currently inaccessible. Here we show that casting ultrathin films of asymmetric block copolymers on topographically defined substrates affords four types of mixed patterns through fine control of film thickness. Analysis of top-view and cross-sectional images revealed different morphological behavior of the film in the trench and on the plateau, which was explained by the difference in the type of boundary imposed by each topographic feature. Exposed domains were chemically modified and selectively decorated with gold nanoparticles, giving rise to nanoparticle superstructures with mixed patterns in a controlled fashion. We envisage utilization of such hierarchical superstructures as plasmon waveguides and metasurfaces.
In this article, I examine several expressions of imaginative practices to unpack the umbrella term scenario. Drawing on my long-term fieldwork on Israel’s annual Turning Point exercises, I examine actual uses of scenarios and distinguish between two different logics of imaginative practices and the modalities in which the future is governed by them, which I refer to as the scenaristic and the simulative. As I demonstrate, these two modalities can be distinguished from each other in terms of their approaches to future uncertainty, their temporalities and the role of imagination within their enactment. To further conceptually develop the logics of imagination, I draw on Deleuze’s and Bergson’s discussions of the concept of fabulation, and I suggest that scenarios and simulations represent two different logics of future-governing that are based on practices of imagination.
Foreign investment is governed by thousands of international investment agreements (IIAs), many of which include investor-state dispute settlement (ISDS) provisions. Member states have played a prominent role in the evolution and shape of this decentralized global investment regime. The EU itself has become an actor in this regime since gaining competence in this area in 2009. This article examines the manners by which investment policies of the EU and its member states have evolved over time and their implications for the EU’s actorness. Using, first, the concept and metric of state regulatory space, we show that the EU is more enthusiastic than its member states about reforms, but that a lack of internal cohesiveness and a competitive external environment limit its actorness. Second, drawing on recent discussions on ISDS reforms, we highlight the increasing ability of the EU to speak up with one voice on global investment rules.
Foreign investment is governed by thousands of international investment agreements (IIAs), many of which include investor-state dispute settlement (ISDS) provisions. Member states have played a prominent role in the evolution and shape of this decentralized global investment regime. The EU itself has become a player in this regime since gaining competency in this area in 2009. This article examines the manners by which investment policies of the EU and its member states have evolved over time and their implications for the EU’s actorness. Using, first, the concept and metric of state regulatory space, we show that the EU is more enthusiastic than its member states about reforms, but that a lack of internal cohesiveness and a competitive external environment limit its actorness. Second, drawing on recent discussions of ISDS reforms, we highlight the increasing ability of the EU to speak up with one voice on global investment rules.
We consider an arbitrary quantum mechanical system, initially in its ground-state, exposed to a time-dependent electromagnetic pulse with a carrier frequency ω0 and a slowly varying envelope of finite duration. By working out a solution to the time-dependent Schrödinger equation in the high-ω0 limit, we find that, to the leading order in ω−10, a perfect self-cancellation of the system’s linear response occurs as the pulse switches off. Surprisingly, the system’s observables are, nonetheless, describable in terms of a combination of its linear density response function and nonlinear functions of the electric field. An analysis of a jellium slab and jellium sphere models reveals a very high surface sensitivity of the considered setup, producing a richer excitation spectrum than accessible within the conventional linear response regime. On this basis, we propose a new spectroscopic technique, which we provisionally name the Nonlinear High-Frequency Pulsed Spectroscopy (NLHFPS). Combining the advantages of the extraordinary surface sensitivity, the absence of constraints by the traditional dipole selection rules, and the clarity of theoretical interpretation utilizing the linear response time-dependent density functional theory, NLHFPS has a potential to evolve into a powerful characterization method for nanoscience and nanotechnology
The international investment agreement regime (IIA Regime) is composed of thousands of IIAs and a system of investor–state dispute settlement. Historically, high-income developing countries (HIDCs) were part of the global South and thus ‘hosts’ of foreign direct investment (FDI). Increasingly, however, these countries have become ‘home’ to investors who are hosted and exposed to political risk abroad. Representing both home and host country interests simultaneously, how do HIDCs balance these crosscutting pressures? We argue that as the position of an HIDC shifts from mostly a recipient towards a sender of significant amounts of FDI, it will be more willing to provide protection to foreign investors at the expense of state regulatory space in its IIAs, thereby increasing its exposure to the IIA Regime. Employing an original data set that measures this exposure for sixty-four HIDCs over six decades, we first show that the degree of HIDC exposure to the IIA Regime varies a great deal. Using a general method of moments (GMM) analysis and controlling for a host of confounding factors, we demonstrate that, indeed, higher levels of FDI outflows as a share of the national economy result in greater exposure to the IIA Regime.
Honey bee queens show extreme fecundity, commonly laying more than a thousand eggs in a single day. It has proven challenging to study the temporal organization of egg-laying behavior because queens are typically active around the clock in the dark cavity of a densely populated nest. To contend with this challenge, we developed two novel methods allowing detailed monitoring of queen activity and egg-laying. We first adapted a high-resolution, continuous, tracking system allowing to track the position of barcode-tagged queens in observation hives with colonies foraging outside. We found that the queen is active ~96% of the day with typically no diurnal rhythm. Next, we developed a new laboratory procedure to monitor egg-laying at single egg resolution under different light regimes. We found that under constant darkness (DD) and temperature conditions, queens laid eggs with no circadian rhythms. Queen fecundity was severely reduced under constant light (LL). Under a 12:12 illumination regime, queen fecundity was comparable to under constant darkness, with a higher number of eggs during the light phase. These daily rhythms in egg-laying continued when these queens were released to DD conditions, suggesting that egg-laying rhythms are influenced by endogenous circadian clocks. These results suggest that honey bee queens are active and lay eggs around the clock with no diurnal rhythms. Light has complex influences on these behaviors, but more studies are needed to determine whether these effects reflect the influence of light directly on the queen or indirectly by affecting workers that interact with the queen.
Antibiotic resistance of bacteria in the biofilm has become a major problem for the treatment of chronic infections. Nanotechnology offers a new approach to fighting against biofilm-associated infections. Here, we report on the synthesis of silver nanoparticles (AgNPs) with epigallocatechin gallate (EGCG) ligand, which is known to present antibacterial activity. We further describe the interaction of EGCG-AgNPs with lysozyme, an antibacterial enzyme abundant in fluids like serum, saliva and tears, and the formation of EGCG-AgNP-lysozyme bioconjugates. Our results demonstrate the formation of lysozyme protein corona as shown by UV-Vis, dynamic light scattering and SDS-PAGE analyses. Using circular dichroism spectroscopy we found that lysozyme preserves its secondary structure at low concentration of EGCG-AgNPs, whereas higher concentrations induce protein structural changes. Furthermore, we have shown in bacterial growth and biofilm formation assays that EGCG presents no antibacterial activity on planktonic Bacillus subtilis cells when bound to AgNPs. It was found that EGCG-AgNPs (>40 nM) inhibit B. subtilis in biofilm forming conditions and the inhibition effect is reduced by lysozyme corona formation on EGCG-AgNPs. Our results demonstrate that EGCG-AgNPs could be used as antibiofilm agents because they showed lower cytotoxicity and significant inhibitory effect on pellicle formation.
