Refraction limit of miniaturized optical systems: a ball-lens example

We study experimentally and theoretically the electromagnetic field in amplitude and phase behind ball-lenses across a wide range of diameters, ranging from a millimeter scale down to a micrometer. Based on the observation, we study the transition between the refraction and diffraction regime. The former regime is dominated by observables for which it is sufficient to use a ray-optical picture for an explanation, e.g., a cusp catastrophe and caustics. A wave-optical picture, i.e. Mie theory, is required to explain the features, e.g., photonic nanojets, in the latter regime. The vanishing of the cusp catastrophe and the emergence of the photonic nanojet is here understood as the refraction limit. Three different criteria are used to identify the limit: focal length, spot size, and amount of cross-polarization generated in the scattering process. We identify at a wavelength of 642 nm and while considering ordinary glass as the ball-lens material, a diameter of approximately 10 µm as the refraction limit. With our study, we shed new light on the means necessary to describe micro-optical system. This is useful when designing optical devices for imaging or illumination

Aquaporin water channels in the nervous system.

The aquaporins (AQPs) are plasma membrane water-transporting proteins. AQP4 is the principal member of this protein family in the CNS, where it is expressed in astrocytes and is involved in water movement, cell migration and neuroexcitation. AQP1 is expressed in the choroid plexus, where it facilitates cerebrospinal fluid secretion, and in dorsal root ganglion neurons, where it tunes pain perception. The AQPs are potential drug targets for several neurological conditions. Astrocytoma cells strongly express AQP4, which may facilitate their infiltration into the brain, and the neuroinflammatory disease neuromyelitis optica is caused by AQP4-specific autoantibodies that produce complement-mediated astrocytic damage

Assessing fidelity of delivery of smoking cessation behavioural support in practice.

Effectiveness of evidence-based behaviour change interventions is likely to be undermined by failure to deliver interventions as planned. Behavioural support for smoking cessation can be a highly cost-effective, life-saving intervention. However, in practice, outcomes are highly variable. Part of this may be due to variability in fidelity of intervention implementation. To date, there have been no published studies on this. The present study aimed to: evaluate a method for assessing fidelity of behavioural support; assess fidelity of delivery in two English Stop-Smoking Services; and compare the extent of fidelity according to session types, duration, individual practitioners, and component behaviour change techniques (BCTs)

Genomic reconstruction of the SARS-CoV-2 epidemic in England.

The evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus leads to new variants that warrant timely epidemiological characterization. Here we use the dense genomic surveillance data generated by the COVID-19 Genomics UK Consortium to reconstruct the dynamics of 71 different lineages in each of 315 English local authorities between September 2020 and June 2021. This analysis reveals a series of subepidemics that peaked in early autumn 2020, followed by a jump in transmissibility of the B.1.1.7/Alpha lineage. The Alpha variant grew when other lineages declined during the second national lockdown and regionally tiered restrictions between November and December 2020. A third more stringent national lockdown suppressed the Alpha variant and eliminated nearly all other lineages in early 2021. Yet a series of variants (most of which contained the spike E484K mutation) defied these trends and persisted at moderately increasing proportions. However, by accounting for sustained introductions, we found that the transmissibility of these variants is unlikely to have exceeded the transmissibility of the Alpha variant. Finally, B.1.617.2/Delta was repeatedly introduced in England and grew rapidly in early summer 2021, constituting approximately 98% of sampled SARS-CoV-2 genomes on 26 June 2021

Defensive Positions: The Politics of Maritime Security in Tokugawa Japan

Defensive Positions focuses on the role of regional domains in early modern Japan’s coastal defense, shedding new light on this system’s development. This examination, in turn, has significant long-term political implications for the involvement of those domains in Tokugawa state formation. Noell Wilson argues that domainal autonomy in executing maritime defense slowly escalated over the course of the Tokugawa period to the point where the daimyo ultimately challenged Tokugawa authorities as the primary military interface with the outside world. By first exploring localized maritime defense at Nagasaki and then comparing its organization with those of the Yokohama and Hakodate harbors during the treaty port era, Wilson identifies new, core systemic sources for the collapse of the shogunate’s control of the monopoly on violence. Her insightful analysis reveals how the previously unexamined system of domain-managed coastal defense comprised a critical third element—in addition to trade and diplomacy—of Tokugawa external relations. Domainal control of coastal defense exacerbated the shogunate’s inability to respond to important military and political challenges as Japan transitioned from an early modern system of parcelized, local maritime defense to one of centralized, national security as embraced by world powers in the nineteenth century.https://egrove.olemiss.edu/libarts_book/1147/thumbnail.jp

Meiji at 150 Podcast, Episode 099, Dr. Noell Wilson (University of Mississippi)

This episode previews a new podcast series, Japan on the Record, a shorter format current events-themed series.  In episode 1, Dr. Noell Wilson details the American influences shaping Japanese deep sea whaling dating to the mid-19th century.Arts, Faculty ofHistory, Department ofNon UBCUnreviewedFacult