Recent Advances in Visible-Light-Mediated Amide Synthesis

Visible-light photoredox catalysis has attracted tremendous interest within the synthetic community. As such, the activation mode potentially provides a more sustainable and efficient platform for the activation of organic molecules, enabling the invention of many controlled radical-involved reactions under mild conditions. In this context, amide synthesis via the strategy of photoredox catalysis has received growing interest due to the ubiquitous presence of this structural motif in numerous natural products, pharmaceuticals and functionalized materials. Employing this strategy, a wide variety of amides can be prepared effectively from halides, arenes and even alkanes under irradiation of visible light. These methods provide a robust alternative to well-established strategies for amide synthesis that involve condensation between a carboxylic acid and amine mediated by a stoichiometric activating agent. In this review, the representative progresses made on the synthesis of amides through visible light-mediated radical reactions are summarized.

Spectators and Spectacle in Quintus’ Posthomerica

Quintus’ literary reputation is on the rise, in the wake of a general reappreciation of late antique literature. In my article I discuss Quintus’ use of embedded focalization: when we look at events through the eyes of one of the characters. Quintus uses this narrative device both in the same way as Homer, but also in original new ways. One such new way is the serial use of embedded focalization at the moment of arrival of a champion. The ample use of embedded focalization can be added to the list of stylistic features which contribute to the well-known visual aesthetics of late antique poetry, such as ekphrasis, miniaturization, enumeration, and the juxtaposition of episodic scenes. But I also argue that Quintus through the ubiquitous presence of spectators frames the action of his story as a spectacle, a race or gladiatorial show, which gods and characters and hence his narratees, watch as if sitting in an amphitheatre or circus.

Processional Culture and Black Mobility in Maggie Washington's Wilmington

This article addresses changes in the built environment of the postbellum American South through an examination of the life histories, parade routes, and costuming practices of the Afro-Caribbean Jonkonnu masking tradition. I juxtapose the stories of two practitioners of the tradition across the color line in turn-of-the-twentieth-century Wilmington, North Carolina. Using a material culturally inflected approach to the study of landscapes, I use these two narratives to deepen the histories of African American processional cultures toward a longer time span and a more immersive, performer-oriented approach. Though few conventional objects of ornamentation and display from these practices survive, this article posits that an approach rooted in the materiality of landscape can help uncover festive cultures that have been understudied or undertheorized in more conventional historical approaches. Further, the ubiquitous presence of Jonkonnu and other Black processional traditions in the post-emancipation city suggests the importance of these and other objects, practices, and larger cultures of celebration in combating white supremacist culture.

Recent Insights into Escherichia coli and Vibrio spp. Pathogenicity and Responses to Stress

The ubiquitous presence of microorganisms is largely attributed to their tremendous capacity to successfully adapt and survive in highly adverse environments [...]

Shokutaku Jigoku Visions of Family Meals in Japanese Cinema

Cooking and dining scenes have been a ubiquitous presence in Japanese cinema since its inception, and the relationship between Japanese people and food has been frequently exploited to play out family dynamics, rites of passage, etc. Therefore, the dining room often becomes the place where drama unfolds in striking contrast with this supposedly safe environment. This paper focuses on three films where dining scenes are particularly relevant – Ozu Yasujirō’s The Flavor of Green Tea Over Rice (1952), Morita Yoshimitsu’s The Family Game (1983) and Miike Takashi’s Visitor Q (2001) – in order to analyse how Japanese cinema has documented the transformation of family relations in time.

Building a Red Navy: Communist Activism and Military Authority in the Baltic Fleet, 1918–1940

This article examines the activities of the Soviet military-political organs in the Baltic Fleet. It shows that the web of party institutions transformed the fleet into a space of political and social activism that had little to do with the strictly military aspects of government policy. Such activism was nevertheless unfailingly promoted, even as it became clear that it compromised core elements of military efficiency such as discipline and well-defined chains of command. This argument has implications for our broader understanding of the nature of the Soviet state. It indicates that once the Bolsheviks’ revolutionary ideology had become institutionalised in the state via the ubiquitous presence of party organs, pragmatic retreats for organisational efficiency became exceptionally difficult to implement.

Signatures of Type III Solar Radio Bursts from Nanoflares: Modeling

There is a wide consensus that the ubiquitous presence of magnetic reconnection events and the associated impulsive heating (nanoflares) are strong candidates for solving the solar coronal heating problem. Whether nanoflares accelerate particles to high energies like full-sized flares is unknown. We investigate this question by studying the type III radio bursts that the nanoflares may produce on closed loops. The characteristic frequency drifts that type III bursts exhibit can be detected using a novel application of the time-lag technique developed by Viall & Klimchuk (2012) even when there are multiple overlapping events. We present a simple numerical model that simulates the expected radio emission from nanoflares in an active region, which we use to test and calibrate the technique. We find that in the case of closed loops the frequency spectrum of type III bursts is expected to be extremely steep such that significant emission is produced at a given frequency only for a rather narrow range of loop lengths. We also find that the signature of bursts in the time-lag signal diminishes as: (1) the variety of participating loops within that range increases; (2) the occurrence rate of bursts increases; (3) the duration of bursts increases; and (4) the brightness of bursts decreases relative to noise. In addition, our model suggests a possible origin of type I bursts as a natural consequence of type III emission in a closed-loop geometry.

Uptake and Accumulation of Nano/Microplastics in Plants: A Critical Review

The ubiquitous presence of microplastics (MPs) and nanoplastics (NPs) in the environment is an undeniable and serious concern due to their higher persistence and extensive use in agricultural production. This review highlights the sources and fate of MPs and NPs in soil and their uptake, translocation, and physiological effects in the plant system. We provide the current snapshot of the latest reported studies with the majority of literature spanning the last five years. We draw attention to the potential risk of MPs and NPs in modern agriculture and their effects on plant growth and development. We also highlight their uptake and transport pathways in roots and leaves via different exposure methods in plants. Conclusively, agricultural practices, climate changes (wet weather and heavy rainfall), and soil organisms play a major role in transporting MPs and NPs in soil. NPs are more prone to enter plant cell walls as compared to MPs. Furthermore, transpiration pull is the dominant factor in the plant uptake and translocation of plastic particles. MPs have negligible negative effects on plant physiological and biochemical indicators. Overall, there is a dire need to establish long-term studies for a better understanding of their fate and associated risks mechanisms in realistic environment scenarios for safe agricultural functions.

Systematic Perturbations of the Thermodynamic Properties in Cool Cores of HIFLUGCS Galaxy Clusters

We present an ensemble X-ray analysis of systematic perturbations in the central hot gas properties for a sample of 28 nearby strong cool-core systems, selected from the HIghest X-ray FLUx Galaxy Cluster Sample (HIFLUGCS). We analyze their cool-core features observed with the Chandra X-ray Observatory. All individual systems in our sample exhibit at least a pair of positive and negative excess perturbations in the X-ray residual image after subtracting the global brightness profile. We extract and analyze X-ray spectra of the intracluster medium (ICM) in the detected perturbed regions. To investigate possible origins of the gas perturbations, we characterize thermodynamic properties of the ICM in the perturbed regions and characterize their correlations between positive and negative excess regions. The best-fit relations for temperature and entropy show a clear offset from the one-to-one relation, T neg / T pos = 1.20 − 0.03 + 0.04 and K neg/K pos = 1.43 ± 0.07, whereas the best-fit relation for pressure is found to be remarkably consistent with the one-to-one relation P neg = P pos, indicating that the ICM in the perturbed regions is in pressure equilibrium. These observed features in the HIFLUGCS sample are in agreement with the hypothesis that the gas perturbations in cool cores are generated by gas sloshing. We also analyze synthetic observations of perturbed cluster cores created from binary merger simulations, finding that the observed temperature ratio agrees with the simulations, T neg/T pos ∼ 1.3. We conclude that gas sloshing induced by infalling substructures plays a major role in producing the characteristic gas perturbations in cool cores. The ubiquitous presence of gas perturbations in cool cores may suggest a significant contribution of gas sloshing to suppressing runaway cooling of the ICM.

A Brain Listening to Itself

The ubiquitous presence of ambiguous voices in Beckett’s work remains an enduring mystery. The narrative work is no exception, to the point that Beckett’s fiction after Murphy (1938) can be read as, to quote The Unnamable (1953), “entirely a matter of voices; no other metaphor is appropriate” (319). Given the alien qualities of these voices, their intrusive independent agency, and their sometimes tormenting phenomenology, two frameworks of interpretation have so far prevailed. On the one hand, there are narratologists such as Brian Richardson (2006) who have proposed an “unnatural” reading of these voices, by arguing that these alien, multiple, sourceless voices cannot be traced back or ascribed to any actual experience within the human domain; that they cannot be “naturalized” (Culler 1975; 2018; see also Fludernik 1996) by the reader. On the other hand, there is a long-standing “pathological” framework, which sees voices in Beckett’s work as a fictional rendering of a wide range of experiences associated with mental illnesses, mostly of auditory-verbal hallucinations (AVHs) typical of schizophrenia. This chapter suggests that an alternative, natural, and non-pathological experience is the target of Beckett’s fictional cognitive models having voices as core modeling elements. By drawing on contemporary cognitive research on inner speech (roughly speaking, the activity of silently talking to, with and within oneself), it is advocated that voices in Beckett’s models target the working of inner speech, only defamiliarized or, as we shall see, “detuned” as a modeling alteration to explore its functioning within human cognition.