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Synthesis of a 2-(2-Trifluoroethoxyphenyl)oxazoline
No full textThe title compound has been prepared in four steps starting from ethyl 2-fluorobenzoate. The final product as well as the intermediates are fully characterised by spectroscopic methods with the 1H and 13C NMR spectra featuring coupling to 19F being particularly informative
Coronal heating driven by random foot point motions:the effects of magnetic field topology
No full textWe investigate the effects of magnetic field geometry on energy injection and dissipation, current sheet formation, magnetic reconnection rates and plasma dynamics in the solar corona when energized by random foot point motions. Using a series of 3D magnetohydrodynamics simulations, we compared the effects of high- and low-amplitude random velocity drivers acting on two different initial magnetic fields; (a) a uniform field case and (b) a tectonics case, in which the field is anchored in localized flux patches. In all simulations, the imposed drivers stress the field, generating small scales and leading to energy dissipation through Ohmic and viscous heating. The rates of energy injection, current formation, magnetic reconnection, and the associated energy dissipation are higher when the field is concentrated in flux patches at the simulation boundary. As such, expected heating rates are larger with a tectonics field. However, when high-amplitude driving is imposed on an initially uniform field, flux patches spontaneously form as the field evolves to become a tectonics field. As a result, energy injection and dissipation rates converge to become independent of the initial field state in the high-amplitude cases. As coronal field foot points are typically embedded in concentrated flux patches, we confirm that tectonics is a viable model for coronal heating. Unsurprisingly, we find that the nature of an initial field only influences heating rates as long as this field persists. However, whether solar atmospheric heating is dominated by transverse foot-point motions, as considered here, or by flux emergence events remains an unanswered question
IRA associates:understanding non-member participation in the provisional IRA
No full textThe wider scholarship on ethno-nationalist terrorism and more specifically, research into the Provisional Irish Republican Army, has long endeavoured to identify the individual actors involved in furthering violence and the motivations which led to their involvement. However, the study of who directly and indirectly participated in the violence of the Northern Ireland Conflict has largely overlooked individuals who directly participated in IRA activities as non-members. This paper begins to fill this knowledge gap by exploring the role of non-members who participated in one or more IRA activities and maintained long-term relationships with the movement as IRA associates. This paper analyses seven IRA associates- a priest, a gangster, a smuggler, two IRA veterans, a British heiress and a schoolteacher turned IRA emissary. Together, they help to form a picture of the relationships and motivational factors which led this diverse cadre of individuals to participate in IRA activities as associates and contributes to a more complete understanding of the range of individuals who participated in IRA activities during the Troubles. The multi-faceted analysis and broader understanding of participation in the Provisional IRA which this research uncovers also demonstrates the need for a more complex and nuanced analysis of non-member or civilian participation in terrorism and political violence as a whole
Managing sustainability alliances:a goal-directed framework
No full textTo address climate change, firms are increasingly forming sustainability alliances. Pursuing sustainability via such alliances is challenging as it means working with multifaceted and not necessarily compatible goals. Moreover, it often requires collaboration among heterogeneous partners outside traditional industrial contexts as well as dealing with wicked problems. This article presents a multiple-case study of eight sustainability alliances in Sweden, identifying managerial challenges and solutions over three phases where such alliances unfold. It offers a framework, tailored to each phase, to help companies fulfill their goals by proactively addressing the challenges posed by the pursuit of sustainability through alliances
Theorizing sectarianism in Syria:toward a framework of analysis
No full textThis chapter examines key approaches and debates about conceptualizing, theorizing, and understanding the causes and consequences of sectarianism in Syria. We seek to understand what factors caused sectarianization but also how it, in turn, affected or impacted, state formation and governance in Syria and Syria’s role in the international relations of MENA. Based on this discussion, the chapter ends with a framework of analysis that can be deployed to systematically chart sectarianism across time and place in Syria. The empirical chapters in the book will employ the framework to organize comparative study of variations, and, in parallel, contribute to testing the framework’s explanatory power. The concluding chapter systematically summarizes the comparisons and draws theoretical conclusions
Evaluation of Bayesian network scoring functions in polychotomous data analysis
No full textBayesian networks (BNs) are probabilistic graphical models used to represent dependencies and independencies among variables. They have been applied widely to many areas in, e.g., biology and medicine, to untangle complex interrelationships, and are now finding wider use in areas such as social science with differing data features, for example highly polychotomous (multi-category) data. To construct BNs, scoring functions guide selection of the most appropriate model. Among these, the BDe scoring function requires specifying hyperparameters that influence the priors on the network parameters. This study evaluates the performance of four scoring functions—AIC, BIC, BDe, and log-likelihood—particularly with highly polychotomous data. We assessed the overall performance of the scoring function, and for BDe, we varied its hyperparameter to evaluate its impact. Performance of the scoring functions was significantly influenced by the number of nodes, network complexity, and sample size. BIC and BDe (with default hyperparameters) generally offered higher precision, especially with larger sample sizes, while log-likelihood tended to overfit, showing high recall but low precision. AIC and BDe required careful tuning based on discrete levels and sample sizes. Optimizing the hyperparameters in BDe was crucial for balancing model complexity and fit. We propose a simulation method for identifying the optimum hyperparameters for using BDe scoring function in real-world data applications. The study provides insights to enhance BN models’ robustness and accuracy, emphasizing the importance of considering sample size and the number of discrete levels when selecting and tuning scoring functions for BN structure learning
High-frequency vessel noise can mask porpoise echolocation
No full textUltrasonic cavitation noise from fast vessels overlaps spectrally with echolocation clicks of toothed whales and therefore has the potential to degrade echolocation performance through auditory masking of returning echoes. Here, we tested that hypothesis by exposing two trained echolocating porpoises carrying DTAGs to two different levels of decidecade noise centered on 2 kHz (non-masking) and 125 kHz (masking) during an active target discrimination task. We found no click level adjustments or effects on discrimination performance in trials with non-masking noise or low-level masking noise. However, when exposed to high-level masking noise of 113±3 dB re. 1 µPa root mean square (RMS), the porpoises increased their mean click source levels by 7-17 dB. Despite this Lombard response of 0.2-0.5 dBsignal/dBnoise, and longer time and more clicks used by the porpoises to perform the task in noise, both animals were still significantly poorer at discriminating the targets (64-85% success rate) than in the other treatments (94-100%), thus demonstrating adverse masking effects. When the porpoises were offered spatial release from masking by relocating the noise source off-axis relative to the animal-to-target axis, echolocation performance was regained. We conclude that moderate levels of high-frequency noise, such as from cavitating vessel propellers several hundred meters from a vessel, can mask porpoise echolocation in a way that cannot be fully compensated for. As biosonar is vital for foraging and navigation around hazards such as gillnets for porpoises and other toothed whales, this study highlights that masking effects should be considered in impact assessments of cavitating vessels around echolocating toothed whales.</p
Vocal accommodation in bonobos
No full textDialects and accents in human speech have a demonstrated social function as markers of group identity and often serve as psychological foundations of trust and cooperation. The extent to which this phenomenon is a feature of primate communication more generally is still debated. Here, we show that the vocal signatures of bonobos, Pan paniscus, belonging to three social groups show group-specific acoustic features independent of genetic relatedness. We compared the barks of 22 adults from the three groups and found that individuals currently living together had more similar barks than individuals that had never met or had lost touch with each other, regardless of their degree of genetic relatedness. We concluded that group-specific vocal accommodation is present in bonobos, suggesting an early evolutionary emergence of vocal plasticity in apes, which could be a means to signal social closeness between individuals.</p
The unsettled frontier:historical imagination and asynchronous belonging on the Amur River
No full textThis article explores the peculiarity of struggles over memory in Soviet-era planned cities in the Russian Far East. It focuses on the contested history of Permskoe, a village founded by peasant settlers from European Russia in 1860, which was later subsumed by Komsomolsk-na-Amure, an urban industrial center constructed in the Stalinist period in the 1930s. Built with the participation of Young Communist League volunteers recruited from across the Soviet Union, the city was held up as a symbol of the triumph of socialist modernization throughout the twentieth century. But following the collapse of the Soviet Union in the 1990s, the city suffered a dramatic reversal of fortunes, with a massive outflow of residents and resources leading to an economic crisis that also occasioned a crisis of identity. One manifestation of this crisis is an initiative seeking to recalculate the city’s age based on the date of Permskoe’s founding. This proposal has been denounced by many residents as an attempt to erase the city’s Soviet history and to downplay the role of communist volunteers in the city’s construction. Drawing on the debates which erupted around this periodization controversy, I argue that the collapse of the Soviet imaginary of linear progress and inability to articulate a new frontier myth resulted in “asynchronous belonging,” characterized by radical polarization around memory and irreconcilable allegiances to different moments in local history
A bacterial network of T3SS effectors counteracts host pro-inflammatory responses and cell death to promote infection
No full textInnate immune signalling and cell death pathways are highly interconnected processes involving receptor-interacting protein kinases (RIPKs) as mediators of potent anti-microbial responses. However, these processes are often antagonised by bacterial type III secretion system (T3SS) effectors, and the cellular mechanisms by which the host retaliates are not completely understood. Here, we demonstrate that during Citrobacter rodentium infection, murine macrophages and colonic epithelial cells exhibit RIPK1 kinase-dependent caspase-8 activation to counteract NleE effector-mediated suppression of pro-inflammatory signalling. While C. rodentium injects into the host cells a second effector, NleB, to block caspase-8 signalling, macrophages respond by triggering RIPK3-mediated necroptosis, whereupon a third T3SS effector, EspL, acts to inactivate necroptosis. We further show that NleB and EspL collaborate to suppress caspase-8 and NLRP3 inflammasome activation in macrophages. Our findings suggest that C. rodentium has evolved to express a complex network of effectors as an adaptation to the importance of cell death for anti-bacterial defence in the host-pathogen arms race.</p