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Greedy base sizes for sporadic simple groups
No full textA base for a permutation group G acting on a set Ω is a sequence ℬ of points of Ω such that the pointwise stabiliser Gℬ is trivial. Denote the minimum size of a base for G by b(G) There is a natural greedy algorithm for constructing a base of relatively small size; denote by (G) the maximum size of a base it produces. Motivated by a longstanding conjecture of Cameron, we determine (G) for every almost simple primitive group G with socle a sporadic simple group, showing that (G) = b(G)
Collapsing Clouds Form Stars:a continuum of resistance in the video works of Som Supaparinya - commissioned essay for Gallery VER (in English and Thai)
No full textThe effect of depth on the composition and saturation of total fatty acids present within the tissues and skeletons of two reef-building corals
No full textCoral lipids and their fatty acid (FA) constituents fulfil a variety of biological functions. Here we report the FA compositions of the total lipids in the tissues and skeletons of Acropora retusa and Pocillopora meandrina at two water depths (5 and 25 m) in Mo’orea, French Polynesia. Saturated FAs C16:0 and C18:0, commonly associated with storage lipids and cell membrane phospholipids, are the dominant FAs within both the tissues and skeletons of both coral species. Polyunsaturated FAs in this study are usually only detected in coral tissues at 5 m depth. Unsaturated FAs contribute significantly more to the total FA pool at 5 m than at 25 m in the tissues of both coral species and in A. retusa compared to P. meandrina at 5 m depth. Unsaturated FAs are involved in regulating membrane structure fluidity and stress resistance. Their increased presence in shallow corals may be a response to the more variable seawater temperatures recorded at this depth, and/or may be attributed to different feeding strategies, possibly due to varying light intensities between depths. Previous research indicates that shallow water corals at the study site are more prone to bleaching, and that Acropora spp. may be more sensitive than Pocillopora spp. Variations in tissue FA composition may relate to this bleaching sensitivity, as unsaturated FAs are susceptible to lipid peroxidation caused by the presence of reactive oxygen species (ROS). Overall, the contributions of FAs to the total FA pool are similar between the tissues and skeletons suggesting a lack of active regulation of FAs within the coral skeleton
How tiny foraminifera can play a massive role in understanding past climates
No full textForaminifera comprise a group of heterotrophic zooplankton, which inhabit all depths within the world's oceans from the sunlit surface ocean to the depths of the abyssal plains. Many species build a shell of calcium carbonate (predominantly calcite), which records vital geochemical information from the oceans as it grows. Studies based on microscopic foraminifera are often at the forefront of pioneering research by palaeoclimatologists into Cretaceous–Cenozoic climates. In this feature, I summarize how foraminifera are obtained from the deep ocean and describe how rapidly evolving planktic foraminifera species can be used to date marine sediments. I then explain how benthic foraminifera can be used to reconstruct high-resolution long-term climate records, focusing on the use of stable oxygen isotopes to elucidate deep ocean temperatures from the greenhouse climate of the late Paleocene–early Eocene
Crash-stop failures in asynchronous multiparty session types
No full textSession types provide a typing discipline for message-passing systems. However, their theory often assumes an ideal world: one in which everything is reliable and without failures. Yet this is in stark contrast with distributed systems in the real world. To address this limitation, we introduce a new asynchronous multiparty session types (MPST) theory with crash-stop failures, where processes may crash arbitrarily and cease to interact after crashing. We augment asynchronous MPST and processes with crash handling branches, and integrate crash-stop failure semantics into types and processes. Our approach requires no user-level syntax extensions for global types, and features a formalisation of global semantics, which captures complex behaviours induced by crashed/crash handling processes. Our new theory covers the entire spectrum, ranging from the ideal world of total reliability to entirely unreliable scenarios where any process may crash, using optional reliability assumptions. Under these assumptions, we demonstrate the sound and complete correspondence between global and local type semantics, which guarantee deadlock-freedom, protocol conformance, and liveness of well-typed processes by construction, even in the presence of crashes
The discussion of gender and citations in submission guidelines of 102 political science journals
No full textCitations of journal articles are a measure of scholarly attention and scientific impact. Across disciplines, including political science, there is evidence indicating the presence of a gender citation gap. The gap represents a gender imbalance in publishing and citations that is likely to be perpetuated as it contributes to follow-up imbalances in hiring or funding decisions. In this paper, we review the submission and publication information of 102 English-language journals from political science. The review is guided by a descriptive research question: How many journals address gender imbalances and gender more generally in their guidelines? We present the results of a mixed-methods content analysis that combines a computational text analysis with the manual, qualitative coding of journal information. We observe that fifteen journals out of 102 address gender and citation behavior by encouraging authors to consider the gender balance of their reference lists. With seven mentions, the share of journals discussing gender and citations is higher for the top-25 journals. There is little discussion of this issue in ECPR journals and APSA section and association journals
Distance matters to sperm whales:behavioural disturbance in response to both sonar received level and source distance
No full textUnderstanding the main drivers of behavioural disturbance in deep-diving cetaceans would improve predictions of anthropogenic noise effects on individual animals, habitats and populations. To investigate the potential roles of received level and source distance on behavioural disturbance, we tagged 14 sperm whales in northern Norway with multi-sensor data loggers and conducted dose-escalation experiments. Each experiment included 1 to 4 tagged individuals and involved multiple vessel passes (‘exposure sessions’, n = 25 total) by a navy frigate or research vessel towing a naval sonar, at different starting distances and maximum source levels. We analysed behaviour state series and proxies for locomotor activity and foraging success with generalized additive mixed models. The probability of occurrence of non-foraging active behaviour was affected by received level, source distance and session order, with decreased foraging effort at higher received levels and shorter distances, and during subsequent sessions (indicating short-term sensitisation). Prey capture attempts decreased with increasing received level when whales kept foraging. Similar to what has been suggested for some populations of blue whales and beaked whales regularly exposed to navy sonar, but unlike northern bottlenose whales in more pristine waters, source distance affected sperm whale behavioural responses on a high-latitude foraging ground
Kenneth Minogue, conservatism, and the challenge of the reactionary global Right
No full textThe reactionary global Right is a pervasive phenomenon characterized by an overarching goal of developing a counter-hegemonic strategy to challenge the liberal-dominated practices and institutions of the contemporary Western world. Although this reactionary global Right is not a unified movement, initiatives like the National Conservatism conference seek to build a transnational coalition. It is undeniable that its adherents represent a potent political force whose influence is steadily growing. Despite the pressing challenges posed by the reactionary global Right, traditional Western political doctrines, particularly conservatism, appear largely ill-equipped to respond effectively to both the movement and the concerns it raises. In some instances, the movement even presents itself as the future of conservatism, exacerbating the significance and urgency of the dilemma faced by contemporary conservative thought. This article contends that Kenneth Minogue’s conservative realism offers valuable insights for shaping the future of conservatism, steering it away from the allure of radicalism embraced by certain factions of the Right in response to an increasingly estranged world. It pursues this argument by examining Minogue’s engagement with the core ideas of the reactionary global Right, noting his sympathy towards their concerns while distancing himself from their proposed solutions. Ultimately, the article claims that Minogue’s perspective offers a robust framework for a civil conservatism that not only addresses the shortcomings of contemporary conservative responses to the reactionary global Right but also preserves core conservative ideas while charting a viable path forward for the future of conservative politics
Hybrid radiation hydrodynamics scheme with adaptive gravity-tree-based pseudo-particles
No full textH II regions powered by ionizing radiation from massive stars drive the dynamical evolution of the interstellar medium. Fast radiative transfer methods for incorporating photoionization effects are thus essential in astrophysical simulations. Previous work by Petkova et al. established a hybrid radiation hydrodynamics (RHD) scheme that couples smoothed particle hydrodynamics (SPH) to grid-based Monte Carlo radiative transfer (MCRT) code. This particle-mesh scheme employs the Exact mapping method for transferring fluid properties between SPH particles and Voronoi grids on which the MCRT simulation is carried out. The mapping, however, can become computationally infeasible with large numbers of particles or grid cells. We present a novel optimization method that adaptively converts gravity tree nodes into pseudo-SPH particles. These pseudo-particles act in place of the SPH particles when being passed to the MCRT code, allowing fluid resolutions to be temporarily reduced in regions which are less dynamically affected by radiation. A smoothing length solver and a neighbour-finding scheme dedicated to tree nodes have been developed. We also describe the new heating and cooling routines implemented for improved thermodynamic treatment. We show that this tree-based RHD scheme produces results in strong agreement with benchmarks, and achieves a speed-up that scales with the reduction in the number of particle-cell pairs being mapped