Spin-induced dynamical scalarization, de-scalarization and stealthness in scalar-Gauss-Bonnet gravity during black hole coalescence

Particular couplings between a scalar field and the Gauss-Bonnet invariant lead to spontaneous scalarization of black holes. Here we continue our work on simulating this phenomenon in the context of binary black hole systems. We consider a negative coupling for which the black-hole spin plays a major role in the scalarization process. We find two main phenomena: (i) dynamical descalarization, in which initially scalarized black holes form an unscalarized remnant, and (ii) dynamical scalarization, whereby the late merger of initially unscalarized black holes can cause scalar hair to grow. An important consequence of the latter case is that modifications to the gravitational waveform due to the scalar field may only occur post-merger, as its presence is hidden during the entirety of the inspiral. However, with a sufficiently strong coupling, we find that scalarization can occur before the remnant has even formed. We close with a discussion of observational implications for gravitational-wave tests of general relativity

Myth and conspiracy among the alt-right : a five-year observation of 4chan’s /pol/

This thesis is the culmination of a five-year observation of the neo-fascist community on 4chan’s /pol/ forum. This observation began at the end of 2016, and continued until the end of 2021, a period which included many key moments in the alt-right’s history, such as the period of confidence following Donald Trump’s election, the fallout of the Unite the Right rally in 2017, and the turn toward terrorism in 2019. Drawing upon this observation, it describes the unique mechanisms present on /pol/ that support radicalisation, and analyses how the use of a mythic narrative binds the movement together and explains their actions. It is not an exhaustive description of the movement or its beliefs – this territory has been covered by others – but instead focuses on using dissecting the stories that underpin the movement’s unique and deeply unusual view of reality. It discusses their conspiracy theories in depth, along with their mythic relationship to the fascisms of the past, and their apocalyptic visions of the future

‘It’s not really our thing’:lessons in engaging care homes in palliative care research

Background: In England and Wales there are just under 400,000 older adults residing in care homes at any one time. Despite this, care home residents are often excluded from epidemiological studies and little routine data are collected within care homes. Data on palliative care provided by care homes is reported to the Care Quality Commission, but the quality of care is often locally determined. There is ongoing research in this area aimed at collecting representative, internationally comparable data, such as the PACE study. Aims: To discuss the challenges encountered in engaging and recruiting care homes across England in the PACE study, a retrospective, cross sectional survey of deaths over three months. The study collected questionnaire data from care home staff, general practitioners and relatives of care home residents on their experiences of palliative care. It aimed to include 200 deceased residents in fifty care homes over a one-year period. Methods: The research team reviewed the barriers and challenges encountered throughout the research process, including developing a representative sampling framework, obtaining ethical approvals, advertising the study and recruiting care homes. Results: There is a lack of clarity regarding where care homes are located within the scope of ethical approval bodies. Recruitment through random sampling was found to be less effective compared to recruitment through ENRICH networks. Barriers to care home participation included concerns regarding sharing information, fear of opening up to potential criticism, lack of resources and misunderstandings regarding confidentiality. Conclusions: The development of care home networks and informal contacts can improve the rate and extent of research involvement. Whilst representativeness can be attained, random samples and ensuring a rigorous sample through these methods of recruitment remains a challenge

Dynamical descalarization in binary black hole mergers

Scalar fields coupled to the Gauss-Bonnet invariant can undergo a tachyonic instability, leading to spontaneous scalarization of black holes. Studies of this effect have so far been restricted to single black hole spacetimes. We present the first results on dynamical scalarization in head-on collisions and quasicircular inspirals of black hole binaries with numerical relativity simulations. We show that black hole binaries can either form a scalarized remnant or dynamically descalarize by shedding off its initial scalar hair. The observational implications of these findings are discussed.Comment: 9 pages, 6 figures. (v2) new references added; (v3) matches published version. For movies of the simulations see https://bhscalarization.bitbucket.i

Developmental trajectories of part-based and configural object recognition in adolescence.

Three experiments assessed the development of children's part and configural (part-relational) processing in object recognition during adolescence. In total, 312 school children aged 7-16 years and 80 adults were tested in 3-alternative forced choice (3-AFC) tasks. They judged the correct appearance of upright and inverted presented familiar animals, artifacts, and newly learned multipart objects, which had been manipulated either in terms of individual parts or part relations. Manipulation of part relations was constrained to either metric (animals, artifacts, and multipart objects) or categorical (multipart objects only) changes. For animals and artifacts, even the youngest children were close to adult levels for the correct recognition of an individual part change. By contrast, it was not until 11-12 years of age that they achieved similar levels of performance with regard to altered metric part relations. For the newly learned multipart objects, performance was equivalent throughout the tested age range for upright presented stimuli in the case of categorical part-specific and part-relational changes. In the case of metric manipulations, the results confirmed the data pattern observed for animals and artifacts. Together, the results provide converging evidence, with studies of face recognition, for a surprisingly late consolidation of configural-metric relative to part-based object recognition

Absence of zero-temperature transmission rate of a double-chain tight-binding model for DNA with random sequence of nucleotides in thermodynamic limit

The zero-temperature transmission rate spectrum of a double-chain tight-binding model for real DNA is calculated. It is shown that a band of extended-like states exists only for finite chain length with strong inter-chain coupling. While the whole spectrum tends to zero in thermodynamic limit, regardless of the strength of inter-chain coupling. It is also shown that a more faithful model for real DNA with periodic sugar-phosphate chains in backbone structures can be mapped into the above simple double-chain tight-binding model. Combined with above results, the transmission rate of real DNA with long random sequence of nucleotides is expected to be poor.Comment: 5 pages, 9 figure