Floppy swimming: Viscous locomotion of actuated elastica

Actuating periodically an elastic filament in a viscous liquid generally breaks the constraints of Purcell's scallop theorem, resulting in the generation of a net propulsive force. This observation suggests a method to design simple swimming devices - which we call "elastic swimmers" - where the actuation mechanism is embedded in a solid body and the resulting swimmer is free to move. In this paper, we study theoretically the kinematics of elastic swimming. After discussing the basic physical picture of the phenomenon and the expected scaling relationships, we derive analytically the elastic swimming velocities in the limit of small actuation amplitude. The emphasis is on the coupling between the two unknowns of the problems - namely the shape of the elastic filament and the swimming kinematics - which have to be solved simultaneously. We then compute the performance of the resulting swimming device, and its dependance on geometry. The optimal actuation frequency and body shapes are derived and a discussion of filament shapes and internal torques is presented. Swimming using multiple elastic filaments is discussed, and simple strategies are presented which result in straight swimming trajectories. Finally, we compare the performance of elastic swimming with that of swimming microorganisms.Comment: 23 pages, 6 figure

Economics of education research: a review and future prospects

In this paper we offer an appraisal of the economics of education research area, charting its history as a field and discussing the ways in which economists have contributed both to education research and to education policy-making. In particular, we highlight the theoretical and methodological contributions that economists have made to the field of education during the last 50 years. Despite the success of the economics of education as a field of inquiry, we argue that some of the contributions made by economists could be limited if the economics of education is seen as quite distinct from the other disciplines working in the field of education. In these areas of common interest, economists need to work side by side with the other major disciplines in the field of education if their contribution to the field is to be maximised, particularly in terms of applying improved methodology. We conclude that the study of education acquisition and its economic and social impact in the economics of education research area is very likely to remain a fertile research ground. Acknowledgement

Germline heterozygous DDX41 variants in a subset of familial myelodysplasia and acute myeloid leukemia

The Brazilian National Council for Scientific and Technological Development), Bloodwise, Children with Cancer and MRC (Medical Research Council, UK)

Peddling a semiotics of fear: a critical examination of scare tactics and commercial strategies in public health promotion

This study critically examines the ways in which the nationwide Diabetes UK/Tesco public health promotion campaign (2013-2014) sought to raise awareness of Type 2 diabetes. Conducting a multimodal critical discourse analysis of six campaign images, we identify the presence of fear-inducing, stigmatising and commercial strategies, through which the campaign emphasises the dangers of diabetes and advocates personal responsibility for assessing both individual and others’ risk of the disease. Specifically, three discursive techniques are deployed in this campaign to achieve these ends: (1) the depiction of grief and amplification of diabetes-related danger, (2) the promotion of diabetes risk and responsibilization of individuals for their health, and (3) the commercial branding and framing of the Diabetes UK/Tesco partnership as providing tools for diabetes prevention and management. Our findings raise concerns about the moral legitimacy of using fear-inducing and commercial strategies in public health campaigns, strategies which do little to address the environmental factors which are associated with increasing rates of the disease

Protocol for a randomised controlled feasibility trial of exercise rehabilitation for people with postural tachycardia syndrome: the PULSE study

Background: Postural orthostatic tachycardia syndrome (POTS) is an autonomic nervous system disorder causing an abnormal cardiovascular response to upright posture. It affects around 0.2% of the population, most commonly women aged 13 to 50 years. POTS can be debilitating; prolonged episodes of pre-syncope and fatigue can severely affect activities of daily living and health-related quality of life (HRQoL). Medical treatment is limited and not supported by randomised controlled trial (RCT) evidence. Lifestyle interventions are first-line treatment, including increased fluid and salt intake, compression tights and isometric counter-pressure manoeuvres to prevent fainting. Observational studies and small RCTs suggest exercise training may improve symptoms and HRQoL in POTS, but evidence quality is low. Methods: Sixty-two people (aged 18–40 years) with a confirmed diagnosis of POTS will be invited to enrol on a feasibility RCT with embedded qualitative study. The primary outcome will be feasibility; process-related measures will include the number of people eligible, recruited, randomised and withdrawn, along with indicators of exercise programme adherence and acceptability. Secondary physiological, clinical and health-related outcomes including sub-maximal recumbent bike exercise test, active stand test and HRQoL will be measured at 4 and 7 months post-randomisation by researchers blinded to treatment allocation. The PostUraL tachycardia Syndrome Exercise (PULSE) intervention consists of (1) individual assessment; (2) 12-week, once to twice-weekly, supervised out-patient exercise training; (3) behavioural and motivational support; and (4) guided lifestyle physical activity. The control intervention will be best-practice usual care with a single 30-min, one-to-one practitioner appointment, and general advice on safe and effective physical activity. For the embedded qualitative study, participants (n = 10 intervention, n = 10 control) will be interviewed at baseline and 4 months post-randomisation to assess acceptability and the feasibility of progressing to a definitive trial. Discussion: There is very little high-quality research investigating exercise rehabilitation for people with POTS. The PULSE study will be the first randomised trial to assess the feasibility of conducting a definitive multicentre RCT testing supervised exercise rehabilitation with behavioural and motivational support, compared to best-practice usual care, for people with POTS. Trial registration: ISRCTN45323485 registered on 7 April 2020

Molecular excitation in the Interstellar Medium: recent advances in collisional, radiative and chemical processes

We review the different excitation processes in the interstellar mediumComment: Accepted in Chem. Re

Evidence-based approach to thrombophilia testing

Thrombophilia can be identified in about half of all patients presenting with VTE. Testing has increased tremendously for various indications, but whether the results of such tests help in the clinical management of patients has not been settled. I use evidence from observational studies to conclude that testing for hereditary thrombophilia generally does not alter the clinical management of patients with VTE, with occasional exceptions for women at fertile age. Because testing for thrombophilia only serves limited purpose this should not be performed on a routine basis

Culture and Subjectivity in Neoliberal and postfeminist times

My aim in this paper is to think through a number of issues concerning the relationship between culture and subjectivity. It seems to me that exploring the relationship of changing forms of political organisation, social relations and cultural practices to changing modes and experiences of subjecthood and subjectivity are among the most important and urgent tasks for critical intellectual work. These questions go to the heart of understanding power, ideology and agency and they require research that is interdisciplinary, psychosocial and intersectional. My particular focus in this short article is on the interrelations between changing representational practices in visual culture and changing subjectivity/ies. I argue that neoliberalism and postfeminism are central to understanding contemporary media culture, and I put the case for research which does not retreat from exploring how these broader social/political/economic/cultural discourses and formations may relate to subjectivity

Synthesis and in vitro and in vivo characterization of highly β1-Selective β-Adrenoceptor partial agonists

β-Adrenoceptor antagonists boast a 50-year use for symptomatic control in numerous cardiovascular diseases. One might expect highly selective antagonists are available for the human β-adrenoceptor subtype involved in these diseases, yet few truly β1-selective molecules exist. To address this clinical need, we re-evaluated LK 204-545 (1),1 a selective β1-adrenoceptor antagonist, and discovered it possessed significant partial agonism. Removal of 1’s aromatic nitrile afforded 19, a ligand with similar β1-adrenoceptor selectivity and partial agonism (log KD of −7.75 and −5.15 as an antagonist of functional β1- and β2-mediated responses, respectively, and 34% of the maximal response of isoprenaline (β1)). In vitro β-adrenoceptor selectivity and partial agonism of 19 were mirrored in vivo. We designed analogues of 19 to improve affinity, selectivity, and partial agonism. Although partial agonism could not be fully attenuated, SAR suggests that an extended alkoxyalkoxy side chain, alongside substituents at the meta- or para-positions of the phenylurea, increases ligand affinity and β1- selectivity