203 research outputs found

    Conformally coupled dark matter

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    Dark matter is obtained from a scalar field coupled conformally to gravitation; the scalar being a relict of Dirac's gauge function. This conformally coupled dark matter includes a gas of very light (m2.25×1034eVm\approx 2.25\times 10^{-34} eV) neutral bosons having spin 0, as well as a time-dependent global scalar field, both pervading all of the cosmic space. The time-development of this dark matter in the expanding F-R-W universe is investigated, and an acceptable cosmological behaviour is obtained.Comment: LaTEX File 10 pages, no figure

    Experimental observation of photonic nodal line degeneracies in metacrystals

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    This is the final version of the article. Available from the publisher via the DOI in this record.Nodal line semimetals (NLS) are three-dimensional (3D) crystals that support band crossings in the form of one-dimensional rings in the Brillouin zone. In the presence of spin-orbit coupling or lowered crystal symmetry, NLS may transform into Dirac semimetals, Weyl semimetals, or 3D topological insulators. In the photonics context, despite the realization of topological phases, such as Chern insulators, topological insulators, Weyl, and Dirac degeneracies, no experimental demonstration of photonic nodal lines (NLs) has been reported so far. Here, we experimentally demonstrate NL degeneracies in microwave cut-wire metacrystals with engineered negative bulk plasma dispersion. Both the bulk and surface states of the NL metamaterial are observed through spatial Fourier transformations of the scanned near-field distributions. Furthermore, we theoretically show that the NL degeneracy can transform into two Weyl points when gyroelectric materials are incorporated into the metacrystal design. Our findings may inspire further advances in topological photonics.This work was financially supported by the European Research Council Consolidator Grant (TOPOLOGICAL). S.Z. acknowledges support from the Royal Society, the Wolfson Foundation, Horizon 2020 Action Project No. 734578 (D-SPA), the Leverhulme Trust (RPG-2012-674), and the Engineering and Physical Sciences Research Council (EP/ J018473/1). B.Y. acknowledges support from the China Scholarship Council (201306110041). A.P.H. acknowledges financial support from EPSRC of the United Kingdom (Grant No. EP/L015331/1). Near-field scanning data were collected by VNA controlled with xyz-stage at G31 at the Department of Physics and Astronomy, University of Exeter, United Kingdo

    Radiatively Induced Neutrino Masses and Large Higgs-Neutrino Couplings in the Standard Model with Majorana Fields

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    The Higgs sector of the Standard Model with one right-handed neutrino per family is systematically analyzed. In a model with intergenerational independent mixings between families, we can account for very light neutrinos acquiring Majorana masses radiatively at the first electroweak loop level. We also find that in such a scenario the Higgs coupling to the light-heavy neutrinos and to the heavy-heavy ones may be remarkably enhanced with significant implications for the production of these heavy neutrinos at high energy colliders.Comment: Making the text of an old paper electronically availabl

    Challenges and opportunities for ex-offender support through community nursing

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    This study was a qualitative case study underpinned by “The Silences Framework” aimed at mapping the ex-offender health pathway towards identifying “touch points” in the community for the delivery of a nurse-led intervention. Participants meeting the study inclusion criteria were quantitatively ranked based on poor health. Participants scoring the lowest and endorsing their ranking through a confirmation of a health condition were selected as cases and interviewed over 6 months. Individuals in the professional networks of offenders contextualized emergent themes. The study indicated that pre-release, offenders were not prepared in prison for the continuity in access to healthcare in the community. On release, reintegration preparation did not routinely enquire whether offenders were still registered with a general practitioner or had the agency to register self in the community. Participants identified the site of post-release supervision as the “touch point” where a nurse-led intervention could be delivere

    Motivations for seeking experimental treatment in Japan

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    In this article on innovative medical treatment for serious conditions in Japan we aim to revise two widespread notions: first, that people living with severe conditions are all waiting for a cure or are impatient to try out experimental treatment, in particular regenerative medicine. Showing that motivations for cure seeking are complex and linked to somatic identity, we argue that gaining a cure also means a new social normality, which for some people narrows the only normality that is meaningful to them; and, second, that people living with a serious (latent) condition necessarily define their lives as not normal in the light of normalization. People with a condition conceptualise normal life variously and multiply in the light of both individual and collective experiences. The two revisions are crucial to attempts at understanding what makes people seek experimental medicine. Comparing the narratives of people with four different conditions – spinal cord injury, Duchenne muscular dystrophy, Diabetes Mellitus type 1 and cardiovascular disease – it becomes clear that the difference between seeking treatment or not largely depends on somatic identities; rather than through notions of (ab)normality, it is more adequately understood in terms of the experience of somatic lacking and wholeness

    The interactions of disability and impairment

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    Theoretical work on disability is going through an expansive period, built on the growing recognition of disability studies as a discipline and out of the political and analytical push to bring disability into a prominent position within accounts of the intersecting social categories that shape people's lives. A current debate within critical disability studies is whether that study should include impairment and embodiment within its focus. This article argues it should and does so by drawing from symbolic interactionism and embodiment literatures in order to explore how differences in what bodies can do-defined as impairments-come to play a role in how people make sense of themselves through social interaction. We argue that these everyday interactions and the stories we tell within them and about them are important spaces and narratives through which impairment and disability are produced. Interactions and stories are significant both in how they are shaped by wider social norms, collective stories and institutional processes, and also how they at times can provide points of resistance and challenges to such norms, stories and institutions. Therefore, the significance of impairment and interaction is the role they play in both informing self-identity and also broader dynamics of power and inequality

    Ideal Weyl points and helicoid surface states in artificial photonic crystal structures (article)

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    The dataset associated with this article is located in ORE at: http://hdl.handle.net/10871/30744This is the author accepted manuscript. The final version is available from AAAS via the DOI in this record.Weyl points are the crossing points of linearly dispersing energy bands in the Brillouin zone of three-dimensional crystals. Weyl points provide the opportunity to explore a variety of intriguing phenomena such as topologically protected surface states and chiral anomalies. However the lack of an ideal Weyl system poses a serious limitation to the further development of Weyl physics and potential applications. Here, by experimentally characterizing a microwave photonic crystal comprised of a three dimensional array of saddle-shaped metallic coils, we observe ideal Weyl points which are related to each other through symmetry operations. Topological surface states exhibiting helicoidal structure in the energy-momentum space have also been demonstrated, which serve as a direct manifestation of the chiral nature of the Weyl points.This work was financially supported by ERC Consolidator Grant (Topological) and Leverhulme Trust (RPG-2012-674). S. Z. acknowledges support from the Royal Society and Wolfson Foundation. B. Y. acknowledges support from China Scholarship Council (201306110041). Y. X. acknowledges support from the National Natural Science Foundation of China (Grant No. 61490713). L. E. B. and A. P. H. acknowledge financial support from EPSRC of the United Kingdom (Grant No. EP/L015331/1). C.F. was supported by the National Key Research and Development Program of China under grant No. 2016YFA0302400 and by NSFC under grant No. 11674370. L.L. was supported by the National key R&D Program of China under Grant No. 2017YFA0303800, 2016YFA0302400 and by NSFC under Project No. 11721404

    The effectiveness of implementation strategies in improving preconception and antenatal preventive care: a systematic review.

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    BACKGROUND: Clinical guideline recommendations for addressing modifiable risk factors are not routinely implemented into preconception and antenatal care. This review assessed the effectiveness of implementation strategies in improving health professional provision of preconception and antenatal care addressing tobacco smoking, weight management and alcohol consumption. METHODS: A systematic review of randomised and non-randomised studies with a parallel comparison group was conducted. Eligible studies used implementation strategy/ies targeted at health professionals to improve at least one element of preconception and/or antenatal care (smoking: ask, advise, assess, assist, arrange; weight/alcohol: assess, advise, refer) compared to usual practice/control or alternative strategies. Eligible studies were identified via CENTRAL, MEDLINE, EMBASE, Maternity and Infant Care, CINAHL and other sources. Random-effects meta-analyses were conducted where appropriate, with other findings summarised using the direction of effect. The certainty of the pooled evidence was assessed using the GRADE approach. RESULTS: Fourteen studies were included in the review. Thirteen were in the antenatal period and 12 tested multiple implementation strategies (median: three). Meta-analyses of RCTs found that implementation strategies compared to usual practice/control probably increase asking (OR: 2.52; 95% CI: 1.13, 5.59; 3 studies; moderate-certainty evidence) and advising (OR: 4.32; 95% CI: 3.06, 6.11; 4 studies; moderate-certainty evidence) about smoking and assessing weight gain (OR: 57.56; 95% CI: 41.78, 79.29; 2 studies; moderate-certainty evidence), and may increase assessing (OR: 2.55; 95% CI: 0.24, 27.06; 2 studies; low-certainty evidence), assisting (OR: 6.34; 95% CI: 1.51, 26.63; 3 studies; low-certainty evidence) and arranging support (OR: 3.55; 95% CI: 0.50, 25.34; 2 studies; low-certainty evidence) for smoking. The true effect of implementation strategies in increasing advice about weight gain (OR: 3.37; 95% CI: 2.34, 4.84; 2 non-randomised studies; very low-certainty evidence) and alcohol consumption (OR: 10.36; 95% CI: 2.37, 41.20; 2 non-randomised studies; very low-certainty evidence) is uncertain due to the quality of evidence to date. CONCLUSIONS: Review findings provide some evidence to support the effectiveness of implementation strategies in improving health professional delivery of antenatal care addressing smoking and weight management. Rigorous research is needed to build certainty in the evidence for improving alcohol and weight gain advice, and in preconception care. TRIAL REGISTRATION: PROSPERO-CRD42019131691

    Carbon fiber masculinity: Disability and surfaces of homosociality

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    In this paper I am concerned with instances in which carbon fiber extends performances of masculinity that are attached to particular kinds of hegemonic male bodies. In examining carbon fiber as a prosthetic form of masculinity, I advance three main arguments. Firstly, carbon fiber can be a site of the supersession of disability that is affected through masculinized technology. Disability can be ‘overcome’ through carbon fiber. Disability is often culturally coded as feminine (Pedersen, 2001; Meeuf, 2009; Garland-Thompson 1997). Building on this cultural construction of disability as feminine, in and as a technology of masculine homosociality (Sedgwick, 1985), carbon fiber reproduced disability as feminine when carbon fiber prosthetic lower legs allowed Oscar Pistorius to compete in the non-disabled Olympic games. Secondly, I argue that carbon fiber can be a homosocial surface; that is, carbon fiber becomes both a surface extension of the self and a third party mediator in homosocial relationships, a surface that facilitates intimacy between men in ways that devalue femininity in both male and female bodies. I examine surfaces as material extensions of subjectivity, and carbon fiber surfaces as vectors of the cultural economies of masculine competition to which I refer. Thirdly, the case of Oscar Pistorius is exemplary of the masculinization of carbon fire, and the associated binding of a psychic attitude of misogyny and power to a form of violent and competitive masculine subjectivity. In this article I explore the affects, economies and surfaces of what I call ‘carbon fiber masculinity’ and discusses Pistorius’ use of carbon fiber, homosociality and misogyny as forms of protest masculinity through which he unconsciously attempted to recuperate his gendered identity from emasculating discourses of disability
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