849 research outputs found
CP-violating axion interactions in effective field theory
Axions are introduced to explain the observed smallness of the
term of QCD. Standard Model extensions typically contain new sources of CP
violation, for instance to account for the baryon asymmetry of the universe. In
the presence of additional CP-violating sources a Peccei-Quinn mechanism does
not remove all CP violation, leading to CP-odd interactions among axions and
Standard Model fields. In this work, we use effective field theory to
parametrize generic sources of beyond-the-Standard-Model CP violation. We
systematically compute the resulting CP-odd couplings of axions to leptons and
hadrons by using chiral perturbation theory. We discuss in detail the
phenomenology of the CP-odd axion couplings and compare limits from axion
searches, such as fifth force and monopole-dipole searches and astrophysics, to
direct limits on the CP-violating operators from electric dipole moment
experiments. While limits from electric dipole moment searches are tight, the
proposed ARIADNE experiment can potentially improve the existing constraints in
a window of axion masses
Logarithmic singularities and quantum oscillations in magnetically doped topological insulators
We report magnetotransport measurements on magnetically doped
(Bi,Sb)Te films grown by molecular beam epitaxy. In Hallbar devices,
logarithmic dependence on temperature and bias voltage are obseved in both the
longitudinal and anomalous Hall resistance. The interplay of disorder and
electron-electron interactions is found to explain quantitatively the observed
logarithmic singularities and is a dominant scattering mechanism in these
samples. Submicron scale devices exhibit intriguing quantum oscillations at
high magnetic fields with dependence on bias voltage. The observed quantum
oscillations can be attributed to bulk and surface transport.Comment: 10 pages, 13 figure
Multilingual gendered identities: female undergraduate students in London talk about heritage languages
In this paper I explore how a group of female university students, mostly British Asian and in their late teens and early twenties, perform femininities in talk about heritage languages. I argue that analysis of this talk reveals ways in which the participants enact ‘culturally intelligible’ gendered subject positions. This frequently involves negotiating the norms of ‘heteronormativity’, constituting femininity in terms of marriage, motherhood and maintenance of heritage culture and language, and ‘girl power’, constituting femininity in terms of youth, sassiness, glamour and individualism. For these young women, I ask whether higher education can become a site in which they have the opportunities to explore these identifications and examine other ways of imagining the self and what their stories suggest about ‘doing being’ a young British Asian woman in London
Multifrequency study of the ring nebula SG13
We investigate the morphology and kinematics of the interstellar medium in
the environs of the open cluster Mrk50, which includes the Wolf-Rayet star
WR157 and a number of early B-type stars. The analysis was performed using
radio continuum images at 408 and 1420 MHz, and HI 21cm line data taken from
the Canadian Galactic Plane Survey, molecular observations of the 12CO (J=1-0)
line at 115 GHz from the Five College Radio Astronomy Observatory and available
mid and far IR observations obtained with the MSX and IRAS satellites,
respectively. This study allowed identification of the radio continuum and
molecular counterpart of the ring nebula SG13, while no neutral atomic
structure was found to be associated. The nebula is also detected in images in
the mid and far infrared, showing the existence of dust well mixed with the
ionized gas. We estimate the main physical parameters of the material linked to
the nebula. The interstellar gas distribution in the environs of Mrk50 is
compatible with a stellar wind bubble created by the mass loss from WR157. The
distribution of young stellar object (YSO) candidates in the region shows that
stellar formation activity may be present in the molecular shell that encircles
the ring nebula.Comment: Accepted for publication in MNRAS, 13 pages, 11 figure
Earthquakes, cancer and cultures of fear: qualifying as a Skills for Life teacher in an uncertain economic climate
The Skills for Life (SfL) initiative followed the Moser Report (1999) and incarnated a Third Way agenda that sought to address England's perceived adult skills deficit. SfL marked a large investment in adult education but also a distinct shift to a more focused, instrumentalist role for Further Education (FE) in England. A new structure of teacher standards and qualifications underpinned this development with its own, newly devised and matriculated knowledge base. Teachers emerged from these new programmes with subject specialisms in Literacy, Numeracy and English for Speakers of Other Languages (ESOL). The landscape that these ‘new professionals' have entered is one that suggests the autonomy of colleges within a competitive market, but this disguises a funding methodology that facilitates ongoing centralised policy intervention. In the last two years policy makers have used this funding methodology to shift monies decisively towards 14-19 provision and away from adult education. This article draws on qualitative data from a study into the experiences of pre and in-service SfL teachers in the final stages of qualification. The data explore the impact of these latest movements in the FE market on these student teachers who are qualifying in some of the newest subjects in FE
The endogenous caspase-8 inhibitor c-FLIPL regulates ER morphology and crosstalk with mitochondria
Components of the death receptors-mediated pathways like caspase-8 have been identified in complexes at intracellular membranes to spatially restrict the processing of local targets. In this study, we report that the long isoform of the cellular FLICE-inhibitory protein (c-FLIPL), a well- known inhibitor of the extrinsic cell death initiator caspase-8, localizes at the endoplasmic reticulum (ER) and mitochondria-associated membranes (MAMs). ER morphology was disrupted and ER Ca2+-release as well as ER-mitochondria tethering were decreased in c-FLIP-/- mouse embryonic fibroblasts (MEFs). Mechanistically, c-FLIP ablation resulted in enhanced basal caspase-8 activation and in caspase-mediated processing of the ER-shaping protein reticulon-4 (RTN4) that was corrected by re-introduction of c-FLIPL and caspase inhibition, resulting in the recovery of a normal ER morphology and ER-mitochondria juxtaposition. Thus, the caspase-8 inhibitor c-FLIPL emerges as a component of the MAMs signaling platforms, where caspases appear to regulate ER morphology and ER-mitochondria crosstalk by impinging on ER-shaping proteins like the RTN4
Succeeding against the odds: can schools ‘compensate for society’?
Education researchers, policy-makers and practitioners in the UK have debated the question of what, and how much, schools can do to mitigate the effects of parental background on educational outcomes over the last half a century. A range of programmes, strategies and interventions have been implemented, and continue to be implemented in an effort to ‘break the link’ between socio-economic disadvantage and low educational outcomes, but educational inequalities have persisted. This paper draws on theoretical and empirical research to offer a new analysis of compensatory education in England across three main phases since the 1960s
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