1,537 research outputs found
Thermohaline mixing and the photospheric composition of low-mass giant stars
We compute full evolutionary sequences of red giant branch stars close to the
luminosity bump by including state of the art composition transport
prescriptions for the thermohaline mixing regimes. In particular we adopt a
self-consistent double-diffusive convection theory, that allows to handle the
instabilities that arise when thermal and composition gradients compete against
each other, and a very recent empirically motivated and parameter free
asymptotic scaling law for thermohaline composition transport. In agreement
with previous works, we find that during the red giant stage, a thermohaline
instability sets in shortly after the hydrogen burning shell (HBS) encounters
the chemical discontinuity left behind by the first dredge-up. We also find
that the thermohaline unstable region, initially appearing at the exterior wing
of the HBS, is unable to reach the outer convective envelope, with the
consequence that no mixing of elements that produces a non-canonical
modification of the stellar surface abundances occurs. Also in agreement with
previous works, we find that by artificially increasing the mixing efficiency
of thermohaline regions it is possible to connect both unstable regions, thus
affecting the photospheric composition. However, we find that in order to
reproduce the observed abundances of red giant branch stars close to the
luminosity bump, thermohaline mixing efficiency has to be artificially
increased by about 4 orders of magnitude from that predicted by recent 3D
numerical simulations of thermohaline convection close to astrophysical
environments. From this we conclude the chemical abundance anomalies of red
giant stars cannot be explained on the basis of thermohaline mixing alone.Comment: 7 pages, 6 figures, accepted for publication in A&
Racism and anti-racism in Europe: a critical analysis of concepts and frameworks
The targets and expressions of racism vary across Europe. This article discusses the relevance of different descriptions and analyses of racism despite the different terms used in different countries such as ‘ethnic minority’, ‘foreigner’ or ‘black’ and different interpretations of which differences matter. It shows the significance of a cross-national European perspective on racism. There are important convergences across European countries in the discourses and practices of racism, particularly the distinction between ‘useful’ and ‘abusive’ migrants. A cross-European perspective can be an important inspiration for anti-racist struggles
International education: a force for peace and cross-cultural understanding?
This paper discusses the notion that the international sojourn has the potential to transform sojourners into cultural mediators who carry the power to improve global relations. A year-long ethnographic study of the adjustment experiences of international postgraduate students in England revealed a universal early enthusiasm for cross-cultural contact that was matched by a widespread adoption of segregated patterns of interacting. The most common friendship networks were described by bonds with conationals, and yet all students attested to an increase in their cultural learning and mindfulness by the end of the sojourn. Nevertheless, intercultural competence was maximised only in those few students who pursued a multicultural strategy of interaction, leading the researcher to call on Higher Education Institutions to instigate policies to encourage lasting cross-cultural contact
Racism, anti-racist practice and social work: articulating the teaching and learning experiences of Black social workers
In the mid 1990s a Black practice teacher programme was established in Manchester and Merseyside with the primary aim to increase the number of Black practice teachers in social work organisations, and in turn provide a supportive and encouraging learning environment for Black student social workers whilst on placement. In the north‐west of England research has been undertaken, to establish the quality of the practice teaching and student learning taking place with Black practice teachers and students. This paper is an exploration of the ideas generated within the placement process that particularly focused on the discourse of racism and ant‐racist practice. Black students and practice teachers explain their understanding of racism and anti‐racist practice within social work. From the research, the paper will critique some of the ideas concerning anti‐racism. In particular, it will question whether anti‐racist social work practice needs to be re‐evaluated in the light of a context with new migrants, asylum seekers and refugees. It will concluded, by arguing that whilst the terms anti‐racism, Black and Minority Ethnic have resonance as a form of political strategic essentialism, it is important to develop more positive representations in the future
Fear of cancer recurrence following allogeneic haematopoietic stem cell transplantation (HSCT) for haematological malignancy: A cross-sectional study.
PURPOSE:The aim of this study was to quantify the prevalence of Fear of Cancer Recurrence (FCR) in patients with a prior haematology malignancy surviving more than one year post allogeneic haematopoietic stem cell transplantation (HSCT), and to identify the demographic, medical and psychological factors associated with FCR occurrence. METHOD:Participants were adult allogeneic HSCT recipients who had undergone the procedure for acute leukaemia or other haematological malignancy between the years 2000-2012 in Sydney, Australia. They completed a purpose designed survey and six other validated instruments which assessed FCR, psychological functioning, quality of life, demographic, social and clinical variables. RESULTS:Of the 364 respondents, approximately 11% of the sample lived with severe FCR while only 5% of subjects reported having no FCR. Variables significantly associated with higher FCR included unemployment, a shorter time (years) post-transplant, not attending to health screening (PAP smear), a secondary diagnosis of skin cancer, younger age, referral to a psychiatrist and taking psychotropic medication. Higher psychological distress (depression, anxiety, stress) and lower quality of life made a significant contribution to the prediction of FCR. CONCLUSIONS:Post HSCT follow-up care should include an assessment and discussion regarding FCR to balance both realistic and unrealistic cancer recurrence risks. Managing FCR is one of the most ubiquitous unmet needs of survivors of haematological disease and it is important that HSCT nurses are both aware of the fear, and are equipped with knowledge on how to help patients navigate it with realistic expectations
At Home and Not At Home: Stuart Hall in conversation with Les Back
Stuart Hall talks to Les Back about his life and work
‘Isles of Wonder’: performing the mythopoeia of utopic multi-ethnic Britain
Within this article, I interrogate the mediated ‘narratives of nation’ told through the London 2012 Olympic Opening Ceremony. Such narratives are not just pedagogic, they are political and ideological processes that require us to pose questions about the place of the past in the present and with regard to who is entitled to speak that past. I suggest that the ceremony performed an ‘aesthetic of selective silence’ and offered a platform to induce nostalgia and identification beyond our own selves while offering a powerful historical teleology: multi-ethnic Britain was given no past, rather, the ‘noises’ that were amplified in the present provided a common, fixed and concretely grounded past that centred on an Anglicized, simple, stable, safe and pure fantasy in which divisions – gendered, classed, raced – were mere historical artifacts. I argue that the ceremony provided for the delivery of a multi-ethnic national fantasy that highlights central issues of being, belonging, privilege and hierarchy within a postcolonial heterophilic Britain, and which reasserts a utopic abstraction of nation and assimilation to core British values
Managing and monitoring equality and diversity in UK sport: An evaluation of the sporting equals Racial Equality Standard and its impact on organizational change
Despite greater attention to racial equality in sport in recent years, the progress of national sports organizations toward creating equality of outcomes has been limited in the United Kingdom. The collaboration of the national sports agencies, equity organizations and national sports organizations (including national governing bodies of sport) has focused on Equality Standards. The authors revisit an earlier impact study of the Racial Equality Standard in sport and supplement it with another round of interview material to assess changing strategies to manage diversity in British sport. In particular, it tracks the impact on organizational commitment to diversity through the period of the establishment of the Racial Equality Standard and its replacement by an Equality Standard that deals with other diversity issues alongside race and ethnicity. As a result, the authors question whether the new, generic Equality Standard is capable of addressing racial diversity and promoting equality of outcomes. © 2006 Sage Publications
An RxLR effector from phytophthora infestans prevents re-localisation of two plant NAC transcription factors from the endoplasmic reticulum to the nucleus
The plant immune system is activated following the perception of exposed, essential and invariant microbial molecules that are recognised as non-self. A major component of plant immunity is the transcriptional induction of genes involved in a wide array of defence responses. In turn, adapted pathogens deliver effector proteins that act either inside or outside plant cells to manipulate host processes, often through their direct action on plant protein targets. To date, few effectors have been shown to directly manipulate transcriptional regulators of plant defence. Moreover, little is known generally about the modes of action of effectors from filamentous (fungal and oomycete) plant pathogens. We describe an effector, called Pi03192, from the late blight pathogen Phytophthora infestans, which interacts with a pair of host transcription factors at the endoplasmic reticulum (ER) inside plant cells. We show that these transcription factors are released from the ER to enter the nucleus, following pathogen perception, and are important in restricting disease. Pi03192 prevents the plant transcription factors from accumulating in the host nucleus, revealing a novel means of enhancing host susceptibility
Immanuel Kant believed in zombies – Multiculturalism and Spirituality in the Postcolonial City
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