553 research outputs found

    On the α−\alpha-decay of deformed actinide nuclei

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    α−\alpha-decay through a deformed potential barrier produces significant mixing of angular momenta when mapped from the nuclear interior to the outside. Using experimental branching ratios and either semi-classical or coupled-channels transmission matrices, we have found that there is a set of internal amplitudes which are essentially constant for all even--even actinide nuclei. These same amplitudes also give good results for the known anisotropic α−\alpha-particle emission of the favored decays of odd nuclei in the same mass region. PACS numbers: 23.60.+e, 24.10.Eq, 27.90.+bComment: 5 pages, latex (revtex style), 2 embedded postscript figures uuencoded gz-compressed .tar file To appear in Physical Review Letter

    Macroscopic superpositions via nested interferometry: finite temperature and decoherence considerations

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    Recently there has been much interest in optomechanical devices for the production of macroscopic quantum states. Here we focus on a proposed scheme for achieving macroscopic superpositions via nested interferometry. We consider the effects of finite temperature on the superposition produced. We also investigate in detail the scheme's feasibility for probing various novel decoherence mechanisms.Comment: 12 pages, 2 figure

    Evolving Identification of Blood Cells Associated with Clinically Isolated Syndrome: Importance of Time since Clinical Presentation and Diagnostic MRI

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    It is not clear how the profile of immune cells in peripheral blood differs between patients with clinically isolated syndrome (CIS) and healthy controls (HC). This study aimed to identify a CIS peripheral blood signature that may provide clues for potential immunomodulatory approaches early in disease. Peripheral blood mononuclear cells (PBMCs) were collected from 18 people with CIS, 19 HC and 13 individuals with other demyelinating conditions (ODC) including multiple sclerosis (MS). Individuals with CIS separated into two groups, namely those with early (≀14 days post-diagnostic magnetic resonance imaging (MRI); n = 6) and late (≄27 days; n = 12) blood sampling. Transitional B cells were increased in the blood of CIS patients independently of when blood was taken. However, there were two time-dependent effects found in the late CIS group relative to HC, including decreased CD56bright NK cells, which correlated significantly with time since MRI, and increased CD141+ myeloid dendritic cell (mDC2) frequencies. Higher CD1c+ B cells and lower non-classical monocyte frequencies were characteristic of more recent demyelinating disease activity (ODC and early CIS). Analysing cell populations by time since symptoms (subjective) and diagnostic MRI (objective) may contribute to understanding CIS

    Levinson's Theorem for Non-local Interactions in Two Dimensions

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    In the light of the Sturm-Liouville theorem, the Levinson theorem for the Schr\"{o}dinger equation with both local and non-local cylindrically symmetric potentials is studied. It is proved that the two-dimensional Levinson theorem holds for the case with both local and non-local cylindrically symmetric cutoff potentials, which is not necessarily separable. In addition, the problems related to the positive-energy bound states and the physically redundant state are also discussed in this paper.Comment: Latex 11 pages, no figure, submitted to J. Phys. A Email: [email protected], [email protected]

    Special Libraries, October 1922

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    Volume 13, Issue 8https://scholarworks.sjsu.edu/sla_sl_1922/1007/thumbnail.jp

    Aesthetics and literature : a problematic relation?

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    The paper argues that there is a proper place for literature within aesthetics but that care must be taken in identifying just what the relation is. In characterising aesthetic pleasure associated with literature it is all too easy to fall into reductive accounts, for example, of literature as merely "fine writing". Belleslettrist or formalistic accounts of literature are rejected, as are two other kinds of reduction, to pure meaning properties and to a kind of narrative realism. The idea is developed that literature-both poetry and prose fiction-invites its own distinctive kind of aesthetic appreciation which far from being at odds with critical practice, in fact chimes well with it

    Identifying Patient-Specific Epstein-Barr Nuclear Antigen-1 Genetic Variation and Potential Autoreactive Targets Relevant to Multiple Sclerosis Pathogenesis

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    Background: Epstein-Barr virus (EBV) infection represents a major environmental risk factor for multiple sclerosis (MS), with evidence of selective expansion of Epstein-Barr Nuclear Antigen-1 (EBNA1)-specific CD4+ T cells that cross-recognize MS-associated myelin antigens in MS patients. HLA-DRB1*15-restricted antigen presentation also appears to determine susceptibility given its role as a dominant risk allele. In this study, we have utilised standard and next-generation sequencing techniques to investigate EBNA-1 sequence variation and its relationship to HLA-DR15 binding affinity, as well as examining potential cross-reactive immune targets within the central nervous system proteome. Methods: Sanger sequencing was performed on DNA isolated from peripheral blood samples from 73 Western Australian MS cases, without requirement for primary culture, with additional FLX 454 Roche sequencing in 23 samples to identify low-frequency variants. Patient-derived viral sequences were used to predict HLA-DRB1*1501 epitopes (NetMHCII, NetMHCIIpan) and candidates were evaluated for cross recognition with human brain proteins. Results: EBNA-1 sequence variation was limited, with no evidence of multiple viral strains and only low levels of variation identified by FLX technology (8.3% nucleotide positions at a 1% cutoff). In silico epitope mapping revealed two known HLA-DRB1*1501-restricted epitopes (‘AEG’: aa 481–496 and ‘MVF’: aa 562–577), and two putative epitopes between positions 502–543. We identified potential cross-reactive targets involving a number of major myelin antigens including experimentally confirmed HLA-DRB1*15-restricted epitopes as well as novel candidate antigens within myelin and paranodal assembly proteins that may be relevant to MS pathogenesis. Conclusions: This study demonstrates the feasibility of obtaining autologous EBNA-1 sequences directly from buffy coat samples, and confirms divergence of these sequences from standard laboratory strains. This approach has identified a number of immunogenic regions of EBNA-1 as well as known and novel targets for autoreactive HLA-DRB1*15-restricted T cells within the central nervous system that could arise as a result of cross-reactivity with EBNA-1-specific immune responses

    Experiences of stigma in healthcare settings among adults living with HIV in the Islamic Republic of Iran

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    <p>Abstract</p> <p>Background</p> <p>People living with HIV (PLHIV) sometimes experience discrimination. There is little understanding of the causes, forms and consequences of this stigma in Islamic countries. This qualitative study explored perceptions and experiences of PLHIV regarding both the quality of healthcare and the attitudes and behaviours of their healthcare providers in the Islamic Republic of Iran.</p> <p>Methods</p> <p>In-depth, semi-structured interviews were held with a purposively selected group of 69 PLHIV recruited from two HIV care clinics in Tehran. Data were analyzed using the content analysis approach.</p> <p>Results and discussion</p> <p>Nearly all participants reported experiencing stigma and discrimination by their healthcare providers in a variety of contexts. Participants perceived that their healthcare providers' fear of being infected with HIV, coupled with religious and negative value-based assumptions about PLHIV, led to high levels of stigma. Participants mentioned at least four major forms of stigma: (1) refusal of care; (2) sub-optimal care; (3) excessive precautions and physical distancing; and (4) humiliation and blaming. The participants' healthcare-seeking behavioural reactions to perceived stigma and discrimination included avoiding or delaying seeking care, not disclosing HIV status when seeking healthcare, and using spiritual healing. In addition, emotional responses to perceived acts of stigma included feeling undeserving of care, diminished motivation to stay healthy, feeling angry and vengeful, and experiencing emotional stress.</p> <p>Conclusions</p> <p>While previous studies demonstrate that most Iranian healthcare providers report fairly positive attitudes towards PLHIV, our participants' experiences tell a different story. Therefore, it is imperative to engage both healthcare providers and PLHIV in designing interventions targeting stigma in healthcare settings. Additionally, specialized training programmes in universal precautions for health providers will lead to stigma reduction. National policies to strengthen medical training and to provide funding for stigma-reduction programming are strongly recommended. Investigating Islamic literature and instruction, as well as requesting official public statements from religious leaders regarding stigma and discrimination in healthcare settings, should be used in educational intervention programmes targeting healthcare providers. Finally, further studies are needed to investigate the role of the physician and religion in the local context.</p
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