184 research outputs found
On electromagnetic contributions in WIMP quests
The effect pointed out by A. B. Migdal in the 40's (hereafter named Migdal
effect) has so far been usually neglected in the direct searches for WIMP Dark
Matter candidates. This effect consists in the ionization and the excitation of
bound atomic electrons induced by the recoiling atomic nucleus. In the present
paper the related theoretical arguments are developed and some consequences of
the proper accounting for this effect are discussed by some examples of
practical interest.Comment: 14 pages, 6 figures, 2 tables, Int. J. Mod. Phys. A (in publication
Quasi-normal frequencies: Key analytic results
The study of exact quasi-normal modes [QNMs], and their associated
quasi-normal frequencies [QNFs], has had a long and convoluted history -
replete with many rediscoveries of previously known results. In this article we
shall collect and survey a number of known analytic results, and develop
several new analytic results - specifically we shall provide several new QNF
results and estimates, in a form amenable for comparison with the extant
literature. Apart from their intrinsic interest, these exact and approximate
results serve as a backdrop and a consistency check on ongoing efforts to find
general model-independent estimates for QNFs, and general model-independent
bounds on transmission probabilities. Our calculations also provide yet another
physics application of the Lambert W function. These ideas have relevance to
fields as diverse as black hole physics, (where they are related to the damped
oscillations of astrophysical black holes, to greybody factors for the Hawking
radiation, and to more speculative state-counting models for the Bekenstein
entropy), to quantum field theory (where they are related to Casimir energies
in unbounded systems), through to condensed matter physics, (where one may
literally be interested in an electron tunelling through a physical barrier).Comment: V1: 29 pages; V2: Reformatted, 31 pages. Title changed to reflect
major additions and revisions. Now describes exact QNFs for the double-delta
potential in terms of the Lambert W function. V3: Minor edits for clarity.
Four references added. No physics changes. Still 31 page
Co-producing across organizational boundaries: promoting asylum seeker integration in Scotland
This paper questions whether asylum seeker integration is promoted through inter-organisational relationships between non-profit and voluntary organisations (NPVOs) and government agencies. It focuses particularly on the role of NPVOs in service delivery (co-management) and in the delivery and planning of public services (co-governance). It presents a research study on the public services provided to asylum seekers in Glasgow and asks the following questions: What role do NPVOs play in the planning and delivery of public services? When planning and delivering public services, to what extent do NPVOs work across organisational boundaries and what kind of relationships exist? And in practice, what makes inter-organisational relationships work? This paper offers new empirical evidence and also contributes to the theoretical debate around the integration of asylum seekers
Pemphigus autoimmunity: Hypotheses and realities
The goal of contemporary research in pemphigus vulgaris and pemphigus foliaceus is to achieve and maintain clinical remission without corticosteroids. Recent advances of knowledge on pemphigus autoimmunity scrutinize old dogmas, resolve controversies, and open novel perspectives for treatment. Elucidation of intimate mechanisms of keratinocyte detachment and death in pemphigus has challenged the monopathogenic explanation of disease immunopathology. Over 50 organ-specific and non-organ-specific antigens can be targeted by pemphigus autoimmunity, including desmosomal cadherins and other adhesion molecules, PERP cholinergic and other cell membrane (CM) receptors, and mitochondrial proteins. The initial insult is sustained by the autoantibodies to the cell membrane receptor antigens triggering the intracellular signaling by Src, epidermal growth factor receptor kinase, protein kinases A and C, phospholipase C, mTOR, p38 MAPK, JNK, other tyrosine kinases, and calmodulin that cause basal cell shrinkage and ripping desmosomes off the CM. Autoantibodies synergize with effectors of apoptotic and oncotic pathways, serine proteases, and inflammatory cytokines to overcome the natural resistance and activate the cell death program in keratinocytes. The process of keratinocyte shrinkage/detachment and death via apoptosis/oncosis has been termed apoptolysis to emphasize that it is triggered by the same signal effectors and mediated by the same cell death enzymes. The natural course of pemphigus has improved due to a substantial progress in developing of the steroid-sparing therapies combining the immunosuppressive and direct anti-acantholytic effects. Further elucidation of the molecular mechanisms mediating immune dysregulation and apoptolysis in pemphigus should improve our understanding of disease pathogenesis and facilitate development of steroid-free treatment of patients
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