731 research outputs found
Density of states at disorder-induced phase transitions in a multichannel Majorana wire
An -channel spinless p-wave superconducting wire is known to go through a
series of topological phase transitions upon increasing the disorder
strength. Here, we show that at each of those transitions the density of states
shows a Dyson singularity , whereas has a power-law singularity for small energies
away from the critical points. Using the concept of
"superuniversality" [Gruzberg, Read, and Vishveshwara, Phys. Rev. B 71, 245124
(2005)], we are able to relate the exponent to the wire's transport
properties at zero energy and, hence, to the mean free path and the
superconducting coherence length .Comment: 4+1 pages, 3 figure
Reentrant topological phase transitions in a disordered spinless superconducting wire
In a one-dimensional spinless p-wave superconductor with coherence length \xi, disorder induces a phase transition between a topologically nontrivial phase and a trivial insulating phase at the critical mean free path l=\xi/2. Here, we show that a multichannel spinless p-wave superconductor goes through an alternation of topologically trivial and nontrivial phases upon increasing the disorder strength, the number of phase transitions being equal to the channel number N. The last phase transition, from a nontrivial phase into the trivial phase, takes place at a mean free path l = \xi/(N+1), parametrically smaller than the critical mean free path in one dimension. Our result is valid in the limit that the wire width W is much smaller than the superconducting coherence length \xi
Need and value of targeted immunosuppressive therapy in giant cell arteritis
Despite the heterogeneity of the giant cell arteritis (GCA) at the level of clinical manifestations and the cellular and molecular players involved in its pathogenesis, GCA is still treated with standardised regimens largely based on glucocorticoids (GC). Long-term use of high dosages of GC as required in GCA are associated with many clinically relevant side effects. In the recent years, the interleukin-6 receptor blocker tocilizumab has become available as the only registered targeted immunosuppressive agent in GCA. However, immunological heterogeneity may require different pathways to be targeted in order to achieve a clinical, immunological and vascular remission in GCA. The advances in the targeted blockade of various molecular pathways involved in other inflammatory and autoimmune diseases have catalyzed the research on targeted therapy in GCA. This article gives an overview of the studies with targeted immunosuppressive treatments in GCA, with a focus on their clinical value, including their effects at the level of vascular inflammation
Towards a low-carbon economy : A nexus-oriented policy coherence analysis in Greece
The sustainable management of natural resources under climate change conditions is a critical research issue. Among the many approaches emerged in recent times, the so-called 'nexus approach' is gaining traction in academic and policy circles. The nexus approach presupposes the analysis of bio-physical, socio-economic and policy interlinkages among sectors (e.g., water, energy, food) for the identification of integrated solutions and the support of policy decisions. Ultimately, the nexus approach aims to identify synergies and trade-offs among the nexus dimensions. Concerning policy, the nexus approach focuses on policy coherence, i.e., the systematic identification and management of trade-offs and synergies between policies across sectors. This paper investigates the coherence between policies on the water-land-energy-food-climate nexus in Greece. The systematic analysis of policy documents led to the elicitation of nexus-related policy objectives and instruments. Then, the coherence among objectives and between objectives and instruments was assessed using the methodology proposed by Nilsson et al. A stakeholder (trans-disciplinary) orientation was adopted and the need to incorporate stakeholders' recommendations as to policy coherence assessment was highlighted. Overall, the findings revealed that climate and food/agricultural policies represent critical future priorities in Greece by stimulating progress in other nexus-related policies (energy, water, land policies) and being positively influenced by them.</p
Visual and semiquantitative assessment of cranial artery inflammation with FDG-PET/CT in giant cell arteritis
BACKGROUND AND AIM: Assessing cranial artery inflammation plays an important role in the diagnosis of cranial giant cell arteritis (C-GCA). However, current diagnostic tests are limited. The use of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT imaging is an established tool for assessing large vessel inflammation but is currently not used for assessment of the cranial arteries. This study aimed to evaluate the accuracy of FDG-PET/CT in the diagnosis of biopsy proven C-GCA and its relation to clinical presentation. METHODS: This retrospective case control study included temporal artery biopsy (TAB) positive C-GCA patients and age- and sex-matched controls. FDG-PET/CT scans were performed according to EANM/EARL guidelines, visually assessed by an experienced nuclear medicine physician, and semiquantitatively assessed using the maximum standardised uptake value (SUVmax). The visual and semiquantitative assessments were performed on the temporal arteries, maxillary arteries, vertebral arteries, and occipital arteries. Clinical signs and symptoms were scored for comparison. RESULTS: A total of 24 C-GCA patients and 24 controls were included in the study. Visual analysis revealed an 83% sensitivity and a 75% specificity. Receiver operating characteristic (ROC) analysis of the semiquantitative assessment revealed a 79% sensitivity and a 92% specificity when measuring SUVmax in the cranial arteries. Visual and semiquantitative assessments showed moderate agreement (Fleiss kappa 0.55). There was a positive correlation between the number of cranial symptoms and the SUVmax in the vertebral artery. CONCLUSION: FDG-PET/CT can reliably diagnose C-GCA by assessing cranial artery inflammation using SUVmax. Extending the use of FDG-PET/CT to include assessment of the cranial arteries may improve its diagnostic value in GCA and provide a suitable alternative to TAB. Moderate agreement between visual and semiquantitative assessment methods suggest diagnostic accuracy may be improved by further standardisation
The water-land-food-energy-climate nexus for a resource efficient Europe.
Î novel methodology for addressing policy
inconsistencies and knowledge gaps that hinder the
transition to a greater resource efficiency Europe is
proposed. We focus on the integration of all different
sectors that interact and influence each other, namely the
âwater- energy- food- land use- climate nexusâ and we
develop tools for identifying and quantifying their complex
interlinkages under the influence of climate change. In
order to achieve this, we employ a series of sophisticated
models (referred to as âthematic modelsâ), each of which
addresses a different nexus dimension, or a combination of
a few, while none addresses all nexus dimensions in an
integrative manner. We use dynamic systems modeling
and other complexity science techniques in order to
âmergeâ different thematic model outputs in a single
coherent result, which is presented to the user in an easyto-comprehend
Serious Game environment. This way, the
effect of policies that are designed to affect one field
(nexus dimension) on others can be quantified and
simulated, thus informing policy-makers for the
unintended consequences of their policies, reducing
uncertainties, covering knowledge gaps and leading to a
resource efficient Europe faste
Towards a paradigm shift in occupational health:the potential of the International Classification of Functioning, Disability and Health (ICF) for preventive practice, research & education
Demographic developments and the structure of our pension system is forcing us to work longer. Nurturing and maintaining the health of the working population calls for a proactive approach by professionals in the field of work and health. This development also requires a paradigm shift among professionals, which will have consequences for academic curricula. This dissertation examines the potential role of the International Classification of Functioning, Disability and Health (ICF) in this paradigm shift. The ICF provides a language and paradigm framework that focuses on health and functioning. Future professionals are being trained in ICF within the context of an exemplary practical example (screening for future long-term absences using the Balansmeter, followed by early intervention by a company doctor) and within an academic curriculum (Master of Work, Health and Career at Maastricht University). ICF appears to be a promising way to prevent long-term absence and may contribute to a paradigm shift in academic curricula, practical implementation and research on work and health
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