131 research outputs found
Magnetic origin of the chemical balance in alloyed Fe-Cr stainless steels: First-principles and Ising model study
Iron-chromium is the base material for most of the stainless steel grades. Recently, new insights into the origins of fundamental physical and chemical characteristics of Fe-Cr based alloys have been achieved. Some of the new results are quite unexpected and call for further investigations. The present study focuses on the magnetic contribution in the atomic driving forces related to the chemical composition in Fe-Cr when alloyed with Al, Ti, V, Mn, Co, Ni, and Mo. Using the ab initio exact muffin-tin orbitals method combined with an Ising-type spin model, we demonstrate that the magnetic moment of the solute atoms with the induced changes in the magnetic moments of the host atoms form the main factor in determining the mixing energy and chemical potentials of low-Cr Fe-Cr based alloys. The results obtained in the present work are related to the designing and tuning of the microstructure and corrosion protection of low-Cr steels. (C) 2014 Elsevier B. V. All rights reserved.</p
Signatures of topological ground state degeneracy in Majorana islands
We consider a mesoscopic superconducting island hosting multiple pairs of
Majorana zero-energy modes. The Majorana island consists of multiple p-wave
wires connected together by a trivial (s-wave) superconducting backbone and is
characterized by an overall charging energy ; the wires are coupled to
normal-metal leads via tunnel junctions. We calculate the average charge on the
island as well as non-local conductance matrix as a function of a p-wave
pairing gap , charging energy and dimensionless junction
conductances . We find that the presence of a topological ground-state
degeneracy in the island dramatically enhances charge fluctuations and leads to
the suppression of Coulomb blockade effects. In contrast with conventional
(s-wave) mesoscopic superconducting islands, we find that Coulomb blockade
oscillations of conductance are suppressed in Majorana islands regardless of
the ratio or the magnitude of the conductances . We also
discuss our findings in relation to the so-called topological Kondo effect.Comment: 27 pages, 6 figures. Submitted versio
Significant Role of Collagen XVII And Integrin beta 4 in Migration and Invasion of The Less Aggressive Squamous Cell Carcinoma Cells
Collagen XVII and integrin alpha 6 beta 4 have well-established roles as epithelial adhesion molecules. Their binding partner laminin 332 as well as integrin alpha 6 beta 4 are largely recognized to promote invasion and metastasis in various cancers, and collagen XVII is essential for the survival of colon and lung cancer stem cells. We have studied the expression of laminin.2, collagen XVII and integrin beta 4 in tissue microarray samples of squamous cell carcinoma (SCC) and its precursors, actinic keratosis and Bowen's disease. The expression of laminin.2 was highest in SCC samples, whereas the expression of collagen XVII and integrin beta 4 varied greatly in SCC and its precursors. Collagen XVII and integrin beta 4 were also expressed in SCC cell lines. Virus-mediated RNAi knockdown of collagen XVII and integrin beta 4 reduced the migration of less aggressive SCC-25 cells in horizontal scratch wound healing assay. Additionally, in a 3D organotypic myoma invasion assay the loss of collagen XVII or integrin beta 4 suppressed equally the migration and invasion of SCC-25 cells whereas there was no effect on the most aggressive HSC-3 cells. Variable expression patterns and results in migration and invasion assays suggest that collagen XVII and integrin beta 4 contribute to SCC tumorigenesis.Peer reviewe
What does regional studies study? From subnational to supra-national regional spaces or Grossraum of sovereign governance
This article makes a case for expanding the scope of current versions of “regional studies” to include greater emphasis upon transnational regions as of equal if not greater importance compared with an exclusive focus upon sub-national regions. The latter more restrictive approach is typically predicated on the continued centrality of state borders against which the dominant notion of regions as subnational entities is constituted and reiterated. Drawing upon a case study of the African Union our study provides a framework, a critically revised Grossraum theory, for addressing the emergence of a new pluralistic and multipolar world order characterised by supra-national regions and regional organizations. Traditional Schmittian notions of Grossraum are shown to be in need of substantial revision before they are able to adequately accommodate and explain the empirical details of our case study
The type-B moral error theory
I introduce a new version of Moral Error Theory, which I call Type-B Moral Error Theory. According to a Type-B theorist there are no facts of the kind required for there to be morality in stricto sensu, but there can be irreducible ‘normative’ properties which she deems, strictly speaking, to be morally irrelevant. She accepts that there are instrumental all things considered oughts, and categorical pro tanto oughts (both of which she deems morally irrelevant), but denies that there are categorical all things considered oughts on pain of requiring ‘queer’ facts to obtain. I detail the most central motivation of this version of the theory against its more traditional rival, according to which there are no irreducible normative properties at all. The motivation is that it, unlike its rival, can successfully be defended against the notorious charge of self-defeat
Effectiveness of Mechanisms and Models of Coordination between Organizations, Agencies and Bodies Providing or Financing Health Services in Humanitarian Crises: A Systematic Review.
BACKGROUND: Effective coordination between organizations, agencies and bodies providing or financing health services in humanitarian crises is required to ensure efficiency of services, avoid duplication, and improve equity. The objective of this review was to assess how, during and after humanitarian crises, different mechanisms and models of coordination between organizations, agencies and bodies providing or financing health services compare in terms of access to health services and health outcomes. METHODS: We registered a protocol for this review in PROSPERO International prospective register of systematic reviews under number PROSPERO2014:CRD42014009267. Eligible studies included randomized and nonrandomized designs, process evaluations and qualitative methods. We electronically searched Medline, PubMed, EMBASE, Cochrane Central Register of Controlled Trials, CINAHL, PsycINFO, and the WHO Global Health Library and websites of relevant organizations. We followed standard systematic review methodology for the selection, data abstraction, and risk of bias assessment. We assessed the quality of evidence using the GRADE approach. RESULTS: Of 14,309 identified citations from databases and organizations' websites, we identified four eligible studies. Two studies used mixed-methods, one used quantitative methods, and one used qualitative methods. The available evidence suggests that information coordination between bodies providing health services in humanitarian crises settings may be effective in improving health systems inputs. There is additional evidence suggesting that management/directive coordination such as the cluster model may improve health system inputs in addition to access to health services. None of the included studies assessed coordination through common representation and framework coordination. The evidence was judged to be of very low quality. CONCLUSION: This systematic review provides evidence of possible effectiveness of information coordination and management/directive coordination between organizations, agencies and bodies providing or financing health services in humanitarian crises. Our findings can inform the research agenda and highlight the need for improving conduct and reporting of research in this field
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