1,518 research outputs found
Positive undecidable numberings in the Ershov hierarchy
We give a su cient condition for an in nite computable family of 1
a sets, to have computable positive but undecidable numberings, where a
is a notation for a nonzero computable ordinal. This extends a theorem
proved by Talasbaeva for the nite levels of the Ershov hierarchy. In par-
ticular the family of all 1 a sets has positive undecidable numberings: this
veri es for all levels of the Ershov hierarchy a conjecture due to Badaev
and Goncharov. We point out also that for every ordinal notation a of a
nonzero ordinal, there are families of 1 a sets having positive numberings,
but no Friedberg numberings: this answers for all levels (whether nite
or in nite) of the Ershov hierarchy, a question originally raised, only for
the nite levels over level 1, by Badaev and Goncharov
Friedberg numberings in the Ershov hierarchy
We show that for every n 1, there exists a 1n -computable family which up to equivalence has exactly one Friedberg numbering which does not induce the least element of the corresponding Rogers semilattice
Study of the Quench Propagation and of the Protection System of the COS-theta NED Dipole Prototype
In this report we present our studies of the propagation of the quench in the NED dipole prototype, to derive a preliminary configuration of the protection system of the magnet (quench protection heaters, dump resistors, etc.). The simulations have been performed by using the code QLASA [1]. In this code, the geometry of the magnet is simplified to a series of solenoidal concentric magnets and the evolution of the quench is calculated with the Wilson's approach [2]. An analogous study has been performed with the CERN code QUABER [3],[4], and the results are discussed in section 3
Management of retinal vein occlusion, who is responsible?
Retinal vein occlusion (RVO) is a common retinal vascular occlusive disorder and is associated with a variety of systemic risk factors. The aim of this study was to investigate whether the underlying diseases were evaluated and managed appropriately by ophthalmologists. We performed a study of 1344 patients with retinal vein occlusion (RVO). Patients were evaluated with a questionnaire including ten closed questions to determine whether ophthalmologists evaluated and informed their patients about the underlying systemic diseases. None of the patients� homocysteine levels were measured. Only a small percentage of the patients were asked about the history of thrombotic diseases or family history of thrombotic diseases. We believe that most ophthalmologists are still not entirely convinced of their responsibility of managing the underlying predisposing factors of RVO. Ophthalmologists should either manage or engage other healthcare providers in the management of RVO to guarantee the patient the best care. © 2016 Tehran University of Medical Sciences. All rights reserved
Exhaustion and endocrine functioning in clinical burnout:An in-depth study using the experience sampling method
Fabrication and Results of the First MgB2 Round Coil Superferric Magnet at LASA
The LASA Laboratory (INFN, Milan) is working in the High Luminosity LHC program to develop, in collaboration with CERN, six different types of High Order corrector magnets. In this framework, in parallel with a conventional design of superferric magnets with LTS conductor, the LASA is focusing on the research of new superconducting materials which may have applications in particle accelerator magnets. To this purpose, LASA is developing a new type of superferric magnet suitable to arbitrary multipole order, called Round Coil Superferric Magnets (RCSM). The iron yoke shaped with an arbitrary number of poles is able to create the desired harmonic component using only one single round coil with a large bending radius suitable for very strain-sensitive superconductors. The electromagnetic design of a sextupole configuration of the magnet and the production of the first superconducting MgB2 round coil prototype have been already presented. In this paper, we expose the optimization of the iron yoke and polar expansions assembly of the first magnet semi-module prototype. The results of the whole powering test are described in detail and the analysis of the magnetic performances are compared with those of classical superferric correctors
Clinical value of bioelectrical properties of cancerous tissue in advanced epithelial ovarian cancer patients
Currently, there are no valid pre-operatively established biomarkers or algorithms that can accurately predict surgical and clinical outcome for patients with advanced epithelial ovarian cancer (EOC). In this study, we suggest that profiling of tumour parameters such as bioelectrical-potential and metabolites, detectable by electronic sensors, could facilitate the future development of devices to better monitor disease and predict surgical and treatment outcomes. Biopotential was recorded, using a potentiometric measurement system, in ex vivo paired non-cancerous and cancerous omental tissues from advanced stage EOC (n = 36), and lysates collected for metabolite measurement by microdialysis. Consistently different biopotential values were detected in cancerous tissue versus non-cancerous tissue across all cases (p < 0.001). High tumour biopotential levels correlated with advanced tumour stage (p = 0.048) and tumour load, and negatively correlated with stroma. Within our EOC cohort and specifically the high-grade serous subtype, low biopotential levels associated with poorer progression-free survival (p = 0.0179, p = 0.0143 respectively). Changes in biopotential levels significantly correlated with common apoptosis related pathways. Lactate and glucose levels measured in paired tissues showed significantly higher lactate/glucose ratio in tissues with low biopotential (p < 0.01, n = 12). Our study proposes the feasibility of biopotential and metabolite monitoring as a biomarker modality profiling EOC to predict surgical and clinical outcomes
The geometrical nature of optical resonances : from a sphere to fused dimer nanoparticles
We study the electromagnetic response of smooth gold nanoparticles with shapes varying from a single sphere to two ellipsoids joined smoothly at their vertices. We show that the plasmonic resonance visible in the extinction and absorption cross sections shifts to longer wavelengths and eventually disappears as the mid-plane waist of the composite particle becomes narrower. This process corresponds to an increase of the numbers of internal and scattering modes that are mainly confined to the surface and coupled to the incident field. These modes strongly affect the near field, and therefore are of great importance in surface spectroscopy, but are almost undetectable in the far field
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