4,027 research outputs found
Properties of N=90 Isotones within the Mean Field Perspective
In recent years, the N=90 isotones have been investigated to a large extent
in relation to studies of quantum phase transitions. In this paper, we use the
mean field approach with pairing-deformation self consistent Total Routhian
Surface (TRS) calculations to study the N=90 isotones and neigh- bouring
nuclei. The important probes, such as moments of inertia, quadrupole moments,
the energy ratio of E(4+1)/E(2+1), octupole and hexadecapole degrees of freedom
are considered and the cal- culated results are compared with the available
experimental data. From a microscopic point of view, the N=90 isotones
characterize the onset of the deformed region and are very well described by
mean field calculations. The results are compared with those from other studies
in beyond mean-field approximations. Shape coexistence phenomena in the region
of interest are discussed.Comment: 7 pages, 10 figure
Dichotomous Hamiltonians with Unbounded Entries and Solutions of Riccati Equations
An operator Riccati equation from systems theory is considered in the case
that all entries of the associated Hamiltonian are unbounded. Using a certain
dichotomy property of the Hamiltonian and its symmetry with respect to two
different indefinite inner products, we prove the existence of nonnegative and
nonpositive solutions of the Riccati equation. Moreover, conditions for the
boundedness and uniqueness of these solutions are established.Comment: 31 pages, 3 figures; proof of uniqueness of solutions added; to
appear in Journal of Evolution Equation
What makes health systems resilient? A qualitative analysis of the perspectives of Swiss NGOs
BACKGROUND: Resilience has become relevant than ever before with the advent of increasing and intensifying shocks on the health system and its amplified effects due to globalization. Using the example of non-state actors based in Switzerland, the aim of this study is to explore how and to what extent NGOs with an interest in global health have dealt with unexpected shocks on the health systems of their partner countries and to reflect on the practical implications of resilience for the multiple actors involved. Consequently, this paper analyses the key attributes of resilience that targeted investments may influence, and the different roles key stakeholders may assume to build resilience. METHODS: This is a descriptive and exploratory qualitative study analysing the perspectives on health system resilience of Swiss-based NGOs through 20 in-depth interviews. Analysis proceeded using a data-driven thematic analysis closely following the framework method. An analytical framework was developed and applied systematically resulting in a complete framework matrix. The results are categorised into the expected role of the governments, the role of the NGOs, and practical future steps for building health system resilience. RESULTS: The following four key 'foundations of resilience' were found to be dominant for unleashing greater resilience attributes regardless of the nature of shocks: 'realigned relationships,' 'foresight,' 'motivation,' and 'emergency preparedness.' The attribute to 'integrate' was shown to be one of the most crucial characteristics of resilience expected of the national governments from the NGOs, which points to the heightened role of governance. Meanwhile, as a key stakeholder group that is becoming inevitably more powerful in international development cooperation and global health governance, non-state actors namely the NGOs saw themselves in a unique position to facilitate knowledge exchange and to support long-term adaptations of innovative solutions that are increasing in demand. The strongest determinant of resilience in the health system was the degree of investments made for building long-term infrastructures and human resource development which are well-functioning prior to any potential crisis. CONCLUSIONS: Health system resilience is a collective endeavour and a result of many stakeholders' consistent and targeted investments. These investments open up new opportunities to seek innovative solutions and to keep diverse actors in global health accountable. The experiences and perspectives of Swiss NGOs in this article highlight the vital role NGOs may play in building resilient health systems in their partner countries. Specifically, strong governance, a bi-directional knowledge exchange, and the focus on leveraging science for impact can draw greater potential of resilience in the health systems. Governments and the NGOs have unique points of contribution in this journey towards resilience and bear the responsibility to support governments to prioritise investing in the key 'foundations of resilience' in order to activate greater attributes of resilience. Resilience building will not only prepare countries for future shocks but bridge the disparate health and development agenda in order to better address the nexus between humanitarian aid and development cooperation
Improving the Quality of Life of Patients With Medical Devices by a Timely Analysis of Adverse Events
Implanted and non-implanted medical devices, including artificial joints, are widely accepted to improve the quality of life of patients. While implant survival rates of over 80% can be accepted for artificial joints, there is still a large need to achieve higher survival rates at 15 years or longer to reduce the need for revisions due to implant failure before the end of the patient's life. Therefore, artificial joints are constantly improved with design changes and new designs, including modified or new materials. Most of these improvements perform as expected, but there are still cases where previously unknown failures occur, requiring premature revisions. A few examples of such unsuccessful improvements in the last 20 years are mentioned in this technical case report. The main focus of this paper is on an acetabular cup that was recalled due to unexpected revisions after a few weeks to a few months in vivo. The main reason for the revisions were small amounts of an oily residue containing endotoxins trapped inside the porous coating applied to the cup to facilitate bone ingrowth. The cup was recalled within 4 months after the company become aware of the problem, and prior to knowing exactly why the cups were failing early. The root cause analysis took several more months to complete. The lessons learned during the analysis are discussed so that similar events in other implantable medical devices can be avoided. The acetabular cup case aims to highlight that a timely root cause analysis, triggered by very few unexplained revisions, will benefit patients and improve the quality of life
Calculation of the spectrum of 12Li by using the multistep shell model method in the complex energy plane
The unbound nucleus Li is evaluated by using the multistep shell model
in the complex energy plane assuming that the spectrum is determined by the
motion of three neutrons outside the Li core. It is found that the ground
state of this system consists of an antibound state and that only this
and a and a excited states are physically meaningful
resonances.Comment: 9 pages, 5 tables, 7 figures, printer-friendly versio
Alpha Decay Hindrance Factors: A Probe of Mean Field Wave Functions
A simple model to calculate alpha-decay Hindrance Factors is presented. Using
deformation values obtained from PES calculations as the only input, Hindrance
Factors for the alpha-decay of Rn- and Po-isotopes are calculated. It is found
that the intrinsic structure around the Fermi surface determined by the
deformed mean field plays an important role in determining the hindrance of
alpha-decay. The fair agreement between experimental and theoretical Hindrance
Factors suggest that the wave function obtained from the energy minima of the
PES calculations contains an important part of the correlations that play a
role for the alpha-decay. The calculated HF that emerges from these
calculations render a different interpretation than the commonly assumed
n-particle n-hole picture.Comment: 7 pages, 9 figure
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