Magnetic fields in circumstellar disks: The potential of Zeeman observations

Context. Recent high angular resolution polarimetric continuum observations of circumstellar disks provide new insights into their magnetic field. However, direct constraints are limited to the plane of sky component of the magnetic field. Observations of Zeeman split spectral lines are a potential approach to enhance these insights by providing complementary information. Aims. We investigate which constraints for magnetic fields in circumstellar disks can be obtained from Zeeman observations of the $113~\mathrm{GHz}$ CN lines. Furthermore, we analyze the requirements to perform these observations and their dependence on selected quantities. Methods. We simulate the Zeeman splitting with the radiative transfer (RT) code POLARIS (Reissl et al. 2016) extended by our Zeeman splitting RT extension ZRAD (Brauer et al. 2017), which is based on the line RT code Mol3D (Ober et al. 2015). Results. We find that Zeeman observations of the $113~\mathrm{GHz}$ CN lines provide significant insights into the magnetic field of circumstellar disks. However, with the capabilities of recent and upcoming instrument/observatories, even spatially unresolved observations would be challenging. Nevertheless, these observations are feasible for the most massive disks with a strong magnetic field and high abundance of CN/H. The most restrictive quantity is the magnetic field strength, which should be at least in the order of $\sim1~\mathrm{mG}$. In addition, the inclination of the disk should be around $60\deg$ to preserve the ability to derive the line-of-sight (LOS) magnetic field strength and to obtain a sufficiently high circularly polarized flux.Comment: 15 pages, 14 figure

Magnetic fields in molecular clouds: Limitations of the analysis of Zeeman observations

Context. Observations of Zeeman split spectral lines represent an important approach to derive the structure and strength of magnetic fields in molecular clouds. In contrast to the uncertainty of the spectral line observation itself, the uncertainty of the analysis method to derive the magnetic field strength from these observations is not been well characterized so far. Aims. We investigate the impact of several physical quantities on the uncertainty of the analysis method, which is used to derive the line-of-sight (LOS) magnetic field strength from Zeeman split spectral lines. Methods. We simulate the Zeeman splitting of the 1665 MHz OH line with the 3D radiative transfer (RT) extension ZRAD. This extension is based on the line RT code Mol3D (Ober et al. 2015) and has been developed for the POLArized RadIation Simulator POLARIS (Reissl et al. 2016). Results. Observations of the OH Zeeman effect in typical molecular clouds are not significantly affected by the uncertainty of the analysis method. We derived an approximation to quantify the range of parameters in which the analysis method works sufficiently accurate and provide factors to convert our results to other spectral lines and species as well. We applied these conversion factors to CN and found that observations of the CN Zeeman effect in typical molecular clouds are neither significantly affected by the uncertainty of the analysis method. In addition, we found that the density has almost no impact on the uncertainty of the analysis method, unless it reaches values higher than those typically found in molecular clouds. Furthermore, the uncertainty of the analysis method increases, if both the gas velocity and the magnetic field show significant variations along the line-of-sight. However, this increase should be small in Zeeman observations of most molecular clouds considering typical velocities of ~1 km/s.Comment: 9 pages, 6 figure

Guaranteed emergence of genuine entanglement in 3-qubit evolving systems

Multipartite entanglement has been shown to be of particular relevance for a better understanding and exploitation of the dynamics and flow of entanglement in multiparty systems. This calls for analysis aimed at identifying the appropriate processes that guarantee the emergence of multipartite entanglement in a wide range of scenarios. Here we carry on such analysis considering a system of two initially entangled qubits, one of which is let to interact with a third qubit according to an arbitrary unitary evolution. We establish necessary and sufficient conditions on the corresponding Kraus operators, to discern whether the evolved state pertains to either one of the classes of 3-qubit pure states that exhibit some kind of entanglement, namely biseparable, W-, and GHZ- genuine entangled classes. Our results provide a classification of the Kraus operators according to their capacity of producing 3-qubit entanglement, and pave the way for extending the analysis to larger systems and determining the particular interactions that must be implemented in order to create, enhance and distribute entanglement in a specific manner.Comment: Two new subsections included. Accepted for publication in The European Physical Journal

Age rationing and prudential lifespan account in Norman Daniels’ Just health

Could age be a valid criterion for rationing? In Just health, Norman Daniels argues that under certain circumstances age rationing is prudent, and therefore a morally permissible strategy to tackle the problem of resource scarcity. Crucial to his argument is the distinction between two problem-settings of intergenerational equity: equity among age groups and equity among birth cohorts. While fairness between age groups can involve unequal benefit treatment in different life stages, fairness between birth cohorts implies enjoying approximate equality in benefit ratios. Although both questions of fairness are distinct, the resolution of the one depends on resolution of the other. In this paper, I investigate whether Daniels’ account of age rationing could be defended as a fair way of setting limits to healthcare entitlements. I will focus on two main points. First, I will consider whether the age group problem could be resolved without appealing to a conception of the good. Second, I will demonstrate that the connection between the age group problem and the birth cohort problem runs deeper than Daniels initially thought—and that it ultimately suggests a method for prioritisation in problem solving strategies

Effect of TiO2 addition on structure, solubility and crystallisation of phosphate invert glasses for biomedical applications

NOTICE: this is the author’s version of a work that was accepted for publication in JOURNAL OF NON-CRYSTALLINE SOLIDS. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in JOURNAL OF NON-CRYSTALLINE SOLIDS, [VOL 356, ISSUE 44-49, (2001)] DOI: 10.1016/j.jnoncrysol.2010.03.02

Stakeholders' views on the use of psychotropic medication in older people: a systematic review.

BACKGROUND: psychotropic medication use has been shown to increase with age and has been associated with increased risk of falls, strokes and mortality. Various guidelines, regulations and tools have been developed to reduce inappropriate prescribing, but this remains high. In order to understand the reasons for this, we aimed to systematically review healthcare professionals', patients' and family caregivers' attitudes towards the use of psychotropic medication in older people. METHODS: a systematic literature search was carried out from inception to September 2020 using PUBMED, EMBASE, PsycINFO and CINAHL and hand-searching of reference lists. Included studies investigated stakeholder views on psychotropic in adults over the age of 65. Findings were thematically synthesised. RESULTS: overall, there was an acceptance of long-term psychotropic medication for older people both living in the community and in residential care. While healthcare professionals were aware of guidelines for the use of benzodiazepines and psychotropic medicines, they identified barriers to following them on individual, team and organisational levels. Alternative non-pharmacological approaches were not always available or accepted by patients. CONCLUSION: psychotropic medicine use in older adults remains a complex issue, which needs to be addressed on a broad level. Attitudes of older people and healthcare professionals encourage long-term use. Meanwhile, various internal and external factors act as barriers to the use of non-drug alternatives in this population. In order to reduce overprescribing of psychotropics, there is a need to increase the acceptability and accessibility of alternative interventions in both care homes and the community

Measuring Polynomial Invariants of Multi-Party Quantum States

We present networks for directly estimating the polynomial invariants of multi-party quantum states under local transformations. The structure of these networks is closely related to the structure of the invariants themselves and this lends a physical interpretation to these otherwise abstract mathematical quantities. Specifically, our networks estimate the invariants under local unitary (LU) transformations and under stochastic local operations and classical communication (SLOCC). Our networks can estimate the LU invariants for multi-party states, where each party can have a Hilbert space of arbitrary dimension and the SLOCC invariants for multi-qubit states. We analyze the statistical efficiency of our networks compared to methods based on estimating the state coefficients and calculating the invariants.Comment: 8 pages, 4 figures, RevTex4, v2 references update

On the Definition of Averagely Trapped Surfaces

Previously suggested definitions of averagely trapped surfaces are not well-defined properties of 2-surfaces, and can include surfaces in flat space-time. A natural definition of averagely trapped surfaces is that the product of the null expansions be positive on average. A surface is averagely trapped in the latter sense if and only if its area $A$ and Hawking mass $M$ satisfy the isoperimetric inequality $16\pi M^2 > A$, with similar inequalities existing for other definitions of quasi-local energy.Comment: 4 page