Rotational stabilization and destabilization of an optical cavity

We investigate the effects of rotation about the axis of an astigmatic two-mirror cavity on its optical properties. This simple geometry is the first example of an optical system that can be destabilized and, more surprisingly, stabilized by rotation. As such, it has some similarity with both the Paul trap and the gyroscope. We illustrate the effects of rotational (de)stabilization of a cavity in terms of the spatial structure and orbital angular momentum of its modes.Comment: 5 pages, 3 figures. Accepted for publication in Physical Review

Continuous mode cooling and phonon routers for phononic quantum networks

We study the implementation of quantum state transfer protocols in phonon networks, where in analogy to optical networks, quantum information is transmitted through propagating phonons in extended mechanical resonator arrays or phonon waveguides. We describe how the problem of a non-vanishing thermal occupation of the phononic quantum channel can be overcome by implementing optomechanical multi- and continuous mode cooling schemes to create a 'cold' frequency window for transmitting quantum states. In addition, we discuss the implementation of phonon circulators and switchable phonon routers, which rely on strong coherent optomechanical interactions only, and do not require strong magnetic fields or specific materials. Both techniques can be applied and adapted to various physical implementations, where phonons coupled to spin or charge based qubits are used for on-chip networking applications.Comment: 33 pages, 8 figures. Final version, a few minor changes and updated reference

The impact of participation restrictions on everyday life in long-term colorectal cancer survivors in the EnCoRe study:A mixed-method study

Purpose: Knowledge about long-term colorectal cancer (CRC) or treatment related health and functioning problems and on its impact on participation of CRC survivors in domestic life and in society is limited. We aimed to explore the nature and impact of cancer (treatment) related participation restrictions on everyday life of long-term CRC survivors, their current satisfaction with participation, and associations of health and functioning problems with participation satisfaction, using the International Classification of Functioning, Disability and Health (ICF) to comprehensively study participation.Method: Mixed-method study in 2-10 years post-diagnosis stage I-III CRC survivors (n = 151) from the cross-sectional part of the EnCoRe study. Participation restrictions were explored by semi-structured interviews in a subsample reporting participation restrictions (n = 10). Role functioning (SF36-Health Survey), fatigue (Checklist Individual Strength), and peripheral neuropathy symptoms (EORTC QLQ-CIPN20) were assessed in all participants and associations with self-reported participation satisfaction were analyzed by multivariable logistic regression models.Results: 19% of CRC survivors reported dissatisfaction with participation. Participation restrictions were reported for interpersonal relationships, work/employment, and social/civic life. CRC survivors reporting better physical and emotional role functioning were significantly less likely to be dissatisfied with their participation, whereas survivors reporting higher levels of fatigue or more peripheral neuropathy symptoms were more likely to be dissatisfied with participation.Conclusions: Colorectal cancer (treatment) related health and functioning problems negatively impacts the ability of nearly 1 in 5 long-term CRC survivors to participate in everyday life situations and their satisfaction with participation. Follow-up care needs to be able to identify and address these problems.</p

L'-band AGPM vector vortex coronagraph's first light on LBTI/LMIRCam

We present the first observations obtained with the L'-band AGPM vortex coronagraph recently installed on LBTI/LMIRCam. The AGPM (Annular Groove Phase Mask) is a vector vortex coronagraph made from diamond subwavelength gratings. It is designed to improve the sensitivity and dynamic range of high-resolution imaging at very small inner working angles, down to 0.09 arcseconds in the case of LBTI/LMIRCam in the L' band. During the first hours on sky, we observed the young A5V star HR\,8799 with the goal to demonstrate the AGPM performance and assess its relevance for the ongoing LBTI planet survey (LEECH). Preliminary analyses of the data reveal the four known planets clearly at high SNR and provide unprecedented sensitivity limits in the inner planetary system (down to the diffraction limit of 0.09 arcseconds).Comment: 9 pages, 4 figures, SPIE proceeding

Facile Synthesis of Tuneable Azophosphonium Salts

Azophosphonium salts have a facile synthesis and can be readily tuned at the para position of the aryl group and at the phosphorus position with the use of bulky phosphines, leading to a range of coloured compounds. A relation between the Hammett sigma(+)(para) constant and the colour and P-31 NMR chemical shift was explored. The compounds were characterised by NMR spectroscopy, UV/Vis spectroscopy and single-crystal X-ray structure crystallography.Peer reviewe

Practical robustness evaluation in radiotherapy - A photon and proton-proof alternative to PTV-based plan evaluation

Background and purpose: A planning target volume (PTV) in photon treatments aims to ensure that the clinical target volume (CTV) receives adequate dose despite treatment uncertainties. The underlying static dose cloud approximation (the assumption that the dose distribution is invariant to errors) is problematic in intensity modulated proton treatments where range errors should be taken into account as well. The purpose of this work is to introduce a robustness evaluation method that is applicable to photon and proton treatments and is consistent with (historic) PTV-based treatment plan evaluations. Materials and methods: The limitation of the static dose cloud approximation was solved in a multi-scenario simulation by explicitly calculating doses for various treatment scenarios that describe possible errors in the treatment course. Setup errors were the same as the CTV-PTV margin and the underlying theory of 3D probability density distributions was extended to 4D to include range errors, maintaining a 90% confidence level. Scenario dose distributions were reduced to voxel-wise minimum and maximum dose distributions; the first to evaluate CTV coverage and the second for hot spots. Acceptance criteria for CTV D98 and D2 were calibrated against PTV-based criteria from historic photon treatment plans. Results: CTV D98 in worst case scenario dose and voxel-wise minimum dose showed a very strong correlation with scenario average D98 (R-2 > 0.99). The voxel-wise minimum dose visualised CTV dose conformity and coverage in 3D in agreement with PTV-based evaluation in photon therapy. Criteria for CTV D98 and D2 of the voxel-wise minimum and maximum dose showed very strong correlations to PTV D98 and D2 (R-2 > 0.99) and on average needed corrections of -0.9% and +2.3%, respectively. Conclusions: A practical approach to robustness evaluation was provided and clinically implemented for PTV-less photon and proton treatment planning, consistent with PTV evaluations but without its static dose cloud approximation. (C) 2019 The Authors. Published by Elsevier B.V

Obstacles and Enablers on the Way towards Integrated Physical Activity Policies for Childhood Obesity Prevention: An Exploration of Local Policy Officials&apos; Views

Background. Limited physical activity (PA) is a risk factor for childhood obesity. In Netherlands, as in many other countries worldwide, local policy officials bear responsibility for integrated PA policies, involving both health and nonhealth domains. In practice, its development seems hampered. We explore which obstacles local policy officials perceive in their effort. Methods. Fifteen semistructured interviews were held with policy officials from health and nonhealth policy domains, working at strategic, tactic, and operational level, in three relatively large municipalities. Questions focused on exploring perceived barriers for integrated PA policies. The interviews were deductively coded by applying the Behavior Change Ball framework. Findings. Childhood obesity prevention appeared on the governmental agenda and all officials understood the multicausal nature. However, operational officials had not yet developed a tradition to develop integrated PA policies due to insufficient boundary-spanning skills and structural and cultural differences between the domains. Tactical level officials did not sufficiently support intersectoral collaboration and strategic level officials mainly focused on public-private partnerships. Conclusion. Developing integrated PA policies is a bottomup innovation process that needs to be supported by governmental leaders through better guiding organizational processes leading to such policies. Operational level officials can assist in this by making progress in intersectoral collaboration visible

Three years of harvest with the vector vortex coronagraph in the thermal infrared

For several years, we have been developing vortex phase masks based on sub-wavelength gratings, known as Annular Groove Phase Masks. Etched onto diamond substrates, these AGPMs are currently designed to be used in the thermal infrared (ranging from 3 to 13 {\mu}m). Our AGPMs were first installed on VLT/NACO and VLT/VISIR in 2012, followed by LBT/LMIRCam in 2013 and Keck/NIRC2 in 2015. In this paper, we review the development, commissioning, on-sky performance, and early scientific results of these new coronagraphic modes and report on the lessons learned. We conclude with perspectives for future developments and applications.Comment: To appear in SPIE proceedings vol. 990

Polypeptide-grafted macroporous polyHIPE by surface-initiated N-Carboxyanhydride (NCA) polymerization as a platform for bioconjugation

A new class of functional macroporous monoliths from polymerized high internal phase emulsion (polyHIPE) with tunable surface functional groups was developed by direct polypeptide surface grafting. In the first step, amino-functional polyHIPEs were obtained by the addition of 4-vinylbenzyl or 4-vinylbenzylphthalimide to the styrenic emulsion and thermal radical polymerization. The obtained monoliths present the expected open-cell morphology and a high surface area. The incorporated amino group was successfully utilized to initiate the ring-opening polymer- ization of benzyl-L-glutamate N-carboxyanhydride (BLG NCA) and benzyloxycarbonyl-L-lysine (Lys(Z)) NCA, which resulted in a dense homogeneous coating of polypeptides throughout the internal polyHIPE surfaces as confirmed by SEM and FTIR analysis. The amount of polypeptide grafted to the polyHIPE surfaces could be modulated by varying the initial ratio of amino acid NCA to amino-functional polyHIPE. Subsequent removal of the polypeptide protecting groups yielded highly functional polyHIPE-g-poly(glutamic acid) and polyHIPE-g- poly(lysine). Both types of polypeptide-grafted monoliths responded to pH by changes in their hydrohilicity. The possibility to use the high density of function (−COOH or −NH2) for secondary reaction was demonstrated by the successful bioconjugation of enhanced green fluorescent protein (eGFP) and fluorescein isocyanate (FITC) on the polymer 3D-scaffold surface. The amount of eGFP and FITC conjugated to the polypeptide-grafted polyHIPE was significantly higher than to the amino- functional polyHIPE, signifying the advantage of polypeptide grafting to achieve highly functional polyHIPEs