Strong converse exponents for a quantum channel discrimination problem and quantum-feedback-assisted communication

This paper studies the difficulty of discriminating between an arbitrary quantum channel and a "replacer" channel that discards its input and replaces it with a fixed state. We show that, in this particular setting, the most general adaptive discrimination strategies provide no asymptotic advantage over non-adaptive tensor-power strategies. This conclusion follows by proving a quantum Stein's lemma for this channel discrimination setting, showing that a constant bound on the Type I error leads to the Type II error decreasing to zero exponentially quickly at a rate determined by the maximum relative entropy registered between the channels. The strong converse part of the lemma states that any attempt to make the Type II error decay to zero at a rate faster than the channel relative entropy implies that the Type I error necessarily converges to one. We then refine this latter result by identifying the optimal strong converse exponent for this task. As a consequence of these results, we can establish a strong converse theorem for the quantum-feedback-assisted capacity of a channel, sharpening a result due to Bowen. Furthermore, our channel discrimination result demonstrates the asymptotic optimality of a non-adaptive tensor-power strategy in the setting of quantum illumination, as was used in prior work on the topic. The sandwiched Renyi relative entropy is a key tool in our analysis. Finally, by combining our results with recent results of Hayashi and Tomamichel, we find a novel operational interpretation of the mutual information of a quantum channel N as the optimal type II error exponent when discriminating between a large number of independent instances of N and an arbitrary "worst-case" replacer channel chosen from the set of all replacer channels.Comment: v3: 35 pages, 4 figures, accepted for publication in Communications in Mathematical Physic

Third Age Men's Experience of Fashion and Clothing: An Interpretative Phenomenological Analysis

This paper is set within the context of the current shift in focus around aging from an objective to a subjective stance, placing the emphasis on individuality (Bennett and Hodkinson; Powell and Gilbert) and resulting in the emergence and development of cultural gerontology. Human biographies have the potential to be interpreted through the relationships between personal and structural factors, and individual and collective experiences. Fashion and clothes, as communicators and mediators between self and society (Entwistle; Craik) can therefore be seen as key factors in understanding aging identities. Contemporary research on fashion and aging concentrates mainly on older women (Twigg). Whilst this research has told us much about how aging women experience fashion, it excludes the parallel considerations of aging men. This paper addresses this gap by presenting research that investigates how older men negotiate their aging bodies through the media of clothing and fashion. Data were collected via in-depth, semi-structured interviews with fve older men and were analyzed using Interpretative Phenomenological Analysis (IPA). The fndings reveal the experience of fashion and clothing of fve older men who, during their lives, have actively engaged with fashion, considered in the contexts of time, space, and “others” (Kaiser)

The normal 3D gleno-humeral relationship and anatomy of the glenoid planes

Knowledge of the normal and pathological three-dimensional (3D) gleno-humeral relationship is imperative when planning and performing a total shoulder arthroplasty. Currently, two-dimensional (2D) parameters are used to describe this anatomy and despite the fact that these 2D measurements have a wide distribution in the normal population, they are commonly accepted. This broad distribution can be explained on one hand by anatomical factors and on the other hand, by positional errors. A 3D CT-scan reconstruction and evaluation can overcome this shortcoming and can be used to determine more accurately the surgical planes on the normal and pathological shoulder joint. There is, however, no consensus on which references should be used when studying this 3D relationship. This thesis describes the normal 3D gleno-humeral relationship and the best glenoid plane to use in surgery, based on 3D CT-scan. Furthermore, a glenoid aiming device that can be of surgical help in the reconstruction of the normal glenoid anatomy was developed based on these measurements

Can an extracorporeal glenoid aiming device be used to optimize the position of the glenoid component in total shoulder arthroplasty?

Purpose: Successful total shoulder arthroplasty (TSA) requires a correct position of the glenoid component. This study compares the accuracy of the positioning with a new developed glenoid aiming device and virtual three-dimensional computed tomography (3D-CT) scan positioning. Materials and Methods: On 39 scapulas from cadavers, a K-wire (KDev) was positioned using the glenoid aiming device. It consists of glenoid components connected to the aiming device, which cover 150 degrees of the inferior glenoid circle, has a fixed version and inclination and is available with several different radii. The aiming device is stabilized at the most medial scapular point. The K-wire is drilled from the center of the glenoid component to this most medial point. All scapulas were also scanned with CT and 3D reconstructed. A virtual K-wire (Kct) was positioned in the center of the glenoid and in the scapular plane. Several parameters were compared. Radius of the chosen glenoid component (rDev) and the virtual radius of the glenoid circle (rCT), spinal scapular length with the device (SSLdev) and virtual (SSLct), version and inclination between KDev and Kct, difference between entry point and exit point ("Matsen"-point). Results: Mean rDev: 14 mm +/- 1.7 mm and mean rCT: 13.5 mm +/- 1.6 mm. There was no significant difference between SSLdev (110.6 mm +/- 7.5 mm) and SSLct (108 mm +/- 7.5 mm). The version of KDev and Kct was -2.53 degrees and -2.17 degrees and the inclination 111.29 degrees and 111.66 degrees, respectively. The distance between the "Matsen-point" device and CT was 1.8 mm. Conclusion: This glenoid aiming device can position the K-wire on the glenoid with great accuracy and can, therefore, be helpful to position the glenoid component in TSA. The level of evidence: II