What is a quantum-mechanical 'weak value' the value of?

A so called 'weak value' of an observable in quantum mechanics (QM) may be obtained in a weak measurement + post-selection procedure on the QM system under study. Applied to number operators, it has been invoked in revisiting some QM paradoxes (e.g., the so called Three Box paradox and Hardy s paradox). This requires the weak value to be interpreted as a bona fide property of the system considered, a par with entities like operator mean values and eigenvalues. I question such an interpretation; it has no support in the basic axioms of quantum mechanics and it leads to unreasonable results in concrete situations

Restoration of scarred vocal folds with stem cell implantation: analyses in a xenograft model

Background: Tissue defects in the vocal fold (VF) caused by trauma, surgical procedures, post radiotherapy often heal with scar formation. The scar tissue causes stiffness of the lamina propria rendering disturbed viscoelastic properties to the VF. A scarred VF causes severe voice problems. Treatment is difficult and presently there is no treatment that heals VF scars. Objectives: The aims of this thesis were to evaluate if human stem cell transplantations have the potential to heal scarred VFs, and if transplanted stem cells regenerate lost tissue in scarred VFs. Study Design: Experimental xenograft model. Methods: The VFs of New Zealand rabbits were scarred by a 1.5–2 mm resection. Human embryonic (hESCs) or mesenchymal (hMSCs) stem cells were thereafter transplanted into the VFs. Analyses for grade of scaring, lamina propria (Lp) thickness, relative content of collagen type I, elastic and dynamic viscoelasticity (G', η'), fluorescence in situ hybridisation for detection of human cells, Verhoeff staining for detection of elastin, alcian blue staining for detection of hyaluronic acid, RT-PCR speciesspecific analysis for collagen type I, and for Nanog expression of pluripotency were performed. Results: Both transplanted hESCs (G’)(η') and hMSCs (G’) significantly improved the viscoelastic properties of the VFs, analyzed at one month. HMSCs also significantly reduced collagen type I content. At three months hMSC treatment significantly reduced both (G’) (η') and showed no significant differences to normal VFs. Also collagen type I content and Lp thickness were significantly reduced and were not significantly higher than in normal VFs. A clinic like setting was studied, where VFs were resected and left to spontaneously heal for 9 weeks. The established scar was thereafter excised, hMSCs transplanted in the wound, and the VFs were analyzed after another ten weeks. The hMSC transplanted VFs showed no significant difference in η', nor in G', nor in Lp-thickness compared to normal VFs, and all three parameters were significantly reduced compared with untreated scarred VFs. The transplanted hESCs showed after one month, by differentiation, regeneration of epithelium, muscle, cartilage and gland tissue in contact with corresponding rabbit native tissue. HMSCs did not differentiate or regenerate tissue. Pluripotent hESCs were shown to survive one month, and hMSCs survived four but not ten weeks in the rabbit VFs. The transplanted VFs showed no malignancy or teratoma formation. The immunosuppressant Tacrolimus used to reduce the host versus graft reaction suppressed the antiscaring effect of the transplanted hMSCs. Conclusion: Both human embryonic and mesenchymal stem cells have the potential to improve healing and to restore the rheological properties of scarred VFs. Human embryonic stem cells transplanted into scarred rabbit vocal folds differentiate and regenerate human tissue compatible with the surrounding native tissue

New wine in old bottles: Quantum measurement - direct, indirect, weak - with some applications

In this, partly pedagogical review, I attempt to give a self-contained overview of the basis of (non-relativistic) QM measurement theory expressed in density matrix formalism. The focus is on applications to the theory of weak measurement, as developed by Aharonov and Vaidman and their collaborators. Their development of weak measurement combined with what they call 'post-selection' - judiciously choosing not only the initial state of a system ('pre-selection') but also its final state - has received much attention recently. Not the least has it opened up new, fruitful experimental vistas, like novel approaches to amplification. But the approach has also attached to it some air of mystery. I will attempt to 'de-mystify' it by showing that (almost) all results can be derived in a straight-forward way from conventional QM. Among other things, I develop the formalism not only to first order but also to second order in the weak interaction responsible for the measurement. This also allows me to derive, more or less as a by-product, the master equation for the density matrix of an open system in interaction with an environment. One particular application I shall treat of the weak measurement is the so called Leggett-Garg inequalities, a k a 'Bell inequalities in time'. I also give an outline, even if rough, of some of the ingenious experiments that the work by Aharonov, Vaidman and collaborators has inspired. If anything is magic in the weak measurement + post-selection approach, it is the interpretation of the so called weak value of an observable. Is it a bona fide property of the system considered? I have no answer to this question; I shall only exhibit the pros and cons of the proposed interpretation.Comment: 65 pages, 8 figure

Perceived and anticipated discrimination in people with mental illness-An interview study.

Background. Studies on perceived discrimination of people with mental illness are largely lacking. The purpose of the study was to investigate perceived discrimination in a sample of users in contact with mental health services in Sweden. Methods. Interviews were conducted with 156 users, asking for perceived and anticipated discrimination during the last 2 years. Background characteristics were also collected. Results. Perceived discrimination was common. Highest frequencies were reported regarding family (54%), avoidance by people who knew about the mental illness (53%) and in making or keeping friends (50%). A majority of those anticipating discrimination regarding job or education seeking, or starting a close relationship did not report having been discriminated in these areas. Previous hospitalizations were associated with discrimination, and age with anticipated discrimination. Conclusions. Public stigma and self-stigma have been reported to have a number of negative consequences for people with mental illness. Discrimination is part of this complex situation and this study showed that this largely affects a number of individual life areas posing an obstacle for social integration. Anticipated discrimination or self-stigma was also prevalent and it is pointed out that this to a great extent is an obstacle on its own without being promoted by actual experiences of discrimination

The conservation value of forests can be predicted at the scale of 1 hectare

To conserve biodiversity, it is imperative to maintain and restore sufficient amounts of functional habitat networks. Therefore, the location of the remaining forests with natural structures and processes over landscapes and large regions is a key objective. Here we integrated machine learning (Random Forest) and open landscape data to scan all forest landscapes in Sweden with a 1 ha spatial resolution with respect to the relative likelihood of hosting High Conservation Value Forests. Using independent spatial stand- and plot-level validation data, we confirmed that our predictions correctly represent different levels of forest naturalness, from degraded to those with high and associated biodiversity conservation values. Given ambitious national and international conservation objectives and increasingly intensive forestry, our model and the resulting wall-to-wall mapping fill an urgent gap for assessing the achievement of evidence-based conservation targets, spatial planning, and designing forest landscape restoration.Decreased availability of plant substrate can explain the decline in autotrophic respiration at constant temperature during the night, according to a simple respiration model with two carbohydrate pools

A 2-year follow-up study of people with severe mental illness involved in psychosocial rehabilitation

Backgrounds. A focus on psychiatric rehabilitation in order to support recovery among persons with severe mental illness (SMI) has been given great attention in research and mental health policy, but less impact on clinical practice. Despite the potential impact of psychiatric rehabilitation on health and wellbeing, there is a lack of research regarding the model called the Psychiatric Rehabilitation Approach from Boston University (BPR). Aim: The aim was to investigate the outcome of the BPR intervention regarding changes in life situation, use of healthcare services, quality of life, health, psychosocial functioning and empowerment. Methods: The study has a prospective longitudinal design and the setting was seven mental health services who worked with the BPR in the county of Halland in Sweden. In total, 71 clients completed the assessment at baseline and of these 49 completed the 2-year follow-up assessments. Results: The most significant finding was an improved psychosocial functioning at the follow-up assessment. Furthermore, 65% of the clients reported that they had mainly or almost completely achieved their self-formulated rehabilitation goals at the 2-year follow-up. There were significant differences with regard to health, empowerment, quality of life and psychosocial functioning for those who reported that they had mainly/completely had achieved their self-formulated rehabilitation goals compared to those who reported that they only had to a small extent or not at all reached their goals. Conclusions: Our results indicate that the BPR approach has impact on clients' health, empowerment, quality of life and in particular concerning psychosocial functioning

Comparison of near-interface traps in Al2_2O3_3/4H-SiC and Al2_2O3_3/SiO2_2/4H-SiC structures

Aluminum oxide (Al2O3) has been grown by atomic layer deposition on n-type 4H-SiC with and without a thin silicon dioxide (SiO2) intermediate layer. By means of Capacitance Voltage and Thermal Dielectric Relaxation Current measurements, the interface properties have been investigated. Whereas for the samples with an interfacial SiO2 layer the highest near-interface trap density is found at 0.3 eV below the conduction band edge, Ec, the samples with only the Al2O3 dielectric exhibit a nearly trap free region close to Ec. For the Al2O3/SiC interface, the highest trap density appears between 0.4 to 0.6 eV below Ec. The results indicate the possibility for SiC-based MOSFETs with Al2O3 as the gate dielectric layer in future high performance devices.Comment: 3 figures. Applied Physics Letters, accepted for publicatio

Sheet-metal press line parameter tuning using a combined DIRECT and Nelder-Mead algorithm

It is a great challenge to obtain an efficient algorithm for global optimisation of nonlinear, nonconvex and high dimensional objective functions. This paper shows how the combination of DIRECT and Nelder-Mead algorithms can improve the efficiency in the parameter tuning of a sheet-metal press line. A combined optimisation algorithm is proposed that determines and utilises all local optimal points from DIRECT algorithm as Nelder-Mead starting points. To reduce the total optimisation time, all Nelder-Mead optimisations can be executed in parallel. Additionally, a Collision Inspection Method is implemented in the simulation model to reduce the evaluation time. Altogether, this results in an industrially useful parameter tuning method. Improvements of an increased production rate of 7% and 40% smoother robot motions have been achieved