Dissipation-induced continuous quantum error correction for superconducting circuits

Quantum error correction (QEC) is a crucial step towards long coherence times required for efficient quantum information processing (QIP). One major challenge in this direction concerns the fast real-time analysis of error syndrome measurements and the associated feedback control. Recent proposals on autonomous QEC (AQEC) have opened new perspectives to overcome this difficulty. Here, we design an AQEC scheme based on quantum reservoir engineering adapted to superconducting qubits. We focus on a three-qubit bit-flip code, where three transmon qubits are dispersively coupled to a few low-Q resonator modes. By applying only continuous-wave drives of fixed but well-chosen frequencies and amplitudes, we engineer an effective interaction Hamiltonian to evacuate the entropy created by eventual bit-flip errors. We provide a full analytical and numerical study of the protocol, while introducing the main limitations on the achievable error correction rates.Comment: 9 pages, 6 figure

Involvement of palliative care in euthanasia practice in a context of legalized euthanasia : a population-based mortality follow-back study

Background: In the international debate about assisted dying, it is commonly stated that euthanasia is incompatible with palliative care. In Belgium, where euthanasia was legalized in 2002, the Federation for Palliative Care Flanders has endorsed the viewpoint that euthanasia can be embedded in palliative care. Aim: To examine the involvement of palliative care services in euthanasia practice in a context of legalized euthanasia. Design: Population-based mortality follow-back survey. Setting/participants: Physicians attending a random sample of 6871 deaths in Flanders, Belgium, in 2013. Results: People requesting euthanasia were more likely to have received palliative care (70.9%) than other people dying non-suddenly (45.2%) (odds ratio=2.1 (95% confidence interval, 1.5-2.9)). The most frequently indicated reasons for non-referral to a palliative care service in those requesting euthanasia were that existing care already sufficiently addressed the patient's palliative and supportive care needs (56.5%) and that the patient did not want to be referred (26.1%). The likelihood of a request being granted did not differ between cases with or without palliative care involvement. Palliative care professionals were involved in the decision-making process and/or performance of euthanasia in 59.8% of all euthanasia deaths; this involvement was higher in hospitals (76.0%) than at home (47.0%) or in nursing homes (49.5%). Conclusion: In Flanders, in a context of legalized euthanasia, euthanasia and palliative care do not seem to be contradictory practices. A substantial proportion of people who make a euthanasia request are seen by palliative care services, and for a majority of these, the request is granted

Descriptions of euthanasia as social representations: comparing the views of Finnish physicians and religious professionals

In many western societies health professionals play a powerful role in people's experiences of dying. Religious professionals, such as pastors, are also confronted with the issues surrounding death and dying in their work. It is therefore reasonable to assume that the ways in which death-related topics, such as euthanasia, are constructed in a given culture are affected by the views of these professionals. This qualitative study addresses the ways in which Finnish physicians and religious professionals perceive and describe euthanasia and conceptualises these descriptions and views as social representations. Almost all the physicians interviewed saw that euthanasia does not fit the role of a physician and anchored it to different kinds of risks such as the slippery slope. Most of the religious and world-view professionals also rejected euthanasia. In this group, euthanasia was rejected on the basis of a religious moral code that forbids killing. Only one of the religious professionals - the freethinker with an atheist world-view - accepted euthanasia and described it as a personal choice, as did the one physician interviewed who accepted it. The article shows how the social representations of euthanasia are used to protect professional identities and to justify their expert knowledge of death and dying

Trends in continuous deep sedation until death between 2007 and 2013 : a repeated nationwide survey

Background: Continuous deep sedation until death is a highly debated medical practice, particularly regarding its potential to hasten death and its proper use in end-of-life care. A thorough analysis of important trends in this practice is needed to identify potentially problematic developments. This study aims to examine trends in the prevalence and practice characteristics of continuous deep sedation until death in Flanders, Belgium between 2007 and 2013, and to study variation on physicians’ degree of palliative training. Methods: Population-based death certificate study in 2007 and 2013 in Flanders, Belgium. Reporting physicians received questionnaires about medical practices preceding the patient’s death. Patient characteristics, clinical characteristics (drugs used, duration, artificial nutrition/hydration, intention and consent), and palliative care training of attending physician were recorded. We posed the following question regarding continuous deep sedation: ‘Was the patient continuously and deeply sedated or kept in a coma until death by the use of one or more drugs’. Results: After the initial rise of continuous deep sedation to 14.5% in 2007 (95%CI 13.1%-15.9%), its use decreased to 12.0% in 2013 (95%CI 10.9%-13.2%). Compared with 2007, in 2013 opioids were less often used as sole drug and the decision to use continuous deep sedation was more often preceded by patient request. Compared to non-experts, palliative care experts more often used benzodiazepines and less often opioids, withheld artificial nutrition/hydration more often and performed sedation more often after a request from or with the consent of the patient or family. Conclusion: Worldwide, this study is the first to show a decrease in the prevalence of continuous deep sedation. Despite positive changes in performance and decision-making towards more compliance with due care requirements, there is still room for improvement in the use of recommended drugs and in the involvement of patients and relatives in the decision-making process

Factors associated with the goal of treatment in the last week of life in old compared to very old patients: a population-based death certificate survey

Background: Little is known about the type of care older people of different ages receive at the end of life. The goal of treatment is an important parameter of the quality of end-of-life care. This study aims to provide an evaluation of the main goal of treatment in the last week of life of people aged 86 and older compared with those between 75 and 85 and to examine how treatment goals are associated with age. Methods: Population-based cross sectional survey in Flanders, Belgium. A stratified random sample of death certificates was drawn of people who died between 1 June and 30 November 2007. The effective study sample included 3,623 deaths (response rate: 58.4%). Non-sudden deaths of patients aged 75 years and older were selected (N = 1681). Main outcome was the main goal of treatment in the last week of life (palliative care or life-prolonging/curative treatment). Results: In patients older than 75, the main goal of treatment in the last week was in the majority of cases palliative care (77.9%). Patients between 75 and 85 more often received life-prolonging/curative treatment than older patients (26.6% vs. 15.8%). Most patient and health care characteristics are similarly related to the main goal of treatment in both age groups. The patient's age was independently related to having comfort care as the main goal of treatment. The main goal of treatment was also independently associated with the patient's sex, cause and place of death and the time already in treatment. Conclusion: Age is independently related to the main goal of treatment in the last week of life with people over 85 being more likely to receive palliative care and less likely to receive curative/life-prolonging treatment compared with those aged 75-85. This difference could be due to the patient's wishes but could also be the result of the attitudes of care givers towards the treatment of older people

Involvement of palliative care services strongly predicts place of death in Belgium

Introduction: Place of death is considered a quality indicator of end-of-life care and enabling people to die were they choose is an important aspiration of palliative care. This study aims to examine the association between involvement of palliative care services and place of death. Methods: Data about patient characteristics, use of general health care, and involvement of palliative care services in nonsudden or expected deaths in all health care settings in 2005-2006 (N = 1690) were collected by a surveillance network of general practitioners (GPs) in Belgium. Bivariate and multivariate associations between involvement of palliative care services and dying at home, in hospital, in a care home, or in a palliative care unit were examined using chi(2) tests and Wald tests. Results: Palliative care services were involved in 21.8% of deaths of those living at home, in 29.1% of those living in care homes, and in 12.4% of deaths in hospital. People were more likely to die in their usual residence rather than in hospital if multidisciplinary palliative home care teams (odds ratio [OR]: 8.4, confidence interval [CI]: 4.7-15.1) or the palliative care reference persons of their care home (OR: 9.4, CI: 3.3-26.7) were involved. Involvement of multidisciplinary palliative support teams in hospitals was associated with lower chances of dying at home (OR: 0.3, CI: 0.1-0.9). High involvement of GPs was not directly associated with out-of-hospital death. Discussion: Involving multidisciplinary palliative home care teams and palliative care reference persons in care homes could support people in dying out-of-hospital. Health care policy-makers should consider strategies to improve involvement of palliative care services in all health care settings

Improving end-of-life care in acute geriatric hospital wards using the Care Programme for the Last Days of Life : study protocol for a phase 3 cluster randomized controlled trial

Background: The Care Programme for the Last Days of Life has been developed to improve the quality of end-of-life care in acute geriatric hospital wards. The programme is based on existing end-of-life care programmes but modeled to the acute geriatric care setting. There is a lack of evidence of the effectiveness of end-of-life care programmes and the effects that may be achieved in patients dying in an acute geriatric hospital setting are unknown. The aim of this paper is to describe the research protocol of a cluster randomized controlled trial to evaluate the effects of the Care Programme for the Last Days of Life. Methods and design: A cluster randomized controlled trial will be conducted. Ten hospitals with one or more acute geriatric wards will conduct a one-year baseline assessment during which care will be provided as usual. For each patient dying in the ward, a questionnaire will be filled in by a nurse, a physician and a family carer. At the end of the baseline assessment hospitals will be randomized to receive intervention (implementation of the Care Programme) or no intervention. Subsequently, the Care Programme will be implemented in the intervention hospitals over a six-month period. A one-year post-intervention assessment will be performed immediately after the baseline assessment in the control hospitals and after the implementation period in the intervention hospitals. Primary outcomes are symptom frequency and symptom burden of patients in the last 48 hours of life. Discussion: This will be the first cluster randomized controlled trial to evaluate the effect of the Care Programme for the Last Days of Life for the acute geriatric hospital setting. The results will enable us to evaluate whether implementation of the Care Programme has positive effects on end-of-life care during the last days of life in this patient population and which components of the Care Programme contribute to improving the quality of end-of-life care

Storage of up-converted telecom photons in a doped crystal

We report on an experiment that demonstrates the frequency up-conversion of telecommunication wavelength single-photon-level pulses to be resonant with a $\mathrm{Pr}^{3+}$:$\mathrm{Y}_2\mathrm{Si}\mathrm{O}_5$ crystal. We convert the telecom photons at $1570\,\mathrm{nm}$ to $606\,\mathrm{nm}$ using a periodically-poled potassium titanyl phosphate nonlinear waveguide. The maximum device efficiency (which includes all optical loss) is inferred to be $\eta_{\mathrm{dev}}^{\mathrm{max}} = 22 \pm 1\,$ (internal efficiency $\eta_{\mathrm{int}} = 75\pm8\,$) with a signal to noise ratio exceeding 1 for single-photon-level pulses with durations of up to 560$\,$ns. The converted light is then stored in the crystal using the atomic frequency comb scheme with storage and retrieval efficiencies exceeding $\eta_{\mathrm{AFC}} = 20\,$ for predetermined storage times of up to $5\,\mu\mathrm{s}$. The retrieved light is time delayed from the noisy conversion process allowing us to measure a signal to noise ratio exceeding 100 with telecom single-photon-level inputs. These results represent the first demonstration of single-photon-level optical storage interfaced with frequency up-conversion

Euthanasia for people with psychiatric disorders or dementia in Belgium : analysis of officially reported cases

Background: Euthanasia for people who are not terminally ill, such as those suffering from psychiatric disorders or dementia, is legal in Belgium under strict conditions but remains a controversial practice. As yet, the prevalence of euthanasia for people with psychiatric disorders or dementia has not been studied and little is known about the characteristics of the practice. This study aims to report on the trends in prevalence and number of euthanasia cases with a psychiatric disorder or dementia diagnosis in Belgium and demographic, clinical and decision-making characteristics of these cases. Methods: We analysed the anonymous databases of euthanasia cases reported to the Federal Control and Evaluation Committee Euthanasia from the implementation of the euthanasia law in Belgium in 2002 until the end of 2013. The databases we received provided the information on all euthanasia cases as registered by the Committee from the official registration forms. Only those with one or more psychiatric disorders or dementia and no physical disease were included in the analysis. Results: We identified 179 reported euthanasia cases with a psychiatric disorder or dementia as the sole diagnosis. These consisted of mood disorders (N = 83), dementia (N = 62), other psychiatric disorders (N = 22) and mood disorders accompanied by another psychiatric disorder (N = 12). The proportion of euthanasia cases with a psychiatric disorder or dementia diagnosis was 0.5% of all cases reported in the period 2002-2007, increasing from 2008 onwards to 3.0% of all cases reported in 2013. The increase in the absolute number of cases is particularly evident in cases with a mood disorder diagnosis. The majority of cases concerned women (58.1% in dementia to 77.1% in mood disorders). All cases were judged to have met the legal requirements by the Committee. Conclusions: While euthanasia on the grounds of unbearable suffering caused by a psychiatric disorder or dementia remains a comparatively limited practice in Belgium, its prevalence has risen since 2008. If, as this study suggests, people with psychiatric conditions or dementia are increasingly seeking access to euthanasia, the development of practice guidelines is all the more desirable if physicians are to respond adequately to these highly delicate requests

Is individual educational level related to end-of-life care use? : results from a nationwide retrospective cohort study in Belgium

Background: Educational level has repeatedly been identified as an important determinant of access to health care, but little is known about its influence on end-of-life care use. Objectives: To examine the relationship between individual educational attainment and end-of-life care use and to assess the importance of individual educational attainment in explaining differential end-of-life care use. Research Design: A retrospective cohort study via a nationwide sentinel network of general practitioners (GPs; SENTI-MELC Study) provided data on end-of-life care utilization. Multilevel analysis was used to model the association between educational level and health care use, adjusting for individual and contextual confounders based upon Andersen's behavioral model of health services use. Subjects: A Belgian nationwide representative sample of people who died not suddenly in 2005-2007. Results: In comparison to their less educated counterparts, higher educated people equally often had a palliative treatment goal but more often used multidisciplinary palliative care services (odds ratios [OR] for lower secondary education 1.28 [1.04-1.59] and for higher [secondary] education: 1.31 [1.02-1.68]), moved between care settings more frequently (OR: 1.68 [1.13-2.48] for lower secondary education and 1.51 [0.93-2.48] for higher [secondary] education) and had more contacts with the GP in the final 3 months of life. Conclusions: Less well-educated people appear to be disadvantaged in terms of access to specialist palliative care services, and GP contacts at the end of life, suggesting a need for empowerment of less well-educated terminally ill people regarding specialist palliative and general end-of-life care use