Matroids and Quantum Secret Sharing Schemes

A secret sharing scheme is a cryptographic protocol to distribute a secret state in an encoded form among a group of players such that only authorized subsets of the players can reconstruct the secret. Classically, efficient secret sharing schemes have been shown to be induced by matroids. Furthermore, access structures of such schemes can be characterized by an excluded minor relation. No such relations are known for quantum secret sharing schemes. In this paper we take the first steps toward a matroidal characterization of quantum secret sharing schemes. In addition to providing a new perspective on quantum secret sharing schemes, this characterization has important benefits. While previous work has shown how to construct quantum secret sharing schemes for general access structures, these schemes are not claimed to be efficient. In this context the present results prove to be useful; they enable us to construct efficient quantum secret sharing schemes for many general access structures. More precisely, we show that an identically self-dual matroid that is representable over a finite field induces a pure state quantum secret sharing scheme with information rate one

Preventing occupational chemical eye injuries: important lessons from poison information centres

BACKGROUND: Occupational exposure to hazardous substances is a major public health problem. In the workplace, eye exposures are common and can be a major cause of morbidity and disability. This commentary discusses the role of poison information centres in providing valuable information on the circumstances and causes of these incidents. OCCUPATIONAL HEALTH SURVEILLANCE: As many eye exposures are easily preventable, there is a need to establish better safety practices in the workplace. Currently, both governments and labour organizations primarily employ injury statistics for the purpose of occupational health surveillance. Identifying risk factors associated with acute exposures in the workplace requires a comprehensive approach using a variety of information resources. Using information from poison information centres can provide invaluable insight into the specifics of the exposure, including the route(s) of exposure, the substances involved and the cause of the exposure. CIRCUMSTANCES OF OCCUPATIONAL EYE EXPOSURES: Exposure to hazardous substances can occur at various time points during work. A prospective study performed by the Dutch Poisons Information Centre showed that cleaning is a high-risk activity for occupational eye exposure. Patients were often exposed to chemical mixtures that frequently contained alkalis or acids. CHEMICAL EYE INJURIES: Symptoms following eye contact with chemicals can vary greatly depending on factors such as the type and concentration of the substance(s) involved, the duration of exposure and the time and duration of irrigation (first-aid measure). Eye contact will usually cause irritation, but in more severe cases, chemical burns will result. Recent studies demonstrate that occupational eye exposures often result in only relatively mild symptoms, such as pain, redness, lacrimation or temporary loss of vision. More severe symptoms, such as corneal abrasion, were reported rarely, which may be explained by prompt eye irrigation. ROOT CAUSES OF OCCUPATIONAL EYE EXPOSURES: To control risks to workers, a hierarchy of prevention and control measures has been established, which employers must take. If elimination or substitution of the dangerous substance is not possible, the exposure can be prevented or reduced by taking organizational (e.g., providing work instructions), technical (e.g., ventilation) and personal (e.g., wearing personal protective equipment) measures. The study performed by the Dutch Poisons Information Centre showed that organizational factors (such as lack of work instructions) and personal factors (such as time pressure and fatigue, and not (adequately) using personal protective equipment), were the main causes of occupational eye exposure. CONCLUSIONS: Poison information centres provide valuable information that can be used to develop prevention strategies to reduce the number of acute occupational exposures in the future. A multidisciplinary approach is essential to ensure that these preventive measures are actually applied in practice. Therefore, all organizations involved (including governments, labour organizations, medical professionals, occupational physicians, occupational hygienists, safety experts and poison information centres) must work closely together

Two Decades of Research on Euthanasia from the Netherlands. What Have We Learnt and What Questions Remain?

Two decades of research on euthanasia in the Netherlands have resulted into clear insights in the frequency and characteristics of euthanasia and other medical end-of-life decisions in the Netherlands. These empirical studies have contributed to the quality of the public debate, and to the regulating and public control of euthanasia and physician-assisted suicide. No slippery slope seems to have occurred. Physicians seem to adhere to the criteria for due care in the large majority of cases. Further, it has been shown that the majority of physicians think that the euthanasia Act has improved their legal certainty and contributes to the carefulness of life-terminating acts. In 2005, eighty percent of the euthanasia cases were reported to the review committees. Thus, the transparency envisaged by the Act still does not extend to all cases. Unreported cases almost all involve the use of opioids, and are not considered to be euthanasia by physicians. More education and debate is needed to disentangle in these situations which acts should be regarded as euthanasia and which should not. Medical end-of-life decision-making is a crucial part of end-of-life care. It should therefore be given continuous attention in health care policy and medical training. Systematic periodic research is crucial for enhancing our understanding of end-of-life care in modern medicine, in which the pursuit of a good quality of dying is nowadays widely recognized as an important goal, in addition to the traditional goals such as curing diseases and prolonging life

Evaluation of Human Interindividual Variation in Bioactivation of Estragole Using Physiologically Based Biokinetic Modeling

The present study investigates interindividual variation in liver levels of the proximate carcinogenic metabolite of estragole, 1′-hydroxyestragole, due to variation in two key metabolic reactions involved in the formation and detoxification of this metabolite, namely 1′-hydroxylation of estragole and oxidation of 1′-hydroxyestragole. Formation of 1′-hydroxyestragole is predominantly catalyzed by P450 1A2, 2A6, and 2E1, and results of the present study support that oxidation of 1′-hydroxyestragole is catalyzed by 17β-hydroxysteroid dehydrogenase type 2 (17β-HSD2). In a first approach, the study defines physiologically based biokinetic (PBBK) models for 14 individual human subjects, revealing a 1.8-fold interindividual variation in the area under the liver concentration-time curve (AUC) for 1′-hydroxyestragole within this group of human subjects. Variation in oxidation of 1′-hydroxyestragole by 17β-HSD2 was shown to result in larger effects than those caused by variation in P450 enzyme activity. In a second approach, a Monte Carlo simulation was performed to evaluate the extent of variation in liver levels of 1′-hydroxyestragole that could occur in the population as a whole. This analysis could be used to derive a chemical-specific adjustment factor (CSAF), which is defined as the 99th percentile divided by the 50th percentile of the predicted distribution of the AUC of 1′-hydroxyestragole in the liver. The CSAF was estimated to range between 1.6 and 4.0, depending on the level of variation that was taken into account for oxidation of 1′-hydroxyestragole. Comparison of the CSAF to the default uncertainty factor of 3.16 for human variability in biokinetics reveals that the default uncertainty factor adequately protects 99% of the populatio

FALCO simulations of high-contrast polarimetry with the Nancy Grace Roman Space Telescope Coronagraph Instrument

The Coronagraph Instrument of the Nancy Grace Roman Space Telescope (Roman Coronagraph) will be capable of both total intensity and polarization measurements of circumstellar disks. The polarimetric performance is impacted by polarization effects introduced by all mirrors before the Wollaston prisms. In this paper, we aim to characterize these effects for the Roman Coronagraph in bands 1 and 4 using the FALCO and PROPER packages. We simulate the effect of polarization aberrations that impact the polarimetric contrast and the instrumental polarization effects to study the polarimetric accuracy. We include spacecraft rolls, but leave out systematic camera noise. We find that polarimetric differential imaging (PDI) improves the contrast by a factor of six. The PDI contrast of $\sim 8 \times 10^{-11}$ is limited by polarized speckles from instrumental polarization effects and polarization aberrations. By injecting polarized companions with at various contrast levels and demodulating their polarimetric signal, we recover their source Stokes vector within 2%.Comment: 16 pages, 16 figures, SPIE Optics + Photonics - Techniques and Instrumentation for Detection of Exoplanets X

Use of Physiologically Based Biokinetic (PBBK) Modeling to Study Estragole Bioactivation and Detoxification in Humans as Compared with Male Rats

The extent of bioactivation of the herbal constituent estragole to its ultimate carcinogenic metabolite 1′-sulfooxyestragole depends on the relative levels of bioactivation and detoxification pathways. The present study investigated the kinetics of the metabolic reactions of both estragole and its proximate carcinogenic metabolite 1′-hydroxyestragole in humans in incubations with relevant tissue fractions. Based on the kinetic data obtained a physiologically based biokinetic (PBBK) model for estragole in human was defined to predict the relative extent of bioactivation and detoxification at different dose levels of estragole. The outcomes of the model were subsequently compared with those previously predicted by a PBBK model for estragole in male rat to evaluate the occurrence of species differences in metabolic activation. The results obtained reveal that formation of 1′-oxoestragole, which represents a minor metabolic route for 1′-hydroxyestragole in rat, is the main detoxification pathway of 1′-hydroxyestragole in humans. Due to a high level of this 1′-hydroxyestragole oxidation pathway in human liver, the predicted species differences in formation of 1′-sulfooxyestragole remain relatively low, with the predicted formation of 1′-sulfooxyestragole being twofold higher in human compared with male rat, even though the formation of its precursor 1′-hydroxyestragole was predicted to be fourfold higher in human. Overall, it is concluded that in spite of significant differences in the relative extent of different metabolic pathways between human and male rat there is a minor influence of species differences on the ultimate overall bioactivation of estragole to 1′-sulfooxyestragol

Risk factors for deliberate self-poisoning among children and adolescents in The Netherlands

INTRODUCTION: In the past decade, the number of deliberate self-poisonings involving young people has increased strongly worldwide. This study aimed to gain insight into risk factors associated with deliberate self-poisonings among children and adolescents reported to the Dutch Poisons Information Center. METHODS: A study was performed between 1 February 2022 and 31 January 2023 involving those aged 8-17 years of age with deliberate self-poisoning. Data were collected on patient characteristics (age, gender, body mass index and living situation) and exposure characteristics (type of toxicant, way of acquiring toxicant and day of exposure). RESULTS: The Dutch Poisons Information Center was consulted about 1,424 deliberate self-poisonings among children and adolescents (10-17 years old). A high percentage of patients were female (85 percent), had a body mass index classified as overweight/obese (27 percent) and lived in a mental healthcare facility (13 percent). Patients mainly exposed themselves to pharmaceuticals, especially over-the-counter medications such as paracetamol (46 percent) and ibuprofen (15 percent). Young people living with parents/caregivers had higher odds of ingesting prescription pharmaceuticals or over-the-counter medication, while those living in a mental healthcare facility were more likely to ingest household products, personal care products or foreign bodies (predominantly batteries). DISCUSSION: This study sheds light on the pervasive issue of deliberate self-poisoning among children and adolescents, advocating for poisoning prevention strategies and promoting mental health of youth. Limitations include reliance on self-reported data from patients and the absence of clinical outcome data. CONCLUSIONS: Female gender, a high body mass index and living in a mental healthcare facility are associated with in increased risk of deliberate self-poisonings in children and adolescents (10-17 years old). Prevention of deliberate self-poisonings among youth could focus on restricting access to medication and other potentially hazardous non-pharmaceuticals, such as household products and batteries, as well as limiting the sales of over-the-counter medication, especially paracetamol, to this young population

Atmospheric aerosol characterization with a ground-based SPEX spectropolarimetric instrument

Stars and planetary system

Attitudes towards terminal sedation: an empirical survey among experts in the field of medical ethics

BACKGROUND: "Terminal sedation" regarded as the use of sedation in (pre-)terminal patients with treatment-refractory symptoms is controversially discussed not only within palliative medicine. While supporters consider terminal sedation as an indispensable palliative medical treatment option, opponents disapprove of it as "slow euthanasia". Against this background, we interviewed medical ethics experts by questionnaire on the term and the moral acceptance of terminal sedation in order to find out how they think about this topic. We were especially interested in whether experts with a professional medical and nursing background think differently about the topic than experts without this background. METHODS: The survey was carried out by questionnaire; beside the provided answering options free text comments were possible. As test persons we chose the 477 members of the German Academy for Ethics in Medicine, an interdisciplinary society for medical ethics. RESULTS: 281 completed questionnaires were returned (response rate = 59%). The majority of persons without medical background regarded "terminal sedation" as an intentional elimination of consciousness until the patient's death occurs; persons with a medical background generally had a broader understanding of the term, including light or intermittent forms of sedation. 98% of the respondents regarded terminal sedation in dying patients with treatment-refractory physical symptoms as acceptable. Situations in which the dying process has not yet started, in which untreatable mental symptoms are the indication for terminal sedation or in which life-sustaining measures are withdrawn during sedation were evaluated as morally difficult. CONCLUSION: The survey reveals a great need for research and discussion on the medical indication as well as on the moral evaluation of terminal sedation. Prerequisite for this is a more precise terminology which describes the circumstances of the sedation

Significant Increase in Deliberate Self-Poisonings Among Adolescents During the Second Year of the COVID-19 Pandemic

PURPOSE: The COVID-19 pandemic has been associated with a decline in mental health of adolescents. The aim of this study was to analyze the rate of deliberate self-poisonings (DSPs) among adolescents reported to the Dutch Poisons Information Center before and during the COVID-19 pandemic. METHODS: A retrospective study from 2016 until 2021 was performed to characterize DSPs among adolescents, and to analyze trends in the number of DSPs. All DSPs among adolescents with the age of 13 up to and including 17 years were included. DSP characteristics included: age, gender, bodyweight, used substance, dose, and treatment advice. Trends in the number of DSPs were analyzed using time series decomposition and Seasonal Autoregressive Integrated Moving Average models. RESULTS: Six thousand nine hundred fifteen DSPs in adolescents were recorded from January first 2016 until December 31st 2021. Females were involved in 84% of adolescent DSPs. A strong increase in the number of DSPs was observed in 2021 (45% increase compared to 2020), which deviated from the predicted trend based on previous years. This increase was most prominent in 13-, 14-, and 15-year-old female adolescents. Commonly involved drugs were paracetamol, ibuprofen, methylphenidate, fluoxetine, and quetiapine. The contribution of paracetamol rose from 33% in 2019 to 40% in 2021. DISCUSSION: The strong increase in the number of DSPs during the second year of the COVID-19 pandemic suggests that long-term containment measures such as quarantines, lockdowns, and school closures may enhance self-harm behavior among adolescents, especially among younger females (13-15 years of age), with a preference for paracetamol as DSP substance