94 research outputs found

    Demonstration of a parity-time symmetry breaking phase transition using superconducting and trapped-ion qutrits

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    Scalable quantum computers hold the promise to solve hard computational problems, such as prime factorization, combinatorial optimization, simulation of many-body physics, and quantum chemistry. While being key to understanding many real-world phenomena, simulation of non-conservative quantum dynamics presents a challenge for unitary quantum computation. In this work, we focus on simulating non-unitary parity-time symmetric systems, which exhibit a distinctive symmetry-breaking phase transition as well as other unique features that have no counterpart in closed systems. We show that a qutrit, a three-level quantum system, is capable of realizing this non-equilibrium phase transition. By using two physical platforms - an array of trapped ions and a superconducting transmon - and by controlling their three energy levels in a digital manner, we experimentally simulate the parity-time symmetry-breaking phase transition. Our results indicate the potential advantage of multi-level (qudit) processors in simulating physical effects, where additional accessible levels can play the role of a controlled environment.Comment: 14 pages, 9 figure

    Family social environment in childhood and self-rated health in young adulthood

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    <p>Abstract</p> <p>Background</p> <p>Family social support, as a form of social capital, contributes to social health disparities at different age of life. In a life-course epidemiological perspective, the aims of our study were to examine the association between self-reported family social environment during childhood and self-reported health in young adulthood and to assess the role of family functioning during childhood as a potential mediating factor in explaining the association between family breakup in childhood and self-reported health in young adulthood.</p> <p>Methods</p> <p>We analyzed data from the first wave of the Health, Inequalities and Social Ruptures Survey (SIRS), a longitudinal health and socio-epidemiological survey of a random sample of 3000 households initiated in the Paris metropolitan area in 2005. Sample-weighted logistic regression analyses were performed to determine the association between the quality of family social environment in childhood and self-rated health (overall health, physical health and psychological well-being) in young adults (n = 1006). We used structural equation model to explore the mediating role of the quality of family functioning in childhood in the association between family breakup in childhood and self-rated health in young adulthood.</p> <p>Results</p> <p>The multivariate results support an association between a negative family social environment in childhood and poor self-perceived health in adulthood. The association found between parental separation or divorce in childhood and poor self-perceived health in adulthood was mediated by parent-child relationships and by having witnessed interparental violence during childhood.</p> <p>Conclusion</p> <p>These results argue for interventions that enhance family cohesion, particularly after family disruptions during childhood, to promote health in young adulthood.</p

    Application of medical and analytical methods in Lyme borreliosis monitoring

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    Lyme borreliosis (LB) is one of the most common tick-borne diseases in the northern hemisphere. It is a chronic inflammatory disease caused by the spirochaete Borrelia burgdorferi. In its early stages, pathological skin lesions, namely erythema chronicum migrans, appear. The lesions, usually localised at the site of the bite, may become visible from a few weeks up to 3 months after the infection. Predominant clinical symptoms of the disease also involve joint malfunctions and neurological or cardiac disorders. Lyme disease, in all its stages, may be successfully treated with antibiotics. The best results, however, are obtained in its early stages. In order to diagnose the disease, numerous medical or laboratory techniques have been developed. They are applied to confirm the presence of intact spirochaetes or spirochaete components such as DNA or proteins in tick vectors, reservoir hosts or patients. The methods used for the determination of LB biomarkers have also been reviewed. These biomarkers are formed during the lipid peroxidation process. The formation of peroxidation products generated by human organisms is directly associated with oxidative stress. Apart from aldehydes (malondialdehyde and 4-hydroxy-2-nonenal), many other unsaturated components such as isoprostenes and neuroprostane are obtained. The fast determination of these compounds in encephalic fluid, urine or plasma, especially in early stages of the disease, enables its treatment. Various analytical techniques which allow the determination of the aforementioned biomarkers have been reported. These include spectrophotometry as well as liquid and gas chromatography. The analytical procedure also requires the application of a derivatization step by the use of selected reagents

    EFFECT OF EXERCISE INTENSITY ON DIFFERENTIATED AND UNDIFFERENTIATED RATINGS OF PERCEIVED EXERTION DURING CYCLE AND TREADMILL EXERCISE IN RECREATIONALLY ACTIVE AND TRAINED WOMEN

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    The purpose of the study is to examine the effect of aerobic exercise intensity on components of the differentiated perceived exertion model in young women performing weight bearing and non-weight bearing aerobic exercise. Subjects were 18-25 yr old women who were recreationally active (n = 19; VO2max = 33.40 ml·kg-1·min-1) and trained (N = 22; VO2max = 43.3 ml·kg-1·min-1). Subjects underwent two graded exercise tests (GXT) on a treadmill and bike which were separated by 48 hours. RPE-Overall, -Legs, and -Chest, as well as oxygen uptake (VO2) and heart rate were recorded each minute. Individual regression analyses were used to identify RPE-Overall,-Legs, and -Chest at 40, 60, 80% VO2max/peak. Separate two factor (site (3) x intensity (3)) ANOVAs with repeated measures on site and intensity were computed for each training status. Furthermore, RPE responses were also examined with a one factor (site (3)) within subject ANOVA with repeated measure on site at the ventilatory breakpoint. For both the recreationally active and trained groups no significant differences were observed for RPE-Overall, -Legs, and -Chest during treadmill exercise. However, for cycling exercise results indicated that RPE-Legs was significantly greater at all exercise intensities than RPE-Overall and RPE-Chest for trained subjects while for recreationally active subjects RPE-Legs was only significantly higher at the highest exercise intensity. Responses at the ventilatory breakpoint during cycle exercise indicated that RPE-Legs was significantly greater than RPE-Chest and RPE-Overall for trained subjects but not for recreationally active subjects. Signal dominance was not observed at an intensity equivalent to the ventilatory breakpoint during treadmill exercise in either of the groups. In recreationally active and trained females signal dominance was demonstrated only during cycling exercise, but not during treadmill exercise. Signal integration could not be demonstrated during cycling and treadmill exercise at various intensitie
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