Explore the vast range of titles available.

Quantum many-body systems display rich phase structure in their low-temperature equilibrium states 1 . However, much of nature is not in thermal equilibrium. Remarkably, it was recently predicted that out-of-equilibrium systems can exhibit novel dynamical phases 2 – 8 that may otherwise be forbidden by equilibrium thermodynamics, a paradigmatic example being the discrete time crystal (DTC) 7 , 9 – 15 . Concretely, dynamical phases can be defined in periodically driven many-body-localized (MBL) systems via the concept of eigenstate order 7 , 16 , 17 . In eigenstate-ordered MBL phases, the entire many-body spectrum exhibits quantum correlations and long-range order, with characteristic signatures in late-time dynamics from all initial states. It is, however, challenging to experimentally distinguish such stable phases from transient phenomena, or from regimes in which the dynamics of a few select states can mask typical behaviour. Here we implement tunable controlled-phase (CPHASE) gates on an array of superconducting qubits to experimentally observe an MBL-DTC and demonstrate its characteristic spatiotemporal response for generic initial states 7 , 9 , 10 . Our work employs a time-reversal protocol to quantify the impact of external decoherence, and leverages quantum typicality to circumvent the exponential cost of densely sampling the eigenspectrum. Furthermore, we locate the phase transition out of the DTC with an experimental finite-size analysis. These results establish a scalable approach to studying non-equilibrium phases of matter on quantum processors. A study establishes a scalable approach to engineer and characterize a many-body-localized discrete time crystal phase on a superconducting quantum processor.

Faster algorithms for combinatorial optimization could prove transformative for diverse areas such as logistics, finance and machine learning. Accordingly, the possibility of quantum enhanced optimization has driven much interest in quantum technologies. Here we demonstrate the application of the Google Sycamore superconducting qubit quantum processor to combinatorial optimization problems with the quantum approximate optimization algorithm (QAOA). Like past QAOA experiments, we study performance for problems defined on the planar connectivity graph native to our hardware; however, we also apply the QAOA to the Sherrington–Kirkpatrick model and MaxCut, non-native problems that require extensive compilation to implement. For hardware-native problems, which are classically efficient to solve on average, we obtain an approximation ratio that is independent of problem size and observe that performance increases with circuit depth. For problems requiring compilation, performance decreases with problem size. Circuits involving several thousand gates still present an advantage over random guessing but not over some efficient classical algorithms. Our results suggest that it will be challenging to scale near-term implementations of the QAOA for problems on non-native graphs. As these graphs are closer to real-world instances, we suggest more emphasis should be placed on such problems when using the QAOA to benchmark quantum processors.It is hoped that quantum computers may be faster than classical ones at solving optimization problems. Here the authors implement a quantum optimization algorithm over 23 qubits but find more limited performance when an optimization problem structure does not match the underlying hardware.

Students with autism spectrum disorder (ASD) are included in general education classes and expected to participate in general education content, such as mathematics. Yet, little research explores academically-based mathematics instruction for this population. This single subject alternating treatment design study explored the effectiveness of concrete (physical objects that can be manipulated) and virtual (3-D objects from the Internet that can be manipulated) manipulatives to teach single- and double-digit subtraction skills. Participants in this study included three elementary-aged students (ages ranging from 6 to 10) diagnosed with ASD. Students were selected from a clinic-based setting, where all participants received medically necessary intensive services provided via one-to-one, trained therapists. Both forms of manipulatives successfully assisted students in accurately and independently solving subtraction problem. However, all three students demonstrated greater accuracy and faster independence with the virtual manipulatives as compared to the concrete manipulatives. Beyond correctly solving the subtraction problems, students were also able to generalize their learning of subtraction through concrete and virtual manipulatives to more real-world applications.

AimSurgical aortic valve replacement (SAVR) improves survival in severe, symptomatic aortic stenosis (AS), but whether it fully restores life expectancy is uncertain. This study aimed to evaluate long-term relative survival following SAVR compared with the general population and identify predictors of any residual survival discrepancies.MethodA total of 1287 patients (median age 71 (63–77) years, 32% female) undergoing SAVR for ≥moderate AS were identified from the Western Australian Heart Valves Study database. Flexible parametric models were used to estimate relative survival.ResultsOver a median follow-up of 47 (23–81) months, 247 (19%) patients died. All‐cause 30‐day, 1‐year, 5‐year and 10-year relative survivals were 97.3%, 97.2%, 93.0% and 83.3%, respectively, compared with an age-matched, sex-matched and year-matched general population. Flexible multivariable modelling indicated impaired left ventricular ejection fraction (LVEF) (45%–60%, excess HR 1.97, 95% CI 1.11 to 3.51, p=0.02; 30%–45%, excess HR 2.40, 95% CI 1.24 to 4.64, p=0.01; <30%, excess HR 2.96, 95% CI 1.18 to 7.39, p=0.02), significant mitral regurgitation (MR) (excess HR 2.28, 95% CI 1.29 to 4.03, p=0.005), Indigenous status (excess HR 4.53, 95% CI 2.03 to 10.12, p<0.001), diabetes mellitus (excess HR 2.30, 95% CI 1.44 to 3.68, p<0.001), estimated glomerular filtration rate (eGFR) 30–59 mL/kg/1.73 m2 (excess HR 2.74, 95% CI 1.33 to 5.65, p=0.006) and eGFR 0–29 mL/kg/1.73 m2 (excess HR 5.75, 95% CI 2.36 to 13.99, p<0.001) were independently associated with long-term excess mortality relative to that of the national comparator, whereas age, sex, year of surgery, concomitant coronary artery bypass graft surgery and symptom status were not.ConclusionIn a contemporary population, relative survival following SAVR for significant AS was reduced compared with an age-matched, sex-matched and year-matched general population. Impaired LVEF, significant MR, Indigenous status, renal impairment and diabetes mellitus were independent predictors of long-term excess mortality. Timely intervention and optimised postoperative follow-up may be crucial for the restoration of normal life expectancy following SAVR.

Efforts to identify meaningful functional imaging-based biomarkers are limited by the ability to reliably characterize inter-individual differences in human brain function. Although a growing number of connectomics-based measures are reported to have moderate to high test-retest reliability, the variability in data acquisition, experimental designs, and analytic methods precludes the ability to generalize results. The Consortium for Reliability and Reproducibility (CoRR) is working to address this challenge and establish test-retest reliability as a minimum standard for methods development in functional connectomics. Specifically, CoRR has aggregated 1,629 typical individuals’ resting state fMRI (rfMRI) data (5,093 rfMRI scans) from 18 international sites, and is openly sharing them via the International Data-sharing Neuroimaging Initiative (INDI). To allow researchers to generate various estimates of reliability and reproducibility, a variety of data acquisition procedures and experimental designs are included. Similarly, to enable users to assess the impact of commonly encountered artifacts (for example, motion) on characterizations of inter-individual variation, datasets of varying quality are included. Design Type(s) Test-retest Reliability Measurement Type(s) nuclear magnetic resonance assay Technology Type(s) functional MRI scanner Factor Type(s) protocol Sample Characteristic(s) Homo sapiens • brain Machine-accessible metadata file describing the reported data (ISA-Tab format)

Abstract Aims Calcific aortic stenosis (CAS) is the most common heart valvulopathy in high-income countries. There is no known treatment for CAS other than replacement of the valve in severe, symptomatic disease. Observational studies and a small openlabel randomized trial have reported that vitamin K1 supplementation may reduce the progression rate of calcification and obstruction in CAS. Methods and results PASSPORT(ACTRN12622000447752) will be a prospective, randomized, double-blind, placebo-controlled clinical trial investigating if nutritional supplementation with 10 mg of vitamin K1 can reduce the rate of valvular calcification and haemodynamic progression in CAS. Patients identified to have mild or moderate CAS based on standard echocardiographic criteria will be randomized 1:1 to vitamin K1 10 mg per day or matched placebo, and followed-up for a mean period of 16 months, ranging from 12 to 21 months. The primary endpoint will be the difference in aortic valve calcification volume, measured by computed tomography aortic valve calcium score, from baseline to follow-up, and secondary endpoints will include the change in echocardiographic progression of CAS, including peak flow velocity, mean pressure gradient, and aortic valve area. The trial is registered with the Australian New Zealand. Clinical Trials Registry (ACTRN12622000447752). The trial has met its recruitment target of 108 participants. Conclusion PASSPORT will be prospective, randomized, double-blind clinical trial powered to demonstrate if oral supplementation with vitamin K1 reduces the progression of valvular calcification and echocardiographic severity of disease in patients with non-severe CAS. The trial results will have implications for the management of CAS, for which there is currently no medical treatment. Graphical Abstract Graphical Abstract

For Ukraine, this may not happen until major combat operations subside or end. Because of its large combat-tested military and geographical position, Ukraine could become one of NATO's most valuable members. In the Cold War, West Germany played a vital role in deterring aggression on the Central Front. In the Cold War, West Germany hosted a huge allied force presence. In Central and East European countries, democratic and economic development came so fast that many soon met the criteria of NATO's Open-Door admission policy - any European state able to contribute to North Atlantic security.

Abstract Aims Bioprosthetic valves are increasingly used for surgical aortic valve replacement (SAVR) in patients ≤ 70 years though the relative benefits compared to mechanical valve replacement remain uncertain. This study aims to compare mortality and other outcomes by prosthesis type for patients aged 50–70 years who received SAVR in a well-characterized Australian cohort. Methods and results Data were prospectively collected at the time of heart valve surgery and linked administrative outcome data. This analysis includes all patients aged 50–70 years who had SAVR in Western Australian public hospitals between 2010 and 2020. The primary endpoint was all-cause mortality. Secondary endpoints were cardiovascular mortality, separately and combined with admission for either non-fatal myocardial infarction or for non-fatal stroke (MACE), major bleeding, and days alive and out of hospital (DAOH). Outcomes, categorized by prosthesis type (mechanical or bioprosthetic), were compared using propensity matching. Within the initial cohort of 706 patients undergoing SAVR (mean age 62.5 years, SD 6), propensity score matching identified 149 patients each with mechanical or bioprosthetic valves. After adjustment, patients who received mechanical valves had lower all-cause mortality [adjusted hazard ratio (aHR) 0.51; 95% confidence interval (CI) 0.27–0.98; P = 0.04] and MACE (aHR 0.53; 95% CI 0.30–0.95; P = 0.03) during median follow-up of 3.6 years. Mechanical valves were associated with increased risk of major bleeding (aHR3.40; 95% CI 1.32–8.77; P = 0.01). There was no difference in risk of cardiovascular mortality, admissions for non-fatal MI, non-fatal stroke, or DAOH by prosthesis type. Conclusion Patients aged 50–70 years who underwent mechanical valve SAVR had lower risk of all-cause mortality and MACE compared with those who received a bioprosthesis, despite higher bleeding risk. Randomized comparisons are necessary to confirm these findings. Lay Summary What is already known on this topic? Bioprosthetic valves are increasingly used for surgical aortic valve replacement in patients ≤ 70 years though the relative benefits of this over mechanical valve replacement are uncertain. What does this study add? This study shows, using propensity score matching, that patients ≤ 70 years who received a mechanical aortic valve replacement had a lower risk of all-cause mortality when compared with those who received a bioprosthetic valve, despite the higher bleeding risk. How will this study affect research and practice? This study highlights the need for randomized control trials to determine which prosthesis type, mechanical or bioprosthetic, is more suitable for patients ≤ 70 years undergoing surgical aortic valve replacement. Graphical Abstract Graphical Abstract

Students with autism spectrum disorder (ASD) are included in general education classes and expected to participate in general education content, such as mathematics. Yet, little research explores academically-based mathematics instruction for this population. This single subject alternating treatment design study explored the effectiveness of concrete (physical objects that can be manipulated) and virtual (3-D objects from the Internet that can be manipulated) manipulatives to teach single- and double-digit subtraction skills. Participants in this study included three elementary-aged students (ages ranging from 6 to 10) diagnosed with ASD. Students were selected from a clinic-based setting, where all participants received medically necessary intensive services provided via one-to-one, trained therapists. Both forms of manipulatives successfully assisted students in accurately and independently solving subtraction problem. However, all three students demonstrated greater accuracy and faster independence with the virtual manipulatives as compared to the concrete manipulatives. Beyond correctly solving the subtraction problems, students were also able to generalize their learning of subtraction through concrete and virtual manipulatives to more real-world applications.