597 research outputs found
Units of rotational information
Entanglement in angular momentum degrees of freedom is a precious resource
for quantum metrology and control. Here we study the conversions of this
resource, focusing on Bell pairs of spin-J particles, where one particle is
used to probe unknown rotations and the other particle is used as reference.
When a large number of pairs are given, we show that every rotated spin-J Bell
state can be reversibly converted into an equivalent number of rotated spin
one-half Bell states, at a rate determined by the quantum Fisher information.
This result provides the foundation for the definition of an elementary unit of
information about rotations in space, which we call the Cartesian refbit. In
the finite copy scenario, we design machines that approximately break down Bell
states of higher spins into Cartesian refbits, as well as machines that
approximately implement the inverse process. In addition, we establish a
quantitative link between the conversion of Bell states and the simulation of
unitary gates, showing that the fidelity of probabilistic state conversion
provides upper and lower bounds on the fidelity of deterministic gate
simulation. The result holds not only for rotation gates, but also to all sets
of gates that form finite-dimensional representations of compact groups. For
rotation gates, we show how rotations on a system of given spin can simulate
rotations on a system of different spin.Comment: 25 pages + appendix, 7 figures, new results adde
Development and test of a mini-Data Acquisition system for the High-Luminosity LHC upgrade of the ATLAS Monitored Drift Tube detector
New front-end electronics including ASICs and FPGA boards are under
development for the ATLAS Monitored Drift Tube (MDT) detector to handle the
large data rates and harsh environment expected at high-luminosity LHC runs. A
mobile Data Acquisition (miniDAQ) system is designed to perform integration
tests of these front-end electronics. In addition, it will be used for surface
commissioning of 96 small-radius MDT (sMDT) chambers and for integration and
commissioning of new front-end electronics on the present ATLAS MDT chambers.
Details of the miniDAQ hardware and firmware are described in this article. The
miniDAQ system is also used to read out new front-end electronics on an sMDT
prototype chamber using cosmic muons and results obtained are shown.Comment: 10 pages, 12 figure
DataAI-6G: A System Parameters Configurable Channel Dataset for AI-6G Research
With the acceleration of the commercialization of fifth generation (5G)
mobile communication technology and the research for 6G communication systems,
the communication system has the characteristics of high frequency, multi-band,
high speed movement of users and large antenna array. These bring many
difficulties to obtain accurate channel state information (CSI), which makes
the performance of traditional communication methods be greatly restricted.
Therefore, there has been a lot of interest in using artificial intelligence
(AI) instead of traditional methods to improve performance. A common and
accurate dataset is essential for the research of AI communication. However,
the common datasets nowadays still lack some important features, such as mobile
features, spatial non-stationary features etc. To address these issues, we give
a dataset for future 6G communication. In this dataset, we address these issues
with specific simulation methods and accompanying code processing
Personalized Estimate of Chemotherapy-Induced Nausea and Vomiting: Development and External Validation of a Nomogram in Cancer Patients Receiving Highly/Moderately Emetogenic Chemotherapy.
Chemotherapy-induced nausea and vomiting (CINV) is presented in over 30% of cancer patients receiving highly/moderately emetogenic chemotherapy (HEC/MEC). The currently recommended antiemetic therapy is merely based on the emetogenic level of chemotherapy, regardless of patient's individual risk factors. It is, therefore, critical to develop an approach for personalized management of CINV in the era of precision medicine.A number of variables were involved in the development of CINV. In the present study, we pooled the data from 2 multi-institutional investigations of CINV due to HEC/MEC treatment in Asian countries. Demographic and clinical variables of 881 patients were prospectively collected as defined previously, and 862 of them had full documentation of variables of interest. The data of 548 patients from Chinese institutions were used to identify variables associated with CINV using multivariate logistic regression model, and then construct a personalized prediction model of nomogram; while the remaining 314 patients out of China (Singapore, South Korea, and Taiwan) entered the external validation set. C-index was used to measure the discrimination ability of the model.The predictors in the final model included sex, age, alcohol consumption, history of vomiting pregnancy, history of motion sickness, body surface area, emetogenicity of chemotherapy, and antiemetic regimens. The C-index was 0.67 (95% CI, 0.62-0.72) for the training set and 0.65 (95% CI, 0.58-0.72) for the validation set. The C-index was higher than that of any single predictor, including the emetogenic level of chemotherapy according to current antiemetic guidelines. Calibration curves showed good agreement between prediction and actual occurrence of CINV.This easy-to-use prediction model was based on chemotherapeutic regimens as well as patient's individual risk factors. The prediction accuracy of CINV occurrence in this nomogram was well validated by an independent data set. It could facilitate the assessment of individual risk, and thus improve the personalized management of CINV
Impact of Different Vegetation Zones on the Velocity and Discharge of Open-Channel Flow
Different types of vegetation widely exist in rivers and wetlands. The vegetation will affect the ecological environment and flow process, thus becoming increasingly significant in river engineering and aquatic environmental management. Previous research on vegetated flow is mainly to understand the flow structure of open channels with fully covered one-layer vegetation. However, vegetation often grows along a river bank and co-exists in different heights. The present paper presents experimental results about the flow characteristics of an open-channel with two sides covered by differently layered vegetation, focusing on the effect of vegetation on the velocity distribution and discharge. Two heights of dowels in 10 cm and 20 cm were used to simulate rigid vegetation and arranged in a linear form on both sides of a channel bed under emergent and fully submerged flow conditions. The velocity at different positions was obtained using ADV (Acoustic Doppler Velocimetry). Measured results demonstrate that there exists a shear layer between free-flow and vegetated zones, indicating that the flow transition occurs between fast-moving flow in the free zone and slowly obstructed flow in the vegetated zone and induces a high shear layer and transverse coherent vortices near the interface. Furthermore, compared with the emergent condition, the discharge through the free-flow region slightly decreases under full submerged conditions while the discharge in the vegetated region increases, indicating that the vegetation does not significantly change the discharge percentage in the free region. These findings on differently-layered vegetation would help riparian management practices to maintain healthy ecological and habitat zones.</jats:p
Strategies for Improving Postpartum Contraception Compared With Routine Maternal Care: A Systematic Review and Meta-Analysis
Objectives: This study aimed to systematically review the effectiveness of service interventions for improving postpartum contraception, including contraceptive use, prevention of repeat pregnancies and induced abortions.Methods: A systematic literature search was conducted in three databases until June 2022 (PROSPERO registration CRD42022328349). Estimates of intervention effects from meta-analyses were represented as odds ratios (OR) with 95% confidence intervals (CI).Results: 16 studies with 14,289 participants were included, with four kinds of interventions recognized. Interventions effect in increasing use of contraceptives and decreasing rates of repeated pregnancy for up to 6 months postpartum (OR = 2.24, 0.06, 95% CI = 1.46–3.44, 0.02–0.22, respectively), with no significant associations with contraceptive use at 12 months postpartum, prevention of postpartum repeat pregnancies and induced abortions during 1 year after childbirth.Conclusion: We concluded that interventions impact the initiation of postpartum contraceptive use and prevention of repeat pregnancy with an overall certainty from low to moderate. These findings highlight the need for additional studies to integrate the beneficial effect of several interventions and then design more feasible strategies, which is important for the maternal and child healthcare systems
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