Perinatal Care in Canada

<p>Abstract</p> <p>Health Issue</p> <p>Canada's standard of perinatal care ranks among the highest in the world, but there is still room for improvement, both in terms of regional differences in care and global comparisons of approaches to care in Canada and elsewhere. Data from the Canadian Perinatal Surveillance System (CPSS) was used to evaluate morbidity and mortality among mothers and infants.</p> <p>Key Findings</p> <p>Maternal mortality rates in Canada dropped to 4.4 per 100,000 live births in 1993–1997 and are among the lowest in the world. Rates of Caesarean section increased from 15.3 per 100 deliveries in 1994 to 19.1 in 1997. Although the infant mortality rate in Canada is among the lowest in the world (5.3–8.8 per 1,000 live births 1990–2000), there are unacceptable disparities between subpopulations. In Aboriginal populations, rates of stillbirth and perinatal mortality are 2–2.5 times the Canadian average. There has been a steady increase in the proportion of births among older women who have the highest risk of preterm births and pregnancy complications.</p> <p>The increasing rate of multiple births has accelerated recently and is of concern as these carry a higher risk of complications and are associated with an increased risk of preterm birth. The costs to the health care system are likely to be high.</p> <p>Data Gaps and Recommendations</p> <p>CPSS data, including economic indicators, needs to be collected in a more timely and uniform manner across Canada. The CPSS should provide an evaluation of how well Canada fares in relation to international standards of perinatal care.</p

Stable nontrivial Z2 topology in ultrathin Bi (111) films: a first-principles study

Recently, there have been intense efforts in searching for new topological insulator (TI) materials. Based on first-principles calculations, we find that all the ultrathin Bi (111) films are characterized by a nontrivial Z2 number independent of the film thickness, without the odd-even oscillation of topological triviality as commonly perceived. The stable nontrivial Z2 topology is retained by the concurrent band gap inversions at multiple time-reversal-invariant k-points and associated with the intermediate inter-bilayer coupling of the multi-bilayer Bi film. Our calculations further indicate that the presence of metallic surface states in thick Bi(111) films can be effectively removed by surface adsorption.Comment: 5 pages, 3 figure

Transitions between the quantum Hall states and insulators induced by periodic potentials

Journal ArticleTransitions between two quantum Hall states or between a quantum Hall state and a Mott insulator induced by periodic potentials are studied in the 1 /TV expansion. The transitions are found to be continuous in the large-TV limit and are described by a critical point that depends on a real parameter 0, which is determined by the topological orders in the quantum Hall states involved in the transition. Some critical exponents and universal quantities are calculated in the large-TV limit and shown to be 0 dependent

Joint Channel-and-Data Estimation for Large-MIMO Systems with Low-Precision ADCs

The use of low precision (e.g., 1-3 bits) analog-to-digital convenors (ADCs) in very large multiple-input multiple-output (MIMO) systems is a technique to reduce cost and power consumption. In this context, nevertheless, it has been shown that the training duration is required to be {\em very large} just to obtain an acceptable channel state information (CSI) at the receiver. A possible solution to the quantized MIMO systems is joint channel-and-data (JCD) estimation. This paper first develops an analytical framework for studying the quantized MIMO system using JCD estimation. In particular, we use the Bayes-optimal inference for the JCD estimation and realize this estimator utilizing a recent technique based on approximate message passing. Large-system analysis based on the replica method is then adopted to derive the asymptotic performances of the JCD estimator. Results from simulations confirm our theoretical findings and reveal that the JCD estimator can provide a significant gain over conventional pilot-only schemes in the quantized MIMO system.Comment: 7 pages, 4 figure

A Novel Route for Preparation of Hollow Carbon Nanospheres Without Introducing Template

A newly developed route for the synthesis of hollow carbon nanospheres without introducing template under hydrothermal conditions was reported. Hollow carbon nanospheres with the diameter of about 100 nm were synthesized using alginate as reagent only. Many instruments were applied to characterize the morphologies and structures of carbon hollow nanospheres, such as XRD, TEM, and Raman spectroscopy. The possible formation and growth mechanism of carbon hollow spheres were discussed on the basis of the investigation of reaction influence factors, such as temperature, time, and content. The findings would be useful for the synthesis of more materials with hollow structure and for the potential use in many aspects. The loading of SnO2on the surface of carbon hollow spheres was processed, and its PL property was also characterized

A Novel Counterfactual Data Augmentation Method for Aspect-Based Sentiment Analysis

Aspect-based-sentiment-analysis (ABSA) is a fine-grained sentiment evaluation task, which analyzes the emotional polarity of the evaluation aspects. Generally, the emotional polarity of an aspect exists in the corresponding opinion expression, whose diversity has great impact on model's performance. To mitigate this problem, we propose a novel and simple counterfactual data augmentation method to generate opinion expressions with reversed sentiment polarity. In particular, the integrated gradients are calculated to locate and mask the opinion expression. Then, a prompt combined with the reverse expression polarity is added to the original text, and a Pre-trained language model (PLM), T5, is finally was employed to predict the masks. The experimental results shows the proposed counterfactual data augmentation method performs better than current augmentation methods on three ABSA datasets, i.e. Laptop, Restaurant, and MAMS.Comment: Camera-ready for ACML 202