Semi-supervised medical image segmentation using adversarial consistency learning and dynamic convolution network

© Copyright The Authors 2022. Popular semi-supervised medical image segmentation networks often suffer from error supervision from unlabeled data since they usually use consistency learning under different data perturbations to regularize model training. These networks ignore the relationship between labeled and unlabeled data, and only compute single pixel-level consistency leading to uncertain prediction results. Besides, these networks often require a large number of parameters since their backbone networks are designed depending on supervised image segmentation tasks. Moreover, these networks often face a high over-fitting risk since a small number of training samples are popular for semi-supervised image segmentation. To address the above problems, in this paper, we propose a novel adversarial self-ensembling network using dynamic convolution (ASE-Net) for semi-supervised medical image segmentation. First, we use an adversarial consistency training strategy (ACTS) that employs two discriminators based on consistency learning to obtain prior relationships between labeled and unlabeled data. The ACTS can simultaneously compute pixel-level and image-level consistency of unlabeled data under different data perturbations to improve the prediction quality of labels. Second, we design a dynamic convolution-based bidirectional attention component (DyBAC) that can be embedded in any segmentation network, aiming at adaptively adjusting the weights of ASE-Net based on the structural information of input samples. This component effectively improves the feature representation ability of ASE-Net and reduces the overfitting risk of the network. The proposed ASE-Net has been extensively tested on three publicly available datasets, and experiments indicate that ASE-Net is superior to state-of-the-art networks, and reduces computational costs and memory overhead. The code is available at: https://github.com/SUST-reynole/ASE-Net.Shaanxi Joint Laboratory of Artificial Intelligence (Grant Number: 2020SS-03); Natural Science Basic Research Program of Shaanxi (Grant Number: 2021JC-47); Key Research and Development Program of Shaanxi (Grant Number: 2022GY-436?2021ZDLGY08-07); 10.13039/501100001809-National Natural Science Foundation of China (Grant Number: 62271296, 61871259, 61861024)

Digitalisation for smarter cities: Moving from a static to a dynamic view

This paper presents a critical review of the literature on smart cities informed by a sociotechnical perspective that views ‘smart city development’ as a dynamic change process that extends to both the technological apparatus of the city and the social environment that produces, maintains and uses it. The conclusions from the review are summarised in six propositions. The propositions contest the mainstream discourse that often culminates in a utopian vision where data collection, processing, analysis and sharing provide solutions to all urban problems and provide direction for the future advancement of smart city research and practice. Using the propositions as guidelines to underpin a multidisciplinary approach, the paper sets out a relational perspective based on notions of boundary spanning, coordination and management that can shed light on previously overlooked aspects of smart city transitions.This work was supported by the Ove Arup Foundation and the Cambridge Centre for Smart Infrastructure and Construction – CSIC [grant reference: RG89525], Department of Engineering, University of Cambridge, Cambridge, United Kingdom

Tribo-induced catalytically active oxide surfaces enabling the formation of the durable and high-performance carbon-based tribofilms

Carbon-containing tribofilms have attracted significant interest in the lubrication research despite a scarcity of information on their high-temperature performance under severe boundary conditions. In this study, high-temperature lubrication of the carbon tribofilm produced from cyclopropane carboxylic acid (CPCa) and NiAl-layered double hydroxide (LDH) nanoparticles was evaluated. NiAl-LDH nanoparticles significantly enhanced the friction stability and antiwear performance of CPCa by over 90% at 50°C and 100°C, comparable to the benchmark zinc dialkyldithiophosphates (ZDDPs). The highly graphitic amorphous carbon tribofilms and the fine-grain intermediate tribolayer constructed by the thermal decomposition products of NiAl-LDH contributed to such excellent lubrication performance. This study paves a pathway in developing functional anti-wear additives for the durable and high-performance carbon-containing tribofilms at high temperatures

Dealing with missing standard deviation and mean values in meta-analysis of continuous outcomes: a systematic review

Background: Rigorous, informative meta-analyses rely on availability of appropriate summary statistics or individual participant data. For continuous outcomes, especially those with naturally skewed distributions, summary information on the mean or variability often goes unreported. While full reporting of original trial data is the ideal, we sought to identify methods for handling unreported mean or variability summary statistics in meta-analysis. Methods: We undertook two systematic literature reviews to identify methodological approaches used to deal with missing mean or variability summary statistics. Five electronic databases were searched, in addition to the Cochrane Colloquium abstract books and the Cochrane Statistics Methods Group mailing list archive. We also conducted cited reference searching and emailed topic experts to identify recent methodological developments. Details recorded included the description of the method, the information required to implement the method, any underlying assumptions and whether the method could be readily applied in standard statistical software. We provided a summary description of the methods identified, illustrating selected methods in example meta-analysis scenarios. Results: For missing standard deviations (SDs), following screening of 503 articles, fifteen methods were identified in addition to those reported in a previous review. These included Bayesian hierarchical modelling at the meta-analysis level; summary statistic level imputation based on observed SD values from other trials in the meta-analysis; a practical approximation based on the range; and algebraic estimation of the SD based on other summary statistics. Following screening of 1124 articles for methods estimating the mean, one approximate Bayesian computation approach and three papers based on alternative summary statistics were identified. Illustrative meta-analyses showed that when replacing a missing SD the approximation using the range minimised loss of precision and generally performed better than omitting trials. When estimating missing means, a formula using the median, lower quartile and upper quartile performed best in preserving the precision of the meta-analysis findings, although in some scenarios, omitting trials gave superior results. Conclusions: Methods based on summary statistics (minimum, maximum, lower quartile, upper quartile, median) reported in the literature facilitate more comprehensive inclusion of randomised controlled trials with missing mean or variability summary statistics within meta-analyses

Work Vs Study : Pengalaman Pelajar Sarjana Kaunseling Unimas Kohot Jabatan Ketua Menteri Sarawak

Kajian ini dijalankan untuk meneroka pengalaman kaunselor pelatih kohot JKM yang sedang mengikuti program Sarjana Kaunseling UNIMAS. Kajian ini berbentuk kualitatif terdiri daripada enam peserta kajian yang menerima Hadiah Latihan dalam Perkhidmatan Awam Negeri Sarawak. Kaedah kajian yang digunakan adalah temubual semi-berstruktur dan data dianalisis menggunakan Analisis Bertema. Hasil dapatan menunjukkan tema utama adalah berkaitan dengan faktor pengalak untuk melanjutkan pelajaran, kesediaan dan penyesuaian, isu dan cara mengatasi cabaran yang dihadapi. Implikasi serta cadangan penambahbaikan terhadap program serta penaja turut dibincangkan

The LKB1-salt-inducible kinase pathway functions as a key gluconeogenic suppressor in the liver

LKB1 is a master kinase that regulates metabolism and growth through adenosine monophosphate-activated protein kinase (AMPK) and 12 other closely related kinases. Liver-specific ablation of LKB1 causes increased glucose production in hepatocytes in vitro and hyperglycaemia in fasting mice in vivo. Here we report that the salt-inducible kinases (SIK1, 2 and 3), members of the AMPK-related kinase family, play a key role as gluconeogenic suppressors downstream of LKB1 in the liver. The selective SIK inhibitor HG-9-91-01 promotes dephosphorylation of transcriptional co-activators CRTC2/3 resulting in enhanced gluconeogenic gene expression and glucose production in hepatocytes, an effect that is abolished when an HG-9-91-01-insensitive mutant SIK is introduced or LKB1 is ablated. Although SIK2 was proposed as a key regulator of insulin-mediated suppression of gluconeogenesis, we provide genetic evidence that liver-specific ablation of SIK2 alone has no effect on gluconeogenesis and insulin does not modulate SIK2 phosphorylation or activity. Collectively, we demonstrate that the LKB1-SIK pathway functions as a key gluconeogenic gatekeeper in the liver

In utero exposure to 25-hydroxyvitamin D and risk of childhood asthma, wheeze, and respiratory tract infections: A meta-analysis of birth cohort studies

BACKGROUND: Studies of the associations between in utero 25-hydroxyvitamin D (25[OH]D) exposure and risk of childhood asthma, wheeze, and respiratory tract infections are inconsistent and inconclusive. OBJECTIVES: We sought to assess associations between 25(OH)D levels in cord blood or maternal venous blood and risk of offspring's asthma, wheeze, and respiratory tract infections. METHODS: Data were derived from PubMed, Embase, Google Scholar, references from relevant articles, and de novo results from published studies until December 2015. A random-effects meta-analysis was conducted among 16 birth cohort studies. RESULTS: Comparing the highest with the lowest category of 25(OH)D levels, the pooled odds ratios were 0.84 (95% CI, 0.70-1.01; P = .064) for asthma, 0.77 (95% CI, 0.58-1.03; P = .083) for wheeze, and 0.85 (95% CI, 0.66-1.09; P = .187) for respiratory tract infections. The observed inverse association for wheeze was more pronounced and became statistically significant in the studies that measured 25(OH)D levels in cord blood (0.43; 95% CI, 0.29-0.62; P < .001). CONCLUSIONS: Accumulated evidence generated from this meta-analysis suggests that increased in utero exposure to 25(OH)D is inversely associated with the risk of asthma and wheeze during childhood. These findings are in keeping with the results of 2 recently published randomized clinical trials of vitamin D supplementation during pregnancy

A review of physical supply and EROI of fossil fuels in China

This paper reviews China’s future fossil fuel supply from the perspectives of physical output and net energy output. Comprehensive analyses of physical output of fossil fuels suggest that China’s total oil production will likely reach its peak, at about 230 Mt/year (or 9.6 EJ/year), in 2018; its total gas production will peak at around 350 Bcm/year (or 13.6 EJ/year) in 2040, while coal production will peak at about 4400 Mt/year (or 91.9 EJ/year) around 2020 or so. In terms of the forecast production of these fuels, there are significant differences among current studies. These differences can be mainly explained by different ultimately recoverable resources assumptions, the nature of the models used, and differences in the historical production data. Due to the future constraints on fossil fuels production, a large gap is projected to grow between domestic supply and demand, which will need to be met by increasing imports. Net energy analyses show that both coal and oil and gas production show a steady declining trend of EROI (energy return on investment) due to the depletion of shallow-buried coal resources and conventional oil and gas resources, which is generally consistent with the approaching peaks of physical production of fossil fuels. The peaks of fossil fuels production, coupled with the decline in EROI ratios, are likely to challenge the sustainable development of Chinese society unless new abundant energy resources with high EROI values can be found