956 research outputs found

    Lightweight and Adaptive FDD Massive MIMO CSI Feedback with Deep Equilibrium Learning

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    In frequency-division duplexing (FDD) massive multiple-input multiple-output (MIMO) systems, downlink channel state information (CSI) needs to be sent from users back to the base station (BS), which causes prohibitive feedback overhead. In this paper, we propose a lightweight and adaptive deep learning-based CSI feedback scheme by capitalizing on deep equilibrium models. Different from existing deep learning-based approaches that stack multiple explicit layers, we propose an implicit equilibrium block to mimic the process of an infinite-depth neural network. In particular, the implicit equilibrium block is defined by a fixed-point iteration and the trainable parameters in each iteration are shared, which results in a lightweight model. Furthermore, the number of forward iterations can be adjusted according to the users' computational capability, achieving an online accuracy-efficiency trade-off. Simulation results will show that the proposed method obtains a comparable performance as the existing benchmarks but with much-reduced complexity and permits an accuracy-efficiency trade-off at runtime.Comment: submitted to IEEE for possible publicatio

    Multiscale modelling and experimental analysis of ultrasonic-assisted drilling of GLARE fibre metal laminates

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    This study aims to evaluate the effectiveness of Ultrasonic-assisted drilling (UAD) of Glass laminate aluminium reinforced epoxy (GLARE) at high cutting speeds (Spindle speeds: 3000–7500 rpm; feed rates 300–750 mm/min) by analysing the thrust force and hole quality metrics (surface roughness, hole size, and burr formations. The research also presents numerical modelling of FMLs under conventional and UAD regimes to predict thrust force using ABAQUS/SIMULIA. The thrust force and exit burrs were reduced by up to 40.83 % and 80 %, respectively. The surface roughness metrics (Ra and Rz) were slightly higher using UAD but remained within the desirable limits of surface roughness for machined aeronautical structures. The discrepancy between the simulation and experimental results was adequate and did not exceed 15 %. The current study shows that it is feasible to drill holes in GLARE using higher cutting parameters and maintain excellent hole quality, which means increased productivity and reduced costs

    A portable breast cancer detection system based on smartphone with infrared camera

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    The traditional detection methods have the disadvantages of radiation exposure, high cost, and shortage of medical resources, which restrict the popularity of early screening for breast cancer. An inexpensive, accessible, and friendly way to detect is urgently needed. Infrared thermography, an emerging means to breast cancer detection, is extremely sensitive to tissue abnormalities caused by inflammation and vascular proliferation. In this work, combined with the temperature and texture features, we designed a breast cancer detection system based on smart phone with infrared camera, achieving the accuracy of 99.21 % with the k-Nearest Neighbor classifier. We compared the diagnostic results of the low resolution, originated from the phone camera, with the high resolution of the conventional infrared camera. It was found that the accuracy and sensitivity decreased slightly, but both of them were over than 98 %. The proposed breast cancer detection system not only has excellent performance but also dramatically saves the detection cost, and its prospect will be fascinating

    Morphology and Ontogenesis of a Marine Ciliate, Euplotes balteatus (Dujardin, 1841) Kahl, 1932 (Ciliophora, Euplotida) and Definition of Euplotes wilberti nov. spec.

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    Euplotes balteatus (Dujardin, 1841) Kahl 1932, collected from coastal waters near Qingdao, northern China, was investigated using live observation and silver staining methods. An improved diagnosis and morphometric data are provided. Euplotes balteatus can be identified by the following combination of characters: 10 frontoventral cirri, 2 widely separated marginal cirri, 2 fine caudal cirri, 8 dorsal kineties and a double-eurystomus type silverline system. Its morphogenesis, which is similar to that of several congeners, can be summarized as follows: (1) the opisthe’s oral primordium appears de novo under the pellicle whereas the old oral apparatus is retained by the proter; (2) two groups of frontoventral transverse cirral anlagen, each with five streaks, occur de novo and then develop into the frontoventral and transverse cirri separately according to the formula of “3:3:3:3:2” from left to right; (3) the anlagen for the marginal cirri occur de novo near the parental oral apparatus; (4) migratory cirri of both dividers derive from the anlagen near the paroral membrane; (5) the dorsal kinety anlagen come from dedifferentiation of the parental structures in the mid-body region; (6) caudal cirri are formed at the posterior ends of the two rightmost dorsal kineties. In the light of the present findings, it was concluded that the Antarctic population of E. balteatus reported by Song and Wilbert (2002) was misidentified. A new species, Euplotes wilberti nov. spec., is established for this population

    Mechanosignaling activation of TGFβ maintains intervertebral disc homeostasis

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    Intervertebral disc (IVD) degeneration is the leading cause of disability with no disease-modifying treatment. IVD degeneration is associated with instable mechanical loading in the spine, but little is known about how mechanical stress regulates nucleus notochordal (NC) cells to maintain IVD homeostasis. Here we report that mechanical stress can result in excessive integrin αv β6-mediated activation of transforming growth factor beta (TGFβ), decreased NC cell vacuoles, and increased matrix proteoglycan production, and results in degenerative disc disease (DDD). Knockout of TGFβ type II receptor (TβRII) or integrin α v in the NC cells inhibited functional activity of postnatal NC cells and also resulted in DDD under mechanical loading. Administration of RGD peptide, TGFβ, and α v β 6-neutralizing antibodies attenuated IVD degeneration. Thus, integrin-mediated activation of TGFβ plays a critical role in mechanical signaling transduction to regulate IVD cell function and homeostasis. Manipulation of this signaling pathway may be a potential therapeutic target to modify DDD

    Taxonomic Studies on Three Marine Ciliates from China, Including a New Species (Ciliophora, Cyrtophorida)

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    The present work investigates the living morphology and infraciliature of three marine cyrtophorid ciliates, which were isolated from Qingdao, China. Compared with its congeners, Orthotrochilia sinica spec. nov. can be distinguished by a combination of features: body slender and elliptical in outline, size about 50–60 × 20–25 μm in vivo, 18–21 somatic kineties, the length of the left perioral kinety treble the length of the right one, two ventrally located contractile vacuoles on the right side, and 25–32 nematodesmal rods. Based on current observations and the previous description, the diagnosis of Trochilioides tenuis (Deroux, 1976) Chen et al. 2011 is improved: cell size 30–40 × 20–35 μm in vivo, oval shaped in outline; consistently three right kineties, four left kineties and seven postoral kineties; a single contractile vacuole; marine habitat. A second species of Trochilioides, T. recta (Kahl, 1923) Chen et al. 2011 is re-described based on a Chinese population. Furthermore, a key to the identification of species of the genus Trochilioides whose infraciliature data are available is supplied, and Chlamydonyx trivialis (Fenchel, 1965) comb. nov. [basionym: Trochilioides trivialis Fenchel, 1965] is suggested

    SPATIAL DISTRIBUTION OF ATMOSPHERIC POLLUTION IN DUHOK URBAN AREA BY USING GIS TOOLS

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    Air pollution is becoming a serious challenge in thickly populated areas in the world. The air pollution in Kurdistan region is clearly noticed, especially in areas where pollution sources and human population are concentrated. Urbanization and economic growth are proceeding at a rapid pace, accompanied by increasing emissions of a mixture of greenhouse gases especially from transporting sector, that positively contribute to accelerate climate change around the globe, and also have impacts on public health and vegetation. In order to decrease the effects that caused by atmospheric pollution, suitable monitoring systems are urgently needed that can rapidly and reliably detect and quantify polluting sources and concentration for monitoring by local authorities in order to restrain more damage of the current pollution levels. In this study, GIS with portable gas detector (K-60 IV) KELISAIKE safety equipment, China, have been used to assess the status of NOx, VOCs and noise pollution at 54 randomly selected urban locations of Duhok city. The measurements were taken during the week and weekend days started from 9 am until 4 pm. The results showed that there is a variation in the values of the three variables NOx, VOCs and noise, where the highest values recorded during working days in the locations distributed along the highway and the city center with heavy traffic load and dense human population in comparison to lowest values obtained during weekend days in locations distributed outskirt of the city with lower population and traffic loads. Therefore, likely such connections exist between the urban traffic density and  low air pollution quality within urban locations around Duhok city

    Estimation of proteinuria as a predictor of complications of pre-eclampsia: a systematic review

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    Background Proteinuria is one of the essential criteria for the clinical diagnosis of pre-eclampsia. Increasing levels of proteinuria is considered to be associated with adverse maternal and fetal outcomes. We aim to determine the accuracy with which the amount of proteinuria predicts maternal and fetal complications in women with pre-eclampsia by systematic quantitative review of test accuracy studies. Methods We conducted electronic searches in MEDLINE (1951 to 2007), EMBASE (1980 to 2007), the Cochrane Library (2007) and the MEDION database to identify relevant articles and hand-search of selected specialist journals and reference lists of articles. There were no language restrictions for any of these searches. Two reviewers independently selected those articles in which the accuracy of proteinuria estimate was evaluated to predict maternal and fetal complications of pre-eclampsia. Data were extracted on study characteristics, quality and accuracy to construct 2 × 2 tables with maternal and fetal complications as reference standards. Results Sixteen primary articles with a total of 6749 women met the selection criteria with levels of proteinuria estimated by urine dipstick, 24-hour urine proteinuria or urine protein:creatinine ratio as a predictor of complications of pre-eclampsia. All 10 studies predicting maternal outcomes showed that proteinuria is a poor predictor of maternal complications in women with pre-eclampsia. Seventeen studies used laboratory analysis and eight studies bedside analysis to assess the accuracy of proteinuria in predicting fetal and neonatal complications. Summary likelihood ratios of positive and negative tests for the threshold level of 5 g/24 h were 2.0 (95% CI 1.5, 2.7) and 0.53 (95% CI 0.27, 1) for stillbirths, 1.5 (95% CI 0.94, 2.4) and 0.73 (95% CI 0.39, 1.4) for neonatal deaths and 1.5 (95% 1, 2) and 0.78 (95% 0.64, 0.95) for Neonatal Intensive Care Unit admission. Conclusion Measure of proteinuria is a poor predictor of either maternal or fetal complications in women with pre-eclampsia

    E-selectin S128R polymorphism and severe coronary artery disease in Arabs

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    BACKGROUND: The E-selectin p. S128R (g. A561C) polymorphism has been associated with the presence of angiographic coronary artery disease (CAD) in some populations, but no data is currently available on its association with CAD in Arabs. METHODS: In the present study, we determined the potential relevance of the E-selectin S128R polymorphism for severe CAD and its associated risk factors among Arabs. We genotyped Saudi Arabs for this polymorphism by PCR, followed by restriction enzyme digestion. RESULTS: The polymorphism was determined in 556 angiographically confirmed severe CAD patients and 237 control subjects with no CAD as established angiographically (CON). Frequencies of the S/S, S/R and R/R genotypes were found as 81.1%, 16.6% and 2.3% in CAD patients and 87.8%, 11.8%, and 0.4% in CON subjects, respectively. The frequency of the mutant 128R allele was higher among CAD patients compared to CON group (11% vs. 6%; odds ratio = 1.76; 95% CI 1.14 – 2.72; p = .007), thus indicating a significant association of the 128R allele with CAD among our population. However, the stepwise logistic regression for the 128R allele and different CAD risk factors showed no significant association. CONCLUSION: Among the Saudi population, The E-selectin p. S128R (g. A561C) polymorphism was associated with angiographic CAD in Univariate analysis, but lost its association in multivariate analysis
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