122 research outputs found

    Transformation Model With Constraints for High Accuracy of 2D-3D Building Registration in Aerial Imagery

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    This paper proposes a novel rigorous transformation model for 2D-3D registration to address the difficult problem of obtaining a sufficient number of well-distributed ground control points (GCPs) in urban areas with tall buildings. The proposed model applies two types of geometric constraints, co-planarity and perpendicularity, to the conventional photogrammetric collinearity model. Both types of geometric information are directly obtained from geometric building structures, with which the geometric constraints are automatically created and combined into the conventional transformation model. A test field located in downtown Denver, Colorado, is used to evaluate the accuracy and reliability of the proposed method. The comparison analysis of the accuracy achieved by the proposed method and the conventional method is conducted. Experimental results demonstrated that: (1) the theoretical accuracy of the solved registration parameters can reach 0.47 pixels, whereas the other methods reach only 1.23 and 1.09 pixels; (2) the RMS values of 2D-3D registration achieved by the proposed model are only two pixels along the x and y directions, much smaller than the RMS values of the conventional model, which are approximately 10 pixels along the x and y directions. These results demonstrate that the proposed method is able to significantly improve the accuracy of 2D-3D registration with much fewer GCPs in urban areas with tall buildings

    Atrial Septal Defect Detection in Children Based on Ultrasound Video Using Multiple Instances Learning

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    Purpose: Congenital heart defect (CHD) is the most common birth defect. Thoracic echocardiography (TTE) can provide sufficient cardiac structure information, evaluate hemodynamics and cardiac function, and is an effective method for atrial septal defect (ASD) examination. This paper aims to study a deep learning method based on cardiac ultrasound video to assist in ASD diagnosis. Materials and methods: We select two standard views of the atrial septum (subAS) and low parasternal four-compartment view (LPS4C) as the two views to identify ASD. We enlist data from 300 children patients as part of a double-blind experiment for five-fold cross-validation to verify the performance of our model. In addition, data from 30 children patients (15 positives and 15 negatives) are collected for clinician testing and compared to our model test results (these 30 samples do not participate in model training). We propose an echocardiography video-based atrial septal defect diagnosis system. In our model, we present a block random selection, maximal agreement decision and frame sampling strategy for training and testing respectively, resNet18 and r3D networks are used to extract the frame features and aggregate them to build a rich video-level representation. Results: We validate our model using our private dataset by five-cross validation. For ASD detection, we achieve 89.33 AUC, 84.95 accuracy, 85.70 sensitivity, 81.51 specificity and 81.99 F1 score. Conclusion: The proposed model is multiple instances learning-based deep learning model for video atrial septal defect detection which effectively improves ASD detection accuracy when compared to the performances of previous networks and clinical doctors

    SARS-CoV-2 delta (B.1.617.2) spike protein adjuvanted with Alum-3M-052 enhances antibody production and neutralization ability

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    BackgroundOptimizing adjuvant is one of the critical methods to improve the vaccine. 3M-052, a novel TLR7/8 agonist which was designed for slow dissemination at the injection site, has a potential as adjuvant, but its performance as a vaccine adjuvant for SARS-CoV-2 (B.1.617.2) spike protein has not been studied. The present study aimed to evaluate the effect of Alum-3M-052 as an adjuvant to improve mice serum antibody titers and pseudovirus neutralization efficiency.MethodFemale Balb/c mice were immunized 3 times at day 0, 7 and 21 intramuscularly with SARS-CoV-2 (B.1.617.2) spike protein and adjuvant (Alum or Alum-3M-052). Mice serum was collected weekly since day 7. Antibody titers of mice serum anti-SARS-CoV-2 (B.1.617.2) IgG and IgM were detected by ELISA. Inhibition rates of mice serum blocking SARS-CoV-2 (B.1.617.2) spike protein binding to ACE2 were detected by SARS-CoV-2 (B.1.617.2) Inhibitor Screening Kit. Neutralization efficiencies of mice serum against both SARS-CoV-2 (BA.2.12.1) pseudovirus and SARS-CoV-2 (B.1.617.2) pseudovirus were detected by pseudovirus neutralizing assay.ResultSerum of mice immunized by SARS-CoV-2 (B.1.617.2) spike protein adjuvanted with Alum-3M-052 had highest antibody titers and higher neutralization efficiency against both SARS-CoV-2 (BA.2.12.1) pseudovirus and SARS-CoV-2 (B.1.617.2) pseudovirus. Besides, neutralization efficiency of anti-SARS-CoV-2 (B.1.617.2) spike protein antibody against SARS-CoV-2 (BA.2.12.1) pseudovirus was lower than that of SARS-CoV-2 (B.1.617.2) pseudovirus.ConclusionAlum-3M-052 rapidly increased the titer of anti-SARS-CoV-2 (B.1.617.2) spike protein neutralizing antibodies and enhanced the neutralization ability against pseudoviruses and variants. This study provided evidence for the application of Alum-3M-052 as an adjuvant in COVID-19 vaccines production

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Fine root distributions of shelterbelt trees and their water sources in an oasis of arid northwestern China

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    Shelterbelt trees play an important role in maintaining the sustainability of oases agricultural ecosystems, but the trees require a considerable amount of water for survival. The objectives of this study were to investigate the root distributions, transpiration and water sources of shelterbelt trees (Gansu Poplar; Populus gansuensis) in order to improve water management efficiency. Fine root and soil water distributions were investigated along three transects that passed through cropland and an adjacent shelterbelt, while sap flow measurements were conducted on six Gansu Poplar trees. Results showed that roots were mainly distributed within 5 m of both sides of an irrigation channel passing between the first and second tree rows. The maximum distance to which trees extended fine roots horizontally was about 18 m from the shelterbelt. In 2-m soil profiles, fine roots were mainly distributed in the 1.4e2.0 m and 0 e0.4 m layers depending on the available water sources. A positive relationship was observed between soil water and fine root mass density. Trees grown near the cropland-shelterbelt border exploited water from cropland irrigation and irrigation channel leakage, greatly enhancing their transpiration. During the growing season of 2013, the mean total transpiration of trees grown farther away from the border (10.75 and 17.45 m) was 216.9 mm, whereas for trees grown nearer to the border (0.85 and 6.30 m) the amounts were 670.1 and 488.7 mm, respectively. If the trees were assumed to absorb the same amount of water from soil, rainfall and groundwater sources, then irrigation water sources provided 67.6% and 55.6% of the water meeting the transpiration requirements of the trees closest to the border. The results have important implications for water management in oasis agricultural areas by limiting the extension of shelterbelt tree roots into adjacent cropland in order to improve irrigation water use efficiency.</div

    Temporal stability analysis identifies soil water relations under different land use types in an oasis agroforestry ecosystem

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    The springwheat&ndash;shelterbelt&ndash;maize agroforestry ecosystemis one of themost common land use patterns occurring in oasis agriculture in the arid zones of northwest China. Soil water interactions were hypothesized to exist between adjacent land use types, and that these interactions could be analyzed by using the soil water content (SWC) measured at the most time-stable locations (MTSLs) under each land use type. Objectives of this study were to (1) identify the MTSLs for the different soil layers under each land use type and (2) to investigate the soil water relations between adjacent land use types using the SWC measured at the identified MTSLs. The SWC was measured in 2012 and 2013 at 10-cm depth intervals within 0&ndash;260 cm soil profiles at 36 locations along three transects that passed through spring wheat, shelterbelt, andmaize subplots. A time-stability analysis ofSWCwas used to identify theMTSLs in the four different soil layers under each of the three land use types. The results indicated that temporal variations in soil water in the same soil layer among the three land use types tended to have similar patterns. The SWC of the different soil layers undermaize exhibited the highest temporal stability among the three land use types. TheSWCmeasured at theMTSLs identified for each soil layer under each land use typewas proven to represent their meanSWC. Correlation analyses of the SWCs measured at theMTSLs between two land use types indicated that soilwater relations occurred between adjacent land use types but not between those that were non-adjacent land use types by the correlation analyses of the SWCs measured at the MTSLs between two land use types. In the upper soil layer (0&ndash;200 cm), soilwater relations weremainly affected by shelterbelt rootwater uptake fromthe adjacent cropland into which the tree roots had extended. In the lower soil layer (200&ndash;260 cm), the soil water relations among the three land use types were due to groundwater recharge, which was a result of crop irrigation that had raised the water table to a level at which it could replenish this soil layer.</div
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