256 research outputs found
Association between ACE gene I/D polymorphisms and hyperandrogenism in women with Polycystic Ovary Syndrome (PCOS) and controls
Geo6D: Geometric Constraints Learning for 6D Pose Estimation
Numerous 6D pose estimation methods have been proposed that employ end-to-end
regression to directly estimate the target pose parameters. Since the visible
features of objects are implicitly influenced by their poses, the network
allows inferring the pose by analyzing the differences in features in the
visible region. However, due to the unpredictable and unrestricted range of
pose variations, the implicitly learned visible feature-pose constraints are
insufficiently covered by the training samples, making the network vulnerable
to unseen object poses. To tackle these challenges, we proposed a novel
geometric constraints learning approach called Geo6D for direct regression 6D
pose estimation methods. It introduces a pose transformation formula expressed
in relative offset representation, which is leveraged as geometric constraints
to reconstruct the input and output targets of the network. These reconstructed
data enable the network to estimate the pose based on explicit geometric
constraints and relative offset representation mitigates the issue of the pose
distribution gap. Extensive experimental results show that when equipped with
Geo6D, the direct 6D methods achieve state-of-the-art performance on multiple
datasets and demonstrate significant effectiveness, even with only 10% amount
of data
Monsoonal control on a delayed response of sedimentation to the 2008 Wenchuan earthquake
Infrequent extreme events such as large earthquakes pose hazards and have lasting impacts on landscapes and biogeochemical cycles. Sediments provide valuable records of past events, but unambiguously identifying event deposits is challenging because of nonlinear sediment transport processes and poor age control. Here, we have been able to directly track the propagation of a tectonic signal into stratigraphy using reservoir sediments from before and after the 2008 Wenchuan earthquake. Cycles in magnetic susceptibility allow us to define a precise annual chronology and identify the timing and nature of the earthquake’s sedimentary record. The grain size and Rb/Sr ratio of the sediments responded immediately to the earthquake. However, the changes were muted until 2 years after the event, when intense monsoonal runoff drove accumulation of coarser grains and lower Rb/Sr sediments. The delayed response provides insight into how climatic and tectonic agents interact to control sediment transfer and depositional processes.This work was funded by the 2nd Tibetan Plateau Scientific
Expedition and Research (2019QZKK0707) and CAS programs (QYZDJ-SSW-DQC033,
XDA2007010202, and 132B61KYSB20170008) grants to Z.J. and SKLLQG grant
(SKLLQGPY1603) to F.Z
Research on the Safety Characteristics of Mixed Traffic Flow under Different Penetration Scenarios of Autonomous Vehicles
Since it will take time for vehicles to be fully automated, research on mixed traffic flow with different levels of vehicles will be the focus in the future. This paper takes L0, L1, L2, L3, L4, L5 vehicles as the research object, selects the Intelligent Diver Model (IDM), Adaptive Cruise Control (ACC) model, F-STCA model and LC2013 model to construct the vehicle\u27s driving behaviour model, builds SUMO (Simulation of Urban Mobility) and Python co-simulation platform to conduct models simulation verification and safety analysis. The results show that: (1) The improved IDM model can realize the error caused by the heterogeneity of driver\u27s personality; the improved ACC model can improve speed and keep a small change range with the interfering vehicle; the improved F-STCA model can expand the vehicle\u27s lane-changing intention and reflect the driver\u27s driving uncertainty. (2) The increase of penetration can increase the number of lane changes in basic sections, but in merging area, they are proportional at low density and inversely proportional at high density; penetration can reduce the occurrence of traffic conflicts and change the distribution of Time-To-Collision (TTC). This paper can predict the evolution law of traffic flow under the new technology, and provide a reference for future traffic planning and management
Apparent timing and duration of the Matuyama-Brunhes geomagnetic reversal in Chinese loess
The Matuyama-Brunhes (MB) geomagnetic reversal in Chinese loess has been studied extensively as an important boundary for land-ocean stratigraphic and paleoclimatic correlations. However, the apparent timing and duration of the MB boundary remain controversial in Chinese loess deposits due to its inconsistent stratigraphic position and the uncertain chronologies. Here we synthesized high-resolution paleomagnetic records from four loess sequences in the central Chinese Loess Plateau and synchronized the loess-paleosol chronology by matching the grain-size variations to orbitally tuned grain-size time series. The synthesized paleomagnetic results reveal consistent features of the MB transition in Chinese loess, including the stratigraphic position (L8/S8 transition), timing (∼808–826 ka), duration (∼14–16 ka), and rapid directional oscillations. Compared with the MB transition in marine records (770–775 ka), the timing of the MB transition is relatively older and longer in Chinese loess, due to a complex interplay between different remanence acquisition mechanisms which occurred during the course of postdepositional physical and chemical processes.</p
A preliminary evaluation of targeted nanopore sequencing technology for the detection of Mycobacterium tuberculosis in bronchoalveolar lavage fluid specimens
ObjectiveTo evaluate the efficacy of targeted nanopore sequencing technology for the detection of Mycobacterium tuberculosis(M.tb.) in bronchoalveolar lavage fluid(BALF) specimens.MethodsA prospective study was used to select 58 patients with suspected pulmonary tuberculosis(PTB) at Henan Chest Hospital from January to October 2022 for bronchoscopy, and BALF specimens were subjected to acid-fast bacilli(AFB) smear, Mycobacterium tuberculosis MGIT960 liquid culture, Gene Xpert MTB/RIF (Xpert MTB/RIF) and targeted nanopore sequencing (TNS) for the detection of M.tb., comparing the differences in the positive rates of the four methods for the detection of patients with different classifications.ResultsAmong 58 patients with suspected pulmonary tuberculosis, there were 48 patients with a final diagnosis of pulmonary tuberculosis. Using the clinical composite diagnosis as the reference gold standard, the sensitivity of AFB smear were 27.1% (95% CI: 15.3-41.8); for M.tb culture were 39.6% (95% CI: 25.8-54.7); for Xpert MTB/RIF were 56.2% (95% CI: 41.2-70.5); for TNS were 89.6% (95% CI: 77.3-96.5). Using BALF specimens Xpert MTB/RIF and/or M.tb. culture as the reference standard, TNS showed 100% (30/30) sensitivity. The sensitivity of NGS for pulmonary tuberculosis diagnosis was significantly higher than Xpert MTB/RIF, M.tb. culture, and AFB smear. Besides, P values of <0.05 were considered statistically significant.ConclusionUsing a clinical composite reference standard as a reference gold standard, TNS has the highest sensitivity and consistency with clinical diagnosis, and can rapidly and efficiently detect PTB in BALF specimens, which can aid to improve the early diagnosis of suspected tuberculosis patients
Comparison of disease resistance of maize varieties from the 1950s to the 2000s in China
The objective of this investigation was to analyze trends in diseases resistance along with genetic gain. Experimental materials consisted of maize varieties selected from each decade beginning with the 1950s. These varieties were evaluated for resistance to maize dwarf mosaic virus (MDMV), maize rough dwarf virus (MRDV), common smut disease (CSD) and head smut disease (HSD) in several different locations. Artificial inoculation was adopted for infection with MDMV and HSD, whereas natural infection was used for infection MRDV and CSD. Results indicated that resistance of the newer varieties to MDMV, CSD, and HSD was greater than that of older varieties, but the correlation to decades was not significant. To date, no variety tested in China has shown resistance to MRDV, which is likely due to a lack of maize germplasm resources resistant to MRDV in China. So the next goal will be to import new germplasm resources and select resistant germplasm as the basis of breeding resistant varieties
Recombinant proteins A29L, M1R, A35R, and B6R vaccination protects mice from mpox virus challenge
Since May 2022, mutant strains of mpox (formerly monkeypox) virus (MPXV) have been rapidly spreading among individuals who have not traveled to endemic areas in multiple locations, including Europe and the United States. Both intracellular and extracellular forms of mpox virus have multiple outer membrane proteins that can stimulate immune response. Here, we investigated the immunogenicity of MPXV structural proteins such as A29L, M1R, A35R, and B6R as a combination vaccine, and the protective effect against the 2022 mpox mutant strain was also evaluated in BALB/c mice. After mixed 15 μg QS-21 adjuvant, all four virus structural proteins were administered subcutaneously to mice. Antibody titers in mouse sera rose sharply after the initial boost, along with an increased capacity of immune cells to produce IFN-γ alongside an elevated level of cellular immunity mediated by Th1 cells. The vaccine-induced neutralizing antibodies significantly inhibited the replication of MPXV in mice and reduced the pathological damage of organs. This study demonstrates the feasibility of a multiple recombinant vaccine for MPXV variant strains
Eccentricity-paced monsoon variability on the northeastern Tibetan Plateau in the Late Oligocene high CO 2 world
Constraining monsoon variability and dynamics in the warm unipolar icehouse world of the Late Oligocene can provide important clues to future climate responses to global warming. Here, we present a ~4-thousand year (ka) resolution rubidium-to-strontium ratio and magnetic susceptibility records between 28.1 and 24.1 million years ago from a distal alluvial sedimentary sequence in the Lanzhou Basin (China) on the northeastern Tibetan Plateau margin. These Asian monsoon precipitation records exhibit prominent short (~110-ka) and long (405-ka) eccentricity cycles throughout the Late Oligocene, with a weak expression of obliquity (41-ka) and precession (19-ka and 23-ka) cycles. We conclude that a combination of eccentricity-modulated low-latitude summer insolation and glacial-interglacial Antarctic Ice Sheet fluctuations drove the eccentricity-paced precipitation variability on the northeastern Tibetan Plateau in the Late Oligocene high CO2 world by governing regional temperatures, water vapor loading in the western Pacific and Indian Oceans, and the Asian monsoon intensity and displacement
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