Multipath estimation based on modified ε-constrained rank-based differential evolution with minimum error entropy

Multipath is one of the dominant error sources for high-precision positioning systems, such as global navigation satellite systems (GNSS). The minimum mean square error (MSE) criterion is usually employed for multipath estimation under the assumption of Gaussian noise. For non-Gaussian noise as appeared in most practical applications, alternative solutions are required for multipath estimation. In this work, a multipath estimation algorithm is proposed based on the minimum error entropy (MEE) criterion under Gaussian or non-Gaussian noises. A key advantage of using MEE is that it can minimize the randomness of error signals, however, the shift-invariance characteristics in MEE may lead to a bias of the estimation result. To mitigate such a bias, an improved estimation strategy is proposed by integrating the second-order central moment of the estimation error together with the prior information of multipath parameters as a constraint. The multipath estimation problem is thus formulated as a constrained optimization problem. A modified ε-constrained rank-based differential evolution (εRDE) algorithm is developed to find the optimal solution. The effectiveness of the proposed algorithm, in terms of reducing the multipath estimation error and minimizing the randomness in the error signal, has been examined through case studies with Gaussian and non-Gaussian noises

Th17 i IL-17 osiągają wyższe stężenia w przebiegu martwicy głowy kości udowej i są dodatnio skorelowane z nasileniem bólu

Objective: Synovitis associated with osteonecrosis of the femoral head (ONFH) is responsible for several clinical symptoms. However, the mechanisms underlying synovitis and the inflammatory environment remain unclear. This study analyzed the proinflammatory mediation expression of IL-17 and Th17, which perform key functions in regulating inflammatory processes in the inflamed synovium and peripheral blood in ONFH. Methods: Synovial fluid from the hips of 23 patients and 5 controls was collected during surgery, and peripheral blood samples were obtained from 34 patients and 9 controls. The expression of IL-17 in the synovium was detected by immunohistochemistry, and the levels of Th17 and IL-17 in the blood were measured by flow cytometry and ELISA. Pain assessment was performed for all the patients and controls. Results: An inflamed synovium was characterized by increased leukocyte infiltration and IL-17 expression in comparison with the control. Preoperative levels of Th17 and IL-17 were significantly higher in the peripheral blood of the ONFH group than those in the controls. The symptoms were also positively correlated with the Th17 levels of the ONFH patients. Conclusion: Th17 cells were recruited to an inflamed synovium, and inflammatory cytokine IL-17 was expressed at an increased level in the hip synovium of ONFH patients, which possibly contributed to clinical syndrome development. Overall, this study will help in identifying new therapeutic strategies for ONFH, especially the targeting of IL-17 to decrease inflammation and pain. Wstęp: Zapalenie błony maziowej związane z martwicą głowy kości udowej (osteonecrosis of the femoral head; ONFH) odpowiada za kilka objawów klinicznych, jednak mechanizmy leżące u podstaw zapalenia błony maziowej oraz środowisko zapalne pozostają niejasne. W niniejszym badaniu poddano analizie ekspresję mediatora zapalenia IL-17 na limfocytach Th17, które pełnią kluczową rolę w regulowaniu procesów zapalnych w objętej stanem zapalnym błonie maziowej i krwi obwodowej w przebiegu ONFH. Materiał i metody: Podczas zabiegów operacyjnych pobrano maź stawową ze stawów biodrowych 23 pacjentów i 5 osób z grupy kon­trolnej, natomiast próbki krwi obwodowej uzyskano od 34 pacjentów i 9 osób z grupy kontrolnej. Ekspresję IL-17 w błonie maziowej wykrywano za pomocą metody immunohistochemicznej, a stężenie Th17 i IL-17 we krwi mierzono metodą cytometrii przepływowej i metodą ELISA. U wszystkich pacjentów i osób z grupy kontrolnej oceniono parametr bólu. Wyniki: Cechą charakterystyczną objętej stanem zapalnym błony maziowej był wzrost nacieczenia limfocytarnego i ekspresji IL-17 w porównaniu z grupą kontrolną. Stężenie Th17 i IL-17 przed wykonaniem zabiegów operacyjnych było znacząco wyższe we krwi obwodowej pacjentów z martwicą głowy kości udowej niż grupy kontrolnej. Również objawy były u tych pacjentów dodatnio skorelowane z poziomem Th17. Wnioski: Limfocyty Th17 były rekrutowane do objętej stanem zapalnym błony maziowej, a cytokina zapalna IL-17 ulegała ekspresji na zwiększonym poziomie w błonie maziowej stawu biodrowego pacjentów z martwicą głowy kości udowej, co prawdopodobnie przyczyniło się do rozwoju zespołu objawów klinicznych. Uogólniając, niniejsze badanie może pomóc zidentyfikować nowe strategie terapeutyczne w martwicy głowy kości udowej, w szczególności ukierunkowane na IL-17 w celu zmniejszenia stanu zapalnego i bólu

Mass-Ratio Distribution of Binaries From the LAMOST-MRS Survey

Binary evolution leads to the formation of important objects crucial to the development of astrophysics, but the statistical properties of binary populations are still poorly understood. The LAMOST-MRS has provided a large sample of stars to study the properties of binary populations, especially for the mass ratio distributions and the binary fractions. We have devised a Peak Amplitude Ratio (PAR) approach to derive the mass ratio of a binary system based on results obtained from its spectrum. By computing a cross-correlation function (CCF), we established a relationship between the derived mass ratio and the PARs of the binary systems. By utilizing spectral observations obtained from LAMSOT DR6 & DR7, we applied the PAR approach to form distributions of the derived mass ratio of the binary systems to the spectral types. We selected the mass ratio within the range of $0.6-1.0$ for investigating the mass-ratio distribution. Through a power-law fitting, we obtained the power index $\gamma$ values of $-0.42\pm0.27$, $0.03\pm0.12$, and $2.12\pm0.19$ for A-, F-, and G-type stars identified in the sample, respectively. The derived $\gamma$-values display an increasing trend toward lower primary star masses, and G-type binaries tend to be more in twins. The close binary fractions (for $P\lesssim 150\,{\rm d}$ and $q\gtrsim 0.6$) in our sample for A, F and G binaries are $7.6\pm 0.5 \%$, $4.9\pm 0.2 \%$ and $3.7 \pm 0.1 \%$, respectively. Note that the PAR approach can be applied to large spectroscopic surveys of stars.Comment: 18 pages, 12 figures, accepted for publication in The Astrophysical Journa

multicenter intraindividual comparison of single dose gadobenate dimeglumine and double dose gadopentetate dimeglumine for mr angiography of the supra aortic arteries the supra aortic value study

BACKGROUND AND PURPOSE: Gadobenate dimeglumine has markedly higher R1 relaxivity compared to gadopentetate dimeglumine meaning that lower doses can be used to achieve similar contrast enhancement. Our aim was to prospectively compare single-dose gadobenate dimeglumine with double-dose gadopentetate dimeglumine for contrast-enhanced MRA of the supra-aortic vasculature. MATERIALS AND METHODS: Forty-six patients (37 men, 9 women; mean age, 63.5 ± 10.1 years) with known or suspected steno-occlusive disease of the supra-aortic vessels underwent 2 identical CE-MRA examinations at 1.5T. Contrast agents were administered in randomized order, with the 2-fold greater volume of gadopentetate dimeglumine injected at a 2 times faster rate. Image assessment was performed by 3 independent blinded readers for vessel anatomic delineation, detection/exclusion of pathology, and global preference. Diagnostic performance (sensitivity, specificity, accuracy, PPV, and NPV) for detection of ≥60% stenosis was determined for 39/46 patients who underwent preinterventional DSA. Data were analyzed by using the Wilcoxon signed-rank, McNemar, and Wald tests in terms of the noninferiority of single-dose gadobenate dimeglumine compared with double-dose gadopentetate dimeglumine. Quantitative enhancement (signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR)) was also compared. RESULTS: All images were technically adequate. No differences (P = 1.0) were noted by any reader for any qualitative parameter. All readers considered single-dose gadobenate dimeglumine and double-dose gadopentetate dimeglumine equivalent in at least 42/46 patients (91.3% three-reader agreement) for all parameters. Nonsignificant superiority for gadobenate dimeglumine was reported for all diagnostic performance indicators (sensitivity: 82.7%–88.5% versus 75.0%–80.8%; specificity: 96.4%–98.6% versus 94.6%–98.6%; accuracy: 94.6%–96.1% versus 92.4%–94.9%; PPV: 81.5%–91.5% versus 73.7%–90.7%; NPV: 96.8%–97.8% versus 95.4%–96.4%). No differences (P > .05) in quantitative enhancement were noted. CONCLUSIONS: The image quality and diagnostic performance achieved with 0.1-mmol/kg gadobenate dimeglumine is at least equivalent to that achieved with 0.2-mmol/kg gadopentetate dimeglumine

Quantitative detection of multi-frequency disturbance signal by ϕ-OTDR system

Recently, the combination of pattern recognition technology and distributed fiber sensing systems has become increasingly common, so whether the disturbance signal can be well recovered has become increasingly important. To verify the recovery and linear response of a distributed fiber optic sensing system to multi-frequency disturbance signals, a heterodyne coherent detection system for phase-sensitive optical time-domain reflectometry is developed. The output beat signal is extracted using the digital in-phase/quadrature demodulation algorithm. The signal can be precisely located on a 7 km length range, and the disturbance signal can be restored well through the phase information. Not only the superposition signal composed of the same signal but also that composed of different kinds of signals can be successfully restored. A fast Fourier transform algorithm is used to obtain the frequency information of the superimposed signal. Combined with the use of a finite impulse response filter, the superposed signal is decomposed according to its frequency components, which perfectly restores the two signals before they are superimposed. In addition, their amplitude is highly linear with the driving voltage of the piezoelectric transducer. The system can fully retain the details of each frequency component in the recovery of multi-frequency disturbance signals. More importantly, in field experiments, the disturbance behavior is well recovered, which has broad prospects in the application of perimeter security

A global monthly field of seawater pH over 3 decades: a machine learning approach

The continuous uptake of anthropogenic CO2 by the ocean leads to ocean acidification, which is an ongoing threat to the marine ecosystem. The ocean acidification rate was globally documented in the surface ocean but limited below the surface. Here, we present a monthly four-dimensional 1°×1° gridded product of global seawater pH, derived from a machine learning algorithm trained on pH observations at total scale and in-situ temperature from the Global Ocean Data Analysis Project (GLODAP). The constructed pH product covers the years 1992–2020 and depths from the surface to 2 km on 41 levels. Three types of machine learning algorithms were used in the pH product construction, including self-organizing map neural networks for region dividing, a stepwise algorithm for predictor selection, and feed-forward neural networks (FFNN) for non-linear relationship regression. The performance of the machine learning algorithm was validated using real observations by a cross validation method, where four repeating iterations were carried out with 25 % varied observations for each evaluation and 75 % for training. The constructed pH product is evaluated through comparisons to time series observations and the GLODAP pH climatology. The overall root mean square error between the FFNN constructed pH and the GLODAP measurements is 0.028, ranging from 0.044 in the surface to 0.013 at 2000 m. The pH product is distributed through the data repository of the Marine Science Data Center of the Chinese Academy of Sciences at http://dx.doi.org/10.12157/IOCAS.20230720.001 (Zhong et al., 2023)

Holocene variability of East Asian summer monsoon as viewed from the speleothem δ18O records in central China

Monsoon precipitation in East China shows distinct spatial distribution and its variability is closely linked with the changes of the East Asian summer monsoon (EASM). Located in the transition zone between the southern subtropical humid climate and the northern warm temperate semi-humid climate, central China is a core region for recognizing and understanding the spatio-temporal variability of the EASM. Using U-series dating and stable isotope analysis on five stalagmites (MG-1, MG-2, MG-7, MG-40 and MG-64) from Magou Cave, Henan Province, Central China, we construct a high-resolution and precisely dated composite stalagmite O time series covering most of the Holocene. This composite record reveals variations in precipitation O between 11.7 and 1.1 ka BP with average resolution of ∼4 yrs. The Magou composite record demonstrates that EASM intensity dominates long-term changes in precipitation O, which generally follows the northern hemisphere summer insolation (NHSI) trend. Both, Ensemble Empirical Mode Decomposition (EEMD) and wavelet filtering analyses real that the amplitudes of long-term (100-500 and 500-3000 yrs) components were slightly reduced between 8.5 and 4.9 ka BP, implying a weakened influence of climatic forcings on centennial and even millennial timescales during this warm period. Variance on 1-30-yr timescales is relatively low and ascribed to sampling resolution. Fourteen weak EASM intervals, including the 8.2 ka event, were identified within the period corresponding broadly with the Holocene Megathermal. Since no cold excursions other than the 8.2 ka event are found in the Greenland ice core records, we tentatively propose that oscillations in tropical sea surface temperature (SST) likely play an important role in steering other weak monsoon events. Aligning the Magou composite record and other moisture records with archaeological records from the study region, it seems that climate change influenced both the spatial distribution and agricultural practices of ancient cultures. However, overall moderate climatic changes in this region, most likely characterized by shifts between subtropical humid climate and warm temperate semi-humid climate, supported a generally consecutive development of ancient cultures without major hiatuses

Effect of optimized thrombus aspiration on myocardial perfusion and prognosis in acute ST-segment elevation myocardial infarction patients with primary percutaneous coronary intervention

ObjectiveTo investigate the impact of optimized thrombus aspiration on myocardial perfusion, prognosis, and safety in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention(primary PCI).MethodsA total of 129 patients with STEMI were randomly allocated into control group (Subgroup A and B) and experimental group(Subgroup C and D). Control group received percutaneous transluminal coronary angioplasty (PTCA),thrombus aspiration and primary PCI. Experimental group received optimized thrombus aspiration and primary PCI. The number of thrombus aspiration was less than 4 times in Subgroup A and C. The number of thrombus aspiration was performed more than 4 times in Subgroups B and D. The classification of thrombi extracted, the TIMI flow grade, the incidence of no-reflow and slow flow, cTFC, TPI and CK-MB at 12 h and 24 h after stenting, ST segment resolution of ECG after stenting, NT-proBNP, LVEFat 24 h, 30 days and 180 days after stenting were compared between groups. The incidence of intraoperative and postoperative bleeding complications, stroke events and major cardiovascular events (MACE) were recorded and compared between groups.ResultsThe classification of thrombi extracted in the experimental group was higher than that in the control group. The TIMI flow grade of the experimental group was better than the control group after thrombus aspiration. After stenting, the advantage still existed, but the difference was not statistically significant. On cTFC, the experimental group was lower than the control group, but the difference was not statistically significant; After stenting the experimental group was significantly lower than the control group. The CK-MB at 12 h and 24 h of the experimental group was lower than the control group. After thrombus aspiration the incidence of no-reflow in the experimental group was significantly lower than that in the control group; after stenting the incidence of no-reflow in the experimental group was still lower than the control group, but no statistically difference. After thrombus aspiration and stenting the incidence of slow flow in the experimental group were lower than that in the control group. After stenting, NT-proBNP at 24 h was lower in the experimental group than that in the control group, However, there was no statistical difference; after stenting, The NT-proBNP in the experimental group was lower than that in the control group at 30 days and 180 days. After stenting, LVEF of the experimental group was significantly higher than the control group at 24 h and 30 days; superiority remained after 180 days but no statistical difference. There was no statistical difference between two groups for intraoperative and postoperative bleeding complications, stroke events, and MACE events. In Subgroup analysis,there was no significant difference in the classification of thrombi extracted, TIMI flow grade, cTFC, CK-MB,NT-proBNP and LVEF between group C and D, but group A was better than group B. Analysis of variance showed that the optimal number of suction was 4–5 times.ConclusionsOptimized thrombus aspiration can significantly improve myocardial perfusion and short-term and medium-term prognosis of STEMI patients after PCI, and reduce the incidence of slow flow and no-reflow. The optimal suction times were 4–5 times. Traditional aspiration method with more aspiration times is harmful to cardiac prognosis. Thrombus aspiration does not increase the incidence of stroke events and is safe.Clinical Trial Registration: identifier, ChiCTR2300073410