Experimental study on natural vibration frequency identification of hydraulic concrete structure using concrete piezoceramic smart module

The identification of structural modal parameter is an important link in the dynamics monitoring and diagnosis for the structural health. The passive monitoring mode of piezoceramic is used to solve the natural vibration frequency identification problem of hydraulic concrete structure. Based on self-made concrete piezoelectric smart module (CPSM), a system is developed to obtain the modal parameters of hydraulic concrete structure. The CPSM is regarded as a sensor to monitor passively the structural natural vibration frequency. The method and process are proposed to identify the natural vibration frequency of hydraulic concrete structure. Based on the physical model and numerical simulation model, the rationality and feasibility of the proposed method are verified

Cyclohexadione-aniline conjugate inhibits proliferation of melanoma cells via upregulation of Mek 1/2 kinase activity

Purpose: To investigate the antiproliferative effect of cyclohexadione-aniline conjugate (CHAC) on melanoma cells, and the mechanism of action involved. Methods: Human melanoma cell lines (B16 F1 and A375) were used in this study. The cells were cultured in RPMI 1640 medium supplemented with 10 % fetal bovine serum (FBS) and 1 % penicillin/streptomycin at 37 °C in a humidified atmosphere of 5 % CO2 and 95 % air. After attaining 70 - 80 % confluency, the cells were treated with serum-free medium and graded concentrations of CHAC (10 – 60 μM) for 24 h. Normal cell culture without CHAC served as control group. B16 F1 and A375 cells were used in logarithmic growth phase in this study. Cell viability and apoptosis were assessed using 3-(4, 5-dimethylthiazol-2-yl) 2, 5-diphe¬nyltetrazolium bromide (MTT) and flow cytometric assays, respectively. Western blotting was used to assess the levels of protein expression of X linked inhibitor of apoptosis (XIAP), survivin, p-Erk 1/2, and p-Mek 1/2. Results: Treatment of B16 F1 and A375 cells with CHAC led to significant and concentrationdependent reductions in their viability (p < 0.05). The proliferation of B16 F1 cells decreased from 93.41 to 32.87 %, while that of A375 cells was reduced from 95.23 to 36.50 %. Treatment of B16 F1 cells with CHAC significantly and concentration-dependently increased the population of cells in G0/G1 phase, and significantly reduced cell proportion in S and G2/M phases (p < 0.05). It also significantly and concentration-dependently promoted apoptosis in B16 F1 cells (p < 0.05). CHAC treatment significantly and concentration-dependently down-regulated the expressions of XIAP and survivin proteins (p < 0.05). Exposure of B16 F1 cells to CHAC significantly and concentration-dependently upregulated the expression of p-Mek 1/2, but down-regulated p-Erk 1/2 protein expression (p < 0.05). Densitometric analysis revealed that the expression of p-Mek 1/2 was increased from 12 to 91 %. Conclusion: The results of this study indicate that CHAC inhibits the proliferation of melanoma cells via upregulation of Mek 1/2 kinase activity, and therefore may find application in the management of melanoma

The effects of anthropogenic greenhouse gases and aerosols on the inter-decadal change of the South China Sea summer monsoon in the late twentieth century

Analysis of observational precipitation indicates that in last few decades, the precipitation in boreal summer (June–August) over the South China Sea (SCS) exhibited an interdecadal variation, characterized by a decrease of 0.59 mm/day from the period 1964–1981 to the period 1994–2011. Accompanied this decrease in precipitation is weakened monsoon circulation featured by an anti-cyclonic circulation anomaly over the SCS in the later period relative to the early period. This work investigates impacts of anthropogenic forcing changes on this interdecadal change in observations, quantify the relative roles of greenhouse gases (GHG) forcing and anthropogenic aerosol (AA) forcing. A set of experiments is designed using the atmospheric component of a state-of-the-art climate model coupled to a multi-level mixed-layer ocean model forced with GHG concentrations and AA emissions in two periods. Modeling results indicate a dominant role of anthropogenic forcing on the observed interdecadal precipitation decrease and weakened monsoon circulation over the SCS in the late twentieth century in which AA forcing plays a more important role compared with GHG forcing. The mechanisms of GHG influences and AA induced changes are revealed by individual forcing experiments. Increasing GHG concentrations can suppress convection over the SCS summer monsoon region by warming the tropical Pacific with an El-Niño like sea surface temperature (SST) pattern, which is associated with a weakened Walker circulation. The changes in AA emissions, mainly through increases in emissions over Asia, lead to cool SST in the north Indian Ocean and the western North Pacific (WNP), and result in changes in meridional SST gradient over the tropical Indian Ocean and the WNP in pre-monsoon seasons. This anomalous meridional SST gradient leads to anomalous local Hadley circulation, characterized by anomalous ascents around the equator and descents over monsoon region, which suppresses convection over the SCS and reduces local precipitation

Statistical Analysis and Calculation Model of Flexibility Coefficient of Low- and Medium-Sized Arch Dam

The flexibility coefficient is popularly used to implement the macroevaluation of shape, safety, and economy for arch dam. However, the description of flexibility coefficient has not drawn a widely consensus all the time. Based on a large number of relative instance data, the relationship between influencing factor and flexibility coefficient is analyzed by means of partial least-squares regression. The partial least-squares regression equation of flexibility coefficient in certain height range between 30 m and 70 m is established. Regressive precision and equation stability are further investigated. The analytical model of statistical flexibility coefficient is provided. The flexibility coefficient criterion is determined preliminarily to evaluate the shape of low- and medium-sized arch dam. A case study is finally presented to illustrate the potential engineering application. According to the analysis result of partial least-squares regression, it is shown that there is strong relationship between flexibility coefficient and average thickness of dam, thickness-height ratio of crown cantilever, arc height ratio, and dam height, but the effect of rise-span ratio is little relatively. The considered factors in the proposed model are more comprehensive, and the applied scope is clearer than that of the traditional calculation methods. It is more suitable for the analogy analysis in engineering design and the safety evaluation for arch dam

Expression of miR-126 and its potential function in coronary artery disease

Objective: This study aimed to explore the role of miR-126 in coronary artery disease (CAD) patients and the potential gene targets of miR-126 in atherosclerosis.Methodology: A total of 60 CAD patients and 25 healthy control subjects were recruited in this study. Among the 60 CAD patients, 18 cases were diagnosed of stable angina pectoris (SAP), 20 were diagnosed of unstable angina pectoris (UAP) and 22 were diagnosed of acute myocardial infarction (AMI). Plasma miR-126 levels from both groups of participants were analyzed by real-time quantitative PCR. ELISA was used to measure plasma level of placenta growth factor (PLGF).Results: The results showed that the miR-126 expression was significantly down-regulated in the circulation of CAD patients compared with control subjects (P<0.01). Plasma PLGF level was significantly upregulated in patients with unstable angina pectoris and acute myocardial infarction (AMI) compared with controls (both P<0.01) the miR-126 expression in AMI was significantly associated with PLGF.Conclusion: miR-126 may serve as a novel biomarker for CAD.Keywords: miR-126; PLGF; PCR; coronary artery disease; atherosclerosi

Detecting Political Biases of Named Entities and Hashtags on Twitter

Ideological divisions in the United States have become increasingly prominent in daily communication. Accordingly, there has been much research on political polarization, including many recent efforts that take a computational perspective. By detecting political biases in a corpus of text, one can attempt to describe and discern the polarity of that text. Intuitively, the named entities (i.e., the nouns and phrases that act as nouns) and hashtags in text often carry information about political views. For example, people who use the term "pro-choice" are likely to be liberal, whereas people who use the term "pro-life" are likely to be conservative. In this paper, we seek to reveal political polarities in social-media text data and to quantify these polarities by explicitly assigning a polarity score to entities and hashtags. Although this idea is straightforward, it is difficult to perform such inference in a trustworthy quantitative way. Key challenges include the small number of known labels, the continuous spectrum of political views, and the preservation of both a polarity score and a polarity-neutral semantic meaning in an embedding vector of words. To attempt to overcome these challenges, we propose the Polarity-aware Embedding Multi-task learning (PEM) model. This model consists of (1) a self-supervised context-preservation task, (2) an attention-based tweet-level polarity-inference task, and (3) an adversarial learning task that promotes independence between an embedding's polarity dimension and its semantic dimensions. Our experimental results demonstrate that our PEM model can successfully learn polarity-aware embeddings. We examine a variety of applications and we thereby demonstrate the effectiveness of our PEM model. We also discuss important limitations of our work and stress caution when applying the PEM model to real-world scenarios.Comment: Submitted to EPJ -- Data Science, under revie

Distinct Patterns of Tropical Pacific SST Anomaly and Their Impacts on North American Climate

A neural-network-based cluster technique, the so-called self-organizing map (SOM), was performed to extract distinct sea surface temperature (SST) anomaly patterns during boreal winter. The SOM technique has advantages in nonlinear feature extraction compared to the commonly used empirical orthogonal function analysis and is widely used in meteorology. The eight distinguishable SOM patterns so identified represent three La Niña–like patterns, two near-normal patterns, and three El Niño–like patterns. These patterns show the varied amplitude and location of the SST anomalies associated with El Niño and La Niña, such as the central Pacific (CP) and eastern Pacific (EP) El Niño. The impact of each distinctive SOM pattern on winter-mean surface temperature and precipitation changes over North America was examined. Based on composite maps with observational data, each SOM pattern corresponds to a distinguishable spatial structure of temperature and precipitation anomaly over North America, which seems to result from differing wave train patterns, extending from the tropics to mid–high latitudes induced by longitudinally shifted tropical heating. The corresponding teleconnection as represented by the National Center for Atmospheric Research Community Atmospheric Model, version 4 (CAM4), was compared with the observational results. It was found that the 16-member ensemble average of the CAM4 experiments with prescribed SST can reproduce the observed atmospheric circulation responses to the different SST SOM patterns, which suggests that the circulation differences are largely SST driven rather than due to internal atmospheric variability

The association between serum uric acid and blood pressure in different age groups in a healthy Chinese cohort

High serum uric acid (sUA) has been reported to be a risk factor for hypertension however, whether this is the case for all age groups is not clear. We examined the association between sUA concentrations and systolic and diastolic blood pressure (SBP and DBP) in different age groups in a cohort of healthy Chinese participants. A total of 1082 healthy participants aged from 41 to 70 years were included. sUA concentration was measured by the uricaseperoxidase method. SBP and DBP were assessed using mercury sphygmomanometry. Hypertension was defined as SBP ≥140 mm Hg or DBP ≥90 mm Hg. Hyperuricemia (HUA) was defined as sUA concentration of >7mg/dL in men and >6mg/dL in women. The association between sUA concentration and SBP and DBP was examined using Pearson's correlation test, multivariate linear regression, and logistic regression analysis. The prevalence of hypertension and HUA increased with age (P<.001). Hypertension was more common in participants that had HUA than in those that did not (38.95% vs 30.16%, P=.02). Higher sUA was significantly associated with higher SBP and DBP in the 41- to 50-year-old participants (SBP, b=0.35, P<.001; DBP, b=.29, P<.001; after adjustment for age, sex, total cholesterol, estimated glomerular filtration rate, and fasting plasma glucose). HUA was also a risk factor for hypertension in this age group (odds ratio 1.425, 95% confidence interval, 1.217–1.668, P<.001). There was no association between sUA concentration and SBP and DBP in the other age groups. In this population of healthy Chinese participants, sUA concentration was positively associated with hypertension only in the 41- to 50-year-old group. Lowering uric acid in this age group may help to reduce the incidence of hypertension

A Sir2-Like Protein Participates in Mycobacterial NHEJ

In eukaryotic cells, repair of DNA double-strand breaks (DSBs) by the nonhomologous end-joining (NHEJ) pathway is critical for genome stability. In contrast to the complex eukaryotic repair system, bacterial NHEJ apparatus consists of only two proteins, Ku and a multifunctional DNA ligase (LigD), whose functional mechanism has not been fully clarified. We show here for the first time that Sir2 is involved in the mycobacterial NHEJ repair pathway. Here, using tandem affinity purification (TAP) screening, we have identified an NAD-dependent deacetylase in mycobacteria which is a homologue of the eukaryotic Sir2 protein and interacts directly with Ku. Results from an in vitro glutathione S-transferase (GST) pull-down assay suggest that Sir2 interacts directly with LigD. Plasmid-based end-joining assays revealed that the efficiency of DSB repair in a sir2 deletion mutant was reduced 2-fold. Moreover, the Δsir2 strain was about 10-fold more sensitive to ionizing radiation (IR) in the stationary phase than the wild-type. Our results suggest that Sir2 may function closely together with Ku and LigD in the nonhomologous end-joining pathway in mycobacteria

Comprehensive identification of alternative back-splicing in human tissue transcriptomes

Circular RNAs (circRNAs) are covalently closed RNAs derived from back-splicing of genes across eukaryotes. Through alternative back-splicing (ABS), a single gene produces multiple circRNAs sharing the same back-splice site. Although many ABS events have recently been discovered, to what extent ABS involves in circRNA biogenesis and how it is regulated in different human tissues still remain elusive. Here, we reported an in-depth analysis of ABS events in 90 human tissue transcriptomes. We observed that ABS occurred for about 84% circRNAs. Interestingly, alternative 5\u27 back-splicing occurs more prevalently than alternative 3\u27 back-splicing, and both of them are tissue-specific, especially enriched in brain tissues. In addition, the patterns of ABS events in different brain regions are similar to each other and are more complex than the patterns in non-brain tissues. Finally, the intron length and abundance of Alu elements positively correlated with ABS event complexity, and the predominant circRNAs had longer flanking introns and more Alu elements than other circRNAs in the same ABS event. Together, our results represent a resource for circRNA research-we expanded the repertoire of ABS events of circRNAs in human tissue transcriptomes and provided insights into the complexity of circRNA biogenesis, expression, and regulation