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In order to solve the dynamic analysis and chaotic motion control problems of the current-mode-controlled Boost converter system, a state equation model in the continuous current mode is established. The evolutionary path of the periodic motion of the system through the doubling bifurcation to the chaotic motion is analyzed by the bifurcation diagram, Poincaré sections and phase portraits. Then, according to the fundamental principle of the resonant parametric perturbation (RPP) method, a controller is designed based on the model-free adaptive control (MFAC) method to output the perturbation amplitude, and the disturbance quantity is calculated according to the perturbation amplitude. By adding a small amplitude disturbance to the controllable parameter of the controlled system, the chaotic motion of the system is guided to expected periodic orbit. The advantage of this method is that no precise mathematical model (PMM) of the system is required. At the same time, the design of the controller is simple and easy to implement. [ABSTRACT FROM AUTHOR]

In order to study the effect of ignition position on the deflagration characteristics of oil mist in ship cabins, a self-constructed simulated cabin experimental platform was created to conduct experiments on the effect of ignition position on oil mist deflagration characteristics. The results indicate that the deflagration process of oil mist under various conditions can be divided into four stages, they are respectively deflagration, turbulent combustion, flame stretch and self-extinguishing. The peak velocity of flame propagation decreases with the increasing of the distance between the ignition position and the nozzle. When the distance increases from 13 cm to 83 cm, the peak velocity decreases by 6 m/s with a reduction of 57.14%. The peak temperature inside the cabin decreases with the increasing of the distance between the ignition position and the nozzle. When the distance increases from 13 cm to 83 cm, the peak temperature decreases by 118.2°C with a reduction of 13.94%. The pressure distribution inside the cabin after ignition increases first and then decreases. As the distance between the ignition position and the nozzle increases, the peak pressure at various positions also increases, and the maximum peak pressure is located at 110 cm in the cabin. At the ignition position of 83 cm, the peak pressure reaches the maximum value of 1.603 MPa, which increases by 0.858 MPa (115.17%) compared with the ignition position of 13 cm. [ABSTRACT FROM AUTHOR]

The pipe structures and opening conditions have an important influence on gas explosion, but little research has been done on the coupling analysis of the two. In order to reveal the effect of pipe structure on the flammability characteristics of hydrogen-air premixed gas under end-opening conditions, the flame structure, flame propagation velocity, explosion pressure and flow field distribution in the explosion process of hydrogen-air premixed gas in different pipe structures were analyzed by numerical simulation. The results show that the flame propagation velocity and pressure are less influenced by the end-opening structure in the initial ignition stage, however, when the flame propagates to the pipe end, the flame propagation velocity in each pipe structure is significantly enhanced. The 90° elbow has a certain inhibitory effect on the flame development, while the T-shaped bifurcation structure can effectively increase the degree of gas detonation. In pipe with large aspect ratio, due to the wall effect, the effect of acoustic oscillation disturbance on the flame front and the air-flow release effect of the end-opening, there are two peaks and two troughs in the pressure rise rate curve of each pipe-line structure. [ABSTRACT FROM AUTHOR]

For the chaotic motion control of a vibro-impact system with clearance, the parameter feedback chaos control strategy based on the data-driven control method is presented in this article. The pseudo-partial-derivative is estimated on-line by using the input/output data of the controlled system so that the compact form dynamic linearization (CFDL) data model of the controlled system can be established. And then, the chaos controller is designed based on the CFDL data model of the controlled system. And the distance between two adjacent points on the Poincaré section is used as the judgment basis to guide the controller to output a small perturbation to adjust the damping coefficient of the controlled system, so the chaotic motion can be controlled to a periodic motion by dynamically and slightly adjusting the damping coefficient of the controlled system. In this method, the design of the controller is independent of the order of the controlled system and the structure of the mathematical model. Only the input/output data of the controlled system can be used to complete the design of the controller. In the simulation experiment, the effectiveness and feasibility of the proposed control method in this article are verified by simulation results. [ABSTRACT FROM AUTHOR]

Objective: This study was designed to investigate the hypothesis that dietary quercetin (QUE) and coated sodium butyrate (SB) supplementation alleviate oxidative stress in the small intestine of diquat (DIQ)-challenged pullets. Methods: A total of 200 13-week-old pullets were divided into four groups: the control group (CON), the DIQ group, the QUE group, and the coated SB group, and injected intraperitoneally with either saline (CON) or diquat (DIQ, QUE, and SB) to induce oxidative stress on day 0. Results: On the first day, the malondialdehyde and superoxide dismutase (SOD) concentrations in the SB group were significantly different from those in the DIQ and QUE groups (p<0.05), and dietary supplementation with SB increased serum glutathione peroxidase (GSH-PX) levels compared with the DIQ group (p<0.05). Quercetin and SB increased the levels of CLAUDIN-1 and zonula occludens-1 (ZO-1) in the jejunum. On the tenth day of treatment, QUE attenuated the decrease in GSH-PX levels compared to those of the CON group (p<0.05), while SB increased SOD, GSH-PX, and total antioxidant capacity levels compared to those of the DIQ group. Nuclear factor erythroid 2-related factor 2 (NRF2) and heme oxygenase-1 (HO-1) mRNA levels in the QUE and SB groups increased (p<0.05) and CLAUDIN-1 mRNA levels in the QUE and SB groups were upregulated compared to those in the DIQ group ileum tissue. Conclusion: Supplementation of QUE and SB demonstrated the ability to relieve oxidative stress in pullets post DIQ-injection with a time-dependent manner and QUE and SB may be potential antioxidant additives for relieving oxidative stress and protecting the intestinal barrier of pullets. [ABSTRACT FROM AUTHOR]

Ultrawideband (UWB) technology has received considerable attention in indoor positioning because of its high ranging accuracy. However, UWB range measurements can be contaminated by the delayed signals resulting from obstruction and reflection in difficult indoor environments. These signals introduce delays to range measurements and degrade positioning accuracy if they are not resolved properly. In order to mitigate the effects of delayed range measurements on positioning and achieve a high-accuracy position estimation, this paper proposes a robust particle-filter-based indoor positioning algorithm. In the proposed algorithm, an outlier detection method is proposed for delayed measurement identification, and a constrained particle sampling method is proposed to optimize the distribution of the predicted particles. The proposed algorithm is assessed rigorously through testing. The test results show that the proposed algorithm can effectively identify delayed range measurements, mitigate their effects on position estimation, and improve positioning accuracy. [ABSTRACT FROM AUTHOR]

The introduction of innovative assessment techniques for the French horn can improve the process of education. The objective is to examine the effectiveness of the proposed assessment methods for improving accuracy on the French horn. The research is based on the experimental design to evaluate the effectiveness of assessment methods using statistical data analysis and paired t-test. The research took place from January to June during the 2020-2021 academic year. The sample involved 183 students from three educational institutions in the People's Republic of China. A preliminary assessment found that the academic performance of students was low. Before the implementation of the proposed assessment methods, an average score was 20.63 points interpreted by the scholars as Do not Meet Academic Expectations. After the introduction of the assessment methods, the post-implementation scores of the academic performance increased by 41.3%. The findings were interpreted as a Satisfactory level of academic performance. The paired t-test revealed significant differences in student performance learning the French horn before and after the introduction of the new assessment methods. The average difference was 3.57 points. Thus, the proposed assessment methods for the French horn playing include (1) playing by ear, (2) Instrumental Scheme Processing, (3) a range practice, and (4) an introductory exam. The research demonstrates that the assessment methods of performance can be used as a part of the standard assessment developed for teachers that include different elements of effective teaching tools and methods. [ABSTRACT FROM AUTHOR]

Objective(s): Gleditsiae spina (GS) is a natural antidepressant but its mechanisms of action remain unclear. In the present study, taxifolin (Tax) was selected to determine the role of flavonoids in the antidepressant effects of GS. Materials and Methods: Urine samples from C57BL/6 mice were analyzed based on ultra performance liquid chromatography-quadrupole time of flight mass spectrometry (UPLC-Q/TOFMS). Then, we investigated the therapeutic effects of GS and Tax in depression models in vivo. An integrated metabolomic approach was used to examine the metabolic profiles of GS/Tax groups and corticosterone model groups (Cor). Metabolic networks in response to GS/Tax treatment were established for the comparison of antidepressant activities. Results: Corticosterone exposure significantly increased serum levels of corticosterone but decreased serum levels of 5-hydroxytryptamine and sucrose consumption (P<0.01). Treatment with GS and Tax improved all measured variables compared to those of the corticosterone-exposed group (P< 0.01). The antidepressant effects of GS and Tax involved the regulation of pentose and glucuronate interconversions, arginine and proline metabolism, phenylalanine metabolism, taurine and hypotaurine metabolism, and the citrate cycle. Conclusion: These findings indicate that flavonoids form the pharmacodynamic basis of the antidepressant effects of GS. Moreover, our findings highlight that integrated metabolomics provides a powerful tool to study the mechanisms and material basis of Chinese herbs. [ABSTRACT FROM AUTHOR]

Metal-free atom transfer radical polymerization (ATRP) was successfully achieved in aqueous media for the first time. Polymerization of poly(ethylene oxide) methyl ether acrylate (PEGA480) was well controlled (Đ < 1.40) under visible light irradiation using tetrabromofluorescein (Eosin Y) as catalyst and pentamethyldiethylenetriamine (PMDETA) as electron donor. A validated kinetic model was developed to investigate the process of photoredox catalytic cycle via reductive quenching pathway. Experimental and simulation results showed that electron donor not only had an important influence on the ATRP activation, but also participated in the ATRP deactivation. Furthermore, the effects of water content, catalyst concentration, and degree of polymerization on the polymerization were studied thoroughly by a series of experiments. Good controllability of the polymerization regulated by light on and off confirmed the high degree of temporal control. The livingness of the chains was proved by a successful chain extension experiment. Both experimental and simulation techniques were used to study aqueous metal-free ATRP, which provided a promising method to synthesize polymers in the absence of metal and organic solvent. [ABSTRACT FROM AUTHOR]

Thermoresponsive random copolymers consisting of poly(N-isopropylacrylamide) (PNIPAM) and polymerized ionic liquid (IL) poly(1,1,3,3-tetramethylguanidine acrylate) (PTMGA) were synthesized via reversible addition-fragmentation chain transfer radical polymerization (RAFT). The reactivity ratios of NIPAM (rNIPAM = 2.11) and TMGA (rTMGA = 0.56) were determined by the extended Kelen-Tödüs method. Glass transition temperatures (Tg) of the copolymers were analyzed, which followed the Fox equation very well. The phase transition behaviors of the copolymers in aqueous solution were studied through UV-vis transmission measurements. Their lower critical solution temperature (LCST) ranged from 30.5 to 73.2 °C, depending on the hydrophilic IL content. The apparent pKa related to LCST was determined, and thus the protonation degree was calculated. The hydrophilicity of the copolymers could be regulated by gas treatments. Bubbling CO2 led to lowering the transition temperature while bubbling N2 resulted in its recovery. This CO2/N2 switchability became more profound with higher IL content. With the ability to undergo reversible protonation caused by the change of pH, the system showed good reversibility in LCST when bubbled with CO2 and N2. SO2 could also be used to lower LCST. However, a basic compound (e.g., NaOH) was required for its recovery. The pH-dependent solution phase transition behavior provided great insight into the LCST regulation mechanism. The widest LCST shifting window (~12 °C) was found between pH 5.16 and 5.96, which could be fulfilled by the CO2 regulation approach. This work provides guidance for the design and synthesis of gas-switchable thermoresponsive polymers based on ionic liquids. [ABSTRACT FROM AUTHOR]

It has been reported that hsa‑microRNA (miRNA/miR)‑372 functions as a tumor suppressor or oncogene in various digestive system tumors, however, its roles in gallbladder cancer (GBC) are yet to be established. The present study aimed to determine the expression and clinical relevance of hsa‑miR‑372 in GBC. The expression of hsa‑miR‑372 in 80 pairs of human GBC tissues and adjacent normal gallbladder tissues was measured by reverse transcription‑quantitative polymerase chain reaction. Subsequently, the associations between hsa‑miR‑372 expression levels and the clinicopathological characteristics of patients with GBC were determined using χ2 test. Furthermore, Kaplan‑Meier method and Cox regression analysis were performed to evaluate the association between hsa‑miR‑372 expression and the prognosis of patients with GBC. Furthermore, a dual‑luciferase reporter assay and western blot analysis were performed to predict and verify the target gene of hsa‑miR‑372. The results demonstrated that markedly lower hsa‑miR‑372 expression was observed in GBC tissues, which was associated with poor prognosis in patients with GBC. Downregulated expression of hsa‑miR‑372 was negatively associated with tumor histological grade, tumor‑node‑metastasis stage, lymph node metastasis and distant metastasis, however, no association was observed between reduced hsa‑miR‑372 expression and patient gender, age, tumor size and gallbladder stones. Multivariate Cox regression analysis revealed that hsa‑miR‑372 expression, histological grade and lymph node metastasis were independent prognostic factors for overall survival in patients with GBC. Chloride intracellular channel 1 (CLIC1) was previously reported to be an effective biomarker for predicting the prognosis of GBC. Notably, the results of the present study indicated that CLIC1 may be a direct target gene of hsa‑miR‑372. In conclusion, the current study provides the first statistically convincing evidence that downregulation of hsa‑miR‑372 may occur in GBC tissues, which may be associated with aggressive and progressive tumor behavior by affecting CLIC1 expression. [ABSTRACT FROM AUTHOR]

For the chaotic motion control of a single-degree-of-freedom vibro-impact system with soft constraint, two-parameter cooperative intelligent optimal control method based on LRS-QPSO (i.e., Local Rotational Search Quantum Particle Swarm Optimization) algorithm optimization SVM (i.e., Support Vector Machines) was proposed. Firstly, in the parameter plane (ω,ζ), the motion distribution of the system and the change of the maximum Lyapunov exponent is obtained by numerical simulation, and the correlation between parameters change and the transition from chaotic motion to periodic motion is analyzed. Secondly, by introducing ω and ζ into the construction of the input variables of the SVM controller, a chaotic motion two-parameter cooperative intelligent optimal control strategy is proposed to meet the requirements of expected control objectives. Therefore, by the virtue of nonlinear mapping characteristics of SVM, the combined effects of ω and ζ on the dynamic state transition of the system can be reflected in the output variables of the controller. Finally, with single parameter ω and single parameter ζ as the research object, the bifurcation diagram, Lyapunov exponential spectrum, and controlled periodic motion orbit diagram are analyzed, and the advantages of two-parameter cooperative intelligent optimal control are compared and analyzed. [ABSTRACT FROM AUTHOR]

Findings from previous studies demonstrating the effects of perceived social exclusion on social behaviors have been inconsistent. We used self-construal as a moderator to test the effects of perceived social exclusion on recycling behavior. A survey of 606 participants was conducted in Beijing, China. Results show that, for the independent self-construal group, perceived social exclusion had significantly negative effects on their recycling attitudes and subjective norms; in contrast, for the interdependent self-construal group, significantly positive effects were identified. In addition, because of differences in their attitudes toward recycling, their subjective norms, and their perceived behavior control, there was a significant difference in recycling behavior between people with a predominantly independent self-construal and people with a predominantly interdependent self-construal. These findings fill gaps in the literature concerning the effects of perceived social exclusion on recycling behavior. [ABSTRACT FROM AUTHOR]

The study examined whether the benefit of deactivating stimulation sites estimated to have broad neural excitation was attributed to improved spectral resolution in cochlear implant users. The subjects' spatial neural excitation pattern was estimated by measuring low-rate detection thresholds across the array [see Zhou (2016). PLoS One 11, e0165476]. Spectral resolution, as assessed by spectral-ripple discrimination thresholds, significantly improved after deactivation of five high-threshold sites. The magnitude of improvement in spectral-ripple discrimination thresholds predicted the magnitude of improvement in speech reception thresholds after deactivation. Results suggested that a smaller number of relatively independent channels provide a better outcome than using all channels that might interact. [ABSTRACT FROM AUTHOR]

Aims Increased aortic stiffness is a fundamental manifestation of hypertension. However, the molecular mechanisms involved remain largely unknown. We tested the hypothesis that abnormal intrinsic vascular smooth muscle cell (VSMC) mechanical properties in large arteries, but not in distal arteries, contribute to the pathogenesis of aortic stiffening in hypertension, mediated by the serum response factor (SRF)/myocardin signalling pathway. Methods and results Four month old male spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats were studied. Using atomic force microscopy, significant VSMC stiffening was observed in the large conducting aorta compared with the distal arteries in SHR (P < 0.001), however, this regional variation was not observed in WKY rats (P > 0.4). The increase of VSMC stiffness was accompanied by a parallel increase in the expression of SRF by 9.8-fold and of myocardin by 10.5-fold in thoracic aortic VSMCs from SHR vs. WKY rats, resulting in a significant increase of downstream stiffness-associated genes (all, P < 0.01 vs. WKY). Inhibition of SRF/myocardin expression selectively attenuated aortic VSMC stiffening, and normalized downstream targets in VSMCs isolated from SHR but not from WKY rats. In vivo, 2 weeks of treatment with SRF/myocardin inhibitor delivered by subcutaneous osmotic minipump significantly reduced aortic stiffness and then blood pressure in SHR but not in WKY rats, although concomitant changes in aortic wall remodelling were not detected during this time frame. Conclusions SRF/myocardin pathway acts as a pivotal mediator of aortic VSMC mechanical properties and plays a central role in the pathological aortic stiffening in hypertension. Attenuation of aortic VSMC stiffening by pharmacological inhibition of SRF/myocardin signalling presents a novel therapeutic strategy for the treatment of hypertension by targeting the cellular contributors to aortic stiffness. [ABSTRACT FROM AUTHOR]

Matrine, an alkaloid component derived from the Sophora root, can inhibit cancer cell proliferation and induce autophagy via p53 associated pathways. However, numerous tumor cells lack functional p53 and little is known about the effect of matrine on the p53-deficient/mutant cancer cells. The present study aimed to assess anticancer effects of matrine in p53-deficient human Hep3B hepatoma cells. The present results demonstrated that matrine caused Hep3B cell apoptosis by suppressing gene expression of minute double-mutant (MDM)2. Notably, it was revealed that matrine inhibited MDM2 at the transcriptional level in a time- and dose-dependent manner. This MDM2 inhibition resulted in induction of the p53 family member, p73; however, the functions of p73 were not induced since matrine-induced p73 failed to activate its target genes, p21 and p53 upregulated modulator of apoptosis. The matrine-induced downregulation of MDM2 led to an inhibition of inhibitor of apoptosis protein 3, which might serve a critical role in matrine-induced apoptosis in MDM2-overexpressing Hep3B cells. Finally, combination therapy of matrine with 100 µM epotoside successfully killed more Hep3B cells, suggesting that matrine can sensitize p53-deficient Hep3B cells to epotoside-induced apoptosis. [ABSTRACT FROM AUTHOR]

Oil/water separation has inspired much research interest because of the damages caused to our natural environment due to oily wastewater. As a leader of advanced separation materials, electrospun polymeric fibrous mats having the properties of special surface wettability, high specific surface area, and high porosity will be a good membrane material for the separation of oily wastewater. Herein, we first prepared pH-responsive polymer poly(dimethylsiloxane)-block-poly(4-vinylpyridine) (PDMS-b-P4VP) mat using electrospinning technology. The PDMS-b-P4VP fibrous mat with a thickness of around 250 μm exhibits good pH-switchable oil/water wettability and is able to effectively separate oil or water from layered oil/water mixtures by gravity driven through adjusting the pH value. Stemming from its porous structure and pH-switchable superwettability, the electrospun PDMS-b-P4VP fibrous mat achieved controllable separations with high fluxes of approximately 9000 L h-1 m-2 for oil (hexane) and 27 000 L h-1 m-2 for water. In addition, extended studies on the polymer/silica nanoparticulate (silica NP) composite fibrous mats show that the addition of an inorganic component improves the thermal stability, pH-switchable wettability, and separation performance of the fibrous mats (approximately 9000 L h-1 m-2 for hexane and 32 000 L h-1 m-2 for water). It can be concluded from the results that both polymer fibrous mats and silica-filled composite fibrous mats are good candidates for on-demand layered oil/water mixture separation. [ABSTRACT FROM AUTHOR]

The objectives of the study were to (1) investigate the potential of using monopolar psychophysical detection thresholds for estimating spatial selectivity of neural excitation with cochlear implants and to (2) examine the effect of site removal on speech recognition based on the threshold measure. Detection thresholds were measured in Cochlear Nucleus® device users using monopolar stimulation for pulse trains that were of (a) low rate and long duration, (b) high rate and short duration, and (c) high rate and long duration. Spatial selectivity of neural excitation was estimated by a forward-masking paradigm, where the probe threshold elevation in the presence of a forward masker was measured as a function of masker-probe separation. The strength of the correlation between the monopolar thresholds and the slopes of the masking patterns systematically reduced as neural response of the threshold stimulus involved interpulse interactions (refractoriness and sub-threshold adaptation), and spike-rate adaptation. Detection threshold for the low-rate stimulus most strongly correlated with the spread of forward masking patterns and the correlation reduced for long and high rate pulse trains. The low-rate thresholds were then measured for all electrodes across the array for each subject. Subsequently, speech recognition was tested with experimental maps that deactivated five stimulation sites with the highest thresholds and five randomly chosen ones. Performance with deactivating the high-threshold sites was better than performance with the subjects' clinical map used every day with all electrodes active, in both quiet and background noise. Performance with random deactivation was on average poorer than that with the clinical map but the difference was not significant. These results suggested that the monopolar low-rate thresholds are related to the spatial neural excitation patterns in cochlear implant users and can be used to select sites for more optimal speech recognition performance. [ABSTRACT FROM AUTHOR]

In this work, a photoinduced iron(III)-based atom transfer radical polymerization (ATRP) without any reducing agents and additional initiators was suggested. In addition, detailed kinetic studies, including the effects of ligand and catalyst concentrations on polymerization kinetics, and the polymerization behaviors using various solvents and monomer types were evaluated for this new polymerization technique. Results showed that photoinduced iron(III)-mediated ATRP using 5000 ppm catalyst loading with 1 equiv of ligand in N,N-dimethylformamide (DMF) produced poly(methyl methacrylate) with low molecular weight distribution (Mw/Mn < 1.45) and that the evolution of molecular weight (Mn) was linearly related to monomer conversion. ¹H NMR analysis confirmed that the resulting polymer prepared through photoinduced ATRP in the present work was initiated by methyl 2,3-dichloroisobutyrate. Facile temporal control and the successful chain extension highlighted the good chain-end functionality of the resulting polymers. In short, this work provided a study on additional alkyl halides initiator-free ATRP and its application in the synthesis of methacrylate polymers with narrow Mw/Mn. [ABSTRACT FROM AUTHOR]

The decrease of psychophysical detection thresholds as a function of pulse rate for a fixed-duration electrical pulse train is referred to as multipulse integration (MPI). The MPI slopes correlate with anatomical and physiological indices of cochlear health in guinea pigs with cochlear implants. The aim of the current study was to assess whether the MPI slopes were related to the spatial spread of activation by electrical stimulation. The hypothesis was that MPI is dependent on the total number of excitable neurons at the stimulation site, with broader neural excitation producing a steeper threshold decrease as a function of stimulation rate. MPI functions were measured at all stimulation sites in 22-site electrode arrays in human subjects. Some sites with steep MPI functions and other sites with shallow functions were assessed for spatial spread of excitation at 900 pps using a forward-masking paradigm. The results showed a correlation between the slopes of the forward-masking functions and the steepness of MPI, with broader stimulation predicting greater integration. The results are consistent with the idea that integration of multiple pulses in a pulse train relies on the number of excitable neurons at the stimulation site. [ABSTRACT FROM AUTHOR]

An increasing number of studies have demonstrated that the dysregulation of long non-coding RNAs (lncRNAs) may serve an important role in tumor progression. Previous studies have reported that the lncRNA, colon cancer associated transcript 2 (CCAT2), was highly expressed in various tumors. However, the function of CCAT2 in hepatocellular carcinoma (HCC) has not yet been elucidated. The aim of the present study was to identify novel oncogene lncRNAs and investigate their physiological function and mechanism in HCC. Using reverse transcription-quantitative polymerase chain reaction, it was observed that CCAT2 was upregulated in HCC tissues and human HCC cell lines. Furthermore, the impacts of CCAT2 on cell proliferation, migration and apoptosis were analyzed using cell migration, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and enzyme-linked immunosorbent assay analysis respectively. The overexpression of CCAT2 using a synthesized vector significantly promoted cell migration and proliferation, and inhibited apoptosis of HCC cells in vitro. The suppression of CCAT2 expression resulted in opposing effects. To the best of our knowledge, the present study is the first to demonstrate that CCAT2 functions as a oncogene in HCC. Further investigation is required to clarify the molecular mechanisms of this lncRNA in HCC development. [ABSTRACT FROM AUTHOR]

An iron- and methyl methacrylate (MMA)-based electrochemically mediated atom transfer radical polymerization (eATRP) system was developed for the first time. Kinetic behaviors, including the effect of applied potential and catalyst loading, were systematically investigated. Results indicated that with more negative electrode potential, the polymerization rate increased until the mass transport limitation was reached. However, reduction of the catalyst loading had adverse effects on polymerization behaviors, such as decreased polymerization rate and increased molecular weight distributions (Mw/Mn). In addition, a kinetic model based on the method of moments was also constructed to explain the mismatch in Mn and Mn,theo. Simulation results showed that slow initiation significantly influenced on the kinetic behaviors in this system. Iron(II) bromide-catalyzed normal ATRP, iron(III) bromide-catalyzed eATRP, and copper(II) bromide-catalyzed eATRP were conducted to compare and elucidate their respective polymerization reaction kinetic characteristics qualitatively. This work expanded the scope of eATRP from a copper-based system to an iron-based system in terms of polymerization kinetics, with the hope of promoting the widespread application of this method. [ABSTRACT FROM AUTHOR]

Background: Helicobacter pylori is an important pathogenic factor in gastric carcinogenesis. Angiogenesis (i.e., the growth of new blood vessels) is closely associated with the incidence and development of gastric cancer. Our previous study found that COX-2 stimulates gastric cancer cells to induce expression of the angiogenic growth factor VEGF through an unknown mechanism. Therefore, the aim of this study was to clarify the role of angiogenesis in H. pylori-induced gastric cancer development.Methods: To clarify the relationship between H. pylori infection and angiogenesis, we first investigated H. pylori colonization, COX-2, VEGF, beta-catenin expression, and microvessel density (MVD) in gastric cancer tissues from 106 patients. In addition, COX-2, phospho-beta-catenin, and beta-catenin expression were measured by western blotting, and VEGF expression was measured by ELISA in H. pylori-infected SGC7901 and MKN45 human gastric cancer cells.Results: H. pylori colonization occurred in 36.8 % of gastric carcinoma samples. Furthermore, COX-2, beta-catenin, and VEGF expression, and MVD were significantly higher in H. pylori-positive gastric cancer tissues than in H. pylori-negative gastric cancer tissues (P < 0.01). H. pylori infection was not related to sex or age in gastric cancer patients, but correlated with the depth of tumor invasion, lymph node metastasis, and tumor-node-metastasis stage (P < 0.05) and correlated with the COX-2 expression and beta-catenin expression(P < 0.01). Further cell experiments confirmed that H. pylori infection upregulated VEGF in vitro. Further analysis revealed that H. pylori-induced VEGF expression was mediated by COX-2 via activation of the Wnt/beta-catenin pathway.Conclusions: The COX-2/Wnt/beta-catenin/VEGF pathway plays an important role in H. pylori-associated gastric cancer development. The COX-2/Wnt/beta-catenin pathway is therefore a novel therapeutic target for H. pylori-associated gastric cancers. [ABSTRACT FROM AUTHOR]

Objective: To study microRNA (miR)-20a expression in hepatocellular carcinoma (HCC) and its effects on the proliferation, migration, and invasion of HepG2. Methods: The real-time polymerase chain reaction was used to detect the expression of miR-20a in HCC tissue and normal tissue, as well as in HCC cell lines and normal liver cells. miR-20a mimic and miR negative control (NC) were transfected into HepG2 cells. MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay was used to detect cell proliferation. Annexin fluorescein isothiocyanate/propidium iodide assay was run to examine the early apoptosis of cells. Transwell chamber assay was carried out to investigate the cell invasion and migration abilities. Results: miR-20a was lowly expressed both in HCC tissues and HCC cell lines. After transfection of exogenous miR-20 mimics, miR-20a expression in HepG2 cells was significantly increased by 61.29% compared to the blank group (P<0.01). MTT assay showed that the growth of HepG2 cells in the miR-20a mimics group was significantly inhibited, and optical density values during the 36-96 hour time period were dramatically decreased compared to the blank group (P<0.01). Apoptosis rates of the miR-20a mimics group were higher than those of the blank and NC groups (both P<0.01). The number of HCC cells after transfection by miR-20a mimics in the G1 and S phases were 15.88% and 7.89%, respectively, which were lower than in the blank and NC groups (both P<0.05). Transwell assay showed that in the miR-20a mimics group the number of cell migration and invasion were 0.459 and 0.501 times that of the blank group (both P<0.01), and the migration and inhibition rates were 54.1% and 51.4%, respectively. After closing target gene CCND1 in HepG2 cells, the number of cell migration and invasion in the small interfering (si)-CCND1 group were 0.444 and 0.435 times that of the si-NC group (P<0.05); and compared to the si-NC group, the migration and inhibition rates were 55.6% and 56.5%, respectively. Conclusion: miR-20a can inhibit the growth, invasion, and migration of HepG2 cells, and is therefore promising as a new molecular target for diagnosis and therapy of HCC. [ABSTRACT FROM AUTHOR]

The present study evaluated the slopes of threshold-versuspulse-rate functions (multipulse integration, MPI) in humans with cochlear implants in relation to recovery from 300-ms forward maskers. MPI has been correlated with spiral ganglion cell density in animals. The present study showed that steeper MPI functions were correlated with faster recovery from forward masking. The findings suggested that the variations in the MPI slopes are explained not only by the quantity of neurons contributing to the integration process but also by the neurons' temporal response characteristics and possibly central inhibition. [ABSTRACT FROM AUTHOR]

Resistance to chemotherapy is a major challenge in the effective treatment of patients with gastric cancer; however, the mechanisms underlying chemoresistance in gastric cancer cells are yet to be elucidated. MicroRNAs (miRNAs) have previously been associated with cancer progression and sensitivity to chemotherapy; therefore, the present study aimed to identify miRNAs that may influence the sensitivity of human gastric cancer cells to cisplatin (DDP) treatment. Initially, miRNAs that were differentially expressed between the DDP-sensitive SGC7901 human gastric cancer cell line and DDP-resistant SGC7901/DDP cell line were identified using high-throughput sequencing technology. miRNA-375 (miR-375), which was shown to be downregulated in the SGC7901/DDP cells, has previously been associated with numerous types of cancer; however, to the best of our knowledge, a role for miR-375 in the DDP-sensitivity of gastric cancer cells has yet to be explored. In the present study, the expression levels of miR-375 were significantly downregulated in the SGC7901/DDP cells, as compared with the SGC7901 cells, as demonstrated by reverse transcription-quantitative polymerase chain reaction. In addition, upregulation of miR-375 significantly enhanced the anti-proliferative and apoptosis-inducing effects of DDP, whereas downregulation of miR-375 decreased these effects. Subsequently, western blot analysis demonstrated that upregulation of miR-375 in the SGC7901/DDP cells increased their sensitivity to DDP treatment via regulating the protein expression levels of erb-b2 receptor tyrosine kinase 2 and phosphorylated-Akt. The results of the present study indicate that the expression levels of miR-375 may influence the sensitivity of human gastric cancer cells to the effects of DDP; thus suggesting that a combination of miR-375 regulation and DDP may be considered a novel strategy in the treatment of patients with chemoresistant gastric cancer. [ABSTRACT FROM AUTHOR]

Litter size is one of the most important economic traits for pig production as it is directly related to production efficiency. To evaluate the effects of the adiponectin (ADIPOQ) gene on porcine litter size, we investigated ADIPOQ polymorphisms in three breeds, Wannan Black pigs, Berkshire pigs, and BW pigs (crossbred pigs produced from mating male Berkshire pigs and female Wannan Black pigs), using the PCR-SSCP method. Three SNPs (c. 178G > A, c. 1165A > G, and c. 1138G > A) were identified. In Wannan Black pigs, association analysis indicated that the c. 178G > A SNP genotype was significantly associated with an effect on total number born (TNB; P < 0.05) and the number born alive (NBA; P < 0.05) in primiparity. The c.1138G > A SNP was significantly associated with an effect on TNB (P < 0.05) and NBA (P < 0.05) in primiparity and multiparity. In addition, three of the nine possible genotype combinations, AACC, AACD, and AGCD, were found. AGCD resulted in primiparous and multiparous sows with the highest TNB. These results indicated that polymorphisms in the ADIPOQ gene could be used for marker-assisted selection programs for the genetic improvement of reproductive characteristics in pigs. [ABSTRACT FROM AUTHOR]

Acute liver failure (ALF) is a kind of complicated syndrome. Furthermore, adipose-derived mesenchymal stem cells (ADMSCs) can serve as a useful cell resource for autotransplantation due to their abundance and micro-invasive accessability. However, it is unknown how ALF will influence the characteristics of ADMSCs and whether ADMSCs from patients suffering from end-stage liver diseases are potential candidates for autotransplantation. This study was designed to compare various properties of ALF-derived ADMSCs with normal ADMSCs in pig models, with regard to their cellular morphology, cell proliferative ability, cell apoptosis, expression of surface antigens, mitochondrial and lysosomal activities, multilineage potency, and expression of liver-specific genes. Our results showed that ALF does not influence the stem cell characteristics and cell activities of ADMSCs. Intriguingly, the expression levels of several liver-specific genes in ALF-derived ADMSCs are higher than in normal ADMSCs. In conclusion, our findings indicate that the stem cell characteristics and cell activities of ADMSCs were not altered by ALF and these cells can serve as a new source for regenerative medicine. [ABSTRACT FROM AUTHOR]

Purpose: Previous studies have reported the association of an insertion/deletion (Ins/Del) polymorphism (rs3783553) in the 3' untranslated region of interleukin-1A (IL-1A) with the risk of cancer, such as oral squamous cell carcinoma, nasopharyngeal carcinoma, and cervical carcinoma. However, the results are still inconsistent. The present meta-analysis aimed to clarify the association of IL-1A rs3783553 polymorphism with cancer risk. Methods: All eligible studies were selected from PubMed, Web of Science, and Chinese National Knowledge Infrastructure up to September 2, 2015. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate cancer risk. Results: A total of ten case-control studies with 4,514 cases and 6,689 controls were included this meta-analysis. We found that IL-1A rs3783553 polymorphism was significantly associated with cancer risk (Ins/Ins + Ins/Del vs Del/Del: OR =0.79, 95% CI =0.67-0.92; Ins/Ins vs Del/Del: OR =0.61, 95% CI =0.47-0.79; Ins/Ins vs Ins/Del + Del/Del: OR =0.67, 95% CI =0.55-0.83; Ins vs Del: OR =0.81, 95% CI =0.72-0.92). In the stratified analyses, significant effects were found among Asian populations (Ins/Ins + Ins/Del vs Del/Del: OR =0.81, 95% CI =0.69-0.95) and cervical carcinoma (Ins/Ins vs Del/Del: OR =0.51, 95% CI =0.34-0.76; Ins/Ins vs Ins/Del + Del/ Del: OR =0.52, 95% CI =0.35-0.78). Conclusion: Our meta-analysis suggests that the IL-1A rs3783553 polymorphism contributes to susceptibility to cancer. However, well-designed studies with larger sample sizes are required to verify the results. [ABSTRACT FROM AUTHOR]

To solve the problem of damage due to large dynamic stress of the lateral plates during working process of the vibration screen, it is necessary to calculate and analyze natural modes and distribution of dynamic stress of lateral plates, which is shown in results that the lateral plate structure shall be optimized. In this paper, with the total weight of the lateral plates for the banana-shaped vibration screen as the optimization objective, frequency constraints as the status variables, optimization for multi-frequency constraints is conducted based on the improved genetic algorithm. Next, a mathematical model of structure parameter optimization for the lateral plates of the vibration screen under frequency constraints is established to carry out optimization design in order to obtain a structure with smaller dynamic stress and lower weight. Sensitivity analysis is added into the improved genetic algorithm, and the optimization efficiency is increased simultaneously. The structure frequency is optimized by means of the improved genetic algorithm. Then, a modal experiment is carried out to the entire vibration screen so as to verify reliability of the finite element model, and the natural characteristics of the vibration screen before and after optimization are analyzed, and the top 6 orders natural frequency and vibration modes of the entire vibration screen are calculated, so as to indicate that optimized vibration screen is improved in terms of material saving, stiffness and stability. In addition, noise is directly related to vibration. As a result, the change of the vibration screen should be also analyzed. Noise of the vibration screen is also tested by sound array technology. Results showed that the radiated noise is reduced after optimization, and optimization in this paper is feasible. [ABSTRACT FROM AUTHOR]

We present an upper bound on the branching fraction of the Higgs boson to invisible particles by recasting a CMS Collaboration search for stop quarks decaying to tt + EmissT. The observed (expected) bound, BF(H → inv.) < 0.40(0.65) at 95% C.L., is the strongest direct limit to date, benefiting from a downward fluctuation in the CMS data in that channel. In addition, we combine this new constraint with existing published constraints to give an observed (expected) bound of BF(H → inv.) < 0.40(0.40) at 95% C.L., and we show some of the implications for theories of dark matter which communicate through the Higgs portal. [ABSTRACT FROM AUTHOR]

Wheel-rail adhesion often reaches its limit states when heavy-haul and high-speed trains traveling. In order to obtain the maximum adhesive force utilization, this paper put forward a dynamic multiple sub-population QPSO algorithm to evolve a neural network, and designed the intelligent optimization controller based on the network to implement the optimized adhesion control of locomotive. By dynamically adjusting the motor torque, it achieved the optimal wheel-rail adhesion force. In simulation study, this paper used a typical test function to test the performance of the dynamic multiple sub-population QPSO algorithm. The simulation results demonstrate the relatively high accuracy and efficiency of the algorithm, and prove that the algorithm can improve the convergence speed and learning ability of the neural network, at the same time, in optimized adhesion control of locomotive, the intelligent optimization controller can also get a good control effect. [ABSTRACT FROM AUTHOR]

Comparisons of performance with cochlear implants and postmortem conditions in the cochlea in humans have shown mixed results. The limitations in those studies favor the use of within-subject designs and non-invasive measures to estimate cochlear conditions. One non-invasive correlate of cochlear health is multipulse integration, established in an animal model. The present study used this measure to relate neural health in human cochlear implant users to their speech recognition performance. The multipulse-integration slopes were derived based on psychophysical detection thresholds measured for two pulse rates (80 and 640 pulses per second). A within-subject design was used in eight subjects with bilateral implants where the direction and magnitude of ear differences in the multipulse-integration slopes were compared with those of the speech-recognition results. The speech measures included speech reception threshold for sentences and phoneme recognition in noise. The magnitude of ear difference in the integration slopes was significantly correlated with the magnitude of ear difference in speech reception thresholds, consonant recognition in noise, and transmission of place of articulation of consonants. These results suggest that multipulse integration predicts speech recognition in noise and perception of features that use dynamic spectral cues. [ABSTRACT FROM AUTHOR]

Background Mosquito coils are the most commonly used household insecticidal product in the world with sales exceeding 50 billion coils, used by two billion people worldwide annually. Despite strong evidence that coils prevent mosquito bites a systematic review concluded that there is no evidence that burning mosquito coils prevents malaria acquisition. Therefore, the current trial was designed to measure and compare prevention of malaria infection by mosquito coils or long-lasting insecticidal net (LLIN) or a combination of the two in Yunnan, China in the Greater Mekong sub-region. Methods A four-arm single blind household-randomized design was chosen as coils emanate insecticide throughout the household. Households enrolled at baseline were randomly allocated by the lottery method to one of the four intervention arms: (i) nothing, (ii) 0.03% transfluthrin coils alone, (iii) deltamethrin long-lasting insecticide treated nets, (LLINs) alone or (iv) a combination of transfluthrin coils and deltamethrin LLINs. All household members were recruited to the study, with only those households excluded with pregnant or breastfeeding mothers, members with chest complaints or allergies or members that regularly slept away from home. The main outcome of interest was Plasmodium falciparum malaria prevalence detected by rapid diagnostic tests (RDTs) during six repeated monthly crosssectional surveys. The secondary outcome of interest was the effect on Plasmodium vivax prevalence detected in the same way. Results A total of 2,052 households were recruited into the study, comprising 7,341 individuals The odds ratios of testing positive by RDT with P. falciparum or P. vivax were >75% lower for all intervention arms compared with the control arm. Coils alone provided 77% protection (95% CI: 50%-89%), LLINs provided 91% protection (95% CI: 72%-97%) and the combination of coils and LLINs provided 94% protection (95% CI: 77%-99%) against P. falciparum compared with the control arm. There was no statistically significant difference between the protective efficacies of the different interventions. Conclusions This is the first robust clinical evaluation of transfluthrin mosquito coils as a means to reduce malaria and the high degree of infection prevented would indicate they represent a potentially highly effective tool, which could be integrated into larger vector control programmes. Trial registration ClinicalTrials.gov Identifier: NCT00442442, March 2007. [ABSTRACT FROM AUTHOR]

While living systems have developed highly efficient ways to convert chemical energy (e.g., ATP hydrolysis) to mechanical motion (e.g., movement of muscle), it remains a challenge to build muscle-like biomimetic systems to generate mechanical force directly from chemical reactions. Here we show that a continuous flow of reactant solution leads to by far the largest volume change to date in autonomous active gels driven by the Belousov-Zhabotinsky reaction. These results demonstrate that microfluidics offers a useful and facile experimental approach to optimize the conditions (e.g., fabrication methods, counterions, flow rates, concentrations of reagents) for chemomechanical transduction in active materials. This work thus provides much needed insights and methods for the development of chemomechanically active systems based on combining soft materials and microfluidic systems. [ABSTRACT FROM AUTHOR]

Objectives: To investigate rates of depression and suicidal ideation in medical students in mainland China and to explore wellness curricula and mental health services available to students. Methods: Second and third year medical students (N=348) at one medical school in mainland China completed the Patient Health Questionnaire-9 (PHQ-9). Based on responses to the PHQ-9, students were labeled as depressed, with suicidal ideation, and/or impaired. Additionally, students' feedback from a focus group (N=30) evaluating the current state of the school's wellness curricula and mental health services was thematically analyzed. Results: A total of 348 students responded (response rate = 99%) to the survey. Forty-seven of 348 (13.5%) students had moderate-severe depression. The mean PHQ-9 score was 6.02 (SD=3.44). Seven and a half percent of students report-ed suicidal ideation. The frequency of depression and suicidal ideation did not differ between second and third year medical students (p = 0.52). Nearly 30% of depressed students reported suicidal ideation. Depression and suicidal ideation were strongly correlated (r = 0.42, p < 0.001). Students with depression (p < 0.0001) or suicidal ideation (p = 0.004) were more likely to be impaired compared to students who were not. Focus group participants reported only off-campus student counseling services available to medical students in distress. No wellness curricula were established. Conclusions: Rates of depression and suicidal ideation are high in medical students in mainland China. Mental health services are deficient and unlikely to address distress in students. Chinese medical schools should offer mental health support and treatment at an early stage, such as wellness curricula and proactive student counseling. [ABSTRACT FROM AUTHOR]

We introduce an approach exploiting the power of polynomial ring algebra to perform SystemVerilog assertion verification over digital circuit systems. This method is based on Groebner bases theory and sequential properties checking. We define a constrained subset of SVAs so that an efficient polynomial modeling mechanism for both circuit descriptions and assertions can be applied. We present an algorithm framework based on the algebraic representations using Groebner bases for concurrent SVAs checking. Case studies show that computer algebra can provide canonical symbolic representations for both assertions and circuit designs and can act as a novel solver engine from the viewpoint of symbolic computation [ABSTRACT FROM AUTHOR]

Hyperekplexia is a neurological disorder associated primarily with mutations in the α1 subunit of glycine receptors (GlyRs) that lead to dysfunction of glycinergic inhibitory transmission. To date, most of the identified mutations result in disruption of surface expression or altered channel properties of α1-containing GlyRs. Little evidence has emerged to support an involvement of allosteric GlyR modulation in human hyperekplexia. Here, we report that recombinant human GlyRs containing α1 or α1β subunits with a missense mutation in the α1 subunit (W170S), previously identified from familial hyperekplexia, caused remarkably reduced potentiation and enhanced inhibition by Zn2+. Interestingly, mutant α1W170Sβ GlyRs displayed no significant changes in potency or maximum response to glycine, taurine, or β-alanine. By temporally separating the potentiating and the inhibitory effects of Zn2+, we found that the enhancement of Zn2+ inhibition resulted from a loss of Zn2+-mediated potentiation. The W170S mutation on the background of H107N, which was previously reported to selectively disrupt Zn2+ inhibition, showed remarkable attenuation of Zn2+-mediated potentiation and thus indicated that W170 is an important residue for the Zn2+-mediated GlyR potentiation. Moreover, overexpressing the α1W170S subunit in cultured rat neurons confirmed the results from heterologous expression. Together, our results reveal a new zinc potentiation site on α1 GlyRs and a strong link between Zn2+ modulation and human disease. [ABSTRACT FROM AUTHOR]

A novel tunable laser with digital concatenated grating reflectors, which has a flatter envelope of reflection peaks, is designed and fabricated. The key concept of the approach is to utilize multi-sampled gratings which have different Bragg wavelengths and the same sampling period. The difference of each Bragg wavelength is integer multiple of the space between the peaks of sampled gratings. Here, nanoimprint lithographic technology is used to fabricate the complex gratings. The typical threshold current of the tunable laser is 34 mA, and the tuning range is larger than 32 nm. The non-uniformity of the output power is less than 2 dB. [ABSTRACT FROM AUTHOR]

We propose a verification solution based on characteristic set of Wu'smethod towards System Verilog assertion checking over digital circuit systems. We define a suitable subset of SVAs so that an efficient polynomialmodeling mechanism for both circuit descriptions and assertions can be applied. We present an algorithm framework based on the algebraic representations using characteristic set of polynomial system. This symbolic algebraic approach is a useful supplement to the existent verification methods based on simulation. [ABSTRACT FROM AUTHOR]

This work presents an efficient solution using computer algebra system to perform linear temporal properties verification for synchronous digital systems. The method is essentially based on both Groebner bases approaches and symbolic simulation. A mechanism for constructing canonical polynomial set based symbolic representations for both circuit descriptions and assertions is studied. We then present a complete checking algorithm framework based on these algebraic representations by using Groebner bases. The computational experience result in this work shows that the algebraic approach is a quite competitive checking method and will be a useful supplement to the existent verification methods based on simulation. [ABSTRACT FROM AUTHOR]

Chinese classrooms present an intriguing paradox to the claim of self-determination theory that autonomy facilitates learning. Chinese teachers appear to be controlling, but Chinese students do not have poor academic performance in international comparisons. The present study addressed this paradox by examining the cultural differences in students' interpretation of teacher controlling behaviors. Affective meanings of teacher controlling behaviors were solicited from 158 Chinese 5th graders and 115 American 5th graders. It was found that the same controlling behaviors of teachers had different affective meanings for different cultural groups (Chinese vs. American) and for groups with different levels of social-emotional relatedness with teachers (high vs. low). Chinese children perceived the behaviors as less controlling than American children and, in turn, reported that they were more motivated in their teachers' class than American children. Regardless of culture, children with high social-emotional relatedness with teachers perceived the behaviors as less controlling than children with low social-emotional relatedness with teachers. It was also found that internalization mediated the relation between social-emotional relatedness and children's learning motivation in both cultures. The findings revealed cultural differences as well as similarities in the psychological process of internalization. [ABSTRACT FROM AUTHOR]

Helicobacter pylori persists deep in the human gastric mucus layer in a harsh, nutrient-poor environment. Survival under these conditions depends on the ability of this human pathogen to invoke starvation/stress responses when needed. Unlike many bacteria, H. pylori lacks starvation/stress-responding alternative sigma factors, suggesting an additional mechanism might have evolved in this bacterium. Helicobacter pylori produces polyphosphate; however, the role and target of polyphosphate during starvation/stress have not been identified. Here we show that polyphosphate accumulated during nutrient starvation directly targets transcriptional machinery by binding to the principal sigma factor in H. pylori, uncovering a novel mechanism in microbial stress response. A positively charged Lys-rich region at the N-terminal domain of the major sigma factor is identified as the binding region for polyphosphate (region P) in vivo and in vitro, revealing a new element in sigma 70 family proteins. This interaction is biologically significant because mutant strains defective in the interaction undergo premature cell death during starvation. We suggested that polyphosphate is a second messenger employed by H. pylori to mediate gene expression during starvation/stress. The putative ‘region P’ is present in sigma factors of other human pathogens, suggesting that the uncovered interaction might be a general strategy employed by other pathogens. [ABSTRACT FROM AUTHOR]

The effects of frequency-place shift on consonant recognition and confusion matrices were examined. Frequency-place shift was manipulated using a noise-excited vocoder with 4 to 16 channels. In the vocoder processing, the location of the most apical carrier band varied from the matched condition (i.e., 28 mm from the base of the cochlear) to a basal shift (i.e., 22 mm from the base) in a step size of 1 mm. Ten normal-hearing subjects participated in the 20-alternative forced-choice test, where the consonants were presented in a /Ca/ context. Shift of 3 mm or more caused the consonant recognition scores to decrease significantly. The effects of spectral resolution disappeared when the amount of shift reached ≥3 mm. Information transmitted for voicing and place of articulation varied with spectral shift and spectral resolution, while information transmitted for manner was affected only by spectral shift but not spectral resolution. Spectral shift has shown specific effects on the confusion patterns of the consonants. The direction of errors reversed as spectral shift increased and the patterns of reversal were consistent across channel conditions. Overall, transmission of the consonant features can be accounted for by the acoustic features of the speech signal. [ABSTRACT FROM AUTHOR]

This paper investigates the design of effective input signals for low-level probing of power systems. In 2005, 2006, and 2008 the Western Electricity Coordinating Council (WECC) conducted four large-scale system-wide tests of the western interconnected power system where probing signals were injected by modulating the control signal at the Celilo end of the Pacific DC intertie. A major objective of these tests is the accurate estimation of the inter-area electromechanical modes. A key aspect of any such test is the design of an effective probing signal that leads to measured outputs rich in information about the modes. This paper specifically studies low-level probing signal design for power-system identification. The paper describes the design methodology and the advantages of this new probing signal which was successfully applied during these tests. This probing input is a multi-sine signal with its frequency content focused in the range of the inter-area modes. The period of the signal is over 2 min providing high-frequency resolution. Up to 15 cycles of the signal are injected resulting in a processing gain of 15. The resulting system response is studied in the time and frequency domains. Because of the new probing signal characteristics, these results show significant improvement in the output SNR compared to previous tests. [ABSTRACT FROM AUTHOR]

Three-dimensional phase field simulations of coupled γ/γ ' microstructural evolution and plastic deformation in single crystal Ni-Al are carried out at micrometer scales. Coherent γ/γ ' microstructures and plastic deformation in γ-channels are described using a single, consistent methodology based on Khachaturyan's phase field microelasticity approach to coherent precipitates and dislocations. In particular, a new set of phase fields is introduced to characterize local density of dislocations from individual active slip systems. To increase the length scale of the phase field simulations, the Kim-Kim-Suzuki (KKS) treatment of γ/γ ' interfaces was adopted. The rafting kinetics, precipitate-matrix inversion process and the corresponding creep deformation are characterized with respect to parameters such as applied stress and lattice misfit. The simulation results on γ '-rafting kinetics and morphological evolution of the γ/γ ' microstructures are compared with available experiment. The model can be used to carry out parametric studies of the effects of material and processing parameters such as alloy composition, external stress and working temperature on γ '-rafting kinetics, morphological evolution and the corresponding creep deformation. [ABSTRACT FROM AUTHOR]

One significant problem in tile-based texture synthesis is the presence of conspicuous seams in the tiles. The reason is that sample patches employed as primary patterns of the tile set may not be well stitched if carelessly picked. In this paper, we introduce a robust approach that can stably generate an ω-tile set of high quality and pattern diversity. First, an extendable rule is introduced to increase the number of sample patches to vary the patterns in an ω-tile set. Second, in contrast to other concurrent techniques that randomly choose sample patches for tile construction, ours uses artificial immune system (AIS) to select the feasible patches from the input example. This operation ensures the quality of the whole tile set. Experimental results verify the high quality and efficiency of the proposed algorithm. [ABSTRACT FROM AUTHOR]

In Helicobacter pylori the stringent response is mediated solely by spoT. The spoT gene is known to encode (p)ppGpp synthetase activity and is required for H. pylori survival in the stationary phase. However, neither the hydrolase activity of the H. pylori SpoT protein nor the role of SpoT in the regulation of growth during serum starvation and intracellular survival of H. pylori in macrophages has been determined. In this study, we examined the effects of SpoT on these factors. Our results showed that the H. pylori spoT gene encodes a bifunctional enzyme with both a hydrolase activity and the previously described (p)ppGpp synthetase activity, as determined by introducing the gene into Escherichia coli relA and spoT defective strains. Also, we found that SpoT mediates a serum starvation response, which not only restricts the growth but also maintains the helical morphology of H. pylori. Strikingly, a spoT null mutant was able to grow to a higher density in serum-free medium than the wild-type strain, mimicking the "relaxed" growth phenotype of an E. coli relA mutant during amino acid starvation. Finally, SpoT was found to be important for intracellular survival in macrophages during phagocytosis. The unique role of (p)ppGpp in cell growth during serum starvation, in the stress response, and in the persistence of H. pylori is discussed. [ABSTRACT FROM AUTHOR]