A dissipativity-based approach to traffic signal control for an over-saturated intersection

In this paper, using the energy concept, the control of traffic flow by traffic lights on an over-saturated single intersection is addressed. By regarding the flow entry of vehicles as the energy stored in the system, we show that the dissipative system theory can be applied. As a result, a state feedback control law is found in terms of the solution of an associated dissipation equation that renders the system non-accumulative, i.e., to get out of the over-saturation situation. The results of the simulations indicate that our control strategy guarantees a high degree of control benefit.     

Reduced plasma ascorbic acid and red cell glutathione contents in sickle cell disease—A preliminary report

Glutathione and ascorbic acid in erythrocytes are suggested to be essential in the detoxification of superoxide radicals and hydrogen peroxide formed during red cell metabolism. In sickle cell patients who are more prone to haemolysis have greater propensity for the formation of superoxide radical and hydrogen peroxide. In the present study conducted on sickle cell patients provide evidence for the presence of reduced levels of both ascorbic acid and glutathione in the red cells. This may seem to suggest that vitamin C supplementation may help such patients who are prone to haemolysis.     

阿尔泰额尔齐斯带东段酸性岩墙群地球化学特征及其地质意义

野外地质调查发现在阿尔泰南缘额尔齐斯构造带东段、额尔齐斯活动断裂与富蕴-锡泊渡断裂之间发育了一套未变形的酸性岩墙群.岩墙群侵位于海西期片麻岩化花岗岩和上石炭统深变质的额尔齐斯组岩层中,薄片鉴定和岩石地球化学分析确定为具有细晶结构的流纹斑岩.岩石的SiO2含量为70.9%～75.38%,K2O＋Na2O含量为7.55%～8.99%;大部分样品Na2O＞K2O,里特曼指数值为1.8～2.5之间,Al2O3=12.80%～14.53%,A/CNK=0.9～1.1,NK/A=0.7～0.9,具有准铝质-弱过铝质、低镁、高钾钠、低钙和锶、高（Fe）mol/（Mg）mol特点,具A型花岗岩类特点,属于亚碱性脉岩.岩石轻稀土富集,大离子亲石元素相对富集,具有明显的中等负铕异常,壳源特征明显.锆石U-Pb二次粒子微探针测年显示岩墙群形成于277～286Ma.推断岩墙是阿尔泰海西期造山运动结束后,在拉张构造环境下的地壳局部熔融产物.     

Validating the Watson Glaser Critical Thinking Appraisal

This study validated the Watson Glaser Critical Thinking Appraisal (WGCTA) on a sample of 273 private university students in Lebanon. For that purpose, evidence for construct validation was investigated through identifying the test’s factor structure and subscale total correlations, in addition to differences in scores by gender, different levels, and streams using a series of ANOVA tests. Evidence for the test’s reliability and concurrent validity was also collected. Moreover, students in five courses that emphasize critical thinking were pre–post tested using the WGCTA. Exploratory factor analysis revealed a unidimensional factor while results showed no significant differences in scores on the WGCTA between males and females or between students at different levels except for graduate students in the Business stream. Furthermore, results revealed significant differences for the senior students between different streams. Finally, results showed no statistically significant changes in the mean scores of students who were pre- and post-tested except for nursing students. The test’s significant correlations with various criterion measures provided evidence of its convergent and divergent validities. The results were discussed in terms of the nature of the construct itself, and the effects of training and effective instructional strategies on growth of critical thinking. Recommendations for future research were proposed.     

Dynamics of a periodically driven chain of coupled nonlinear oscillators

A 1D chain of coupled oscillators is considered, including the Duffing-type nonlinearity, viscous damping, and kinematic harmonic excitation. The equations of motion are presented in a non-dimensional form. The approximate equations for the vibrational amplitudes and phases are derived by means of the classical averaging method. A simple analysis of the resulting equations allows one to determine the conditions for the two basic synchronous steady-states of the system: the in-phase and anti-phase motions. The relations between the required excitation frequency and the natural frequencies of the abbreviated (linear) system are discussed. The validity of these predictions is examined by a series of numerical experiments. The effect of the model parameters on the rate of synchronization is analyzed. For the purpose of systematic numerical studies, the cross-correlation of time-series is used as a measure of the phase adjustment between particular oscillators. Finally, some essential issues that arise in case of the mechanical system with dry friction are indicated.     

Overweight and obesity versus concentrations of VEGF-A,sVEGFR-1, and sVEGFR-2 in plasma of patients with lower limb chronic ischemia

Objective

Being overweight or obese comprises a significant risk factor for atherosclerosis. Fat tissue also generates factors stimulating angiogenesis, the process by which new blood vessels form. The purpose of this paper is to assess concentrations of the vascular endothelial growth factor A (VEGF-A) and its soluble type-1 and type-2 receptors (sVEGFR-1 and sVEGFR-2) in plasma of patients with peripheral arterial disease (PAD) depending on the level of nutrition according to body mass index (BMI).

Methods

The study group included patients suffering from symptomatic PAD (n=46) in Fontaine classes IIa–IV without any history of neoplastic disease and who have a normal BMI (n=15), are overweight (n=21) or are obese (n=10). The control group (n=30) consisted of healthy non-smoking volunteers who were neither overweight nor obese. Venous blood plasma samples were collected from both groups at rest in the morning to determine plasma concentrations of VEGF-A, sVEGFR-1, and sVEGFR-2 using the enzymelinked immunosorbent assay (ELISA) method.

Results

The group of patients with PAD co-existent with being overweight or obese tended to have higher mean concentration levels of VEGF-A and sVEGFR-2 when compared with patients suffering from PAD with normal BMI. A statistically significant positive correlation was obtained between BMI and average plasma concentrations of sVEGFR-2 (R=0.37, P=0.0103). However, no significant correlation was noticed between BMI and VEGF-A or sVEGFR-1 concentrations.

Conclusions

A positive correlation determined between the level of antiangiogenic factor and BMI value may be indicative of the linearly growing prevalence of some antiangiogenic factors in patients with metabolic disorders, which may be one of numerous factors contributing to incomplete efficiency of collateral circulation development in patients with PAD.

     

贯彻《规程》精神 挖掘图书馆职能

介绍了兴隆县教育局贯彻落实教育部颁发的《中小学图书馆(室)规程(修订)》精神，以卓有成效的举措挖潜图书馆职能，促进学生健康发展的实践与体会。