Circulating vascular endothelial growth factor and nitric oxide in patients with liver cirrhosis: A possible association with liver function impairment

Hemodynamic disorders of liver cirrhosis complicated with portal hypertension are associated with an increased angiogenesis in animal model of portal hypertension and cirrhosis which were linked to increased expression of vascular endothelial growth factor (VEGF) and nitric oxide (NO). The aim of study was to evaluate the serum concentration of VEGF and total nitric oxide (NO) in liver cirrhosis and the possible association with the degree of liver insufficiency. VEGF and NO were measured in serum of 64 patients with liver cirrhosis by ELISA and spectrophotometry respectively. The significant increase of serum VEGF was observed in liver cirrhosis compared to healthy individuals as well as serum NO (106.1 ± 66.7 vs. 41.5 ± 6 pg/mL, P < 0.05; 113.5 ± 65.8 vs. 20.8 ± 3.8 μmol/l, P< 0.001, respectively). Serum VEGF and NO showed significant associations with biochemical indices of liver function and with Child-pugh score where they were increased respectively to the degree of liver insufficiency. A significant association of raised serum NO in early stage of portal hypertension reflect its benefit in early expect of portal hypertension but, high serum VEGF in late stage may reflect its prognostic value in liver cirrhosis.     

Robust integral backstepping control for sensorless IPM synchronous motor controller

In this paper, a sensorless speed control for interior permanent magnet synchronous motors (IPMSM) is designed by combining a robust backstepping controller with integral actions and an adaptive interconnected observer. The IPMSM control design generally requires rotor position measurement. Then, to eliminate this sensor, an adaptive interconnected observer is designed to estimate the rotor position and the speed. Moreover, a robust nonlinear control based on the backstepping algorithm is designed where an integral action is introduced in order to improve the robust properties of the controller. The stability of the closed-loop system with the observer–controller scheme is analyzed and sufficient conditions are given to prove the practical stability. Simulation results are shown to illustrate the performance of the proposed scheme under parametric uncertainties and low speed. Furthermore, the proposed integral backstepping control is compared with the classical backstepping controller.     

Contrasting perceptions of an innovation in engineering education

There has been considerable criticism about the effectiveness and appropriateness of degree courses in engineering over recent years. In part the criticism have related to inadequate preparation for the profession and in part to the traditional methods of teaching. As a reaction to these criticism, attempts were made at one particular technological institution to change the way in which parts of one particular course were taught. The first problem was created by a relatively high failure rate in examinations. In addition, it was felt that problem-solving was an important skill which had been inadequately taught through the conventional lecture course. Previous research had suggested that audiotapes on which students could work and take notes at their own pace might improve the examination results and help with problem-solving skills relevant to the professional engineer. The innovator found evidence for the success of the innovation in terms of a decreased failure rate and his own satisfaction with the changed emphasis in his part of the degree course. However, an independent evaluation based on interviews and observation found that other members of staff, and the students, all held different perceptions of the effectiveness of the innovation. The contrasting perceptions reflected, in part, the extent to which the staff had been involved with the innovation, and the purposes of the students in using the innovative materials and techniques. The study points up difficulties in introducing an innovation into higher education and shows the importance of the very different perceptions held by those who come into contact with the innovation. Implications for understanding the impact of learning environments on student learning, and for the introduction of innovations, are discussed.     

The group dynamics approach: A sociopsychological approach for testing the effect of discovery and expository teaching on the science achievement and attitude of young Egyptian students

The purpose of this study was to compare the effectiveness of two instructional modes, discovery and expository, for teaching science knowledge, both application and recall, and science attitude to fifth-grade male and female Egyptian students. The population used for this study consisted of 276 fifth-grade students in two Egyptian schools. Twelve 45-min science classes meeting over a 21-day period made up the treatment period, with each of the two teachers instructing six of the 12 class periods for all eight subgroups of students. The results warrant the following conclusions: Fifth-grade Egyptian students taught by the discovery method scored higher in science achievement, both recall and application, than students taught by the expository method. Students taught by the discovery method scored higher in science attitude than students taught by the expository method. Female Egyptian students scored in science achievement and science attitude similar to males.     

A context-based integrative framework for e-government initiatives

The recent advances in the Internet technology have propelled the development of related applications in electronic communications and transactions, including electronic commerce and electronic government (e-government). There has been a proliferation of e-government initiatives worldwide undertaken under different forms of government, socioeconomic settings, and technological conditions. Nonetheless, the relationship between an e-government initiative and its context has not received adequate attention in the e-government literature. This paper provides an organizing framework that maps the core values (goals) of e-government to two fundamental factors; namely, the degree of e-government readiness and the level of democratization. The framework addresses the importance of the relationship between the context within which e-government initiatives are undertaken and the goals of those initiatives. From a conceptual perspective, this framework underscores the pivotal importance of the context of an e-government initiative in influencing the goals of this initiative. From a practical viewpoint, the framework provides a roadmap for policy makers to formulate policy goals of e-government initiatives commensurate with their respective environments.     

Inhibitory activities of microalgal extracts against Epstein-Barr virus DNA release from lymphoblastoid cells

This study aimed to assess the inhibitory activities of methanol extracts from the microalgae Ankistrodesmus convolutus, Synechococcus elongatus, and Spirulina platensis against Epstein-Barr virus (EBV) in three Burkitt's lymphoma (BL) cell lines, namely Akata, B95-8, and P3HR-1. The antiviral activity was assessed by quantifying the cell-free EBV DNA using real-time polymerase chain reaction (PCR) technique. The methanol extracts from Ankistrodesmus convolutus and Synechococcus elongatus displayed low cytotoxicity and potent effect in reducing cell-free EBV DNA (EC(50)<0.01 μg/ml) with a high therapeutic index (>28000). After fractionation by column chromatography, the fraction from Synechococcus elongatus (SEF1) reduced the cell-free EBV DNA most effectively (EC(50)=2.9 μg/ml, therapeutic index>69). Upon further fractionation by high performance liquid chromatography (HPLC), the sub-fraction SEF1'a was most active in reducing the cell-free EBV DNA (EC(50)=1.38 μg/ml, therapeutic index>14.5). This study suggests that microalgae could be a potential source of antiviral compounds that can be used against EBV.     

Convergence Between Platforms in the Newsroom

Through ethnographic observation and content analysis, this study aims to classify the Al-Jazeera Mubasher (AJM) newsroom according to the Schantin model of newsrooms, describe the network’s convergence level based on the Dailey, Demo, and Spillman Dynamic Scale Model, and present a unique model elucidating how, specifically, convergence works at AJM. Based on the Schantin model of newsrooms, AJM can be classified as a second-generation newsroom, a “cross-media platforms newsroom.” Convergence among the different platforms of AJM is considerable, but still below full convergence level. Accordingly, the AJM newsroom can be classified into the fourth level of the Dailey et al. Dynamic Scale Model — “content sharing.” The unique AJM-specific model presented near the end of this paper depicts the ways in which different AJM platforms function and interact inside the newsroom, explains the degree of convergence between platforms, and classifies the newsroom in terms of its convergence level.