Effect of psychological stress on the salivary alpha amylase and cortisol levels in EFL teachers

Background: Job stress threatens teachers’ well-being and health. Identifying physiological factors that underline job stress is crucial for teachers’ health and students’ learning. This cross sectional study examined the cycle of stress biomarkers (salivary cortisol and alpha amylase) over the course of teaching among Iranian English teachers. Materials and Methods: 59 English teachers from two foreign language institutes in Bushehr province, southern Iran volunteered to participate in this study. The participants’ saliva samples were collected three times over the course of a usual teaching day (before class, during class, and after class). Salivary alpha amylase and cortisol levels were analyzed in the biomarker Sina Lab in Bushehr using commercially available and research-based kinetic reaction (sAA) (Pars Test) and immunoassay (cortisol) kits (IBL). Results: A significant pattern was found for alpha amylase while cortisol did not show any significant change over the course of teaching. Conclusion: The findings highlighted the usefulness and importance of measuring physiological biomarkers in studying teachers’ stress

Switched Reluctance Motor Topologies: A Comprehensive Review

Switched reluctance motor (SRM) is gaining much interest in industrial applications such as wind energy systems and electric vehicles due to its simple and rugged construction, high‐speed operation ability, insensitivity to high temperature, and its features of fault tolerance. With continued research, different topologies have emerged presenting less torque ripple, high efficiency, high power factor, and high power density. However, there has always been a trade‐off between gaining some of the advantageous and losing some with each new technology. In this chapter, various SRM topologies, design, principle of operation, and respective phase switching schemes are extensively reviewed, and their advantages and drawbacks are discussed. On the other hand, some of SRM limitations (such as excitation penalty, control complexity, noise, and vibration) have prompted research into the incorporation of permanent magnets into the basic SRM structure, and therefore, the chapter also includes discussion on a new class of SRM with permanent magnet assist (PM‐assist) called doubly salient permanent magnet (DSPMM). The DSPM motor incorporates the merits of both the PM brushless motor and the SRM

Estimation of left ventricular end diastolic pressure (lvedp) in patients with ischemic heart disease by echocardiography and compare it with the results of cardiac catheterization

<strong>BACKGROUND:</strong> Doppler echocardiography has been proposed as an appropriate non-invasive<br />assay to estimate left ventricular end diastolic pressure (LVEDP). The aim of present research<br />was to estimate the LVEDP in patients with ischemic heart disease by echocardiography and<br />compare it with the results of cardiac catheterisation and to determine the effect of different<br />echocardiographic variables on its measurement.<br /><strong>METHODS:</strong> In this descriptive-analytic study, patients with diagnosed ischemic heart disease<br />were selected by nonrandomized sampling method. Selected population underwent M-mode<br />and pulse doppler echocardiographic evaluation and parameters such as Q-Mitral valve E<br />(Q-MVE), Q-Aortic valve closure (Q-AVC), Aortic valve closure-E (AVC-E), Q-Mitral valve<br />closure/Aortic valve closure-E (Q-MVC/AVC-E), left ventricle-deceleration time (LV-DT), peak<br />velocity-deceleration time (PV-DT) and A/E velocity time integral (A/E VTI) were evaluated.<br />Immediately after echocardiography all patients underwent left heart catheterization for LVEDP<br />measurement. The relation between different echocardiographic measurements and LVEDP,<br />obtained by cardiac catheterization, was evaluated.<br /><strong>RESULTS:</strong> In this study, 47 patients with ischemic heart disease with mean age (&plusmn;SD) of<br />53 &plusmn; 13 were studied. There was a significant correlation between LVDEP and A/E VTI (r=0.44,<br />P = 0.001, and also between LVEDP and PV-DT in patients with A/E VTI &ge;1.1(r = -0.58, P = 0.02).<br />There was a significant correlation between LVEDP and Q-MVC/AVC-E in patients with LVEDP<br />&gt;18mmHg (r = 0.76, P= 0.03) and those with LVEDP &le;18 mmHg and A/E VTI &lt; 1.1<br />(r = 0.37, P= 0.03). The correlation between LVEDP and A/E VTI was more significant in men,<br />in patients aged &gt; 50 years with EF &gt; 55%, without LVH, without MR and those with coronary<br />artery disease (P &lt; 0.05).<br /><strong>CONCLUSION:</strong> Some echocardiographic indices such as A/E VTI, Q-MVC/AVC-E and PV-DT<br />are able to measure LVEDP especially in male patients aged &gt; 50 years, without LVH, without<br />MR and those with coronary artery disease but it is necessary to determine specific conditions<br />and factors affecting these indices, by further studies.<br /><strong>Keywords:</strong> LVEDP, Coronary Artery Disease, Echocardiography

A Multicriteria Optimization for Flight Route Networks in Large-Scale Airlines Using Intelligent Spatial Information

Air route network optimization, one of the airspace planning challenges, effectively manages airspace resources toward increasing airspace capacity and reducing air traffic congestion. In this paper, the structure of the flight network in air transport is analyzed with a multi-objective genetic algorithm regarding Geographic Information System (GIS) which is used to optimize this Iran airlines topology to reduce the number of airways and the aggregation of passengers in aviation industries organization and also to reduce changes in airways and the travel time for travelers. The proposed model of this study is based on the combination of two topologies – point-to-point and Hub-and-spoke – with multiple goals for causing a decrease in airways and travel length per passenger and also to reach the minimum number of air stops per passenger. The proposed Multi-objective Genetic Algorithm (MOGA) is tested and assessed in data of the Iran airlines industry in 2018, as an example to real-world applications, to design Iran airline topology. MOGA is proven to be effective in general to solve a network-wide flight trajectory planning. Using the combination of point-to-point and Hub-and-spoke topologies can improve the performance of the MOGA algorithm. Based on Iran airline traffic patterns in 2018, the proposed model successfully decreased 50.8% of air routes (184 air routes) compared to the current situations while the average travel length and the average changes in routes were increased up to 13.8% (about 100 kilometers) and up to 18%, respectively. The proposed algorithm also suggests that the current air routes of Iran can be decreased up to 24.7% (89 airways) if the travel length and the number of changes increase up to 4.5% (32 kilometers) and 5%, respectively. Two intermediate airports were supposed for these experiments. The computational results show the potential benefits of the proposed model and the advantage of the algorithm. The structure of the flight network in air transport can significantly reduce operational cost while ensuring the operation safety. According to the results, this intelligent multi-object optimization model would be able to be successfully used for a precise design and efficient optimization of existing and new airline topologies

The comparison of total antioxidant capacity of serum and saliva between patients with type-2 diabetes mellitus and control

Background and aim: In human body, there are a number of special systems to defend the damages caused by antioxidant. In some diseases the defense system against antioxidant activity alters and this alteration may be used in recognizing and the processing of different diseases. Diabetes is one of the most common and important chronic illnesses in which the antioxidant capacity is altered. The aim of this research was to determine and compare the antioxidant capacity of both serum and saliva of diabetics compare to the control group. Method: This is a cross - sectional research in which those under studying are 42 people of with typeII diabetes mellitus coming and going to the Arak diabetes center as the case group with 42 people of control group which were in the same age and sex with the people in the case group from the point of total antioxidant capacity in serum and saliva were compared. The capacity of antioxidant in serum and saliva was measured by FRAP method. Results: The average and standard deviation (mean±SD) of the total antioxidant capacity of serum and saliva in case group were in range: 2.51±0.088, 1.90±0.110 and in control group were: 2.90±0.107, 1.97±0.098 . (P=0.001, 0.74) From the statistical viewpoint, the increase in the total antioxidant capacity of serum in case group was meaningful, but the decrease in the total antioxidant capacity in saliva was not meaningful. Conclusion: Our results showed that the antioxidant capacity in the patients, s serum was higher than that in the control group. However, this difference was not observed in the saliva of these two groups. Conclusively, if this capacity of antioxidant is used in recognizing and processing of the disease, this difference should be taken into account