Exploring the impacts of using Geogebra software on secondary school students’ misconceptions in trigonometric functions

Background and Objectives: Previous studies in Iran have explored the impact of using technology on improving students’ mathematical understanding. However, no study was conducted in relation to the impact of using technology on students’ mathematical misconceptions. This study explored the impact of using software in developing students’ misconceptions. In detail, the impact of using GeoGebra software on secondary school students’ misconceptions related to concepts such as angle scale, trigonometric angles, periodicity, minimum and maximum of trigonometric functions were explored using a two-tier diagnostic test. One of the novelties of this study is the use of a two-tier diagnostic test to explore misconceptions resulting from using the software. Methods: The statistical population of this study comprises all grade 11 students of Golbahar and Golmakan in the academic year 2015-2016. Three classes were chosen from two different schools in these cities, one was considered as the control group (40 students) and the other two classes were considered as the experimental group (26 students). The instruments were a pre-test and a post-test (two-tier diagnostic test).‎ Four categories of misconceptions were identified based on the relevant literature and students’ responses to the pre-test. Finally, these misconceptions were analyzed by the chi-square test. Findings: The findings showed that Geogebra software helped students in the experimental group enormously in understanding concepts such as periodicity‎, ‎identifying minimum and maximum of trigonometric functions‎, ‎and prevented developing misconceptions related to them. Analyzing students’ responses in the control group that received traditional teaching showed that several students did not able to calculate the periodicity of trigonometric functions. This difficulty observed both when students calculated the periodicity from the graphs and also when calculated the periodicity from the algebraic form of trigonometric functions. The strength of using the software includes observing many trigonometric graphs in the software environment, the ability to place trigonometric functions with different input on a coordinate axis and comparing them, and the manipulations performed by the students themselves on trigonometric graphs. These strengths prevented students from developing misconceptions about the concepts of frequency and minimum and maximum values. However, in relation to trigonometric angles‎, ‎using the software caused developing more misconceptions for the test group, and had no significant impact on preventing misconceptions in relation to the scale of angle‎. It seems due to the nature of the angle scale, in which the conversion from radians to degrees (or vice versa) is done by a series of mathematical operations, using Geogebra could not impact students’ misconceptions in this matter. Conclusion: The results of this study indicate that teachers should be very cautious in selecting and using teaching aids in the classroom to prevent developing mathematical misconceptions associated with using the teaching aids. Therefore, we recommend mathematics education researchers and mathematics curriculum planners to conduct several studies on different softwares frequently used in mathematics classes, determine the pros and cons of these tools, and share their results with mathematics teachers. Sharing these results will help mathematics teachers to adapt their teaching accordingly based on the findings of these studies.   ===================================================================================== COPYRIGHTS  ©2020 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

The activation pattern of trunk and lower limb muscles in an electromyographic assessment; comparison between ground and treadmillwalking

Background: Due to biomechanical differences, various patterns of muscle contraction are expected to occur while walking over ground versus when walking on a treadmill. Objectives: This study aimed to compare amplitude and duration of activation of selected trunk and lower extremity muscles during over-ground and treadmill walking. Materials and Methods: Through a simple sampling method, 19 sedentary healthy men within the age range of 20-40 were selected. Surface electromyography of rectus abdominis, external oblique, longissimus and multifidus muscles as the selected trunk muscles and vastus medialis, vastus lateralis and hamstrings as the selected lower limb muscles were recorded. Results: In each gait cycle, there were no statistically significant differences in duration of selected trunk as well as lower limb muscles activitybetweentreadmillandover-ground walking. Howeverthemeanamplitude of rectus abdominis (P=0.005), longissimus (P = 0.018) and multifidus (P = 0.044) as the selected trunk muscles as well as the mean amplitude of vastus lateralis (P = 0.005) and vastus medialis (P < 0.001) as the lower limb muscles was greater on treadmill compared with over ground. Conclusions: Due to the stabilizing role of trunk and lower limb muscles during walking, these muscles seem to be active throughout the entire gait cycle. The increased muscle amplitude on treadmill can demonstrate that more motor units may be recruited during the contraction,which can be helpful in prescribing the appropriate type of exercise especially for patients with core muscle weakness. © 2016, Sports Medicine Research Center

One common polymorphism of cholesteryl ester transfer protein gene in Iranian subjects with and without primary hypertriglyceridemia

Primary hypertriglyceridemia is considered to be a major risk factor for pancreatitis, atherosclerosis and coronary heart disease. Cholesteryl ester transfer protein gene polymorphisms known to be associated with changes in lipid levels. This study was performed by using polymerase chain reaction and restriction fragment length polymorphisms. Genotype distribution and allelic frequencies of polymorphism were determined and compared in primary hypertriglyceridemic and normotriglyceridemic subjects. The results showed that plasma cholesteryl ester transfer protein activity was significantly higher in primary hypertriglyceridemia than in controls (p = 0.001). In this study all individuals with B2B2 genotype had lower plasma cholesteryl ester transfer protein activity, higher high-density lipoprotein than B1B1 and B1B2 genotypes, whereas triglyceride was significantly decreased in this genotype. The genotype and allelic frequencies for this polymorphism differed significantly between primary hypertriglyceridemic patients and controls (p = 0.014 and p = 0.027, respectively). In both groups, CETP Taq 1B polymorphism (presence of B 2 allele) correlated significantly with HDL-C (r = 0.207 and 0.300 in control and patient groups, respectively) and CETP activity (r = -0.193 for controls and r = -0.132 for patients). Taq 1B polymorphism of cholesteryl ester transfer protein gene was associated with changes in lipids profile and plasma cholesteryl ester transfer protein activity in the selected population. © 2007 Asian Network for Scientific Information

Real-Time Diagnostic Integrity Meets Efficiency: A Novel Platform-Agnostic Architecture for Physiological Signal Compression

Head-based signals such as EEG, EMG, EOG, and ECG collected by wearable systems will play a pivotal role in clinical diagnosis, monitoring, and treatment of important brain disorder diseases. However, the real-time transmission of the significant corpus physiological signals over extended periods consumes substantial power and time, limiting the viability of battery-dependent physiological monitoring wearables. This paper presents a novel deep-learning framework employing a variational autoencoder (VAE) for physiological signal compression to reduce wearables' computational complexity and energy consumption. Our approach achieves an impressive compression ratio of 1:293 specifically for spectrogram data, surpassing state-of-the-art compression techniques such as JPEG2000, H.264, Direct Cosine Transform (DCT), and Huffman Encoding, which do not excel in handling physiological signals. We validate the efficacy of the compressed algorithms using collected physiological signals from real patients in the Hospital and deploy the solution on commonly used embedded AI chips (i.e., ARM Cortex V8 and Jetson Nano). The proposed framework achieves a 91% seizure detection accuracy using XGBoost, confirming the approach's reliability, practicality, and scalability

Causes and indications for reoperation in valve replacement and coronary artery bypass graft (CABG) in 915 patients in cardiac surgery department in Imam Khomeini Hospital, 1374-77

Valvular and coronary artery disease are among the most important causes of disability and death in the world and Iran as well. Every year, half a million death because of these diseases is reported in United State. The incidence of degenerative and valvular diseases of heart is increasing. Considering the industrialization of our country, the incidence of these kind of problems are increasing as well. In this study, there is an attempt to recognize the causes of cardiac surgery. We conducted a retrospective study in 915 cardiac surgery patients (630 CABG and 285 valve replacement) from 1374 to 1377. In CABG patients, there were 46 cases of reoperation (78.3 percent male 21.7 percent female). The most reoperations for bleeding was less than 24 hours in 90.3 percent. In valvular patients the causes of reoperation were: A) Valvular complications (female/male=3/1), B) Non valvular complications (female/male=1/3). The most common nonvalvular complication was bleeding (66.6 percent). The most common valvular complication was bioprosthetic valve degeneration. The meantime between two operation in valvular complications was 11.8 years. In all cases (915) the incidence of bleeding was 3.8 percent, mediastinitis 0.8 percent, cardiac tamponade 0.8 percent and GI bleeding 0.5 percent

Aortic valve replacement: conventional versus authors&apos; offered method

&quot;nBackground: The usage of pericardium of patient himself, for support of anastomosis lines may carry benefits in patients undergoing aortic valve replacement with pulmonary autograft (Ross). The aim of the present study was to compare the short term results of aortic valve replacement with pulmonary autograft with routine and offered methods. &quot;nMethods: In a non-randomized clinical trial, 64 patients who referred to cardiac surgery ward of Imam Khomeini hospital Tehran Iran from December 2002 to December 2006 for aortic valve replacement with pulmonary autograft with two different methods. In the first two years of this study all of the patients were operated with routine procedure (group A, n=28) and during the next two years, all of them were operated with authors&apos; offered method in which the patient`s pericardium was used for support of anastomosis lines (group B, n=36). Some of clinical parameters and outcome were compared between two groups. &quot;nResults: There were no significant differences between mean of age, sex, pathology, preoperative and postoperative EF in two groups. In group B, the mean pump time was significantly lower than group A (144.09&amp;plusmn;26 vs. 179.64&amp;plusmn;25 min). The mean Cross-clamp time was significantly lower in group B (118.5&amp;plusmn;22 vs. 136.93&amp;plusmn;19 min) Need for blood transfusion in ICU was significantly lower in group B (35.71% vs. 68.57%). Mean ICU Stay and Postoperative Hospital Stay were significantly lower in group B (1.3&amp;plusmn;0.3 vs. 1.9&amp;plusmn;0.7 and 5.2&amp;plusmn;0.9 vs. 5.9&amp;plusmn;1.5 days respectively). Overall mortality was four death (6.25%) which was not significant between two groups. &quot;nConclusions: The usage of patient&apos;s pericardium for support of anastomosis lines in patients undergoing aortic root replacement with pulmonary autograft carry advantages to routine procedure and its utilization is advocated in other centers

Short communication: Prevalence and antibiotic resistance of Staphylococcus aureus isolated from bovine clinical mastitis

The aims of this study were to determine the prevalence and antibiotic resistance of Staphylococcus aureus isolated from bovine clinical mastitis in Varamin, Tehran Province, Iran. All of the isolated Staph. aureus were identified by morphology and culture and confirmed using the API Staph identification system (bioMérieux, Marcy-l’Étoile, France). Antibiotic resistance genes were detected by PCR with oligonucleotide primers specific for each gene. Staphylococcus aureus was recovered from 43 of 207 (20.1%) bovine clinical milk samples. Using disk diffusion, methicillin-resistant Staph. aureus was detected in 5 of 43 (11.6%) samples. The pathogen showed high resistance against penicillin G (86%) and tetracycline (76.7%). The blaZ (penicillin) (86%), tetM (tetracycline), and ermC (erythromycin) genes (39.5% each) were the most prevalent antibiotic resistance genes. The findings of this study are useful for designing specific control programs for bovine clinical mastitis caused by Staph. aureus in this region of Iran

Prevalence and antimicrobial resistance of Listeria, Salmonella, and Yersinia species isolates in ducks and geese

The aims of this study were to determine the prevalence and antimicrobial resistance of Listeria, Salmonella, and Yersinia spp. isolated from duck and goose intestinal contents. A total of 471 samples, including 291 duck and 180 goose intestinal contents, were purchased from wet markets between November 2008 and July 2010. Listeria, Salmonella, and Yersinia spp. were isolated from 58 (12.3%), 107 (22.7%), and 80 (17%) of the samples, respectively. It was concluded that Listeria ivanovii, Salmonella Thompson, and Yersinia enterocolitica were the predominant serovars among Listeria, Salmonella, and Yersinia spp., respectively. Moreover, resistance to tetracycline was common in Listeria (48.3%) and Salmonella spp. (63.6%), whereas 51.3% of the Yersinia spp. isolates were resistant to cephalothin. Therefore, continued surveillance of the prevalence of the pathogens and also of emerging antibiotic resistance is needed to render possible the recognition of foods that may represent risks and also ensure the effective treatment of listeriosis, salmonellosis, and yersiniosis