FMCE-PHQ-9 Assessment with Rasch Model in Detecting Concept Understanding, Cheating, and Depression amid the Covid-19 Pandemic

This research aims to see the ability of the FMCE-PHQ-9 test instrument amid the Covid-19 pandemic to measure conceptual understanding, cheating, and depression in students. The research was conducted on 64 physics education students at Sulthan Thaha Saifuddin State Islamic University Jambi. The instrument consists of 47 force and motion material items to fit the Winsteps 3.65.0 program. The analysis results using the Rasch Model showed that the MNSQ Outfit was 1.00 in the person column and 0.1 in the item column. Judging from the ZSTD value of 0.57 for the person and 0.1 for the item, the Points Measure value correlated with 0.4 to 0.85 while the item reliability value was 0.73 and the Cronbach's Alpha value was 0.56. therefore, the test instrument using the Rasch proclamation model found 31 fit items. The analysis results show that the concept ability was poor since, on average, the students could only answer questions with a low index of difficulty category. The research results on the level of cheating obtained data that 100 percent of students were not indicated to have the same pattern. Lastly, for the level of depression, only 16 percent of students did not experience depression, while 84 percent of students experienced it.

Should we teach free-body diagrams before or after Newton’s Laws?

There are two interesting lesson sequences for teaching force and motion in high-school physics. These are teaching free-body diagrams before Newton’s laws (FbN) and teaching Newton’s laws before free-body diagrams (NbF). Both sequences were found in physics textbooks. Different authors adopted the sequence that they believe it would affect student understanding better. However, some physics experts did not agree with this. It is therefore interesting to know if we should teach with the FbN or NbF sequence. This motivates us to study the effect of such lesson sequences on student understanding of force and motion. The sample group was grade-10 students from two physics courses in 2020. One course was taught with the FbN sequence (29 students) and the other with the NbF sequence (34 students). Their understanding was evaluated by using an assessment test which consisted of three parts including (1) Newtonian concept, (2) problem solving, and (3) free-body diagrams. The result shows that for the Newtonian concept part, the average scores are 11% for the FbN and 13% for the NbF sequence. The average scores of the problem-solving part are 13% and 9% and those of the free-body diagram part are 41% and 48% for the FbN and NbF sequences, respectively. The scores of all parts between the two sequences were not significantly different. In addition, student difficulties found in all parts were similar. However, a larger number of students who could provide the equation of motion (F = ma) in the problem-solving part was found in the FbN sequence. We might conclude that teaching free-body diagrams before or after Newton’s laws did not affect student understanding in the topic of force and motion. Detail of student difficulties in both sequences will be further discussed.

The actomyosin interface contains an evolutionary conserved core and an ancillary interface involved in specificity

Plasmodium falciparum, the causative agent of malaria, moves by an atypical process called gliding motility. Actomyosin interactions are central to gliding motility. However, the details of these interactions remained elusive until now. Here, we report an atomic structure of the divergent Plasmodium falciparum actomyosin system determined by electron cryomicroscopy at the end of the powerstroke (Rigor state). The structure provides insights into the detailed interactions that are required for the parasite to produce the force and motion required for infectivity. Remarkably, the footprint of the myosin motor on filamentous actin is conserved with respect to higher eukaryotes, despite important variability in the Plasmodium falciparum myosin and actin elements that make up the interface. Comparison with other actomyosin complexes reveals a conserved core interface common to all actomyosin complexes, with an ancillary interface involved in defining the spatial positioning of the motor on actin filaments.