Constructivist Approach to Learning Activity: The Case of Junior Secondary Students’ Misconception on the Three States of Matter in Basic Science, Nigeria

The paper focuses on the misconceptions of students on the states of matter and suggests the need for scienceteachers to adopt the 7E model in order to reduce these misconceptions and promote students’ learning. The paperdevelops and proposes a learning activity based on a systematic review of scholarly articles, thesis, and curriculumthat investigated the subject matter. The 7E model consists of phases such as elicit, engage, explore, explain,elaborate, evaluate, and extend. The researchers prepared a specific lesson plan on identifying the properties andstructures of states of matter using the 7Es learning cycle specifying the teacher’s activities and the correspondingstudents’ activities. The 7E model is recommended for teaching states of matter based on studies that found theapproach to be effective in helping students eliminate scientific misconception and improve understanding

Classification of Myoelectric Signal using Spectrogram Based Window Selection

This paper presents a study of the classification of myoelectric signal using spectrogram with different window sizes. The electromyography (EMG) signals of 40 hand movement types are collected from 10 subjects through NinaPro database. By employing spectrogram, the EMG signals are represented in time-frequency representation.  Ten features are extracted from spectrogram for performance evaluation. In this study, two classifiers namely support vector machine (SVM) and linear discriminate analysis (LDA) are used to evaluate the performance of spectrogram features in the classification of EMG signals. To determine the best window size in spectrogram, three different Hanning window sizes are examined. The experimental results indicate that by applying spectrogram with optimize window size and LDA, the highest mean classification accuracy of 91.29% is obtained

A Detail Study of Wavelet Families for EMG Pattern Recognition

Wavelet transform (WT) has recently drawn the attention of the researchers due to its potential in electromyography (EMG) recognition system. However, the optimal mother wavelet selection remains a challenge to the application of WT in EMG signal processing. This paper presents a detail study for different mother wavelet function in discrete wavelet transform (DWT) and continuous wavelet transform (CWT). Additionally, the performance of different mother wavelet in DWT and CWT at different decomposition level and scale are also investigated. The mean absolute value (MAV) and wavelength (WL) features are extracted from each CWT and reconstructed DWT wavelet coefficient. A popular machine learning method, support vector machine (SVM) is employed to classify the different types of hand movements. The results showed that the most suitable mother wavelet in CWT are Mexican hat and Symlet 6 at scale 16 and 32, respectively. On the other hand, Symlet 4 and Daubechies 4 at the second decomposition level are found to be the optimal wavelet in DWT. From the analysis, we deduced that Symlet 4 at the second decomposition level in DWT is the most suitable mother wavelet for accurate classification of EMG signals of different hand movements.

Tree Water Uptake and Suction Distribution on Tropical Residual Soil Slope

This paper present an exploration of soil matric suction effected by water uptake via tree root at toe of slope on various condition between wet condition (high rainfall) and dry condition (prolonged no rainfall). Matric suction generated by active root tree has substantial influence soil moisture content on residual soil slope. A field monitoring was carried out to collect matric suction data at slope in two conditions; with a tree located at toe of slope and absent of a tree. The installations of instruments particularly at slope with tree at toe were placed within vicinity of the tree with certain depths and distances. The matric suction data from field monitoring was influence by the rainfall events that lead to the instability of soils slope. Analysis of soil matric suction distribution pattern indicates that the highest matric suction value was at shallower depth and proximity of tree. The matric suction profiles obtained from field monitoring are applied as an input data to develop soil matric suction contour. The effect of transpiration driven by active root zone generated matric suction on soil at vicinity of tree may create dry soil to increase soil shear strength

Plastic pollution in the ocean

Plastic pollution in the ocean was first reported by scientists in the 1970s, yet in recent years it has drawn tremendous attention from the media, the public, and an increasing number of scientists spanning diverse fields, including polymer science, environmental engineering, ecology, toxicology, marine biology, and oceanography. In the oceans, the threat to marine life comes in various forms, such as overexploitation and harvesting, dumping of waste, pollution, alien species, land reclamation, dredging and global climate change. The extremely visible nature of much of this contamination is easy to convey in shocking images of piles of trash on coastlines, marine mammals entangled in fishing nets, or seabird bellies filled with bottle caps, cigarette lighters, and colourful shards of plastic. Even without these images, anyone who has visited a beach has certainly encountered discarded cigarette butts, broken beach toys left behind, or pieces of fishing gear or buoys that have washed ashore

In vitro antigenicity and cross-reaction of the outer membrane proteins of Pasteurella haemolytica A2, A7 and A9

The outer membrane proteins of Pasteurella haemolytica A2, A7 and A9 were subjected to SDS-PAGE and immunoblotting. The molecular weights of the polypeptide bands ranged between 33 to 97 kDa. The major polypeptide bands for P. haemolytica A2 were 33.4, 39.2 and 45 kDa while the minor polypeptide bands were 50, 58.7, 66.2, 84.7 and 97.4 kDa. Analysis of the outer membrane proteins of P. haemolytica A7 revealed two major protein bands of 33.4 and 45 kDa and three minor polypeptide of 40, 50 and 66.2 kDa. There were three major (33.4, 37.5 and 45 kDa) and one minor protein band (50 kDa) in the outer membrane proteins of P. haemolytica A9. There was one major protein band from each of the P. haemolytica A2, A7 and A9, which was unique to the respective serotype and appeared to represent the respective serotype. These were the 39.2 kDa band for P. haemolytica A2, the 40 kDa band for P. haemolytica A7 and the 37.5 kDa band for P. haemolytica A9. Following homologous immunoblot, all the serotypes showed pronounced antigenicity at the 30 kDa band. Heterologous immunoblot using the antiserum of P. haemolytica A2 did not reveal any antigenic band of P. haemolytica A9 but revealed antigenic bands at 30 and 31 kDa of P. haemolytica A7. Heterologous immunoblot using the antiserum of P. haemolytica A7 revealed antigenic band at 30 kDa of all the three serotypes while the antiserum of P. haemolytica A9 failed to reveal any common antigenic band between all three serotypes. Thus, the 30 kDa band of P. haemolytica A7 may be a suitable candidate for a sub-unit Vaccine against pneumonic pasteurellosis of sheep and goats

Moringa oleifera seeds as natural coagulant for water treatment

Developing countries and third world countries are facing potable water supply problems because of inadequate financial resources. The cost of water treatment is increasing and the quality of river water is not stable due to suspended and colloidal particle load caused by land development and high storm runoff during the rainy seasons especially in a country like Malaysia. During the rainy seasons the turbidity level increases and the need for water treatment chemicals increase as well, which leads to high cost of treatment which the water treatment cannot sustain. As a result, the drinking water that reaches the consumer is not properly treated. Therefore, it is of great importance to find a natural alternative for water coagulant to treat the turbidity. It has been found that Moringa oleifera is the best natural coagulant discovered yet, that can replace aluminium sulphate (Alum) which is used widely all around the world. The study is focusing in Moringa oleifera seeds to find the active constituents which are responsible about the coagulation mechanism and improving the coagulation property. This will help in producing this alternative locally as Moringa oleifera is grown in Malaysia and other tropical countries and can be of great benefit for water treatment

Phytochemical and bioactivity studies of zingiber amaricans blume.

Phytochemical studies on the rhizomes of Zingiber amaricans afforded zerumbone1 as the major constituent, together with sterol mixtures containing, stigmasterol2, β-sitosterol3, cholesterol4 and campesterol5. The structures of the isolated compounds were elucidated using spectroscopic methods. The crude extracts and isolated pure compounds were examined for their bioactivity against phatogenic microbes and cancer cell lines. Zerumbone1 shows moderate cytotoxic activity against human lymphoblastic T leukemia cell