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Catfish is playing an important role in aquaculture production; it is one of the primary commodities of inlandfisheries industry. Catfish meat has a yield of 49% and resulted in 51% of waste products. Thus catfish waste product has potency as source of fish oil which riches of omega-3. The Purpose of this study was to evaluate the suitable extaction method to obtain the high quality of fish oil from catfish skin. Based on the oxidative quality analysis data obtained extraction temperature of 60°C gives the best quality of fish oil with parameters such as peroxide value, free fatty acid, p-anisidine value, acid value and total oxidation of 38 meq/kg, 0.45%, 107,5 meq/kg, 895 mg KOH/kg and 187.5, respectively. The best yield was 18.75% which was obtained at extraction temperature of 75 °C. It was concluded that best extraction at 60°C, for 30 minutes, with solvent and sample ratio 1:1.

The purpose of this study was to determine the yield, chemical compositions, amino acids, minerals, and heavy metal residues (Pb, Hg) of fresh and boiled mussel. Amino acid was analyzed usingHPLC, minerals and heavy metals were examined using AAS and phosphorus by spectrophotometer, fatty acids by GC, and cholesterol by Liebermann-Buchard. The results showed that the chemical composition of water content, ash, protein and lipid of mussels meat were decreased about 6.09%, 2.25%, 1.39%, 0.42%, respectively after boiled while carbohydrate was increased 4.07% and the amino acids were decreased after boiling. The Ca, Mg, K, P, Na, Cu were declined after boiled, while Co, Fe, Mn and Zn were incraseed. In addition, the Pb was decreased after boiled while Hg and Se were not detected in both fresh and boiled mussel meat. SAFA fatty acids was 38.71% (fresh) and 37.31% (boiled), MUFA 8.13% (fresh) and 8.02% (boiled), PUFA 10.31% (fresh) and 8.77% (boiled), and the cholesterol contents were 102.57 mg/100 g of fresh and 100.97mg/100 g for boiled mussel meat.

The purpose of this study was to compare two treatments, namely the use of hands-on activity media and computer-based media on the conceptual understanding of mathematics and the reasoning ability of junior high school students. In order to obtain complete information about the comparison of the two, researchers also use groups without learning media as a controller. This research approach is quantitative using quasi-experimental methods. The study design was a nonequivalent comparison group design involving seventh-grade students in Bandung Indonesia, totaling 243 people. The research data were obtained using tests of conceptual understanding and mathematical reasoning. The results showed that: the ability to understand mathematical concepts from groups of students who use computer-based media differs significantly from groups of students who use hands-on activity media and control groups. Meanwhile, the ability to understand mathematical concepts of students using hands-on activity media did not differ significantly from the control group. The mathematical reasoning abilities of groups of students who use computer-based media differ significantly from groups of students who use hands-on activity media and control groups. Furthermore, students' mathematical reasoning abilities using hands-on activity media differ significantly from the control group. The use of media, both hands-on activity and computer-based media, contribute to the achievement of student reasoning, especially on the topic of plane geometry being studied. Students can build an understanding of concepts based on their abilities.

Background Strategies to increase body resistance and prevent disease in aquaculture include using vaccines, antibiotics, and probiotics. Today, the use of antibiotics with natural ingredients is becoming a trend. Sargassum sp is a natural ingredient that contains high antioxidants and antibiotics. Methods This research was conducted from March to May 2022 at the Biotechnology Laboratory, Faculty of Fisheries and Marine, Universitas Riau, in two stages: 1) the sensitivity of extracts of Sargassum sp. and 2) the application of Sargassum sp. extract orally in tilapia ( O. niloticus). The parameters measured were clear zone, minimum inhibitory concentration, LD 50 test of leaf extract of Sargassum sp. in tilapia ( O. niloticus), hemoglobin levels, hematocrit, total leukocytes, total erythrocytes, leukocyte differentiation, and survival rate. Data on hematology parameters were tabulated and analyzed using a One-Way ANOVA followed by a Student Newman Keuls (SNK) test when deemed necessary. Results The results showed that the extract of Sargassum sp. inhibited the growth of Aeromonas hydrophila bacteria with a clear zone of 6.5-15.0 mm, which is classified as resistant. At doses of 2000, 2500, and 3000 ppm, it did not cause death in fish for 96 hours (LD 50). Hematological parameters can be a sign of the health status of fish. Tilapia given Sargassum sp. in different doses gave an effect between treatments after 30 days of rearing and post-test against A. hydrophila bacteria (pSargassum sp. extract was in the normal or healthy range. Healthy tilapia had erythrocyte counts ranging from 1.34-2.11×10 6 cells/mm 3, hematocrit 26.17-33.19%, hemoglobin 6.26-11.2 g/dL and total leukocytes 1.01-1.50×10 4 cells/mm 3 and total erythrocytes 5.88-9.13×10 4 cells/ mm 3. Conclusions A dose of 3000 ppm provided the highest health improvement against A. hydrophila bacterial infection.

Background: Strategies to increase body resistance and prevent disease in aquaculture include using vaccines, antibiotics, and probiotics. Today, the use of antibiotics with natural ingredients is becoming a trend. One of the natural ingredients that contain high antioxidants and antibiotics is Sargassum sp. Methods: This research was conducted from March to May 2022 at the Biotechnology Laboratory, Faculty of Fisheries and Marine, Universitas Riau, in two stages: 1) the sensitivity of extracts of Sargassum sp. and 2) the application of Sargassum sp. extract orally in tilapia ( O. niloticus). The parameters measured were clear zone, minimum inhibitory concentration, LD 50 test of leaf extract of Sargassum sp. in tilapia ( O. niloticus), hemoglobin levels, hematocrit, total leukocytes, total erythrocytes, leukocyte differentiation, and survival rate. Data on hematology parameters were tabulated and analyzed using a One-Way ANOVA followed by a Student Newman Keuls (SNK) test when deemed necessary. Results: The results showed that the extract of Sargassum sp. inhibited the growth of Aeromonas hydrophila bacteria with a clear zone of 6.5-15.0 mm, which is classified as resistant. At doses of 2000, 2500, and 3000 ppm, it did not cause death in fish for 96 hours (LD 50). Hematological parameters can be a sign of the health status of fish. Tilapia given Sargassum sp. in different doses gave an effect between treatments, both after 30 days of rearing and post-test against A. hydrophila bacteria (pSargassum sp. extract was in the normal or healthy range. Healthy tilapia had erythrocyte counts ranging from 1.34-2.11×10 6 cells/mm 3, hematocrit 26.17-33.19%, hemoglobin 6.26-11.2 g/dL and total leukocytes 1.01-1.50×10 4 cells/mm 3 and total erythrocytes 5.88-9.13×10 4 cells/ mm 3. Conclusions: A dose of 3000 ppm provided the highest health improvement against A. hydrophila bacterial infection.

This study explored the perceptions of students from different types of schools in Malaysia towards their online learning engagement during COVID-19's movement control order using Fredricks et al.'s framework of behavioural, cognitive, and emotional engagement. In addition to these variables, external support provided to the students was also considered. To this end, a questionnaire that examined the students' general online practices and online learning engagement was administered. Seven hundred sixty-eight students from four different types of secondary schools (national, Chinese, international, and high performing schools) responded to the questionnaire. The findings from the ANOVA analysis indicated that generally the respondents demonstrated positive online learning practices. However, the amount of time spent interacting with teachers online should be much improved. The findings also indicated significant differences in perceptions towards online learning engagement and external support based on school types.

Background: Strategies to increase body resistance and prevent disease in aquaculture include using vaccines, antibiotics, and probiotics. Today, the use of antibiotics with natural ingredients is becoming a trend. One of the natural ingredients that contain high antioxidants and antibiotics is Sargassum sp. Methods: This research was conducted from March to May 2022 at the Biotechnology Laboratory, Faculty of Fisheries and Marine, Universitas Riau, in two stages: 1) the sensitivity of extracts of Sargassum sp. and 2) the application of Sargassum sp. extract orally in tilapia ( O. niloticus). The parameters measured were clear zone, minimum inhibitory concentration, LD 50 test of leaf extract of Sargassum sp. in tilapia ( O. niloticus), hemoglobin levels, hematocrit, total leukocytes, total erythrocytes, leukocyte differentiation, and survival rate. Data on hematology parameters were tabulated and analyzed using a One-Way ANOVA followed by a Student Newman Keuls (SNK) test when deemed necessary. Results: The results showed that the extract of Sargassum sp. inhibited the growth of Aeromonas hydrophila bacteria with a clear zone of 6.5-15.0 mm, which is classified as resistant. At doses of 2000, 2500, and 3000 ppm, it did not cause death in fish for 96 hours (LD 50). Hematological parameters can be a sign of the health status of fish. Tilapia given Sargassum sp. in different doses gave an effect between treatments, both after 30 days of rearing and post-test against A. hydrophila bacteria (pSargassum sp. extract was in the normal or healthy range. Healthy tilapia had erythrocyte counts ranging from 1.34-2.11×10 6 cells/mm 3, hematocrit 26.17-33.19%, hemoglobin 6.26-11.2 g/dL and total leukocytes 1.01-1.50×10 4 cells/mm 3 and total erythrocytes 5.88-9.13×10 4 cells/ mm 3. Conclusions: A dose of 3000 ppm provided the highest health improvement against A. hydrophila bacterial infection.

This research aims to explore the use of ethnomathematics in revealing mathematical representations and in the formulation of a calculation system used in the "Marosok" trading tradition by the Minangkabau tribe in West Sumatra. Ethnomathematics studies ideas in various cultural activities practiced by ethnic, social, or professional groups. The tradition involves nonverbal communication, such as shaking hands with 'Marosok' or touching covered fingers to obtain price agreements in trading livestock. Therefore, this study was conducted using qualitative approaches and the ethnographic method via field notes, unstructured interviews, and documentation studies. The findings showed that mathematical representations of finger symbols and gestures in the "Marosok" Tradition contain basic numbers. These include half, one, two, two and a half, three, four, five, etc. with functions, such as addition and subtraction, which are used to obtain other numbers needed in livestock trading transactions using specific formulas.

Over the last decade, issues regarding attributions for success and failure in the learning of English have garnered much interest among Asian researchers. Of particular interest is the tendency of Asian learners to be self-critical when it comes to attributions for failure in the learning of English. This tendency has commonly been linked to the influence of the socio-cultural context in which the learners have grown up and has been described as a prevalent trait among collectivist societies such as those that exist in many Asian countries. More recently, it has been suggested that a contributory factor for this behaviour is the students' high respect for teachers. The present study was an attempt to investigate to what extent that claim is true. The researchers examined whether or not there is a relationship between self-critical tendency and teacher-centeredness between students of different proficiency levels in the learning of English in a Malaysian context. A mixed-method design comprising questionnaires and individual group interviews was employed. The findings revealed that in general learners who displayed teacher-centred tendency were likely to be self-critical by attributing failure to personal factors. However, difference in proficiency levels did account for some variation in results. Although both tendencies should be seen in a positive light, recommendations with regard to educational implications are outlined.