Application of Projects of Constructing Devices in Physics Teaching and Learning for Tanzanian Secondary Schools

This study investigated the extent of application of projects of constructing devices (CDs) in ordinary level secondary school physics teaching and learning in Tanzania. The study design was a survey using both qualitative and quantitative methods of data collection and analysis. The study was conducted in Dar es Salaam and Morogoro regions, where six secondary schools were involved namely Azania, Biafra, Kambangwa, Kigurunyembe, Kilakala and Morogoro. A total of 146 respondents were involved, including six secondary schools, 25 physics teachers and 115 Form IV students in 2008. The data were collected through questionnaires, focus group discussion and documentary review. The findings revealed that there are reasonable numbers of proposed projects of CDs in the 1996 and 2007 physics syllabi through which students can learn physics by constructing devices and developing a variety of competences. It has also been revealed in the findings that, the extent of application of projects of CDs in secondary school physics teaching and learning to be low, due to a number of constraints including low competence of teachers, lack of working tools, inadequate materials for constructing devices, and lack of physics laboratory equipment and materials. The findings disclosed many benefits of applying projects of CDs in physics teaching and learning such as making physics popular to many students; constructing devices that can be used as physics teaching aids for own school use; enhance students' achievement in physics tests and examinations; improve students' confidence in studying physics; localize physics to the surroundings of the students; develop creativity and innovative mind among students to construct other devices; develop problem solving skills among students; and promot application of the knowledge of physics in daily life. Based on the findings, it can be concluded that, the low application of projects of CDs in physics teaching and learning is caused by many constraints which must be addressed by collaboration among education stakeholders. The study recommends that, the application of projects of CDs in physics teaching and learning should be promoted by conducting in-service training for physics teachers and by providing to schools all the basic requirements needed for effective implementation of the strategy

Timing and Synchronization of the Breeding Period in Pilumnus vespertilio (Crustacea: Pilumnidae) in Subtropical Okinawa, Japan

Observations on the temporal occurrence of copulating pairs, ovigerous females, monthly brooding periods, and embryo development stages in Pilumnus vespertilio Fabricius were carried out in the wild on Okinawa Island, Japan. The relationship between the female gonad and hepatopancreas during a reproductive period was also studied. These reproductive activities were observed in relation to the lunar cycles. An inverse relationship between mass of the hepatopancreas and development of the gonad was observed. Mating and breeding activities were perfectly synchronized with the lunar periodicity. Five broods from May to September were observed in a single breeding period, and the average brooding period was 21.2 days with an interlude of 8.5 ± 3.1 days between broods/months. The shortest interlude was between May and June (4 days). A sixth brood that started in October was not followed to the end because it started with very few ovigerous females. Embryo development time in days decreased with each stage and averaged 5.3 days per stage. Copulating activity and appearance of ovigerous females during successive broods (months) were clearly synchronized with the lunar cycle. Although copulating frequency was highest after the full moon, nearly 100% of females were ovigerous around the new moon. All females of anyone sample carried eggs of the same development stage. All females released their larvae 1-3 days before full moon, coinciding with a high tide. Larvae are probably released during this time as a survival strategy against predators such as planktivorous fish and against adverse intertidal conditions during other times

Masking material as a form of food storage in Tiarinia cornigera and Micippa platipes (Brachyura, Majidae)

Masking or decorating, which means attaching materials to the body, was investigated in two spider crabs Tiarinia cornigera and Micippa platipesin the subtropical waters of Okinawa, Japan. This life strategy was compared between sites over a period of time. All crabs of different ages and sizes attached materials, in one combination or the other, on their bodies proportionate to their carapace sizes. Older or larger crabs had their carapaces more completely covered with the materials than young or smaller crabs. Similar materials were found at all sites and had equal selective precedences by crabs. Red algae, particularly Gelidiella sp, was the most frequently selected material over the other groups of brown, green algae and sand. The brown algae Dictyota linearis was the most dominant species in the stomach contents. However, this species like a few others was not selected for masking. Availability and probably the nutritive values of the algal species are discussed as probable reasons for selection of these materials for masking. These materials were strategically selected, stored on carapaces and used as food sources. Tanzania Journal of Science Vol. 32 (2) 2006: pp. 91-10

Évaluation de la recherche agricole en Afrique australe

Dans IDL-833

Evaluation of agricultural research in Southern Africa

In IDL-906