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Observation result in cell biology (CB) learning showed that most students assumed cell biology as a complex and abstract material. The level of conceptual understanding was still relatively low observable from inadequate test results. Misconception on cell structure as a dense and non-porous structure was reported; this can be seen from students’ drawing on cell membranes. One solution to overcome the above problem was to develop contemporary teaching materials in the form of e-module based on Edmodo mobile (based android) so that students can easily access them by their smartphone. The research objective was to develop an Edmodo android cell biology module. Research and development (R&D) method were applied in this study. The development model used was Thiagarajan 4D, which is defined, design, and develop. The instruments used were the e-module validation questionnaire by experts (material and media experts, practitioners) and the feasibility test questionnaire on 24 students. The result showed that Edmodo mobile on CB developed through Thiagarajan 4D has valid criteria. Thus, it can be used in cell biology learning.

A more interactive and fun microbiology learning solution by utilizing information technology is the development of interactive multimedia of microbiological material based on Edmodo Android. The purpose of this research is to produce interactive multimedia microbiology based on Edmodo Android. The research method used is research and development. Interactive multimedia microbiology based on Edmodo Android developed with Thiagarajan development model. The research is done through define stage, design stage, and develop stage. The data of the research are validation questionnaire from media experts, microbiology material experts, and practitioners. The research data is corrected by using the percentage of eligibility criteria.

The development of multimedia based on science, technology, engineering, and mathematics (STEM) to empower students critical thinking skills has not been optimally carried out. The purpose of this research was to develop multimedia of human anatomy and physiology material based on STEM which improve students' critical thinking skills. This research and development (R&D) used 4D Thiagarajan development model which consisted of define, design, develop, and disseminate. The instruments used were interview guidelines, observation sheets, questionnaires, and test. The data obtained consisted of quantitative and qualitative data. The quantitative data was obtained from the test results and the assessments of respondents using a Likert scale, while the qualitative data in the form of experts recommendations. The results showed that the media developed were classified as valid with the scores were 96.89% (media aspects), 97.53% (usefulness), and 85.22% (readability). Furthermore, the prerequisite test results showed that the data are spread normally (p>0.05) and homogeneously (p>0.05) so that the ANACOVA test is continued. The ANACOVA test results showed that students' critical thinking skills taught with multimedia were significantly difference (sig <0.05).This study recommends the use of multimedia in learning human anatomy and physiology.

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This study investigates the distribution of total mercury (T-Hg) and methylmercury (MeHg) in the soil and water around the artisanal and small-scale gold mining (ASGM) area along the Cikaniki River, West Java, Indonesia. The concentration of T-Hg and MeHg in the forest soil ranged from 0.07 to 16.7 mg kg and from <0.07 to 2.0 μg kg, respectively, whereas it ranged from 0.40 to 24.9 mg kg and from <0.07 to 56.3 μg kg, respectively, in the paddy field soil. In the vertical variation of the T-Hg of forest soil, the highest values were observed at the soil surface, and these values were found to decrease with increasing depth. A similar variation was observed for MeHg and total organic carbon content (TOC), and a linear relationship was observed between them. Mercury deposited on the soil surface can be trapped and retained by organic matter and subjected to methylation. The slope of the line obtained for the T-Hg vs. TOC plot became larger near the ASGM villages, implying a higher rate of mercury deposition in these areas. In contrast, the plots of MeHg vs. TOC fell along the same trend line regardless of the distance from the ASGM village. Organic carbon content may be a predominant factor in controlling MeHg formation in forest soils. The T-Hg concentration in the river water ranged from 0.40 to 9.6 μg L. River water used for irrigation can prove to be a source of mercury for the paddy fields. The concentrations of Hg and Hg in river water showed similar variations as that observed for the T-Hg concentration. The highest Hg concentration of 3.2 μg L can be attributed to the waste inflow from work sites. The presence of Hg in river water can become a source of mercury present in the atmosphere along the river. MeHg concentration in the river water was found to be 0.004-0.14% of T-Hg concentration, which was considerably lower than the concentrations of other Hg species. However, MeHg comprised approximately 0.2% of the T-Hg in paddy field soil. Mercury deposited from the atmosphere and the river water can be subjected to methylation. Paddy fields are very important ecosystems; therefore, the effect of MeHg on these ecosystems and human beings should be further investigated.

Two Acacia seed orchards, one each of A. mangium and A. auriculiformis, in Central Java have suffered high losses from root rot associated with a species of Ganoderma that is distinct from G. philippii, which causes extensive losses in A. mangium plantations in Sumatra and Kalimantan. Ganoderma steyaertanum was consistently isolated from roots of affected trees in the Javanese orchards and pathogenicity was confirmed by satisfying Koch's postulates. The mode of spread of the pathogen was examined by analysing the distribution of tree deaths in the A. mangium seed orchard and conducting somatic incompatibility tests among G. steyaertanum isolates from diseased trees. Spatial analyses indicate that, after an initially random disease distribution, the pattern of tree deaths was clustered. This is consistent with spore colonisation of thinned stumps followed by vegetative spread through root-to-root contact, as has been observed for other root pathogens such as Heterobasidion annosum. Somatic incompatibility tests demonstrated high genetic variability of the pathogen with root-to-root spread also confirmed.