The recirculating aquaculture system (RAS) is a cultivation system that minimizes water changes and can optimize high stocking densities (SD). The purpose of this study was to determine the effect of nursery culture in high stocking density with RAS on survival rate (SR), specific growth rate (SGR), relative length (LR), weight gain (WG), length gain (LG)and feed utility efficiency (FUE) of juvenile catfish. The study used a completely randomized design with 4 treatments and 3 replications: R3000 (SD of 3,000 fish/m2 with RAS); NR3000 (SD of 3,000 fish/m2 without RAS); R4000 (SD of 4,000 fish/m2 with RAS); NR4000 (SD of 4,000 fish/m2 without RAS). Juvenile catfish measuring 3.3±0.2 cm were reared for 21 days and water changes were carried out every 2 weeks in the RAS and every 2 days in the non-RAS. The results showed that the SR was not significantly different for all treatments. The highest SGR, LR, WG, LG and FUE were shown in the R4000 treatment (p<0.05). Water quality parameters, especially total ammonia nitrogen in the RAS treatment had a lower value than without RAS. The abundance of total bacteria in the RAS treatment was more than without RAS. This study showed that the density of 4,000 fish/m2 with the RAS was able to provide better catfish nursery production performance than without RAS.

The electrokinetic remediation method can function as a primary or secondary technology and can be applied in conjunction with other physical and biological methods, such as soil washing, phytoremediation, and bioremediation. Environmental impacts arising from the electrokinetic remediation process can be determined using life cycle assessment analysis (LCA) or other tools. This study compared the conventional electrokinetic remediation strategy with two hybrid strategies: electrokinetic-phytoremediation (EKR-Phyto) and electrokinetic-bioremediation (EKR-Bio). The environmental performance of the three strategies is then tested through LCA analysis. The database used was The Ecoinvent, and the freeware software used during the inventory stage was OpenLCA. The impact assessment stage was used in the Recipe I (2016) midpoints, Available Water Remaining (AWARE) midpoint, Intergovernmental Panel Climate Change (IPCC) midpoint (2003), UNEP Society of Environmental Toxicology (USEtox) midpoint, and cumulative energy demand midpoint. The significance of the analysis results was not obtained for the GWP parameter but for the freshwater eutrophication parameter. Among the three strategies, the EKR-Phyto strategy showed the highest significance in eutrophication but the lowest significance in land change. Substitution of chemical fertilizers into natural fertilizers in the EKR-Phyto strategy can be an opportunity for environmental sustainability. The highest impact for ecological analysis of the three strategies was EKR-Phyto in terms of GWP, the sum of primary energy, Acidification Potential (AP), and Photochemical Ozone Creation Potential (POCP).

Natural medicine is safer than modern or synthetic medicine because it has few side effects if used correctly. The aim of this research is an introduction test to know the barrier power of sarang tawon angkut-angkut extracts (Eumennes coarcatus) as a natural antimicrobial for avoiding Escherichia coli growth. Kirby bauer method (paper disk method) is used in this research. Sarang tawon angkut-angkut extract is used for the sample and 0.5 mL Escherichia coli bacterial suspension. The result of this research showed that sarang tawon angkut-angkut extract has barrier power as naturally antimicrobial in Escherichia coli growth with 4.2 mm average of barrier zone with weak antibacterial activity. This research concludes that sarang tawon angkut-angkut extract has potency as an antimicrobial. ABSTRAKPenggunaan obat alami dinilai lebih aman dari pada obat modern atau sintetis karena memiliki efek samping yang relatif kecil jika digunakan secara tepat. Penelitian ini bertujuan untuk uji pendahuluan mengetahui adanya daya hambat ekstrak sarang tawon angkut-angkut (Eumennes coarcatus) sebagai antimikroba alami untuk mencegah pertumbuhan bakteri Escherichia coli. Metode yang digunakan adalah metode Kirby bauer (metode kertas cakram). Sampel yang digunakan adalah ekstrak sarang tawon angkut-angkut dan suspense bakteri 0,5 mL bakteri Escherichia coli. Hasil penelitian menunjukkan bahwa ekstrak sarang tawon angkut-angkut memiliki daya hambat sebagai antimikroba alami dalam pertumbuhan Escherichia coli dengan rata-rata diameter zona hambat yaitu 4,2 mm dengan aktivitas antibakteri lemah. Kesimpulan penelitian ini adalah ekstrak sarang tawon angkut-angkut memiliki potensi sebagai senyawa antimikroba.

) and upper layer (8-10 m). Abiotic factors (Temperature and light intensity) were measured at each location. Non crop vegetation was analyzed by line intercept method and tree vegetation was analyzed by complete count method. Data of structure community comparison each location was analyzed by important value and diversity (Index Shannon-Whienner). The degree of same level composition between two location was analyzed by Index Bray-Curtis and variation vertical analyzed by anova. Canopy Arthropod composition and relation with abiotic factors was analyzed by Pearson