Judul: Isolation and Identification of Aspergillus sp. in Tilapia (Oreochromis sp.) Sold for Consumption
Abstrak: Penelitian ini mendeteksi keberadaan Aspergillus sp. pada ikan nila yang dijual untuk konsumsi manusia di Desa Pasarean Kabupaten Bogor. Lima puluh ekor ikan diambil sampelnya untuk deteksi keberadaan Aspergillus. Tanda-tanda klinis ikan terkikis sirip, insang, pendarahan, dan luka. Keberadaan cendawan patogen dikonfirmasi melalui swab dari kulit, insang, dan kloaka dan selanjutnya dikulturkan pada Potato Dextrosa Agar (PDA). Pengamatan makroskopis dan mikroskopis dilakukan untuk menentukan spesies Aspergillus. Hasil penelitian menunjukkan terdapat empat spesies Aspergillus yang teridentifikasi, yaitu A. terreus (2%); A. flavus (4%); A. fumigatus (42%); dan A. niger (4%), dan koinfeksi antara A. fumigatus dan A. flavus (2%); koinfeksi A. fumigatus dan A. terreus (2%); dan koinfeksi A. fumigatus, A. flavus dan A. niger (2%). Prevalensi aspergillosis total sebesar 58%. Penelitian lebih lanjut diperlukan untuk meningkatkan pemahaman tentang penyakit cendawan dalam sistem akuakultur, yang mengarah pada strategi pencegahan dan pengendalian yang efektif, sehingga memastikan keamanan dan keberlanjutan praktik akuakultur di Indonesia., This study investigates the occurrence of Aspergillus sp. in tilapia sold for human consumption at Pasarean village of Bogor District. Fifty fish were sampled for Aspergillus detection. The clinical signs of fish are eroded fins, gills, haemorrhages, and wounds. The presence of pathogenic fungi was confirmed through fungal isolation from the skin, gills, and cloaca and subsequent culturing on Potato Dextrose Agar (PDA). Macroscopic and microscopic observations determined the species of Aspergillus. The results show that four Aspergillus species were identified, including A. terreus (2%), A. flavus (4%), A. fumigatus (42%), and A. niger (4%), with the occurrence of coinfection between A. fumigatus and A. flavus (2%), A. fumigatus and A. terreus (2%) and between A. fumigatus, A. flavus and A. niger (2%) giving a total prevalence of 58%. Further research is necessary to enhance the understanding of fungal diseases in aquaculture systems, leading to effective prevention and control strategies, thus ensuring the safety and sustainability of aquaculture practices in Indonesia.
Keyword: Aspergillus sp., aquaculture, threat, pathogenic fungi, tilapia

Judul: Exploration of Parasites Nile Tilapia (Oreochromis niloticus) from The Local Fish Seller in Dramaga, Bogor
Abstrak: Besarnya komoditas perikanan ikan nila secara nasional terus mengalami peningkatan. Namun, dalam usaha budidaya ikan ini berbagai kendala ditemui, salah satunya adalah penyakit yang disebabkan oleh parasit. Penelitian ini bertujuan untuk mengidentifikasi parasit yang ada pada ikan nila (Oreochromis niloticus) dari toko penjual ikan di Dramaga, Bogor, Jawa Barat. Sampel ikan nila diambil sebanyak 14 ekor dengan rata-rata panjang ± 22 cm dan bobot tubuh ± 195 gram. Sampel diambil dari insang, sirip dada, sirip anal, sirip caudal, sirip dorsal, sisik, dan usus ikan. Sampel diperiksa dengan metode natif. Sampel dari usus dilakukan pewarnaan Ziehl Neelsen. Sampel darah ikan diambil untuk dilakukan ulas darah dan diberi pewarnaan Giemsa. Berdasarkan hasil pengamatan, ditemukan parasit Trichodina sp. sebanyak 85,71% (n=14) dengan intensitas 27,83 individu/ekor dan insang sebagai organ yang paling banyak terinfeksi. Tingkat infeksi parasit yang ditemukan dengan pewarnaan Ziehl Neelsen adalah Myxobolus sp. (57,14%), Cryptosporidium spp. (35,71%), dan Cyclospora sp. (14,29%). Sedangkan, tingkat infeksi parasit darah yang ditemukan yaitu Haemogregarina sp. (50%). Informasi mengenai keberadaan parasit pada ikan nila ini menjadi sangat penting diketahui bagi pembudidaya untuk mengendalikan parasit secara tepat dan efektif., The demand for tilapia fishing goods has recently expanded on a national scale. One of the difficulties this fish farming operation encountered was the parasite-caused illness. The aims of this study were to explore parasites in tilapia (Oreochromis niloticus) from the local fish seller in Dramaga, Bogor, West Java. A total of 14 tilapia were sampled, with an average length of 22 cm and a body weight of 195 grams. Fish gills, pectoral fins, caudal fins, tail fins, dorsal fins, scales, and intestines were collected. The methods used in this study were wet mount examination, gut samples were stained with Ziehl Neelsen, and blood samples from fish were obtained and stained with Giemsa for analysis. The findings revealed that Trichodina sp. (85.71 percent) was present in several organs, with the gills being the most heavily affected organ. The intensity of this parasite was 27.83 individuals/head. The parasites detected by Ziehl Neelsen staining were Myxobolus sp. (57.14 %), Cryptosporidium spp. (35.71 %), and Cyclospora sp. (14.29%). The type of blood parasite found was identified as Hemogregarina sp (50%). Our findings are very important information for initiating the development of a treatment strategy to prevent parasite infection in tilapia fish farms.
Keyword: Oreochromis niloticus, parasit darah, parasit saluran pencernaan, tingkat infeksi

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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