Judul: Aktivitas Insektisida Campuran Ekstrak Buah Piper aduncum (Piperaceae) dan Sapindus rarak (Sapindaceae) terhadap Larva Crocidolomia pavonana
Abstrak: Crocidolomia pavonana is an important pest of Brassicaceous vegetable crops. Piper aduncum and Sapindus rarak fruit extracts are potential for the control of C. pavonana larvae. Insecticidal activity of P. aduncum and S. rarak fruit extracts as well as their mixtures was evaluated against C. pavonana larvae in the laboratory. Ethyl acetate P. aduncum (EtPa) extract as well as methanolic S. rarak (MeSr) and aqueous S. rarak (AqSr) extracts were tested separately and in mixtures against second-instar larvae C. pavonana by a leaf-residue feeding method. In general, mortality of C. pavonana larvae in the treatment with all test extracts increased sharply between 24 and 48 hours after treatment (HAT). Based on LC50 and LC95 at 72 HAT, EtPa extract was about 7.7 and 8.1 times and 14.5 and 12.8 times, respectively, more toxic to C. pavonana larvae than MeSr and AqSr extracts. At LC95 level, EtPa + MeSr extract mixture (1:10 w/w) was about 1.64 times more toxic to the test larvae than EtPa + AqSr extract mixture (1:10 w/w). Based on combination index at 48, 72, and 96 HAT assessment, EtPa and MeSr extract mixture at LC50 level as well as EtPa and AqSr extract mixture at LC50 and LC95 levels had additive joint action, while EtPa and MeSr extract mixture at LC95 was weakly synergistic. In addition to lethal effect, the treatment with all test materials delayed the development of C. pavonana larvae from second-instar to fourth instar. Thus, EtPa, MeSr, and AqSr extracts as well as the mixtures between EtPa and S. rarak extracts are potential alternatives for the control of C. pavonana pest.
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Judul: Sinergisme campuran ekstrak Buah Piper aduncum (PIPERACEAE) dan Daun Tephrosia vogelii (LEGUMINOSAE) terhadap Larva Crocidolomia pavonana
Abstrak: Hama Crocidolomia pavonana merupakan salah satu faktor pembatas penting yang dapat mengurangi hasil panen dalam budi daya tanaman kubis-kubisan (Brassicaceae). Salah satu alternatif pengendalian yang efektif dan ramah lingkungan adalah menggunakan insektisida nabati. Penelitian ini bertujuan mengetahui sinergisme campuran ekstrak buah Piper aduncum (BPa) dan daun Tephrosia vogelii (DTv) dengan nisbah konsentrasi 1:1, 1:4, 1:5, 4:1, dan 5:1 terhadap larva C. pavonana. Bahan tumbuhan diekstraksi dengan pelarut etil asetat lalu ekstrak BPa dan DTv yang diperoleh diuji secara tunggal dan campuran terhadap larva instar II C. pavonana menggunakan metode celup daun. Berdasarkan LC50 pada 96 jam setelah perlakuan (JSP), ekstrak DTv lebih toksik 2.34 kali daripada ekstrak BPa serta campuran ekstrak pada nisbah konsentrasi 1:1, 1:4, 1:5, 4:1, dan 5:1 lebih toksik 4.45, 2.00, 2.30, 1.34, dan 1.64 kali daripada ekstrak BPa dan campuran ekstrak pada nisbah konsentrasi 1:1 lebih toksik 1.90 kali daripada ekstrak DTv. Berdasarkan indeks kombinasi pada LC50, campuran ekstrak BPa+DTv 1:1 bersifat sinergistik kuat. Berdasarkan hasil penelitian ini, campuran ekstrak BPa+DTv 1:1 paling berpotensi untuk digunakan dalam pengendalian C. pavonana.
Keyword: Botanical insecticide mixtures, Crocidolomia pavonana, Piper

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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