Judul: Ecology Service Tumbuhan Herba untuk Lebah Trigona sp.
Abstrak: Herbaceous plants are able to flower any time, give them opportunity to interact with insects. This study aimed to analyze the diversity of pollen collected by Trigona sp. in herbaceous ecosystem and counted the percentage of pollen viability from the pollen basket. Trigona's nest was adapted at plot and the herbaceous plants with their pollen were identified. Pollen were took from hind legs at 07.00, 08.00 and 09.00 am. Pollen slide were make by acetolysis and SEM methods. Pollen were identified and examined of viability. Identification herbaceous plants and their pollen on plot showed that there were 7 herbaceous plants: Kyllinga monocephala, Cleome rutidosperma, Pennisetum polystachyon, Ageratum conyzoides, Brachiaria mutica, Cyperus orodatus, and Eleutheranthera ruderalis. Otherwise pollen which were collected by Trigona sp. consist of 11 kinds of pollen from 6 families, that were Sapindaceae, Leguminosae, Loranthaceae, Malvaceae, Symplocaceae, and unidentified family. Viability of pollen ranged from 88.8% to 99.8%. The result of identification herbacious plants and pollen that were taken by Trigona sp. indicated that there was not similarity therefore, it was no interaction between herbaceous plants in the plot with Trigona sp.
Keyword: Bogor Agricultural University (IPB), viability, Trigona sp, pollen, interaction, herbaceous plants

Judul: Aktivitas dan Produktivitas Lebah Trigona laeviceps di Kebun Polikultur dan Monokultur Pala (Myristica fragrans)
Abstrak: Trigona laeviceps is belong to the family Apideae. It has belong to no sting (stingless bee) and produce propolis, honey and bee pollen. This study aimed to study and compare the activity and productivity of Trigona laeviceps in polyculture and monoculture plantation nutmeg (Myristica fragrans). The study used completely randomized with type of garden (policultures and monocultures of nutmeg) Trigona activity and productivity (honey, pollen, propolis and development of colonies) were the variables and the obtained data were analyzed by ANOVA T - test with 95% confidence interval. observation the activity in and out in the morning until late afternoon (from 06:00 to 17:00), and productivity seen from the weight indication colony, honey, propolis and bee pollen. Trigona bee activity in the nutmeg monoculture plantation (83 %) was higher than in polyculture garden (84 %) and determined by light intensity. Activity in the garden polyculture affected by temperature pollen and propolis production percentages were higher in policulture plantation, while Trigona colonies in nutmeg monoculture had a better development. However, in this study, ambient factors (temperature, Rh, and light intensity) do not significantly determined variation in Trigona productions.
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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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