Judul: Analisis Karakter Morfologi, Anatomi, dan Struktur Sekretori Tanaman Ciplukan (Physalis angulata L.).
Abstrak: Ciplukan (Physalis angulata L.) merupakan tanaman herba yang tumbuh liar sebagai gulma di lading dan tersebar luas di daerah tropis dan sub tropis. Di berbagai negara tumbuhan ini dimanfaatkan sebagai obat tradisional. Penelitian ini bertujuan mengetahui keanekaragaman morfologi ciplukan di lingkungan tumbuh dengan iklim mikro yang relatif sama, mengetahui struktur anatomi tanaman dan struktur sekretori, serta kandungan senyawa yang terdapat di dalamnya. Pengamatan morfologi menggunakan tumbuhan liar yang tumbuh di lapang. Karakter yang diamati meliputi perawakan tumbuhan, daun, batang, bunga, dan buah. Analisis karakter morfologi menunjukkan variasi dari bentuk helai daun, bentuk tepi daun, diameter bunga, panjang tangkai bunga, panjang buah, diameter buah, dan panjang tangkai buah. Pengamatan struktur anatomi, sekretori, dan histokimia menggunakan tumbuhan yang ditanam di rumah kaca. Organ tumbuhan yang diamati meliputi daun, batang, dan akar. Analisis karakter anatomi menunjukkan kerapatan stomata pada sisi abaksial lebih besar dibandingkan sisi adaksial, namun ukurannya lebih besar pada sisi adaksial. Trikoma kelenjar yang terdiri atas satu sel basal, satu sel tangkai, dan empat sel kepala ditemukan pada helai daun dan batang ciplukan. Hasil uji histokimia mengungkap akumulasi dua senyawa metabolit sekunder yaitu alkaloid dan terpenoid pada trikoma kelenjar.
Keyword: alkaloid, histokimia, Physalis angulata, trikoma kelenjar

Judul: Toksisitas Ekstrak Ciplukan (Physalis angulata) Berdasarkan Uji Letalitas Larva Udang
Abstrak: Physalis angulata known as ciplukan in Indonesia is widely used as herbal medicinal plant. Studies on this plant revealed its potency as antidiabetic, antioxidant, antimicrobial, and antiasthma, but the toxicity is not reported yet. This study aimed to determine the toxicity of leaf extracts from ciplukan by using brine shrimp lethality test (BSLT). Phytochemical test of crude ethanolic extract indicated the presence of alkaloids, flavonoids, and steroids. Ethanol crude extract was extracted by liquid-liquid extraction and gave 2 extracts, namely n-hexane and ethyl acetate extracts. BSLT results showed that all the extracts were toxic. n- Hexane extract was the most toxic extract with value of LC50 3 ppm, indicating its potency as anticancer.
Keyword: Bogor Agricultural University (IPB), Physalis angulata, ciplukan, brine shrimp lethality test

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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