Judul: The Growth of Various Types of Indonesia Arrowleaf Sida (Sida rhombifolia L.) on Several Compositions of Growing Media
Abstrak: Sidaguri (Sida rhombifolia L.) merupakan tanaman berkhasiat obat yang masih jarang dibudidayakan. Pengambilan sidaguri dari alam secara terus menerus mengancam keberadaan sidaguri. Penelitian ini bertujuan untuk mengetahui jenis bahan perbanyakan, komposisi media tanam, dan interaksi keduanya untuk menghasilkan bibit dengan pertumbuhan optimal dan efisien. Rancangan percobaan yang digunakan adalah Rancangan Kelompok Lengkap Teracak (RKLT) faktorial dengan tiga ulangan. Terdapat tiga perlakuan jenis bahan perbanyakan yaitu benih, setek batang, dan setek pucuk serta empat komposisi media tanam yaitu tanah, tanah + kompos, tanah + kompos + arang sekam, dan tanah + kompos + pasir (1:1 v/v). Hasil penelitian menunjukkan bahwa terdapat perlakuan yang menghasilkan bibit paling baik berdasarkan pengaruh jenis bahan perbanyakan, namun komposisi media tanam dan interaksi kedua faktor tidak menunjukkan hasil yang berbeda nyata. Bahan perbanyakan yang baik digunakan sebagai bibit sidaguri yaitu setek batang yang menunjukkan hasil paling baik pada peubah daya tumbuh (56,67%), tinggi tanaman (29,4 cm), dan jumlah cabang (3,55) yang dicapai pada umur 8 MST., Indonesia arrowleaf sida (Sida rhombifolia L.) is a medicinal plant which is still rarely cultivated. Taking sidaguri from nature continuously threatens the existence of sidaguri. The study aims to determine the type of propagation material, the composition of growing media and their interaction to produce seedling with optimal growth. The experimental design used was a factorial complete randomized group design with three replications. There were three treatments for the type of propagation material, seeds, stem cuttings, and shoot cuttings as well as four composition of growing media, topsoil, topsoil + compost, topsoil + compost + paddy husk charcoal, and topsoil + compost + sand. The results showed that there was a treatment that produce best seedling based on the type of propagation material, but the composition of the growing media and the interaction of the two factors did not show significantly different results. A good propagation material used as arrowleaf sida seedling is stem cuttings which showed the best result on growth percentage (56,67%), plant height (29,4 cm), and number of branches (3,55) achieved at 8 weeks of age.
Keyword: plant propagation material, cell differentiation, malvaceae, plant growing media, bahan perbanyakan, diferensiasi sel, malvaceae, media tanam

Judul: Classification of Sidaguri’s Stem (Sida rhombifolia) Based on Different Cultivation Ages using LC-MS/MS Combined with Chemometrics
Abstrak: Sidaguri (Sida rhombifolia) merupakan jenis tanaman yang telah banyak dimanfaatkan sebagai obat tradisional karena kandungan metabolit bioaktif di dalamnya. Kandungan metabolit di dalam batang tanaman tersebut dipengaruhi oleh beberapa faktor, salah satunya adalah usia tanam. Penelitian ini bertujuan mengidentifikasi kandungan metabolit ekstrak batang spesies tersebut dengan usia tanam berbeda menggunakan LC-MS/MS dan dikelompokkan menggunakan principal component analysis (PCA). Sampel diekstraksi menggunakan metanol (LC-MS grade) dengan sonikasi. Sebanyak 21 senyawa teridentifikasi secara putatif pada ekstrak batang sidaguri dengan usia tanam 3, 4, dan 5 bulan. Senyawasenyawa tersebut termasuk ke dalam golongan asam fenolat, fenolik aldehida, alkaloid, steroid, flavonoid, kumarin, asam amino dan asam lemak. Berdasarkan hasil pengelompokan dengan PCA menggunakan variabel luas pita 21 metabolit yang teridentifikasi, ekstrak sidaguri mengelompok sesuai dengan usia tanam masing-masing dengan total plot skor sebesar 78%., Sidaguri (Sida rhombifolia) is a plant widely used as a traditional medicine because of its bioactive metabolite content. The metabolites in sidaguri were affected by some factors, such as cultivation age. This study aimed to identify metabolites based on diferrent cultivation ages and classify them using principal component analysis (PCA). Samples from 3, 4, and 5 months post planting were extracted using methanol (LC-MS grade) using sonication. Twenty-one metabolites were putatively identified from all extracts. These metabolites belong to phenolic acids, phenolic aldehydes, alkaloids, steroids, flavonoids, coumarins, amino acids and fatty acids. Based on clustering result by PCA using 21 identified metabolites peak area, each extract was grouped according to cultivation ages with a total score plot of 70%.
Keyword: Sida rhombifolia, LC-MS/MS, metabolite profiling, PCA

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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