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: Metabolite Profiling of Leaves Extracts of Sida rhombifolia L. with Different Planting Age Using Liquid Chromatography-Mass Spectrometry
Abstrak: Sidaguri (Sida rhombifolia L.) adalah tanaman obat yang diyakini khasiatnya oleh masyarakat sebagai obat asam urat, antihipertensi, dan lain sebagainya. Penelitian ini bertujuan mengidentifikasi komposisi metabolit bioaktif daun sidaguri. Analisis ekstrak daun sidaguri diklasifikasikan berdasarkan umur tanam tiga, empat, dan lima bulan menggunakan kromatografi cair-spektrometri massa (LC-MS/MS) dan dikelompokan menggunakan analisis komponen utama (PCA). Kromatogram LC-MS/MS diolah menggunakan perangkat lunak Thermo Scientific Xcalibur 4.2 dan Compound Discoverer 3.2. Analisis multivariat menggunakan perangkat lunak The Unscrambler X 10.4. Sebanyak 36 metabolit berhasil teridentifikasi dalam ekstrak. Metabolit tersebut termasuk dalam golongan alkaloid, asam fenolat, flavonoid, kumarin, steroid, dan golongan lain. Ekstrak daun sidaguri terkelompok ke dalam kelasnya masing-masing, yaitu umur tanam 3, 4, dan 5 bulan dengan total varians 77%., Sida rhombifolia L. (sidaguri) is a medicinal plant that is believed to be useful by the community as a gout drug, antihypertensive, and so on. This study aims to identify the composition of bioactive metabolites of sidaguri leaves. Analysis of sidaguri leaf extract was classified based on the planting age of three, four, and five months using liquid chromatography-mass spectrometry (LC-MS/MS) and grouped using principal component analysis (PCA). The LC-MS/MS chromatograms were processed using Thermo Scientific Xcalibur 4.2 and Compound Discoverer 3.2 software. Multivariate analysis using The Unscrambler X 10.4 software. A total of 36 metabolites were identified in the extract. These metabolites are included in the group of alkaloids, phenolic acids, flavonoids, coumarins, steroids, and other groups. Sidaguri leaf extracts were grouped into their respective classes, namely 3, 4, and 5 months of planting age with a total variance of 77%.
Keyword: LC-MS/MS, metabolit sekunder, PCA, Sida rhombifolia L., LC-MS/MS, PCA, Sida rhombifolia L., secondary metabolites

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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