Judul: Kontrol Optimum Penyakit Tifoid Menggunakan Model SCIR
Abstrak: Karya ilmiah ini membahas masalah pengendalian penyakit tifoid yang penyebarannya dirumuskan dalam model SCIR. Tiga variabel kontrol diperkenalkan ke dalam model, yaitu laju vaksinasi, laju peningkatan imunitas dan laju pengobatan. Prinsip maksimum Pontryagin diterapkan agar mendapatkan kondisi optimalitas untuk dipenuhi oleh variabel kontrol. Metode Runge-Kutta orde empat digunakan dalam menentukan solusi numerik dari kontrol optimum. Tujuh skenario pengendalian dievaluasi untuk melihat tingkat efektivitas, yaitu penerapan variabel kontrol tunggal, penerapan dua variabel kontrol dan penerapan tiga variabel kontrol. Hasil dalam solusi numerik menunjukkan bahwa penerapan skenario VII dapat menurunkan jumlah individu rentan, terinfeksi, dan carrier sehingga mengoptimumkan jumlah individu pulih.
Keyword: kontrol optimum, metode Runge-Kutta orde 4, prinsip maksimum Pontryagin, tifoid

Judul: Masalah Kontrol Optimum Linear dan Taklinear pada Model SIR dengan Vaksinasi dan Pengobatan.
Abstrak: Dalam karya ilmiah ini dibahas masalah pengendalian penyakit yang dinamika penyebarannya dinyatakan dalam Model . Dua buah variabel kontrol ditambahkan ke dalam model, yaitu laju vaksinasi dan laju pengobatan. Ada dua model kontrol optimum yang dibahas berdasarkan bentuk fungsional objektif, yaitu model linear dan model taklinear. Prinsip maksimum Pontryagin diterapkan untuk mendapatkan kondisi optimalitas yang harus dipenuhi oleh variabel-variabel yang terlibat. Selanjutnya, metode Runge-Kutta orde empat digunakan untuk menentukan solusi numerik model kontrol optimum. Tiga skenario pengendalian diterapkan untuk melihat tingkat efektivitasnya, yaitu penerapan kontrol secara sendiri dan secara bersamaan. Solusi numerik menunjukkan bahwa seluruh skenario dapat menurunkan jumlah individu terinfeksi dengan usaha minimum. Model linear dan taklinear menghasilkan strategi pengendalian yang tidak jauh berbeda. Model linear menghasilkan fungsi kontrol optimum kontinu bagian demi bagian, sedangkan model taklinear menghasilkan fungsi kontrol kontinu dari waktu awal hingga waktu akhir.
Keyword: kontrol optimum, prinsip maksimum Pontryagin, bang-bang control, metode Runge-Kutta

Judul: Systematics of Desmos (Annonaceae) in Malesia
Abstrak: Desmos is a woody climbing genus of Annonaceae which has been widely used as traditional medicine in several countries such as China, Indo-China, Thailand, and Peninsular Malaysia to treat dysentery, vertigo, fever, and postpartum. Phylogenetic studies on Desmos showed a close relationship between Desmos and Dasymaschalon. They share similar moniliform monocarpic fruits, but their flowers are different. It has been debated among Annonaceae researchers whether both genera should be treated as the same or distinct genus. Therefore, investigation on the taxonomic delimitation of Desmos species and Dasymaschalon will be necessary. Plastid genome (plastome) identification, leaf epidermal section of Desmos species and Dasymaschalon species, a taxonomic revision of Desmos in Malesia using morphological data, the spatial distribution of Desmos species in Malesia, and morphological and genetic variation in Desmos chinensis population using ISSR marker were used to investigate taxonomic delimitation of Desmos. Plastome study of Desmos chinensis and Dasymaschalon dasymaschalum was carried out to determine the origin, evolution, phylogenomics, and identify marker candidates for Desmos and Dasymaschalon or with other genera in Annonaceae. We discovered that the plastome of Desmos chinensis was circular with the size of 167,677 bp (smaller than Dasymaschalon dasymaschalum), consist of 111 genes, including 78 protein-coding genes, 29 transfer RNAs, and 4 ribosomal RNAs. The plastome showed a typical quadripartite structure, i.e., large single copy (LSC), small single copy (SSC), and two inverted repeats (IRs). The plastome of Dasymaschalon dasymaschalum was 191,488 bp in length, which also exhibited a typical quadripartite structure (LSC, SSC, and two IRs). Desmos chinensis and Dasymaschalon dasymaschalum showed different copies of accD, ndhD, ndhF, rps18, and ycf2. Protein coding genes of rpoB, rpoC1, rbcL, matK, rpl32, infA, and rpl36 were identified based on nucleotide diversity, sequence variability, and parsimony-informative sites. The genes are defined as molecular marker candidates of plastome for phylogenetic, barcoding, and population genetic research. We predicted that Desmos chinensis and Dasymaschalon dasymaschalum separated at ca. 64 million years ago during the Paleocene. Leaf anatomical feature study was carried to support the taxonomic delimitation of interspecific Desmos and intergeneric of Desmos and Dasymaschalon. Leaf anatomy in the paradermal section of 20 taxa (12 species of Desmos, eight species of Dasymaschalon) have been carried out. According to the leaf epidermal section, Desmos and Dasymaschalon are two distinct genera mainly distinguished based on the anticlinal wall undulation of epidermal cells and supported by variation of the crystal type and size. The anticlinal wall undulation of Desmos was almost straight to slightly wavy and never sinuous; meanwhile, Dasymaschalon varies from almost straight to deeply sinusoid. The crystals of Desmos consist of rhombohedral, druse type A, and druse type B crystals, whereas Dasymaschalon has prism, druse type A, druse type B, and druse type C crystals. The recent taxonomic revision using the morphological data was mainly based on the examination of about 1374 specimens from BO, L, WAN, ANDA, SING, SAN, K, P, HUH herbaria. The Desmos species in Malesia consists of eight species: D. acutus, D. chinensis, D. chryseus, D. dunalii, D. pedunculosus, D. subbiglandulosus, two new records: D. lawii and D. macrocarpus, and one
Keyword: Dasymaschalon, Desmoid clade, Magnoliid, plastid genome, phylogenomics analysis