Judul: The dynamics of interstitial meiofaunal community in the Dompak Strait Waters, Riau Archipelago
Abstrak: A study on the dynamics of interstitial meiofaunal community in the different ecosystems have been carried out in the Dompak Strait waters (Riau Archipelago). This study were investigated on different four seasons throughout a year, from May 2005 to April 2006. Based on the site assessments, six sampling site (A1, A2, A3, B1, B2 and C) were chosen to represent research sites. In each sampling site, sediment samples were taken from three sampling points. The sediment was extracted by means of PVC cores (Ø = 5 cm), in which six layers were separated (i.e. 0–5 cm, 5–10 cm, 10–15 cm, 15–20 cm, 20–25 cm and 25–30 cm). The meiofaunal were extracted by using swirl-decantation method, elutria tion method, and sieving method. Specimen were preserved and stained for observation and identification. The data on interstitial meiofauna were analyzed statistically th rough calculates of abundance, diversity index, evenness index, t-test, Anova test, Euclidean distance, and cluster analysis. One-way and two-way nested analysis of variance (Anova) test were used to determine the significance of interstitial meiofaunal differences between sites, between strata and between seasons. Regression analysis were used to investigate relationships between interstitial meiofauna with environmental parameters. Anova and regression analysis were run using the software SPSS 11.5.
Keyword: site specific genus, seagrass, mangrove habitats, bare area habitas, habitat types

Judul: Struktur Komunitas Meiofauna Pada Ekosistem Mangrove Kuala Langsa, Aceh Timur
Abstrak: Meiofauna merupakan hewan metazoa diantara makrofauna dan mikrofauna yang hidup di ruang antar partikel sedimen dan berperan penting dalam kesuburan perairan. Tujuan penelitian ini adalah untuk mengetahui struktur komunitas meiofauna dengan karakteristik fisika-kimia pada ekosistem mangrove Kuala Langsa, Aceh Timur. Penelitian dilakukan pada 29 Agustus 2022 di 3 Stasiun. Sampel meiofauna diambil menggunakan pipa paralon atau corer (ø: 5 cm; tinggi: 10 cm). Sejumlah parameter fisika-kimia lingkungan diukur dan dianalisa hubungannya menggunakan analisis komponen utama (PCA) dan analisis korespondensi (CA) dengan hasil ditemukannya banyak meiofauna dan ragam jenis mangrove pada Stasiun 3. Hasil pengamatan meiofauna pada ekosistem mangrove Kuala Langsa terdiri dari 8 filum, 12 kelas, 17 ordo, 22 famili, dan 23 genus dengan dominasi Platyhelminthes. Jenis mangrove yang mendominasi adalah spesies Rhizophora mucronata. Kelimpahan meiofauna banyak ditemukan pada wilayah penelitian dengan dominasi substrat pasir, kerapatan mangrove dan bahan organik yang tinggi., Meiofauna is a metazoan animal between macrofauna and microfauna that lives in spaces between sediment particles and plays an important role in water fertility. The purpose of this study was to determine the meiofauna community structure with physicochemical characteristics in the Kuala Langsa mangrove ecosystem, East Aceh. Research was conducted on August 29, 2022 at 3 Stations. The meiofauna samples were taken using a paralon pipe or corer (ø: 5 cm; height: 10 cm). A number of environmental physico-chemical parameters were measured and analyzed using principal component analysis (PCA) and correspondence analysis (CA) with the results discovery of many meiofauna and variety of mangrove species at Station 3. The results of meiofauna observations in the Kuala Langsa mangrove ecosystem consisted of 8 phyla, 12 classes, 17 orders, 22 families, and 23 genus with the dominance of Platyhelminthes. The dominating mangrove species is Rhizophora mucronata. Abundance of meiofauna is found in research area with the dominance of sand substrate, mangrove density and high organic matter.
Keyword: Abundance, Kuala Langsa, Mangrove, Substrate

Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf