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: Community Structure and Distribution Bentic Mollusc Taxes in Mangrove Ecosystem in Kuala Langsa, East Aceh
Abstrak: Keanekaragaman moluska bentik di ekosistem mangrove Kuala Langsa, Aceh Timur belum banyak dipelajari. Tujuan dari penelitian ini untuk mengidentifikasi dan menganalisis keanekaragaman moluska bentik yang berkaitan dengan ekosistem mangrove. Pengambilan data mangrove dan sampel moluska bentik menggunakan transek kuadrat 10×10 m2 , 5×5 m2 , dan 1×1 m2 dengan metode purposive sampling. Moluska bentik yang ditemukan pada lokasi penelitian terdiri dari dua kelas dan 17 spesies. Keterkaitan moluska bentik terhadap vegetasi mangrove menggunakan Correspondent Analysis (CA) menunjukkan bahwa C. nicobaricum dan E. aurisjudae berasosiasi erat dengan mangrove Avicennia sp.. Hasil juga menunjukkan C. carcellesi, N. polita, dan P. glaucum berasosiasi erat dengan mangrove R. apiculata. Keterkaitan stasiun terhadap parameter lingkungan menggunakan Principal Component Analysis (PCA) menunjukkan bahwa Stasiun 1 dipengaruhi kuat oleh parameter salinitas dan suhu sedangkan Stasiun 2 dan Stasiun 3 dipengaruhi kuat oleh substrat berpasir.
Keyword: bentic molluscs, distribution, diversity, mangroves, relatedness

Judul: A Continuous Vaccination Strategy in the SVIR Epidemic Model
Abstrak: Vaccination is conducted to minimize the spread of a disease. The vaccination is usually done several times within a fixed time interval. In the SVIR model, it is assumed that individuals do not get immediate immunity following a vaccination program. So according to process of vaccination on SVIR model, there are two strategies, i.e. the continuous vaccination strategy (CVS) and the pulse vaccination strategy (PVS). In this study, only the CVS strategy in epidemic model SVIR is considered. Results of the study indicate that dynamics of the CVS system depends on the basic reproductive number. If the basic reproductive number is less than one, then the disease-free fixed point is asymptotically stable. It means that the disease will eventually disappear from the population. Conversely, if the basic reproductive number is greater than one, then the endemic fixed point is asymptotically stable, which means that the disease will remain exist in the population. Simulation result shows that the vaccination would minimize the spread of disease by reducing the basic reproductive number. If the time for the vaccinated recipients to obtain the immunity, as well as a possibility of vaccinated recipients to be infected are neglected, then the disease will be eradicated. This condition is called an over-evaluating effect of vaccination.
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