Judul: Analisis Pendapatan dan Livelihood Assets Nelayan Pari Air Tawar di Sungai Musi, Kota Palembang, Sumatera Selatan
Abstrak: Pari air tawar berperan terhadap fungsi ekologis maupun ekonomi di Sungai Musi, namun keberadaan pari air tawar di Sungai Musi terancam akibat faktor alam dan manusia. Pari air tawar telah masuk dalam daftar spesies terancam punah yang dikeluarkan oleh IUCN dan peraturan perundang-undangan di Indonesia. Pari air tawar menjadi salah satu livelihood masyarakat di Sungai Musi. Penelitian ini bertujuan untuk mendeskripsikan tingkat trofik pari air tawar, karakteristik, pendapatan, dan livelihood assets nelayan pari air tawar. Analisis dilakukan dengan metode systematic literature review, statistik deskriptif, analisis pendapatan, dan analisis livelihood assets. Hasil penelitian menunjukkan bahwa pari air tawar merupakan predator menengah. Nelayan pari air tawar memiliki karakteristik armada berukuran 1,2 – 3 GT dan menggunakan berbagai jenis alat tangkap. Nelayan memiliki karakteristik sosial ekonomi berupa nelayan skala kecil dan sebagian besar pengeluaran untuk konsumsi dan modal melaut. Rata-rata pendapatan responden nelayan sekitar Rp419.648,56 – Rp671.375,00 per trip per hari dengan R/C ratio > 1. Share penerimaan per trip per hari dari hasil tangkapan pari air tawar pada keempat kecamatan bernilai rendah hingga sangat rendah yaitu sekitar 0,09 – 25,72 pada musim paceklik dan 0,09 – 39,73 pada musim normal. Livelihood assets nelayan di Kota Palembang memiliki nilai indeks keberlanjutan sedang yaitu bernilai 0,48 – 0,50., Freshwater stingrays play a crucial role in the Musi River's ecological and economic functions. However, their existence in this river is currently threatened by a combination of natural and human factors. Recognizing their vulnerable status, freshwater stingrays have been listed as endangered species by the IUCN and are subject to regulations in Indonesia. The livelihoods of many individuals along the Musi River depend on freshwater stingrays. This study aims to provide a comprehensive description of the trophic level of freshwater stingrays, as well as the characteristics, income, and livelihood assets of fishermen engaged in catching them. The research methodology employed a systematic literature review, descriptive statistics, income analysis, and livelihood assets analysis. The findings indicate that freshwater stingrays occupy an intermediate position within the predator hierarchy. The fishing boats used by freshwater stingray fishermen typically range from 1,2 to 3 GT, and they employ various types of fishing gear. Socioeconomic characteristics of the fishermen reveal predominantly small-scale fisheries, with a major portion of their expenses allocated towards consumption and fishing capital. The average daily income of the surveyed fishermen ranges from IDR 419.648,56 to IDR 671.375,00, with an R/C ratio > 1. The share of daily revenue derived from the catch of freshwater stingrays in the four sub-districts is relatively low, ranging from 0,09 to 25,72 during the lean season and 0,09 to 39,73 during the normal season. Assessing the sustainability of fishermen's livelihood assets in Palembang City, it is found that the value exhibits a moderate sustainability index, ranging from 0,48 to 0,50.
Keyword: characteristics of fishermen, elasmobranch, livelihood assets, systematic literature review

Judul: Biodiversity of Protected Freshwater Stingray in Musi River, South Sumatera
Abstrak: Sungai Musi memiliki keanekaragaman hayati yang tinggi. Sungai Musi merupakan salah satu habitat ikan pari air tawar yang keberadaannya sangat langka dan hingga saat ini informasinya masih terbatas. Penelitian ini bertujuan untuk mendeskripsikan dan menganalisis keanekaragaman spesies ikan pari air tawar di Sungai Musi bagian tengah Provinsi Sumatera Selatan. Metode yang digunakan untuk mendeskripsikan ikan pari air tawar menggunakan pendekatan morfologis. Adapun keanekaragaman ikan pari air tawar dianalisis menggunakan pendekatan indeks keanekaragaman, indeks kemerataan, dan indeks dominansi. Ikan pari air tawar yang didapatkan sebanyak 42 ekor, yang terdiri dari enam spesies (Fluvitrygon signifer, Fluvitrygon oxyrhynchus, Fluvitrygon cf. oxyrhynchus, Fluvitrygon kittipongi, Pastinachus stellurostris, dan Urogymnus polylepis). Ikan pari air tawar di Sungai Musi memiliki kesamaan karakteristik, yaitu warna cakram dorsal kecoklatan hingga kehitaman, ekor sangat panjang seperti cambuk, terdapat 2 duri sengat, dan memiliki mata yang kecil. Hasil analisis menunjukkan bahwa keanekaragaman spesies ikan pari air tawar di Sungai Musi memiliki nilai H’= 1,38 dengan persebaran yang merata dan tak ada spesies yang mendominasi., The Musi River has a high biodiversity. The Musi River is one of the habitats of freshwater stingrays whose existence is very rare and until now the information is still limited. This study aims to describe and analyze the diversity of freshwater stingray species in the middle part of Musi River, South Sumatra Province. The method used to describe freshwater stingrays uses a morphological approach. The diversity of freshwater stingrays was analyzed using the diversity index, evenness index, and dominance index approaches. There were 42 freshwater stingrays that obtained during research, consisted of six species (Fluvitrygon signifer, Fluvitrygon oxyrhynchus, Fluvitrygon cf. oxyrhynchus, Fluvitrygon kittipongi, Pastinachus stellurostris, and Urogymnus polylepis). Freshwater stingrays in the Musi River have similar characteristics, namely brownish to blackish color of the dorsal disc, very long whip-like tail, 2 stinging spines, and small eyes. The analysis showed that the species diversity of freshwater rays in the Musi River has a value of H'= 1.38 with an even distribution and no dominant species.
Keyword: diversity, freshwater stingray, Musi River, protected

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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