Judul: Identifikasi Molekuler Kompleks Spesies Himantura uarnak (Batoidea: Dasyatidae) di Indonesia.
Abstrak: Stingrays are one of the cartilaginous fish, apart of sharks and skates, and one of Indonesia's fishery resources. Almost of elasmobranch fishes are economically important fish. The refined products and live specimens of this fish are a lot of traded. Himantura uarnak, H. undulata and H. leoparda are stingray species in Himantura and Dasyatidae family, which are the most popular stingrays in Indonesia waters. The stingrays are major target species were used as a consumable product and trading products. Levels of species diversity of cartilaginous fish in Indonesia are very high, and also Indonesia is listed as one of the countries that use elasmobranch resources the highest in the world. Generally, this study aims to identify each species of H. uarnak species complex through molecular approaches. While specifically, this study aims to estimate the evolutionary process of species divergence and to determine the relationship between species. The methods were used in this study included field sampling, sample collection, and specimen identification, collection of genetic samples, analysis of genetic samples and data analysis . Size polymorphism nuclear DNA markers (intron EPIC) were used. Polymorphism alleles translated into genotypes and alleles frequency of five introns loci. The results of Bayesian analysis and Correspondence Analysis (CA) produced informative diagram of the population structure showed 4 different clusters. Cluster 1 and 4 were H. leoparda, Cluster 2 indicated as H. undulata and the Cluster 3 was H. uarnak. Cluster 1 was a variant of Cluster 4, in this time called as H. leoparda var.1. Separation of four clusters according to nuclear DNA need to be proved by mitochondria DNA maker by cytochrome c oxidase subunit I (COI) and cytochrome b (cyt b). Molecular approaches were using mitochondrial DNA gene cytochrome c oxidase subunit I (COI) and cytochrome b produced 4 main groups (Group I, II, III and IV). Both of these molecular approaches showed each individual of groups were in consistent clade and the main group. Hence the H. uarnak species complex in Indonesian waters were divided into 4 main groups, and each was a particular species. The Group I and IV were the two group species that have been released as H. leoparda and Group I was H. leoparda var. 1 identified as cryptic species. Group II was one individual who grouped as H. undulata. Group III was one of other group that identified as H. uarnak and in accordance with the morphological characteristic through spotting pettern. Morphological approach to identified the stingrays of Himantura uarnak species complex clearly less accurate than the molecular approaches. Morphological approach should not be used to identify a species complex in stingrays without helped by other approaches.
Keyword: Himantura uarnak species complex, intron EPIC, cyt b, COI, spotting pattern

Judul: Molecular Identification of the Freshwater Stingrays Based on COI Gene Markers in Musi River, Palembang, South Sumatera
Abstrak: Ikan pari dari famili Dasyatidae memiliki karakteristik yang hampir mirip, sehingga diperlukan metode yang akurat dalam validasi spesiesnya. Selain itu, ketersediaan informasi dan data ilmiah mengenai genetik ikan pari air tawar masih minim di Indonesia. Oleh karena itu, penelitian ini bertujuan untuk mengidentifikasi spesies, kekerabatan genetik, dan keragaman genetik ikan pari air tawar berdasarkan variasi basa nukleotida Gen COI di Sungai Musi, Sumatera Selatan. Pengambilan sampel dilakukan pada bulan Februari hingga Mei 2023 di Sungai Musi. Analisis laboratorium dilakukan pada bulan Juni hingga September 2023. Ekstraksi DNA sampel menghasilkan 12 DNA total. Hasil penelitian menunjukkan dua spesies ikan pari air tawar berhasil divalidasi, yaitu Fluvitrygon signifer dan Pastinachus stellurostris dengan kemiripan 99,30% hingga 100%. Sementara itu, pari tutul (kode B) dan pari sungai tepi putih moncong panjang (kode C) belum tervalidasi secara genetik, dengan tingkat kemiripan 89,24% hingga 89,70%.Keragaman genetik ikan pari air tawar di Sungai Musi tergolong rendah, dengan rentang nilai haplotype Hd 0-0,667. Hasil konstruksi pohon filogeni menunjukkan Fluvitrygon signifer dan Pastinachus stellurostris memiliki kekerabatan jauh dengan pari tutul dan pari tepi putih moncong panjang., Stingrays from the family Dasyatidae have almost similar characteristics, so accurate methods are needed to validate the species. Apart from that, the availability of scientific information and data about the genetics of freshwater stingrays is still minimal in Indonesia. Therefore, this study aims to identify species, genetic relationships and genetic diversity of freshwater stingrays based on nucleotide base variations of the COI gene in the Musi River, South Sumatra. Sampling was carried out from June to September 2023. DNA extraction of the samples produced 12 DNAs in total. The research results showed species freshwater stingrays were successfully validated, namely Fluvitrygon signifer and Pastinachus stellurostris with 99,30% to 100% similarity. The spotted ray (code B) and the long-snouted white edge ray (code C) have not been genetically validated yet, with a similarity level of 89,24% to 89,70%. The genetic diversity of freshwater stingrays in the Musi River is relatively low, with a range of haplotype Hd values of 0-0,667. The results of the phylogenetic tree construction show Fluvitrygon signifer and Pastinachus stellurostris distantly related to marbled whipray and long-snouted white edge ray.
Keyword: COI, identifikasi morfologi, pari air tawar, sungai musi

Judul: Kinerja model pengering bangunan tembus cahaya dari plastik tahan UV untuk pengeringan buah kopi
Abstrak: Kopi merupakan komoditas ekspor yang memerlukan pengeringan sebelum dikonsumsi, sehingga kemampuannya dapat disimpan dalam waktu lama sangat menentukan mutu dan nilai ekonominya. Penyediaan sarana pengeringan yang memadai sangat dibutuhkan untuk mencapai tujuan tersebut. Sebuah model bangunan tembus cahaya untuk pengeringan kopi skala 1.5 ton sudah dirancang dan diuji coba. Bangunan tersebut berukuran 6 m x3 m, tinggi 2.46 m terbagi menjadi dua. yaitu atap 0.56 m dengan sudut kemiringan 32.4" dan dinding 1.9 m membentuk sudut kemiringan 85.6" terhadap lantai. Plastik tahan UV menutupi atap dan dindingnya. Penelitian ini bertujuan menguji kinerja model pengering bangunan tembus cahaya pada kapasitas maksimum. Percobaan dilakukan dengan mengeringkan kopi pada ketebalan 30 cm dan 40 cm (kapasitas penuh) dibantu blower 0.5 11P, 220 volt untuk mengalirkan udara pengering di dalam bangunan tembus cahaya dan mengeluarkan uap air bahan yang telah diuapkan dari bangunan tersebut. Hasil percobaan memperlihatkan bahwa penutup transparan mampu memanfaatkan 70% radiasi matahari yang jatuh di permukaannya. Pada kondisi radiasi termanfaatkan rata-rata sebesar 435.1 W/m². laju aliran udara sebesar 2520...
Keyword: