Judul: Stress Response of Mahseer Tor douronensis (Valenciennes, 1842) Fingerlings on Ammonia Variability
Abstrak: Domestikasi dan budidaya ikan semah (Tor douronensis) sangat diperlukan untuk mempertahankan kelestariannya. Proses ini membutuhkan kondisi lingkungan yang baik untuk mendukung pertumbuhan dari spesies tersebut. Penelitian ini bertujuan untuk mengevaluasi tingkat toleransi benih ikan semah terhadap variasi konsentrasi amonia yang diukur berdasarkan respon stres ikan tersebut. Percobaan skala laboratorium dilakukan dengan tiga perlakuan, yaitu konsentrasi amonia rendah (<0,4 mg/L), sedang (0,4–0,79 mg/L) dan tinggi (0,8–1,3 mg/L). Tiap perlakuan terdiri dari tiga ulangan. Benih ikan semah yang digunakan pada penelitian ini memiliki ukuran panjang 11,18± 0,8 cm dan bobot 14,91±0,1 g. Pengamatan dan analisis data dilakukan terhadap kualitas air, pertumbuhan ikan, dan parameter darah pada ikan. Hasil penelitian menunjukkan bahwa paparan amonia pada kisaran 0,4–1,3 mg/L menyebabkan benih ikan semah mengalami stres yang ditunjukkan dengan pertumbuhan yang menurun, meningkatnya kadar glukosa dan kortisol serta menurunnya kadar hemoglobin. Berdasarkan penelitian ini, dapat disimpulkan bahwa konsentrasi amonia yang dapat ditolerir benih ikan semah yaitu <0,4 mg/L., Domestication and aquaculture of mahseer (Tor douronensis) are essential to maintain its sustainability. These processes require good environmental conditions to support the growth of cultured species. This study aims to evaluate the tolerance level of mahseer fingerlings to various ammonia concentrations based on their stress response. Experimental laboratory trials were conducted with three treatments: low (<0.4 mg/L), medium (0.4–0.79 mg/L), and high (0.8–1.3 mg/L) ammonia concentrations. Each treatment was carried out with three replicates. Mahseer’s fingerlings used in this study have length of 11.18±0.8 cm and a weight of 14.91±0.1 g. Observations and data analysis were carried out on water quality, fish growth, and fish blood parameters. Results showed that ammonia exposure at 0.4–1.3 mg/L caused stress in mahseer fingerlings as indicated by a decrease in growth, increase in glucose and cortisol levels, and decrease in hemoglobin levels. According to this study, it can be concluded that the tolerable concentration of ammonia exposure in mahseer fingerlings is < 0.4 mg/L.
Keyword: Ammonia, Domestication, Fish, Tor douronensis, Stress

Judul: Pengaruh Salinitas Terhadap Respon Fisiologis Benih Ikan Semah (Tor douronensis)
Abstrak: Salinitas merupakan salah satu faktor lingkungan di perairan yang dapat mempengaruhi kelangsungan hidup dan pertumbuhan biota, terutama ikan semah (Tor douronensis). Penelitian ini bertujuan untuk menganalisis pengaruh salinitas terhadap respon fisiologis benih ikan semah (Tor douronensis). Penelitian ini dilaksanakan dari Juni sampai Oktober 2021. Rancangan penelitian yang digunakan berupa rancangan acak lengkap (RAL) sebanyak lima perlakuan salinitas (0 ppt, 2 ppt, 4 ppt, dan 8 ppt) dengan ulangan sebanyak tiga kali. Parameter yang diteliti adalah parameter kualitas air, fisiologis ikan, dan pertumbuhan. Hasil penelitian menunjukkan salinitas media pemeliharaan berpengaruh terhadap parameter pertumbuhan. Kisaran salinitas yang optimum untuk pertumbuhan benih ikan semah pada salinitas 2 ppt. Kadar hemoglobin tertinggi pada salinitas 0 ppt sebesar 7,70±0,61 g/dL dan terendah pada salinitas 8 ppt sebesar 4,90±0,85 g/dL. Kadar glukosa tertinggi dan terendah pada salinitas 6 ppt sebesar 63,33±8,08 mg/dL dan 45,33±8,50 mg/dL di salinitas 0 ppt. Kortisol tertinggi dan terendah pada salinitas 8 ppt sebesar 469,59±222,05 ng/ml dan 29,15±29,78 ng/ml di salinitas 0 ppt. Peningkatan salinitas di atas 4 ppt menyebabkan benih ikan semah mengalami stres., Salinity is one of the environmental factors in the waters that can affect the survival and growth of biota, especially semah fish (Tor douronensis). This study aims to analyze the effect of salinity on the physiological response of semah fish seed (Tor douronensis). This research was conducted from June to October 2021. The research design used was a completely randomized design (CRD) with five salinity treatments (0 ppt, 2 ppt, 4 ppt, and 8 ppt) with three replications. The parameters studied were parameters of water quality, fish physiology, and growth. The results showed that the salinity of the rearing media had an effect on the growth parameters. The optimum salinity range for the growth of semah fish seed was at a salinity of 2 ppt. The highest hemoglobin level at 0 ppt salinity was 7.70±0.61 g/dL and the lowest at 8 ppt salinity was 4.9±0.85 g/dL. The highest and lowest glucose levels at salinity of 6 ppt were 63.33±8.08 mg/dL and 45.33±8.50 mg/dL at salinity of 0 ppt. The highest and lowest cortisol at 8 ppt salinity was 469.59±222.05 ng/ml and 29.15±29.78 ng/ml at 0 ppt salinity. An increase in salinity above 4 ppt causes fish to experience stress.
Keyword: glukosa, hemoglobin, kortisol, salinitas, Tor douronensis, cortisol, hemoglobin, glucose, salinity, Tor douronensis

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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