Judul: THE EFFECT OF DIFFERENT pH EXPOSURES TOWARD STRESS LEVEL OF Tor douronensis SEEDS (VALENCIENNES, 1842)
Abstrak: Ikan semah (Tor douronensis) adalah anggota dari marga Cyprinidae yang saat ini terancam oleh eksploitasi dan degredasi habitat sehingga upaya domestikasi perlu dilakukan agar pemanfaatan dan restocking dilakukan secara beriringan. Untuk keberhasilan domestikasi, pemeliharaan benih ikan semah membutuhkan kualitas air optimal dimana pH merupakan salah satu faktor kunci dalam pemeliharaan ikan air tawar. Penelitian ini bertujuan untuk menganalisis respon fisiologis benih ikan semah terhadap perubahan pH. Penelitian dilaksanakan pada Juni sampai Oktober 2021 dengan meneliti kualitas air, pertumbuhan, dan darah. Rancangan penelitian yang digunakan adalah Rancangan Acak Lengkap (RAL) dengan empat perlakuan pH berbeda yaitu pH 6, 7, 8, dan 9. Larutan asam nitrat (HNO3) 10% digunakan untuk menurunkan pH, sedangkan larutan natrium hidroksida (NaOH) 0,4% untuk meningkatkan pH. Hasil penelitian menunjukkan sintasan dan pertumbuhan terbaik terjadi pada perlakuan pH 7, sedangkan pH 9 tidak sesuai untuk pertumbuhan dan kelangsungan hidup benih ikan semah. Kondisi stres sebagai respon terhadap pH yang tidak sesuai ditunjukkan oleh meningkatnya konsentrasi kortisol dan penurunan konsentrasi hemoglobin yang terjadi pada perlakuan pH 9., Mahseer fish (Tor douronensis) is a cyprinid family member, threatened by high exploitation and habitat degradation. Therefore, domestication attemps are needed for sustainable utilization, from which harvesting and restocking are equally implemented. For domestication success, mahseer seeds rearing needs optimum water quality, of which pH is among the critical factor for freshwater species. This research is aimed to analyze the physiological response of mahseer fish seeds to pH changes. The research was conducted from June to October 2021 by observing water quality, growth, and blood. The research design was the Completely Randomized Design (CRD) with four different pH treatments; 6, 7, 8, and 9. The solution of 10% nitric acid (HNO3) was used to lower the pH, whereas 0,4% natrium hydroxide (NaOH) was used to increase the pH level. The results showed that the best pH for survival and growth rate was 7, whereas pH 9 was unsuitable and resulted in stress to mahseer seeds. The stress condition caused by inappropriate pH was shown by increased cortisol concentration and a decrease in hemoglobin concentration that occur in the pH 9 treatment.
Keyword: cortisol, mahseer, pH, stress, weight

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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