Judul: The Quality of Chilled Local Ram Semen After a Rest Period from the Breeding Program
Abstrak: Istirahat kawin dalam waktu lama memengaruhi kualitas semen. Tujuan penelitian ini adalah mengevaluasi kualitas semen cair domba lokal Indonesia yang diistirahatkan kawin. Semen dikoleksi dari empat ekor domba menggunakan vagina buatan. Semen segar dievaluasi secara makroskopis dan mikroskopis. Semen kemudian diencerkan dengan pengencer Tris-fruktosa-kuning telur (Tris) atau Na sitrat-fruktosa-kuning telur (Na sitrat) hingga konsentrasi 50x106 sel/0,2 mL. Semen cair dikemas dalam tabung sentrifugasi dan disimpan dalam lemari pendingin (4−5 ◦C). Motilitas progresif dan viabilitas spermatozoa semen cair dievaluasi setiap 24 jam selama 4 hari. Pengaruh lingkar skrotum (LS) terhadap semen segar maupun semen cair juga dievaluasi. Hasil penelitian menunjukkan bahwa semen segar memiliki volume 1,08±0,12 mL, warna putih susu, konsistensi encer hingga kental, pH 6,42±0,13, gerakan massa 2,94±0,13, konsentrasi 4941±926,84x106 /mL, motilitas progresif 79,38±2,17%, viabilitas 87,74±3,48%, dan abnormalitas total 7,99±3,14%. Istirahat kawin meningkatkan konsentrasi dan abnormalitas spermatozoa semen segar. LS memengaruhi motilitas, viabilitas, konsentrasi, dan abnormalitas spermatozoa semen segar. Namun, istirahat kawin tidak memengaruhi kualitas semen cair. Tris mempertahankan motilitas dan viabilitas spermatozoa semen cair lebih baik dibandingkan dengan Na sitrat. Motilitas dan viabilitas spermatozoa semen cair kelompok LS 29 cm lebih baik dibandingkan dengan kelompok LS 23 cm. Istirahat kawin disimpulkan memengaruhi kualitas semen segar, namun tidak memengaruhi kualitas semen cair domba lokal., A long period of sexual rest influences the semen quality. The objective of this study is to evaluate the quality of chilled Indonesian local ram semen after it was rested from the breeding program. Semen was collected from four local rams using an artificial vagina. Fresh semen was examined macroscopically and microscopically. Semen was diluted in Tris-fructose-egg yolk (Tris) or sodium citrate-fructose-egg yolk (Na citrate) to a final concentration of 50x106 cell/0.2 mL. Chilled semen was packed in a centrifugal tube and stored in the refrigerator (4−5◦C). Sperm progressive motility and viability of chilled semen were examined every 24 hours for 4 days. The effect of the scrotal circumference (SC) on fresh and chilled semen was also investigated. The results showed that the fresh semen had a volume of 1.08±0.12 mL, milky-white color, thin to thick consistency, pH of 6.42±0.13, mass movement of 2.94±0.13, concentration of 4941±926.84x106 sperm/ mL, progressive motility of 79.38±2.17%, viability of 87.74±3.48%, and total abnormality of 7.99±3.14%. Sexual rest increased fresh semen concentration and sperm abnormality. SC affected sperm motility, viability, concentration, and abnormality of ram fresh semen. Sexual rest did not affect the quality of chilled semen. Tris extenders preserved viability and motility of ram sperm better than Na citrate. The sperm motility and viability in chilled semen from SC of 29 cm were better than semen from SC of 23 cm. This study concluded that sexual rest had effects on the fresh semen but showed no significant effect on chilled local ram semen.
Keyword: chilled semen, ram, scrotal circumference, semen extenders, sexual rest

Judul: Quality of Chilled Ram in Tris Egg Yolk-Glucose  Diluent with Melatonin as an Antioxidant
Abstrak: Radikal bebas dan stres oksidatif selama pengolahan semen menyebabkan kerusakan membran plasma spermatozoa yang mengakibatkan penurunan motilitas dan viabilitas. Melatonin merupakan antioksidan yang efektif untuk menetralkan radikal bebas dan mengurangi kerusakan oksidatif sehingga mampu melindungi spermatozoa. Penelitian ini bertujuan mengevaluasi pengaruh penambahan melatonin dan menentukan dosis efektif melatonin dalam pengencer tris kuning telur-glukosa terhadap kualitas semen cair domba yang disimpan pada suhu 4 °C. Koleksi semen dilakukan dengan metode vagina buatan, kemudian semen dievaluasi secara makroskopis dan mikroskopis. Semen dengan motilitas sebesar ≥70% diencerkan pada kelompok tris kuning telur-glukosa (TKTG), tris kuning telur-glukosa dengan melatonin 0,5 Mm (TKTG + M0,5), tris kuning telur-glukosa dengan melatonin 1 mM (TKTG + M1), tris kuning telur-glukosa dengan melatonin. 2 mM (TKTG + M2). Semen cair disimpan selama 5 hari (H0–H5) pada suhu 4 °C, kemudian dievaluasi kualitas semennya setiap 24 jam. Parameter evaluasi semen berupa motilitas, viabilitas, abnormalitas, dan membran plasma utuh spermatozoa. Hasil penelitian menunjukkan kualitas semen cair tidak berbeda signifikan pada H0 (P>0,05). Penambahan melatonin secara umum, memiliki nilai lebih tinggi daripada kontrol dan mampu melindungi serta mempertahankan kualitas semen cair. Pengencer TKTG + M1 berdasarkan hasil penelitian, adalah perlakuan terbaik yang ditunjukkan dengan nilai dari parameter lebih tinggi daripada perlakuan lainnya., Free radicals and oxidative stress during semen processing damage the plasma membrane of spermatozoa resulting in reduced motility and viability. Melatonin is an antioxidant that can neutralize free radicals and reduce oxidative damage so it can protect spermatozoa. The aim of this study was to evaluate the effect of adding melatonin and determine the effective dose to tris egg yolk-glucose diluents on the quality of chilled ram semen stored at 4 °C. Semen was collected using an artificial vagina, and then examined macroscopically and microscopically. Semen with motility of ≥70% was grouped into different extenders: tris egg yolk glucose (TEYG), tris egg yolk glucose extender with 0.5 mM melatonin (TEYG + M0.5), tris egg yolk glucose extender with 1 mM melatonin (TEYG + M1), tris egg yolk glucose extender with 2 mM melatonin (TEYG + M2). All semen samples were stored at 4 °C for 5 days (H0–H5) and examined every 24 hours. Semen were examined for spermatozoa motility, viability, abnormality, and membrane plasma integrity. The results showed that there were no significant changes of semen quality on H0 (P>0.05). In general, the melatonin supplemented groups had a higher value than the control. Melatonin supplementation is able to protect and maintain the quality of chilled semen. In addition, the result showed that TEYG + M1 extender was the best extender treatment, which was indicated by higher values than other treatments.
Keyword: antioxidant, free radicals, melatonin, ram, tris egg yolk-glucose

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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